All 18 First Semester Major Topic SummariesTo be used to study for the 2009-2010 APES Final

#1 Earth Science Concepts

Geological Time Scale

The geological time scale provides a system of chronologic measurement to time that is used by geologists, paleontologists and other earth scientist to describe the timing and relationships between events that have occurred during the history of the Earth. The Earth itself is about 4.57 billion years old. Different spans of time on the time scale are distinguished by their length and major events during that time. We currently live in the Phanerozoic Eon, Cenozoic Era, Quaternary Period, Holocene Epoch, and Atlantic Age.

Plate Tectonics, Earthquakes, Volcanism

Plate tectonic is the theory that postulates the movement of sections of the Earth’s crust, creating earthquakes, volcanic activity, and the buildup of continental masses over long periods of time. The lithosphere, Earth’s crust, is broken up into what are called tectonic plates. Tectonic plates are able to move because the Earth’s lithosphere has a higher strength and lower density than the underlying asthenosphere. Some 14 major plates and a few minor ones make up the lithosphere. Subduction zones are found where an oceanic plate slides under a continental plate. Collision zones are found where two continental plates converge, resulting in uplifting into mountain ranges. Transform faults are boundaries where two plates are sliding past each other.

An earthquake is the result of a sudden release of energy in the Earth’s crust that creates seismic waves. At the Earth’s surface, earthquakes manifest themselves by shaking and sometimes displacing the ground. When a large earthquake is centered offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.

A volcano is an opening in a planet’s surface or crust, which allows hot magna, ash, and gasses to escape from below the surface. Volcanoes are generally found where tectonic plates are diverging or converging. Volcanoes can also form where there is stretching or thinning of the Earth’s crust.

Seasons

A season is a division of the year, marked by changes in weather. Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth’s axis relative to the plane of revolution. Seasons are usually marked by changes in the intensity of sunlight that reaches the Earth’s surface, variations of which may cause animals to go into hibernation or to migrate, and plants to be dormant. In some parts of the world, special “seasons” are loosely defined based upon important events such as a hurricane season, tornado season or a wildfire season.

Solar Intensity

Solar intensity means how strong the sun hits the ground. Different bodies of the Solar System receive light of intensity inversely proportional to the square of their distance from the Sun. Latitude

Latitude gives the location of a place on Earth north or south of the equator. Lines of Latitude are the imaginary horizontal lines shown running east-to-west (or west-to-east) on maps that run either north or south of the equator.

#2 Global Water Resources and UseFreshwater: .024% of Earth’s water supplies are available as freshwater. The hydrologic cycle constantly purifies and recycles water. Freshwater is an irreplaceable part of Earth’s natural capital, and is being constantly degraded by human involvement. Irrigation is the biggest use of freshwater, followed by industrial and domestic.Saltwater: Largest saltwater stores are the Oceans of Earth. Saltwater is too expensive to desalinize for human use and consumption.

Ocean Circulation: Warm ocean currents are corridors of warm water moving tropics pole ward where they release energy to the air. Cold ocean currents are corridors of cold water moving from higher latitudes toward the equator.Agricultural use: used for irrigation, second largest use of water in the US, up to 70 % of the water taken from rivers and groundwater goes into irrigation. Water for agriculture requires one hundred times

more than we use for personal needs.Industrial use: 15% of world wise water use is industrial; in 2000, industries withdrew and estimate of 19,700 million gallons per day. Industrial water use includes water used for fabricating, processing, washing, diluting, cooling, or transporting a product; incorporating water into a product; or for sanitation needs in the facility.Domestic use: Used for every day human activities such as drinking, cooking, bathing, etc. Water is either supplied by a city/county (public supplied) or acquired from personal wells.Surface and Groundwater Issues: Over pumping of aquifers faster than aquifer can replenish erosion, fertilizer and pesticides used in agriculture, and eutrophication cause pollution and other issues which reduce availability and usability of surface and ground water. Global Problems: The source of water pollution is humans; their activities in factories, homes, and waste treatment centers cause toxic chemicals, which leak into groundwater stores. Conservation: 1972 amendments to the Clean Water Act allowed for better regulation to reduce direct pollutant discharges into waterways. The Water Quality Act of 1987 and the CWA form a basis of US efforts to control pollution of US surface water.Cadillac Desert: 1997 motion picture describing William Mulholland’s search for a new source of water to supply southern California. After discovering the Owens River and Owens River Valley, Mulholland drew up plans for the first Los Angeles aqueduct. Construction began in 1908, and the aqueduct was finally opened on November 5th, 1913. After its opening, the Los Angeles area grew dramatically, due to the reliable water supply.

