A comparison among eucalypt, poplar and willow characteristics with particular reference to a coppice, growth-modelling approach

A comparative overview is made of a suite of characteristics related to physiological processes of development, growth and productivity of three functionally related genera, namely eucalypt (Eucalyptus), poplar (Populus) and willow (Salix). The approach provides basic information for top-down as well as bottom-up models, with particular reference to coppice growth and productivity. Eucalypt, poplar and willow are similar in many aspects but differ in others. All three genera have similar indeterminate shoot growth, leaf life span and biomass development patterns. Information on the development of leaf area index is central to current models of biomass production. However, there are very few data in the literature on the time-course of leaf area development for short-rotation crops, particularly after coppicing. There is considerable evidence that coppicing schedules affect the spatial and temporal development of canopy structure. More information is needed on how canopy development in coppice regrowth differs from that in plantations of seedlings or first-rotation cuttings, if comparative assessment of the three genera in a longer term silvicultural context is to be meaningful. Key components are leaf size and photosynthetic rates during sprouting, in relation to carbohydrate status of the stool. The longer term responses must take into account the interaction between coppicing schedules and the susceptibility of new shoots to herbivory and disease.