@article{SeiboldHothornGossneretal.2021,
  author    = {Seibold, Sebastian and Hothorn, Torsten and Gossner, Martin M. and Simons, Nadja K. and Bl{\"u}thgen, Nico and M{\"u}ller, J{\"o}rg and Ambarl{\i}, Didem and Ammer, Christian and Bauhus, J{\"u}rgen and Fischer, Markus and Habel, Jan C. and Penone, Caterina and Schall, Peter and Schulze, Ernst-Detlef and Weisser, Wolfgang W.},
  title     = {Insights from regional and short-term biodiversity monitoring datasets are valuable: a reply to Daskalova et al. 2021},
  series = {Insect Conservation and Diversity},
  volume    = {14},
  journal   = {Insect Conservation and Diversity},
  number    = {1},
  doi       = {10.1111/icad.12467},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228309},
  pages     = {144 -- 148},
  year      = {2021},
  abstract  = {Reports of major losses in insect biodiversity have stimulated an increasing interest in temporal population changes. Existing datasets are often limited to a small number of study sites, few points in time, a narrow range of land-use intensities and only some taxonomic groups, or they lack standardised sampling. While new monitoring programs have been initiated, they still cover rather short time periods. Daskalova et al. 2021 (Insect Conservation and Diversity, 14, 1-18) argue that temporal trends of insect populations derived from short time series are biased towards extreme trends, while their own analysis of an assembly of shorter- and longer-term time series does not support an overall insect decline. With respect to the results of Seibold et al. 2019 (Nature, 574, 671-674) based on a 10-year multi-site time series, they claim that the analysis suffers from not accounting for temporal pseudoreplication. Here, we explain why the criticism of missing statistical rigour in the analysis of Seibold et al. (2019) is not warranted. Models that include 'year' as random effect, as suggested by Daskalova et al. (2021), fail to detect non-linear trends and assume that consecutive years are independent samples which is questionable for insect time-series data. We agree with Daskalova et al. (2021) that the assembly and analysis of larger datasets is urgently needed, but it will take time until such datasets are available. Thus, short-term datasets are highly valuable, should be extended and analysed continually to provide a more detailed understanding of insect population changes under the influence of global change, and to trigger immediate conservation actions.},
  language  = {en}
}
@article{RedlichZhangBenjaminetal.2022,
  author    = {Redlich, Sarah and Zhang, Jie and Benjamin, Caryl and Dhillon, Maninder Singh and Englmeier, Jana and Ewald, J{\"o}rg and Fricke, Ute and Ganuza, Cristina and Haensel, Maria and Hovestadt, Thomas and Kollmann, Johannes and Koellner, Thomas and K{\"u}bert-Flock, Carina and Kunstmann, Harald and Menzel, Annette and Moning, Christoph and Peters, Wibke and Riebl, Rebekka and Rummler, Thomas and Rojas-Botero, Sandra and Tobisch, Cynthia and Uhler, Johannes and Uphus, Lars and M{\"u}ller, J{\"o}rg and Steffan-Dewenter, Ingolf},
  title     = {Disentangling effects of climate and land use on biodiversity and ecosystem services—A multi-scale experimental design},
  series = {Methods in Ecology and Evolution},
  volume    = {13},
  journal   = {Methods in Ecology and Evolution},
  number    = {2},
  doi       = {10.1111/2041-210X.13759},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258270},
  pages     = {514-527},
  year      = {2022},
  abstract  = {Climate and land-use change are key drivers of environmental degradation in the Anthropocene, but too little is known about their interactive effects on biodiversity and ecosystem services. Long-term data on biodiversity trends are currently lacking. Furthermore, previous ecological studies have rarely considered climate and land use in a joint design, did not achieve variable independence or lost statistical power by not covering the full range of environmental gradients. Here, we introduce a multi-scale space-for-time study design to disentangle effects of climate and land use on biodiversity and ecosystem services. The site selection approach coupled extensive GIS-based exploration (i.e. using a Geographic information system) and correlation heatmaps with a crossed and nested design covering regional, landscape and local scales. Its implementation in Bavaria (Germany) resulted in a set of study plots that maximise the potential range and independence of environmental variables at different spatial