#3 Soil and Soil Dynamics

Soil is complex, unconsolidated mixture of inorganic, organic, and living material that is found on the immediate surface of the earth that supports plant life. Soil consists of dirt and sediments. One of the most important factors of a soil is its chemical backbone from the parent rock. For example, limestone is basic and other rocks which comes from limestone has basic pH too. Climate affects the making of the soil because before the parent rock can become part of the soil, it must be broken down physically and chemically. Rain, for example, can take out elements and weaken the chemical bonds so that it may be broken down easier into soil. Water and wind can also break down the rock. Time is also an important factor. Depending on the type of rock, the act of breaking the rock down from rock to soil can take from a couple years to thousands and thousands of years. Human activity also affects the soil. Soil has many layers usually denoted by letters: O, A, B, C, and E. The O layer is usually comprised of organic materials from the dead animals, dead leaves, and detritus. The A layer is organic materials mixed with inorganic materials, for example water. The B level is where the minerals and clay are. Layer C contains the parent inorganic material for the soil.

Alfisols are a well-developed, highly fertile soil that forms in forests. These soils have undergone some leaching (water stripping some chemicals from the soil as it percolates through it), leaving them with a subsurface layer of clay. This clay allows these soils to remain moist, which helps to keep them fertile. They are usually found in temperate zones, which make them ideal for farming. Aridisols, as the name implies, are soils that form in regions that are dry for long periods of the year. These soils have a high calcium carbonate concentration, with layers of clay, silica, salt, and gypsum in the subsurface regions. Mollisols are found in grassland areas and have a relatively rich, dark-colored surface zone as a result of the organic matter from the being added from the grass. The fertile nature of these soils makes them excellent media for growing grain crops. Oxisols are the heavily oxidized soils found in tropical and subtropical rainforest. These soils have undergone heavy amounts of weathering and are very low in fertility outside of the very thin layer of organic material on the surface. Because water has leached most of the other minerals out of the soil, oxisols are very high in concentrations of aluminum and iron and are mined extensively in countries where rainforest are being chopped down. Andisols are formed from the ash and ejecta from volcanoes. These soils are very high in glass grains and materials with pores. This latter property means that these soils have a high ability to hold water. Erosion is a gravity driven process that moves solid (sediment, soil, and other particles) in the natural environment or their source and deposits them elsewhere. It usually occurs due to transport by wind, water, or ice; by down-slop creep of soil and other material under the force of gravity; or by living organisms, such as burrowing animals, in the case of bioerosion. Other soil problems are overuse, salinization, acidification, or other chemical soil contamination.The main idea is that rocks are continually changing from one type to another and back again, as forces inside the earth bring them closer to the surface (where they are weathered, eroded, and compacted) and forces on the earth sink them back down (where they are heated, pressed, and melted). So the elements that make up rocks are never created or destroyed — instead, they are constantly being recycled.Soil conversation is a set of management strategies for prevention of soil being eroded from the earth’s surface or becoming chemically altered by overuse, salinization, acidification, or other chemical soil contamination.

#4. Ecosystem StructureBiological Populations and Communities

Population of different species. Living within an area and creates communities. An ecosystem is formed by the interaction of a community of organism and their physical environment. Members of a population can be dispersed in 3 ways:

Clumped- some areas within the habitat are dense with organisms while others contain few members Random – little interaction between members of the population. Leading to random pacing patters Uniform – fairly uniform spacing between individuals.

Ecological Niches – particular area w/in habitat, occupied by an organism. Includes the function of that organism w/in that ecological community. Specific adaptation acquired through evolution. To describe an organism niche involves a description of the organism’s adaptive trait habitat and place in the food web.Interactions among SpeciesThey can benefit one or both species, harm one or both species, or not affect one of the species involved.

Amenalism (-) (O) – interaction between 2 species whereby one species suffers and the other species is not affected. Usually occurs when one organism releases a chemical compound that is detrimental to another organism.

Commensalism (+) (O) - interaction between 2 species whereby one organism benefits and the other species is not affected. Forms of it include phoresy-one using another for transportation, inquilism- use for housing, metabiosis-using something another created.

Competition (-) (-) - the driving force of evolution whether it is for competition for food, mating partners, or territory. Intraspecific competition results in the organism that is best suited for change.

Mutualism (+) (+) – interaction between 2 species whereby both species benefit. Symbiosis- lifelong positive interaction that involves close physical and/or biochemical contact such as the relationship between trees and mycorrhizal fungi.

Parasitism (+) (-) – interaction between 2 species whereby one species is benefited at the expense of another. Ectoparasite –lives on host. Biotrophic parasites must keep their hosts alive (viruses). Necrotrophs- kill their hosts. Social parasites benefit parasites and harms hosts.Predation (+) (-) – hunt and kill prey.

Saprotrophism (+) (-) – obtain nutrients from dead or decaying plants or animals through absorption of soluble organic compoundsKeystone Species - a species that has a disproportionate effect on its environment relative to its biomass. Such species affect many other organisms in an ecosystem and help to determine the types and numbers of various others species in a community. The organism is similar to the keystone in an archway; while the keystone is under the least pressure of any of the stones in an arch, the arch still collapses without it. Similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measures of biomass or productivity.

