Sustaining Biodiversity The Ecosystem Approach Chapter 9 Types

Sustaining Biodiversity: The Ecosystem Approach Chapter 9

Types of Forests n Old-growth- not seriously disrupted for at least several hundred years n Second-growth - results from secondary succession n Tree plantation or tree farm - managed tract of uniformly aged trees of one or two species. Clear cut when commercially valuable, then replanted.

Major Services of Forests Natural Capital Ecological services of world’s forests valued at $4. 7 trillion per year Forests Ecological Services Support energy flow and chemical cycling >>> Much greater than Economic Services Fuelwood Lumber Reduce soil erosion Absorb and release water Pulp to make paper Value of ecological services much greater than value of economic services Purify water Purify air Mining Influence local and regional climate Livestock grazing Store atmospheric carbon Recreation Provide numerous wildlife habitats Jobs Fig. 9 -4, p. 181

Types of Forest Management n Even-aged management (= industry forestry) trees maintained @ about same age and size- simplified tree plantation- 1 -2 fast-growing species harvested on rotation cycle n Rotation cycles: - 25 -30 years (temperate), 6 -10 years (tropical) n Uneven-aged management- variety of species w/ range of ages & sizes. Goals: biodiversity, sustainable high quality timber n Sustainable management intensive management of as little as 20% of world’s forests could meet current and future demand for commercial wood / fiber

Tree Plantation

Management Strategies: Rotation Cycles Weak trees removed Seedlings planted Clear cut 25 15 30 Years of growth 10 5 Growth faster in tropical countries (6 -10 years)

Degradation of Forests from Logging Roads n Increased erosion and sediment runoff n Habitat fragmentation n Biodiversity loss n Pathways for pests, diseases, and invasive species n More accessible for humans

Degradation of Forests Highway Old growth

Degradation of Forests Cleared plots for grazing Cleared plots for agriculture Highway

Degradation from Clear-cut Logging

Tradeoffs of Clear-cutting Forests Trade-Offs Clear-Cutting Forests Advantages Disadvantages Higher timber yields Reduces biodiversity Maximum economic return in shortest time Disrupts ecosystem processes Can reforest with genetically improved fast-growing trees Destroys and fragments some wildlife habitats Leaves moderate to large openings Short time to establish new stand of trees Needs less skill and planning Increases soil erosion Increases sediment water pollution and flooding when done on steep slopes Best way to harvest tree plantations Good for tree species needing full or moderate sunlight for growth Eliminates most recreational value for several decades

Harmful Effects of Deforestation Natural Capital Degradation Deforestation • Decreased soil fertility from erosion • Runoff of eroded soil into aquatic systems • Premature extinction of species with specialized niches • Loss of habitat for migratory species such as birds and butterflies • Regional climate change from extensive clearing • Releases CO 2 into atmosphere from burning and tree decay • Accelerates flooding © 2006 Brooks/Cole - Thomson

Global Outlook: Extent of Deforestation n Extensive deforestation by humans over past 8, 000 years (20 - 50% reduction) n Deforestation continues n Some reforestation in North America and Europe. However, tree plantation ≠ old growth forest n Some regrown tropical forests show increased tree cover

Protecting Tropical Forests Solutions Sustaining Tropical Forests Prevention Protect most diverse and endangered areas Restoration Reforestation Educate settlers about sustainable agriculture and forestry Phase out subsidies that encourage unsustainable forest use Add subsidies that encourage sustainable forest use Rehabilitation of degraded areas Protect forests with debt-for-nature swaps, conservation easements, and conservation concessions Certify sustainably grown timber Reduce illegal cutting Reduce poverty Slow population growth Concentrate farming and ranching on already-cleared areas

World’s Forests n Deforestation n Economic value of forests: value of ecological services could be as high as $4. 7 trillion / year. Value of ecological services >>> economic value n Should we make economic estimates? ”Our economic system has been constructed under the premise that natural services are free. ” Profits are short term, services long-term n Sustainable management of forests n Certifying sustainably grown timber 2002 Mitsubishi agreed to certify practices as sustainable (Home Depot & Lowes sell only certified wood)

Sustainable Forestry Solutions Sustainable Forestry • Grow more timber on long rotations • Rely more on selective cutting and strip cutting • No clear-cutting, seed-tree, or shelterwood cutting on steeply sloped land • No fragmentation of remaining large blocks of forest • Sharply reduce road building into uncut forest areas • Leave most standing dead trees and fallen timber for wildlife habitat and nutrient recycling • Certify timber grown by sustainable methods • Include ecological services of trees and forests in estimating economic value © 2006 Brooks/Cole - Thomson Conserves biodiversity, water & soil resources

