TY  - JOUR
A1  - Gebert, Friederike
A1  - Steffan-Dewenter, Ingolf
A1  - Moretto, Philippe
A1  - Peters, Marcell K.
T1  - Climate rather than dung resources predict dung beetle abundance and diversity along elevational and land use gradients on Mt. Kilimanjaro
JF  - Journal of Biogeography
N2  - 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.
KW  - altitudinal gradients
KW  - diversity gradients
KW  - enercy-richness hypothesis
KW  - food resources
KW  - insect abundance
KW  - land use
KW  - Scarabaeidae
KW  - temperature‐richness hypothesis
KW  - temperature‐mediated resource exploitation hypothesis
KW  - species‐area hypothesis
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-204701
VL  - 47
IS  - 2
SP  - 371
EP  - 381
ER  -