TY - GEN A1 - Stiegler, Jonas A1 - von Hoermann, Christian A1 - Müller, Jörg A1 - Benbow, Mark Eric A1 - Heurich, Marco T1 - Carcass provisioning for scavenger conservation in a temperate forest ecosystem T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Carrion plays an essential role in shaping the structure and functioning of ecosystems and has far‐reaching implications for biodiversity conservation. The change in availability and type of carcasses throughout ecosystems can involve negative effects for scavenging communities. To address this issue, there have been recent conservation management measures of carrion provision in natural systems. However, the optimal conditions under which exposing carcasses to optimize conservation outcomes are still limited. Here, we used camera traps throughout elevational and vegetational gradients to monitor the consumption of 48 deer carcasses over a study period of six years by evaluating 270,279 photographs resulting out of 15,373 trap nights. We detected 17 species visiting carcass deployments, including five endangered species. Our results show that large carcasses, the winter season, and a heterogeneous surrounding habitat enhanced the frequency of carcass visits and the species richness of scavenger assemblages. Contrary to our expectations, carcass species, condition (fresh/frozen), and provision schedule (continuous vs single exposure) did not influence scavenging frequency or diversity. The carcass visitation frequency increased with carcass mass and lower temperatures. The effect of large carcasses was especially pronounced for mesopredators and the Eurasian lynx (Lynx lynx ). Lynx were not too influenced in its carrion acquisition by the season, but exclusively preferred remote habitats containing higher forest cover. Birds of prey, mesopredators, and top predators were also positively influenced by the visiting rate of ravens (Corvus corax ), whereas no biotic or abiotic preferences were found for wild boars (Sus scrofa ). This study provides evidence that any ungulate species of carrion, either in a fresh or in previously frozen condition, attracts a high diversity of scavengers especially during winter, thereby supporting earlier work that carcass provisions may support scavenger communities and endangered species. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 955 KW - anthropogenic food subsidies KW - carrion ecology KW - diversity KW - nature conservation KW - necrobiome KW - vertebrate scavenger KW - wildlife management Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-471099 SN - 1866-8372 IS - 955 ER - TY - JOUR A1 - Stiegler, Jonas A1 - von Hoermann, Christian A1 - Müller, Jörg A1 - Benbow, Mark Eric A1 - Heurich, Marco T1 - Carcass provisioning for scavenger conservation in a temperate forest ecosystem JF - Ecosphere N2 - Carrion plays an essential role in shaping the structure and functioning of ecosystems and has far‐reaching implications for biodiversity conservation. The change in availability and type of carcasses throughout ecosystems can involve negative effects for scavenging communities. To address this issue, there have been recent conservation management measures of carrion provision in natural systems. However, the optimal conditions under which exposing carcasses to optimize conservation outcomes are still limited. Here, we used camera traps throughout elevational and vegetational gradients to monitor the consumption of 48 deer carcasses over a study period of six years by evaluating 270,279 photographs resulting out of 15,373 trap nights. We detected 17 species visiting carcass deployments, including five endangered species. Our results show that large carcasses, the winter season, and a heterogeneous surrounding habitat enhanced the frequency of carcass visits and the species richness of scavenger assemblages. Contrary to our expectations, carcass species, condition (fresh/frozen), and provision schedule (continuous vs single exposure) did not influence scavenging frequency or diversity. The carcass visitation frequency increased with carcass mass and lower temperatures. The effect of large carcasses was especially pronounced for mesopredators and the Eurasian lynx (Lynx lynx ). Lynx were not too influenced in its carrion acquisition by the season, but exclusively preferred remote habitats containing higher forest