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Digital Library Digital Library

Books & book chapters Miscellaneous works

7-2011

Rangeland condition monitoring: A guide for pastoral lessees Rangeland condition monitoring: A guide for pastoral lessees

David Warburton

Follow this and additional works at: https://researchlibrary.agric.wa.gov.au/books Part of the Natural Resources Management and Policy Commons

Recommended Citation Recommended Citation

Warburton, D. (2011), Rangeland condition monitoring: A guide for pastoral lessees. Department of Agriculture and Food, Western Australia, [Perth]. Book.

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RANGELAND CONDITION MONITORING

A GUIDE FOR PASTORAL LESSEES

David Warburton

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The Chief Executive Officer of the Department of Agriculture and Food and the State of Western Australia accept no liability whatsoever by reason of negligence or otherwise arising from the use or release of this information or any part of it.

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Contents

Introduction ...1

Rangeland Condition Monitoring...1

Monitoring Rangelands...2

Rangeland types ...2

Rangeland plant species...2

Indicator species ...2

Soil surface condition ...3

Change in rangeland condition (trend) ...4

Other indicators of range condition trend ...4

THE RANGELAND CONDITION MONITORING (RCM) PROCESS ...5

1. Site location ...6

2. Site installation ...8

3. Initial site assessment...11

Grassland Method ... 11

Shrubland Method ... 15

4. Site re-assessment...18

Determining range condition trend – Grassland ... 18

Determining range condition trend – Shrubland ... 19

Glossary...21

Appendices ...21

Appendix 1: Steel peg dimensions...23

Appendix 2: Site Installation Sheet ...24

Appendix 3: Site Assessment Recording Sheet – Grassland...25

Appendix 4: Site Assessment Recording Sheet – Shrubland...27

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Introduction

This publication is a guide for the installation and assessment of monitoring sites, and reporting of rangeland condition trend required for the Rangeland Condition Monitoring (RCM) system of the Pastoral Lands Board of Western Australia (PLB).

The permanent rangeland monitoring sites installed in the RCM process can be used as a simple tool to monitor and evaluate the impact of livestock and seasons on the health of the perennial vegetation. They will also enable land managers to demonstrate if their management practices are maintaining or improving rangeland condition.

Rangeland Condition Monitoring

Monitoring indicators of rangeland condition, and reporting monitoring data and rangeland condition trend assessment to the PLB is a mandatory requirement for pastoral lessees in Western Australia under Sections 95, 109 and 113 of the Land Administration Act 1997.

Statutory Obligations under the Land Administration Act 1997

Government obligation

Section 95 Functions of the Board

(c) to ensure that pastoral leases are managed on an ecologically sustainable basis

Lessee obligation

Section 109 Management of land under a Pastoral Lease

(2) The lessee must use methods of best pastoral and environmental management practice, appropriate to the area where the land is situated, for the management of stock and for the management, conservation and regeneration of pasture for grazing.

(4) The lessee must maintain the indigenous pasture and other vegetation on the lease to the satisfaction of the Board.

Section 113 Annual Returns

(1) A pastoral lessee must, after 30 June in each year and not later than 31 December in that year, submit to the Board a return in an approved form of any information required by the Board relating to the land under lease or the activities on the land.

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Monitoring Rangelands Rangeland types

Pastoral rangelands in Western Australia occur as two distinct types:

• Grasslands – vegetation characterised by perennial tussock and hummock grasses, occurring primarily in the Kimberley and Pilbara regions.

• Shrublands – vegetation characterised by shrubs with a variable mulga (Acacia aneura) or eucalypt overstorey, occurring primarily in the Gascoyne, Murchison, Goldfields and Nullarbor districts.

Both shrublands and grasslands occur in the Gascoyne and Ashburton districts.

Monitoring techniques must be appropriate to the vegetation type being assessed.

Therefore, grasslands and shrublands require different monitoring methods. This manual describes both methods. However, it should be remembered that the site layout is identical to both methods.

