Abstract

The competition for C. candidissimum and G. ulmifolia was estimated in two successional stages of the deciduous forest. A sample design was composed of a central tree, belonging to the species of interest, and their ten closest neighbors; with 30 repetitions per species, making a total of 60 units of sampling. The diameter up to 1,30 meters of height (d), the height, the diameter and the shape of the tree tops, and the distance from each competitor to the central tree were measured. The above-ground biomass (AGB), the distances weighted by dimensions index (DR) and the tree top superposition index (ISC) were estimated. In addition, a method of relativizing the DR was proposed for each competing species in accordance to the ecological weight that has in the study forests (DRR) according to the importance value index (IVI). It was discovered that both central species have a high competition rate with their closest neighbors, both in DR and in ISC. The trend between DR and AGB was described through the stages of the development of C. candidissimum and G. ulmifolia and the relationship of the behavior with the inverted “J” distribution. By concluding the DRR, the competition for both species was mainly at intraspecific levels, and Quadrella odoratissima (Jacq.) Hutch. and Coccoloba venosa L. are potentially competitors in this ecosystem. It was determined that C. candidissimum tends to reduce the competition levels as it passes from one successional stage to another (p<0,05), while G. ulmifolia remains this constant competition.

Key words: Interspecific competition; competition index; biomass above ground; tree top superposition index; phytosociology