Many shades of green: the dynamic tropical forest–savannah transition zones
Many shades of green: the dynamic tropical forest–savannah transition zones
复制标题
多种绿色色调：充满活力的热带森林-草原过渡区
DOI：
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Y. Malhi
中科院分区：
文献类型：
--
作者：
I. Oliveras;Y. Malhi
森林-草原过渡区是热带地区最广泛的生态交错带，将两个生产力最高的陆地生态系统分开。在这里，我们回顾了目前对影响这一转变的因素的理解，以及它在当地或全球变化的各种驱动因素下可能如何变化。在最广泛的尺度上，过渡的位置由可用水量决定，在局部尺度上受火势、食草压力和土壤特性的空间变化的强烈调节。这种转变的频繁动态性质表明，森林和稀树草原可以作为替代的稳定状态存在，通过火-草反馈和树荫-灭火反馈来维持和分隔。然而，这一理论仍然存在争议，主要生物和非生物驱动因素的相对贡献及其相互作用尚未完全了解。这些驱动因素与全球、大陆、区域和地方尺度的各种生态过程和属性相互作用。生物和非生物驱动因素和过程的进化历史在这些转变的当前分布及其物种组成和生态系统功能中发挥着重要作用。该生态交错带可能对气候和其他驱动因素的变化敏感，但也可能通过负反馈过程保持稳定。有大量证据表明，这些转变正在当代全球和地方的变化中发生转变，但转变的方向因地区而异。然而，仍然不确定这些转变将如何应对当前快速、多方面的持续变化，以及不断增加的人类影响力将如何与这些转变相互作用。本文是主题“热带草地生物群落：将生态、人类利用和保护联系起来”的一部分。
The forest–savannah transition is the most widespread ecotone in tropical areas, separating two of the most productive terrestrial ecosystems. Here, we review current understanding of the factors that shape this transition, and how it may change under various drivers of local or global change. At broadest scales, the location of the transition is shaped by water availability, mediated strongly at local scales by fire regimes, herbivory pressure and spatial variation in soil properties. The frequently dynamic nature of this transition suggests that forest and savannah can exist as alternative stable states, maintained and separated by fire–grass feedbacks and tree shade–fire suppression feedback. However, this theory is still contested and the relative contributions of the main biotic and abiotic drivers and their interactions are yet not fully understood. These drivers interplay with a wide range of ecological processes and attributes at the global, continental, regional and local scales. The evolutionary history of the biotic and abiotic drivers and processes plays an important role in the current distributions of these transitions as well as in their species composition and ecosystem functioning. This ecotone can be sensitive to shifts in climate and other driving factors, but is also potentially stabilized by negative feedback processes. There is abundant evidence that these transitions are shifting under contemporary global and local changes, but the direction of shift varies according to region. However, it still remains uncertain how these transitions will respond to rapid and multi-faceted ongoing current changes, and how increasing human influence will interact with these shifts. This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’.
影响因子：
14.6
作者：
Martijn Gough
通讯作者：
Martijn Gough