Litterfall quantity and quality and nutrient status in a young stand under Norway spruce and broadleaved species

In Europe, because of previous intense forest use in the past centuries, the plantation of coniferous stands, especially Norway spruce with high production potential has been a common strategy. However, the characteristics of Norway spruce such a s susceptibility to windfall, forest dieback and soil acidification have caused negative ecological impacts at many sites. Conversion of conifers into deciduous or mixed stands has been suggested in order to improve ecological conditions and biodiversity o f forest ecosystems. In this study, six broadleaved species were planted at the same site, thus being subjected to similar condition in terms of soil type, land use history and climate. The aim of this research was to study of foliar nutrient status and nu trient return to the forest floor through litterfall 11 years after conversion of Norway spruce (Picea abie s (L.) KARST.) into a mixed stand with common alder (Alnus glutinosa (L.) GAERTN.), european beech (Fagus sylvatica L.), pedunculate oak (Quercus rob ur L.), silver birch (Betula pendula ROTH.), goat willow (Salix caprea L.) and rowan (Sorbus aucuparia L.). Our results revealed that tree species had a different foliar nutrient status and an effect on nutrient input fluxes through litterfall. For example , litter nutrient contents (N, Ca, Mg, K) were highest under alder, rowan and willow. Total litterfall and nutrient fluxes from leaf litter were highest under rowan. Our results demonstrate that, on poor sites, plantation of pioneer species, especially row an, may improve the nutrient status of the forest floor through higher input in litterfall.