Belova, O. 2005. Foraging Character of Deer Cervidae and Brown Hare Lepus europaeus on the Littoral Area of Pure Pine Forests in Lithuania. Baltic Forestry, 11 (2): 94-108

The main herbivorous mammals as Cervidae go in with hares Leporidae into general trophic chain as primary consumers. The basic interaction between these animals and forest woody vegetation mostly evidences in the feeding relations. Therefore the feeding character in herbivorous animals is the important item of this study. Limited factors could come drivers of the animal impact to forest. On the other hand, the interaction between animals and forest woody plants requires not only elements of this interaction but also an environment where this interaction comes to pass. Therefore, the habitat preference should be considered. We aimed to reveal the foraging character of deer and hares, and assess the animal - forest woody plants’ interaction by considering the above-mentioned notes. We employed the integrated method of belt transects (sample unit is 100 x 4 metres) and sample plots (50 x 2 metres, or 100m²). The method of pellet group count has been used to assess the number and distribution of the local populations of investigated animal species, the age structure and sex ratio of local populations of moose and red deer, and age structure of roe deer local population. We identified animal age and sex by pellet groups. Woody plants and their shoots within the feeding space of animals (that is from h = 0,1 to 2,2 m) were counted dividing damaged and untouched shoots. Browsing intensity I, and the share of woody species in animal diet P, were calculated by the consumption of all species of forest woody vegetation. Habitat preference of stands of the different age classes, composition and forest site types were estimated. The total number of sample plots is 504, and the total length of the route is 79.9 km on the study area of 2,736 hectares. The specific climatic and geomorphologic diversity of landscape and local conditions as well as the absence of agricultural landed property determine the low carrying capacity and specific structure of the local fauna and their adaptations, as the mixed forest-forest edge ecotype in hares and forest ecotype in roe deer. The coexistence of forest plants and animals is directly and indirectly influenced not only by the determined abiotic and biotic factors but also by human factors including forest management, hunting and its restrictions, supplemental feeding in winter, picking of mushrooms and berries, and other recreational activities. The mentioned activities are particularly obvious on the study territory while the forests are managed by the separate regime that is approved by the legal acts for protected areas. The animal density is less than the permissible density in pure pine forests while there is the aberrant sex ratio and age structure in local populations. That is the indicator of disfavour in living conditions. Habitat preference values and plant consumption intensity varied temporally depending on the stand composition, forest site type and forest age as well as variability of the main weather parameters. The main criteria of the animal-plant interaction are the consumption of shoots and the browsing intensity of the main woody species. The shoot consumption in conifers more than 40-50% and more than 20-30% in deciduous species is the criterion of the irreversible decline in the certain species (e.g. Populus tremula, Frangula alnus).

Key words: herbivores, pure pine forests, protected area, population parameters, habitat preference, browsing intensity, level of shoot consumption.