More stories

  • in

    Smartphone app reveals that lynx avoid human recreationists on local scale, but not home range scale

    United Nations. (Department of Economic and Social Affairs, Population Division, 2019).Tucker, M. A. et al. Moving in the Anthropocene: Global reductions in terrestrial mammalian movements. Science 359, 466–469. https://doi.org/10.1126/science.aam9712 (2018).ADS 
    CAS 
    Article 
    PubMed 

    Google Scholar 
    Tablado, Z. & Jenni, L. Determinants of uncertainty in wildlife responses to human disturbance. Biol. Rev. 92, 216–233. https://doi.org/10.1111/brv.12224 (2017).Article 
    PubMed 

    Google Scholar 
    IUCN. IUCN Programme 2017–2020. (2016).IUCN. The IUCN Red List of Threatened Species. Version 2021–3. (2021).Balmford, A. et al. Walk on the wild side: estimating the global magnitude of visits to protected areas. PLoS Biol. 13, 6. https://doi.org/10.1371/journal.pbio.1002074 (2015).CAS 
    Article 

    Google Scholar 
    Balmford, A. et al. A global perspective on trends in nature-based tourism. PLoS Biol. 7, 6. https://doi.org/10.1371/journal.pbio.1000144 (2009).CAS 
    Article 

    Google Scholar 
    Seto, K. C., Guneralp, B. & Hutyra, L. R. Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools. Proc. Natl. Acad. Sci. U. S. A. 109, 16083–16088. https://doi.org/10.1073/pnas.1211658109 (2012).ADS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    Chen, G. Z. et al. Global projections of future urban land expansion under shared socioeconomic pathways. Nat. Commun. 11, 12. https://doi.org/10.1038/s41467-020-14386-x (2020).ADS 
    CAS 
    Article 

    Google Scholar 
    Larson, C. L., Reed, S. E., Merenlender, A. M. & Crooks, K. R. Effects of recreation on animals revealed as widespread through a global systematic review. PLoS ONE 11, 21. https://doi.org/10.1371/journal.pone.0167259 (2016).CAS 
    Article 

    Google Scholar 
    Frid, A. & Dill, L. Human-caused disturbance stimuli as a form of predation risk. Conserv. Ecol. 6, 16 (2002).
    Google Scholar 
    Moen, G. K., Stoen, O. G., Sahlen, V. & Swenson, J. E. Behaviour of solitary adult scandinavian brown bears (Ursus arctos) when approached by humans on foot. PLoS ONE 7, 7. https://doi.org/10.1371/journal.pone.0031699 (2012).CAS 
    Article 

    Google Scholar 
    Le Grand, L. et al. Behavioral and physiological responses of scandinavian brown bears (ursus arctos) to dog hunts and human encounters. Front. Ecol. Evol. 7, 9. https://doi.org/10.3389/fevo.2019.00134 (2019).Article 

    Google Scholar 
    Johnson, D. H. The comparison of usage and availability measurements for evaluating resource preference. Ecol. (Washington D C) 61, 65–71. https://doi.org/10.2307/1937156 (1980).Article 

    Google Scholar 
    Zimmermann, B., Nelson, L., Wabakken, P., Sand, H. & Liberg, O. Behavioral responses of wolves to roads: scale-dependent ambivalence. Behav. Ecol. 25, 1353–1364. https://doi.org/10.1093/beheco/aru134 (2014).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    Heinemeyer, K. et al. Wolverines in winter: indirect habitat loss and functional responses to backcountry recreation. Ecosphere https://doi.org/10.1002/ecs2.2611 (2019).Article 

    Google Scholar 
    Ladle, A. et al. Grizzly bear response to spatio-temporal variability in human recreational activity. J. Appl. Ecol. 56, 375–386. https://doi.org/10.1111/1365-2664.13277 (2019).Article 

    Google Scholar 
    Coppes, J., Burghardt, F., Hagen, R., Suchant, R. & Braunisch, V. Human recreation affects spatio-temporal habitat use patterns in red deer (Cervus elaphus). PLoS ONE 12, 19. https://doi.org/10.1371/journal.pone.0175134 (2017).CAS 
    Article 

    Google Scholar 
    Kautz, T. M. et al. Large carnivore response to human road use suggests a landscape of coexistence. Global Ecol. Conserv. 30, e01772 (2021).Article 

    Google Scholar 
    Chapron, G. et al. Recovery of large carnivores in Europe’s modern human-dominated landscapes. Science 346, 1517–1519. https://doi.org/10.1126/science.1257553 (2014).ADS 
    CAS 
    Article 
    PubMed 

    Google Scholar 
    Ordiz, A., Bischof, R. & Swenson, J. E. Saving large carnivores, but losing the apex predator?. Biol. Conserv. 168, 128–133. https://doi.org/10.1016/j.biocon.2013.09.024 (2013).Article 

    Google Scholar 
    Estes, J. A. et al. Trophic downgrading of planet earth. Science 333, 301–306. https://doi.org/10.1126/science.1205106 (2011).ADS 
    CAS 
    Article 
    PubMed 

    Google Scholar 
    Ordiz, A. et al. Habituation, sensitization, or consistent behavioral responses? Brown bear responses after repeated approaches by humans on foot. Biol. Conserv. 232, 228–237. https://doi.org/10.1016/j.biocon.2019.01.016 (2019).Article 

    Google Scholar 
    Smith, T. S., Oyster, J., Partridge, S. D., Martin, I. E. & Sisson, A. Assessing American black bear response to human activity at Kenai Fjords National Park, Alaska. Ursus 23, 179–191. https://doi.org/10.2192/ursus-d-11-00020.1 (2012).Article 

    Google Scholar 
    Wam, H. K., Eldegard, K. & Hjeljord, O. Minor habituation to repeated experimental approaches in Scandinavian wolves. Eur. J. Wildl. Res. 60, 839–842. https://doi.org/10.1007/s10344-014-0841-0 (2014).Article 

    Google Scholar 
    Sweanor, L. L., Logan, K. A. & Hornocker, M. G. Puma responses to close approaches by researchers. Wildl. Soc. Bull. 33, 905–913. https://doi.org/10.2193/0091-7648(2005)33[905:Prtcab]2.0.Co;2 (2005).Article 

    Google Scholar 
    Coppes, J., Ehrlacher, J., Thiel, D., Suchant, R. & Braunisch, V. Outdoor recreation causes effective habitat reduction in capercaillie Tetrao urogallus: a major threat for geographically restricted populations. J. Avian Biol. 48, 1583–1594. https://doi.org/10.1111/jav.01239 (2017).Article 

    Google Scholar 
    Coppes, J. et al. Habitat suitability modulates the response of wildlife to human recreation. Biol. Conserv. 227, 56–64. https://doi.org/10.1016/j.biocon.2018.08.018 (2018).Article 

    Google Scholar 
    Gundersen, V., Vistad, O. I., Panzacchi, M., Strand, O. & van Moorter, B. Large-scale segregation of tourists and wild reindeer in three Norwegian national parks: Management implications. Tourism Manage. 75, 22–33. https://doi.org/10.1016/j.tourman.2019.04.017 (2019).Article 

    Google Scholar 
    Filla, M. et al. Habitat selection by Eurasian lynx (Lynx lynx) is primarily driven by avoidance of human activity during day and prey availability during night. Ecol. Evol. 7, 6367–6381. https://doi.org/10.1002/ece3.3204 (2017).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    Andersen, O., Gundersen, V., Wold, L. C. & Stange, E. Monitoring visitors to natural areas in wintertime: issues in counter accuracy. J. Sustain. Tour. 22, 550–560. https://doi.org/10.1080/09669582.2013.839693 (2014).Article 

    Google Scholar 
    Marion, S. et al. A systematic review of methods for studying the impacts of outdoor recreation on terrestrial wildlife. Glob. Ecol. Conserv. 22, e00917 (2020).Article 

    Google Scholar 
    Corradini, A. et al. Effects of cumulated outdoor activity on wildlife habitat use. Biol. Conserv. 253, 8. https://doi.org/10.1016/j.biocon.2020.108818 (2021).Article 

    Google Scholar 
    Jager, H., Schirpke, U. & Tappeiner, U. Assessing conflicts between winter recreational activities and grouse species. J. Environ. Manage. 276, 9. https://doi.org/10.1016/j.jenvman.2020.111194 (2020).Article 

    Google Scholar 
    Linnell, J. D. C., Broseth, H., Odden, J. & Nilsen, E. B. Sustainably harvesting a large Carnivore? Development of Eurasian Lynx populations in Norway during 160 years of shifting policy. Environ. Manage. 45, 1142–1154. https://doi.org/10.1007/s00267-010-9455-9 (2010).ADS 
    Article 
    PubMed 

    Google Scholar 
    Andren, H. et al. Survival rates and causes of mortality in Eurasian lynx (Lynx lynx) in multi-use landscapes. Biol. Conserv. 131, 23–32. https://doi.org/10.1016/j.biocon.2006.01.025 (2006).Article 

    Google Scholar 
    Manly, B., McDonald, L., Thomas, D., McDonald, T. & Erickson, W. Resource Selection by Animals (Dordrecht: Kluwer Academic Publishers, 2002).Odden, J., Linnell, J. D. C. & Andersen, R. Diet of Eurasian lynx, Lynx lynx, in the boreal forest of southeastern Norway: the relative importance of livestock and hares at low roe deer density. Eur. J. Wildl. Res. 52, 237–244. https://doi.org/10.1007/s10344-006-0052-4 (2006).Article 

    Google Scholar 
    Gervasi, V., Nilsen, E. B., Odden, J., Bouyer, Y. & Linnell, J. D. C. The spatio-temporal distribution of wild and domestic ungulates modulates lynx kill rates in a multi-use landscape. J. Zool. 292, 175–183. https://doi.org/10.1111/jzo.12088 (2014).Article 

    Google Scholar 
    Arnemo, J. M. & Evans, A. Biomedical protocols for free-ranging brown bears, wolves, wolverines and lynx (Hedmark University College Evenstad, 2017).
    Google Scholar 
    Padgham, M., Lovelace, R., Salmon, M. & Rudis, B. osmdata. J. Open Source Softw. 2, 305 (2017).
    ADS 
    Article 

    Google Scholar 
    R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. (2020).Northrup, J. M., Hooten, M. B., Anderson, C. R. & Wittemyer, G. Practical guidance on characterizing availability in resource selection functions under a use-availability design. Ecology 94, 1456–1463. https://doi.org/10.1890/12-1688.1 (2013).Article 
    PubMed 

    Google Scholar 
    Horne, J. S., Garton, E. O., Krone, S. M. & Lewis, J. S. Analyzing animal movements using Brownian bridges. Ecology 88, 2354–2363. https://doi.org/10.1890/06-0957.1 (2007).Article 
    PubMed 

    Google Scholar 
    Calenge, C. The package “adehabitat” for the R software: a tool for the analysis of space and habitat use by animals. Ecol. Model. 197, 516–519. https://doi.org/10.1016/j.ecolmodel.2006.03.017 (2006).Article 

    Google Scholar 
    Therneau, T. A Package for Survival Analysis in R. R package version 3.2–7. (2020).Fay, M. P., Graubard, B. I., Freedman, L. S. & Midthune, D. N. Conditional logistic regression with sandwich estimators: Application to a meta-analysis. Biometrics 54, 195–208. https://doi.org/10.2307/2534007 (1998).CAS 
    Article 
    PubMed 
    MATH 

    Google Scholar 
    Prima, M.-C., Duchesne, T. & Fortin, D. Robust inference from conditional logistic regression applied to movement and habitat selection analysis. PLoS ONE 12, e0169779 (2017).Article 

    Google Scholar 
    Basille, M. et al. Selecting habitat to survive: the impact of road density on survival in a large carnivore. PLoS ONE 8, 11. https://doi.org/10.1371/journal.pone.0065493 (2013).CAS 
    Article 

    Google Scholar 
    Basille, M. et al. What shapes Eurasian lynx distribution in human dominated landscapes: selecting prey or avoiding people?. Ecography 32, 683–691. https://doi.org/10.1111/j.1600-0587.2009.05712.x (2009).Article 