A classic keystone species is a small predator that prevents a particular herbivorous species from eliminating dominant plant species. Since the prey numbers are low, the keystone predator numbers can be even lower and still be effective. Yet without the predators, the herbivorous prey would explode in numbers, wipe out the dominant plants, and dramatically alter the character of the ecosystem.

They can be predators, mutualists, or ecosystem engineers- any organism that creates or modifies habitatsExamples: sea stars, sea otters in kelp forests, jaguars in central and south America, grizzly bears in North America, prairie dogs

Species Diversity - organisms that live in different environments are specifically adapted to their particular biomeEx: Aquatic, desert, grassland, forest, temperate scrub forest land, tundra organisms.

Edge Effects - how local environment changes along some type of boundary or edge.Forest edges created when trees are harvested, especially when clear-cut (tree canopies provide shade and retain moisture so young

trees can grow. Sunlight makes the land warmer and drier.)Edge effect is result of two different conditions influencing plants and animals that live on the edge. Edge species are species that can

adapt to both environments.Major Terrestrial and Aquatic Biomes

Deserts – 15 and 25⁰ N and S latitude. Generally in the interior of continents. Takes up about 20% land mass. Rainfall <20 in. little nutrients, not abundant in organic matter. Little hummus in the soil profile.

Tropical Rainforests – high, constant temperature (27 C) rainfall- 75-100 km/yr. high species diversity. Dense vegetation. Soil low in nutrients, mostly stored in vegetation. Decomposition of organic material very fast due to temperature and moisture. Leaching is high. Humans are clearing it for agriculture and cattle raising, using technique called slash and burn.

Temperate Deciduous Forests – rapid decomp due to mild temp and precipitation. Results in small amount of litter on the surface. Soil generally poor in nutrients. Mild climate, diverse understory with tall deciduous trees. Low density of small animals. Shade prevents much ground vegetation.

Chaparral (temperate shrubland) - avg rainfall: 30-40 in/yr/ dense shrub growth. Slow decomp during dry months. Few large mammals. Hot dry summer, mild cool rainy winter.

Grassland – too dry for forests, too wet for deserts. Seasonal rainfall. Moderate temp. Occupies approx. 25% of land area. Few trees and shrubs due to fire and water availability. Soil rich in organic matter. Upper soil horizon rich in hummus.

Savannas – warm year round. Scattered with trees/ dry followed by rainy seasons. Grassland with deciduous shrubs and trees. Food limited in dry season. Soil rich in nutrients. Resource for predators- a lot of bird and grazing animals.

Tundra - 60⁰ N latitude and above. Alpine tundra located in mountainous areas. Above tree line with well drained soil. Small rodents and insects. Arctic tundra- frozen, treeless plain. Low rainfall and avg temp. Poor drainage. Low vegetation, soil has few nutrients, little decomp.

Temperate boreal forest – taiga. 45-60 N latitude. 17% land surface. Cold climate. High latitude/altitude. Poor soil. A lot of leaching. ⁰Acidic soil. Low temp. Slow decomp. Small trees. Little light in understory. Low biodiversity. Fire, storm, insect infestation.

Productivity of Biomes Ecosystem Type  Net Primary Productivity(Kilocalories / square meter / year)  Approx.Kilocalories/square meter/ day

Tropical Rain Forest  9000  25 Estuary  9000  25 Swamps and Marshes  9000  25 Savanna 3000  8 Temperate Grassland  2000  6 Deciduous Temperate Forest  6000  16  Boreal Forest  3500  10 Polar Tundra  600  2 Desert  < 200  1

#5 Energy Flow: Photosynthesis and Cellular Respiration; Food Webs and Trophic Levels; Ecological Pyramids; 10% Energy Transfer

Photosynthesis: chemical process in plants converting light energy to chemical energy and storing it as sugar bonds

6CO2 + 6H20 (+ light energy) → C6H12O6 + 6 O2

Cellular Respiration: to release the energy required for the work done by that cell; purpose is to release the potential energy contained in organic molecules to perform the activities of the organism

C6H12O6 + 6 O2 → 6CO2 + 6H20 (+ light energy)

Food Webs: the interconnection of food chains

As you move up the food chain, there is less energy available.

Most of the energy obtained is used as heat. Heat is the lowest form of energy. Once the energy is used as heat, it will never be recycled.

Trophic levels: feeding levels in a food chain

Primary producers → consumers (herbivore) → consumers (carnivore) → decomposers

10% Energy Transfer and the Ecological Pyramid The sun loses 90% of its energy as heat and the other 10%

goes to the producers The sun’s energy is absorbed by the producers, where 10% of the energy is passed to the primary

consumer. As you move up the pyramid, the consumer will only gain 10% of the energy from its prey.

