Hudgens Brian R, Haddad Nick M
Department of Zoology, Box 7617, North Carolina State University, Raleigh, North Carolina 27695-7617, USA.
Am Nat. 2003 May;161(5):808-20. doi: 10.1086/374343. Epub 2003 May 2.
Connecting isolated patches of habitat in fragmented landscapes with corridors is a popular conservation strategy. This strategy is also controversial in large part because of uncertainty about what characteristics of a species and its environment promote corridor use. In this article we address the question, For what types of species will populations benefit from corridors? We asked this question using a model of two logistically growing populations connected by migration in which both emigration and migration success were determined by the presence or absence of a corridor. We found that in the short run (e.g., during recovery from disaster), corridors are most effective for species with fast-growing populations that have low survivorship when dispersing through unsuitable (matrix) habitat. We also found that emigration rates and habitat-specific mortality rates are key determinants of the effects of corridors on population size. In the long term, corridors are most likely to benefit species with slow-growing populations that have low survivorship when dispersing through matrix habitat. Our results confirm the major conclusions from previous empirical studies of corridor benefits. However, most studies fail to consider the most appropriate questions to determine the potential benefits of habitat corridors. First, what is the time scale of the conservation goal? Corridors have positive effects on different suites of species in the short and long term. Second, is the major threat of local extinction due to sustained population decline or boom-bust cycles? Third, what is the migration rate through the matrix? Fourth, what fraction of migrants dispersing through the matrix successfully immigrate to another patch?
通过廊道连接破碎景观中孤立的栖息地斑块是一种常见的保护策略。该策略在很大程度上也存在争议，这主要是因为对于物种及其环境的哪些特征会促进廊道的使用存在不确定性。在本文中，我们探讨这样一个问题：对于哪些类型的物种，其种群会从廊道中受益？我们通过一个两个逻辑斯谛增长种群通过迁移相连的模型来探讨这个问题，在该模型中，迁出和迁移成功均由廊道的存在与否决定。我们发现，在短期内（例如，从灾难中恢复期间），廊道对于那些种群增长迅速、在不适宜（基质）栖息地中扩散时存活率低的物种最为有效。我们还发现，迁出率和特定栖息地死亡率是廊道对种群规模影响的关键决定因素。从长期来看，廊道最有可能使那些种群增长缓慢、在通过基质栖息地扩散时存活率低的物种受益。我们的结果证实了先前关于廊道益处的实证研究的主要结论。然而，大多数研究未能考虑确定栖息地廊道潜在益处的最恰当问题。首先，保护目标的时间尺度是什么？廊道在短期和长期对不同的物种组合有积极影响。其次，局部灭绝的主要威胁是由于种群持续下降还是繁荣 -衰退周期？第三，通过基质的迁移率是多少？第四，通过基质扩散的迁移者成功迁入另一个斑块的比例是多少？
