According to the data by International Union for Conservation of Nature (IUCN), the main reason for a decline in populations both of a hermit beetle and of other species of plants and animals dependent on veteran trees is the disappearance of suitable habitats.
Generally, old trees perish before the new equivalent ones grow up, in unused pastures veteran trees are overgrown and overshaded by shrubs and young trees of a poor value, while in the parks suffer from poor maintenance skills. Many issues can be named, however, it is more important to notice that long term conservation of habitats for species dependent on old veteran trees depends on two factors: longevity of veteran trees and the suitable age structure of remaining trees to replace veteran trees in the future. Therefore, to make an efficient and enduring ecological network for species dependent on veteran trees, one of the main actions is the maintenance of veteran trees and their immediate surroundings.
These actions will be implemented either by following nature management plans prepared for areas of importance for the hermit beetle habitat protection or specific maintenance plans for individual trees or groups of trees prepared by proficient tree care experts. By following measures of the nature management plans, actions will be taken in the areas officially designated as important for conservation of the hermit beetle – Kaunas Oak Park and slope of the Neris river by Verkiai.
Trees in the corridors, connecting the officially designated areas, will be selected for the maintenance according to such parameters:
• Veteran trees or groups of them, identified as existing or potential habitat of the hermit beetle. These trees are still of a fairly good condition and the main purpose of their maintenance would be to prolong life of the tree and, if necessary, re-establish environment suitable for spreading of species dependent on veteran trees;
• Veteran trees or groups of them without traces of hermit beetle but with potential of becoming a suitable habitat for species dependent on veteran trees. In the future these trees will supplement or replace the present trees, in this way ensuring long existence of important habitats.
• Trees or groups of them poorly maintained in the past but evaluated as potential habitats of a hermit beetle. Trees fallen in this category are mainly injured by the human activity and will be maintained by opening and cleaning up hollows filled with concrete or covered in any other way, restoring crowns of improperly trimmed trees etc. In this way, microclimate of the trees will be re-established accordingly improving vital functions of these giants.
Implementing maintenance actions of veteran trees and their environment, abandoned habitats will be restored, errors of poor past maintenance will be corrected, life of these trees will be prolonged as well as opportunities for survival of the species dependent on veteran trees and their spread in the ecological network will be created.