Changes in particulate organic matter passing through a large shallow lowland lake

Estonian Academy of Sciences. Proceedings

Kai Piirsoo¹ 

关键词: particulate organic matter;    rivers;    lakes;    algal species;    food web.;   

DOI  :  10.3176/proc.2018.1.05

学科分类：化学（综合）

来源: Teaduste Akadeemia Kirjastus

【 摘 要 】

Different sources of particulate organic matter (POM) as well as its composition affect the biological food web andhence the self-purification potential and water quality of rivers. We studied the effect of a large shallow lake on the POM poolof the water passing through it. Over four years, we analysed monthly the amount and composition of POM and a set ofenvironmental variables in the inflows and in the outflow of Lake Võrtsjärv (Estonia). In the inflows, the live pool of POMconsisted of phytoplankton – small crypto-, dino-, and chlorophytes. The concentration of chlorophyll a (Chl a), as a proxy ofphytoplankton biomass, was positively correlated with temperature and total phosphorus and negatively with dissolved silica, totalnitrogen, and discharge. In the outflow, the share of the live component of POM was much larger than in the inflows but was alsodominated by phytoplankton represented by grazing resistant filamentous cyanobacteria. Chl a was positively correlated with totalphosphorus, temperature, pH, and precipitation, and negatively with dissolved silica, total nitrogen, and discharge in the outflow.The different amounts, composition, and seasonal dynamics of POM in the inflows and in the outflow have potentially substantialimpacts on the food web with a predominating classical pathway in the inflows versus a detrital pathway in the outflow.

【 授权许可】

CC BY-NC