Douglasgran

The douglas fir could replace the Norway spruce we now have in Sweden as the climate changes

What happens with the Swedish forest when the climate changes? There is a risk that our native spruce, which is dominant in southern Sweden, will not do as well as today. Cecilia Malmqvist at Linnaeus University has carried out research on the douglas fir, an alternative to the Swedish spruce that provides valuable timber and probably would be better at handling climate change.

Anyone who has seen an antiques programme on TV is well aware how important it is with provenance. That is to say information on the origin and history of an object. Provenence is important also within the forestry industry, where the term signifies the origin of a seed or plant that is planted. The right provenence and, therefore, the right characteristics, can be crucial for finding a type of tree that can handle a certain climate and provide a good yield.

In a new doctoral thesis from Linnaeus University, Cecilia Malmqvist has looked into the possibilities for growing douglas fir in Sweden. The douglas fir comes from North America and is the second tallest coniferous tree in the world, next to the redwood. It is interesting since it provides high-quality timber with a wide field of application and is more likely to withstand climate change than our Swedish spruce. However, the douglas fir is sensitive in the rejuvenation stage and this is what Cecilia Malmqvist has focused her reseach on.

"I have, among other things, carried out research on plants with seven different provenances, both from coastal areas and from the inland in Canadian British Columbia – how they develop frost tolerance in autumn and how they put forth new sprouts in spring, which has an impact on the risk of getting frostbites. My results point to a number of factors that are important for the development of young plants; factors that can be used as guidance when choosing plant material and rejuvenation method, in order to increase the possibilities for a successful rejuvenation", Malmqvist explains.

Plants from inland areas start to put forth sprouts earlier in the spring than plants from coastal areas, which make them more vulnerable to spring frost. The coastal plants, on the other hand, are more likely to be affected by autumn frost or frost drought, since they develop frost tolerance later in the autumn. In field tests, the survival rate was higher among inland provenances than among coastal provenances, which to a larger extent died from frost drought.

"My research also shows that it is possible to freeze-store douglas fir plants in the nursery following the same routines as for Norway spruce, given that it is done late in the autumn when the frost tolerance has had the time to develop. I also found clear evidence that ground preparation is important; it reduces the risk of attacks from vermin and makes it easier for the root system to develop.

Cecilia Malmqvist is a certified forester and practices what she preaches – she owns and cultivates forest at Småländska höglandet since many years back. Cecilia came to Växjö in 2001 in connection to the university's launch of its sustainable forestry curses. Her curiosity for unanswered questions, combined with her will to develop educations and activities led her to start doing research.

"I actually have plantations with douglas fir on my property since way back, and this has turned out both good and bad. In one of the plantations, basically all plants died during the first year, probably as a result of poor plant preparation in combination with an attack from large pine weevils. If I were to rejuvenate today, I would chose plants with inland provenance, take great care with the ground preparation and the game treatment and, if possible, plant under a protective screen", Malmqvist concludes.

More information

Cecilia Malmqvist, researcher at the department of forestry and wood technology, Linnaeus University, phone, +4672-571 65 11, email cecilia.malmqvist@lnu.se
Annika Sand, senior press officer, phone, +4676-830 01 05