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    Age as a primary driver of the gut microbial composition and function in wild harbor seals

    Koenig, J. E. et al. Succession of microbial consortia in the developing infant gut microbiome. Proc. Natl. Acad. Sci. 108, 4578–4585 (2011).ADS 
    PubMed 
    Article 

    Google Scholar 
    Bäckhed, F. et al. Dynamics and stabilization of the human gut microbiome during the first year of life. Cell Host Microbe 17, 690–703 (2015).PubMed 
    Article 
    CAS 

    Google Scholar 
    Tanaka, M. & Nakayama, J. Development of the gut microbiota in infancy and its impact on health in later life. Allergol. Int. 66, 515–522 (2017).PubMed 
    Article 
    CAS 

    Google Scholar 
    Xu, C., Zhu, H. & Qiu, P. Aging progression of human gut microbiota. BMC Microbiol. 19, 1–10 (2019).Article 

    Google Scholar 
    Yatsunenko, T. et al. Human gut microbiome viewed across age and geography. Nature 486, 222–227 (2012).ADS 
    PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Nagpal, R. et al. Ontogenesis of the gut microbiota composition in healthy, full-term, vaginally born and breast-fed infants over the first 3 years of life: A quantitative bird’s-eye view. Front. Microbiol. 8, 1–9 (2017).Article 

    Google Scholar 
    Smith, S. C., Chalker, A., Dewar, M. L. & Arnould, J. P. Y. Age-related differences revealed in Australian fur seal Arctocephalus pusillus doriferus gut microbiota. FEMS Microbiol. Ecol. 86, 246–255 (2013).PubMed 
    Article 
    CAS 

    Google Scholar 
    Janiak, M. C. et al. Age and sex-associated variation in the multi-site microbiome of an entire social group of free-ranging rhesus macaques. Microbiome 9, (2021).Toro-Valdivieso, C., Toro, F., Stubbs, S., Castro-Nallar, E. & Blacklaws, B. Patterns of the fecal microbiota in the Juan Fernández fur seal (Arctocephalus philippii). MicrobiologyOpen 10, 1–19 (2021).Article 
    CAS 

    Google Scholar 
    Medeiros, A. W. et al. Characterization of the faecal bacterial community of wild young South American (Arctocephalus australis) and Subantarctic fur seals (Arctocephalus tropicalis). FEMS Microbiol. Ecol. 92, 1–8 (2016).Article 
    CAS 

    Google Scholar 
    Bik, E. M. et al. Marine mammals harbor unique microbiotas shaped by and yet distinct from the sea. Nat. Commun. 7, 10516 (2016).ADS 
    PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Numberger, D., Herlemann, D. P. R., Jürgens, K., Dehnhardt, G. & Schulz-Vogt, H. Comparative analysis of the fecal bacterial community of five harbor seals (Phoca vitulina). MicrobiologyOpen 5, 782–792 (2016).PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Pacheco-Sandoval, A. et al. The Pacific harbor seal gut microbiota in Mexico: Its relationship with diet and functional inferences. PlosOne 14, (2019).Nelson, T. M., Rogers, T. L., Carlini, A. R. & Brown, M. V. Diet and phylogeny shape the gut microbiota of Antarctic seals: A comparison of wild and captive animals. Environ. Microbiol. 15, 1132–1145 (2013).PubMed 
    Article 
    CAS 

    Google Scholar 
    Glad, T. et al. Ecological characterisation of the colonic microbiota in Arctic and sub-Arctic seals. Microbiol. Ecol. 60, 320–330 (2010).Article 
    CAS 

    Google Scholar 
    Delport, T. C., Power, M. L., Harcourt, R. G., Webster, K. N. & Tetu, S. G. Colony location and captivity influence the gut microbial community composition of the Australian sea lion (Neophoca cinerea). Appl. Environ. Microbiol. 82, 3440–3349 (2016).ADS 
    PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Stoffel, M. A. et al. Early sexual dimorphism in the developing gut microbiome of northern elephant seals. Mol. Ecol. 29, 2109–2122 (2020).PubMed 
    Article 

    Google Scholar 
    Tian, J., Du, J., Han, J., Song, X. & Lu, Z. Age-related differences in gut microbial community composition of captive spotted seals (Phoca largha). Mar. Mamm. Sci. 36, 1231–1240 (2020).Article 

    Google Scholar 
    Wu, G. D. et al. Linking long-term dietary patterns with gut microbial enterotypes. Science 334, 105–108 (2011).ADS 
    PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Bigg, M. A. Harbour seal: Phoca vitulina and P. largha. In Handbook of Marine Mammals Vol. 2 (eds Ridgeway, S. H. & Harrison, R. J.) 1–27 (Academic Press, 1981).
    Google Scholar 
    Parracho, H., McCartney, A. L. & Gibson, G. R. Probiotics and prebiotics in infant nutrition. Proc. Nutr. Society 66, 405–411 (2007).Article 

    Google Scholar 
    Marques, T. M. et al. Programming infant gut microbiota: Influence of dietary and environmental factors. Curr. Opin. Biotechnol. 21, 149–156 (2010).PubMed 
    Article 
    CAS 

    Google Scholar 
    Palmer, C., Bik, E. M., DiGiulio, D. B., Relman, D. A. & Brown, P. O. Development of the human infant intestinal microbiota. PLoS Biol. 5, 1556–1573 (2007).Article 
    CAS 

    Google Scholar 
    Mitsuoka, T. Intestinal flora and aging. Nutr. Rev. 50, 438–446 (1992).PubMed 
    Article 
    CAS 

    Google Scholar 
    Bowen, W., Oftedal, O. & Boness, D. Mass and energy transfer during lactation in a small phocid, the harbor seal (Phoca vitulina). Physiol. Zool. 65, 844–866 (1992).Article 

    Google Scholar 
    Bowen, W. D., Boness, D. J. & Iverson, S. J. Diving behaviour of lactating harbour seals and their pups during maternal foraging trips. Can. J. Zool. 77, 978–988 (1999).Article 

    Google Scholar 
    Jørgensen, C., Lydersen, C., Brix, O. & Kovacs, K. M. Diving development in nursing harbour seal pups. J. Exp. Biol. 204, 3993–4004 (2001).PubMed 
    Article 

    Google Scholar 
    Muelbert, M. M. C. & Bowen, W. D. Duration of lactation and postweaning changes in mass and body composition of harbour seal, Phoca vitulina, pups. Can. J. Zool. 71, 1405–1414 (1993).Article 

    Google Scholar 
    Kim, M., Cho, H. & Lee, W. Y. Distinct gut microbiotas between southern elephant seals and Weddell seals of Antarctica. J. Microbiol. 58, 1018–1026 (2020).PubMed 
    Article 
    CAS 

    Google Scholar 
    Kershaw, J. L. & Hall, A. J. Seasonal variation in harbour seal (Phoca vitulina) blubber cortisol—A novel indicator of physiological state?. Sci. Rep. 6, 1–9 (2016).Article 
    CAS 

    Google Scholar 
    Madison, A. & Kiecolt-Glaser, J. K. Stress, depression, diet, and the gut microbiota: Human–bacteria interactions at the core of psychoneuroimmunology and nutrition. Curr. Opin. Behav. Sci. 28, 105–110 (2019).PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Thompson, P. M., Miller, D., Cooper, R. & Hammond, P. S. Changes in the distribution and activity of female harbour seals during the breeding season: implications for their lactation strategy and mating patterns. J. Anim. Ecol. 63, 24 (1994).Article 

    Google Scholar 
    Raulo, A. et al. Social behaviour and gut microbiota in red-bellied lemurs (Eulemur rubriventer): In search of the role of immunity in the evolution of sociality. J. Anim. Ecol. 87, 388–399 (2018).PubMed 
    Article 

    Google Scholar 
    Song, S. J. et al. Cohabiting family members share microbiota with one another and with their dogs. Elife 2013, 1–22 (2013).
    Google Scholar 
    Fernández-Martin, E. M., Heckel, G., Schramm, Y. & García-Aguilar, M. C. The timing of pupping and molting of the Pacific harbor seal, Phoca vitulina richardii, at Punta Banda Estuary, Baja California, Mexico. Cienc. Mar. 42, 195–208 (2016).Article 

    Google Scholar 
    Oates, S. C. Survival, movements, and diet of juvenile harbor seals along central California. [Master’s thesis, San Jose State University]. (2005). https://doi.org/10.31979/etd.ra96-xhge.Germain, L. R., Mccarthy, M. D., Koch, P. L. & Harvey, J. T. Stable carbon and nitrogen isotopes in multiple tissues of wild and captive harbor seals (Phoca vitulina) off the California coast. Mar. Mamm. Sci. 28, 542–560 (2012).Article 
    CAS 

    Google Scholar 
    Brassea-Pérez, E., Schramm, Y., Heckel, G., Chong-Robles, J. & Lago-Lestón, A. Metabarcoding analysis of the Pacific harbor seal diet in Mexico. Mar. Biol. 166, (2019).Davis, T. A., Nguyen, H. V., Costa, D. P. & Reeds, P. J. Amino acid composition of pinniped milk. Comp. Biochem. Physiol. B Biochem. Mol. Biol. 110, 633–639 (1995).PubMed 
    Article 
    CAS 

    Google Scholar 
    Sauvé, C. C., van de Walle, J., Hammill, M. O., Arnould, J. P. Y. & Beauplet, G. Stomach temperature records reveal nursing behaviour and transition to solid food consumption in an unweaned mammal, the harbour seal pup (Phoca vitulina). PLoS ONE 9, (2014).Fernández Martín, E. M. Fenología de los nacimientos, estado de salud de las crías, y estructura genética poblacional de Phoca vitulina richardii en México [Doctoral thesis, Universidad Autónoma de Baja California, Mexico]. (2018).Gresse, R. et al. Gut microbiota dysbiosis in postweaning piglets: Understanding the keys to health. Trends Microbiol. 25, 851–873 (2017).PubMed 
    Article 
    CAS 

    Google Scholar 
    Sommer, F. et al. The gut microbiota modulates energy metabolism in the hibernating brown bear Ursus arctos. Cell Rep. 14, 1655–1661 (2016).PubMed 
    Article 
    CAS 

    Google Scholar 
    Ni, Y. et al. Distinct composition and metabolic functions of human gut microbiota are associated with cachexia in lung cancer patients. ISME J. 15, 3207–3220 (2021).PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Pacífico, C. et al. Unveiling the bovine epimural microbiota composition and putative function. Microorganisms 9, 1–23 (2021).Article 
    CAS 

    Google Scholar 
    Fenn, K. et al. Quinones are growth factors for the human gut microbiota. Microbiome 5, 161 (2017).PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Rodríguez, J. M. et al. The composition of the gut microbiota throughout life, with an emphasis on early life. Microb. Ecol. Health Disease 26, (2015).Thompson, P. M., Mackay, A., Tollit, D. J., Enderby, S. & Hammond, P. S. The influence of body size and sex on the characteristics of harbour seal foraging trips. Can. J. Zool. 76, 1044–1053 (1998).Article 

    Google Scholar 
    van Parijs, S. M., Thompson, P. M., Tollit, D. J. & Mackay, A. Distribution and activity of male harbour seals during the mating season. Anim. Behav. 54, 35–43 (1997).Article 

    Google Scholar 
    Bjorkland, R. H. et al. Stable isotope mixing models elucidate sex and size effects on the diet of a generalist marine predator. Mar. Ecol. Prog. Ser. 526, 213–225 (2015).ADS 
    Article 

    Google Scholar 
    Schwarz, D. et al. Large-scale molecular diet analysis in a generalist marine mammal reveals male preference for prey of conservation concern. Ecol. Evol. 8, 9889–9905 (2018).PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Boulva, J. Temporal variations in birth period and characteristics of newborn harbour seals. Rapports et procPs-verbaux, Reunions du Conseil International pour I’Exploration de la Mer 169, 405–408 (1975).
    Google Scholar 
    Bhute, S. S., Ghaskadbi, S. S. & Shouche, Y. S. Rare biosphere in human gut: A less explored component of human gut microbiota and its association with human health. In Mining of Microbial Wealth and MetaGenomics (eds Kalia, V. C. et al.) 133–142 (Springer Nature Singapore Ptd Ltd, 2017). https://doi.org/10.1007/978-981-10-5708-3.Chapter 

    Google Scholar 
    Brown, R. F. & Mate, B. R. Abundance, movements, and feeding habits of harbor seals, Phoca vitulina, at Netarts and Tillamook Bays, Oregon. Fishery Bull. 81, 291–301 (1983).
    Google Scholar 
    Higgins, R. Bacteria and fungi of marine mammals: A review. Can. Veterinary J. 41, 105–116 (2000).CAS 

    Google Scholar 
    Gilbert, M. J. et al. Campylobacter blaseri sp. nov., isolated from common seals (Phoca vitulina). Int. J. Syst. Evolut. Microbiol. 68, 1787–1794 (2018).Article 
    CAS 

    Google Scholar 
    Agnese, E. D. et al. Comparative microbial community analysis of fur seals and salmon aquaculture in Tasmania. Authorea. https://doi.org/10.22541/au.160253843.32636436/v1 (2020).Article 

    Google Scholar 
    Rivas, A. J., Lemos, M. L. & Osorio, C. R. Photobacterium damselae subsp. damselae, a bacterium pathogenic for marine animals and humans. Front. Microbiol. 4, 1–6 (2013).Article 

    Google Scholar 
    Fouz, B., Toranzo, A. E., Milan, M. & Amaro, C. Evidence that water transmits the disease caused by the fish pathogen Photobacterium damselae subsp. damselae. J. Appl. Microbiol. 88, 531–535 (2000).PubMed 
    Article 
    CAS 

    Google Scholar 
    Hundenborn, J., Thurig, S., Kommerell, M., Haag, H. & Nolte, O. Severe Wound Infection with Photobacterium damselae ssp. damselae and Vibrio harveyi, following a laceration injury in marine environment: A case report and review of the literature. Case Rep. Med. 2013, (2013).Lubinsky-Jinich, D., Schramm, Y. & Heckel, G. The Pacific Harbor Seal’s (Phoca vitulina richardii) breeding colonies in Mexico: Abundance and distribution. Aquat. Mamm. 43, 73–81 (2017).Article 

    Google Scholar 
    Arias-Del Razo, A. et al. Distribution of four pinnipeds (Zalophus californianus, Arctocephalus philippii townsendi, Phoca vitulina richardii, and Mirounga angustirostris) on Islands off the west coast of the Baja California Peninsula, Mexico. Aquat. Mamm. 43, 40–51 (2017).Article 

    Google Scholar 
    Caporaso, J. G. et al. Global patterns of 16S rRNA diversity at a depth of millions of sequences per sample. Proc. Natl. Acad. Sci. USA. 108, 4516–4522 (2011).ADS 
    PubMed 
    Article 

    Google Scholar 
    Kozich, J. J., Westcott, S. L., Baxter, N. T., Highlander, S. K. & Schloss, P. D. Development of a dual-index sequencing strategy and curation pipeline for analyzing amplicon sequence data on the MiSeq Illumina sequencing platform. Appl. Environ. Microbiol. 79, 5112–5120 (2013).ADS 
    PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Robertson, K. M., Lauf, M. L. & Morin, P. A. Genetic sexing of pinnipeds: A real-time, single step qPCR technique. Conserv. Genet. Resour. 10, 213–218 (2018).Article 

    Google Scholar 
    Martin, M. Cutadapt removes adapter sequences from high-throughput sequencing reads. EMBnet.journal 17, 10–12 (2011).Article 

    Google Scholar 
    Callahan, B. J. et al. DADA2: High-resolution sample inference from Illumina amplicon data. Nat. Methods 13, 581–583 (2016).PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.r-project.org/ (2019). Accessed 3 June 2021.McMurdie, P. J. & Holmes, S. Phyloseq: An R package for reproducible interactive analysis and graphics of microbiome census data. PLoS ONE 8, (2013).Oksanen, J. et al. vegan: Community Ecology Package. R package version 2.5-4. https://cran.r-project.org/package=vegan (2019). Accessed 3 June 2021.Andersen, K. S., Kirkegaard, R. H., Karst, S. M. & Albertsen, M. ampvis2: An R package to analyse and visualise 16S rRNA amplicon data. bioRxiv. https://doi.org/10.1101/299537 (2018).Article 

    Google Scholar 
    Wickham, H. ggplot2: Elegant Graphics for Data Analysis (Springer-Verlag, 2016).MATH 
    Book 

    Google Scholar 
    Salinas, H. & Ramirez-Delgado, D. ecolTest: Community Ecology Tests. (2021).Love, M. I., Huber, W. & Anders, S. Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2. Genome Biol. 15, 1–21 (2014).Article 
    CAS 

