A Revegetation Guide for Mallee Woodlands 2

A REVEGETATION GUIDE FOR MALLEE WOODLANDS

Who this guide is for multiple stems emerging from This introductory guide is for people a ground level swelling called wishing to learn, or be reminded the lignotuber. The understory about, the basic principles and is variable from dense heath or practices of planting trees and salt bush to sparse grasslands shrubs for revegetation of Mallee (Photos 1, 2 & 3). Temperate Woodlands in the southern regions woodlands are dominated by of Australia. This guide describes single trunk eucalypts and usually eight key steps that need to be occur in areas of higher rainfall. These are dealt with in a separate followed to help ensure a successful Photo 1. A mallee woodland with a dense and revegetation project. revegetation guide. diverse understory.

The importance of Mallee Woodlands STEP 1. Mallee Woodlands occur in Assess site conditions southern Australia, from the coast to far inland, including north western Victoria, central and Revegetation is needed when south western New South Wales, there are local constraints throughout South Australia and into that limit the natural return southern Western Australia with of woodland plant species. Photo 2. A mallee woodland in a low rainfall area small areas found in Queensland Constraints include: with a moderately dense understory. and the Northern Territory. Mallee Woodlands are usually associated Recruitment with landscapes that receive 200 • Lack of seed; -400 mm of rain per year, but • Lack of suitable sites for seed also occur in areas with up to 600 germination (establishment mm per year in south eastern and niche); south western Australia. In arable areas, Mallee has been widely Altered physical environment cleared for agriculture, a process • Temperature extremes - hotter optimistically repeated in marginal and colder than within a areas. Most intact remnants are natural woodland; located now only in conservation • Wind exposure that can Photo 3. A mallee woodland with a very sparse understory found in a low rainfall reserves and on pastoral land. quickly dry out young plants; zone. Mallee Woodlands are dominated • Lack of fire or too frequent by low open eucalypt trees with fire. A REVEGETATION GUIDE FOR MALLEE WOODLANDS 3

Hostile soil conditions for • Harvesting firewood and simple revegetation should be native plants timber; based on a cost vs. benefits, your • Soil compaction from • Carbon sequestration; and objectives and the importance cultivation, vehicles and • Amenity value. of the restoration in the bigger livestock; picture. • Soil erosion by wind and Historically the objective of water; restoration has been to fully Landscape context • Nutrient enrichment (high recreate the native vegetation Ideally revegetation or restoration levels of Phosphorus and believed to have occupied the should buffer and re-connect Nitrogen – good for weeds but site before it was degraded. existing high quality native not most native plants); This has been done by Alcoa vegetation remnants, particularly • Carbon depletion causing poor in Western Australia for Jarrah areas protected by covenants or in soil structure; forest where vegetation was reserves. • Rainfall runs off rather than removed for bauxite mining and infiltrating into the soil (water in Victoria by Dr. Paul Gibson- In many landscapes wildlife, repelling soils); Roy where complex grasslands particularly birds, but can be • Lack of soil microbes that have been recreated. However, used for prioritising connectivity greatly assist native plant comprehensive restoration of between remnant mallee patches. survival and; hundreds of plant species is costly Revegetation is then focused on • growth. ($30-$70,000/ha). In contrast, buffering and re-connecting key revegetation usually only goes woodland remnants to create Threats to mallee plant part way to re-establishing a ‘stepping stones’ or ‘corridors’ survival diverse mallee indistinguishable along these identified broad routes • Weed competition from from healthy native remnants. and may facilitate the movement pasture grasses and weed; The greatest diversity of plants is of wildlife in response to climate • Insect pest; found within the groundcover of change. Strategic revegetation • Grazing by sheep, cattle, high quality woodlands (grasses of this sort provides resilience horses, goats and rabbit; and wildflowers). A diverse mallee to climate change and improves • Browsing by native mammals. understory, including mosses and biodiversity at both a patch and a lichens can be difficult to restore landscape scale. Examine your site to determine if so mallee revegetation tends to you have any of these constraints. focus on trees and shrubs. It is recommended that If you do, then active revegetation revegetation planners consult is likely to be needed, and you will In many cases, where the site is with the surrounding neighbours need to address these threats to so altered that the physical and and local community to identify successful establish a diversity of chemical environment no longer opportunities for linkages with Mallee plants. matches that occupied by the adjacent revegetation work. This original mallee vegetation, a can achieve ecological benefits and compromise may be needed. You some costs savings, but it is also STEP 2. may have to use species that look a process that allows community Set clear site objectives like those that originally occupied concerns to be raised about the site but are much hardier – possible increased fire hazards and i.e. create a structural mimic of pests. There are many different reasons the original mallee woodland to plant locally native mallee using species tolerant of the new species. These includes: conditions. In really tough sites, just getting a couple of species • Wildlife habitat and dispersal of trees and shrubs to thrive is a corridors; major accomplishment. • Shade and shelter for livestock; A decision on whether to attempt • Salinity management ; full restoration, or scale back to A REVEGETATION GUIDE FOR MALLEE WOODLANDS 4

control is most suitable for patchy, Commonly, up to three STEP 3. random, plantings with seedlings applications of herbicide may be Site preparation (tubestock). necessary:

