The effects of geomorphology, soil and climate on the trajectory of aboveground biomass accumulation of beech (Fagus sylvatica L.) at the southern range margin

Abstract

Forest ecosystems are among the most important carbon sinks in the terrestrial biomes. Therefore, the estimation of aboveground biomass accumulation is of fundamental importance for understanding the contribution of forest stands to the global carbon budget. In this study, we proposed a modelling approach to estimate aboveground biomass of beech forests in the Central Apennine based on stand age, climatic variables, topographic features and soil parameters. Using forest inventory data from the local forest management plans, international databases, and mixed-effect linear model, we identified stand age as a major driver of beech forests aboveground biomass. Climatic variables had generally higher influence than soil and topographic features, probably as a consequence of the homogeneous calcareous substrate which favoured the development of soils which are highly suitable for the growth of beech. Temperature range and seasonality were the most important climatic variables. Interestingly, we found that the aboveground biomass in Apennine beech forests is strongly site-specific. Different management approaches during the past centuries, i.e. presence or absence of conversion interventions of the analysed stands, are probably responsible for the growing site's significant influence. By highlighting the ideal locations for allocating the functions of forest production or evaluating the value of ecosystem services that regulate the climate, this study will help to improve both the precision of carbon budget modelling and decision-making in nature conservation and forest management.