Specom - a single tree model of pine stand/raw humus soil ecosystem

Abstract

A concept of ‘single plant ecosystem’ (SPE) as a structural and functional cell of terrestrial ecosystems is treated in forest stand/soil interaction modelling. The implementation of the SPE model for Scots pine ( Pinus sylvestris L.) and raw humus soil of middle taiga allows the simulation of young pine stand growth and soil changes (SPECOM model). The pine submodel and SPECOM model have a high degree of sensitivity to needle life duration; the raw-humus submodel demonstrates real inhibition of nitrogen release in such forest soils. The SPE model (subroutine of SPECOM model) reflects pine response to different nitrogen levels. The SPECOM model shows the same behaviour and differentiation of stand structure and soil cover, and demonstrates that dominant trees’ growth is limited by lack of nitrogen while suppressed trees grow slowly due to PAR deficiency. Model application shows that impact of pollution leads to complex effects on stand and soil even in the case of stand injury only.