US Forests n Reforestation n Old-growth forests still decline n Forest fires: surface, crown, and ground

Surface and Crown Forest Fires Ground fire = underground surface fire, common in northern peat bogs

Minimizing Forest Damage from Fire n n Prescribed burning- reduce underbrush Allow small fires in National Parks, forests & wilderness to burn (if people & property not threatened) n Defensible space- clear 200 feet around buildings n Effects of the Healthy Forests Initiative Timber Co. allowed to take large/medium trees in Nat. Forests if they clear away smaller, fire-prone trees- criticized by fire scientists (large tree most fire resistant, logging creates slash)

Reintroducing Wolves to Yellowstone (1995) n Why wolves were killed- n Wolf protection 1974 listed as endangered species n Ecological importance- Keystone predator- culled 2 million killed 1850 - 1900 to “make the west safe for livestock and big-game animals” herds of bison, elk, caribou and mule deer, keep coyote pop low, … n Yellowstone controversy- ranchers, hunters, miners all opposed n Importance of biodiversity- ecological success- willow & aspen re-growth in riparian areas, more beavers, elk carcasses feed grizzlies, coyote population reduced, squirrel & fox pop increase = more food for eagles & hawks

Establishing, Designing, Protecting Nature Reserves n Currently 12% of earth’s land is “protected” n Include large to moderate tracts of land n Preserve biodiversity n Involve government, businesses, and private groups n Buffer zone concept: biosphere reserves n Costa Rica’s accomplishments n Adaptive ecosystem management n Emergency action and biodiversity hot spots n Wilderness

Biosphere Reserve Core area Buffer zone 1 Buffer zone 2 Tourism and education center Human settlements Research station Fig. 8 -23, p. 174

Biodiversity Hot Spots Fig. 8 -26, p. 176

Types of US Public Lands (35% of US is public land) n n n Multiple-use lands: National Forest System; Natural Resource Lands (BLM) Moderately restricted-use lands: Natural Wildlife Refuges Restricted-use lands: Natural Park System; Natural Wilderness Preservation System

US Federal Public Lands National parks and preserves National forests (and Xs) National wildlife refuges Fig. 8 -6 b, p. 158

Logging in U. S. National Forests Trade-Offs Logging in U. S. National Forests Advantages Disadvantages Helps meet country’s timber needs Provides only 4% of timber needs Cut areas grow back Ample private forest land to meet timber needs Keeps lumber and paper prices down Has little effect on timber and paper prices Damages nearby rivers and fisheries Provides jobs in nearby communities Promotes economic growth in nearby communities *Recreation in national forests provides more local jobs and income for local communities than logging Decreases recreational opportunities

Kenaf Holds potential to greatly reduce pressure to cut trees for paper

Ecological Restoration = “process of repairing damage caused by humans to the biodiversity & dynamics of natural ecosystems” n Restoration, rehabilitation and replacement n Creating artificial ecosystems 4 Principles of Ecological Restoration: 1. Mimic nature 2. 3. Recreate important ecological niches Rely on pioneer, keystone and foundational species and natural ecological succession 4. Control or remove nonnative species n Accomplishments in Costa Rica

Restoration of a Stream Bank Area restored in 10 years after banning grazing and off-road vehicles.

Major Human Impacts on Aquatic Biodiversity n Loss and degradation of habitat is greatest threat n Damage to coral reefs and other habitats n Dredging / trawler operations destroy bottom habitats n Overfishing n Premature extinction

Degradation of the Ocean Floor Fig. 8 -29, p. 179

Protecting and Sustaining Marine Biodiversity n Protecting endangered and threatened species n Establish large and unpolluted protected areas- marine reserves work. n Integrated coastal management n Protect wetlands n Prevent overfishing n Regulate and prevent pollution

Managing Fisheries Solutions Managing Fisheries Fishery Regulations Set catch limits well below the maximum sustainable yield Bycatch Improve monitoring and enforcement of regulations Use net escape devices for seabirds and sea turtles Economic Approaches Sharply reduce or eliminate fishing subsidies Use wide-meshed nets to allow escape of smaller fish Ban throwing edible and marketable fish back into the sea Aquaculture Charge fees for harvesting fish and shellfish from publicly owned offshore waters Restrict coastal locations for fish farms Certify sustainable fisheries Depend more on herbivorous fish species Protected Areas Establish no-fishing areas Nonative Invasions Establish more marine protected areas Filter organisms from ship ballast water Rely more on integrated coastal management Dump ballast water far at sea and replace with deep-sea water Consumer Information Label sustainably harvested fish Publicize overfished and Control pollution more strictly Kill organisms in ship ballast water Fig. 8 -30, p. 181