FLUCTUATING ASYMMETRY INDICATES LEVELS OF COMPETITION IN AN EVEN-AGEDPOPLAR CLONE

Fluctuating asymmetries are small random deviations from perfect bilat eral symmetry that result from imperfect regulation of development. Re cently, fluctuating asymmetry has been suggested as a tool for monitor ing levels of ecological stress within and between populations. Unfort unately, such comparisons of fluctuating asymmetry may be confounded b y genetic or age differences among environments. In this study we use a genetically controlled field experiment to determine differences in fluctuating asymmetry due solely to different competitive regimes. We determined fluctuating asymmetry in poplar leaf shape for leaves taken from an even-aged clone grown in six different competitive regimes. W e show that increases in intra- and interspecific competition increase fluctuating asymmetry in the leaves of this clone. This supports the use of fluctuating asymmetry as a tool for detecting common environmen tal stresses such as competition.