    Google Scholar 
    Lozupone, C. & Knight, R. UniFrac: A new phylogenetic method for comparing microbial communities. Appl. Environ. Microbiol. 71, 8228–8235 (2005).ADS 
    PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Lozupone, C., Lladser, M. E., Knights, D., Stombaugh, J. & Knight, R. UniFrac: An effective distance metric for microbial community comparison. ISME J. 5, 169–172 (2011).PubMed 
    Article 

    Google Scholar 
    Martinez Arbizu, P. pairwiseAdonis: Pairwise multilevel comparison using adonis. R package version 0.4. (2020).Douglas, G. M. et al. PICRUSt2 for prediction of metagenome functions. Nat. Biotechnol. 38, 685–688 (2020).PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Caspi, R. et al. The MetaCyc database of metabolic pathways and enzymes-A 2019 update. Nucleic Acids Res. 48, D455–D463 (2020).Article 
    CAS 

    Google Scholar  More

  • in

    The Subantarctic Rayadito (Aphrastura subantarctica), a new bird species on the southernmost islands of the Americas

    Vaurie, C. Taxonomy and geographical distribution of the Furnariidae (Aves, Passeriformes). Bulletin of the AMNH; v. 166, article 1. Bull. Am. Museum Nat. Hist. 166, 1–357 (1980).
    Google Scholar 
    Hahn, I. & Römer, U. New observations of the Masafuera Rayadito Aphrastura masafuerae. Cotinga 6, 17–19 (1996).
    Google Scholar 
    Hahn, I. & Römer, U. Threatened avifauna of the Juan Fernández Archipelago, Chile: The impact of introduced mammals and conservation priorities. Cotinga 17, 66–72 (2002).
    Google Scholar 
    Remsen, J. V. Family Furnariidae (Ovenbirds) Vol 8 162–348 (Lynx Edicions, 2003).
    Google Scholar 
    Moreno, J., Merino, S., Lobato, E., Rodríguez-Gironés, M. A. & Vásquez, R. A. Sexual dimorphism and parental roles in the Thorn-tailed Rayadito (Furnariidae). Condor 109, 312–320 (2007).Article 

    Google Scholar 
    Moreno, J., Merino, S., Vásquez, R. A. & Armesto, J. J. Breeding biology of the Thorn-tailed Rayadito (Furnariidae) in south-temperate rainforests of Chile. Condor 107, 69–77 (2005).Article 

    Google Scholar 
    Rozzi, R. & Jiménez, J. Sub-Antarctic Magellanic Ornithology: The First Decade of Long-term Bird Studies at the Omora Ethnobotanical Park, Cape Horn Biosphere Reserve, Chile (Universidad de Magallanes, Chile-University of North Texas Press, 2014).
    Google Scholar 
    Schlatter, R. & Riveros, G. Historia natural del Archipiélago Diego Ramírez, Chile. Ser. Cie. Ina. 47, 87–112 (1997).
    Google Scholar 
    Barroso, O. et al. Scientific collaboration with the Chilean Navy for long-term ornithological studies in the Diego Ramírez Archipelago: First year-round monitoring of Gonzalo Island’s bird assemblage. Anal. Inst. Patagonia 48, 149–168 (2020).Article 

    Google Scholar 
    Botero-Delgadillo, E. et al. Range-wide genetic structure in the thorn-tailed rayadito suggests limited gene flow towards peripheral populations. Sci. Rep. 10, 1–14 (2020).Article 
    CAS 

    Google Scholar 
    Aguirre, F. et al. Gradientes climáticos y su influyente rol sobre los ecosistemas terrestres de la Reserva de Biosfera Cabo de Hornos, Chile. Anal. Inst. Patagonia (In press).Rozzi, R. et al. Parque Marino Cabo de Hornos-Diego Ramírez, Informe Técnico para la Propuesta de Creación (Universidad de Magallanes, 2017).
    Google Scholar 
    Johnson, A. W. & Goodall, J. The Birds of Chile and Adjacent Regions of Argentina, Bolivia and Peru (Platt Establecimientos Graficos, 1967).
    Google Scholar 
    Tomasevic, J. A., Hodum, P. J. & Estades, C. F. On the ecology and conservation of the critically endangered Masafuera Rayadito (Aphrastura masafuerae). Ornitol. Neotrop. 21, 535–543 (2010).
    Google Scholar 
    Ippi, S., Anderson, C. B., Rozzi, R. & Elphick, C. S. Annual variation of abundance and composition in forest bird assemblages on Navarino Island, Cape Horn Biosphere Reserve, Chile. Ornitol. Neotrop. 20, 231–245 (2009).
    Google Scholar 
    Rozzi, R., Martínez, D., Willson, M. F. & Sabag, C. In Ecología de los Bosques Nativos de Chile (eds Armesto, J. J. et al.) 135–152 (Editorial Universitaria, 1996).
    Google Scholar 
    Hahn, I., Römer, U. & Schlatter, R. Distribution, habitat use, and abundance patterns of land bird communities on the Juan Fernández Islands, Chile. Ornitol. Neotrop. 16, 371–385 (2005).
    Google Scholar 
    Vergara, P. M. & Marquet, P. A. On the seasonal effect of landscape structure on a bird species: The thorn-tailed rayadito in a relict forest in northern Chile. Landsc. Ecol. 22, 1059–1071 (2007).Article 

    Google Scholar 
    Kelt, D. A. et al. The avifauna of Bosque Fray Jorge National Park and Chile’s Norte Chico. J. Arid Environ. 126, 23–36 (2016).ADS 
    Article 

    Google Scholar 
    Espíndola-Hernández, P., Castaño-Villa, G. J., Vásquez, R. A. & Quirici, V. Sex-specific provisioning of nutritious food items in relation to brood sex ratios in a non-dimorphic bird. Behav. Ecol. Sociobiol. 71, 65 (2017).Article 

    Google Scholar 
    Pisano Valdés, E. & Schlatter, R. P. Vegetación y flora de las islas Diego Ramírez (Chile). 1. Características y relaciones de la flora Vascular. Anal. Inst. Patagonia 12, 183–194 (1981).
    Google Scholar 
    Pisano Valdés, E. & Schlatter, R. P. Vegetación y flora de las islas Diego Ramírez (Chile). 2. Comunidades vegetales vasculares. Anal. Inst. Patagonia 12, 195–204 (1981).
    Google Scholar 
    Mackenzie, R. et al. Vascular flora and vegetational types at the long-term socio-ecological studies site, Gonzalo Island, Diego Ramírez Archipelago (56°31’S), Chile. Anal. Inst. Patagonia 48, 139–148 (2020).Article 

    Google Scholar 
    Rozzi, R. et al. Un centinela para el monitoreo del cambio climático y su impacto sobre la biodiversidad en la cumbre austral de América: La nueva red de estudios a largo Plazo Cabo de Hornos. Anal. Inst. Patagonia 48, 45–81 (2020).Article 

    Google Scholar 
    Robertson, G. et al. Continued increase in the number of black-browed albatrosses (Thalassarche melanophris) at Diego Ramírez, Chile. Polar Biol. 40, 1035–1042 (2017).Article 

    Google Scholar 
    Arroniz-Crespo, M. et al. Bryophyte-cyanobacteria associations during primary succession in recently deglaciated areas of Tierra del Fuego (Chile). PLoS One 9, e96081 (2014).ADS 
    PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Rozzi, R. et al. Cape Horn Biosphere Reserve: A challenge for biodiversity conservation, and implementation of sustainable development in southernmost South America. Anal. Inst. Patagonia 36, 55–70 (2007).
    Google Scholar 
    Rozzi, R. et al. principles for biocultural conservation at the southern tip of the Americas: The approach of the Omora Ethnobotanical Park. Ecol. Soc. 11, 25 (2006).Article 

    Google Scholar 
    R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, 2019).Gonzalez, J. & Wink, M. Genetic differentiation of the Thorn-tailed Rayadito Aphrastura spinicauda (Furnariidae: Passeriformes) revealed by ISSR profiles suggests multiple palaeorefugia and high recurrent gene flow. Ibis 152, 761–774 (2010).Article 

    Google Scholar 
    Filatov, D. A. ProSeq: A software for preparation and evolutionary analysis of DNA sequence data sets. Mol. Ecol. Notes 2, 621–624 (2002).CAS 
    Article 

    Google Scholar 
    Excoffier, L. & Lischer, H. E. Arlequin suite ver 3.5: A new series of programs to perform population genetics analyses under Linux and Windows. Mol. Ecol. Resour. 10, 564–567 (2010).PubMed 
    Article 

    Google Scholar 
    Hammer, Ø., Harper, D. A. & Ryan, P. D. PAST: Paleontological statistics software package for education and data analysis. Palaeontol. Electron. 4, 9 (2001).
    Google Scholar 
    Bandelt, H.-J., Forster, P. & Röhl, A. Median-joining networks for inferring intraspecific phylogenies. Mol. Biol. Evol. 16, 37–48 (1999).CAS 
    PubMed 
    Article 

    Google Scholar 
    Pons, O. & Petit, R. Measwring and testing genetic differentiation with ordered versus unordered alleles. Genetics 144, 1237–1245 (1996).CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Excoffier, L., Smouse, P. E. & Quattro, J. M. Analysis of molecular variance inferred from metric distances among DNA haplotypes: Application to human mitochondrial DNA restriction data. Genetics 131, 479–491 (1992).CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Botero-Delgadillo, E. et al. Variation in fine-scale genetic structure and local dispersal patterns between peripheral populations of a South American passerine bird. Ecol. Evol. 7, 8363–8378 (2017).PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Botero-Delgadillo, E., Quirici, V., Vásquez, R. A. & Kempenaers, B. Heterozygosity-fitness correlations in a continental island population of Thorn-tailed Rayadito. J. Hered. 111, 628–639 (2020).PubMed 
    Article 

    Google Scholar 
    Goudet, J. & Jombart, T. hierfstat: Estimation and tests of hierarchical F-statistics. R package version 0.04-22. https://CRAN.R-project.org/package=hierfstat (2015).Jombart, T. adegenet: A R package for the multivariate analysis of genetic markers. Bioinformatics 24, 1403–1405 (2008).CAS 
    PubMed 
    Article 

    Google Scholar 
    Beugin, M. P., Gayet, T., Pontier, D., Devillard, S. & Jombart, T. A fast likelihood solution to the genetic clustering problem. Methods Ecol. Evol. 9, 1006–1016 (2018).PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Peakall, R. & Smouse, P. E. GENALEX 6: Genetic analysis in Excel. Population genetic software for teaching and research. Mol. Ecol. Notes 6, 288–295 (2006).Article 

    Google Scholar 
    Piry, S. et al. GENECLASS2: A software for genetic assignment and first-generation migrant detection. J. Hered. 95, 536–539 (2004).CAS 
    PubMed 
    Article 

    Google Scholar 
    Paetkau, D., Calvert, W., Stirling, I. & Strobeck, C. Microsatellite analysis of population structure in Canadian polar bears. Mol. Ecol. 4, 347–354 (1995).CAS 
    PubMed 
    Article 

    Google Scholar 
    Paetkau, D., Slade, R., Burden, M. & Estoup, A. Genetic assignment methods for the direct, real-time estimation of migration rate: A simulation-based exploration of accuracy and power. Mol. Ecol. 13, 55–65 (2004).CAS 
    PubMed 
    Article 

    Google Scholar 
    Du Sert, N. P. et al. Reporting animal research: Explanation and elaboration for the ARRIVE guidelines 20. PLoS Biol. 18, e3000411 (2020).Article 
    CAS 

    Google Scholar 
    Linnaeus, C. Systema Naturae per regna tria naturae. Secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Vol. 1 (Impensis Direct Laurentii Salvii, 1758).Gray, G. R. A List of the Genera of Birds, with an Indication of the Typical Species of Each Genus, Compiled from Various Sources (Richard and John E. Taylor, 1940).
    Google Scholar 
    Oberholser, H. C. Some untenable names in ornithology. Proc. Acad. Nat. Sci. Philadelphia 20, 201–216 (1899).
    Google Scholar 
    Derryberry, E. P. et al. Lineage diversification and morphological evolution in a large-scale continental radiation: The Neotropical ovenbirds and woodcreepers (Aves: Furnariidae). Evol. Int. J. Organ. Evol. 65, 2973–2986 (2011).Article 

    Google Scholar 
    Fjeldsa, J., Christidis, L. & Ericson, P. G. The Largest Avian Radiation: The Evolution of Perching Birds, or the Order Passeriformes (Lynx Edicions, 2020).
    Google Scholar 
    Munsell Color Charts. Munsell Soil Color Charts (Munsell Color Company, 2000).
    Google Scholar 
    Mittermeier, R. A. et al. Wilderness and biodiversity conservation. Proc. Natl. Acad. Sci. 100, 10309–10313 (2003).ADS 
    CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Lomolino, M., Riddle, B. & Whittaker, R. (Oxford University Press, 2016).Whittaker, R. J. Island Biogeography: Ecology, Evolution, and Conservation (Oxford University Press, 1998).
    Google Scholar 
    Botero-Delgadillo, E. et al. Ecological and social correlates of natal dispersal in female and male Thorn-tailed Rayadito (Aphrastura spinicauda) in a naturally isolated and fragmented habitat. Auk Ornithol. Adv. 136, ukz016 (2019).
    Google Scholar 
    Botero-Delgadillo, E., Serrano, D., Orellana, N., Poblete, Y. & Vásquez, R. A. Effects of temperature and time constraints on the seasonal variation in nest morphology of the Thorn-tailed Rayadito (Aphrastura spinicauda). Emu-Austral Ornithol. 117, 181–187 (2017).Article 

    Google Scholar 
    Cornelius, C. Spatial variation in nest-site selection by a secondary cavity-nesting bird in a human-altered landscape. Condor 110, 615–626 (2008).Article 

    Google Scholar 
    Quilodrán, C. S., Estades, C. F. & Vásquez, R. A. Conspecific effect on habitat selection of a territorial cavity-nesting bird. Wilson J. Ornithol. 126, 534–543 (2014).Article 

    Google Scholar 
    Quilodrán, C. S., Vásquez, R. A. & Estades, C. F. Nesting of the Thorn-tailed Rayadito (Aphrastura spinicauda) in a pine plantation in southcentral Chile. Wilson J. Ornithol. 124, 737–742 (2012).Article 

    Google Scholar 
    Wright, N. A., Steadman, D. W. & Witt, C. C. Predictable evolution toward flightlessness in volant island birds. Proc. Natl. Acad. Sci. 113, 4765–4770 (2016).ADS 
    CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Sandvig, E. M., Coulson, T. & Clegg, S. M. The effect of insularity on avian growth rates and implications for insular body size evolution. Proc. R. Soc. B 286, 20181967 (2019).PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Reznick, D. N. et al. Eco-evolutionary feedbacks predict the time course of rapid life-history evolution. Am. Nat. 194, 671–692 (2019).PubMed 
    Article 

    Google Scholar 
    Clavel, J. & Morlon, H. Accelerated body size evolution during cold climatic periods in the Cenozoic. Proc. Natl. Acad. Sci. 114, 4183–4188 (2017).ADS 
    CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Philippi, R. & Landbeck, L. Beitrage zur Fauna Chiles. Arch Naturgesch 32, 121–132 (1866).
    Google Scholar 
    Vaurie, C. Taxonomy and geographical distribution of the Furnariidae (Aves, Passeriformes). Bull. AMNH 166, 1 (1980).
    Google Scholar 
    Vuilleumier, F. A quantitative survey of speciation phenomena in Patagonian birds. Ornitol. Neotrop. 2, 5–28 (1991).
    Google Scholar 
    Ippi, S., Vasquez, R. A., van Dongen, W. F. & Lazzoni, I. Geographical variation in the vocalizations of the suboscine Thorn-tailed Rayadito Aphrastura spinicauda. Ibis 153, 789–805 (2011).Article 

    Google Scholar 
    Imberti, S. Internet Bird Collection: Thorn-tailed Rayadito (Aphrastura spinicauda). https://macaulaylibrary.org/asset/204019791 (2001).Mikula, P. et al. A global analysis of song frequency in passerines provides no support for the acoustic adaptation hypothesis but suggests a role for sexual selection. Ecol. Lett. 24, 477–486 (2021).PubMed 
    Article 

    Google Scholar 
    Meirmans, P. G. & Hedrick, P. W. Assessing population structure: FST and related measures. Mol. Ecol. Resour. 11, 5–18 (2011).PubMed 
    Article 

