Maintaining integrity compared with maintaining rare and threatened taxa in remnant bushland in subhumid Tasmania

Abstract

The native vegetation remnants in the agricultural country of subhumid Tasmania are important strongholds for regionally and globally rare and threatened species. A detailed survey of the best 100 of these remnants indicated that there was no relationship between the size, age and juxtaposition of the remnants and an index of rare and threatened species, either in the data set as a whole or in phytosociologically defined subsets. Rare and threatened species were found in remnants of widely varying integrity, as indicated by native and exotic species richness and cover. Some species were only found in remnants that were of poor integrity. Efforts to preserve vegetation remnants need to be directed towards both those that are representative and of high integrity, and those that contain rare and threatened species. No great coincidence can be expected, because the causes of maintenance of good condition are not necessarily the causes of survival of many rare and threatened taxa.