Background information of groundwater dependent ecosystems (GDE) on Estonian Gauja-Koiva river basin Elve Lode & Martin Küttim
Content Some facts about the Koiva river Something about GDEs Ecological data base of GDEs in Koiva river catchment Known spring-fens in Koiva river catchment
Location of Koiva river and it catchment Length of the Koiva river (in Estonia) = 26 km, i.e. between 228-254 km from the mouth of the Gauja river Catchment area (in Estonia) = 1302 km 2 (ca 25% from all Gauja river catchment) (EELIS data base; Eesti NSV jõgede, ojade ja kraavide ametlik nimestik, 1986)
Koiva river stream network The longest river in the catchment is the Mustjõgi river (L= 84 km, F= 1820 km 2, in Estonia 994 km 2 ) Totally there are about 50 flowing water bodies in the Koiva river basin data base, but 80% of them are brooks (EELIS data base; Eesti NSV jõgede, ojade ja kraavide ametlik nimestik, 1986)
Groundwater-Dependent Ecosystems (GDEs) are ecosystems that rely upon groundwater for their continued existence Groundwater-Dependent Terrestrial Ecosystems (GWDTEs) are wetlands which critically depend on groundwater flows and /or chemistries Prerequisites for occurrence of GDEs or GWDTEs P 1. General atmosphere-ground conditions a) Availability of sufficient water (mainly from the atmosphere) b) Availability to form recharge and discharge areas on the landscape
2. Interaction between general hydro-geological conditions and surface topology, i.e. type of GDEs or GWDTEs a) Availability to form regional groundwater dependent ecosystems on the landscape or a) Availability to form local groundwater dependent ecosystems on the landscape https://wetlandinfo.ehp.qld.gov.au/wetlands/ecology/aquatic-ecosystems-natural/groundwater-dependent/springecosystems-of-the-surat-and-southern-bowen-basins/#top-overview
3. Ecosystem dynamics within non-disturbed atmosphere-hydro-geologic-surface topology conditions, - as a reference a) Dynamics of discharge area hydrology, i.e. water quantity and quality in wet phase and dry phase b) Dynamics of ecosystems plant cover, i.e. horizontal zonation and it dynamics in wet phase and dry phase Example of ecological zonation of regional groundwater dependent ecosystem on the ground 1. Zone of permanent inundation and/or flowing discharge 2. Zone of aeration and reduced saturation 3. Saturated shoulder of the mound 4. Non-wetland area 5. Discharge tail during the wet phase 6. Wetland to non-wetland transition zone 7. Discharge tail during dry phase 8. Discharge tail during the dry phase https://wetlandinfo.ehp.qld.gov.au/wetlands/ecology/aquatic-ecosystemsnatural/groundwater-dependent/spring-ecosystems-of-the-surat-and-southern-bowenbasins/type-1 Type 1a Wetlands located in off-stream environments, within floodplains
Example of ecological zonation of regional groundwater dependent ecosystem Example of ecological zonation of mixed groundwater dependent ecosystem and influenced by surface water flows Type 2 Semi-permanent brackish, palustrine wetlands with minor wetland soils and minor vegetation cover, mainly connected to regional groundwater systems Type 3 Permanent to semi-permanent riverine wetlands with minor wetland soils and moderate vegetation cover, sourced from local and regional groundwater systems and significantly influenced by surface water flows https://wetlandinfo.ehp.qld.gov.au/wetlands/ecology/aquatic-ecosystems-natural/groundwater-dependent/spring-ecosystems-of-the-surat-and-southern-bowen-basins/#type type-2 & type-3
Examples of ecological zonation of local groundwater dependent ecosystem Type 4 & 5 Semi-permanent fresh riverine-to-palustrine wetlands with minor wetland soils and moderate vegetation cover, mainly connected to local groundwater systems. https://wetlandinfo.ehp.qld.gov.au/wetlands/ecology/aquatic-ecosystems-natural/groundwater-dependent/spring-ecosystems-of-the-surat-and-southern-bowenbasins/#type 4 & type-5
Questions needed to answer * What is the list of the terminology what we will agree to use? Groundwater-Dependent Ecosystems (GDEs) (are ecosystems that rely upon groundwater for their continued existence) or Groundwater dependent terrestrial ecosystems (GWDTEs) (are wetlands which critically depend on groundwater flows and /or chemistries) * What is the spring mire? Not all fens are the spring mires and not all springs are forming spring mires! * What are the threshold values (TVs) for the GDEs or GWDTE? (Groundwater dependent terrestrial ecosystem (GWDTE) threshold values (TVs) are groundwater chemical concentrations which have been derived from empirical evidence) * How to mesaure and report the ecosystem conditions? 1) General atmosphere-ground conditions 2) Interaction between general hydro-geological conditions and surface topology 3) Ecosystem dynamics within non-disturbed atmosphere-hydro-geologic-surface topology conditions, as a reference 4) Disturbances
Ecological data base of Koiva river catchment Red polygons 1. Matsi spring mire 3 areas 2. Varstu spring mire 1 area Green polygons 3. 1411A, 1421 4. 3131, 3113
Spring fens in Estonia (Paal & Leibak 2011) Spring fens in South-Estonia (Ilomets et al 2012) Symbols: green dots - calcareous spring fens in good state; blue squares - drained sites; red triangles - abandoned tufa deposits or damaged sites
Spring fen vegetation
Spring fen vegetation: community composition Cotton-grasses: Eriophorum angustifolium E. latifolium Schoenus ferrugineus Sesleria caerulea Sedges: Carex davalliana C. hostiana C. dioica C. diandra C. rostrata Pinguicula vulgaris etc
Environmental factors controlling the vegetation composition High water table Low fluctuation of water table Stabile temperature Low availability of nutrients High ph Precipitation of tufa (?)
Water table ~ vegetation (Küttim 2013)
Spring fens in Koiva catchment Matsi Varstu More?
Matsi spring fens (Ilomets et al 2014) Location: Võru county, Varstu parish, Matsi village Geologically: in Võru-Hargla valley, by the Mustjõgi river Area: 4.6 ha (in three parts) Northern part 3.4 ha In a relatively good state, but surrounded by the ditches and a road Mostly open habitats, but wooded in drier part Vegetation: Dominated everywhere by Menyanthes trifoliata Sedges (Carex lasiocarpa, C. rostrata) Abundant Epipactis palustris (protected II cat.!)
Matsi spring fens (Ilomets et al 2014)
Matsi spring fens (Ilomets et al 2014) Oppressional springs (igritsevad) in the northern and central part, overflowing water in the south Tufa precipitation in the northern and central part, iron precipitation in the south Water table near surface (5...11 cm below surface) Minor slope (1 m per 50 m) ph 6.9...7.7 Sedge-brown moss peat with tufa layers
Thank You!