COMPETITION VERSUS GROWTH OF TREES IN A RAINFOREST AT AMAPÁ STATE – BRAZIL

• Autor(a) principal: Vatraz, Silvane
• Data de Publicação: 2018
• Outros Autores: Silva, José Natalino Macedo, Alder, Denis
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Ciência Florestal (Online)
• Texto Completo: https://periodicos.ufsm.br/cienciaflorestal/article/view/33358
• topic: competition indexes; natural forest; diameter growth; Amazônia.; índices de competição; floresta natural; crescimento em diâmetro; Amazônia.

The objective of this study is to make, comparatively, of different distance independent competition indices (IID) in three dimensions of plots, and to identify those that more correlate with diametric increment (IPA DAP), in order to determine which best explains inter-tree competition in the arboreal stratum in a dense ombrophylous forest. This study was conducted with the Project Good Management data (Embrapa / CIFOR / ITTO) - Sustainable management of production forests on a commercial scale in the Brazilian Amazon, developed by Embrapa Amazônia Oriental in the area of Jari Florestal SA, in the municipality of Vitória do Jari, State of Amapá. Three permanent plots were used of one hectare each (100 x 100 m), on which were measured all trees with DBH ≥ 20 cm. The following IIDs were compared: G (basal area / ha), BAL (Basal Area of Larger Trees), Glover and Hool and Stage. The competition indices were evaluated by analysis of linear correlation coefficients between each index and the PAI DBH (cm-1) variable. The significance of the correlation coefficients was evaluated by p value (α = 0.05). All variations of indexes tested resulted in correlations of up to 20%, considered to be very weak. This indicates that IIDs can represent only partially the competition in tropical natural forests. However, among the indexes, the BAL index is the IID that presented the highest correlation with the PAI DBH (r = -0.212 and p = 0.000) in plots of 50 mx 50 m and, therefore, even if it has a low correlation, it is the indicated for competition studies on diametric growth in natural tropical forests. A spatial relationship of the IIDs was detected, where the correlation decreases with the increase of the plot size. Additional research is recommended to evaluate the effects of competition on tree growth, as well to increase understanding of intraspecific and interspecific competition in order to improve knowledge of the competition dynamics in tropical forests.