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Published byHailey Worley Modified over 9 years ago
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What is Close-to-Nature Silviculture in a Changing World? Kevin L. O’Hara University of California - Berkeley
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What’s in a name? new perspectives retention forestry holistic forestry ecoforestry restoration forestry new forestry ecological silviculture back to nature irregular forestry common sense forestry continuous cover forestry excellent forestry close-to-nature forestry ecosystem management near-natural forestry nature-based forestry ecological silviculture holistic forestry sustainable forestry diversity- oriented silviculture new forestry
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Close-to-nature Possibly the original “natural silviculture” movement Close-to-nature, and other names/movements, are reactions to abusive practices Attached to single tree selection silviculture Evolved to emphasize species mixtures and irregular age/stand structures Successful in central Europe
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Pro Silva organization Founded 1989 Movement primarily in central Europe
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Pro Silva Principles “guaranteed continuity of naturalness” “Adopt a holistic approach involving continuous forest cover” “Selection felling and tending at all stages of development” (i.e., selection systems) “Working towards a balance on as small a scale as possible between increment and harvesting in each management unit” “use of natural regeneration” “Restricting the use of exotics…”
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Plenter System Single-tree selection system in central Europe Is it “natural” “we can conclude that, as a general rule, plentering is a man-made system, which need man’s intervention in the form of structure intervention … to maintain it in the long run.” – J.-P. Schutz 2001
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What is “Natural” Depends on context (background, location, relation to other stands, etc) Unmodified by humans Perception may not be rooted in ecology Changes with time Perception of “balance of nature”
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“Naturalness” A fuzzy concept A social construct (culture, values, beliefs) A conditioning response A condition with minimal human interference Natural or naturalness is desirable in our cultures Some view all management as undesirable
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Disturbance Emulation Common theme of contemporary silviculture Viewed as contributing to “naturalness” Involves using silviculture to follow types and frequencies of disturbances Requires knowledge about disturbance regimes But not really new
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Ranges of variability Historical range of variability – applies to disturbance regimes – and therefore to silviculture Future range of variability – integrates knowledge of historical range of variability with – social values – guiding principles to meet human needs and provide ecosystem services
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Examples from western North America
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Western larch Lodgepole pine Douglas-fir Grand fir
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Diameter distribution - Washington Cascades
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(Cobb et al. 1993)
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North American silviculture Fortunate to have very good understanding of “natural” disturbance patterns Very few places were traditional single tree selection works Instead, it is a complex set of variable disturbance regimes and species adaptations to these regimes Requires a highly varied silviculture – not just one approach
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Is “close-to-nature” a bad idea? Basic premise is good Extremely important to understand natural processes Name has become a surrogate for “light” silviculture, for selection systems (particularly single tree selection), and natural regeneration options Perhaps becoming too restrictive Perhaps false advertising?
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The future… Climate change Invasives Pollution New disturbance regimes Greater human demands on forests
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Better than nature! If forests are managed to provide the values that humans desire, then we have already improved on natural processes Outside known historical ranges of variation Meeting management objectives in ways that nature cannot
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Marsh was a keen observer who noted the potential improvement of natural forests through silviculture
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Summary Points New age labels that use the words “nature”, or “balance”, or “holistic” are really just advertising The silvicultural approaches of close-to-nature are neither natural, nor sound silviculture in many forests We should not to limit our options by excluding artificial regeneration, exotics, unprecedented species mixtures, or even-aged silviculture Our responsibility is to be better than nature, to meet human needs in ways that are sustainable and build upon our unique understanding of forest dynamics
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Better than nature!
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