@article{PetersHempAppelhansetal.2016, author = {Peters, Marcell K. and Hemp, Andreas and Appelhans, Tim and Behler, Christina and Classen, Alice and Detsch, Florian and Ensslin, Andreas and Ferger, Stefan W. and Frederiksen, Sara B. and Gebert, Frederike and Haas, Michael and Helbig-Bonitz, Maria and Hemp, Claudia and Kindeketa, William J. and Mwangomo, Ephraim and Ngereza, Christine and Otte, Insa and R{\"o}der, Juliane and Rutten, Gemma and Costa, David Schellenberger and Tardanico, Joseph and Zancolli, Giulia and Deckert, J{\"u}rgen and Eardley, Connal D. and Peters, Ralph S. and R{\"o}del, Mark-Oliver and Schleuning, Matthias and Ssymank, Axel and Kakengi, Victor and Zhang, Jie and B{\"o}hning-Gaese, Katrin and Brandl, Roland and Kalko, Elisabeth K.V. and Kleyer, Michael and Nauss, Thomas and Tschapka, Marco and Fischer, Markus and Steffan-Dewenter, Ingolf}, title = {Predictors of elevational biodiversity gradients change from single taxa to the multi-taxa community level}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, doi = {10.1038/ncomms13736}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169374}, year = {2016}, abstract = {The factors determining gradients of biodiversity are a fundamental yet unresolved topic in ecology. While diversity gradients have been analysed for numerous single taxa, progress towards general explanatory models has been hampered by limitations in the phylogenetic coverage of past studies. By parallel sampling of 25 major plant and animal taxa along a 3.7 km elevational gradient on Mt. Kilimanjaro, we quantify cross-taxon consensus in diversity gradients and evaluate predictors of diversity from single taxa to a multi-taxa community level. While single taxa show complex distribution patterns and respond to different environmental factors, scaling up diversity to the community level leads to an unambiguous support for temperature as the main predictor of species richness in both plants and animals. Our findings illuminate the influence of taxonomic coverage for models of diversity gradients and point to the importance of temperature for diversification and species coexistence in plant and animal communities.}, language = {en} } @article{ClassenEardleyHempetal.2020, author = {Classen, Alice and Eardley, Connal D. and Hemp, Andreas and Peters, Marcell K. and Peters, Ralph S. and Ssymank, Axel and Steffan-Dewenter, Ingolf}, title = {Specialization of plant-pollinator interactions increases with temperature at Mt. Kilimanjaro}, series = {Ecology and Evolution}, volume = {10}, journal = {Ecology and Evolution}, number = {4}, doi = {10.1002/ece3.6056}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235959}, pages = {2182-2195}, year = {2020}, abstract = {Aim: Species differ in their degree of specialization when interacting with other species, with significant consequences for the function and robustness of ecosystems. In order to better estimate such consequences, we need to improve our understanding of the spatial patterns and drivers of specialization in interaction networks. Methods: Here, we used the extensive environmental gradient of Mt. Kilimanjaro (Tanzania, East Africa) to study patterns and drivers of specialization, and robustness of plant-pollinator interactions against simulated species extinction with standardized sampling methods. We studied specialization, network robustness and other network indices of 67 quantitative plant-pollinator networks consisting of 268 observational hours and 4,380 plant-pollinator interactions along a 3.4 km elevational gradient. Using path analysis, we tested whether resource availability, pollinator richness, visitation rates, temperature, and/or area explain average specialization in pollinator communities. We further linked pollinator specialization to different pollinator taxa, and species traits, that is, proboscis length, body size, and species elevational ranges. Results: We found that specialization decreased with increasing elevation at different levels of biological organization. Among all variables, mean annual temperature was the best predictor of average specialization in pollinator communities. Specialization differed between pollinator taxa, but was not related to pollinator traits. Network robustness against simulated species extinctions of both plants and pollinators was lowest in the most specialized interaction networks, that is, in the lowlands. Conclusions: Our study uncovers patterns in plant-pollinator specialization along elevational gradients. Mean annual temperature was closely linked to pollinator specialization. Energetic constraints, caused by short activity timeframes in cold highlands, may force ectothermic species to broaden their dietary spectrum. Alternatively or in addition, accelerated evolutionary rates might facilitate the establishment of specialization under warm climates. Despite the mechanisms behind the patterns have yet to be fully resolved, our data suggest that temperature shifts in the course of climate change may destabilize pollination networks by affecting network architecture.