Metapopulation extinction in fragmented landscapes: Using bacteria and protozoa communities as model ecosystems
Metapopulation extinction in fragmented landscapes: Using bacteria and protozoa communities as model ecosystems
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DOI：
10.1086/286082
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发表时间：
1997-11-01
影响因子：
2.9
通讯作者：
Burkey, TV
中科院分区：
文献类型：
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作者：
Burkey, TV
由于涉及漫长的时间尺度以及难以确定灭绝是否实际发生，灭绝研究极其困难。栖息地细分或破碎化对灭绝风险的影响更难研究，因为这需要在大空间尺度上对栖息地斑块进行大量复制，并控制处理之间的面积效应。我利用简单的小型细菌和原生动物群落来研究因栖息地丧失和栖息地破碎化而导致的灭绝情况。我研究了几种不同的群落结构，每种都有三个营养级。与大多数集合种群研究（包括实验性和理论性的）不同，这些研究往往涉及本质上不稳定的物种相互作用，我特意使用了在大量培养物中能持续存在的群落结构。我记录了顶级捕食者在不同大小的单一栖息地斑块以及具有不同细分程度但可用栖息地总量相同的破碎化系统中的灭绝时间。栖息地丧失缩短了孤立种群的灭绝时间。破碎化系统比同等总面积的相应未破碎（连续）系统灭绝得更快。未破碎的种群比有或没有亚种群之间扩散廊道的破碎化系统（集合种群）持续时间更长。事实上，通过扩散廊道连接碎片的破碎化系统比亚种群完全相互隔离的系统灭绝得明显更快。如果这些结果延伸到更多“自然系统”，这表明在强调在破碎景观中广泛建立野生动物廊道的管理计划中需要谨慎。
Extinction is notoriously difficult to study because of the long timescales involved and the difficulty in ascertaining that extinction has actually occurred. The effect of habitat subdivision, or fragmentation, on extinction risk is even harder to study, as it requires copious replication of habitat patches on large spatial scales and control of area effects between treatments, I used simple small-scale communities of bacteria and protozoa to study extinction in response to habitat loss and habitat fragmentation. I studied several different community configurations, each with three trophic levels, Unlike most metapopulation studies (experimental as well as theoretical), which have tended to deal with inherently unstable species interactions, I deliberately used community configurations that were persistent in large stock cultures. I recorded the time to extinction of the to;; predator in single habitat patches of different sizes and in fragmented systems with different degrees of subdivision but the same amount of available habitat, Habitat loss reduced the time to extinction of isolated populations, Fragmented systems went extinct sooner than corresponding unfragmented (continuous) systems of the same overall size. Unfragmented populations persisted longer than fragmented systems (metapopulations) with or without dispersal corridors between subpopulations. In fact, fragmented systems where the fragments were linked by dispersal corridors went extinctly significantly sooner than those where subpopulations were completely isolated from each other. If these results extend to more ''natural systems, it suggests a need for caution in management programs that emphasize widespread establishment of wildlife corridors in fragmented landscapes.