cover. Birds of prey, mesopredators, and top predators were also positively influenced by the visiting rate of ravens (Corvus corax ), whereas no biotic or abiotic preferences were found for wild boars (Sus scrofa ). This study provides evidence that any ungulate species of carrion, either in a fresh or in previously frozen condition, attracts a high diversity of scavengers especially during winter, thereby supporting earlier work that carcass provisions may support scavenger communities and endangered species. KW - anthropogenic food subsidies KW - carrion ecology KW - diversity KW - nature conservation KW - necrobiome KW - vertebrate scavenger KW - wildlife management Y1 - 2020 U6 - https://doi.org/10.1002/ecs2.3063 SN - 2150-8925 VL - 11 IS - 4 PB - ESA CY - Ithaca, NY ER - TY - JOUR A1 - Zimmermann, Heike Hildegard A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Kruse, Stefan A1 - Müller, Juliane A1 - Stein, Ruediger A1 - Tiedemann, Ralf A1 - Herzschuh, Ulrike T1 - Changes in the composition of marine and sea-ice diatoms derived from sedimentary ancient DNA of the eastern Fram Strait over the past 30 000 years JF - Ocean Science N2 - The Fram Strait is an area with a relatively low and irregular distribution of diatom microfossils in surface sediments, and thus microfossil records are scarce, rarely exceed the Holocene, and contain sparse information about past richness and taxonomic composition. These attributes make the Fram Strait an ideal study site to test the utility of sedimentary ancient DNA (sedaDNA) metabarcoding. Amplifying a short, partial rbcL marker from samples of sediment core MSM05/5-712-2 resulted in 95.7 % of our sequences being assigned to diatoms across 18 different families, with 38.6 % of them being resolved to species and 25.8 % to genus level. Independent replicates show a high similarity of PCR products, especially in the oldest samples. Diatom sedaDNA richness is highest in the Late Weichselian and lowest in Mid- and Late Holocene samples. Taxonomic composition is dominated by cold-water and sea-ice-associated diatoms and suggests several reorganisations – after the Last Glacial Maximum, after the Younger Dryas, and after the Early and after the Mid-Holocene. Different sequences assigned to, amongst others, Chaetoceros socialis indicate the detectability of intra-specific diversity using sedaDNA. We detect no clear pattern between our diatom sedaDNA record and the previously published IP25 record of this core, although proportions of pennate diatoms increase with higher IP25 concentrations and proportions of Nitzschia cf. frigida exceeding 2 % of the assemblage point towards past sea-ice presence. KW - last glacial maximum KW - surface temperatures KW - species composition KW - greenland shelf KW - Disko Bay KW - phytoplankton KW - communities KW - variability KW - diversity KW - Svalbard Y1 - 2019 VL - 16 IS - 5 PB - Springer CY - Tokyo ER - TY - GEN A1 - Zimmermann, Heike Hildegard A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Kruse, Stefan A1 - Müller, Juliane A1 - Stein, Ruediger A1 - Tiedemann, Ralf A1 - Herzschuh, Ulrike T1 - Changes in the composition of marine and sea-ice diatoms derived from sedimentary ancient DNA of the eastern Fram Strait over the past 30 000 years T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The Fram Strait is an area with a relatively low and irregular distribution of diatom microfossils in surface sediments, and thus microfossil records are scarce, rarely exceed the Holocene, and contain sparse information about past richness and taxonomic composition. These attributes make the Fram Strait an ideal study site to test the utility of sedimentary ancient DNA (sedaDNA) metabarcoding. Amplifying a short, partial rbcL marker from samples of sediment core MSM05/5-712-2 resulted in 95.7 % of our sequences being assigned to diatoms across 18 different families, with 38.6 % of them being resolved to species and 25.8 % to genus level. Independent replicates show a high similarity of PCR products, especially in the oldest samples. Diatom sedaDNA richness is highest in the Late Weichselian and lowest in Mid- and Late Holocene samples. Taxonomic composition is dominated by cold-water and sea-ice-associated diatoms and suggests several reorganisations – after the Last Glacial Maximum, after the Younger Dryas, and after the Early and after the Mid-Holocene. Different sequences assigned to, amongst others, Chaetoceros socialis indicate the detectability of intra-specific diversity using sedaDNA. We detect no clear pattern between our diatom sedaDNA record and the previously published IP25 record of this core, although proportions of pennate diatoms increase with higher IP25 concentrations and proportions of Nitzschia cf. frigida exceeding 2 % of the assemblage point towards past sea-ice presence. