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    No impact of nitrogen fertilization on carbon sequestration in a temperate Pinus densiflora forest

    SettingThis study was conducted in approximately 40-year-old naturally regenerated P. densiflora stands in Wola National Experimental Forest in Gyeongnam province in South Korea (35°12′ N, 128°10′ E; Table 1). The productivity of this forest is low, with a dominant tree height of 10 m at 20 years of age. Over the last 10 years, the mean annual precipitation was 1490 mm, of which one third fell during summer (July–August), and the mean temperature was 13.1 °C. The vegetation growing season generally lasts for approximately 200 days, extending from early April to October. The soil texture is a silt loam originating from sandstone and shale (clay 13.0 ± 0.8%, silt 44.1 ± 1.3%, sand 42.9 ± 1.6%; n = 18). The given texture results in volumetric water contents at 13.4 ± 0.7% (m3 m−3) at permanent wilting point (1500 kPa) and 40.7 ± 1.2% at field capacity (10 kPa)55. The understory is covered with Lespedeza spp., Quercus variabilis, Q. serrata, Smilax china, and Lindera glauca.In 2010, we selected two adjacent P. densiflora stands approximately 100 m apart from each other (180 m and 195 m above sea level, on slopes of 15° and 33°, both stands face south). Following a completely randomized design, we established nine plots (10 × 10 m2 with a 5 m untreated buffer) within each stand, of which three were randomly assigned to annual NPK fertilization, three to PK fertilization, and the rest to a control treatment without fertilization. The fertilizer, composed of urea, fused superphosphate and potassium chloride (N3P4K1) or P4K1 was added manually by deposition on the forest floor for 3 years in April 2011, April 2012, and March 2013. Over these 3 years, the NPK plots received 33.9 g N, 45 g P, and 11.1 g K m−2, while the PK plots received 45 g P and 11.1 g K m−2.Tree and stand measurementsThe standing biomass of trees was estimated using a combination of site-specific allometric equations based on destructive harvesting56 and repeated measurements of the dimensions of all trees in each plot (5–18 trees plot−1). The stem diameter at 1.2 m (D) was measured for all trees in each plot for which D was ≥ 6 cm. Selecting a representative tree in size for each plot within the 4 × 4 m2 center of the plot, we measured the tree height (H) and crown base for the representative trees. Measurements were performed in April and September 2011, September 2012–2014, and October 2021. We observed no effect of fertilization on the relationship between D and H or between D and crown base, so we assumed no effect on the allometric functions for foliage or branch biomass. A dendrometer band (Series 5 Manual Band, Forestry Suppliers Inc., Jackson, MS, USA) was installed on 18 representative trees (one per plot) to monitor radial growth monthly.Three 0.25 m2 circular litter traps were installed 60 cm above the forest floor in each plot in April 2011. Litter was collected at 3-month intervals between June 2011 and March 2015. The litter from each trap was transported to the laboratory and then oven-dried at 65 °C for 48 h. All dried samples were separated into needles, bark, cones, branches, and miscellaneous components, and weighed separately.In September 2014, we estimated the biomass of understory vegetation, separately for woody plants and herbaceous plants. All woody plants  More

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    Towards circular plastics within planetary boundaries

    Goal and scope of the studyThe goal of this study was to assess the planetary footprints of GHG mitigation strategies for the global production of plastics. To calculate planetary footprints, we apply LCA in combination with the planetary boundaries framework as proposed by ref. 22. As GHG mitigation strategies, we consider recycling, bio-based production and production via CCU, and compare their planetary footprints to the planetary footprints of fossil-based plastics. We use a bottom-up model covering >90% of global plastic production for 2030 (and 2050, Supplementary Information, section 3). The bottom-up model builds on the plastic production system from ref. 10 and includes plastic production, the supply chain and the disposal of plastics at the end of life.Functional unitIn LCA, the functional unit quantifies the functions of the investigated product system. In this study, the function of the product system is the production and disposal of >90% of global plastics. To cover >90% of global plastics, we define the functional unit as the yearly global production and disposal of 14 large-volume plastics (summarized in Supplementary Table 5). We estimated the yearly production volumes for 2030 and 2050 based on the production volumes in 2015 and the annual growth rates shown in Supplementary Table 5.Our assessment includes plastic disposal. However, the production and disposal of plastics do not necessarily occur in the same year. For instance, while polyolefins used for plastic packaging have an average lifetime of 6 months, the average lifetime of polyurethane used in construction is 35 years11. Including the lifetime of plastics, and hence, the temporal difference between production and disposal, would lead to an increasing plastic stock. An increasing stock, in turn, represents a carbon sink during the production year that appears to enable the production of net-negative GHG emission plastics based on biomass or CCU. However, the plastic stock is not a permanent carbon sink, which would be required for producing net-negative GHG emission plastics55. To avoid misleading conclusions about net-negative bio- and CCU-based plastics, we assign the planetary footprints from disposal to the year of plastic production. Thereby, we conservatively assess the planetary footprints of plastics.In addition, we address the challenge highlighted in ref. 56 that the increasing demand for plastics renders determining the absolute sustainability of plastics difficult. We meet this challenge by assuming a steady-state production system with a recurring functional unit in the same amount every year. We thereby analyse discrete scenarios with constant consumption levels for plastics. Therefore, our conclusions depend on the accuracy of the demand forecasts and apply only to the production volumes considered.System boundariesWe use cradle-to-grave system boundaries, including plastic production and supply chain, potential recycling and final disposal at the end of life. Assessing the use phase of plastics is not possible because of a lack of data. The versatile properties of plastics result in a wide range of applications that cannot be represented in a single study. Furthermore, it would be necessary to consider not only the emissions of the use phase (probably relatively small) but also the system-wide environmental consequences of using plastics in each application compared to other materials. Thus, a consequential assessment of the plastic use phase is desirable but beyond the scope of this study.The plastics supply chain includes several intermediate chemicals such as monomers, solvents or other reactants. The bottom-up model covers the production of all intermediate chemicals in the foreground system. As a background system, we use aggregated datasets from the LCA database ecoinvent. A list of all intermediate chemicals and all aggregated datasets can be found in Supplementary Information, section 1. In addition, the foreground system of the bottom-up model does not include environmental impacts from infrastructure and transportation because of a lack of data. However, we consider the environmental impacts of infrastructure and transportation from other industrial sectors by aggregated datasets, for example, from electricity generation and biomass cultivation.The bottom-up model includes the best available fossil-based technologies and the following technologies for plastic disposal and virgin production based on biomass and CCU.Plastic waste disposalThe bottom-up model includes three options for plastic waste disposal: landfilling, incineration with energy recovery and recycling. Plastic waste can occur in several forms: as sorted fraction of municipal solid waste, as mixed plastics and residues from sorting, and as residues from mechanical recycling. For all fractions, we include waste incineration with energy recovery and landfilling.Landfilled plastic waste is assumed to degrade by approximately 1% of the contained carbon, which is in line with the ecoinvent database45. Mechanical recycling is only modelled for sorted fractions of packaging waste owing to impurities of mixed and non-packaging wastes. In contrast, chemical recycling can be applied to all plastic fractions. In this study, we model chemical recycling as pyrolysis to refinery feedstock, that is, naphtha. The pyrolysis has yields of 29 to 69% depending on the type of plastic (details in Supplementary Information, section 1). Furthermore, we include options for chemical recycling of plastic waste to monomers, which are still early-stage technologies. To derive the minimal necessary recycling rate in Fig. 5, we apply an optimistic scenario with a 95% yield of chemical recycling processes following common modelling in life-cycle inventories of chemicals (Supplementary Information, section 3)57. All calculations are constrained to maximum recycling rates of 94% as the remaining 6% are assumed to be the minimal landfilling rate until the middle of the century11. The assumption is based on historical trends in end-of-life treatment of plastics.Bio-based productionBio-based GHG mitigation is frequently discussed in the literature and is often associated with competition with the food industry58. To avoid competition with the food industry, the bottom-up model is restricted to lignocellulosic biomass as feedstock, that is, energy crops, forest residues and by-products from other industrial biomass processes (for example, bagasse). In this study, unless mentioned otherwise, we model biomass as energy crops because of their potential for large-scale application (Supplementary Information, section 3). However, we conduct a sensitivity analysis for other lignocellulosic biomass sources to assess the sustainability of bio-based plastics in more detail.For each biomass type, we account for the carbon uptake during the biomass growth phase by giving a credit corresponding to the biomass carbon content. We do not consider land use change emissions as current literature lacks an assessment of land use change effects on other Earth-system processes besides climate change.For biomass processing, we include the following high-maturity processes: gasification to syngas and fermentation to ethanol, and the subsequent conversion to methanol and ethylene (Supplementary Table 1). Methanol and ethylene can be further converted to propylene and aromatics, which all together represent the building blocks for all plastics in this study.CCU-based productionCCU-based plastic production particularly requires CO2 and hydrogen. For CO2 supply, we consider CO2 capture from highly concentrated point sources within the plastics supply chain. Highly concentrated point sources include the conventional fossil-based processes, ammonia production, steam methane reforming, ethylene oxide production, the bio-based processes for ethanol and syngas, and plastic waste incineration. Capturing from processes within the plastics supply chain is limited by the amount of CO2 emitted by these processes and avoids the corresponding emissions. For these processes, we considered the energy demand for compressing the CO2 with 0.4 MJ of electricity59. For waste incineration, we consider a decrease in energy output when capturing CO2. All further CO2 sources are conservatively approximated by direct air capture. For 1 kg CO2 captured via direct air capture, we include an uptake of 1 kg of CO2 equivalent while considering the energy demand of 1.29 MJ electricity and 4.19 MJ heat60.Hydrogen for CCU is produced by water electrolysis, with an overall efficiency of 67%61. Previous studies have already shown that renewable electricity is required for CCU to be environmentally beneficial13. Thus, we conduct a sensitivity analysis for multiple electricity technologies to assess their influence on the sustainability of CCU-based plastics (Supplementary Information).For CCU-based production, we include high-maturity technologies, such as CO2-based methanol and methane, as well as subsequent production of olefins and aromatics (Supplementary Table 1). We do not consider CCS as an additional scenario, as fossil resources and storage capacities are ultimately limited. Therefore, CCS may serve as an interim solution for GHG mitigation but stands in contrast to long-term sustainability as the goal of this study.Pathway definitionWe assess nine pathways for the plastics industry towards sustainability. Pathway 1 is fossil-based plastic production (current recycling rate of 23%) that serves as a reference. We also include two pathways that combine all circular technologies: Pathway 2, which minimizes the climate change impact (climate-optimal), and pathway 3, which minimizes the maximal transgression of the share of SOS of the plastics industry (balanced) (Fig. 2). To assess the impact of switching from fossil to renewable feedstocks, we introduce pathway 4, which is bio-based, and pathway 5, which is CCU-based (Fig. 3). Pathways 4 and 5 include the current recycling rate of 23%. In addition, we introduce three pathways with the maximum recycling rates of 94%: pathway 6, in which the remaining virgin production is based on fossil resources; pathway 7, in which it is based on biomass; and pathway 8, in which it is based on CO2 (Fig. 3). Pathway 9 combines biomass, CCU and recycling, and additionally includes chemical recycling of polymers to monomers to calculate the minimal recycling rate to achieve sustainable plastics (Fig. 5).The planetary boundaries frameworkWe follow the recommendations for absolute environmental sustainability assessment in ref. 29 and choose the planetary boundaries framework for the assessment. The planetary boundaries framework suits the goal of the study best because of its precautionary principles for the definition of environmental thresholds, the SOS. We assess eight of the nine Earth-system processes suggested in ref. 21, namely, climate change, ocean acidification, changes in biosphere integrity, the biogeochemical flow of nitrogen and phosphorus (referred to as N cycle and P cycle), aerosol loading, freshwater use, stratospheric ozone depletion, and land-system change. We do not assess the Earth-system process of novel entities since neither control variables nor the boundary itself is yet adequately defined22. We consider the global boundaries for the Earth-system processes in line with the scope of this study. These global boundaries and the corresponding calculation of planetary footprints are subject to assumptions and thus incorporate uncertainty (Supplementary Information, section 2).For the two subprocesses for climate change (namely, atmospheric CO2 concentration and energy imbalance at the top-of-atmosphere), we only consider the energy imbalance at the top-of-atmosphere quantified by radiative forcing. We focus on radiative forcing, as the control variable is more inclusive and fundamental, and the global limits are stricter than for atmospheric CO2 concentration21. Thereby, we conservatively assess climate change.Biosphere integrity is divided into functional and genetic diversity of species. Preserving functional diversity ensures a stable ecosystem by maintaining all ecosystem services. We assess the functional diversity of species using the method proposed in ref. 18. The method covers the mean species abundance loss caused by the two main stressors, direct land use and GHG emissions, as a proxy for the biodiversity intactness index. Genetic diversity provides the long-term ability of the biosphere to persist under and adapt to gradual changes of the environment21. Genetic diversity is often approximated by the global extinction rate. However, using the global extinction rate does not fully cover variation of genetic composition, resulting in high uncertainties when quantifying genetic diversity18. Thus, we focus on functional diversity.Downscaling of the safe operating spaceAs the plastics industry accounts for only a fraction of all human activities, we assign a share of the SOS to plastics. The plastics industry should operate within its assigned share to be considered environmentally sustainable. To assign a share of SOS to the plastics industry, we apply utilitarian downscaling principles. Utilitarian downscaling principles are tailored to maximize welfare in society29. We approximate welfare by consumption expenditure on plastics as an economic indicator for consumer preferences and human needs62. An extensive discussion on the other downscaling principles and their implications can be found in Supplementary Information.Although the final consumption expenditures on plastics are negligible, the industry consumes plastics to produce other goods and services. Accordingly, plastics are produced mostly in the upstream supply chain to support the final consumption of other goods and services. Thus, consuming other goods and services induces plastic production. To account for this inducement of plastic production, we used the total global plastic production xplastics to represent the global intermediate and final consumption expenditure on plastics. For this purpose, we use the gross output vector x of the product-by-product input–output table of EXIOBASE for the year 2020 (ref. 63). To calculate the share of SOS of the plastics industry, we divide the total global plastic production xplastics by the gross world product. The gross world product equals the total global final consumption expenditure. Analogously, we also consider the end-of-life treatment of plastics to be consistent with the system boundaries of the environmental assessment.We estimate the share of SOS for the plastics industry for 2030 and 2050 based on data for the year 2020. Accordingly, we assume that the market share of the plastics industry and, therefore, its share of SOS do not change in the coming years despite the increasing production volume of plastics. Thereby, we implicitly assume that all industries grow equally economically. Alternatively, economic forecasting models could estimate future market shares of plastics. However, applying economic forecasting models is complex, and the results would still be highly uncertain, especially if industry pursues low-carbon technology pathways. Therefore, estimating future market shares is beyond the scope of this study.Technology choice modelTo calculate the planetary footprint of plastics, we use a bottom-up model of the plastics industry. The model builds on the technology choice model (TCM) that allows for linear optimization of production systems27. The TCM represents the production system based on the following elements: technologies, intermediate flows, elementary flows and final demands. Ref. 27 describes each element in detail.The TCM is based on the established computational structure of LCA64. This structure arranges the data that represent the physical production system in the technology matrix A and the elementary flow matrix B. In the technology matrix A, columns represent technologies, and rows represent intermediate flows. Therefore, the coefficient aij of the A matrix corresponds to an intermediate flow i that is either produced (aij  > 0) or consumed (aij  More