Rangeland plant species

Rangeland plants are either perennials, annuals or biennials.

Perennial plants live for more than two years and include:

• Trees, e.g. mulga or beefwood

• Shrubs, e.g. pearl bluebush or mimosa bush

• Sub-shrubs, e.g. golden bluebush

• Grasses, e.g. ribbon grass or woolly butt grass

Annual plants complete their life cycle within a single year, e.g. button grass or everlasting daisies.

The other group are the biennial plants. These are neither annual or perennial, but are plants that require more than one season to complete a life cycle, but rarely survive beyond two years, e.g. limestone grass or roly poly.

Indicator species

Change in plant species composition is the major measure of rangeland condition health. Healthy rangelands contain diverse and reasonably stable populations of perennial plant species of varying palatability. Different plants exhibit varying responses to changes in grazing pressure and seasons, which can lead to change over time in plant species composition. Therefore, the presence, increase or decline

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For RCM purposes, these indicator plant species will be referred to as desirable and undesirable plants. Desirable perennial plants are productive and palatable to domestic stock, and drive pastoral production. Excessive grazing of rangeland pastures reduces or removes desirable perennial plants. This loss may indicate a decline in range condition.

Undesirable perennial plants are typically unpalatable and of limited value to stock.

Excessive grazing may cause undesirable species to increase in density, at the expense of desirable perennial plants. This increase may indicate a decline in range condition.

Conversely, an improvement in range condition may be indicated by an increase in the density of desirable perennial plants and/or a reduction in the density of undesirables.

Intermediate species include a large group of perennial plants that may or may not be palatable but typically do not increase to any great extent when other palatable species are removed. The presence or absence of intermediate species cannot be used with any confidence as an indicator of the “health” of rangeland vegetation.

Soil surface condition

Rangeland condition health is also indicated by soil surface characteristics. Soil surface condition describes the soil’s capacity to retain water, and to remain stable under variable conditions. Management to achieve this may include retaining critical levels of ground cover and/or limiting the degree of pasture utilisation.

Soil surface condition in the RCM system is described as:

Very Good: Stable soil surfaces, abundant accumulated decomposing litter in places, many physical barriers (including live plants) to retard water flows and promote infiltration.

Good: Soil surface mostly stable, some accumulated litter and live plants, minor evidence of loss of water or litter from site, but ability of site to intercept resources sub-optimal.

Fair: Some litter but with little evidence of decomposition, some signs of topsoil loss, reduced objects (including few live plants) to intercept water flows.

Poor: Significant topsoil loss, little to intercept water flows, little litter present.

Very Poor: Almost total loss of topsoil, exposed surfaces shedding resources, little to intercept water flows, no accumulated litter, no live plants, poor infiltration.

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Change in rangeland condition (trend)

Rangeland condition trend refers to the change in health or condition of the rangeland. It is described by noting changes to the density of indicator plant species and/or soil surface condition. Rangeland condition trend should not be confused with an absolute measure of rangeland condition (good, fair or poor).

Trend requires that rangeland condition is judged relative to the situation recorded at an earlier date. Therefore, data from at least two points in time are required to assess trend. The base resource can improve, decline or remain stable. Essentially, a positive trend (improvement) is an increase in palatable and productive perennial plant species, and variables such as good litter cover and stable soil surface.

Conversely, a declining trend may be evident as a reduction in the density of palatable and productive perennial plant species, an increase in undesirable plant species, or a reduction in soil cover or soil stability.

Rangeland condition trend indicates how the prevailing management strategies are physically affecting the country.

Other indicators of range condition trend

In addition to changes in the density of desirable and undesirable plants, there are other indicators of trend that are important in pastoral management and are included in Rangeland Condition Monitoring.

In grassland environments, an increase in the density of woody perennial plant species has the potential to suppress the growth of desirable perennial grasses and may also increase mustering difficulty. Such an increase is usually an indication of a decline in range condition.

