Integrating Commercial, Aesthetic & Environmental Objectives by: John Meadows

The Sunshine Coast hinterland is one region of South East Qld where small-scale farm forestry is a developing industry with significant future potential. This region contains an array of large commercial and smaller ‘hobby’ farms on which woodlots are becoming increasingly common.

A culture of commercial tree growing is swiftly gaining momentum amongst private, small-scale landholders and so too is the environmental awareness of these landholders. Local farm forestry support groups are encouraging a whole of landscape approach to integrate trees with other farm uses, using mixtures of Eucalypts and/or rainforest species for multiple purposes. There is an abundance of small to large parcels of suitable, previously cleared former farmland available for planting to achieve multiple objectives, including timber production.

Description of the Case Study

Site Specifics: The property is located in the Cooroy region of Noosa Shire. Total property area is ~9.5 ha, two-thirds of which were cleared paddocks when the current owners purchased the block in 1994. These areas had historically been used for cropping (pineapple, banana, and beans) and then for cattle grazing for ~2.5 years before treeplanting efforts began in late 1997.

The soil is derived of phyllites that have been weathered and heavily leached over time to produce acidic clay soils. They are of reasonable structure, with a gradational profile and are of generally low to occasionally moderate fertility.

Management Objectives:

• To revegetate / restore tree cover to previously grazed paddock areas as a means of reducing weed and grass growth and subsequent maintenance effort and costs.
• To generate some financial returns from the mixed Eucalyptus species farm forestry venture, while also maintaining some form of eucalypt tree cover in perpetuity.
• Create economical, environmental (soil stabilisation, habitat value, conservation of local flora and fauna spp, clean air etc.) and aesthetic (green ‘trees in the landscape’ outlook) benefits for the property through the integration of timber production and conservation oriented tree planting efforts

Mixed Eucalypt Plantation Establishment Method & Maintenance:

The plantation was established between September 1997 and April 1998. Overall ~1.5ha has been planted and the trees are around 7 years old as of April 2005. A mix of species was selected based on their compatibility with the locality and site conditions.

Species planted are Grey Gum (Eucalyptus propinqua), Forest Red Gum (E. tereticornis), Tallowwood (E. microcorys), Bloodwood (Corymbia. intermedia), Blackbutt (E. pilularis), Large Fruited Red Mahogany (E. pellita), White Mahogany (E. acmenoides), Spotted Gum (Corymbia maculata) and Gympie Messmate (E. cloeziana).

 Mixed Eucalypt plantation with resident grazing donkey

The plantation was designed and established under the guidance and assistance of the Noosa and District Landcare Farm Forestry Project. This planting forms part of a wider farm forestry development and promotional effort conducted over the past 9 years by this organization.

Initial site preparation began in late July 1997 and involved woody weed removal, slashing and spraying of grasses, deep ripping along contours, and follow-up spraying of rip lines in preparation for tree planting. Tree seedlings of local provenance were sourced from the Noosa Landcare Farm Forestry Nursery at Pomona. Around 1,100 trees/ha were planted and watered in, and hand watering was conducted over the next 6 months due to unseasonably dry conditions. Ongoing maintenance has involved slashing and spraying of weeds as required. No fertiliser has been applied to the trees and some regular form pruning has been implemented where it has been deemed necessary to improve future merchantability of stems.

First thinning materials 

During early August 2004 some contract silvicultural works were undertaken. This included slashing of grass and weeds, thinning that removed approximately 175 stems/ha (the majority of these were severely suppressed and/or defective stems) and pruning the remaining trees to a height of approximately 4.5m. The stand now contains approximately 775 stems/ha at age 7.

Plantation Performance:

Data generated from an initial forest inventory suggests that at age 5, the mixed species plantation had an average stem DBHOB of ~9cm and average tree height of ~8m. Approximately 30 – 40% of the plantation presents very good form, is in a healthy and vigorous condition and is deemed to be closer to what could be considered the expected averages (DBHOB ~15cm, Height ~12m) for a Eucalypt plantation in this region at this age.

Discussion & Recommendations:

Data obtained from the inventory undertaken in May 2003 showed that of the average surviving 950 stems/ha (at age 5), approximately 200 – 250/ha were obviously suppressed and exhibited no potential for future product delivery; they were simply competing for limited site resources. Ideally, these and more stems would have been removed at an early age in a non-commercial thin. This lack of early stand thinning and the fact that no fertilizer was applied on soils of low – moderate fertility are deemed to be factors contributing to the lower than could be expected performance to date on this site. Additional to this is the mix of species used, which have displayed differing performance in terms of growth rates and form. A cost of such a mixture is the difference in MAI that could be achieved if compared to a monoculture of the best performing species on the site, however, the carefully selected species mix used has created higher aesthetic and biodiversity values than a monoculture could. This is a good example of a productivity trade off resulting from a multiple objective, small-scale farm forestry investment.

The recent thinning operation is considered a good start towards preventing the stand from becoming further ‘locked-up’, and ensuring the quality, dominant stems have the necessary space to grow to their potential. However, a second thin will be essential, and should be conducted ASAP to ensure that an improved MAI can be realized. Essentially, it is now widely accepted (through results generated from a range of studies) that in order to grow large Eucalypt logs in a 25 – 30 year period, you must thin early and hard.

The very small scale of this venture could create difficulties in relation to marketing issues, such as engaging an interested buyer and ensuring harvest and haulage costs do not preclude an acceptable stumpage rate for the forest products. A strong marketing effort will be required. Pruned Stand Certification (independent verification that pruning has been conducted in a timely and appropriate manner to optimize higher-value clearwood for sawlogs) may be an option, as could be on-site milling to produce sawn timber. This could significantly improve the stumpage value, but will also involve production costs. Therefore, when considering such a value-adding strategy, the final outcome should be considered in terms of profits realized.

•  Tree planting efforts havehelped to stabilize

• soils and inproved the aesthetic appeal of the farm

Future management strategies for this multiple objective venture are not clear-cut, and so some alternative options are suggested here that may assist in integrating productive and long-term conservation and aesthetic benefits. An experimental approach could be to attempt to convert the plantation to a naturally regenerating, mixed species and age class forest through a number of silvicultural treatments including strategic thinning, coppice selection and the use of fire. Further strategies could include the retention of suitable habitat recruitment trees, use of a variety of nest boxes, creating snags, allowing a component of coarse woody debris to accumulate on the forest floor, and the natural recruitment or planting of understorey species such as wattles and other important food source species for a range of wildlife. Such approaches would likely involve further timber production trade-offs, but would meet the owners’ other important goals of retaining some Eucalypt tree cover in perpetuity for long-term conservation/aesthetic benefits and would also promote structural and functional complexity to further enhance biodiversity values.

Finally, Noosa Shire Council’s Local Law 10 – Vegetation Management 2003 should be considered for the future management of this farm forestry investment. The harvesting of timber as part of a forestry practice requires a permit under this Law. This Law also provides an opportunity for landowners to register a farm forestry plot with the Council, reportedly to aid the Council’s mapping of farm forestry projects within the Shire, but more importantly, to ensure a forest owners ‘right to harvest’ a planted forest. This is a recommended approach to clearly display the management objectives / intentions for this investment, and to hopefully protect the investors’ future property rights against any unnecessary Local Government ‘red tape’.

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