AP Environmental Science Unit 5 Land and Water Use

Unit 5: Land and Water Use ● Resource Utilization ○ “The Tragedy of the Commons” ■ Serves as a foundation for modern conservation ● Conservation - the management or regulation of a resource ○ Different from preservation ● Preservation - the maintenance of a species or ecosystem in order to ensure its perpetuation ○ Renewable & Non-renewable Resources ■ Renewable Resources ● Resources that can be regenerated quickly ○ Eg: Hardwood trees take 50 years to mature; It’s widely considered the crossover point of nonrenewable and renewable resources. ■ Nonrenewable Resource ● Things like minerals and fossil fuels ● Typically formed by very slow geologic processes ■ Main Sources of Energy ● Fossil Fuels ○ Provide 65% of the world’s electricity ○ Formed from the fossilized remains of once-living organisms; over time, this organic matter was exposed to intense heat & pressure, eventually breaking the organic molecules down into oil, coal, and natural gas ● Nuclear Energy ○ The world’s primary non-fossil fuel, nonrenewable energy source ○ In the U.S., 20% of electrical energy is provided by nuclear power plants ○ Worldwide, more than 400 nuclear power plants produce approximately 13% of the world’s electrical energy ○ China and India lead the world in the creation of new nuclear facilities ● Renewable Energy ○ Bottomless energy source = advantage ○ Examples include biomass, solar, wind, geothermal, and hydropower energy ○ Globally, only 15% of our energy needs are currently met using renewable energy sources ○ Energy storage limitations hinder the expansion of renewable storage ● Agriculture ○ Agricultural Innovations ■ Neolithic Agricultural Revolution - the period of time during which people transitioned from hunting and gathering for food to an organized system of farming ● Vegetative planting - where shoot, stems, and roots of existing wild plants are collected and grown together ↓ ● Seed agriculture - fertilized seed grains and fruits of plants are collected and planted together ↓ ● Horticulture - the domestication of plants by rejecting poorly growing crops and taking seeds from productive, heartier crops to grow future generations ↓ ● Animal domestication - the process in which selected animal populations become accustomed to human provision and control; was established as an alternative to hunting & fishing ↓ ● Animal husbandry - productive breeds were purposely interbred or hybridized for reproduction ■ Second Agricultural Revolution - technological innovations in agriculture and manufacturing that drastically reduced labor requirements and increased the scale of farm production ● Green Revolution - the time after the Industrial Revolution when farming became mechanized and crop yields in industrialized nations booms ○ Positive Effects ■ Mechanization, fertilizers, and pesticides that led to improved crop production on small plots of land and a reduction in world hunger ■ Decreased food costs ■ Affordable irrigation pumps that move water to farming regions ■ Genetic engineering allowing farmers to modify crops with beneficial traits and create high-yield seeds ■ Biotechnology research resulting in the development of vaccines, antibiotics, and growth hormones ○ Negative Effects ■ Suffering small farms due to their inability to capitalize on economies of scale ■ Detrimental environmental impact caused by the increased use of energy, materials, and machinery ■ Chemical use leading to eutrophication and causes explosive algae growth and water pollution ■ Use of fertilizers and pesticides resulting in pesticide resistance ■ Genetic engineering resulting in distrust ● Agricultural Activity & the Environment ○ Irrigation ■ Problem ● Repeated irrigation can cause serious problem , including a significant buildup of salts on the soil’s surface, which makes the lands unusable for crops ■ How the Problem is Being Addressed ● To combat this salinization of the land, farmers have begun flooding fields with massive amounts of water in order to move the salt deeper into the soil ■ Drawbacks ● The large amounts of water can waterlog plant roots, which will kill the crops; this process also causes the water table of the region to rise ● The water for these irrigation farms comes from underground aquifers which are being depleted at a rapid rate ○ Prevention of Soil Degradation ■ Intercropping ● Also called strip cropping ● The practice of planting bands of different crops across a hillside ● Can also prevent some erosion by creating an extensive network of roots ■ Contour Plowing ● Rows of crops are plowed across the hillside; prevents the erosion that can occur when rows are cut up and down on a slope ■ Terracing ● Aids in preventing in soil erosion