Sustaining Biodiversity: The Ecosystem Approach Chapter 8

Core Case Study: North American Gray Wolf  Reduced to a few hundred  Keystone species  Restoration proposal angered ranchers, hungers, loggers  1995, reintroduced in Yellowstone, 136 by 2007  Positive ripple effect after reintroduction

The Gray Wolf Fig. 8-1, p. 149

8-1 How Are We Affecting the Earth’s Biodiversity and Why Should We Protect It?  Concept 8-1A We are degrading and destroying biodiversity in many parts of the world and these threats are increasing.  Concept 8-1B We should protect biodiversity because it exists and because of its usefulness to us and other species.

Loss of Biodiversity  Earth’s biodiversity depleted and degraded  83% land surface disturbed  Degradation of aquatic biodiversity  Ecological fishprint unsustainable

Why Protect Biodiversity  Intrinsic value  Instrumental value  Nonuse values Existence Aesthetic Bequest

Endangered Orangutans Fig. 8-2, p. 152

8-2 How Should We Manage and Sustain Forests?  Concept 8-2 We can sustain forests by recognizing the economic value of their ecological services, protecting old-growth forests, harvesting trees no faster than they are replenished, and making most paper from fast- growing plants and agricultural residues instead of trees.

Forest Services  Forests 30% of earth’s land surface  Economic services  Ecological services

Types of Forests  Old-growth forests  Second-growth forests  Tree plantation

Natural Capital: Forests Fig. 8-3, p. 153

Old-growth Forest Fig. 8-4, p. 154

Short Rotation Cycle Forestry

Fig. 8-5, p. 154 Years of growth Weak trees removed Seedlings planted Clear cut 30 yrs 25 yrs 5 yrs10 yrs 15 yrs

Loss of Original Forests  46% in 8,000 years, most since 1950  Most in tropical areas, developing countries  Estimated loss of 40% intact forests within next 20 years

Natural Capital Degradation: Deforestation Fig. 8-6, p. 155

Science Focus: Putting a Price Tag on Nature’s Ecological Services  Estimated value of earth’s ecological services $33.2 trillion per year $4.7 trillion per year for forests  Need to start factoring values into land use

Roads and Forests

Fig. 8-7, p. 156 Cleared plots for agriculture New highway Old growth Highway Cleared plots for grazing

Fig. 8-7, p. 156 New highway Old growth Cleared plots for agriculture Highway Cleared plots for grazing Stepped Art

Good News on Forests  2000–2005 net total forested area stabilized or increased  Most of the increase due to tree plantations  Net loss of terrestrial biodiversity

Return of Forests in the United States (1)  U.S. forests Cover ~30% of land Contain ~80% of wildlife species Supply ~67% of nation’s surface water  Forest cover greater now than in 1920  Secondary succession

Return of Forests in the United States (2)  Second- and third-growth forests fairly diverse  More wood grown than cut  40% of forests in National Forest System  Forests transformed into tree plantations

Individuals Matter: Butterfly in a Redwood Tree  Julia Hill – “Butterfly” – two years on a platform of California redwood tree  Protest clear-cutting of the ancient trees  Nonviolent civil disobedience  Lost battle, but her tree was saved

Controversy over the National Forests  Forest service mandate Principle of sustainable yield Principle of multiple use  Timber companies push for tree cutting to be primary goal

Harvest Methods (1)  Step one – build roads Erosion Invasive species Open up for human invasion  Step two – logging operations Selective cutting Strip cutting Clear cutting

Forest Harvesting Methods

Fig. 8-8a, p. 156 Clear stream (a) Selective cutting

Fig. 8-8b, p. 156 Muddy stream (b) Clear-cutting

Fig. 8-8c, p. 156 Cut 1 year ago (c) Strip cutting Uncut Clear stream Uncut Cut 3–10 years ago Dirt road

Clear-cut Logging Fig. 8-9, p. 157

Trade-offs: Clear-cutting Forests Fig. 8-10, p. 157

Forests and Fires  Surface fires Burn undergrowth only Cool fire Ecological benefits  Crown fires Burn the entire tree Hot fire Occur in forests with lack of surface fires

Management of Forest Fires  Fire suppression in all types of forests  Some forests naturally fire adapted  Restoration of fire’s natural role

Forest Fires Fig. 8-11, p. 158

Science Focus: Certifying Sustainably Grown Timber  Forest Steward Council certification of forest operations Environmentally sound practices Sustainable yield harvest Minimal erosion from operations Retention of dead wood for wildlife habitat

Solutions: Sustainable Forestry Fig. 8-12, p. 159

Trees and Paper  Many trees are cut for paper production  Alternatives Pulp from rice straw and agricultural residues (China) Kenaf (U.S.)

