Relations between vegetation and water level in groundwater dependent terrestrial ecosystems (GWDTEs)

Abstract

Alkaline wetlands and fens are groundwater dependent, terrestrial ecosystems (GWDTEs) existing throughout the temperate zone. They contain a large number of protected and endangered plant species and their ecological status is threatened by insufficient groundwater quality and quantity. However, management and conservation of fens are constrained by limited knowledge on the relations between vegetation and measurable hydrological conditions. This study investigates the relations between vegetation and water level dynamics in groundwater dependent wetlands in Denmark. A total of 35 wetland sites across Denmark were included in the study. The sites represent a continuum of wetlands with respect to vegetation and hydrological conditions. Water level was measured continuously using pressure transducers at each site. Metrics expressing different hydrological characteristics, such as mean water level and low and high water level periods, were calculated based on the water level time series. A complete plant species list was recorded in plots covering 78.5 m 2 at each site. Community metrics such as total number of species and the number of bryophytes were generated from the species lists and Ellenberg Indicator scores of moisture, pH and nutrients were calculated for each site. The water level correlates with the number of typical fen species of vascular plants, whereas bryophytes are closer connected to the stable water level conditions provided by groundwater seepage. The water level variability is proved to be a significant limiting factor for species diversity in wetlands, which should be considered along with the fertility in order to access the habitat quality. The study provides new insight in the water level preferences for GWDTEs which is highly needed in the management and assessment of anthropogenic damage to these ecosystems.

The Ecological Relationship of Groundwater–Soil–Vegetation in the Oasis–Desert Transition Zone of the Shiyang River Basin

“…As vegetation growth relies on water, groundwater is an important ecological water source in addition to limited precipitation [6][7][8]. Groundwater depth (GWD) is an important factor affecting the growth of ecological vegetation [9][10][11][12]. Greater GWD leads to lower vegetation fractional coverage (VFC) [9,11], whereas lesser GWD causes salinization [13], which can restrict vegetation growth and affect VFC.…”

Comparison of commonly used ecological scales with the Belgard Plant Ecomorph System

“…A value set of environmental factors for vascular plants in Central Europe is defined in this scale (Ellenberg 1979(Ellenberg , 1988Ellenberg et al, 1991). It is widely used both in Europe and adjacent territories (Kalusová et al, 2016;Berg et al, 2017;Britton et al, 2017;Čeplová et al, 2017;Chmura et al, 2017;Hülber et al, 2017;Muir, 2017;Pruchniewicz, 2017;Santini et al, 2017;Johansen et al, 2018;Roeling et al, 2018). Its modern version was supplemented and adapted by many foreign authors (Douda et al, 2016;Dyderski et al, 2016;Ewald & Ziche, 2016;Koch et al, 2016;Van Dobben & de Vries, 2016;Elst et al, 2017;Mitchell et al, 2017;Vitasović Kosić et al, 2017;Kılıç et al, 2018;Kosanic et al, 2018).…”

Evidence of karstification in chalk and limestone aquifers connected with stream systems and possible relation with the fish ecological quality ratio in Denmark

“…Around 15% of the ice-free continental land surface consists of carbonate rocks (Goldscheider et al 2020), and more than 9% of the world's population depends on water from karst aquifers (Stevanovic 2019)-for example, groundwater from karst systems in Southern Europe and South-West China contributes 50% or more to regional freshwater supplies (Lu 2007;Hartmann et al 2014;Chen et al 2017;Kurkova et al 2019). Clean and sufficient groundwater from these important aquifers in Denmark and elsewhere contribute to the maintenance of the ecological status in groundwater-dependent ecosystems associated with springs, river valleys, and the river network (Bonnaci et al 2009) throughout wet and dry seasons in a cold climate (Graeber et al 2017;Johansen et al 2018) and warmer climate (Liu et al 2009). A recent assessment of the quantitative status of Danish groundwater bodies in relation to the European Water Framework Directive River Basin Management Plans has revealed that about six of the 30 large chalk and limestone groundwater bodies are in poor quantitative status due to overexploitation of the aquifers (European Commission 2006;Henriksen et al 2021a).…”