TY  - JOUR
A1  - Classen, Alice
A1  - Eardley, Connal D.
A1  - Hemp, Andreas
A1  - Peters, Marcell K.
A1  - Peters, Ralph S.
A1  - Ssymank, Axel
A1  - Steffan-Dewenter, Ingolf
T1  - Specialization of plant-pollinator interactions increases with temperature at Mt. Kilimanjaro
JF  - Ecology and Evolution
N2  - 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.
KW  - altitudinal gradient
KW  - climate change
KW  - ecological network
KW  - functional traits
KW  - generalization
KW  - mutualistic interactions
KW  - network specialization index (H2′)
KW  - pollination
KW  - robustness
KW  - specialization
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235959
VL  - 10
IS  - 4
ER  - 
TY  - JOUR
A1  - Peters, Marcell K.
A1  - Hemp, Andreas
A1  - Appelhans, Tim
A1  - Behler, Christina
A1  - Classen, Alice
A1  - Detsch, Florian
A1  - Ensslin, Andreas
A1  - Ferger, Stefan W.
A1  - Frederiksen, Sara B.
A1  - Gebert, Frederike
A1  - Haas, Michael
A1  - Helbig-Bonitz, Maria
A1  - Hemp, Claudia
A1  - Kindeketa, William J.
A1  - Mwangomo, Ephraim
A1  - Ngereza, Christine
A1  - Otte, Insa
A1  - Röder, Juliane
A1  - Rutten, Gemma
A1  - Costa, David Schellenberger
A1  - Tardanico, Joseph
A1  - Zancolli, Giulia
A1  - Deckert, Jürgen
A1  - Eardley, Connal D.
A1  - Peters, Ralph S.
A1  - Rödel, Mark-Oliver
A1  - Schleuning, Matthias
A1  - Ssymank, Axel
A1  - Kakengi, Victor
A1  - Zhang, Jie
A1  - Böhning-Gaese, Katrin
A1  - Brandl, Roland
A1  - Kalko, Elisabeth K.V.
A1  - Kleyer, Michael
A1  - Nauss, Thomas
A1  - Tschapka, Marco
A1  - Fischer, Markus
A1  - Steffan-Dewenter, Ingolf
T1  - Predictors of elevational biodiversity gradients change from single taxa to the multi-taxa community level
JF  - Nature Communications
N2  - 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.
KW  - community ecology
KW  - macroecology
KW  - tropical ecology
KW  - biodiversity
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-169374
VL  - 7
ER  -