Inquiring into the causes of depressed folivory in a fragmented temperate forest

Folivory is lower in forest fragments of the Maulino forest than in continuous stands. We experimentally assessed whether depressed folivory is related to a reduction in foliar palatability caused by the more xeric microclimate of forest fragments. We compared leaf anatomy at fragments and continuous forest for four tree species (Aristotelia chilensis, Cryptocarya alba, Nothofagus glauca and Gevuina avellana), and evaluated consumption of leaves of the two different habitats by insect species (Sericoides viridis and Ormiscodes rufosignata).Anatomy of leaves of fragments differs from that from continuous forest in at least one of the traits, for all the plant species. However, not all species exhibit more sclerophyllous traits in forest fragments. A. chilensis exhibits the greatest number of changes, being more sclerophyllous in fragments. In palatability trials, there were no differences in the consumption of leaves of fragments versus leaves of continuous forest. Therefore, depressed folivory levels in forest remnants of the Maulino forest do not seem to be attributable to reduced foliar palatability, suggesting that changes in the insect assemblage, and not palatability, account for reduced herbivory in fragmented forests.