Optimum plot size for estimate carbon stock from above ground tree biomass from phytophysiognomies in Eastern Amazon.

Abstract

This work was developed in Jutaituba farm, located in the county of Portel, Pará. The study was carried out by means of a pilot inventory with the purpose of estimating the carbon stock in above ground tree biomass from various phytophysiognomies found in the analyzed property. The main goal of this effort is to analyze the size of the ideal plot to be utilized in the definitive inventory. It was used Stratified Sampling and sample unities with dimensions of 10x250 m (2500 m²), in wich all the living individuals' measured CAP shown a DAP above 30 cm. For the plot size analysis it was utilized the Intraclass Correlation Coefficient method. Through the pilot inventory it was estimated the carbon stock average in above ground tree biomass of 188,54 Mg C.ha^-1 (143,07 a 234,02 Mg C.ha^-1) with a sampling error of 24% and 95% significance. Therefore, for a sampling error of 10% and 95% significance it would be needed 187 sample unities. By means of the plot size study, the size of the plot could be reduced as a way to reduce the costs of the inventory without harm to the estimations of the variable of interest. The dimension of the sampling unity to be utilized in the definitive inventory will be 10 x 200 m (2000 m²).