    Google Scholar 
    Davies, B. J. et al. The evolution of the Patagonian Ice Sheet from 35 ka to the present day (PATICE). Earth Sci. Rev. 204, 103152 (2020).Article 

    Google Scholar 
    Lamy, F. et al. Glacial reduction and millennial-scale variations in Drake Passage throughflow. Proc. Natl. Acad. Sci. 112, 13496–13501 (2015).ADS 
    CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Rozzi, R. et al. Integrating ecology and environmental ethics: Earth stewardship in the southern end of the Americas. Bioscience 62, 226–236 (2012).Article 

    Google Scholar 
    Collins, R. & Cruickshank, R. H. The seven deadly sins of DNA barcoding. Mol. Ecol. Resour. 13, 969–975 (2013).CAS 
    PubMed 

    Google Scholar 
    De Queiroz, K. Species concepts and species delimitation. Syst. Biol. 56, 879–886 (2007).PubMed 
    Article 

    Google Scholar 
    Sendell-Price, A. T. et al. The genomic landscape of divergence across the speciation continuum in island-colonising silvereyes (Zosterops lateralis). G3 Genes Genomes Genet. 10, 3147–3163 (2020).CAS 

    Google Scholar 
    Päckert, M., Martens, J., Wink, M., Feigl, A. & Tietze, D. T. Molecular phylogeny of Old World swifts (Aves: Apodiformes, Apodidae, Apus and Tachymarptis) based on mitochondrial and nuclear markers. Mol. Phylogenet. Evol. 63, 606–616 (2012).PubMed 
    Article 

    Google Scholar 
    Lerner, H. et al. Phylogeny and new taxonomy of the booted eagles (Accipitriformes: Aquilinae). Zootaxa 4216, 301–320 (2017).Article 

    Google Scholar 
    De Silva, T. N., Peterson, A. T., Bates, J. M., Fernando, S. W. & Girard, M. G. Phylogenetic relationships of weaverbirds (Aves: Ploceidae): A first robust phylogeny based on mitochondrial and nuclear markers. Mol. Phylogenet. Evol. 109, 21–32 (2017).PubMed 
    Article 

    Google Scholar 
    Schüttler, E. et al. New records of invasive mammals from the sub-Antarctic Cape Horn Archipelago. Polar Biol. 42, 1093–1105 (2019).Article 

    Google Scholar 
    Martin, A. & Richardson, M. Rodent eradication scaled up: Clearing rats and mice from South Georgia. Oryx 53, 27–35 (2019).Article 

    Google Scholar 
    Schüttler, E., Klenke, R., McGehee, S., Rozzi, R. & Jax, K. Vulnerability of ground-nesting waterbirds to predation by invasive American mink in the Cape Horn Biosphere Reserve, Chile. Biol. Conserv. 142, 1450–1460 (2009).Article 

    Google Scholar  More

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    Decomposing virulence to understand bacterial clearance in persistent infections

    Fly population and maintenanceWe used an outbred population of Drosophila melanogaster established from 160 Wolbachia-infected fertilised females collected in Azeitão, Portugal54, and given to us by Élio Sucena. For at least 13 generations prior to the start of the experiments the flies were maintained on standard sugar yeast agar medium (SYA medium: 970 ml water, 100 g brewer’s yeast, 50 g sugar, 15 g agar, 30 ml 10% Nipagin solution and 3 ml propionic acid; ref. 61), in a population cage containing at least 5000 flies, with non-overlapping generations of 15 days. They were maintained at 24.3 ± 0.2 °C, on a 12:12 h light-dark cycle, at 60–80 % relative humidity. The experimental flies were kept under the same conditions. No ethical approval or guidance is required for experiments with D. melanogaster.Bacterial speciesWe used the Gram positive Lactococcus lactis (gift from Brian Lazzaro), Gram negative Enterobacter cloacae subsp. dissolvens (hereafter called E. cloacae; German collection of microorganisms and cell cultures, DSMZ; type strain: DSM-16657), Providencia burhodogranariea strain B (gift from Brian Lazzaro, DSMZ; type strain: DSM-19968) and Pseudomonas entomophila (gift from Bruno Lemaitre). L. lactis43, Pr. burhodogranariea44 and Ps. entomophila45 were isolated from wild-collected D. melanogaster and can be considered as opportunistic pathogens. E. cloacae was isolated from a maize plant, but has been detected in the microbiota of D. melanogaster46. All bacterial species were stored in 34.4% glycerol at −80 °C and new cultures were grown freshly for each experimental replicate.Experimental designFor each bacterial species, flies were exposed to one of seven treatments: no injection (naïve), injection with Drosophila Ringer’s (injection control) or injection with one of five concentrations of bacteria ranging from 5 × 106 to 5 × 109 colony forming units (CFUs)/mL, corresponding to doses of approximately 92, 920, 1,840, 9200 and 92,000 CFUs per fly. The injections were done in a randomised block design by two people. Each bacterial species was tested in three independent experimental replicates. Per experimental replicate we treated 252 flies, giving a total of 756 flies per bacterium (including naïve and Ringer’s injection control flies). Per experimental replicate and treatment, 36 flies were checked daily for survival until all flies were dead. A sub-set of the dead flies were homogenised upon death to test whether the infection had been cleared before death or not. To evaluate bacterial load in living flies, per experimental replicate, four of the flies were homogenised per treatment, for each of nine time points: one, two, three, four, seven, 14, 21, 28- and 35-days post-injection.Infection assayBacterial preparation was performed as in Kutzer et al.24, except that we grew two overnight liquid cultures of bacteria per species, which were incubated overnight for approximately 15 h at 30 °C and 200 rpm. The overnight cultures were centrifuged at 2880 × g at 4 °C for 10 min and the supernatant removed. The bacteria were washed twice in 45 mL sterile Drosophila Ringer’s solution (182 mmol·L-1 KCl; 46 mol·L-1 NaCl; 3 mmol·L-1 CaCl2; 10 mmol·L-1 Tris·HCl; ref. 62) by centrifugation at 2880 × g at 4 °C for 10 min. The cultures from the two flasks were combined into a single bacterial solution and the optical density (OD) of 500 µL of the solution was measured in a Ultrospec 10 classic (Amersham) at 600 nm. The concentration of the solution was adjusted to that required for each injection dose, based on preliminary experiments where a range of ODs between 0.1 and 0.7 were serially diluted and plated to estimate the number of CFUs. Additionally, to confirm post hoc the concentration estimated by the OD, we serially diluted to 1:107 and plated the bacterial solution three times and counted the number of CFUs.The experimental flies were reared at constant larval density for one generation prior to the start of the experiments. Grape juice agar plates (50 g agar, 600 mL red grape juice, 42 mL Nipagin [10% w/v solution] and 1.1 L water) were smeared with a thin layer of active yeast paste and placed inside the population cage for egg laying and removed 24 h later. The plates were incubated overnight then first instar larvae were collected and placed into plastic vials (95 × 25 mm) containing 7 ml of SYA medium. Each vial contained 100 larvae to maintain a constant density during development. One day after the start of adult eclosion, the flies were placed in fresh food vials in groups of five males and five females, after four days the females were randomly allocated to treatment groups and processed as described below.Before injection, females were anesthetised with CO2 for a maximum of five minutes and injected in the lateral side of the thorax using a fine glass capillary (Ø 0.5 mm, Drummond), pulled to a fine tip with a Narishige PC-10, and then connected to a Nanoject II™ injector (Drummond). A volume of 18.4 nL of bacterial solution, or Drosophila Ringer’s solution as a control, was injected into each fly. Full controls, i.e., naïve flies, underwent the same procedure but without any injection. After being treated, flies were placed in groups of six into new vials containing SYA medium, and then transferred into new vials every 2–5 days. Maintaining flies in groups after infection is a standard method in experiments with D. melanogaster that examine survival and bacterial load (e.g. refs. 22, 63, 64). At the end of each experimental replicate, 50 µL of the aliquots of bacteria that had been used for injections were plated on LB agar to check for potential contamination. No bacteria grew from the Ringer’s solution and there was no evidence of contamination in any of the bacterial replicates. To confirm the concentration of the injected bacteria, serial dilutions were prepared and plated before and after the injections for each experimental replicate, and CFUs counted the following day.Bacterial load of living fliesFlies were randomly allocated to the day at which they would be homogenised. Prior to homogenisation, the flies were briefly anesthetised with CO2 and removed from their vial. Each individual was placed in a 1.5 mL microcentrifuge tube containing 100 µL of pre-chilled LB media and one stainless steel bead (Ø 3 mm, Retsch) on ice. The microcentrifuge tubes were placed in a holder that had previously been chilled in the fridge at 4 °C for at least 30 min to reduce further growth of the bacteria. The holders were placed in a Retsch Mill (MM300) and the flies homogenised at a frequency of 20 Hz for 45 s. Then, the tubes were centrifuged at 420 × g for one minute at 4 °C. After resuspending the solution, 80 µL of the homogenate from each fly was pipetted into a 96-well plate and then serially diluted 1:10 until 1:105. Per fly, three droplets of 5 μL of every dilution were plated onto LB agar. Our lower detection limit with this method was around seven colony-forming units per fly. We consider bacterial clearance by the host to be when no CFUs were visible in any of the droplets, although we note that clearance is indistinguishable from an infection that is below the detection limit. The plates were incubated at 28 °C and the numbers of CFUs were counted after ~20 h. Individual bacterial loads per fly were back calculated using the average of the three droplets from the lowest countable dilution in the plate, which was usually between 10 and 60 CFUs per droplet.D. melanogaster microbiota does not easily grow under the above culturing conditions (e.g. ref. 42) Nonetheless we homogenised control flies (Ringer’s injected and naïve) as a control. We rarely retrieved foreign CFUs after homogenising Ringer’s injected or naïve flies (23 out of 642 cases, i.e., 3.6 %). We also rarely observed contamination in the bacteria-injected flies: except for homogenates from 27 out of 1223 flies (2.2 %), colony morphology and colour were always consistent with the injected bacteria (see methods of ref. 65). Twenty one of these 27 flies were excluded from further analyses given that the contamination made counts of the injected bacteria unreliable; the remaining six flies had only one or two foreign CFUs in the most concentrated homogenate dilution, therefore these flies were included in further analyses. For L. lactis (70 out of 321 flies), P. burhodogranaeria (7 out of 381 flies) and Ps. entomophila (1 out of 71 flies) there were too many CFUs to count at the highest dilution. For these cases, we denoted the flies as having the highest countable number of CFUs found in any fly for that bacterium and at the highest dilution23. This will lead to an underestimate of the bacterial load in these flies. Note that because the assay is destructive, bacterial loads were measured once per fly.Bacterial load of dead fliesFor two periods of time in the chronic infection phase, i.e., between 14 and 35 days and 56 to 78 days post injection, dead flies were retrieved from their vial at the daily survival checks and homogenised in order to test whether they died whilst being infected, or whether they had cleared the infection before death. The fly homogenate was produced in the same way as for live flies, but we increased the dilution of the homogenate (1:1 to 1:1012) because we anticipated higher bacterial loads in the dead compared to the live flies. The higher dilution allowed us more easily to determine whether there was any obvious contamination from foreign CFUs or not. Because the flies may have died at any point in the 24 h preceding the survival check, and the bacteria can potentially continue replicating after host death, we evaluated the infection status (yes/no) of dead flies instead of the number of CFUs. Dead flies were evaluated for two experimental replicates per bacteria, and 160 flies across the whole experiment. Similar to homogenisation of live flies, we rarely observed contamination from foreign CFUs in the homogenate of dead bacteria-injected flies (3 out of 160; 1.9 %); of these three flies, one fly had only one foreign CFU, so it was included in the analyses. Dead Ringer’s injected and naïve flies were also homogenised and plated as controls, with 6 out of 68 flies (8.8%) resulting in the growth of unidentified CFUs.Statistical analysesStatistical analyses were performed with R version 4.2.166 in RStudio version 2022.2.3.49267. The following packages were used for visualising the data: “dplyr”68, “ggpubr”69, “gridExtra”70, “ggplot2”71, “plyr”72, “purr”73, “scales”74, “survival”75,76, “survminer”77, “tidyr”78 and “viridis”79, as well as Microsoft PowerPoint for Mac v16.60 and Inkscape for Mac v 1.0.2. Residuals diagnostics of the statistical models were carried out using “DHARMa”80, analysis of variance tables were produced using “car”81, and post-hoc tests were carried out with “emmeans”82. To include a factor as a random factor in a model it has been suggested that there should be more than five to six random-effect levels per random effect83, so that there are sufficient levels to base an estimate of the variance of the population of effects84. In our experimental designs, the low numbers of levels within the factors ‘experimental replicate’ (two to three levels) and ‘person’ (two levels), meant that we therefore fitted them as fixed, rather than random factors84. However, for the analysis of clearance (see below) we included species as a random effect because it was not possible to include it as a fixed effect because PPP is already a species-level predictor. Below we detail the statistical models that were run according to the questions posed. All statistical tests were two-sided.Do the bacterial species differ in virulence?To test whether the bacterial species differed in virulence, we performed a linear model with the natural log of the maximum hazard as the dependent variable and bacterial species as a factor. Post-hoc multiple comparisons were performed using “emmeans”82 and “magrittr”85, using the default Tukey adjustment for multiple comparisons. Effect sizes given as Cohen’s d, were also calculated using “emmeans”, using the sigma value of 0.4342, as estimated by the package. The hazard function in survival analyses gives the instantaneous failure rate, and the maximum hazard gives the hazard at the point at which this rate is highest. We extracted maximum hazard values from time of death data for each bacterial species/dose/experimental replicate. Each maximum hazard per species/dose/experimental replicate was estimated from an average of 33 flies (a few flies were lost whilst being moved between vials etc.). To extract maximum hazard values we defined a function that used the “muhaz” package86 to generate a smooth hazard function and then output the maximum hazard in a defined time window, as well as the time at which this maximum is reached. To assess the appropriate amount of smoothing, we tested and visualised results for four values (1, 2, 3 and 5) of the smoothing parameter, b, which was specified using bw.grid87. We present the results from b = 2, but all of the other values gave qualitatively similar results (see Supplementary Table 2). We used bw.method = “global” to allow a constant smoothing parameter across all times. The defined time window was zero to 20 days post injection. We removed one replicate (92 CFU for E. cloacae infection) because there was no mortality in the first 20 days and therefore the maximum hazard could not be estimated. This gave final sizes of n = 14 for E. cloacae and n = 15 for each of the other three species.$${{{{{rm{Model}}}}}},1:,{{log }}left({{{{{rm{maximum}}}}}},{{{{{rm{hazard}}}}}}right), sim ,{{{{{rm{bacterial}}}}}},{{{{{rm{species}}}}}}$$Are virulence differences due to variation in pathogen exploitation or PPP?To test whether the bacterial species vary in PPP, we performed a linear model with the natural log of the maximum hazard as the dependent variable, bacterial species as a factor, and the natural log of infection intensity as a covariate. We also included the interaction between bacterial species and infection intensity: a significant interaction would indicate variation in the reaction norms, i.e., variation in PPP. The package “emmeans”82 was used to test which of the reaction norms differed significantly from each other. We extracted maximum hazard values from time of death data for each bacterial species/dose/experimental replicate as described in section “Do the bacterial species differ in virulence?”. We also calculated the maximum hazard for the Ringer’s control groups, which gives the maximum hazard in the absence of infection (the y-intercept). We present the results from b = 2, but all of the other values gave qualitatively similar results (see results). We wanted to infer the causal effect of bacterial load upon host survival (and not the reverse), therefore we reasoned that the bacterial load measures should derive from flies homogenised before the maximum hazard had been reached. For E. cloacae, L. lactis, and Pr. burhodogranariea, for all smoothing parameter values, the maximum hazard was reached after two days post injection, although for smoothing parameter value 1, there were four incidences where it was reached between 1.8- and 2-days post injection. Per species/dose/experimental replicate we therefore calculated the geometric mean of infection intensity combined for days 1 and 2 post injection. In order to include flies with zero load, we added one to all load values before calculating the geometric mean. Geometric mean calculation was done using the R packages “dplyr”68, “EnvStats”88, “plyr”72 and “psych”89. Each mean was calculated from the bacterial load of eight flies, except for four mean values for E. cloacae, which derived from four flies each.For Ps. entomophila the maximum hazard was consistently reached at around day one post injection, meaning that bacterial sampling happened at around the time of the maximum hazard, and we therefore excluded this bacterial species from the analysis. We removed two replicates (Ringer’s and 92 CFU for E. cloacae infection) because there was no mortality in the first 20 days and therefore the maximum hazard could not be estimated. One replicate was removed because the maximum hazard occurred before day 1 for all b values (92,000 CFU for E. cloacae) and six replicates were removed because there were no bacterial load data available for day one (experimental replicate three of L. lactis). This gave final sample sizes of n = 15 for E. cloacae and n = 12 for L. lactis, and n = 18 for Pr. burhodogranariea.$${{{{{rm{Model}}}}}},2 :,{{log }}({{{{{rm{maximum}}}}}},{{{{{rm{hazard}}}}}}), sim ,{{log }}({{{{{rm{geometric}}}}}},{{{{{rm{mean}}}}}},{{{{{rm{bacterial}}}}}},{{{{{rm{load}}}}}}),\ times ,{{{{{rm{bacterial}}}}}},{{{{{rm{species}}}}}}$$To test whether there is variation in pathogen exploitation (infection intensity measured as bacterial load), we performed a linear model with the natural log of infection intensity as the dependent variable and bacterial species as a factor. Similar to the previous model, we used the geometric mean of infection intensity combined for days 1 and 2 post injection, for each bacterial species/dose/experimental replicate. The uninfected Ringer’s replicates were not included in this model. Post-hoc multiple comparisons were performed using “emmeans”, using the default Tukey adjustment for multiple comparisons. Effect sizes given as Cohen’s d, were also calculated using “emmeans”, using the sigma value of 2.327, as estimated by the package. Ps. entomophila was excluded for the reason given above. The sample sizes per bacterial species were: n = 13 for E. cloacae, n = 10 for L. lactis and n = 15 for Pr. burhodogranariea.$${{{{{rm{Model}}}}}},3:,{{log }}({{{{{rm{geometric}}}}}},{{{{{rm{mean}}}}}},{{{{{rm{bacterial}}}}}},{{{{{rm{load}}}}}}), sim ,{{{{{rm{bacterial}}}}}},{{{{{rm{species}}}}}}$$Are persistent infection loads dose-dependent?We tested whether initial injection dose is a predictor of bacterial load at seven days post injection22,25. We removed all flies that had a bacterial load that was below the detection limit as they are not informative for this analysis. The response variable was natural log transformed bacterial load at seven days post-injection and the covariate was natural log transformed injection dose, except for P. burhodogranariea, where the response variable and the covariate were log-log transformed. Separate models were carried out for each bacterial species. Experimental replicate and person were fitted as fixed factors. By day seven none of the flies injected with 92,000 CFU of L. lactis were alive. The analysis was not possible for Ps. entomophila infected flies because all flies were dead by seven days post injection.$${{{{{rm{Model}}}}}},4:,{{log }}({{{{{rm{day}}}}}},7,{{{{{rm{bacterial}}}}}},{{{{{rm{load}}}}}}), sim ,{{log }}({{{{{rm{injection}}}}}},{{{{{rm{dose}}}}}}),+,{{{{{rm{replicate}}}}}},+,{{{{{rm{person}}}}}}$$Calculation of clearance indicesTo facilitate the analyses of clearance we calculated clearance indices, which aggregate information about clearance into a single value for each bacterial species/dose/experimental replicate. All indices were based on the estimated proportion of cleared infections (defined as samples with a bacterial load that was below the detection limit) of the whole initial population. For this purpose, we first used data on bacterial load in living flies to calculate the daily proportion of cleared infections in live flies for the days that we sampled. Then we used the data on fly survival to calculate the daily proportion of flies that were still alive. By multiplying the daily proportion of cleared flies in living flies with the proportion of flies that were still alive, we obtained the proportion of cleared infections of the whole initial population – for each day on which bacterial load was measured. We then used these data to calculate two different clearance indices, which we used for different analyses. For each index we calculated the mean clearance across several days. Specifically, the first index was calculated across days three and four post injection (clearance index3,4), and the second index was calculated from days seven, 14 and 21 (clearance index7,14,21).Do the bacterial species differ in clearance?To test whether the bacterial species differed in clearance, we used clearance index3,4, which is the latest timeframe for which we could calculate this index for all four species: due to the high virulence of Ps. entomophila we were not able to assess bacterial load and thus clearance for later days. The distribution of clearance values did not conform to the assumptions of a linear model. We therefore used a Kruskal-Wallis test with pairwise Mann-Whitney-U post hoc tests. Note that the Kruskal-Wallis test uses a Chi-square distribution for approximating the H test statistic. To control for multiple testing we corrected the p-values of the post hoc tests using the method proposed by Benjamini and Hochberg90 that is implemented in the R function pairwise.wilcox.test.$${{{{{rm{Model}}}}}},5:,{{{{{{rm{clearance}}}}}},{{{{{rm{index}}}}}}}_{3,4}, sim ,{{{{{rm{bacterial}}}}}},{{{{{rm{species}}}}}}$$Do exploitation or PPP predict variation in clearance?To assess whether exploitation or PPP predict variation in clearance we performed separate analyses for clearance index3,4 and clearance index7,14,21. As discussed above, this precluded analysing Ps. entomophila. For each of the two indices we fitted a linear mixed effects model with the clearance index as the response variable. As fixed effects predictors we used the replicate-specific geometric mean log bacterial load and the species-specific PPP. In addition, we included species as a random effect.In our analysis we faced the challenge that many measured clearance values were at, or very close to zero. In addition, clearance values below zero do not make conceptual sense. To appropriately account for this issue, we used a logit link function (with Gaussian errors) in our model, which restricts the predicted clearance values to an interval between zero and one. Initial inspections of residuals indicated violations of the model assumption of homogenously distributed errors. To account for this problem, we included the log bacterial load and PPP as predictors of the error variance, which means that we used a model in which we relaxed the standard assumption of homogenous errors and account for heterogenous errors by fitting a function of how errors vary. For this purpose, we used the option dispformula when fitting the models with the function glmmTMB91.$${{{{{rm{Model}}}}}},6 :,{{{{{{rm{clearance}}}}}},{{{{{rm{index}}}}}}}_{3,4},{{{{{rm{or}}}}}},{{{{{{rm{clearance}}}}}},{{{{{rm{index}}}}}}}_{7,14,21}, \ sim ,{{log }}({{{{{rm{geometric}}}}}},{{{{{rm{mean}}}}}},{{{{{rm{bacterial}}}}}},{{{{{rm{load}}}}}}),+,{{{{{rm{PPP}}}}}}+{{{{{{rm{bacterial}}}}}},{{{{{rm{species}}}}}}}_{{{{{{rm{random}}}}}}}$$Does longer-term clearance depend upon the injection dose?In contrast to the analyses described above, we additionally aimed to assess the long-term dynamics of clearance based on the infection status of dead flies collected between 14 and 35 days and 56 to 78 days after injection. Using binomial logistic regressions, we tested whether initial injection dose affected the propensity for flies to clear an infection with E. cloacae or Pr. burhodogranariea before they died. The response variable was binary whereby 0 denoted that no CFUs grew from the homogenate and 1 denoted that CFUs did grow from the homogenate. Log-log transformed injection dose was included as a covariate as well as its interaction with the natural log of day post injection, and person was fitted as a fixed factor. Replicate was included in the Pr. burhodogranariea analysis only, because of unequal sampling across replicates for E. cloacae. L. lactis injected flies were not analysed because only 4 out of 39 (10.3%) cleared the infection. Ps. entomophila infected flies were not statistically analysed because of a low sample size (n = 12). The two bacterial species were analysed separately.$${{{{{rm{Model}}}}}},7 :,{{{{{rm{CFU}}}}}},{{{{{{rm{presence}}}}}}/{{{{{rm{absence}}}}}}}_{{{{{{rm{dead}}}}}}}, sim ,{{log }}({{log }}({{{{{rm{injection}}}}}},{{{{{rm{dose}}}}}})),\ times ,{{log }}({{{{{rm{day}}}}}},{{{{{rm{post}}}}}},{{{{{rm{injection}}}}}}),+,{{{{{rm{replicate}}}}}},+,{{{{{rm{person}}}}}}$$To test whether the patterns of clearance were similar for live and dead flies we tested whether the proportion of live uninfected flies was a predictor of the proportion of dead uninfected flies. We separately summed up the numbers of uninfected and infected flies for each bacterial species and dose, giving us a total sample size of n = 20 (four species × five doses). For live and for dead homogenised flies we had a two-vector (proportion infected and proportion uninfected) response variable, which was bound into a single object using cbind. The predictor was live flies, and the response variable was dead flies, and it was analysed using a generalized linear model with family = quasibinomial.$${{{{{rm{Model}}}}}},8:,{{{{{rm{cbind}}}}}}({{{{{rm{dead}}}}}},{{{{{rm{uninfected}}}}}},,{{{{{rm{dead}}}}}},{{{{{rm{infected}}}}}}), sim ,{{{{{rm{cbind}}}}}}({{{{{rm{live}}}}}},{{{{{rm{uninfected}}}}}},,{{{{{rm{live}}}}}},{{{{{rm{infected}}}}}})$$Reporting summaryFurther information on research design is available in the Nature Research Reporting Summary linked to this article. More

