The past week of roundtable discussions has made for interesting and stimulating reading. The "hat" I'd like to throw into this arena is the role of disturbance in creating and maintaining sustainable ecosystems. There have been several messages regarding even-aged vs uneven-aged management, the maximum allowable size of gaps (er, clearcuts), and so forth. However, different ecosystems developed under different disturbance regimes, and many of these ecosystems are characterized by even-aged forests. In some areas, even-aged patches are small, and the landscape is more or less uneven-aged (Ponderosa pine in the west, for example). In other areas, disturbances were catastrophic, and entire landscapes contain trees of similar age. The biodiversity we all want to protect is a product of an ecosystem's inherent disturbance regime. And in many instances, that included disturbance by native peoples over thousands of years. Disturbance regimes acted as an environmental sieve; what came "out the bottom" is the complement of plants and animals (most of which we may be unaware or know little about) that we refer to as biodiversity. If we want to sustain biodiversity within all types of ecosystems, we cannot a priori decide that only certain management practices will or won't be acceptable. I'll be the first to admit that large industrial clearcuts are 1) ugly and 2) don't really mimic a large stand replacing fire (as is so often stated). But the aftermath of the Mt. St. Helens eruption wasn't exactly aesthetic (fascinating, yes!) and it wasn't the FIRST eruption and the forests it destroyed developed under a disturbance regime that included sporadic - very sporadic - volcanic eruptions, as well as catastrophic fires and activity by a suite of insects and pathogens. We need to decouple biases against particular sorts of management, and instead focus on the types, frequencies, magnitudes of disturbances that generated the biodiversity we want to protect. Then, we must couple our management practices with extensive monitoring to determine the effects of those practices on ecosystem structures and functioning - NOT merely on individual species. I hope this generates some ideas, controversy, comments. Ann Camp Research Silviculturist Wenatchee Forestry Sciences Lab Wenatchee, WA USA fswa/s=a.camp/ou1-r06f17a@mhs.attmail.com
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