Water use and
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Integrated Brushwood plantings for NRM benefits to farming systems
Brushwood, also called broombush, is a name given to a group of similar Melaleucas. Until recently
these plants were all considered to be one highly variable species, Melaleuca uncinata. By breaking it
up into separate species, each with clearly defined traits, we can now better match the plants to differ-
ent sites and applications. For example, some of the species have better salt and waterlogging toler-
ance, or a form more amenable to brushwood fencing. By being able to name that species we know
we are getting those characteristics we want, rather than having to use a lengthy description of the
features. A list of the species in the complex is given on page 4.
Brushwood plantings can be multi-purpose additions to the farm landscape. They can offer pro-
tection from wind and water erosion, contribute to the mitigation of salinity and waterlogging,
provide wildlife habitat, as well as being a potential source of farm income.
Observations in Western Australia have shown that growth of 50cm to 60cm in the first
year can be expected. These growth rates can be considered conservative, as they have
been achieved at high density (4000 stems per hectare), in gravelly sands with a rainfall of
Brushwood species grow naturally in a wide range of landscape positions, from hilltops
and versatile, and while they will grow on low nutrient soils, shallow rock, sandy clay
and deep sands, like any other tree crop their growth and productivity will be enhanced
with better soils and nutrient levels. Within their natural range, multiple species within
the complex frequently co-occur.
A single row of trees provides little protection from strong winds
Wind erosion strips away nutrients, organic matter, clay and silt and so represents an expensive
export from the farm. Exposure in crops and pasture induces water stress, and reduces photosynthesis
and growth. In animals it causes energy use to be redirected and can lead to lamb or post shearing
losses. The situation is resolved by the provision of suitable shelter, in the form of windbreaks,
shelterbelts and stock havens.
The best year round treatment for the wind hazard will come from integrated plantings of perennial
shrubs and trees as windbreaks across the landscape. Design criteria relating to height, orientation,
spacing, porosity etc. are well documented, and this technical information, along with species
selection needs to be applied on a site by site basis. Brushwood species can play a key role here, as
they are widespread across both the Wheatbelt and local landscapes, and commonly occur on the
light to medium soils that are especially prone to erosion. Their shrubby form, multiple stems and
dense foliage makes them ideal windbreaks.
A network of windbreak plantings can be demonstrated as cost effective in its own right, with the
land taken out of production being compensated by the increased productivity of the remainder
of the farmland. Brushwood is also a potentially commercial crop, however if you plan to harvest
windbreak plantings, give some consideration to management strategies at harvest time, such as
maintaining stubble or pasture growth, or harvesting alternate hedges of plants to maintain some
plantings are appropriate. For belt plantings, multiple rows can be planted 2m apart, with brushwood
plants as close as half a metre apart. The alley spacing should then be adapted to suit the land
Brushwood plantings can consist
alleys to protect fragile soils and
integrated with standard agricultural
practices. A well designed system
can easily be incorporated by land
managers using guidance systems.
It has also now been found that
brushwood stands can be control
grazed and can provide excellent
shelter for stock.
Water use and salinity control
Waterlogging reduces plant growth and diminishes agricultural productivity. The rainfall, the
the extent of waterlogging. Revegetation is a good option for addressing this problem as it deals
with the excess water in situ, rather than exporting it off site where it may contribute to flooding
or downstream waterlogging. Research has shown that it is possible to lower watertables in the
lower rainfall areas with alley plantings. Farm plantings located near saline seeps in the Avon
have been observed to lower water tables and reduce spread of salinity. In dealing with water
erosion and salinity in the landscape, land managers should consider Melaleucas for harsh sites,
to increase total water use. In the WA Wheatbelt, some of the brushwood species grow naturally
on waterlogged and saline areas.
For upper and mid slope areas, the combination of trees and surface water drainage provides
an optimal treatment, as trees along regularly spaced banks achieve maximum growth using
water accumulated by the banks. These plantings can be expanded to a wider belt of trees at
critical areas such as the break of slope and where contour lines cross drainage lines. The surface
water drains put crop work and vehicle movement on the contour which reduces fuel usage and
consequently cropping costs. This contour planning divides up paddocks into management units
and the addition of trees to this arrangement causes no further disruption to the working of the
paddock. This system also complements other farming aims such as minimising wind and water
Revegetation can also be targeted to susceptible areas, such as waterways and creeklines where
there will generally be minimal disruption to farming practice and often significant ancillary
benefits such as wildlife habitat protection and enhancement, and nutrient stripping.
