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This page gives you information on Camphor Laurel.  These fact sheets have been written

by Bruce Scott, Far North Coast Weeds.

• Camphor Laurel and other Lessons

• Camphor Laurel Fact Sheet No. 1 - Declaration of Camphor Laurel as noxious weed.

• Camphor Laurel Fact Sheet No. 2 - Control of Camphor Laurel, Herbicide Use, Techniques for killing Camphor Laurel trees.

Camphor Laurel, Cinnamomum camphora, is a native of China, Taiwan and Japan. Although one species, there are several genotypes found in Northern NSW and South East Queensland. Camphor Laurel is an invasive trees which can form dense forests that can almost be monocultures.

Camphor Laurel was widely planted as shade trees on farms and in school yards. It was used commonly as feature trees in parks and gardens.

Camphor Laurel is spread mainly by direct seed drop, but many native bird species are responsible for spread over large distances from the source trees.

Camphor Laurel has some excellent qualities, but it is its sinister side that has attracted so much attention in NSW. This paper will concentrate on the negative, or sinister aspects of Camphor Laurel as well as control strategies. It is its adverse impacts on the environment that has lead to the declaration of Camphor Laurel in some parts of NSW.

It is currently a W4(d) category noxious weed in 8 shires on the far north coast of NSW. The North Coast Weeds Advisory Committee is pushing for its declaration in all coastal shires from Taree to the Queensland border. Under the NSW system of declaration, a weed can have specific control conditions attached to its declaration. The W4(d) declaration for Camphor Laurel is similar to a Queensland P2 classification, but with some conditions attached. A separate sheet on the declaration is available at the poster display area.

As with all weed control, an integrated approach is essential. Quite often Camphor Laurel is found co-habiting with other potentially worse weeds, such as privet. Remove the Camphor Laurel and the privet thrives. Poorly planned removal can result in even worse adverse impacts on the environment. In most situations a replacement planting program is recommended.

It has been estimated that at least 30% of the Camphor Laurel trees in NSW and South East Queensland are under three years old and under about three metres high. The rate of spread is alarming considering that many of the trees were planted over 100 years ago. Very few have been planted in the last 10 years or so.

It appears that the level of viable seed production increases dramatically once the trees are over 30 years old. The reasons for this are not readily apparent. It is the rate of spread that is the most alarming aspect of this weed.

Camphor Laurel is characterised by an extensive, shallow root system. Very little other vegetation will grow under Camphor Laurel trees. Some people blame this on the toxic effects of leachates from the roots of the Tree (allelopathy), but I believe that the dense shallow root system out competes other vegetation for moisture and nutrients. The dense canopy also restrict penetration of light. Many species will germinate and establish under a camphor canopy, but very few will develop to normal size.

As the soil surface is relatively bare under the trees the soil is prone to washing from the root area. In many cases gullying has resulted from the initial soil disturbance.

Most native riparian vegetation has a deep fibrous root system that binds deep into the stream banks. Often the roots bind under the steam bed to reduce the risk of deepening the stream bed. Camphor Laurel does neither. Its shallow roots are often undermined by strong flows in streams. The result is a widening of the stream, cutting out of corners and the eventual toppling of the trees into the stream. Where the Camphor Laurel is a virtual monoculture, the banks under the trees are bare and that soil is washed from the roots, resulting in silting up further down stream. Camphor Laurel is possibly better than no stabilising vegetation, but is considered by Aquatic Vegetation Specialist, Geoff Sainty, as worse than the notorious Black Willow, Salix nigra, for destabilising stream banks.

A study by Dr R. A. Bishop showed that leachate from the leaves of Camphor Laurel killed fingerlings of juvenile rainbow fish, Melanotaenia duboulayi. Preliminary trials by J. Friend show that leachates kill tadpoles and frogs of some species. It has also been hypothesised that leachates affect microflora and microfauna in streams. This could affect all marine species higher in the food chain.

Camphor Laurel quickly forms dense forests when left unchecked. The effect of this is to reduce the natural regeneration of bushlands. Many of the Camphor Laurel forests occur on stream lines, or on the edges of native bushland remnants. The strong competition for light, nutrients and moisture restricts the natural ability of the vegetation to regenerate itself. The Camphor Laurel also shades native edge plants, altering their natural habitat and relative status in the ecosystem.

Camphor Laurel also restricts the growth and production of pastures, resulting in reduced productivity.

Some species of birds have accepted Camphor Laurel fruits as a valuable part of their winter diet. There have been several reports of Camphor Laurel tainting eggs. Geese eggs have been sterilised by the geese consuming Camphor fruit as part of their diet, compared to a control group not fed camphor fruit and producing healthy goslings. Floyd, an eminent botanist and naturalist reported deaths of pigeons eating Camphor fruits as early as 1950.