scales. Stratifying the state of Bavaria into five climate zones (reference period 1981-2010) and three prevailing land-use types, that is, near-natural, agriculture and urban, resulted in 60 study regions (5.8 × 5.8 km quadrants) covering a mean annual temperature gradient of 5.6-9.8°C and a spatial extent of ~310 × 310 km. Within these regions, we nested 180 study plots located in contrasting local land-use types, that is, forests, grasslands, arable land or settlement (local climate gradient 4.5-10°C). This approach achieved low correlations between climate and land use (proportional cover) at the regional and landscape scale with |r ≤ 0.33| and |r ≤ 0.29| respectively. Furthermore, using correlation heatmaps for local plot selection reduced potentially confounding relationships between landscape composition and configuration for plots located in forests, arable land and settlements. The suggested design expands upon previous research in covering a significant range of environmental gradients and including a diversity of dominant land-use types at different scales within different climatic contexts. It allows independent assessment of the relative contribution of multi-scale climate and land use on biodiversity and ecosystem services. Understanding potential interdependencies among global change drivers is essential to develop effective restoration and mitigation strategies against biodiversity decline, especially in expectation of future climatic changes. Importantly, this study also provides a baseline for long-term ecological monitoring programs.},
  language  = {en}
}
@phdthesis{Mayr2021,
  author    = {Mayr, Antonia Veronika},
  title     = {Following Bees and Wasps up Mt. Kilimanjaro: From Diversity and Traits to hidden Interactions of Species},
  doi       = {10.25972/OPUS-18292},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-182922},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Chapter 1 - General Introduction One of the greatest challenges of ecological research is to predict the response of ecosystems to global change; that is to changes in climate and land use. A complex question in this context is how changing environmental conditions affect ecosystem processes at different levels of communities. To shed light on this issue, I investigate drivers of biodiversity on the level of species richness, functional traits and species interactions in cavity-nesting Hymenoptera. For this purpose, I take advantage of the steep elevational gradient of Mt. Kilimanjaro that shows strong environmental changes on a relatively small spatial scale and thus, provides a good environmental scenario for investigating drivers of diversity. In this thesis, I focus on 1) drivers of species richness at different trophic levels (Chapter 2); 2) seasonal patterns in nest-building activity, life-history traits and ecological rates in three different functional groups and at different elevations (Chapter 3) and 3) changes in cuticular hydrocarbons, pollen composition and microbiomes in Lasioglossum bees caused by climatic variables (Chapter 4). Chapter 2 - Climate and food resources shape species richness and trophic interactions of cavity-nesting Hymenoptera Drivers of species richness have been subject to research for centuries. Temperature, resource availability and top-down regulation as well as the impact of land use are considered to be important factors in determining insect diversity. Yet, the relative importance of each of these factors is unknown. Using trap nests along the elevational gradient of Mt. Kilimanjaro, we tried to disentangle drivers of species richness at different trophic levels. Temperature was the major driver of species richness across trophic levels, with increasing importance of food resources at higher trophic levels in natural antagonists. Parasitism rate was both related to temperature and trophic level, indicating that the relative importance of bottom-up and top-down forces might shift with climate change. Chapter 3 - Seasonal variation in the ecology of tropical cavity-nesting Hymenoptera Natural populations fluctuate with the availability of resources, presence of natural enemies and climatic variations. But tropical mountain seasonality is not yet well investigated. We investigated seasonal patterns in nest-building activity, functional traits and ecological rates in three different insect groups at lower and higher elevations separately. Insects were caught with trap nests which were checked monthly during a 17 months period that included