FACTORS AFFECTING POPULATION-DENSITIES OF THE COMMON WOMBAT, VOMBATUS-URSINUS, IN PLANTATIONS OF PINUS-RADIATA

Population densities of wombats were estimated in eucalypt forest, and in 1- 3-, 6-, 10-, 15-, 20- and 25-year-old pine plantations. There w as a significant difference in the numbers of wombats inhabiting the d ifferent types and ages of forest. Factors contributing to the fluctua ting population densities were investigated. There was a strong correl ation between the number of wombats and the number of medium and major burrows in an area. Where burrows are not the limiting factor, grass (the dominant food of the wombat) becomes an important requirement. Th ese findings are of particular importance in the management of plantat ions if the aim is to sustain wombat populations in all stages of pine forest. Management strategies to enhance the multiple use of pine pla ntations should aim to minimise disturbance of burrows throughout fore stry operations. In particular, burrows should be conserved during the initial clearing stages. The timing of thinning of plantations also a ffects the availability of food in plantations. At present, this is le ft until the canopy has completely closed over and no grasses are pres ent. This initial thinning could be brought forward.