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    Genetic structuring and invasion status of the perennial Ambrosia psilostachya (Asteraceae) in Europe

    Van Kleunen, M. et al. Global exchange and accumulation of non-native plants. Nature 525, 100–101 (2015).Article 
    ADS 
    PubMed 

    Google Scholar 
    Simberloff, D. et al. Impacts of biological invasions: What’s what and the way forward. Trends Ecol. Evol. 28, 58–66 (2013).Article 
    PubMed 

    Google Scholar 
    Fried, G., Chauvel, B., Reynaud, P. & Sache, I. Decreases in crop production by non-native weeds, pests, and pathogens. In Impact of Biological Invasions on Ecosystem Services (ed. Vilà, M.) 83–101 (Springer, 2017).Chapter 

    Google Scholar 
    Nentwig, W., Mebs, D. & Vilà, M. Impact of non-native animals and plants on human health. In Impact of Biological Invasions on Ecosystem Services (ed. Vilà, M.) 277–293 (Springer, 2017).Chapter 

    Google Scholar 
    Smith, M., Cecchi, L., Skjøth, C. A., Karrer, G. & Šikoparija, B. Common ragweed: A threat to environmental health in Europe. Environ. Int. 61, 115–126 (2013).Article 
    CAS 
    PubMed 

    Google Scholar 
    Strother, J. L. Ambrosia L. in Flora of North America, Vol. 21 efloras.org. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=101325 (2007). Accessed 10 August 2022.Oswalt, M. L. & Marshall, G. D. Ragweed as an example of worldwide allergen expansion. All. Asth. Clin. Immun. 4, 130–135 (2008).Article 

    Google Scholar 
    Payne, W. W. Biosystematic studies of four widespread weedy species of ragweeds, Ambrosia: Compositae. PhD Thesis, University of Michigan (1962).Burbach, G. J. et al. Ragweed sensitization in Europe—GA(2)LEN study suggests increasing prevalence. Allergy 64, 664–665 (2009).Article 
    CAS 
    PubMed 

    Google Scholar 
    Ghosh, B. et al. Immunological and molecular characterization of Amb P V allergens from Ambrosia psilostachya (western ragweed) pollen. J. Immunol. 152, 2882–2889 (1994).Article 
    CAS 
    PubMed 

    Google Scholar 
    Karrer, G. et al. Ambrosia in Europe. Habitus, Leaves, Seeds, 6 European Ragweed Species. Comparison of traits. EU-COST-Action FA-1203 ‘Sustainable management of Ambrosia artemisiifolia in Europe’. http://internationalragweedsociety.org/smarter/wp-content/uploads/6AmbrosiaSpecies.pdf (2016). Accessed 10 August 2022.Essl, F. et al. Biological flora of the British Isles: Ambrosia artemisiifolia L.. J. Ecol. 103, 1069–1098 (2015).Article 

    Google Scholar 
    Payne, W. W. A re-evaluation of the genus Ambrosia (Compositae). J. Arnold Arbor. 45, 401–438 (1964).Article 

    Google Scholar 
    Müller-Schärer, H. et al. Cross-fertilizing weed science and plant invasion science. Basic Appl. Ecol. 33, 1–13 (2018).Article 

    Google Scholar 
    Chapman, D. S. et al. Modelling the introduction and spread of non-native species: International trade and climate change drive ragweed invasion. Glob. Change Biol. 22, 3067–3079 (2016).Article 
    ADS 

    Google Scholar 
    Mang, T., Essl, F., Moser, D. & Dullinger, S. Climate warming drives invasion history of Ambrosia artemisiifolia in central Europe. Preslia 90, 59–81 (2018).Article 

    Google Scholar 
    Liu, X.-L. et al. The current and future potential geographical distribution of common ragweed, Ambrosia artemisiifolia in China. Pak. J. Bot. 53, 167–172 (2021).ADS 

    Google Scholar 
    Allard, H. A. The North American ragweeds and their occurrence in other parts of the world. Science 98, 292–293 (1943).Article 
    ADS 
    CAS 
    PubMed 

    Google Scholar 
    Greuter, W. Compositae (pro parte majore) in Compositae. Euro+Med Plantbase – the information resource for Euro-Mediterranean plant diversity (ed. Greuter, W. & Raab-Straube, E. von) https://europlusmed.org/cdm_dataportal/taxon/76610e67-b2d4-4aef-a785-c4555af5b150 (Accessed 22 August 2022).Abramova, L. M. Expansion of invasive alien plant species in the Republic of Bashkortostan, the Southern Urals: Analysis of causes and ecological consequences. Russ. J. Ecol. 43, 352–357 (2012).Article 

    Google Scholar 
    Montagnani, C., Gentili, R., Smith, M., Guarino, M. F. & Citterio, S. The worldwide spread, success, and impact of ragweed (Ambrosia spp.). Crit. Rev. Plant. Sci. 36, 139–178 (2017).Article 

    Google Scholar 
    Vermeire, L. T. & Gillen, R. L. Western ragweed effects on herbaceous standing crop in Great Plains grasslands. J. Range Manag. 53, 335–341 (2000).Article 

    Google Scholar 
    Reece, P. E., Brummer, J. E., Northup, B. K., Koehler, A. E. & Moser, L. E. Interactions among western ragweed and other sandhills species after drought. J. Range Manag. 57, 583–589 (2000).Article 

