Litterfall, litter stock and water holding capacity in post-mining forest restoration ecosystems, Eastern Amazon

Abstract

The objective of this study was to evaluate the litterfall deposition, the decomposition rate (KL) and the water holding capacity (WHC) of litter stored in the soil in two areas degraded by mining submitted to different methods of forest restoration: induction of natural regeneration (NR) and planting seedlings of native forest species (PS) with a forest fragment (FF) used as reference. The litterfall deposition was collected monthly over 12 months in collectors of 0.25 m2. The KL was estimated by the relation between annual litter production and litter stock in the soil surface. WHC was determined in the rainy and dry period. The litterfall deposition was lower in PS with values of 6.61 ± 0.20, 10.75 ± 0.52 and 11.83 ± 0.72 Mg ha-1 yr-1 for PS, NR and FF respectively. The KL and WHC were significantly lower in PS when compared to NR and FF, and WHC decreased significantly from the rainy season to the dry season. The induction of natural regeneration was the more effective restoration method for degraded areas regarding litterfall deposition, decomposition and water retention capacity, surpassing planting native tree species and approaching a native forest fragment.