ABSTRACT
An unparalleled floral diversity is found in the continental deserts of Central Asia that stretch for thousands of miles from Iran and Afghanistan across Uzbekistan, Turkmenistan into Western China and Mongolia. Two major pressures subject Central Asian deserts to powerful forces that lead to desertification, namely, their extremely dynamic environments plus a host of human driven activities. Great natural contrasts exist in these continental environments, e.g., with mostly autumn-winter rains and almost absence of rainfall in summer along with quite high and low annual temperature fluctuations, and complicated desert, mountain, steppe and plain relief. Human activities demand lands, waters, plants, and other natural resources for activities such as domestic livestock grazing, fuels, cropping agriculture, irrigation, dams, reservoirs and canals, mining, drilling, roads, dwellings, and other human infrastructures. Such extreme natural environmental changes coupled with human activities often induce dynamic detrimental environments for the growth and seed reproduction of plants; indeed difficult environments for all biological life forms.
