TY - JOUR

T1 - Nutrient limitation of woody debris decomposition in a tropical forest

T2 - contrasting effects of N and P addition

AU - Chen, Yao

AU - Sayer, Emma

AU - Li, Zhian

AU - Mo, Qifeng

AU - Li, Yingwen

AU - Ding, Yongzhen

AU - Wang, Jun

AU - Lu, Xiankai

AU - Tang, Jianwu

AU - Wang, Faming

N1 - This is the peer reviewed version of the following article: Chen, Y., Sayer, E. J., Li, Z., Mo, Q., Li, Y., Ding, Y., Wang, J., Lu, X., Tang, J. and Wang, F. (2016), Nutrient limitation of woody debris decomposition in a tropical forest: contrasting effects of N and P addition. Funct Ecol, 30: 295–304. doi:10.1111/1365-2435.12471 which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12471/abstract This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.

PY - 2016/2

Y1 - 2016/2

N2 - 1.Tropical forests represent a major terrestrial store of carbon (C), a large proportion of which is contained in the soil and decaying organic matter. Woody debris plays a key role in forest C dynamics because it contains a sizeable proportion of total forest C. Understanding the factors controlling the decomposition of organic matter in general, and woody debris in particular, is hence critical to assessing changes in tropical C storage.2.We conducted a factorial fertilization experiment in a tropical forest in South China to investigate the influence of nitrogen (N) and phosphorus (P) availability onwoody debris decomposition using branch segments (5-cm diameter) of four species (Acacia auriculaeformis, Aphanamixis polystachya, Schefflera octophylla, Carallia brachiata) in plots fertilized with +N, +P, or +NP, and controls.3.Fertilization with +P and +NP increased decomposition rates by 5-53% and the magnitude was species-specific. Contrary to expectations, we observed no negative effect of +N addition on decay rates or mass loss of woody debris in any of the four study species. Decomposition rates of woody debris were higher in species with lower C:P ratios regardless of treatment.4.We observed significant accumulation of P in the woody debris of all species in plots fertilized with +P and +NP during the early stages of decomposition. N-release from woody debris of Acacia (N-fixing) was greater in the +P plots towards the end of the study, whereas fertilization with +N had no impact on the patterns of nutrient release during decomposition.5.Synthesis: Our results indicate that decomposition of woody debris is primarily constrained by P availability in this tropical forest. However, contrary to expectations, +N addition did not exacerbate P-limitation. It is conceivable that decay rates of woody debris in tropical forests can be predicted by C:P or lignin:P ratios but additional work with more tree species is needed to determine whether the patterns we observed are more generally applicable.

AB - 1.Tropical forests represent a major terrestrial store of carbon (C), a large proportion of which is contained in the soil and decaying organic matter. Woody debris plays a key role in forest C dynamics because it contains a sizeable proportion of total forest C. Understanding the factors controlling the decomposition of organic matter in general, and woody debris in particular, is hence critical to assessing changes in tropical C storage.2.We conducted a factorial fertilization experiment in a tropical forest in South China to investigate the influence of nitrogen (N) and phosphorus (P) availability onwoody debris decomposition using branch segments (5-cm diameter) of four species (Acacia auriculaeformis, Aphanamixis polystachya, Schefflera octophylla, Carallia brachiata) in plots fertilized with +N, +P, or +NP, and controls.3.Fertilization with +P and +NP increased decomposition rates by 5-53% and the magnitude was species-specific. Contrary to expectations, we observed no negative effect of +N addition on decay rates or mass loss of woody debris in any of the four study species. Decomposition rates of woody debris were higher in species with lower C:P ratios regardless of treatment.4.We observed significant accumulation of P in the woody debris of all species in plots fertilized with +P and +NP during the early stages of decomposition. N-release from woody debris of Acacia (N-fixing) was greater in the +P plots towards the end of the study, whereas fertilization with +N had no impact on the patterns of nutrient release during decomposition.5.Synthesis: Our results indicate that decomposition of woody debris is primarily constrained by P availability in this tropical forest. However, contrary to expectations, +N addition did not exacerbate P-limitation. It is conceivable that decay rates of woody debris in tropical forests can be predicted by C:P or lignin:P ratios but additional work with more tree species is needed to determine whether the patterns we observed are more generally applicable.

KW - Coarse woody debris

KW - CWD

KW - Decay

KW - Decomposition

KW - Fertilization

KW - fine woody debris

KW - nutrient addition

KW - tropical soil

U2 - 10.1111/1365-2435.12471

DO - 10.1111/1365-2435.12471

M3 - Journal article

VL - 30

SP - 295

EP - 304

JO - Functional Ecology

JF - Functional Ecology

SN - 0269-8463

ER -