抚顺平山水库退役后植物群落及管理建议

Plant communities after decommissioning of Pingshan reservoir in Fushun and relevant proposals

调查了抚顺平山水库退役后所保留大坝的不同位置及库底裸露后形成的河流缓冲带的植物群落。结果发现,大坝上不同位置的植物种类变化明显。大坝上部的植物种类最多,以菊科和禾本科植物为主;植物群落总盖度平均在60%左右,各种植物的分盖度均在20%以下,其中分盖度较高的种类是菊科的茵陈蒿和禾本科的狗尾草。大坝中下部的植物种类数明显减少,且没有明显的优势科;群落总盖度约40%,各种植物的分盖度均低于15%,其中分盖度较高的种类有葎草、小花鬼针草、狭叶荨麻和沼泽蕨。大坝下部群落总盖度在65%左右,其中分盖度较大的植物有小飞蓬、狭叶荨麻、水葱和藨草。库底裸露后形成的河岸缓冲带一多半种植了农作物,近河水湿生境中的野生植物以蓼科、菊科、禾本科植物种类居多;群落的平均总盖度约为85%,野稗居绝对优势,其次是马唐。测定了河流水质指标,发现总氮污染较为严重,达到地表水IV类水标准,这与农田施用化肥有关。建议水库大坝拆除前应做好生态规划,拆坝后应通过人为干预植被演替过程,尽快形成乔灌草相结合的植物群落,发挥植被的水源涵养和滤除污染物的作用,保证河流的水量和水质,从而达到预期的水库拆坝后的流域管理效果。

The plant communities on the dam and river buffer zone were investigated after the decommissioning of Pingshan reservoir in Fushun. The result showed that plant species changed obviously at different position on the dam. The highest number of plant species appeared on the top of the dam. Most of them were belonged to the composite and grass family. The average coverage was about 60% and the coverage of different species were all lower than 20%. Artemisia scoparia and Setaria viridis had higher coverage than other species. The species decreased obviously on the middle and the bottom of the dam and there were no dominant plant family. The coverage of community on the middle of dam was about 40% and the coverage of different species were all lower than 15%. The coverage of Humulus scandens, Bidens parviflora, Urtica angustifolia and Thelypteris palustris were higher than other species. The coverage of plant community on the lower part of the dam was about 65%. The species of Conyza canadensis, Urtica angustifolia, Scirpus validus and Scirpus triqueter had higher coverage than others. More than half part of the naked bottom of reservoir became farmland. Most wild plant species on the wet land near the river belonged to the polygonaceae, composite and grass family. The community coverage was about 85% and Echinochloa crusgalli and Digitaria sanguinalis were the dominant species. Some chemical indexes of the river water were measured and TP was the most serious pollutant and the reason was the use of chemical fertilizer in the farmland. Some proposals were given according to the result. Ecological planning should be made before dismantling the dam. The administration should keep to watershed management principals. The community success should be accelerate by human method to establish community including trees, shrubs and grasses in order to exert ecological function of water conservation and removal pollutants, etc.