    Google Scholar 
    Wagner, W. H. & Beals, T. F. Perennial ragweeds (Ambrosia) in Michigan, with description of a new, intermediate Taxon. Rhodora 60, 177–204 (1958).
    Google Scholar 
    Hansen, A. Ambrosia L. In Flora Europaea Vol. 4 (eds Tutin, T. G. et al.) (Cambridge University Press, 1976).
    Google Scholar 
    Sell, P. & Murrell, G. Flora of Great Britain and Ireland, Campanulaceae–Asteraceae Vol. 4, 513–514 (Cambridge University Press, 2006). Book 

    Google Scholar 
    Pignatti, S. Flora d’Italia Vol. 3 (Edagricola, 1982).
    Google Scholar 
    Amor Morales, À., Navarro Andrés, F. & Sánchez Anta, M. Datos corológicos y morfológicos de las especies del género Ambrosia L. (Compositae) presentes en la Península Ibérica. Bot. Complut. 36, 85–96 (2012).Article 

    Google Scholar 
    Karrer, G. Ambrosia. In Flora d’Italia 2nd edn, Vol. 3 (eds Guarino, R. & La Rosa, M.) 808–810 (Edagricola, 2018).
    Google Scholar 
    Rich, T. C. G. Ragweeds (Ambrosia L.) in Britain. Grana 33, 38–43 (1994).Article 

    Google Scholar 
    Chauvel, B., Fried, G., Monty, A., Rossi, J. P. & Le Bourgeois, T. Analyse de Risques Relative à L’ambroisie à Épis Lisses (Ambrosia Psilostachya DC.) et Élaboration de Recommandation De gestion (ANSES, 2017).
    Google Scholar 
    Lawalreé, A. Les Ambrosia adventices en Europe occidentale. Bull. Jard. Botan. l’Etat Bruxelles 18, 305–315 (1947).Article 

    Google Scholar 
    Karrer, G. Interessante Gefäßpflanzenfunde aus Österreich, 1. Neilreichia 12, 183–187 (2021).
    Google Scholar 
    Bassett, I. J. & Crompton, C. W. The biology of Canadian weeds. 11. Ambrosia artemisiifolia L. and A. psilostachya DC. Can. J. Plant Sci. 55, 463–476 (1975).Article 

    Google Scholar 
    Djemaa, S. Caractérisation de la banque de graines de l’Ambroisie à épis lisses Ambrosia psilostachya DC (Asteraceae) et moyens de contrôle de cette espèce envahissante et allergène (Rapport de stage de Master 1 – Université de Montpellier 2 – Master IEGB, 2014).Chun, Y. J., Le Corre, V. & Bretagnolle, F. Adaptive divergence for a fitness-related trait among invasive Ambrosia artemisiifolia populations in France. Mol. Ecol. 20, 1378–1388 (2011).Article 
    PubMed 

    Google Scholar 
    Genton, B. J. et al. Isolation of five polymorphic microsatellite loci in the invasive weed Ambrosia artemisiifolia (Asteraceae) using an enrichment protocol. Mol. Ecol. Notes 5, 381–383. https://doi.org/10.1111/j.1365-294X.2005.02750.x (2005).Article 
    CAS 

    Google Scholar 
    Genton, B. J., Shykoff, J. A. & Giraud, T. High genetic diversity in French invasive populations of common ragweed, Ambrosia artemisiifolia, as a result of multiple sources of introduction. Mol. Ecol. 14, 4275–4285 (2005).Article 
    CAS 
    PubMed 

    Google Scholar 
    Gaudeul, M., Giraud, T., Kiss, L. & Shykoff, J. A. Nuclear and chloroplast microsatellites show multiple introductions in the worldwide invasion history of common Ragweed Ambrosia artemisiifolia. PLoS One 6, e17658. https://doi.org/10.1371/journal.pone.0017658 (2011).Article 
    ADS 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Chun, Y. J., Fumanal, B., Laitung, B. & Bretagnolle, F. Gene flow and population admixture as the primary post-invasion processes in common ragweed (Ambrosia artemisiifolia) populations in France. New Phytol. 185, 1100–1107 (2010).Article 
    PubMed 

    Google Scholar 
    Gladieux, P. et al. Distinct invasion sources of common ragweed (Ambrosia artemisiifolia) in Eastern and Western Europe. Biol. Invasions 13, 933–944 (2010).Article 

    Google Scholar 
    Li, X.-M., Liao, W.-J., Wolfe, L. M. & Zhang, D.-Y. No evolutionary shift in the mating system of North American Ambrosia artemisiifolia (Asteraceae) following its introduction to China. PLoS One 7(2), e31935. https://doi.org/10.1371/journal.pone.0031935 (2012).Article 
    ADS 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Kočiš Tubić, N., Djan, M., Veličković, N., Anačkov, G. & Obreht, D. Microsatellite DNA variation within and among invasive populations of Ambrosia artemisiifolia from the southern Pannonian Plain. Weed Res. 55, 268–277 (2015).Article 

    Google Scholar 
    Ciappetta, S. et al. Invasion of Ambrosia artemisiifolia in Italy: Assessment via analysis of genetic variability and herbarium data. Flora 223, 106–113 (2016).Article 

    Google Scholar 
    Meyer, L. et al. New gSSr and EST-SSR markers reveal high genetic diversity in the invasive plant Ambrosia artemisiifolia L. and can be transferred to other invasive Ambrosia species. PLoS One 12(5), e0176197. https://doi.org/10.1371/journal.pone.0176197 (2017).Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Van Boheemen, L. A. et al. Multiple introductions, admixture and bridgehead invasion characterize the introduction history of Ambrosia artemisiifolia in Europe and Australia. Mol. Ecol. 26, 5421–5434 (2017).Article 
    PubMed 

    Google Scholar 
    Kropf, M., Huppenberger, A. S. & Karrer, G. Genetic structuring and diversity patterns along rivers—Local invasion history of Ambrosia artemisiifolia (Asteraceae) along the Danube River in Vienna (Austria) shows non-linear pattern. Weed Res. 58, 131–140 (2018).Article 
    CAS 

    Google Scholar 
    Sun, Y. & Roderick, G. K. Rapid evolution of invasive traits facilitates the invasion of common ragweed Ambrosia artemisiifolia. J. Ecol. 107, 2673–2687 (2019).Article 

    Google Scholar 
    Li, F. et al. Patterns of genetic variation reflect multiple introductions and pre-admixture sources of common ragweed (Ambrosia artemisiifolia) in China. Biol. Invasions 21, 2191–2209 (2019).Article 

    Google Scholar 
    Payne, W. W., Raven, P. H. & Kyhos, D. W. Chromosome numbers in Compositae. IV. Ambrosieae. Am. J. Bot. 51, 419–424 (1964).Article 

    Google Scholar 
    Miller, H. E., Mabry, T. J., Turner, B. L. & Payne, W. W. Infraspecific variation of sesquiterpene lactones in Ambrosia psilostachya (Compositae). Am. J. Bot. 55, 316–324 (1968).Article 
    CAS 

    Google Scholar 
    Del Amo Rodriguez, S. & Gomez-Pompa, A. Variability in Ambrosia cumanensis (Compositae). Syst. Bot. 1, 363–372 (1976).Article 

    Google Scholar 
    Grünwald, N. J., Everhart, S. E., Knaus, B. J. & Kamvar, Z. N. Best practices for population genetic analyses. Phytopathology 107, 1000–1010 (2017).Article 
    PubMed 

    Google Scholar 
    Arnaud-Haond, S., Stoeckel, S. & Bailleul, D. New insights into the population genetics of partially clonal organisms: When seagrass data meet theoretical expectations. Mol. Ecol. 29, 3248–3260 (2020).Article 
    PubMed 

    Google Scholar 
    Falush, D., Stephens, M. & Pritchard, J. K. Inference of population structure using multilocus genotype data: Linked loci and correlated allele frequencies. Genetics 164, 1567–1587 (2003).Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Watkinson, A. & Powell, J. Seedling recruitment and the maintenance of clonal diversity in plant populations—A computer simulation of Ranunculus repens. J. Ecol. 81, 707–717 (1993).Article 

    Google Scholar 
    Balloux, F., Lehmann, L. & de Meeus, T. The population genetics of clonal and partially clonal diploids. Genetics 164, 1635–1644 (2003).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    Kamvar, Z. N., Tabima, J. F. & Grünwald, N. J. Poppr: A r package for genetic analysis of populations with clonal, partially clonal, and/or sexual reproduction. PeerJ 2, e281. https://doi.org/10.7717/peerj.281 (2014).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    Bonin, A. et al. How to track and assess genotyping errors in population genetics studies. Mol. Ecol. 13, 3261–3273 (2004).Article 
    CAS 
    PubMed 

    Google Scholar 
    Guretzky, J., Anderson, A. & Fehmi, J. Grazing and military vehicle effects on grassland soils and vegetation. Great Plains Res. 16, 51–61 (2006).
    Google Scholar 
    Vitalos, M. & Karrer, G. Dispersal of Ambrosia artemisiifolia seeds along roads: the contribution of traffic and mowing machines. NeoBiota 8, 53–60 (2009).
    Google Scholar 
    Karrer, G. Das österreichische Ragweed Projekt—übertragbare Erfahrungen. The Austrian Ragweed Project—Experiences and Generalisations. Julius-Kühn-Archiv 445, 27–33 (2014).
    Google Scholar 
    Lemke, A., Buchholz, S., Kowarik, I., Starfinger, U. & von der Lippe, M. Interaction of traffic intensity and habitat features shape invasion dynamics of an invasive alien species (Ambrosia artemisiifolia) in a regional road network. NeoBiota 64, 155–175 (2021).Article 

    Google Scholar 
    Orlić, M., Gačić, M. & La Violette, P. E. The currents and circulation of the Adriatic Sea. Oceanol. Acta 15, 109–124 (1992).
    Google Scholar 
    Fumanal, B., Chauvel, B., Sabatier, A. & Bretagnolle, F. Variability and cryptic heteromorphism of Ambrosia artemisiifolia seeds: What consequences for its invasion in France?. Ann. Bot. 100, 305–313 (2007).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    González, L. et al. An Atlantic Odissey: The fate of invading propagules across the coastline of the Iberian Peninsula. In 15th Ecology and Management of Alien Plant Invasions (EMAPi) Book of Abstracts: Integrating Research, Management and Policy (eds Pyšek, P. et al.) 24 (Institute of Botany, Czech Academy of Sciences, 2019).
    Google Scholar 
    Ward, S. Genetic analysis of invasive plant populations at different spatial scales. Biol. Invasions 8, 541–552 (2006).Article 

