Forestry and Climate Change
There are many connections between forestry and climate change. Among them are questions regarding how afforestation, forest management and wood utilisation can help to mitigate global warming. Another group of questions concerns how trees and forests and forestry will react to climate change. These have to do with genetic adaptation of trees, changes in forest ecosystems and adaptive management.
For over 20 years, the IFS has maintained that afforestation of treeless land can be effective in sequestering carbon, a position now backed up by a great deal of research. Using afforestation, we have the possibility of sequestering a significant part, or even all of the CO2 released by Icelanders, depending on how much people are willing to invest. Afforestation has been named as part of Iceland´s climate strategy, along with soil conservation and reclamation of wetlands, but at the same time, funding for afforestation was among the parts of the state budget cut most after 2008.
As regards adaptation of tree species, most concern has been with continued use of Siberian larch, which is not well enough adapted to mild winters. As winters continue to become milder, it seems likely that Siberian larch will cease to be a viable option at some point, at least in the lowlands. The other main tree species seem better able to tolerate mild winters.
Breeding and testing programmes are ongoing for European x Siberian hybrid larch, black cottonwood and Sitka spruce, as well as for Icelandic birch to straighten it out a little and subalpine fir (Abies lasiocarpa) for Christmas tree production. Such tree improvement programmes are essential in dealing with adaptation in the face of climate change, both because of the knowledge gained about the trees in the course of breeding and testing and also because of the capacity to react relatively rapidly to changing conditions, for example by selecting better genetic material and getting it into seed or cutting production fairly quickly.
Adaptation of existing forests to new insects and pathogens is another challenge and more difficult to deal with. As elsewhere, new forest pathogens and damaging insects regularly become established in Iceland, aided by global warming or global trade or both. The way to deal with them is through selection and breeding of tolerant trees. That way, damaged forests can theoretically be replaced by better material. However, that is expensive from a practical standpoint unless it can be paid for by timber sales as part of regular forest harvesting and regeneration.
On the other hand, a warming climate is not all bad. One of the effects will be to increase the potential forest area in Iceland. Already, the maximum elevation for productive forestry has increased by about 100 m since the 1980s, creating the potential for afforestation of large areas on mountainsides and the periphery of the central highlands. Of course, conditions for forestry are more complex than simply looking at annual or growing season temperatures. Wind exposure increases with elevation and radiative frost during the summer increases with distance from the coast, both making forest establishment more difficult. Nevertheless, it seems likely that large areas in the lower parts of the central highlands will become potential forest land within this century.