Quantifying population-level conservation impacts for a perpetual conservation program on private land

Area-based targets, such as percentages of regions protected, are popular metrics of success in the protection of nature. While easily quantified, these targets can be uninformative about the effectiveness of conservation interventions and should be complemented by program impact evaluations. However, most impact evaluations have examined the effect of protected areas on deforestation. Studies that have extended these evaluations to more dynamic systems or different outcomes are less common, largely due to data availability. In these cases, simulations might prove to be a valuable tool for gaining an understanding of the potential range of program effect sizes. Here, we employ simulations of wetland drainage to estimate the impact of the United States Fish and Wildlife Service Small Wetlands Acquisition Program (SWAP) across a ten-year period in terms of wetland area, and breeding waterfowl and brood abundance in the Prairie Pothole Region of North Dakota, South Dakota, and Montana. Using our simulation results, we estimate a plausible range of program impact for the SWAP as an avoided loss of between 0.00% and 0.02% of the carrying capacity for broods and breeding waterfowl from 2008-2017. Despite the low programmatic impact that these results suggest, the perpetual nature of SWAP governance provides promising potential for a higher cumulative conservation impact in the long term if future wetland drainage occurs.

Automated summary

Area-based targets for nature protection are commonly used, but they may not effectively measure the success of conservation interventions. Most impact evaluations focus on the effect of protected areas on deforestation, while evaluations on dynamic systems or different outcomes are less common due to data availability. Simulations offer a valuable tool to estimate the potential impact of conservation programs, as shown by a simulation of wetland drainage in North Dakota, South Dakota, and Montana. The results suggest a low programmatic impact, but the long-term governance of the program holds promise for cumulative conservation impact if future wetland drainage occurs.