A landscape approach for cost‐effective large‐scale forest restoration

Abstract

Achieving global targets for forest restoration will require cost‐effective strategies to return agricultural land to forest, while minimizing implementation costs and negative outcomes for agricultural production. We present a landscape approach for optimizing the cost‐effectiveness of large‐scale forest restoration. Across three different landscapes within Brazil's Atlantic Forest biodiversity hotspot, we modelled landscape scenarios based on spatially explicit data on the probability of natural regeneration, restoration costs, land opportunity costs, and forest restoration outcomes for increasing carbon stocking and landscape connectivity. We compare benefits of our cost‐reduction approach to the legally mandated riparian restoration and randomly distributed approaches. Compared with riparian prioritization and considering both implementation and opportunity costs, our cost‐reduction scenario produced the greatest savings (20.9%) in mechanized agricultural landscapes. When only considering implementation costs, our cost‐reduction scenario led to the highest savings (38.4%) in the landscape with highest forest cover where natural regeneration potential is highest and enables cost‐effective carbon stocking and connectivity. Synthesis and applications. We present a guide for forest restoration planning that maximizes specific outcomes with minimal costs and reduction of agricultural production. Furthermore, we show how policies could encourage prioritization of low‐cost restoration via natural regeneration, increasing cost‐effectiveness. While our study focuses on Brazil's Atlantic Forest, the approach can be parameterized for other regions.

Effects of restoration on tree communities and carbon storage in rainforest fragments of the Western Ghats, India

“…By contrast, the absence of a relationship between the effects of active restoration on carbon storage and isolation suggests that active restoration could provide benefits for climate change mitigation in isolated and in well-connected fragments, at least over the relatively short timeframes (e.g., 10-15 yr) targeted by major climate change policies (United Nations 2015). Collectively, these findings underscore the importance of considering multiple components of recovery (Gatica-Saavedra et al 2017), and accounting for spatial heterogeneity in natural regeneration (Molin et al 2018), in prioritizing active and passive interventions within restoration strategies for degraded forests.…”

“…), and accounting for spatial heterogeneity in natural regeneration (Molin et al. ), in prioritizing active and passive interventions within restoration strategies for degraded forests.…”

Fostering natural forest regeneration on former agricultural land through economic and policy interventions

“…A major advantage of natural regeneration as an ecological restoration approach is the substantially reduced implementation costs compared to tree planting , Cruz-Alonso et al 2019. In Atlantic Forest landscapes with relatively high forest cover, where natural regeneration is most likely, costs of site preparation and tree planting are reduced by 38% (Molin et al 2018). Because of these lower costs, considerably larger areas can be restored using assisted natural regeneration approaches compared to widespread tree planting (Chazdon and Guariguata 2016).…”

“…In agricultural landscapes, patches of forest regeneration are more likely to be found adjacent to existing old-growth forest remnants , and natural regeneration is more likely to occur and have better biodiversity outcomes in landscapes with more forest cover (Crouzeilles et al 2016(Crouzeilles et al , 2020. Deforested areas on steep slopes with less intensive prior land use and close to forest remnants are the most likely to regenerate spontaneously (Rezende et al 2015, Molin et al 2018). A systematic review of drivers of tropical forest cover expansion through natural regeneration found that proximity to forest remnants, steep slopes, high forest cover at the landscape scale and proximity to watercourses were the most important biophysical factors (Borda-Niño et al 2020).…”

Disentangling chronic regeneration failure in endangered woodland ecosystems

“…Ecosystems heavily modified or displaced by agriculture may be at risk of ecological collapse due to the loss of biotic components or ecological functions (Keith et al 2013, Bland et al 2018. Ecological restoration of such ecosystems requires facilitation of natural regeneration processes, which is often augmented by large-scale, active revegetation programs (Vesk and MacNally 2006, Molin et al 2018, Rohr et al 2018. Ecological interventions are expensive and have high uncertainty, and conservation budgets are typically small (Curtis and Lockwood 2000, McLeod 2004, Cooke et al 2010, so an understanding of the processes underpinning success and failure is critical.…”