title: Decomposition and carbon cycling of dead trees in tropical forests of the central Amazon.
abstract: Decomposition rate constants were measured for boles of 155 large dead trees (>10 cm diameter) in central Amazon forests. Mortality data from 21 ha of permanent inventory plots, monitored for 10-15 years, were used to select dead trees for sampling. Measured rate constants varied by over 1.5 orders of magnitude (0.015-0.67 year-1), averaging 0.19 year-1with predicted error of 0.026 year. Wood density and bole diameter were significantly and inversely correlated with rate constants. A tree of average biomass was predicted to decompose at 0.17 year-1. Based on mortality data, an average of 7.0 trees ha-1year-1died producing 3.6 Mg ha-1year-1of coarse litter (>10 cm diameter). Mean coarse litter standing-stocks were predicted to be 21 Mg ha-1, with a mean residence time of 5.9 years, and a maximum mean carbon flux to the atmosphere of 1.8 Mg C ha-1year-1. Total litter is estimated to be partitioned into 16% fine wood, 30% coarse wood, and 54% non-woody litter (e.g., leaves, fruits, flowers). Decomposition rate constants for coarse litter were compiled from 20 globally distributed studies. Rates were highly correlated with mean annual temperature, giving a respiration quotient (Q10) of 2.4 (10°C-1).
authors.affiliation: Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA, , , , , , US.
authors.forename: J Q
authors.initials: JQ
authors.lastname: Chambers
authors.affiliation: Departamento de Silvicultura Tropical, Instituto Nacional de Pesquisas da Amazônia (INPA, National Institute of Amazon Research), CP-478, Manaus, Amazonas, 69011-970, Brazil e-mail: jeff@inpa.gov.br, , , , , , BR.
authors.forename: N
authors.initials: N
authors.lastname: Higuchi
authors.affiliation: Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA, , , , , , US.
authors.forename: J P
authors.initials: JP
authors.lastname: Schimel
authors.affiliation: Biological Dynamics of Forest Fragments Project, INPA, CP-478, Manaus, Amazonas, 69011-970, Brazil, , , , , , BR.
authors.forename: L V
authors.initials: LV
authors.lastname: Ferreira
authors.affiliation: Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA, , , , , , US.
authors.forename: J M
authors.initials: JM
authors.lastname: Melack
keywords: Carbon cycling models; Coarse surface litter; Global biogeochemistry; Key words Wood decomposition; Tree mortality