More energy is obtained when eating lower on the ecological pyramid.

Energy Flow

Courtesy of Marietta College

• The sun loses 90% of its energy as heat and the other 10%goes to the producers.

• As you move up the food chain, there is less energy available.

• Most of the energy obtained is used as heat.

• Heat is the lowest form of energy.

• Once the energy is used as heat, it will never be recycled.

Biomass Pyramids

Courtesy of University of Winnipeg

Diagram showing the biomass at each trophic level of a food chain

The sun’s energy is absorbed by the producers, where 10% of the energy is passed to the primary consumer. As you move up the pyramid, the consumer will only gain 10% of the energy from its prey.

Therefore, you obtain more energy by eating lower on the biomass pyramid

#6 Ecosystem Diversity Diversity is the variety of different plant or animal species in a habitat or ecosystem. The number of species of plants, animals, and microorganisms are the diversity of genes in these species. The different ecosystems on the planet, such as deserts, rainforests and coral reefs are all part of a diversity system. Biodiversity is important because it boosts ecosystem productivity. For example, a larger number of plant species means a greater variety of crops; greater species diversity ensures natural sustainability for all life forms; and healthy ecosystems can better withstand and recover from a variety of disasters. We still need to preserve the diversity in wildlife.

Natural selection evolves the evolution of a species that is best adapted to survive the environment. It’s the traits that a species passes on to its offspring so that it can survive it its habitat. Over generations a species evolves and becomes more efficient then it once was. It is survival of the fittest and the so-called weak tend to die out. With the feeding habits of the 13 finches on the Galapagos Islands, Darwin studied their beaks and later found this could help them survive by finding food.

Evolution refers to change over time, or transformation over time. Evolution requires that all natural forms arose from their ancestors and adapted over time to their environments, thus leading to variation. In evolution, there are many rules for the survival of a species. There are also numerous ways in which evolution occurs, the most noted are Natural Selection and Adaptation.

Ecosystem Services are the processes by which the environment produces resources that we often take for granted such as clean water, timber, and habitat for fisheries, and pollination of native and agricultural plants. Natural ecosystems and the plants and animals within them provide humans with services that would be very difficult to duplicate. Over 100,000 different animal species — including bats, bees, flies, moths, beetles, birds, and butterflies — provide free pollination services for example. One third of human food comes from plants pollinated by wild pollinators. Unfortunately, we take advantage of our ecosystem services. Many human activities disrupt ecosystems every day including:

Runoff of pesticides, fertilizers, and animal wastes Pollution of land, water, and air resources Introduction of non-native species Over-harvesting of fisheries Destruction of wetlands Erosion of soils Deforestation Urban sprawl

The choices we make today in how we use land and water resources will have enormous consequences on the future sustainability of earth’s ecosystems and the services they provide.

#7: Natural Ecosystem Change-Climate shifts, species movement, ecological successionWhaaaaat? Climate Change, what are you talking about? Over

the last few decades scientists have observed that there has been a slow but

steady rise in the Earth’s average temperature. This is mostly caused by the

increase in anthropogenic greenhouse gas concentrations. The three

major gases are: carbon dioxide, methane, and nitrous oxide. These gases

absorb the heat radiating from the Earth and trap it so that it heats the lower

atmosphere. The increase in the Earth’s temperature will lead to changes such as lessening of ice sheets

and glaciers, lost of biodiversity, continued rising average of ocean levels, frequency in duration of storms,

increase in number of hot days, and countless other issues. Adaptations to the warmer climate will need to

occur at many levels of society. Technological improvements like

carbon sequestration and the reduction of emissions from engines,

behavioral changes such as turning off lights to conserve

electricity, and policy changes such as enacting new likes and

legislation will all be necessary in the next few decades.

Where art thou, species?! As the world’s climate changes,

many species are being forced out of their habitats. While some species are able to migrate to a cooler

territory, those in the tropics have no where else to go ): The key dangers of moving small numbers of

organisms to a new location for purposes of reintroduction are inbreeding, hybridization or interbreeding

with local species, and failure of survival. They newly established population may carve its own

evolutionary path and form a new species or subspecies.

Ecowhat?! Succession who?! Ecological succession is when species of plants/animals are continually coming and

going; evolving and dying out. If ecological succession begins in a virtually lifeless area, such as the area bellowing a

retreating glacier, it is called primary succession. Secondary succession is ecological succession that takes place

where an existing community has been cleared (by events

such as fire, tornado, or human impact), but the soil has been

left intact. The organisms in the first stages of either type of

succession are referred to as pioneer species. The final stage

of succession, in which there is a dynamic balance between

the abiotic and biotic components of the community, is

referred to as the climax community. An example of

ecological succession is:

#8Natural Biogeochemical Cycles

Carbon Cycle: Carbon moves around when things eat each other, geological sedimentation of carbon in ocean and when fossil fuels are burned.

