Title: Chapter 11 Sustaining Terrestrial Biodiversity: Managing and Protecting Ecosystems
1Chapter 11Sustaining Terrestrial Biodiversity
Managing and Protecting Ecosystems
2Chapter 11 Overview Questions
- How have human activities affected the earths
biodiversity? - What is conservation biology? What role does
bioinfomatics play in helping sustain
biodiversity? - What are the major types of public lands in the
United States, and how are they used? - Why are forest resources important, and how are
they used, managed, and sustained?
3Chapter 11 Overview Questions (cont.)
- How should forests in the United States be used,
managed, and sustained? - How serious is tropical deforestation, and how
can we help sustain tropical forests? - What problems do parks face, and how should we
manage them? - How should we establish, design, protect, and
manage terrestrial nature reserves? - What is wilderness, and why is it important?
4Chapter 11 Overview Questions (cont.)
- What is ecological restoration, and why is it
important? - What can we do to help sustain the earths
terrestrial biodiversity?
5Core Case Study Reintroducing Wolves to
Yellowstone
- Endangered Species
- 1850-1900 two million wolves were destroyed.
- Keystone Species
- Keeps prey away from open areas near stream
banks. - Vegetation reestablishes.
- Species diversity expands.
Figure 11-1
6HUMAN IMPACTS ON TERRESTRIAL BIODIVERSITY
- We have depleted and degraded some of the earths
biodiversity and these threats are expected to
increase.
Figure 11-3
7Why Should We Care About Biodiversity?
- Use Value For the usefulness in terms of
economic and ecological services. - Nonuse Value existence, aesthetics, bequest for
future generations.
8MANAGING AND SUSTAINING FORESTS
- Forests provide a number of ecological and
economic services that researchers have attempted
to estimate their total monetary value.
Figure 11-7
9Types of Forests
- Old-growth forest uncut or regenerated forest
that has not been seriously disturbed for several
hundred years. - 22 of worlds forest.
- Hosts many species with specialized niches.
10Types of Forests
- Second-growth forest a stand of trees resulting
from natural secondary succession. - Tree plantation planted stands of a particular
tree species.
Figure 11-8
11Global Outlook Extent of Deforestation
- Human activities have reduced the earths forest
cover by as much as half. - Losses are concentrated in developing countries.
Figure 11-12
12- 34 hotspots identified by ecologists as important
and endangered centers of biodiversity.
Figure 11-24
13Case Study Deforestation and the Fuelwood Crisis
- Almost half the people in the developing world
face a shortage of fuelwood and charcoal. - In Haiti, 98 of country is deforested.
- MIT scientist has found a way to make charcoal
from spent sugarcane.
14Harvesting Trees
- Building roads into previously inaccessible
forests paves the way for fragmentation,
destruction, and degradation.
Figure 11-9
15Harvesting Trees
- Trees can be harvested individually from diverse
forests (selective cutting), an entire forest can
be cut down (clear cutting), or portions of the
forest is harvested (e.g. strip cutting).
16Harvesting Trees
Effects of clear-cutting in the state of
Washington, U.S.
Figure 11-11
17Solutions
- We can use forests more sustainably by
emphasizing - Economic value of ecological services.
- Harvesting trees no faster than they are
replenished. - Protecting old-growth and vulnerable areas.
Figure 11-13
18CASE STUDY FOREST RESOURCES AND MANAGEMENT IN
THE U.S.
- U.S. forests cover more area than in 1920.
- Since the 1960s, an increasing area of old
growth and diverse second-growth forests have
been clear-cut. - Often replace with tree farms.
- Decreases biodiversity.
- Disrupts ecosystem processes.
19Types and Effects of Forest Fires
- Depending on their intensity, fires can benefit
or harm forests. - Burn away flammable ground material.
- Release valuable mineral nutrients.
20Solutions Controversy Over Fire Management
- To reduce fire damage
- Set controlled surface fires.
- Allow fires to burn on public lands if they dont
threaten life and property. - Clear small areas around property subject to fire.
21Solutions Controversy Over Fire Management
- In 2003, U.S. Congress passed the Healthy Forest
Restoration Act - Allows timber companies to cut medium and large
trees in 71 of the national forests. - In return, must clear away smaller, more
fire-prone trees and underbrush. - Some forest scientists believe this could
increase severe fires by removing fire resistant
trees and leaving highly flammable slash.
22Controversy over Logging in U.S. National Forests
- There has been an ongoing debate over whether
U.S. national forests should be primarily for - Timber.
- Ecological services.
- Recreation.
- Mix of these uses.
Figure 11-16
23Solutions Reducing Demand for Harvest Trees
- Tree harvesting can be reduced by wasting less
wood and making paper and charcoal fuel from
fibers that do not come from trees. - Kenaf is a promising plant for paper production.
24American Forests in a Globalized Economy
- Timber from tree plantations in temperate and
tropical countries is decreasing the need for
timber production in the U.S. - This could help preserve the biodiversity in the
U.S. by decreasing pressure to clear-cut
old-growth and second-growth forests. - This may lead to private land owners to sell less
profitable land to developers. - Forest management policy will play a key role.
25CASE STUDY TROPICAL DEFORESTATION
- Large areas of ecologically and economically
important tropical forests are being cleared and
degraded at a fast rate.
26CASE STUDY TROPICAL DEFORESTATION
- At least half of the worlds terrestrial plant
and animal species live in tropical rain forests. - Large areas of tropical forest are burned to make
way for cattle ranches and crops.
27Why Should We Care about the Loss of Tropical
Forests?
- About 2,100 of the 3,000 plants identified by the
National Cancer Institute as sources of
cancer-fighting chemicals come from tropical
forests.
Figure 11-17
28Causes of Tropical Deforestation and Degradation
- Tropical deforestation results from a number of
interconnected primary and secondary causes.