Solutions: Kenaf Fig. 8-13, p. 159

8-3 How Serious Is Tropical Deforestation and How Can It Be Reduced?  Concept 8-3 We can reduce tropical deforestation by protecting large forest areas, teaching settlers about sustainable agriculture and forestry, using government subsidies that encourage sustainable forest use, reducing poverty, and slowing population growth.

Tropical Forests  Cover 6% of earth’s land area  Habitat for 50% of terrestrial plants and animals  Vulnerable to extinction – specialized niches  Rapid loss of 50,000–170,000 km 2 per year

Burning of a Tropical Forest Fig. 8-14, p. 160

Destruction of Tropical Forests Fig. 8-15, p. 161

Causes of Tropical Forest Deforestation and Degradation  Population growth and poverty  Government subsidies  International lending agencies encourage development

Effects of Tropical Deforestation  Fragmentation of remaining patches  Remaining forests get drier and may burn Degrades biodiversity CO 2 to the atmosphere Accelerates climate change

How to Protect Tropical Forests  Teach settlers to practice small-scale sustainable agriculture  Harvest renewable resources from the forests  Debt-for-nature swaps  Conservation concessions  Gentler logging methods

Solutions: Sustaining Tropical Forests Fig. 8-16, p. 162

Individuals Matter: Wangari Maathai and Kenya’s Green Belt Movement  Backyard small tree nursery  Organized poor women  Women paid for each surviving seedling planted Breaks cycle of poverty Reduces environmental degradation People walk less distance to get fuelwood  Sparked projects in +30 African countries

8-4 How Should We Manage and Sustain Grasslands?  Concept 8-4 We can sustain the productivity of rangeland by controlling the number and distribution of livestock and by restoring degraded rangeland.

Grasslands  Provide important ecological services  Second most used and altered ecosystem by humans  42% grazed by cattle, sheep, and goats – rangeland and pasture  Overgrazing

Manage Rangelands Sustainably  Practice rotational grazing  Fence out riparian zone areas  Suppress invader plants  Replant barren soil with seeds  Employ controlled burns to control exotic vegetation

San Pedro River Rangelands Fig. 8-17, p. 164

8-5 How Should We Manage and Sustain Parks and Nature Reserves?  Concept 8-5 Sustaining biodiversity will require protecting much more of the earth’s remaining undisturbed land area, starting with the most endangered biodiversity hot spots.

National Parks  >1,100 national parks in 120 countries  Only 1% of parks in developing countries are protected  Local people invade parks to survive

Problems Protecting National Parks  Illegal logging  Illegal mining  Wildlife poaching  Most parks too small to protect large animals  Invasion of nonnative species

Stresses on U.S. National Parks  Biggest problem popularity  Damage from nonnative species  Threatened islands of biodiversity

Natural Capital Degradation: Off-road Vehicles Fig. 8-18, p. 165

Nature Reserves Occupy a Fraction of Earth  12% of earth’s land protected  Only 5% fully protected – 95% reserved for human use  Need for conservation Minimum 20% of land in biodiversity reserves Protection for all biomes

Solutions for Protection  Requires action – bottom-up political pressure  Nature Conservancy – world’s largest private system of reserves  Buffer zones around protected areas  Locals to manage reserves and buffer zones

Solutions: National Parks Fig. 8-19, p. 166

Case Study: Costa Rica  Superpower of biodiversity  Conserved 25% of its land, 8 megareserves  Government eliminated deforestation subsidies  Paid landowners to maintain and restore tree coverage  Goal to make sustainable forestry profitable

Model Biosphere Reserve Fig. 8-20, p. 167

Biosphere Reserve Buffer zone 2 Human settlements Research station Visitor education center Core area Buffer zone 1

Costa Rica’s Megareserve Network Fig. 8-21, p. 167

Protecting Wilderness Protects Biodiversity  Wilderness  Minimum size >4,000 km 2  Preserves natural capital  Centers for evolution

