Distribuição diamétrica de indivíduos arbóreos adultos e regenerantes em área de Caatinga em processo de recuperação

This study aimed to determine the diameter distribution of arboreal and regenerating individuals in an area of Caatinga in recovery process. The work was developed at the NUPEARIDO farm, Patos – PB, where adult individuals of the species Mimosa tenuiflora and Cnidoscolus quercifolius were planted in 2008 and in 2014, the secondary Handroanthus impetiginosus and Amburana cearensis. Diameter measurements were performed at breast level (DBH) and at ground level (DNS), for the trees and regenerants of both species, respectively. Mortality of secondary species and soil moisture content were also observed over the months of the year. The results showed that the arboreal individuals of both pioneer species are centered in the diameter class II (12-22 cm). As for regenerants, the largest number of individuals is found in diameter class I (0.2-12 mm) for Mimosa tenuiflora and class II (12 – 22 mm) for Cnidoscolus quercifolius. The high mortality of secondary species was found. The largest diameters were found in the first diametric classes, in which the climatic conditions may be related to the development of the species and the regeneration process in an area undergoing recovery requires time to adapt to local conditions. Este estudo teve como objetivo determinar a distribuição diamétrica dos indivíduos arbóreos e regenerantes em área de Caatinga em processo de recuperação. O trabalho foi desenvolvido na fazenda NUPEARIDO, Patos – PB, onde indivíduos adultos das espécies Mimosa tenuiflora e Cnidoscolus quercifolius foram plantados em 2008 e em 2014, as secundárias Handroanthus impetiginosus e Amburana cearensis. Foi realizada a medição do diâmetro ao nível do peito (DAP) e ao nível do solo (DNS), para os arbóreos e regenerantes de ambas as espécies, respectivamente. Também observou-se a mortalidade das espécies secundárias e o teor de umidade do solo ao longo dos meses do ano. Os resultados mostraram que os indivíduos arbóreos de ambas as espécies pioneiras encontram-se centrados na classe de diâmetro II (12-22 cm). Quanto aos regenerantes, o maior número de indivíduos encontra-se na classe de diâmetro I (0,2-12 mm) para a Mimosa tenuiflora e classe II (12 – 22 mm) para a Cnidoscolus quercifolius. Constatou-se a alta mortalidade das espécies secundárias. Os maiores diâmetros foram encontradas nas primeiras classes diamétricas, em que as condições climáticas podem estar relacionadas ao desenvolvimento das espécies e o processo de regeneração em área em processo de recuperação requer tempo para sua adaptação às condições do local. ABSTRACT: This study aimed to determine the diameter distribution of arboreal and regenerating individuals in an area of Caatinga in recovery process. The work was developed at the NUPEARIDO farm, Patos – PB, where adult individuals of the species Mimosa tenuiflora and Cnidoscolus quercifolius were planted in 2008 and in 2014, the secondary Handroanthus impetiginosus and Amburana cearensis. Diameter measurements were performed at breast level (DBH) and at ground level (DNS), for the trees and regenerants of both species, respectively. Mortality of secondary species and soil moisture content were also observed over the months of the year. The results showed that the arboreal individuals of both pioneer species are centered in the diameter class II (12-22 cm). As for regenerants, the largest number of individuals is found in diameter class I (0.2-12 mm) for Mimosa tenuiflora and class II (12 – 22 mm) for Cnidoscolus quercifolius. The high mortality of secondary species was found. The largest diameters were found in the first diametric classes, in which the climatic conditions may be related to the development of the species and the regeneration process in an area undergoing recovery requires time to adapt to local conditions.