Figure 11-18
29Solutions
Sustaining Tropical Forests
Restoration
Prevention
Protect most diverse and endangered
areas Educate settlers about sustainable
agriculture and forestry Phase out subsidies
that encourage unsustainable forest use Add
subsidies that encourage sustainable forest
use Protect forests with debt-for-nature swaps
and conservation easements Certify sustainably
grown timber Reduce illegal cutting Reduce
poverty Slow population growth
Reforestation Rehabilitation of degraded
areas Concentrate farming and ranching on
already-cleared areas
Fig. 11-19, p.213
30Kenyas Green Belt MovementIndividuals Matter
- Wangari Maathai founded the Green Belt Movement.
- The main goal is to organize poor women to plant
(for fuelwood) and protect millions of trees. - In 2004, awarded Nobel peace prize.
p.214
31MANAGING AND SUSTAINING GRASSLANDS
- Almost half of the worlds livestock graze on
natural grasslands (rangelands) and managed
grasslands (pastures). - We can sustain rangeland productivity by
controlling the number and distribution of
livestock and by restoring degraded rangeland.
32MANAGING AND SUSTAINING GRASSLANDS
- Overgrazing (left) occurs when too many animals
graze for too long and exceed carrying capacity
of a grassland area.
33MANAGING AND SUSTAINING GRASSLANDS
- Example of restored area along the San Pedro
River in Arizona after 10 years of banning
grazing and off-road vehicles.
34Case Study Grazing and Urban Development in the
American West
- Ranchers, ecologists, and environmentalists are
joining together to preserve the grasslands on
cattle ranches. - Paying ranchers conservation easements (barring
future owners from development). - Pressuring government to zone the land to prevent
development of ecologically sensitive areas.
35NATIONAL PARKS
- Countries have established more than 1,100
national parks, but most are threatened by human
activities. - Local people invade park for wood, cropland, and
other natural resources. - Loggers, miners, and wildlife poachers also
deplete natural resources. - Many are too small to sustain large-animal
species. - Many suffer from invasive species.
36Case Study Stresses on U.S. National Parks
- Overused due to popularity.
- Inholdings (private ownership) within parks
threaten natural resources. - Air pollution.
37- Suggestions for sustaining and expanding the
national park system in the U.S.
Figure 11-20
38NATURE RESERVES
- Ecologists call for protecting more land to help
sustain biodiversity, but powerful economic and
political interests oppose doing this. - Currently 12 of earths land area is protected.
- Only 5 is strictly protected from harmful human
activities. - Conservation biologists call for full protection
of at least 20 of earths land area representing
multiple examples of all biomes.
39NATURE RESERVES
- Large and medium-sized reserves with buffer zones
help protect biodiversity and can be connected by
corridors.
- Costa Rica has consolidated its parks and
reserves into 8 megareserves designed to sustain
80 if its biodiversity.
Figure 11-21
40NATURE RESERVES
- A model biosphere reserve that contains a
protected inner core surrounded by two buffer
zones that people can use for multiple use.
Figure 11-22
41NATURE RESERVES
- Geographic Information System (GIS) mapping can
be used to understand and manage ecosystems. - Identify areas to establish and connect nature
reserves in large ecoregions to prevent
fragmentation. - Developers can use GIS to design housing
developments with the least environmental impact.
42NATURE RESERVES
- We can prevent or slow down losses of
biodiversity by concentrating efforts on
protecting global hot spots where significant
biodiversity is under immediate threat. - Conservation biologists are helping people in
communities find ways to sustain local
biodiversity while providing local economic
income.
43NATURE RESERVES
- Wilderness is land legally set aside in a large
enough area to prevent or minimize harm from
human activities. - Only a small percentage of the land area of the
United States has been protected as wilderness.
44ECOLOGICAL RESTORATION
- Restoration trying to return to a condition as
similar as possible to original state. - Rehabilitation attempting to turn a degraded
ecosystem back to being functional. - Replacement replacing a degraded ecosystem with
another type of ecosystem. - Creating artificial ecosystems such as
artificial wetlands for flood reduction and
sewage treatment.
45ECOLOGICAL RESTORATION
- Five basic science-based principles for
ecological restoration - Identify cause.
- Stop abuse by eliminating or sharply reducing
factors. - Reintroduce species if necessary.
- Protect area form further degradation.
- Use adaptive management to monitor efforts,
assess successes, and modify strategies.
46Will Restoration Encourage Further Destruction?
- There is some concern that ecological restoration
could promote further environmental destruction
and degradation. - Suggesting that any ecological harm can be
undone. - Preventing ecosystem damage is far cheaper than
ecological restoration.
47WHAT CAN WE DO?
- Eight priorities for protecting biodiversity
- Take immediate action to preserve worlds
biological hot spots. - Keep intact remaining old growth.
- Complete mapping of worlds biodiversity for
inventory and decision making. - Determine worlds marine hot spots.
- Concentrate on protecting and restoring lake and
river systems (most threatened ecosystems).
48WHAT CAN WE DO?
- Ensure that the full range of the earths
ecosystems are included in global conservation
strategy. - Make conservation profitable.
- Initiate ecological restoration products to heal
some of the damage done and increase share of
earths land and water allotted to the rest of
nature.
49What Can You Do?
Sustaining Terrestrial Biodiversity
Adopt a forest. Plant trees and take care
of them. Recycle paper and buy recycled paper
products. Buy sustainable wood and wood
products. Choose wood substitutes such as
bamboo furniture and recycled plastic outdoor
furniture, decking, and fencing. Restore a
nearby degraded forest or grassland. Landscape
your yard with a diversity of plants natural to
the area. Live in town because suburban sprawl
reduces biodiversity.
Fig. 11-25, p. 222