ENVIRONMENTAL SCIENCE 13e CHAPTER 9: Sustaining Biodiversity: The Ecosystem Approach

Wangari Maathai and the Green Belt Movement Began in Kenya in 1977 Organizes poor women in rural Kenya 50,000 members protect forests Planted 20 million trees –Fruits –Building materials –Firewood Similar programs in 30 African countries 2004: Nobel Peace Prize

9-1 What Are Major Threats to Forest Ecosystems? Concept 9-1 Ecologically valuable forest ecosystems are being cut and burned at unsustainable rates in many parts of the world.

Types of Forests Forests cover 30% of earth’s land surface Old-growth forests Second-growth forests Tree plantation

Fig. 9-2, p. 180

Fig. 9-3, p. 180

Years of growth Weak trees removed Seedlings planted Clear cut 30 yrs 25 yrs 5 yrs10 yrs 15 yrs Fig. 9-3, p. 180

Fig. 9-4, p. 181

Natural Capital Fuelwood Lumber Pulp to make paper Mining Livestock grazing Recreation Jobs Support energy flow and chemical cycling Reduce soil erosion Absorb and release water Purify water and air Influence local and regional climate Store atmospheric carbon Provide numerous wildlife habitats Ecological Services Economic Services Forests

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 Ecological services can be a sustainable source of ecological income

Fig. 9-A, p. 181

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

Fig. 9-5, p. 182

Cleared plots for agriculture New highway Old growth Highway Cleared plots for grazing Fig. 9-5, p. 182

New highway Old growth Cleared plots for agriculture Highway Cleared plots for grazing Stepped Art Fig. 9-5, p. 182

Fig. 9-6, p. 182

Clear stream (a) Selective cutting Fig. 9-6, p. 182

Muddy stream (b) Clear-cutting Fig. 9-6, p. 182

Cut 1 year ago (c) Strip cutting Uncut Clear stream Uncut Cut 3–10 years ago Dirt road Fig. 9-6, p. 182

Stepped Art (b) Clear-cutting Muddy stream Uncut Cut 1 year ago Dirt road Cut 3–10 years ago Uncut Clear stream (a) Selective cutting (c) Strip cutting Clear stream Fig. 9-6, p. 182

Fig. 9-7, p. 182

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

Fig. 9-8, p. 183

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

Fig. 9-9, p. 184

Fig. 9-10, p. 184

Good News on Forests 2000–2007 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 Some forests transformed into tree plantations

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 Some second-growth forests

Causes of Tropical Forest Deforestation and Degradation Population growth and poverty Economic reasons –Logging –Ranching –Farming Government subsidies Fires raise temperatures and reduce rainfall

Fig. 9-11, p. 186

Natural Capital Degradation Not valuing ecological services Crop and timber exports Government policies Poverty Population growth Roads Fires Settler farming Cash crops Cattle ranching Logging Tree plantations Basic CausesSecondary Causes Settler farming Cattle ranching Tree plantations Cash crops Logging Roads Fires Major Causes of the Destruction and Degradation of Tropical Forests

Fig. 9-12, p. 187

9-2 How Should We Manage and Sustain Forests? Concept 9-2 We can sustain forests by emphasizing the economic value of their ecological services, removing government subsidies that hasten their destruction, protecting old- growth forests, harvesting trees no faster than they are replenished, and planting trees.

Fig. 9-13, p. 188

Management of Forest Fires (1) Fire suppression in all types of forests Increased amounts of underbrush Increased probability of crown fires

Management of Forest Fires (2) Prescribed fires Allow some fires to burn Thin vegetation from forests Thin around vulnerable homes Decrease flammability of homes

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

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

Fig. 9-14, p. 189

Ways to Reduce Tropical Deforestation Debt-for-nature swaps Conservation concessions Gentler logging methods Encourage use of wood substitutes

Fig. 9-15, p. 190

Sustaining Tropical Forests Protect the most diverse and endangered areas Educate settlers about sustainable agriculture and forestry Subsidize only sustainable forest use Protect forests with debt-for-nature swaps and conservation concessions Certify sustainably grown timber Reduce poverty Slow population growth Encourage regrowth through secondary succession Rehabilitate degraded areas Concentrate farming and ranching in already-cleared areas Prevention Solutions Restoration

9-3 How Should We Manage and Sustain Grasslands? Concept 9-3 We can sustain the productivity of rangeland by controlling the number and distribution of grazing livestock and by restoring degraded grasslands.

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

Fig. 9-16, p. 191

Manage Rangelands Sustainably Practice rotational grazing Fence out riparian zone areas Suppress invader plants –Herbicides –Mechanical removal –Controlled burning –Short-term trampling

Fig. 9-17, p. 191

9-4 How Should We Manage and Sustain Parks and Nature Reserves? Concept 9-4 We need to put more resources into sustaining existing parks and nature reserves and into protecting much more of the earth’s remaining undisturbed land area.

