Increased productivity within environmental limits (FFR/Scion)
Issue
- More intensive management is required to ensure forestry remains profitable and competitive for land in NZ.
- Increasing productivity to raise profitability will require more efficient resource use with reduced inputs.
- Society is placing more pressure on rural land users to reduce environmental impacts of intensification.
Potential benefits/costs
Financial returns from increasing productivity are very large:
- Increasing the MAI from 17m3 /ha/yr in 2013 to 25m3 /ha/yr. by 2025 will generate an additional $1.3 billion in value.
- An additional $1.5 billion is generated by 2040 if MAI can be increased from 25m3 /ha/yr to 40m3 /ha/yr.
Demonstrating forest management practices are sustainable is a prerequisite for freedom to operate and access to many markets.
Research
Research has focused on short- and long-term field trials to quantify the effects of forest management practices on long-term site productivity.
Doubling productivity, FOA’s target, in a sustainable way requires new research approaches such as novel biological agents to promote plant growth. It will also require manipulation of sites to increase carrying capacity, without compromising environmental limits imposed by regulators.
Outcomes
There has been an increase in productivity of over 20% in planted forests in New Zealand since the implementation of research programmes in the 1970s.
Long term sustainability has been demonstrated in the Long Term Site Productivity Plots (LTSP 1 series) where both stem and whole tree harvest productivity was maintained in the second rotation.
A set of soil quality indicators has been identified and can now be used to assess changes in site quality with intensification.
Large positive responses to fertiliser have been achieved on some sites in the LTSP 2 trials, but these were not always predictable.
Increases in productivity to date have occurred without significant increases in resource use (e.g. water / nutrients).
Conclusion
Research to date from long term trials has demonstrated that current forest management practices are sustainable.
The opportunity for increasing productivity through the intensification of management practices is clearly large, but ongoing research will be needed to ensure these practices are sustainable.