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    Impact report: how biodiversity coverage shapes lives and policies

    Callie Veelenturf measured the pH, conductivity and temperature near a leatherback sea turtle’s nest during research in Equatorial Guinea.Credit: Jonah Reenders

    This picture of marine conservation biologist Callie Veelenturf won the Nature Careers photo competition in 2018 — an event Veelenturf credits with kick-starting her career. She went on to assist in drafting a law that will help to protect species and habitats in Panama.Since 2021, editors at Nature have been tracking instances such as this, in which our journalism and opinion articles have had an impact. Here, we look at three times when content on biodiversity affected researchers, communities or policies. As well as shaping Veelenturf’s conservation work, Nature articles have raised the profile of a proposal to protect part of the Antarctic Ocean and fuelled discussions of carbon-tax proposals to fund tropical-forest conservation.Protect PanamaIn the prize-winning photo, Veelenturf was pictured with a leatherback sea turtle (Dermochelys coriacea) in Equatorial Guinea, where she was collecting data for her master’s degree at Purdue University Fort Wayne, Indiana, in 2016. She and biologist Jonah Reenders, now a photographer based in San Francisco, California, spent nearly half a year there, living in tents on Bioko Island, and Reenders took the picture of her as she measured the pH, conductivity and temperature of the sand near the leatherback’s nest.After the photo was published, a deluge of e-mails and messages “gave me this network, almost overnight, of other sea-turtle conservationists doing similar things around the world”, says Veelenturf, who is now based in Arraiján, Panama. “All of a sudden I was an ‘us’.”The photo award also validated her hard work, Veelenturf says, contradicting a common assumption that sea-turtle research just meant relaxing on the beach. Karla Barrientos-Muñoz, a Colombian sea-turtle conservationist at the Fundación Tortugas del Mar, based in Medellín, wrote that Veelenturf’s win was for all women in sea-turtle conservation. “It made me feel part of this community,” Veelenturf says.Inspired, she founded a non-profit organization called the Leatherback Project, based in Norfolk, Massachusetts, and later won a National Geographic Explorers grant, allowing her to perform the first scientific survey of sea turtles in Panama’s Pearl Islands archipelago. Here, her team worked with local communities to study the nesting sites and foraging grounds of olive ridley (Lepidochelys olivacea), green (Chelonia mydas), hawksbill (Eretmochelys imbricata) and eastern Pacific leatherback sea turtles.While doing fieldwork, Veelenturf read David Boyd’s book The Rights of Nature (2017), which described how some lawyers had fought to earn legal rights for nature. Such laws, which now exist in at least nine countries, make it easier to conserve the environment, because organizations can sue to protect a rainforest or stream. She went on to work with environmentally minded congress member Juan Diego Vásquez Gutiérrez and Panamanian legal advisers to draft a similar law for Panama, which is especially rich in biodiversity. Vásquez sponsored the legislation, and after more than a year of debate and revision by the public and in the national assembly, it was signed into law on 24 February 2022.Protect the AntarcticIn October 2020, a Comment article argued that the seas around the western Antarctic Peninsula should be designated a marine protected area. Overfishing there is removing large numbers of shrimp-like crustaceans called Antarctic krill (Euphausia superba), affecting the region’s entire web of species, including penguins, whales and seals, which feed on krill. The peninsula is also one of the fastest-warming ecosystems on the planet.A proposal for a marine protected area in the Antarctic must be approved by the groups of governments that make up the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). Cassandra Brooks, a marine scientist at University of Colorado Boulder who co-authored the Nature piece and sits on CCAMLR’s non-voting science delegation, says that the Comment was sent to all the commission’s government delegations and observer groups. “If we can raise the issue in the public,” Brooks says, “it does help raise the issue within that diplomatic space.”The western Antarctic Peninsula proposal is one of three on the table for the next CCAMLR meeting in October 2022. It took ten years for CCAMLR to declare the Ross Sea a marine protected area. “The Antarctic does not have ten years,” says Comment co-author Carolyn Hogg, a conservation biologist at the University of Sydney in Australia.News stories about the article were published globally, including in China, India, South Korea and Malaysia. Hogg says it increased her visibility and further raised her profile with the Australian government. She is working with the government to ensure that the country’s threatened-species policy is informed by the latest genomic research. The goal is to give endangered populations the best chance of survival by preserving as much genetic diversity as possible.Hogg and Brooks wrote the piece with other women, some of whom were part of Homeward Bound, a global leadership programme for women in science, technology, engineering, mathematics and medicine. Many Homeward Bound participants and alumnae — 288 women from at least 30 countries — co-signed it and worked to translate it into many languages, “showing CCAMLR that this large community of women scientists from all over the world is watching, and going to hold them accountable”, Brooks says.Antarctica tends to be “both diplomatically and scientifically dominated by men”, she notes, and the impact of this global community of women was inspiring.Carbon tax for tropical forestsTropical countries should adopt a carbon tax, urged another Comment in February 2020, creating a levy on fossil fuels that should be used to conserve tropical forests. Costa Rica and Colombia had already adopted such a tax, and several other countries, including Indonesia, Brazil and Peru, are now considering implementing one, says Sebastian Troëng, executive vice-president of conservation partnerships at Conservation International who is based in Brussels and co-authored the piece.After the article was published, the authors made sure it was widely discussed. One of them, environmental economist Edward Barbier at Colorado State University in Fort Collins, presented the proposal at major meetings. These included the World Bank–International Monetary Fund forum in April 2022 and the Global Peatlands Initiative of the United Nations Framework Convention on Climate Change, at the 2021 climate summit COP26, in Glasgow, UK. The carbon-pricing proposal can be applied to any ecosystem, Barbier says. “Peatlands are ideal, because you’re saving probably the most carbon-dense ecosystem on our planet.”Meanwhile, Troëng’s colleagues presented the proposal to representatives from the finance and environment ministries of Chile, Mexico, Peru, Ecuador, Colombia and Costa Rica. “Since then, we’ve been working directly with government ministries,” he says, to strengthen the existing carbon-tax system in Colombia and to establish similar systems in Peru and Singapore. “I think what people appreciate the most is the fact that two countries have already done it, so it’s not just a theory or a wild idea, but it’s actually working,” Barbier says.“It’s always challenging to say, was it this paper that made something happen?” notes Troëng, on the impact of the article. “But it’s part of this growing consensus that nature plays an extremely important role in how we address climate change.” More

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    Using of geographic information systems (GIS) to determine the suitable site for collecting agricultural residues

    MaterialsStudy areaThe Sinbilawin town is located southeast of Dakahleia Governorate, Egypt. It is bounded to the east by the Timai El-Amded city, west by the Aga city, north by the Mansoura city and to the south by the Diarb Negm city. The Sinbilawin lies between 31° 27′ 38.07″ E longitude and 30° 53′ 1.55″ N latitude (Google Earth) (Fig. 1). The total area of Sinbilawin town is about 304.5 km2 with total cultivated area of Sinbilawin is about 64,362.28 Faddens5. The Sinbilawin town is characterized a flat land.Figure 1Map of the Sinbilawin city, 2015 (study area).Full size imageRice strawThe total area of rice crop in Egypt is 1,215,830 faddan and the production of rice is 4,817,964 tons. The average of productivity is 3.963 tons5. The total area of rice crop in Sinbilawin center is 34,078.12167 faddan and the production of rice straw is 148,376.1417 tons. The rice area map is shown in Fig. 2.Figure 2Rice area map.Full size imageDataGIS is a powerful tool which used for computerized mapping and spatial analysis. GIS is used in many applications such as geology, protection, natural resource management, risk management, urban planning, transportation, and various aspects of modeling in the environment. Also, it is using for decision making22. In this study GIS is used to select the best site to be suggested to collect the rice straw as shown in flowchart of Fig. 3.Figure 3Flowchart of rice straw collecting from Sinbilawin center.Full size imageSoftware programs

    a.