While perennial grasses are usually a lesser component of shrublands, they are a primary driver of livestock productivity as well as performing an important ecological role. Therefore, the loss or reduction of perennial grasses in a shrubland environment may indicate a decline in range condition.

Conversely, a reduction in woody species in grasslands or an increase in perennial grasses in shrublands, may be indicative of an improvement in range condition.

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THE RANGELAND CONDITION MONITORING (RCM) PROCESS

Establishing a rangeland monitoring system in either Grassland or Shrubland, for Rangeland Condition Monitoring, requires four important steps:

1. Site location – selecting a location for a site within a paddock or management unit.

2. Site installation – setting up of the physical hardware (posts, corner pegs, etc.), and recording the site characteristics (location, indicator species).

3. Initial site assessment – obtaining and reporting the baseline data for each site, that is, the frequency or number of the nominated indicator species, and the initial site photograph.

4. Site re-assessment – reassessing the sites on a three year cycle (one third of the sites each year). This requires obtaining and reporting data of the indicator species, a site photograph and assessment of range condition trend.

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1. Site location

The selection of the location of a rangeland monitoring site is a critical step in the monitoring process. Sites should be considered a permanent installation; the location cannot be readily changed once the site is in the RCM ‘system’.

Many pastoral leases have an existing network of monitoring sites for management purposes at the paddock level. In most instances, these sites are ideally located for use in the RCM system and their layout is compatible with the RCM design. Lessees should consider using these sites in their RCM site network.

Note: WARMS (Western Australian Rangeland Monitoring System) sites are not suitable for RCM purposes and cannot be used as RCM sites.

When selecting a site, all the following factors must be considered:

Distance from water – sites must be within the grazing radius of domestic stock, but outside the ‘sacrifice zone’ adjacent to a stock water. Experience has shown that a distance between 1.5 km to 3 km from a water point is applicable in most circumstances.

Note: The salinity of the stock water and/or the pasture will affect the grazing radius of the livestock.

See Table 1 to determine a suitable distance from stock water points.

Table 1 Site distance from nearest water in relation to water quality and pasture type

Pasture Type Water Quality Saline (saltbush,

bluebush or lakeside)

Non-saline (grassland, hummock grassland, mulga shrubland) Less than 5000 ppm* 1.0 – 2.5 km 1.5 – 3.5 km More than 5000 ppm* 0.75 – 1.5 km 1.5 – 3.5 km

* 5000 ppm = 909 ms/m = 350 grains/gal

Pasture type/land system – sites should be placed in country that is:

i. preferred by livestock,

ii. responsive to grazing management (that is, in such a state that it can either improve or decline), and

iii. representative of a significant portion of the paddock or management unit.

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Avoid placing sites on:

o pasture types of low or very low productivity, e.g. hard spinifex,

o pasture types of insignificant area, e.g. a small patch of saltbush amongst mulga, or drainage tracts, or

o transition zones between pasture types.

Sites should also be:

o situated at least 100 m away from roads, fences or other structures that may lead to modified grazing pressure, and

o easy to locate for re-assessment.

Consider whether a site is likely to be affected by future development of fences, tracks or stock water.

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2. Site installation

Once you have chosen a site location based on the characteristics set out in Site location, determine the pasture type from the land system map where available and record it on the Site Installation Sheet. Ideally, the site should contain four indicator species important to the pasture type, of which two would be desirable and two undesirable.

Note: If only one desirable species is present, it is acceptable to substitute an intermediate. If no desirables are present, it is likely the location is unsuitable and another location should be chosen.

The layout of a site is important to ensure that data can be collected in a consistent manner both at other sites across the lease and when sites are reassessed. The site layout for the RCM system is identical for both grassland and shrubland sites, and is illustrated in Figure 1.

After selecting a site location according to the guidelines in Site location, the procedure to install a monitoring site is as follows.

Note: It is recommended you leave your vehicle at least 50 m away, and walk to the site.

