Jatropha cultivation in Malawi and Mozambique: impact on ecosystem services, local human well-being, and poverty alleviation

Jatropha-based biofuels have undergone a rapid boom-and-bust cycle in southern Africa. Despite strong initial support by governments, donors, and the private sector, there is a lack of empirical studies that compare the environmental and socioeconomic impacts of Jatropha’s two dominant modes of production: large plantations and smallholder-based projects. We apply a rapid ecosystem services assessment approach to understand the impact of two Jatropha projects that are still operational despite widespread project collapse across southern Africa: a smallholder-based project (BERL, Malawi) and a large plantation (Niqel, Mozambique). Our study focuses on changes in provisioning ecosystem services such as biofuel feedstock, food, and woodland products that can have important effects on human well-being locally. Qualitative information is provided for other regulating and cultural ecosystem services. Although at this stage no impact is tremendously positive or negative, both projects show some signs of viability and local poverty alleviation potential. However, their long-term sustainability is not guaranteed given low yields, uncertain markets, and some prevailing management practices.

Ancient clam gardens, traditional management portfolios, and the resilience of coupled human-ocean systems

Indigenous communities have actively managed their environments for millennia using a diversity of resource use and conservation strategies. Clam gardens, ancient rock-walled intertidal beach terraces, represent one example of an early mariculture technology that may have been used to improve food security and confer resilience to coupled human-ocean systems. We surveyed a coastal landscape for evidence of past resource use and management to gain insight into ancient resource stewardship practices on the central coast of British Columbia, Canada. We found that clam gardens are embedded within a diverse portfolio of resource use and management strategies and were likely one component of a larger, complex resource management system. We compared clam diversity, density, recruitment, and biomass in three clam gardens and three unmodified nonwalled beaches. Evidence suggests that butter clams (Saxidomus gigantea) had 1.96 times the biomass and 2.44 times the density in clam gardens relative to unmodified beaches. This was due to a reduction in beach slope and thus an increase in the optimal tidal range where clams grow and survive best. The most pronounced differences in butter clam density between nonwalled beaches and clam gardens were found at high tidal elevations at the top of the beach. Finally, clam recruits (0.5-2 mm in length) tended to be greater in clam gardens compared to nonwalled beaches and may be attributed to the addition of shell hash by ancient people, which remains on the landscape today. As part of a broader social-ecological system, clam garden sites were among several modifications made by humans that collectively may have conferred resilience to past communities by providing reliable and diverse access to food resources.