Provenance variation in fuchsia (Fuchsia excorticata) in relation to palatability to possums
- Landcare Research, P.O. Box 69, Lincoln, Canterbury, New Zealand
Fuchsia (Fuchsia excorticata) has been heavily browsed and often killed by brushtail possums (Trichosurus vulpecula) in many New Zealand indigenous forests, but remains healthy at some sites despite long histories of possum occupation. To determine whether fuchsia varied genetically in its palatability to possums, material from six widely dispersed stands (provenances) was propagated, and leaf chemistry, leaf morphology, growth rate, and palatability to captive possums was compared. Leaf specific gravity, nitrogen, and phosphorous levels in field-collected foliage varied between palatable and apparently unpalatable provenances of fuchsia. However, these variables, and palatability to captive possums, were similar in propagated material from all provenances. To test the hypothesis that selective browsing had eliminated the more palatable or susceptible genotypes at sites where possums have been present for long periods. we tested the relationship between variation within provenances of measured variables and length of possum occupation at each site, but no significant relationships were found. These results suggest that phenotypic or situational differences rather than genetic variation between the six provenances may help explain observed regional differences in fuchsia health.