Desempenho silvicultural de espécies arbóreas de rápido crescimento em área de restauração florestal no sudoeste do Paraná

Abstract

To mitigate the damage caused by human activities, ecological restoration has become the main alternative to protect natural resources and conserve biodiversity. However, there is little information about the silvicultural performance of native species used in restoration projects. This study aimed the initial development of pioneer tree species and their potential for use in restoration projects. The tree seedlings were planted in December 2010, forming models of alternate rows, spaced 3 m between rows and 2 m between plants. The experiment was done in four randomized blocks, each block being a portion of 40 x 54 m, containing 360 seedlings of 70 native species. In this work we chose to evaluate 13 species of rapid growth, represented by 756 individuals. Data collection occurred every six months until 3.5 years of age, there was obtained stem diameter information, height, crown diameter, crown density and survival. Scatter plots were constructed to verify the correlation between the variables, allometric relationships, growth models and cluster analysis. The species that showed a less survival was Piptadenia gonoacantha (Mart.) J.F. Macbr (58,54%). Was found greater growth in height in the early stages, which decreases over time, occurring greater investments in crown area and stem diameter. The growth rate in stem diameter was greater for Mimosa scabrella Benth. (8.88354 mm.mês-1); height Croton floribundus Spreng. (0.20425 m.mês-1) and Zanthoxylum rhoifolium Lam (0.23537 m.mês-1); canopy area for M. scabrella (0.98285 m².mês-1), Croton urucurana Baill. (0.94160 m².mês-1) and C. floribundus (0.92060 m².mês-1). The species showing a rapid growth in area of canopy and canopy density, fulfilling the role of sombreadoras were: M. scabrella, Solanum mauritianum Scop., Trema micrantha (L.) Blume.. and C. urucurana. Inga uruguensis Hook. & Arn. classified how non-pioneer, showed an rapid growth and excellent canopy density. Bauhinia forficata Link., P. gonoacantha and Alchornea triplinervia (Spreng.) Müll. Arg. were the species with smaller silvicultural performance that proved to be inefficient as sombreadoras. To accelerate the establishment of a continuous and sustainable forest in the region is recommended intensify the use of species with greater silvicultural performance, increasing the guarantee of success.