Preliminary study on recovery and optimization of submerged macrophyte community in Lake Erhai, China

??????????????????????????????????????????????????????.2016?7????????????????????????????2011???????????????????????1980s?????70%??????1960s?????Ottelia acuminata????????Stuckenia pectinata??????Najas marina???????????Potamogeton maackianus??????Ceratophyllum demersum??????Vallisneria natans?.???????????0~2.5 m???????????????Trapa maximowiezii????????????????????2.5~4 m?????????????????????????????????????>4 m????????????????????????????????.?????????????????????????????????????????????????????????????????????????.???????????????????????????????????????????????????????????????.;With the increasing exogenous nutrients, continued declining water quality, year-to-year algae biomass, and sharply fluctuating levels, succession rate of submerged macrophyte community in Lake Erhai increases over past several decades. The survey July 2016 showed that was seriously degraded, number species significantly lower than recent (2011) historical level, distribution area fell by more 70% from high, dominant were transformed Ottelia acuminata, Stuckenia pectinata Najas marina (1960s) to Ceratophyllum demersum, Potamogeton maackianus Vallisneria natans. Submerged macrophytes mainly suffered stress caused Trapa maximowiezii shallow waters (0-2.5 m), faced simplification structure overgrowth C. demersum P. with medium depth (2.5-4 subjected shrinkage deep (>4 which severely inhibited its positive ecological functions. By comparing structures before after implementation vegetation restoration management project Erbin Village, a typical bay Erhai, we found artificial optimization measures positively improved plant communities various areas different depths Village. abundance restored diversity indicators improved. Therefore, put forward suggestions countermeasures for optimal eutrophic lake bays view provide basis follow-up projects ecosystem Erhai.