SMALL VARIATIONS OVER LARGE SCALES: FLUCTUATING ASYMMETRY OVER THE RANGE OF TWO OAK SPECIES

Fluctuating asymmetry (FA) represents small, random variation from symmetry, and it has been used as an indicator of plant stress at relatively local scales. In this study, variation in FA was examined at the landscape scale across the whole distributional range of the two oak species Quercus myrtifolia and Quercus chapmanii in Florida. Oak leaf morphology was evaluated in 40 sites covering similar to 170,000 km(2). Plants growing on coastal/edge sites exhibited significantly higher levels of FA than did plants inhabiting inland/center sites. For myrtle oaks, levels of FA were also spatially structured, and sites were positively spatially autocorrelated at small distances, indicating that sites that were closer exhibited similar levels of environmental stress and FA. Our results have shown that FA, a reliable measurement of plant stress at local scales, can also be used as a biological tool for monitoring the quality of the environment at larger spatial scales, increasing its usefulness in studies across the full range of plant species.