three dry and three rainy seasons. Insects were grouped according to their functional guilds. All groups showed strong seasonality in nest-building activity which was higher and more synchronised among groups at lower elevations. Seasonality in nest building activity of caterpillar-hunting and spider-hunting wasps was linked to climate seasonality while in bees it was strongly linked to the availability of flowers, as well as for the survival rate and sex ratio of bees. Finding adaptations to environmental seasonality might imply that further changes in climatic seasonality by climate change could have an influence on life-history traits of tropical mountain species. Chapter 4 - Cryptic species and hidden ecological interactions of halictine bees along an elevational Gradient Strong environmental gradients such as those occurring along mountain slopes are challenging for species. In this context, hidden adaptations or interactions have rarely been considered. We used bees of the genus Lasioglossum as model organisms because Lasioglossum is the only bee genus occurring with a distribution across the entire elevational gradient at Mt. Kilimanjaro. We asked if and how (a) cuticular hydrocarbons (CHC), which act as a desiccation barrier, change in composition and chain length along with changes in temperature and humidity (b), Lasioglossum bees change their pollen diet with changing resource availability, (c) gut microbiota change with pollen diet and climatic conditions, and surface microbiota change with CHC and climatic conditions, respectively, and if changes are rather influenced by turnover in Lasioglossum species along the elevational gradient. We found physiological adaptations with climate in CHC as well as changes in communities with regard to pollen diet and microbiota, which also correlated with each other. These results suggest that complex interactions and feedbacks among abiotic and biotic conditions determine the species composition in a community. Chapter 5 - General Discussion Abiotic and biotic factors drove species diversity, traits and interactions and they worked differently depending on the functional group that has been studied, and whether spatial or temporal units were considered. It is therefore likely, that in the light of global change, different species, traits and interactions will be affected differently. Furthermore, increasing land use intensity could have additional or interacting effects with climate change on biodiversity, even though the potential land-use effects at Mt. Kilimanjaro are still low and not impairing cavity-nesting Hymenoptera so far. Further studies should address species networks which might reveal more sensitive changes. For that purpose, trap nests provide a good model system to investigate effects of global change on multiple trophic levels and may also reveal direct effects of climate change on entire life-history traits when established under different microclimatic conditions. The non-uniform effects of abiotic and biotic conditions on multiple aspects of biodiversity revealed with this study also highlight that evaluating different aspects of biodiversity can give a more comprehensive picture than single observations.},
  subject      = {land use},
  language  = {en}
}
@phdthesis{Koenig2018,
  author    = {K{\"o}nig, Julia Maria},
  title     = {Fungal grass endophytes and their dependence on land-use intensity},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-163890},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Plant-associated fungi can affect the plants' interaction with herbivores and other microorganisms. For example, many common forage grasses are infected with Epichlo{\"e} endophytes. The endophytes systemically colonize the aerial parts of the plants. They produce bioprotective alkaloids that can negatively affect insects and livestock feeding on the grasses, and interact with other fungal species which living from the plants' nutrients. Environmental conditions strongly influence Epichlo{\"e} endophytes. Endophyte-mediated effects on herbivores are more pronounced under increased temperatures and the endophytes may benefit from land use in managed grasslands. Under the framework of the large-scale German project "Biodiversity Exploratories", I investigated whether infection rates and alkaloid concentrations of Epichlo{\"e} festucae var. lolii in Lolium perenne (Chapter I) and Epichlo{\"e} endophytes (E. uncinata, E. siegelii) in Festuca pratensis (Chapter II) depend on land use and season. Further I analysed, whether foliar fungal assemblages of L. perenne are affected by the presence of Epichlo{\"e} endophytes (Chapter IV).},
