IB+ESS+EXAM+NOTES

=__** IB ESS EXAM NOTES **__= =__** TOPIC 1: Systems and Models **__=

· **Systems:** an assemblage of parts and their relationship forming a functioning entirety or whole o Open systems: exchanges matter and energy o Closed systems: exchanges only energy o Isolated systems: neither matter nor energy and is theoretical

· **Laws of thermodynamics** o 1st: energy is neither created nor destroyed, only changes forms o 2nd: the entropy of a closed system increases; when energy is transformed into work, some energy is always lost as waste heat

· **Equilibrium** oSteady-state: in open systems, continuous inputs and outputs of energy and matter, system as a whole remains in a constant state, no long term changes. o Static: no change over time; when the state of equilibrium is distributed, the system adapts a new equilibrium; can’t occur in living systems o Stable: the system returns to the same equilibrium after disturbances o Unstable: system returns to a new equilibrium after disturbances

· **Feedback** o Positive: results in a further decrease of output and the system is destabilized and pushed into a new state of equilibrium o Negative: tends to neutralize or counteract any deviation from an equilibrium and tends to stabilize systems · **Transfers and transformations** o Transfers: - The movement of material through living organisms - Movement of material in non-living process - The movement of energy o Transformations - Matter to matter - Energy to energy - Matter to energy - Energy to matter

· **The Gaia model** o Views earth as a living organism o The earth has a “disease”

=__** TOPIC 2: Ecosystems **__=

latent heat: heat that is either taken in or produced when water changes from state to state Different Biomes: It is estimated that tropical rainforest produces 40% of NPP of terrestrial ecosystems. But the problems it has, are that 50% of human population live near the equator, so they damage the biome, they are exploited for human economical needs.
 * Definitions:**
 * Biotic factors: living components
 * Abiotic factors: non-living physical and chemical components
 * Species: a particular type of organism
 * Population: a group of individuals of the same species living in the same area at the same time
 * Habitat: the environment where a species normally lives
 * Ecological niche: how an organism makes a living
 * Community: a group of populations living and interacting with each other in a common habitat
 * Ecosystem: a community of independent organisms (biotic factors) and the physical environment (abiotic factors) which they inhabit
 * Biome: a collection of ecosystems sharing common climatic conditions
 * Respiration: a process of breaking down food in order to release energy
 * Photosynthesis: a process of producers making their own food (glucose) and producing oxygen from water and carbon dioxide
 * Biomass: the living mass of an organism or organisms but sometimes refers to dry mass
 * Gross Productivity: the total gain in energy or biomass per unit area per unit time
 * o GPP: by producers
 * o GSP: by consumers
 * Net Productivity: the total gain in energy or biomass per unit area per unit time after allowing for losses to respiration
 * o NPP: by producers
 * o NSP: by consumers
 * Biomes:**
 * climate
 * latitude (distance from equator)
 * altitude (height above sea level)
 * wind and water currents
 * P/E ratio (precipitation over evaporation ratio)
 * **//Tropical Rainforest//** – hot and wet areas with broadleaved ever green forest. Within 50 north or south of the equator. High rainfall and high temperature, high insolation as near equator. There are amazingly high levels of biodiversity, many species and many individuals of specie. There are very large evergreen trees, small shrubs, orchids.
 * **//Desert//** – dry areas which are usually hot in the day and cold in the night, there are tropical, temperate and cold deserts. It covers 20-30% of earths surface, about 300 of north or south of the equator. Water is limited in the deserts. There are few species and very low biodiversity, there are only the ones who adapted to the conditions. Soil can be rich, because the nutrients are not washed away from the water. NPP is low because the amount of plants and animals are limited, because of the water. Desertification is the human activity.


 * **//Temperate Grassland//** – fairly flat areas, that are covered with grass, they are located 400 – 600 from the equator, either north or south. The net productivity is not very high, because its only grass that grows on the land, nothing else. And with that the animals that are growing are small size as well. Humans use grass lands for the crops.
 * **//Temperate Forest -//** mild climate and deciduous forest. Located 400 – 600 north or south of the equator, it has 4 seasons, there also are fewer species than tropical rainforest, it has the second highest NPP after the tropical rainforest. Much of the temperate forests, have been cleared because of human activities.


