One of the goals of research in forest ecology is the development of simple indices as "proxies" in order to assess biological complexity in forests (e.g., structural and compositional diversity in forest stands). Many indices have been proposed to quantify forest stand diversity, but a general agreement on their use is yet not reached. Information theory and indices based on it are well-developed tools in ecological research and can respond to these requirements. In this short note, the recent literature on forest structural assessment is briefly summarized; then, one of the main properties of Shannon's entropy, namely the "recursivity", is proposed as a useful way for combining forest stand structure and species diversity into a single index
