A GRAZIERS' GUIDE TO THE MALLEE COUNTRY OF WESTERN NSW

Mallee country- what should you do with it?

Are you happy that you are doing the right thing with it? Are you worried about the fire hazard? Is mustering taking too long? Are weeds invading your country? Do you know what condition your mallee is in? ARE YOU MANAGING YOUR PROPERTY EFFE01VELY?

Although mallee is one of the less pastorally productive range types, there are still options available to increase sustainable production.

'Sustainable' production is production without degradation to the soil and the pasture. If these have been degraded (if soil starts to erode or unpalatable plants become dominant), animal production drops as pasture quality and quantity are lowered.

There are lots of constraints to production in mallee country, and perhaps the greatest is one that is common throughout western NSW ­unreliable rainfall. By planning for dry spells and drought, you can save yourself a lot of problems.

This booklet aims to help you understand and manage mallee lands more effectively.

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This diagram shows just how

frequently droughts have occurred. We

must expect them to continue

occurring regularly.

Mallee lands, characterised by multi-stemmed eucalypts, occur across southern Australia, generally on wind-formed (aeolian) landforms, with sandy soils.

Mallee rangelands occur in the 250 to 380 mm rainfall zone. However, drought is a fact of life in these areas, and the rainfall will often be less than 100 mm per year. The rainfall tends to fall mainly in winter in the southern areas, while in the northern mallee areas (between Ivanhoe and Cobar) rainfall is more evenly spread throughout the year.

Another feature that occurs repeatedly in the mallee is fire-in fact, mallee is a fire-promoting vegetation type. Major wildfires raged through large areas of the mallee during the summers of 1957-58, 1964-65, 1974-75, 1976-77 and 1984-85.

In general, mallee soils erode readily once stripped of vegetation and are low in fertility. The soils on the dunes tend to be sands, whereas in the swales and plains calcareous red or brown earths are more common.

The mallee in western NSW is most commonly used for gazing, although some areas with higher and/or more reliable rainfall have been developed for cropping. Another significant land use is conservation of the mallee habitat and land type. In fact, about 1800 km2 or almost 10% of the mallee in NSW is conserved in National Parks and Nature Reserves. Other land uses in the mallee include

Siliceous Sand Calcareous Earth honey production, eucalyptus oil production and harvesting of broombush for brush fencing.

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The Mallee Ecosystem Like many rangeland types, the mallee ecosystem is very

resilient in the face of changes such as drought, fire, rainfall and even grazing. Changes occur in the quantity and diversity of the vegetation, but they are rarely permanent.

Mallee trees dominate the vegetation in mallee communities. They have very deep root systems (roots have been found at depths of 28 m) and are thus able to obtain soil moisture at depth. This means that their growth rate is not affected by individual wet or dry periods. In fact, unlike the more shallowly rooted herbaceous species, mallee eucalypts tend to grow in summer, even though this is the drier season. The herbaceous species commonly grow from early autumn to late spring. The sandy soils of the mallee country tend to favour mallee trees rather than herbaceous plants because most of the water in the soil is found at depth rather than near the surface. As well, mallees concentrate rainfall down their stems to the base of the tree, to such an extent that the amount of water in the soil around the base can be up to ten times higher than the actual rain received. Mallee eucalypts therefore suppress the herbaceous (or pasture) layer in all except wet periods. Consequently, following a fire, it is possible for the pasture layer to flourish for a period of time in the absence of competition from the mallee trees. It is probable that in 'pre-European times’ fire was a more frequent event than it is today. It has been suggested that if fire were more frequent now, dense stands of woody shrubs would be less common, since they are susceptible to fire when young.

Mallee Eucalypts

• pointed mallee (Eucalyptus socialis) and congoo mallee (E. dumosa) are the most common species

• trees are usually multi-stemmed. The stems or trunks increase in size yearly in the absence of fire

• main growth period is in summer (October to March) • litter production is highest in summer • regeneration is usually from lignotubers (the 'mallee root')

rather than from seed • seedlings are suppressed, developing mainly after some form

of disturbance - for example, a spring burn followed by good autumn rain

• highly resilient to natural or wildfire; even if above ground part of plant is completely burnt, shoots are produced from the lignotuber

• repeated autumn burns (carried out whenever there is sufficient fuel - i.e., every four to five years in open mallee containing speargrass) will reduce mallee density

Mallee Eucalypt - Yorrel

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Common Mallee

Big Mallee

Mallee Types Mallee can be classified into many different types according to

different criteria. The types that follow are only one way of classifying the mallee, based on the type of mallee trees occurring and what other plants occur with them.