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1195 KW - last glacial maximum KW - surface temperatures KW - species composition KW - greenland shelf KW - Disko Bay KW - phytoplankton KW - communities KW - variability KW - diversity KW - Svalbard Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-525154 SN - 1866-8372 IS - 5 ER - TY - THES A1 - Meyer-Lucht, Yvonne T1 - Does variability matter? Major histocompatibility complex (MHC) variation and its associations to parasitism in natural small mammal populations T1 - Die Vielfalt der MHC Immungene und ihre Bedeutung in der Parasitenabwehr in natürlichen Kleinsäugerpopulationen N2 - The adaptive evolutionary potential of a species or population to cope with omnipresent environmental challenges is based on its genetic variation. Variability at immune genes, such as the major histocompatibility complex (MHC) genes, is assumed to be a very powerful and effective tool to keep pace with diverse and rapidly evolving pathogens. In my thesis, I studied natural levels of variation at the MHC genes, which have a key role in immune defence, and parasite burden in different small mammal species. I assessed the importance of MHC variation for parasite burden in small mammal populations in their natural environment. To understand the processes shaping different patterns of MHC variation I focused on evidence of selection through pathogens upon the host. Further, I addressed the issue of low MHC diversity in populations or species, which could potentially arise as a result from habitat fragmentation and isolation. Despite their key role in the mammalian evolution the marsupial MHC has been rarely investigated. Studies on primarily captive or laboratory bred individuals indicated very little or even no polymorphism at the marsupial MHC class II genes. However, natural levels of marsupial MHC diversity and selection are unknown to date as studies on wild populations are virtually absent. I investigated MHC II variation in two Neotropical marsupial species endemic to the threatened Brazilian Atlantic Forest (Gracilinanus microtarsus, Marmosops incanus) to test whether the predicted low marsupial MHC class II polymorphism proves to be true under natural conditions. For the first time in marsupials I confirmed characteristics of MHC selection that were so far only known from eutherian mammals, birds, and fish: Positive selection on specific codon sites, recombination, and trans-species polymorphism. Beyond that, the two marsupial species revealed considerable differences in their MHC class II diversity. Diversity was rather low in M. incanus but tenfold higher in G. microtarsus, disproving the predicted general low marsupial MHC class II variation. As pathogens are believed to be very powerful drivers of MHC diversity, I studied parasite burden in both host species to understand the reasons for the remarkable differences in MHC diversity. In both marsupial species specific MHC class II variants were associated to either high or low parasite load highlighting the importance of the marsupial MHC class II in pathogen defence. I developed two alternative scenarios with regard to MHC variation, parasite load, and parasite diversity. In the ‘evolutionary equilibrium’ scenario I assumed the species with low MHC diversity, M. incanus, to be under relaxed pathogenic selection and expected low parasite diversity. Alternatively, low MHC diversity could be the result of a recent loss of genetic variation by means of a genetic bottleneck event. Under this ‘unbalanced situation’ scenario, I assumed a high parasite burden in M. incanus due to a lack of resistance alleles. Parasitological results clearly reject the first scenario and point to the second scenario, as M. incanus is distinctly higher parasitised but parasite diversity is relatively equal compared to G. microtarsus. Hence, I suggest that the parasite load in M. incanus is