Money for something? Investigating the effectiveness of biodiversity conservation interventions in the Northern Plains of Cambodia
Despite substantial investments in biodiversity conservation interventions over the past two decades there is relatively little evidence about whether interventions work, and how they work. Whether an intervention is deemed to “work” depends upon how goals are defined and then measured, which is complex given that different stakeholders have very different expectations for any intervention (including species conservation, habitat protection, human wellbeing or participation goals), and because the process of measuring impacts can involve a simplification of more sophisticated ideals. These questions were investigated for a suite of biodiversity conservation interventions, implemented during 2005-2012 in the Northern Plains landscape of Cambodia. The interventions included the establishment of Protected Areas (PAs), village-level land-use planning, and three different types of Payments for Environmental Services (PES) instituted within the PAs. The PES programmes were (1) direct payments for species protection; (2) community-managed ecotourism linked to wildlife and habitat protection; and (3) payments to keep within land-use plans.
The impact evaluation compared the results of each of the interventions with appropriate matched controls, considering both environmental and social impacts between 2005-2011. Both PAs and PES delivered additional environmental outcomes: reducing deforestation rates significantly in comparison with controls and protecting species for those cases where appropriate data was available. PAs increased security of access to land and forest resources for local households, benefiting forest resource users, but restricting households’ ability to expand and diversify their agriculture. PES impacts on household wellbeing were related to the magnitude of the payments provided: the two higher-paying PES programmes had significant positive impacts for participants, whereas a lower-paying programme that targeted biodiversity protection had no detectable effect on livelihoods, despite its positive environmental outcomes. Households that signed up to the higher-paying PES programmes, however, typically needed more capital assets and hence they were less poor and more food secure than other villagers. Therefore, whereas the impacts of PAs on household wellbeing were limited overall and varied between livelihood strategies, the PES programmes had significant positive impacts on livelihoods for those that could afford to participate. This is one of the first evaluations of the social impacts of PES that has been completed globally.
The PA authorities were primarily effective at deterring external drivers of biodiversity loss, especially large-scale developments, land grabbing and in-migration, and had much more limited impact on local residents as the impact evaluation results demonstrated. The PES programmes had little or no effect on the external drivers, and instead explicitly targeted the behaviour of local residents. The three PES programmes differed in the extent to which they rewarded changes in individual or collective behaviour, and whether or not they were managed locally or externally. Household-level, conditional, payments were more effective at changing individual behaviour than collective payments; although there was evidence that both types of payments did lead to protection of forests at the village scale. Village-managed PES programmes empowered a subset of households that were then effective at enforcing regulations within the village. Externally managed PES programmes were more popular and viewed as fairer, but did not change collective behaviour. The general conclusion is that the design and institutional arrangements of PES programmes determines how participants perceive the programmes, and then the extent to which they bring about changes in behaviour.