Equipment

The following equipment is required to mark out or install each monitoring site (grassland and shrubland) in the paddock:

Two star pickets Picket driver (dolly)

Six steel pegs (preferably galvanised) – see Appendix 1 for design

Hammer

Measuring tape (100 metres in length)

Permanent site identification tag (with fastener) Site Installation Sheet – see Appendix 2

Land system and station map (if available)

Global Positioning System (GPS) unit (if available)

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Figure 1 Site installation Method

Step out the approximate boundary of the site to ensure that the site area is appropriate; for example make sure you can see the two steel pickets from the rear of the site, and that all the target species are contained within the site.

Position steel peg A in the centre rear of the proposed site, as indicated in Figure 1.

Position a second steel peg (B) in the centre front of the site 13.5m from the rear peg, along the axis of the site. Since a photograph needs to be taken, orientate the site more or less in a north-south direction. This avoids taking a photograph directly into the sun.

Position two star pickets (C & D) along the line of pegs A and B. The first star picket (C) should be located 22 m from peg A (8.5 m from peg B), and the second star picket (D) 32 m from peg A (10 m from picket C). This will fix the exact location and orientation of the site. These steel pickets will assist in locating the site in the future.

Position two steel pegs (E and F) 6.5 m either side of the centre rear peg (A) as shown in Figure 1. Then position another two steel pegs (G and H) 2.5 m

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While standing at picket D, record and note down the GPS coordinates for the site (if available) and the access directions from the nearest permanent named point (e.g. windmill, yards, etc.) on the Site Installation Sheet. Mark the site on the station map.

Record the name of the nearest permanent water point and its distance (as the crow flies) from the monitoring site on the Site Installation Sheet.

Finally, ensure all the necessary fields on the Site Installation Sheet (Appendix 2) are complete.

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3. Initial site assessment

All monitoring sites must be assessed in the first year to provide a baseline assessment for the determination of subsequent rangeland condition trend.

Following initial site assessment, one third of all sites must be assessed each year.

Grassland Method

Grassland assessment determines the frequency of selected perennial grasses.

Equipment

The following equipment is required to photograph and assess each site:

• 0.5 m2 quadrat (70 x 70 cm) (grassland only and supplied by the PLB)

• Measuring tape (100 metres in length and supplied by PLB)

• Small signboard to display site identification and date (for use during photography of site)

• Tripod or other suitable support for signboard

• Digital camera

• Site Assessment Recording Sheet – Grassland (Appendix 3) Method

The method to assess a grassland site is as follows (see Figure 1):

1. With the start of the 100 m tape attached at B, mark out the perimeter of the site, moving in a clockwise direction (viewed from above) (Figure 1) via pegs G, then E, A, F, H, and back to B. Then, stretch the tape directly from B to A and attach it at A. Keep the tape taut, but not over-tight, at all times.

2. A frequency assessment (species presence or absence) must be made at 2 m intervals along the tape starting at the 1 m mark. Place the centre base of the quadrat exactly on the 1.0 m mark of the tape as illustrated in Figure 2.

On the Site Assessment Recording Sheet, individually record if any of the four indicator species are rooted within the quadrat by placing a tick in the appropriate box (see Figure 3).

Repeat this procedure at exactly 2 m intervals on the tape (1, 3, 5, , 49 m) to give 25 frequency ratings per monitoring site (see Figure 4).

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Figure 2 Frequency rating using a quadrat on tape

Place the centre of the base of the quadrat exactly on the metre mark of the measuring tape.

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3. Next, count the number of woody species (trees and shrubs greater than 1 m high) on the site (the area contained within the measuring tape) and record this observation on the Site Assessment Recording Sheet as in Figure 5.

4. To assess the soil surface condition, examine the monitoring site, paying particular attention to the presence (or absence) of any material on the soil surface that would interrupt the flow of water (grass butts, leaf litter, etc.), and whether any soil is being lost to erosion. Classes for this assessment are listed on the Site Assessment Recording Sheet. Record this observation on the Site Assessment Recording Sheet as in Figure 5.

