Author: Site Owner

By Paul Oester, OSU Forestry & Natural Resources Extension Agent – Union, Umatilla & Wallowa Counties

Resilience is a term that is bounced around a lot when discussing ways our forests can adapt to changing environments. But, what does it mean? Basically, it’s the capacity of a forest to withstand (absorb) a disturbance or external pressure and return, over time, to its pre-disturbance state¹. We all would like our forests to be resilient in the face of natural disturbances such as fire, insects, disease and wind so they can keep providing us with clean water, wildlife habitat, beautiful vistas, grass for livestock and timber production.  We want to protect what we have.  A resilient forest is one that will experience disturbance, for example fires and insect outbreaks still occur, but will both withstand the disturbance without major change and grow with the components they had before the disturbance.  Because a changing climate may bring new types of extreme events, it is important to engage management methods that promote resilience so that forests may have a higher chance of returning to desired conditions.

Eastern Oregon has experienced a significant trend of increasing temperatures during the summer months, a decreasing moisture trend and more fire activity. Our springs tend to come earlier and falls stretch out longer. We’ve seen a documented increase in the length of fire seasons, fires that are hotter and more difficult to put out, and increased moisture stress on trees. What can we do to create forests resilient to these pressures?  It is generally assumed that “healthy” forests are more resilient to change². The answer then has to do with applying forest practices that are preventive and can alter forests from an “unhealthy” to a healthy condition.

Some of the possible prescriptions and practical strategies are:

• Thinning that includes fuels reduction operations in dense forests.
• If you pile the slash in a thinning, be sure and go back and burn the piles. Studies have shown that when slash piles are left on site, treated and untreated areas burn the same. On steep slopes thin a bit wider because flame lengths are longer.
• Work with your neighbors to help make your forests more resilient through collaborative preventive practices that decrease wildfire, insect and disease risk.
• When thinning, leave the most vigorous trees, those with long crowns and healthy foliage.
• Develop a wildfire preparedness plan that includes considerations for building new ponds or upgrading existing ponds to allow for pumper or helicopter access, maintaining or expanding adequate ingress and egress, and establishing fire breaks at high risk areas along your property boundary.
• Adopt forest management practices that lower risks from insects and disease such as sanitation/salvage cuts, fostering a diverse forest, knowing locally important insects and diseases and how to mitigate infection risk.
• Promote diversity in terms of species composition, forest structure, stands of different ages, and include snags and large downed wood.
• Be vigilant about conducting early detection, rapid-removal of any new invasive exotic plants, insects, diseases and animals in your area and forest.
• Take care to match the best species for the site conditions. Understand tree tolerances and biology, and implement management practices including planting and thinning that match the right species to the environmental conditions, e.g. plant more drought hardy trees, like ponderosa pine, on south and west slopes or rouge out grand fir during thinning if it is growing on drier sites.
• Be more aware of vegetation competition when planting and control competitors where needed even on better sites. Grasses and other plants aggressively compete for water and nutrients and planted seedlings have a tough time competing, especially the first couple of years after planting.

In summary, creating or promoting resiliency in the dry forests of Oregon hinges on a multi-pronged approach. It’s about knowing your forest, and developing a preventive management strategy that includes enhancing diversity across the landscape, promoting the health and vigor of trees and stands, decreasing wildfire risk through practices such as wide thinning and fuels reduction, and being proactive and prepared in the event of a wildfire.

References:
¹Thompson, I., Mackey, B. McNulty, S., Mosseler, A. (2009). Forest resilience, biodiversity and climate change. A synthesis of the biodiversity/resilience/stability relationship in forest ecosystems. Secretariat of the Convention on Biological Diversity, Montreal. Technical Series no. 43, 67 p.

²Promote Resilience to Change, March 16, 2015. In: Climate, Forests & Woodlands Community of Practice.