1. Depending on the weeds Mallee plantings are most likely to present, a first spray may be succeed if you’ve prepared the site applied in the late spring or well. The primary purpose of site early summer of the year prior preparation is to build adequate to revegetation to help deal soil moisture before planting and with warm season weeds such control competition (weeds and as kikuyu or couch grass and browsing animals). These are the wireweed. two most important factors in mallee revegetation. 2. At least one spray should be applied in autumn and winter to control weeds which Weed control Photo 4. An area spot sprayed with a knock down Access to moisture throughout herbicide, a weed control technique suitable for directly compete with small the soil profile is essential for small areas. seedlings for moisture and the survival and growth of newly light. Autumn application is germinated seeds or newly suggested if significant rain transplanted seedlings. Soil falls in March or April that moisture must be built up in the stimulate germination and 12-24 months prior to planting growth of weeds. A further by removing plants that would application can follow further otherwise use this moisture. Try to rain in May-June. Ideally, the minimise soil disturbance because first application in the year it will increase evaporation. The of planting or seeding should usual method for achieving this be done 6-8 weeks before is to use herbicides to maintain a revegetation. weed free soil surface after initial 3. A further spray is often soil preparation. Photo 5. A large site Strip sprayed recently direct seeded as well as seedlings hand planted and needed just prior to planting, protected by tree guards. particularly if planting or direct Weeds compete with newly seeding in early spring. established plants for moisture Treat a mallee planting like a high and light. Many weeds are more value crop. Most herbicides should efficient at drawing moisture be applied to actively growing Care must be taken in sandy from the soil than new seedlings, weeds. Getting to know the weeds soils, which are prone to wind resulting in reduced growth or on your site and when they are and water erosion, not to leave plant death. Plants which struggle actively growing is recommended. bare soil exposed for extended in the first few years never reach Spraying when weeds are moisture periods. It may be necessary to their full potential or growth stressed or after frosts or other retain some weed cover on the rate. Weeds should be controlled stresses should be minimized. soil by using a selective herbicide in an area at least 1m in radius or rope-wick applicator. This will around new plants for around 2 Timing of herbicide application slightly reduce moisture depletion years to ensure the plants are needs to be flexible and ideally and seed set whilst retaining soil vigorous enough to out-compete occur 1-2 weeks after rain when binding benefits. Alternatively, weeds. Weed control can be new weeds have just germinated reducing the width of the sprayed split into two categories; spot and older weeds are actively strip or spot can perform a similar control (Photo 4) and strip control growing. Most importantly, function. Spraying strips at right (Photo 5). Strip control is most herbicide applications should be angles to the prevailing wind suitable for dense linear plantings applied well before planting or or along the contour can also such as direct seeding and spot sowing. mitigate erosion from wind and A REVEGETATION GUIDE FOR MALLEE WOODLANDS 5 water. and may move below the seeder scalping depth in deep sands.