    Google Scholar 
    Bouyer, Y. et al. Eurasian lynx habitat selection in human-modified landscape in Norway: effects of different human habitat modifications and behavioral states. Biol. Conserv. 191, 291–299. https://doi.org/10.1016/j.biocon.2015.07.007 (2015).Article 

    Google Scholar 
    Heggem, E. S. F., Mathisen, H. & Frydenlund, J. J. N. R. AR50–Arealressurskart i målestokk 1: 50 000. Et heldekkende arealressurskart for jord-og skogbruk. (2019).Hijmans, R. J. raster: Geographic Data Analysis and Modeling. R package version 3.4–5. (2020).Bivand, R. & Lewin-Koh, N. maptools: Tools for Handling Spatial Objects. R package version 1.1–1. https://CRAN.R-project.org/package=maptools. (2021).Akaike, H. in IEEE Transactions on Automatic Control Vol. 19 716–723 (1974).Burnham, K. P. & Anderson, D. R. Model selection and multimodel inference—a practical information-theoretic approach.2nd edn. Springer, New York (2002).Hastie, T. J. & Tibshirani, R. J. Generalized additive models. Vol. 43 (CRC press, 1990).Wood, S. N. Stable and efficient multiple smoothing parameter estimation for generalized additive models. J. Am. Stat. Assoc. 99, 673–686. https://doi.org/10.1198/016214504000000980 (2004).MathSciNet 
    Article 
    MATH 

    Google Scholar 
    Vazquez, C., Rowcliffe, J. M., Spoelstra, K. & Jansen, P. A. Comparing diel activity patterns of wildlife across latitudes and seasons: Time transformations using day length. Methods Ecol. Evol. 10, 2057–2066. https://doi.org/10.1111/2041-210x.13290 (2019).Article 

    Google Scholar 
    Rowcliffe, M. activity: Animal Activity Statistics. R package version 1.3.1. (2021).Olson, L. E., Squires, J. R., Roberts, E. K., Ivan, J. S. & Hebblewhite, M. Sharing the same slope: behavioral responses of a threatened mesocarnivore to motorized and nonmotorized winter recreation. Ecol. Evol. 8, 8555–8572. https://doi.org/10.1002/ece3.4382 (2018).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    Squires, J. R., Olson, L. E., Roberts, E. K., Ivan, J. S. & Hebblewhite, M. Winter recreation and Canada lynx: reducing conflict through niche partitioning. Ecosphere 10, 22. https://doi.org/10.1002/ecs2.2876 (2019).Article 

    Google Scholar 
    Belotti, E., Mayer, K., Kreisinger, J., Heurich, M. & Bufka, L. Recreational activities affect resting site selection and foraging time of Eurasian lynx (Lynx lynx). Hystrix 29, 181–189. https://doi.org/10.4404/hystrix-00053-2018 (2018).Article 

    Google Scholar 
    Sunde, P., Stener, S. O. & Kvam, T. Tolerance to humans of resting lynxes Lynx lynx in a hunted population. Wildlife Biol. 4, 177–183 (1998).Article 

    Google Scholar 
    Heurich, M. et al. Activity patterns of Eurasian Lynx are modulated by light regime and individual traits over a wide latitudinal range. PLoS ONE 9, 20. https://doi.org/10.1371/journal.pone.0114143 (2014).CAS 
    Article 

    Google Scholar 
    Bischof, R., Gjevestad, J. G. O., Ordiz, A., Eldegard, K. & Milleret, C. High frequency GPS bursts and path-level analysis reveal linear feature tracking by red foxes. Sci. Rep. 9, 13. https://doi.org/10.1038/s41598-019-45150-x (2019).CAS 
    Article 

    Google Scholar 
    Bouyer, Y. et al. Tolerance to anthropogenic disturbance by a large carnivore: the case of Eurasian lynx in south-eastern Norway. Anim. Conserv. 18, 271–278. https://doi.org/10.1111/acv.12168 (2015).MathSciNet 
    Article 

    Google Scholar 
    Venter, Z. S., Barton, D. N., Gundersen, V., Figari, H. & Nowell, M. Urban nature in a time of crisis: recreational use of green space increases during the COVID-19 outbreak in Oslo, Norway. Environ. Res. Lett. 15, 11. https://doi.org/10.1088/1748-9326/abb396 (2020).CAS 
    Article 

    Google Scholar 
    Sun, Y. R., Du, Y. Y., Wang, Y. & Zhuang, L. Y. Examining associations of environmental characteristics with recreational cycling behaviour by street-level strava data. Int. J. Environ. Res. Public Health 14, 12. https://doi.org/10.3390/ijerph14060644 (2017).Article 

    Google Scholar 
    Griffin, G. P. & Jiao, J. Where does bicycling for health happen? analysing volunteered geographic information through place and plexus. J. Transp. Health 2, 238–247. https://doi.org/10.1016/j.jth.2014.12.001 (2015).Article 

    Google Scholar 
    Conrow, L., Wentz, E., Nelson, T. & Pettit, C. Comparing spatial patterns of crowdsourced and conventional bicycling datasets. Appl. Geogr. 92, 21–30. https://doi.org/10.1016/j.apgeog.2018.01.009 (2018).Article 

    Google Scholar  More

  • in

    A novel approach for reliable qualitative and quantitative prey spectra identification of carnivorous plants combining DNA metabarcoding and macro photography

    A combined DNA metabarcoding/in-situ macro photography approach to reliably analyse carnivorous plant prey spectraResults indicate that DNA metabarcoding allows for reliable analysis of prey spectra composition in carnivorous plants at a taxonomic resolution and level of completeness unachievable by traditional morphology-based approaches (as performed, for example, by4,5,6,7,9,10,11). Even in remote tropical northern Western Australia, where many (if not most) arthropod species have not yet been accessioned into the BOLD or GenBank barcode reference libraries, this method identified over 90% of obtained OTUs from our sample set; most of them at family-level, but 41% to genus-level, and 17% even down to species rank (Supplementary Data S1). Lekesyte et al.27 were able to identify 80% of the analysed prey items found on D. rotundifolia in England to species-level. However, their sampling was performed in western Europe, whose entomofauna is comparatively well studied taxonomically and has an excellent coverage in the BOLD reference library of DNA barcodes41. New insect barcodes are regularly added to the BOLD library through large-scale initiatives such as the international Barcode of Life Project (iBOL; https://ibol.org/) and its Australian node Australian Barcode of Life Network (ABOLN), hence accuracy of future metabarcoding research performed in Australia can be expected to increase to similar levels soon.In-situ macro photography was found to provide a valuable plausibility control tool for the prey taxa identified by metabarcoding. While many of the smaller prey taxa detected by metabarcoding were impossible to identify in the in-situ macro photographs due to their tendency to quickly degenerate after digestion into small, shapeless “crumbs”8, this control method considerably reduced the amount of prey taxa detected which were not actually present as prey in the Drosera samples. This flaw of metabarcoding is most commonly a consequence of procedural errors resulting in cross-contamination within the DNA extraction procedure27, usually resulting in low read numbers. However, in-situ macro photographs may also fail to detect species if prey captured by the sundew escaped from the trap33,42, or was stolen by larger animals. In both cases, a DNA imprint left on the Drosera leaves as excretions, detached scales, hairs or, frequently, as autotomised (shedded) body parts42 could have been detected by metabarcoding. Additionally, some barcoding-detected taxa may not constitute prey if they were associated with another captured prey taxon (either as part of its diet, or as a parasite). The latter may explain some barcode hits for taxa not immediately apparent from the in-situ macro photographs, as they are (endo)parasites of captured prey taxa. This was likely the case in the detected Strepsiptera (stylops) which are frequently contained as larvae and adult females in their hymenopteran and orthopteran hosts43. However, insect endoparasites and other non-obvious prey taxa were by default not excluded by the very conservative approach of pictorial plausibility control. Additionally, in the case of endoparasites, these organisms would also contribute to plant nutrition as “bycatch” after being digested together with their host, despite not having been actively attracted to the carnivorous traps. Finally, the control method tested in this study showed that even heavily digested prey items in the samples had sufficient amounts of intact (mitochondrial) DNA present to be detected by metabarcoding, as we found no instance of any prey item being clearly identifiable in the macro photographs but not present in the barcoding data.Prey spectra composition of the studied Drosera speciesThe analysed prey spectra of the three studied species from D. sect. Arachnopus most commonly contained flying insects (especially of the orders Diptera and Hemiptera, both present in 100% of the samples; Fig. 3), thus confirming earlier in-situ macro photography-based studies of closely-related D. sect. Arachnopus species by Krueger et al.8. All members of D. sect. Arachnopus are characterised by a large, erect growth habit and thread-like aerial leaves which usually do not contact the ground8,32, thereby excluding most ground-dwelling arthropods as prey. This result is also similar to other prey spectra studies of erect-leaved Drosera from different geographic areas, where flying insects (particularly Diptera) unanimously comprised almost the entire recorded prey5,11,44. Furthermore, this study confirmed the result of Krueger et al.8 that Hemiptera—and within this order especially the Cicadellidae—are exceptionally common in the prey spectra of D. sect. Arachnopus compared with all other, previously studied Drosera. A possible explanation for this may be the relatively high abundance of Cicadellidae in tropical habitats45 compared to subtropical or temperate habitats where the above-mentioned previous Drosera prey spectra studies were conducted.Of the five most commonly detected orders, Lepidoptera generally comprised the largest prey items in terms of body size or wingspan, respectively. This prey order was exceptionally common in D. finlaysoniana, being present in 100% of samples and also visually conspicuous in the in-situ photographs. Since this Drosera species had by far the largest trapping leaves among the three species studied with an average leaf length of 10.4 ± 0.6 cm (Suppl Appendix S7), and exhibits the largest leaves in D. section Arachnopus32, this may represent an example of large prey items being more easily captured by species with larger trapping leaves33. Additionally, the sampled population of D. finlaysoniana was huge and dense (see Supplementary Figure S1), probably attracting larger prey and enabling capture of larger prey items by “collective” trapping46. Alternatively, Fleischmann30 suggested that captured Lepidoptera themselves could attract further individuals of the same species by pheromone release, potentially explaining the very high numbers of this insect order observed in D. finlaysoniana.Differences among observed prey spectraComparison of prey spectra between the three studied Drosera species revealed significant differences at arthropod family-level but not at the higher level of arthropod orders, indicating that at a coarse taxonomic resolution, the same five arthropod orders (Diptera, Hemiptera, Hymenoptera, Lepidoptera and Thysanoptera) generally comprise most of the prey in D. sect. Arachnopus, regardless of given Drosera species or habitat. However, as strong differences were discovered in the ANOSIM comparison at family-level, it can be concluded that differences might likely increase with finer taxonomic resolution of prey taxa, a conclusion also reached by the carnivorous plant prey spectra meta-analysis of Ellison & Gotelli47. While these differences may be partially attributed to different morphological traits of the three species such as leaf scent8,30 or eglandular appendages31, the very high ANOSIM R-values returned and the large number of prey families contributing nearly equally to dissimilarity (Table 2) indicate that the most likely explanation is very different available prey spectra at the three study sites. Indeed, significant differences among different study sites, even within the same species, were previously reported for Drosera rotundifolia by Lekesyte et al.27 and for four species from D. sect. Arachnopus by Krueger et al.8. Notably, the three study sites feature different habitat types and climate regimes (Supplementary Fig. S1).Analyses indicate that there is likely little specialisation in prey capture by the three studied Drosera species. For example, the relatively high detection rate of Lepidoptera in the samples of D. finlaysoniana and D. hartmeyerorum compared to D. margaritacea may be explained by the lake margin habitats of the former two species, while the latter species was found in a completely dry drainage channel lacking any nearby waterbodies (Supplementary Fig. S1). Lepidoptera are likely to occur in much higher concentrations near water sources, especially during the dry season (May to November) when the surrounding areas are lacking other water sources (G. Bourke in Fleischmann30).Estimating prey quantityIn addition to providing a plausibility control for the compositional prey analysis by metabarcoding, the in-situ macro photography method facilitated an estimation of prey quantity per sample. Metabarcoding by itself is currently not a reliable tool for prey quantification due to the lack of a linear relationship between the number of sequence reads and organism biomass26,27.In contrast to Krueger et al.8, who generally found more prey items on larger trapping leaves in species of D. sect. Arachnopus (even when values were compared as per cm of trapping leaf length), the species with the largest leaves studied here (D. finlaysoniana) captured significantly less prey items than the smaller-leaved species D. margaritacea and D. hartmeyerorum (Fig. 4). However, while Krueger et al.8 was able to compare sympatric species (thus minimising any potential effects of the habitat or region on prey spectra), the three species in this study were studied at three different, geographically distant sites. While it is possible that overall prey abundance in the habitat was much lower at the D. finlaysoniana study site (Site 1), it can be hypothesised that the low total prey capture observed in this species may be due to the very large and extremely dense population resulting in strong intraspecific competition for prey (see Supplementary Fig. S1). This effect of population structure on prey capture has also been observed by Gibson48 and Tagawa and Watanabe46 who found a significant negative correlation between total prey capture and population density in different species of Drosera.Conclusions and outlookOur study is the first to employ a DNA metabarcoding approach supported by controls for species presence to analyse carnivorous plant prey spectra. When combined with in-situ macro photography, this method is clearly superior in terms of taxonomic resolution and completeness for analysis of environmental bulk samples (containing different organisms in highly variable states of preservation), as used here for the reconstruction of prey spectra of carnivorous plants. The capability of this method increases with new reference barcodes being regularly added to DNA barcode libraries (such as BOLD and NCBI GenBank) and it thus has the potential to become the standard methodology for future carnivorous plant prey spectra research.Additional studies are needed to test this method for other carnivorous plant species and genera, especially those possessing different trap types. Within Western Australia, three additional trap types occur: snap traps (Aldrovanda), suction traps (Utricularia) and pitfall traps (Cephalotus). In particular, it might be expected that in-situ macro photography will not work as well for the extremely small, typically submerged traps of Aldrovanda and Utricularia (which also completely enclose their captured, microscopic prey items49), potentially necessitating usage of alternative control methods for metabarcoding data. Furthermore, even within Drosera (adhesive traps) some species may require adjustments to the methodology presented here as they accumulate captured prey in a central point via tentacle movement (e.g., many climbing tuberous Drosera) or their leaves may be very difficult to place on paper sheets with the sticky side facing upwards (e.g., all pygmy Drosera). The latter problem may be solved by using reverse action forceps and photographing the leaves while held in place by the forceps.Extensive sampling of sites with co-occurring species from D. sect. Arachnopus is clearly required to better understand the ecological role of trap scent and eglandular appendages in this section. For example, manipulation experiments involving the removal of all yellow blackberry-shaped appendages of D. hartmeyerorum (which have been hypothesised to function as visual prey attractants31) and subsequent metabarcoding prey spectra comparisons of mutilated plants lacking emergences with control plants are proposed. Potential effects of population density on prey spectra (as hypothesised here for D. finlaysoniana) could be studied by comparing prey spectra of individual plants from within mass populations with more exposed-growing individuals of the same population. More

