Social as much as environmental: the drivers of tree biomass in smallholder forest landscape restoration programmes

Geoff J Wells,Rohit Jindal,Janet Fisher,Casey M Ryan

doi:10.1088/1748-9326/ab96d1

Abstract

A major challenge for forest landscape restoration initiatives is the lack of quantitative evidence on how social factors drive environmental outcomes. Here we conduct an interdisciplinary quantitative analysis of the environmental and social drivers of tree biomass accumulation across 639 smallholder farms restoring native tree species in Mexico, Uganda and Mozambique. We use environmental and social data to assess the relative effects of key hypothesised drivers on aboveground biomass accumulation at the farm-level over ten years. We supplement this with a qualitative analysis of perspectives from local farmers and agroforestry technicians on the potential causal mechanisms of the observed social effects. We find that the material wellbeing of farmers (e.g. assets) and access to agroforestry knowledge explain as much variation in biomass as water availability. Local perspectives suggest that this is caused by the higher adaptive capacity of some farmers and their associated ability to respond to social-ecological shocks and stresses. Additionally, the variation in biomass between farms increased over time. Local perspectives suggested that this was caused by emergent exogenous and stochastic influences which cannot be reliably predicted in technical analyses and guidance. To deal with this persistent uncertainty, local perspectives emphasised the need for flexible and adaptive processes at the farm- and village-levels. The consistency of these findings across three countries suggests these findings are relevant to similar forest restoration interventions. Our findings provide novel quantitative evidence of a social-ecological pathway where the adaptive capacity of local land users can improve ecological processes. Our findings emphasize the need for forest restoration programmes to prioritise investment in the capabilities of local land users, and to ensure that rules support, rather than hinder, adaptive management.

Highlights

Forest landscape restoration (FLR) initiatives are at the forefront of efforts to reverse environmental degradation in terrestrial ecosystems (Chazdon et al, 2017)
Others emphasise the importance of institutional and social contexts that support good governance and adaptive management for sustainable and socially beneficial restoration (Mansourian, 2016; Van Oosten, 2013b). This divergence of perspectives on the drivers of environmental outcomes extends to the related fields of conservation and payments for ecosystem services (Ezzine-de-Blas et al, 2016; Naeem et al, 2015; Pascual et al, 2014; Soule, 2013), and to the fields of land system science where existing models and approaches continue to struggle to integrate local-level social factors and context (Stephanson and Mascia, 2014; Iwamura et al, 2018)
Our work offers novel evidence on the importance of social factors in driving outcomes in FLR and similar initiatives

Summary

Introduction

Forest landscape restoration (FLR) initiatives are at the forefront of efforts to reverse environmental degradation in terrestrial ecosystems (Chazdon et al, 2017). Others emphasise the importance of institutional and social contexts that support good governance and adaptive management for sustainable and socially beneficial restoration (Mansourian, 2016; Van Oosten, 2013b). This divergence of perspectives on the drivers of environmental outcomes extends to the related fields of conservation and payments for ecosystem services (Ezzine-de-Blas et al., 2016; Naeem et al, 2015; Pascual et al, 2014; Soule, 2013), and to the fields of land system science where existing models and approaches continue to struggle to integrate local-level social factors and context (Stephanson and Mascia, 2014; Iwamura et al, 2018)

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Discussion

Conclusion