Victorian Central Highlands Forest Management Study
This study is set in native montane ash forests in Victoria. Study sites are stratified across different age classes and disturbance histories.
Major theme: forest management and ecology
The Landscape of the Central Highlands of Victoria
The Central Highlands of Victoria are located about 50 km NE of Melbourne (click to see map). They are characterised by the tall Mountain Ash (Eucalyptus regnans) and Alpine Ash (E. delegatensis). The Mountain Ash is the tallest flowering plant in the world, reaching more than 100m in height. Only the American redwoods are taller (but the redwoods are conifers, so don't flower).
The regions in which these forests occur are very wet, and often contain patches of rainforest. The Ash Forests are extraordinarily diverse often with multiple strata levels from the canopy, through the midstorey and understorey to a forest floor rich in different microhabitats and species. These forests contain microhabitats that are less well known, such as logs and leaf litter on the forest floor, tree hollows, or under the long strips of bark that peel off the trees each year. A healthy forest has trees of different ages - some old or dead trees with lots of hollows, younger trees that will grow tomorrow's hollows, and saplings.
Natural resource managment
The Mountain Ash forests are prized for their straight timber, which has been harvested extensively and intensively for more than a century. The harvesting method used is clearfelling in small coups followed by a burn. The post-harvesting fire is used to clear the ground of fallen logs and branches to provide space for the recruitment of new trees, and to trigger the germination of eucalypt seeds in a nutrient-rich ash bed.
The Central Highlands forests also provide water for Melbourne, and some large, pristine and very old forests are preserved in water catchments. Very old forests provide a lot more water for human use than young forests (eg forests growing after harvesting), because young trees use a lot of water while growing.
Biodiversity in the forest
These tall forests are home to a suit of animals, some of which are found no-where else. Of particular importance are the possums and gliders which rely on the tall forest trees for food, shelter and protection. Many of these arboreal mammals live in hollows in trees, and the availability of hollows can limit the population. Trees usually develop hollows when they are quite old, so old forests have more hollows than young forests. Logging the forests can reduce the number of tree hollows available for the arboreal mammals, sometimes with dire consequences for the mammal species.
One such mammal, reliant on a certain shape and type of tree hollow, is the endangered Leadbeater's Possum. This tiny possum is restricted to the tall forests of the Central Highlands, and tree hollows appear to be a very limiting resource. About 40 years after the first discovery of the Leadbeater's Possum, it was presumed extinct, until it was re-discovered in 1961 near Marysville in the Central Highlands. Leadbeater's Possum, one of Victoria's faunal emblems, is threatened by clearfell logging practices, so finding ways to ensure the survival of this amazing small animal is both difficult and very important.
The tall Mountain Ash forests are prone to rare but large disturbance events like broad-scale bushfires, such as those that occurred in 1939 (Black Friday) and 1983 (Ash Wednesday). Fire events such as this, when combined with a second large disturbance like salvage logging, can reduce the hollow resource available for hollow-dependent fauna, until new hollows form (usually many generations of possums later).
Understanding how these tall forests function, and what the needs are of the many animals that live in them, are key questions important in the management of our forest resources.
Sub-projects conducted in the Central Highlands of Victoria
Leadbeater's Possum home page
The Ecology and Habitat Requirements of Leadbeater's Possum
Patterns of use of nest-boxes by forest vertebrates
Long-term monitoring of arboreal marsupials
Long-term study of the Mountain Brushtail Possum
Relationship between forest floor and small mammal populations
Comparison of hairtubes
Monitoring forest mammals with microchips
The cutting experiment
Our work in the Victorian Central Highlands is made possible by support from the Victorian Governments Department of Primary Industries, Department of Sustainability and Environment and Forest and Wood Products Australia.