The natural cycles of the forest – already compromised from a century of commercial management – are being impacted by climate change. However, wise management choices could restore the forest's capacity to absorb CO2 from the atmosphere and help to stabilize the climate.
Carbon sequestration is the process where plants pull CO2 from the atmosphere and transform it into organic carbon (C). Carbon is captured first in living things and then deposited deep in the Earth over time. In both its gas and mineral forms, carbon is a vital and volatile component of the Earth’s ecosystems and is necessary for life to exist. This carbon cycle has been in motion for millennia, determining the level of CO2 in the atmosphere and the climate conditions on the surface of the Earth. Fossil fuels are ancient, deep deposits of carbon that are mined and released back into the atmosphere by human actions. While life on Earth has persisted through many different and even extreme climates, humans and many of the species we share habitats with are now faced with the threat of a climate we are not adapted to.
Industrial forest management can release large amounts of carbon into the atmosphere and logging is the primary source of land-use related carbon emissions in Oregon. Not only does logging emit CO2, but it also reduces a forest’s carbon sequestration & storage capacity over time because trees that would have continued to capture and store carbon for decades or centuries into the future are gone.
This loss is significant because Paciﬁc Northwest forests are some of the best carbon-storing ecosystems in the world. Nine of the top ten carbon sequestering National Forests, including Mt. Hood National Forest, are in the Pacific Northwest. A recent study found that total carbon stocks in Oregon’s forests could theoretically double if forests were managed for maximum carbon sequestration. This could be achieved by protecting mature and old forests that already store large amounts of carbon, and by increasing the commercial logging rotation age by 30–50 years.
For the PNW, climate change means higher temperatures and extreme weather patterns that adversely impact water, wildlife and natural disturbance regimes.
Many models suggest precipitation and temperature patterns are changing in the Pacific Northwest resulting in more rain instead of snow and more rain-on-snow events (a leading cause of landslides and flooding) in the winter and longer drought periods in the summer.
Fish & Wildlife
As Oregon streams experience higher winter flow and reduced summer flows, while temperature rises and the variability of precipitation increases, the impacts on populations of threatened salmon are disastrous. Warmer air temperatures combined with lower summer stream flows will increase water temperatures and cause thermal stress and possibly death to adult & juvenile salmon.
Beavers as Climate Change Mitigation
Current research predicts that climate change will severely alter precipitation and temperature patterns in the Pacific Northwest by midcentury, resulting in both more flood events and drought in forested ecosystems. On the Clackamas watershed specifically, river flow has already shifted to greater rain-driven flows and less snow-melt driven flows. This combined with less summertime flow is a significant concern for both drinking water and salmon habitat. These changes are projected to be most prominent in the highest elevation watersheds, where flows are currently most dependent on winter snow accumulation. By working proactively to defend and restore the natural processes of the forest ecosystem, we can mitigate the local impacts of climate change on Mt. Hood’s watersheds.
How do beavers mitigate the effects of climate change?
- Improves water security and quality for municipal, ranching, and agricultural users. Beaver dams, ponds and resulting wetlands and wet meadows increase temporary surface water and groundwater in the headwaters resulting in water being more slowly and sustainably released. This stabilizes river flows during droughts and damaging flood events, recharges aquifers, and helps to offset the impacts of drought and decrease the frequency and magnitudes of downstream flooding. Abundant wetlands and ponds lead to improved water quality (i.e. cooler stream temperatures, less sediment) because beaver ponds and dams act as a giant water filter, resulting in cleaner water downstream. Restoring beaver populations is important as water coming from national forests is used as drinking water for a large percentage of Oregonians and contributes to water used for ranching and agriculture.
- Creates carbon capture and storage areas. Wetlands and wet meadows extract carbon from the air and store it in roots and decaying matter below ground, and in the abundant riparian vegetation above ground. Beaver ponds also capture and store carbon as dead vegetation is submerged under water. This natural process of carbon capture and storage related to wetlands, wet meadows and ponds directly addresses climate change and is currently an underutilized climate change response strategy.
- Creates wildfire safe zones for wildlife and livestock and aid in post-fire recovery. An increase in size, severity, and frequency of wildfires is expected and currently seen with climate change. The increase in abundance, size, and distribution of wetlands, wet meadows, and ponds across the state creates safe zones during wildfire for wildlife and livestock to retreat to. Forage and habitat recover more quickly post-fire than upland vegetation because of the presence of abundant water and the fact that many riparian plants are fire-adapted and respond favorably to the disturbance. Beaver ponds and wetlands/wet meadows help maintain downstream water quality by trapping sediment that might erode off hillslopes post-fire.
Climate scientists have found that climate change is resulting in higher average temperatures, drier summer conditions and more frequent instances of extreme fire weather, causing the fire season to begin earlier and last longer.
Bark is a founding member of the Pacific NW Forest Climate Alliance, where we work with allies across the region to promote forest management that increases carbon storage and supports climate resilient ecosystems.