The first herbicide application In addition, the scalping blade or should use just a knockdown disc of a direct seeder clears away chemical that kills all actively the weed seed bank in the topsoil growing plants. Residual and removes any germinated herbicides may provide longer weeds leaving a ‘clean’ strip for term weed control and kill new mallee seed germination (Photo weeds that germinate after 8). This scalp results in at least spring rains. Generally, residual a few months of reduced weed herbicides like Simazine will be in establishment post-sowing but the second herbicide application only in the narrow scalped area. as a cocktail with a translocated Photo 8. The scalped seed bed created by a direct seeder, then freshly treated with a knockdown such as Glyphosphate. ‘Dustex strip’ (bitumen emulsion) in the seeding However follow the 30/30 rule. row to reduce wind erosion and seed loss. Wait until at least 30 mm of rainfall has fallen before direct seeding on Make sure your equipment is soil treated with a residual. Such appropriate to the size of the job. a rainfall will move the herbicide Backpack sprayers are suitable for through the soil. Or wait until spraying small areas or individual 30 days have past after residual weeds, while a spray unit with a herbicide application by which tank mounted on a ute or quad time, in the absence of rain, the bike will be necessary for larger herbicide will begin to break down. areas. For very large areas, a So in dry years, use of residuals boom spray will be more efficient. may be wasted as they are only activated in the presence of soil Photo 6. A direct seeder with a large disc that Where large woody weeds are to moisture. A residual such as scalps a clean seed bed. Note the single be controlled, it is more efficient calibrated seed box on top and press Simazine is ideally applied to bare wheel at the bottom rear. This disc seeder to do so before revegetation moist soil. is particularly suited to lighter soils and commences, this reduces off- requires little horsepower (e.g. a ute). target herbicide impacts or Residual herbicides should not be physical damage which can result used just prior to revegetation that from weed control practices. relies on germination of native seed. These herbicides should not It may not be possible to meet be used at all in sites dependent these exacting weed control on natural regeneration. Residual standards outlined above, but herbicides can be particularly experience shows that the nearer useful with direct seeding. All your operation comes to meeting direct seeding machines (Photos 6 these standards and timing and 7) scalp a narrow strip of soil outlined above for weed control using a scalping blade or disc. The the better your mallee plantings seeder also cultivates a seedbed in will survive and grow. the scalped area into which seed is sown. One objective of the scalp Browse control is to remove any residual herbicide Regardless of the quality of weed Photo 7. A ’V Blade’ direct seeder is particularly left from a previous spray. suited to heavier or stony soils, but requires control a mallee planting will fail if However, residual herbicides more horsepower (a tractor rather than a ute). heavily browsed (eaten). Seedlings should generally be avoided in are particularly attractive to free-draining deep sandy soils. browsing animals and easily killed Residual herbicides are mobile by them. Your assessment of site A REVEGETATION GUIDE FOR MALLEE WOODLANDS 6 conditions (Step 1) should have specific advice should be sought Tree guards also protect planted identified which browsing animals before implementing pest control. seedlings from heavy frosts and pose a threat (e.g. livestock, feral Although shooting is a common provide some shade and wind goats and deer, rabbits and hares, control technique it is usually not protection during summer. Guard snails, or natives like kangaroos an efficient option for long-lasting only those high value and costly and wallabies). control. seedlings that are particularly susceptible to pest and wind An ordinary stock fence is usually Tips damage. Using tree guards on any sufficient in areas where it is Try to control foxes soon after scale is a time consuming activity only domestic stock that have controlling rabbits and hares to and adds significantly to costs. to be excluded, or the numbers prevent foxes from switching to of native browsing animals are native prey or stock. There are a variety of deterrents low. However where plantings available (e.g. WR1 and D-Ter), are established to buffer and The control of free-ranging pests that can be applied to the leaves connect healthy mallee remnants, usually requires the co-operation of plants and, through various animal proof fencing will be of surrounding landowners to mechanisms, discourage browsing. needed (consider hinge-lock prevent rapid re-invasion of the However these can only be wallaby fencing or rabbit proof revegetation site. practically applied in a glasshouse netting). Fencing is a major cost or nursery and, once planted, any to a revegetation project, but Where plantings abut remnant new leaves will be susceptible to remember a mallee woodland is a vegetation and where mammal browsing. high value ‘crop’. browsing control is problematic, tree guards can be placed around Even when all controls are in place, It is most important to implement seedlings to prevent heavy grazing. there will be some plant losses, so an integrated pest control program In some cases this alone can deter either plant more the first year, or for as long as possible in the lead grazing, but more often limits the budget to replant the second year. up to revegetation to minimise extent of the grazing to the tips grazing pressure. Integrated in above the guard. Whilst this may Soil preparation this sense means using a broad not eliminate grazing it does allow Ground preparation techniques are range of control strategies in seedlings to develop a healthy used to soften the soil, increase a co-ordinated manner in and root system which prevents pulling water infiltration, soil aeration and around the planting site. Below is the entire seedling out of the allow for easier root development. a table showing possible control ground, and will allow the plant to Ground preparation will vary options. Note that permits are reach greater sizes when grazing according to soil type, site history required to conduct most of these pressure is reduced. and establishment technique being activities and professional site- used. Many mallee plantings will A REVEGETATION GUIDE FOR MALLEE WOODLANDS 7 fail if proper ground preparation is not be done around more than half you are going to revegetate. Get not done. of a single tree to ensure that it is out and have a good walk. If in not severely impacted. doubt contact the landholder Ripping on contours when the and consult local authorities if subsoil is dry is suggested for There are many widely available necessary. compacted soils to re-aerate soil treatments that can improve these soils and allow for easy use the structure and water-holding Insect control of manual planting tools. It is not capacity of the soil, but they do Insects can entirely defoliate plants recommended for deep sands or add considerable cost to planting in the field. This is particularly a calcrete. Riplines will allow ready projects. Such products include risk immediately after planting absorption of moisture through the water crystals, gypsum, compost, when seedlings are small and soil and often produce a reservoir coconut fibre and TerraCottem®. highly nutritious. In areas at of soil moisture, particularly if Inoculants of soil biota, such as risk (particularly near a healthy weeds that emerge along riplines Wattle-Grow®, can be added to woodland remnant) a systemic are quickly controlled. If practical, both direct seeding and seedlings insecticide tablet can be placed rip and plant on level contours. to increase the nitrogen-fixing under the seedling or systemic This will improve water infiltration ability of Acacias and some pea insecticide can be injected into and reduce the risk of erosion on species. the soil around the root bowl hilly country. before planting (usually in the One simple way of maximising soil nursery). Treating insect attack Rows