Friday, August 10, 2007

PS 72-165: Host infestation patterns of the massive liana Hydrangea serratifolia (Hydrangeaceae) in a Chilean temperate rainforest

Mylthon Jimenez-Castillo, Universidad Austral de Chile and Christopher H. Lusk, Macquarie University.

As competition from lianas reduces fitness of host trees, lianas could influence community composition and structure if potential host species differ in susceptibility to infestation. Here we examine the relationships of host species and stem diameter with infestation frequency in a Chilean temperate rainforest by the massive liana Hydrangea serratifolia (H. et A.) F. Phil (Hydrangeaceae), which climbs using adventitious roots. We recorded presence or absence of H. serratifolia in a random sample of 515 trees ≥ 10 cm diameter. 54% of trees were infested by at least one individual of H. serratifolia. Although there was significant interspecific variation in infestation frequency, this variation was not systematically related to light requirements of host tree species. Probability of infestation increased with diameter for most host tree species and old trees were found to be infested by small liana stems supporting the proposal that lianas which attach by adventitious roots can colonise host stems of any size.