摘要
附着藻类是湖泊中主要的生产者,尤其是草型湖泊。但与浮游藻类相比,针对附着藻类初级生产的研究还相对较少。采用原位调查与实验模拟相结合的方法测定2014—2015年间白洋淀附植藻类和附泥藻类的现存量和初级生产力,并对附着藻类初级生产与白洋淀水体理化参数的关系进行分析。结果表明,不同采样季节的附植藻类和附泥藻类的叶绿素a分别为34.83—245.22μg/cm^2和26.08—297.40μg/cm^2,无灰干重分别为0.46—5.21g/m^2和0.61—5.81g/m^2。两种附着藻类的生物量都在8月最高,4月和11月最低。空间分布上,南刘庄、府河入口的附着藻类生物量显著高于采蒲台和枣林庄。白洋淀附植藻类和附泥藻类的年均总初级生产分别为494.20mg C m^(-2)d^(-1)和474.45mg C m^(-2)d^(-1),呼吸速率为522.63mg C m^(-2)d^(-1)和508.98mg C m^(-2)d^(-1),净初级生产为-28.44mg C m^(-2)d^(-1)和-34.52mg C m^(-2)d^(-1)。白洋淀附着藻类初级生产力具有明显的时空分布规律,8月最高,6月次之,4月和11月最低,空间分布呈自西向东递减的趋势,在府河入淀口和南刘庄处最高,枣林庄和采蒲台最低。水质较好的区域的净初级生产力为正值,表明这些区域附着藻类以自养型群落为主,水质较差区域的净初级生产力为负值,则该区域以异养型群落为主。运用冗余分析法(RDA)探讨附着藻类与水质因子之间的关系,并采用向前引入法对水质因子进行逐步筛选,Monte Carlo置换检验结果显示,总磷、浮游植物叶绿素a、高锰酸盐指数、氨氮、水温、透明度、溶解氧和氮磷比是影响附着藻类生物量和初级生产的关键水质因子。附着藻类的总初级生产与水体富营养化程度呈正相关关系。
Estimation of algal primary production is important for understanding the energy flow in aquatic ecosystems.Periphytic algae are believed to be the major primary producers in lakes,especially in macrophyte-dominated lakes.However,there have been relatively few studies on periphyton primary production than those on phytoplankton in lakes.We studied periphyton in eight different disturbed sites in Baiyangdian Lake during four seasons.Biomass was measured in the laboratory using sampled periphyton,and the metabolism of shallow epiphytic and epipelic algal communities in Baiyangdian Lake was measured using changes in dissolved oxygen in chambers in situ.The relationship between the metabolism of periphyton（epiphyton and epipelon）and water physicochemical parameters was analyzed.The results showed that chlorophyll a（chla）concentrations of epiphyton and epipelon varied from 34.83 to 245.22μg/cm^2 and from 26.08 to 297.40μg/cm^2,and the ash-free dry weights（AFDW）varied from 0.46 to 5.21 g/m^2 and 0.61 to 5.81 g/m^2,respectively,at different sampling times.The biomass of periphyton was the highest in August,and were the lowest in April and November.In April and November,the chla of epiphyton was significantly higher than that of epipelon,and significantly lower than that of epipelon in June and August.Biomass varied significantly among sites.Both chla and AFDW of two periphytons were significantly higher in polluted areas（inlet and Nanliuzhuang）than in clear water areas（Shaochedian and Caiputai）.Annual gross primary productivity（GPP）of epiphyton and epipelon in Baiyangdian Lake was494.20 and 474.45 mg C m^-2d^-1,respiratory rate（R）was 522.63 and 508.98 mg C m^-2d^-1,and net primary productivity（NPP）was-28.44 and-34.52 mg C m^-2d^-1in 2014 and 2015,respectively.The distribution of periphyton metabolism in Baiyangdian Lake exhibited significant temporal and spatial variation.GPP of periphyton was the highest in August,and the lowest in April and November,similar to biomass.The spatial distribution of periphyton GPP exhibited a decreasing trend from west to east.The NPP values were positive in clear water areas,indicating that the periphyton in these areas were autotrophic communities,whereas the NPP values were negative and the periphyton communities were heterotrophic in polluted areas.Multivariate ordination techniques were used to analyze the effects of water quality on the periphyton biomass and primary production using CANOCO version 4.5.The results of redundancy analysis（RDA）with forward selection indicated that total phosphorus,chlorophyll a,permanganate index,ammonia nitrogen,water temperature,Secchi Disc depth,dissolved oxygen,and N/P ratio were the most important environmental factors affecting periphyton primary productivity during the study period.Significantly positive correlations occurred between GPP and water trophic status.
出处
《生态学报》
CAS
CSCD
北大核心
2018年第2期443-456,共14页
Acta Ecologica Sinica
基金
国家自然科学基金项目(41401615)
南京中医药大学院所基本科研业务费专项(CAFYBB2014QB050)
南京中医药大学林业新技术所基本科研业务费专项(CAFINT 2013K06)
关键词
附着藻类
浮游藻类
初级生产力
白洋淀
periphyton
phytoplankton
primary productivity
Baiyangdian Lake