}, language = {en} } @article{LaswayPetersNjovuetal.2022, author = {Lasway, Julius V. and Peters, Marcell K. and Njovu, Henry K. and Eardley, Connal and Pauly, Alain and Steffan-Dewenter, Ingolf}, title = {Agricultural intensification with seasonal fallow land promotes high bee diversity in Afrotropical drylands}, series = {Journal of Applied Ecology}, volume = {59}, journal = {Journal of Applied Ecology}, number = {12}, doi = {10.1111/1365-2664.14296}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-311877}, pages = {3014 -- 3026}, year = {2022}, abstract = {The exponential increase in the human population in tandem with increased food demand has caused agriculture to be the global-dominant form of land use. Afrotropical drylands are currently facing the loss of natural savannah habitats and agricultural intensification with largely unknown consequences for bees. Here we investigate the effects of agricultural intensification on bee assemblages in the Afrotropical drylands of northern Tanzania. We disentangled the direct effects of agricultural intensification and temperature on bee richness from indirect effects mediated by changes in floral resources. We collected data from 24 study sites representing three levels of management intensity (natural savannah, moderate intensive and highly intensive agriculture) spanning an extensive gradient of mean annual temperature (MAT) in northern Tanzania. We used ordinary linear models and path analysis to test the effects of agricultural intensity and MAT on bee species richness, bee species composition and body-size variation of bee communities. We found that bee species richness increased with agricultural intensity and with increasing temperature. The effects of agricultural intensity and temperature on bee species richness were mediated by the positive effects of agriculture and temperature on the richness of floral resources used by bees. During the off-growing season, agricultural land was characterized by an extensive period of fallow land holding a very high density of flowering plants with unique bee species composition. The increase in bee diversity in agricultural habitats paralleled an increasing variation of bee body sizes with agricultural intensification that, however, diminished in environments with higher temperatures. Synthesis and applications. Our study reveals that bee assemblages in Afrotropical drylands benefit from agricultural intensification in the way it is currently practiced. However, further land-use intensification, including year-round irrigated crop monocultures and excessive use of agrochemicals, is likely to exert a negative impact on bee diversity and pollination services, as reported in temperate regions. Moreover, several bee species were restricted to natural savannah habitats. To conserve bee communities and guarantee pollination services in the region, a mixture of savannah and agriculture, with long periods of fallow land should be maintained.}, language = {en} } @article{LaswayKinaboMremietal.2021, author = {Lasway, Julius V. and Kinabo, Neema R. and Mremi, Rudolf F. and Martin, Emanuel H. and Nyakunga, Oliver C. and Sanya, John J. and Rwegasira, Gration M. and Lesio, Nicephor and Gideon, Hulda and Pauly, Alain and Eardley, Connal and Peters, Marcell K. and Peterson, Andrew T. and Steffan-Dewenter, Ingolf and Njovu, Henry K.}, title = {A synopsis of the Bee occurrence data of northern Tanzania}, series = {Biodiversity Data Journal}, volume = {9}, journal = {Biodiversity Data Journal}, doi = {10.3897/BDJ.9.e68190}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265018}, year = {2021}, abstract = {Background Bees (Hymenoptera: Apoidea: Anthophila) are the most important group of pollinators with about 20,507 known species worldwide. Despite the critical role of bees in providing pollination services, studies aiming at understanding which species are present across disturbance gradients are scarce. Limited taxononomic information for the existing and unidentified bee species in Tanzania make their conservation haphazard. Here, we present a dataset of bee species records obtained from a survey in