The Aukštumala raised bog

  The Aukštumala raised bog is situated in the western part of Lithuania, in the Kintu Silutes District in the northern part of the Nemunas Delta Regional Park (6 km north-west of Silutes between the lake Krokų Lankan Tenenis and the lower reaches of the river Minija .

CA Weber & Augstumal

   The world’s first scientific monograph was written about the raised bog of Aukstumala (CA Weber 1902 : Über die Vegetation und des Enstehnung des Hochmoors von Augstumal im Memeldelta mit auf vergleichenden Ausblicke auf andere Hochmoore der Erde).

Weber Augstumal

Protection & Threats

   Peat mining was carried out in Aukstumala for over 100 years, with negative ecological impacts also on the protected, western part of the bog. Since 1995 the western part is protected as the Aukštumala telmological reserve. The reserve was established in order to preserve and restore the Aukštumala high moor ecosystem, to safeguard valuable habitats for rare and endangered species of both flora and fauna.

The raised bog, as well as the entire Nemunas Delta Regional Park, are included in the Ramsar Convention, and figure as Natura 2000 areas.

 

 

Habitats of European importance

Habitats of European importance are protected by the base of Habitat directive 1992 92/43/EEB. The main aim of this directive is to ensure favourable protection status of habitats and species by all means, connecting them to a net of protected areas called NATURA 2000. There are 53 types of European importance areas in Lithuania.

5 types of habitats of European importance can be found in Aukštumla Thelmological Reserve: active raised bogs (7110*), degraded raised bogs (7120), bog woodlands (91D0*), natural dystrophic lakes (3160), depressions on peat substrates of the Rhynchosporion (7150).

Pavadinimas

Active raised bogs (7110*) occupies less than half (47%) of reserve’s territory. These are not affected or very slightly affected, very acid, poor in minerals, ombrotrophic raised bog habitats. Treeless open active raised bog habitats with well expressed Sphagnum moss cover and plenty of Oxycoccus palustris, insectivorous plants Drosera rotundifolia, D. anglica, red listed plant Trichophorum cespitosum, Rhynchospora alba, Andromeda polifolia and small Pinus sylvestris trees are mostly found in the western and central parts of the reserve.

 Degraded raised bogs (7120*) are mostly found in the edges of the reserve, places which are adjacent to peat mining fields, territories which were drained by the ditches or in any other place where hydrology is strongly affected by human activity. These habitats occupy 12% of the reserve‘s territory. 

Degradavusi aukštapelkė

Due to the changes of the hydrological regime, the process of mineralization accelerates. As a result the coverage of Sphagnum mosses start to decrease and the growth of trees like Pinus sylvestris, Betula pubescens, B. pendula and schrubs like Caluna vulgaris intensify. These habitats are capable to restore to active raised bogs if hydrological regime will be restored to a level which is favorable to bog forming plant species.

Bog woodlands (91D0*) covers less than 1 % of the reserve‘s territory. These woodlands penetrate to the active raised bog habitats, where layer of peat is thinner and more mineralized. 

DSC03991

Ground Water level is constantly high, although not so high as in the surrounding active raised bogs. Pinus sylvestris dominates the tree layer with a strong intermixture of Betula pubescens and B.pendula. Ledum palustre, Vaccinium uliginosum V. vitis-idaea, Rubus chamaemorum in the layer of herbs and shrubs. The moss cover consist of Sphagnum species mostly.

 

 Raised bog Aukštumala is famous for abundance of natural dystrophic lakes (3160). Although, there are 380 lakes counted of various size (the biggest 0,20 ha) and ecological condition, they overall cover only 1% of reserve’s territory.

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 Dystrophic lakes are mostly found in the surrounding of active raised bogs an bog woodlands in the eastern and western part of the Aukštumala. The biggest lakes are in the eastern part of reserve, which is suffering from the negative hydrological impact from adjacent peat mining fields

Pioneer habitats of depressions on peat substrates of Rhynchosporion (7150) are found in places where freeze, water or fire makes damage to the peat surface. Fragments of these habitats occur in the northeast part (burnt place) of the bog. 

Plikų durpių saidrynaii 7150 tikslesne

The surface of the peat is covered by sparse layer of grass, dominated by Rhynchospora alba. Sporadic individuals of Drosera rotundifolia, D. Anglija can also be found. Coverage of mosses is poor.

  Almost 40% of reserve‘s territory are strongly damaged or degraded and therefore do not satisfy requirements for habitats of European importance. These habitats occur in the edges of the reserve, where influence of anthropogenic activity (drainage ditches, peat mining etc.) is evident. Trees and shrubs grows intensively in 40–400(500) m area around the bog

Nature values

  More than 200 plant species are found in Aukštumala. This bog still has a high importance for protected species. 10 plant species listed in Lithuanian Red List grow here. Deergrass (Trichophorum cespitosum) population is probably in the best condition. This plant forms Eriophoro-Trichophoretum cespitosi communities in the treeless open active raised bog habitats. Aukštumala is also the only raised bog in Lithuania where cross-leaved Heath (Erica tetralix) and Sphagnum imbricatum can be found. In the surroundings of dystrophic lakes Tall Bog Sedge (Carex magellanica) was inventoried in 2012. 

Tyrulinė erika (Erica tetralix)  J. Sendžikaitė

Erica tetralix

  Aukštumala is a part of NemunasDeltaRegionalPark, which is considered as very important migratory rout not only for bird species, but for bats and butterflies as well. 4 mammal, 18 bird and 5 insect species listed in Lithuanian Red List can be found here.

  tikutis_kamanosTerritory is extremely important for some of the bird species, which require presence of typical raised bog habitats. In open areas and in the woods, which surrounds the bog, curlews (Numnius arquata), goldens plowers (Pluvialis apricaria), black grouses (Tetrao tetrix), cranes (Grus grus), wood sandpipers (Tringa ochropus), great grey shrikes (Lanius excubitor) can be met during the migration or breeding period.

Aukštumala in map