Thinning, a silvicultural technique used in forest management, is a stand manipulation operation designed to modify tree growth. Where trees are managed under a commercial regime, competition is reduced by removing adjacent stems that exhibit less favourable timber quality potential. When left in a natural state trees will 'self-thin' but this process of natural selection can be unreliable in some circumstnces. An example of this can be found in the Box-Ironbark forests and woodlands of Victoria (Australia) where a large proportion of trees are multi-stemmed regrowth (or coppice) resultant from timber cutting in the decades gone by.
Ecological thinning is where the primary aim of forest thinning is to increase growth of selected trees, favouring development of wildlife habitat (such as hollows) rather than focussing on increased timber yields. Ecological thinning can be considered a new approach to landscape restoration for some types of eucalypt forests and woodlands in Australia.
Ecological thinning research
Research programs under way in various parts of the world (e.g. USA and Australia) are aimed at providing an alternate approach in forest management where conservation objectives are a high priority. Methods of ecological thinning being developed on silvicultural techniques for local forest types. Ecological thinning is being developed using two principles: 1. appropriate stem reduction to reduce competition and 2. retention of trees (selection) that are more suitable for wildlife (i.e. not timber production). An example of ecological thinning research is the project in Victoria's Box-Ironbark forests, investigating various thinning and timber removal methods under an Adaptive Management or AEM framework. The primary objective is to generate (over time) a number of forest habitat values (i.e. tree hollows) that are crucial for wildlife conservation.
