Impacts on biodiversity
From the April 2008 edition of Agriculture Today.
Hazard Reduction
The positive influence biodiversity has on production and ecosystem functioning, both on farms and in native forests is a key reason for maintaining biodiverse communities.Climate change impacts - particularly increased frequency of droughts and wildfires - pose serious threats to Australia’s forest ecosystems and its biodiversity.
Warmer temperatures may also see increased pressure for protective measures (see photo), such as more frequent prescribed (hazard reduction) burning, say NSW DPI Forestry specialists.
Long term forest ecology experiments dating back to the 1980s provide extensive data on biodiversity and its response to logging and prescribed burning.
The experiments co-ordinated by the NSW Department of Primary Industries (DPI) forest biodiversity research team will provide essential baseline data for assessing climate change impacts.
One use of the data is to model scenarios of the effect on biodiversity of the increased droughts and prescribed burning expected with climate change.
Recent research has identified an unexpected area of potential climate change impact in forests.
It has been found that prevailing climate has a large influence on flowering patterns and nectar production of eucalypts.
While the key triggers for most tree species are not yet known, cold minimum temperatures appear to stimulate flowering and nectar production in some species.
Eucalypts form the most important source of nectar for honeybees in NSW, not to mention the vast array of nectar-dependent fauna, including birds, bats, gliders and native invertebrates.
Clearly much remains to be learnt, but having access to long-term data about how species respond to disturbances in their environment, including drought and bushfires, will assist those in the business of managing native vegetation, be it in forests or on farms.
- Brad Law, Frank Lemckert and Rod Kavanagh
Frogs signal species’ coping capacities
Many species, both native and introduced, are limited in their natural distributions by climate.
As an example, climate change represents a particularly serious issue to Australia's frogs, which are a litmus of change.
Current long term monitoring of frog populations, like those in Dorrigo and in the Watagan Mountains near Gosford, will provide important information to assess whether the reproductive cycles of species are successfully shifting to cope with the altered weather patterns.
All frog species use climatic cues to determine reproduction and changes in climate will inevitably influence their reproductive success.
Some require heavy rains to cue their breeding activity and use temporary pools for their reproduction.
Less rain and higher temperature means pools dry earlier and tadpoles often will not survive.
Reduced frequency and sizes of floods in more inland areas will see greatly reduced opportunities for the species that rely on these opportunistic events for optimal breeding success.
Conversely, warmer conditions are likely to see earlier starts to breeding seasons, which may increase opportunities, but may also bring some species into competition with others that normally breed in the colder months.
Further information about the impact of climate changes can be found at www.dpi.nsw.gov.au/research/topics/climate-change/impacts-on-industry
