Using ecological thresholds to evaluate the costs and benefits of set-asides in a biodiversity hotspot

Abstract

Ecological set-asides are a promising strategy for conserving biodiversity in human-modified landscapes; however, landowner participation is often precluded by financial constraints. We assessed the ecological benefits and economic costs of paying landowners to set aside private land for restoration. Benefits were calculated from data on nearly 25,000 captures of Brazilian Atlantic Forest vertebrates, and economic costs were estimated for several restoration scenarios and values of payment for ecosystem services. We show that an annual investment equivalent to 6.5% of what Brazil spends on agricultural subsidies would revert species composition and ecological functions across farmlands to levels found inside protected areas, thereby benefiting local people. Hence, efforts to secure the future of this and other biodiversity hotspots may be cost-effective.

Implications of vegetation clearing biases for the interpretation of landscape-scale species-area relationships

“…'forest specialist' vs 'disturbance tolerant') De Camargo & Currie, 2015), it would be a useful next step to examine the landscape-specific relationships we present here for subsets of our broad bird community. In particular, observations that sensitive species decline and are lost from landscapes at higher levels of vegetation cover than observed thresholds reflecting the response of the broader assemblage (Banks-Leite et al, 2014), underscores the importance of considering groups of species with different levels of sensitivity/tolerance to disturbance.…”

“…Piecewise regressions identify a threshold, or 'point of abrupt change' (Ficetola & Denoël, 2009), below which the rate of decline in species richness with decline in vegetation area changes. Such thresholds have the potential to act as explicit reference points upon which vegetation clearing or revegetation targets can be based (Huggett, 2005;Swift & Hannon, 2010), and have been identified from several studies examining species-area relationships at the landscape level Banks-Leite et al, 2014;Ochoa-Quintero et al, 2015;Richmond et al, 2015). However, a lack of consistency in threshold values across different studies has been cited as a limitation of the generality of thresholds for informing applied conservation (Johnson, 2013;Matthews et al, 2014a).…”

“…Banks-Leite et al (2014) explored how enhancing landscape-scale forest cover above a threshold of 30%-a value derived from several aggregated datasets on the response of forestspecialist and disturbance-adapted species to forest loss-could guide the management of 143 million hectares of land in the Atlantic Forest region of Brazil. In particular, a focus on restoring forest in landscapes close to, but below, the threshold value of cover was advocated as a means by which to prioritise management actions to achieve a maximum biodiversity benefit (Banks-Leite et al, 2014). In observing a sharp decline of woodland bird species richness below 10% vegetation cover, advocated that landscape-scale native vegetation extent be maintained at well above 10% to avoid the rapid species loss associated with this threshold being breached.…”

“…A graphical depiction of how combining data from different landscape types subject to vegetation clearing bias can affect the shape of observed species-area relationships is presented in Figure 1.1 (reproduced from ). Thresholds, which were a key focus of the analysis, represent a highly attractive management tool, especially for establishing conservation targets (Swift & 8 Hannon, 2010), and have been identified from a number of landscape-scale studies of the relationship between species richness and habitat area Banks-Leite et al, 2014;Ochoa-Quintero et al, 2015;Richmond et al, 2015). Spurious thresholds, which arise as a function of the confounding effect of vegetation clearing bias, undermine the applied value of the concept for guiding conservation actions such as vegetation protection or restoration targets.…”

“…The prioritisation was guided by an observed threshold in the species-area relationship of 43% forest cover, below which species richness rapidly declined (Ochoa-Quintero et al, 2015). Banks-Leite et al (2014) explored how enhancing landscape-scale forest cover above a threshold of 30%-a value derived from several aggregated datasets on the response of forestspecialist and disturbance-adapted species to forest loss-could guide the management of 143 million hectares of land in the Atlantic Forest region of Brazil. In particular, a focus on restoring forest in landscapes close to, but below, the threshold value of cover was advocated as a means by which to prioritise management actions to achieve a maximum biodiversity benefit (Banks-Leite et al, 2014).…”