Dispersion and aggregation patterns of tree species in Araucaria Forest, Southern Brazil.

Studies about dispersal syndromes and spatial distribution can provide information about species ecology. However, few studies analyze these ecological patterns in different vegetation layers. In this work, we verified the relationship between the dispersion syndromes and the spatial distribution in different layers in Araucaria Forest. We sampled 180 plots with size and inclusion criteria that changed according to the vegetative layer. We sampled 15,545 individuals in 103 tree species. We found significant differences between the number of species in the dispersion syndromes (χ2 = 11.52; P ≤ 0.05) and spatial distribution patterns (χ2 = 10.94; P ≤ 0.05), being zoochoric and tends to clustering the most predominant. We also found a significant interaction between the dispersion syndromes and spatial distribution patterns in the analyzed layers (F = 1,044; P < 0.0001), with anemochoric species characterized by random distribution, autochoric in the cluster distribution and zoochoric in the tends to clustering. The results demonstrate that the tree species of the different layers are related to the type of dispersion and the aggregation pattern.