Benefits of Trees on Farms

 There are many on-farm benefits that can be gained by incorporating private forestry into agricultural enterprises.

Well designed and managed farm plantations and native forest areas can improve property production and diversity, generating a mix of economic and environmental benefits, including:

production of timber for on farm uses such as poles, posts, firewood; diversifying farm income through sale of timber and other forest products; increased productivity of existing farm enterprises through provision of shade and shelter for crops and stock, and    supplementary stock fodder reserves; and improved sustainability of farming systems through control of dryland salinity and waterlogging, soil conservation, habitat and farm ecosystem diversity, and enhanced aesthetics.

Often there is one major reason for growing trees on a farm, but other benefits can also be obtained. Capturing multiple benefits involves careful design to integrate the trees into the farm enterprises and landscape.

Benefits of Trees on Farms

Growing commercial trees on farms can have wide ranging benefits to the landowner and the wider community through direct commercial gain from the timber, increases in productivity of other farm enterprises, provision of habitat and reversal of land degradation.

Returns from Timber

Commercial trees including timber belts, wood lots and farm plantations can provide good returns for the tree grower. Depending on the plantation regime, returns can be made from thinnings as early as age 7, and clear fall between ages 12 and 35.

Shelter

Trees provide significant shelter to stock and other farm assets. This increases the productivity of stock as they don't have to burn as much energy just to keep warm. This energy can be transferred into growth or wool production. Strategically placed trees on farms can improve the work environment by reducing the wind. Shelter also reduces wind erosion as lower velocity winds will not transport as much soil in the dry times of the year.

Shade

During the hot summer months, stock can become stressed in the extreme heat. Shade can help reduce water use and increase the comfort of the animals. This makes stock more productive.

Absorption of greenhouse gasses

Growing trees absorb the greenhouse gas, Carbon Dioxide (CO2). The growth process of trees stores CO2 in the wood and leaves of the tree, helping to lower the CO2 levels in the atmosphere. Even when the trees are harvested, most of the CO2 remains locked up in timber, paper and other forest products. Using timber rather than steel or concrete as a construction material also has a significant reduction on CO2 levels as shown in the table below.

Building Material	Net Carbon Emitted in the construction of 1m3 (kg)
Treated Timber	-228
Glue Laminated Timber	-168
Structural Steel	8117
Reinforced Concrete	182
Aluminium	6325

Improved water quality in our streams and rivers

Well placed commercial trees can help improve the quality of our waterways. The deep roots of trees intercept water, and take up the nutrients from fertilisers and animal waste that flow into the waterways and cause algal blooms in the Gippsland lakes. The deep roots of trees also reduce rapid water runoff and help prevent soil entering the watercourses that increases the turbidity of the streams.

More details can be found in "Forestry in the agricultural landscape" located on this website.

Habitat for wildlife

Planted trees on farms can provide significant habitat for wildlife. Although not quite as good as native forest, they can provide significant habitat for birds, mammals and invertebrates. Planted commercial trees can also help link remnant patches of native vegetation so that animals can travel between the patches to breed or feed. Increasing the biodiversity and numbers of insect eating birds and spiders can help reduce the number of insects present on the farm. This will help productivity of other farming enterprises.

Erosion control

Trees are important in controlling erosion as the deep roots help hold the soil together. This reduces soil losses, and in areas of high erosion can stabilise the soil and return degraded land back into productive areas.

The leaves of trees intercept rainfall, reducing the energy of the droplets before they hit the ground. This helps reduce the impact of rainfall disturbing the soil and soil and water mixing. The reduced energy of the water droplets helps reduce rapid surface water runoff reducing the amount of soil that the water can collect on its journey to the watercourses.

Reducing salinity

Large scale clearing of Australia's agricultural land has resulted in salinity in some areas. As trees were removed, evapo-transporation was reduced resulting in some of the shallow aquifers filling up, bringing the natural occurring salts in the soil to the surface. Planting trees in groundwater recharge zones will help lower the water table in some salt affected areas. The recharge zones are generally at the break of slope, where one area slopes down to a flat or depression. In Gippsland, the region with the highest risk of salinity is in the Bengworden area on the Red Gum Plains between Stratford and Bairnsdale. Priority areas for tree planting are the recharge zones of the sand rises.

Reduced pressure on native vegetation to provide forest products

All farms need forest and timber products including fence posts, stock yard rails, building materials and firewood. On many of farms these products are supplied from patches of native vegetation, which if not managed correctly can lead to degradation. By growing trees commercial trees on farms, these can supply some of the forest product needs of the farms.

Plantations can benefit wildlife
by Richard Loyn