Achieving biodiversity net gain by addressing governance gaps underpinning ecological compensation policies

Biodiversity compensation policies have emerged around the world to address the ecological harms of infrastructure expansion, but historically compliance is weak. The Westminster government is introducing a requirement that new infrastructure developments in England demonstrate they achieve a biodiversity net gain (BNG). We sought to determine the magnitude of the effects of governance gaps and regulator capacity constraints on the policy's potential biodiversity impacts. We collated BNG information from all new major developments across six early‐adopter councils from 2020 to 2022. We quantified the proportion of the biodiversity outcomes promised under BNG at risk of noncompliance, explored the variation in strategies used to meet developers’ biodiversity liabilities, and quantified the occurrence of simple errors in the biodiversity metric calculations. For large developments and energy infrastructure, biodiversity liabilities frequently met within the projects’ development footprint. For small developments, the purchase of offsets was most common. We estimated that 27% of all biodiversity units fell into governance gaps that exposed them to a high risk of noncompliance because they were associated with better‐condition habitats delivered on‐site that were unlikely to be monitored or enforced. More robust governance mechanisms (e.g., practical mechanisms for monitoring and enforcement) would help ensure the delivery of this biodiversity on‐site. Alternatively, more biodiversity gains could be delivered through off‐site biodiversity offsetting. For the latter case, we estimated that the demand for offsets could rise by a factor of 4; this would substantially increase the financial contributions from developers for conservation activities on private land. Twenty‐one percent of development applications contained a simple recurring error in their BNG calculations. One‐half of these applications were approved by councils, which may indicate under‐resourcing in council development assessments. Our findings demonstrate that resourcing and governance shortfalls risk undermining the policy's effectiveness

The ecological outcomes of biodiversity offsets under “no net loss” policies: A global review

No net loss (NNL) biodiversity policies mandating the application of a mitigation hierarchy (avoid, minimize, remediate, offset) to the ecological impacts of built infrastructure are proliferating globally. However, little is known about their effectiveness at achieving NNL outcomes. We reviewed the English-language peer-reviewed literature (capturing 15,715 articles), and identified 32 reports that observed ecological outcomes from NNL policies, including >300,000 ha of biodiversity offsets. Approximately one-third of NNL policies and individual biodiversity offsets reported achieving NNL, primarily in wetlands, although most studies used widely criticized area-based outcome measures. The most commonly cited reason for success was applying high offset multipliers (large offset area relative to the impacted area). We identified large gaps between the global implementation of offsets and the evidence for their effectiveness: despite two-thirds of the world’s biodiversity offsets being applied in forested ecosystems, we found none of four studies demonstrated successful NNL outcomes for forested habitats or species.We also found no evidence for NNL achievement using avoided loss offsets (impacts offset by protecting existing habitat elsewhere). Additionally, we summarized regional variability in compliance rates with NNL policies. As global infrastructural expansion accelerates, we must urgently improve the evidence-base around efforts to mitigate development impacts on biodiversity

'Nature positive' must incorporate, not undermine, the mitigation hierarchy

For the concept of nature positive to succeed as the lodestar for international action on biodiversity conservation, it must build upon lessons learned from the application of the mitigation hierarchy — or risk becoming mere greenwash

