滇中五湖水生植物区系及沉水植物群落特征

AQUATIC FLORA AND ASSEMBLAGE CHARACTERISTICS OF SUBMERGED MACROPHYTES IN FIVE LAKES OF THE CENTRAL YUNNAN PROVINCE

选择云南中部5个高原湖泊在雨季和旱季对其水生植被开展了两次系统调查。共采集到水生植物80种,隶属于33科64属。其中湿生植物39种,挺水植物19种,沉水植物12种,漂浮植物7种,浮叶根生植物3种。区系分析表明5个湖泊水生植物区系地理成分多样,以世界分布类型为主,热带和温带性质的属分别有22属(占总属数的34.4%)和20属(占总属数的31.3%),表明该植物区系具有比较明显的亚热带性质。对各湖泊沉水植物优势种类和沉水植物群落类型的分析表明耐污种篦齿眼子菜在滇池、星云湖、杞麓湖这3个富营养化湖泊中均占优势。而这些湖泊沉水植物群落类型也较为单一,主要为篦齿眼子菜、马来眼子菜等单优群丛。环境分析表明,研究湖泊沉水植物分布主要受水深、透明度以及底泥总氮含量的影响。

Aquatic plants in 5plateau lakes of the central Yunnan Province were investigated during the dry and wet seasons.Altogether 80species belonging to 33families and 64genera were recorded.Among them were 39wetland plants,19emergent,12submerged,7floating and 3floating-leaved ones.The flora was found to be diverse in its geographical characteristic.Cosmopolitan was the main floristic elements.There were 22tropical(account for 34.4%of the total genera)and 20temperate genera(account for 31.7%of the total genera),indicating the subtropical characteristics of the flora.In the assemblage of submerged macrophytes,Potamogeton pectinatus,an pollution-tolerant species,was the dominant species in Lake Dianchi,Lake Xingyunhu,Lake Qiluhu.Meanwhile,the submerged macrophytes associations in these three eutrophic lakes were relative simple,with monodominant association such as Potamogeton pectinatus association and Potamogeton malaianus association.Environmental analyses demonstrated that the water depth,Secchi depth and total nitrogen of sediment were the important factors influencing the submerged macrophyte assemblages in these lakes.