nothern Tanzania i.e. Kilimanjaro, Arusha and Manyara regions. Our findings serve as baseline data necessary for understanding the diversity and distribution of bees in the northern parts of the country, which is a critical step in devising robust conservation and monitoring strategies for their populations. New information In this paper, we present information on 45 bee species belonging to 20 genera and four families sampled using a combination of sweep-netting and pan trap methods. Most species (27, ~ 60\%) belong to the family Halictidae followed by 16 species (35.5\%) from the family Apidae. Megachilidae and Andrenidae were the least represented, each with only one species (2.2\%). Additional species of Apidae and Megachilidae sampled during this survey are not yet published on Global Biodiversity Information Facility (GBIF), once they will be available on GBIF, they will be published in a subsequent paper. From a total of 953 occurrences, highest numbers were recorded in Kilimanjaro Region (n = 511), followed by Arusha (n = 410) and Manyara (n = 32), but this pattern reflects the sampling efforts of the research project rather than real bias in the distributions of bee species in northern Tanzania.}, language = {en} } @article{NjovuSteffanDewenterGebertetal.2021, author = {Njovu, Henry K. and Steffan-Dewenter, Ingolf and Gebert, Friederike and Schellenberger Costa, David and Kleyer, Michael and Wagner, Thomas and Peters, Marcell K.}, title = {Plant traits mediate the effects of climate on phytophagous beetle diversity on Mt. Kilimanjaro}, series = {Ecology}, volume = {102}, journal = {Ecology}, number = {12}, doi = {10.1002/ecy.3521}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257343}, year = {2021}, abstract = {Patterns of insect diversity along elevational gradients are well described in ecology. However, it remains little tested how variation in the quantity, quality, and diversity of food resources influence these patterns. Here we analyzed the direct and indirect effects of climate, food quantity (estimated by net primary productivity), quality (variation in the specific leaf area index, leaf nitrogen to phosphorus and leaf carbon to nitrogen ratio), and food diversity (diversity of leaf traits) on the species richness of phytophagous beetles along the broad elevation and land use gradients of Mt. Kilimanjaro, Tanzania. We sampled beetles at 65 study sites located in both natural and anthropogenic habitats, ranging from 866 to 4,550 m asl. We used path analysis to unravel the direct and indirect effects of predictor variables on species richness. In total, 3,154 phytophagous beetles representing 19 families and 304 morphospecies were collected. We found that the species richness of phytophagous beetles was bimodally distributed along the elevation gradient with peaks at the lowest (˜866 m asl) and upper mid-elevations (˜3,200 m asl) and sharply declined at higher elevations. Path analysis revealed temperature- and climate-driven changes in primary productivity and leaf trait diversity to be the best predictors of changes in the species richness of phytophagous beetles. Species richness increased with increases in mean annual temperature, primary productivity, and with increases in the diversity of leaf traits of local ecosystems. Our study demonstrates that, apart from temperature, the quantity and diversity of food resources play a major role in shaping diversity gradients of phytophagous insects. Drivers of global change, leading to a change of leaf traits and causing reductions in plant diversity and productivity, may consequently reduce the diversity of herbivore assemblages.}, language = {en} } @article{ThormannRaupachWagneretal.2011, author = {Thormann, Birthe and Raupach, Michael J. and Wagner, Thomas and W{\"a}gele, Johann W. and Peters, Marcell K.}, title = {Testing a Short Nuclear Marker for Inferring Staphylinid Beetle Diversity in an African Tropical Rain Forest}, series = {PLoS ONE}, volume = {6}, journal = {PLoS ONE}, number = {3}, doi = {10.1371/journal.pone.0018101}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142666}, pages = {e18101}, year = {2011}, abstract = {Background: The use of DNA based methods for assessing biodiversity has become increasingly common during the last years. Especially in speciose biomes as tropical rain forests and/or in hyperdiverse or understudied taxa they may efficiently complement morphological approaches. The most successful molecular approach in this field is DNA barcoding based on cytochrome c oxidase I (COI) marker, but other markers are used as well. Whereas most studies