  • in

    Assessment of deep convolutional neural network models for species identification of forensically-important fly maggots based on images of posterior spiracles

    Of which at the third instar, the external morphology of larvae is quite similar; thus, the morphological identification used to differentiate between its genera or species, generally includes cephalophalyngeal skeleton, anterior spiracle, and posterior spiracles. The morphology of the posterior spiracle is one of the important characteristics for identification. A typical morphology of the posterior spiracle of third stage larvae was shown in Fig. 2. Based on studying under light microscopy, the posterior spiracle of M. domestica was clearly distinguished from the others. On the other hand, the morphology of the posterior spiracle of C. megacephala and A. rufifacies was quite similar. For C. megacephala and C. rufifacies, the peritreme, a structure encircling the three spiracular openings (slits), was incomplete and slits were straight as shown Fig. 2A,B, respectively. The complete peritreme encircling three slits was found in L. cuprina and M. domestica as shown in Fig. 2C,D, respectively. However, only the slits of M. domestica were sinuous like the M-letter (Fig. 2D). Their morphological characteristics found in this study were like the descriptions in the previous reports23,24,25.Figure 2Morphology of posterior spiracles of four different fly species after inverting the image colors; (A) Chrysomya (Achoetandrus) ruffifacies, (B) Chrysomya megacephala, (C) Lucilia cuprina, (D) Musca domestica.Full size imageFor model training, four of the CNN models used for species-level identification of fly maggots provided 100% accuracy rates and 0% loss. Number of parameter (#Params), model speed, model size, macro precision, macro recall, f1-score, and support value were also presented in Table 1. The result demonstrated that the AlexNet model provided the best performance in all indicators when compared among four models. The AlexNet model used the least number of parameters while the Resnet101 model used the most. For model speed, the AlexNet model provided the fastest speed, while the Densenet161 model provided the slowest speed. For the model size, the AlexNet model was the smallest, while the Resnet101 model was the largest which corresponded to the number of parameters used. Macro precision, macro recall, f1-score and support value of all models were the same.Table 1 Comparison of model size, speed, and performances of each studied model (The text in bold indicates the best value in each category).Full size tableAs the training results presented in the supplementary data (Fig. S1), all models provided 100% accuracy and 0% loss in the early stage of training ( More

  • in

    European-wide forest monitoring substantiate the neccessity for a joint conservation strategy to rescue European ash species (Fraxinus spp.)

    Hill, L. et al. The£ 15 billion cost of ash dieback in Britain. Curr. Biol. 29(9), R315–R316 (2019).CAS 
    PubMed 

    Google Scholar 
    Pliûra, A. & Heuertz, M. EUFORGEN Technical Guidelines for Genetic Conservation and Use for Common Ash (Fraxinus excelsior) (Bioversity International, 2003).
    Google Scholar 
    Dufour, S. & Piégay, H. Geomorphological controls of Fraxinus excelsior growth and regeneration in floodplain forests. Ecology 89(1), 205–215 (2008).CAS 
    PubMed 

    Google Scholar 
    Mitchell, R. J. et al. Ash dieback in the UK: a review of the ecological and conservation implications and potential management options. Biol. Conserv. 175, 95–109 (2014).
    Google Scholar 
    Przybył, K. Fungi associated with necrotic apical parts of Fraxinus excelsior shoots. For. Pathol. 32(6), 387–394 (2002).
    Google Scholar 
    Vasaitis, R., & Enderle, R. Dieback of European ash (Fraxinus spp.)-consequences and guidelines for sustainable management. Dieback of European ash (Fraxinus spp.). Report on COST Action FP1103 FRAXBACK. ISBN978-91-576-8696-1. (SLU Swedish University of Agricultural Sciences, 2017).Børja, I. et al. Ash dieback in Norway-current situation. In Dieback of European ash (Fraxinus spp.): Consequences and Guidelines for Sustainable Management (eds Vasaitis, R. & Enderle, R.) 166–175 (Swedish University of Agricultural Sciences, 2017).
    Google Scholar 
    Ghelardini, L. et al. From the Alps to the Apennines: Possible spread of ash dieback in Mediterranean areas. In Dieback of European ash (Fraxinus spp.): Consequences and Guidelines for Sustainable Management (eds Vasaitis, R. & Enderle, R.) 140–149 (Swedish University of Agricultural Sciences, 2017).
    Google Scholar 
    Marçais, B., Husson, C., Godart, L. & Cael, O. Influence of site and stand factors on Hymenoscyphus fraxineus-induced basal lesions. Plant. Pathol. 65(9), 1452–1461 (2016).
    Google Scholar 
    Queloz, V., Hopf, S., Schoebel, C. N., Rigling, D. & Gross, A. Ash dieback in Switzerland: History and scientific achievements. In Dieback of European ash (Fraxinus spp.): Consequences and Guidelines for Sustainable Management (eds Vasaitis, R. & Enderle, R.) 68–78 (Swedish University of Agricultural Sciences, 2017).
    Google Scholar 
    Orton, E. S. et al. Population structure of the ash dieback pathogen, Hymenoscyphus fraxineus, in relation to its mode of arrival in the UK. Plant. Pathol. 67(2), 255–264 (2018).CAS 
    PubMed 

    Google Scholar 
    Enderle, R., Stenlid, J. & Vasaitis, R. An overview of ash (Fraxinus spp.) and the ash dieback disease in Europe. CAB Rev. 14, 1–12 (2019).
    Google Scholar 
    Heinze, B., Tiefenbacher, H., Litschauer, R. & Kirisits, T. Ash dieback in Austria: History, current situation and outlook. in Dieback of European Ash (Fraxinus spp.): Consequences and Guidelines for Sustainable Management, 33–52 (2017).Coker, T. L. et al. Estimating mortality rates of European ash (Fraxinus excelsior) under the ash dieback (Hymenoscyphus fraxineus) epidemic. Plants People Planet 1(1), 48–58 (2019).
    Google Scholar 
    Cleary, M., Nguyen, D., Stener, L. G., Stenlid, J., & Skovsgaard, J. P. Ash and ash dieback in Sweden: A review of disease history, current status, pathogen and host dynamics, host tolerance and management options in forests and landscapes. Dieback of European Ash (Fraxinus spp.): Consequences and Guidelines for Sustainable Management, 195–208 (2017).Stocks, J. J., Buggs, R. J. & Lee, S. J. A first assessment of Fraxinus excelsior (common ash) susceptibility to Hymenoscyphus fraxineus (ash dieback) throughout the British Isles. Sci. Rep. 7(1), 1–7 (2017).
    Google Scholar 
    Díaz-Yáñez, O. et al. The invasive forest pathogen Hymenoscyphus fraxineus boosts mortality and triggers niche replacement of European ash (Fraxinus excelsior). Sci. Rep. 10(1), 1–10 (2020).
    Google Scholar 
    Enderle, R., Metzler, B., Riemer, U. & Kändler, G. Ash dieback on sample points of the national forest inventory in south-western Germany. Forests 9(1), 25 (2018).
    Google Scholar 
    Klesse, S. et al. Spread and severity of ash dieback in Switzerland: Tree characteristics and landscape features explain varying mortality probability. Front. For. Glob. Change 4, 18 (2021).
    Google Scholar 
    Timmermann, V., Potočić, N., Ognjenović, M. & Kirchner, T. Tree crown condition in 2020. In Forest Condition in Europe: The 2021 Assessment ICP Forests Technical Report under the UNECE Convention on Long-range Transboundary Air Pollution (Air Convention) (eds Michel, A. et al.) (Thünen Institute, 2021).
    Google Scholar 
    Chumanová, E. et al. Predicting ash dieback severity and environmental suitability for the disease in forest stands. Scand. J. For. Res. 34(4), 254–266 (2019).
    Google Scholar 
    Solheim, H. & Hietala, A. M. Spread of ash dieback in Norway. Balt. For. 23(1), 1–6 (2017).
    Google Scholar 
    Kjær, E. D. et al. Genetics of ash dieback resistance in a restoration context: Experiences from Denmark. In Dieback of European ash (Fraxinus spp.): Consequences and Guidelines for Sustainable Management (eds Vasaitis, R. & Enderle, R.) 106–114 (Swedish University of Agricultural Sciences, 2017).
    Google Scholar 
    Madsen, C. L. et al. Combined progress in symptoms caused by Hymenoscyphus fraxineus and Armillaria species, and corresponding mortality in young and old ash trees. For. Ecol. Manage. 491, 119177 (2021).
    Google Scholar 
    Trapiello, E., Schoebel, C. N. & Rigling, D. Fungal community in symptomatic ash leaves in Spain. Balt. For. 23(1), 68–73 (2017).
    Google Scholar 
    Grosdidier, M., Ioos, R. & Marçais, B. Do higher summer temperatures restrict the dissemination of Hymenoscyphus fraxineus in France?. For. Pathol. 48(4), e12426. https://doi.org/10.1111/efp.12426 (2018).Article 

