Evidence shortfalls in the recommendations and guidance underpinning ecological mitigation for infrastructure developments

Abstract

1. In the United Kingdom and European Union, legal protection of species from the impacts of infrastructure development depends upon a number of ecological mitigation and compensation (EMC) measures to moderate the conflict between development and conservation. However, the scientific evidence supporting their effectiveness has not yet been comprehensively assessed.2. This study compiled the measures used in practice, identified and explored the guidance that informed them and, using the Conservation Evidence database, evaluated the empirical evidence for their effectiveness.3. In a sample of 50 U.K. housing applications, we identified the recommendation of 446 measures in total, comprising 65 different mitigation measures relating to eight taxa. Although most (56%) measures were justified by citing published guidance, exploration of the literature underpinning this guidance revealed that empirical evaluations of EMC measure effectiveness accounted for less than 10% of referenced texts. Citation network analysis also identified circular referencing across bat, amphibian and reptile EMC guidance. Comparison with Conservation Evidence synopses showed that over half of measures recommended in ecological reports had not been empirically evaluated, with only 13 measures assessed as beneficial.4. As such, most EMC measures recommended in practice are not evidence based.The limited reference to empirical evidence in published guidance, as well as the circular referencing, suggests potential 'evidence complacency' , in which evidence is not sought to inform recommendations. In addition, limited evidence availability indicates a thematic gap between conservation research and mitigation practice.More broadly, absence of evidence on the effectiveness of EMC measures calls into question the ability of current practice to compensate for the impact of development on protected species, thus highlighting the need to strengthen requirements for impact avoidance. Given the recent political drive to invest in infrastructureThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

A mixed methodology for evaluating use of evidence in conservation planning

“…Existing evidence not applicable to area or region or issue; existing evidence narrow and systematic reviews lacking, inhibiting generalizability Cvitanovic et al, 2016;Christie et al, 2020;Gutzat & Dormann, 2020;Hunter et al, 2021 Complexity and uncertainty…”

“…Remarkably, few studies address this aspect of the science–practice interface (Fabian et al., 2019). Most of these rely only on interviews (Gutzat & Dormann, 2020) or surveys of conservation planners or practitioners (e.g., Cook et al., 2010; Fabian et al., 2019; Pullin & Knight, 2005); evaluate only the use of scientific evidence in the peer‐reviewed literature (Cvitanovic et al., 2016; Hunter et al., 2021); and focus on information used without further investigating the processes by which evidence is applied. We found only 1 study incorporating both formal document analysis and survey methods (Pullin et al., 2004); it examined management plans of major United Kingdom conservation organizations.…”

A home for all within planetary boundaries: pathways for meeting England’s housing needs without transgressing national climate and biodiversity goals

“…This is justifiable on the grounds of zu Ermgassen et al ( 2021) who identified in their sample of developments achieving net gain that the vast majority (93%) of biodiversity units were delivered on-site; although we recognise the government's own market analysis suggests up to 50% of units may be delivered off-site (eftec, 2021). In Section 5 we then draw on results from recent evaluations of Biodiversity Net Gain and species mitigation measures to discuss improvements required to deliver this aim (Hunter et al, 2021;zu Ermgassen et al, 2021).…”

“…ensuring that regulators have sufficient tools to enforce the delivery of Biodiversity Net Gain; zu . In addition, the evidence base behind the effectiveness of species mitigation measures for housing development impacts remains weak, with only 29% of species mitigation measures demonstrably successful at preventing harms to wildlife of new housing (Hunter et al, 2021). Using only evidence-based mitigation techniques would increase confidence that housing expansion does not trade-off against wildlife abundance goals.…”

Principles for the production of evidence‐based guidance for conservation actions

“…We examined the inclusion of evidence in conservation guidance in the United Kingdom and Ireland to understand the level of transparency in the following: methods of production, source of information underlying the recommendations, date of the source material used to write the guidance, and the reporting of uncertainty in the recommendations based on the strength of the evidence. Although well‐formulated and presented guidance can result in the effective translation of evidence into practice (Walsh et al, 2015), poorly formulated guidance can lead to misdirection or misguided decisions, resource waste and could even do more harm than good (Hunter et al, 2021; Pullin & Knight, 2005).…”