Australian savannas have been subject to a variety of
climate and land management histories.
There has been little research conducted in the
Australian tropical savannas where climate conditions are highly variable.
Jan
|
Feb
|
Mar
|
Apr
|
May
|
June
|
July
|
Aug
|
Sept
|
Oct
|
Nov
|
Dec
|
Annual
|
|
Mean
|
198
|
211
|
157
|
28
|
7.1
|
3.6
|
1.7
|
0.1
|
3.1
|
23.6
|
51.3
|
135.9
|
828.2
|
This table indicates the mean precipitation of Northern
Australia in mm. Based on this table, Australia Savanna receives the most
amount of rain from December to March, when areas in the south of Australia
receive the least. A scenario of 'plausible future climate' for the Australian
region (Anon., 1988), made solely for the purpose of evaluating the impact of
climatic change, suggested increases in summer rainfall (+30%) and decreases in
winter rainfall (-20%) in Australian Savanna. The large impact of such
plausible scenarios on savannas (McKeon 1988; Graetz, Walker & Walker,
1988) indicates the importance of developing a capability to expect the savanna
response to climate change. In northern Australian savannas the likely outcome
of such a climate change may affect the areas used for cropping (McKeon et al.,
1988; Russell, 1988) and forestry (for preservation or timber). The global
effect of climate change on cropping areas (existing and potential) elsewhere
in the world could affect the economic viability of the Australian export grain
and pastoral industries and hence the future of savanna lands. Comparative
studies of savanna processes across wide geographical boundaries (for example,
Mott et al., 1985) would provide the basis for prediction of savanna response
to climate change.
Geographic
information systems will prove valuable in indicating the change in savanna
land use with respect to climate change (Graetz et al., 1988). Similarly Busby (1988)
has shown how geographical information systems using vegetation/environment
relationships can anticipate the changes in forest and wildlife habitats.
However, our capability to plan for these changes to savannas is likely to be
limited by the understanding of environment/vegetation/ wildlife relationships
(Braithwaite, 1985; Bowman & Minchin, 1987). The real value of such studies
will be in the rapid evaluation of the impact of climate change as forecast by
current global circulation models (Tucker, 1988). Current increases in
greenhouse gases (Pearman, 1988) suggest that large changes in climate are
likely to occur during (and beyond) the next 50 years (Tucker, 1988).
In
the Northern Australian savannas there’s still a lot of tree-clearing and
vegetation management which are important issues. People clear trees in
Savannas to make them better for pasture production. People often stop the
fires which would naturally clear the land. Australian Savanna is relatively
ancient but due to these human interferences, Australian Savannas would not be
Savannas what they used to be.
Average Yearly Precipitation in Australian Savanna
(source: bushblitz.teachlive.org.au)