By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington, & Yamhill Counties

Risk management – it sounds like a bureaucratic job title. Nonetheless, risk management factors into countless decisions that woodland owners make. Whether you call it hedging your bets, keeping your options open, or not putting all your eggs in one basket, these are all ways of saying that you are managing risk.

Risk management involves weighing the potential positive and negative consequences of a proposed action against the consequences if no action is taken. People apply these principles to all kinds of everyday situations. For example, when choosing a homeowner’s insurance policy, you consider the likelihood of various circumstances to occur. If you live in or near a floodplain, you may purchase flood insurance, even if it’s highly uncertain whether there will be a flood. If a flood occurs and damages your home, and you are insured, the benefit far exceeds the cost of your insurance policy; however, if you are not insured, you may face a personal and financial crisis. If no flood occurs and you are insured, you have only sacrificed the cost of the policy; if you are not insured, you suffer no negative consequences.

Now, consider how the situation would differ for a homeowner on a ridgetop. Would he/she be as likely to purchase flood insurance?

In this example, flooding is the risk, and the magnitude of the risk depends on the location of the house (floodplain or ridgetop). Some risks you probably already consider in managing your forest include seedling survival, insect outbreaks, storm damage, fire, and changes in market conditions. But climate change might impact the magnitude of these risks.

It often takes a catastrophic event for people to think about risk and respond to it. For example, ten years since Hurricane Katrina devastated the forest industry in Mississippi, tree farmers have adapted. Shifting plantations to species that are more wind-resilient, shortening rotations, and developing markets for storm-damaged trees are all tangible strategies that have been implemented there to reduce the risk from future extreme storm events. Climate projections indicate the frequency of strong storms in the southeast U.S. will rise.

Not all climate change risks will come in the form of catastrophic events, and managing for them might be more subtle than in the previous example. Applying climate change risk management to your own forest could look like this:

1. Consider a potential effect that climate change may have in your region.
2. Consider how that effect might impact forest growth and function and/or your infrastructure.
3. Determine what, if anything, you can do to mitigate these impacts.
4. Decide on a course of action based on the possible positive and negative consequences of action vs. no action.

Here are some hypothetical examples.

Hotter summers, more fire danger…can I do anything about it?

Let’s say you are a woodland owner in the Willamette Valley, who logs infrequently and in the summertime. Fire has always been part of Oregon forests even on the west side, but climate scientists suggest that we will experience more and larger fires due to hotter and drier summers. So while on the west side we are accustomed to thinking about fire mostly as a hypothetical; in the future there might be more specific and greater fire-related risks to consider; for example:

1. The risk of a fire quickly escaping if it starts;
2. The risk to your home and forest if firefighters are working elsewhere or cannot easily access your property;
3. The risk that forest operations on your property will be limited or shut down more frequently due to fire danger.

There are ways to manage these risks, but as we move down the list above, the strategies become more complex or costly. Being vigilant about carrying fire tools during fire season, checking vehicle exhaust systems, and not smoking in the woods are easy and inexpensive ways to prevent a fire start in the first place. The second risk takes more effort to manage, involving creating defensible space, fire breaks, and access for fire trucks. The third might mean that you need to have more flexibility in the timing of logging, hauling and other projects. A logging job that was intended for the summer might extend later into the fall, meaning wet roads to contend with. Minimizing that risk could mean costly road improvements. The lesson here is that not all risks can be eliminated. Risk management means weighing the options and deciding on an acceptable level of risk.

Fewer showers, more downpours…what about my roads?
Let’s say your forest road descends into a hollow where it crosses a small stream. Climate models say that while total annual rainfall will continue to fluctuate widely, we might see an uptick in the frequency and magnitude of extreme or heavy rain events. The effect might be that your road experiences more erosion pressure – more water moving across the road, in ditches, and under the road at cross drains and the stream crossing. Culverts on forest roads are designed to accommodate peak storm flows, but it is possible that the heaviest storms of the future will be more than your current culvert can handle, and could result in a road washout, soil erosion, stream sedimentation and degraded aquatic habitat. However, replacing a culvert is costly.

