Tree diversity promotes functional dissimilarity and maintains functional richness despite species loss in predator assemblages
The effects of species loss on ecosystems depend on the functional characteristics of the species, i.e. the functional diversity, in a community. However, how functional diversity is impacted by environmental changes in natural ecosystems is only poorly understood. This particularly applies to higher trophic levels, which play a crucial role in regulating ecosystem processes and might be strongly affected by human-induced environmental changes. We analyzed how functional richness, evenness, and divergence of important generalist predators—epigeic spiders—are affected by changes in woody plant species richness, plant phylogenetic diversity, and stand age in highly diverse subtropical forests in China. Functional evenness and divergence of spiders increased with woody plant richness and stand age, whereas functional richness was not affected. Plant phylogenetic diversity had no effect on spider functional diversity. The results contrast with patterns in spider species richness, which was negatively related to plant richness in the studied forests, and suggest that functional redundancy among spiders decreased with increasing woody plant richness. Moreover, higher functional dissimilarity within spider assemblages with increasing woody plant richness indicates that the relative distribution of abundant predators in functional trait space has a strong potential to impact on ecological functions, independent of patterns in species richness or the overall available trait space. Regarding the generally hypothesized promoting effects of plant diversity on predators, our results are only supportive in the context of functional diversity (and here only for trait distributions within the overall functional trait space, and not for the size of this space), and not for patterns in species richness. Explicitly considering the functional diversity and its relationship with species richness is thus crucial for a better understanding of how predator assemblages can impact on ecosystem functions in such highly diverse, natural ecosystems.
2012-12-05 16:27:43 UTC
final
SP08e Diversity and functional effects of herbivores, predators and saproxylics in a phytodiverse subtropical forest ecosystem
Andreas Schuldt
andreas.schuldt@forst.uni-goettingen.de
Stefan Michalski
stefan.michalski@ufz.de
Thorsten Assmann
assmann@uni.leuphana.de
Walter Durka
walter.durka@ufz.de
Helge Bruelheide, Prof.
helge.bruelheide@botanik.uni-halle.de
Oliver Purschke
oliver.purschke@idiv.de
Andreas Schuldt
andreas.schuldt@forst.uni-goettingen.de
CSPs: Herb layer characterization of the central plot in the CSPs
side
true
Alexandra Erfmeier
aerfmeier@ecology.uni-kiel.de
Sabine Both
sabine.both@botanik.uni-halle.de
https://data.botanik.uni-halle.de/bef-china/datasets/184/download
https://data.botanik.uni-halle.de/bef-china/datasets/184/download.csv?separate_category_columns=true
CSPs: Comparative study plot (CSP) information to be shared with all BEF-China scientists
main
false
Helge Bruelheide, Prof.
helge.bruelheide@botanik.uni-halle.de
Karin Nadrowski
nadrowski@uni-leipzig.de
https://data.botanik.uni-halle.de/bef-china/datasets/205/download
https://data.botanik.uni-halle.de/bef-china/datasets/205/download.csv?separate_category_columns=true
CSPs: Phylogenetic tree of woody species in the Gutianshan National Reserve
main
false
Stefan Michalski
stefan.michalski@ufz.de
Walter Durka
walter.durka@ufz.de
https://data.botanik.uni-halle.de/bef-china/datasets/240/download
https://data.botanik.uni-halle.de/bef-china/datasets/240/download.csv?separate_category_columns=true
Oecologia
2013-02-24
accepted