Herbivory effects on leaf litter decomposition vary with special leaf
area in temperate mixed deciduous forest
Abstract
Insect herbivore has great impacts on biogeochemical cycling in forest
ecosystem, but experimental tests on the herbivory-decomposability
relationship at the inter-specific level are rare. We conducted a
400-day field decomposition experiment in a temperate mixed deciduous
forest and measured mass remaining rate, decomposition constant, total
loss of carbon (C) and nitrogen (N) of litter leaf with/without obvious
damage by chewing insects for different tree species. We found that
herbivory effect on initial litter quality (C: N ratio) varied with
species, showing a markedly negative effect on M. alba (-5.78%) and
positive effect on Q. acutissima (+5.35%). Herbivory damage increased
decomposition constant for M. alba and L. formosana with higher special
leaf area, but decreased it for D. kaki and Q. acutissima with lower
special leaf area. The contrasting effects of insect herbivory on litter
decomposition could be attributed to the variability of litter initial
quality caused by herbivory. Our finding that herbivore damage showed
inter-specific variability in both litter quality and decomposition rate
suggests that herbivory induced feedbacks to nutrient cycling and
ecosystem function should be estimated at the species level in
multi-species mixed deciduous forest.