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.

中文翻译：

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北美和欧洲淡水生物多样性补偿的合规性和生态系统功能

人类发展引起的土地利用变化是生物多样性丧失的主要驱动因素。为了减少这些影响，数十亿美元用于生物多样性补偿。然而，评估抵消项目有效性的研究仍然很少，这些研究检查项目的整体合规性和功能等组成部分。我们审查了淡水生态系统中的 577 个抵消项目，包括衡量项目规模、水生系统类型（例如，湿地和小溪）、抵消措施（例如，增强、恢复和创造）以及对项目合规性和功能的评估成功。项目信息来自科学和政府数据库以及灰色文献。尽管对抵消项目进行了大量投资，但关键问题仍然存在。虽然合规性和功能是相互关联的，高度的合规性并不能保证高度的功能。然而，相对于面积的大项目比小项目具有更好的功能。当项目以生产力或特定生态系统特征为目标，以及多个互补的管理目标到位时，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。总之，我们发现的关系突出了可能有助于改善抵消结果的特定生态过程。恢复性措施比创建全新的生态系统更有可能实现目标。总之，我们发现的关系突出了可能有助于改善抵消结果的特定生态过程。恢复性措施比创建全新的生态系统更有可能实现目标。总之，我们发现的关系突出了可能有助于改善抵消结果的特定生态过程。