Commercial prospects for Brushwood
Several potentially commercial products can be realised from brushwood. The most promising of
these is its use in the manufacture of fencing panels for landscaping. Some of the species in the
complex have significant quantities of essential oils in their leaves (Brophy et al). Like all woody
plantings on farms, potential exists for the trading of the carbon sequestered by these plants. The
flowers are considered to be a good source of nectar, and both plantations and native stands are
popular locations for bee keepers to locate their hives. Most of the species in the complex have the
capacity to resprout after the aerial stems are harvested. Thought to be an evolutionary response
to fire, this mechanism means that once established, the plants can be harvested multiple times
without the need to replant.
Are there biodiversity benefits
from planting Brushwood?
The shrubby growth habit, dense
foliage, and peeling bark of
Melaleuca stands can provide
habitat for many animals and
insects. Melaleucas have a strong
scent and attract many insects. Many
small birds have been observed to
nest in these shrubs. The elusive
underground orchid, Rhizanthella
in association with the Melaleuca
This Avon Catchment Council project is funded with investment from the Australian Government.
Photos courtesy of Helen Job, Tim Emmott and Monica Durcan.
Text and edits thanks to Wayne O'Sullivan
• Brophy, J.J., Goldsack, R.J., Craven, L.A. and O’Sullivan, W. An investigation of the
leaf oils of the Western Australian broombush complex
(Melaleuca uncinate sens.lat.) (Myrtaceae). J. Essential Oil Research. 18, 591-599.
• Craven, L.A., Lepschi BJ., Broadhurst, L., Byrne, M. Taxonomic revision of the
broombush complex in Western Australia CSIRO 29/6/2004.
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The species of the “brushwood complex” -
Recent field work and taxonomic study of what was known as Melaleuca
• Melaleuca uncinata occurs east of a line from near Lake King to Coolgardie in Western Australia, across to Victoria. This spe-
cies is the mainstay of the brushwood fencing industry, and also has high oil foliage. It grows on lower slope, flat, sandy loams.
• Melaleuca atroviridis has two forms. Although taxonomically they are inseparable, ecologically they have traits which are very
different, and because the species is potentially of commercial significance the distinction is important to state.
The “sprouter form” grows high in the landscape in the northern central Wheatbelt. It grows on deep, pale yellow acidic sands.
It has a strong coppice ability, good Brushwood fencing potential and good leaf oil.
The “seeder form” grows low in the landscape from the north-central Wheatbelt through to the eastern Wheatbelt and Great
Southern. Grows on slightly acidic loams, clayey sand to sandy clay. Good salt and waterlogging tolerance, strong growth, but
cannot be relied on to resprout after harvest. This is the tallest growing of all the species and forms.
• Melaleuca hamata is a sprouting species which is wide spread across the wheatbelt including sites which are seasonally wa-
terlogged. Generally grows on mildly acidic, shallow granite soils. Its wide geographic range and variable form means that
provenance selection will be important if the intent of a planting is for a commercial outcome.
• Melaleuca osullivanii grows naturally along the Swan coastal plain from Perth to Busselton. It grows on grey sands over clay
in seasonally waterlogged areas. An important habitat plant but poor form for Brushwood fencing.
• Melaleuca concreta is a highly variable species occurring from North of Perth to Kalbarri, and as far inland as Wongan Hills
area. It grows in a range of habitats from waterlogged depressions to deep sand ridges. In the northern part of its range it occurs
on shallow sandstone. It has a variable but generally poor form.
• Melaleuca scalena grows naturally with Melaleuca lateriflora and Casurina obesa. It is found from Wyalkatchem to Mount
Walker, west to Albany Hwy in the Upper Great Southern. It occurs on grey clayey sand, and shallow duplex soils. It is seldom
a vigorous or well formed species.
• Melaleuca stereophloia is a tall growing vigorous species found in the northern Wheatbelt, extending into the Gascoyne. It has
a high cineole oil, coppices well and has good brushwood potential. It occurs on acidic loamy sands and duplex soils.
• Melaleuca zeteticorum is a salt tolerant, spreading species which extends from the central wheatbelt to the goldfields. It occurs
on the margin of salt lakes and across red sandy loam plains. Usually low growing with poor form, it has high oil content in the
• Melaleuca exuvia is a poor shrub or small tree restricted distribution east of the Wheatbelt. Its salmon coloured peeling papery
bark give it exceptional potential as an ornamental plant for the arid zone. Grows in sand soils on the margins of salt lakes.
• Melaleuca vinnula is a small flat leaf shrub from the central to eastern Wheatbelt. It grows on clayey sands.