CO2 in the air Enters plant Enters food web

Becomes detritus, eaten by detritus feeders/ decomposers

Phytoplankton remove CO2 from inorganic carbonates in sea water Enter marine food web By decomposers

Phosphorous Cycle: The shortage of phosphorous in an ecosystem can be a limiting factor and an excess can cause unwanted algal growth. Phosphate (PO4

3-) is found in rock and soil minerals. As it breaks down, the ions are released and absorbed by plants from the soil. It then is consumed by a primary consumer, and continues through the food chain. It is then released by cell respiration or is decomposed and is released in the waste material.

Sulfur Cycle: Within the terrestrial portion, the cycle begins with the weathering of rocks, releasing the stored sulfur and comes into contact with air where it is converted into sulfate (SO4). The sulfate is taken up by plants and microorganisms and is converted into organic forms; animals then consume these organic forms through foods they eat, thereby moving the sulfur through the food chain. As organisms die and decompose, some of the sulfur is again released as a sulfate and some enters the tissues of microorganisms.

Nitrogen Cycle: Nitrogen Gas (N2) is converted to ammonia (NH3) which is then converted to NO3 (by nitrogen fixation- lightening) or NH4 by rhizobium, the bacteria in legumes, which provide nutrients for plants. The plants are then eaten by animals, which die, resulting in ammonification. The aquatic ecosystems acquire nitrogen in the form of NH3 or NH4 by eutrophication. Aquatic plants are then eaten by animals, which then reenter cycle.

Water Cycle: Water rises into the atmosphere through evaporation or transpiration (through plants) and returns through condensation and precipitation. Hadley cells and rain shadows affect precipitation. The Hadley cell affects precipitation because on one side, dry air absorbs moisture, and when it ascends it releases the moisture. The rain shadow affects precipitation because the warm, moist air dries by the time it reaches the top of the mountain. The leeward side of the mountain is dry. Assimilation is the ability of water to purify itself.

Conservation of Matter: The first law of thermodynamics: Energy is neither created nor destroyed.The second law of thermodynamics: In an energy conversion, some of the usable energy is always lost (i.e. in the form of heat)

Photosynthesis Consumed

Goes to

soil

Consumed Respiration

#9 Agriculture, Feeding a Growing Population

Human nutritional requirements The human diet must provide the following:

Calories: enough to meet our daily energy needs Amino Acids: There are 9 “essential” amino acids that we

need for protein synthesis Fatty Acids: There are 3 “essential” fatty acids that we

cannot synthesize from other precursors Minerals, inorganic ions: We need 18 different ones; a few like calcium in relatively

large amounts; most, like zinc, in “trace” amounts Vitamins: 12 small organic molecules that we cannot synthesize from other

precursors in our dietTypes of agriculture

Conventional Agriculture : is mono-cropping (planting only one crop year-round). Mono-cropping eliminates diversity. This type of agriculture is based on maximizing the output of a narrow range of species.

Sustainable Agriculture : integrates three main goals: environmental stewardship, farm profitability, and prosperous farming communities.

Green Revolution – a significant increase in agricultural productivity resulting from the introduction of high-yield varieties of grains, the use of pesticides, and improved management techniques.

Genetic engineering and crop production Crop production is the amount of crops produced in a year and is a complex business,

requiring many skills and covering a variety of operations throughout the year. Genetic engineering refers to manipulating genes in a way that does not occur naturally.

The organism’s genes are manipulated indirectly. It also alters the structure and characteristics of genes directly.

Deforestation – is the clearance of naturally occurring forests by the processes of humans' logging and/or burning of trees in a forested area.

Irrigation – is an artificial application of water to the soil. It is usually used to assist the growing of crops in dry areas and during periods of inadequate rainfall. Repeated irrigation can cause serious problem, including a significant buildup of salts on the soil’s surface that make the land unusable for crops.

Sustainable agriculture – agriculture that maintains the integrity of soil and water resources such that it can be continued indefinitely.

Sustainable yield – the amount of food required to sustain a population. Developed nations would have high amounts of crop, which leads to crop surpluses.

#10 Agriculture, Controlling Pests

Types of Pesticides (mostly a Second Semester Topic-according to Dr. Griffith) Biodegradable- means that it can be broken down in soil in a feasible amount of time Non biodegradable- means that the pesticide cannot be broken down in an amount of time that makes is

useful (example- DDT) DDT- was originally used as a pesticide for plants, but was being consumed by animals. When these

animals were eaten by predators, the DDT made its way up the food chain (bioaccumulation). A written source is Silent Spring by Rachel Carson. DDT is non biodegradable, hydrophobic and lipophilic. The means it cannot be broken down naturally, dissolved in water, and it lives in the fats of animals

Cost of Pesticide Use The more pesticides are used, the more likely the pests are to become resistant to them. Since the pests

become immune to the pesticides people, the farmers think that they need to use more pesticides. This costs more money and does not get rid of the pests

Have effects on human. (Remember movie where the little boy had cancer) Pesticides do not add humus to the soil. Humus is what provides the soil with the nutrients that it needs.

