It is expected that climate change will impact the region’s native vegetation through modifications to vegetation communities, such as loss of particular plant species and changes to community structure, as a result of higher temperature and lower rainfall, changes to natural fire and flooding regimes and climatic conditions favouring new and established weed species. Native vegetation will play an important role in climate change mitigation, mainly through its role in carbon sequestration.
Under a changing climate, vegetation communities that currently rely on wet climates with consistently high levels of rainfall are most vulnerable. Examples include the rainforests and wet forests of the Otway Ranges.
Other vegetation communities vulnerable to this scenario of climate change will be the riparian communities of the region, especially those found along the smaller tributaries that feed into the larger river systems. These vegetation communities are dependent on regular flooding or at least periods of inundation from heavy rainfall events. Examples include the riparian forests and woodlands found in the upper catchments.
Not all vegetation communities are highly vulnerable to this scenario of climate change. Communities such as Coastal Scrubs, Salt Tolerant Shrublands and Heathy Woodlands are all quite resilient to hotter and drier conditions. Should such conditions eventuate, these communities are likely to have greater capacities to cope with change in both temperature and reduced rainfall because they occur naturally in such conditions today.
However, climate change can have other - perhaps greater- impacts on native vegetation. One important driver is through changes to existing fire regimes, with more frequent and intense bushfires projected alongside smaller windows of opportunity for prescribed burning (whether ecological or fuel reduction focussed).
This has potentially serious ramifications for vegetation communities already restricted in extent; either naturally or through fragmentation e.g. native grasslands. All vegetation communities will respond to climate change. Some may be able to adapt, for example by altering their floristic compositions and/or structures, or changing their reproductive processes. However, some species may not be able to adapt and so we will see changes in community composition or even replacement of one community type by others more resilient to altered ecological processes. We are also likely to see establishment of new vegetation communities.