State Forest Assessments: Climate Change Threatens Our Forests
The 2008 Farm Bill called on each state to complete a Statewide Forest Resource Assessment and Strategy by June 2010. Those assessments have now been published, and climate change is mentioned as a serious threat to forest health in all regions of the country. Climate change is acknowledged as directly affecting forests by altering temperatures, humidity, and precipitation. Also the assessment noted that climate change is worsening other threats that have historically plagued forests.
The forest is a living ecosystem, and threats to the forest do not occur in isolation. Invasive pests, disease, wildfire frequency and intensity, drought, altered precipitation patterns, altered stream flows, suitability as wildlife habitat, forest diversity and structure, productivity, and provision of ecosystem services all have been recognized as being impacted by climate change. These threats contribute to additional tree stress, and are further exacerbated by climate change, setting up a cycle of stress that is threatening forest health.
Some highlights:
Insect outbreaks and invasive species:
Increased tree stress from a variety of factors including drought and disturbance from more intense storms and more frequent and intense wildfires leave the forests more vulnerable to insects and invasives. Changes in climate conditions may make areas more favorable for new species, not historically common to a particular area. Damaging insects, whether native or exotic, can adjust much more quickly to climatic changes than trees, giving them a great advantage over their hosts.
Species diversity and forest structure:
Conditions may become less favorable for important tree species in some areas. Tree mortality will increase for more sensitive species, or species currently growing at the edges of their current range. For some key tree species, this will have a great effect on the structure of the forest, potentially impacting overall forest productivity and suitability as wildlife habitat. It will also likely diminish the aesthetic quality of the forest if widespread die-offs occur as species migrate northward to follow shifts in temperatures.
Increased frequency and intensity of wildfires:
Wildfires are another major concern, and are expected to increase in frequency and intensity because of longer periods of dry conditions and drought, higher fuel buildup from increased tree mortality and storm damage. Increased fire frequency and intensity will increase firefighting and fire prevention costs, reduce productivity and yields, threaten communities, and reduce water quality.
Altered precipitation:
Precipitation events may become less frequent, resulting in periodic droughts, but may also become more intense, resulting in more flash flooding and higher fluctuations in groundwater and open water levels. In combination with earlier snow melts, stream flows may become very different than they are today, impacting discharge, velocity, sediment loads, timing of high-water events, etc. Decreased groundwater levels may also cause saltwater intrusion into groundwater in coastal states, adding to tree stress and mortality.
Given the significant impacts of climate change on forests, the U.S. Forest Service has developed a National Roadmap for Responding to Climate Change, which will, according to USDA Secretary Tom Vilsack, “ make forests more resilient to climate change impacts, manage greenhouse gas emissions and increase carbon storage.” At the recent climate change meeting in Cancun,Mexico, Secretary Vilsack said that, climate change is “one of the greatest threats facing our planet.”
“Farmers, ranchers and forest owners have a great deal to contribute to mitigating climate change … and they can benefit by embracing a range of conservation practices” according to the Secretary. In Cancun, he announced $15 million in Conservation Innovation Grant funds and other assistance to support large-scale demonstration projects to accelerate the adoption of new approaches to reduce greenhouse gas (GHG) and promote carbon sequestration on private lands. As part of this, NRCS will provide financial assistance to support eligible producers as they implement conservation practices associated with these selected GHG projects.
At the press conference, the Secretary noted that climate change is a “very serious issue for forest management.” To help “do right for our natural resources” and help “ranchers, farmers and forest owners maximize opportunities,” Secretary Vilsack discussed a voluntary program to improve carbon markets. He emphasized that developing carbon markets offers another possible income stream for forest owners. Developing markets is important the Secretary noted to “keep people on their land and in their rural communities.”