Evaluating the impact of biodiversity offsetting on native vegetation

Biodiversity offsetting is a globally influential policy mechanism for reconciling trade‐offs between development and biodiversity loss. However, there is little robust evidence of its effectiveness. We evaluated the outcomes of a jurisdictional offsetting policy (Victoria, Australia). Offsets under Victoria's Native Vegetation Framework (2002–2013) aimed to prevent loss and degradation of remnant vegetation, and generate gains in vegetation extent and quality. We categorised offsets into those with near‐complete baseline woody vegetation cover (“avoided loss”, 2702 ha) and with incomplete cover (“regeneration”, 501 ha), and evaluated impacts on woody vegetation extent from 2008 to 2018. We used two approaches to estimate the counterfactual. First, we used statistical matching on biophysical covariates: a common approach in conservation impact evaluation, but which risks ignoring potentially important psychosocial confounders. Second, we compared changes in offsets with changes in sites that were not offsets for the study duration but were later enrolled as offsets, to partially account for self‐selection bias (where landholders enrolling land may have shared characteristics affecting how they manage land). Matching on biophysical covariates, we estimated that regeneration offsets increased woody vegetation extent by 1.9%–3.6%/year more than non‐offset sites (138–180 ha from 2008 to 2018) but this effect weakened with the second approach (0.3%–1.9%/year more than non‐offset sites; 19–97 ha from 2008 to 2018) and disappeared when a single outlier land parcel was removed. Neither approach detected any impact of avoided loss offsets. We cannot conclusively demonstrate whether the policy goal of ‘net gain’ (NG) was achieved because of data limitations. However, given our evidence that the majority of increases in woody vegetation extent were not additional (would have happened without the scheme), a NG outcome seems unlikely. The results highlight the importance of considering self‐selection bias in the design and evaluation of regulatory biodiversity offsetting policy, and the challenges of conducting robust impact evaluations of jurisdictional biodiversity offsetting policies

Using technology to improve the management of development impacts on biodiversity

Funder: The research was funded through a long‐term collaboration between Conservational International and Chevron.Abstract: The mitigation hierarchy (MH) is a prominent tool to help businesses achieve no net loss or net gain outcomes for biodiversity. Technological innovations offer benefits for business biodiversity management, yet the range and continued evolution of technologies creates a complex landscape that can be difficult to navigate. Using literature review, online surveys, and semi‐structured interviews, we assess technologies that can improve application of the MH. We identify six categories (mobile survey, fixed survey, remote sensing, blockchain, data analysis, and enabling technologies) with high feasibility and/or relevance to (i) aid direct implementation of mitigation measures and (ii) enhance biodiversity surveys and monitoring, which feed into the design of interventions including avoidance and minimization measures. At the interface between development and biodiversity impacts, opportunities lie in businesses investing in technologies, capitalizing on synergies between technology groups, collaborating with conservation organizations to enhance institutional capacity, and developing practical solutions suited for widespread use

What Works in Conservation 2018

This book provides an assessment of the effectiveness of 1277 conservation interventions based on summarized scientific evidence. The 2018 edition contains new chapters covering practical global conservation of primates, peatlands, shrublands and heathlands, management of captive animals as well as an extended chapter on control of freshwater invasive species. Other chapters cover global conservation of amphibians, bats, birds and forests, conservation of European farmland biodiversity and some aspects of enhancing natural pest control, enhancing soil fertility and control of freshwater invasive species. It contains key results from the summarized evidence for each conservation intervention and an assessment of the effectiveness of each by international expert panels. The accompanying website www.conservationevidence.com describes each of the studies individually, and provides full references

What Works in Conservation 2020

Is reduced tillage in arable fields beneficial for farmland biodiversity? Is prescribed burning in grasslands beneficial for bird conservation? Does livestock exclusion from degraded peatlands benefit peatland conservation? Is the provision of artificial shelters effective for subtidal benthic invertebrate conservation? Do wind turbine modifications reduce bat fatalities? Does adding topsoil increase the abundance of heathland plants? Are interventions to reduce road impacts on amphibians effective? Do herbicides control invasive parrot's feather? What Works in Conservation has been created to provide practitioners with answers to these and many other questions about practical conservation.This book provides an assessment of the effectiveness of 1614 conservation interventions based on summarized scientific evidence. The 2020 edition contains new material on bat conservation and our first marine chapter, on Subtidal benthic invertebrate conservation. Other chapters cover practical global conservation of primates, peatlands, shrublands and heathlands, management of captive animals as well as an extended chapter on control of freshwater invasive species, the global conservation of amphibians, bats, birds and forests, conservation of European farmland biodiversity and some aspects of enhancing natural pest control, enhancing soil fertility and control of freshwater invasive species. It contains key results from the summarized evidence for each conservation intervention and an assessment of the effectiveness of each by international expert panels. The accompanying website www.conservationevidence.com describes each of the studies individually, and provides full references. This is the fourth edition of What Works in Conservation, which is revised on an annual basis