Weath. Clim. Soc. http://doi.org/r8f (2014)

Credit: KEREN SU/CHINA SPAN / ALAMY

Climate variability increases farmers' risk of sowing failure by challenging their ability to anticipate rainfall and synchronize sowing accordingly. Observing changes in the practices of farming communities is crucial to better understand adaptation to future climate change, but requires costly long-term studies.

Caroline Mwongera, of AGAP Joint Research Unit, France, and colleagues used a space-and-time substitution approach to observe adaptation to climatic change. They compared two communities that migrated along the slope of Mount Kenya, Africa: the Tharaka community moved from the lowlands (750 m) to the midlands (950 m) and the Mwimbi went from upland (1100 m) to the midlands. Here, changes in location corresponded to changes in time, as induced by environmental alteration. The researchers surveyed 40 farms from 2009 to 2011 (a period including both short and long rainy seasons). They found significant differences in sowing failure risks between the two communities across seasons. They attributed the differences to the role of historical and social factors — such as better experience in managing rainfall variability and within-community exchange of drought-resistant seeds — in the adaptation process.