Future wood properties in Australian forests: effects of temperature, rainfall and elevated CO₂

ABSTRACT

While focus is often placed on possible reductions in forest growth and timber volume yield under different future climates, less attention is paid to changes in wood properties, such as wood density. In this paper we explore the literature on climate effects on wood properties, with a particular focus on Australian plantations and forests. We also present results from modelling exercises, designed to explore possible growth and wood property changes in two Australian forestry regions under a hotter and wetter future, or a hotter and drier future. While the effects of different climates on tree growth and wood formation are complex and difficult to generalise, some broad tendencies can be identified. Temperature has varied effects on wood properties, but much research has shown that the density of wood is higher when formed under higher temperatures. Similarly, an elevated concentration of atmospheric CO₂ (eCO₂) has been found to have variable effects, but trees in eCO₂ environments can produce higher density wood. The effects of water deficits are clearer: in general, trees produce higher density wood in drier environments, through a combination of narrower rings, higher proportions of latewood, and thicker walled/narrower cells. The extent to which, when other factors such as changes in transport efficiencies are taken into account, losses in wood volume under different future climates may be compensated by increases in wood density, or other changes in wood properties, needs to be clarified.

KEYWORDS:

• xylem formation
• pinus radiata
• cambium
• CABALA
• wood quality

Acknowledgements

The authors acknowledge the funding support of Forest and Wood Products Australia (FWPA) and CSIRO Australia, as well as support from Sappi forests (South Africa) and Forestry South Australia, where research activities were undertaken to produce data presented here.

Disclosure statement

No potential conflict of interest was reported by the authors.