Farm Forestry Opportunities in the Port Phillip Region
Note number: AG 1072
Published: November 2002
Reviewed: August 2008
A feasibility study was conducted into the opportunities for farm forestry in the Port Phillip and Westernport region. This study explored the realistic prospects for farm forestry development within region. It examined land capability and suitability, potential markets, and land management issues relating to farm forestry development.
Land capability
The study examined the capability of land to support the growth of several tree species commonly used in farm forestry plantations. Pulpwood plantations of blue gum (Eucalyptus globulus) and shining gum (Eucalyptus nitens) were assessed. Also assessed was radiata pine (Pinus radiata) grown under the multiple thinning regime where the trees are planted at high density, thinned multiple times and remain unpruned (Refer to Agriculture Note AG1070: Radiata pine planning and establishment).
Land capability was assessed using a variety of factors depending on the species being grown and the end product. The five critical factors used in determining the capability to grow the eucalypt species for pulp are outlined below.
Moisture availability
Moisture availability is the amount of water that the soil can store that is available for plant use.
Temperature regime
Temperature correlates strongly with altitude and the average annual temperature correlates with the length of the growing season. However temperature is only important to the growth rate where moisture is not limited.
Soil drainage
Drainage was determined using an estimation of the depth and duration of the soil wetness, waterlogging and aeration. It is affected by soil permeability, slope, depth, position in the landscape, runoff and seepage
Rooting conditions
Rooting conditions relate to soil composition and structure. A deep uniform sand or loam would have good rooting conditions whereas a shallow uniform massive clay would have poor rooting conditions. The depth to an impenetrable hardpan or the bedrock is an important factor in determining the rooting conditions of a soil.
Nutrient availability
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The availability of nutrients was determined by three factors:
- Chemical: the presence of nutrients and their availability to plants.
- Physical: soil characteristics that affect aeration, water availability and root penetration.
- Biological: the soil biota and their affects on nutrient recycling.
The capability of the land to support radiata pine plantations was assessed using knowledge of the soil type and rainfall data for the region. Using extensive long-term growth data from plantations around Victoria the capability of the land to support Pine could then be calculated, the map shown in Figure 1 was generated from the results of this assessment.
The feasibility study found that significant areas in the eastern part of the region may be suitable for radiata pine plantations grown under the multiple thinning regime. Only small areas were suitable for commercial plantations of blue gum or shining gum for pulpwood.
Species options
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Commercial tree plantations in the Port Phillip region can enhance agricultural production while providing financial returns. However, high land values (see Figure 2) mean that purchasing land solely to plant trees may not be economically viable.
Of course, profitability will vary depending on individual site conditions and the product grown. The study recommended several plantation models covering several species that are suitable for areas within the Port Phillip and Westernport region (see Figure 3 for sub-region boundaries). Several plantation models were considered in the study.
Sawlog models
Eucalypt sawlogs
Sydney blue gum/spotted gum/shining gum clearwood plantations grown over a rotation of up to 30 years. This involves a great deal more management including probably two thinnings, the first of which would not yield any commercial product and three pruning efforts to realise a clearwood log of about six metres. This plantation method would be most suitable for the higher rainfall regions in the Yarra Valley/Dandenong Ranges and the West Gippsland Hills areas. The aim of this regime is to produce a high value product so it is more suited to smaller plantings than pulpwood plantations and can be used in shelterbelts and windbreaks.
Unpruned radiata pine sawlogs
The multiple thinning radiata pine regime calls for a rotation length of about 30 years, this includes two or three thinnings. The initial stocking of the plantation is about 1100 trees per hectare and after the final thinning it will be around 300-400 trees per hectare. This plantation regime is suitable for most parts of the Port Phillip and Westernport Catchment, although it is not recommended for areas with an annual average rainfall of less than 700 mm per year.
Pruned radiata pine and blackwood sawlogs
Radiata pine clearwood and blackwood clearwood regimes are a possibility in the higher rainfall areas in the north east and eastern parts of the region.
Pulpwood
Blue gum/shining sum pulpwood grown over a 15-year rotation, with minimal management. The areas recommended for this regime were Yarra Valley/Dandenong Ranges, West Gippsland Hills, Mornington Peninsula and parts of the West Gippsland Plains.
Firewood
Sugar gum or red gum firewood plantations are the best commercial options in the lower rainfall parts of the region to the west and north of Melbourne. They are based on direct seeding in rows that can be used as shelter belts, harvesting could occur after as little as ten years depending on growth rates. The proximity of Melbourne, a major fire wood market makes this a particularly attractive option for lower productivity sites.