Case Study: Controversy over Wilderness Protection in the U.S.  1964 Wilderness Act  Roadless Rule protects 400,000 sq. miles  Pressure from oil, gas, mining, and logging

Protecting Global Biodiversity Hotspots  17 megadiversity countries in tropics and subtropics  Two-thirds of biodiversity  Developing countries economically poor and biodiversity rich  Protect biodiversity hotspots

34 Global Hotspots Fig. 8-22, p. 169

Biodiversity Hotspots in the U.S. Fig. 8-23, p. 169

8-6 What Is the Importance of Restoration Ecology?  Concept 8-6 Sustaining biodiversity will require a global effort to rehabilitate and restore damaged ecosystems.

Ecological Restoration  Ecological Restoration  Restoration  Rehabilitation  Replacement  Creating artificial ecosystems

Science-based Principles for Restoration  Identify cause of degradation  Stop abuse by reducing factors  Reintroduce species if necessary  Protect area from further degradation

Case Study: Ecological Restoration of Tropical Dry Forest in Costa Rica  One of world’s largest ecological restoration projects  Restore a degraded tropical dry forest and reconnect it to adjacent forests  Involve 40,000 people in the surrounding area – biocultural restoration  Ecotourism

Will Restoration Encourage Further Degradation  Some worry environmental restoration suggests any harm can be undone  Scientists disagree Restoration badly needed Altered restored site better than no restoration

What Can You Do? Fig. 8-24, p. 171

8-7 How Can We Help Sustain Aquatic Biodiversity?  Concept 8-7 We can sustain aquatic biodiversity by establishing protected sanctuaries, managing coastal development, reducing water pollution, and preventing overfishing.

Three Patterns of Aquatic Biodiversity  Greatest biodiversity in coral reefs, estuaries, and deep-ocean floor  Higher near the coast than in open sea  Higher in the bottom region of ocean than in surface layer

Human Impacts on Aquatic Ecosystems  Destroyed or degraded by human activities  Ocean floor degradation 150 times larger than area clear-cut annually  75% of most valuable fish species overfished  Likely extinction 34% marine fish species 71% freshwater species

Effects of Bottom Trawling Fig. 8-25, p. 172

Why Is Protection of Marine Biodiversity So Difficult?  Human aquatic ecological footprint expanding  Not visible to most people  Viewed as an inexhaustible resource  Most ocean areas outside jurisdiction of a country

Solutions for Marine Ecosystems  Protect endangered and threatened species  Establish protected marine sanctuaries  Marine reserves – work well and quickly  Integrated coastal management  Protect existing coastal wetlands

Solutions: Managing Fisheries Fig. 8-26, p. 173

8-8 What Should Be Our Priorities for Protecting Biodiversity?  Concept 8-8 Sustaining the world’s biodiversity requires mapping terrestrial and aquatic biodiversity, protecting terrestrial and aquatic hotspots and old-growth forests, initiating ecological restoration projects worldwide, and making conservation profitable.

Priorities for Protecting Biodiversity  Map terrestrial and aquatic biodiversity  Immediately preserve biodiversity hotspots  Keep old-growth forests intact  Protect and restore lakes and rivers  Initiate ecological restoration  Make conservation profitable

Animation: Ocean Provinces PLAY ANIMATION

Animation: Humans Affect Biodiversity PLAY ANIMATION

Animation: Habitat Loss and Fragmentation PLAY ANIMATION

Animation: Area and Distance Effects PLAY ANIMATION

Animation: Succession PLAY ANIMATION

Animation: Hubbard Brook Experiment PLAY ANIMATION

Animation: Effects of Air Pollution in Forests PLAY ANIMATION

Animation: Effects of Deforestation PLAY ANIMATION

Animation: Biodiversity Hot Spots PLAY ANIMATION

Animation: Resources Depletion and Degradation PLAY ANIMATION

Animation: Species Diversity By Latitude PLAY ANIMATION

Video: Easter Island PLAY VIDEO

Video: New Species Found PLAY VIDEO

Video: Bachelor Pad at the Zoo PLAY VIDEO

Video: Desertification in China PLAY VIDEO

Video: U.S. Forests PLAY VIDEO

Video: Marine Sanctuary PLAY VIDEO

Video: Sea Turtle Release PLAY VIDEO