Unit VI Land Use
Land Breakdown
US Land Use 55% of land in US is privately owned Remaining land is owned by the government
Land Use
Wilderness Parks and Wildlife Refuges Wilderness Wilderness Act (1964) Managed by
National Parks 1 st Park 1872 National Park Service Currently includes parks Primary goal Teach people about the natural environment, management of natural resources and history of a site
National Parks Threats to U.S. Parks Natural Regulation
Wildlife Refuge National Wildlife Refuge System Represent all major ecosystems founds in the US Mission
National Forests Managed for multiple uses Road building is an issue Clearcutting is an issue
Forest Management Traditional Forest Management
Forest Management Ecological Sustainable Forest Management
Harvesting Trees
Deforestation Results of Deforestation Decreased soil fertility Uncontrolled soil erosion Production of hydroelectric power (silt build up behind dams) Increased sedimentation of waterways Formation of deserts Extinction of species Global climate changes
Rangelands Rangelands
Rangelands Overgrazing leaves ground barren Land degradation Desertification
Rangelands Make up of total US land area Pressure from developers to subdivide Public rangeland managed by: Conditions of public rangeland are slowly improving
Agricultural Land US has 300 million acres of prime farmland Suburban sprawl
Food Production Methods Croplands Rangelands Fisheries
World Food Security Feeding growing population is difficult Annual grain production (left) has increased since 1970 Grain per person has not (right)
Crop Production
Animals as Food Constitute of the calories consumed in developed countries Only comprise of calories consumed in developing countries
Principle Types of Agriculture Industrialized agriculture
Principle Types of Agriculture Subsistence Agriculture Traditional agricultural methods, which are dependent on labor and large amounts of land Most common type of agricultural practice
Challenges of Producing More Crop and Livestock Domestication and Genetic Diversity
Challenges of Producing More Crop and Livestock Increasing Crop Yields
Challenges of Producing More Crop and Livestock Increasing Livestock Yields Hormone supplements Antibiotics
Antibiotic Use and Resistance
Genetic Engineering Manipulation of genes by taking specific gene from a cell of one species and placing it into the cell of an unrelated species
Genetically Modified Organisms (GMOs) Add beneficial characteristics to crops
Genetically Modified Organisms (GMOs)
Safety in Genetic Engineering Studies have shown them to be safe for human consumption Concerns about GMO seed or pollen spreading in wild GMOs are not currently labeled Backlash against GMOs
Environmental Impacts of Agriculture
Sustainable Agriculture Examples: Natural Predator-prey relationships instead of pesticides Crop selection Crop rotation and conservation tillage Supplying nitrogen with legumes Organic agriculture Integrated Pest Management (IPM)
Fisheries No nation lays claim to open ocean Resource susceptible to overuse and degradation
Overharvesting Fisheries
Commercial Fishing Methods
World Seafood Harvest
Fisheries of the World - Problems Ocean Pollution - dumping ground Aquaculture
Fisheries of the World - Problems Aquaculture (continued)
Pesticides Broad spectrum pesticide 1 st Generation Pesticide
Pesticides Second generation pesticide
Problems with Pesticides Evolution of Genetic Resistance
Pesticide Resistance Pesticide Treadmill Resistance Management
Problems with Pesticides Imbalances the Ecosystem
Problems with Pesticides Persistence, Bioaccumulation, and Biomagnification Bioaccumulation: The buildup of a persistent pesticide or other toxic substance in an organisms body Biomagnication: Increased concentration of toxic chemicals in tissues of organisms at higher trophic levels
IPM Systems Approach - Integrated Pest Management (IPM) Conventional pesticides are used sparingly when other methods fail
Integrated Pest Management
Systems Approach - Integrated Pest Management (IPM)
Manufacture and Use of Banned Pesticides Some US companies still make banned or seriously restricted pesticides May lead to the importation of food tainted with banned pesticides Global ban of persistent organic pollutants
Manufacture and Use of Banned Pesticides - The Dirty Dozen