Avaliação da implantação de Bertolletia excelsa Bonpl. em área de recuperação ambiental

Abstract

Decisions made about degraded area recovery methodologies are currently based on studies that monitor and measure the survival, diameter growth, and height growth of seedlings over time. However, due to the complexity of working with native species, it is n ecessary to analyze the relationship of these variables with other parameters obtained in continuous monitoring, in order to add greater knowledge of the development of the plantation and to indicate which resources available offer better response in the r ecovery areas. Thus, the present study aimed to seek and propose a way to optimize the recovery projects of a recovering area, by evaluating growth in height and diameter, relationships between seedling morphometric and mortality indicators of Bertholletia excelsa. Bonpl. (Castanheira). This study was conducted at Santa Rita da União Farm - Block III, rural area of Canaã dos Carajás - PA. The area has 4 hectares, divided into four blocks with 1 hectare each. We evaluated 259 Castanheira seedlings planted in five different treatments. We analyze Diameter growth with different fertilizer rates by analysis of variance (ANAVA) and Logistic Regression (Logit) to evaluate mortality. The seedlings mortality distribution was analyzed with the diameter at ground height (DC), height (AP), number of leaves (NF) and distance of the regeneration seedlings (DR). Intermediate classes of CD, AP and NF, but no mortality relationship with DR. The seedlings of Castanheira presented lower mortality rate when planted with DC> 6 mm and AP > 78 cm (0.39% and 6.95%, respectively). It is recommended that the seedlings be planted in the field only when they reach these values of diameter and height. Through the analysis of ANAVA, it was found that the effects of block and treatments do not have means with statistical differences of DC - the effect of different doses of fertilizers did not affect the growth averages - as well as the effect of different sites (blocks) was not statistically differentiated for this variable. The Logit regression model for the survival dependent variable and independent variables: treatments, blocks, herbivory events, condition (full sun or shade) leaf number and distance of regeneration - indicated as a result - only treatments, blocks and herbivory were significant in response to seedling survival. Treatments containing NPK in their composition and the third evaluated block resulted in lower probability of seedling survival, while seedlings that underwent seedling survival. Herbivore attacks were more likely to survive.