Changes in particulate organic matter passing through a large shallow lowland lake
Laen...
Kuupäev
2018
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Estonian Academy Publishers
Abstrakt
Different sources of particulate organic matter (POM) as well as its composition affect the biological food web and
hence the self-purification potential and water quality of rivers. We studied the effect of a large shallow lake on the POM pool
of the water passing through it. Over four years, we analysed monthly the amount and composition of POM and a set of
environmental variables in the inflows and in the outflow of Lake Võrtsjärv (Estonia). In the inflows, the live pool of POM
consisted of phytoplankton – small crypto-, dino-, and chlorophytes. The concentration of chlorophyll a (Chl a), as a proxy of
phytoplankton biomass, was positively correlated with temperature and total phosphorus and negatively with dissolved silica, total
nitrogen, and discharge. In the outflow, the share of the live component of POM was much larger than in the inflows but was also
dominated by phytoplankton represented by grazing resistant filamentous cyanobacteria. Chl a was positively correlated with total
phosphorus, 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 substantial
impacts on the food web with a predominating classical pathway in the inflows versus a detrital pathway in the outflow.
This study was supported by the institutional research funding (IUT 21-2) of the Estonian Ministry of Education and Research and by the MARS project ‘Managing Aquatic Ecosystems and Water Resources under Multiple Stress’ funded under the 7th EU Framework Programme, Theme 6 ‘Environment including climate change’ (Contract No. 603378). We are grateful to Dr. Jonne Kotta and to the two anonymous reviewers for valuable comments on the manuscript. Mrs Ester Jaigma kindly revised the English text of the manuscript. The publication costs of this article were covered by the Estonian Academy of Sciences.
This study was supported by the institutional research funding (IUT 21-2) of the Estonian Ministry of Education and Research and by the MARS project ‘Managing Aquatic Ecosystems and Water Resources under Multiple Stress’ funded under the 7th EU Framework Programme, Theme 6 ‘Environment including climate change’ (Contract No. 603378). We are grateful to Dr. Jonne Kotta and to the two anonymous reviewers for valuable comments on the manuscript. Mrs Ester Jaigma kindly revised the English text of the manuscript. The publication costs of this article were covered by the Estonian Academy of Sciences.
Kirjeldus
Märksõnad
particulate organic matter, rivers, lakes, algal species, food web, articles