Sampling system for estimating woody debris in an urban mixed tropical forest

Abstract

Woody debris, defined as standing and downed deadwood, consists in an essential component of the forest carbon stock. However, few studies have been carried out to get an efficient and accurate sampling procedure for estimating it. This work proposes two methodologies to estimate the woody debris volume in a Brazilian mixed tropical forest: 1) two-stage systematic sampling, using a mixed methodology, in which the Strand's method is applied to standing dead trees and stumps, and line intercept sampling is used to fallen trees and branches; and 2) ratio estimate of the sum of cross-sectional areas of deadwood pieces and forest basal area, aiming to obtain the total woody debris volume indirectly in the natural forest. Conversions for biomass and carbon stocks were made applying the mean basic density on the estimates of deadwood volumes. Both methodologies are accurate for woody debris volume estimates, with a sampling error equal to 16.1% (methodology 1) and 5.7% (methodology 2), at a 95% probability level. Thus, the methodology 2 has potential to be used in strategic forest inventories of woody debris, such as in National Forest Inventories, due to increasing importance of its quantification in all forest ecosystems.

Effects of differences in aboveground dead organic matter types on the stand‐scale necromass and CO2 efflux estimates in a subtropical forest in Okinawa Island, Japan

“…Previous studies showed that leaf litter and FWD were spatially autocorrelated with a range ≤5 m in planted pine forests (Penne et al, 2010). It has also been reported that the spatial distribution of CWD does not show spatial autocorrelation in tropical forests (Péllico et al, 2018). Collectively, these studies suggest that the spatial autocorrelation of DOM depends on topography, forest type, and DOM type.…”