乌伦古湖水生植被研究

STUDY ON AQUATIC VEGETATION IN WULUNGU LAKE, XINJIANG

于1987年7月和1989年7,8月对乌伦古湖水生植被及其生态环境作了调查。结果表明,水位回升扭转了水生植被的退缩趋势,新生滩地上次生植物群落的形成使得Ⅳ区以北的水生植被总面积由1985年的813ha增加到1989年的4365ha,总储量由7700t增加到41750t。芦苇占现有植被区面积的81％。和总储量的68％。现有水生植被正处在迅速演变之中,随着植被的发育,植被总面积将会减小到3500ha左右,但总储量将会逐年增加。植被现有生产力约58955t,对渔业和环境十分重要,应加强对其开发利用。

Wulungu Lake, a semi-salt water lake in the northwestern part of Xinjiang, has a surface area of 81 800 ha and only less than 1% of it is covered by aquatic vegetation. Surrounded by arid desert, Wulungu Lake and its aquatic vegetation are of great importance to fishery and to the environment.According to results of investigations made from 1978-1985, the water level of Wulungu Lake had been dropping. It was not until the end of 1987 when the Second Erdis River Diversion Project to replenish the lake water, was implemented that the water level of the lake began to be restored rapidly.In July, 1987 and in July to August, 1989 the detailed investigation on the effects of water level changes on the aquatic vegetation and its environment, was carried out. Results revealed that (1) the restoration of water level resuled in an increase in the aquatic vegetation coverage from 813 ha in 1985 to 4 365 ha in 1989, and an increase in the total standing biomass from 7 700t to 41 750t of the aquatic vegetation; (2) among 53 species of vascular plants in the-lake, reed (Phragmhes communis Trin.) which was the most dominant species made up 68% of the total standing biomass and covered 81% of the total area of the aquatic vegetation. Po-tamogeton pectinatus and P. perfoliatus, the subdominant species, made up 11% and 8% of the total standing biomass respectively; (3) the vegetation was still in a process of rapid succession because the deeply-inundated reed was disappearing and the newly-formed plant communities in the shallow areas were developing. Under stable water level, the total area of aquatic vegetation would possibly decrease to about 3 500 ha and the total standing biomass would possibly increase steadily year by year; (4) with a productivity of about 58 955t per year, it is apparent that the aquatic vegetation played an important role in the primary production and fishery of the lake. If it had not b en properly used the lake water would be organically polluted especially in area IV. Thus, periodic harvest is needed to remove products of aquatic plant from the lake.