Elve Lode & Martin Küttim
Background information of groundwater dependent ecosystems (GDE) on Estonian
Gauja-Koiva river basin
5-6 July, 2018, Salacgriva, Latvia
5-6 July, 2018, Salacgriva, Latvia
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
5-6 July, 2018, Salacgriva, Latvia
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 km2 (ca 25% from all Gauja river catchment) (EELIS data base; Eesti NSV jõgede, ojade ja kraavide ametlik nimestik, 1986)
5-6 July, 2018, Salacgriva, Latvia
Koiva river stream network
The longest river in the catchment is the Mustjõgi river (L= 84 km, F= 1820 km2, in Estonia 994 km2)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)
5-6 July, 2018, Salacgriva, Latvia
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
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
Prerequisites for occurrence of GDEs or GWDTEs
5-6 July, 2018, Salacgriva, Latvia
2. Interaction between general hydro-geological conditions
and surface topology, i.e. type of GDEs or GWDTEsa) 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/spring-
ecosystems-of-the-surat-and-southern-bowen-basins/#top-overview
5-6 July, 2018, Salacgriva, Latvia
3. Ecosystem dynamics within non-disturbed
atmosphere-hydro-geologic-surface topology conditions, - as a referencea) 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
Type 1a Wetlands located in off-stream environments,
within floodplains
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-ecosystems-
natural/groundwater-dependent/spring-ecosystems-of-the-surat-and-southern-bowen-
basins/type-1
5-6 July, 2018, Salacgriva, Latvia
Example of ecological zonation of regional
groundwater dependent ecosystem
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
Example of ecological zonation of mixed
groundwater dependent ecosystem and
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
5-6 July, 2018, Salacgriva, Latvia
Type 4 & 5 Semi-permanent fresh riverine-to-palustrine wetlands with minor wetland soils and moderate vegetation cover,
mainly connected to local groundwater systems.
Examples of ecological zonation of local groundwater dependent ecosystem
https://wetlandinfo.ehp.qld.gov.au/wetlands/ecology/aquatic-ecosystems-natural/groundwater-dependent/spring-ecosystems-of-the-surat-and-southern-bowen-
basins/#type 4 & type-5
5-6 July, 2018, Salacgriva, Latvia
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
5-6 July, 2018, Salacgriva, Latvia
„Ecological data base“ of Koiva river catchment
Red polygons1. Matsi spring mire – 3 areas
2. Varstu spring mire – 1 area
Green polygons3. 1411A, 1421
4. 3131, 3113
5-6 July, 2018, Salacgriva, Latvia
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 fens in Estonia (Paal & Leibak 2011)
5-6 July, 2018, Salacgriva, Latvia
Spring fen vegetation
5-6 July, 2018, Salacgriva, Latvia
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
5-6 July, 2018, Salacgriva, Latvia
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 (?)
5-6 July, 2018, Salacgriva, Latvia
Water table ~ vegetation (Küttim 2013)
5-6 July, 2018, Salacgriva, Latvia
Spring fens in Koiva catchment
• Matsi
• Varstu
• More?
5-6 July, 2018, Salacgriva, Latvia
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.!)
5-6 July, 2018, Salacgriva, Latvia
Matsi spring fens (Ilomets et al 2014)
5-6 July, 2018, Salacgriva, Latvia
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
5-6 July, 2018, Salacgriva, Latvia
5-6 July, 2018, Salacgriva, Latvia
5-6 July, 2018, Salacgriva, Latvia
Thank You!