干旱区生态环境知识资源中心

In this article we study how the arid ecosystems of lower southern California were opened to different kinds of agriculture. In this isolated and arid region modern forms of agriculture were unknown to the indigenous inhabitants and were only introduced in the 18(th) century by Jesuit missionaries and their accompanying ranchers. Based on indigenous knowledge of the local environment and on the adaptation of Mediterranean and Middle Eastern oases culture, the ranch society and economy developed efficient strategies that allowed them to enjoy the sustainable use of water, soil and other natural resources of the oases where they had established themselves, thereby maintaining these fragile ecosystems and building an original cultural landscape. From the last decades of the 19(th) century, however, the perforation of wells permitted the extension and diversification of agriculture. The greatest ecological disturbances were due to overuse of land and water between 1950 and 1990. The deterioration of the ecosystems and its dire socioeconomic consequences showed that the region was in no way suitable for large scale production of grain; while the high volume of water required by industrial plants caused soil exhaustion. Using an environmental historical approach, based on the ranchero relationship with the environment, one may identify the means and circumstances whereby agriculture in the region could have experienced sustainable development.