You might consider the following questions when determining a future course of action:

• What is the capacity of your existing culvert? Has it come close to overflowing in the past?
• If it was not replaced and it failed in a heavy storm, what would be the ecologic and economic consequences? How dependent are you on the road for access?
• What would be the cost of replacing the culvert with a larger one?
• Which of the two above scenarios would be more costly and have a greater impact on access and use of the property?

The bottom line is that forest managers have always tolerated risk, because forces of nature, market conditions, and other factors are beyond their control. Climate change may exacerbate some risks and negate others. Future articles in this series will delve into strategies that can be employed to reduce risks to managed forests in light of climate change.

By Jason O’Brien, OSU Forestry and Natural Resources Extension – Oregon Master Naturalist Program Coordinator

The media is buzzing with reports about fire, drought and extreme heat. And climate change is often attached to these stories. But does climate science explain how today’s extreme weather relates, if at all, to global climate change? This article will highlight some of these relationships.

First, let’s review definitions of weather, climate and climate change. Weather is the state of the atmosphere at a place and time that determines if it is hot, dry, sunny, rainy, windy, etc. Climate is the average weather condition (e.g. average temperature) over time. Climate change is a change in the typical or average weather of a region or city. This could be a change in a region’s average annual rainfall, for example, or a change in a city’s average temperature for a given month or season. Under normal conditions, a range of weather conditions that deviate from averages (e.g. severe, extreme storms) can exist. Such extremes are not necessarily related to climate change.

Weather this year

2015 has been a significant year for extreme weather in Oregon, in particular, temperature and drought. According to a search of average temperatures in 2015 from January through August (the latest data available), Oregon has had the warmest year on record, departing from the 20^th century average by an increase of 5.0°F¹. The warm winter temperatures created a situation where Oregon’s snowpack peaked at the lowest levels measured in the last 35 years, with 60-90% below normal amounts in the western Cascades, and melted 3 months early (eastern Oregon fared only slightly better)². This has resulted in severe or extreme drought conditions over much of Oregon despite precipitation levels being only moderately below average³. As of the writing of this article, Oregon Governor Kate Brown has declared drought declarations in 25 of the state’s 36 counties⁴.

Is this climate change?

All of this current weather leads many to ask if it is related to climate change. Climate scientists say that it is hard to attribute the current drought directly to climate change. Rather, they suggest that it aligns with anomalous patterns in the jet stream, a warm patch of ocean water off the PNW coast (the “Blob”), and a strengthening El Niño. That said, it is important to put such extremes into context according to the latest climate change science. Climate scientists project that average annual temperatures will increase in the Pacific Northwest 3°F to 10°F by the end of this century (compared to the period 1970 to 1999), depending largely on how much heat-trapping gases (Carbon dioxide (CO₂), Methane (CH₄), Nitrous oxide (N₂O)) accumulate over this timeframe⁵. Temperature increases are projected to be largest in summer. For precipitation, projections are for a 10% reduction in rainfall during the summer⁵. Additionally, the April 1st snowpack, an indicator of natural water storage available for the warm season, is projected to decline by as much as 40% in the Cascades by the 2040s⁶. In other words, the “extreme” warm and dry weather we’ve experienced this year may be more like an “average” year in the future, whereas the future extreme years will be even more extreme.

 

What does this mean for our environment and for us?

Temperature

The past summer was the warmest on record for the Pacific Northwest. Climate model projections indicate that the largest increases in temperature will occur during the summer months⁵. Large increases in summer temperatures, along with decreased precipitation expected during this same period are likely to impact forests. These will be driven by water deficits, increasing tree stress and mortality, vulnerability to insects, and fuel flammability⁵. Further, forest managers will need to adapt to these changes, which will affect the plant hardiness zones for the most economically valuable tree species. This is particularly challenging when viewed over the entire life of a tree, when decisions about rate of growth and time to harvest must be planned. And, the ecology of whole forest ecosystems is projected to change (e.g. subalpine & alpine forests), threatening associated wildlife species⁷.

