SAMPLING PROCESSES FOR Carapa guianensis AUBL. IN THE AMAZON

Abstract

HIGHLIGHTSThe process of adaptive cluster sampling (ACS) is not legally viable.The processes of systematic sampling and simple random are legally viable.The use of larger parcels in the ACS overestimates the variable of interest.The higher the share in the ACS, the greater the sampling intensity. ABSTRACTThe objective of this study was to analyze the adaptive cluster sampling (ACS), simple random sampling (SRS) and systematic sampling (SS) processes to obtain the number of ha-1 trees of Carapa guianensis Aubl. in the Amazon. The data were obtained through 100% inventory and sampling simulations, considering a DBH ≥ 25 cm, a sampling intensity of 4%, a maximum error of 10% and plots of 0.09, 0.16 and 0.25 ha. The last two sizes were only used to analyze their effect on the ACS estimators. The processes were evaluated for accuracy, precision (E % ) and confi dence interval (CI), while the mean ha -1 of the processes were compared with that of the 100% inventory by the Z test. The ACS process showed no signifi cant difference between its average ha -1 trees and the 100% inventory, and it was also the most accurate and the only one whose CI was true. However, it presented a fi nal sample intensity 3.6 times greater than the simple and systematic random samplings, in addition to E % above 10%, which makes it unacceptable, legally, and economically unfeasible. The other processes had densities signifi cantly higher than the 100% inventory, with sample intensities lower than ACS and E % lower than 10%, making them legally viable. The use of larger plots in the ACS implies larger clusters and a greater tendency to underestimate the number of trees, resulting in larger sample errors and less accuracy. v.24 n.3 2018 SAMPLING PROCESSES FOR Carapa guianensis AUBL. IN THE AMAZON FOREST 170 CERNE VIEIRA et al.

Multipropósito de Hymenaea courbaril L. em uma área de manejo florestal comunitário na Amazônia

“…A distribuição tendendo à normalidade é consequência do baixo recrutamento de plantas jovens, ocasionado, possivelmente, pela baixa produção de sementes e taxa de germinação, além da mudança do estágio sucessional da floresta de inicial para mais avançado. Ainda podem ser resultados do ritmo lento de desenvolvimento das árvores, o que é associado à espécies de ciclo longo com pequeno número de sementes e germinação lenta, e das alterações climáticas, as quais tem gerado condições de menor precipitação, o que afeta a capacidade de alguma espécies de reproduzirem-se e estabelecerem árvores jovens (VIEIRA et al 2018). Todos esses eventos, provavelmente ocorreram décadas atrás na UPA nº 10, fazendo com que a B Adv.…”