Chapter 18 Land Resources

Overview of Chapter 18 o Land Use World land use World land use US land use US land use o Wilderness Park and Wildlife Refuges National Parks National Parks Wildlife Refuge Wildlife Refuge o Forests Forest management Forest management Deforestation Deforestation o Rangeland and Agricultural Land o Wetlands and Coastal Areas o Conservation of Land Resources

Land Use- Worldwide

Land Use- United States

o 55% of US land is privately owned o Remainder of land is owned by government Most federally owned land is in Alaska and 11 western states Most federally owned land is in Alaska and 11 western states

Managing Public and Private Land o Public Planning and Land Use Land use decisions are complex and have multiple effects Land use decisions are complex and have multiple effects Must take into account all repercussions of proposed land use Must take into account all repercussions of proposed land use o Management of Federal Land Wide-Use Movement Wide-Use Movement Environmental Movement Environmental Movement

Wilderness Parks and Wildlife Refuges o Wilderness A protected area of land in which no human development is permitted A protected area of land in which no human development is permitted o Wilderness Act (1964) Set aside federally owned land as part of National Wilderness Preservation System Set aside federally owned land as part of National Wilderness Preservation System No development permitted (including roads) No development permitted (including roads) o Managed by NPS, USFS, FWS & BLM

Wilderness o Some areas have a limited number of permitted human guests to reduce impact o Other problems include invasive species

National Park System o Created in 1916 o Currently includes 58 parks o Primary goal Teach people about the natural environment, management of natural resources and history of a site Teach people about the natural environment, management of natural resources and history of a site Yosemite National Park

National Park System o Threats to U.S. Parks Crime & Vandalism Crime & Vandalism Traffic jams Traffic jams Pollution of the soil, water and air Pollution of the soil, water and air Originating both inside and outside the park Originating both inside and outside the park Resource violations Resource violations o Natural Regulation Policy to let nature take it course Policy to let nature take it course No culling wildlife No culling wildlife No suppressing wildfire No suppressing wildfire

Wildlife Refuges o National Wildlife Refuge System (1903) o Represent all major ecosystems founds in the US o Mission To preserve lands and waters for the conservation of fishes, wildlife and plants of the US To preserve lands and waters for the conservation of fishes, wildlife and plants of the US o Recreation (including hunting and fishing) are permitted Cannot impede conservation efforts Cannot impede conservation efforts

Forests o Role in Hydrologic Cycle (right) o Forest Management o Deforestation o Forest Trends in the US o Trends in Tropical Forests o Boreal Forests

Forest Management o Traditional Forest Management Low diversity- monocultures (right) Low diversity- monocultures (right) Managed for timber production Managed for timber production o Ecological Sustainable Forest Management Environmentally balanced Environmentally balanced Diverse trees Diverse trees Prevent soil erosion Prevent soil erosion Preserve watersheds Preserve watersheds Wildlife corridors- unlogged Wildlife corridors- unlogged

Harvesting Trees

Harvesting Trees - Clearcutting

Deforestation o Temporary or permanent clearance of large expanses of forest for agriculture or other use o World forests shrank 90 million acres from 2000–2005 o Causes Fire Fire Expansion of agriculture Expansion of agriculture Construction of roads Construction of roads Tree harvest Tree harvest Insect and disease Insect and disease

Deforestation o Results Decreased soil fertility Decreased soil fertility Uncontrolled soil erosion Uncontrolled soil erosion Production of hydroelectric power (silt build up behind dams) Production of hydroelectric power (silt build up behind dams) Increased sedimentation of waterways Increased sedimentation of waterways Formation of deserts Formation of deserts Extinction of species Extinction of species Global climate changes Global climate changes

Forest Trends in US o Most temperature forest are steady or expanding o Returning stands lack biodiversity of original forests o More than half of US forest are privately owned (right) Forest Legacy Program Forest Legacy Program Conservation easement Conservation easement