on steep slopes ● Terraces are flat platforms that are cut into the hillside to provide a level planting surface; this reduces the soil runoff from the slope ■ No-Hill Method ● Farmers plant seeds without using a plow to turn the soil, reduces the levels of CO2 let into the environment by plowing ■ Crop Rotation ● Can provide soils with nutrients when legumes are part of the cycle of crops in an area ○ Types of Pesticides ■ Biological ● Living organisms are used to control pests ○ Eg: Bacteria, ladybugs, milky spore disease, parasitic wasps, and certain viruses ■ Carbamates ● Affect the nervous systems of pests ■ Chlorinated Hydrocarbons & Other Persistent Organic Compounds (POPs) ● Chlorinated Hydrocarbons are synthetic organic compounds belonging to the group of persistent organic pollutants ■ ■ ■ ■ ○ Eg: DDT pesticide ● POPS are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Fumigants ● Used to sterilize soil and prevent pest infestation of stored grain Inorganic ● Broad-based pesticides ● Includes arsenic, copper, lead, and mercury. ● Highly toxic and accumulate in the environment Organic/Natural ● Natural poisons derived from plants such as tobacco or chrysanthemum Organophosphates ● Extremely toxic but remain in the environment for only a brief time ○ Eg: Malathium ● Livestock & Overgrazing ○ Livestock Grazing ■ The shifting of animal herds between grazing pastures in area where dry grassland is common ■ A sustainable practice, as long as the grazing area is sufficient for the number of animals ○ Overgrazing ■ Occurs when too many people and too many animals are placing population pressure on too little land ■ Has led to significant amounts to dry grasslands being denuded, eroded, and desertified ■ Harmful to the soil because it leads to erosion and soil compaction ■ Solutions include rotating animals from site to site and away from their source of water, and overall control of herd numbers ○ Animal Waste ■ Manure not used as fertilizer due to difficulty with transport ■ Has become the most widespread source of water pollution in the United States ● Forestry ○ Deforestation ● The removal of trees for agricultural purposes or purposes of exportation ● Slash & Burn - severely reduces the amount of available forest and contributes to deforestation; an area of vegetation is cut down and burned before being planted with crops ○ Tree Plantations and Old Growth Forests ■ Old Growth Forests ● Have never been cut or seriously disturbed for several hundred years ● Contains incredible biodiversity, with nyriad habitats and highly evolved intricate niches for a multitude of organisms ■ Second Growth Forests ● Areas where cutting has occurred and a new, younger forest has arisen naturally ■ Plantations & Tree Farms ● Planted and managed tracts of trees of the same age that are harvested for commercial use ○ Forest Management ● Silviculture - the management of forest plantations for the purpose of harvesting timber ● Clear-Cutting - the removal of all of the trees in an area ● Selective Cutting - the removal of select trees in an area ● Natural Events & Forest Fires ○ Humans control the areas that affect the quality of food and the number of trees that are available to use by: ■ Removing infected trees ■ Removing select trees ■ Using chemical and natural pest controls ■ Carefully inspecting imported trees and tree products ■ Developing pest and disease-resistant species of trees ● Rangelands ■ Are diverse in nature, consisting of desert, wet and dry grasslands, and mountainous meadows ■ Approximately 770 million acres are rangelands; 46% of it is governed ● Types of Mining ○ Strip Mining ■ Controversial type of mining ■ Strips the surface layer of soil and rock in order to expose a seam of mineral ore ■ Least expensive and least dangerous method of mining for coal ■ Has a detrimental effect on the environment ○ Mountaintop Removal ■ Most extreme form of strip mining ■ Mostly associated with coal mining in the Appalachian Mountains ■ Transforms the summits of mountains and destroys ecosystems ○ Shaft Mining ■ Vertical tunnels are built to access ■ Excavate minerals that are unreachable ● Fishing ○ Fishing Techniques ■ Drift Nets ● Nets float through the water and catch everything in their path ■ Long-Lining ● The use of long lines with baited hooks that are taken by numerous aquatic organisms ■ Bottom Trawling ● The ocean floor is scraped by heavy nets that smash everything in their path ○ Overfishing & Aquaculture ● About 69% of major fish stocks of the world are either overexploited or fully exploited ● About 20% of the stocks are moderately overexploited ● About 8% are either recovering from depletion or depleted ■ Aquaculture - raising aquatic species in captivity for harvesting