COMMON MALLEE is the most widespread type occurring in NSW It consists of low, multi-stemmed mallee trees (Eucalyptus spp.) which are closely spaced. When very dense and low, it is known as 'whipstick' mallee. Associated trees include sugarwood (Myoporum platycarpum), rosewood (Heterodendrum oleifolium), needlewood (Hakea leucoptera) and butterbush (Pittosporum phylliraeoides). Wattles (Acacia spp.), cassias (Cassia spp.), turkey bushes (Eremophila spp.), hopbushes (Dodonaea spp.) and other woody shrubs are also usually present.

BIG MALLEE is dominated by larger 'bull' mallee trees. The shrub storey is often sparse. Saltbushes (Atriplex spp.) and bluebushes (Maireana spp.) may be present. In wet years speargrasses (Stipa spp.) can become abundant. This type of mallee country is reasonably good grazing country and can be cheaply improved by burning.

SALTBUSH MALLEE is similar to Big Mallee but good stands of saltbushes (Chenopodium spp. and Atriplex spp.) or bluebushes (Maireana spp.) are present.

PORCUPINE GRASS MALLEE typically occurs on the sandy infertile soils of dune crests and extensive inter-dune sand plains. The understorey is dominated by porcupine grass (Triodia irritans). This type is unsuitable for clearing because of its highly erodible soils.

SCRUB MALLEE supports a moderate to dense understorey of shrubs such as broombush (Melaleuca uncinata) and occurs throughout but is most common in the higher rainfall areas.

Saltbush Mallee

Scrub Mallee

Porcupine Grass Mallee

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IMPORTANT SPECIES IN THE MALLEE Of the 270 or so species recorded in the mallee of western

NSW, some have particular significance to the rangeland manager. Some are important for forage, others are weeds, some have value as soil binders, and the presence of others can reveal something about the condition of the pasture. Some examples:

Dodonaea attenuata (narrow-leaf hopbush) • a mufti-stemmed shrub occurring mainly in open areas and

on abandoned cropping paddocks • a woody weed - suppresses pasture production and

reduces carrying capacity • may be browsed, especially by cattle, when other forage is

absent • seedlings are susceptible to drought and commonly die

during their first or second dry summer • fire can kill adult plants, and does kill seedlings, but also

promotes germination of seeds • fire can be used to control invasion of this shrub if there

is sufficient grass fuel, particularly when the plants are young

• follow-up burns are necessary to control emerging seedlings

• grazing management is important following fire - seedlings can be stressed by allowing large quantities of grass to remain over dry summer periods

• control of outlying shrubs, particularly those less than 1 m tall, is important in limiting speed of invasion

• large-scale infestations can be controlled on areas where regular cropping is possible

Melaleuca uncinata (broombush) • a mufti-stemmed shrub occurring mainly on the deep red sandy

soils and loams of the eastern mallee lands • regenerates after fire, shooting from ground level not grazed by

stock • harvested for brush fences

Sclerolaena diacantha (grey copperburr) • short-lived perennial plant grows throughout the year,

particularly in the warmer months, if moisture is available • highly resistant to drought • responds to isolated rainfall events • a major herbage species after fire • good drought forage

Sclerolaena diacantha Grey copperburr (Photo: Plants of Western NSW)

Dodonaea attenuata Narrow-leaf Hopbush

Melaleuca uncinata Broombush (Photo: NPWS)

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Stipa sp. Speargrass (Photo: Plants of Western NSW)

Stipa spp. (speargrasses) • previously known as 'variable speargrass; there are now a number of

separate species recognised • short-lived perennial grasses, growing mainly in winter or after

good summer rains • can respond to rain during any season • shoots from the butt for a number of years if seasons are suitable • palatable and good feed when actively growing, that is, in

winter or after summer rain • seeding generally occurs in spring and early summer • following a good growing season, seeds can be a serious

problem to stock health, lodging in the eyes, lips and skin • prolific winter growth is likely to carry over into summer and

provide fuel for fires

Triodia irritans (porcupine grass) • a hummock-forming grass • common on dune crests and sandplains but occurs throughout the

mallee • growth occurs mainly in spring and summer or after fire a fire-promoting species • a useful binder of sand dunes • its presence is an indicator of very sandy soil which is liable

to drift if cleared.

