A diatom functional-based approach to assess changing environmental conditions in temporary depressional wetlands

Abstract

Functional-based assessments to identify the effects of human-induced disturbances on diatom communities are increasingly used. However, information on the response of functional groups to natural disturbances in temporary depressional wetlands is limited although important for the development of temporary wetland biological assessments. We assessed how diatom life-form and ecological guilds responded to a seasonal hydrological and hydrochemical gradient in three least human-disturbed, temporary depressional wetlands. We assigned species to their respective life-form and ecological guild groups and compared metric composition along the gradient. Overall, temporal variability in alkalinity and ionic composition, essentially Na + , as well as hydrological factors, wetland depth and total relative evapotranspiration (ETo), were good predictors of diatom species and functional group composition. Low profile guilds dominated by pioneer life-forms showed the strongest relationship with higher disturbance levels (i.e. increasing Na + , alkalinity with a decrease in depth). Similarly, the planktonic guild and tube-living, rosette and adnate lifeforms dominated at higher disturbance levels whereas the high profile diatoms displayed the reverse trend. Our study shows the effectiveness of functional-based assessments beyond traditional species-based approaches for understanding and predicting community responses to temporal changes in environmental conditions. We also highlight the benefit of using both life-forms and ecological guilds where a broad set of metrics can enhance our 2 understanding of the mechanisms relating diatom composition to environmental stressors and provide signs of underlying ecological processes.

Expanding the trait-based concept of benthic diatoms: Development of trait- and species-based indices for conductivity as the master variable of ecological status in continental saline lakes

“…The number of studies using trait-based approaches in benthic algal communities has been rapidly increasing (e.g. Gottschalk and Kahlert, 2012, Riato et al, 2017, Zorzal-Almeida et al, 2017. The first multimetric trait-based indices of benthic diatoms were developed without the geographical extension to Europe (Potapova and Carlisle, 2011;Tapolczai et al, 2017).…”

“…Berthon et al, 2011, Lange et al, 2016, Soininen et al, 2016, Tapolczai et al, 2017. As to lakes, the trait-based approach of benthic diatoms has only been applied in very few cases (Gottschalk and Kahlert, 2012;Rimet el al., 2016;Riato et al, 2017;Zorzal-Almeida et al, 2017).…”

The Use of Winter Water Temperature and Food Composition by the Copepod Cyclops vicinus (Uljanin, 1875) to Provide a Temporal Refuge from Fish Predation

“…Winter supports a lower aquatic macrophyte abundance and bountiful nutrients, which makes it a suitable season for Bacillariophyceae growth even in low water temperatures [ 71 ]. Thus, winter dominance of Bacillariophyceae is found in various regions, including Korea [ 71 , 72 , 73 ].…”

Benthic Diatoms in River Biomonitoring—Present and Future Perspectives within the Water Framework Directive

“…In recent years, trait-based approaches have started to emerge as a potential tool for ecological status/quality assessment [94][95][96][97]. Traits are defined as "any morphological, physiological or phenological measurable feature at the individual level" [98] and are more tightly linked to ecosystem functioning than species; thus, their study provides a more integrative ecological assessment potential at the ecosystem level [88].…”