Abstract

Variation in the vegetation in and adjacent to a Puffinus tenuirostris breeding colony at Cape Queen Elizabeth, Bruny Island, Tasmania is related much more closely to burrow density, bare ground and soil dryness than to either the phosphorus or organic content of the soils. Between 1977 and 1992, burrow density declined on average by 0.11 per m². In the parts of the rookery where burrow density decreased, Rhagodia candolleana Moq. increased its cover. Where burrow density remained constant or increased, Pteridium esculentum (G.Forster) Cockayne and Lomandra longifolia Labill. had declining cover. The major overall changes were increases in the cover of the succulent scramblers Tetragonia implexicoma (Miq.)J.D.Hook and Rhagodia candolleana at the expense of Pteridium esculentum and Lomandra longifolia.