Litter decomposition in four woody species in a Mediterranean climate: Weight loss, N and P dynamics

Decomposition dynamics in leaves and needles of two Mediterranean shrubs and two pine species growing in the Sierra de Filabres (Almeria. Spain) was investigated during 2 years using the litter bag technique. The species studied are representative of the vegetation of the study area and differ greatly in their foliar traits. Results are discussed in relation to the initial litter qualify (C, N and P) and through the application of the exponential decay model. The mass lost at the end of study varied in the order: Pinus pinaster < Pinus nigra < Cistus laurifolius < Adenocarpus decorticans. Differences in annual rates of decomposition among species are consistent with the particular chemical and structural attributes of their leaves. The mass of decomposing litter remaining after 2 years was positively associated with the initial C:N ratio. Weight loss and nutrient release were fastest in the leguminous A. decorticans. The results suggest the importance of both structure and elemental concentration of initial litter for decomposition dynamics in Mediterranean species. (C) 2000 Annals of Botany Company.