Remedial Tree Planting Programs
Facing the salinity crisis in Aust.

Impressive as the extent of eucalypt plantings carried out this year have been, they may well pale into insignificance once the real transformation of traditional Australian farmland begins.

The National Farmers Federation, the Australian Conservation Foundation and the CSIRO have embarked on an historic joint venture; to chart the impending degradation of Australia from rising water tables, impregnated with billions of tonnes of ancient salts the dregs of eons of erosion, leaching and prehistoric oceans, dissolved into the groundwater then plan how best to treat this impending disaster while there still may be time. In short, to look at a whole new way to make a living from the land, while working within its ecological limits.

The ride on the sheep's back is clearly over and Western Victoria is seeing the economic realities of this new paradigm: at current wool prices, good land is worth between $120-$160 per hectare, an unbelievably low figure considering what it was once worth. In contrast, land is selling for up to $700 per hectare for bluegum plantings, or portions of properties are being leased for 20 years at around $170 per hectare per year, paid in advance each January. Six big companies have entered the bluegum plantation business, with a combined market capitalisation of around $2 billion and competition for good land is fierce. The target product is wood fibre for global markets, but with concern about eucalypt monocultures, many graziers are also looking at plantings of other sawlog species for long term investments and also remedial plantings to repair damaged land and to provide more biodiversity.

On a wider scale, across the centre of Australia's agricultural heartland, the Murray-Darling basin, and in the broadacre wheatlands of Southwest Western Australia, conditions are now so bad in places that real concern is expressed about the entire future of farming. Before white settlement began, Australia had a subtle balancing act of hydrology that took millions of years to develop, with deep-rooted trees and other perennials acting like pumps. Huge clearing programs have upset this balance and massive plantings of tree species and deep-rooted perennials may be the only answer to lower the insidious rising salt. Big numbers, like planting five million hectares of trees have been discussed, but this remedial task cannot be just left to commercial interests alone. A strategic approach must be made to treat every catchment area in the most effective way, utilising the most effective species.

Pressing need to reduce salinity but still with a commercial end-product

The trick will be to find a way to produce a commercially attractive end product to minimise the cost to taxpayers and individual farmers. Low rainfall areas present particular problems, with few new options to bolster the hopes of declining numbers of farmers. Maritime pine may be planted further inland than Tasmanian bluegums and other native species are being investigated for timber and chemical extracts, with a patented process being developed by CSIRO to produce activated carbon, elecricity and eucalyptus oil from mallee species.

The problem is too extensive and too important to be just left to individual farmers; a coordinated national response will be required. Technological change alone cannot reduce salinity, as it has done with other polution problems such as automobile emissions, but there are a range of actions which could address the problem and all involve lowering the water table. Trees and deep-rooted lucerne pastures are the most obvious, but other considerations include fast flow irrigation methods, as well as pumping water out of the ground and reusing it. Engineering will also have a substantial part to play in arresting the salinity crisis.

Politically, this is all a time bomb, which is why there has been a lot of denial going on in rural sectors in the past. For example, professional hydrological advice says that 80% of the wheatland areas of WA need to be planted to woody species in order to restore degraded land. The economic and sociological implications of this are overwhelming.

Ultimately, when a firm scientific basis is established, the massive scale of dryland afforestation needed will have to be commercially driven, to attract capital as well as to minimise the impact on the already depleted economy of the inland regions. Mixed tree plantings pump water from the soil at different levels, making them better able to prevent fresh rainfall from reaching the water table. Some species, such as river red gum, E.camaldulensis, send roots down to the unsaturated area just above the watertable, while others, such as yellow gum, E.Ieucoxylon, extract water from much drier soil nearer the surface. Mixed plantings are going to be more efficient in their capacity to lower the watertable than plantations of single species, which is again going to make it more challenging to find commercially viable plantation species and efficient systems to plant them. Particularly when coupled with the complexities of graduated plantings, different harvesting regimes and rotation lengths and quite possibly separate markets. Markets for trees and wood products must be identified first and it will require a significant change in thinking to plan plantings with the customer as the focus.

This is a major change in land use for traditional woolgrowing areas like Western Victoria and it could be even more dramatic for Western Australia. A similar conversion took place in the Southern states of the USA in the middle of last century, when almost all the old cotton belt was converted into pine forests. Substantial sociological changes took place, not all of them welcome at the time, but on balance it is generally agreed that the economic benefits to the region were substantial.

This is not a time to embark on a career in agronomy or wool technology, but the changes about to occur in rural Australia are going to bring untold opportunities to a new breed of farseeing landowners, investors, contractors and research technicians. The Sydney Futures Exchange plans to launch a carbon trading market this year and NSW is moving to allow electricity retailers to include forest plantations as part of their greenhouse abatement measures. A major change in outlook is occurring with forestry: no longer are trees being seen just for their knockdown value, but all their economic values are now being considered, in particular their ability to restore environmental damage from past land-clearing and ensure sustainable farming systems for the future.