Decomposition rates of American chestnut (Castanea dentata) wood and implications for coarse woody debris pools

作者：de Bruijn Arjan; Gustafson Eric J; Kashian Daniel M; Dalgleish Harmony J; Sturtevant Brian R; Jacobs Douglass F^*

来源：Canadian Journal of Forest Research, 2014, 44(12): 1575-1585.

DOI：10.1139/cjfr-2014-0270

• American chestnut
• coarse woody debris
• decomposition
• carbon cycling
• carbon sequestration
• forest carbon simulations
• forest growth
• modeling
• plantation development

Observations of the rapid growth and slow decomposition of American chestnut (Castanea dentata (Marsh.) Borkh.) suggest that its reintroduction could enhance terrestrial carbon (C) sequestration. A suite of decomposition models was fit with decomposition data from coarse woody debris (CWD) sampled in Wisconsin and Virginia, U.S. The optimal (two-component exponential) model was integrated with generic growth curves and documented longevity and typical stem density to evaluate how CWD and biomass pools relate to decomposition. CWD decomposed faster in Wisconsin (4.3% +/- 0.3% per year) than in Virginia (0.7% +/- 0.01% per year), and downed dead wood decomposed faster (8.1% +/- 1.9% per year) than standing dead wood (0.7% +/- 0.0% per year). We predicted considerably smaller CWD pools in Wisconsin (maximum 41 +/- 23 Mg C.ha(-1)) than in Virginia (maximum 98 +/- 23 Mg C.ha(-1)) ; the predicted biomass pool was larger in the faster growing Wisconsin trees (maximum 542 +/- 58 Mg C.ha(-1)) compared with slower growing trees in Virginia (maximum 385 +/- 51 Mg C.ha(-1)). Sensitivity analysis indicated that accurate estimates of decomposition rates are more urgent in fertile locations where growth and decomposition are rapid. We conclude that the American chestnut wood is intermediate in resistance to decomposition. Due to the interrelatedness of growth and decomposition rates, CWD pool sizes likely do not depend on species alone but on how the growth and decomposition of individual species vary in response to site productivity.

• 出版日期2014-12