The benefits of maintaining and improving the health of native bush are numerous but they are not always obvious.
Biodiversity is the variety of life, including genetic variation, species, and assemblages of species called communities. Over the last 200 years most of the natural vegetation of the drier parts of Tasmania has been converted to improved pastures, semi-natural pastures, crop land, roads, dams, gardens and buildings. This has meant that the types of natural vegetation that occurred on the flattest and most fertile land have been largely destroyed. Many species that were once common are now found in a few small populations. If we are to maintain the variety of life on our small planet we must look after those species and communities that have been most depleted. In Tasmania most of these occur on private land.
Most owners of remnant bush appreciate its natural beauty. They feel personal satisfaction knowing that they are helping maintain native species and preserving some of the original landscape settled by their forebears.
Rural landscapes of rolling pastures interspersed with remnant native bush are part of our national heritage and are as much a part of the Australian identity as icons like Tasmania's wilderness. With changing land use, land degradation and rural tree decline we are losing that landscape.
Farmers who understand and appropriately use native bush for grazing reap a number of benefits even though native pasture supports fewer sheep per hectare than improved pasture. It does not require expensive inputs such as fertiliser or insecticides, and it is associated with fewer animal health problems. It also requires less maintenance than improved pastures and expensive works like erosion rehabilitation are generally unnecessary.
Many rural properties supplement their income by offering farm or colonial accommodation. The people who use this type of accommodation are often nature lovers who appreciate the opportunity for bush walks. Properties with remnant bush are more likely to attract visitors than those that are purely farming operations.
Real estate values
Land containing native bush is aesthetically attractive which increases its real estate value.
With the high cost of firewood, fence posts and construction timber any wood that can be collected from the bush on a property will help save money. Wood gathered from remnants can be sold for firewood, timber or pulp. However, some trees with hollows should be left standing to provide nesting sites for native birds. Florists sell the flowers and foliage of many of the plants found in bush remnants. The sale of seed for horticulture and forestry can provide good financial returns to the landholder. There is also a growing market for native grass seed.
Livestock and crop production can be increased when remnant vegetation acts as a windbreak, provides shade, and prevents soil moisture loss. Remnant vegetation reduces cold and heat stress in livestock, increases wool production and stock live weight, and reduces birth mortality.
Native bush is valuable for grazing as sheep grazed on it produce highly-valued fine and superfine wool. It can be used to help prevent scouring and worm infestations in sheep. Native grasses are more drought resistant than introduced pasture grasses so rough grazing country can provide valuable drought relief. In native pastures the cover of perennial grasses is often higher than that in improved pastures. The main native perennial grass, kangaroo grass, grows best in summer when introduced grasses are dying back.
Remnant bush offers soil conservation benefits. The higher ground cover in native and semi-native vegetation results in less loss of topsoil than when the ground is ploughed. Native forest or woodland keeps the watertable low which helps to prevent dryland salting of crop land and improved pastures.
Natural protection against pests and diseases
Trees in larger patches of remnant bush can better withstand dieback, insect attack and disease. The soils of native pastures contain insects that break down soils and litter, and eat pests. Native pastures are less susceptible to damage from pasture grubs than improved pastures. Native vegetation may also provide future biological controls for pest species such as the corby grub. In Victoria a parasitic species found on prickly box is thought to help control cockchafer beetles. Bush along streams acts as a filter for contaminants and may reduce the transport of diseases into watercourses.
Retention of plant nutrients
Large amounts of nutrients are held in the leaf and other litter on the ground. Deep-rooted trees can use nutrients leached from the surface soil layers.
Some of the relatives of important agricultural crops are found in the Tasmanian bush. These plants may provide valuable genetic material in the future. For example, soya beans are the world's main protein crop. Fourteen of the 16 soya bean species grow only in Australia and three of these grow in Tasmania. The Australian species do not suffer from rust so they may provide important genetic material for drought or frost resistant varieties. Many of our rare herbs such as the paper daisy are widely used in horticulture. Other native plants such as the native pepper and the yam daisy may prove to be profitable crops in view of the diversification of Australian cuisine. Their survival in the wild will ensure that their genetic resources are available for future development.