  subject      = {Endophytische Pilze},
  language  = {en}
}
@article{KoenigGuerreiroPeršohetal.2018,
  author    = {K{\"o}nig, Julia and Guerreiro, Marco Alexandre and Peršoh, Derek and Begerow, Dominik and Krauss, Jochen},
  title     = {Knowing your neighbourhood - the effects of Epichlo{\"e} endophytes on foliar fungal assemblages in perennial ryegrass in dependence of season and land-use intensity},
  series = {PeerJ},
  volume    = {6},
  journal   = {PeerJ},
  number    = {e4660},
  doi       = {10.7717/peerj.4660},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176814},
  year      = {2018},
  abstract  = {Epichlo{\"e} endophytes associated with cool-season grass species can protect their hosts from herbivory and can suppress mycorrhizal colonization of the hosts' roots. However, little is known about whether or not Epichlo{\"e} endophyte infection can also change the foliar fungal assemblages of the host. We tested 52 grassland study sites along a land-use intensity gradient in three study regions over two seasons (spring vs. summer) to determine whether Epichlo{\"e} infection of the host grass Lolium perenne changes the fungal community structure in leaves. Foliar fungal communities were assessed by Next Generation Sequencing of the ITS rRNA gene region. Fungal community structure was strongly affected by study region and season in our study, while land-use intensity and infection with Epichlo{\"e} endophytes had no significant effects. We conclude that effects on non-systemic endophytes resulting from land use practices and Epichlo{\"e} infection reported in other studies were masked by local and seasonal variability in this study's grassland sites.},
  language  = {en}
}
@article{HudsonNewboldContuetal.2014,
  author    = {Hudson, Lawrence N. and Newbold, Tim and Contu, Sara and Hill, Samantha L. L. and Lysenko, Igor and De Palma, Adriana and Phillips, Helen R. P. and Senior, Rebecca A. and Bennett, Dominic J. and Booth, Hollie and Choimes, Argyrios and Correia, David L. P. and Day, Julie and Echeverria-Londono, Susy and Garon, Morgan and Harrison, Michelle L. K. and Ingram, Daniel J. and Jung, Martin and Kemp, Victoria and Kirkpatrick, Lucinda and Martin, Callum D. and Pan, Yuan and White, Hannah J. and Aben, Job and Abrahamczyk, Stefan and Adum, Gilbert B. and Aguilar-Barquero, Virginia and Aizen, Marcelo and Ancrenaz, Marc and Arbelaez-Cortes, Enrique and Armbrecht, Inge and Azhar, Badrul and Azpiroz, Adrian B. and Baeten, Lander and B{\´a}ldi, Andr{\´a}s and Banks, John E. and Barlow, Jos and Bat{\´a}ry, P{\´e}ter and Bates, Adam J. and Bayne, Erin M. and Beja, Pedro and Berg, Ake and Berry, Nicholas J. and Bicknell, Jake E. and Bihn, Jochen H. and B{\"o}hning-Gaese, Katrin and Boekhout, Teun and Boutin, Celine and Bouyer, Jeremy and Brearley, Francis Q. and Brito, Isabel and Brunet, J{\"o}rg and Buczkowski, Grzegorz and Buscardo, Erika and Cabra-Garcia, Jimmy and Calvino-Cancela, Maria and Cameron, Sydney A. and Cancello, Eliana M. and Carrijo, Tiago F. and Carvalho, Anelena L. and Castro, Helena and Castro-Luna, Alejandro A. and Cerda, Rolando and Cerezo, Alexis and Chauvat, Matthieu and Clarke, Frank M. and Cleary, Daniel F. R. and Connop, Stuart P. and D'Aniello, Biagio and da Silva, Pedro Giovani and Darvill, Ben and Dauber, Jens and Dejean, Alain and Diek{\"o}tter, Tim and Dominguez-Haydar, Yamileth and Dormann, Carsten F. and Dumont, Bertrand and Dures, Simon G. and Dynesius, Mats and Edenius, Lars and Elek, Zolt{\´a}n and Entling, Martin H. and Farwig, Nina and Fayle, Tom M. and Felicioli, Antonio and Felton, Annika M. and Ficetola, Gentile F. and Filgueiras, Bruno K. C. and Fonte, Steve J. and Fraser, Lauchlan H. and Fukuda, Daisuke and Furlani, Dario and Ganzhorn, J{\"o}rg U. and Garden, Jenni G. and Gheler-Costa, Carla and Giordani, Paolo and Giordano, Simonetta and Gottschalk, Marco S. and Goulson, Dave and Gove, Aaron D. and Grogan, James and Hanley, Mick E. and Hanson, Thor and Hashim, Nor R. and Hawes, Joseph E. and H{\´e}bert, Christian and Helden, Alvin J. and Henden, John-Andr{\´e} and Hern{\´a}ndez, Lionel and Herzog, Felix and Higuera-Diaz, Diego and Hilje, Branko and Horgan, Finbarr G. and Horv{\´a}th, Roland and Hylander, Kristoffer and Horv{\´a}th, Roland and Isaacs-Cubides, Paola and Ishitani, Mashiro and Jacobs, Carmen T. and Jaramillo, Victor J. and Jauker, Birgit and Jonsell, Matts and Jung, Thomas