    Google Scholar 
    Stroheker, S., Queloz, V. & Nemesio-Gorriz, M. First report of Hymenoscyphus fraxineus causing ash dieback in Spain. New Dis. Rep. 44(2), e12054 (2021).
    Google Scholar 
    Chandelier, A., Gerarts, F., San Martin, G., Herman, M. & Delahaye, L. Temporal evolution of collar lesions associated with ash dieback and the occurrence of Armillaria in Belgian forests. For. Pathol. 46(4), 289–297. https://doi.org/10.1111/efp.12258 (2016).Article 

    Google Scholar 
    Gross, A., Holdenrieder, O., Pautasso, M., Queloz, V. & Sieber, T. N. H ymenoscyphus pseudoalbidus, the causal agent of E uropean ash dieback. Mol. Plant Pathol. 15(1), 5–21 (2014).CAS 
    PubMed 

    Google Scholar 
    Clark, J. & Webber, J. The ash resource and the response to ash dieback in Great Britain. In Dieback of European ash (Fraxinus spp.): Consequences and Guidelines for Sustainable Management (eds Vasaitis, R. & Enderle, R.) 228–237 (Swedish University of Agricultural Sciences, 2017).
    Google Scholar 
    Dandy, N., Marzano, M., Porth, E. F., Urquhart, J. & Potter, C. Who has a stake in ash dieback? A conceptual framework for the identification and categorisation of tree health stakeholders. In Dieback of European ash (Fraxinus spp.): Consequences and Guidelines for Sustainable Management (eds Vasaitis, R. & Enderle, R.) 15–26 (Swedish University of Agricultural Sciences, 2017).
    Google Scholar 
    Kjær, E. D., McKinney, L. V., Nielsen, L. R., Hansen, L. N. & Hansen, J. K. Adaptive potential of ash (Fraxinus excelsior) populations against the novel emerging pathogen Hymenoscyphus pseudoalbidus. Evol. Appl. 5(3), 219–228 (2012).PubMed 

    Google Scholar 
    Plumb, W. J. et al. The viability of a breeding programme for ash in the British Isles in the face of ash dieback. Plants People Planet 2(1), 29–40 (2020).
    Google Scholar 
    Evans, M. R. Will natural resistance result in populations of ash trees remaining in British woodlands after a century of ash dieback disease?. R. Soc. Open Sci. 6(8), 190908 (2019).ADS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Buggs, R. J. A. Changing perceptions of tree resistance research. Plants People Planet 2, 2–4. https://doi.org/10.1002/ppp3.10089 (2020).Article 

    Google Scholar 
    Tomlinson, I. & Potter, C. ‘Too little, too late’? Science, policy and Dutch Elm Disease in the UK. J. Hist. Geogr. 36(2), 121–131 (2010).
    Google Scholar 
    Kelly, L. J. et al. Convergent molecular evolution among ash species resistant to the emerald ash borer. Nat. Ecol. Evol. 4, 1116–1128. https://doi.org/10.1038/s41559-020-1209-3 (2020).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    Sollars, E. S. et al. Genome sequence and genetic diversity of European ash trees. Nature 541(7636), 212–216 (2017).ADS 
    CAS 
    PubMed 

    Google Scholar 
    Stocks, J. J. et al. Genomic basis of European ash tree resistance to ash dieback fungus. Nat. Ecol. Evol. 3(12), 1686–1696 (2019).PubMed 
    PubMed Central 

    Google Scholar 
    Volkovitsh, M. G., Bieńkowski, A. O. & Orlova-Bienkowskaja, M. J. Emerald ash borer approaches the borders of the european union and kazakhstan and is confirmed to infest European ash. Forests 12(6), 691 (2021).
    Google Scholar 
    Eichhorn, J. et al. Part IV: Visual Assessment of Crown Condition and Damaging Agents. in Manual on Methods and Criteria for Harmonized Sampling, Assessment, Monitoring and Analysis of the Effects of Air Pollution on Forests. (Thünen Institute of Forest Ecosystems, 2016). Annex http://www.icp-forests.org/manual.htm.Koontz, M. J., Latimer, A. M., Mortenson, L. A., Fettig, C. J. & North, M. P. Cross-scale interaction of host tree size and climatic water deficit governs bark beetle-induced tree mortality. Nat. Commun. 12(1), 1–13 (2021).
    Google Scholar 
    Taccoen, A. et al. Climate change impact on tree mortality differs with tree social status. For. Ecol. Manage. 489, 119048 (2021).
    Google Scholar 
    Therneau, T. A Package for Survival Analysis in R. https://cran.r-project.org/web/packages/survival/vignettes/survival.pdf. Accessed 26 May 2021Godaert, L. et al. Prognostic factors of inhospital death in elderly patients: A time-to-event analysis of a cohort study in Martinique (French West Indies). BMJ Open 8(1), e018838 (2018).PubMed 
    PubMed Central 

    Google Scholar 
    Sargeran, K., Murtomaa, H., Safavi, S. M. R., Vehkalahti, M. M. & Teronen, O. Survival after diagnosis of cancer of the oral cavity. Br. J. Oral Maxillofac. Surg. 46(3), 187–191 (2008).PubMed 

    Google Scholar 
    Cox, D. R. Regression models and life-tables. J. R. Stat. Soc. B 34(2), 187–202 (1972).MathSciNet 
    MATH 

    Google Scholar 
    Aalen, O. O. A linear regression model for the analysis of life times. Stat. Med. 8(8), 907–925 (1989).CAS 
    PubMed 

    Google Scholar 
    Therneau, T. M., & Grambsch, P. M. The cox model. In Modeling survival data: extending the Cox model, pp. 39–77. (Springer, 2000).Neumann, M., Mues, V., Moreno, A., Hasenauer, H. & Seidl, R. Climate variability drives recent tree mortality in Europe. Glob. Change Biol. 23(11), 4788–4797 (2017).ADS 

    Google Scholar 
    Senf, C., Buras, A., Zang, C. S., Rammig, A. & Seidl, R. Excess forest mortality is consistently linked to drought across Europe. Nat. Commun. 11(1), 1–8 (2020).
    Google Scholar 
    Haylock, M. R. et al. A European daily high-resolution gridded data set of surface temperature and precipitation for 1950–2006. J. Geophys. Res. Atmos. 113, D20 (2008).
    Google Scholar 
    R Development Core Team. RStudio, R: A Language and Environment for Statistical Computing (R Development Core Team, 2017).Holt, C. C. Forecasting Trends and Season-Als by Exponentially Weighted Averages. (Carnegie Institute of Technology, Pittsburgh ONR memorandum no. 52, 1957)Hyndman, R. J. & Khandakar, Y. Automatic time series forecasting: the forecast package for R. J. Stat. Softw. 27(3), 1–22 (2008).
    Google Scholar  More

  • in

    Frequency-dependent Batesian mimicry maintains colour polymorphism in a sea snake population

    Van Gossum, H., Sherratt, T. N., Cordero-Rivera, A. & Córdoba-Aguilar, A. The evolution of sex-limited colour polymorphism. In Dragonflies and Damselflies: Model Organisms for Ecological and Evolutionary Research (ed. Córdoba-Aguilar, A.) 219–231 (Oxford University Press, 2008).
    Google Scholar 
    Hughes, J. M. & Jones, M. P. Shell colour polymorphism in a mangrove snail Littorina sp. (Prosobranchia: Littorinidae). Biol. J. Linn. Soc. 25, 365–378 (1985).
    Google Scholar 
    Sinervo, B., Bleay, C. & Adamopoulou, C. Social causes of correlational selection and the resolution of a heritable throat color polymorphism in a lizard. Evolution 55, 2040–2052 (2001).CAS 
    PubMed 

    Google Scholar 
    Westerman, E. L. et al. Does male preference play a role in maintaining female limited polymorphism in a Batesian mimetic butterfly? Behav. Process. 150, 47–58 (2018).CAS 

    Google Scholar 
    Vane-Wright, R. I. An integrated classification for polymorphism and sexual dimorphism in butterflies. J. Zool. 177, 329–337 (1975).
    Google Scholar 
    Timmermans, M. J., Srivathsan, A., Collins, S., Meier, R. & Vogler, A. P. Mimicry diversification in Papilio dardanus via a genomic inversion in the regulatory region of engrailed–invected. Proc. R. Soc. B 287, 20200443 (2020).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Brodie, E. D. III. & Janzen, F. J. Experimental studies of coral snake mimicry: Generalized avoidance of ringed snake patterns by free-ranging avian predators. Funct. Ecol. 9, 186–190 (1995).
    Google Scholar 
    Banci, K. R., Eterovic, A., Marinho, P. S. & Marques, O. A. Being a bright snake: Testing aposematism and mimicry in a neotropical forest. Biotropica 52, 1229–1241 (2020).
    Google Scholar 
    Wüster, W. et al. Do aposematism and Batesian mimicry require bright colours? A test, using European viper markings. Proc. R. Soc. B 271, 2495–2499 (2004).PubMed 
    PubMed Central 

    Google Scholar 
    Valkonen, J. K. & Mappes, J. Resembling a viper: Implications of mimicry for conservation of the endangered smooth snake. Conserv. Biol. 28, 1568–1574 (2014).PubMed 

    Google Scholar 
    Sinervo, B. & Lively, C. M. The rock–paper–scissors game and the evolution of alternative male strategies. Nature 380, 240–243 (1996).ADS 
    CAS 

    Google Scholar 
    Moon, R. M. & Kamath, A. Re-examining escape behaviour and habitat use as correlates of dorsal pattern variation in female brown anole lizards, Anolis sagrei (Squamata: Dactyloidae). Biol. J. Linn. Soc. 126, 783–795 (2019).
    Google Scholar 
    Le Rouzic, A., Hansen, T. F., Gosden, T. P. & Svensson, E. I. Evolutionary time-series analysis reveals the signature of frequency-dependent selection on a female mating polymorphism. Am. Nat. 185, E182–E196 (2015).PubMed 

    Google Scholar 
    Udyawer, V. et al. Future directions in the research and management of marine snakes. Front. Mar. Sci. 5, 399 (2018).
    Google Scholar 
    Goiran, C., Bustamante, P. & Shine, R. Industrial melanism in the seasnake Emydocephalus annulatus. Curr. Biol. 27, 2510–2513 (2017).CAS 
    PubMed 

    Google Scholar 
    Goiran, C., Brown, G. P. & Shine, R. Niche partitioning within a population of sea snakes is constrained by ambient thermal homogeneity and small prey size. Biol. J. Linn. Soc. 129, 644–651 (2020).
    Google Scholar 
    Shine, R., Shine, T. & Shine, B. Intraspecific habitat partitioning by the sea snake Emydocephalus annulatus (Serpentes, Hydrophiidae): The effects of sex, body size, and colour pattern. Biol. J. Linn. Soc. 80, 1–10 (2003).
    Google Scholar 
    Udyawer, V., Goiran, C. & Shine, R. Peaceful coexistence between people and deadly wildlife: why are recreational users of the ocean so rarely bitten by sea snakes? People Nat. 3, 335–346 (2021).
    Google Scholar 
    Heatwole, H. Sea Snakes 2nd edn. (Krieger Publishing, 1999).
    Google Scholar 
    Shine, R., Shine, T. G., Brown, G. P. & Goiran, C. Life history traits of the sea snake Emydocephalus annulatus, based on a 17-yr study. Coral Reefs 39, 1407–1414 (2020).
    Google Scholar 
    Goiran, C., Dubey, S. & Shine, R. Effects of season, sex and body size on the feeding ecology of turtle-headed sea snakes (Emydocephalus annulatus) on IndoPacific inshore coral reefs. Coral Reefs 32, 527–538 (2013).ADS 

    Google Scholar 
    Olsson, M., Stuart-Fox, D. & Ballen, C. Genetics and evolution of colour patterns in reptiles. Semin. Cell Dev. Biol. 24, 529–541 (2013).PubMed 

    Google Scholar 
    Shine, R., Brischoux, F. & Pile, A. J. A seasnake’s colour affects its susceptibility to algal fouling. Proc. R. Soc. B 277, 2459–2464 (2010).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    White, G. C. & Burnham, K. P. Program MARK: Survival estimation from populations of marked animals. Bird Study 46, S120–S139 (1999).
    Google Scholar 
    Packard, G. C. & Boardman, T. J. The misuse of ratios, indices, and percentages in ecophysiological research. Physiol. Zool. 61, 1–9 (1988).
    Google Scholar 
    Lukoschek, V. & Shine, R. Sea snakes rarely venture far from home. Ecol. Evol. 2, 1113–1121 (2012).PubMed 
    PubMed Central 