    Google Scholar 
    Halkett, F., Simon, J.-C. & Balloux, F. Tackling the population genetics of clonal and partially clonal organisms. Trends Ecol. Evol. 20, 194–201 (2005).Article 
    PubMed 

    Google Scholar 
    Kočiš Tubić, N., Djan, M., Veličković, N., Anačkov, G. & Obreht, D. Gradual loss of genetic diversity of Ambrosia artemisiifolia L. populations in the invaded range of central Serbia. Genetika 46, 255–268 (2014).Article 

    Google Scholar 
    Suehs, C. M., Affre, L. & Médail, F. Invasion dynamics of two alien Carpobrotus (Aizoaceae) taxa on a Mediterranean island: I. Genetic diversity and introgression. Heredity 92, 31–40 (2004).Article 
    CAS 
    PubMed 

    Google Scholar 
    Stoeckel, S. et al. Heterozygote excess in a self-incompatible and partially clonal forest tree species—Prunus avium L. Mol. Ecol. 15, 2109–2118 (2005).Article 

    Google Scholar 
    Balloux, F. Heterozygote excess in small populations and the heterozygote-excess effective population size. Evolution 58, 1891–1900 (2004).PubMed 

    Google Scholar 
    Hansson, B. & Westerberg, L. On the correlation between heterozygosity and fitness in natural populations. Mol. Ecol. 11, 2467–2474 (2002).Article 
    PubMed 

    Google Scholar 
    Hewitt, A., Rymer, P., Holford, P., Morris, E. C. & Renshaw, A. Evidence for clonality, breeding system, genetic diversity and genetic structure in large and small populations of Melaleuca deanei (Myrtaceae). Aust. J. Bot. 67, 36–45 (2019).Article 

    Google Scholar 
    Dlugosch, K. M. & Parker, I. M. Founding events in species invasions: Genetic variation, adaptive evolution, and the role of multiple introductions. Mol. Ecol. 17, 431–449 (2008).Article 
    CAS 
    PubMed 

    Google Scholar 
    Novak, S. J. & Mack, R. N. Genetic bottlenecks in alien plant species: influences of mating systems and introduction dynamics. In Species Invasions: Insights into Ecology, Evolution, and Biogeography (eds Sax, D. F. et al.) 201–228 (Sinauer Associates, 2005).
    Google Scholar 
    Karnkowski, W. Pest Risk Analysis and Pest Risk Assessment for the territory of the Republic of Poland (as PRA area) on Ambrosia spp., updated version. (Torun, 2001).Karrer, G. et al. Ausbreitungsbiologie und Management einer extrem allergenen, eingeschleppten Pflanze – Wege und Ursachen der Ausbreitung von Ragweed (Ambrosia artemisiifolia) sowie Möglichkeiten seiner Bekämpfung. (Final Report, BMLFUW, Vienna, Austria). https://dafne.at/projekte/ragweed (2011). Accessed 10 August 2022.Honnay, O. & Jacquemyn, H. A meta-analysis of the relation between mating system, growth form and genotypic diversity in clonal plant species. Evol. Ecol. 22, 299–312 (2008).Article 

    Google Scholar 
    Vallejo-Marín, M., Dorken, M. E. & Barrett, S. C. H. The ecological and evolutionary consequences of clonality for plants mating. Annu. Rev. Ecol. Syst. 41, 193–213 (2010).Article 

    Google Scholar 
    McKey, D., Elias, M., Pujol, B. & Duputiè, A. The evolutionary ecology of clonally propagated domesticated plants. New Phytol. 186, 318–332 (2010).Article 
    PubMed 

    Google Scholar 
    WFO Ambrosia psilostachya DC. http://www.worldfloraonline.org/taxon/wfo-0000137200 (accessed 21 July 2022).Tomasello, S., Stuessy, T. F., Oberprieler, C. & Heubl, G. Ragweeds and relatives: Molecular phylogenetics of Ambrosiinae (Asteraceae). Mol. Phylogenet. Evol. 130, 104–114 (2019).Article 
    CAS 
    PubMed 

    Google Scholar 
    Délye, C., Matéjicek, A. & Gasquez, J. PCR-based detection of resistance to Acetyl-CoA carboxylase-inhibiting herbicides in black-grass (Alopecurus myosuroides Huds) and ryegrass (Lolium rigidum Gaud). Pest Manag. Sci. 58, 474–478 (2002).Article 
    PubMed 

    Google Scholar 
    Adamack, A. T. & Gruber, B. PopGenReport: Simplifying basic population genetic analyses in R. Methods Ecol. Evol. 5, 384–387 (2014).Article 

    Google Scholar 
    Brookfield, J. F. Y. A simple new method for estimating null allele frequency from heterozygote deficiency. Mol. Ecol. 5, 453–455 (1996).Article 
    CAS 
    PubMed 

    Google Scholar 
    Harper, J. L. Population Biology of Plants (Academic Press, 1977).
    Google Scholar 
    Lambertini, C. et al. Genetic diversity in three invasive clonal aquatic species in New Zealand. BMC Genet. 11(52), 1–18. https://doi.org/10.1186/1471-2156-11-52 (2010).Article 
    CAS 

    Google Scholar 
    Peakall, R. & Smouse, P. E. GenAlEx 6.5: Genetic analysis in excel. Population genetic software for teaching and research—An update. Bioinformatics 28, 2537–2539 (2012).Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Brown, A. H. D., Feldman, M. W. & Nevo, E. Multilocus structure of natural populations of Hordeum spontaneum. Genetics 96, 523–536 (1980).Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Goudet, J. Hierfstat, a package for R to compute and test hierarchical F-statistics. Mol. Ecol. Notes 5, 184–186 (2005).Article 

    Google Scholar 
    Pritchard, J. K., Stephens, M. & Donnelly, P. Inference of population structure using multilocus genotype data. Genetics 155, 945–959 (2000).Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Evanno, G., Regnaut, S. & Goudet, J. Detecting the number of clusters of individuals using the software STRUCTURE: A simulation study. Mol. Ecol. 14, 2611–2620 (2005).Article 
    CAS 
    PubMed 

    Google Scholar 
    Kropf, M., Comes, H. P. & Kadereit, J. W. An AFLP clock for the absolute dating of shallow-time evolutionary history based on the intraspecific divergence of southwestern European alpine plant species. Mol. Ecol. 18, 697–708 (2009).Article 
    PubMed 

    Google Scholar 
    Nei, M. Genetic distance between populations. Am. Nat. 106, 283–292 (1972).Article 

    Google Scholar 
    Jombart, T. adegenet: A r package for the multivariate analysis of genetic markers. Bioinformatics 24, 1403–1405 (2008).Article 
    CAS 
    PubMed 

    Google Scholar 
    Venables, W. N. & Ripley, B. D. Modern Applied Statistics with S 4th edn. (Springer, 2002).Book 
    MATH 

    Google Scholar 
    Keenan, K., McGinnity, P., Cross, T. F., Crozier, W. W. & Prodöhl, P. A. diversity: An R package for the estimation and exploration of population genetics parameters and their associated errors. Methods Ecol. Evol. 4, 782–788 (2013).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).Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar  More

  • in

    Ontogenetic changes in the body structure of the Arctic fish Leptoclinus maculatus

    Meyer Ottesen, C. A. et al. Early life history of the daubed shanny (Teleostei: Leptoclinus maculatus) in Svalbard waters. Mar. Biodivers. 41(3), 383–394 (2011).Article 

    Google Scholar 
    Murzina, S.A. Role of Lipids and Their Fatty Acid Components in Ecological and Biochemical Adaptations of Fish of the Northern Seas. Dr. Sci. Thesis (IPEE RAS, 2019).Murzina, S. A. et al. Tiny but fatty: Lipids and fatty acids in the Daubed Shanny (Leptoclinus maculatus), a small fish in Svalbard waters. Biomolecules 10, 368 (2020).Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Falk-Petersen, S., Falk-Petersen, I. B. & Sargent, J. R. Structure and function of an unusal lipid storage organ in the Arctic fish Lumpenus maculatus Fries. Sarsia 71(1), 1–6 (1986).Article 
    CAS 

    Google Scholar 
    Murzina S.A. The Role of Lipids and Their Fatty Acid Components in the Biochemical Adaptations of the Daubed Shanny Leptoclinus maculatus F. of the Northwestern Coast of Svalbard. PhD Thesis 184 (IB KarRC RAS, 2010)Pekkoeva, S. N. et al. Ecological role of lipids and fatty acids in the early postembryonic development of daubed shanny, Leptoclinus maculatus (Fries, 1838) from Kongsfjorden, West Spitsbergen in winter. Rus. J. Ecol. 48(3), 240–244 (2017).Article 
    CAS 

    Google Scholar 
    Hovde, S. C., Albert, O. T. & Nilssen, E. M. Spatial, seasonal and ontogenetic variation in diet of Northeast Arctic Greenland halibut (Reinhardtius hippoglossoides). ICES J. Mar. Sci. 59, 421–437 (2002).Article 

    Google Scholar 
    Labansen, A. L., Lydersen, C., Haug, T. & Kovacs, K. M. Spring diet of ringed seals (Phoca hispida) from northwestern Spitsbergen. Norway. ICES J. Mar. Sci. 64, 1246–1256 (2007).Article 

    Google Scholar 
    Moser, H. G. Morphological and functional aspect of marine fish larvae. in Marine Fish Larvae—Morphology, Ecology, and Relation to Fisheries (ed. Lasker, R.). 89–131. (University of Washington Press, 1981).Moser, H. G. et al. Ontogeny and systematics of fishes. in American Society Ichthyologists Herpetologists Special Publication. Vol. 760 (Allen Press, 1984).Webb, J. F. Larvae in fish development and evolution in The Origin and Evolution of Larval Forms. 109–158 (Academic Press, 1999).Govoni, J. J., Olney, J. E., Markle, D. F. & Curtsinger, W. R. Observations on structure and evaluation of possible functions of the vexillum in larval Carapidae (Ophidiiformes). Bull. Mar. Sci. 34, 60–70 (1984).
    Google Scholar 
    Pekkoeva, S. N. et al. Fatty acid composition of the postlarval daubed shanny (Leptoclinus maculatus) during the polar night. Polar Biol. 43, 657–664 (2020).Article 

