Choosing appropriate temporal and spatial scales for ecological restoration
Choosing appropriate temporal and spatial scales for ecological restoration
复制标题
选择合适的时空尺度进行生态修复
作者：
J. Callicott
经典的生态恢复似乎默默地认为克莱门特的“自然平衡”范式是理所当然的：植物演替在一个顶峰群落中终止，该群落保持平衡，直到外来干扰，之后演替过程重新开始，直到达到顶峰。人类干扰被认为是非自然的，在欧洲入侵时就已经在西半球开始了。因此，经典的生态恢复有一个明确和明确的目标，可以被设想为旨在缩短最终导致某一地点达到高潮的自然过程，这可能取决于该地点在“定居”时的状态。根据生态学中新的“自然变迁”范式，一个特定的地点是没有变化的，而且是不断变化的。人类干扰无处不在且由来已久，并在一定的时空尺度上被“并入”。因此，过去10,000年中任何可能被选为恢复工作基准的时刻似乎都是武断的。因此，两位著名的自然资源保护者建议，在更新世大型动物人为灭绝之前，北美更新世-全新世交界处的生态条件是生态恢复的目标。这一建议明确假定进化的时间尺度和大陆空间尺度是生态恢复的适当参照系。然而，生态恢复应以生态时空尺度为框架，在时间上可以参照干扰机制等生态过程来界定，在空间上可以参照景观、生态系统和生物省等生态单元来界定。生态时空尺度还有助于在科学上区分本地物种和外来物种，这在生态恢复和保护生物多样性的实践中发挥着如此重要的作用。由于定居后的人类干扰已经超出了这类规模的限度，因此可以从科学上证明，定居条件是恢复工作的适当目标，而不需要诉诸过时的目的论的平衡概念，也不需要忽视土著人民的存在和生态影响。
Classic ecological restoration seems tacitly to have taken the Clementsian “balance of nature” paradigm for granted: plant succession terminates in a climax community which remains at equilibrium until exogenously disturbed after which the process of succession is restarted until the climax is reached. Human disturbance is regarded as unnatural and to have commenced in the Western Hemisphere at the time of European incursion. Classic ecological restoration thus has a clear and unambiguous target and may be conceived as aiming to foreshorten the natural processes that would eventually lead to the climax of a given site, which may be determined by its state at “settlement”. According to the new “flux of nature” paradigm in ecology a given site has notelos and is constantly changing. Human disturbance is ubiquitous and long-standing, and at certain spatial and temporal scales is “incorporated”. Any moment in the past 10,000 years that may be selected as a benchmark for restoration efforts thus appears to be arbitrary. Two prominent conservationists have therefore suggested that the ecological conditions in North America at the Pleistocene—Holocene boundary, prior to the anthropogenic extinction of the Pleistocene megafauna, be the target for ecological restoration. That suggestion explicitly assumes evolutionary temporal scales and continental spatial scales as the appropriate frame of reference for ecological restoration. However, ecological restoration should be framed in ecological spatio-temporal scales, which may be defined temporally in reference to ecological processes such as disturbance regimes and spatially in reference to ecological units such as landscapes, ecosystems, and biological provinces. Ecological spatio-temporal scales are also useful in achieving a scientifically defensible distinction between native and exotic species, which plays so central a role in the practice of ecological restoration and the conservation of biodiversity. Because post-settlement human disturbances have exceeded the limits of such scales, settlement conditions can be justified scientifically as appropriate targets of restoration efforts without recourse to obsolete teleological concepts of equilibria and without ignoring the presence and ecological influence of indigenous peoples.