CORVALLIS, Ore. – Remnants of native Pacific Northwest forests can be protected and integrated safely into housing and other urban developments, and a new guide from the Oregon State University Extension Service shows how.
"Stands, groves or patches of native trees – such as Oregon white oak, Western red cedar, red alder, bigleaf maple and Douglas-fir – are often found in urban or urbanizing areas," said Derek Godwin, one of the authors of the guide and staff chair of the OSU Extension Service in Marion County.
"As forests in the Pacific Northwest become more fragmented through urbanization and development, we lose a significant amount of the ecosystem services that forests provide, such as control of stormwater, flood prevention and mitigation of greenhouse gases."
These ecosystems are remnants of the larger forests that once covered the area, Godwin said, and range from less than a quarter acre to several acres in size. "Conservation of existing groves of native trees often provides greater economic and environmental benefit than preserving individual trees in the developing landscape," he said.
The guide provides best management practices developed and recommended by professional arborists, urban and community foresters and landscape architects, Godwin said. "Use of this basic, practical information gives trees on development sites the chance to survive and thrive after the construction process."
Some of the management practices that protect native forest remnants include fencing the entire stand to protect understory vegetation and soil, as well as trees, during construction.
"Active tree protection involves physical protective barriers and is generally required during any site disturbance that may impact retained trees, such as grading, building construction and trenching for utility installation," Godwin said.
Other recommendations in the guide are on tree care and pruning, planting, removal and replacement. To protect tree roots from disturbance, the guide also explains how to determine the critical root zone around each tree.
"Tree Protection on Construction and Development Sites: A Best Management Practices Guidebook for the Pacific Northwest" is available online at http://ir.library.oregonstate.edu/jspui/bitstream/1957/13729/1/EM8994.pdf. Printed copies of the guide (EM 8994), for $5 plus shipping and handling, may be ordered from Extension's online publications catalog, http://extension.oregonstate.edu/catalog/abstract.php?seriesno=EM+8994, or by calling 800-561-6719.