[Characteristics of standing vegetation and soil seed bank in desert riparian forest in lower reaches of Tarim River under effects of river-flooding].

An investigation was made on the standing vegetation and soil seed bank in desert riparian forest in lower reaches of Tarim River under effects of river-flooding. The results showed that the standing vegetation in non-flooded and flooded sites was composed of 14 species in 13 genera of 8 families, and 26 species in 21 genera of 10 families, respectively, and some shallow-rooted and hygrophilous species were recorded in flooded sites. The indices per unit area plant species number, vegetative coverage, plant density, and species diversity of the vegetation were all higher in flooded than in non-flooded sites.

[Effects of soil salt on the niche of main plant species in alpine meadow].

By using Levins niche breadth index and Cowell similarity index, the niche breadth and niche similarity of main plant species in Bayanbulak alpine meadow were calculated, based on 3 resources dimensions (soil moisture, organic matter, and available K) along four gradients of soil salt content. The results showed that with the increase of soil salt content, the average niche breadth of main constructive species Carex stenocarpa based on the 3 resources dimensions decreased from 0.4433 to 0.

Changes in groundwater levels and the response of natural vegetation to transfer of water to the lower reaches of the Tarim River.

Restoration and reconstruction of the degraded Tarim River ecosystem is an important challenge. A goal of an ecological water conveyance project is to protect and restore the natural vegetation in the lower reaches of Tarim River by transferring water from Bosten Lake, through the river channel, to the lower reaches. This study describes the changes in groundwater depth during the water transfer and the respondence of riparian vegetation to alterations in groundwater levels.

The natural vegetation responses to the groundwater change resulting from ecological water conveyances to the lower Tarim River.

This paper takes the ecological water conveyance project (EWCP) that transfers water from the Bosten Lake, to Daxihaizi Reservoir, and finally to the Taitema Lake as a case study to analyze the dynamic change of the groundwater depth, the vegetation responses to the elevation of the groundwater depth as well as the relationship between the groundwater depth and the natural vegetation. The results from many years' monitoring in field indicate: (1) the groundwater depth has been elevating gradually with the increase in the times of watering and the elevation range has been expanding continuously in the lower reaches of Tarim River. Correspondingly, the natural vegetation has a favorable response to the elevation of the groundwater depth.

[Effect of translating water on vegetation at the lower reaches of Tarim river].

Due to human irrational resource exploit in recent 50 years, many environment problems have appeared at the lower reaches of Tarim River, the environment degradation of this region became seriously. In order to restore green corridor and improve the environment at the lower reaches of Tarim River, the project of transporting water to the lower reaches of Tarim River was carried out from June 14, 2000 and the water reached Taitema lake finally. After two years' monitoring and analyzing in this region, it was found that the ground-water level went up and much extremely degraded vegetation was restored.