2278 measurable net gain, because it often does not include (or does not standardize) the full set of condition/EV metrics, the final area to be offset, additionality, and post-implementation monitoring results. The analysis of the case studies was structured around a logical sequence that links application of the mitigation hierarchy, quantification of residual impact and the design of offset measures. First, after the documented application of prevention, minimization and restoration measures, significant residual impacts on fragile ecosystems—mainly wetlands—were identified, which formally triggered the regulatory requirement for Environmental Offset Plans (PCA) within the approved environmental management instruments. For each case, the biophysical characterization of the impacted ecosystem made it possible to estimate a pre-impact ecological value (EV0), using the indicators defined in MINAM’s ecosystem guides. In parallel, selection of the receiving ecosystem for the offset was based on functional and structural equivalence criteria, considering attributes such as hydrology, vegetation structure and anthropogenic pressures, from which the ecological value of the ecosystem to be offset (EV) was estimated. The difference between both values (ΔEV) represents the expected ecological gain of the PCA and is the central metric for evaluating whether the offset is oriented toward no net loss or toward net gain of biodiversity. This gain, together with the initial condition of the receiving ecosystem, determines the area required for the offset, showing that PCA sizing does not respond to fixed surface ratios, but to ecological functionality and the technical assumptions applied. The quantitative results summarized in Table 1 and shown in Figure 2 indicate that the relationship between ecological gain (ΔEV) and the area to be offset is not linear. Cases with extensive areas associated with moderate gains are observed and, in contrast, cases with reduced areas that achieve equal or higher gains—confirming the importance of the initial ecological condition and the functional approach in offset design. This approach makes it possible to link PCA results with emerging disclosure frameworks such as TNFD, particularly in the quantitative evaluation of impacts and gains, without assuming that a gain estimated at the design stage guarantees ecologically verifiable outcomes over time—reinforcing the need for robust Monitoring, Reporting and Verification (MRV) systems.
RkJQdWJsaXNoZXIy MTM0Mzk2