It is also spongy, so it helps prevent erosion. Since it does not add humus, it reduces the soil’s water and nutrient holding capacity. This makes the soil more susceptible to erosion.

Benefits of Pesticide Use Inorganic chemical fertilizers are easily found,

bought, transported, stored, and used. Because of this, they are very convenient for farmers,

and excellent and getting rid of pests. They are also relatively cheap, which makes

them attractive to farmers

Integrated Pest Management A program consisting of two or more methods of pest control carefully integrated together and designed

to avoid economic loss from pests It’s goal is to minimize the use of environmentally hazardous synthetic chemicals One type of IPM is crop rotation, which means growing crops in the same patch of land that are infected

by different pests. This doesn’t allow the pests to settle and reproduce

#11 Major Semester 1 Topic: RangelandsWhat are rangelands? Expansive grasslands with native vegetation. Examples of rangeland biomes: savannas, deserts, tundras.Why are rangelands important? Most of our food comes from animals that are farmed, like cows, which are grazed on grasslands.

*Important concepts: deforestation, federal rangelands, wildernessDeforestation: Forest is removed and the land is used for other purposes, like grazing. The forest is not allowed to regrow.

Reasons for deforestation: conversion into pastures and agricultural landConsequences of deforestation: productivity is reduced, nutrients reduced, biodiversity is diminished, soil

becomes prone to erosion, change in the water cycle, a major carbon dioxide sink is lost (forests remove CO2 from the air), the land no longer yields forest products, people lose their livelihoods.

Types of forest management: Rotation: monitoring a stand of trees from growth to harvest Even-aged management: trees of a uniform age are managed until harvest, cut down, and

replanted. This continues the cycle in a dependable sequence Clear-cutting: removing an entire stand at a time. This severely decreases biodiversity and

affects adjacent ecosystems. Uneven-aged management:

o Selective cutting: some mature trees are removed in small groups, leaving behind a forest that continues to function

o Shelter-wood cutting: cutting the mature trees in groups over a specific period (i.e. 10 years) which allows time for the trees to reproduce, provide seeds, and give shelter to growing seedlings

Federal Rangelands: a commons (remember tragedy of the commons!) that is owned by the federal government (i.e. a national park or national forest). Federal rangelands are important because they protect important ecosystems, raise awareness about endangered species, and allow people to enjoy the beauty of natural lands. Wilderness: federal land that is designated off-limits to development of any kind but is open to public recreation, such as hiking, nature study, and other activities that have minimal impact on the land.

*Other concepts: overgrazing, desertification, rangeland managementOvergrazing: contributes to erosion, soil degradation, and a loss of nutrients. Desertification: A loss of more than 10% productivity due to erosion, soil compaction, forest removal, overgrazing, drought, salinization, climate change, and depletion of water sources. Makes the land more desert-like. Rangeland Management: managing the natural resources on the rangeland

CLEAR-CUTTING IS BAD. FEDERAL PROTECTION IS GOOD.

#12 Energy Concepts

1 st law of thermodynamics -energy is neither created nor destroyed but may be converted to one form or another (example: photosynthesis-energy from sun converted to chemical energy in the bonds that hold together atoms in carbohydrates)

2 nd law of thermodynamics - when energy is changed from one form to another some useful energy is always degraded into lower quality energy (usually heat), (Example: food chain and 10% rule)

entropy (disorder) of the universe is increasing

Units of Energy Energy units: Joule (J), Calorie (cal) Power Units Watt (W), Horsepower (hp)

Conversions: We will do this next semester according to Dr. Griffith

Renewable EnergySolar, Wind, and hydroelectric energy are renewable because their supplies are not deleted by human use

Hydroelectric energy-generated by the force of water, electricity is created when water turns a turbine. Release no pollutants, only thermal pollutant Must dam rivers, may disrupt fish in water sources

Solar energy-active collection using solar panels

Wind energy-wind turns turbine creating energy

NonrenewableCoal, oil, natural gas because they have a limited amount available

#13 Water Pollution

Types of water pollution include: contaminants from sewage plants, industrial waste, pesticides and fertilizers from agricultural run-off. Four categories of water pollution: toxic pollution, nutrient pollution, sediment pollution, and bacterial pollution

Main Causes: -Manufacturing plants use the water to carry away waste that can contain phosphates, nitrates, lead, mercury and other harmful and toxic substances.

-Ground water pollution occurs when harmful elements, such as oil, debris, chemicals and other contaminants get washed up by rainwater and then seep back into underground water supplies called ground water.

