The main factor determining the dynamics of the lake ecosystem under excessive nutrient loading (a case study on the Naroch Lakes)
T. I. Kazantseva1,2, B. V. Adamovich3, A. F. Alimov1, T. M. Mikheeva3, T. V. Zhukova3, R. Z. Kovalevskaya3, V. N. Solntsev2
1Zoological Institute of RAS, St. Petersburg, Russia
2Almazov National Medical Research Centre, St. Petersburg, Russia
3Belarusian State University, Minsk, Belarus
Keywords: озерные экосистемы, многолетняя динамика, устойчивость, трофический статус, метод главных компонент, метод SSA, интерпретация главного фактора, Нарочанские озера, lake ecosystems, multiannual dynamics, ecological stability, trophic state, Principal Components Analysis, Singular Spectrum Analysis, main factor interpretation, Naroch Lakes
Abstract
The system of the Naroch Lakes, including eutrophic lake Batorino, mesotrophic lake Myastro and oligo-mesotrophic lake Naroch, served as a model object for the study of the factors which initially influence the state of particular lake ecosystem affected by variable nutrient loading. During the 1970s - 2000s, these lakes have been going through the stages of anthropogenic eutrophication, de-eutrophication and bentification. The set of continuous data based on the seasonal means of the eight parameters form each lake for the period 1978-2015 had been analyzed by Principal Component and Singular Spectrum Analysis (SSA, or “Caterpillar”). In addition, we considered the dynamics of the trophic index of each lake, which had been calculated earlier at the same data set. The first main component contributed to the condition of the lakes Batorino, Myastro and Naroch on 63 %, 65 % and 43 % respectively. Comparison of all results allowed us to interpret the first main component as the stability of the lake ecosystem under variable nutrient loading, which is inversely related to the water body trophic state.
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