US National Forests o Managed for multiple uses Timber harvest Timber harvest Livestock forage Livestock forage Water resource and watershed protection Water resource and watershed protection Mining, hunting, fishing, etc. Mining, hunting, fishing, etc. o Road building is an issue Provides logging companies with access to forest Provides logging companies with access to forest o Clearcutting is an issue

Case-In-Point Tongass National Park o One of world’s few temperate rainforests o Prime logging area o Modified 1997 Forest Plan o Roadless Area Conservation Rule (2000) o Politics rules government agencies

Trends in Tropical Forests o Tropical rainforests (below) and tropical dry forests

Disappearing Tropical Rain Forests o Population growth Cannot account for all of it Cannot account for all of it o Immediate causes Subsistence agriculture Subsistence agriculture Commercial logging Commercial logging Cattle ranching Cattle ranching o Other causes Mining Mining Hydroelectric power Hydroelectric power

Disappearing Tropical Dry Forests o Primarily destroyed for fuelwood Used for heating and cooking Used for heating and cooking

Boreal Forests o World’s largest biome o Extensive clearcutting Primary source of world’s industrial wood and wood fiber Primary source of world’s industrial wood and wood fiber

Rangeland and Agricultural lands o Rangeland Land that is not intensively managed and is used for grazing livestock Land that is not intensively managed and is used for grazing livestock

Rangeland Degradation and Deforestation o Overgrazing leaves ground barren Animals exceed their carrying capacity Animals exceed their carrying capacity o Land degradation Natural or human-induced process that decreases future ability of land to support crops or livestock Natural or human-induced process that decreases future ability of land to support crops or livestock o Desertification Degradation of once fertile land into nonproductive desert Degradation of once fertile land into nonproductive desert

Rangeland Trends in US o Make up 30% of total US land area 2/3 privately owned 2/3 privately owned o Pressure from developers to subdivide o Public rangeland managed by: Taylor Grazing Act (1934) Taylor Grazing Act (1934) Federal Land Policy and Management Act (1976) Federal Land Policy and Management Act (1976) o Conditions of public rangeland are slowly improving Grazing fees is an issue Grazing fees is an issue

Agricultural Land o US has 300 million acres of prime farmland o Much is being overtaken by suburban sprawl Parking lots Parking lots Housing developments Housing developments Shopping malls Shopping malls

Wetlands o Lands that are usually covered with water for at least part of the year o Have characteristic soils and water- tolerant vegetation o Benefits Habitat for migratory waterfowl and wildlife Habitat for migratory waterfowl and wildlife Recharge groundwater Recharge groundwater Reduce damage from flooding Reduce damage from flooding Improve water quality Improve water quality Produce many commercially important products Produce many commercially important products

Wetlands o Human activity that threatens wetlands Drainage for agriculture or mosquito control Drainage for agriculture or mosquito control Dredging for navigation Dredging for navigation Construction of dams, dykes or seawalls Construction of dams, dykes or seawalls Filling in for solid waste disposal Filling in for solid waste disposal Road building Road building Mining for gravel, fossil fuels, etc. Mining for gravel, fossil fuels, etc. o Shrinking 58,500 acres per year

Restoring Wetlands o No Net Loss of Wetlands: o Development of wetlands is allowed if corresponding amount of previously converted wetland is restored o Not all wetland restorations are successful

Coastlines o Coastal wetlands Provide food and habitat for many aquatic animals Provide food and habitat for many aquatic animals Historically regarded as wasteland Historically regarded as wasteland o US starting to see importance of protecting this environment Retaining seawalls (right) Retaining seawalls (right)

Coastal Demographics o Many coastal areas overdeveloped 3.8 billion people live within 150km of coastline 3.8 billion people live within 150km of coastline 6.4 billion people will likely live there by billion people will likely live there by 2025 o United States 14 of 20 largest US cities along coast 14 of 20 largest US cities along coast 19 of 20 most densely populated countries along coasts 19 of 20 most densely populated countries along coasts

