Friends of The Pinnacle   defeating the weed menace
fotpin's Native Grass Restoration Project
 
  

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Restoring native grasses to the understorey of The Pinnacle
New knowledge that will aid recovery of degraded box-gum grassy woodlands

A Friends of The Pinnacle project funded by:
ACT Environment Grant 2010-11
Caring for Our Country Community Action Grant 2010-2011
Canberra Labor Club 2010-2011


Project Methodology and Implementation Plan

Methods

The project will run for three years as we assess changes in soil nutrients, and native and exotic plant cover. We will have ten replicate experimental blocks (see Figure 1), with five in areas with high weed cover (weed sites), and five in areas with 50-75% weed cover and >5% cover of native grass.

Figure 1. Ten study sites have been established, including five that have very high weed cover (weeds), and five with some native grass cover (stipa).

plot map

 

Each experimental block will include two plots (see Figure 2). One plot in each block will be fenced to exclude herbivores, the other will remain open. Each plot will have five 5 x 5m quadrats, with a slashed buffer between quadrats. One of five treatments will be applied to each quadrat:

1.  Burn in spring before exotic grasses set seed
2.  Slash and remove cuttings before exotic grasses set seed
3.  Direct drill a crop plant and harvest
4.  Add sugar every four months
5.  Do nothing

Fig 2 Figure 2. Diagram of one experimental block (of 10). It consists of two plots, each with five 5 m × 5 m quadrats and each quadrat has a different treatment. A 1 m buffer strip (which is slashed) separates quadrats. Treatments will be randomly allocated to quadrats.

fenced plot

The following measurements will be taken in each quadrat:

  • Soil nutrients.
  • Percent cover of native and exotic plants (to species level).
  • Estimates of herbivory
  • Erosion risk (using a landscape function analysis approach).

plant surveys

Implementing the Project

Treatments

Slash: Using scythes, FOTPIN will remove as much biomass as possible from the experimental sites before exotic plants have set seed, and after spring growth has finished (slash twice). Slash will be weighed, and samples collected for nutrient analysis

Sugar: Apply 0.5kg of sugar per m2 on sugar quadrats three times per year.

Burn. Burn all plants, timed to remove exotic seed sources as far as possible. Burn plans and implementation will be undertaken by ACT Parks & Conservation.

Crop. Apply herbicide or slash weeds to allow crops to grow. Direct drill (to minimise soil disturbance) a crop plant (that is sterile or will not become established as a weed itself). Harvest the crop and weigh then sample for nutrient analysis.

treatments

 

Soil nutrient measurement
Phosphorus is in a chemical equilibrium between available and unavailable forms. As we remove available P, some of the unavailable P dissolves from soil to which it is bound, becoming available. This means we need to know how much total P there is in weedy sites compared with sites in good condition without weeds to determine how much P we might need to remove from the soil. We also need to measure available P, as this concentration influences the success of many native plants. Finally we need to measure P in the weeds and crop that we remove, so that we know how many times we will need to remove vegetation to have an impact on soil P. We also need to measure Nitrogen availability (total, nitrate and ammonium), because these influence the capacity of crops to grow (and remove P), but also influence native plant success. Nutrients will be measured in each quadrat in autumn each year. The autumn measures are timed to detect maximum nitrogen levels (before annuals have started to regrow).

Key Milestones and Timetable

Milestones Activities Key Dates
1 Peg corners of experimental plots, undertake initial soil analyses Oct-10
2 Initial plant surveys complete. Dec-10
3 Fencing installed Jan-11
4 Plant herbivory, and erosion surveys Apr-11
5 Soil samples collected Apr-11
6 All treatments implemented May-11
7 Review of progress and revise workplan if needed Jul-11
8 Harvest crop (collect harvest for P analysis)
Sugar treatments
Sep-11
9 Plant herbivory, and erosion surveys, burning, slashing treatments Oct-11
10 Sugar treatments Jan-12
11 Plant herbivory, and erosion surveys Apr-12
12 Soil samples collected Apr-12
13 Plant native grass seedlings in one quarter and native grass seed in another quarter of each quadrat Apr-12
14 Second crop planting if needed
Sugar treatments
May-12
15 Review of progress and revise workplan if needed Jul-12
16 Harvest crop (collect harvest for P analysis)
Sugar treatments
Sep-12
17 Plant herbivory, and erosion surveys, burning, slashing treatments Oct-12
18 Sugar treatments Jan-13
19 Plant herbivory, and erosion surveys Apr-13
20 Soil samples collected Apr-13
21 Sugar treatments May-13
22 Final report and completed plan for next phase of implementation and research Dec-13

 

project home methods & implementation plot map current activities findings full project description
[pdf, 274 kB]

 

 
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