Leaf size is more sensitive than leaf fluctuating asymmetry as an indicator of plant stress caused by simulated herbivory

Fluctuating asymmetry (FA), defined as small, random departures away from perfect symmetry, is frequently recommended a sensitive and universal indicator of environmental stress imposed by both abiotic biotic factors. However, the sensitivities FA other morphological traits are rarely compared directly. Here, we tested hypothesis that leaf FA, rather than size, more to simulated herbivory. We performed blind measurements length same leaves juvenile mountain birches (Betula pubescens var. pumila) after removal 0, 2, 4, 8 16% their area during five consequent years. The in defoliated was 88% control birches, indicating herbivory stressful for trees. By contrast, did not differ significantly between despite sufficient (91%) power statistical analysis. Thus, stress. This low sensitivity stress, discovered with use methods, contrasts large pool earlier studies, many which have been likely influences confirmation bias. urge publication ‘negative’ or inconclusive results currently remain underreported due