S. and Kapoor, Vena and Kati, Vassiliki and Katovai, Eric and Kessler, Michael and Knop, Eva and Kolb, Annette and K{\"o}r{\"o}si, {\`A}d{\´a}m and Lachat, Thibault and Lantschner, Victoria and Le F{\´e}on, Violette and LeBuhn, Gretchen and L{\´e}gar{\´e}, Jean-Philippe and Letcher, Susan G. and Littlewood, Nick A. and L{\´o}pez-Quintero, Carlos A. and Louhaichi, Mounir and L{\"o}vei, Gabor L. and Lucas-Borja, Manuel Esteban and Luja, Victor H. and Maeto, Kaoru and Magura, Tibor and Mallari, Neil Aldrin and Marin-Spiotta, Erika and Marhall, E. J. P. and Mart{\´i}nez, Eliana and Mayfield, Margaret M. and Mikusinski, Gregorz and Milder, Jeffery C. and Miller, James R. and Morales, Carolina L. and Muchane, Mary N. and Muchane, Muchai and Naidoo, Robin and Nakamura, Akihiro and Naoe, Shoji and Nates-Parra, Guiomar and Navarerete Gutierrez, Dario A. and Neuschulz, Eike L. and Noreika, Norbertas and Norfolk, Olivia and Noriega, Jorge Ari and N{\"o}ske, Nicole M. and O'Dea, Niall and Oduro, William and Ofori-Boateng, Caleb and Oke, Chris O. and Osgathorpe, Lynne M. and Paritsis, Juan and Parrah, Alejandro and Pelegrin, Nicol{\´a}s and Peres, Carlos A. and Persson, Anna S. and Petanidou, Theodora and Phalan, Ben and Philips, T. Keith and Poveda, Katja and Power, Eileen F. and Presley, Steven J. and Proen{\c{c}}a, V{\^a}nia and Quaranta, Marino and Quintero, Carolina and Redpath-Downing, Nicola A. and Reid, J. Leighton and Reis, Yana T. and Ribeiro, Danilo B. and Richardson, Barbara A. and Richardson, Michael J. and Robles, Carolina A. and R{\"o}mbke, J{\"o}rg and Romero-Duque, Luz Piedad and Rosselli, Loreta and Rossiter, Stephen J. and Roulston, T'ai H. and Rousseau, Laurent and Sadler, Jonathan P. and S{\´a}fi{\´a}n, Szbolcs and Salda{\~n}a-V{\´a}squez, Romeo A. and Samneg{\aa}rd, Ulrika and Sch{\"u}epp, Christof and Schweiger, Oliver and Sedlock, Jodi L. and Shahabuddin, Ghazala and Sheil, Douglas and Silva, Fernando A. B. and Slade, Eleanor and Smith-Pardo, Allan H. and Sodhi, Navjot S. and Somarriba, Eduardo J. and Sosa, Ram{\´o}n A. and Stout, Jane C. and Struebig, Matthew J. and Sung, Yik-Hei and Threlfall, Caragh G. and Tonietto, Rebecca and T{\´o}thm{\´e}r{\´e}sz, B{\´e}la and Tscharntke, Teja and Turner, Edgar C. and Tylianakis, Jason M. and Vanbergen, Adam J. and Vassilev, Kiril and Verboven, Hans A. F. and Vergara, Carlos H. and Vergara, Pablo M. and Verhulst, Jort and Walker, Tony R. and Wang, Yanping and Watling, James I. and Wells, Konstans and Williams, Christopher D. and Willig, Michael R. and Woinarski, John C. Z. and Wolf, Jan H. D. and Woodcock, Ben A. and Yu, Douglas W. and Zailsev, Andreys and Collen, Ben and Ewers, Rob M. and Mace, Georgina M. and Purves, Drew W. and Scharlemann, J{\"o}rn P. W. and Pervis, Andy},
  title     = {The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts},
  series = {Ecology and Evolution},
  volume    = {4},
  journal   = {Ecology and Evolution},
  number    = {24},
  doi       = {10.1002/ece3.1303},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-114425},
  pages     = {4701 - 4735},
  year      = {2014},
  abstract  = {Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1\% of the total number of all species described, and more than 1\% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.},
  language  = {en}
}
@phdthesis{Hoiss2013,
  author    = {Hoiß, Bernhard},
  title     = {Effects of climate change, extreme events and management on plants, pollinators and mutualistic interaction networks},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87919},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {I. Climate change comprises average temperatures rise, changes in the distribution of precipitation and an increased amount and intensity of extreme climatic events in the last decades. Considering these serious changes in the abiotic environment it seems obvious that ecosystems also change. Flora and fauna have to adapt to the fast changing conditions, migrate or go extinct. This might result in shifts in biodiversity, species composition, species interactions and in ecosystem functioning and services. Mountains play an important role in the research of these climate impacts. They are hotspots of biodiversity and can be used as powerful natural experiments as they provide, within short distances, the opportunity to research changes in the ecosystem induced by different climatic contexts. In this dissertation two approaches were pursued: i) surveys of biodiversity, trait dominance and assembly rules in communities