Chapter 10 Sustaining Terrestrial Biodiversity: The Ecosystem Approach

Core Case Study: Reintroducing Wolves to Yellowstone  Endangered Species two million wolves were destroyed two million wolves were destroyed.  Keystone Species Keeps prey away from open areas near stream banks. Keeps prey away from open areas near stream banks. Vegetation reestablishes. Vegetation reestablishes. Species diversity expands. Species diversity expands. Figure 10-1

HUMAN IMPACTS ON TERRESTRIAL BIODIVERSITY  We have depleted and degraded some of the earth’s biodiversity and these threats are expected to increase. Figure 10-2

Why Should We Care About Biodiversity?  Intrinsic Value Ethical—organisms exist so they should be allowed to do so. Figure 10-3

Why Should We Care About Biodiversity?  Instrumental Value 1. Use Value: For the usefulness in terms of economic, medical, recreational and ecological services. 6% of GDP, 5% Growth Figure 10-3

Why Should We Care About Biodiversity?  Instrumental Value 2. Nonuse Value: existence, aesthetics, bequest for future generations. Figure 10-3

Ecosystem Approach  What species and ecosystems?  Locate and protect most endangered ecosystems.  Biodiversity friendly development  Refuges, sanctuaries, etc. (USFWS-Natl. Refuge System Improvement Act)

Wisconsin Forest Land

 Approx. 16 million acres of forest land in Wisconsin.  60% is privately owned  The rest is incorporated into state, county, federal and tribal land holdings.  1.5 million acres in the Chequamegon-Nicolet National Forest  5.7 million acres of public land—not all forested

TIMBER!!!  Is it bad to cut down a tree?  “Fern Gully” or Paul Bunyan?

MANAGING AND SUSTAINING FORESTS  Forests provide a number of ecological and economic services that researchers have attempted to estimate their total monetary value. Figure 10-4

Types of Forests  Old-growth forest: uncut or regenerated forest that has not been seriously disturbed for several hundred years. 22% of world’s forest. 22% of world’s forest. Hosts many species with specialized niches. Hosts many species with specialized niches. Figure 10-5

Types of Forests  Second-growth forest: (63%)a stand of trees resulting from natural secondary succession.  Tree plantation: (5%) planted stands of a particular tree species. Figure 10-6

Global Outlook: Extent of Deforestation  Human activities have reduced the earth’s forest cover by as much as half.  Losses are concentrated in developing countries.  % degrade/yr  40% OG in 2 decades Figure 10-7

Current Forestry Trends Global Forest Resources Assessment 2010 Global Forest Resources Assessment 2010

Harvesting 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). Figure 10-9

Harvesting Trees Effects of clear-cutting in the state of Washington, U.S. Figures and 10-11

Harvesting Trees  Building roads into previously inaccessible forests paves the way for fragmentation, destruction, and degradation. Figure 10-8

Solutions  We can use forests more sustainably by emphasizing: Economic value of ecological services. Economic value of ecological services. Harvesting trees no faster than they are replenished. Harvesting trees no faster than they are replenished. Protecting old-growth and vulnerable areas. Protecting old-growth and vulnerable areas. Figure 10-12

CASE STUDY: FOREST RESOURCES AND MANAGEMENT IN THE U.S.  U.S. forests cover more area than in (40% is in protected forests) (40% is in protected forests)  Since the 1960’s, an increasing area of old growth and diverse second-growth forests have been clear-cut. (MONOCULTURE) Often replace with tree farms. Often replace with tree farms. Decreases biodiversity. Decreases biodiversity. Disrupts ecosystem processes. Disrupts ecosystem processes.

FIRE  Are forest fires natural?  Are forest fires good?  Bad??  Explain!!!

Types and Effects of Forest Fires  Depending on their intensity, fires can benefit or harm forests. Burn away flammable ground material. Burn away flammable ground material. Release valuable mineral nutrients. Release valuable mineral nutrients. Figure 10-13

Solutions: Controversy Over Fire Management  To reduce fire damage: Set controlled surface fires. Set controlled surface fires. Allow fires to burn on public lands if they don’t threaten life and property. Allow fires to burn on public lands if they don’t threaten life and property. Clear small areas around property subject to fire. Clear small areas around property subject to fire.

Controversy over Logging in U.S. National Forests  There has been an ongoing debate over whether U.S. national forests should be primarily for: Timber. Timber. Ecological services. Ecological services. Recreation. Recreation. Mix of these uses. Mix of these uses. Figure 10-14

Solutions: 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. 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. 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. Some forest scientists believe this could increase severe fires by removing fire resistant trees and leaving highly flammable slash.

Solutions: 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. Kenaf is a promising plant for paper production. Figure 10-15

CASE STUDY: TROPICAL DEFORESTATION  At least half of the world’s 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. Figure 10-17

Why 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 10-18

Fig , p. 207 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 Restoration Reforestation Rehabilitation of degraded areas Concentrate farming and ranching on already-cleared areas Solutions Sustaining Tropical Forests Prevention

NATIONAL 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. Local people invade park for wood, cropland, and other natural resources. Loggers, miners, and wildlife poachers also deplete natural resources. Loggers, miners, and wildlife poachers also deplete natural resources. Many are too small to sustain large-animal species. Many are too small to sustain large-animal species. Many suffer from invasive species. Many suffer from invasive species.

Case Study: Stresses on U.S. National Parks  Overused due to popularity.  Inholdings (private ownership) within parks threaten natural resources.  Air pollution. Figure 10-23

 Suggestions for sustaining and expanding the national park system in the U.S. Figure 10-24

 34 hotspots identified by ecologists as important and endangered centers of biodiversity. Figure 10-26

NATURE RESERVES  Ecologists call for protecting more land to help sustain biodiversity, but powerful economic and political interests oppose doing this. Currently 12% of earth’s land area is protected. Currently 12% of earth’s land area is protected. Only 5% is strictly protected from harmful human activities. Only 5% is strictly protected from harmful human activities. Conservation biologists call for full protection of at least 20% of earth’s land area representing multiple examples of all biomes. Conservation biologists call for full protection of at least 20% of earth’s land area representing multiple examples of all biomes.

How Would You Vote?  Should at least 20% of the Earth's land area be strictly protected from economic development? a. No. Such protections would encourage people to poach and illegally extract resources from the expanded reserves. a. No. Such protections would encourage people to poach and illegally extract resources from the expanded reserves. b. Yes. The project is desperately needed to protect the Earth's biodiversity. b. Yes. The project is desperately needed to protect the Earth's biodiversity.

NATURE 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% of its biodiversity. Figure 10-10B

NATURE 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. 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. Developers can use GIS to design housing developments with the least environmental impact.

NATURE 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.

Wilderness Areas in US   *area of 1500 sq. miles that is protected from air, water, noise pollution (us!!)   4.6% of US land, only 413 areas in lower 48, only 4 fit the square mileage for wilderness, squ miles in Natl. Forest was protected by Roadless Rule until 2005 when the Bush Admin. Dropped the rule and allowed mining, etc.   Biologists say preserve wilderness as:   *as natural capital (natural capital)   *centers for evolution

ECOLOGICAL 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.

How Would You Vote?  Should we mount a massive effort to restore ecosystems we have degraded even though this will be quite costly?