Multiple environmental gradients affect spatial variation in the productivity of a tropical bird population
Multiple environmental gradients affect spatial variation in the productivity of a tropical bird population
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DOI：
10.1111/j.1365-2656.2011.01816.x
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发表时间：
2011-05-01
影响因子：
4.8
通讯作者：
Norris, Ken
中科院分区：
文献类型：
--
作者：
Burgess, Malcolm D.;Nicoll, Malcolm A. C.;Norris, Ken
P > 1。生境质量的空间变化及其人口统计结果对动物种群的调控具有重要意义。从理论上讲，栖息地质量通常被视为从“差”到“好”的单一梯度，但在野生种群中，有可能存在多个环境梯度，这些梯度决定了人口的空间变化。了解环境梯度对于获得重要种群过程的机制见解非常重要，而且对于了解种群如何应对环境变化也很重要。在这里，我们利用600只毛里求斯红隼的详细长期数据，探讨了栖息地和海拔梯度及其对种群持久性的影响。这些数据使我们能够从统计上将人口的空间变化从个人或环境质量的变化中分离出来，并探索其与栖息地和地形的关系。在这个季节繁殖较早的鸟类有更高的繁殖成功率，我们发现不同地区的繁殖时间差异很大。这种变化主要是由海拔引起的，随着海拔的增加，鸟类的繁殖逐渐推迟。从卵到羽翼阶段（独立于时间）的羽化前存活率和招募也在不同的领地之间存在显著差异。这种变异是由繁殖地周围的栖息地驱动的，随着农业入侵的增加，导致生存和补充减少。综上所述，我们的研究结果表明，可能存在多种环境梯度影响野生种群生产力的空间变化，因此环境变化可能通过多种不同的途径通过改变空间过程对种群动态产生影响。
P>1. Spatial variation in habitat quality and its demographic consequences have important implications for the regulation of animal populations. Theoretically, habitat quality is typically viewed as a single gradient from 'poor' to 'good', but in wild populations it is possible that there are multiple environmental gradients that determine spatial variation in demography.2. Understanding environmental gradients is important to gain mechanistic insights into important population processes, but also to understand how populations might respond to environmental change. Here, we explore habitat and elevation gradients and their implications for population persistence using detailed long-term data on 600 individuals of the Mauritius kestrel. These data allow us to statistically separate spatial variation in demography from variation arising out of individual or environmental quality and explore its relationships with habitat and topography.3. Birds that breed earlier in the season have higher reproductive success, and we found that the timing of breeding varies significantly between territories. This variation is primarily driven by elevation, with birds breeding progressively later as elevation increases.4. Pre-fledging survival from the egg to fledgling stage (independently of timing), and recruitment, also varied significantly between territories. This variation is driven by the habitat surrounding breeding sites with increasing agricultural encroachment causing survival and recruitment to decline.5. Taken together, our results suggest that there are likely to be multiple environmental gradients affecting spatial variation in productivity in wild populations, and hence multiple and different routes through which environmental change might have consequences for population dynamics by modifying spatial processes.