are usually spaced at least 4 moisture in a seedling’s root zone after planting is more difficult m apart to prevent over-crowding is to form a water bowl around the and more costly. Major problems and to allow access in the future plant. This is a slight depression arise with treating for insect attack (especially for weed spraying). The up to 1m in diameter around the when trees are more advanced most efficient method of direct root ball with a built up rim of soil, and growing in the field because seeding large flatter paddocks is to finishing at soil level. This prevents generally, any effective insecticide use cropping circles, starting along rainfall runoff from leaving the that kills the pest species will also the outside edge of the paddock root zone and, if on a sloping kill desirable predator or pollinator (or fraction of the paddock) and site, can be constructed to gather species. progressively seeding smaller nearby runoff. However, creating and smaller “circles’’. This avoids such depressions can only be Some insects, particularly Red- constant lifting and lowering of justified for small sites planted to legged Earth Mites, also consume seeders at the end of rows. It also costly or rare species. roots of young plants. By the time avoids straight row look of seeding In areas where sand drift can blow the impact is evident above ground results. This obviously does seeds away or expose seedling (whitening and leaf deformation), not apply to paddock boundary roots, a seeding row can be the damage underground is usually revegetation belts and should be protected by applying a bitumen significant so it pays to look for used with discretion in hilly areas emulsion to which secures the signs before planting. Often signs with erosion-prone soils. soil surface but doesn’t prevent of these pests are evident in germination (Photo 8). These surrounding crops and vegetation Ripping is also used when products can also create a barrier and should be inspected in the planting adjacent to established which prevents ants from removing lead up to revegetation to ensure mallee vegetation because mature seeds.Click here or here for more effective control. Control usually mallee trees have far reaching information. involves applying a soil active surface roots which will compete insecticide to the root zone of the with the seedlings for moisture ‘Dial before you dig’ seedlings. Ensure the entire area just like weeds do. Severing lateral Site preparation, even the shallow is treated to prevent the pests roots with a ripper is a non-lethal scalp of a direct seeder, could establishing in other areas of the way to reduce this competition. cause damage to cultural heritage, revegetation. This type of ripping should be at threatened species, pipelines, least 5 m away from the base of powerlines, or underground cables. mature mallee trees and should First have a close look at the site Ants are often found moving A REVEGETATION GUIDE FOR MALLEE WOODLANDS 8 seeds, particularly Acacias, from populations (>500 individuals) direct seeding rows to their growing on similar sites within the nests. This is rarely a significant same region so they are naturally problem as little seed is destroyed adapted to the environment of in the process compared to the your site. Rainfall, soil, altitude, amount sown. Sowing the seed aspect, slope and position to a suitable depth or mixing are important factors in plant magnesium carbonate and other adaptation (Text Box 1). deterrents with the seed mix is usually sufficient to discourage An exception to this principle ants. is where the environment has changed to the extent that some local species can no longer survive. Secondary salinity, STEP 4. compacted soil structure, more frequent frost, increased aridity Choose species or waterlogging are reasons you to suit local conditions may need to select alternative species that don’t normally occur locally (for example salt bushes for Choose mallee species that sites that have recently become occur in similar soil-landscape saline). A ‘nursery’ planting of non environments. Where possible, local species may first be required choose locally occurring plant to reduce wind exposure, water species that match the relative logging, salinity or other factors abundance found in remnant hostile to restoration of locally mallee nearby on similar soils native species. Text Box 1. and slopes (Text Box 2). It is not can greatly reduce seed supply in realistic to restore all species Securing a supply of seed has to some eucalypt species three years that occur on a site because of be considered at least a year in later. Ordering native seed is not limitations in seed collection, advance to sowing. The fruits of the same as buying a packet of propagation, establishment and about 80% of native species in veggie seeds from the shops! cost. Select a mix of species southern Australia are ripe only in that provide multiple layers of summer. Fortunately, most mallee Note, when seed collecting from vegetation (habitat structure). eucalypts have persistent fruits public land make sure to obtain Include overstorey species (mallee that are collectable all year round. the required permits your relevant eucalypts), medium sized trees Seed of other required species state agency responsible for (often Acacias), large shrubs such as Acacia, Dodonaea, Senna, conservation. Always obtain (Acacia, Melaleuca, and Senna) and chenopods, and grasses may only permission from the land owner small shrubs (often chenopods). be available for short periods in when collecting from private land. Multiple layers of vegetation late spring through summer. provide food for pollinators, For uncommon species, seed is nesting sites for insectivorous Planning has to be in place for generally unavailable from seed birds and help resist the invasion seed collection (e.g. locking suppliers and can require a special of weeds. But most importantly up paddocks for grass seed permit to collect. Sometimes, choose native plant species that harvesting) or seed purchase. seed nurseries (orchards) have to will survive in your site. Dead Seed suppliers need advance be established specifically to grow seedlings don’t provide habitat nor notice in order to collect quality rare plants for seed collection. fix carbon. seed and process it appropriately. Once plants reach maturity seed Like any crop, native seed quantity is collected and stored for use in Seed for the chosen species should varies from year to year based restoration. The seed of these come from large and healthy on rainfall. A drought one year species is often so valuable that A REVEGETATION GUIDE FOR MALLEE WOODLANDS 9 it is better to plant seedlings layers (structure) and respond Seed quantity rather than use the seed for direct well to direct seeding: Acacia, Estimating the quantity of seed seeding. Allocasuarina, Atriplex, Banksia, needed for a revegetation project is Callitris, Dodonaea, Eucalyptus, complex because there are so many Getting the right mix of seed Hakea, Leptospermum, Melaleuca, variables to consider including: for mallee revegetation is a Senna, and Maireana. complex task. The amount of • planting method – direct each species required is dictated The Victorian Department of seeding or seedlings grown in a by the germination rate and the Sustainability and Environment’s nursery; desired density of each species EVC Bioregion Benchmarks and • distance between planting rows and it usually takes experience to the Nature Conservation Society (often 3-5 m); get this balance right. The most of South Australia’s Bushland • desired stem densities of trees, important task is to ensure that Condition Monitoring benchmarks shrubs and ground cover; you choose species which match provide good guidelines for • seed viability which varies; your objectives and have the species composition in remnant between species, seasons and best chances of germination and vegetation. This can guide your whether germinated in the survival. species selection when trying nursery or paddock; and to mimic naturally occurring • size and longevity of species A typical mallee revegetation compositions. – short lived and small species site contains the following are usually planted at higher genera, which provide multiple densities than long lived and large trees.