Other species of importance or abundance in the mallee include:

Asphodelus fistulosus onion weed weed Atriplex stipitata bitter forage, including

saltbush during drought Dissocarpus paradoxus cannon ball forage, including

during drought Enchylaena tomentosa ruby forage, including

saltbush during drought Goodenia spp. goodenias pasture Haloragis odontocarpa toothed forage, particularly

raspwort after fire Maireana pentatropis erect mallee drought forage

bluebush Myoporum platycarpum sugarwood fodder tree Zygophyllum apiculatum gall weed forage

Triodia irritans Porcupine grass

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GRAZING There are several grazing systems that can be used on mallee

lands; however, it isn't possible to recommend just one for general adoption. This is because of the different situation on each property, with regard to both improvements (water, fences, etc.) and mallee types.

Continuous grazing needs a permanent supply of water. When used in paddocks containing more productive open country as well as areas of dense mallee, stock generally tend to graze the open country. Whenever there is a flush of pasture growth, they move into the mallee as well. This results in a form of opportunistic grazing, which is when the mallee is stocked only in good seasons when there is plenty of feed and water. Opportunistic grazing is possibly the most commonly used grazing system in the mallee.

Forms of rotational grazing are not widely accepted in the mallee and there is no documented evidence as to which is more appropriate. Some graziers practise drought reserve grazing, allowing stock to graze the mallee during droughts once the more productive open country on the property has been used. The logic behind this is that the open country is rested when it needs it most - i.e., during drought - and during good seasons the mallee has a chance to recover. However, other graziers believe that the mallee will be eaten out by vermin during good seasons if it is not stocked. Some graziers use every opportunity to burn 'porcupine grass mallee: Any rain that falls will then produce far more feed in these sites than on the heavier soils in more open mallee. Summer grazing is also practised. In general stock can be mustered on water points; however, in wet or humid summers, when mustering is more difficult, flystrike may result in heavy stock losses. Take care also during high-fire-risk summers not to place stock in potentially dangerous situations.

For graziers with significant amounts of other types of country, or who have mixed farming enterprises, there is the option of not using the mallee at all, particularly if it is unwatered or difficult to water.

Stocking Rates and Carrying Capacities One of the few aspects you can alter to influence the health and

composition of your pasture is the stocking rate. General experience in semi-arid lands has shown that lighter stocked properties are more profitable in the long run than more heavily stocked ones. Actual stocking rates vary according to the type of mallee. Porcupine grass mallee has the lowest rates with estimates of one sheep to fifteen to twenty hectares or even lower if there are dense woody shrubs. Saltbush mallee can carry slightly higher numbers, but the most productive is Big Mallee with about one sheep to ten hectares. Higher stocking rates are possible when other rangeland types occur within the mallee.

Carrying capacities are the numbers of animals that can survive the greatest period of stress each year on a given land area without causing degradation. Soil conservationists are available to assess the carrying capacity of your property if desired. In doing so, they take into account rainfall, soil characteristics, drought forage, pasture, tree and shrub cover and property improvements. If stocking rates are adjusted to the suggested carrying capacity, the country will stay in good condition for up to twelve months into a drought. Further adjustments (destocking) will be required to maintain the country in good condition if the drought continues longer than twelve months.

For more information on low-risk stocking and grazing rates, see Range Notes 1 and 2, produced by the Soil Conservation Service.

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Dense speargrass growthfollowing rain

Drought No-one in the mallee can avoid drought; however, it is possible

to plan for it and reduce its total cost. Being prepared for a drought -knowing when to destock, etc. - can make life a lot easier. Make decisions related to drought as early as possible. Keep stocking rates low enough during good years to ensure that grasses and drought forage are not depleted. Resist the desire to restock immediately following a drought as the risk of degradation to pastures is highest at this time.