Effects: -Thermal Pollution: Hot water discharge from factories can change the temperature and chemistry of the water-Toxins in the water are lethal: Blood diseases, heart disease and nervous system disorders are commonly linked to the effects of water pollution-Dissolved Oxygen level is lowered due to the increase in BOD and therefore fish and other life may die because of lack of oxygen.

Cultural Eutrophication: Process which speeds up natural eutrophication because of human activity. Due to clearing of land and building of towns and cities, runoff water is accelerated and more nutrients such as phosphates and nitrate are supplied to the lakes and ponds..These nutrients result in an excessive growth of plant life known as an algal bloom. This not only changes the lake's natural food web, but also reduces the amount of dissolved oxygen in the water for organisms to breathe. Water Purification: -Filtration and sedimentation, biological processes such as slow sand filters or activated sludge, chemical process such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light are all ways to purify water.

Sewage Treatment: Sewage can be treated close to where it is created (in septic tanks, biofilters or aerobic treatment systems), or collected and transported via a network of pipes and pump stations to a municipal treatment plant (see sewerage and pipes and infrastructure).

Solution: -Clean Water Act in 1972 puts limitations on the types and amounts of material that can be discharged into our bodies of water, and also sets quotas on the amounts of pollutants that can be in water before it becomes unsafe for use by humans and wildlife.

-On a smaller scale we can help by becoming educated on how to avoid pollution. This can include the proper disposal of household chemicals so they don’t make their way untreated into bodies of water or water supplies and making sure your car isn’t leaking fluids that can get mixed in with runoff when it rains and cause ground water pollution.

# 14: Loss of Biodiversity:

Endangered and Extinct Species: -Main Causes: Habitat loss due to overuse or pollution of natural habitats.

Building homes in natural habitats (clear cutting of forests for farm/graze land) Overuse of natural resources for economic benefits (ecosystem capital) Pollution of natural habitats(smog, chemical runoff into water, climate change) Introduction of invasive species threaten the native organisms and the local

biodiversity

Some Species that are Endangered or Extinct: Black-Footed Ferret: Prairie Dogs in Wyoming were killed b/c they were threatening

crops. However, this also hurt the Ferret population. They were thought to be extinct, but in 1987 18 were found, captured, and bred. The Captive Breeding Program brings their number to over 1000.

Whooping Crane: Eggs raised by sandhill cranes in recovery effort Red Wolf: Only 17 remained in North Carolina before a restoration program started.

Wolves are released onto some private property. Peregrine Falcon: Numbers affected by DDT spraying—bioaccumulation Spotted Owl: Habitat loss due to clear-cutting of forests

Relevant Laws and Treaties:

Lacey Act of 1900: Prohibits interstate commerce in illegally killed wildlife. 1973 Endangered Species Act: Protection of endangered/threatened species AND their

habitats CITES: An international treating somewhat protecting endangered and threatened species by

restricting trade in the species or products

Why should we even prevent the loss of biodiversity? Intrinsic, aesthetic values. Economic values of ecosystem capital from natural habitats(trees for wood, fish for food, etc)

When biodiversity is lost, then ecosystem capital also decreases. Possibility of some species that have medicinal properties such as the Pacific Yew tree that

produces the anti-tumor drug Taxol.

#15 Population Biology Concepts

Reproductive StrategiesDepending on the type of animal, many different reproductive strategies can be used. An animal that uses the R-strategy reproduces many small offspring at an early age. Often times, these offspring go unprotected, and the mother does not care for them. Since they are unprotected, many must be produced to ensure that a substantial amount will survive to reproduction age and restart the cycle. An animal that follows the K-strategy waits until later to reproduce and only gives a few offspring. In turn, however, this animal cares for its small amount of offspring to ensure that they survive to reproductive age. Animals that produce less offspring will often produce less often, and animals that produce many will mate many times in their lifetime. An example of an R-strategist is a frog. An example of  K-strategist is a human.

Carrying CapacityThe carrying capacity of a population is the limit of of the population size that can live sustainably, or without degrading effects in the long term.  Carrying capacity can be improved with advances in technology but often times, carrying capacity is lowered due to environmental pressures.  As an area's ability to support life diminishes, so does the carrying capacity.  If the population greatly exceeds the carrying capacity, the population will experience a J-curve that will end in an inevitable crash and in some circumstances, extinction of a population. 

Population CurvesThere are two types of population curves, a J-curve and the S-curve.  These two curves are the general trends that populations follow.

J-CurveA J-curve is characterized by a quick, exponential increase in population followed a sharp and even quicker crash.  J-curves occur under optimal conditions when either a predato has become extinct of prey has become plentiful.  After the J-curve crash, a population may restart the trend again which happens most often with pests.  Otherwise the population may become extinct.

S-curveAn S-curve is characterized by a gradual increase followed by small oscillations about the carrying capacity.  When this occurs, the population is said to be in equilibrium and this is caused because of environmental resistance.  These populations can live sustainably for many years.

