Environmental degradation of desert oases

Destruction of oasis ecosystems
Most of the world's dry lands are considered to be at 'high risk' or 'very high risk' of losing their ability to support useful species of plant and animal life. As much as 30% of the earth's land surface, covering part of one hundred nations and occupied by one sixth of the world's population, is designated as at least 'threatened'.
(D) Detailed problems