Environmental Factors Affecting Distribution and Diversity of Phytoplankton in the Irkutsk Reservoir Ecosystem in June 2023

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Studying correlations between phytoplankton communities and environmental factors is critical for understanding how aquatic ecosystems function. The high sensitivity of phytoplankton to changes in these factors makes it possible to control the state of the ecosystem of water bodies. Artificial lakes often demonstrate increased trophic status, inducing changes in phytoplankton structure. In this paper, we studied phytoplankton in June 2023 (hydrological spring) in two ecosystems, South Baikal and the Irkutsk Reservoir, that are connected by a water course but have different environmental parameters. The gradient of environmental parameters from the lake towards the reservoir revealed peculiarities in the distribution of some microalgae species. Microscopy and statistical analysis showed that water temperature was the most important factor affecting the structure of the communities. The warmer water of the reservoir, in contrast to the lake, demonstrated a twofold increase in species number, abundance, and biomass. Downstream from the reservoir, we observed a succession in the dominating Baikal species complex, its supplementation, and replacement with other species typical of the summer period and Baikal bays. The trophic status of the reservoir during the study may be described as oligotrophic, with local traits of mesotrophicity; its water refers to Class I and Class II and may be qualified as clean.

Related collections

Most cited references 22

Record: found
Abstract: found
Article: not found

Ecologically meaningful transformations for ordination of species data

Pierre Legendre, Eugene Gallagher (2001)

This paper examines how to obtain species biplots in unconstrained or constrained ordination without resorting to the Euclidean distance [used in principal-component analysis (PCA) and redundancy analysis (RDA)] or the chi-square distance [preserved in correspondence analysis (CA) and canonical correspondence analysis (CCA)] which are not always appropriate for the analysis of community composition data. To achieve this goal, transformations are proposed for species data tables. They allow ecologists to use ordination methods such as PCA and RDA, which are Euclidean-based, for the analysis of community data, while circumventing the problems associated with the Euclidean distance, and avoiding CA and CCA which present problems of their own in some cases. This allows the use of the original (transformed) species data in RDA carried out to test for relationships with explanatory variables (i.e. environmental variables, or factors of a multifactorial analysis-of-variance model); ecologists can then draw biplots displaying the relationships of the species to the explanatory variables. Another application allows the use of species data in other methods of multivariate data analysis which optimize a least-squares loss function; an example is K-means partitioning.

0 comments Cited 508 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: not found
Book: not found

Limnological Analyses

Robert G. Wetzel, Gene Likens (2000)

0 comments Cited 186 times – based on 0 reviews

Bookmark

Record: found
Abstract: found
Article: not found

The light: nutrient ratio in lakes: the balance of energy and materials affects ecosystem structure and process.

Melissa Guildford, James Elser, T Chrzanowski … (1997)

The amounts of solar energy and materials are two of the chief factors determining ecosystem structure and process. Here, we examine the relative balance of light and phosphorus in a set of freshwater pelagic ecosystems. We calculated a ratio of light: phosphorus by putting mixed-layer mean light in the numerator and total P concentration in the denominator. This light: phosphorus ratio was a good predictor of the C:P ratio of particulate matter (seston), with a positive correlation demonstrated between these two ratios. We argue that the balance between light and nutrients controls "nutrient use efficiency" at the base of the food web in lakes. Thus, when light energy is high relative to nutrient availability, the base of the food web is carbon rich and phosphorus poor. In the opposite case, where light is relatively less available compared to nutrients, the base of the food web is relatively P rich. The significance of this relationship lies in the fact that the composition of sestonic material is known to influence a large number of ecosystem processes such as secondary production, nutrient cycling, and (we hypothesize) the relative strength of microbial versus grazing processes. Using the central result of increased C:P ratio with an increased light: phosphorus ratio, we make specific predictions of how ecosystem structure and process should vary with light and nutrient balance. Among these predictions, we suggest that lake ecosystems with low light: phosphorus ratios should have several trophic levels simultaneously carbon or energy limited, while ecosystems with high light: phosphorus ratios should have several trophic levels simultaneously limited by phosphorus. Our results provide an alternative perspective to the question of what determines nutrient use efficiency in ecosystems.