There have been some reports of some pigeons adapting their breeding cycle and migratory patterns to feed on Camphor Laurel on the lowlands. These birds play a vital role in the spread of native plant seeds, and such changes could affect the distribution of some species.

Most of the worlds camphor oil is synthetic. There is a niche market prepared to pay a premium for natural oils of suitable quality. Natural camphor oil is actually a blend of a number of oils and contaminants. One of those contaminants is safrole. Safrole is a deadly carcinogen. Camphor oil is banned for human use in the USA (J. Friend 1999).

Delta Energy, Sunshine Sugar and NSW State Forests are investigating a joint venture to utilise Camphor Laurel timber to generate renewable energy, at the Condong sugar mill, as part of the Governments commitment to reducing greenhouse gas emissions. They estimate that by 2002 they will be burning about 150,000 tonnes of Camphor Laurel per annum. Even that is still less than the estimated rate of spread in the Tweed Shire alone..

Traditionally Camphor Laurel has been used in small quantities for arts and crafts and for a limited degree for furniture. There appears to be big potential to export logs to China and flat pack furniture to the USA and Europe. The problem is that these markets require large quantities and guaranteed supply. The infrastructure would need to be developed to cater for these markets. One Lismore joinery has a lucrative trade in selling Camphor Laurel coffins to China. A number of NSW millers and manufacturers have had success through internet selling, but on a relatively small scale.

The large numbers of Camphor Laurel trees is removing copious quantities of CO2 from the atmosphere. It is important that any strategy to control Camphor Laurel should include a tree replacement strategy.

Timing is not critical for most herbicides but general precautions should be observed. Trees should not be under stress. Treatment during winter is probably less effective than at other times of the year.

Seedlings can be readily pulled by hand. Ring-barking is not particularly effective due to the trees ability to sucker readily. As much of the Camphor Laurel occurs on stream banks and steep slopes, the use of bulldozers and other machinery is discouraged. If any roots are left, particularly if they are exposed, they will sucker. Mulching can be effective to control seedlings, but the seedlings of native species are also affected.

Many herbicides are registered for Camphor Laurel control. They can be applied by at least as many techniques.

The following table is a guide to registered herbicides and their application techniques

Note:

Some of the following comments refer to non registered application techniques. If you want to use these techniques you first must apply for an off-label permit from the National Registration Authority in Canberra.

*Tordon TCH is not registered for use on Camphor Laurel, but the FNCCC has a permit for its use in northern NSW. Copies of the permit and its application are available to anyone wishing to apply for a similar one. Contact the author.

Glyphosate is not as effective on trees over 25 cm in diameter as Tordon TCH. It is more effective if used neat rather than diluted. For best results on trees over 25 cm diameter apply twice as many cuts as specified on the label. That is 6.5 cm centres rather than 13 cm centres.

Grazon DS is very cost effective on trees up to 3 metres high.

A great deal is known of the adverse effects of Camphor Laurel on the environment, but there are many areas with questions over them. Many of the questions could be answered through under-graduate or post-graduate research.

The North Coast Weeds Advisory Committee has established a Camphor Laurel taskforce which will monitor the effectiveness of control strategies and promote further investigations into control options, value adding and environmental impacts. The Committee will have a Camphor Laurel control kit available by mid 2000. It will cover a wide range of topics related to Camphor Laurel management

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CAMPHOR LAUREL FACT SHEET N^o 1  

Declaration

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CAMPHOR LAUREL FACT SHEET N^o 2  

The invasion of Camphor Laurel is an important issue for catchment management on the North coast. Camphor Laurel spreads rapidly, indefinitely dominates areas of natural regeneration and reduces the amount of land available for agricultural and pastoral production.

Recent preliminary research indicates that Camphor Laurel leaves may be toxic to fish, and possibly some frog species. This supports the belief that the diversity of native fish communities is less in sections of streams where riparian vegetation is dominated by Camphor Laurel.

If we are to reduce the incidence of Camphor Laurel we must kill it faster than it spreads.

CONTROL METHODS:

1. USE OF HERBICIDES

Camphor trees are most effectively killed using herbicides. It is important to use the correct technique to ensure a kill first time. Before using any herbicide, read and heed the label, it is your legal responsibility and legal protection.