Conservation and Land Resources o All types of ecosystems must be preserved o Four criteria of importance: Areas lost or degraded since European colonization Areas lost or degraded since European colonization Number of present examples of a particular ecosystem (or the total area) Number of present examples of a particular ecosystem (or the total area) Estimate of the likelihood that a given ecosystem will lost a significant area or be degraded in next 10 years Estimate of the likelihood that a given ecosystem will lost a significant area or be degraded in next 10 years Number of threatened and endangered species living in the ecosystem Number of threatened and endangered species living in the ecosystem

Conservation and Land Resources

Soil and Mineral Resources o Types of rocks Igneous Igneous Sedimentary Sedimentary Metamorphic Metamorphic

Igneous o o Igneous rocks (―fire-formed ‖ )—from hardened magma and lava a) intrusive—coarse-grained igneous rocks below the surface b) extrusive—fine-grained igneous rocks above the surface

Sedimentary o o Sedimentary rocks (―settling)—from sediment, being compacted and cemented a) compaction—weight pressing the pieces together b) cementation— minerals gluing the pieces together c) types of sediment: sand, silt, clay, gravel, bone chips, pieces of shells,

Sedimentary Con’t Formation: o o a) clastic—from sediment compaction and cementation o o b) chemical—from water-soluble minerals o o temperatures o o c) organic—from plant or animal remains (coal, limestone)

Metamorphic o o Metamorphic rocks (―changed form)— from temperature and pressure o o extremes, and chemical change 1) formation a) metamorphism—a change in rock b) contact metamorphism—affects a small area; local heating c) regional metamorphism—affects a large area; tectonics

Rock Cycle o o rock cycle—changes in rock forms, from one type to another type, by different o o 1) formation of igneous rock a) melting and cooling any existing rock b) hardening of magma or lava o o 2) formation of sedimentary rock: weathering and erosion to form sediment; compaction and cementation o o 3) formation of metamorphic rock: heating and pressurizing any existing rock

Soil A. Soil characteristics o o 1) Soil profiles a) horizons—horizontal soil layers b) soil profile—vertical “slices” through soil layers

How is Soil Formed? o How is soil formed? Soils are dynamic, forming continuously over a long period of time. Soil types differ, depending on the parent materials from which they came and from the surrounding environment. The way in which soil forms depends on: parent material parent material climate climate topography topography living organisms living organisms time time

Soil Components o Soil is a natural medium made up of five major components: mineral particles: clay, silt, sand and gravel mineral particles: clay, silt, sand and gravel organic matter: decaying plant and animal material organic matter: decaying plant and animal material water water air air living organisms (soil biota): ranging from bacteria, fungi and earthworms living organisms (soil biota): ranging from bacteria, fungi and earthworms *A healthy soil should have a balance of these components.

Soil Texture o o Soil texture—classification based on particle size a) soil separates—rock fragments of varying size: Sand, Silt, Clay

o o Size of sand, silt and clay particles o o Name Particle Diameter Very coarse sand 2.0 to 1.0 millimeters Coarse sand 1.0 to 0.5 millimeters Medium sand 0.5 to.25 millimeters Fine sand 0.25 to 0.10 millimeters Very fine sand 0.10 to 0.05 millimeters Silt 0.05 to millimeters Clay below millimeters

Loam o o loam—common soil type: 40% sand, 40% silt, and 20% clay

Weathering o o weathering— breaking up of the crust; the wearing down of rock, liberating minerals physical (mechanical) weathering—from wind, water, weather, or other environmental events o o chemical weathering—from chemical reactions between water and atmospheric gases and bedrock o o biological weathering—from activities of organisms

Soil Erosion and Degradation o Erosion: movement of soil from one place to another; caused by wind, usually water

Erosion o Usually caused by moving water Sheet erosion Sheet erosion Rill erosion Rill erosion

Losing Topsoil o Makes soil less fertile and less able to hold water o Sediment clogs ditches, boat channels, reservoirs, and lakes

