Drought negatively affects communities on a foundation tree: growth rings predict diversity |
| |
Authors: | Adrian C Stone Catherine A Gehring Thomas G Whitham |
| |
Institution: | (1) Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA;(2) Merriam-Powell Center for Environmental Research, Flagstaff, AZ, USA |
| |
Abstract: | Understanding how communities respond to extreme climatic events is important for predicting the impact of climate change
on biodiversity. The plant vigor and stress hypotheses provide a theoretical framework for understanding how arthropods respond
to stress, but are rarely tested at the community level. Following a record drought, we compared the communities of arthropods
on pinyon pine (Pinus edulis) that exhibited a gradient in physical traits related to environmental stress (e.g., growth rate, branch dieback, and needle
retention). Six patterns emerged that show how one of the predicted outcomes of climate change in the southwestern USA (i.e.,
increased drought severity) alters the communities of a foundation tree species. In accordance with the plant vigor hypothesis,
increasing tree stress was correlated with an eight to tenfold decline in arthropod species richness and abundance. Trees
that were more similar in their level of stress had more similar arthropod communities. Both foliage quantity and quality
contributed to arthropod community structure. Individual species and feeding groups differed in their responses to plant stress,
but most were negatively affected. Arthropod richness (r
2 = 0.48) and abundance (r
2 = 0.48) on individual trees were positively correlated with the tree’s radial growth during drought. This relationship suggests
that tree ring analysis may be used as a predictor of arthropod diversity, which is similar to findings with ectomycorrhizal
fungi. A contrast of our findings on arthropod abundance with published data on colonization by mutualistic fungi on the same
trees demonstrates that at low stress these two communities respond differently, but at high stress both are negatively affected.
These results suggest that the effect of extreme climatic events such as drought on foundation tree species are likely to
decrease multi-trophic diversity and shift arthropod community composition, which in turn could cascade to affect other associated
taxa. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|