At the end of September, JSC “Latvijas valsts meži” (LVM) began work in the European Union designated Natura 2000 area, the “Posolnīca” nature reserve, to restore the esker forest located there, which is rare throughout Europe. The biotechnical measures being carried out simultaneously will improve living conditions for the rare and protected plant species and capercaillie inhabiting the area.
The significant habitat diversification work will be carried out over a total area of 51.27 hectares – 49.4 hectares in the nature reserve and 1.87 hectares in the adjacent capercaillie micro-reserve. First, the density of trees in the area will be reduced; spruces, deciduous trees, and shrubs have grown thick, creating undesirable shading for the species living there, which require sunlight to survive. The work carried out will ensure a favourable environment for rare species found in Latvia, such as the dragonhead (Dracocephalum ruyschiana), forest and meadow pasqueflower, Hungarian sainfoin, and the common clubmoss. Several lekking sites for the protected capercaillie are also known in the “Posolnīca” area. For the capercaillie, just like for rare sun-loving plants, it is important that the forest remains sparse and open. Overly dense forest stands prevent the capercaillie from having a good view of the area, which is important for the bird to protect itself from natural predators.
“In younger forest stands, pine trees will be thinned to create sunlit openings, which will ensure the natural regeneration of pines and the restoration of a mosaic-like structure in the forest floor.
During the work, biologically old and large trees, junipers, as well as dead standing trees, stumps, and fallen logs will be preserved. Across the entire work area, clusters of fallen logs around the sites of especially protected, rare species will be kept intact and left undisturbed.
Part of the logging residue will be removed from the area and sent for further processing into wood chips for fuel, but another part of the logging residue will be burned on-site in several piles. Afterwards, patches of exposed mineral soil will be created in scattered locations throughout the nature reserve as homes for rare sun-loving species. These will be created next to existing sites of especially protected vascular plant species and in historical locations to increase the probability that the rare plants will return and bloom again, producing new seeds,” explains LVM Northern Latgale environmental planning specialist Diāna Marga.
Under the supervision of a nature expert
All work has been carefully planned by certified nature experts in the fields of plants, habitats, and birds, and coordinated with the responsible institutions. The locations of rare and protected species have been marked throughout the work area and must be treated with special care during the operations. Furthermore, several tasks in areas where rare species sites have been recorded will be supervised by a certified plant species expert.
Due to the large scale of the work and the vastness of the territory, logging operations will be carried out using standard forestry machinery. As much as possible, it will move along existing technological corridors, natural tracks, and compartment boundaries. If necessary, winding corridors will be created to bypass and protect preserved trees, sites of protected species, and clusters of fallen logs.
“After the management work in the “Posolnīca” esker forest habitat is completed, environmental conditions will change locally – in place of the once overgrown areas, there will be sparser stands where trees alternate with openings and preserved, untouched patches, creating not a uniform stand resembling a plantation, but a fine, diverse, lace-like pattern with varied structures,” explains habitat specialist and LVM board member Ieva Rove.
By carrying out these management measures, the objectives for the establishment of the especially protected nature area will be met – preserving a habitat that is very rare in Latvia and the European Union – coniferous forests on esker landforms – with its characteristic complex of rare and protected species in good, long-term condition.
Simulating natural disturbances
The existence of an esker forest requires natural disturbances – wind, fire, or regular disturbances in the forest floor, which maintain open sand and gravel areas. If these disturbances are lacking, pine forests gradually become overgrown, and the living conditions required by various plant and animal species disappear.
Therefore, under the guidance of LVM nature experts, a set of biotechnical measures has been developed to imitate natural disturbances. For example, by thinning the forest stand, the effects of wind and fire will be simulated so that rare plant species receive sufficient sunlight. Such a habitat should also have open, sunlit areas with exposed topsoil for rare sun-loving species to seed into. Naturally, these would be provided by fires, which are now limited; therefore, the work will purposefully reduce shading and create openings where piles of branches will be burned. Burning is also necessary to consume excess nutrients that are detrimental to this forest and promote overgrowth.
The “Posolnīca” nature reserve is one of 14 especially protected nature areas where, by the end of 2023, LVM is improving and restoring EU-significant habitats and promoting suitable conditions for the sustainable existence of protected species' habitats as part of the Cohesion Fund (CF) project “Implementation of management measures in especially protected nature areas and micro-reserves to improve the conservation status of habitats and species”. Similar work specifically for the restoration of rare esker forest has already been successfully carried out by LVM under this project in the “Numernes valnis” nature reserve and “Driksnas sils” nature park.