Effects of large aboveground biomass loss events on the deadwood and litter mass dynamics of seasonal tropical forests in Cambodia

Abstract

Dead organic matter (DOM), which includes deadwood (DW) and litter (LT), plays an important role in forest ecosystem functions. To date, little DOM data have been collected in the seasonal forests of Indochina. We monitored DW and LT masses in Cambodian seasonal forests during a period of 10 years at intervals of 1‒2 years in 22 permanent sample plots (PSPs) in evergreen forest (EF, n=10) and deciduous forest (DF, n=12) deployed across Cambodia. We found that large aboveground biomass (AGB) loss events, which were probably caused by logging, increased DW mass and DOM carbon stock. However, such AGB loss events did not necessarily affect LT masses (i.e., coarse LT [CLT] and fine LT including partly decomposed roots to a soil depth of 5 cm [FLT]). The mean DOM carbon stock and masses of DW, LT, CLT, and FLT during the study period had no significant relationships with AGB in either EF or DF. DOM and its components exhibited large spatial variations, suggesting that additional sampling is required for greater precision. The Cambodian seasonal forest was characterized by a relatively small DW mass, possibly due to anthropogenic removal of DW and dying trees.