Although trees have been grown intensively for centuries, short-rotation forestry (SRF) is a relatively new concept which emerged in the 1960s in parallel with the increasing need for producing fibre for the pulp industries and,more recently, for producing biomass for energy purposes. The quantity and quality of woody biomass produced under SRF systems is a result of many complex ecophysiological interactions. The environment around the growing crop may be altered in many ways, such as by mechanical site preparation, changing the planting densities, irrigation, addition of fertilisers, etc. The planting material itself can be controlled through tree breeding. It is of great importance, even in systems grown for energy, to gain understanding about how resource allocation between individuals can be influenced by planting design and management. As a consequence, there is a need for understanding within-stand processes and for the ability to predict the long-term consequences of plant-plant interactions in coppice systems. Future within-stand dynamics and the resulting stand structure cannot be predicted without a firm understanding of the processes involved in competition between individuals within a stand. The objective of this paper is to give a conceptual framework for modelling short-rotation forestry systems, and coppice systems in particular, in such a way that plant-plant interactions can be included. Therefore, we begin by defining competition and its spatial scale, and discuss the response of individual trees and populations to competition. We examine some existing simulation models for their ability to take account of intraspecific competition. We exemplify relevant within-stand characteristics which we would like to see included in a model, and translate these in terms of ''model output'' which we would like to obtain from a future growth model. Copyright (C) 1996 Elsevier Science Ltd.