Sustaining Terrestrial Biodiversity: The Ecosystem Approach G. Tyler Miller’s Living in the Environment 13th Edition Chapter 23

Key Concepts Human land use Types and uses of US public lands Forests and forest management Implications of deforestation Management of parks Establishment and management of nature preserves Importance of ecological restoration

Land Use in the World Fig. 23-2 p. 595

Land Ownership and Use in the United States Rangeland and pasture 29%

Types of US Public Lands Multiple-use lands: National Forests; National Resource Lands Moderately-restricted use lands: National Wildlife Refuges Restricted-use lands: National Park System; National Wilderness Preservation System

US Public Lands Fig. 23-4 p. 596

Managing US Public Land Primary goal to protect biodiversity and ecological functions No subsidies or tax breaks for use Public should get fair compensation Users held responsible for actions (Aldo Leopold’s Land-Use Ethic)

Managing and Sustaining Forests Ecological Importance of Forests Food webs and energy flow Water regulation Influence local-regional climate Numerous habitats and niches Air purification Carbon sequestration

Managing and Sustaining Forests Economic Importance of Forests Fuelwood (50% of global forest use) Industrial timber and lumber Pulp and paper Medicines Mineral extraction Recreation

Layers of Biodiversity Forest Structure Layers of Biodiversity Fig. 23-9 p. 601

Types of Forests Old-growth (frontier) forests Second-growth forests Tree farms/plantation Fig. 23-18 p. 609

Forest Management Rotation cycle Even-aged management Industrial forestry Uneven-aged management Improved diversity Sustainable production Selective cutting Multiple-use

Management Strategies Fig. 23-11 p. 601 Short Rotation Cycle Fig. 23-12 p. 602

Logging Roads result in increased erosion and runoff habitat fragmentation pathways for exotic species accessibility to humans Fig. 23-13 p. 602

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).

Tree Harvesting Methods Selective cutting high grading Shelterwood cutting Seed-tree cutting Clearcutting Strip cutting Fig. 23-14 p. 603

What is happening to the world’s forests? Forests are renewable resources as long as the rate of cutting and degradation does not exceed the rate of re-growth.

Sustainable Forestry Longer rotations Selective or strip cutting Minimize fragmentation Improved road building techniques Certified sustainable grown (See Solutions p. 598)

Pathogens Fungal Diseases Chestnut blight Dutch elm disease Insect Pests Bark beetles Gypsy moth

Fire (intermittent natural fires set by lightening) Depending on their intensity, fires can benefit or harm forests.

Surface/Ground Fire Burn away flamable ground material Release mineral nutrients Increase activity of nitrogen-fixing bacteria Stimulate germination of some seeds Help control pathogens and insects

Crown Fire Destroys most vegetation Kills wildlife Increases soil erosion

Fire Management Prevention Prescibed burning Presuppression For more than 70 years, firefighting has been a high priority for forest managers.

Fire Management “Only you can prevent forest fires.” In 1989, the US spent over $1 billion and lost 33 lives in efforts to stop forest fires. Smokey the Bear

Forest Resources and Management in the United States Sustained yield potentially renewable resources should not be harvested or used faster than they can be reproduced Multiple Use Wildlife, timber harvests, watershed protection, recreation, livestock grazing Only 3% of timber harvest comes from national forests Substitutes for tree products Tree-free fibers

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.

TROPICAL DEFORESTATION Large areas of ecologically and economically important tropical forests are being cleared and degraded at a fast rate.

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.

Tropical Deforestation Issues Rapid and increasing deforestation 0.6-2.0% per year Loss of biodiversity Madagascar Case Study Cultural extinction Should we be protecting the rights of the earth’s remaining indigenous cultures? Unsuitable agriculture and ranching Clearing for cash crop plantations Increasing forest fires Commercial logging Fuelwood

Rapid population growth Bromeliad Orchid Toucan Scarlet macaw Golden lion marmoset Blue morpho butterfly Primary Causes Rapid population growth Poverty Exploitive government policies Secondary Causes: Roads Logging Cattle ranching Cash crops Unsustainable peasant farming Tree plantations Flooding from dams Mining Oil drilling

Reducing Tropical Deforestation Identification of critical ecosystems Reducing poverty and population growth Sustainable tropical agriculture Encourage protection of large tracts Less destructive harvesting methods Debt-for-nature swaps

Debt-for-Nature Swaps Participating countries act as custodians for protected forest reserves in return for foreign aid or debt relief

The Fuelwood Crisis Planting fast-growing fuelwood plants Burning wood more efficiently (new stove designs) Switching to other fuels (root-fuel plants) Fig. 23-25 p. 618

U.S. National Parks Goals To preserve nature in parks To make nature more available to the public Sometimes these two goals are in conflict with one another.

Managing and Sustaining National Parks - Threats Most parks too small to maintain biodiversity Invasion of exotic species a threat Limited Funding Popularity a major problem Traffic jams and air pollution Visitor impact Nearby human activity mining, logging, grazing, power plants, development

Managing and Sustaining National Parks - Solutions Principle of natural regulation parks will be self sustaining if left alone considered a misguided policy Suggestions require integrated management plan increase budgets locate commercial facilities outside park boundaries survey conditions and types of wildlife raise entrance fees limit visitors increase pay for park rangers encourage volunteers encourage individual and corporate donations

Managing Nature Reserves: Establishment and Design Should include some moderate disturbances Design should sustain natural ecological processes Round Large Heterogeneous Buffer zones

Model Nature Reserves contains a protected inner core surrounded by two buffer zones that people can use for multiple use.

Managing Nature Reserves: Establishment and Design Gap analysis Maps of topography, vegetation, hydrology, land ownership, and existing nature reserves Estimates of geographic distribution of plants and animals by regions Superimpose species distribution maps on vegetation maps to determine unprotected areas, gaps with high species diversity, unprotected pockets of rare species.

Managing Nature Reserves Protect most important areas Biodiversity hotspots Wilderness areas Protection of undeveloped lands from human exploitation by legally setting them aside. Wilderness – areas “of undeveloped land affected primarily by the forces of nature, where man is a visitor and does not remain”

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

Ecological Restoration What is here? What will nature permit us to do here? What will nature help us to do here? Restoration Return to pre-existing condition Mitigation – protect, restore, or create a similar ecosystem of roughly the same size Rehabilitation Restore some of the natural species and ecosystem functions (i.e. remove pollutants) Replacement Replacing a degraded ecosystem with another type of ecosystem

WHAT CAN WE DO? Eight priorities for protecting biodiversity: Take immediate action to preserve world’s biological hot spots. Keep intact remaining old growth forests. Complete mapping of world’s biodiversity for inventory and decision making. Determine world’s marine hot spots.

WHAT CAN WE DO? Concentrate on protecting and restoring lake and river systems (most threatened ecosystems). Ensure that the full range of the earths ecosystems are included in global conservation strategy. Make conservation profitable. Initiate ecological restoration products to heal some of the damage done and increase share of earth’s land and water allotted to the rest of nature.