Evaluation of the Morisita Index for Determination of the Spatial Distribution of Species in a Fragment of Araucaria Forest

The Morisita index is widely used to evaluate the spatial distribution patterns of species in a native forest. Thus, by analysing the spatial behaviour of individuals in some special cases, this study obtained and then discussed the critical values for the application of the Morisita index. In the aggregate classification, importance was given to the way the equation was used and on the meaning of the maximum index value. For the uniform distribution, the behaviour of species was presented with one and more than one individual per plot. Additionally, we discussed the values that generated indetermination in the index results, and, in this situation, we suggested the use of the ratio variance/mean as an alternative index for the spatial classification of species distribution. A table was also organized with examples to elucidate the analyses and to lead to a discussion of the reported situations.