    Google Scholar 
    Pekkoeva, S. N. et al. Ecological groups of the Daubed Shanny Leptoclinus maculatus (Fries, 1838), an Arcto-boreal species, regarding growth and early development. Rus. J. Ecol. 49(3), 253–259 (2018).Article 

    Google Scholar 
    Schindelin, J. et al. Fiji: An open-source platform for biological-image analysis. Nat. Methods 9(7), 676–682 (2012).Article 
    CAS 
    PubMed 

    Google Scholar 
    R Core Team. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing. Version 12/2021. (R Foundation for Statistical Computing, 2020.)Kabakoff, R. R in Action: Data Analysis and Graphics with R 588 (DMK Press, 2014).
    Google Scholar 
    Murzina, S. A. et al. Oogenesis and lipids in gonad and liver of daubed shanny (Leptoclinus maculatus) females from Svalbard waters. Fish Physiol. Biochem. 38(5), 1393–1407 (2012).Article 
    CAS 
    PubMed 

    Google Scholar 
    Kondakova, E. A., Efremov, V. I. & Nazarov, V. A. Structure of the yolk syncytial layer in Teleostei and analogous structures in animals of the meroblastic type of development. Biol. Bull. 43(3), 208–215 (2016).Article 

    Google Scholar 
    Webster, M., Witkin, K. L. & Cohen-Fix, O. Sizing up the nucleus: Nuclear shape, size and nuclear-envelope assembly. J. Cell Sci. 122(10), 1477–1486 (2009).Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Jevtić, P., Edens, L. J., Vuković, L. D. & Levy, D. L. Sizing and shaping the nucleus: mechanisms and significance. Curr. Opin. Cell Biol. 28, 16–27 (2014).Article 
    PubMed 

    Google Scholar 
    Kondakova, E. A., Efremov, V. I. & Kozin, V. V. Common and specific features of organization of the yolk syncytial layer of teleostei as exemplified in Gasterosteus aculeatus L. Biol. Bull. 46(1), 26–32 (2019).Article 

    Google Scholar 
    Enders, A. C. Reasons for diversity of placental structure. Placenta 30, 15–18 (2009).Article 

    Google Scholar 
    Carvalho, L. & Heisenberg, C. P. The yolk syncytial layer in early zebrafish development. Trends Cell Biol. 20(10), 586–592 (2010).Article 
    CAS 
    PubMed 

    Google Scholar 
    Jaroszewska, M. & Dabrowski, K. Utilization of yolk: transition from endogenous to exogenous nutrition in fish. in Larval Fish Nutrition. 183–218 (2011).Kondakova, E. A., Efremov, V. I. & Bogdanova, V. A. Structure of the yolk syncytial layer in the larvae of whitefishes: A histological study. Russ. J. Dev. Biol. 48(3), 176–184 (2017).Article 
    CAS 

    Google Scholar 
    Kondakova, E. A. & Bogdanova, V. A. The fate of the yolk syncytial layer during postembryonic development of Stenodus leucichthys nelma. Ann. Zool. Fenn. 58(4–6), 155–160 (2021).
    Google Scholar 
    Chanet, B. & Meunier, F. J. The anatomy of the thyroid gland among “fishes”: phylogenetic implications for the Vertebrata. Cybium 38(2), 89–116 (2014).
    Google Scholar 
    Zenzerov, V.S. Features of the Structure and Functioning of the Thyroid Gland of Fish in the Barents Sea. Doctor of Science Thesis. Vol. 42 (PetrGU, 2007).Chalde, T. & Miranda, L. A. Pituitary–thyroid axis development during the larval–juvenile transition in the pejerrey Odontesthes bonariensis. J. Fish Biol. 91(3), 818–834 (2017).Article 
    CAS 
    PubMed 

    Google Scholar 
    Otero, A. P., Rodrigues, R. V., Sampaio, L. A., Romano, L. A. & Tesser, M. B. Thyroid gland development in Rachycentron canadum during early life stages. An. Acad. Bras. Ciênc. 86(3), 1507–1516 (2014).Article 
    PubMed 

    Google Scholar 
    Nilsson, M. & Fagman, H. Development of the thyroid gland. Development 144(12), 2123–2140 (2017).Article 
    CAS 
    PubMed 

    Google Scholar 
    Eales, J. G. & Brown, S. B. Measurement and regulation of thyroidal status in teleost fish. Rev. Fish Biol. Fish. 3(4), 299–347 (1993).Article 

    Google Scholar 
    Raine, J. C. & Leatherland, J. F. Morphological and functional development of the thyroid tissue in rainbow trout (Oncorhynchus mykiss) embryos. Cell Tissue Res. 301(2), 235–244 (2000).Article 
    CAS 
    PubMed 

    Google Scholar 
    de Jesus, E. G., Inui, Y. & Hirano, T. Cortisol enhances the stimulating action of thyroid hormones on dorsal fin-ray resorption of flounder larvae in vitro. Gen. Comp. Endocrinol. 79(2), 167–173 (1990).Article 
    PubMed 

    Google Scholar 
    Inui, Y. & Miwa, S. Metamorphosis of flatfish (Pleuronectiformes). in Metamorphosis in Fish. 107–153 (Taylor & Francis, 2012)Nemova, N. N., Rendakov, N. L., Pekkoeva, S. N., Nikerova, K. M. & Murzina, S. A. Dynamics of estradiol level during metamorphosis in the Daubed Shanny (Leptoclinus maculatus, Fries, 1838) from Spitsbergen Island. Dokl. Biol. Sci. 482, 188–190 (2018).Article 
    CAS 
    PubMed 

    Google Scholar 
    Icardo, J. M. The teleost heart: A morphological approach in Ontogeny and Phylogeny of the Vertebrate Heart. 35–53 (Springer, 2012).Icardo, J. M. Heart morphology and anatomy. in Fish Physiology. 1–54 (Academic Press, 2017).Hu, N., Yost, H. J. & Clark, E. B. Cardiac morphology and blood pressure in the adult zebrafish. Anatomic. Rec. 264(1), 1–12 (2001).Article 
    CAS 

    Google Scholar 
    Icardo, J. M., Colvee, E., Cerra, M. C. & Tota, B. The bulbus arteriosus of stenothermal and temperate teleosts: A morphological approach. J. Fish Biol. 57, 121–135 (2000).Article 

    Google Scholar 
    Benjamin, M., Norman, D., Santer, R. M. & Scarborough, D. Histological, histochemical and ultrastructural studies on the bulbus arteriosus of the sticklebacks, Gasterosteus aculeatus and Pungitius pungitius (Pisces: Teleostei). J. Zool. 200(3), 325–346 (1983).Article 

    Google Scholar 
    Braun, M. H., Brill, R. W., Gosline, J. M. & Jones, D. R. Form and function of the bulbus arteriosus in yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus) and blue marlin (Makaira nigricans): static properties. J. Exp. Biol. 206(19), 3311–3326 (2003).Article 
    PubMed 

    Google Scholar 
    Icardo, J. M. Conus arteriosus of the teleost heart: Dismissed, but not missed. Anat. Rec. Part A Discov. Mol. Cell. Evolut. Biol. 288(8), 900–908 (2006).Article 

    Google Scholar 
    Tota, B. Vascular and metabolic zonation in the ventricular myocardium of mammals and fishes. Comp. Biochem. Physiol. A Physiol. 76(3), 423–437 (1983).Article 
    CAS 

    Google Scholar 
    Gardinal, M. V. B. et al. Myocardium arrangement and coronary vessel distribution in the ventricle of three neotropical freshwater teleosts. Zool. Sci. 35(4), 360–367 (2018).Article 

    Google Scholar 
    BuzeteGardinal, M. V. et al. Heart structure in the Amazonian teleost Arapaima gigas (Osteoglossiformes, Arapaimidae). J. Anat. 234(3), 327–337 (2019).Article 
    CAS 

    Google Scholar 
    Icardo, J. M. & Colvee, E. The atrioventricular region of the teleost heart. A distinct heart segment. Anatomic. Rec. Adv. Integr. Anat. Evolut. Biol. 294(2), 236–242 (2011).Article 

    Google Scholar 
    Kock, K. H. Antarctic icefishes (Channichthyidae): A unique family of fishes. A review, Part I. Polar Biol. 28, 862–895 (2005).Article 

    Google Scholar 
    Cocca, E. et al. Genomic remnants of alpha-globin genes in the hemoglobinless antarctic icefishes. Proc. Natl. Acad. Sci. 92(6), 1817–1821 (1995).Article 
    ADS 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    di Prisco, G., Cocca, E., Parker, S. K. & Detrich, H. W. III. Tracking the evolutionary loss of hemoglobin expression by the white-blooded Antarctic icefishes. Gene 295(2), 185–191 (2002).Article 
    PubMed 

    Google Scholar 
    Sidell, B. D. & O’Brien, K. M. When bad things happen to good fish: The loss of hemoglobin and myoglobin expression in Antarctic icefishes. J. Exp. Biol. 209(10), 1791–1802 (2006).Article 
    CAS 
    PubMed 

    Google Scholar 
    Kaufman, Z. S. Adaptation of aquatic organisms to existence in high latitudes. Proc. Karelian Sci. Center Russ. Acad. Sci. 1, 3–19 (2015).
    Google Scholar 
    Jakubowski, M. Dimensions of respiratory surfaces of the gills and skin in the Antarctic white-blooded fish, Chaenocephalus aceratus Lönnberg (Chaenichthyidae). Z. Mikrosk.-Anat. Forschung. 96(1), 145–156 (1982).CAS 

    Google Scholar 
    Graham, J. B. Air-breathing fishes: The biology, diversity, and natural history of air-breathing fishes. in Encyclopedia of Fish Physiology. 1861–1874 (Elsevier, 2011).Maniatis, G. M. & Ingram, V. M. Erythropoiesis during amphibian metamorphosis: I. Site of maturation of erythrocytes in Rana catesbeiana. J. Cell Biol. 49(2), 372–379 (1971).Article 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Maruyama, K., Yasumasu, S. & Iuchi, I. Characterization and expression of embryonic and adult globins of the teleost Oryzias latipes (medaka). J. Biochem. 132(4), 581–589 (2002).Article 
    CAS 
    PubMed 