 * **//Arctic Tundra –//** Tree less plain with permafrost, cold and very low precipitation, dark nights. It is 10% of lands surface, it is located on the arctic cap. Water is limiting but the fire can stop the climax community forming. There are no trees but there Is a thick mat, covered by mosses and grasses. It has very low biodiversity, and soil is poor. With that the NPP is very low, humans use it for mining.


 * Ecosystem Structure:**
 * Food chains and trophic levels**
 * food chain: shows a flow of energy from one organism to the next
 * food web: shows a complex network of interrelated food chains
 * trophic level: a position that an organism or a group of organisms in a community occupies in a food chain
 * producers or autotrophs: which manufacture their own food from inorganic substances
 * consumers or heterotrophs: which feed on autotrophs or other heterotrophs to obtain energy
 * decomposers: consumers that obtain energy from dead organisms
 * detritivores: consumers that derive their food from detritus or decomposing organic material
 * Ecological pyramids**
 * o pyramid of numbers: shows the number of organisms at each trophic level in a food chain
 * advantages:
 * o easy method of giving an overview
 * o good for comparing changes in population numbers over different times
 * disadvantages:
 * o all organisms included regardless of their size
 * o numbers can be too great to represent accurately
 * o pyramid of biomass: contains the biomass at each trophic level
 * § advantages:
 * overcomes the problems of pyramids of numbers
 * § disadvantages:
 * only uses samples from populations, so it’s impossible to measure biomass exactly
 * organisms must be killed to measure dry mass
 * o pyramid of productivity: contains the flow of energy through each trophic level; shows the energy being generated and available as food to the next trophic level during a fixed period of time
 * § advantages:
 * shows the actual energy transferred and allows for rate of production
 * § disadvantages:
 * very difficult and complex to collect energy data as the rate of biomass production over time is required
 * o bioaccumulation and biomagnification
 * § bioaccumulation: increase in concentration in one organism over time
 * § biomagnification: increase in concentration with the increase in trophic levels
 * o trophic efficiency: only 10% of the energy is transferred to the next, so the trophic efficiency=10%


 * Population Interactions**
 * A population is a group of organisms of the same species living in the same area at the same time and capable of interbreeding.
 * Population density is the average number of individuals in a stated area.

//Competition//
 * Competition between members of the same species is **//Intraspecific//** competition.
 * Individuals of the different species, competeting for the same resource is called **//Interspecific//** competition.
 * The other outcome is that one species may totally outcompete the other, this is the principle of **//Competitive exclusion.//**

//Predation// – happens when one animal, the predator, eats another animal, the prey. //Herbivory// – is defined as an animal eating green plant. //Parasiti//sm - is a relationship between two species in which one species lives in or on another gaining its food from it. //Mutualism// - s a relationship between two or more species in which both or all benefit and none suffer.

=**Succession**= Succession.
 * Succession is the change in species composition in an ecosystem over time
 * It may occur on bare ground where soul formation starts the process or where no soil has already formed, or where the vegetation has been removed.
 * Early in succession, GPP and respiration are low and so NPP is high as biomass accumulates.

To see the stages of primary succession go to page 266. Table 14.1

See Fig. 14.1 on page 266.
 * Primary succession involves the colonization of newly created land by organisms.

See Fig. 14.2 on page 267
 * Primary succession starts on dry land is called a **//xerosere//**. A succession in water is a **//hydrosere.//**


 * Succession progresses in stages from pioneer species, that are adapted to live in limiting environments, to stable developed community. This final community is termed a climax community.

To see the secondary succession process in time, go to page 268 and find Fig. 14.3


 * Secondary succession occurs on souls that are already developed and ready to accept seeds carried in by the wind. Also there are often dormant seeds left in the soil from previous community. This shortens the number of seral stages the community goes through.

