摘要：Post fire Nothofagus pumilio forests of NW Patagonia are characterized by a low regeneration. The restoration of native vegetation mainly depends on the type and history of disturbance, the size and composition of the seed bank, the sprouting capacity of species and the environmental conditions, which allow species expression. Management practices aiming to recover soil organic matter concentration may increase nutrient availability, water storage capacity, size and composition of seed banks and seedling survival. Therefore, they might be an important tool to be used in the recovery of these ecosystems. The objective of this work was to study the seed bank in different microsites of a burned Nothofagus pumilio forest and the effect of biosolids compost application on its size and composition. The valuation of compost is mainly referred to its capacity to improve the quality and quantity of soil organic matter (amendment value) and nutrient content (fertilizer value) of degraded soils. The study was carried out in a forest that burned in 1996, located at Challhuaco valley in the Reserve of Nahuel Huapi National Park, Argentina. This valley represents a typical transitional zone between forest and ecotone and it is characterized by a high impact of human activities. Sampling was performed in two seasons (end of winter and start of summer 2002) at three microsites (litter and soils with and without litter accumulation). The seedling emergence technique was used to determine the size and composition of seed banks. Exotic and herbaceous species with a transient seed bank strategy prevailed. This strategy increased the susceptibility to adverse climatic conditions and did not contribute to system stability. Litter constituted an important reservoir of the persistent seed bank but did not promote high species diversity. Biosolids compost application added viable seeds, favored seedling abundance (end of winter) and enhanced species richness (end of winter and start of summer), mainly due to exotic species. It had different effect on several species and produced low benefit in native vegetation recovery. Apparently, the seed bank strategy did not constitute an effective tool in vegetation recovery. These results confirm the need to apply restoration strategies that promote the re-vegetation in burned N. pumilio forests
