A Test for Spatial Pattern at Several Scales Using Data from a Grid of Contiguous Quadrats

SUMMARY Detection of the different scales of pattern in plant communities is an important area of plant ecological research, and various tests of pattern have been devised. The method of pattern detection which is ecologically most meaningful suffers from the lack of valid tests of significance for the individual scales of pattern once the overall departure from a random distribution has been established. Various tests which partially or completely overcome this deficiency are discussed and exemplified and their small sample distributional properties examined. It is concluded that a set of tests, based on randomisation arguments, provides a fully valid method testing simultaneously for pattern at various scales.