Department of Renewable Resources, University of Alberta, 751 General Services Building, Edmonton, Alberta, T6G 2R3, Canada.
Toronto and Region Conservation Authority, Research and Knowledge Management, Watershed Strategies, 101 Exchange Avenue, Vaughan, Ontario, L4K 5R6, Canada.
Conserv Biol. 2020 Feb;34(1):41-53. doi: 10.1111/cobi.13343. Epub 2019 Jun 3.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects' compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.
土地利用变化是导致生物多样性丧失的主要原因之一。为了减少这些影响，数十亿美元被用于生物多样性补偿。然而，评估抵消项目效果的研究，包括项目的整体合规性和功能等方面的研究仍然很少。我们审查了 577 个淡水生态系统中的补偿项目，其中包括项目规模、水生系统类型（如湿地和小溪）、补偿措施（如增强、恢复和创建），以及对项目合规性和功能成功的评估。项目信息来自科学和政府数据库以及灰色文献。尽管在补偿项目上投入了大量资金，但仍存在一些关键问题。尽管合规性和功能相互关联，但高合规性并不保证高度的功能。然而，相对于面积而言，大型项目的功能优于小型项目。当项目针对生产力或特定生态系统特征，并采用多种互补的管理目标时，功能会得到改善。恢复性措施比创建全新的生态系统更有可能实现目标。总的来说，我们发现的这些关系突出了可能有助于改善补偿结果的具体生态过程。
