is missing citations or needs footnotes. Please help add inline citations to guard against copyright violations and factual inaccuracies. (December 2009) An oasis in the Negev Desert of Israel created by trees planted by the Jewish National Fund. In geography, an oasis (plural: oases) or cienega (Southwestern United States) is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source. Oases also provide habitat for animals and even humans if the area is big enough..