Enhancing forest productivity with soil sciences
Our ability to understand and manage the links between soil properties and forest productivity is being expanded by the “Growing Confidence in Forestry’s Future” (GCFF) programme.
With the growing global demand for wood products and the realisation of a soon-to-be shortage of harvestable trees, Scion’s soil scientists are leading projects to improve the productivity of New Zealand’s planted forest estate through understanding and managing soil.
“Forest health and productivity is dependent upon soil at all stages of development, from seedlings in the nursery to mature stands in the forest. However, assessing soil properties is a complex and often costly process, which has restricted research into forest soils in the past,” says soil microbiologist Dr Simeon Smaill. “The GCFF programme is giving us an opportunity to explore how soil and soil processes respond to management practices in partnership with forestry stakeholders.
“There are strong links between the physical, chemical and biological properties of soil, and forest performance. By promoting beneficial interactions it is possible to make trees grow faster, stay healthier and be more tolerant to stress, using techniques that can be applied in new and existing plantations. As part of this work we are developing new methodologies in soil microbial and genetic analysis.
“We want to explore why different tree genotypes that are planted in the same site can recruit different, and sometimes better, soil microbes. Good site preparation can enhance the beneficial activity of microbes too, so by understanding the science behind these phenomena, we can tailor management activities to get most out of soil and the resident microbial community.”
Simeon says this work may be expanded in the future to examine triggers that regulate the activity of harmful pathogenic soil microbes, providing new options to help control tree diseases.”
“Ensuring the long-term sustainability of soil resources is also a key component of the GCFF programme,” says soil scientist Loretta Garrett. “This is important to the maintenance of both forest productivity and industry licence to operate over multiple rotations.
“Our goal is to establish long term management systems for forest soils that are economical to establish, and that enhance the environmental benefits they provide.”
To achieve this goal, the GCFF programme is driving efforts to bring new levels of precision to forest soil monitoring and management. This includes the use of new tools such as a sensing device capable of measuring soil properties by projecting electro-magnetic pulses underground to a depth of 1.6 metres. Combining this with traditional soil sampling methods will make it possible for Scion’s scientists to characterise forest soils in far greater detail than ever before.
Embedded in all of Scion’s soil research is the need to understand how New Zealand’s forest soils will respond to climate change. Simeon and Loretta have led recent pan-CRI efforts to identify how soil processes will respond to the various impacts of climate change, and the likely implications for our primary sector industries.