rather the consequence than the cause for its low MHC diversity. MHC variation and its associations to parasite burden have been typically studied within single populations but MHC variation between populations was rarely taken into account. To gain scientific insight on this issue, I chose a common European rodent species. In the yellow necked mouse (Apodemus flavicollis), I investigated the effects of genetic diversity on parasite load not on the individual but on the population level. I included populations, which possess different levels of variation at the MHC as well as at neutrally evolving genetic markers (microsatellites). I was able to show that mouse populations with a high MHC allele diversity are better armed against high parasite burdens highlighting the significance of adaptive genetic diversity in the field of conservation genetics. An individual itself will not directly benefit from its population’s large MHC allele pool in terms of parasite resistance. But confronted with the multitude of pathogens present in the wild a population with a large MHC allele reservoir is more likely to possess individuals with resistance alleles. These results deepen our understanding of the complex causes and processes of evolutionary adaptations between hosts and pathogens. N2 - In einer sich ständig verändernden Umwelt ist es unverzichtbar, sich fortwährend zu verändern und anzupassen. Dabei gründet sich das Anpassungsvermögen oder das evolutionäre Potential einer Art auf ihre genetische Variabilität. In der Krankheitsabwehr ist die Variabilität der Immungene ein besonders wichtiges und effektives Instrument, weil Pathogene sehr vielfältig sind und schnell evolvieren. Im Rahmen meiner Doktorarbeit habe ich mich mit der Variabilität des Immungen-Komplexes MHC (major histocompatibility complex) beschäftigt, der eine Schlüsselrolle in der Immunabwehr bei Vertebraten einnimmt. Anhand verschiedener Arten und Populationen von Kleinsäugern habe ich den Einfluss der MHC Vielfalt auf den Parasitenbefall unter natürlichen Bedingungen untersucht. Dabei interessierte mich insbesondere das Vorkommen geringer MHC Variabilität in Populationen, das möglicherweise eine Folge von Lebensraum-fragmentierung und Isolation ist. Obwohl Beuteltiere eine zentrale Rolle in der Evolution der Säugetiere spielen, ist über ihren MHC bislang nur sehr wenig bekannt. Einige Studien befassten sich mit Labor- oder Zootieren, und deuteten auf geringe oder sogar gar keine Variation im MHC Klasse II bei Beuteltieren hin. Allerdings gab es bislang nahezu keine Studien an frei lebenden Beuteltieren, deshalb war bislang ein natürliches Ausmaß der MHC Variabilität unbekannt. Anhand von zwei endemischen neotropischen Beuteltieren aus dem brasilianischen Küstenregenwald (Gracilinanus microtarsus, Marmosops incanus) habe ich überprüft, ob sich diese geringe MHC Vielfalt unter natürlichen Freilandbedingungen bestätigt. Erstmals konnte ich zeigen, dass der MHC II bei Beuteltieren charakteristische Merkmale positiver Selektion aufweist, die bisher nur von placentalen Säugern, Vögeln und Fischen bekannt waren: Positive Selektion auf spezifischen Aminosäurepositionen, Rekombination und Trans-Species-Polymorphismus. Darüber hinaus unterschieden sich die beiden Beuteltierarten beträchtlich in ihrer MHC II Variabilität. Während M. incanus sich als relativ wenig divers erwies, zeigte G. microtarsus eine zehnmal höhere Vielfalt und widerlegt damit die generelle Gültigkeit der ursprünglich angenommenen geringen MHC II Variabilität bei Beuteltieren. Um diese beachtlichen Diversitätsunterschiede zwischen den beiden Arten zu erklären, habe ich die Parasitenbelastung untersucht. Bei beiden Arten konnte ich nachweisen, dass bestimmte MHC Varianten mit entweder hoher oder niedriger Parasitenbelastung verknüpft waren. Solche Assoziationen spiegeln Pathogen-vermittelte Selektion wider, untermauern die Funktionalität des MHC Klasse II bei Beuteltieren und weisen auf dieselbe Bedeutsamkeit des MHC wie bei placentalen Säuger, Vögeln und Fischen hin. Ich entwickelte zwei alternative evolutionäre Szenarien, unter denen eine geringe MHC Variabilität denkbar ist. Im Szenario des ‘evolutionären Gleichgewichts’ ist geringe MHC Variabilität die Folge eines verminderten Selektionsdruckes durch wenige Parasiten, sodass eine geringe Parasitendiversität zu erwarten ist. Alternativ könnte