    Google Scholar 
    Shine, R. All at sea: Aquatic life modifies mate-recognition modalities in sea snakes (Emydocephalus annulatus, Hydrophiidae). Behav. Ecol. Sociobiol. 57, 591–598 (2005).
    Google Scholar 
    Shine, R., Shine, T. G., Brown, G. P. & Goiran, C. Population dynamics of the sea snake Emydocephalus annulatus (Elapidae, Hydrophiinae). Sci. Rep. 11, 20701 (2021).ADS 

    Google Scholar 
    Rancurel, P. & Intes, A. Le requin tigre, Galeocerdo cuvieri Lacepede, des eaux neocaledoniennes examen des contenus stomacaux. Tethys 10, 195–199 (1982).
    Google Scholar 
    Heatwole, H. Predation on sea snakes. In The Biology of Sea Snakes (ed. Dunson, W. A.) 233–250 (University Park Press, 1975).
    Google Scholar 
    Ineich, I. & Laboute, P. Les serpents marins de Nouvelle-Calédonie (IRD éditions, 2002).
    Google Scholar 
    Kerford, M. R., Wirsing, A. J., Heithaus, M. R. & Dill, L. M. Danger on the rise: diurnal tidal state mediates an exchange of food for safety by the bar-bellied sea snake Hydrophis elegans. Mar. Ecol. Progr. Ser. 358, 289–294 (2008).ADS 

    Google Scholar 
    Masunaga, G., Kosuge, T., Asai, N. & Ota, H. Shark predation of sea snakes (Reptilia: Elapidae) in the shallow waters around the Yaeyama Islands of the southern Ryukyus, Japan. Mar. Biodivers. Rec. 1, e96 (2008).
    Google Scholar 
    Wirsing, A. J. & Heithaus, M. R. Olive-headed sea snakes Disteria major shift seagrass microhabitats to avoid shark predation. Mar. Ecol. Progr. Ser. 387, 287–293 (2009).ADS 

    Google Scholar 
    Goiran, C. & Shine, R. The ability of damselfish to distinguish between dangerous and harmless sea snakes. Sci. Rep. 10, 1377 (2020).ADS 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Norman, M. D., Finn, J. & Tregenza, T. Dynamic mimicry in an Indo-Malayan octopus. Proc. R. Soc. B 268, 1755–1758 (2001).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Pernetta, J. C. Observations on the habits and morphology of the sea snake Laticauda colubrina (Schneider) in Fiji. Can. J. Zool. 55, 1612–1619 (1977).
    Google Scholar 
    Randall, J. E. A review of mimicry in marine fishes. Zool. Stud. 44, 299–328 (2005).
    Google Scholar 
    Dudgeon, C. L. & White, W. T. First record of potential Batesian mimicry in an elasmobranch: Juvenile zebra sharks mimic banded sea snakes? Mar. Freshw. Res. 63, 545–551 (2012).
    Google Scholar 
    Sullivan Caldwell, G. & Wolff Rubinoff, R. Avoidance of venomous sea snakes by naive herons and egrets. Auk 100, 195–198 (1983).
    Google Scholar 
    Sanders, K. L., Malhotra, A. & Thorpe, R. S. Evidence for a Müllerian mimetic radiation in Asian pitvipers. Proc. R. Soc. B 273, 1135–1141 (2006).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Raveendran, D. K., Deepak, V., Smith, E. N. & Smart, U. A new colour morph of Calliophis bibroni (Squamata: Elapidae) and evidence for Müllerian mimicry in Tropical Indian coral snakes. Herpetol. Notes 10, 209–217 (2017).
    Google Scholar  More

  • in

    Residual characteristics and safety assessment of the insecticides spiromesifen and chromafenozide in lettuce and perilla

    Chemicals and materialsAnalytical standard ( > 99% purity) of spiromesifen, BSN2060-enol, and chromafenozide were purchased from AB Solution Co., Ltd., Hwaseong-si, Gyeonggi-do, Republic of Korea. HPLC grade water and acetonitrile were supplied by Merck, Darmstadt, Germany. QuEChERS kit (4.0 g magnesium sulfate, 1.0 g sodium chloride, 1.0 g sodium citrate tribasic dihydrate, 0.5 g disodium citrate sesquihydrate) were obtained from Phenomenex, California, USA. Individual stock solutions of the target compounds were prepared in acetonitrile and stored at − 20 °C before use.Field experimentsThe trials were carried out in a greenhouse farm during the season 2018 at two different sites (with approximately 24 km distance between both sites) located in Chuncheon and Hongcheon-gun, Gangwon-do, Republic of Korea following the method described by the Organization for Economic Co-operation and Development (OECD)38. The field test of lettuce (Latuca sativa L.) crop was conducted in Chuncheon city, and perilla (Perilla frutescens (L.) Britton) crop in Hongcheon city. The area of each field was divided into two plots (treatment and control). The treatment plots were further divided into three replicates (subplots 33 m2). The control plot was separated by a buffer zone of 3 m2 from the treated site. To minimize spray overlap, buffer zones (1 m) were set up between subplots. The commercial products of spiromesifen 20% SC diluted 2000 times and chromafenozide 5% EC diluted 1000 times were sprayed twice at 7-days intervals using an automatic sprayer. After the second spray samples (lettuce and perilla leaves) were collected from each subplot at 0 (2 h after spraying), 1, 3, 5, and 7 days according to the Korean RDA23 method. Thirty samples 1.0 kg each from the collected crop were placed in polyethylene bag and labeled. After collection, the samples were transported to the laboratory, where they were chopped and homogenized. The homogenized samples were kept frozen at − 20 °C until analysis.We confirm all plant samples used in the current work comply with the IUCN Policy Statement on Research Involving Species at Risk of Extinction and the Convention on the Trade in Endangered Species of Wild Fauna and Flora.Samples pretreatmentA QuEChERS method was used for the extraction of the targeted compounds from lettuce and perilla leaves. A 10 g of previously homogenized samples were weighed into a 50 mL polypropylene centrifuge tube and mixed with 10 mL of water followed by 10 mL of acetonitrile. The samples were shaken at 1500 rpm in a shaker machine for 10 min. Then commercial QuEChERS kit was added, and the mixtures were shaken vigorously for 2 min in a shaker. Subsequently, the samples were centrifuged at 3584 g-force for 10 min. After centrifugation, the supernatant was filtered with a 0.22 μm membrane filter and transferred into the glass vial for instrumental analysis.LC-MS/MS analysisQuantitative determination of the tested compounds was carried out by using HPLC system Dionex Ultimate 3000 (Thermo Science, USA) coupled with tandem mass spectrometry (MS/MS) (TSQ Quantum Access Max (Thermo Science, USA). Water (solvent A) and acetonitrile (solvent B) containing 0.1% formic acid and 5 mM ammonium format were used as mobile phase at a flow rate of 0.4 mL/min and injection volume 1.0 µL. To obtain desirable chromatographic peaks, two different instrumental conditions were used. The chromatographic separation of spiromesifen was separated by Capcell core-C18 (2.1 mm I.D. × 150 mm × 2.7 μm, Shiseido Co., Ltd., Tokyo, Japan) and BSN2060-enol was performed by C18 column (Poroshell 120 SB-Ag, 2.1 mm I.D. × 100 mm × 2.7-μm, Agilent Technologies, Santa Clara, California, USA) with a gradient elution as follows (mobile phase B%): 0.0 min, 5.0%; 2.0 min 5%; 2.5 min, 95%; 6.0 min, 95%; 6.5 min, 5.0%; 10 min, 5.0%. Likewise, chromafenozide was separated by C18 column (Imtakt Unison UK-C18, 2.0 mm I.D. × 100 mm × 3.0-μm, Imtakt, Portland, USA) with a gradient elution as follows (mobile phase B%): 0.0 min, 5%; 1.0 min, 5.0%; 1.5 min, 90%; 5.0 min, 90%; 7.0 min, 5.0%; 10 min, 5.0%. An MS/MS system (TSQ quantum ultra, Thermo Science, USA) equipped with an electrospray ionization source operating in positive mode (ESI+) was used. The MS/MS parameters and selected product ions are shown in supplementary Tables S2 and S3.The calculation of spiromesifen total residuesThe total residues in lettuce and perilla samples were calculated using Eq. (1)23.Total residues of spiromesifen (mg/kg) = spiromesifen + (BSN2060 residue × 1.36). The conversion factor was calculated as follow;$${1}.{36},{text{(conversion}},{text{factor)}} = frac{{370.49left( {{text{spiromesifen}},{text{MW}}} right)}}{{272.34{ }left( {{text{BSN}}2060,{text{MW}}} right)}}$$
    (1)
    where MW molecular weight.Initial deposition calculationThe initial residues of spiromesifen and chromafenozide deposition in lettuce and perilla leaves were calculated from 0-day according to Eq. (2) described by Kang et al.12 as follow;$${text{A }},({text{mg}}/{text{kg}}) = {text{B(mg}}/{text{kg)}} times frac{100}{{{text{C}}({text{% }})}} times frac{1}{{text{E}}} times 1000$$
    (2)
    A: Initial residue (mg/kg), B: Residues (mg/kg) on 0 day, C: active ingredients, E: dilution factor.Method validationThe analytical method was validated in terms of different performance criteria such as linearity, accuracy, precision, and method limit of quantitation (MLOQ). Matrix-matched standards were used to construct the calibration curve by evaporating (0.01, 0.05, 0.1, 0.2, 0.5, 0.7 and 1.0 mg/kg) working solution (1 mL) and re-dissolved in the extract of control sample. The linearity of the matrix-matched calibration curve was evaluated by the values of the correlation coefficient (R2). The accuracy and precision were obtained in terms of recovery (70–120%) and repeatability (n = 3). The recoveries were determined by spiking the analytes at two concentrations levels (0.1 mg/L) and (0.5 mg/L) in 10 g control samples and were quantified by comparing the response of analytes in samples with response in calibration standard solutions prepared in matrix. The repeatability expressed as the relative standard deviation (RSD) of the analyzed samples was calculated from three repetitions. The MLOQ was calculated by Eq. (3) taking into consideration the following factors: the instrument limit of detection, volume of extraction solvent, injection volume, dilution factor, and sample amount39,40.$${text{MLOQ}},{text{(mg}}/{text{kg)}} = {text{A(ng)}} times frac{{text{B(mL)}}}{{{text{C(}}upmu {text{L)}}}} times frac{{text{D}}}{{text{E(g)}}}$$
    (3)
    where A: instrument limit of detection, B: volume of extraction solvent, C: injection volume, D: dilution factor, E: sample amount.Half-life calculationThe dissipation patterns of spiromesifen and chromafenozide in lettuce and perilla leaves over time were found following the first-order kinetics model28. The half-life was determined by the following equation:$${text{C}}_{{text{t}}} = {text{C}}_{0} times {text{e}}^{{ – {text{kt}}}} ,{text{DT}}_{{{5}0}} = {text{ln2}}/{text{k}}$$where Ct is the concentration of the insecticide, C0 represents the initial residue concentration of insecticide, t is the time (days) after insecticide application, and k is the constant rate.Safety assessmentIn this study, the safety assessments (percent acceptable daily intake; %ADI) of the target insecticides that are consumed with lettuce and perilla leaves were calculated by the ratio of estimated daily intake (EDI) to acceptable daily intake (ADI). The EDI was calculated using insecticide concentration and average consumption of food commodities per person per day. In addition, the theoretical maximum daily intakes (TMDIs) of both insecticides were calculated using the maximum residue limits (MRLs) and average body weight (60 kg) of adults in Republic of Korea. TMDIs were calculated following the equation described by Kim et al.41.$$begin{aligned} & {text{ADI (mg}}/{text{person}}/{text{day)}} = {text{ADI}},({text{mg}}/{text{kg}}/{text{body weight}}/{text{day}}),{text{of target insecticide}} times {text{6}}0,({text{average body weight}}) \ & {text{EDI (mg}}/{text{kg}}/{text{person)}} = {text{concentration of target insecticide (mg}}/{text{kg)}} times {text{ daily food intake (g)}} \ & % {text{ADI}} = {text{EDI}}/{text{ADI}} times {text{1}}00 \ & {text{TMDI}}% = sum % {text{ADI of all registered crops}} \ end{aligned}$$ More

