Australian Centre for Biodiversity, School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
Conserv Biol. 2010 Jun;24(3):691-700. doi: 10.1111/j.1523-1739.2009.01419.x. Epub 2010 Jan 11.
Habitat connectivity is required at large spatial scales to facilitate movement of biota in response to climatic changes and to maintain viable populations of wide-ranging species. Nevertheless, it may require decades to acquire habitat linkages at such scales, and areas that could provide linkages are often developed before they can be reserved. Reserve scheduling methods usually consider only current threats, but threats change over time as development spreads and reaches presently secure areas. We investigated the importance of considering future threats when implementing projects to maintain habitat connectivity at a regional scale. To do so, we compared forward-looking scheduling strategies with strategies that consider only current threats. The strategies were applied to a Costa Rican case study, where many reserves face imminent isolation and other reserves will probably become isolated in the more distant future. We evaluated strategies in terms of two landscape-scale connectivity metrics, a pure connectivity metric and a metric of connected habitat diversity. Those strategies that considered only current threats were unreliable because they often failed to complete planned habitat linkage projects. The most reliable and effective strategies considered the future spread of development and its impact on the likelihood of completing planned habitat linkage projects. Our analyses highlight the critical need to consider future threats when building connected reserve networks over time.
生境连通性需要在大的空间尺度上实现，以促进生物对气候变化的响应和迁移，并维持广布物种的可行种群。然而，在这样的尺度上获得生境连接可能需要几十年的时间，而能够提供连接的区域往往在它们能够被预留之前就已经开发了。保护区规划方法通常只考虑当前的威胁，但随着发展的蔓延和到达目前安全的区域，威胁会随着时间的推移而发生变化。我们研究了当在区域尺度上实施维持生境连通性的项目时，考虑未来威胁的重要性。为此，我们将前瞻性的规划策略与仅考虑当前威胁的策略进行了比较。这些策略应用于哥斯达黎加的一个案例研究，其中许多保护区面临着迫在眉睫的隔离，而其他保护区在更远的未来可能会被隔离。我们根据两个景观尺度的连通性指标来评估策略，一个是纯粹的连通性指标，另一个是连接的栖息地多样性指标。那些只考虑当前威胁的策略是不可靠的，因为它们经常无法完成计划的生境连接项目。最可靠和有效的策略考虑了未来的发展蔓延及其对完成计划的生境连接项目的可能性的影响。我们的分析强调了随着时间的推移建立连通的保护区网络时，必须考虑未来威胁的关键需求。
