Gap models are individual-based models for forests. They simulate dynamic multispecies assemblages over multiple tree-generations and predict forest responses to altered environmental conditions. Their development emphases designation of the significant biological and ecological processes at appropriate time/space scales. Conceptually, they are with consistent with A.G. Tansley’s original definition of “the ecosystem”. An example microscale application inspects feedbacks among terrestrial vegetation change, air-quality changes from the vegetation’s release of volatile organic compounds (VOC), and climate change effects on ecosystem production of VOC’s. Gap models can allocate canopy photosynthate to the individual trees whose leaves form the vertical leaf-area profiles. VOC release depends strongly on leaf physiology by species of these trees. Leaf-level VOC emissions increase with climate-warming. Species composition change lowers the abundance of VOC-emitting taxa. In interactions among ecosystem functions and biosphere/atmosphere exchanges, community composition responses can outweigh physiological responses. This contradicts previous studies that emphasize the warming-induced impacts on leaf function. As a mesoscale example, the changes in climate (warming) on forests including pest-insect dynamics demonstrates changes on the both the tree and the insect populations. This is but one of many cases that involve using a gap model to simulate changes in spatial units typical of sampling plots and scaling these to landscape and regional levels. As this is the typical application scale for gap models, other examples are identified. The insect/climate-change can be scaled to regional consequences by simulating survey plots across a continental or subcontinental zone. Forest inventories at these scales are often conducted using independent survey plots distributed across a region. Model construction that mimics this sample design avoids the difficulties in modelling spatial interactions, but we also discuss simulation at these scales with contagion effects. At the global-scale, successful simulations to date have used functional types of plants, rather than tree species. In a final application, the fine-scale predictions of a gap model are compared with data from micrometeorological eddy-covariance towers and then scaled-up to produce maps of global patterns of evapotranspiration, net primary production, gross primary production and respiration. New active-remote-sensing instruments provide opportunities to test these global predictions.

中文翻译：

---

跨微尺度到大尺度时空的差距模型：Tansley生态系统概念的例子

差距模型是基于个人的森林模型。他们模拟了多代树木的动态多物种组合，并预测森林对变化的环境条件的反应。他们的发展着重于在适当的时空尺度上指定重要的生物和生态过程。从概念上讲，它们符合AG Tansley最初对“生态系统”的定义。一个示例微尺度应用程序检查了陆地植被变化，植被释放挥发性有机化合物（VOC）引起的空气质量变化以及气候变化对VOC的生态系统产生的影响之间的反馈。间隙模型可以将冠层光合产物分配给单个树，这些树的叶子形成垂直的叶面积轮廓。VOC的释放在很大程度上取决于这些树种的叶片生理。随着气候变暖，叶面VOC排放量增加。物种组成的变化降低了挥发性有机物排放类群的数量。在生态系统功能与生物圈/大气层交换之间的相互作用中，群落组成的反应可能超过生理反应。这与以前的研究相矛盾，后者强调了变暖对叶片功能的影响。作为一个中尺度的例子，森林中气候（变暖）的变化（包括虫害昆虫的动态）证明了树木和昆虫种群的变化。这只是涉及使用间隙模型来模拟典型样地的空间单位变化并将其缩放至景观和区域水平的众多情况之一。由于这是间隙模型的典型应用规模，因此可以确定其他示例。可以通过模拟整个大陆或次大陆带的调查样地，将昆虫/气候变化按区域后果定标。这些规模的森林清单通常使用分布在一个地区的独立调查区进行。模仿此样本设计的模型构建避免了对空间相互作用进行建模的困难，但我们还讨论了在这些尺度上具有传染效应的模拟。在全球范围内，迄今为止成功的模拟使用的是植物的功能类型，而不是树木。在最终应用中，将间隙模型的精细预测与微气象涡动-协方差塔的数据进行比较，然后按比例放大以生成全球蒸散量，净初级生产，初级总生产和呼吸的全球格局图。