THE ROLE OF SPECIES COMPOSITION AND STRUCTURE OF GROUND COVER IN THE SPATIAL DISTRIBUTION OF GROUSE HABITATS
M. A. Novikova, Ya. A. Novikov
Federal State Budgetary Educational Institution of Higher Education «Saint-Petersburg State Forest Technical University», Saint Petersburg, Russian Federation
Keywords: black grouse, habitat, forage base, vegetation structure, forage plants, illumination, population viability
Abstract
It has been established that the black grouse ( Lyrurus tetrix (Linnaeus)), when choosing a habitat, is primarily oriented to the presence of a wide variety of forage plants (at least 8-11 species) that can meet the needs of both adults and young at different stages of development. At the same time, the share of fodder plants in the total phytomass of the grass and shrub layer should be at least 55-77 %. In addition, the most important factor is the optimal protective properties of habitats - low and sparse herbage improves visibility and maneuverability, and the mosaic alternation of edges and glades provides shelter from raptors. The presence of tree canopy also provides protection from predators. We quantified the threshold values of forage plant reserves, light availability under the forest canopy, and stand characteristics (closeness, height, and diameter), which can maintain a viable black grouse population. Quantitative indicators of species diversity, proportion of forage plants, phytomass reserves, lighting and stand structure necessary to maintain a viable black grouse population were identified. It was found that in case of predominance of one of the factors (either only forage base or only protective conditions) optimal habitats of the species are not formed. The most attractive habitats are those with a mosaic combination of open and closed areas that provide all the ecological needs of the species. The results can be used to optimize black grouse forest habitats by preserving biotope mosaic, maintaining the necessary level of illumination, and enriching the forage base.
|
