小兴凯湖的水生植被及其生态作用

本文论述了小兴凯湖水生植物的种类组成、植被类型、生物量及其在湖泊淤积和渔业中的作用。该湖属老年期湖泊,水生维管束植物共有25科56种,优势种为竹叶眼子菜、荇菜、芦、菰等。植被类型可划分为沉水植被、浮叶植被和挺水植被等三个亚型,包括12个主要植物群丛。全湖水生植物总生物量(湿重)为196380吨;以植物现存量计算,草食性鱼类的年生产力应为78.75吨。由于水生植物大量繁殖,为减缓湖泊的垫平作用,可适量放养草食性鱼类,控制住水生植物的过量繁殖;同时引种一些经济水生植物,压住水中杂草的生长。

AQUATIC VEGETATION OF SMALL XINGKAI LAKE AND ITS ECOLOGICAL EFFECTS

The species composition, vegetation type and biomass of the aquatic vegetation and its effects on fishery and lake silt were discussed in this paper. Small Xingkai lake is in the old stage of development. There are about 56 species of vascular plants belonging to 24 families. The dominant species are Potamogewn crispus, Nymphoides peltata, Phragmitis communis and Zizania caduciflora. The vegetation can be classified into the emergent subtype, the floating-leaved subtype and the submergent subtype, including 12 main plant associations. The total biomass (wet) of vascular plants in the lake is about 196 380 tons. The biomass of emergent plants is about 88 950 tons, that of submergent plants about 58 500 tons and that of floating-leaved plants about 48 300 tons. The estimated potential annual production of herbivorous fish is 78.75 tons. During the last 20 years, due to the abundant growth of aquatic plants, the depth of silt in Small Xingkai Lake has increased by 17cm, and water surface decreased by about 1 000 hectares. In order to slow down the silt accumulation, wild aquatic plants should be controlled by rearing herbivorous fishes and introducing economic aquatic plants.