the reed marshes are diminished because of artificial activity, village civilization and concreted river bank in middle and small rivers of china, its effect of purify water quality is lost.
我国中小河流两岸自生的芦苇群落由于人类活动的严重干扰、农村的城市化和河岸的混凝土化,导致芦苇自然群落大面积减少,其具有的凈化水质等环境保护作用在丧失。