Decomposition and nutrient release dynamics of leaf litter from shrub species in evergreen woodlands

Abstract

Mediterranean evergreen woodlands include a wide diversity of shrub species. It is essential to increase the knowledge about the nutrient cycling of the more relevant shrub species to assess the properfunctioning, management options and conservation policies of these ecosystems. In an oak woodland(southern Portugal), we evaluated the litterfall of seven shrub species by using litter traps for 1 year. Thedecomposition study of each leaf litter and respective nutrient release took place under the canopy ofthe respective species, using the litterbag method for 2.5 years. Leaf litter (58–86%) was the maincomponent of litterfall. The annual potential return of N to the soil ranged 0.26–3.55 g m−2 year−1, whileP reached 0.020–0.32 g m−2 year−1. After 2.5 years, the remaining organic matter was in the range 35–56%,and the decomposition rate varied between 0.28–0.56 year−1 (Quercus coccifera and Myrtus communis,respectively). No indicator of leaf litter quality explained differences in decomposition rates of studied leaf litters, while nutrient release dynamics is mostly related to leaf litter mineral composition. TheMediterranean evergreen woodlands management may benefit from combining shrub species with lowdecomposition rates (e.g. Q. coccifera) and others exhibiting faster nutrient release (e.g. Olea europaea var. sylvestris).