Plant community characteristics and degradation mechanisms of the desert
riparian zone in the lower reaches of the Ugan River, China
Abstract
The vegetation in the desert riparian zone represents a critical barrier
in the maintenance of the ecosystem’s balance. However, in recent years,
the vegetation degradation of the riparian zone have seriously hindered
economic development and ecological environment conservation. Based on a
field investigation and literature, the mechanisms of vegetation
degradation in the lower reaches of the Ugan River are discussed in this
study through the analysis of plant coverage, diversity, substitution
rate, distribution pattern, grey correlation analysis, and the
relationship with groundwater depth. The results showed that the
vegetation coverage in this region is relatively low when the water
depth exceeds 4 meters. Furthermore, the Shannon-Wiener index, the
Simpson index and the Pielou index have all decreased with increases in
water depth. Woody plants are the main species maintaining the
ecological balance of the region with an aggregation distribution
pattern. The degradation of vegetation is the result of the lack of
water sources and intense water consumption caused by human
activities(especially agricultural). To promote the ecological balance
and vegetation restoration, the relative optimal water depth range can
be maintained within 2 to 5 meters and proper control human
activities.besides the degraded vegetation can gradually be restored
using point and surface (i.e., flowering in the center and spreading to
the surrounding areas).