Spatial occurrence patterns of species in Araucaria Forest in Paraná

Abstract

This study evaluated the spatial distribution of species Ilex paraguariensis, Ocotea porosa, Ocotea puberula and Capsicodendron dinisii, typical of the Araucaria Forest Montana, using data from permanent sample plots located in São João do Triunfo, Paraná State, Brazil. The individuals with diameter at breast height equal or higher than 10 cm were analyzed and identified and its geographic coordinates were demarcated. Thus, were evaluated the frequency of individuals, number of subplots with its occurrence and the calculation of the Moran Index (MI). The mean values of frequency were 48 individuals ha^-1 to I. paraguariensis, 12 individuals ha^-1 O. porosa, 15 individuals ha^-1 to O. puberula and 20 individuals ha^-1 to C. dinisii. By the pattern of occurrence different results were shown, the species C. dinisii and I. paraguariensis showed grouped status on plot A and random in plots B, C and D. The specie O. porosa presented grouped in plot A, the plot B there were not enough individuals to calculate the MI and the plots C and D showed a random status. The specie O. puberula presented dispersed in part A, random in B and C and grouped in D. Heterogeneity is characteristic of the native forest, and changes in these patterns for the same species can be assigned precisely the characteristics of the sample units, such as variation between the number of individuals of a parcel to another, the presence or absence of gaps and interaction with other species.