Preferences of two mammalian herbivores for tree seedlings and potential cover crops in plantation forestry

Newly established plantations are often damaged by heavy browsing. This is a major economic problem. Vegetation management involving the use of cover crops is a potential method for reducing browsing damage to plantation seedlings. An important first step in determining whether this is feasible is to determine the relative preferences of browsing herbivores for seedlings and crops. We conducted a no-choice feeding trial with red-bellied pademelons (Thylogale billardierii) and common brushtail possums (Trichosurus vulpecula) to determine their relative preferences for two common plantation species: Eucalyptus nitens and Pinus radiata, and three potential legume cover crops: bitter lupin (Lupinus albus), sweet lupin (L. angustifolius) and broad bean (Vicia faba L. cv Coles Dwarf). Pademelons exhibited a strong preference for P. radiata, but did not eat much of the legumes. Possums showed no significant preferences for any of the plants offered. A paired-choice feeding trial with pademelons demonstrated that bitter lupin was less preferred and oats (Avena sativa variety Esk) were more preferred than E. nitens. These results can now be integrated with an understanding of feeding behaviour at higher scales (e.g. vegetation patch) in order to design effective vegetation management for reducing browsing damage.