Wildfires

Extreme temperatures and drought during the driest months of the year are likely to bring more severe and larger wildfires, exacerbated by historic fire suppression practices. Already this year, Oregon has experienced wildfires that have destroying dozens of homes, consumed thousands of acres of forest, shrub and grassland, and in Washington, claimed the lives of three wildland firefighters. As the 2015 fire season begins to wind down, Oregon has experienced nearly 600,000 acres burned⁸.

 

What other extreme events might we expect with a changing climate?

Heavy Rain, Floods, and Landslides

In 1996, the Willamette Valley and parts of the Coast Range were hit by massive flooding. Heavy rain events in January, followed by cold temperatures, heavy snowfall in the Cascades, and more heavy rain and warming temperatures, created the right conditions for this flood, which struck in February⁹. According to climate models, we could expect more high rain events during winter and spring months. Regional climate models project increases of up to 20% in extreme daily precipitation⁵.

Averaged over the Pacific Northwest, the number of days with more than one inch of precipitation is projected to increase 13% during a 30-year period from 2041 to 2070, compared with 1971 to 2000.

This scenario assumes current rising emissions trends. Increases in heavy downpours, similar to the winter of 1996, could increase flood risk in mixed rain-snow and rain-dominant watersheds, such as in the Cascades and Coast Range. Further, landslides could increase due to soil saturation, combined with intense human development and unstable slopes⁶. This presents relevant challenges to forest managers as they consider when and where to harvest, establish roads, and consider the effects of runoff on sensitive fish-bearing streams and rivers.

The Upshot

Extreme weather events viewed in isolation are not necessarily tied to climate change. However, climate models project more extreme weather conditions related to temperature and precipitation. Combined with the effects of human management decisions over the last century, these changes in climate may mean more severe consequences to our environment, economy and society. How we handle these situations is a matter of our ability to adapt and mitigate for extreme events over the next century.

Citations:

1. National Centers for Environmental Information (NCEI) – National Oceanic and Atmospheric Administration (NOAA): http://www.ncdc.noaa.gov/temp-and-precip/climatological-rankings
2. Oregon Basin Outlook Report, June 1, 2015. USDA-NRCS. 37pp. Taken on August 19, 2015 from ftp://ftp.wcc.nrcs.usda.gov/states/or/watersupply/2015/WSOR_2015_Jun.pdf
3. Palmer Drought Severity Index. US Drought Portal. Taken on August 19, 2015 from https://www.drought.gov/drought/content/products-current-drought-and-monitoring-drought-indicators/palmer-drought-severity-index
4. State of Oregon Water Resources Department: Drought Watch. Taken on August 19, 2015 from http://www.oregon.gov/owrd/pages/wr/drought.aspx.
5. National Climate Assessment – Northwest. 2014. http://nca2014.globalchange.gov/report/regions/northwest.
6. USGCRP (2009). Global Climate Change Impacts in the United States . Karl, T.R., J. M. Melillo, and T. C. Peterson (eds.). United States Global Change Research Program. Cambridge University Press, New York, NY, USA. http://globalchange.gov/usimpacts/pdfs/climate-impacts-report.pdf
7. Shafer, S., Harmon, M., Neilson, R., Seidl, R., St. Clair, B., & Yost, A. The Potential Effects of Climate Change on Oregon’s. http://www.fs.fed.us/pnw/olympia/silv/publications/opt/660_ShaferEtal2010.pdf
8. InciWeb – Incident Information System. Taken on Sepember 25, 2015 from http://inciweb.nwcg.gov/state/38/20/.
9. Flood of 1996: Nearly two decades ago, huge flood struck Portland, Oregon City. The Oregonian. February 10, 2015. http://www.oregonlive.com/history/2015/02/flood_of_1996_two_decades_ago.html