Land capability conclusions
The feasibility study found that the capability of the land to support productive tree growth depended on the price of log products (this is dependent on market conditions, location and infrastructure), land prices and a range of social and environmental features.
The study suggested that the greatest potential for farm forestry in the Port Phillip and Westernport Catchment Region lay in integrating tree growing with existing agricultural practices. The return from forest products at the end of the rotation would add further value to the environmental and
productivity benefits realised whilst the trees are growing.
Sub-region opportunities
The Feasibility study identified six sub-regions within the Port Phillip and Westernport Catchment region (Figure 3). Within each sub-region specific opportunities for farm forestry to combat land management issues were identified.
Western
Management of eucalypt shelterbelts for firewood production will provide agricultural and environmental benefits. On the Bellarine Peninsula there is some potential for radiata pine to be managed under the multiple thinning regime. Planting of trees can also provide assistance in the management of serrated tussock and the erosion caused by wind and water.
Benefits
- Income from firewood
- Reduced cost of pest plant control
- Increase or maintenance of income from agriculture
- Erosion management
Northern
Eucalypts grown in strategically located shelterbelts can be managed for firewood production, limit the spread of serrated tussock, and improve agricultural productivity through protection of pasture and stock from exposure. There is also potential for conventional radiata pine production in some areas. Trees can be a valuable tool in combating erosion caused by wind and water which is a major land management issue in this area.
Benefits
- Pest plant control
- Income from timber
- Increase or maintenance of income from agriculture
- Erosion management
Yarra Valley/Dandenong Ranges
Small-scale pine clearwood plantations may be integrated with other agricultural uses, subject to local government planning requirements. Eucalypt (shining gum and Sydney blue gum)
sawlog production is a good option, particularly on higher productivity sites. Trees offer a productive use of land contaminated by the use of organochlorides on the eastern border of the region.
Benefits
- Income from high value logs
- Improved agricultural production
- Profitable use of contaminated land
West Gippsland Hills
On high productivity sites most plantation options can be grown as a commercial crop whilst also increasing agricultural production. Large-scale plantations of eucalypt pulpwood or radiata pine are suitable, as are blackwood and eucalypt clearwood. Trees can be used to combat the increase in soil acidification caused by the overuse of nitrogen fixing crops and nitrogenous fertilisers. These nutrients are leached beyond the shallow root zone of pasture species. Trees are deeper rooted and able to access these nutrients and return them to the nutrient cycle.
Benefits
- Income from high value logs or eucalypt pulp logs
- Improved agricultural production
- Avert soil acidification
West Gippsland Plains
Radiata pine is a suitable plantation species in this area (check local government planning requirements). Firewood production is also a good option for most of the sub-region. Parts of this area are susceptible to dryland salinity due to the replacement of deep-rooted native vegetation with shallow rooted pastures and crops. Planting trees in shelterbelts and windbreaks for firewood production can help alleviate this problem.
Benefits
- Income from the sale of wood products
- Improved agricultural productivity
- Prevention of areas of dryland salinity
Mornington Peninsula
Small-scale pine clearwood plantations may be integrated with other agricultural uses, subject to local government planning requirements. Small scale eucalypt plantations for sawn timber production. Spotted Gum may be grown in suitable frost-free coastal areas.
Benefits
- Income from high value logs
- Improved agricultural productivity
Conclusion
The study found that there is land suitable for farm forestry in the region. High land prices mean that purchasing properties for farm forestry alone is not economically viable. However other benefits from the planting of trees can improve overall farm productivity, and this combined with the return from the forestry enterprise will improve overall farm productivity.
Further References
Baker, R., Poynter, M. and Wareing, K. (1999). Feasibility Study of Farm Forestry Development in the Port Phillip and Westernport Region, Department of Natural Resources and Environment.
See Agriculture Notes:
AG0772: Sawlog silviculture for eucalypts
AG0775: Thinning eucalypts for sawlogs
AG0810: Radiata pine for farm forestry
AG0851: Blue gum for farm forestry
AG1070: Radiata pine planning and establishment
AG1072: Timber processors and markets in the Port Phillip region
Contact Services Available from DPI
Private Forestry website: www.dpi.vic.gov.au/privateforestry
Acknowledgement
This Information Note was originally developed by Gavin Brock, November 2002. It was updated by Karen Johnson , Farm Services Victoria in August 2008.
