Colonial rainfed farming strategies in an extremely arid insular environment: Niche construction on Lanzarote, Canary Islands, Spain.

Abstract

The island of Lanzarote in the Canary Islands was first settled by people from northern Africa in the first millennium BC and then colonized by Spain in the late fifteenth century. This colonial legacy reflects an intensive land use driven by a European commodities market that experienced a series of boom-and-bust cycles. Although arid and seemingly resource limited, colonial farmers in the sixteenth to nineteenth centuries copied water capture techniques from the Indigenous population, were strategic in terms of field placement, and engaged in a range of niche construction techniques. An analysis of 420 soil samples for their chemical properties (e.g., pH, electrical conductivity, nutrients) has revealed that sixteenth to nineteenth agricultural infrastructure in the form of open fields, terraces, water capture basins, and mulched fields was constructed on the landscape avoiding areas of high soil salinity and placement was tailored to variations in terrain slope, elevation, and rainfall. These improvements fundamentally changed ecosystem relations resulting in increased agricultural productivity. A series of eolian and volcanic events in the eighteenth century resulted in environmental changes requiring counteractive responses and new processes of niche reconfiguration. Large tracts of land were initially removed from production, but processes of niche construction created new opportunities. These included constructing mulched pits for cultivating sweet potato and tephra mulching for enhanced moisture conservation and accelerated growth of cochineal insect (Dactylopius coccus) production on cactus host plants. Cochineal production lasted for a period of sixty years (ca. AD 1825–1885) before a collapse of the market caused by the invention of chemical substitutes.