Técnica nucleadora de transposição de galhadas em diferentes espaçamentos no semiárido da Paraíba.

Abstract

The technique of transposition of sets of tree branches aims at producing safe shelters for the wildlife, as it is one of the most important techniques for nucleation in restoration projects. This study aimed at evaluating the restorative capacity of the tree branches transposition technique in different spaces in degraded area at the Seridó Desertification Center, in the town of Várzea, PB. The research was conducted from February 2015 to February 2016 at the Cachoeira de São Porfírio Farm. We used the experimental design of randomized blocks, with five treatments represented by different distances between the branches (5.0 m x 5.0 m; 10.0 m x 10.0 m; 15.0 m x 15.0 m; 20.0 m x 20.0 m as well as a control treatment distributed within the preserved area) in four replications. In each plot, four sets of tree branches 0.7m x 0.7m x 0.7m were installed. We analyzed the organic matter content, the chemical composition, the soil water content, the temperature of the soil inside and outside the branches in the depths of 0.0, 7.5 and 15 cm and the height of the branches to follow their decomposition. The data was submitted to analysis of variance and the amounts compared by Tukey test at 5% significance. It was found that there was no significant difference in height of branches between treatments, however, there was some decomposition of the material that constitute the branches throughout the months of the study. Soil temperature variance analysis revealed significant interaction between the three depths and the twelve months of the study (p <0.05). The soil thermal regime was influenced by the use of branches as the smallest thermal amplitudes occurred inside the branches on every month of the research. The water content in the soil varied during the study period due to local rainfall, where the months of January and February /2016 presented the highest rainfall and lowest temperature range. They also had the highest water content value in the soil (about 2% and 12% respectively). The soil organic matter content in the treatments was not affected in the two periods studied, however, there was an increase in organic matter in the final analysis. The branches had become effective by the presence of the local birds, as there was some evidence found at the site such as excrement, feathers and animal burrows show the recovery of ecological functions. We conclude that, with the presence of branches, the soil temperature showed lower amplitudes throughout the experimental period when compared to bare soil; the branches reduced the material of its composition over the twelve months of study; there was an increase in organic matter content in the areas occupied by the branches; the organic matter from the reduction of branches and materials incorporated into them underwent mineralization, considering the high phosphorus content obtained at the end of the experiment; the branches functioned as a shelter and refuge for the local fauna and showed itself to be important in the process of restoring degraded areas, providing nucleating effect in the experimental area.