Response of Background Herbivory in Mature Birch Trees to Global Warming

Given the time scale based on duration of exposure to global warming, natural climate-gradient studies and experimental manipulations have detected long-term (decades centuries) short-term (years decades) ecological responses warming. Combination these two complementary approaches within a single study may enable prediction likely processes To understand how warming affects plant–herbivore interactions canopy Erman’s birch, we combined an elevational gradient experiment involving mature birch trees in which soil tree branches were warmed separately. In study, herbivory by chewing insects plant growth increased as elevation decreased, concentrations condensed tannins total phenolics leaves decreased. experiment, alone herbivory, addition branch amplified effect herbivory. Soil decreased tannin concentration, led further reduction. The variation was best explained content leaves. Our results demonstrate that due combination important driver trees. similar tendencies short- imply is increase background decreasing canopy.