Grass Seeds Grass seeds become a problem to stock following

particularly wet seasons. Speargrasses produce sharp seeds that pierce the sheep's skin causing loss of appetite and condition. The seeds can also accumulate under the chin and around the legs to such an extent that they inhibit movement. The physical irritation to the sheep can be so extreme that they may die of starvation or thirst rather than track through dense speargrass areas. Solutions to this problem include:

• deliberate overgrazing of small areas to prevent seeding • slashing tracks through dense, mature stands so stock can

move between watering points and 'safe' grazing areas • the running of cattle, which are reported to remove seed heads at

flowering time • occasionally cropping paddocks in suitable areas, decreasing the

occurrence of speargrasses, and providing a refuge in 'grass seed years'.

Mustering ProblemsMustering can be a time-consuming process in mallee

country because vision is limited by the dense vegetation. Aswell, stock in mallee country tend to disperse into small flocks,spread over a wide area.

There are several techniques that can be used to makemustering quicker and easier. During hot, dry periods, stock can bemustered off water points. In cooler periods, some graziers havehad success mustering along windward fencelines after two or threedays of continuous strong wind because sheep tend to graze intothe wind. Mustering is also easier if the mallee has been opened upby fire or by mechanical means.

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CLEARING/CROPPING Clearing, either for cropping or for encouraging pasture growth,

is an option that in some cases may be worthwhile considering. However, it is not always advisable to clear mallee. In many cases, if there is other, more productive country available, the best idea is to leave the mallee unused and concentrate on other country on your property. However, if you do decide to clear some of your mallee land, you must first apply to the Western Lands Commission, as all clearing in the Western Division is subject to the Commission's approval.

How to Clear Mechanical clearing is usually carried out in winter. A common

method involves bulldozers linked by heavy chains. Bulldozing with scrub rakes is also common. This is followed by windrowing, stump removal and mechanised stick-raking. It is particularly important to remove stumps if the land is being cleared for cropping.

(This gives more options with the type of tillage equipment you can use.) Where clearing is for pastoral purposes only, the clearing program may run over several years; if clearing is for cropping, it is generally no more than three years from the start of clearing to the first crop.

Another method of clearing is by using fire. In mallee communities where speargrasses are abundant, a series of autumn burns (say, three times in seven to ten years) will effectively thin the mallee without causing the soil disturbance associated with mechanical clearing. More details on clearing mallee using fire can be found in the following section.

Several phases are needed in the clearing process to overcome the repeated regeneration of the mallee tree from lignotubers (stumps). Where to Clear

There are a number of points to consider when deciding where on the property to clear. Firstly, any mallee on dunes should not be cleared at all - the soil on dunes is very sandy and unstable if exposed and may erode if the protective vegetation is removed. Also, the dunes are the least fertile areas and can conserve only very low amounts of water. Mallee on swales and flats is more suited to being cleared. Other points to consider include:

• proximity to the homestead (due to the possibility of dust during clearing and cultivation)

• ease of watering • proximity to sources of vermin (which can damage crops) • accessibility to transport (if intending to crop the cleared land). Big mallee is more easily cleared than the denser whipstick

mallee. In fact, dense whipstick mallee is rarely cleared other than for specialised purposes, such as laneways for ease of mustering or through speargrass-affected areas and clearing for fencelines or for holding paddocks.

It is important to retain shelterbelts around cleared areas. They help reduce wind erosion and also act as reserves for native species, including forage plants. The Western Lands Commission imposes conditions regarding width, location, etc., of shelterbelts. Copies of the schedule of conditions are available from the Western Lands Commission.

Benefits of Clearing When correctly carried out, clearing and cropping can:

• generate additional income • help control woody weed infestations • permit easier access for fire control • provide opportunity for more productive pastures to be

sown

Erosion caused by clearing and cropping

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• increase carrying capacity • help control vermin by removing habitat provide drought • fodder if some of the crop is stored, either as hay or grain • reduce grass seed problems.

Limitations Because clearing and cropping alters the natural soil/vegetation

balance so drastically, there are a number of limitations, besides salinity, to be aware of. The first, and most important, is that clearing can lead to soil erosion if cleared land is not managed properly. Poor management practices include bare fallowing (rather than stubble retention) and the overgrazing of pasture between crops. Erosion will also occur if the crop fails or if it is not sown once the initial cultivation has produced a bare surface. Cultivating at high speed using conventional tillage methods also encourages soil erosion by damaging what little natural soil structure there is. Successful opportunistic cropping in these areas ultimately depends on equipment that retains, rather than destroys, vegetative residues.

