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Restoring Ecological Health of America’s Forests. Wally Covington Regents’ Professor, School of Forestry a nd Executive Director, Ecological Restoration Institute Northern Arizona University. The Least Y ou N eed to Know. America’s forests are out of whack
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Restoring Ecological Health of America’s Forests Wally Covington Regents’ Professor, School of Forestry and Executive Director, Ecological Restoration Institute Northern Arizona University
The Least You Need to Know • America’s forests are out of whack • Frequent fire forests, in particular, have unnaturally high tree densities and fuel loads • Under these conditions, fire intensity and size have been steadily increasing • Research shows that restoration can solve forest health problems and provide economic benefits • We must increase the scale and pace of treatments
What Do We Mean by the Term Frequent Fire Forests? • Forests which over evolutionary time have become adapted to frequent, low intensity surface fire • Examples include longleaf pine, red pine, ponderosa pine, Jeffrey pine, and a wide range of dry oak-hickory forests • Under natural conditions, these frequent fires kept tree populations in check, recycled nutrients, and prevented fuel accumulation
Unnaturally High Tree Densities and Climate Change are a Recipe for Disaster • Tree densities in many forest types in the U.S. exceed the carrying capacity of the land, especially in frequent fire forest types • Excessive tree densities (20 to 100 times natural densities) make forests weak and vulnerable to unnatural insect and disease outbreaks and increasingly large and devastating crown fires
How Did Forests Become Excessively Dense and at Risk? • Overgrazing eliminated natural surface fires • Fire suppression allowed tree establishment far beyond the carrying capacity of the land • We failed to adequately control tree density and fuel loading
Increased Tree Density and Timber Volume Have Come at Costs to Other Resources • decreased stream flow • decreased groundwater recharge • decreased herbaceous production • decreased wildlife habitat • decreased biological diversity • increased fuel loading and crown fire risk • increased susceptibility to unnatural insect and disease outbreaks
Principles for Developing Restoration Prescriptions • Protect old trees which are rare • Retain post-settlement trees needed to re-establish sustainable forest structure • Thin and remove excess trees; where feasible, provide wood for economic uses • Burn at more or less natural intervals to hold tree densities and fuel loads in check
We must act a scale and pace in keeping with the character of the crises at hand. Large, collaborative landscape scale projects are our best hope.
The catastrophic “mega-fires” of 2000, 2002, and 2011, and the bark beetle outbreaks of 2000, 2007, and 2010 were predicted • The trend will continue until we intervene, and intervene in a big way. • Tree densities must be reduced to levels consistent with natural conditions
Comprehensive ecological restoration is prudent. It not only reduces crown fire threat, but converts forest which have become a liability into an asset for present and future generations.
Scientific and technical support for restoring the ecological and economic health of forested landscapes eri.nau.edu Diane Vosick, Director of Policy and Partnerships