Natural regeneration dynamics of three species of lianas in forest gaps - Moju, Pará state, Brazil

Abstract

Lianas or vines are forest components with poorly defined ecological function that intertwine the treetops, making logging difficult. This study evaluated the ecological behavior of Rourea krukovii, Derris amazonica and Arrabidea nigrescens species of lianas around gaps classified as small, medium and large, after logging. Around these gaps, 10 m x 50 m transects were installed from the borders into the forest. Each transect was divided into 10 m squared plots , numbered 1 to 5, in order to measure individuals with diameter at breast height (DBH) ≥ 5 cm. Sub-plots of 4 m2 were installed in plots 1, 3 and 5 to measure individuals with total height ≥ 10 cm and DBH < 5 cm. The behavior of species was evaluated by the Natural Regeneration Rate (RR) related to the variables that indicate gradients of light, such as gap size, distance from the gap border, monitoring time, and Periodical Annual Increment in height (PAI). The species assessed presented different responses with respect to the light gradients established by the factors studied, and it was not possible to classify them as tolerant or intolerant species. None of the species showed significant influences of the factors gap size and distance from the gap border on the RR. However, Arrabidea nigrescens showed influence of monitoring time on these factors at the end of the study. PAI in height decreased over time for the three species studied, indicating the influence of the competition suffered by these species in relation to growth factors.