Change in the pasture composition is another form of degradation that can accompany clearing and cropping. The useful native perennial species decline and are replaced by annuals (often weeds) and less useful perennials. This results in less protection of the soil during dry periods, which are regular features of western NSW. One of the problem perennial weeds that invades is onion weed. It becomes more abundant with both irregular cultivation and overgrazing.

Salinisation is a third form of degradation that may occur as a result of widespread clearing. The effect of mallee clearing on soil salinity and groundwater levels has not yet been fully determined, but it has been shown in Victoria and South Australia that clearing on some sandy soil types increases waterflow to groundwater systems by up to 300 times. Although water tables in NSW are still mainly 20 m or more below the surface, there is concern among scientists that widespread clearing could see water tables rise to the level where productivity could be seriously and permanently affected, particularly along the Murray River.

< Erosion caused by clearing and cropping

< Invasion of punty bush following cropping of cleared land

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FIRE Mallee is fire-prone country. The vegetation is highly

flammable because of the high amount of litter fuel it produces. As well, porcupine grass, speargrasses and mallee leaves themselves are very flammable

Wildfire Wildfires are highly likely when dried off speargrasses are

abundant, particularly if there is a lot of dry electrical storm activity. The huge bushfires of summer 1974-75 were caused by lightning strikes after a particularly wet season.

Control of wildfires is best, but not totally, achieved by infrequent prescribed burns to reduce the fuel load. After a number of years, a mosaic of burnt and unburnt mallee land develops, growing herbage and giving protection from fire. As well, a network of fire trails has been created in several mallee areas to improve access for firefighting and to form lines for burning off. Fire as a Management Tool

Fire can be used to manage the density and species composition of mallee lands. It is perhaps the most effective tool available to managers of mallee country. Fire can be used for several purposes:

• to increase forage • to control woody weeds • to reduce wildfire hazard • to open up mallee.

Different results can be achieved by varying the season and frequency of the fire.

Fires in mallee country are followed by a flush of herbage that can last for several years. The fire reduces the canopy foliage (of mallee eucalypts, etc.) and the density of shrubs. A number of native pasture species such as toothed raspwort are adapted to fire and rapidly recolonise the area following suitable rains. Multiple autumn burns (up to three in ten years) can lead to an opening up of the mallee by reducing the density of the mallee eucalypts. This is only possible, however, in mallee with abundant speargrasses and more reliable coolseason rainfall. If the understorey is dominated by porcupine grass, burns are usually possible only once every fifteen to twenty years.

Leaf, twig and bark litter shed by mallee trees is highly inflammable (Photo: WLC)

Dr Jim Noble, of CSIRO, has demonstrated the cost-effectiveness of clearing by fire at ‘Earl’; west of Euston. After a wildfire in 1975, three prescribed burns were carried out in 1980, 1982 and 1985, with the following results:

� doubling of the stocking rate � gross margins increased from $2.31 to $5.00 per hectare � lamb weaning increased by 30% � stock management, particularly mustering, vastly

improved.

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A major advantage of clearing by fire rather than with bulldozers is that fire will thin mallee only where sufficient fuel is present. The

A flush of herbage following fire several years earlier (Photo: Jim Noble, CSIRO)

dunes, potentially erodible, do not carry sufficient fuel for such frequent burns. Thus forage production can be maximised while maintaining soil stability. These less frequently burnt areas also act as reserves for native plants and animals as well as preventing erosion.

In contrast to autumn burns, which cause a substantial reduction in mallee eucalypts, spring burns encourage seedling regeneration.

Woody plants can also be managed by fire. The germination of narrow-leaf hopbush, like many other woody shrubs, can be enhanced by fire. However, the seedlings are killed by fire, so if burns are timed to coincide with seedling establishment or when shrubs are small, some measure of control can be achieved. Seedling establishment generally coincides with high quantities of grass fuel (that is, after a wet season). This is the time to attack. By the time the grass is dry enough to burn, it is of little feed value and fire can be used to control young shrubs and prevent future problems. Such germinations and good seasons may occur every six to twenty years, and judicious burning at those times may well be sufficient to control most infestations. More detailed information on management of woody weeds can be found in the Soil Conservation Service publication "Woody Weeds Their Ecology and Control"; and in Soil Conservation Service Soil Note No 13/84.