eine geringe MHC Variabilität aber auch Folge eines kürzlich erlittenen Verlustes an genetischer Variabilität sein, beispielsweise durch ein Flaschenhalsereignis. Unter diesem Szenario des ‘Ungleichgewichts’ wäre bei M. incanus im Falle eines potentiellen Verlustes von Resistenzallelen eine starke Parasitenbelastung zu erwarten. Die parasitologischen Ergebnisse widersprechen dem ersten und deuten eher auf das zweite Szenario. M. incanus war deutlich stärker parasitiert als G. microtarsus, wohingegen die Parasitendiversität bei beiden Arten ungefähr gleich war. Die hohe Parasitenbelastung bei M. incanus ist offenbar weniger der Auslöser als vielmehr eine Folge seiner geringen MHC Vielfalt zu sein. Üblicherweise werden sowohl die Variabilität des MHC als auch seine Verknüpfung mit Parasitenbelastung innerhalb von einzelnen Populationen untersucht, nur selten wird die Variation zwischen Populationen in Betracht gezogen. Um Erkenntnisse auf dieser Ebene zu gewinnen, habe ich den Zusammenhang zwischen genetischer Vielfalt und Parasitenbelastung nicht auf der Ebene des Individuums, sondern auf der Populationsebene anhand der europäischen Gelbhalsmaus (Apodemus flavicollis) erforscht. Dabei wurden Populationen mit unterschiedlicher genetischer Variabilität am MHC und an neutralen genetischen Markern (Mikrosatelliten) betrachtet. Ich konnte nachweisen, dass Populationen, die über ein großes Spektrum verschiedener MHC Allele verfügen, besser gegen starke Parasitenbelastung gewappnet sind als Populationen mit einer geringen Anzahl MHC Allele. In einer MHC-diversen Population ist die Gegenwart von Individuen mit Resistenzallelen deutlich wahrscheinlicher, und damit die Überlebenswahrscheinlichkeit der Population. Diese Ergebnisse erweitern und vertiefen unsere Erkenntnisse zu die komplexen evolutionären Vorgängen und Mechanismen zwischen Wirt und Parasit in ihrem fortwährenden Wettstreit. KW - Haupthistokompatibilitätskomplex KW - Kleinsäuger KW - Parasitierung KW - Immunsystem KW - Vielfalt KW - major hhistocompatibility complex KW - small mammals KW - parasitism KW - immune system KW - diversity Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-36419 ER - TY - JOUR A1 - Rjosk, Camilla A1 - Richter, Dirk A1 - Luedtke, Oliver A1 - Eccles, Jacquelynne Sue T1 - Ethnic Composition and Heterogeneity in the Classroom: Their Measurement and Relationship With Student Outcomes JF - The journal of educational psychology N2 - This study explores various measures of the ethnic makeup in a classroom and their relationship with student outcomes. We examine whether measures of ethnic diversity are related to achievement (mathematics, reading) and feeling of belonging with one’s peers over and above commonly investigated composition characteristics. Multilevel analyses were based on data from a representative sample of 18,762 elementary school students in 903 classrooms. The proportion of minority students and diversity measures showed negative associations with student outcomes in separate models. Including diversity measures and the proportion of minority students, diversity of minority students mostly lost its significance. However, the results suggest that diversity measures may provide additional information over and above other classroom characteristics for some student outcomes. The various measures of diversity led to comparable results. (PsycINFO Database Record (c) 2017 APA, all rights reserved) KW - ethnic composition KW - diversity KW - multilevel analysis KW - academic achievement KW - classroom Y1 - 2017 U6 - https://doi.org/10.1037/edu0000185 SN - 0022-0663 SN - 1939-2176 VL - 109 SP - 1188 EP - 1204 PB - American Psychological Association CY - Washington ER - TY - GEN A1 - Westbury, Michael V. A1 - Hartmann, Stefanie A1 - Barlow, Axel A1 - Wiesel, Ingrid A1 - Leo, Viyanna A1 - Welch, Rebecca A1 - Parker, Daniel M. A1 - Sicks, Florian A1 - Ludwig, Arne A1 - Dalen, Love A1 - Hofreiter, Michael T1 - Extended and continuous decline in effective population size results in low genomic diversity in the world's rarest hyena species, the brown hyena T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Hyenas (family Hyaenidae), as the sister group to cats (family Felidae), represent a deeply diverging branch within the cat-like carnivores (Feliformia). With an estimated population size of <10,000 individuals worldwide, the