Practical verification of food supply to game in conditions of large-scale shelterwood system

Abstract

In the hunting district Hády (897 ha), which is operated by the Křtiny Training Forest Enterprise, 383 samples of biomass utilizable as wildlife forage were collected and analysed; they were also quantified on the basis of surface coverage of grass and woody undergrowth. Grass and herbaceous biomass production in forest stands was 180,740 kg (average 0.02 kg/m<sup>2</sup>), on road shoulders and other areas it amounted to 25,213 kg (average 0.150 kg/m<sup>2</sup>). The greatest diversity of plant species (72) was detected on the other areas. In total, forest and other areas provide 205,953 kg of utilizable grass and herbaceous biomass available during the vegetation period. Production of woody biomass, i.e. buds and shoots, amounted to 307,243 kg (average 0.035 kg/m<sup>2</sup>). The woody component of food in this locality was represented mainly by the species of beech, hornbeam, maple, and ash. Evaluation of sample plots revealed that the area covered by herbs and grasses in the studied forest unit was reduced due to a large-scale shelterwood system. On the other hand, a markedly increased supply of food from woody biomass was found to be available in the form of buds, leaves and shoots. The number of individuals in the advance regeneration of woody species in undergrowth ranged between 270 and 380,000 pcs/ha. Average values used for the calculation of utilizable energy in biomass were obtained from a laboratory measurement of biomass samples and complemented with data from literature. Average values of forest herbs and grasses = 0.60 MJ; buds, leaves and shoots in the growing season = 0.75 MJ. Average daily food consumption was converted to net digestible energy in MJ. In order to estimate food sufficiency with respect to quality energy requirements were calculated on the basis of the metabolic size of roe deer and hare bodies. In the quantitative assessment of available food supply, the standardized game stock would utilize 51% of grass and herbaceous forage and 7.5% of food from woody biomass. In the qualitative assessment of available food supply it was demonstrated that energy requirements of roe deer and hare were fully covered by their daily quantitative consumption of herbaceous, grass and woody biomass.