The KI Narrow-leaved Mallee Woodland ecological community is a terrestrial vegetation based community associated with drier, temperate landscapes on Kangaroo Island. It typically is a mallee woodland but can occur in a number of vegetation states, ranging from mallee forest to woodland to shrubland, depending on the nature of and timeframe since disturbance.
Kangaroo Island Narrow-leaved Mallee (Eucalyptus cneorifolia) Woodland
Status: Critically Endangered on the EPBC Act list
Government evidence of impact of climate change:
Conservation Advice for Kangaroo Island Narrow-leaved Mallee (Eucalyptus cneorifolia) Woodland
Climate Change Climate change is now understood to pose a serious long term threat to terrestrial; coastal and aquatic ecosystems and to have the potential to change the ecology of these environments.
The potential large scale impacts of climate change could influence the species composition of this ecological community through their responses to disturbance and the very nature of those disturbances.
Projected change in annual temperature and rainfall forecast by climate change models on KI.
Understorey plant diversity can increase markedly in response to appropriate fire regimes.
Altered fire regimes; including inappropriate application of burn intensity and season; and skewed age distribution of patches.
Low intensity fire has been identified as a threat.
Altered fire regimes; notably fire suppression; has resulted in a strongly skewed age distribution of patches of the ecological community whereby most patches are maintained in a low diversity senescent stage that have not been burnt for 30 years; in some cases 60 years or more.
The habitat characteristics of mallee systems; however; show variable rates of development in response to fire (Haslem et al.; 2011) and this is presumed to impact on the fauna and flora influenced by these characteristics over time.
For instance; understorey vegetation cover may increase rapidly in response to fire; as obligate seeder and resprouter species respond quickly to the fire stimulus.
Fire is essential to the long term persistence of plant diversity in the ecological community; as many woody plant species persist in the ecological community as a long lived seed bank and require heat and or smoke from periodic fires to stimulate their germination.
The passage of a hot fire has several key impacts upon the ecological community (Pisanu; 2007).
As the time after fire increases; plant species with short to medium life spans progressively die out from the ecological community.
Fire also impacts on the diversity and abundance of fauna.
A study of the impact of fire on the spider fauna of the ecological community identified 31 families subfamilies in unburnt plots with the numerically dominant families being the Zodariidae (ant spiders) and Gnaphosidae (ground running spiders) (Marsh; 2012).
The high degree of fragmentation currently experienced by the ecological community may exacerbate the impacts of altered fire regime and skewed age structure of patches.
In summary; the altered fire regimes on eastern KI have suppressed the natural vegetation dynamics of the ecological community and maintained an age distribution of patches that is skewed to the simpler; low diversity senescent state of the ecological community.
The long term suppression of fire within mallee vegetation could contribute to continuing detrimental change; in terms of biodiversity loss.