Summary

The project will assess biophysical interactions and trade-offs between tree and fodder growth, and livestock productivity, in commercial Caribbean pine (Pinus caribaea var. hondurensis) silvopastoral systems in northern Queensland.

It will bring together forestry and livestock production experts, environmental and carbon consultants to evaluate the opportunity of the sector to meet a growing demand for softwood timber products while creating an additional income stream for Northern Australia’s graziers.

Researchers will measure and model the returns from field trials with cattle grazed in widely spaced commercial pine forests and compare the returns from carbon sequestration and combined timber and beef production returns with traditional grazing only activities on cleared farmland.

Three scenarios (treatments) will be evaluated:

1. Commercial pine plantation (833 trees per hectare) with permitted grazing (F)
2. Silvopastoral system in pine plantation with dual timber and livestock purpose (SPS) at 556 trees per hectare
3. Silvopastoral system in pine plantation with dual timber and livestock purpose (SPS) at 333 trees per hectare.

Pine forest stands in the region have an initial tree stocking of around 800-1000 stems per ha with typically high grass biomass in the early years, prior to canopy closure. Tree density will be reduced in the SPS treatments by removing some of the planted rows. These treatments would have a spatial arrangement of paired rows with 10-20 m wide alleys (inter-rows).

Expected outcomes

Key outcomes from the research will include:

1. Estimates of timber, pasture, cattle and carbon yields in combination and benchmarked against a pasture only system.
2. Modelled financial and enterprise profitability outcomes, which will be used to inform investors and landowners on the potential costs and benefits of adopting a pine based silvopastoral system.

This information will lead to positive impacts in terms of:

1. Improved returns through combining timber and beef production through silvopastoral systems
2. Opportunities for income diversification for landholders who invest in timber plantings with long-term increases in farm productivity
3. Mitigation of GHG emissions where silvopastoral systems and forestry systems are established on cleared pasture land
4. Improved community understanding of the productivity and co-benefits associated with silvopastoral systems in the region
5. Expansion of the plantation estate in the region (where economically viable).

This project will provide a rigorous analysis of the economic performance of silvopastoral systems at a regional level, including potential benefits for both the grazing (red meat) and timber industries and co-benefits to society (i.e. carbon sequestration).