5. Next, position the signboard for the photograph, preferably at or close to peg B (using a support if vegetation obscures the signboard). Write the site identification and date of assessment clearly on the board so that they will be visible in the photograph.

6. Stand at star picket C and photograph the site. Adjust the camera zoom so that the site perimeter is just inside the photograph, and keep a small amount of sky in the top of the image.

Note: While it may be preferable to take the photograph from an elevated position, such as from a stepladder, consider that all subsequent photographs will need to be taken from the same perspective.

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Figure 5 Recording woody weeds and soil surface condition

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Shrubland Method

Shrubland assessment determines the density of selected perennial shrubs.

Equipment

The following equipment is required to photograph and assess each site:

• Measuring tape (100 metres in length supplied by PLB)

• Small signboard to display site identification and date (for use during photography of site)

• Tripod or other suitable support for signboard

• Digital camera

• Site Assessment Recording Sheet – Shrubland (see Appendix 4) Method

The method to assess a shrubland site is as follows (see Figure 1 on Page 8):

1. With the start of the 100 m tape attached at B, mark out the perimeter of the site, moving in a clockwise direction (viewed from above) (Figure 1) via pegs G, then E, A, F, H, and back to B. It is recommended that the tape then be stretched directly from B to A to divide the site in half (for ease of counting).

Keep the tape taut, but not over-tight, at all times.

2. Count the number of live indicator shrubs present on the site. Record each of the counts on the Site Assessment Recording Sheet (Figure 6).

Hint: Since the tape from B to A splits the site in half, count each side separately, and sum the results to give the final count for each species.

Note: Chenopod shrub mounds with multiple stems should be counted as one plant provided individual stems are no more than 30 cm apart. Only count plants that have at least half of their base anchored on the site (inside the tape). Only count shrubs if they are branched and more than 15 cm high.

3. Assess the number of live perennial grass plants on the monitoring site (an exact count is not required), and record this observation on the Site Assessment Recording Sheet as in Figure 7. There is no need to differentiate between individual grass species.

4. To assess the soil surface condition, examine the monitoring site, paying particular attention to the presence (or absence) of any material on the soil surface that would interrupt the flow of water (grass butts, leaf litter, etc.), and whether any soil is being lost to erosion. Classes for this assessment

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5. Next, position the signboard for the photograph, preferably at or close to peg B (using a tripod if vegetation obscures it). The site identification and date of assessment should be written on the board so that they will be clearly visible in the photograph.

6. Stand at star picket C and photograph the site. Adjust the camera zoom so that the site perimeter is just inside the photograph, and keep a small amount of sky in the top of the image.

Note: While it may be preferable to take the photograph from an elevated position such as from a stepladder, consider that all subsequent photographs will need to be taken from the same perspective.

Figure 6 Recording shrub counts

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Figure 7 Recording perennial grass and soil surface condition

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4. Site re-assessment

The re-assessment of an RCM site is identical to the initial assessment apart from two important differences. These are:

1. At re-assessment, the assessment sheets will automatically contain the data from the previous assessment;

2. At re-assessment, you are required to make an assessment of range condition trend (change) at the site, by comparing the current data with the data from the previous assessment.

Determining range condition trend – Grassland

Assessment of range condition trend at a grassland monitoring site must be determined using the change in:

i) frequency of the indicator perennial grass species, ii) density of woody species, and

iii) change in soil surface condition (if any) e.g. poor to fair.

This is illustrated in Figure 8.

Make the assessment: What is the range condition trend at the site? Consider what data from the monitoring site supported this assessment (for example, frequency of desirable perennial grasses and soil surface condition). Record this assessment on the recording sheet, as illustrated in Figure 9.

Improved

Remained the same

Declined

Increased frequency of desirables Decreased frequency of undesirables

Decreased frequency of desirables Increased frequency of undesirables

More palatable perennial grasses Fewer ‘holes’

Fewer palatable perennial grasses Decline in soil surface condition

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Figure 9 Recording the assessment

In terms of using this data and assessment in ongoing management decisions, consider what are the implications of this trend, and what is causing it?

