Crecimiento diamétrico arbóreo en bosques de Sierra de Lema, Guayana venezolana: primeras evaluaciones

in order to describe and analyze the tree diameter growth in forests along an altitudinal gradient (290-1395masl) in the region of la escalera, successive tree surveys were undertaken in 22 plots of 0.1ha located at 6 sites during variable monitoring periods from 1 to 5 years. this gradient is located in la escalera, in the sierra de lema, southeastern venezuela, and comprises 3 bioclimates: wet tropical, wet lower premontane and moist upper premontane. two stem distribution patterns of growth classes were identified: one with center at the class from -0.2 to 0.3cm and another with center at the class from 0.3 to 0.6cm. the average values of the current annual increment in diameter (caidbh) in the gradient ranged between 0.39 and 0.21cm. no significant differences were found among bioclimates, among sites, and between monitoring periods. only the caidbh among crown illumination classes and diameter classes showed significant differences (p<0.0001). the largest caidbh rates (>0.5cm) in the gradient corresponded to emergent trees, usually with diameter >30cm. the crown illumination is a useful indicator to explain differences of tree growth. the limitations and future trends of this study are discussed.