Variações anuais na produção de frutos e sementes de castanheira-do-brasil (bertholletia excelsa bonpl., lecythidaceae) em florestas nativas de Roraima

Abstract

The objective of the present study was to evaluate annual production variations between populations and individuals in native Brazilian nut groves of Roraima. Data were obtained from five permanent plots of 300 m x 300 m installed in the municipalities of Caracaraí and São João da Baliza. Every tree presenting the diameter at breast height (DBH) greater than or equal to 10 cm were measured and identified using aluminum number labels attached to the stem by nails. During the falling of fruits (March-July) all the trees were visited on two occasions: in the middle and at the end of this period. The fruits of each tree were counted, and seeds were weighed using a digital balance scale accurate to 50 g. The fruit and seed production varied among populations and individuals, and the majority did not produce fruits every year. In a high production year, the yield is up to fifty-two times greater than in the low production years. The total production was concentrated on a small number of trees with one year of peak production (mast-year).