Fire hazard can be reduced by developing a mosaic pattern of areas with varying fuel loads. This is done by burning different areas at different times. Fire does not endanger the mallee ecosystem; in fact, the mallee ecosystem is adapted to fire. There is a need for regular burns to ensure the health and species diversity of mallee lands. Fire is a natural process operating in the mallee.

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Conducting a Prescribed Burn Conducting a prescribed burn is not a particularly difficult task;

the ingredients for success are experience, commonsense and good preparation. It is desirable to develop a plan for conducting a prescribed burn six to twelve months before the event. The first step is to examine the fuel available. A decision on how to burn the area should be made at this stage. A map of the area to be burnt should be drawn, and neighbours and relevant bodies (Shire Councils, Bushfire Brigades, etc.) should be informed.

Because the mallee is so flammable, pay considerable attention towards constructing adequate firebreaks, particularly during high fire risk seasons. If firebreaks are to be burnt, do it when there is a low risk of escape. They should be at least 40 m wide.

The decision on when to burn an area is based on information about the flammability of fuel, the forecast temperatures, wind speed, wind direction and wind duration and the availability of personnel. Weather conditions greatly influence rate of fire spread and success of the burn.

The most common method of lighting up is to ignite a fire line with a drip torch, either with or against the wind, to form a headfire or backfire respectively. If there is little wind, a second line of fire may be lit to ‘draw in the fire’ thereby increasing the rate of spread. Where fuel is discontinuous, individual patches may be lit by traversing the area in a grid line fashion. In these systems of lighting up, the operator may walk or ride on a vehicle with the drip torch in hand.

Until recently, prescribed burning has been limited to relatively small parcels of mallee due to the logistical coordination required for large-scale burning. Aerial ignition has many advantages over other methods, including: • large areas can be ignited in a short time (two or three hours) • It can be quickly employed when conditions are at their best • it overcomes problems of discontinuous fuel the risk of a

high-intensity fire developing (because of high fuel loads) is minimised by lighting many small fires that soon join up.

There are several bushfire prevention schemes operating in the mallee country. They provide a valuable service in all fire-related matters. Their charter is to maintain a network of fire trails and to monitor fuel loads. They also advocate hazard reduction burning.

Lighting up with a drip torch

A prescribed burn (Photo: NPWS)

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WATER Water is the lifeblood of any property, and the provision of

watering points opens up areas to grazing that would otherwise be unusable. Much of the mallee country is unwatered - i.e., is beyond the generally accepted 5 km limit that sheep will walk from a watering point. This is partly because many properties have other, more productive types of country which are improved in preference to mallee and partly because surface water is hard to obtain.

A well-designed distribution system, which both reduces stock daily walking distances and services under-utilised grazing lands, will be cost-effective to the landholder. Location

There are several points to note when deciding on the location of watering points. Because the watering point will suffer intense grazing and trampling, it should be in the least fragile environment possible. A sand dune near to a watering point is likely to become very degraded by the continual movement of stock. Corners of paddocks should be avoided to help prevent the concentration of stock in confined areas and the formation of stockpads along fencelines.

Erosion around a water point aggravated by a nearby gateway. \

Good excavated earthen tanks, common throughout western NSW, are not as common in the mallee because of the lack of good catchments and suitable impermeable subsoils. Many mallee graziers have installed expensive pipeline networks to reticulate pumped water from permanent sources, such as the Murray or Darling Rivers, to watering troughs up to 80 km distant. In some cases a single pumping source on the river can serve several properties away from the river with the advantages of sharing the capital cost.

Watering systems give the grazier better control of grazing animals including domestic stock, feral goats and kangaroos, since individual watering troughs can be shut off wherever grazing is not required in specific areas or paddocks. Efficient watering systems introduce a further responsibility to the grazier - by eliminating 'water drought’; the grazier must adjust grazing pressures to avoid damage to perennial forage reserves.

The Soil Conservation Service can help you with watering your property in the following ways: • assessing water requirements for stock and domestic uses • advising on suitable sites for ground tanks • advising on drought-proofing of properties • advising on water quality • advising on licensing requirements • assisting with pumping equipment, pipeline, tank and • trough selection and performance checking • providing certain financial assistance

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'MALLEE VALE' - An Action Plan FIRE • Bill's and Joe's Paddocks are most suited to a controlled burn because

dunes are well spaced, and when the fuel load on the adjacent open country is low it forms a natural firebreak. The roads and fencelines can be used to break the burn into manageable units. There is relatively good potential for future water supply extensions from the bore and from the house tank should there be no bore or tank sites available.