depending on the climatic context and different management regimes were conducted (chapters II and III) and ii) the effects of experimental climate treatments on essential ecosystem features along the altitudinal gradient were assessed (chapters IV, V and VI). II. We studied the relative importance of management, an altitudinal climatic gradient and their interactions for plant species richness and the dominance of pollination types in 34 alpine grasslands. Species richness peaked at intermediate temperatures and was higher in grazed grasslands compared to non-managed grasslands. We found the climatic context and also management to influence the distribution and dominance structures of wind- and insect-pollinated plants. Our results indicate that extensive grazing maintains high plant diversity over the full subalpine gradient. Rising temperatures may cause an upward shift of the diversity peak of plants and may also result in changed species composition and adaptive potential of pollination types. III. On the same alpine grasslands we studied the impact of the climatic context along an altitudinal gradient on species richness and community assembly in bee communities. Species richness and abundance declined linearly with increasing altitude. Bee species were more closely related at high altitudes than at low altitudes. The proportion of social and ground-nesting species, as well as mean body size and altitudinal range of bees, increased with increasing altitude, whereas the mean geographic distribution decreased. Our results suggest that community assembly at high altitudes is dominated by environmental filtering effects, while the relative importance of competition increases at low altitudes. We conclude that ongoing climate change poses a threat for alpine specialists with adaptations to cool environments but low competitive capacities. IV. We determined the impacts of short-term climate events on flower phenology and assessed whether those impacts differed between lower and higher altitudes. For that we simulated advanced and delayed snowmelt as well as drought events in a multi site experiment along an altitudinal gradient. Flower phenology was strongly affected by altitude, however, this effect declined through the season. The manipulative treatments caused only few changes in flowering phenology. The effects of advanced snowmelt were significantly greater at higher than at lower sites, but altitude did not influence the effect of the other treatments. The length of flowering duration was not significantly influenced by treatments. Our data indicate a rather low risk of drought events on flowering phenology in the Bavarian Alps. V. Changes in the structure of plant-pollinator networks were assessed along an altitudinal gradient combined with the experimental simulation of potential consequences of climate change: extreme drought events, advanced and delayed snowmelt. We found a trend of decreasing specialisation and therefore increasing complexity in networks with increasing altitude. After advanced snowmelt or drought networks were more specialised especially at higher altitudes compared to control plots. Our results show that changes in the network structures after climate manipulations depend on the climatic context and reveal an increasing susceptibility of plant-pollinator networks with increasing altitude. VI. The aim of this study was to determine the combined effects of extreme climatic events and altitude on leaf CN (carbon to nitrogen) ratios and herbivory rates in different plant guilds. We found no overall effect of climate manipulations (extreme drought events, advanced and delayed snowmelt) on leaf CN ratios and herbivory rates. However, plant guilds differed in CN ratios and herbivory rates and responded differently to altitude. CN ratios of forbs (legume and non-legume) decreased with altitude, whereas CN ratios of grasses increased with altitude. Further, CN ratios and herbivory rates increased during the growing season, indicating a decrease of food plant quality during the growing season. Insect herbivory rates were driven by food plant quality. Contrasting altitudinal responses of forbs versus grasses give reason to expect changed dominance structures among plant guilds with ongoing climate change. VII. This dissertation contributes to the understanding of factors that determine the composition and biotic interactions of communities in different climates. The results presented indicate that warmer climates will not only change species richness but also the assembly-rules for plant and bee communities depending on the species' functional traits. Our investigations provide insights in the resilience of different ecosystem features and processes towards climate change and how this resilience depends on the environmental context. It seems that mutualistic interactions are more susceptible to short-term climate events than flowering phenology and antagonistic interactions such as herbivory. However, to draw more general conclusions more empirical data is needed.},