    Google Earth program
    Google Earth combines the power of Google Search with satellite imagery, maps, Terrain and 3D buildings to put the world’s geographic information at your fingertips. It displays satellite images of varying resolution of the Earth’s surface, allowing users to see things like cities and houses looking perpendicularly down or at an oblique angle, with perspective23.

    b.

    Image Processing and Analysis Software (ENVI) program
    It has been used to separate layers from the satellite image as layer of road, layer of urban, layer of canal and layer of sites to the rice crop planting. ENVI 5.6.2 Classic is the ideal software for the visualization, analysis and presentation of all types of digital imagery. ENVI Classic’s complete image-processing package includes advanced, yet easy-to-use, spectral tools, geometric correction, terrain analysis, radar analysis, raster and vector GIS capabilities, extensive support for images from a wide variety of sources, and much more24.

    c.

    GIS program
    ArcGIS Desktop 10.1 will be using in the present study. It is the newest version of a popular GIS software which produced by ESRI. ArcGIS Desktop is comprised of a set of integrated applications. All figure numbers were created using GIS software.

    Design a model for assembling rice strawArcGIS10.1 was selected in this study to design a model for selecting the suitable sites to collect rice straw amounts in Sinbilawin center. To achieve the former goal must be gotten the satellite images (landsat 8) for the province of Dakahleia and the Sinbilawin center. These images were called operation land imager (OLI). Thus, layers will be obtained from the satellite images such as water channels, drainages, urban areas, main and sub- roads, rice crop areas and sites. ENVI program has been used to separate layers and place it in a file which named (Shp. file) for easy insertion in ArcGIS10.1 program. In this present study, design a model will be done on the main layers which will be obtained from the satellite image as follows:

    Location and the administrative limits of Dakahleia Governorate and Sinbilawin center.

    The rice crop area and sites in Dakahleia governorate as the main layer.

    Layer of rice area and their sites in Sinbilawin center. Sinbilawin center was selected in the study because it is cultivated largest rice area in Dakahleia and Dakahleia biggest governorate cultivates rice.

    Layer of roads network in Sinbilawin center. The network of roads was included the main roads and submain to aggregation rice straw. Given the problems associated with transport cost, disposal, and issues that arise from inadequate agriculture crop residues management, the collect units become essential to be nearest of the network of road to facilitate the process of transportation and minimize cost.

    Layer of the urban locations in Sinbilawin center. Crop residues collection sites have an enormous impact on urban in general due to contamination and fires. This study proposes the collecting rice straw sites not be near of the urban, because it causes many health problems for the population.

    Layer of the canal locations in Sinbilawin center. Collecting rice straw sites must be nearest from the source of water as canal for safety, protect it from fire and important for any recycle operation.

    Layer of the drain locations in Sinbilawin center. Also, drain is important as the source of water but less than canal.

    Arc GIS 10.1 to select the suitable sites for assembling rice strawThree Scenarios were suggesting for completing the design of the modeling to select best sites for collecting rice straw. From the three scenarios wall be reached to the best collecting sites for rice straw in Sinbilawin center as follows:

    The first scenario: Modeling for Sinbilawin center
    In this case, modeling was running on the Sinbilawin center as the whole unit.

    The second scenario: Modeling for the village in Sinbilawin center.
    The Sinbilawin center consists of 97 villages and some other area surrounding. In this case, modeling was running on each village and each accessory in Sinbilawin center.

    The third scenario: Modeling for the best site in each village in Sinbilawin center.
    In this case, the modeling was running on each best site which located in each village (on the 97 sites in Sinbilawin center).

    MethodsTo achieve the former objective in this study wall be done as follows:

    Location and the administrative limits of Dakahleia Governorate and Sinbilawin center were uploaded as map by Google earth program.

    The rice crop area and sites in Dakahleia governorate. The data of area and sites to rice crop in Dakahleia governorate were collected from the Ministry of Agricultural—Central Administration of Economy and Statistics as numerical data for each center in Dakahleia governorate. Map for Dakahleia governorate was obtained via satellite image from the Remote Sensing Authority.

    Rice production (ton) = Cultivated area(fed)*Average production (4.354 ton/fed)5.

    Total rice straw (ton) = Rice production (ton) / 2.5.

    Satellite image layersAreas and sites of satellite layers for rice in Sinbilawin centerArea and sites of rice crop in Sinbilawin center as the database were obtained and collected Extraction layer from the Ministry of Agricultural. Central Administration of Economy and Statistics as numerical data for each village. Sinbilawin map as layer of molding was obtained via satellite image from the Remote Sensing Authority. It was used with ArcGIS 10.1 software to inference the sites and area of rice crop in the Sinbilawin center villages.Layer for the road network in Sinbilawin centerThe network of roads is very important factor and effective for collecting rice straw. The network roads map as the layer was extracted from satellite image via the Remote Sensing Authority. It was used with ArcGIS 10.1 software to inference the main and sub roads in the Sinbilawin center.Layer for the urban locations in Sinbilawin centerCrop residues collection sites have an enormous impact on urban general due to contamination, environmental pollution and fires, which are causing many health problems for the population. The urban map as the layer was extracted from satellite image via the Remote Sensing Authority. It was used with ArcGIS 10.1 software to appear all the urban sites in the Sinbilawin center.Layer for the water source in Sinbilawin centerRice straw collection sites must be nearest from the source of water as canal for safety and protect it from fire also water is very important for any recycle operation. The canal map as the layer was extracted from satellite image via the Remote Sensing Authority. It was used with ArcGIS 10.1 software to appear all source of water as canal in the Sinbilawin center.Layer for the drain locations in Sinbilawin centerThe drain is important as the source of water but less than canal. The drain map as the layer was extracted from satellite image via the Remote Sensing Authority. It was used with ArcGIS 10.1 software to appear all drain in the Sinbilawin center.ArcGIS 10.1 to select the suitable sites for collecting rice strawModeling was designed as shown in Fig. 4 to apply with the three scenarios.Figure 4Short form for modeling to select suitable sites to assembly rice straw.Full size imageFrom the three scenarios shall be reached to the best collecting sites for recycling rice straw in Sinbilawin center as follows:

    The first scenario was running modeling for Sinbilawin center.

    The second scenario was running modeling for the village in it.

    The third scenario was running modeling for the best site in each village in it.

    Different steps were running with modeling to select the best sites to assembly rice straw in Sinbilawin center: 1- Euclidean distance. 2- Reclassify (or changes). 3-Weighted overlay. Assuming common measurement scale and weights for each layer according to its importance as follows:—Roads 50%, Channels 40%, Urban 10% so that the total is 100%0.4- Select Layer by Location (Data Management). In this step, order of selecting layer sites was given through Arc tool box at ArcGIS10.1 for selecting sites through the Arc toolbox at ArcGIS10.1 software as follow: 1- Intersection with roads. 2- Intersection with canals water.Total cost of collecting rice strawTransportation for collecting crop residues is important factors because it affects the success or failure of crop residues utilization. GIS was used to determine suitable sites for collecting rice straw and converting it through given parameters as:

    Total length of road (km).

    Total weight of rice straw (ton).

    Speed of tractor in sub roads (30 km/h)

    Total time of transfer (h).

    All experimental protocols were approved by Benha University Research Committee and all methods used in this study was carried out according to the guidelines regulations of Benha University. This work is approved by the ethic committee at Benha University. More

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    Mild movement sequence repetition in five primate species and evidence for a taxonomic divide in cognitive mechanisms

    Study subjectsWe conducted foraging experiments on strepsirrhines (Nindividuals = 18) at the Duke Lemur Center (DLC), North Carolina, from February to November 201513. Our sample includes six fat-tailed dwarf lemurs (3–16 years of age, 3 males, 3 females), six gray mouse lemurs (3–7 years of age, all female), and six aye-ayes (17–32 years of age, 2 males, 4 females). Because these species are solitary and nocturnal, most animals were housed singly and were kept on a reversed light cycle such that they were active and could be tested during the day. Housing conditions were similar for all individuals, and they were all fed daily in a similar manner with a diet that included fruits, vegetables, meal worms, and monkey chow (details in13).All vervet data were collected on wild animals (Nindividuals = 12) at Lake Nabugabo, Uganda (0°22′–12° S and 31°54′ E) during four separate field seasons (April-June 2013, Double Trapezoid array, M group15; June–September 2013, Pentagon array, M group24; August–September 2015, Z-array, M group12; July–August 2017, Pentagon array, KS group25). M group was composed of between 21–28 individuals, containing 2–3 adult males, 7–9 adult females, 2 subadult males, 1–3 subadult females, and 9–12 juveniles and infants. KS group was composed of 39–40 individuals including 5 adult males, 11 adult females, 3 sub-adult males, 5 sub-adult females, and 15–16 juveniles and infants. All individuals were reliably identified based on natural features (details in12,15,24,25). Outside of foraging experiments, wild vervets were not provision fed.All Japanese macaque data (Nindividuals = 10) were collected at the Awajishima Monkey Centre (AMC), Awaji Island, Japan (34°14′43.6″ N and 134°52′59.9″ E) between July and August 2019 (Z-array26). AMC is a privately-run tourist and conservation center visited by a large group of free-ranging Japanese macaques (~ 400 individuals) called the “Awajishima group”47. The group is composed of different-aged individuals of both sexes, with bachelor males and bachelor male groups living around the periphery48. The Awajishima group forages on wild foods for much of their dietary requirements but is also provision-fed a combination of wheat and soybeans, supplemented with peanuts, fruits, and vegetables twice daily for ~ 10 months of the year (details in47,49,50).Study designNavigation arraysThe strepsirrhines and vervets were tested on a “double-trapezoid” shaped multi-destination array with six feeding platforms13,15, modified from17 (Fig. 1a), where there were 720 possible routes (6!). Three different double-trapezoid arrays were built to account for differences in body size: one for the smaller dwarf and mouse lemurs, one for the mid-sized aye-ayes, and one for the larger, wild vervets. Arrays were scaled such that the distance from platform 1–2 (the shortest distance between targets) was approximately twice the body length of the subject species. Vervets were additionally tested on a Z-shaped array with six feeding platforms (720 possible routes, Fig. 1b12), and a pentagon-shaped array with five feeding platforms (120 possible routes, Fig. 1c24,25,46). Japanese macaques were tested on an identically sized Z-array26.Figure 1Design of the navigational arrays used, with (a) the Double Trapezoid array used for Cheirogaleus medius, Microcebus murinus, Daubentonia madagascariensis, and Chlorocebus pygerythrus. Three different arrays were built and scaled to the body size of animals (see “Methods”). (b) The Z-array used for C. pygerythrus and Macaca fuscata. The same size array was used for both species because they are similar in adult body lengths (vervet mean range from four sites: 34.5–42.6 cm51, Japanese macaque mean range from six sites: 48.9–59.7 cm52. (c) The Pentagon used for C. pygerythrus. Distances here are unitless but roughly proportional to the body size of each species tested. Created in R version 4.0.4 and ProCreate.Full size imageFor strepsirrhine trials, DLC staff captured individuals in their enclosures and transported them in padded crates to the testing room. The dwarf and mouse lemur array was set up in a specially designed box (0.91 × 1.83 m) with a small compartment to contain strepsirrhines for rebaiting between trials. The aye-aye array was set up on the ground in a room measuring 2.44 × 4.27 m, where subjects stayed during the duration of their daily trials13. Vervet and macaque trials occurred when individual monkeys voluntarily left their group to participate in foraging experiments alone. Vervet arrays were set up using wooden feeding platforms (0.75 m long, 0.75 m wide × 0.75 m high) placed in an outdoor clearing measuring roughly 10 × 14 m in the home range of the study group. Japanese macaque arrays were also set up using small wooden feeding tables (0.40 m long, 0.30 m wide, 0.21 m high), covered in green plastic labeled with the platform number. Two identical arrays were built in neighbouring provision-feeding fields at the AMC (Near Lower Field: ~ 10 × 35 m, and Far Lower Field: ~ 15 × 45 m).In these studies, all platforms were baited with a single food item. The reward used varied by species (strepsirrhines: grape piece, apple piece, honey, agave nectar, or nut butters, vervets: slice of banana, piece of popcorn; macaques: single peanut or piece of sweet potato). Strepsirrhines have sensory adaptations for using olfaction to locate food53, while the cercopithecoids are heavily reliant on vision to locate resources54, so we ensured that each platform was baited with identical food items within a trial that smelled and looked the same to avoid biasing where the animals chose to go. Platforms for the wild monkeys were not rebaited between trials until all animals were ≥ 20 m away and the entire sequence could be rebaited before their return15,24,25,26.For all species, we started a trial when the tested individual entered the array and took the reward at a platform. We then recorded each successive platform visit (including revisits to empty platforms) until all rewards had been collected ending the trial. In our analyses, we included a total of 852 trials collected over six navigational experiments, completed by 40 unique individuals (18 lemurs, 12 vervets, 10 macaques) (Table 2).Table 2 Individuals and trial sample size included in the analysis.Full size tableData simulationsIn addition to empirically collected data, we simulated agents learning to travel efficiently in the same set of arrays using a simple iterative-reinforcement learning model based on the one used by Reynolds et al.6 to test for traplining behavior in bumblebees. In this model, agents move randomly between locations in an array until they visit all locations, then reset for another trial. If the agent completed a trial by travelling less distance than on previous trials, the probability of the agent repeating location-to-location transitions that occurred in that trial increased for future trials by a reinforcement factor. Initial transition probabilities were inversely proportional to the distance between two locations. Unlike Reynolds et al.6 our simulated agents started at a random location and were not required to return to that location to complete the trial. This matches the trial structure used in our experiments (open-TSP), and reflects multiple central place foraging patterns in primates55. Finally, agents could not return to the location they had just come from, using an “avoid the last location” behavioral heuristic observed in nectivores56,57, which prevented agents from getting stuck in “loops” between two locations (S1 Simulation Validation).Within each of the arrays used to collect empirical data, we ran simulations with reinforcement factors of 1 (no reinforcement), 1.2 (mild reinforcement), and 2 (strong reinforcement). For each array and reinforcement factor combination, we ran 100 agents that each completed 120 trials, where there was an equal probability of starting each trial at any location. Then, for each array and reinforcement factor combination, we ran 100 additional simulations per species tested in the given array, where the probability of starting a trial at any location was equal to the empirically observed location-starting probabilities of the respective species.These simulations were designed to help us test predictions of our two hypotheses regarding primate learning and decision making within the arrays. If primates learn to solve navigational arrays efficiently by reinforcing movements between platform pairs, they should exhibit overall greater receptiveness in their sequences of location visits than reinforcement factor 1 simulations, and a greater decrease over time in total distance travelled to complete the arrays. If primates are pre-disposed to navigate arrays using heuristics, they should exhibit shorter distances travelled on initial trials than in simulations.Data analysisFrom the raw sequences of locations visited in each trial, we calculated two metrics: minimum distance traveled, and the proportion of platform revisits that occurred within identical 3-platform visit sequences (determinism-DET)18. All calculations were done using R version 4.0.458 and packages rstan59 and tidyverse60. A fully reproducible data notebook containing this work, as well as all analyzed data, is available at https://github.com/aqvining/Do-Primates-Trapline. All figures were created by AQV in R version 4.0.4 and ProCreate.Distance traveledTo calculate minimum distance traveled, we created a distance matrix for each resource array containing the relative linear distance between any two resource locations. These minimum linear distances approximate the distances traveled by the animals, which may not necessarily be linear. We then summed the linear distances for all transitions made in a trial. Because resource arrays were scaled to the subject species’ body size, these relative distances were standardized.DeterminismGiven a sequence of observations, Ayers et al.63 defines determinism (DET) as the proportion of all matching observation-pairs (recurrences) that occur within matching sub-sequences of observations (repeats) of a given length (minL). This metric has been previously used to distinguish sequences of resource visitation generated by traplining behaviour from sequences generated by known processes of random movement within a given resource array18,61,62. It has several advantages in the analysis of foraging patterns, including the ability to detect repeated sequences between non-consecutive foraging bouts, imperfect repeats in sequences (i.e., omission or addition of a particular site), and distinguishing between forward- and reverse-order sequence repeats63.We adapted the methods of63 to calculate the number of recurrences and repeats generated by the sequence of location visits in each trial of our experiments and simulations. Based on an analysis of the sensitivity of DET scores to the parameterization of minL, we set minL to three for our calculations (S2 Sensitivity Analysis).Statistical analysesLearning ratesWe modelled distance travelled as a function of trial number, species, and individual. Metrics of animal performance on learned tasks are known to follow power functions over time and experience64, so we a priori applied log transformations to distance travelled and trial number, then fit a linear model. Thus, in the resulting model, the intercept can be interpreted as an estimated distance travelled on the first trial and the slope can be interpreted as the exponent of a learning curve. We modelled species and individual effects on the intercept by summing an estimated grand mean (µ0), species level deviation (µsp,j), and individual level deviation (µid,i). We treated species and individual level effects on the learning rate parameter (slope) the same way, summing a grand mean (b0), species level deviation (bsp,j), and individual level deviation (bid,i). We estimated additional parameters for the variance of individual level deviations in intercept and slope (σµID and σbID, respectively). Finally, after finding residuals in an initial analysis to have variances predicted by trial number and species, we estimated a separate error variance for each species (σε,sp) and weighted the standard deviations of the resulting error distributions by dividing them by the square root of one plus the trial number.We set regularizing priors on the model parameters, assuming distances travelled would remain within one order of magnitude of the most efficient route, but not setting any strict boundaries. For the grand mean of the intercept, we used a normal distribution centered around twice the minimum possible distance required to visit all platforms in the array, with a variance of one. For the grand mean of the slope and all species and individual level deviations to the slope and intercept, we used normal distributions centered at zero with variance of one. For all error terms, we used half-cauchy priors with a location parameter of zero and a scale parameter of one. The full, hierarchical definition of the model is given in Eq. (1).$$Distance sim {mu }_{0}+ {mu }_{sp,j}+ {mu }_{id, i}+left({b}_{0}+ {b}_{sp, j}+ {b}_{id,i}right)Trial+ epsilon$$$${mu }_{0} sim mathrm{N}(4.78, 1)$$$${mu }_{sp}, {b}_{0}, {b}_{sp} sim mathrm{N}(mathrm{0,1})$$$${mu }_{id} sim mathrm{N}(0, {sigma }_{mu ID})$$$${b}_{id} sim mathrm{N}(0, {sigma }_{bID})$$$$epsilon sim mathrm{N}(0, {sigma }_{epsilon ,sp}/sqrt[2]{1+Trial})$$$${sigma }_{mu ID}, {sigma }_{bID}, {sigma }_{epsilon } sim mathrm{Half Cauchy}(mathrm{0,1})$$DeterminismTo compare DET between species, and between empirical and simulated data, we created a binomial model of expected repeats generated in a trial given the number of recurrences (Eq. 2).$$Repeats sim binom(Recursions, DET)$$$$DET= {logit}^{-1}(alpha)$$$$alpha={a}_{0}+Sp+Src+ Int+ID$$$${a}_{0}, Sp, Src, Int sim mathrm{N}(0, 1)$$$$ID sim mathrm{N}(0, {sigma }_{ID})$$$${sigma }_{ID}sim mathrm{Half Cauchy}(mathrm{0,1})$$where a0 is the mean intercept, Sp is one of four coefficients determined by the species (simulations are of the “species” which was used to assign its starting-location probabilities), Src is one of four coefficients determined by the source (empirical data and each level of reinforcement factor), Int is one of 16 interaction coefficients (each possible combination of Sp and Src), and ID is a varying effect of the individual. Because the length of a sequence affects DET, we limit our analysis of DET to the sequences generated by a subject’s or an agent’s first ten trials. Subjects that completed fewer than ten trials were excluded from this portion of the analysis. More

