CONCEPT 10-2 227
10-2 How Should We Manage and Sustain Forests?
CONCEPT 10-2 We can sustain forests by emphasizing the economic value of their
ecological services, protecting old-growth forests, harvesting trees no faster than
they are replenished, and using sustainable substitute resources.▲
Figure 10-17 Ways to grow and harvest trees more sustainably
(Concept 10-2). Question: Which three of these solutions do you
think are the most important? Why?■ Identify and protect forest areas high in biodiversity■ Rely more on selective cutting and strip cutting■ No clear-cutting on steep slopes■ No logging of old-growth forests■ Sharply reduce road building into uncut forest areas■ Leave most standing dead trees and fallen timber for
wildlife habitat and nutrient recycling■ Plant tree plantations primarily on deforested and
degraded land■ Certify timber grown by sustainable methods■ Include ecological services of forests in estimating their
economic valueSOLUTIONS
Sustainable Forestry
We Can Manage Forests
More Sustainably
Biodiversity researchers and a growing number of for-
esters have called for more sustainable forest manage-
ment. Figure 10-17 lists ways to achieve this goal (Con-greenhouse gas emissions, making Brazil the world’s
fourth largest emitter of such gases.
A 2005 study by forest scientists found that wide-
spread fires in the Amazon are changing weather pat-
terns by raising temperatures and reducing rainfall.
Resulting droughts dry out the forests and make them
more likely to burn—another example of a runaway
positive feedback loop Concept 2-5A, p. 44, and
Figure 2-11, p. 45). This process is converting
deforested areas of tropical forests to tropical grassland
(savanna)—an example of reaching an irreversible eco-
logical tipping point. When the forests disappear, rainfall
declines and yields of the crops planted on the land dropsharply. Models project that if current burning and de-
forestation rates continue, 20–30% of the Amazon will
be turned into savanna in the next 50 years, and per-
haps all of it could be so converted by 2080.THINKING ABOUT
Tropical Forests
Why should you care whether most of the world’s remaining
tropical forests are burned or cleared and converted to sa-
vanna within your lifetime? What are three things you could
do to help slow the rate of this depletion and degradation of
the earth’s natural capital?cept 10-2). Certification of sustainably grown timber and
of sustainably produced forest products can help people
consume forest products more sustainably (Science
Focus, p. 228). GREEN CAREER: Sustainable forestryWe Can Improve the Management
of Forest Fires
In the United States, the Smokey Bear educational
campaign undertaken by the Forest Service and the
National Advertising Council has prevented countless
forest fires. It has also saved many lives and prevented
billions of dollars in losses of trees, wildlife, and human
structures.
At the same time, this educational program has
convinced much of the public that all forest fires are
bad and should be prevented or put out. Ecologists
warn that trying to prevent all forest fires increases
the likelihood of destructive crown fires (Figure 10-9,
right) by allowing accumulation of highly flammable
underbrush and smaller trees in some forests.
According to the U.S. Forest Service, severe fires
could threaten 40% of all federal forest lands, mainly
because of fuel buildup resulting from past rigorous fire
protection programs (the Smokey Bear era), increased
logging in the 1980s that left behind highly flammable
logging debris (called slash ), and greater public use of
federal forest lands.
Ecologists and forest fire experts have proposed
several strategies for reducing fire-related harm to
forests and people. One approach is to set small, con-
tained surface fires to remove flammable small trees