Commentary: Forestry may hold key to spotted owl's existence
Issue Date: June 14, 2006
California Farm Bureau Federation
By Larry Irwin
The U.S. Fish and Wildlife Service recently decided not to list the California spotted owl under the Endangered Species Act, citing stable populations in the Sierra Nevada and expectations of habitat improvements resulting from forest thinning efforts.
Thousands of loggers, sawmill workers and forestry professionals in the Pacific Northwest lost their jobs in the late 1980s and 1990s as concerns over spotted owl habitat virtually shut down forest management.
Now, ironically, forestry may hold the key to the owl's existence.
Research has shown that what was once generally accepted as fact--that forest management is on the verge of destroying the owl's last remaining habitat--is one of many myths that surround this predatory bird. It ranks right up there with "spotted owls only live in old-growth forests."
The spotted owl has proven to be a far more adaptive creature than many originally believed. It thrives in old-growth forests, but not exclusively.
In many areas, it does best in a mix of forest conditions and needs young forests that provide suitable hunting grounds. If you want to find productive habitat for spotted owls in coastal redwood forests, for example, look for places with thick cover for nesting near more open brushy places with lots of wood rats and pocket gophers.
In fact, extensive tracts of old-growth forests are not conducive to nesting success among spotted owls, in part because the animals lower in its food chain need a more diverse habitat. A mosaic of forest types on the landscape--a balanced mix of old-growth stands, hardwoods, brushy vegetation, young trees and middle-age trees--apparently gives the spotted owl everything it needs to be successful.
In many areas, however, that mosaic is absent on the landscape. Instead, what appears to be a risk-averse approach--a simplistic "no-touch" short-term focus--has combined with old land management practices to introduce a potentially devastating threat: uncharacteristically intense wildfire.
Where forest management has been severely restricted, many forests have become dangerously overcrowded. In dense forests, flames burn hotter and cause greater ecosystem damage than under natural conditions. Now, unnaturally intense wildfire poses one of the two biggest threats to the spotted owl. The other is competition from the larger and more aggressive barred owl, a recent invader from eastern forests.
Some observers view harvest activities aimed at reducing fuel loads as detrimental to owl habitat. But a century of fire suppression plus a hands-off forest management approach has increased the fire risk to unacceptable levels. Furthermore, research shows that the impact of some harvesting on habitat may be only short-term and that owls may immediately increase their use of stands treated by selective harvesting.
Clearly, spotted owl habitat in at-risk forests needs to be managed. That large numbers of owls persist on California's private forestlands may offer some valuable insights. Private forestland owners manage their lands to mitigate the risk of catastrophic fire, provide good tree-growing conditions and conserve wildlife habitat.
Noted early 20th-century wildlife ecologist Aldo Leopold observed that the same factors that once harmed wildlife and their habitats--like the ax, cattle, plow, hunting and fire--can be used judiciously and creatively to restore them. To a major extent, that is exactly what is happening in California. Forest management that delivers high-quality wood products can create even more high-quality wildlife habitat by establishing or maintaining certain habitat features.
How the spotted owl ultimately responds to the invasive barred owl remains to be seen. There may be little that forest managers can do to influence that outcome. However, the barred owl seems to do best in cool, moist, dense forests, whereas the spotted owl may do best in drier, slightly more open forests. Adaptive management experiments may provide some important answers.
But we can address the fire threat and adopt forest management policies that encourage establishing a mosaic of forest types on the landscape. Doing so would benefit the spotted owl and support biodiversity in our forestlands.
(Larry Irwin, Ph.D., is a principal scientist for the National Council for Air & Stream Improvement Inc., a non-profit forestry research and environmental management organization headquartered in North Carolina. He manages the council's Western Wildlife Program. He may be contacted at firstname.lastname@example.org.)
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