  subject      = {Klima{\"a}nderung},
  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{GebertSteffanDewenterMorettoetal.2019,
  author    = {Gebert, Friederike and Steffan-Dewenter, Ingolf and Moretto, Philippe and Peters, Marcell K.},
  title     = {Climate rather than dung resources predict dung beetle abundance and diversity along elevational and land use gradients on Mt. Kilimanjaro},
  series = {Journal of Biogeography},
  volume    = {47},
  journal   = {Journal of Biogeography},
  number    = {2},
  doi       = {10.1111/jbi.13710},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204701},
  pages     = {371 -- 381},
  year      = {2019},
  abstract  = {Aim: While elevational gradients in species richness constitute some of the best depicted patterns in ecology, there is a large uncertainty concerning the role of food resource availability for the establishment of diversity gradients in insects. Here, we analysed the importance of climate, area, land use and food resources for determining diversity gradients of dung beetles along extensive elevation and land use gradients on Mt. Kilimanjaro, Tanzania. Location: Mt. Kilimanjaro, Tanzania. Taxon: Scarabaeidae (Coleoptera). Methods: Dung beetles were recorded with baited pitfall traps at 66 study plots along a 3.6 km elevational gradient. In order to quantify food resources for the dung beetle community in form of mammal defecation rates, we assessed mammalian diversity and biomass with camera traps. Using a multi-model inference framework and path analysis, we tested the direct and indirect links between climate, area, land use and mammal defecation rates on the species richness and abundance of dung beetles. Results: We found that the species richness of dung beetles declined exponentially with increasing elevation. Human land use diminished the species richness of functional groups exhibiting complex behaviour but did not have a significant influence on total species richness. Path analysis suggested that climate, in particular temperature and to a lesser degree precipitation, were the most important predictors of dung beetle species richness while mammal defecation rate was not supported as a predictor variable. Main conclusions: Along broad climatic gradients, dung beetle diversity is mainly limited by climatic factors rather than by food resources. Our study points to a predominant role of temperature-driven processes for the maintenance and origination of species diversity of ectothermic organisms, which will consequently be subject to ongoing climatic changes.},
  language  = {en}
}
@phdthesis{Gebert2022,
  author    = {Gebert, Friederike},
  title     = {Mammals and dung beetles along elevational and land use gradients on Mount Kilimanjaro: diversity, traits and ecosystem services},
  doi       = {10.25972/OPUS-19195},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191950},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Despite belonging to the best described patterns in ecology, the mechanisms driving biodiversity along broad-scale climatic gradients, like the latitudinal gradient in diversity, remain poorly understood. Because of their high biodiversity, restricted spatial ranges, the continuous change in abiotic factors with altitude and their worldwide occurrence, mountains constitute ideal study systems to elucidate the predictors of global biodiversity patterns. However, mountain ecosystems are increasingly threatened by human land use and climate change. Since the consequences of such alterations on mountainous biodiversity and related ecosystem services are hardly known, research along elevational gradients is also of utmost importance from a conservation point of view. In addition to classical biodiversity research focusing on taxonomy, the significance of studying functional traits and their prominence in biodiversity ecosystem functioning (BEF) relationships is increasingly acknowledged. In this dissertation, I explore the patterns and drivers of mammal and dung beetle diversity