Text Box 2. A REVEGETATION GUIDE FOR MALLEE WOODLANDS 10

STEP 5. Select quality seedlings

Only use healthy seedlings The size and root structure of seedlings is critical to their survival after transplanting and to their long term survival. Poor root development in the nursery can result in dead plants in the paddock, slow growth, instability in windy conditions and in the long-term, self-strangulation by spiralling roots.

Nursery containers should be chosen to produce healthy roots with lots of strong growing tips. Lots of roots are more important than lots of leaves. Root development should be sufficient so that potting media does not collapse on removal of the seedling from the container. Photo 9. Fluted nursery pots promote downward Photo 10. These well grown eucalypt seedlings Nursery systems should allow for pointing roots, rather than spiraling roots that are being hardened off to promote frost and maximum air pruning of roots. can develop in smooth and round tubes. Note drought resistance. also the air pruning of the roots at the bottom Modern nursery tubes are fluted of the pot. (rather than smooth and round) so that roots are directed downwards This is usually achieved by Genetics (Photo 9). placing seedlings outside of It is vital to use the appropriate hothouses or shade houses and seed source for restoration In addition, slots and holes in ceasing fertilising. Seedlings that plantings (Text Box 3). A the sides of the tubes air-prune are not hardened properly will local native seed source has roots so root-binding does not usually be set back or killed when traditionally been the rule of occur. Seedlings should also transplanted. thumb. However there are be ordered or germinated with circumstances where this may not enough growing time to be able Where ever possible get seedlings be the best choice: to meet specifications. This is from a local nursery, so your usually a minimum of 6 months plants have been hardened off 1. Where the local seed source before planting, but can be up to to local conditions. It’s tough to is in a different landscape 18 months. mimic a light frost in a nursery at position (e.g. from a gully the coast. It is important to ensure when the planting will be on A good quality seedling is seedlings are well watered before a ridge). It is better to match generally 10-20 cm tall, not root leaving the nursery and being for site (ecological position) bound, and has been hardened planted on site. Most nurseries than to automatically choose before delivery (Photo 10). take back the pots to be cleaned the closest local native seed Hardening involves exposing and reused, so don’t leave them at source. a seedling to more natural your planting site. conditions such as wind, full sun 2. Where the local native seed and reduced nutrient availability. source is an isolated tree or scattered population. Out- A REVEGETATION GUIDE FOR MALLEE WOODLANDS 11

weeds are well controlled over winter, though a spring planting may require watering seedlings over summer.

