Metrics and Equivalence in Conservation Banking

Abstract

Offsets are increasingly used to compensate for unavoidable development impacts on species and habitats. Many offset programs pursue no net loss, but research on the success of these programs is lacking, including research on conservation banking’s success in conserving protected species under the US Endangered Species Act. This article provides a case study analysis of two conservation banks in the state of California, comparing the conservation gains provided by banks with the losses from development impacts. It provides an analysis of credits and metrics to determine whether the gains are equal to the losses in terms of type, condition, and amount. Results do show that the gains exceed the losses in terms of acreage. However, the program uses indirect metrics (acreage), and the equivalence of the losses and gains, besides habitat type and size, is not reflected. Banks provide a baseline in their documentation and conduct monitoring of species abundance and habitat quality, but they do not use it to measure additional conservation gains. More detailed metrics and transparent indices to certify the acres in production could allow for a quantification of conservation benefits and an evaluation of program success. However, selecting standardized metrics is challenging because they need to be species-specific to reflect the goal of species recovery, and still be operational in practice.

Bundling of Ecosystem Services in Conservation Offsets: Risks and How They Can Be Avoided

“…Another example where bundling may lead to unwanted losses is the Sparling Ranch Conservation Bank in California analysed by [10]. Credits are awarded per hectare of land that is habitat for the California Tiger Salamander (Ambystoma californiense) and the California Red-Legged Frog (Rana draytonii).…”

Financial Analysis of Habitat Conservation Banking in California

“…Since conservation credit markets are created and regulated by state policies, these results are very much dependent on state legislation and underlying payment mechanisms. Data limitations, such as continuous update of RIBITS database; lack of publicly available market transaction and credit price data; lack of HCBs cost data; inconsistent metrices and equivalency has been an issue in depth understanding of HCB market [2,18,37,38]. We do not recommend generalizing our findings in places with different regulations or approaches on incentivized conservation.…”

Flexibility trade‐offs in conservation offsets

“…For flexibility in type, a region is usually considered to consist of several ecosystem types, and if offsets occur on only a hectare basis, rather than explicitly considering each ecosystem type separately, the preservation of all types cannot be guaranteed (Bull et al., 2015; Grimm, 2021). I simplified the analysis by considering only a single target type whose preservation was compromised by offsetting due to the presence of other types in the model region.…”