• The burn would be from the south-west; in other words, burning into the property. There is thus less chance of the fire getting away into neighbouring properties. Open Plains

• The dense mallee in Mallee Paddock could give a better grazing response once burnt, but there are lots of dunes that would be best left unburnt, and the fire would not be as easy to manage Open Mallee

(firebreaks, water, neighbours, etc.). WOODY WEED CONTROL

Dense Mallee with • Destruction, or at least active containment, of the two small well-spaced sandhills

patches of woody weeds is essential to protect the grazing productivity of the rest of the property.

Dense Mallee with close • Because of the small area of the woody weeds, an intensive sandhills

control program can be carried out with the costs being apportioned over the remainder of the productive country, since this action will prevent spread. Dense Mallee

CLEARING AND OPPORTUNITY CROPPING Clearing should be undertaken only after serious consideration. Options are limited and depend on the resources and location of the Watered area property (e.g., favourable rainfall zone, stable soils, etc.).

Woody weed infestation

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• Development of open mallee or open plains country may be cheapest initially, but increase in returns will not be as high as developing the dense mallee. • Clearing of some of the level, dense mallee in the north-east corner of Bore Paddock should result in a greater increase in production. The soil in this area may be expected to be better for low rainfall crop production. Also, this area is already fenced on two sides. However, it is isolated from the homestead, lacks a water supply and is adjacent to large expanses of undeveloped country which will act as a harbour for crop predators. • Cropping to control the patch of woody weeds near the house should be considered as, although small, this area is adjacent to water and the homestead, and percentage increase in return would be high. WATER • A further watering point at the eastern end of Road Paddock is essential. Water from here could be piped into Joe's Paddock as well. • Piping of water away from the bore site is recommended to reduce the concentration of stock on the country around the bore. It would also make more of the property available for grazing. • A pipeline/trough system from the house tank (depending on its capacity) into Joe's Paddock, or the establishment of a watering point (tank or bore) in this paddock is, recommended. • Extension of water into Mallee Paddock is not justified unless this country is developed.

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RANGE CONDITION AND ASSESSMENT It is important to be able to identify the condition or 'health'

of your rangeland if you are to make proper decisions on its use. Mallee is fairly resilient in its uncleared state; changes in condition may therefore be difficult to detect. Good condition in the various types of mallee has not as yet been documented. However, those experienced in the area will have a feeling for what 'good condition' is. For example in saltbush mallee, any decline in the edible shrubs (saltbushes and bluebushes) should be apparent, and would be a sign of declining condition.

Being aware of pasture condition is simply a matter of knowing:

• what it is like now • what its potential is • whether it is changing, and if so • whether the trend is upwards (improving towards its

potential) or downwards. There are three levels at which you can observe your country in

order to assess its condition - looking at it (observing), developing a photographic record (recording), and measuring changes (measuring).

1. OBSERVING Become aware of what you are looking at. The pasture's basic

condition can be masked by factors such as recent grazing history, season, rainfall and fire history. By recognising the effects of these factors, as well as basic features which indicate condition, you can begin to assess your pasture.

Features Indicating Condition Principal Indicators What species are present? Check for edible perennials (although only a minor component of most types of mallee, they are important) and for weeds such as wild sage (Salvia verbenaca) and onion weed. Is there a wide variety of species present? Are there any woody weeds (narrow-leaf hopbush, punty bush [Cassia eremophila], turpentine [Eremophila sturtii])? Can you see any signs of erosion? Is there an organic (mossy) crust on the soil surface?

Features Which May Mask Condition Effect of Grazing Is there a browse line? Any evidence of dung? Are aerial parts of plants missing? Effect of Season

Some species are abundant at certain times of the year or after certain events - e.g., speargrasses are abundant after good winter rain. Pasture condition is different to seasonal condition. Effect of Fire Can you tell if the country has been burnt recently? Some species (known as fire increasers) are more abundant after a fire and can indicate how long ago the fire occurred e.g., a herbage flush will last for two to three years after a fire. Desert poplar (Codonocarpus cotinifolius), which establishes after a fire, will grow for fifteen years or so.

