Deadwood stocks increase with selective logging and large tree frequency in Gabon.
Abstract
Deadwood is a major component of aboveground biomass (AGB) in tropical forests and
is important as habitat and for nutrient cycling and carbon storage. With deforestation
and degradation taking place throughout the tropics, improved understanding of the
magnitude and spatial variation in deadwood is vital for the development of regional
and global carbon budgets. However, this potentially important carbon pool is poorly
quantified in Afrotropical forests and the regional drivers of deadwood stocks are
unknown. In the first large-scale study of deadwood in Central Africa, we quantified
stocks in 47 forest sites across Gabon and evaluated the effects of disturbance (logging),
forest structure variables (live AGB, wood density, abundance of large trees), and
abiotic variables (temperature, precipitation, seasonality). Average deadwood stocks
(measured as necromass, the biomass of deadwood) were 65 Mg ha-1 or 23% of live AGB.
Deadwood stocks varied spatially with disturbance and forest structure, but not abiotic
variables. Deadwood stocks increased significantly with logging (+38 Mg ha-1 ) and
the abundance of large trees (+2.4 Mg ha-1 for every tree >60 cm dbh). Gabon holds
0.74 Pg C, or 21% of total aboveground carbon in deadwood, a threefold increase over
previous estimates. Importantly, deadwood densities in Gabon are comparable to those
in the Neotropics and respond similarly to logging, but represent a lower proportion
of live AGB (median of 18% in Gabon compared to 26% in the Neotropics). In forest
carbon accounting, necromass is often assumed to be a constant proportion (9%) of
biomass, but in humid tropical forests this ratio varies from 2% in undisturbed forest
to 300% in logged forest. Because logging significantly increases the deadwood carbon
pool, estimates of tropical forest carbon should at a minimum use different ratios
for logged (mean of 30%) and unlogged forests (mean of 18%).
Type
Journal articleSubject
aboveground biomass (AGB)carbon storage
coarse woody debris (CWD)
deadwood
necromass
tropical forest
Biomass
Carbon
Forestry
Forests
Gabon
Trees
Tropical Climate
Permalink
https://hdl.handle.net/10161/15863Published Version (Please cite this version)
10.1111/gcb.13453Publication Info
Carlson, Ben S; Koerner, Sally E; Medjibe, Vincent P; White, Lee JT; & Poulsen, John
R (2017). Deadwood stocks increase with selective logging and large tree frequency in Gabon.
Glob Chang Biol, 23(4). pp. 1648-1660. 10.1111/gcb.13453. Retrieved from https://hdl.handle.net/10161/15863.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
Collections
More Info
Show full item recordScholars@Duke
John Poulsen
Associate Professor of Tropical Ecology
John Poulsen is an ecologist with broad interests in the maintenance and regeneration
of tropical forests and conservation of biodiversity. His research has focused on
the effects of anthropogenic disturbance, such as logging and hunting, on forest structure
and diversity, abundance of tropical animals, and ecological processes. He has conducted
most of his research in Central Africa, where he has also worked as a conservation
manager, directing projects to sustainably manage natural resources i

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info