Techniques for planting seedlings There is a broad range of approaches to revegetation and no single approach will necessarily work for every site. Usually a combination of direct seeding and planting of seedlings delivers the best value for money (Photo 11). This combination allows for the easiest establishment of the Text Box 3. greatest diversity of species that breeding trees like eucalypts form multiple layers of vegetation. will have poor quality seed if the tree is an isolated paddock tree, regardless of the health of Text Box 4. the trees. Self pollinated seed is weak and seedlings will grow slowly and there will be high STEP 6. death rates amongst seedlings. Planting and sowing Collect seed from the nearest healthy intact population of the species containing at least 100 When to plant Mallee typically occurs in individuals in close proximity. low rainfall areas with winter Photo 11. An example of a large site where dominant rainfall. Just like a seedlings from a nursery have been 3. Where there is expected to machine planted with alternate strips direct be a shift climate in during wheat crop, planting seedlings or seeded. A combination of establishment the life of long-lived species sowing native seeds is dependent methods are often needed to achieve high plant diversity at least cost. such as eucalypt trees, it may on soil moisture - timing is critical. be necessary to include in Planting is usually conducted For planting seedlings, some the seed lot seeds from lower immediately after the first good methods may reduce plant deaths, altitude or drier sites than the rains of the season between May but the price to implement the local native to take account of and June and ideally, before mid method may outweigh the cost to climate change. August. However rainfall can replant dead seedlings. The right be irregular and planting plans technique(s) depends on the size of must be flexible. If the season is your planting and the risks you’re Poor quality seed will result in too dry you must be prepared to willing to take. oor revegetation, so make sure put off planting until next year. it’s healthy (Text Box 4). Once A year delay in seeding is much Broad-scale planting (tens to collected, it is important to easier than delaying planting hundreds of hectares) typically conduct viability tests on your seedlings raised in a nursery. uses experienced forestry seeds so you know the sowing Or consider an early spring contractors to do the planting. rates needed to germinate planting to allow for build up of Experienced planters will plant sufficient quantities of seed for soil moisture over winter and faster than novices and will also your restoration plantings. See warmer soil temperatures for ensure that seedlings are planted the Florabank web site for some quick germination and growth. in the correct manner including simple techniques. If planting in spring, make sure the correct depth, minimise root A REVEGETATION GUIDE FOR MALLEE WOODLANDS 12 damage and construct effective extract solution to the roots water depressions. Planting before planting. It is believed machines can also be used to this reduces root shock and cover large areas rapidly and can promotes root growth. This is be useful where manual planting most efficiently applied prior to labour is scarce. However, planting planting. machines are only suitable in soils with little to no rock and cannot Another technique to reduce operate within rows that have also moisture loss and planting shock been direct seeded. In any event, is to dip seedlings in, or spray on, planting machines will still require anti-transpirants such as Envy® at least two people. Generally prior to planting. Click here. hand planting using planting tubes (e.g. Pottiputkis) and kidney trays or planting belts is more efficient and preferred.

Planting a site yourself can be a demanding process and may lead to delays in completion but will reduce costs. Volunteer planters can help given the right training and supervision, deliver excellent Photo 12. An example of the use of tree guards and weed mats to promote seedling outcomes cost-effectively. survival. This is a more expensive approach best suited for small sites or in-fill plantings. Traditionally, individual plants in small plantings have been protected using a planting bag, milk carton, coreflute guard or flexible netting and protected at the base using a hessian or newspaper weed mat (Photo 12). Large scale plantings are not normally protected with tree guards unless some really palatable species need to be protected near remnant patches Text Box 5. of mallee. If guards are used they should be removed before they inhibit the plants and whilst they can still be easily removed. This is usually following the second summer.

If the topsoil is not moist at the time of planting, seedlings should be watered, but this can be impractical for large plantings, so wait for rain before planting. Experience shows that survival rates can be dramatically increased by applying a sea-weed A REVEGETATION GUIDE FOR MALLEE WOODLANDS 13 A REVEGETATION GUIDE FOR MALLEE WOODLANDS 14

