TY - JOUR

T1 - Tree diversity increases levels of herbivore damage in a subtropical forest canopy

T2 - evidence for dietary mixing by arthropods?

AU - Brezzi, Matteo

AU - Schmid, Bernhard

AU - Niklaus, Pascal A.

AU - Schuldt, Andreas

PY - 2017/2/1

Y1 - 2017/2/1

N2 - Plant diversity has been linked to both increasing and decreasing levels of arthropod herbivore damage in different plant communities. So far, these links have mainly been studied in grasslands or in artificial tree plantations with low species richness. Furthermore, most studies provide results from newly established experimental plant communities where trophic links are not fully established or from stands of tree saplings that have not yet developed a canopy. Here, we test how tree diversity in a species-rich subtropical forest in China with fully developed tree canopy affects levels of herbivore damage caused by different arthropod feeding guilds. Methods We established 27 plots of 30 × 30 m area. The plots were selected randomly but with the constraint that they had to span a large range of tree diversity as required for comparative studies in contrast to sample surveys. We recorded herbivore damage caused by arthropod feeding guilds (leaf chewers, leaf skeletonizers and sap feeders) on canopy leaves of all major tree species. Important Findings Levels of herbivore damage increased with tree species richness and tree phylogenetic diversity. These effects were most pronounced for damage caused by leaf chewers. Although the two diversity measures were highly correlated, we additionally found a significant interaction between them, whereby species richness increased herbivory mostly at low levels of phylogenetic diversity. Tree species with the lowest proportion of canopy leaf biomass in a plot tended to suffer the highest levels of herbivore damage, which is in contrast to expectations based on the resource concentration hypothesis. Our results are in agreement with expectations of the dietary mixing hypothesis where generalist herbivores with a broad spectrum of food plants benefit from increased resource diversity in tree species-rich forest patches.

AB - Plant diversity has been linked to both increasing and decreasing levels of arthropod herbivore damage in different plant communities. So far, these links have mainly been studied in grasslands or in artificial tree plantations with low species richness. Furthermore, most studies provide results from newly established experimental plant communities where trophic links are not fully established or from stands of tree saplings that have not yet developed a canopy. Here, we test how tree diversity in a species-rich subtropical forest in China with fully developed tree canopy affects levels of herbivore damage caused by different arthropod feeding guilds. Methods We established 27 plots of 30 × 30 m area. The plots were selected randomly but with the constraint that they had to span a large range of tree diversity as required for comparative studies in contrast to sample surveys. We recorded herbivore damage caused by arthropod feeding guilds (leaf chewers, leaf skeletonizers and sap feeders) on canopy leaves of all major tree species. Important Findings Levels of herbivore damage increased with tree species richness and tree phylogenetic diversity. These effects were most pronounced for damage caused by leaf chewers. Although the two diversity measures were highly correlated, we additionally found a significant interaction between them, whereby species richness increased herbivory mostly at low levels of phylogenetic diversity. Tree species with the lowest proportion of canopy leaf biomass in a plot tended to suffer the highest levels of herbivore damage, which is in contrast to expectations based on the resource concentration hypothesis. Our results are in agreement with expectations of the dietary mixing hypothesis where generalist herbivores with a broad spectrum of food plants benefit from increased resource diversity in tree species-rich forest patches.

KW - Biology

KW - arthropod herbivore damage

KW - feeding guilds

KW - forest canopy

KW - generalist herbivores

KW - leaf biomass

KW - resource dilution

KW - specialist herbivores

KW - tree species richness

KW - tree phylogenetic diversity

UR - http://www.scopus.com/inward/record.url?scp=85014510073&partnerID=8YFLogxK

U2 - 10.1093/jpe/rtw038

DO - 10.1093/jpe/rtw038

M3 - Journal articles

VL - 10

SP - 13

EP - 27

JO - Journal of Plant Ecology

JF - Journal of Plant Ecology

SN - 1752-9921

IS - 1

ER -