2. RECORDING Being aware of what you are looking at is a good start to range

condition assessment, but it is not enough. As most changes are gradual and easily overlooked, it is a good idea to start taking photographs at the same place over a period of

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years. A photograph will record not only the details we forget, but also those details overlooked in the first place. The main requirement when taking a photo in a paddock is to take it at the same spot, in the same direction, and at the same angle. To do this, it is necessary to mark a permanent site (photopoint).

3. MEASURING Photographs often do not show • the degree of change (quantity changes), and • the type of change (quality changes). The simplest method of measuring these changes in quality and

quantity of vegetation is by step-pointing. Step-pointing is a tested scientific method for estimating vegetation cover and is sensitive enough to identify significant changes in vegetative composition. Step-pointing involves pacing along a line and recording the ground cover directly under a mark at the toe of your boot at each step.

Further details on photo-assessment and step-pointing can be found in Range Note No. 4, produced by the Soil Conservation Service.

The main aim of photo-assessment and step-pointing is to note changes in the pasture. Do not ignore the effect of season. Many species may 'explode' in number only when the right conditions come about. During 'off' seasons such species may not be evident; however, this does not necessarily mean they are totally absent from the pasture.

It is important to be aware of the density of woody weeds (shrubs such as narrow-leaf hopbush, turpentine, Punty bush, etc.). They can encroach relatively unnoticed, particularly during good seasons when they can be masked by a tall grass cover. They are easiest to control when they are establishing as seedlings rather than when they are fully grown.

Soil erosion is another factor to check when comparing consecutive photos. Although accelerated erosion in uncleared mallee is uncommon, it can occur, and if you can recognise it in its early stages and adjust your stocking rates accordingly, you can avoid serious degradation. Points to look for include:

• evidence of soil movement, particularly on very sandy soils • scalding and rifling around drainage depressions • erosion along tracks in sloping country.

Erosion is most likely to occur during or immediately after drought.

If rangeland is in good condition, an organic crust may be present on the soil surface, erosion will be minimal, undesirable species such as woody weeds will be sparse or absent, and a wide variety of species including good forage species will be present. However, because seasons are very variable, not all such species will be abundant or even present at any one time. It is the pasture mix which is important in assessing condition, not necessarily the bulk of pasture present.

The health and production of your stock, and the health and stability of your mallee soils, are directly dependent on the health and production of your pasture. It is often too late to adequately resolve a problem if you wait until stock condition starts to deteriorate. It is far better to be able to act as soon as pasture condition is seen to deteriorate. In this way you are safeguarding your stock as well as your basic resources - the pasture and the soil.

Taking account of the pasture condition, the effect of season, the fire history, and any other relevant factors . . .

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There is a wide range of assistance available to you as a rangeland manager. The Soil Conservation Service has produced a number of publications relevant to rangeland management. These include:

• Plants of Western New South Wales - a comprehensive record illustrating and describing the plants of the area

• Range Notes - leaflets covering topics relevant to western NSW such as stocking rates, pasture assessment and soil types

• Soil Notes - leaflets on a range of topics, including wind erosion and fire control of woody weeds

• Rangeland Reviews - reviews of information relevant to the various types of rangeland country

• Woody Weeds - Their Ecology and Control - detailed information on methods of controlling woody weeds, particularly by fire.

In addition, soil conservationists are available to give professional advice on any matter relating to soil and land management. This includes the provision of Property Resource Plans, which show land types, fences, watering points and tracks. They also contain a report which describes land types, suggests land management options and assesses carrying capacity of land types and paddocks.

As well, there are several other publications that may be helpful: • Management of Australia's Rangelands by G.N. Harrington,

A.D. Wilson and M.D. Young, CSIRO. Chapters 10 and 15 (on fire and mallee) are particularly recommended

• The Use of Trees and Shrubs in the Dry Country of Australia by N. Hall et al. Aust. Govt. Publishing Service. This book covers a wider range of topics than the title suggests.

Compiled by Sue Jacobs, from a review of the Mallee Rangelands by Rob Scriven, and material contributed by rangeland researchers and advisers in western NSW Graphic design by George Biagioni. ISBN 0 7305 5564 X. Produced with funds from the National Soil Conservation Program, 1988.