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

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 58 major national parks Biggest problem is popularity Damage from nonnative species Threatened islands of biodiversity Need $6 billion for overdue repairs

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 “Ecological insurance policy” Buffer zones around protected areas Locals to manage reserves and buffer zones United Nations: 531 biosphere reserves in 105 countries

Science Focus: Reintroducing the Gray Wolf to Yellowstone National Park Reduced to a few hundred in lower 48 by 1973 Keystone species Restoration proposal angered ranchers, hunters, loggers reintroduced in Yellowstone, 124 by 2008 Positive ripple effect after reintroduction

Fig. 9-B, p. 193

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 Boosts ecotourism

Fig. 9-18, p. 194

Caribbean SeaNicaragua Panama Costa Rica Buffer zone National parkland Pacific Ocean

Protecting Wilderness Protects Biodiversity Wilderness Preserves biodiversity Centers for evolution

Case Study: Controversy over Wilderness Protection in the U.S Wilderness Act Ten-fold increase from 1970 to % of U.S. land protected, 75% of that in Alaska

9-5 How Can We Help to Sustain Terrestrial Biodiversity? Concept 9-5 We can help to sustain terrestrial biodiversity by identifying and protecting severely threatened areas (biodiversity hotspots), rehabilitating damaged ecosystems (using restoration ecology), and sharing with other species much of the land we dominate (using reconciliation ecology).

Three Principles to Protect Ecosystems 1.Map and inventory the world’s terrestrial and aquatic ecosystems 2.Locate and protect the most endangered ecosystems, with a focus on biodiversity 3.Seek to restore as many degraded ecosystems as possible

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

Fig. 9-19, p. 196

Supplement 4, Fig. 2, p. S16

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

Restoration Ecology Creating new habitats to conserve species diversity in areas where people live, work, play People learn to protect local species and ecosystems Sustainable ecotourism Golden Gate Park in San Francisco

Fig. 9-20, p. 198

9-6 How Can We Help to Sustain Aquatic Biodiversity? Concept 9-6 We can help to sustain aquatic biodiversity by establishing protected sanctuaries, managing coastal development, reducing water pollution, and preventing overfishing.

Impacts on Aquatic Ecosystems (1) Destroyed or degraded by human activities Coastal habitats disappearing 2-10 times faster than tropical forest Rising sea levels will destroy coral reefs and some low islands Ocean floor degradation 150 times larger than area clear-cut annually

Impacts on Aquatic Ecosystems (2) Freshwater habitat disruption –Dams –Water withdrawals from rivers Likely extinction –34% marine fish species –71% freshwater species –Greater than any other group of species

Fig. 9-21, p. 199

Overfishing Fishery Fishprint 157% overfishing 90% of large open-ocean fishes have disappeared since 1950

Fig. 9-22, p. 200

Case Study: Industrial Fish Harvesting Methods Trawler fishing Purse-seine fishing Longlining Drift-net fishing

Fig. 9-23, p. 201

Float Trawler fishing Drift-net fishing Purse-seine fishing Sonar Long line fishing lines with hooks Fish farming in cage Spotter airplane Deep sea aquaculture cage Fish caught by gills Buoy

Fish farming in cage Spotter airplane Trawler fishing Sonar Purse-seine fishing Long line fishing lines with hooks Deep sea aquaculture cage Drift-net fishing Float Buoy Fish caught by gills Stepped Art Fig. 9-23, p. 201

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

Fig. 9-24, p. 202

Managing Fisheries Fishery Regulations Set catch limits well below the maximum sustainable yield Improve monitoring and enforcement of regulations Economic Approaches Sharply reduce or eliminate fishing subsidies Charge fees for harvesting fish and shellfish from publicly owned offshore waters Certify sustainable fisheries Protect Areas Establish no-fishing areas Establish more marine protected areas Rely more on integrated coastal management Consumer Information Label sustainably harvested fish Publicize overfished and threatened species Bycatch Dump ballast water far at sea and replace with deep-sea water Filter organisms from ship ballast water Kill organisms in ship ballast water Nonnative Invasions Depend more on herbivorous fish species Control pollution more strictly Restrict coastal locations for fish farms Aquaculture Ban throwing edible and marketable fish back into the sea Use net escape devices for seabirds and sea turtles Use wide-meshed nets to allow escape of smaller fish Solutions

Three Big Ideas from This Chapter - #1 The economic values of the important ecological services provided by the world’s ecosystems need to be included in the prices of goods and services.

Three Big Ideas from This Chapter - #2 We can sustain terrestrial biodiversity by protecting severely threatened areas, restoring damaged ecosystems, and sharing with other species much of the land we dominate.

Three Big Ideas from This Chapter - #3 We can sustain aquatic biodiversity by establishing protected sanctuaries, managing coastal development, reducing water pollution, and preventing overfishing.

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