Fine litter chemistry, early-stage decay, and nitrogen dynamics under plantations and primary forest in Lowland Amazonia

• Published in: Soil biology & biochemistry 1998-12, Vol.30 (14), p.2159-2169
• Main Authors: Smith, C.K., Gholz, H.L., de Assis Oliveira, F.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Brazil; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; Organic matter; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Soil science
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/S0038-0717(98)00099-6

One year field exposures of leaf litter from replicated plots of Pinus caribaea var. hondurensis Barrett and Golfari, Carapa guianensis Aubl., Euxylophora paraensis Hub., a Leguminosae combination ( Dalbergia nigra Fr. All., Dinizia excelsa Ducke, Parkia multijuga Benth.), and adjacent upland ( terra firme) forest at the Curuá-Una Forest Reserve, Pará, Brazil were used to examine the factors controlling leaf litter decay and N dynamics in a lowland tropical environment. Initial leaf litter N concentrations ranged from 4.4 ( P. caribaea) to 16.3 mg g −1 dry matter (Leguminosae), and initial lignin concentrations from 190.8 (Leguminosae) to 459.3 mg g −1 dry matter (forest). Pinus caribaea leaf litter lost the least mass (28%), and the Leguminosae leaf litter the most (61%), during the year long incubations. Initial and 1-y proximate C fractions, N concentrations and polyphenol concentrations were not related to mass loss. Annual N accumulation or depletion from leaf litter under the plantations and forest was related to C loss ( R 2=0.93, P=0.007) and holocellulose loss ( R 2=0.84, P=0.02). When leaf litter was placed outside its stand of origin, there was a significant location effect on decay rates, indicating that differences in the physical and biological microenvironments under the monospecific plots affected litter decomposition.