    Google Scholar 
    Brownlie, A. et al. Characterization of embryonic globin genes of the zebrafish. Dev. Biol. 255(1), 48–61 (2003).Article 
    CAS 
    PubMed 

    Google Scholar 
    Feng, J. et al. Channel catfish hemoglobin genes: Identification, phylogenetic and syntenic analysis, and specific induction in response to heat stress. Comp. Biochem. Physiol. D Genom. Proteom. 9, 11–22 (2014).CAS 

    Google Scholar 
    Miwa, S. & Inui, Y. Thyroid hormone stimulates the shift of erythrocyte populations during metamorphosis of the flounder. J. Exp. Zool. 259(2), 222–228 (1991).Article 
    CAS 

    Google Scholar 
    Hansen, A., Reutter, K. & Zeiske, E. Taste bud development in the zebrafish, Danio rerio. Dev. Dyn. 223(4), 483–496 (2002).Article 
    PubMed 

    Google Scholar 
    Wang, C. A. et al. The development of pharyngeal taste buds in Hucho taimen (Pallas, 1773) larvae. Iran. J. Fish. Sci. 15(1), 426–435 (2016).ADS 

    Google Scholar 
    Fraser, G. J., Graham, A. & Smith, M. M. Conserved deployment of genes during odontogenesis across osteichthyans. Proc. R. Soc. Lond. Ser. B Biol. Sci. 271(1555), 2311–2317 (2004).Article 

    Google Scholar 
    Zambonino-Infante, J. L. et al. Ontogeny and physiology of the digestive system of marine fish larvae. in Feeding and Digestive Functions of Fishes. 281–348 (Science Publishers, 2008)Rønnestad, I. et al. Feeding behaviour and digestive physiology in larval fish: Current knowledge, and gaps and bottlenecks in research. Rev. Aquac. 5, S59–S98 (2013).Article 

    Google Scholar 
    Wallace, R. A. & Selman, K. Physiological aspects of oogenesis in two species of stickelebacks, Gasterosteus aculeatus (L.) and Apeltes quadracus (Mitchill). J. Fish Biol. 14, 551–564 (1979).Article 

    Google Scholar  More

  • in

    Astrobiologists train an AI to find life on Mars

    Artificial intelligence (AI) and machine learning could revolutionize the search for life on other planets. But before these tools can tackle distant locales such as Mars, they need to be tested here on Earth.A team of researchers have successfully trained an AI to map biosignatures — any feature which provides evidence of past or present life — in a three-square-kilometre area of Chile’s Atacama Desert. The AI substantially reduced the area the team needed to search and boosted the likelihood of finding living organisms in one of the driest places on the planet. The results were reported on 6 March in Nature Astronomy1.Kimberley Warren-Rhodes, a senior research scientist at the SETI Institute in Mountain View, California, and lead author on the paper, has been chasing biosignatures since the early 2000s, when she realized how few tools existed to study the biology of other planets. She wanted to combine her background in statistical ecology with emerging technologies such as AI to help mission scientists, “who are under a lot of pressure to find biosignatures” but tightly constrained in how they do so. Rovers that are controlled remotely from Earth, for example, can travel only limited distances and collect relatively few specimens, placing a premium on sampling locations that are the most likely to yield life. Mission scientists base these predictions in part on Mars analogues on Earth, where scientists scour extreme habitats to determine how and where living organisms thrive.Searching for lifeBeginning in 2016, Warren-Rhodes’ group travelled to the high, parched plateau of the Atacama Desert — a proposed Mars analogue at an elevation of around 3,500 metres in the Chilean Andes — to search for rock-dwelling, photosynthetic organisms called endoliths. To fully characterize the environment, the researchers collected everything from drone footage to geochemical analyses to DNA sequences. Together, this data set mimics the types of information researchers are collecting on Mars with orbital satellites, drones and rovers.Warren-Rhodes’ team fed its data into an AI-based convolutional neural network (CNN) and a machine-learning algorithm that in turn predicted where life was most likely to be found in the Atacama.

    Aerial view (left) and ground view from a rover of a biosignature probability map of the same area.Credit: M. Phillips, K. A. Warren-Rhodes & F. Kalaitzis

    By targeting their sample collection on the basis of AI feedback, the researchers were able to reduce their search area by up to 97% and increase their likelihood of finding life by up to 88%. “At the end, you could plop us down, and instead of wandering around for a long time, it would take us a minute to find life,” Warren-Rhodes says. Specifically, the team found that endoliths in the Atacama were most often found in a mineral called alabaster — which is porous and retains water — and tended to aggregate in transitional areas between various microhabitats, such as where sand and alabaster crystals abut one another.“I’m very impressed and very happy to see this suite of work,” says Kennda Lynch, an astrobiologist at the Lunar and Planetary Institute in Houston, Texas, who studies biosignatures. “It’s really cool that they can show some success with an AI to help predict where to go and look.”Graham Lau, an astrobiologist at the Blue Marble Space Institute of Science who is based in Boulder, Colorado, worked on another Mars analogue in the Canadian Arctic as a graduate student, to study how biology influences the formation of rare minerals that can serve as biosignatures on other planets. “Ever since I first read Frank Herbert’s Dune as a young child, I was struck by this idea of applying ecology to planets,” he says. But up until the last decade or so, the tools and data weren’t available to address such questions with scientific rigour. “The place where we have almost unlimited data possibilities is through these orbital observations and drone imaging,” he says, “and I do see this paper as being one of many pieces along the pathway to doing these larger analyses.”Deceptively simpleThe new method will need to be verified across multiple ecosystems, Lau and Lynch say, including those with more complex geology and greater biodiversity. The Atacama, Lau notes, is relatively simple in terms of the habitats and the types of life that are likely to be found there. And on Mars, the high level of ultraviolet radiation striking the planet’s surface means that scientists might need to detect clues that hint at life below ground.

    NASA’s Perseverance rover collected its first rock sample from an area in Mars’ Jezero Crater.Credit: NASA/JPL-Caltech/ASU/MSSS

    Ultimately, Warren-Rhodes says she would like to see a comprehensive database of different Mars analogues that could feed valuable information to mission scientists planning their next sampling run. Her team’s advance, she adds, might appear “deceptively simple” to anyone who grew up watching Star Trek explorers scanning alien worlds with a tricorder. But, it represents an important advance in extraterrestrial research, in which biology has often lagged behind chemistry and geology. Imagine, for instance, virtual-reality headsets that feed mission scientists real-time data as they scan a surface, using a rover’s ‘eyes’ to direct their activities. “To have our team make one of these first steps towards reliably detecting biosignatures using AI is exciting,” she says. “It’s really a momentous time.” More

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    Extinction drives a discontinuous temporal pattern of species–area relationships in a microbial microcosm system