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    Wildfire-dependent changes in soil microbiome diversity and function

    Dennison, P. E., Brewer, S. C., Arnold, J. D. & Moritz, M. A. Large wildfire trends in the western United States, 1984–2011. Geophys. Res. Lett. 41, 2928–2933 (2014).
    Google Scholar 
    Higuera, P. E. & Abatzoglou, J. T. Record‐setting climate enabled the extraordinary 2020 fire season in the western United States. Glob. Change Biol. https://doi.org/10.1111/gcb.15388 (2020).Parks, S. A. & Abatzoglou, J. T. Warmer and drier fire seasons contribute to increases in area burned at high severity in western US forests from 1985 to 2017. Geophys. Res. Lett. 47, e2020GL089858 (2020).Benavides-Solorio, J. D. D. & MacDonald, L. H. Measurement and prediction of post-fire erosion at the hillslope scale, Colorado Front Range. Int. J. Wildl. Fire 14, 457–474 (2005).
    Google Scholar 
    Pierson, D. N., Robichaud, P. R., Rhoades, C. C. & Brown, R. E. Soil carbon and nitrogen eroded after severe wildfire and erosion mitigation treatments. Int. J. Wildl. Fire 28, 814–821 (2019).CAS 

    Google Scholar 
    Rhoades, C. C., Entwistles, D. & Butler, D. The influence of wildfire extent and severity on streamwater chemistry, sediment and temperature following the Hayman Fire, Colorado. Int. J. Wildl. Fire 20, 430–442 (2011).CAS 

    Google Scholar 
    Chambers, M. E., Fornwalt, P. J., Malone, S. L. & Battaglia, M. A. Patterns of conifer regeneration following high severity wildfire in ponderosa pine – dominated forests of the Colorado Front Range. For. Ecol. Manage. 378, 57–67 (2016).
    Google Scholar 
    Rhoades, C. C. et al. The legacy of a severe wildfire on stream nitrogen and carbon in headwater catchments. Ecosystems 22, 643–657 (2019).CAS 

    Google Scholar 
    Strickland, M. S., Lauber, C., Fierer, N. & Bradford, M. A. Testing the functional significance of microbial community composition. Ecology 90, 441–451 (2009).PubMed 

    Google Scholar 
    van der Heijden, M. G. A., Bardgett, R. D. & van Straalen, N. M. The unseen majority: soil microbes as drivers of plant diversity and productivity in terrestrial ecosystems. Ecol. Lett. 11, 296–310 (2008).PubMed 

    Google Scholar 
    Mendes, R. et al. Deciphering the rhizosphere microbiome for disease-suppressive bacteria. Science 332, 1097–1100 (2011).CAS 
    PubMed 

    Google Scholar 
    Hart, S. C., DeLuca, T. H., Newman, G. S., MacKenzie, M. D. & Boyle, S. I. Post-fire vegetative dynamics as drivers of microbial community structure and function in forest soils. For. Ecol. Manage. 220, 166–184 (2005).
    Google Scholar 
    Pressler, Y., Moore, J. C. & Cotrufo, M. F. Belowground community responses to fire: meta-analysis reveals contrasting responses of soil microorganisms and mesofauna. Oikos 128, 309–327 (2019).
    Google Scholar 
    Pulido-Chavez, M. F., Alvarado, E. C., DeLuca, T. H., Edmonds, R. L. & Glassman, S. I. High-severity wildfire reduces richness and alters composition of ectomycorrhizal fungi in low-severity adapted ponderosa pine forests. For. Ecol. Manage. 485, 118923 (2021).
    Google Scholar 
    Villadas, P. J. et al. The soil microbiome of the Laurel Forest in Garajonay National Park (La Gomera, Canary Islands): comparing unburned and burned habitats after a wildfire. Forests 10, 1051 (2019).
    Google Scholar 
    Dove, N. C. & Hart, S. C. Fire reduces fungal species richness and in situ mycorrhizal colonization: a meta-analysis. Fire Ecol. 13, 37–65 (2017).
    Google Scholar 
    Ibáñez, T. S., Wardle, D. A., Gundale, M. J. & Nilsson, M.-C. Effects of soil abiotic and biotic factors on tree seedling regeneration following a boreal forest wildfire. Ecosystems https://doi.org/10.1007/s10021-021-00666-0 (2021).Whitman, T. et al. Soil bacterial and fungal response to wildfires in the Canadian boreal forest across a burn severity gradient. Soil Biol. Biochem. 138, 107571 (2019).CAS 

    Google Scholar 
    Brown, S. P. et al. Context dependent fungal and bacterial soil community shifts in response to recent wildfires in the Southern Appalachian Mountains. For. Ecol. Manage. 451, 117520 (2019).
    Google Scholar 
    Ferrenberg, S. et al. Changes in assembly processes in soil bacterial communities following a wildfire disturbance. ISME J. 7, 1102–1111 (2013).PubMed 
    PubMed Central 

    Google Scholar 
    Knelman, J. E., Schmidt, S. K., Garayburu-Caruso, V., Kumar, S. & Graham, E. B. Multiple, compounding disturbances in a forest ecosystem: fire increases susceptibility of soil edaphic properties, bacterial community structure, and function to change with extreme precipitation event. Soil Syst. 3, 1–1, 40 (2019).Zhang, L. et al. Habitat heterogeneity induced by pyrogenic organic matter in wildfire-perturbed soils mediates bacterial community assembly processes. ISME J. 5, 1943–1955 (2021).
    Google Scholar 
    Tas, N. et al. Impact of fire on active layer and permafrost microbial communities and metagenomes in an upland Alaskan boreal forest. ISME J. https://doi.org/10.1038/ismej.2014.36 (2014).Yang, S. et al. Fire affects the taxonomic and functional composition of soil microbial communities, with cascading effects on grassland ecosystem functioning. Glob. Change Biol. 26, 431–442 (2020).
    Google Scholar 
    Dove, N. C., Safford, H. D., Bohlman, G. N., Estes, B. L. & Hart, S. C. High‐severity wildfire leads to multi‐decadal impacts on soil biogeochemistry in mixed‐conifer forests. Ecol. Appl. 30, eap.2072 (2020).
    Google Scholar 
    Pérez-Valera, E., Goberna, M. & Verdú, M. Fire modulates ecosystem functioning through the phylogenetic structure of soil bacterial communities. Soil Biol. Biochem. 129, 80–89 (2019).
    Google Scholar 
    SantaCruz-Calvo, L., González-López, J. & Manzanera, M. Arthrobacter siccitolerans sp. nov., a highly desiccation-tolerant, xeroprotectant-producing strain isolated from dry soil. Int. J. Syst. Evol. Microbiol. 63, 4174–4180 (2013).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Mongodin, E. F. et al. Secrets of soil survival revealed by the genome sequence of Arthrobacter aurescens TC1. PLoS Genet. 2, 2094–2106 (2006).CAS 

    Google Scholar 
    Bourguignon, N., Isaac, P., Alvarez, H., Amoroso, M. J. & Ferrero, M. A. Enhanced polyaromatic hydrocarbon degradation by adapted cultures of actinomycete strains. J. Basic Microbiol. 54, 1288–1294 (2014).CAS 
    PubMed 

    Google Scholar 
    Fischer, M. S. et al. Pyrolyzed substrates induce aromatic compound metabolism in the post-fire fungus, Pyronema domesticum. Front. Microbiol. 12, 729289 (2021).PubMed 

    Google Scholar 
    Arora, P. K. & Sharma, A. New metabolic pathway for degradation of 2-nitrobenzoate by Arthrobacter sp. SPG. Front. Microbiol. 6:551, 1–6 (2015).Ren, L. et al. Insight into metabolic versatility of an aromatic compounds-degrading Arthrobacter sp. YC-RL1. Front. Microbiol. 9:2438, 1–15 (2018).Cobo-Díaz, J. F. et al. Metagenomic assessment of the potential microbial nitrogen pathways in the rhizosphere of a mediterranean forest after a wildfire. Microb. Ecol. 69, 895–904 (2015).PubMed 

    Google Scholar 
    Dove, N. C., Taş, N. & Hart, S. C. Ecological and genomic responses of soil microbiomes to high-severity wildfire: linking community assembly to functional potential. ISME J. https://doi.org/10.1038/s41396-022-01232-9 (2022).Adkins, J., Docherty, K. M., Gutknecht, J. L. M. & Miesel, J. R. How do soil microbial communities respond to fire in the intermediate term? Investigating direct and indirect effects associated with fire occurrence and burn severity. Sci. Total Environ. 745, 140957 (2020).CAS 
    PubMed 

    Google Scholar 
    Newton, G. L., Buchmeier, N. & Fahey, R. C. Biosynthesis and functions of mycothiol, the unique protective thiol of Actinobacteria. Microbiol. Mol. Biol. Rev. 72, 471–494 (2008).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Reina-Bueno, M. et al. Role of trehalose in heat and desiccation tolerance in the soil bacterium Rhizobium etli. BMC Microbiol. 12, 207 (2012).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Schimel, J. P. Life in dry soils: effects of drought on soil microbial communities and processes. Annu. Rev. Ecol. Evol. Syst. 49, 409–432 (2018).
    Google Scholar 
    Musto, H. et al. Correlations between genomic GC levels and optimal growth temperatures in prokaryotes. FEBS Lett. 573, 73–77 (2004).CAS 
    PubMed 

    Google Scholar 
    Yakovchuk, P. Base-stacking and base-pairing contributions into thermal stability of the DNA double helix. Nucleic Acids Res. 34, 564–574 (2006).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Mooshammer, M. et al. Decoupling of microbial carbon, nitrogen, and phosphorus cycling in response to extreme temperature events. Sci. Adv. 3, e1602781 (2017).PubMed 
    PubMed Central 

    Google Scholar 
    Weissman, J. L., Hou, S. & Fuhrman, J. A. Estimating maximal microbial growth rates from cultures, metagenomes, and single cells via codon usage patterns. Proc. Natl Acad. Sci. USA 118, 1–10 e2016810118 (2020).Long, A. M., Hou, S., Ignacio-Espinoza, J. C. & Fuhrman, J. A. Benchmarking microbial growth rate predictions from metagenomes. ISME J. 15, 183–195 (2021).CAS 
    PubMed 

    Google Scholar 
    Karlin, S., Mrázek, J., Campbell, A. & Kaiser, D. Characterizations of highly expressed genes of four fast-growing bacteria. J. Bacteriol. 183, 5025–5040 (2001).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Scott, M., Gunderson, C. W., Mateescu, E. M., Zhang, Z. & Hwa, T. Interdependence of cell growth and gene expression: origins and consequences. Science 330, 1099–1102 (2010).CAS 
    PubMed 

    Google Scholar 
    Faria, S. R. et al. Wildfire-induced alterations of topsoil organic matter and their recovery in Mediterranean eucalypt stands detected with biogeochemical markers. Eur. J. Soil Sci. 66, 699–713 (2015).CAS 

    Google Scholar 
    Chen, H., Rhoades, C. C. & Chow, A. T. Characteristics of soil organic matter 14 years after a wildfire: a pyrolysis-gas-chromatography mass spectrometry (Py-GC-MS) study. J. Anal. Appl. Pyrolysis 152, 104922 (2020).CAS 

    Google Scholar 
    Knicker, H. Pyrogenic organic matter in soil: its origin and occurrence, its chemistry and survival in soil environments. Quat. Int. 243, 251–263 (2011).
    Google Scholar 
    Bahureksa, W. et al. Nitrogen enrichment during soil organic matter burning and molecular evidence of Maillard reactions. Environ. Sci. Technol. https://doi.org/10.1021/acs.est.1c06745 (2022).Boye, K. et al. Thermodynamically controlled preservation of organic carbon in floodplains. Nat. Geosci. 10, 415–419 (2017).CAS 

    Google Scholar 
    LaRowe, D. E. & Van Cappellen, P. Degradation of natural organic matter: a thermodynamic analysis. Geochim. Cosmochim. Acta 75, 2030–2042 (2011).CAS 

    Google Scholar 
    Fuchs, G., Boll, M. & Heider, J. Microbial degradation of aromatic compounds – from one strategy to four. Nat. Rev. Microbiol. 9, 803–816 (2011).CAS 
    PubMed 

    Google Scholar 
    Pingree, M. R. A. & DeLuca, T. H. Function of wildfire-deposited pyrogenic carbon in terrestrial ecosystems. Front. Environ. Sci. https://doi.org/10.3389/fenvs.2017.00053 (2017).Trubl, G. et al. Soil viruses are underexplored players in ecosystem carbon processing. mSystems 3, 1–21 e00076-18 (2018).Ahlgren, N. A., Ren, J., Lu, Y. Y., Fuhrman, J. A. & Sun, F. Alignment-free (d_2^ast) oligonucleotide frequency dissimilarity measure improves prediction of hosts from metagenomically-derived viral sequences. Nucleic Acids Res. 45, 39–53 (2017).Kuzyakov, Y. & Mason-Jones, K. Viruses in soil: nano-scale undead drivers of microbial life, biogeochemical turnover and ecosystem functions. Soil Biol. Biochem. 127, 305–317 (2018).CAS 

    Google Scholar 
    Knowles, B. et al. Lytic to temperate switching of viral communities. Nature 531, 466–470 (2016).CAS 
    PubMed 