brown hyena (Parahyaena brunnea) represents the rarest of the four extant hyena species and has been listed as Near Threatened by the IUCN. Here, we report a high-coverage genome from a captive bred brown hyena and both mitochondrial and low-coverage nuclear genomes of 14 wild-caught brown hyena individuals from across southern Africa. We find that brown hyena harbor extremely low genetic diversity on both the mitochondrial and nuclear level, most likely resulting from a continuous and ongoing decline in effective population size that started similar to 1 Ma and dramatically accelerated towards the end of the Pleistocene. Despite the strikingly low genetic diversity, we find no evidence of inbreeding within the captive bred individual and reveal phylogeographic structure, suggesting the existence of several potential subpopulations within the species. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 589 KW - evolution KW - hyena KW - genomics KW - population genomics KW - diversity Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-414132 SN - 1866-8372 IS - 589 ER - TY - JOUR A1 - Westbury, Michael V. A1 - Hartmann, Stefanie A1 - Barlow, Axel A1 - Wiesel, Ingrid A1 - Leo, Viyanna A1 - Welch, Rebecca A1 - Parker, Daniel M. A1 - Sicks, Florian A1 - Ludwig, Arne A1 - Dalen, Love A1 - Hofreiter, Michael T1 - Extended and continuous decline in effective population size results in low genomic diversity in the world's rarest hyena species, the brown hyena JF - Molecular biology and evolution N2 - Hyenas (family Hyaenidae), as the sister group to cats (family Felidae), represent a deeply diverging branch within the cat-like carnivores (Feliformia). With an estimated population size of <10,000 individuals worldwide, the brown hyena (Parahyaena brunnea) represents the rarest of the four extant hyena species and has been listed as Near Threatened by the IUCN. Here, we report a high-coverage genome from a captive bred brown hyena and both mitochondrial and low-coverage nuclear genomes of 14 wild-caught brown hyena individuals from across southern Africa. We find that brown hyena harbor extremely low genetic diversity on both the mitochondrial and nuclear level, most likely resulting from a continuous and ongoing decline in effective population size that started similar to 1 Ma and dramatically accelerated towards the end of the Pleistocene. Despite the strikingly low genetic diversity, we find no evidence of inbreeding within the captive bred individual and reveal phylogeographic structure, suggesting the existence of several potential subpopulations within the species. KW - evolution KW - hyena KW - genomics KW - population genomics KW - diversity Y1 - 2018 U6 - https://doi.org/10.1093/molbev/msy037 SN - 0737-4038 SN - 1537-1719 VL - 35 IS - 5 SP - 1225 EP - 1237 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Huang, Sichao A1 - Herzschuh, Ulrike A1 - Pestryakova, Luidmila Agafyevna A1 - Zimmermann, Heike Hildegard A1 - Davydova, Paraskovya A1 - Biskaborn, Boris A1 - Shevtsova, Iuliia A1 - Stoof-Leichsenring, Kathleen Rosemarie T1 - Genetic and morphologic determination of diatom community composition in surface sediments from glacial and thermokarst lakes in the Siberian Arctic JF - Journal of paleolimnolog N2 - Lakes cover large parts of the climatically sensitive Arctic landscape and respond rapidly to environmental change. Arctic lakes have different origins and include the predominant thermokarst lakes, which are small, young and highly dynamic, as well as large, old and stable glacial lakes. Freshwater diatoms dominate the primary producer community in these lakes and can be used to detect biotic responses to climate and environmental change. We used specific diatom metabarcoding on sedimentary DNA, combined with next-generation sequencing and diatom morphology, to assess diatom diversity in five glacial and 15 thermokarst lakes within the easternmost expanse of the Siberian treeline ecotone in Chukotka, Russia. We obtained 163 verified diatom sequence types and identified 176 diatom species morphologically. Although there were large differences in taxonomic assignment using the two approaches, they showed similar high abundances and diversity of Fragilariceae and Aulacoseiraceae. In particular, the genetic approach detected hidden within-lake variations of fragilarioids in glacial lakes and dominance