Estimation of root biomass and root surface area in a broad-ieaved secondary forest in the southern part of Kyoto prefecture

Abstract

Root biomass and surface area were estimated using two methods in a broad-leaved secondary forest in southern part of Kyoto Prefecture. Root systems (n = 6) were dug out as samples. Dry weights and diameters of all roots in each sample were measured in detail to establish allometric relationships for estimating root biomass and root surface area from stem-basal diameter. Using data from the DBH census in the study site in 1999, biomass and surface area were calculated for three size classes of coarse root. Sample soil blocks were taken to estimate biomass and surface area of small-diameter roots. Silhouette image analysis was used to measure surface area of roots with diameters less than 2 mm. Total estimated root biomass for the study site was 23.41 t ha -1, and TR ratio (Top/Root) was 4.36. Total root surface area was estimated to be 3.50 m2 m2, and 75% of root surface area was occupied by roots less than 2 mm in diameter.