There are four main techniques for herbicide application:

l.1 Tree frilling - stem injection

Use a Tordon axe, normal axe or heavy tomahawk to cut pockets around the trunk at waist height as shown below, or a tree injection spear to cut pockets close to the base of the trunk in a similar fashion. With the axe or spear still in the cut, lean the top outwards to open up a pocket. It is essential to inject the herbicide into each pocket immediately, or at most, within 30 seconds of inflicting the cut. Pockets must penetrate the trunk to a depth which reaches the sapwood and they must be angled downwards to enable the herbicide to pool.

Technique for using an axe

A recently developed, physically easier and more effective method is available using a battery powered drill and hydraulic injection delivering 20mls of 1:10 (one part herbicide to 10 parts water). This method is much more time consuming, but the results are excellent. A separate promotion sheet is available from FNCCC.

The use of a drill and then squirting spray solution into the hole, without it being under pressure, often gives very poor results, as the herbicide does not effectively enter the Cambium layer.

Herbicides registered for stem injection: Glyphosate based products; Tordon TCH.

 

Diameter of stem	Number of cuts (pockets) required
10 cm	2 cuts
20 cm	5 cuts
30 cm	7 cuts
40 cm	10 cuts
50 cm	12 cuts
60cm	14 cuts

l.2. Basal bark method

This is an effective, quick and relatively easy method of treating saplings and regrowth with a diameter at the base of the tree of less than 10cm. Spray or paint the whole stem(s) from ground level to a height of 30cms. If spraying, use low pressure and avoid off target damage.

Herbicides registered for basal bark applications: Garlon 600®, Access®

1.3. Foliar Spray

This method involves spraying the foliage of individual Camphor trees up to 3m in height. For large accessible areas of infestation a tractor with a PTO pump, herbicide tank, hose reel and handgun can be used. For smaller areas without tractor access, use a backpack spray unit. To keep track of which trees have been treated, it is advisable to use a tracer dye. Avoid spraying native plants where these are to be retained. There is a high risk of off target damage (damage to plants you want to keep) when foliar sprays are used

Herbicides registered for basal bark applications: Grazon® (properly used, does not kill surrounding grass), Garlon 600®

4. Cut stump method

Good results have been reported using this method, however there are risks of regrowth if the stump and roots are not killed. Second attempts at control are best avoided.

Cut the trunk(s) at waist height - or lower if preferred (easier) and immediately apply herbicide mixture by brush or spray to all cut and damaged surfaces of the stump(s).

Herbicides registered for basal bark applications: Garlon 600®, Access®

2. REFORESTATION/NATIVE REGENERATION

Camphor Laurel has established most prolifically on cleared and neglected farmland. It has not generally invaded established native forest as mature, fruiting specimens.

Therefore, particularly on less productive agricultural and non-agricultural land, there are opportunities for reforestation of areas infested with Camphor or areas of potential Camphor infestation using appropriate local native species. Reforestation/regeneration, as a means of Camphor Laurel control, will only ultimately succeed under conditions of a dominant canopy of native species. The method of Camphor removal/control/management will depend on the degree and age of the infestation.

3. SEEDLING MANAGEMENT

Camphor Laurel need not become a local weed problem if seedlings are either prevented from establishing or otherwise controlled when very young. Such control measures should be a normal part of effective land management. Very young Camphor Laurels are readily hand pulled. Young trees are readily and cheaply controlled with foliar sprays, cut stump or basal bark treatments. Removal of mature trees will reduce the local seed source, and consequently reduce the number of seedlings emerging.

4 NOTES ON HERBICIDE USE

It is recommended that, before using any herbicide, you undertake the National Farm Chemical Users Program or equivalent training. This nationally accredited course teaches you how to handle, mix and use farm chemicals in ways to minimize harm to yourself, your family, your livestock, crops and gardens and to the environment. Many providers teach this short course.

Tordon TCH is widely used for Camphor control, however it is not registered for that purpose. The Far North Coast County Council has a permit which allows landholders to use this product for stem injection. Apply as for eucalypts on the label. A condition of the Permit PER1145 is that persons wishing to use Tordon TCH for Camphor Laurel should obtain and read a copy of the Permit before using the herbicide. Copies are available, free, from Far North Coast County Council.

• Seek the advice of staff with chemical training at your rural stores outlet and follow instructions on herbicide labels.

• When spraying, choose a calm day, and dress appropriately.

• Results from herbicide use are most effective when the plant is actively growing.

• Avoid inhalation and skin contact when using all herbicides.

Many people use Glyphosate based products in ways not included on the label. This is illegal, unless a permit has been obtained from the National Registration Authority in Canberra. NP&WS has a permit for land under their control.