of centric Aulacoseira species, whereas Lindavia ocellata was predominant using morphology. In thermokarst lakes, sequence types and valve counts also detected high diversity of Fragilariaceae, which followed the vegetation gradient along the treeline. Ordination analyses of the genetic data from glacial and thermokarst lakes suggest that concentrations of sulfate (SO42-), an indicator of the activity of sulfate-reducing microbes under anoxic conditions, and bicarbonate (HCO3-), which relates to surrounding vegetation, have a significant influence on diatom community composition. For thermokarst lakes, we also identified lake depth as an important variable, but SO42- best explains diatom diversity derived from genetic data, whereas HCO3- best explains the data from valve counts. Higher diatom diversity was detected in glacial lakes, most likely related to greater lake age and different edaphic settings, which gave rise to diversification and endemism. In contrast, small, dynamic thermokarst lakes are inhabited by stress-tolerant fragilarioids and are related to different vegetation types along the treeline ecotone. Our study demonstrated that genetic investigations of lake sediments can be used to interpret climate and environmental responses of diatoms. It also showed how lake type affects diatom diversity, and that such genetic analyses can be used to track diatom community changes under ongoing warming in the Arctic. KW - diatoms KW - diversity KW - glacial lakes KW - sedimentary DNA KW - Siberian arctic KW - thermokarst Y1 - 2020 U6 - https://doi.org/10.1007/s10933-020-00133-1 SN - 0921-2728 SN - 1573-0417 VL - 64 IS - 3 SP - 225 EP - 242 PB - Springer CY - Dordrecht ER - TY - GEN A1 - Romero-Munoz, Alfredo A1 - Fandos, Guillermo A1 - Benítez-López, Ana A1 - Kuemmerle, Tobias T1 - Habitat destruction and overexploitation drive widespread declines in all facets of mammalian diversity in the Gran Chaco T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Global biodiversity is under high and rising anthropogenic pressure. Yet, how the taxonomic, phylogenetic, and functional facets of biodiversity are affected by different threats over time is unclear. This is particularly true for the two main drivers of the current biodiversity crisis: habitat destruction and overexploitation. We provide the first long-term assessment of multifaceted biodiversity changes caused by these threats for any tropical region. Focussing on larger mammals in South America's 1.1 million km(2) Gran Chaco region, we assessed changes in multiple biodiversity facets between 1985 and 2015, determined which threats drive those changes, and identified remaining key areas for all biodiversity facets. Using habitat and threat maps, we found, first, that between 1985 and 2015 taxonomic (TD), phylogenetic (PD) and functional (FD) diversity all declined drastically across over half of the area assessed. FD declined about 50% faster than TD and PD, and these declines were mainly driven by species loss, rather than species turnover. Second, habitat destruction, hunting, and both threats together contributed similar to 57%, similar to 37%, and similar to 6% to overall facet declines, respectively. However, hunting pressure increased where TD and PD declined most strongly, whereas habitat destruction disproportionally contributed to FD declines. Third, just 23% of the Chaco would have to be protected to safeguard the top 17% of all three facets. Our findings uncover a widespread impoverishment of mammal species richness, evolutionary history, and ecological functions across broad areas of the Chaco due to increasing habitat destruction and hunting. Moreover, our results pinpoint key areas that should be preserved and managed to maintain all facets of mammalian diversity across the Chaco. More generally, our work highlights how long-term changes in biodiversity facets can be assessed and attributed to specific threats, to better understand human impacts on biodiversity and to guide conservation planning to mitigate them. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1370 KW - biodiversity facets KW - extinction drivers KW - functional diversity KW - functional richness KW - overhunting KW - phylogenetic diversity KW - taxonomic KW - diversity KW - traits Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-567696 SN - 1866-8372 IS - 4 ER -