Niche expansion and temperature sensitivity of tropical African montane forests
Niche expansion and temperature sensitivity of tropical African montane forests
复制标题
热带非洲山地森林的生态位扩展和温度敏感性
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
J. Russell
中科院分区：
文献类型：
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作者：
S. Ivory;R. Early;D. Sax;J. Russell
目标 气候和土地利用变化将通过改变物种范围和群落组成对未来的生态系统产生巨大影响。在制定保护策略时，通常会创建相关的物种分布模型来评估单个物种的风险。这些模型基于气候平衡的假设，因此现代范围代表了物种繁衍生息的全部条件。然而，古生态记录说明了当今物种不平衡的例子，最近的研究表明，许多物种可能出现在比以前想象的更广泛的气候环境中。由于温度敏感性和地理范围有限，山地生态系统被认为面临着不成比例的风险。然而，在非洲热带地区，古生态记录显示，山地森林类群多次扩展到低地，这表明它们可能对温暖的温度具有耐受性。
地点非洲。
方法我们整合古生态和古气候数据，以便比较当前发现物种的气候条件与过去的气候条件。我们使用物种分布模型根据现代分布和古生态记录中的分布构建非洲山地物种的潜在现代范围，以评估物种范围的平衡。
结果我们发现，许多非洲山地树木过去曾生活在较温暖的气候中，这表明当前的低海拔边界不是由气候决定的。有趣的是，古分布与现代分布之间最不平衡的物种是那些现代分布对温度敏感性最小的物种。根据现代和古分布绘制的物种潜在范围图清楚地表明，当今低地地区存在适合对温度不太敏感的物种的气候条件。
主要结论 这些结果表明，这些森林树木的当前范围并不一定能反映气候变化的风险，并且人类土地利用可能是未来许多物种的主要压力。
Aim Climate and land-use change will have a dramatic impact on future ecosystems through alterations to species ranges and community composition. When forming conservation strategies, correlative species distribution models are often created to assess risks for individual species. These models are based on the assumption of climatic equilibrium, such that the modern range is representative of the full range of conditions under which species could thrive. However, the palaeo-ecological record illustrates examples of disequilibrium in species today, and recent studies suggest that many species could occur in much broader climatic settings than previously thought. Montane ecosystems are thought to be at disproportionate risk due to temperature sensitivity and restricted geographical ranges. However, in the Afrotropics the palaeo-ecological record shows that montane forest taxa expanded into the lowlands numerous times, suggesting a possible tolerance to warm temperatures.
Location Africa.
Methods We integrate palaeo-ecological and palaeo-climatic data in order to compare climate conditions in which species are currently found with those in the past. We use species distribution models to construct potential modern ranges for Afromontane species based on modern distributions and distributions in the palaeo-ecological record in order to evaluate the equilibrium of species ranges.
Results We show that many Afromontane trees have occupied warmer climates in the past, which suggests that the current low-elevation boundaries are not set by climate. Interestingly, the species with the largest disequilibrium between palaeo- and modern distributions are those whose modern distributions show the least temperature sensitivity. Mapping of species potential ranges based on modern and palaeo- distributions clearly shows that suitable climate conditions exist today in the lowlands for less temperature-sensitive species.
Main conclusions These results imply that the current range of these forest trees does not necessarily inform risk from climatic change, and that human land use may be the major pressure for many species in the future.