POTENTIAL IMPACTS:
FORESTRY
Forestland covers almost half
of the state of Oregon (30 million of 62 million acres). As a result,
the state of Oregon’s forests has a significant and direct impact
on the states economy, as well as the health and well-being of its
citizens. In addition to timber production, Oregon’s forests protect
freshwater supplies, provide habitat for wildlife, and recreational
opportunities for people.
According to the Western Wood
Products Association, Oregon leads all other states in timber production.
In 2008, Oregon forests produced 4.7 billion board-feet of lumber.
This number represents a 23.5% drop from 2007. The 2008 wholesale
value of Higher temperatures will directly affect tree growth, water
needs and evapotranspiration, impacts of forest insects, and wildfire.
Oregon’s lumber was nearly 43 percent lower than 2007 at $1.26 billion.
The Climate Leadership Institute
(CLI) at the University of Oregon and the Climate Impacts Group
(CIG) at the University of Washington have found that the following
aspects of climate change will have the greatest impact on Oregon’s
forests (CLI, 2007; CIG, 2009):
- Average annual
temperatures are projected to increase 2°F by the 2020s and 3°F
by the 2040s compared with averages for 1970-1999.
- Average annual
precipitation is not currently projected to change significantly,
but more winter precipitation will likely fall as rain.
- Atmospheric
carbon dioxide concentrations are expected to increase.
As a result of the above likely climatic changes,
the CLI and the CIG found that:
- Snowpack is
expected to melt earlier in the spring.
- Higher temperatures
and altered precipitation regimes will directly affect tree growth,
water needs and evapotranspiration, impacts of forest insects,
and wildfire. For instance, model results suggest that more water
will be available for forests during the winter months (due to
a greater percentage of winter precipitation falling as rain,
rather than snow, as a result of warmer temperatures). But, research
also suggests less water availability for forests in the summer
months. For species that are water limited in the summer months,
this could negatively impact their growth.
- Climate change
could impact the economic contribution of Oregon’s forests both
directly (e.g., by affecting rates of tree growth and relative
abundance of different tree species) and indirectly (e.g., by
changing the magnitude of damage from fire or forest insects).
- The fire season
will be extended.
- Due to the CO2
fertilization effect and warming, forests that are not limited
by some other resource (water, light, nitrogen, etc) may see increased
growth.
- Future fire
models suggest a doubling or tripling of area burned in the PNW
by the 2080’s. The median regional area burned is projected to
increase from about 0.5 millions acres to 0.8 million acres in
the 2020’s (a 60% increase), 1.1 million acres in the 2040’s (a
120% increase), and 2.0 million acres (a 300% increase) in the
2080’s.
- Acres burned
strongly influence fire suppression costs and may also influence
related expenditures such as costs for fire prevention programs.
If suppression costs rise in proportion to acres burned—i.e.,
increase 60% by the 2020s and 120% by the 2040s—state expenditures
by the Oregon Department of Forestry (ODF) could rise from $40-64
million at the turn of the century to $64-102 million by the 2020s
and $88-141 million by the 2040s (with all figures in constant
2005 dollars). Federal suppression expenditures—by USFS and BLM
in an area that includes both Oregon and Washington—could rise
from $40-188 million at the turn of the century to $64-301 million
by the 2020s and $88- 414 million by the 2040s. A rough estimate
allocates approximately 60% of these federal expenditures to Oregon,
which translates into a rise in federal expenditures in Oregon
from $24-114 million at the turn of the century to $38-180 million
by the 2020s and $53-$248 million by the 2040s.
- The full range
of economic impacts of wildfire—including lost timber value, lost
recreational expenditures, lost ecosystem services such as water
purification, and health and environmental costs related to air
pollution, hydrology, and other forest changes—could be many times
larger than thefire preparedness and control costs described above.
- Climate
change could have significant effects (both positive and negative)
on the extent and severity of Mountain Pine Beetle (MPB) outbreaks.
This is due to a variety of factors including; increased vulnerability
of trees when in a water stressed state (which makes them more
vulnerable to MPB infestation); and changes in the range where
climatic conditions are favorable for the MPB. In all probability,
MPB attacks will be more successful and occur at higher elevations.
- Urban forests
and the urban-wildland interface may also face growing wildfire
risks as temperatures rise. Fires in these areas threaten homes
and businesses as well as air qualty, recreation, and quality
of life.
- Economic impacts
unrelated to wildfires—e.g., from forest insects or changes in
tree growth rates attributable to climate change—are unknown and
may be either positive or negative. Forest management strategies
such as thinning may reduce the severity of fires, but are not
likely to reduce the frequency. More research is needed on the
ecological effects and economic costs and benefits of thinning.
- Forest-related
economic opportunities created by climate change might include
carbon sequestration and biomass-based energy production. More
research is needed on both of these potential opportunities to
determine their economic and ecological feasibility.
- The most economically
important timber species in the PNW is the Douglas Fir. Models
suggest its range will decrease in the 21st century.
The full
text of the CLI publication may be found online . The full
text of the
CIG publication may be found here.
References
Climate
Impacts Group, University of Washington, 2009: Forest
ecosystems, disturbance, and climatic change in Washington State,
USA. Chapter 7 in: “ The Washington
Climate Change Impacts Assessment: Evaluating Washington's Future
in a Changing Climate.”
Climate
Leadership Institute, 2007: "Economic
Impacts of Climate Change on Forest Resources in Oregon,"
A Preliminary Analysis.
Oregon
Dept of Forestry, 2005,: Oregon Forests Report, 22.