5 MECHANICAL/PHYSICAL REMOVAL

5.1 Seedlings

Young seedlings are readily removed by hand pulling. This is cheap and inexpensive. The bigger the seedlings get, the more expensive removal becomes. In areas where Camphor Laurel is declared, occupiers will be required to fully and continuously suppress and destroy all trees under 3 metres in height. In areas where Camphor Laurel is not declared, removal of young trees is still recommended. Saplings can be readily pulled from the ground with a tractor and chain. Care should be exercised to ensure the hitch point is low and the chain is strong enough.

Where the use of herbicides is to be avoided, some of the following may be tried. They are not as effective as herbicide treatments.

Saplings may be cut off close to the ground and the stump covered with heavy grade black plastic. This should be held to the ground with soil or deep mulch to prevent the development of suckers. An alternative is to cut the sapling off and pour diesel on the cut surface and cover with a deep layer of mulch. Any suckers that come through should be immediately removed.

5.2 Trees

Mechanical removal of trees is often undesirable due to negative impacts on the environment. Camphor Laurel has a dense, wide but shallow root system. Removing trees with bulldozers etc leads to massive soil disturbance. This can lead to further soil degradation particularly on steep slopes and on stream banks. Landholders are encouraged to utilize the above ground parts of the tree for value adding purposes, even if these do not cover the full cost of controlling the tree it can offset the costs. The nature of the root system makes them undesirable species on stream banks. They do not bind the banks or stream bed together. Some people consider them to be better than no trees on the banks, but the quicker they are replaced, the less the stream will be silted up. On stream banks it is often appropriate to control every second or third tree pre,or post planting of replacement species. In some situations it may be better to control small groups of trees alternating the areas on either side of the stream. Remember that a permit may be required from the Department of Land and Water Conservation before removing any trees from stream banks or steep slopes.

OTHER ISSUES

1. COMMERCIAL HARVESTING – VALUE ADDING

To offset costs of control, the potential for sale of marketable Camphor products should be investigated. The Northern Rivers Regional Development Board has initiated research into value adding Camphor products on the local and export markets.

If existing stands of Camphor are intended for commercial use they should be managed accordingly. If timber slabs or planks are the required outcome then the trees should be managed to produce only one straight stem.

2 PLANNING YOUR ACTIONS

For effective results in Camphor Laurel control it is essential to plan. Consideration should be given to:

• What laws may affect the removal at particular sites.
• What affect the removal may have on the environment
• What are the affects on the environment if the trees are not controlled
• On stream banks and steep slopes a staged removal over a number of years may be the safest approach.
• If the Camphor is growing in an area where it is declared noxious, it may be necessary to develop a management plan if the trees are not to be removed within one year.
• It may be necessary to use a range of control strategies depending on where the trees are growing.
• A planned tree replacement strategy is recommended.
• Camphor can provide some protection for emerging native species, particularly some rainforest species.

3 LAWS ON TREE REMOVAL

Permission is required, and conditions apply, to destroy trees on steep land (over 18⁰ slopes) and within 20 metres of streams. Consult your Department of Land and water Conservation office for details. The phone numbers are: Murwillumbah (02) 6672 5488, Alstonville (02) 6628 6009, Grafton (02) 6640 2000.

Many other Acts could influence how and where you control Camphor Laurel. These will be summarized in a Camphor Laurel Control Kit being compiled as part of a Camphor Laurel & Bitou Bush project, being managed by the North Coast Weeds Advisory Committee. The Project Officer is Tim Scanlon.4 OTHER FACT SHEETS

5 YOU CAN HAVE YOUR SAY

If you know of ways to control Camphor Laurel that are not included here, send details to Tim Scanlon If you feel more research about the specific impacts of Camphor Laurel is required, or if you have information from the internet, or from research, or from any other source, that you think others should be aware of, send it to Tim.

Tim may be contacted at: Tim Scanlon, 1/107 Ocean Parade, Coffs Harbour 2450. His phone and fax number is (02) 6652 4003. His e-mail address is tims@midcoast.com.au

For further advice on Camphor Laurel control contact:

Bruce Hungerford

Dept. Land and Water Conservation Far North Coast County Council Clarence Valley Weed Authority

Murwillumbah Casino Maclean

(02) 6672 5488 (02) 6662 2396 (02) 6645 2555

Fax ( Fax (02) 6662 5511 Fax (02) 6645 4017

This Fact Sheet, compiled by Bruce Scott, General Manager of Far North Coast County Council is based on a Tweed-Brunswick Information Sheet prepared by Bruce Hungerford, Catchment Manager with Department of Land & Water Conservation, Murwillumbah in January 1998. Approval to use the information contained in it is appreciated.

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