Nursery practices influence comparative damage to juvenile blue gum by wallabies (Wallabia bicolor) and European rabbits (Oryctolagus cuniculus)

Anecdotal reports suggest that some provenances of juvenile blue gum are browsed less frequently by wallabies and rabbits in plantations. Trials were conducted as randomised free-choice experiments using single species enclosures of wallabies and rabbits to investigate differential selection of juvenile blue gum. In the first experiment, nine morphometrically similar provenances of blue gum and a single provenance of Monterey pine were randomly selected from nursery stock Variability in the provenances damaged by both wallabies and rabbits was highly significant (P<0.001) and this appeared to substantiate field observations of differential damage. In a second experiment, six provenances of blue gum, including four which in the previous experiment had showed extremes of damage by rabbits and wallabies, were propagated and maintained using homogenous conditions and nursery treatments. Variation in seedling damage caused by wallabies and rabbits was eliminated. The contrasting results of both experiments suggest that, while the mechanism responsible for causing differential damage is unknown, in general, nursery practices may greatly influence the selection of juvenile blue gum by both wallabies and rabbits and account for field observations of differential rates of damage to blue gum provenances. The authors suggest that, identification of the mechanisms responsible will have practical application in the management of browsing damage. (C) 1998 Elsevier Science B.V. All rights reserved.