Biomass and Element Content of Foliage and Aboveground Litterfall on the Three Long-Term Experimental Beech Sites: Dynamics and Significance

Abstract

The amount and dynamics of litterfall in a forest stand is recognised as an integrated response, reflecting biologically (hereditary defined) controlled processes of shedding of leaves, roots, bark, fruits and other plant components and the physiologically controlled factors of environmental nature (climate, water availability, nutritional supply and toxicity parameters). Changes in the dynamics of litterfall components (leaves, fruits, florescence, seeds, twigs, etc.), in the short-term, is primarily a reflection of climatic perturbations affecting water and nutrient supply. For example, drought conditions in the early summer preceding mast year (mast year−1) were found to be a very strong predictor of mast production in beech stands of Europe and eastern North America (Piovesan and Adams 2001). An unusually moist, cool summer the year before the drought (mast year−2) increased the predictability of mast production which was associated with carbohydrate build up within the trees which might prime them for floral induction the following year (mast year−1). There is, however, very little known of the accumulation and redistribution of nutrients in association with masting in beech. Litterfall constitutes the transfer of energy between different trophic levels, where energy-rich plant materials are transferred for use by microbial and faunal populations in and on the soil. Despite the significance of litterfall in many ecosystem processes, the main emphasis on litterfall studies during the earlier periods had been to describe the fluctuations, distribution and composition of litterfall (Viro 1955; Kittredge 1948). Emphasis has now shifted to study the role of litterfall in ecosystem functioning especially its role in nutrient cycling processes in forest ecosystems (Khanna and Ulrich 1991). The aim of many studies in forest ecosystems is to develop management options where sustainability of ecosystem productivity and ecological functioning have been appropriately achieved, and for that purpose litterfall can act as a useful indicator. One such parameter is leaf biomass that is related to the health of forest ecosystems, which can be directly deduced from leaf litter, especially in deciduous stands. Another one is the decomposition rate of litterfall components which depends on the quality of litter fall and is thus closely related to the functionality and activity of microbial and faunal populations in soils (Chaps. 12, 12, this volume). Thus, litter fall quality of overstorey and understorey vegetation is closely related to the biodiversity on a forest site. Some essential components of the multi-functions of a forest ecosystem that are closely related to the amount and quality of litterfall are: C source for microbial activity, food for animals (biodiversity) and the use of nutrients for the growth and activity of flora and fauna.