Competition Indexes to Evaluate Tree Growth in a Semi-Deciduous Seasonal Forest

Ilvan Medeiros Lustosa Junior,Ricardo De Oliveira Gaspar,Renato Vinícius Oliveira Castro,Juliana Baldan Costa Neves Araújo,Fabiana De Gois Aquino

doi:10.1590/2179-8087.010716

Abstract

ABSTRACT Most of the studies that analyze the behavior of tree competition approach even-aged plantations. Therefore, it is possible to notice a lack of this kind of information regarding natural forests with high biodiversity. The objective of this study was to evaluate the competition in a fragment of Semi-Deciduous Seasonal Forest, according to the ecologic group, light depending and non-depending groups for all species sampled in the fragment. The Distance Independent Competition Index and Semi-Distance Independent Competition Index were applied in this study. The basal area in larger trees index, without the radius of influence, was the most efficient to analyze how the competition affects the growth of the specimens in the studied fragment. It was stated that evaluating the competition per ecologic group is more efficient. The results confirm that the forest competition cannot be determined by considering only a fixed radius of influence that embraces the neighbors and the subject tree.

Highlights

AND OBJECTIVESForest competition consists in a direct relation between increase of demand for resources which are necessary for the plants’ growth and decrease of its availability
The biggest standard deviation found to the diameter at breast height (DBH) variable was from the successional climax group, while for the Ht variable, groups of all species presented a greater dispersion of values in relation to the average (Table 4)
When analyzing the relation between standard deviation and correlations found amongst competition indexes and those variables in question, one may find that lower and non-significant correlations belonged to those groups, which presented a greater variation amongst data in relation to the average

Summary

Introduction

Forest competition consists in a direct relation between increase of demand for resources which are necessary for the plants’ growth and decrease of its availability. Depletion or even scarcity of those resources results in some profound implications for ecology and forest handling. It is believed that the competition process among trees retracts diameter’s growth and increases mortality rate (Lee, 1971). One of the techniques utilized to evaluate forest competition consists of applying competition indexes. According to Boivin (2010), a variety of them, spatial or not, were developed to estimate competition’s effect on individual trees’ growth or within a tree stand. To Castro (2014), efficiency in growth’s modeling on an individual’s tree level can be greater with the usage of competition indexes

Objectives

Methods

Results