Critical NumberThe critical number is the level at which if a population descends below, the population may not be able to recover and would eventually go extinct.  Sometimes the critical number may be more than the number in a certain flock, indicating interaction between groups is necessary for survival.

#16: Human Population Dynamics

Historical Population Sizes

Courtesy of: http://www.flame.org/~cdoswell/Earth_Abides/population_curve.gif

Distribution Fertility Rates

Age-structure diagrams

Population pyramids for 4 stages of the demographic transition modelCourtesy of: http://en.wikipedia.org/wiki/File:Dtm_pyramids.png

Demographic transition

Until the 1800’s, after the industrial revolution, human population has remained pretty consistent. However, since then, because of technology, medicine, and agriculture, the human population has increased exponentially, currently at about 6.8 billion and ever increasing.

Of these 6.8 billion people, the large majority is distributed in a few countries, and in developing countries as opposed to developed.

China and India each contain about 1/5 of the world’s population

Developing countries’ age-structure diagrams (pictured and explained below) are usually shaped like the first one because they have so many kids!

Families in developing countries have more kids and faster growing populations because of a lack of…

o Family planningo Access to contraceptiveso Infant survival (many

young kids die from disease, etc.)

Growth rate-how fast a country’s population grows based on birth rate-death rate

(B.R.-D.R.)/10=% rate of growth

Doubling times-70/ percent rate of growth

Courtesy of: http://www.eoearth.org/upload/thumb/0/04/Figure_4_Classic_Stages_of_Demographic_Transition.gif/300px-Figure_4_Classic_Stages_of_Demographic_Transition.gif

Stage 1: Primitive stability, high crude death rate and crude birth rateStage 2: Declining crude death rateStage 3: Declining crude birth rateStage 4: Modern stability, low crude death rate and low crude birth rate

#17 Human Population Size~ 6,796,029,975 or 6.8 Billionfrom http://www.census.gov/main/www/popclock.html

Strategies for sustainability:

Promoting development of countries:Efforts to reduce population size by helping countries undergo demographic transition to reach “modern stability.”

Ways to reduce population: Increase availability of birth control Reduce infant mortality Increase education Raise status of women Eradicate poverty

Millennium Project:Set up millennium development goals (MDGs) for solving population problems in the new millennium. Many groups, including the U.N. Agency and many NGOs and government agencies are working achieving the goals.

World Bank:Agency under the U.N. that provides loans to low-income developing countries. Good and bad. Focused on development, not environmentalism. May also increase countries’ debt.

Case Study:KeralaSouthwestern province in India. Low fertility rate of 1.8 (below replacement level). Lower infant mortality rate and higher life expectancy than rest of India. Stable population because of public policy commitment to health care and education.

National Policies:China’s One Child Policy was enacted in the 1970’s to limit China’s population growth. It is very controversial for its creation of a gender gap in China and many other reasons.

#18 Impacts of Human Population Growth

Hunger:  the most commonly used term to describe the social condition of people who frequently experience, or live with the threat of experiencing, the physical sensation of hunger

Malnutrition: is a general term for a condition caused by improper diet or nutrition

Famine: a widespread scarcity of food that may apply to any faunal species, which phenomenon is usually accompanied by regional malnutrition, starvation, epidemic, and increased mortality

Starvation: a "state of exhaustion of the body caused by lack of food." This state may precede death

Disease: a disordered or incorrectly functioning organ, part, structure, or system of the body resulting from the effect of genetic or developmental errors, infection, poisons, nutritional deficiency or imbalance, toxicity, or unfavorable environmental factors; illness; sickness; ailment.

For example, in Kenya AIDS is the leading cause of death and because of the lack of funds they are unable to get necessary medical help.

Habitat Destruction: As human population grows, organism’s habitats are displaced or destroyed, reducing biodiversity. Other organisms that occupied the habitat have reduced the carrying capacity so that populations decline and extinction becomes more likely.

For example, mining, logging, trawling, or urban sprawl are all contribute to habitat destruction.

Economic Effects:

Population growth has very powerful effects on the economy. It is estimated that approximately one acre of land is lost due to expansion and urbanization for every person born in the United States. The more people there are, the lower the standard of living. There is not enough home grown food in the country so food, medicine and supplies have to be imported from other countries, which costs more and affects the economy. The United States is the world’s largest food exporter, and if a higher percentage of our food had to go towards our citizens, then there is a question of the future survival of millions around the world depending on our exports.

Resource Use:A necessary result of increasing population is expansion and urbanization. Unfortunately the land is also affected by these things, including the loss of cropland due to erosion, water logging and salinization. The growing human population also has a significant detrimental intake of our world’s fresh water. The water used in agriculture is being depleted in America at 130% of its recharge rate, proving our lack in making our water resources sustainable in comparison to our population. At the current rate of our usage, even with vast improvement in sustainability, in the next 30 to 50 years, there will be no fossil fuels left on this planet due to human overpopulation.