    Google Scholar 
    Hewelke, E. et al. Soil functional responses to natural ecosystem restoration of a pine forest peucedano-pinetum after a fire. Forests 11, 286 (2020).
    Google Scholar 
    Mahoney, D. P. & LaFavre, J. S. Coniochaeta extramundana, with a synopsis of other Coniochaeta species. Mycologia 73, 931–952 (1981).
    Google Scholar 
    Yang, T. et al. Distinct fungal successional trajectories following wildfire between soil horizons in a cold‐temperate forest. New Phytol. 227, 572–587 (2020).CAS 
    PubMed 

    Google Scholar 
    Steindorff, A. S. et al. Comparative genomics of pyrophilous fungi reveals a link between fire events and developmental genes. Environ. Microbiol. 23, 99–109 (2021).CAS 
    PubMed 

    Google Scholar 
    Viswanath, B., Rajesh, B., Janardhan, A., Kumar, A. P. & Narasimha, G. Fungal laccases and their applications in bioremediation. Enzyme Res. 2014, 1–21 163242 (2014).Bouskill, N. J., Mekonnen, Z., Zhu, Q., Grant, R. & Riley, W. J. Microbial contribution to post-fire tundra ecosystem recovery over the 21st century. Commun. Earth Environ. 3, 26 (2022).
    Google Scholar 
    Yeager, C. M., Northup, D. E., Grow, C. C., Barns, S. M. & Kuske, C. R. Changes in nitrogen-fixing and ammonia-oxidizing bacterial communities in soil of a mixed conifer forest after wildfire. Appl. Environ. Microbiol. 71, 2713–2722 (2005).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Ward, N. L. et al. Three genomes from the Phylum Acidobacteria provide insight into the lifestyles of these microorganisms in soils. Appl. Environ. Microbiol. 75, 2046–2056 (2009).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    García-Fraile, P., Benada, O., Cajthaml, T., Baldrian, P. & Lladó, S. Terracidiphilus gabretensis gen. nov., sp. nov., an abundant and active forest soil acidobacterium important in organic matter transformation. Appl. Environ. Microbiol. 82, 560–569 (2016).PubMed 
    PubMed Central 

    Google Scholar 
    Eichorst, S. A., Kuske, C. R. & Schmidt, T. M. Influence of plant polymers on the distribution and cultivation of bacteria in the Phylum Acidobacteria. Appl. Environ. Microbiol. 77, 586–596 (2011).CAS 
    PubMed 

    Google Scholar 
    Banerjee, S. et al. Network analysis reveals functional redundancy and keystone taxa amongst bacterial and fungal communities during organic matter decomposition in an arable soil. Soil Biol. Biochem. 97, 188–198 (2016).CAS 

    Google Scholar 
    Costa, O. Y. A., Raaijmakers, J. M. & Kuramae, E. E. Microbial extracellular polymeric substances: ecological function and impact on soil aggregation. Front. Microbiol. 9, 1–14 (2018).
    Google Scholar 
    Smith, S. E. & Read, D. Mycorrhizal symbiosis. Soil Sci. 137, 204 (1984).
    Google Scholar 
    Douglas, R. B., Parker, V. T. & Cullings, K. W. Belowground ectomycorrhizal community structure of mature lodgepole pine and mixed conifer stands in Yellowstone National Park. For. Ecol. Manage. 208, 303–317 (2005).
    Google Scholar 
    Anthony, M. A. et al. Forest tree growth is linked to mycorrhizal fungal composition and function across Europe. ISME J. https://doi.org/10.1038/s41396-021-01159-7 (2022).Marx, D. H., Bryan, W. C. & Cordell, C. E. Survival and growth of pine seedlings with Pisolithus ectomycorrhizae after two years on reforestation sites in North Carolina and Florida. For. Science. 23, 363–373 (1977).
    Google Scholar 
    Franco, A. R., Sousa, N. R., Ramos, M. A., Oliveira, R. S. & Castro, P. M. L. Diversity and persistence of ectomycorrhizal fungi and their effect on nursery-inoculated Pinus pinaster in a post-fire plantation in Northern Portugal. Microb. Ecol. 68, 761–772 (2014).PubMed 

    Google Scholar 
    Kipfmueller, K. F. & Baker, W. L. A fire history of a subalpine forest in south-eastern Wyoming, USA. J. Biogeogr. 27, 71–85 (2000).
    Google Scholar 
    Key, C. H. & Benson, N. C. Landscape Assessment (LA) Sampling and Analysis Methods General Techical Report (USDA Forest Service, 2006).Parson, A., Robichaud, P. R., Lewis, S. A., Napper, C. & Clark, J. T. Field Guide for Mapping Post-fire Soil Burn Severity General Technical Report (USDA Forest Service, 2010); https://doi.org/10.2737/RMRS-GTR-243Miesel, J. R., Hockaday, W. C., Kolka, R. K. & Townsend, P. A. Soil organic matter composition and quality across fire severity gradients in coniferous and deciduous forests of the southern boreal region. J. Geophys. Res. Biogeosci. 120, 1124–1141 (2015).CAS 

    Google Scholar 
    Bundy, L. G. & Meisinger, J. J., Weaver, R. W., Angle, S., Bottomley, P., Bezdicek, D., Smith, S., Tabatabai, A., Wollum, A. (Eds.) in Methods of Soil Analysis: Part 2 Microbiological and Biochemical Properties 951–984 (Macmillan, 2018). https://doi.org/10.2136/sssabookser5.2.c41McDowell, W. H. et al. A comparison of methods to determine the biodegradable dissolved organic carbon from different terrestrial sources. Soil Biol. Biochem. 38, 1933–1942 (2006).CAS 

    Google Scholar 
    Thomas, G. W., Sparks, D. L., Page, A. L., Helmke, P. A., Loeppert, R. H., Soltanpour, P. N., Tabatabai, M. A., Johnston, C. T., Sumner, M. E. (Eds.) in Methods of Soil Analysis: Part 3 Chemical Methods, 5.3 475–490 (1996).Dittmar, T., Koch, B., Hertkorn, N. & Kattner, G. A simple and efficient method for the solid-phase extraction of dissolved organic matter (SPE-DOM) from seawater. Limnol. Oceanogr. Methods 6, 230–235 (2008).CAS 

    Google Scholar 
    Tolić, N. et al. Formularity: software for automated formula assignment of natural and other organic matter from ultrahigh-resolution mass spectra. Anal. Chem. 89, 12659–12665 (2017).PubMed 

    Google Scholar 
    Bramer, L. M. et al. ftmsRanalysis: an R package for exploratory data analysis and interactive visualization of FT-MS data. PLoS Comput. Biol. 16, e1007654 (2020).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Caporaso, J. G. et al. Ultra-high-throughput microbial community analysis on the Illumina HiSeq and MiSeq platforms. ISME J. 6, 1621–1624 (2012).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Quast, C. et al. The SILVA ribosomal RNA gene database project: improved data processing and web-based tools. Nucleic Acids Res. 41, D590–D596 (2012).PubMed 
    PubMed Central 

    Google Scholar 
    Kõljalg, U. et al. UNITE: a database providing web‐based methods for the molecular identification of ectomycorrhizal fungi. New Phytol. 166, 1063–1068 (2005).PubMed 

    Google Scholar 
    Bolyen, E. et al. Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2. Nat. Biotechnol. 37, 852–857 (2019).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Callahan, B. J. et al. DADA2: high-resolution sample inference from Illumina amplicon data. Nat. Methods 13, 581–583 (2016).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Nguyen, N. H. et al. FUNGuild: an open annotation tool for parsing fungal community datasets by ecological guild. Fungal Ecol. 20, 241–248 (2016).
    Google Scholar 
    R Core Team. R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, 2021).Oksanen, J. et al. (2020). vegan: Community Ecology Package. R package version 2.5-7. https://CRAN.R-project.org/package=veganMcMurdie, P. J. & Holmes, S. phyloseq: an R package for reproducible interactive analysis and graphics of microbiome census data. PLoS ONE 8, e61217 (2013).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Segata, N. et al. Metagenomic biomarker discovery and explanation. Genome Biol. 12, R60 (2011).PubMed 
    PubMed Central 

    Google Scholar 
    Joshi, N. & Fass, J. Sickle: A Sliding-window, Adaptive, Quality-based Trimming Tool for Fastq Files, v1.33 (2011).Li, D., Liu, C.-M., Luo, R., Sadakane, K. & Lam, T.-W. MEGAHIT: an ultra-fast single-node solution for large and complex metagenomics assembly via succinct de Bruijn graph. Bioinformatics 31, 1674–1676 (2015).CAS 
    PubMed 

    Google Scholar 
    Kang, D. D. et al. MetaBAT 2: an adaptive binning algorithm for robust and efficient genome reconstruction from metagenome assemblies. PeerJ 7, e7359 (2019).PubMed 
    PubMed Central 

    Google Scholar 
    Parks, D. H., Imelfort, M., Skennerton, C. T., Hugenholtz, P. & Tyson, G. W. CheckM: assessing the quality of microbial genomes recovered from isolates, single cells, and metagenomes. Genome Res. 25, 1043–1055 (2015).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Chaumeil, P.-A., Mussig, A. J., Hugenholtz, P. & Parks, D. H. GTDB-Tk: a toolkit to classify genomes with the Genome Taxonomy Database. Bioinformatics 36, 1925–1927 (2019).PubMed Central 

    Google Scholar 
    Olm, M. R., Brown, C. T., Brooks, B. & Banfield, J. F. dRep: a tool for fast and accurate genomic comparisons that enables improved genome recovery from metagenomes through de-replication. ISME J. 11, 2864–2868 (2017).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Bowers, R. M. et al. Minimum information about a single amplified genome (MISAG) and a metagenome-assembled genome (MIMAG) of bacteria and archaea. Nat. Biotechnol. 35, 725–731 (2017).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Emms, D. M. & Kelly, S. OrthoFinder: phylogenetic orthology inference for comparative genomics. Genome Biol. 20, 238 (2019).PubMed 
    PubMed Central 

    Google Scholar 
    Katoh, K. MAFFT: a novel method for rapid multiple sequence alignment based on fast Fourier transform. Nucleic Acids Res. 30, 3059–3066 (2002).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Capella-Gutierrez, S., Silla-Martinez, J. M. & Gabaldon, T. trimAl: a tool for automated alignment trimming in large-scale phylogenetic analyses. Bioinformatics 25, 1972–1973 (2009).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Nguyen, L. T., Schmidt, H. A., Von Haeseler, A. & Minh, B. Q. IQ-TREE: a fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. Mol. Biol. Evol. 32, 268–274 (2015).CAS 
    PubMed 

    Google Scholar 
    Seppey, M., Manni, M. & Zdobnov, E. M., Walker, J. M. (Ed.) BUSCO: assessing genome assembly and annotation completeness. Gene prediction 227–245 (Humana Press, 2019). https://doi.org/10.1007/978-1-4939-9173-0_14Parra, G., Bradnam, K. & Korf, I. CEGMA: a pipeline to accurately annotate core genes in eukaryotic genomes. Bioinformatics 23, 1061–1067 (2007).CAS 
    PubMed 

    Google Scholar 
    Bushmanova, E., Antipov, D., Lapidus, A. & Prjibelski, A. D. RnaSPAdes: a de novo transcriptome assembler and its application to RNA-Seq data. Gigascience 8, 1–13 (2019).CAS 

    Google Scholar 
    Grigoriev, I. V. et al. MycoCosm portal: gearing up for 1000 fungal genomes. Nucleic Acids Res. 42, 699–704 (2014).
    Google Scholar 
    Shaffer, M. et al. DRAM for distilling microbial metabolism to automate the curation of microbiome function. Nucleic Acids Res. 48, 8883–8900 (2020).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Eddy, S. R. Accelerated profile HMM searches. PLoS Comput. Biol. 7, e1002195 (2011).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Aramaki, T. et al. KofamKOALA: KEGG ortholog assignment based on profile HMM and adaptive score threshold. Bioinformatics 36, 2251–2252 (2020).CAS 
    PubMed 

    Google Scholar 
    Anders, S., Pyl, P. T. & Huber, W. HTSeq–a Python framework to work with high-throughput sequencing data. Bioinformatics 31, 166–169 (2015).CAS 
    PubMed 

    Google Scholar 
    Love, M. I., Huber, W. & Anders, S. Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2. Genome Biol. 15, 550 (2014).PubMed 
    PubMed Central 

    Google Scholar 
    Smid, M. et al. Gene length corrected trimmed mean of M-values (GeTMM) processing of RNA-seq data performs similarly in intersample analyses while improving intrasample comparisons. BMC Bioinformatics 19, 236 (2018).PubMed 
    PubMed Central 

    Google Scholar 
    Robinson, M. D., McCarthy, D. J. & Smyth, G. K. edgeR: a Bioconductor package for differential expression analysis of digital gene expression data. Bioinformatics 26, 139–140 (2010).CAS 
    PubMed 

    Google Scholar 
    Guo, J. et al. VirSorter2: a multi-classifier, expert-guided approach to detect diverse DNA and RNA viruses. Microbiome 9, 37 (2021).PubMed 
    PubMed Central 

    Google Scholar 
    Nayfach, S. et al. CheckV assesses the quality and completeness of metagenome-assembled viral genomes. Nat. Biotechnol. 39, 578–585 (2021).CAS 
    PubMed 

    Google Scholar 
    Guo, J., Vik, D., Pratama, A. A., Roux, S. & Sullivan, M. B. Viral Sequence Identification SOP with VirSorter2 (2021); protocols.io. https://doi.org/10.17504/protocols.io.btv8nn9wBland, C. et al. CRISPR recognition tool (CRT): a tool for automatic detection of clustered regularly interspaced palindromic repeats. BMC Bioinformatics 8, 209 (2007).PubMed 
    PubMed Central 

    Google Scholar 
    Skennerton, C. T., Imelfort, M. & Tyson, G. W. Crass: identification and reconstruction of CRISPR from unassembled metagenomic data. Nucleic Acids Res. 41, e105 (2013).CAS 
    PubMed 
    PubMed Central 

    Google Scholar  More

  • in

    Physiological responses to low CO2 over prolonged drought as primers for forest–grassland transitions

    Bond, W. Open Ecosystems (Oxford Univ. Press, 2019).Beerling, D. J. & Osborne, C. P. The origin of the savanna biome. Glob. Change Biol. 12, 2023–2031 (2006).Article 

    Google Scholar 
    Haverd, V. et al. Coupling carbon allocation with leaf and root phenology predicts tree–grass partitioning along a savanna rainfall gradient. Biogeosciences 13, 761–779 (2016).CAS 
    Article 

    Google Scholar 
    Kgope, B. S., Bond, W. J. & Midgley, G. F. Growth responses of African savanna trees implicate atmospheric [CO2] as a driver of past and current changes in savanna tree cover. Austral Ecol. 35, 451–463 (2010).Article 

    Google Scholar 
    Kulmatiski, A. & Beard, K. H. Woody plant encroachment facilitated by increased precipitation intensity. Nat. Clim. Change 3, 833–837 (2013).CAS 
    Article 

    Google Scholar 
    Mitchell, P. J. et al. Drought response strategies define the relative contributions of hydraulic dysfunction and carbohydrate depletion during tree mortality. N. Phytol. 197, 862–872 (2013).CAS 
    Article 

    Google Scholar 
    Schutz, A. E. N., Bond, W. J. & Cramer, M. D. Juggling carbon: allocation patterns of a dominant tree in a fire-prone savanna. Oecologia 160, 235–246 (2009).PubMed 
    Article 

    Google Scholar 
    Wigley, B., Cramer, M. & Bond, W. Sapling survival in a frequently burnt savanna: mobilisation of carbon reserves in Acacia karroo. Plant Ecol. 203, 1 (2009).Article 

    Google Scholar 
    Edwards, E. J., Osborne, C. P., Strömberg, C. A. E., Smith, S. A. & Consortium, C. G. The origins of C4 grasslands: integrating evolutionary and ecosystem science. Science 328, 587–591 (2010).CAS 
    PubMed 
    Article 

    Google Scholar 
    Spriggs, E. L., Christin, P.-A. & Edwards, E. J. C4 photosynthesis promoted species diversification during the Miocene grassland expansion. PLoS ONE 9, e97722 (2014).PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    McKay, R. M. et al. Antarctic Cenozoic climate history from sedimentary records: ANDRILL and beyond. Phil. Trans. R. Soc. A 374, 20140301 (2016).PubMed 
    Article 
    CAS 

    Google Scholar 
    Beerling, D. J. & Royer, D. L. Convergent Cenozoic CO2 history. Nat. Geosci. 4, 418–420 (2011).CAS 
    Article 

