Transcript CH 23

Sustaining Terrestrial Biodiversity:
The Ecosystem Approach
G. Tyler Miller’s
Living in the Environment
13th Edition
Chapter 23
Dr. Richard Clements
Chattanooga State Technical Community College
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 Use in the United States
Rangeland
and pasture
29%
Fig. 23-3 p. 595
Types of US Public Lands
 Multiple-use lands: National Forests;
National Resource Lands –Land uses? Mining,
logging, oil/gas drilling, atv, hunting, commercial fishing
 Moderately-restricted use lands:
National Wildlife Refuges – permitted logging
and mining, hunting, fishing, camping
 Restricted-use lands: National Park System;
National Wilderness Preservation System –
camping, hiking, highly restricted logging/mining, fishing with permits
US Public Lands
Fig. 23-4
p. 596
Managing US Public Land
Biodiversity and ecological function
No subsidies or tax breaks for use
Public should get fair compensation
Users held responsible for actions
Takings and property rights
Managing and Sustaining Forests
Ecological Importance of Forests
Food webs and energy flow
Water regulation-removing trees alters water cycle and soil
Water holding capacity
Local and regional climate
Numerous habitats and niches
Air purification
Managing and Sustaining Forests
Economic Importance of Forests
Fuelwood (50% of global forest use)-
Developing countries rural use of fuelwood, urban areas use coal but require wood to create
Alternatives are often dung, removes nutrients that would be part of manure, forests are
depleted in circle around urban areas.
Industrial timber and lumber
Pulp and paper-3 most polluting industry in N. Am. Due to
rd
Chlorine bleaches –water, air, soil pollution
Medicines
Mineral extraction and recreation
Forest Structure
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
Multiple-use
Management Strategies
Fig. 23-11 p. 601
Fig. 23-12 p. 602
Logging Roads
Increased erosion and runoff
Habitat fragmentation
Pathways for exotic species
Accessibility to humans Fig. 23-13 p. 602
Harvesting Trees
 Selective cutting
 High-grading
 Shelterwood cutting
 Seed-tree cutting
 Clearcutting
 Strip cutting
Fig. 23-14 p. 603
Sustainable Forestry
Longer rotations
Selective or strip cutting
Minimize fragmentation
Improved road building techniques
Certified sustainable grown-ecosystem approach
Pg. 606
(See Solutions p. 598)
Pathogens
Fungal Diseases
Chestnut blight
Dutch elm disease
Dogwood Anthracnose
Insect Pests
Bark beetles
Gypsy moth
Woolly adelgid (hemlock)
Fire
Surface fires
Crown fires
Fig. 23-17 p. 607
Forest Resources and
Management in the United States
Habitat for threatened and endangered
species
Water purification services
Recreation
3% of timber harvest
Sustainable yield and multiple use
Substitutes for tree products
Tropical Deforestation
 Rapid and increasing
 Loss of biodiversity
 Cultural extinction
 Unsustainable agriculture and ranching
 Clearing for cash crop plantations
 Commercial logging
 Fuelwood
Degradation of Tropical Forests
Fig. 23-22
p. 615
Reducing Tropical Deforestation
 Identification of critical ecosystems
 Reducing poverty and population growth
 Sustainable tropical agriculture
 Encourage protection of large tracts- government
policies
 Debt-for-nature swaps
 Less destructive harvesting methods
The Fuelwood Crisis
 Planting fast-growing fuelwood plants
 Burning wood more efficiently
 Switching to other fuels= cheap and easy to construct solar
ovens
Fig. 23-25 p. 618
Managing and Sustaining National
Parks
 Most parks are too small to maintain
biodiversity
 Invasion by exotic species
 Popularity a major problem-since end of WWII
 Traffic jams and air pollution
 Visitor impact (noise)
 Natural regulation
 Better pay for park staff
Establishing, Designing, and
Managing Nature Reserves
 Include some moderate disturbance
 Sustain natural ecological processes
 Protect most important areas
 Buffer zones
 Gap analysis
 Wilderness areas
See Solutions p. 625
Ecological Restoration
Ecological restoration
Restoration ecology
Rehabilitation
Replacement
See Individuals Matter p. 630
Creating artificial ecosystems
Natural restoration