Pacific Northwest: Dead & dying trees stabilize biodiversity, logging ends it!
This scientific paper speaks about how forest which aren’t logged /
managed create stable ecological habitats / functions regardless of
how many trees in the forest are alive or dead. It’s yet another reason why logging / management is the only true and real cause / reason for the unraveling of forest biodiversity in the Pacific Northwest. –Editor, Forest Policy Research
Venture into a forest almost anywhere across the country and you might
hear the distinctive drumming of a woodpecker, 24 species of which
live year-round in North America. trees peppered with rectangular
feeding holes, or spot a crow-sized, black-and-white bird with a
sinuous neck and pointy scarlet crest hammering away—that would be the
pileated woodpecker, the biggest of the tribe.
Click link for full text/increase funding for writer/producer of these
words: http://www.fs.fed.us/pnw/
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Its quirky looks and laughing call inspired that early star of
animation, Woody the Woodpecker. However, in real life, this
bird—whose Latin name, Dryocopus pileatus, means “tree cleaver”—is no
cartoon character, but a major player in forest ecosystems. Its
industrious tree excavating and foraging benefit as many as two dozen
forest species and contribute generously to the recycling of forest
nutrients. These and other services have earned pileateds the status
of a “keystone” species.
Forests are dynamic, constantly evolving places, and in northeastern Oregon’s Wallowa-Whitman National Forest, where Bull began her work in 1973, a series of events has radically altered sections of the
forest over the last 30 years. “The forests described in our earlier
studies have changed from large, continuous areas of mature and old
conifers with more than 70-percent canopy cover to relatively open
canopies and an increasing number of snags [standing dead wood] and
logs, so we no longer have the conditions that our guidelines had been
written for,” Bull explains. “The effects of natural disturbances have
not been described for most of our forest species,” she adds. However,
that changed for the pileated woodpecker with the recent publication
of research spanning 30 years.
The map of home ranges occupied by
nesting pairs compiled between 1973 and 1983 indicated that the study
area had reached its carrying capacity in terms of the number of
nesting pairs it was supporting,” notes Nicole Nielsen-Pincus, now a
wildlife biologist, “and the population appeared stable during the
1989–90 period.”By 2003, however, tree density in many home ranges had
greatly diminished. Fieldwork and geographic information system (GIS)
studies showed that 75 percent of once lushly canopied grand fir
stands had shrunk to less than 30-percent canopy closure. “Going into
the postdisturbance research, we expected to see that the birds had
been most adversely affected by this loss.
Instead, we found that even
where mortality was high among grand fir and Douglas-fir, as long as
extensive logging and fuel reduction treatments had not occurred and
an abundance of large live or dead trees and logs remained, the
pileateds were still there,” Nielsen-Pincus says. Specifically, “in
six of the seven study areas, the number of nesting pairs remained the
same or fluctuated by a single pair, and the same approximate home
ranges were occupied,” Bull explains. “In the seventh area, extensive
regeneration harvests had taken place in 1991. We found that nesting
pairs no longer occupied home ranges impacted by this logging
activity, and the number of nesting pairs had decreased from the
previous five, to one—a drop of 80 percent.” Similarly, a history of
logging activity proved to be the major factor affecting pileated
efforts in fledging young—a critical measure in how well the habitat
is meeting their needs, as Bull points out. “The amount of unharvested
area and forest with more than 60-percent canopy closure was
considerably greater, and the amount of area harvested considerably
less, in home ranges occupied by pairs that successfully raised young,
compared to pairs that failed to,” she explains. None of the other
factors evaluated—forest type and structural stage (young,mature, or
old-growth), differed between pairs that were successful in producing
offspring, and those that were not.
Pacific Northwest Research Station, USDA Forest Service
Click link for full text/increase funding for writer/producer of these
words: http://www.fs.fed.us/pnw/
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