    Google Scholar 
    Pagani, M. et al. The role of carbon dioxide during the onset of Antarctic glaciation. Science 334, 1261–1264 (2011).CAS 
    PubMed 
    Article 

    Google Scholar 
    Zachos, J., Pagani, M., Sloan, L., Thomas, E. & Billups, K. Trends, rhythms, and aberrations in global climate 65 Ma to present. Science 292, 686–693 (2001).CAS 
    PubMed 
    Article 

    Google Scholar 
    Zhisheng, A., Kutzbach, J. E., Prell, W. L. & Porter, S. C. Evolution of Asian monsoons and phased uplift of the Himalaya–Tibetan plateau since Late Miocene times. Nature 411, 62–66 (2001).CAS 
    PubMed 
    Article 

    Google Scholar 
    Charles-Dominique, T. et al. Spiny plants, mammal browsers, and the origin of African savannas. Proc. Natl Acad. Sci. USA 113, E5572–E5579 (2016).CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Bellasio, C. & Farquhar, G. D. A leaf-level biochemical model simulating the introduction of C2 and C4 photosynthesis in C3 rice: gains, losses and metabolite fluxes. N. Phytol. 223, 150–166 (2019).CAS 
    Article 

    Google Scholar 
    Sage, R. F. & Coleman, J. R. Effects of low atmospheric CO(2) on plants: more than a thing of the past. Trends Plant Sci. 6, 18–24 (2001).CAS 
    PubMed 
    Article 

    Google Scholar 
    Reich, P. B., Hobbie, S. E. & Lee, T. D. Plant growth enhancement by elevated CO2 eliminated by joint water and nitrogen limitation. Nat. Geosci. 7, 920–924 (2014).CAS 
    Article 

    Google Scholar 
    Ward, J. K., Tissue, D. T., Thomas, R. B. & Strain, B. R. Comparative responses of model C3 and C4 plants to drought in low and elevated CO2. Glob. Change Biol. 5, 857–867 (1999).Article 

    Google Scholar 
    Scholes, R. J. & Archer, S. R. Tree–grass interactions in savannas. Annu. Rev. Ecol. Syst. 28, 517–544 (1997).Article 

    Google Scholar 
    February, E. C. & Higgins, S. I. The distribution of tree and grass roots in savannas in relation to soil nitrogen and water. S. Afr. J. Bot. 76, 517–523 (2010).Article 

    Google Scholar 
    February, E. C., Higgins, S. I., Bond, W. J. & Swemmer, L. Influence of competition and rainfall manipulation on the growth responses of savanna trees and grasses. Ecology 94, 1155–1164 (2013).PubMed 
    Article 

    Google Scholar 
    Fynn, R. W. S. & Naiken, J. Different responses of Eragrostis curvula and Themeda triandra to rapid- and slow-release fertilisers: insights into their ecology and implications for fertiliser selection in pot experiments. Afr. J. Range Forage Sci. 26, 43–46 (2009).Article 

    Google Scholar 
    Osmolovskaya, N. et al. Methodology of drought stress research: experimental setup and physiological characterization. Int. J. Mol. Sci. 19, 4089 (2018).PubMed Central 
    Article 

    Google Scholar 
    Quirk, J., Bellasio, C., Johnson, D. A., Osborne, C. P. & Beerling, D. J. C4 savanna grasses fail to maintain assimilation in drying soil under low CO2 compared with C3 trees despite lower leaf water demand. Funct. Ecol. 33, 388–398 (2019).Article 

    Google Scholar 
    Taylor, S. H. et al. Physiological advantages of C4 grasses in the field: a comparative experiment demonstrating the importance of drought. Glob. Change Biol. 20, 1992–2003 (2014).Article 

    Google Scholar 
    Bellasio, C., Quirk, J. & Beerling, D. J. Stomatal and non-stomatal limitations in savanna trees and C4 grasses grown at low, ambient and high atmospheric CO2. Plant Sci. 274, 181–192 (2018).CAS 
    PubMed 
    Article 

    Google Scholar 
    Kipchirchir, K. O., Ngugi, K. R., Mwangi, M. S., Njomo, K. G. & Raphael, W. Water stress tolerance of six rangeland grasses in the Kenyan semi-arid rangelands. Am. J. Agric. For. 3, 222–229 (2015).
    Google Scholar 
    Kadioglu, A. & Terzi, R. A dehydration avoidance mechanism: leaf rolling. Bot. Rev. 73, 290–302 (2007).Article 

    Google Scholar 
    Bittman, S. & Simpson, G. M. Drought effect on leaf conductance and leaf rolling in forage grasses. Crop Sci. 29, 338–344 (1989).Article 

    Google Scholar 
    O’Toole, J. C. & Cruz, R. T. Response of leaf water potential, stomatal resistance, and leaf rolling to water stress. Plant Physiol. 65, 428–432 (1980).PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Redmann, R. E. Adaptation of grasses to water stress—leaf rolling and stomate distribution. Ann. Mo. Bot. Gard. 72, 833–842 (1985).Article 

    Google Scholar 
    Volder, A., Tjoelker, M. G. & Briske, D. D. Contrasting physiological responsiveness of establishing trees and a C4 grass to rainfall events, intensified summer drought, and warming in oak savanna. Glob. Change Biol. 16, 3349–3362 (2010).Article 

    Google Scholar 
    Medeiros, J. S. & Ward, J. K. Increasing atmospheric [CO2] from glacial to future concentrations affects drought tolerance via impacts on leaves, xylem and their integrated function. N. Phytol. 199, 738–748 (2013).CAS 
    Article 

    Google Scholar 
    Quirk, J., McDowell, N. G., Leake, J. R., Hudson, P. J. & Beerling, D. J. Increased susceptibility to drought-induced mortality in Sequoia sempervirens (Cupressaceae) trees under Cenozoic atmospheric carbon dioxide starvation. Am. J. Bot. 100, 582–591 (2013).CAS 
    PubMed 
    Article 

    Google Scholar 
    Nackley, L. L. et al. CO2 enrichment does not entirely ameliorate Vachellia karroo drought inhibition: a missing mechanism explaining savanna bush encroachment. Environ. Exp. Bot. 155, 98–106 (2018).CAS 
    Article 

    Google Scholar 
    Apgaua, D. M. et al. Elevated temperature and CO2 cause differential growth stimulation and drought survival responses in eucalypt species from contrasting habitats. Tree Physiol. 39, 1806–1820 (2019).CAS 
    PubMed 
    Article 

    Google Scholar 
    Bond, W. J. What limits trees in C4 grasslands and savannas? Annu. Rev. Ecol. Syst. 39, 641–659 (2008).Article 

    Google Scholar 
    Valladares, F. & Niinemets, Ü. Shade tolerance, a key plant feature of complex nature and consequences. Annu. Rev. Ecol. Evol. Syst. 39, 237–257 (2008).Article 

    Google Scholar 
    Dohn, J. et al. Tree effects on grass growth in savannas: competition, facilitation and the stress-gradient hypothesis. J. Ecol. 101, 202–209 (2013).Article 

    Google Scholar 
    Jacobsen, J. V., Hanson, A. D. & Chandler, P. C. Water stress enhances expression of an α-amylase gene in barley leaves. Plant Physiol. 80, 350–359 (1986).CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Brodersen, C. & McElrone, A. Maintenance of xylem network transport capacity: a review of embolism repair in vascular plants. Front. Plant Sci. https://doi.org/10.3389/fpls.2013.00108 (2013).Chitarra, W. et al. Gene expression in vessel-associated cells upon xylem embolism repair in Vitis vinifera L. petioles. Planta 239, 887–899 (2014).CAS 
    PubMed 
    Article 

    Google Scholar 
    Hasibeder, R., Fuchslueger, L., Richter, A. & Bahn, M. Summer drought alters carbon allocation to roots and root respiration in mountain grassland. N. Phytol. 205, 1117–1127 (2015).CAS 
    Article 

    Google Scholar 
    Bradford, K. J. & Hsiao, T. C. in Physiological Plant Ecology II: Water Relations and Carbon Assimilation (eds Lange, O. L. et al.) 263–324 (Springer Berlin Heidelberg, 1982).Knox, K. J. E. & Clarke, P. J. Nutrient availability induces contrasting allocation and starch formation in resprouting and obligate seeding shrubs. Funct. Ecol. 19, 690–698 (2005).Article 

    Google Scholar 
    Hoffmann, W. A., Orthen, B. & Franco, A. C. Constraints to seedling success of savanna and forest trees across the savanna–forest boundary. Oecologia 140, 252–260 (2004).PubMed 
    Article 

    Google Scholar 
    Palacio, S., Maestro, M. & Montserrat-Martí, G. Seasonal dynamics of non-structural carbohydrates in two species of Mediterranean sub-shrubs with different leaf phenology. Environ. Exp. Bot. 59, 34–42 (2007).CAS 
    Article 

    Google Scholar 
    Hoffmann, W. A., Bazzaz, F. A., Chatterton, N. J., Harrison, P. A. & Jackson, R. B. Elevated CO2 enhances resprouting of a tropical savanna tree. Oecologia 123, 312–317 (2000).CAS 
    PubMed 
    Article 

    Google Scholar 
    Galvez, D. A., Landhausser, S. M. & Tyree, M. T. Root carbon reserve dynamics in aspen seedlings: does simulated drought induce reserve limitation? Tree Physiol. 31, 250–257 (2011).PubMed 
    Article 

    Google Scholar 
    Poorter, H. et al. A meta-analysis of responses of C3 plants to atmospheric CO2: dose–response curves for 85 traits ranging from the molecular to the whole-plant level. N. Phytol. https://doi.org/10.1111/nph.17802 (2022).Sevanto, S., Mcdowell, N. G., Dickman, L. T., Pangle, R. & Pockman, W. T. How do trees die? A test of the hydraulic failure and carbon starvation hypotheses. Plant Cell Environ. 37, 153–161 (2014).CAS 
    PubMed 
    Article 

    Google Scholar 
    Scheiter, S. et al. Fire and fire-adapted vegetation promoted C4 expansion in the late Miocene. N. Phytol. 195, 653–666 (2012).Article 

    Google Scholar 
    Quirk, J., Bellasio, C., Johnson, D. A. & Beerling, D. J. Response of photosynthesis, growth and water relations of a savannah-adapted tree and grass grown across high to low CO2. Ann. Bot. Lond. 124, 77–90 (2019).Article 
    CAS 

    Google Scholar 
    Davies, J. et al. in AGU Fall Meeting Abstracts EP41D-2374. https://ui.adsabs.harvard.edu/abs/2019AGUFMEP41D2374D/abstractMills, A. J., Rogers, K. H., Stalmans, M. & Witkowski, E. T. F. A framework for exploring the determinants of savanna and grassland distribution. BioScience 56, 579–589 (2006).Article 

    Google Scholar 
    Staver, A. C., Botha, J. & Hedin, L. Soils and fire jointly determine vegetation structure in an African savanna. N. Phytol. 216, 1151–1160 (2017).CAS 
    Article 

    Google Scholar 
    Cardoso, A. W. et al. Winners and losers: tropical forest tree seedling survival across a West African forest–savanna transition. Ecol. Evol. 6, 3417–3429 (2016).PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Mitchard, E. T. A. & Flintrop, C. M. Woody encroachment and forest degradation in sub-Saharan Africa’s woodlands and savannas 1982–2006. Phil. Trans. R. Soc. B https://doi.org/10.1098/rstb.2012.0406 (2013).Midgley, G. F. & Bond, W. J. Future of African terrestrial biodiversity and ecosystems under anthropogenic climate change. Nat. Clim. Change 5, 823–829 (2015).Article 

    Google Scholar 
    Bond, W. J. & Midgley, G. F. Carbon dioxide and the uneasy interactions of trees and savannah grasses. Phil. Trans. R. Soc. B 367, 601–612 (2012).CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Ripley, B. S., Gilbert, M. E., Ibrahim, D. G. & Osborne, C. P. Drought constraints on C4 photosynthesis: stomatal and metabolic limitations in C3 and C4 subspecies of Alloteropsis semialata. J. Exp. Bot. 58, 1351–1363 (2007).CAS 
    PubMed 
    Article 

    Google Scholar 
    McAusland, L. et al. Effects of kinetics of light-induced stomatal responses on photosynthesis and water-use efficiency. N. Phytol. 211, 1209–1220 (2016).Article 

    Google Scholar 
    Osborne, C. P. & Sack, L. Evolution of C4 plants: a new hypothesis for an interaction of CO2 and water relations mediated by plant hydraulics. Phil. Trans. R. Soc. B 367, 583–600 (2012).CAS 
    PubMed 
    PubMed Central 
    Article 

    Google Scholar 
    Pearcy, R. W. & Ehleringer, J. Comparative ecophysiology of C3 and C4 plants. Plant Cell Environ. 7, 1–13 (1984).CAS 
    Article 

    Google Scholar 
    Moncrieff, G. R., Scheiter, S., Bond, W. J. & Higgins, S. I. Increasing atmospheric CO2 overrides the historical legacy of multiple stable biome states in Africa. N. Phytol. 201, 908–915 (2014).CAS 
    Article 

    Google Scholar 
    Bond, W. J. & Midgley, G. F. A proposed CO2-controlled mechanism of woody plant invasion in grasslands and savannas. Glob. Change Biol. 6, 865–869 (2000).Article 

    Google Scholar 
    Polley, H. W., Johnson, H. B., Marino, B. D. & Mayeux, H. S. Increase in C3 plant water-use efficiency and biomass over glacial to present CO2 concentrations. Nature 361, 61–64 (1993).Article 

    Google Scholar 
    Stevens, N., Lehmann, C. E., Murphy, B. P. & Durigan, G. Savanna woody encroachment is widespread across three continents. Glob. Change Biol. 23, 235–244 (2017).Article 

    Google Scholar 
    Charles-Dominique, T., Midgley, G. F., Tomlinson, K. W. & Bond, W. J. Steal the light: shade vs fire adapted vegetation in forest–savanna mosaics. N. Phytol. 218, 1419–1429 (2018).Article 

    Google Scholar 
    Higgins, S. I. & Scheiter, S. Atmospheric CO2 forces abrupt vegetation shifts locally, but not globally. Nature 488, 209–212 (2012).CAS 
    PubMed 
    Article 

    Google Scholar 
    Bellasio, C., Fini, A. & Ferrini, F. Evaluation of a high throughput starch analysis optimised for wood. PLoS ONE 9, e86645 (2014).PubMed 
    PubMed Central 
    Article 
    CAS 

    Google Scholar 
    Kozloski, G. V., Rocha, J. B., Ribeiro Filho, H. M. N. & Perottoni, J. Comparison of acid and amyloglucosidase hydrolysis for estimation of non‐structural polysaccharides in feed samples. J. Sci. Food Agric. 79, 1112–1116 (1999).CAS 
    Article 

    Google Scholar 
    Bellasio, C., Beerling, D. J. & Griffiths, H. An Excel tool for deriving key photosynthetic parameters from combined gas exchange and chlorophyll fluorescence: theory and practice. Plant Cell Environ. 39, 1180–1197 (2016).CAS 
    PubMed 
    Article 

    Google Scholar 
    Bellasio, C., Beerling, D. J. & Griffiths, H. Deriving C4 photosynthetic parameters from combined gas exchange and chlorophyll fluorescence using an Excel tool: theory and practice. Plant Cell Environ. 39, 1164–1179 (2016).CAS 
    PubMed 
    Article 

    Google Scholar 
    Ethier, G. J. & Livingston, N. J. On the need to incorporate sensitivity to CO2 transfer conductance into the Farquhar–von Caemmerer–Berry leaf photosynthesis model. Plant Cell Environ. 27, 137–153 (2004).CAS 
    Article 

    Google Scholar 
    von Caemmerer, S. Biochemical Models of Leaf Photosynthesis (CSIRO, 2000).Bellasio, C. & Griffiths, H. Acclimation to low light by C4 maize: implications for bundle sheath leakiness. Plant Cell Environ. 37, 1046–1058 (2014).CAS 
    PubMed 
    Article 

    Google Scholar 
    Fini, A., Bellasio, C., Pollastri, S., Tattini, M. & Ferrini, F. Water relations, growth, and leaf gas exchange as affected by water stress in Jatropha curcas. J. Arid Environ. 89, 21–29 (2013).Article 

    Google Scholar 
    Ghannoum, O., Caemmerer, S. V. & Conroy, J. P. The effect of drought on plant water use efficiency of nine NAD-ME and nine NADP-ME Australian C4 grasses. Funct. Plant Biol. 29, 1337–1348 (2002).CAS 
    PubMed 
    Article 

    Google Scholar  More