The relative conservation impact of strategies that prioritize biodiversity representation, threats, and protection costs

Abstract

Despite exponential increases in the coverage of protected areas (PAs) over recent decades, global biodiversity continues to decline. One explanation for this lack of success is that the efficacy of conservation prioritization strategies is rarely measured in terms of conservation "impact," which requires comparing proposed PA networks to a counterfactual scenario in which no intervention is applied. This approach contrasts with measuring efficacy using surrogates for conservation impact, such as the extent, total biodiversity value, or representativeness of a proposed PA network. However, implementing an experimental counterfactual scenario is difficult because of time, funding, and ethical constraints. Here, we use an alternative and complementary approach: an ex-post analysis with counterfactual outcomes measured using historical empirical data on changes in biodiversity in unprotected landscapes. This approach allows for the comparison of different retrospectively implemented prioritization strategies to a real counterfactual outcome. In our analysis, we predict the impact of several alternative PA prioritization strategies in Queensland, Australia, using high-resolution datasets of vegetation clearing, habitat type, and land acquisition cost. Our results show that achieving conventional conservation targets does not equate to achieving impact, and that alternative, and relatively simple, prioritization strategies can achieve far greater impacts.

The impact of strictly protected areas in a deforestation hotspot

“…To reliably quantify the impact, we chose to constrain our analysis to strictly protected areas to avoid conflating several additional economic, political or social drivers. Nonetheless, the results of these analyses support recommendations for outcome‐based targets (Visconti et al, 2019b) focused on preventing threatening processes (Sacre, Weeks, Bode, & Pressey, 2020). Using rigorous evaluation measures for conservation interventions, we can quantify the impact of conservation interventions leading to measurable outcomes for biodiversity.…”

“…The total cleared area is the product of the number of pixels by 0.0625 (or the area of one pixel in square kilometres). Bode, & Pressey, 2020). Using rigorous evaluation measures for conservation interventions, we can quantify the impact of conservation interventions leading to measurable outcomes for biodiversity.…”

The mismeasure of conservation

“…of protection [28], so increases in representation can be accompanied by, and conceal, ongoing avoidable loss of biodiversity [29]. This limitation applies particularly to metrics based on evenness [30] or average representation [31] across features.…”

“…Or (ii) what will happen to matched, unprotected sites over the future simulation period as an indicator of what will happen to protected sites in the absence of protection [105]?Approach 3. Factual[29]: what would have happened to sites that were unprotected at the start of the past time series if they had been protected during the past time series? Counterfactual: what happened to sites over the past time series in the absence of protection?…”

Using Theory of Change to improve post‐2020 conservation: A proposed framework and recommendations for use

“…Conservation interventions are frequently inhibited by contextually inappropriate approaches and governance arrangements, often less suited to complex systems (Armitage, Mbatha, Muhl, Rice, & Sowman, 2020; Game, Meijaard, Sheil, & McDonald‐Madden, 2014). More specifically, conservation priority‐setting and area‐based strategies promote quantity over quality, and are often ineffectively managed (Bhola et al, 2020; Geldmann et al, 2018; Pressey et al, 2017; Sacre et al, 2020). Furthermore, the social impacts of conservation, such as the displacement of local communities, their exclusion from decision‐making, and the inequitable distribution of conservation costs and benefits, require increased recognition, monitoring, and reconciliation (Armitage et al, 2020; Kaplan‐Hallam & Bennett, 2018).…”