Direct and plant‐mediated effects of climate on bird diversity in tropical mountains. Issue 24 (13th November 2020)

• Record Type: Journal Article
• Authors: Vollstädt, Maximilian G. R.; Albrecht, Jörg; Böhning‐Gaese, Katrin; Hemp, Andreas; Howell, Kim M.; Kettering, Laura; Neu, Alexander; Neuschulz, Eike Lena; Quitián, Marta; Santillán, Vinicio E.; Töpfer, Till; Schleuning, Matthias; Fritz, Susanne A.
• Is Part Of: Ecology and evolution. Volume 10:Issue 24(2020)
• Page Start: 14196
• Page End: 14208
• Publication Date: 2020-11-13
• Subjects: Andes -- fruiting plants -- functional diversity -- intercontinental comparison -- Mt. Kilimanjaro -- resource effects; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.7014
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Aim: Although patterns of biodiversity across the globe are well studied, there is still a controversial debate about the underlying mechanisms and their generality across biogeographic scales. In particular, it is unclear to what extent diversity patterns along environmental gradients are directly driven by abiotic factors, such as climate, or indirectly mediated through biotic factors, such as resource effects on consumers. Location: Andes, Southern Ecuador; Mt. Kilimanjaro, Tanzania. Methods: We studied the diversity of fleshy‐fruited plants and avian frugivores at the taxonomic level, that is, species richness and abundance, as well as at the level of functional traits, that is, functional richness and functional dispersion. We compared two important biodiversity hotspots in mountain systems of the Neotropics and Afrotropics. We used field data of plant and bird communities, including trait measurements of 367 plant and bird species. Using structural equation modeling, we disentangled direct and indirect effects of climate and the diversity of plant communities on the diversity of bird communities. Results: We found significant bottom‐up effects of fruit diversity on frugivore diversity at the taxonomic level. In contrast, climate was more important for patterns of functional diversity, with plant communities being mostly related to precipitation, and bird communities being most strongly related to temperature. Main conclusions: Our results illustrate the general importance of bottom‐up mechanisms for the taxonomic diversity of consumers, suggesting the importance of active resource tracking. Our results also suggest that it might be difficult to identify signals of ecological fitting between functional plant and animal traits across biogeographic regions, since different species groups may respond to different climatic drivers. This decoupling between resource and consumer communities could increase under future climate change if plant and animal communities are consistently related to distinct climatic drivers. Abstract : Although patterns of biodiversity across the globe are well studied, there is still a controversial debate about the underlying mechanisms and their generality across biogeographic scales. We found significant bottom‐up effects of fruit diversity on frugivore diversity at the taxonomic level. In contrast, climate was more important for patterns of functional diversity, with plant communities being mostly related to precipitation, and bird communities being most strongly related to temperature.