Data from: Decay classes of coarse woody debris in a lowland Dipterocarp forest: implications for volume, density and carbon estimates

Coarse woody debris (CWD) is a critical structural and functional
component of forest ecosystems. In tropical forests, developing a
decomposition classification is required for vigorous estimates of the
role of CWD in carbon (C) and nutrient cycling and habitat diversity. This
study considered the relationship between decay class, termite
infestation, wood density, and C content of CWD in a lowland Dipterocarp
forest in Southern Vietnam. The termite infestation averaged 73% by number
and 32% by volume of all CWD pieces. Microbial and termite-driven
decomposition was separated in the suggested decay classification system.
Five decay classes were assigned to CWD items based on the proportion of
wood consumed by invertebrates, as well as softness and moisture of the
remaining wood. The proportion of wood volume consumed by termites in the
1st, 2nd, 3rd, 4th, and 5th decay classes averaged 2, 5, 15, 48 and 77%,
respectively. The bulk density of wood of the 1st, 2nd, 3rd, 4th, and 5th
decay classes averaged 0.628, 0.501, 0.332, 0.169 and 0.071 g cm-3,
respectively. The C concentration in wood averaged 42% and did not depend
on decay class. The total C content in CWD decreased with decomposition
and averaged 0.259, 0.199, 0.121, 0.037, and 0.009 g cm-3 in the CWD of
the 1st, 2nd, 3rd, 4th, and 5th decay classes, respectively. We conclude
that in Dipterocarp forests the inventories of CWD by decay classes should
include estimates of proportions of wood, termite soil substrate, and wood
voids.