龙感湖水生植被

于１９９３年９月对龙感湖水生植被及环境进行了调查研究。龙感湖有水生植物２６科３８属５０种，依据优势种群划分９个群丛，其分布面积２８３．５ｋｍ＾２，占全湖总面积的８９．７％，植被现有年生产力达２１４７７３０ｔ，对渔业生产和生态环境具有十分重要的意义。建议对该湖植被应合理开发利用，如果围网养鱼得到广泛地发展，渔业生产潜力每年可达４１８１．８ｔ。

Aquatic vegetation in longgan lake

Aquatic vegetation and environment in Longgan Lake are investigated in September, 1993. The results show that the aquatic flora in the lake covers 26 families, 38 genus, 50 species. The distribution area is 283. 5km2, making up 89. 7% of the lake. Based on the domi-nent association combinations and structures, the following 9 association types can be cate-goried: (1) Zizania caduciflora ass. ; (2) Nelumbo nucifera ass. ; (3) Nelumbo nucifera-Trapa bicornis ass. ; (4) Hydrilla verticillata + Vallisneria spiralis+Ceratophyllum demersum ass. ; (5) Hydrilla verticillata + Potamogeton maackianus ass. ; (6) Vallisneria spiralis ass. ; ( 7 ) Potamogeton malaianus- Vallisneria spiralis ass. ; ( 8 ) Trapa natans-Potamogeton mela-ianus + Myrinphyllum spicatum - Hydrilla verticillata ass. ; ( 9 ) Potamogeton malaianus + Myriophyllum spicatum ass. After comparing the aquatic vegetation association types and their distribution in 1980 and 1993, the authors make some suggestions, i.e. : the annual 2147730t of aquatic vegetation should be exploited and utilized in a reasonable way; a net increase of 4181. 8t/a in fishery potential may be reached when pen-fish-farming is widely populariged.