  • in

    Impact of different enzymes on biofilm formation and mussel settlement

    Zobell, C. E. & Allen, E. C. The significance of marine bacteria in the fouling of submerged surfaces. J. Bacteriol. 29, 239–251 (1935).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Flemming, H. C. et al. Biofilms: An emergent form of bacterial life. Nat. Rev. Microbiol. 14, 563–575 (2016).CAS 
    PubMed 

    Google Scholar 
    Shikuma, N. J. & Hadfield, M. G. Marine biofilms on submerged surfaces are a reservoir for Escherichia coli and Vibrio cholerae. Biofouling 26, 39–46 (2010).CAS 
    PubMed 

    Google Scholar 
    Maki, J., Rittschof, D., Schmidt, A., Snyder, A. & Mitchell, R. Factors controlling attachment of bryozoan larvae: A comparison of bacterial films and unfilmed surfaces. Biol. Bull. 177, 295–302 (1989).
    Google Scholar 
    Satuito, C. G., Natoyama, K., Yamazaki, M. & Fusetani, N. Inductin of attachment and metamorphosis of laboratory cultures mussel Mytilus edulis galloprovincialis larvae by microbial film. Fish. Sci. 61, 223–227 (1995).CAS 

    Google Scholar 
    Bao, W., Yang, J., Satuito, C. G. & Kitamura, H. Larval metamorphosis of the mussel Mytilus galloprovincialis in response to Alteromonas sp. 1: Evidence for two chemical cues?. Mar. Biol. 152, 657–666 (2007).
    Google Scholar 
    Liang, X. et al. Polyurethane, epoxy resin and polydimethylsiloxane altered biofilm formation and mussel settlement. Chemosphere 218, 599–608 (2019).ADS 
    CAS 
    PubMed 

    Google Scholar 
    Huggett, M. J., Williamson, J. E., De Nys, R., Kjelleberg, S. & Steinberg, P. D. Larval settlement of the common Australian sea urchin Heliocidaris erythrogramma in response to bacteria from the surface of coralline algae. Oecologia 149, 604–619 (2006).ADS 
    PubMed 

    Google Scholar 
    Yang, J. et al. Larval settlement and metamorphosis of the mussel Mytilus coruscus in response to monospecific bacterial biofilms. Biofouling 29, 247–259 (2013).CAS 
    PubMed 

    Google Scholar 
    Qian, P. Y., Thiyagarajan, V., Lau, S. C. K. & Cheung, S. C. K. Relationship between bacterial community profile in biofilm and attachment of the acorn barnacle Balanus amphitrite. Aquat. Microb. Ecol. 33, 225–237 (2003).
    Google Scholar 
    Leroy, C., Delbarre, C., Ghillebaert, F., Compere, C. & Combes, D. Effects of commercial enzymes on the adhesion of a marine biofilm-forming bacterium. Biofouling 24, 11–22 (2008).CAS 
    PubMed 

    Google Scholar 
    Beigbeder, A. et al. On the effect of carbon nanotubes on the wettability and surface morphology of hydrosilylation-curing silicone coatings. Nanostruct. Polym. Nanocomp 5, 37–43 (2009).
    Google Scholar 
    Lee, S. H., Pumprueg, S., Moudgil, B. & Sigmund, W. Inactivation of bacterial endospores by photocatalytic nanocomposites. Colloids Surf. B Biointerfaces 40, 93–98 (2005).CAS 
    PubMed 

    Google Scholar 
    Alzieu, C. Tributyltin: Case study of a chronic contaminant in the coastal environment. Ocean Coast. Manag. 40, 23–36 (1998).
    Google Scholar 
    Yang, J. L. et al. Chromosome-level genome assembly of the hard-shelled mussel Mytilus coruscus, a widely distributed species from the temperate areas of East Asia. GigaScience 10, giab024 (2021).PubMed 
    PubMed Central 

    Google Scholar 
    Liang, X. et al. The flagellar gene regulates biofilm formation and mussel larval settlement and metamorphosis. Int. J. Mol. Sci. 21, 710 (2020).CAS 
    PubMed Central 

    Google Scholar 
    Liang, X. et al. Bacterial cellulose synthesis gene regulates cellular c-di-GMP that control biofilm formation and mussel larval settlement. Int. Biodeterior. Biodegrad. 165, 105330 (2021).CAS 

    Google Scholar 
    Peng, L. H. et al. A bacterial polysaccharide biosynthesis-related gene inversely regulates larval settlement and metamorphosis of Mytilus coruscus. Biofouling 36, 753–765 (2020).CAS 
    PubMed 

    Google Scholar 
    Chang, R. H. et al. Complete genome sequence of Shewanella marisflavi ECSMB14101, a red pigment synthesizing bacterium isolated from the East China Sea. Mar. Genom. 58, 100846 (2021).
    Google Scholar 
    Sutherland, I. W. Polysaccharide lyases. FEMS Microbiol. Rev. 16, 323–347 (1995).CAS 
    PubMed 

    Google Scholar 
    Flemming, H. C. & Wingender, J. The biofilm matrix. Nat. Rev. Microbiol. 8, 623–633 (2010).CAS 
    PubMed 

    Google Scholar 
    Kristensen, J. B. et al. Antifouling enzymes and the biochemistry of marine settlement. Biotechnol. Adv. 26, 471–481 (2008).CAS 
    PubMed 

    Google Scholar 
    Pettitt, M., Henry, S., Callow, M., Callow, J. & Clare, A. Activity of commercial enzymes on settlement and adhesion of cypris larvae of the barnacle Balanus amphitrite, spores of the green alga Ulva linza, and the diatom Navicula perminuta. Biofouling 20, 299–311 (2004).CAS 
    PubMed 

    Google Scholar 
    McDougald, D., Rice, S. A., Barraud, N., Steinberg, P. D. & Kjelleberg, S. Should we stay or should we go: Mechanisms and ecological consequences for biofilm dispersal. Nat. Rev. Microbiol. 10, 39–50 (2012).CAS 

    Google Scholar 
    Boyd, A. & Chakrabarty, A. Role of alginate lyase in cell detachment of Pseudomonas aeruginosa. Appl. Environ. Microbiol. 60, 2355–2359 (1994).ADS 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Kaplan, J. B., Ragunath, C., Velliyagounder, K., Fine, D. H. & Ramasubbu, N. Enzymatic detachment of Staphylococcus epidermidis biofilms. Antimicrob. Agents Chemother. 48, 2633–2636 (2004).CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Walker, J., Bradshaw, D., Fulford, M. & Marsh, P. Microbiological evaluation of a range of disinfectant products to control mixed-species biofilm contamination in a laboratory model of a dental unit water system. Appl. Environ. Microbiol. 69, 3327–3332 (2003).ADS 
    CAS 
    PubMed 
    PubMed Central 

    Google Scholar 
    Wiater, A., Szczodrak, J. & Rogalski, J. Hydrolysis of mutan and prevention of its formation in streptococcal films by fungal α-d-glucanases. Process Biochem. 39, 1481–1489 (2004).CAS 

    Google Scholar 
    Dobretsov, S., Xiong, H., Xu, Y., Levin, L. A. & Qian, P.-Y. Novel antifoulants: Inhibition of larval attachment by proteases. Mar. Biotechnol. 9, 388–397 (2007).CAS 

    Google Scholar 
    Carl, C. et al. Enhancing the efficacy of fouling-release coatings against fouling by Mytilus galloprovincialis using nanofillers. Biofouling 28, 1077–1091 (2012).CAS 
    PubMed 

    Google Scholar 
    Patel, P., Callow, M. E., Joint, I. & Callow, J. A. Specificity in the settlement–modifying response of bacterial biofilms towards zoospores of the marine alga Enteromorpha. Environ. Microbiol. 5, 338–349 (2003).CAS 
    PubMed 

    Google Scholar 
    Thostenson, E. T., Ren, Z. & Chou, T. Advances in the science and technology of carbon nanotubes and their composites: A review. Compos. Sci. Technol. 61, 1899–1912 (2001).CAS 

    Google Scholar 
    Beigbeder, A. et al. Marine fouling release silicone/carbon nanotube nanocomposite coatings: On the importance of the nanotube dispersion state. J. Nanosci. Nanotechnol. 10, 2972–2978 (2010).CAS 
    PubMed 

    Google Scholar 
    Frogley, M. D., Ravich, D. & Wagner, H. D. Mechanical properties of carbon nanoparticle-reinforced elastomers. Compos. Sci. Technol. 63, 1647–1654 (2003).CAS 

    Google Scholar 
    G., A. Seawater Composition. Online edition. SBCC Marine Science. Santa Barbara City College. http://www.marinebio.net/marinescience/02ocean/swcomposition.htm. (2004).Shipovskov, S., Ferapontova, E. E., Gazaryan, I. & Ruzgas, T. Recombinant horseradish peroxidase-and cytochrome c-based two-electrode system for detection of superoxide radicals. Bioelectrochemistry 63, 277–280 (2004).CAS 
    PubMed 

    Google Scholar 
    Aehle, W. Enzymes in Industry: Production and Applications (Wiley, 2007).
    Google Scholar 
    Walker, G. Larval settlement: Historical and future perspectives. Crustacean Issues 10, 69–86 (1995).
    Google Scholar 
    Tomarelli, R., Charney, J. & Harding, M. L. The use of azoalbumin as a substrate in the colorimetric determination or peptic and tryptic activity. J. Lab. Clin. Med. 34, 428–433 (1949).CAS 
    PubMed 

    Google Scholar 
    Somogyi, M. Modifications of two methods for the assay of amylase. Clin. Chem. 6, 23–35 (1960).CAS 
    PubMed 

    Google Scholar 
    Sinegani, A. A. S. & Emtiazi, G. The relative effects of some elements on the DNS method in cellulase assay. J. Appl. Sci. Environ. Manag. 10, 93–96 (2006).
    Google Scholar 
    Li, Y. et al. Effects of bacterial biofilms on settlement of plantigrades of the mussel Mytilus coruscus. Aquaculture 433, 434–441 (2014).
    Google Scholar 
    Yang, J. et al. Effects of biofilms on settlement of plantigrades of the mussel Mytilus coruscus. J. Fish. China 37, 904–909 (2013) ((In Chinese with English Abstract)).
    Google Scholar 
    Hu, X. M. et al. Reduction of mussel metamorphosis by inactivation of the bacterial thioesterase gene via alteration of the fatty acid composition. Biofouling 37, 911–921 (2021).CAS 
    PubMed 

    Google Scholar  More

  • in

    Newly initiated carbon stock, organic soil accumulation patterns and main driving factors in the High Arctic Svalbard, Norway

    Walker, D. A. et al. The circumpolar Arctic vegetation map. J. Veg. Sci. 16, 267–282 (2005).Article 

    Google Scholar 
    Raynolds, M. K. et al. A raster version of the Circumpolar Arctic Vegetation Map (CAVM). Remote Sens. Environ. 232, 111297 (2019).ADS 
    Article 

    Google Scholar 
    Danell, K. What Is the Arctic? In Which Ways Is the Arctic Different? In Arctic Ecology (ed. Thomas, D. N.) 1–22 (University of Helsinki, 2021).
    Google Scholar 
    Tarnocai, C. et al. Soil organic carbon pools in the northern circumpolar permafrost region. Global Biogeochem. Cycles 23(2), 1–11. https://doi.org/10.1029/2008GB003327 (2009).CAS 
    Article 