Techniques for direct Niche seeding is a variation Direct seeding machinery seeding on mechanical direct seeding There are many different types Direct seeding involves a machine where seed is hand-sown in small of direct seeding machines (see sowing seeds at a predetermined patches rather than continuous photos 6&7) however they all rate directly into the soil drawn lines (Photo 13), giving sites a consist of three elements; by a 4WD ute or ATV/quad bike natural appearance. This method (see direct seeding machinery uses less seed than mechanical 1. A blade or disc that removes below). Sowing seeds directly direct seeding, but is more time the top soil to a depth of 30-60 on-site has the potential to consuming and best suited to small mm; establish many more species than sites or in-fill plantings to enhance 2. A seed box, or boxes, full of those propagated in a nursery. diversity. native plant seeds, and possibly Direct seeding is often cheaper, a filler (sawdust or sand) to but is generally a less reliable help the seed flow evenly down method for establishing trees a tube that delivers the seed to and shrubs. Root development the middle of the scalped area; in directly sown seedlings is not and at risk of poor root development that can occur in seedling raised 3. A wheel that presses the seed in the nursery. Seedlings from onto the soil surface to prevent direct seedling will generally it being blown away and it also have much greater genetic Photo 13. A cluster of eight Acacia pycnantha ensures seed to soil contact seedlings emerge from a spot treated variability than planted nursery- with herbicide then hand sown with which reduces the rate of raised seedlings. The biggest seed. Thinning may be useful in this harvesting by ants. problem associated with direct example. seeding mallee is that there is Basic direct seeders have only often insufficient rain in a single Species that are widespread and one seed box and can be towed fall to satisfy the germination have seed that is easily collected behind a quad bike or ute. Several requirements for all species in (hence relatively cheap) and machines are mounted on tractor the seed mix, or not enough to germinate well are particularly linkage. More complex seeders sustain seedlings over summer. suited in direct seeding mixes. have multiple seed boxes each Nursery raised seedlings are delivering a different seed mix, Large seeded species like particularly suited to species so that in a single pass a complex Acacias and Sennas tend to that are rare or threatened, or structure can be created. germinate first and most reliably those with seed that is difficult or and dominate the site, whilst time-consuming to collect (hence These bigger machines are Eucalypts germinate later in expensive) or those species that generally towed behind a four warmer conditions. This can germinate poorly in the paddock. wheel drive ute or tractor. give plantings a skewed species composition. An experienced Melaleucas and Leptospermums do A consistent feature of direct direct seeding operator can not have robust root systems and seeding is to scalp (scrape) away modify seeding rates to account will generally only be successful in topsoil. Scalping is an effective for this, or you can use a direct seeding in wet years in low technique to control weeds, combination of direct seeding rainfall Mallee areas. In Victoria, remove excess nutrients that are and nursery seedlings, or be successful sowing of mallee concentrated in the topsoil and prepared to thin out seedlings. Eucalypt species has been mainly remove water repelling soil crusts, Another drawback is the need with the larger seeded species. as well as creating a channel in to collect large volumes of Similarly, Buloke and Blackbox which to capture and concentrate seed, although as direct seeding (Eucalyptus largiflorens) have been water around the seeds. However, technology improves, the generally unsuccessful in direct scalping may remove too much volume of seed required steadily seeding and are usually established soil nutrient. Recent research decreases. in sites by planting nursery-raised in Western Australia has shown seedlings. a benefit from a small dose of A REVEGETATION GUIDE FOR MALLEE WOODLANDS 15 fertiliser being included in the within a large planting of trees and STEP 7. direct seeding mix. Click here. shrubs. The main variation in common Seed preparation Maintenance direct seeders is the type of Some seeds will require treatment scalping disc; either a circular disc before seeding to overcome natural After planting, the new seedlings or a V blade. A circular disc cuts germination inhibitors and increase are vulnerable to weeds, browsing a shallow narrow scalp making the chances of germination. There and insect pests. They will need it suitable for shallow or heavy are many forms of treatment, for to be closely monitored to ensure soils (Photo 6). A “V blade” cuts example, hard-coated seed species high survival and good growth. a deep wide scalp (Photo 14). such as Acacia and Senna should In dry periods supplementary V Blades are robust machines be scarified (cutting or sanding) watering may be needed. making them suitable for areas or placed in boiling water (most with large loose rocks. The ‘Rolls Acacias) or very hot water (e.g. All revegetation sites should be Royce’ direct seeder is a modified native peas and some Acacias, e.g. regularly inspected post-planting. turf making machine used for A. salicina, A. oswaldii) then rinsed in Check for any problems such as bowling greens (Photo 15). It cold water. A soak in diluted smoke browsing by livestock, damage creates diverse native grassland water for 20-30 minutes can also from rabbits, red-legged earth in a single pass, after the top help break dormancy. Water treated mite infestation, or an over soil has been removed from the seeds should then be dried to at abundance of weeds. whole paddock. This approach least a flowable state to allow easy to re-establishing the grassy or transport through the seed box. If weeds are mainly grassy weeds, herbaceous understory of mallee grass-selective herbicides (e.g. could be applied to smaller areas Other species may need to have Fusilade™) may be applied as an awns, wings or appendages overspray using a boom if the removed in order to travel through newly emerged broad-leaf native the seeder. The CSIRO Publishing seedlings are considered hard book Growing Australian Native enough. A follow up spray is Plants from Seed (details below) often necessary in the first year to is one of the best sources of pre- control summer weeds which can germination treatment information. compete with the new seedlings The Australian Native Plants Society for the scarce moisture at this also has an informative website time of year. Seek advice from a on seed preparation for sowing, herbicide specialist if in doubt. click here for further information.

In addition, CSIRO Australian Tree Weed control is usually not Photo 14. A V blade seeder mounted on a Seed Centre Operations Manual tractor creating a suitable seed bed for necessary once seedlings have has comprehensive information on native species. This robust machine is established above the height of particularly suited to stony sites such as the germination and treatment of surrounding weeds. However, this one. many Acacia, Eucalypt and other if the season is poor it may be Australian tree species. Click here. advantageous to implement control work to maximise soil Acacias, just like other legumes moisture levels. Shielded such as Lucerne have a symbiosis equipment will be an advantage in with nitrogen fixing soil bacteria. this situation. However, bacteria specifically co- evolved with Acacias may be missing in long cultivated soil. Studies have shown superior germination, survival and growth in Acacias inoculated with specific strains of bacteria. Photo 15. A turf seeder modified to sow a A mix of these bacteria (Wattle diversity of grasses and wildflowers. Grow™) may be available. A REVEGETATION GUIDE FOR MALLEE WOODLANDS 16

