Rural livelihoods and access to natural capital: Differences between migrants and non-migrants in Madagascar.

BACKGROUND: Although natural resources play a central role in rural livelihoods across the globe, little research has explored the relationship between migration and natural capital use, particularly in combination with other livelihood capitals (i.e., human, social, financial and physical). OBJECTIVE: Grounded in the rural livelihood framework, this paper explores the association between the livelihood capital availability, especially natural capital, for migrants and non-migrants in rural Madagascar. METHODS: Data from the 2008/2009 Demographic and Health Survey are used in combination with satellite imagery of vegetation coverage (Normalized Difference Vegetation Index, NDVI) to proxy natural resources. Hierarchical multilevel models allow for inclusion of cross-level interactions between migrant status and proximate natural resources as determinants of the status of livelihood assets. RESULTS: Three key findings emerge. First, higher levels of proximate natural resources are associated with greater financial, human, and social capital for both migrants and non-migrants. Second, migrants have, on average, greater financial, physical, human, and social capital than non-migrants, and urban-to-rural migrants do exceptionally well on all capital asset categories. Third, migrants residing in areas with higher levels of natural capital tend to have significantly higher levels of human capital (education). CONCLUSION: Although we cannot examine livelihood strategies per se, the results suggest variation in livelihood potential among migrants and non-migrants in rural Madagascar, with migrants tending to have greater capital assets. In addition, access to natural resources is a central livelihood strategy.

Major players on the microbial stage: why archaea are important.

As microbiology undergoes a renaissance, fuelled in part by developments in new sequencing technologies, the massive diversity and abundance of microbes becomes yet more obvious. The Archaea have traditionally been perceived as a minor group of organisms forced to evolve into environmental niches not occupied by their more 'successful' and 'vigorous' counterparts, the bacteria. Here we outline some of the evidence gathered by an increasingly large and productive group of scientists that demonstrates not only that the Archaea contribute significantly to global nutrient cycling, but also that they compete successfully in 'mainstream' environments. Recent data suggest that the Archaea provide the major routes for ammonia oxidation in the environment. Archaea also have huge economic potential that to date has only been fully realized in the production of thermostable polymerases. Archaea have furnished us with key paradigms for understanding fundamentally conserved processes across all domains of life. In addition, they have provided numerous exemplars of novel biological mechanisms that provide us with a much broader view of the forms that life can take and the way in which micro-organisms can interact with other species. That this information has been garnered in a relatively short period of time, and appears to represent only a small proportion of what the Archaea have to offer, should provide further incentives to microbiologists to investigate the underlying biology of this fascinating domain.