    Google Scholar 
    Hugelius, G. et al. Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw. Proc. Natl. Acad. Sci. U.S.A. 117(34), 20438–20446. https://doi.org/10.1073/pnas.1916387117 (2020).ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    Loisel, J. et al. A database and synthesis of northern peatland soil properties and Holocene carbon and nitrogen accumulation. Holocene 24(9), 1028–1042. https://doi.org/10.1177/0959683614538073 (2014).ADS 
    Article 

    Google Scholar 
    Gallego-Sala, A. V. et al. Latitudinal limits to the predicted increase of the peatland carbon sink with warming. Nat. Clim. Chang. 8(10), 907–913. https://doi.org/10.1038/s41558-018-0271-1 (2018).ADS 
    CAS 
    Article 

    Google Scholar 
    Yu, Z., Beilman, D. W. & Jones, M. C. Sensitivity of Northern Peatland carbon dynamics to holocene climate change. Carbon Cycl. Northern Peatl. C https://doi.org/10.1029/2008GM000822 (2009).Article 

    Google Scholar 
    Svendsen, J. & Mangerud, J. Paleoclimatic inferences from glacial fluctuations on Svalbard during the last 20 000 years. Clim. Dyn. 6(3–4), 213–220. https://doi.org/10.1007/BF00193533 (1992).Article 

    Google Scholar 
    Farnsworth, W. R. et al. Holocene glacial history of Svalbard: Status, perspectives and challenges. Earth Sci. Rev. 208(April), 103249. https://doi.org/10.1016/j.earscirev.2020.103249 (2020).CAS 
    Article 

    Google Scholar 
    D’Andrea, W. J. et al. Mild Little Ice Age and unprecedented recent warmth in an 1800 year lake sediment record from Svalbard. Geology 40(11), 1007–1010. https://doi.org/10.1130/G33365.1 (2012).ADS 
    CAS 
    Article 

    Google Scholar 
    Miller, G. H., Landvik, J. Y., Lehman, S. J. & Southon, J. R. Episodic Neoglacial snowline descent and glacier expansion on Svalbard reconstructed from the 14C ages of ice-entombed plants. Quatern. Sci. Rev. 155, 67–78. https://doi.org/10.1016/j.quascirev.2016.10.023 (2017).ADS 
    Article 

    Google Scholar 
    Røthe, T. O. et al. Arctic Holocene glacier fluctuations reconstructed from lake sediments at Mitrahalvøya, Spitsbergen. Quatern. Sci. Rev. 109, 111–125. https://doi.org/10.1016/j.quascirev.2014.11.017 (2015).Article 

    Google Scholar 
    van der Bilt, W. G. M. et al. Reconstruction of glacier variability from lake sediments reveals dynamic Holocene climate in Svalbard. Quatern. Sci. Rev. 126, 201–218. https://doi.org/10.1016/j.quascirev.2015.09.003 (2015).ADS 
    Article 

    Google Scholar 
    Allaart, L. et al. Glacial history of the Åsgardfonna Ice Cap, NE Spitsbergen, since the last glaciation. Quatern. Sci. Rev. https://doi.org/10.1016/j.quascirev.2020.106717 (2021).Article 

    Google Scholar 
    Humlum, O. et al. Late-Holocene glacier growth in Svalbard, documented by subglacial relict vegetation and living soil microbes. Holocene 15(3), 396–407. https://doi.org/10.1191/0959683605hl817rp (2005).ADS 
    Article 

    Google Scholar 
    Yang, Z., Yang, W., Yuan, L., Wang, Y. & Sun, L. Evidence for glacial deposits during the Little Ice Age in Ny-Alesund, western Spitsbergen. J. Earth Syst. Sci. https://doi.org/10.1007/s12040-019-1274-7 (2020).Article 

    Google Scholar 
    AMAP – ARCTIC MONITORING AND ASSESSMENT PROGRAMME. (2019). Arctic Climate Change Update 2019: An update to key findings of Snow, Water, Ice, and Permafrost in the Arctic (SWIPA) 2017. Assessment Report, 12. https://www.amap.no/documents/doc/amap-climate-change-update-2019/1761.Nordli, Ø. et al. Polar Res. 39, 3614. https://doi.org/10.33265/polar.v39.3614 (2020).Article 

    Google Scholar 
    Førland, E. J., Benestad, R., Hanssen-Bauer, I., Haugen, J. E. & Skaugen, T. E. Temperature and precipitation development at svalbard 1900–2100. Adv. Meteorol. 2011, 1–14. https://doi.org/10.1155/2011/893790 (2011).Article 

    Google Scholar 
    Van Der Knaap, W. O. (1988). A pollen diagram from Broggerhalvoya, Spitsbergen: changes in vegetation and environment from ca. 4400 to ca. 800 BP. Arctic & Alpine Research, 20(1), 106–116. Doi: https://doi.org/10.2307/1551703Rozema, J. et al. A vegetation, climate and environment reconstruction based on palynological analyses of high arctic tundra peat cores (5000–6000 years BP) from Svalbard. Plant Ecol. 182(1–2), 155–173. https://doi.org/10.1007/s11258-005-9024-0 (2006).Article 

    Google Scholar 
    Nakatsubo, T. et al. Carbon accumulation rate of peatland in the High Arctic, Svalbard: Implications for carbon sequestration. Polar Sci. 9(2), 267–275. https://doi.org/10.1016/j.polar.2014.12.002 (2015).ADS 
    Article 

    Google Scholar 
    Magnússon, B., Magnússon, S. & Fridriksson, S. (2009). Developments in plant colonization and succession on Surtsey during 1999–2008. Surtsey Res. pp. 57–76.Zwolicki, A., Zmudczyńska-Skarbek, K. M., Iliszko, L. & Stempniewicz, L. Guano deposition and nutrient enrichment in the vicinity of planktivorous and piscivorous seabird colonies in Spitsbergen. Polar Biol. 36(3), 363–372. https://doi.org/10.1007/s00300-012-1265-5 (2013).Article 

    Google Scholar 
    Leblans, N. I. W. et al. Effects of seabird nitrogen input on biomass and carbon accumulation after 50 years of primary succession on a young volcanic island Surtsey. Biogeosciences 11(22), 6237–6250. https://doi.org/10.5194/bg-11-6237-2014 (2014).ADS 
    Article 

    Google Scholar 
    Zmudczyńska-Skarbek, K. et al. Transfer of ornithogenic influence through different trophic levels of the Arctic terrestrial ecosystem of Bjørnøya (Bear Island), Svalbard. Soil Biol. Biochem. 115, 475–489. https://doi.org/10.1016/j.soilbio.2017.09.008 (2017).CAS 
    Article 

    Google Scholar 
    Hodkinson, I. D., Coulson, S. J. & Webb, N. R. Community assembly along proglacial chronosequences in the high arctic: vegetation and soil development in north-west Svalbard. J. Ecol. 91(4), 651–663. https://doi.org/10.1046/j.1365-2745.2003.00786.x (2003).Article 

    Google Scholar 
    Ravolainen, V. et al. High Arctic ecosystem states: Conceptual models of vegetation change to guide long-term monitoring and research. Ambio 49(3), 666–677. https://doi.org/10.1007/s13280-019-01310-x (2020).Article 
    PubMed 
    PubMed Central 

    Google Scholar 
    van der Wal, R. & Brooker, R. W. Mosses mediate grazer impacts on grass abundance in arctic ecosystems. Funct. Ecol. 18(1), 77–86. https://doi.org/10.1111/j.1365-2435.2004.00820.x (2004).Article 

    Google Scholar 
    Vanderpuye, A. W., Elvebakk, A. & Nilsen, L. Plant communities along environmental gradients of high-arctic mires in Sassendalen Svalbard. J. Veg. Sci. 13(6), 875–884. https://doi.org/10.1111/j.1654-1103.2002.tb02117.x (2002).Article 

    Google Scholar 
    Le Moullec, M., Pedersen, Å. Ø., Stien, A., Rosvold, J. & Hansen, B. B. A century of conservation: the ongoing recovery of svalbard reindeer. J. Wildl. Manag. 83(8), 1676–1686. https://doi.org/10.1002/jwmg.21761 (2019).Article 

    Google Scholar 
    Garfelt-Paulsen, I. M. et al. Don’t go chasing the ghosts of the past: habitat selection and site fidelity during calving in an Arctic ungulate. Wildl. Biol. https://doi.org/10.2981/wlb.00740 (2021).Article 

    Google Scholar 
    Moreau, M., Mercier, D., Laffly, D. & Roussel, E. Impacts of recent paraglacial dynamics on plant colonization: a case study on Midtre Lovénbreen foreland, Spitsbergen (79°N). Geomorphology 95(1–2), 48–60. https://doi.org/10.1016/j.geomorph.2006.07.031 (2008).ADS 
    Article 

    Google Scholar 
    Moreau, M., Laffly, D. & Brossard, T. Recent spatial development of Svalbard strandflat vegetation over a period of 31 years. Polar Res. 28(3), 364–375. https://doi.org/10.1111/j.1751-8369.2009.00119.x (2009).Article 

    Google Scholar 
    Wietrzyk, P., Wȩgrzyn, M. & Lisowska, M. Vegetation diversity and selected abiotic factors influencing the primary succession process on the foreland of Gåsbreen Svalbard. Pol. Polar Res. 37(4), 493–509. https://doi.org/10.1515/popore-2016-0026 (2016).Article 

    Google Scholar 
    Divine, D. et al. Thousand years of winter surface air temperature variations in Svalbard and northern norway reconstructed from ice-core data. Polar Res. 30(SUPPL.1), 1–12. https://doi.org/10.3402/polar.v30i0.7379 (2011).ADS 
    Article 

    Google Scholar 
    Van Pelt, W. et al. A long-term dataset of climatic mass balance, snow conditions, and runoff in Svalbard (1957–2018). Cryosphere 13(9), 2259–2280. https://doi.org/10.5194/tc-13-2259-2019 (2019).ADS 
    Article 

    Google Scholar 
    Johansen, B. E., Karlsen, S. R. & Tømmervik, H. Vegetation mapping of Svalbard utilising Landsat TM/ETM+ data. Polar Rec. 48(1), 47–63. https://doi.org/10.1017/S0032247411000647 (2012).Article 

    Google Scholar 
    Norwegian Polar Institute. Available online at: https://npolar.no (2021).Norwegian Meteorological Institute. Available online at: https://seklima.met.no (2019).Kelly, T. J. et al. The vegetation history of an Amazonian domed peatland. Palaeogeogr. Palaeoclimatol. Palaeoecol. 468(November), 129–141. https://doi.org/10.1016/j.palaeo.2016.11.039 (2017).Article 

    Google Scholar 
    Estop-Aragonés, C. et al. Limited release of previously-frozen C and increased new peat formation after thaw in permafrost peatlands. Soil Biol. Biochem. 118, 115–129. https://doi.org/10.1016/j.soilbio.2017.12.010 (2018).CAS 
    Article 

    Google Scholar 
    Blaauw, M., Christen, J. A. & Aquino-Lopez, M. A. rplum: Bayesian Age-Depth Modelling of Cores Dated by Pb-210. R package version 0.2.2. https://CRAN.R-project.org/package=rplum (2021).R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria (2020).Heiri, O., Lotter, A. F. & Lemcke, G. Loss on ignition as a method for estimating organic and carbonate content in sediments: Reproducibility and comparability of results. J. Paleolimnol. 25(1), 101–110. https://doi.org/10.1023/A:1008119611481 (2001).ADS 
    Article 

    Google Scholar 
    Booth, R. K., Lamentowicz, M. & Charman, D. J. Preparation and analysis of testate amoebae in peatland palaeoenvironmental studies. Mires and Peat 7(2), 1–7 (2010).
    Google Scholar 
    Charman, D., Hendon, D. & Woodland, W. A. The Identification of Testate Amoebae (Protozoa: Rhizopoda) in Peats (Quaternary Research Association, 2000).
    Google Scholar 
    Siemensma, F. J. Microworld, world of Amoeboid Organisms. World-Wide Electronic Publication, Kortenhoef, the Netherlands. Available online at: https://www.arcella.nl (2019).Payne, R. J. & Mitchell, E. A. D. How many is enough? Determining optimal count totals for ecological and palaeoecological studies of testate amoebae. J. Paleolimnol. 42(4), 483–495. https://doi.org/10.1007/s10933-008-9299-y (2009).ADS 
    Article 