STEP 8. Monitor to Learn and Improve

Follow a five-year project cycle for planting such as the wildlife that maximum success, with 2 years has colonised your site, if wildlife of preparation before planting habitat was one of your objectives. and three years of monitoring It makes no sense to unfairly judge and maintenance afterwards. the habitat quality of a site if the Monitoring should start at the original objective was simply to beginning of a project. Monitoring establish a windbreak with some should record what is done at each hardy native trees and shrubs. step of any revegetation project (Figure 1). Successful restoration Horses for courses projects show that effective There are no universally applicable monitoring benefits from setting methods for monitoring outcomes, clear objectives and goals and because the right method depends these can be easily forgotten a few on site objectives. There are years later. Too often monitoring standard methods for monitoring starts at the wrong end of this birds if the site objective is to sequence (Figure 1). provide bird habitat. Similarly there are methods to assess the There is a common desire to reduction in salinity and erosion monitor restoration outcomes. risks if these are site objectives. However, it is also prudent to first Objectives should define monitor (record) the Objectives monitoring. However, the table and Strategies of a restoration below provides a guide to the project, followed by a record of ‘generic’ kinds of monitoring data the Actions implemented (e.g. that need to be collected for any species planted), then the Results type of planting. Click here to of those actions (e.g. dead or alive download key monitoring data for plants). Finally, assess the long revegetation sites (adapted from term ecological outcomes of your CSIRO/ABARES research).

Figure 1. A framework that identifies the multiple points at which monitoring is needed to improve revegetation practices and identify outcomes. The thick arrows indicate the consequences of implementation and the thin arrows indicate key interpretation and learning feedback loops (from Freudenberger 2012) A REVEGETATION GUIDE FOR MALLEE WOODLANDS 17 18

Knight, A.J.P., Beale, P.E. and Further Reading Acknowledgments Dalton, G.S. (1998) Direct Seeding of Funds for the preparation and Australian National Botanic Gardens Native Trees and Shrubs in Low publication of this guide were (2012) Growing Native Plants on the Rainfall Areas and on Non-wetting provide by the Australian Web. Sands in South Australia. Government through the Berkinshaw, T. (2006) Native Agroforestry Systems 39: 225-239. Biodiversity Fund. The guide was Vegetation of the Murray Region. compiled by James McGregor with Mallee Catchment Management Finsbury Green Printing. assistance from Jess Gardner and Authority (2009) Revegetation for Jim Robinson. Editorial services were Birchip Cropping Group (2009) Salinity Control. provided by Dr David Freudenberger Ecosystem Function Project – A Mallee Catchment Management and Dr Jason Cummings. Graphic Glovebox Guide to Understanding and Authority (2010) Revegetation with design was provided by Landcare Improving Ecosystem Function in the Indigenous Vegetation. Australia Ltd. Wimmera Mallee. Mallee Catchment Management Disclaimer Bonney, N. (2003) What Seed is Authority (2011) Monitoring the The views and opinions expressed in That? Finsbury Press. Success of Revegetation Works in the this publication are those of the authors and do not necessarily Brown, W., Kuys, J., New, B. and Mallee 2010. reflect those of the Australian Voigt, B. (2001) Revegetation and Munro, N. and Lindenmayer, D. Government or the Minister for Vegetation Guidelines. (2011). Planting for Wildlife. A Sustainability, Environment, Water, Carr, D., Bonney, N. and Millsom, D. Practical Guide to Restoring Native Population and Communities. (2007) The Effect of Sowing Season Woodlands. CSIRO Publishing, on the Reliability of Direct Seeding. Collingwood. Rural Industries Research and Murray Mallee Local Action Planning Development Corporation. Association (2005) Revegetation Fact

Clarke, I., Stokes, Z. and Wallace, R. Sheet: Collecting Native Plant Seed. (2010) Habitat Restoration Planning Northern and Yorke Natural Guide for Natural Resource Managers. Resources Management Board Department for Environment and (2010) Fact Sheet: Direct Seeding. Natural Resources. Ralph, M. (2003) Growing Native Corr, K. (2003) Revegetation Trees from Seed. CSIRO Publishing. Techniques. A Guide for Establishing Native Vegetation in Victoria. Woodall, G.S. (2010) Improving the Compiled by Greening Australia with Direct Sowing of Commercial Native funding from Alcoa World Alumina Plants in Agricultural Lands of and the Commonwealth Southern Australia. Rural Industries Government’s Natural Heritage Research and Development Trust. Corporation. Flannery F., Carr, D., Rawlings, K. Further Assistance (2006) Thinking Bush: Thinking For further assistance or advice we Seeds. Greening Australia. suggest you try contacting:

Jonson, J. (2010) Ecological Greening Australia Restoration of Cleared Agricultural ph 1300 886 589 Land in Gondwana Link: Lifting the or find us on the web page Bar at ‘Peniup’. Ecological Management and Restoration (11) Your Regional NRM (catchment) 1:16-26. Organisation