The Responses and Survival of Organisms in Fire-Prone Environments
The Responses and Survival of Organisms in Fire-Prone Environments
复制标题
易发生火灾的环境中生物的反应和生存
DOI：
10.1007/978-3-642-69805-7_13
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
P. Frost
中科院分区：
文献类型：
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作者：
P. Frost
火是一种广泛存在的自然现象，影响着许多生态系统的结构、组成和动态。在南部非洲，草原、稀树草原和芬博斯生态系统特别容易遭受经常性火灾，火灾被认为对其生物群落的演变和维持具有重要意义（Phillips 1930; West 1971; Kruger 1977b）。本综述的重点是火灾对植物和动物的影响，以及它们避免、减少、恢复或利用这些影响的方法。火可以直接作用于个体，导致其死亡或破坏或破坏组织，从而影响其生长和繁殖；也可以间接作用于个体，通过改变个体所处的环境，从而创造不同的挑战和机会。火可能具有诱变作用（Howe 1976），但要使其具有重要意义，必须与适当的生态机会和一些选择性优势相结合。在试图确定在火灾易发环境中赋予优势的那些特征时，有必要提出一个警告，不要太轻易地认为这些特征是对火灾环境及其影响的适应。虽然潜在的优势可以被识别出来，但这并不一定意味着这些特征是由自然选择形成的，以服务于特定的功能（Williams 1966）。它们可能根本不是通过自然选择产生的，或者它们可能是通过自然选择形成的，以服务于完全不同的功能，在这种情况下，额外的优势可能只不过是原始功能的偶然结果。这并不意味着这些特征和反应对火灾不重要。有些可能会限制生物体适应火灾状态变化的能力；其他的可能作为预适应，使携带者更容易被选择。所有这些都对促进群落结构和生态系统功能的模式很重要。在接下来的章节中，在可能的情况下，将尝试区分那些似乎是适应火灾制度而不是适应其他生态环境的特征和反应。尽管如此，目前对这些特征的理解水平是这样的，这些解释应该被视为未来研究的假设，而不是作为适应或其他方式的记录实例。
Fire is a widespread, naturally occurring phenomenon of great antiquity, influencing the structure, composition and dynamics of many ecosystems. within· southern Africa, grassland, savanna and fynbos ecosystems in particular are subjected to recurrent fires and fire is considered to have been of major importance in the evolution and maintenance of their biotas (Phillips 1930; West 1971; Kruger 1977b).The focus of this review is on the effects of fire on plants and animals and the means by which they avoid, minimise, recover from, or exploit these effects. Fire may act directly on an individual, either through causing its death or by damaging or destroying tissue, thereby affecting growth and reproduction, or it may also act indirectly, through changing the environment within which an individual functions, thereby creating different challenges and opportunities. Fire may be mutagenic (Howe 1976) though for this to be significant it must be coupled with an appropriate ecological opportunity and some selective advantage. In attempting to identify those features which confer advantage in a fire-prone environment it is necessary to interpose a caveat about presuming too readily that these features are adaptations to the circumstances of fire and its effects. Although potential advantages may be identified, this does not necessarily mean that these features were shaped by natural selection to serve that particular function (Williams 1966). They may not have originated through natural selection at all, or they may have been shaped by natural selection to serve completely different functions, in which case the additional advantage may be nothing more than the fortuitous consequence of the original function. This does not mean that such traits and responses are unimportant with respect to fire. Some may constrain the ability of an organism to accommodate changes in fire regime; others may serve as preadaptations, predisposing the bearer to further selection. All are important in contributing to the patterns of community structure and ecosystem functioning. In the sections that follow, an attempt will, where possible, be made to differentiate between those traits and responses which seem to be adaptations to fire regime rather than to other ecological circumstances. None the less, present levels of understanding of these features is such that these interpretations should be treated as hypotheses for future research, rather than as documented instances of adaptation, or otherwise, to fire.