    Google Scholar 
    Swindles, G. T. et al. Testing peatland water-table depth transfer functions using high-resolution hydrological monitoring data. Q. Sci. Rev. 120, 107–117. https://doi.org/10.1016/j.quascirev.2015.04.019 (2015).ADS 
    Article 

    Google Scholar 
    Amesbury, M. J. et al. Development of a new pan-European testate amoeba transfer function for reconstructing peatland palaeohydrology. Quatern. Sci. Rev. 152, 132–151. https://doi.org/10.1016/j.quascirev.2016.09.024 (2016).ADS 
    Article 

    Google Scholar 
    Amesbury, M. J. et al. Towards a Holarctic synthesis of peatland testate amoeba ecology: Development of a new continental-scale palaeohydrological transfer function for North America and comparison to European data. Quatern. Sci. Rev. 201, 483–500. https://doi.org/10.1016/j.quascirev.2018.10.034 (2018).ADS 
    Article 

    Google Scholar 
    Zhang, H. et al. Testate amoeba as palaeohydrological indicators in the permafrost peatlands of north-east European Russia and Finnish Lapland. J. Quat. Sci. 32(7), 976–988. https://doi.org/10.1002/jqs.2970 (2017).Article 

    Google Scholar 
    Sim, T. G. et al. Pathways for Ecological Change in Canadian High Arctic Wetlands Under Rapid Twentieth Century Warming. Geophys. Res. Lett. 46(9), 4726–4737. https://doi.org/10.1029/2019GL082611 (2019).ADS 
    Article 

    Google Scholar 
    Elmendorf, S. C. et al. Global assessment of experimental climate warming on tundra vegetation: Heterogeneity over space and time. Ecol. Lett. 15(2), 164–175. https://doi.org/10.1111/j.1461-0248.2011.01716.x (2012).Article 
    PubMed 

    Google Scholar 
    Lupascu, M. et al. High Arctic wetting reduces permafrost carbon feedbacks to climate warming. Nat. Clim. Chang. 4(1), 51–55. https://doi.org/10.1038/nclimate2058 (2014).ADS 
    CAS 
    Article 

    Google Scholar 
    Bjorkman, A. D. et al. Status and trends in Arctic vegetation: Evidence from experimental warming and long-term monitoring. Ambio 49(3), 678–692. https://doi.org/10.1007/s13280-019-01161-6 (2020).MathSciNet 
    Article 
    PubMed 

    Google Scholar 
    Egli, M., Mavris, C., Mirabella, A. & Giaccai, D. Soil organic matter formation along a chronosequence in the Morteratsch proglacial area (Upper Engadine, Switzerland). CATENA 82(2), 61–69. https://doi.org/10.1016/j.catena.2010.05.001 (2010).CAS 
    Article 

    Google Scholar 
    Prach, K. & Rachlewicz, G. Succession of vascular plants in front of retreating glaciers in central Spitsbergen. Polish Polar Research 33(4), 319–328. https://doi.org/10.2478/v10183-012-0022-3 (2012).Article 

    Google Scholar 
    Låg, J. Special Peat Formations in Svalbard. Acta Agric. Scand. 30(2), 205–210. https://doi.org/10.1080/00015128009435267 (1980).Article 

    Google Scholar 
    Serebryannyy, L. P., Tishkov, A. A., Malyasova, Y. S., Solomina, O. N. & Il’ves, E. O.,. Reconstruction of the development of vegetation in Arctic high latitudes. Polar Geogr. Geol. 9(4), 308–320. https://doi.org/10.1080/10889378509377261 (1985).Article 

    Google Scholar 
    Surova, T. G., Troitskiy, L. S., Skobeyeva, Y. I. & Punning, Y. M. K. Glacioclimatic conditions in the european arctic in the late holocene. Polar Geogr. Geol. 11(1), 50–57. https://doi.org/10.1080/10889378709377310 (1987).Article 

    Google Scholar 
    Surova, T. G., Troitskiy, L. S., Skobeyeva, Y. I. & Troitskiy, Y. M. K. Changes in glacioclimatic conditions on svalbard during the subboreal period. Polar Geogr. Geol. 12(3), 221–226. https://doi.org/10.1080/10889378809377366 (1988).Article 

    Google Scholar 
    Låg, J. Peat Accumulation in Steep Hills at Alkhornet Spitsbergen. Acta Agric. Scand. 40(3), 217–219. https://doi.org/10.1080/00015129009438554 (1990).Article 

    Google Scholar 
    Oliva, M. et al. Sedimentological characteristics of ice-wedge polygon terrain in adventdalen (Svalbard) environmental and climatic implications for the late Holocene. Solid Earth 5(2), 901–914. https://doi.org/10.5194/se-5-901-2014 (2014).ADS 
    Article 

    Google Scholar 
    Van der Knaap, W. O. Past Vegetation and Reindeer on Edgeoya (Spitsbergen) Between c. 7900 and c. 3800 BP, Studied by Means of Peat Layers and Reindeer Faecal Pellets. J. Biogeogr. 16(4), 379. https://doi.org/10.2307/2845229 (1989).Article 

    Google Scholar 
    Røthe, T. O., Bakke, J., Støren, E. W. N. & Bradley, R. S. Reconstructing holocene glacier and climate fluctuations from lake sediments in Vårfluesjøen Northern Spitsbergen. Front. Earth Sci. 6(July), 1–20. https://doi.org/10.3389/feart.2018.00091 (2018).Article 

    Google Scholar 
    Alsos, I. G. et al. Sedimentary ancient DNA from Lake Skartjørna, Svalbard: assessing the resilience of arctic flora to Holocene climate change. Holocene 26(4), 627–642. https://doi.org/10.1177/0959683615612563 (2016).ADS 
    Article 

    Google Scholar 
    Klimowicz, Z., Melke, J. & Uziak, S. Peat soils in the Bellsund region Spitsbergen. Pol. Polar Res. 18(1), 25–39 (1997).
    Google Scholar 
    Yang, Z. et al. Total photosynthetic biomass record between 9400 and 2200 BP and its link to temperature changes at a High Arctic site near Ny-Ålesund Svalbard. Polar Biol. 42(5), 991–1003. https://doi.org/10.1007/s00300-019-02493-5 (2019).Article 

    Google Scholar 
    Vickers, H. et al. Changes in greening in the high arctic: insights from a 30-year AVHRR max NDVI dataset for Svalbard. Environ. Res. Lett. https://doi.org/10.1088/1748-9326/11/10/105004 (2016).Article 

    Google Scholar 
    Van Der Knaap, W. O. Human influence on natural Arctic vegetation in the 17th century and climatic change since AD 1600 in northwest Spitsbergen: a paleobotanical study. Arct. Alp. Res. 17(4), 371–387. https://doi.org/10.2307/1550863 (1985).Article 

    Google Scholar 
    Martín-Moreno, R., Allende Álvarez, F. & Hagen, J. O. ‘Little Ice Age’ glacier extent and subsequent retreat in Svalbard archipelago. Holocene 27(9), 1379–1390. https://doi.org/10.1177/0959683617693904 (2017).ADS 
    Article 

    Google Scholar 
    Rachlewicz, G., Szczuziński, W. & Ewertowski, M. Post-“Little Ice Age” retreat rates of glaciers around Billefjorden in central Spitsbergen Svalbard. Pol. Polar Res. 28(3), 159–186 (2007).
    Google Scholar 
    Matthews, J. A. & Whittaker, R. J. Vegetation succession on the storbreen glacier foreland, Jotunheimen, Norway : a review. Arct. Alp. Res. 19(4), 385–395 (1987).Article 

    Google Scholar 
    Beyens, L. & Chardez, D. Evidence from testate amoebae for changes in some local hydrological conditions between c. 5000 BP and c. 3800 BP on Edgeøya (Svalbard). Polar Res. 5(2), 165–169. https://doi.org/10.1111/j.1751-8369.1987.tb00619.x (1987).Article 

    Google Scholar 
    Lawrence, D. M., Koven, C. D., Swenson, S. C., Riley, W. J. & Slater, A. G. Permafrost thaw and resulting soil moisture changes regulate projected high-latitude CO2 and CH4 emissions. Environ. Res. Lett. https://doi.org/10.1088/1748-9326/10/9/094011 (2015).Article 

    Google Scholar 
    Isaksen, K., Benestad, R. E., Harris, C. & Sollid, J. L. Recent extreme near-surface permafrost temperatures on Svalbard in relation to future climate scenarios. Geophys. Res. Lett. 34(17), 1–5. https://doi.org/10.1029/2007GL031002 (2007).Article 

    Google Scholar 
    Cable, S., Elberling, B. & Kroon, A. Holocene permafrost history and cryostratigraphy in the High-Arctic Adventdalen Valley, central Svalbard. Boreas 47(2), 423–442. https://doi.org/10.1111/bor.12286 (2018).Article 

    Google Scholar 
    König, M., Kohler, J. & Nuth, C. Glacier Area Outlines–Svalbard, v1.0, http://data.npolar.no/dataset/89f430f8-862f-11e2-8036-005056ad0004 Delivered by CryoClim service (2013).Box, J. E. et al. Key indicators of Arctic climate change: 1917–2017. Environ. Res. Lett. 14(4), 045010. https://doi.org/10.1088/1748-9326/aafc1b (2019).ADS 
    CAS 
    Article 

    Google Scholar 
    Zhang, H. et al. Decreased carbon accumulation feedback driven by climate-induced drying of two southern boreal bogs over recent centuries. Glob. Change Biol. 26(4), 2435–2448. https://doi.org/10.1111/gcb.15005 (2020).ADS 
    Article 

    Google Scholar 
    Szymański, W., Wojtuń, B., Stolarczyk, M., Siwek, J. & Waścińska, J. Organic carbon and nutrients (N, P) in surface soil horizons in a non-glaciated catchment SW Spitsbergen. Pol. Polar Res. 37(1), 49–66. https://doi.org/10.1515/popore-2016-0006 (2016).Article 

    Google Scholar 
    Hugelius, G. et al. Estimated stocks of circumpolar permafrost carbon with quantified uncertainty ranges and identified data gaps. Biogeosciences 11(23), 6573–6593. https://doi.org/10.5194/bg-11-6573-2014 (2014).ADS 
    Article 

    Google Scholar 
    Palmtag, J. et al. Storage, landscape distribution, and burial history of soil organic matter in contrasting areas of continuous permafrost. Arct. Antarct. Alp. Res. 47(1), 71–88. https://doi.org/10.1657/AAAR0014-027 (2015).Article 

    Google Scholar 
    Siewert, M. B. et al. Comparing carbon storage of Siberian tundra and taiga permafrost ecosystems at very high spatial resolution. J. Geophys. Res. Biogeosci. 120, 1973–1994 (2015).CAS 
    Article 

    Google Scholar 
    Wojcik, R., Palmtag, J., Hugelius, G., Weiss, N. & Kuhry, P. Land cover and landform-based upscaling of soil organic carbon stocks on the Brøgger Peninsula, Svalbard. Arct. Antarct. Alp. Res. 51(1), 40–57. https://doi.org/10.1080/15230430.2019.1570784 (2019).Article 

    Google Scholar 
    Yoshitake, S. et al. Vegetation development and carbon storage on a glacier foreland in the High Arctic, Ny-Ålesund Svalbard. Polar Sci. 5(3), 391–397. https://doi.org/10.1016/j.polar.2011.03.002 (2011).ADS 
    Article 

    Google Scholar 
    Mack, M. C. et al. Carbon loss from an unprecedented Arctic tundra wildfire. Nature 475(7357), 489–492. https://doi.org/10.1038/nature10283 (2011).ADS 
    CAS 
    Article 
    PubMed 

    Google Scholar 
    Cooper, E. J., Dullinger, S. & Semenchuk, P. Late snowmelt delays plant development and results in lower reproductive success in the High Arctic. Plant Sci. 180(1), 157–167. https://doi.org/10.1016/j.plantsci.2010.09.005 (2011).CAS 
    Article 
    PubMed 

    Google Scholar  More