Method of determining relations between the extent of damage in farm crops, big game numbers, and environmental conditions

Abstract

1981: Method, of determining relations between the extent of damage in farm crops, big game numbers, and environmental conditions. Acta theriol., 26, 32: 469-481 [With 6 Tables]. With the use of statistical methods it is possible to forecast the extent of damage in farm crops done by big game (red deer and wild boars). Mathematical model for a definite number of animals in definite ecological environment and on definite area was solved with the aid of multiple regression analysis. Studies, carried out during years 1973-1975, included 23 lowland forest districts situated within the Silesian Land. Data collected in each forest district concerned the size of animal populations, information on environmental characters related with their behaviour, as well as the area and value of damage inflicted in farm crops. There were obtained regression equations illustrating economic and ecological aspects of the situation prevailing in hunting grounds. Resulting from the model characters at most affecting both the area damaged and the value of compensation were: (1) numbers of wild boars, (2) contribution of the fresh mixed coniferous forest in the total study area, (3) area proportion of the fresh coniferous forest, (4) area of forest stands with the prevalence of pine (Pinus silvestris L.) and larch (Larix decidua Mill.), (5) area of lb (11-20 years old) and lia (21-30 years old) age-classes of forest stands, and (6) size of the forest area within the unit studied. The model may be useful in manipulating numbers of individual populations: It is also helpful in the selection of habitat features, since it states which of them cooperate in the process of damage formation. It yields also numerous indicationr. for further research. [Institute of Planning and Arrangement of Rural Areas, Agric. Acad.