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.

How wolves have helped sustain biodiversity in Yellowstone  Less elk on stream banks  Growth of aspens, cottonwoods, willow trees  Water temperature lower for trout  Beavers have returned  Scavengers and Grizzly feed on leftovers  Coyote population lower which allows increase in smaller animal population  More food for eagles and hawks

Why is biodiversity important form of natural capital? Structure and function of ecosystem Control population of pest and other species Options for adaptation Supply of food Medicines and drugs

Why 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.

34 hotspots identified by ecologists as important and endangered centers of biodiversity.

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 Forests Natural Capital Fuelwood Lumber Pulp to make paper Mining Livestock grazing Recreation Jobs Economic Services Ecological Services

3 Major types of forests based on age structure  Old-growth  Second-growth  Tree plantation

 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.

Second-growth forest – natural secondary ecological succession that develops after human activity or after natural forces

Tree plantation – managed tract of trees, uniformly aged trees, one or few types of trees

Decreased soil fertility from erosion Runoff of eroded soil into aquatic systems Premature extinction of species with specialized niches Loss of habitat for native species and migratory species such as birds and butterflies Regional climate change from extensive clearing Release of CO 2 into atmosphere Acceleration of flooding Natural Capital Degradation Deforestation

Ways to reduce fuelwood crisis  Plant small plantation of fast growing trees  Burn wood more efficiently (wood stove)  Burn renewable sun-dried roots of guards and squash plants

Kenya’s Green Belt Movement: Individuals 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.

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

Harmful effects of logging roads  Increase erosion and sediment runoff  Habitat fragmentation  Biodiversity loss  Exposure to invasion by nonnatives  Open access to farmers, ranchers, ORVs  Logging roads disqualify the land for protection as wilderness

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).

Benefits of selective cutting  Reduces crowding  Removes diseased trees  Encourages growth of younger trees  Maintains a stand of trees of different species and different ages  Allows forest to be used of multiple purposes

Harvesting Trees Effects of clear-cutting in the state of Washington, U.S.

Higher timber yields Maximum profits in shortest time Can reforest with fast- growing trees Short time to establish new stand of trees Needs less skill and planning Good for tree species needing full or moderate sunlight Disadvantages Reduces biodiversity Disrupts ecosystem processes Destroys and fragments wildlife habitats Leaves large openings Increases water pollution, flooding, and erosion on steep slopes Eliminates most recreational value Trade-Offs Clear-Cutting Forests Advantages

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.

Identify and protect forest areas high in biodiversity Grow more timber on long rotations Rely more on selective cutting and strip cutting Stop clear-cutting on steep slopes Cease logging of old-growth forests Prohibit fragmentation of remaining large blocks offorest 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 forests in estimating their economic value Plant tree plantations on deforested and degraded land Shift government subsidies from harvesting trees to planting trees Sustainable Forestry Solutions

3 types of fires which can affect forest ecosystems  Surface fire  Crown fires  Ground fires

Surface fire in Okefenokee Swamp, GA

Brunswick, GA Okefenokee Swamp Fire, May 2007 Altamaha River Savannah, GA 600,000 acres scorched Worst fire in Georgia and Florida history

Fire Management To reduce fire damage: –Set controlled surface fires (prescribed burns) –Allow fires to burn on public lands if they don’t threaten life and property –Clear small areas around property subject to fire

Prescribed Burning Reduces the amount of dead and dying plant materials that hinder plant growth Recycles nutrients from old plant growth for use by growing plants Promotes germination, growth, and flowering of native plants Increases the diversity of native plant life Controls encroachment of woody brush and trees into grasslands, including invasive species Decreases the amount of flammable organic matter on soil surface

Grassland Management Recent studies in the Southwest have shown when burning is returned to the ecosystem and is coupled with sound grazing management, desirable species return more rapidly than when either procedure is applied alone

Longleaf pine ecosystem

Longleaf pine and grassland forest of the Southern Coastal Plain – an endangered ecosystem Fire climax community – species in ecosystem resistant to fire and depend on fire Longleaf pine is the dominant tree species – w/o fire the longleaf will be crowded out by other tree species One of the most diverse N. American ecosystems north of the tropics – many endemic rare plants and animals Grass stage the longleaf is protected from surface fire while its tap root develops deep into the soil

The cone of the longleaf pine can remained closed for several years and open up and release its seeds after a fire After the grass stage the longleaf pine quickly grows upward to avoid ground fires Gopher tortoise

Healthy Forest Restoration Act  Removes most fire resistant trees – promotes growth of highly flammable young trees (not good)  Removing the large and medium trees leaves behind highly flammable slash

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

Ways we use wood inefficiently  Inefficient use of construction materials  Excess packaging  Junk mail  Inadequate paper recycling  Failure to reuse wooden shipping containers

Examples of cash crops grown on land which was once a tropical rainforest  Sugarcane  Bananas  Pineapples  Soybean  Palm oil  Coffee

Ways to protect tropical forests  Educate settlers about sustainable agriculture and forestry  Add subsidies that encourage sustainable forest use  Protect forests with debt-for-nature swap and conservation easements  Reduce illegal harvesting  Certify sustainable grown timber

Ecological services provided by grasslands  Soil formation  Erosion control  Nutrient cycling  Storage atmospheric carbon  Gene pools for crossbreeding grain crops  Maintaining biodiversity  Provide habitat and food

Effects of overgrazing  Decrease grass cover  Exposes soil to erosion by water and wind  Soil compaction  Enhances invasion by sagebrush, mesquite, cactus, and cheat grass

o Grasslands and herbivores can coexist o Rangeland and pasture use must be adjusted to the carrying capacity of the land o Cattle can be shifted from one pasture to another o Fencing and planned distribution of water sources can help promote a more uniform use of rangeland o Periodic burns also help Rangeland Management: A sustainable approach

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.

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% if its biodiversity.

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. –Developers can use GIS to design housing developments with the least environmental impact. The World Wildlife Federation (WWF) is researching how to connect these giant panda habitats using wildlife corridors so the pandas can find new food sources and potential mates

Benefits of habitat corridors Helps support more species Allow species to migrate naturally Allow wildlife to shift their native range if necessary

Problems associated with habitat corridors (threats to isolated populations) Allowing movement of nonnative species Disease can move between habitats Fire can move between habitats Increase exposure of migrating animals to natural predators Increase exposure to hunters Costly to acquire, protect, and manage

Examples of ecological restoration  Replanting forests  Restoring grasslands  Restoring wetlands and stream banks  Reclaiming urban industrialized areas (known as brownfield sites)  Reintroducing native species  Removing invasive species  Removing unnecessary dams

How do scientists “speed up” the recovery of ecosystems?  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.

Restoring a stream bank eroded away from poor stewardship

Razing a dam

Artificial Reef

Restoration of longleaf pine forestlongleaf

ECOLOGICAL RESTORATION  Five basic science-based principles for ecological restoration: Identify cause. Identify cause. Stop abuse by eliminating or sharply reducing factors. Stop abuse by eliminating or sharply reducing factors. Reintroduce species if necessary. Reintroduce species if necessary. Protect area form further degradation. Protect area form further degradation. Use adaptive management to monitor efforts, assess successes, and modify strategies. Use adaptive management to monitor efforts, assess successes, and modify strategies.

Pacific loon THE END