Environmental Engineering Reference
In-Depth Information
contributed to this decline (Crone 2005). Today, tourism and recreation are the
region's fastest-growing industries (Colt, Dugan, and Fay 2007) due to the natural
beauty, abundant wildlife, and outstanding recreational opportunities on the Tongass.
Residents currently face rising energy costs, decreasing job opportunities, and sig-
nificant outmigration from communities. According to 2009 data from the Alaska De-
partment of Labor, southeast Alaska has the state's largest rate of population decline
(5.6 percent loss) since 2000, and no area in the region has had long-term population
growth during that time. A lack of jobs and economic opportunity is the common cul-
prit for the outmigration trend. Although logging jobs represent a very small percent-
age of the regional workforce, the dominant cultural role of timber cannot be over-
stated. While some residents pin their hopes on a revival of the industry, others are
more circumspect and recognize that not only is old-growth timber harvest highly
controversial, supply is rapidly dwindling and increasingly uneconomical to process.
The regional economic trends and the transitioning timber industry represent an op-
portunity for innovative forest management activities that meet broader stakeholder
values.
Ecological Effects of Past Management
There is a profound need for ecological restoration on the Tongass. Decades of large-
scale old-growth, clear-cut timber harvest have left a degraded landscape, including
failing roads and unnaturally dense stands of second-growth forest (Tongass National
Forest 2006). Thousands of miles of roads and damaged culverts affect watershed
quality and fish habitat and impair watershed functions through erosion and prevent-
ing the migration of anadromous fish. Early timber harvests targeted trees lining
stream banks, removing critical supplies of future large woody debris. Instream resto-
ration efforts are directed at decommissioning roads, repairing culverts, and adding
large woody debris to restore structural complexity for fish habitat.
In addition to affecting streams, past timber harvest has left more than 430,000
acres of young forest on the Tongass (U.S. Forest Service 2008), much of it in dire
need of management. After clear-cutting, forests pass through three phases before re-
turning to late-successional, old-growth conditions: stand initiation, stem exclusion,
and understory reinitiation. In the temperate coastal rainforests of southeast Alaska,
the stem exclusion phase begins about thirty years after initial harvest, when dense
stands of young trees crowd together, create a closed canopy, reduce light, and signif-
icantly affect forage availability for a wide variety of wildlife, particularly key species,
such as Sitka black-tailed deer (
Odocoileus hemionus sitkensis
). Unlike many areas of
the North American continent, fire is not the dominant natural disturbance in south-
east Alaska, therefore restoration treatments in young forest stands are not designed to
reduce or modify wildfire risk, but rather to increase forage for deer and improve habi-
tat for other wildlife species. Thinning for restoration purposes in nondevelopment
land use designations remains experimental on the Tongass and includes several tech-
niques such as variable spacing, gapping, girdling, and individual tree selection (Har-
ris 2009). Gaps and variable spacing are intended to mimic natural disturbances, such
