Case Study 2: Weed monitoring in a river catchment

Background information
You are employed by the Department of Conservation as a senior research officer. Your minister (Honorable Mrs Mary Rivers) has recently announced a weed strategy policy. The policy states that Gamba Grass (Andropogon gayanus) and Mission Grass (Pennisetum polystachion) are a fire hazard and must be eradicated from all public and private lands.

Both grasses were introduced to the NT as experimental pasture for the cattle industry. They share many similarities, including their African origin, prolific seed production and ability to colonise non-pastoral land. Both grasses have thrived in the tropical environment of northern Australia. The introduction and rapid spread of Mission and Gamba Grass has greatly increased fuel loading (tonnes per hectare of flammable material) of the wooded savanna ecosystem common throughout the region. This substantial increase in fuel loading, combined with the later curing time of these grasses, has the potential for a major change in the fire regime across the entire Top End.

Further information on Gamba and Mission Grass is provided on the Northern Territory Fire and Rescue Service (NTFRS) web site at
http:///www.nt.gov.au/pfes/fire/Mission_Gamba_Grass.html

You have been asked to design a monitoring program for the Daly River catchment to be used as a model for the rest of the state. No budget has been set at this point, and part of your job is to provide estimates of the costs involved. The time frame for the project is set at 5 years.

There are grand plans for the future development of the catchment. There are approximately 4,000 km2 suitable for cotton growing and other horticultural crops (mainly mangoes and cashews). In addition, with the improvement of pastures, more intensive cattle grazing will be possible. To give students an idea of the extent of the proposed development, a map of part of the catchment, classified in relation to different future land uses, is shown.

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Aims
The aims of the monitoring program are to

• provide information on current distribution of both weed species
• determine environments most at risk of infestation of both weed species
• monitor fuel loads (specifying between native and exotic fuels)
• determine changes in composition of native plant species due to weed infestation.

Location of catchment
The catchment covers approximately 20,000 km2, which is equivalent to the area of Kakadu National Park.

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Much of the catchment is used for pastoralism, with some area in conservation reserves and the remaining area is aboriginal land.

Existing vegetation
There are 11 vegetation communities present within the catchment identified from the Northern Territory vegetation map (Wilson et al. 1990).

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9 - Eucalyptus tetrodonta & E. miniata woodland, sorghum understorey

12 - E. miniata & E. tetrodonta woodland, spinifex understorey

13 - E. tetrodonta & E. miniata woodland with spinifex understorey

15 - E. tectifica & E. latifolia woodland, sorghum understorey

17 - E. dichromophloia & E. tetrodonta woodland, grassland understorey

19 - E. terminalis & E. patellaris woodland with grassland understorey

21 - E. tintinnans low woodland, sorghum understorey

29 - E. phoenicea woodland with spinifex understorey

44 - Terminalia arostrata woodland, grassland understorey

50 - Melaleuca minutifolia low woodland, sorghum understorey

Blue shading - riparian forest (either Melaleuca or monsoon forests)

References
Wilson, B.A, Brocklehurst, P.S., Clark, M.J., and Dickinson, K.J.M. (1990). Vegetation survey of the Northern Territory. Technical Report No. 49. Parks and Wildlife Commission of the Northern Territory, Darwin.

When preparing your proposal make sure to note the following

Length 1500-2500 words (please don't go over this limit)

In your proposal outlining and justifying the weed-monitoring program for the minister to review, be sure to follow the basic structure below:

1.Title
2. Table of Contents
3. Introduction
4. Methods and Justification (sub-section this as you wish). Be sure to include

• sampling design (include seasonal timing)
• types of data to be collected
• descriptive statistics to be used
  NB. you are encouraged to consider and include statistical analyses to be used but will not be marked on this component
• proforma data sheet/s design
• outline and justify methods of data collection

5. Costs, time and staff required

• staff required
• cost and time budget for planning, sampling and report writing

6. References

• the proposal must be fully referenced
  

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