Estimation of the volume, biomass and carbon content of coarse woody debris within two forest types in the State of São Paulo, Brazil

Coarse woody debris (CWD) is an important form of dead wood that can store a significant amount of carbon. Few studies have been conducted on dead biomass in Brazil, especially in the Atlantic Forest and Cerrado ecosystems. The objective of this study was to conduct stratified line intersect sampling using two design configurations (straight-line and cross-shaped) with three different segment lengths (100, 150 and 200 m) to estimate the number, volume, biomass and carbon content of CWD elements in the State of Sao Paulo, Brazil. Two forest types were examined: a seasonal semi-deciduous forest (SSF) and a Cerrado sensu stricto (CSS) ecosystem. The most accurate design for the SSF and the CSS forest types were the 200m cross-shaped and 150m cross-shaped, respectively. The parameter estimates for the SSF forest type were 198 CWD elements ha(-1), volume of 15.7m(3) ha(-1), biomass of 6.7 Mg ha(-1), and carbon content of 3.3 Mg C ha(-1). The CWD estimates for the CSS type were 95 CWD elements ha(-1), 3.3m(3) ha(-1) volume, 1.3 Mg ha(-1) biomass, and 0.67 Mg C ha-1 carbon content. Forest type can influence the amounts of CWD elements; ignoring this information when selecting a sampling design can lead to less accurate estimates of necromass stock. This type of study is very important for determining an appropriate sampling design for future inventories.