    Preparation of the pao cai soupFirst, 35 kg of white radish (Raphanus sativus), 35 kg of cabbage (Brassica oleracea), 2 kg of chili pepper (Capsicum frutescens), 1 kg of ginger (Zingiber officinale), 1 kg of peppercorns (Zanthoxylum bungeanum), 2.5 kg of rock sugar, and 210 kg of cold boiled water (containing 6% salt) were divided into six ceramic jars. After 7 days of natural fermentation at room temperature, the pao cai was filtered out with sterile gauze to obtain 200 kg of pao cai soup. To ensure an even distribution of microorganisms in the soup, the soup was mixed well and then left to rest for 12 h, the supernatant was taken, and the soup was left to rest for 12 h again.The plants used in this study were cultivated vegetables which purchased from the vegetable market at the study site. All local, national or international guidelines and legislation were adhered to in the production of this study.Establishment of the microcosm systemSeventy-eight for each size of 10 ml, 20 ml, 50 ml, 100 ml, 250 ml, 500 ml, and 1000 ml sterile glass culture flasks were filled with pao cai soup, the bottle mouth was sealed with sterile sealing film, and the bottle was capped without leaving any air (Fig. 1). Each flask became a microcosm and was cultured in a 25 °C incubator.Figure 1Schematic diagram of the establishment of the microcosmic system.Full size imageSample collectionBefore the microcosm system was established, a sample of well-mixed pao cai soup was taken as a reference to establish background biodiversity. The microbial community dynamics should change the fastest at the beginning of the microcosm system establishment and gradually become slower over time. Considering the workload and cost, this study collected samples daily for 1–10 day after the establishment of the microcosm and then collected every 2 days for 10–30 day and every 5 days for 30–60 day. Three different microcosms of the same volume were established. Monitoring was carried out for 60 days, and a total of 546 samples of 7 volumetric gradients were obtained at 26 time points. At the time of sampling, the pao cai soup in the microcosm was mixed, and 50 mL of sample (10 mL of sample was collected for microcosm systems with a volume of less than 50 mL) was collected. The sample was centrifuged at 8000 rpm for 10 min, the supernatant was collected for pH determination, and the pellet was stored in a − 80 °C freezer.Microbial analysesMicrobial DNA was extracted from pao cai samples using the E.Z.N.A.® Soil DNA Kit (Omega Biotek, Norcross, GA, U.S.) according to the manufacturer’s protocols. For bacteria, we targeted the V3-V4 region of the 16S ribosomal RNA (rRNA) gene, using the 338F (5′-ACTCCTACGGGAGGCAGCAG-3′) and 806R (5′-GGACTACHVGGGTWTCTAAT-3′) primer pairs. For fungi, we targeted the ITS1-1F region of the nuclear ribosomal internal transcribed spacer region (ITS rDNA) gene, using ITS1-1F-F (5′-CTTGGTCATTTAGAGGAAGTAA-3′) and ITS-1F-R (5′-GCTGCGTTCTTCATCGATGC-3′). PCRs were performed in triplicate in a 20 μL mixture containing 4 μL of 5 × FastPfu Buffer, 2 μL of 2.5 mM dNTPs, 0.8 μL of each primer (5 μM), 0.4 μL of FastPfu Polymerase and 10 ng of template DNA. The PCR program for the 16S rRNA gene was as follows: 3 min of denaturation at 95 °C; 27 cycles of 30 s at 95 °C, 30 s of annealing at 55 °C, and 45 s of elongation at 72 °C; and a final extension at 72 °C for 10 min. For the ITS1-1F region, the PCR program was as follows: samples were initially denatured at 98 °C for 1 min, followed by 30 cycles of denaturation at 98 °C for 10 s, primer annealing at 50 °C for 30 s, and extension at 72 °C for 30 s. A final extension step of 5 min at 72 °C was added to ensure complete amplification of the target region. The resulting PCR products were extracted from a 2% agarose gel, further purified using the AxyPrep DNA Gel Extraction Kit (Axygen Biosciences, Union City, CA, USA) and quantified using QuantiFluor™-ST (Promega, Madison, WI, USA).Purified amplicons were pooled in equimolar amounts and paired-end sequenced (2 × 300) on an Illumina NovaSeq platform (Illumina, San Diego, CA, USA) according to standard protocols. The analysis was conducted by following the “Atacama soil microbiome tutorial” of QIIME2 docs along with customized program scripts (https://docs.qiime2.org/2019.1/). Briefly, raw data FASTQ files were imported in the QIIME2 system using the qiime tools import program. Demultiplexed sequences from each sample were quality filtered, trimmed, denoised, and merged, and then the chimeric sequences were identified and removed using the QIIME2 DADA2 plugin to obtain the feature table of amplicon sequence variants (ASVs)24. Compared with traditional OTU that clusters at 97% similarity, ASV has higher accuracy, equivalent to 99% similarity clustering. The QIIME2 feature-classifier plugin was then used to align ASV sequences to the pretrained GREENGENES 13_8 99% database (trimmed to the V3-V4 region bound by the 338F/806R primer pair for bacteria) and UNITE database (for fungi) to generate the taxonomy table25. Any contaminating mitochondrial and chloroplast sequences were filtered using the QIIME2 feature-table plugin. Based on the sequence number of the lowest sample, perform the resampling to make the sequence number equal for each sample. Due to the random nature of sequencing, ASVs specific to each sample in this study were present. To reduce the uncertainty introduced by the sequencing process, we filtered out rare ASVs with less than 0.001% of the total sequence volume.Data analysisIn this study, the data of fungi and bacteria were integrated and analyzed, and all microbial diversity appearing in the text represent the sum of all fungi and bacteria. Species richness is equal to the number of taxa, which is equal to the total number of all bacterial and fungal ASVs. The vegan package in R 4.2.1 was used to calculate the species richness of each sample based on the ASV feature table26. Using flask volume instead of area, SAR fitting was performed using a semi-logarithmic model, and its significance was tested. The semi-logarithmic model is the function S = c + b*logA, where S is species richness, A is area (in this case, volume is used instead), and b and c are fit parameters27.The microcosmic system in this study is hermetically sealed, and all microorganisms originate from a single portion of well-mixed paocai soup (ie species pool). The speciation process in the 60-day experimental system should be negligible due to the short experimental period. The extinction rate of a microcosm system is equal to the number of ASVs lost in the microcosm system compared to the species pool divided by the total number of ASVs in the species pool. The extinction rate is the number of extinct ASVs in each system compared to the species pool. Pearson correlation analysis was performed with volume as the independent variable and extinction rate as the dependent variable to determine the correlation between volume and extinction rate at each time point. When microorganisms of a microcosmic system disappear entirely or cannot be detected, the microcosm is recorded as an annihilated microcosm. The annihilation rate at a time point is equal to the number of microcosms annihilated at that time, divided by the total number of microcosms. The difference between the extinction rate and annihilation rate defined in this paper is that the extinction rate is for ASVs within each sample, and the annihilation rate is for microcosmic system at each sampling time point. The two indicators jointly characterize the local extinction of microorganisms from different perspectives. Non-linear regression with a bell-shaped form was performed with time as an independent variable and pH and annihilation rate as dependent variables, and regression lines were plotted based on R 4.2.1.According to the taxonomy table, bacterial ASVs were divided into acid-producing and non-acid-producing categories, and their extinction rates were calculated separately. The agricola, ggplot2, vegan and ggpubr packages were used to draw alpha diversity box plots and perform the Wilcoxon rank sum test for differences between groups26,28,29,30. Non-metric multidimensional scaling (NMDS) analysis was performed with the vegan package based on Bray–Curtis dissimilarity. In addition, the potential Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologue (KO) functional profiles of microbial communities were predicted with PICRUSt31. Resistance-related genes were screened using the gene function predictions. The relationship between the relative abundance of resistance-related genes and the volume of the microcosm was analysed by Pearson correlation, and a forest map was plotted to present the results. More

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    Climate, caribou and human needs linked by analysis of Indigenous and scientific knowledge

    Forbes, B. C. & Kumpula, T. The ecological role and geography of reindeer (Rangifer tarandus) in Northern Eurasia. Geogr. Compass 3, 1356–1380 (2009).Article 

    Google Scholar 
    Post, E. & Pedersen, C. Opposing plant community responses to warming with and without herbivores. Proc. Natl Acad. Sci. USA 105, 12353–12358 (2008).Article 
    CAS 

    Google Scholar 
    Berkes, F., Colding, J. & Folke, C. Navigating Social-Ecological Systems: Building Resilience for Complexity and Change (Cambridge Univ. Press, 2003).Tremblay, R., Landry-Cuerrier, M. & Humphries, M. M. Culture and the social-ecology of local food use by Indigenous communities in northern North America. Ecol. Soc. 25, 8 (2020).Kenny, T.-A., Fillion, M., Simpkin, S., Wesche, S. & Chan, L. Caribou (Rangifer tarandus) and Inuit nutrition security in Canada. Ecohealth 15, 590–607 (2018).Article 

    Google Scholar 
    Benson, K. Gwich’in Knowledge of Porcupine Caribou: State of Current Knowledge and Gaps Assessment (Department of Cultural Heritage, Gwich’in Tribal Council, 2019); https://thelastgreatherd.com/wp-content/uploads/2020/06/GTC-current-knowledge-and-gaps-assessment.pdfParlee, B. & Caine, K. When the Caribou Do Not Come: Indigenous Knowledge and Adaptive Management in the Western Arctic (UBC Press, 2018).Herds: Status of Herds (CircumArctic Rangifer Monitoring and Assessment Network, accessed 3 November 2021); https://carma.caff.is/herdsFesta-Bianchet, M., Ray, J. C., Boutin, S., Côté, S. D. & Gunn, A. Conservation of caribou (Rangifer tarandus) in Canada: an uncertain future. Can. J. Zool. 89, 419–434 (2011).Article 

    Google Scholar 
    Gunn, A. Voles, lemmings and caribou: population cycles revisited? Rangifer 23, 105–111 (2003).Article 

    Google Scholar 
    Ferguson, M. A. D., Williamson, R. G. & Messier, F. Inuit knowledge of long-term changes in a population of Arctic tundra caribou. Arctic 51, 201–219 (1998).Article 

    Google Scholar 
    Beaulieu, D. Dene traditional knowledge about caribou cycles in the Northwest Territories. Rangifer 32, 59–67 (2012).Article 

    Google Scholar 
    Mallory, C. D. & Boyce, M. S. Observed and predicted effects of climate change on Arctic caribou and reindeer. Environ. Rev. 26, 13–25 (2018).Article 

    Google Scholar 
    Uboni, A. et al. Long-term trends and role of climate in the population dynamics of Eurasian reindeer. PLoS ONE 11, e0158359 (2016).Article 

    Google Scholar 
    Chapin, F. S. III et al. Directional changes in ecological communities and social-ecological systems: a framework for prediction based on Alaskan examples. Am. Nat. 168, S36–S49 (2006).Article 

    Google Scholar 
    Tengö, M. et al. Weaving knowledge systems in IPBES, CBD and beyond – lessons learned for sustainability. Curr. Opin. Environ. Sustain. 26, 17–25 (2017).Article 

    Google Scholar 
    Berkes, F. Sacred Ecology 4th edn (Routledge, 2018).Stuart Chapin, F. III et al. Earth stewardship: science for action to sustain the human-earth system. Ecosphere 2, 89 (2011).Parlee, B. L., Sandlos, J. & Natcher, D. C. Undermining subsistence: barren-ground caribou in a ‘tragedy of open access’. Sci. Adv. 4, e1701611 (2018).Article 

    Google Scholar 
    Johnson, J. T. et al. Weaving Indigenous and sustainability sciences to diversify our methods. Sustain. Sci. 11, 1–11 (2016).Article 
    CAS 

    Google Scholar 
    Reid, A. J. et al. ‘Two-eyed seeing’: an Indigenous framework to transform fisheries research and management. Fish Fish. 22, 243–261 (2021).Article 

    Google Scholar 
    Tengö, M., Brondizio, E. S., Elmqvist, T., Malmer, P. & Spierenburg, M. Connecting diverse knowledge systems for enhanced ecosystem governance: the multiple evidence base approach. AMBIO 43, 579–591 (2014).Article 

    Google Scholar 
    Aminpour, P. et al. The diversity bonus in pooling local knowledge about complex problems. Proc. Natl Acad. Sci. USA 118, e2016887118 (2021).Article 
    CAS 

    Google Scholar 
    Henri, D. A. et al. Weaving Indigenous knowledge systems and Western sciences in terrestrial research, monitoring and management in Canada: a protocol for a systematic map. Ecol. Solut. Evid. 2, e12057 (2021).Article 

    Google Scholar 
    Ljubicic, G. J., Mearns, R., Okpakok, S. & Robertson, S. Nunami iliharniq (learning from the land): reflecting on relational accountability in land-based learning and cross-cultural research in Uqšuqtuuq (Gjoa Haven, Nunavut). Arct. Sci. 8, 252–291 (2022).Article 

    Google Scholar 
    Stern, E. R. & Humphries, M. M. Interweaving local, expert, and Indigenous knowledge into quantitative wildlife analyses: a systematic review. Biol. Conserv. 266, 109444 (2022).Article 

    Google Scholar 
    Bourgeon, L., Burke, A. & Higham, T. Earliest human presence in North America dated to the last glacial maximum: new radiocarbon dates from Bluefish Caves, Canada. PLoS ONE 12, e0169486 (2017).Article 

