Commercial forestry has in recent decades become highly dependent on a small number of conifer species, particularly Sitka spruce. Adaptation and resilience of productive forestry is affected by risks from climate change and a number of high impact tree pests and diseases. These risks have prompted policy, practical and industrial concerns about over-reliance on a small number of tree species.

There is renewed interest in alternative conifer species including western red cedar, firs, western hemlock and Douglas fir, all of which can produce valuable timber if grown competently on well-selected sites. Most research about diversification focuses on the biological and economic aspects of these changes. However, change in practice will only come if the people who produce, manage, harvest and buy the trees are willing and able to work in different ways.

This report considers the implications of a shift in forest management through the lens of species diversity. 

Key findings include:
  • Species choice is a social as well as an economic and technical choice, because different people involved in land use have different objectives and preferences.
  • Tree nursery producers, forest managers and sawmill businesses all influence species choice through supply and demand relations, as well as through preferences and shared values
  • Stakeholders experience risk in different ways.
    • Nursery businesses are bearing the most tangible component of risk at the outset, and paying the cost of low confidence in policy direction.
    • Sawmills are adapting to a wide range of species, and more than they are usually credited with.
    • The private investment forestry sector is the least interested in change, because most of their clients are driven by the search for high returns on their investments.
    • Public forest managers are committed to diversification but are forced to take an experimental approach because of the scarcity of experience and site-specific information on cultivating alternative species.
  • Both private and public forest managers identify deer populations, and their preference for browsing species other than spruce, as a particular constraint to commercial diversification.