GroundEco partners visit pilot areas in Estonia and Latvia

The objective of the project is to enhance the sustainable management of common groundwater resources and associated ecosystems in the transboundary Gauja-Koiva river basin. It is planned that Latvian partners will adapt the existing methodology, developed by Estonian partners, in order to identify from groundwater dependent ecosystems and later in cooperation with the project partners will test it in pilot areas - Kazu leja in Priekuli district, Latvia and in Matsi spring mire complex in Estonia.

This partner meeting was held to jointly visit both pilot sites, discuss fieldworks carried out so far and additional research needed. In Matsi spring mire territory active research work is currently being carried out by Estonian partners studying the structure of groundwaters, seasonal water level changes and to identify potential loads. Representatives of the Geological Survey of Estonia and the Tallinn University Institute of Ecology demonstrated the installed groundwater monitoring network, explained the geology of territory and research methodology, as well as the data obtained so far.

Visiting the pilot site in Latvia - Kazu leja, project partners marked the main similarities between the pilot territories of both countries, thus analyzing the possibility to ensure correct verification and interpretation of methodology in both pilot areas. The visit was led by the lead researcher of the University of Latvia Andis Kalvans, who later presented the data about Kazu leja, its geological characteristics and planned research. In turn, Nature Conservation Agency ecologist Agnese Priede emphasized the importance of vegetation research in these studies.

Pilot area description

Matsi, GroundEco pilot area in Estonia

The GroundEco project pilot area in Estonia, Matsi, consists of three spring-fed mire polygons on the lower part of slope in Mustjõgi River valley, a tributary of Koiva (Gauja) River. In total the spring mire covers 4.6 hectares, the largest patch covers 3.4 hectares. Deposits (layers) of tufa and iron (III) oxide are found during the most recent investigation. The substrate conditions in the spring mire are alkaline, with plant species composition that indicates carbonate-rich conditions (pH varies from 6.9 to 8), e.g. vascular plants Epipactis palustris, Dactylorhiza spp. The dominating vascular plant species are sedges Carex lasiocarpa and Carex rostrata, Menyanthes trifoliata, but many other species such as Equisetum fluviatile, Myosotis palustris, Stellaria crassifolia, Cardamine amara, etc. are present. Patches of Carex paniculata tussocks are present in some sections perhaps indicating more fluctuating water table conditions. In moss layer, Aulacomnium palustre, Hylocomium umbratum, Tomenthypnum nitens, Calliergonella cuspidata, Plagiomnium spp., etc. occur. In some patches on the mire margins Sphagnum warnstorfii hummocks with Oxycoccus spp. and Drosera spp. are found.

The spring mire is in rather good, near-natural condition, however, it is evidently affected by drainage ditches at the margins and beaver activity.

Most of spring mire is open, treeless, but the areas around ditches are overgrown with forest (predominantly birches with admixture of spruces). The drained parts are typical with drier conditions and absence of some ecosystem components (species, mire structures) which may be found in open, wettest parts.

Kazu leja, GroundEco pilot area in Latvia

The GroundEco project pilot area in Latvia, Kazu leja, that is referred as Kazu grava (~100 hectares), is a well-pronounced subglacial valley that adjoins Gauja primeval valley. The slopes of valley are overgrown with mixed forest, whereas the valley bottom is covered by fen and grassland vegetation. At the north-western end of the Kazu leja Lībāni-Jaunzemji tufa deposites are located. Once it had one of the largest volumes of tufa reserves in Latvia. Tufa extraction took place during the first half of the 20th century and probably earlier as well. Tufa deposits filled a side ravine of the Kazu leja as well as formed outwash cone at the base of the main valley. Today most of the tufa is extracted leaving largely disturbed overgrown landscape of pits ponds and channels. Notably an outcrop of solid tufa and cascading waterfall on top of it is an artefact of mining as well.

On the southern slope of Kazu leja, carbonate-rich petrifying springs are discharging both at the bottom and upper part of the slope. The springs form specific habitats, mostly of small size, with peculiar species composition which depend on presence of tufa deposits and permanently moist air conditions (plant communities Cratoneurion commutati and Carici remotae). The plant communities are dominated by mosses, such as Cratoneuron commutatum, Pallustriella commutata, Pellia endiviifolia, etc.

The largest spring complex in the western part of Kazu leja valley forms two waterfalls with spring-specific vegetation, however, the largest waterfall is heavily trampled, thus part of the vegetation is regularly unfavourably affected by many visitors. In addition, melioration system from adjacent fields is discharging in the same water course raising concerns for excess nutrient input.

On the bottom of the valley, there is a spring-fed fen with a small, strongly altered stream. The fen has been heavily affected by drainage (both sub-surface drainage and ditch) and peat extraction in the past, thus most or even all the original vegetation has been destroyed. Today the area is affected also by beaver activity. The vegetation has formed on fen peat, but the substrate and hydrological conditions must be explored in detail during the pilot study. In the lowest part with wet conditions, the vegetation forms Scheuchzerio-Caricetea fuscae plant community dominated by sedge Carex rostrata with negligible moss cover (indicates habitat alteration). Patches of dense reed Phragmites australis stands are present. The upper part of the valley bottom is dominated by Phalaris arunindinacea, a graminoid species of moderately moist conditions. Throughout the valley, invasive alien plant species, such as Heracleum sosnowskyi, Impatiens glandulifera and Solidago canadensis, are spreading, threatening the habitats and spring-specific species and communities.

The wetland at the base of the main valley is obviously fed by the calcareous springs emerging at the slopes of the Kazu leja as well as precipitation. Another water source might be groundwater discharging at the base of valley masked by the vegetation and peat deposits. The proportional contribution of these water sources both in terms and water quantity and minerals is not known and will be investigated during the pilot study. The springs with highest hypsometrical level of discharge cold be affected by diffuse agricultural pollution as well.

Kazu leja is known for its richness in rare, protected species, some of them strongly related to groundwater-dependent ecosystems, e.g. Primula farinosa, Stellaria crassifolia, several orchids. However, most of species records are rather old and outdated. A detailed investigation is necessary to explore the current condition. The abiotic site conditions and biotic components (vegetation, invertebrates) will be explored in detail during summer 2019.

The author of pilot site descriptions: Agnese Priede (Nature Conservation Department) and GroundEco project team.

To implement GroundEco activities together will work representatives from Latvian Environment, Geology and Meteorology Centre (lead partner) (LV), Ministry of the Environment (EE), Geological Survey of Estonia (EE), Tallinn University (EE), Nature Conservation Agency (LV), University of Latvia (LV) and Vidzeme Planning Region (LV).

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Project "Joint management of groundwater dependent ecosystems in transboundary Gauja-Koiva river basin” (GroundEco) is being implemented within the Interreg V - A Estonia - Latvia Cross - border cooperation programme 2014 – 2020 (www.estlat.eu). More about project (HERE). 

This publication reflects the views of the author. The managing authority of the programme is not liable for how this information may be used.