aim at identifying or describing species, there are only few attempts to use DNA markers for inventorying all animal species found in environmental samples to describe variations of biodiversity patterns. Methodology/Principal Findings: In this study, an analysis of the nuclear D3 region of the 28S rRNA gene to delimit species-like units is compared to results based on distinction of morphospecies. Data derived from both approaches are used to assess diversity and composition of staphylinid beetle communities of a Guineo-Congolian rain forest in Kenya. Beetles were collected with a standardized sampling design across six transects in primary and secondary forests using pitfall traps. Sequences could be obtained of 99\% of all individuals. In total, 76 molecular operational taxonomic units (MOTUs) were found in contrast to 70 discernible morphospecies. Despite this difference both approaches revealed highly similar biodiversity patterns, with species richness being equal in primary and secondary forests, but with divergent species communities in different habitats. The D3-MOTU approach proved to be an efficient tool for biodiversity analyses. Conclusions/Significance: Our data illustrate that the use of MOTUs as a proxy for species can provide an alternative to morphospecies identification for the analysis of changes in community structure of hyperdiverse insect taxa. The efficient amplification of the D3-marker and the ability of the D3-MOTUs to reveal similar biodiversity patterns as analyses of morphospecies recommend its use in future molecular studies on biodiversity.}, language = {en} } @article{SchleuningFarwigPetersetal.2011, author = {Schleuning, Matthias and Farwig, Nina and Peters, Marcell K. and Bergsdorf, Thomas and Bleher, B{\"a}rbel and Brandl, Roland and Dalitz, Helmut and Fischer, Georg and Freund, Wolfram and Gikungu, Mary W. and Hagen, Melanie and Garcia, Francisco Hita and Kagezi, Godfrey H. and Kaib, Manfred and Kraemer, Manfred and Lung, Tobias and Naumann, Clas M. and Schaab, Gertrud and Templin, Mathias and Uster, Dana and W{\"a}gele, J. Wolfgang and B{\"o}hning-Gaese, Katrin}, title = {Forest Fragmentation and Selective Logging Have Inconsistent Effects on Multiple Animal-Mediated Ecosystem Processes in a Tropical Forest}, series = {PLoS ONE}, volume = {6}, journal = {PLoS ONE}, number = {11}, doi = {10.1371/journal.pone.0027785}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-140093}, pages = {e27785}, year = {2011}, abstract = {Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle direct from biodiversity-related indirect effects of human disturbance on multiple ecosystem processes. Fragmentation increased decomposition and reduced antbird predation, while selective logging consistently increased pollination, seed dispersal and army-ant raiding. Fragmentation modified species richness or community composition of five taxa, whereas selective logging did not affect any component of biodiversity. Changes in the abundance of functionally important species were related to lower predation by antbirds and higher decomposition rates in small forest fragments. The positive effects of selective logging on bee pollination, bird seed dispersal and army-ant raiding were direct, i.e. not related to changes in biodiversity, and were probably due to behavioural changes of these highly mobile animal taxa. We conclude that animal-mediated ecosystem processes respond in distinct ways to different types of human disturbance in Kakamega Forest. Our findings suggest that forest fragmentation affects ecosystem processes indirectly by changes in biodiversity, whereas selective logging influences processes directly by modifying local environmental conditions and resource distributions. The positive to neutral effects of selective logging on ecosystem processes show that the functionality of tropical forests can be maintained in moderately disturbed forest fragments. Conservation concepts for tropical forests should thus include not only remaining pristine forests but also functionally viable forest remnants.}, language = {en} } @article{KronauerPetersSchoningetal.2011, author = {Kronauer, Daniel J. C. and Peters, Marcell K. and Schoning, Caspar and Boomsma, Jacobus J.