along elevational and land use gradients on Mt. Kilimanjaro, Tanzania. Furthermore, I investigate the predictors of dung decomposition by dung beetles under different extinction scenarios. Mammals are not only charismatic, they also fulfil important roles in ecosystems. They provide important ecosystem services such as seed dispersal and nutrient cycling by turning over high amounts of biomass. In chapter II, I show that mammal diversity and community biomass both exhibited a unimodal distribution with elevation on Mt.Kilimanjaro and were mainly impacted by primary productivity, a measure of the total food abundance, and the protection status of study plots. Due to their large size and endothermy, mammals, in contrast to most arthopods, are theoretically predicted to be limited by food availability. My results are in concordance with this prediction. The significantly higher diversity and biomass in the Kilimanjaro National Park and in other conservation areas underscore the important role of habitat protection is vital for the conservation of large mammal biodiversity on tropical mountains. Dung beetles are dependent on mammals since they rely upon mammalian dung as a food and nesting resource. Dung beetles are also important ecosystem service providers: they play an important role in nutrient cycling, bioturbation, secondary seed dispersal and parasite suppression. In chapter III, I show that dung beetle diversity declined with elevation while dung beetle abundance followed a hump-shaped pattern along the elevational gradient. In contrast to mammals, dung beetle diversity was primarily predicted by temperature. Despite my attempt to accurately quantifiy mammalian dung resources by calculating mammalian defecation rates, I did not find an influence of dung resource availability on dung beetle richness. Instead, higher temperature translated into higher dung beetle diversity. Apart from being important ecosystem service providers, dung beetles are also model organisms for BEF studies since they rely on a resource which can be quantified easily. In chapter IV, I explore dung decomposition by dung beetles along the elevational gradient by means of an exclosure experiment in the presence of the whole dung beetle community, in the absence of large dung beetles and without any dung beetles. I show that dung decomposition was the highest when the dung could be decomposed by the whole dung beetle community, while dung decomposition was significantly reduced in the sole presence of small dung beetles and the lowest in the absence of dung beetles. Furthermore, I demonstrate that the drivers of dung decomposition were depend on the intactness of the dung beetle community. While body size was the most important driver in the presence of the whole dung beetle community, species richness gained in importance when large dung beetles were excluded. In the most perturbed state of the system with no dung beetles present, temperature was the sole driver of dung decomposition. In conclusion, abiotic drivers become more important predictors of ecosystem services the more the study system is disturbed. In this dissertation, I exemplify that the drivers of diversity along broad-scale climatic gradients on Mt. Kilimanjaro depend on the thermoregulatory strategy of organisms. While mammal diversity was mainly impacted by food/energy resources, dung beetle diversity was mainly limited by temperature. I also demonstrate the importance of protected areas for the preservation of large mammal biodiversity. Furthermore, I show that large dung beetles were disproportionately important for dung decomposition as dung decomposition significantly decreased when large dung beetles were excluded. As regards land use, I did not detect an overall effect on dung beetle and mammal diversity nor on dung beetle-mediated dung decomposition. However, for the most specialised mammal trophic guilds and dung beetle functional groups, negative land use effects were already visible. Even though the current moderate levels of land use on Mt. Kilimanjaro can sustain high levels of biodiversity, the pressure of the human population on Mt. Kilimanjaro is increasing and further land use intensification poses a great threat to biodiversity. In synergy wih land use, climate change is jeopardizing current patterns and levels of biodiversity with the potential to displace communities, which may have unpredictable consequences for ecosystem service provisioning in the future.},
  subject      = {Kilimandscharo},
  language  = {en}
}