摘要
水生植物与浮游植物是湖泊清水稳态和浊水稳态的优势初级生产者代表类群。洱海是云贵高原第二大淡水湖泊,经历了从贫营养、中营养到富营养化初期的过程。文章根据文献资料分析了从1977到2009年期间沉水植物种类、水生植物分布面积、浮游植物细胞数量等变化,研究发现伴随着藻类水华暴发频次的增加,沉水植物种类、水生植物分布面积随时间显著减少,浮游植物细胞数量显著增加。通过对1985—2009年水体总磷和总氮分析发现,营养盐与浮游植物细胞数量成显著正相关;而同期水体透明度显著降低,并且与沉水植物种类数成显著正相关,与浮游植物细胞数量成显著负相关;同期气温随时间显著升高,且与浮游植物细胞数量成显著正相关;同期洱海水位波动也很大。水体氮磷营养含量的增加、透明度降低、气候变暖、水位波动等是影响洱海草藻长期变化的重要因素。在气候变暖的背景下,控制水体氮磷等营养含量、提高透明度、提高沉水植物种类多样性、科学制定合理的水位是促使洱海保持清水稳态、避免进入浊水稳态要采用的重要措施。
Macrophytes is dominant in clear-water, while phytoplankton is dominant in turbid state. Lake Erhai is the second largest freshwater lake in Yunnan Province, Southwestern of China. Over decades, it has gone through transfor- mation from oligotrophic to eutrophic. The submerged macrophytes species （SMS）, distribution of maerophytes （DM） and phytoplankton cell numbers （Phyt） of Lake Erhai were analyzed from 1977 to 2009, on the basis of data referring historical literatures. On account of the algal bloom appeared frequently, SMS and DM decreased with the increase of years （P 〈 0.05） and Phyt increased （P 〈 0.001）. Total phosphorus （TP） as well as nitrogen （TN） increased from 1985 to 2009 （TP, P 〈 0.054; TN, P 〈 0.01） and had positive correlation with Phyt （TP, P 〈 0.01; TN, P 〈 0.001）, Seechi depth （SD） of water decreased （P 〈 0.05） and had positive correlation with the SMS and negative correlation with Phyt （both P 〈 0.001）. Moreover, air temperature （T） on Lake Erhai increased from 1977 to 2008 （P 〈 0.01） and had positive correlation with Phyt （P 〈 0.05）. Besides, annually averaged water level had wide variation. Neosalanx taihuensis was first introduced to Lake Erhai in 1984, and survived successfully in 1991. Its production had increased with years, which advanced Phyt through top-down by eating zooplankton. These findings demonstrate that the changes of nutrients, sec- chi depth of water, climate warming, water level, and invasive species impacted the dynamic of macrophytes and phytoplankton of Lake Erhai from 1977 to 2009. We suggests to reduce the nutrients loading, increase SD and biodiver- sity of submerged macrophytes, control the negative effects from the invasive species, and keep reasonably water level to protect lake from eutrophication, especially under climate wanning.
出处
《水生生物学报》
CAS
CSCD
北大核心
2013年第5期912-918,918+915-917,共7页
Acta Hydrobiologica Sinica
基金
国家水专项洱海项目(No.2008ZX07105-005)
国家自然科学基金(31170439和30870428)资助
关键词
沉水植物
浮游植物
气候变暖
富营养化
稳态
影响因素
Submerged macrophytes
Phytoplankton
Climate wanning
Eutrophication
Steady-State
Affect factors