• What has the season been like, how intense was the rain and when did it fall?

• Are unmanaged grazers (kangaroos, feral stock) having an impact?

• Are there any other factors which may have had an influence on this trend (wildfire, flood event)?

• Given the trend, should I adjust grazing pressure in this paddock?

Determining range condition trend – Shrubland

Assessment of range condition trend at a shrubland monitoring site must be determined using the change in:

i) the number (count) of the four (4) indicator shrub species, ii) density of live perennial grass plants, and

iii) soil surface condition change (if any) e.g. fair to good.

This is illustrated in Figure 10.

Make the assessment: What is the range condition trend at the site? Consider what data from the monitoring site supported this assessment (for example, number of desirable shrubs and soil surface condition stable). Record this assessment on the recording sheet, as illustrated in Figure 11.

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Figure 10 Indicators of rangeland condition trend in shrublands

Figure 11 Recording the assessment

In terms of using this data and assessment in ongoing management decisions, consider what are the implications of this trend, and what is causing it?

• What has the season been like, how intense was the rain and when did it fall?

• Are unmanaged grazers (kangaroos, feral stock) having an impact?

• Are there any other factors which may have had an influence on this trend (wildfire, flood event)?

• Given the trend, should I adjust grazing pressure in this paddock?

Improved

Remained the same

Declined

More desirable shrubs Fewer undesirable shrubs

Fewer desirable shrubs More undesirable shrubs Decreased biomass

Reduced landscape function

More perennial grass Increased biomass

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Glossary

Annual plants complete their life cycle within a single year Baseline the initial RCM site assessment

Biennial plants neither annual nor perennial; plants that require more than one season to complete a life cycle, but rarely survive beyond two years

Chenopod salt-tolerant shrubs such as saltbushes, bluebushes and samphires

Plant density plant spacing

Desirable plants productive and palatable to domestic stock and drive pastoral production

Frequency the number of times a plant is present

Grasslands vegetation characterised by perennial tussock and hummock grasses, occurring primarily in the Kimberley and Pilbara regions

Grazing radius between 1.5 km to 3 km from a water point Hummock grasses grasses that grow in mounds such as spinifex Indicator species plants that either increase or decrease in

population density and distribution in response to grazing pressure

Intermediate plants a large group of plants that may or may not be palatable but do not increase to any great extent when other palatable species are removed

Perennial plants plants that live for more than two years Sacrifice zone the area adjacent to a stock water

Shrublands vegetation characterised by shrubs with a variable mulga (Acacia aneura) or eucalypt overstorey, occurring primarily in the Gascoyne, Murchison, Goldfields and Nullarbor districts

Soil surface condition describes the soil’s capacity to retain water and ensure soil stability

Tactical grazing management seizing opportunities to influence vegetation change for the better and to reduce the risk of

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Range condition trend the change in condition of the base resource (vegetation and soil)

Tussock grasses grasses that grow in clumps such as Buffel grass or Mitchell grass

Undesirable plants plants that are unpalatable and of limited value to stock

Woody perennial species trees and shrubs greater than 1 m high

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Appendix 1: Steel peg dimensions

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Appendix 2: Site Installation Sheet

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Appendix 3: Site Assessment Recording Sheet – Grassland

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Appendix 4: Site Assessment Recording Sheet – Shrubland

Figure

Table 1  Site  distance  from  nearest  water  in  relation  to  water  quality  and  pasture type
Figure 1  Site installation  Method
Figure 2  Frequency rating using a quadrat on tape
Figure 5  Recording woody weeds and soil surface condition
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References

Related documents

4 Annual Audit Compliance Report Form Section E – Details of non-compliance with licence condition Figure 2 – Process Water Pond and Monitoring and Recovery Bore Locations

Department of Water and Environmental Regulation 2 Annual Audit Compliance Report Form Section E – Details of Non-Compliance with Licence Condition Please use a separate page for