作者: Peter M. Attiwill
DOI: 10.1016/0378-1127(94)90114-7
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摘要: The extensive literature on natural disturbance in forests is reviewed terms of the hypotheses: (1) that a major force moulding development, structure and function forests; (b) management for all their benefits can be controlled so effects contained within those which result from disturbance. causal factors are both endogenous exogenous; there difficulties formal characterization recovery after As to latter, acceptance classical generalizations nature succession has led particular assessment interpretation recovery. Tree fall, creates gaps, fundamental development many forests, been most intensively studied tropical Central America Amazon temperate North America. Tree fall part autogenic change; mechanisms gap-filling subsequent growth species composition vary widely with forest type geography. Disturbance by wind particularly difficult characterize. Wind varies along continuum; blow-down an individual tree may mostly due processes ageing decay, whereas catastrophic hurricanes cyclones defined as wholly exogenous. Nevertheless, resilience diversity following hurricane remarkable. A number studies support view hurricane-prone areas not stable steady-state ecosystem but rather heterogeneity maintained catastrophe. ability regenerate suckers coincidence regenerative space gregarious flowering important components response rainforest disturbance. For much world, ‘fire dominant fact history’. examples, fire its northern boreal oak-pine north-western sub-alpine effect intensity frequency. That, together popular unnatural therefore unacceptable, places great demands benefits, including national parks reserves. These also affect other ecosystems, such Mediterranean-type shrublands heathlands where diversity, productivity cycles regeneration degradation governed disturbance. Shifting agriculture traditional form used at least 240 million people humid tropics. Shifting agriculture, wind, lightning fire, exogenous little soil fertility re-establishes abandonment. increases, decreases current problems clearing improved pasture uncontrolled logging resulting degraded ecosystems. Regeneration follows often death trees caused outbreaks insects coniferous This herbivory halts increasing stagnation (as measured decreasing rates production nutrient cycling) reinitiates succession. Other disturbances occur through damage ice-storms, snow avalanches, erosional earthquake landslides, volcanic activity; Nothofagus Chile New Zealand determined mass movements. An supports hypothesis ecosystems. It our should based ecological understanding Whether or we want do this, extent derive forest, timber, depends social attitudes. Whereas humanism treat conservation wise husbanding interests traditions harmony, animism give unalienable rights. conclusion this review framework knowledge component provides basis manage renewable resource utilized ‘retain richness mankind's continuing benefit’. Nowhere more desperately needed than protection world's peoples cultures.