    Google Scholar 
    Kuhnlein, H. V., McDonald, M., Spigelski, D., Vittrekwa, E. & Erasmus, B. in Indigenous Peoples’ Food Systems: the Many Dimensions of Culture, Diversity and Environment for Nutrition and Health (eds Kuhnlein, H. V. et al.) Ch. 3 (FAO, Centre for Indigenous Peoples’ Nutrition and Environment, 2009).Porcupine Caribou Technical Committee. Porcupine Caribou Annual Summary Report 2018–2019 (Porcupine Caribou Management Board, Whitehorse, Yukon, 2019); https://pcmb.ca/wp-content/uploads/2020/06/PCH_annual_summ_report_Nov29_2019_FINAL.pdfIPCC. Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) (Cambridge Univ. Press, 2013).Zhang, X. et al. in Canada’s Changing Climate Report (eds Bush, E. & Lemmen, D. S.) Ch. 4 (Government of Canada, 2019).Griffith, B. et al. in Arctic Refuge Coastal Plain Terrestrial Wildlife Research Summaries Biological Science Report USGS/BRD BSR-2002-0001 (eds Douglas, D. C. et al.) 8–37 (US Geological Survey, 2002).Russell, D. & Gunn, A. Vulnerability Analysis of the Porcupine Caribou Herd to Potential Development of the 1002 lands in the Arctic National Wildlife Refuge, Alaska (Environment Yukon, Canadian Wildlife Service and GNWT Department of Environment and Natural Resources, 2019); https://pcmb.ca/wp-content/uploads/2021/10/Russell-and-Gunn-PCH-vulnerability-analysis-2019.pdfKruse, J. A. et al. Modeling sustainability of Arctic communities: an interdisciplinary collaboration of researchers and local knowledge holders. Ecosystems 7, 815–828 (2004).Berman, M., Nicolson, C., Fofinas, G., Tetlichi, J. & Martin, S. Adaptation and sustainability in a small Arctic community: results of an agent-based simulation model. Arctic 57, 401–414 (2004).Article 

    Google Scholar 
    Kofinas, G., Aklavik, Arctic Village, Old Crow & Fort McPherson. in The Earth is Faster Now: Indigenous Observations of Arctic Environmental Change (eds Krupnik, I. & Jolly, D.) 55–91 (Arctic Research Consortium of the United States, 2002).Eamer, J. in Bridging Scales and Knowledge Systems: Concepts and Applications in Ecosystem Assessment (eds Reid, W. V. et al.) 185–206 (Island Press, 2006).Shipley, B. Cause and Correlation in Biology: a User’s Guide to Path Analysis, Structural Equations and Causal Inference with R 2nd edn (Cambridge Univ. Press, 2016).Parlee, B. & Furgal, C. Well-being and environmental change in the Arctic: a synthesis of selected research from Canada’s International Polar Year program. Clim. Change 115, 13–34 (2012).Article 

    Google Scholar 
    Kofinas, G. P. The Costs of Power Sharing: Community Involvment in Canadian Porcuine Caribou Co-management. PhD thesis, Univ. of British Columbia (1998).Ford, J. D. et al. Including indigenous knowledge and experience in IPCC assessment reports. Nat. Clim. Change 6, 349–353 (2016).Article 

    Google Scholar 
    Brinkman, T. J. et al. Arctic communities perceive climate impacts on access as a critical challenge to availability of subsistence resources. Clim. Change 139, 413–427 (2016).Article 

    Google Scholar 
    McNeil, P., Russell, D. E., Griffith, B., Gunn, A. & Kofinas, G. Where the wild things are: seasonal variation in caribou distribution in relation to climate change. Rangifer 25, 51–63 (2005).Berman, M. & Kofinas, G. Hunting for models: grounded and rational choice approaches to analyzing climate effects on subsistence hunting in an Arctic community. Ecol. Econ. 49, 31–46 (2004).Article 

    Google Scholar 
    Hansen, B. B. et al. Climate events synchronize the dynamics of a resident vertebrate community in the High Arctic. Science 339, 313–315 (2013).Article 
    CAS 

    Google Scholar 
    Collings, P., Marten, M. G., Pearce, T. & Young, A. G. Country food sharing networks, household structure, and implications for understanding food insecurity in Arctic Canada. Ecol. Food Nutr. 55, 30–49 (2016).Article 

    Google Scholar 
    BurnSilver, S., Magdanz, J., Stotts, R., Berman, M. & Kofinas, G. Are mixed economies persistent or transitional? Evidence using social networks from Arctic Alaska. Am. Anthropol. 118, 121–129 (2016).Article 

    Google Scholar 
    Baggio, J. A. et al. Multiplex social ecological network analysis reveals how social changes affect community robustness more than resource depletion. Proc. Natl Acad. Sci. USA 113, 13708–13713 (2016).Article 
    CAS 

    Google Scholar 
    Gagnon, C. A. et al. Merging Indigenous and scientific knowledge links climate with the growth of a large migratory caribou population. J. Appl. Ecol. 57, 1644–1655 (2020).Article 

    Google Scholar 
    Houde, N. The six faces of traditional ecological knowledge: challenges and opportunities for Canadian co-management arrangements. Ecol. Soc. 12, 34 (2007).Article 

    Google Scholar 
    Fancy, S. G., Pank, L. F., Whitten, K. R. & Regelin, W. L. Seasonal movements of caribou in Arctic Alaska as determined by satellite. Can. J. Zool. 67, 644–650 (1989).Article 

    Google Scholar 
    Porcupine Caribou Technical Committee. Porcupine Caribou Annual Summary Report 2014 (Porcupine Caribou Management Board, Whitehorse, Yukon, 2014); https://pcmb.ca/wp-content/uploads/2021/07/PCH_annual_summ_report_2014_2015_NOV19_FINAL.pdfEastland, W. G. Influence of Weather on Movements and Migrations of Caribou. PhD thesis, Univ. of Alaska (1991).Tyler, N. J. C. Climate, snow, ice, crashes, and declines in populations of reindeer and caribou (Rangifer tarandus L.). Ecol. Monogr. 80, 197–219 (2010).Article 

    Google Scholar 
    Hansen, B. B., Aanes, R. & Saether, B. E. Feeding-crater selection by high-arctic reindeer facing ice-blocked pastures. Can. J. Zool. 88, 170–177 (2010).Article 

    Google Scholar 
    Solberg, E. J. et al. Effects of density-dependence and climate on the dynamics of a Svalbard reindeer population. Ecography 24, 441–451 (2001).Article 

    Google Scholar 
    Hansen, B. B., Aanes, R., Herfindal, I., Kohler, J. & Sæther, B.-E. Climate, icing, and wild arctic reindeer: past relationships and future prospects. Ecology 92, 1917–1923 (2011).Article 

    Google Scholar 
    Langlois, A. et al. Detection of rain-on-snow (ROS) events and ice layer formation using passive microwave radiometry: a context for Peary caribou habitat in the Canadian Arctic. Remote Sens. Environ. 189, 84–95 (2017).Article 

    Google Scholar 
    Russell, D. E., Gunn, A. & White, R. G. CircumArctic collaboration to monitor caribou and wild reindeer. Arctic 68, 6–10 (2015).Article 

    Google Scholar 
    Russell, D. E. et al. CARMA’s MERRA-based caribou range climate database. Rangifer 33, 145–152 (2013).Article 

    Google Scholar 
    ArcGIS version 10 (Environmental Systems Resource Institute, 2010).Cai, J., Russell, D. & Whitfield, P. Methodology and Algorithms for Constructing CARMA Bio-climate Tables (Simon Fraser Univ., 2011).Stenseth, N. C. & Mysterud, A. Weather packages: finding the right scale and composition of climate in ecology. J. Anim. Ecol. 74, 1195–1198 (2005).Article 

    Google Scholar 
    Pebesma, E. J. & Bivand, R. S. Classes and methods for spatial data in R. R News 5, 9–13 (2005).Bivand, R. S., Pebesma, E. J. & Gomez-Rubio, V. Applied Spatial Data Analysis with R 2nd edn (Springer, 2013).Bivand, R. S., Keitt, T. & Rowlingson, B. Rgdal: Bindings for the Geospatial Data Abstraction Library. R package version 0.8-16 (R Foundation for Statistical Computing, 2014); https://cran.r-project.org/web/packages/rgdal/index.htmlBivand, R. S. & Rundel, C. Rgeos: Interface to Geometry Engine – Open Source (GEOS). R package version 0.3-4 (R Foundation for Statistical Computing, 2014); https://cran.r-project.org/web/packages/rgeos/index.htmlLefcheck, J. S. piecewise SEM: piecewise structural equation modelling in R for ecology, evolution and systematics. Methods Ecol. Evol. 7, 573–579 (2016).Article 

    Google Scholar 
    Shipley, B. Confirmatory path analysis in a generalized multilevel context. Ecology 90, 363–368 (2009).Article 

    Google Scholar 
    Thomas, D. W. et al. Common paths link food abundance and ectoparasite loads to physiological performance and recruitment in nestling blue tits. Funct. Ecol. 21, 947–955 (2007).Article 

    Google Scholar 
    Shipley, B. The AIC model selection method applied to path analytic models compared using a d-separation test. Ecology 94, 560–564 (2013).Article 

    Google Scholar 
    Burnham, K. P. & Anderson, D. R. Model Selection and Multimodel Inference: a Practical Information-Theoretic Approach (Springer, 2002).Schielzeth, H. Simple means to improve the interpretability of regression coefficients. Methods Ecol. Evol. 593, 103–113 (2010).Article 

    Google Scholar  More

  • in

    Pathways to sustainable plastics

    OECD Global Plastics Outlook. Economic drivers, Environmental Impacts and Policy Options (OECD, 2022).Jambeck, J. R. et al. Science 347, 768–771 (2015).Article 
    CAS 

    Google Scholar 
    Bachmann, M. et al. Nat. Sustain. https://doi.org/10.1038/s41893-022-01054-9 (2023).Article 

    Google Scholar 
    Rockström, J. et al. Nature 461, 472–475 (2009).Article 

    Google Scholar 
    Bjørn, A. et al. Environ. Res. Lett. 15, 083001 (2020).Article 

    Google Scholar 
    van den Berg, N. J. et al. Clim. Change 162, 1805–1822 (2020).Article 

    Google Scholar 
    Bjørn, A. et al. Curr. Clim. Change Rep. 8, 53–69 (2022).Article 

    Google Scholar 
    Ryberg, M. W. et al. Ecol. Indic. 88, 250–262 (2018).Article 

    Google Scholar 
    Bunsen, J. et al. Ecol. Indic. 121, 107022 (2021).Article 

    Google Scholar 
    Persson, L. et al. Environ. Sci. Technol. 56, 1510–1521 (2022).Article 
    CAS 

    Google Scholar 
    Ryberg, M. W. et al. J. Clean. Prod. 276, 123287 (2020).Article 

    Google Scholar  More