TOWARDS STATISTICAL DEFINITION OF ECOLOGICAL RANGE - CASE OF QUERCUS SUBER

The general problem of constructing gross climatic limits from analysis of a map of species distribution is raised. A study of the distribution of Q. suber suggests that the use of measures of central tendency rather than an attempt to define limits may provide a more fruitful approach to such problems. Use of the standard deviation, together with the mean, provides a probabilistic measure of plant ranges which may provide a useful tool in locating climatically analogous areas for plant introduction.