Using a mix of high technology and on-ground
experience, land health researchers—supported by Tropical
Savannas CRC and National Land & Water Resources
Audit—have developed an effective method for assessing
landscape and pasture condition. It will be a valuable tool to help
land users and agencies in north Australia manage landscapes
sustainably.
Introduction
| Accounting for good and bad seasons |
Taking account of land use history | Developing easy ground monitoring | References | More information
|
THE method was developed jointly by the NT Department of Lands,
Planning & Environment and CSIRO, and uses new techniques of
on-ground assessment that are simple to use but give an accurate
measure of a landscape’s capacity to capture nutrients.
This information is combined with satellite data on the history
of the land via a sophisticated program stored in a laptop
computer. The end result is an assessment of long-term land
condition that looks beyond temporary effects of good or bad
seasons. The new tool’s development comes from a number of
strands of research.
Land condition in the tropical savannas fluctuates wildly as
part of the normal seasonal variation in rainfall and fire. To
“filter out” these fluctuations, it was necessary to
develop a very good understanding, through basic field research, of
how different land types respond to grazing management, climate and
fire.
Field studies over many years and satellite records were used to
build up a history of landscapes so the underlying trends in
condition and the long-term response to management of different
landscapes could be identified.
New techniques in on-the-ground assessment reduce time required
per data collection point from two hours to 20 minutes. This is
based on LFA (Landscape Function Analysis) using soil, vegetation,
patchiness and slope; indicators for the capacity of a landscape to
capture nutrients.
This information is then integrated with the historic satellite
data via a sophisticated Geographical Information System. These new
ways of monitoring condition are not only faster but also simpler,
and have a good chance of being adopted by land managers.
These methods were developed from an extensive study of the
Victoria River Downs and adjacent pastoral properties. Using the
new techniques, researchers were able to distinguish between land
types in the VRD that were resilient to changing climate and human
management and those which were not.
This research has tremendous applicationsthere are already land
managers looking to adopt these technologies to identify areas that
are over- or under-grazed. Such information should improve
properties’ long-term prospects, both in economic and
ecological terms.
These techniques allow rangeland monitoring to be carried out on
a much broader scale than before, and could be usefully adopted by
various agencies when assessing the impact of land use.
At present, this technology is being applied over the East
Kimberley/Victoria River District in north-west Australia, the
Sturt Plateau in the NT and the Burdekin River catchment in north
Queensland. However, it could also be adapted for use in more
temperate environments.
1. Marks, A.R. & Jolly, P. (1987),
‘Extreme corrosivity of the Northern Territory Coastal
Groundwater supplies—origin, effects and materials of
construction’, Australian Institute of Engineers Hydrology
Conference, May 11-15, 1987, Darwin. 9pp.
2. Cook, P.G., Hatton, T.H., Pidsley, D.,
Herczeg, A.L., Held, A. & O’Grady, A. (1998) 'Water
balance of a tropical woodland ecosystem, northern Australia: a
combination of micro-meteorological, soil physical and groundwater
chemical approaches', Journal of Hydrology vol. 210, pp
161-177.
3. Walker, B.H. & Seffen, W.L. (1993)
'Rangelands and global change', Rangeland Journal 15, 95-103.
