Linkages between Macrophyte Functional Traits and Water Quality: Insights from a Study in Freshwater Lakes of Greece

Abstract

Freshwater ecologists have shown increased interest in assessing biotic responses to environmental change using functional community characteristics. With this article, we investigate the potential of using functional traits of the aquatic plants to assess eutrophication in freshwater lakes. To this end we collected macrophyte and physicochemical data from thirteen lakes in Greece and we applied a trait-based analysis to first identify discrete groups of macrophytes that share common functional traits and then to assess preliminary responses of these groups to water quality gradients. We allocated 11 traits that cover mostly growth form and morphological characteristics to a total of 33 macrophyte species. RLQ and fourth corner analysis were employed to explore potential relationships between species, trait composition and environmental gradients. In addition, a hierarchical cluster analysis was conducted to discriminate groups of plants that share common trait characteristics and then the position of the groups along the environmental gradients was assessed. The results showed total phosphorus, chlorophyll-a, conductivity, pH and Secchi disk depth as main drivers of the environmental gradients. Hierarchical cluster analysis showed a clear separation of macrophyte assemblages with discrete functional characteristics that appeared to associate with different environmental drivers. Thus, rooted submerged plants were related with higher Secchi disk depth, conductivity and alkalinity whereas rooted floating-leaved plants showed a preference for enriched waters with phosphorus and nitrogen. In addition, free-floating plants were related positively with nitrogen and increased pH. Although we did not identify specific trait patterns with environmental drivers, our findings indicate a differentiation of macrophytes based on their functional characteristics along water quality gradients. Overall, the presented results are encouraging for conducting future monitoring studies in lakes focused on the functional plant trait composition, as expanding the current approach to additional lakes and using quantifiable functional characteristics will provide more insight about the potential of trait-based approaches as ecological assessment systems.

The Macrophyte Index for Rivers (MIR) as an Advantageous Approach to Running Water Assessment in Local Geographical Conditions

“…Macrophytes, as a vital component of aquatic ecosystems, are among the groups of organisms considered by the WFD for river assessment. Plants are sensitive indicators of the aquatic environment, able to detect eutrophication [2,[5][6][7][8][9], and to some extent also acidification [10], water flow [11], and morphological degradation [8]. Furthermore, aquatic plants respond to various other environmental factors, including light, temperature, and substrate [12].…”

Modelling of ecological status of Polish lakes using deep learning techniques

“…The relationship between conductivity and macrophyte development is generally strong since this factor reflects the trophic state of lakes well (Stefanidis and Papastergiadou 2019;Szoszkiewicz et al 2014;Toivonen and Huttunen 1995). Generally, the water transparency does have a large influence on submerged macrophytes, whereas emergent plants are less strongly influenced by underwater conditions (Middelboe and Markager 1997;Stefanidis and Papastergiadou 2019;Toivonen and Huttunen 1995). Therefore, shallow lakes are generally more abundant in emergent plants, which are less dependent on water transparency than submerged ones, and the impact of other trophy-related metrics is more evident.…”

A biodiversity evaluation framework for restoration of aquatic macrophyte communities in shallow lakes driven by hydrological process management

“…These were related to resource utilization and nutritional levels that had been previously measured and used in functional diversity studies (X. Liu & Wang, 2018;Petchey & Gaston, 2006;Stefanidis & Papastergiadou, 2019).…”

“…It can be quantified as taxonomic diversity (based on the species that are present) (Gagic et al, 2015; Magurran, 2004) and functional diversity (based on the functional groups, which represent groups of species that perform a similar ecological role) (Mason, Mouillot, Lee, & Wilson, 2005; Mouillot, Villeger, Scherer‐Lorenzen, & Mason, 2011). Macrophyte alpha diversity is driven by local‐scale variation in environmental characteristics (H. Fu, Lou, et al, 2018; X. Liu & Wang, 2018; Stefanidis & Papastergiadou, 2019). Beta diversity refers to the differences of species composition among communities, and relates to environmental gradients or patterns (Whittaker, 1960).…”

“…Macrophyte alpha diversity is driven by local-scale variation in environmental characteristics (H. X. Liu & Wang, 2018;Stefanidis & Papastergiadou, 2019). Beta diversity refers to the differences of species composition among communities, and relates to environmental gradients or patterns (Whittaker, 1960).…”