 |
| Titel |
After trees die: quantities and determinants of necromass across Amazonia |
| VerfasserIn |
K.-J. Chao, O. L. Phillips, T. R. Baker, J. Peacock, G. López-González, R. Vásquez Martínez, A. Monteagudo, A. Torres-Lezama |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 6, no. 8 ; Nr. 6, no. 8 (2009-08-11), S.1615-1626 |
| Datensatznummer |
250003951
|
| Publikation (Nr.) |
 copernicus.org/bg-6-1615-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
| The Amazon basin, one of the most substantial biomass carbon pools on earth,
is characterised by strong macroecological gradients in biomass, mortality
rates, and wood density from west to east. These gradients could
affect necromass stocks, but this has not yet been tested. This study aims
to assess the stocks and determinants of necromass across Amazonian
forests. Field-based and literature data were used to find relationships
between necromass and possible determinants. Furthermore, a simple model was
applied to estimate and extrapolate necromass stocks across terra firma Amazonian
forests. In eight northwestern and three northeastern Amazonian permanent
plots, volumes of coarse woody debris (≥10 cm diameter) were measured
in the field and the density of each decay class was estimated. Forest structure
and historical mortality data were used to determine the factors controlling
necromass. Necromass is greater in forests with low stem mortality rates
(northeast) rather than in forests with high stem mortality rates (northwest) (58.5±10.6
and 27.3±3.2 Mg ha−1, respectively). Using all published necromass values, we find that necromass across
terra firma forests in Amazonia is positively related to both forest dynamics
(mortality mass inputs and a surrogate for decomposition rate (average wood density of
living trees)) and forest structure (biomass), but is better explained by
forest dynamics. We propose an improved method to estimate
necromass for plots where necromass has not been measured. The estimates,
together with other actual measurements of necromass, were scaled-up to
project a total Amazonian necromass of 9.6±1.0 Pg C. The ratio of
necromass (on average weighted by forest region) to coarse aboveground
biomass is 0.127. Overall, we find (1) a strong spatial trend in necromass
in parallel with other macroecological gradients and (2) that necromass is a
substantial component of the carbon pool in the Amazon. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|