The environmental niche separation between charophytes and angiosperms in the northern Baltic Sea. Issue 1 (2nd January 2018)

• Record Type: Journal Article
• Authors: Herkül, Kristjan; Torn, Kaire; Möller, Tiia
• Is Part Of: Botany letters. Volume 165:Issue 1(2018)
• Page Start: 115
• Page End: 127
• Publication Date: 2018-01-02
• Subjects: Submerged aquatic vegetation -- brackish water -- charophytes -- angiosperms -- niche separation -- coexistence -- specialization -- habitat; Botany -- Periodicals; Botany; Botany; Electronic journals; Periodicals; Periodical; 580
• DOI: 10.1080/23818107.2017.1399824
• Languages: English
• ISSNs: 2381-8107

Abstract

Abstract: Charophytes and angiosperms are the most important primary producers and habitat modifiers in shallow soft-bottom fresh and brackish water bodies. The sheltered bays of the low-salinity northern Baltic Sea provide unique habitats, where euryhaline macrophytes of both freshwater and marine origin can thrive. The regional cohabitation of several species, with generally similar biological traits, raises questions about the mechanisms underlying the coexistence. Generally, sympatric populations rely on niche separation to reduce competition pressure that, in turn, facilitates long-term coexistence. A large benthos biomass data-set, covering the whole extent of the Estonian sea area, the northern Baltic Sea, together with a set of 13 environmental variables (bathymetrical, hydrodynamical, chemical, biological) was used to test the potential niche separation between regionally coexisting charophytes and angiosperms. A constrained correspondence analysis indicated both the grouping of some species and a distinct niche separation of others. The niche centers of angiosperms Zostera marina, Zannichellia palustris, and Potamogeton perfoliatus diverged most strongly from all the other species, while those of Chara connivens and Myriophyllum spicatum nearly coincided. Depth, salinity, and duration of ice were the most influential environmental gradients that discerned the environmental niches of the species. Comparison of the breadths of the environmental niche spaces, occupied by the studied species, showed highly species-specific results. Within the studied species, Z. palustris and Z. marina had the lowest niche specialization, and C. connivens had the highest specialization. Altogether, among the angiosperms the variability of the environmental niche breadth was higher compared to the charophytes.