}, title = {Hybridization in East African swarm-raiding army ants}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68798}, year = {2011}, abstract = {Background: Hybridization can have complex effects on evolutionary dynamics in ants because of the combination of haplodiploid sex-determination and eusociality. While hybrid non-reproductive workers have been found in a range of species, examples of gene-flow via hybrid queens and males are rare. We studied hybridization in East African army ants (Dorylus subgenus Anomma) using morphology, mitochondrial DNA sequences, and nuclear microsatellites. Results: While the mitochondrial phylogeny had a strong geographic signal, different species were not recovered as monophyletic. At our main study site at Kakamega Forest, a mitochondrial haplotype was shared between a "Dorylus molestus-like" and a "Dorylus wilverthi-like" form. This pattern is best explained by introgression following hybridization between D. molestus and D. wilverthi. Microsatellite data from workers showed that the two morphological forms correspond to two distinct genetic clusters, with a significant proportion of individuals being classified as hybrids. Conclusions: We conclude that hybridization and gene-flow between the two army ant species D. molestus and D. wilverthi has occurred, and that mating between the two forms continues to regularly produce hybrid workers. Hybridization is particularly surprising in army ants because workers have control over which males are allowed to mate with a young virgin queen inside the colony.}, subject = {Zoologie}, language = {en} } @article{GebertSteffan‐DewenterKronbachetal.2022, author = {Gebert, Friederike and Steffan-Dewenter, Ingolf and Kronbach, Patrick and Peters, Marcell K.}, title = {The role of diversity, body size and climate in dung removal: A correlative and experimental approach}, series = {Journal of Animal Ecology}, volume = {91}, journal = {Journal of Animal Ecology}, number = {11}, doi = {10.1111/1365-2656.13798}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-293907}, pages = {2181 -- 2191}, year = {2022}, abstract = {The mechanisms by which climatic changes influence ecosystem functions, that is, by a direct climatic control of ecosystem processes or by modifying richness and trait compositions of species communities, remain unresolved. This study is a contribution to this discourse by elucidating the linkages between climate, land use, biodiversity, body size and ecosystem functions. We disentangled direct climatic from biodiversity-mediated effects by using dung removal by dung beetles as a model system and by combining correlative field data and exclosure experiments along an extensive elevational gradient on Mt. Kilimanjaro, Tanzania. Dung removal declined with increasing elevation, being associated with a strong reduction in the richness and body size traits of dung beetle communities. Climate influenced dung removal rates by modifying biodiversity rather than by direct effects. The biodiversity-ecosystem effect was driven by a change in the mean body size of dung beetles. Dung removal rates were strongly reduced when large dung beetles were experimentally excluded. This study underscores that climate influences ecosystem functions mainly by modifying biodiversity and underpins the important role of body size for dung removal.}, language = {en} } @article{BrenzingerMaihoffPetersetal.2022, author = {Brenzinger, Kristof and Maihoff, Fabienne and Peters, Marcell K. and Schimmer, Leonie and Bischler, Thorsten and Classen, Alice}, title = {Temperature and livestock grazing trigger transcriptome responses in bumblebees along an elevational gradient}, series = {iScience}, volume = {25}, journal = {iScience}, number = {10}, doi = {10.1016/j.isci.2022.105175}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301276}, year = {2022}, abstract = {Climate and land-use changes cause increasing stress to pollinators but the molecular pathways underlying stress responses are poorly understood. Here, we analyzed the transcriptomic response of Bombus lucorum workers to temperature and livestock grazing. Bumblebees sampled along an elevational gradient, and from differently managed grassland sites (livestock grazing vs unmanaged) in the German Alps did not differ in the expression of genes known for thermal stress responses. Instead, metabolic energy production pathways were upregulated in bumblebees sampled in mid- or high elevations or during cool temperatures. Extensive grazing pressure led to an upregulation of genetic pathways involved in immunoregulation and DNA-repair. We conclude that widespread bumblebees are tolerant toward temperature fluctuations in temperate mountain environments. Moderate temperature increases may even release bumblebees from metabolic stress. However, transcriptome responses to even moderate management regimes highlight the completely underestimated complexity of human influence on natural pollinators.}, language = {en} }