Causing and Correcting Erosion 1) overcultivation—frequent plowing o o a) crop rotation—alternating the type of crops grown o o b) no-till agriculture—weed control, planting, and covering up all at once (low-till farming—decrease the amount of tilling) o o c) contour-strip cropping—cultivation along sloping ground o o d) shelter belts—“belts” of trees planted around farmland to reduce wind erosion o o e) problems with fertilizers  inorganic chemical fertilizer does not replenish organic material  mineral content remains high but soil degrades anyway

Erosion Causes and Corrections o o 2) overgrazing—animals stripping vegetation at a rate too fast for natural growth patterns to counteract it a) public lands BLM, Bureau of Land Management BLM leases grazing land the acceptable amount of grazing animals is high

Causes and Corrections o o 3) deforestation—depletion of forest land U.N. Food & Agriculture Organization (FAO) a) causes increased leaching and erosion b) worst-case scenario—layers above the subsoil are gone o o 4) the other end of the erosion problem: Where do the particles go? displaced sediments can wash into rivers and streams

Irrigation and Salinization o o E. Irrigation and Salinization 1) irrigation—controlled introduction of water to an area a) flood irrigation—diverted canals b) central-pivot irrigation—water pumped from a central area 2) salinization—salts accumulating in and on the soil, hindering plant growth

Salinization o Salinization = accumulation of salts Stunts crop growth Stunts crop growth Lowers yields Lowers yields Kills plants Kills plants Ruins the land Ruins the land o Cure: Take land out of production Take land out of production Install drainage pipe Install drainage pipe Flush soil with low-salt water Flush soil with low-salt water

Soil Conservation o Conventional-tillage farming Land is plowed and soil broken up and smoothed to make a planting surface Land is plowed and soil broken up and smoothed to make a planting surface Land is usually plowed in fall, left bare in winter Land is usually plowed in fall, left bare in winter o Conservation-tillage farming Special tillers break up and loosen subsurface soil without turning over topsoil Special tillers break up and loosen subsurface soil without turning over topsoil Special planting machines inject seeds, fertilizers and weed killers into slits make in unplowed soil Special planting machines inject seeds, fertilizers and weed killers into slits make in unplowed soil Saves fuel, cuts costs, hold more water in soil, keeps soil from getting packed down, allows more crops to be grown during a season Saves fuel, cuts costs, hold more water in soil, keeps soil from getting packed down, allows more crops to be grown during a season

Soil Conservation o Terracing: reduces erosion on steep slows Retains water and controls runoff Retains water and controls runoff Good choice for mountains Good choice for mountains

Soil Conservation o Contour Farming – on gentle sloping land Plowing and planting crops in rows across rather than up and down the slope Plowing and planting crops in rows across rather than up and down the slope

Soil Conservation o Strip Cropping: a row crop alternates with another crop The cover crop traps soil that erodes from the row crop The cover crop traps soil that erodes from the row crop Catches and reduces water runoff to help prevent the spread of pests and plant diseases Catches and reduces water runoff to help prevent the spread of pests and plant diseases

Soil Conservation o Alley Cropping: is a form of intercropping Several crops are planted together in strips or alleys between trees or shrubs Several crops are planted together in strips or alleys between trees or shrubs Trees provide shade Trees provide shade Trimmings from trees/shrubs provide mulch (green manure) Trimmings from trees/shrubs provide mulch (green manure)

Soil Conservation o Windbreaks: o Forest Farming:

o Riparian Forest Buffers: Perennial vegetation planted Perennial vegetation planted between cropland or pastures and streams, lakes, wetlands ect - Reduces runoff and non-point source pollution by trapping sediment, filtering excess nutrients, and degrading pesticides

Maintaining Soil Fertility o Fertilizers Organic: Organic: Animal Manure Animal Manure Green manure Green manure Compost Compost o Crop Rotation

Mining Surface mining – used to retrieve shallow mineral deposits - Open pit mining:

Surface Mining o Dredging

Mining o Strip Mining

Mining o Mountain Top Removal

Subsurface Mining o Used to remove ores too deep to be extracted by surface mining