Produção Nacional
Revisado por pares
Leaf Decomposition in a Dry Season Irrigation Experiment in Eastern Amazonian Forest Regrowth
2007; Wiley; Volume: 39; Issue: 5 Linguagem: Inglês
10.1111/j.1744-7429.2007.00313.x
ISSN1744-7429
AutoresSteel Silva Vasconcelos, Daniel J. Zarin, Maria Beatriz Silva da Rosa, Francisco de Assis Oliveira, C. J. R. de Carvalho,
Tópico(s)Ecology and Vegetation Dynamics Studies
ResumoABSTRACT Leaf‐litter decomposition is a major component of carbon and nutrient dynamics in tropical forest ecosystems, and moisture availability is widely considered to be a major influence on decomposition rates. Here, we report the results of a study of leaf‐litter decomposition of five tree species in response to dry‐season irrigation in a tropical forest regrowth stand in the Brazilian Amazon; three experiments differing in the timing of installation and duration allowed for an improved resolution of irrigation effects on decomposition. We hypothesized that decomposition rates would be faster under higher moisture availability in the wet season and during dry‐season irrigation periods in the treatment plots, and that decomposition rates would be faster for species with higher quality leaves, independent of treatment. The rates of decomposition ( k ) were up to 2.4 times higher in irrigated plots than in control plots. The highest k values were shown by Annona paludosa (0.97 to 1.26/yr) while Ocotea guianensis (0.73 to 0.85/yr) had the lowest values; intermediate rates were found for Lacistema pubescens (0.91 to 1.02/yr) and Vismia guianensis (0.91 to 1.08/yr). These four tree species differed significantly in leaf‐litter quality parameters (nitrogen, phosphorus, lignin, and cellulose concentrations, as well as lignin:nitrogen and carbon:nitrogen ratios), but differences in decomposition rates among tree species were not strictly correlated with leaf‐litter quality. Overall, our results show that dry‐season moisture deficits limit decomposition in Amazonian forest regrowth.
Referência(s)