The influence of hydromorphological modifications of the littoral zone in lakes on macrophytes

Abstract

The study aimed at determining the influence of hydromorphological modifications of the littoral zone in lakes on the occurrence and quantitative diversity of macrophytes. The field research was carried out at the peak of the growing season (June -September) between 2006 and 2009. Altogether, 457 transects were studied, located in 5 lakes. Studies on the hydromorphology were performed with the method of Lake Habitat Survey (LHS), and on macrophytes − with the method of transects. The studied sites were divided into 3 groups of different intensity of morphological transformations. The identified groups constituted the starting point for the analysis of influence exerted by transformations on macrophytes. The obtained results indicate that hydromorphological modifications * Corresponding author: szyjus.up@gmail.com of lakes are an important ecological factor affecting the occurrence and quantitative diversity of macrophytes. The transformations recorded in the studied reservoirs resulted mostly from recreational exploitation. They were responsible for mechanical elimination of dominant species, which led to an increased number of taxa, synanthropization and an average level of hemeroby as well as a decrease in the total vegetation cover. Helophytes were the most negatively affected group by the transformations, which reduce their contribution in the vegetation cover, whereas macroscopic filamentous algae and elodeids were positively affected.

Disentangling and ranking the influence of multiple stressors on macroinvertebrate communities in a tropical river system

“…Freshwater ecosystems are threatened by a wide range of anthropogenic stressors such as overexploitation, water pollution, land-use change (e.g., urbanization), habitat degradation, damming, and climate change (Schäfer, Kühn, Malaj, König, & Gergs, 2016). Consequently, spatial contrasts in lotic macroinvertebrate assemblages have been ascribed to physico-chemical and hydromorphological conditions (river fragmentation, morphological alteration, and hydrological regime pressures-including water abstraction and flow regulation) (Garcia de Jalón et al, 2013;Jusik & Macioł, 2014). Stream ecology research has therefore moved from merely identifying forces structuring spatial patterns in community composition to management-oriented studies of multiple stressor effects (Pavlin, Birk, Hering, & Urbanič, 2011).…”

Emergent wetland vegetation data recording: Does an optimal period exist?

“…It is related to environmental changes and their interactions with the vegetation and other parts of the wetland ecosystem along the temporal gradient (Hrivnák, ). Considering that emergent wetland communities are typical for the littoral zone (Jusik & Macioł, ), naturally or artificially initiated changes in water regimes can be considered as one of the factors responsible for their variability (Sutela, Aroviita, & Keto, ; Zohary & Ostrovsky, ). The frequency with which the hydrophase and/or littoral ecophase alternate with the limosal and/or terrestrial ecophase and the duration of certain ecophases are considered to be the components of the water regime that have the greatest influence on seasonal change.…”

Assessing the ecological effects of hydromorphological pressures on European lakes

“…The metrics are similar to those used in river assessment (e.g., Böhmer et al 2004) and describe the decrease of taxon richness and diversity (Brauns et al 2007, increase of nonnative taxa (Pilotto et al 2015, Pätzig et al 2018, Porst et al 2019, increase of r-strategists (Urbanič et al 2012, and a change from more specialized and sensitive taxa toward generalists and tolerant taxa (Brauns et al 2007, Urbanič 2014. Few studies address the effects of man-made alterations to lake shorelines on macrophyte (Jusik and Macioł 2014) and fish communities (Gafny et al 1992, Mehner et al 2005, Lewin et al 2014, Cummings et al 2017.…”