Details

Autor(en) / Beteiligte

• Njovu, Henry K.
• Peters, Marcell K.
• Schellenberger Costa, David
• Brandl, Roland
• Kleyer, Michael
• Steffan‐Dewenter, Ingolf
• Si, Xingfeng

Titel

Leaf traits mediate changes in invertebrate herbivory along broad environmental gradients on Mt. Kilimanjaro, Tanzania

Ist Teil von

• The Journal of animal ecology, 2019-11, Vol.88 (11), p.1777-1788

Ort / Verlag

England: Blackwell Publishing Ltd

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Temperature, primary productivity, plant functional traits, and herbivore abundances are considered key predictors of leaf herbivory but their direct and indirect contributions to community‐level herbivory are not well understood along broad climatic gradients. Here, we determined elevational herbivory patterns and used a path analytical approach to disentangle the direct and indirect effects of climate, land use, net primary productivity (NPP), herbivore abundance, and plant functional traits on community‐level invertebrate herbivory along the extensive elevational and land use gradients at Mt. Kilimanjaro, Tanzania. We recorded standing leaf herbivory caused by leaf chewers, leaf miners and leaf gallers on 55 study sites distributed in natural and anthropogenic habitats along a 3,060 m elevation gradient. We related the total community‐level herbivory to climate (temperature and precipitation), NPP, plant functional traits (specific leaf area, leaf carbon‐to‐nitrogen [CN] ratio and leaf nitrogen‐to‐phosphorus [NP] ratio) and herbivore abundances. Leaf herbivory ranged from 5% to 11% along the elevation gradient. Total leaf herbivory showed unimodal pattern in natural habitats but a strongly contrasting bimodal pattern in anthropogenic habitats. We also detected some variation in the patterns of leaf herbivory along environmental gradients across feeding guilds with leaf chewers being responsible for a disproportionally large part of herbivory. Path analyses indicated that the variation in leaf herbivory was mainly driven by changes in leaf CN and NP ratios which were closely linked to changes in NPP in natural habitats. Similarly, patterns of leaf herbivory in anthropogenic habitats were best explained by variation in leaf CN ratios and a negative effect of land use. Our study elucidates the strong role of leaf nutrient stoichiometry and its linkages to climate and NPP for explaining the variation in leaf herbivory along broad climatic gradients. Furthermore, the study suggests that climatic changes and nutrient inputs in the course of land use change may alter leaf herbivory and consequently energy and nutrient fluxes in terrestrial habitats. The authors' findings advance the debate on the role of plant functional traits in predicting ecosystem functions by showing its relevance across broad climatic gradients and at the level of ecological communities.