The fallen tree--a source of diversity

When thinking of and dealing with diversityin a forest, conventional vision focuses onstructure and habitat. Diversity, however,has another dimension--one that is only nowbeing perceived: function. The basic compo-nents of structural and functional diversityare inseparably interwoven in a forest. Abroadened ;philosophical view of management--aforest versus a commodity--is necessary ifcertain structurally related functions, suchas retention of water and cycling of nutri-ents in large, fallen trees, are to beoptions in managed forests of the future. Wehave used an automobile engine as a metaphorin discussing some of the functions that"drive" the forest system because many of anengine's parts are unseen and little under-stood by the average person.- Yet that personcan get a learner's permit and then a licenseto drive the automobile. The average driverknows little about engines, with the resultthat many automobiles are barely functional.Future generations cannot afford the conse-quences of our ignorance while we learn howto manage forests.