Changes occurring during a succession (refer to Fig. 14.4 on page 268) Species diversity in successions
 * the size of organisms increases
 * energy flow becomes more complex
 * soil depth, humus, water-holding capacity, mineral content and cycling increase
 * Biodiversity increases and then falls as the climax community is reached
 * NPP and GPP rise and then fall
 * Production: respiration ratio falls
 * Early stages of succession: few species
 * Species diversity increases with the succession
 * Increase continues until a balance is reached between possibilities for new species to establish, existing species to expand their range and local extinction

=__** TOPIC 3: Human Population, Carrying Capacity and Resource U **____** se **__= = = ** Population dynamics **

** Exponential growth or geometric growth ** When the population is growing, and there are no limiting factors slowing the growth.

** Density-dependent limiting factors (biotic factors when effects depend on the population density) ** · Negative feedback mechanism- lead to stability of the population · ** Internal **– factors act within species 1. Limited food supply lead to intraspecific competition 2. Lack of suitable territory 3. Survival of the fittest <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l2 level1 lfo1; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** External ** – factors act between different species (predation and disease) <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l12 level1 lfo3; tab-stops: 45.0pt; text-indent: -9.0pt;">1. Predation – pray animals increase, predators increase -> pray decreases and the predators decrease <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l12 level1 lfo3; tab-stops: 45.0pt; text-indent: -9.0pt;">2. Disease – at high populations spreads fast ** S-curves ** ** The visual picture of the curves **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l18 level1 lfo4; tab-stops: 45.0pt; text-indent: -9.0pt;">· Start with exponential growth <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l18 level1 lfo4; tab-stops: 45.0pt; text-indent: -9.0pt;">· Then the growth slows down <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l18 level1 lfo4; tab-stops: 45.0pt; text-indent: -9.0pt;">· Finally constant size ** Other facts: ** <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l0 level1 lfo6; tab-stops: 45.0pt; text-indent: -9.0pt;">· Consistent with carrying capacity of the environment <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l0 level1 lfo6; tab-stops: 45.0pt; text-indent: -9.0pt;">· Environmental resistance

** Density-independent limiting factors (abiotic factors when effects do not depend on the population density) ** <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l2 level1 lfo1; tab-stops: 45.0pt; text-indent: -9.0pt;">· Climate <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l2 level1 lfo1; tab-stops: 45.0pt; text-indent: -9.0pt;">· Weather <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l2 level1 lfo1; tab-stops: 45.0pt; text-indent: -9.0pt;">· Volcanic eruptions <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l2 level1 lfo1; tab-stops: 45.0pt; text-indent: -9.0pt;">· Floods

** J- curves ** <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l14 level1 lfo5; tab-stops: 45.0pt; text-indent: -9.0pt;">· “Boom and bust” – population grows exponentially and suddenly collapses <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l14 level1 lfo5; tab-stops: 45.0pt; text-indent: -9.0pt;">· The collapse is referred to as overshoot <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l14 level1 lfo5; tab-stops: 45.0pt; text-indent: -9.0pt;">· The sudden collapse usually caused by abiotic factors <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l14 level1 lfo5; tab-stops: 45.0pt; text-indent: -9.0pt;">· The J-curves usually occur in: <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l1 level1 lfo7; tab-stops: 45.0pt; text-indent: -9.0pt;">1. Microbes <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l1 level1 lfo7; tab-stops: 45.0pt; text-indent: -9.0pt;">2. Invertebrates <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l1 level1 lfo7; tab-stops: 45.0pt; text-indent: -9.0pt;">3. Fish <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l1 level1 lfo7; tab-stops: 45.0pt; text-indent: -9.0pt;">4. Small mammals

** K-and r-selected species ** ** K-selected species **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Long life <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Slower growth <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Late maturity <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Fewer large offspring <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· High parental care and protection <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· High investment in individual offspring <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Adapted to stable environment <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Later stages of succession <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Niche specialists <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Predators <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Regulated mainly by internal factors <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Higher trophic level <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l3 level1 lfo8; tab-stops: 45.0pt; text-indent: -9.0pt;">· Trees, albatrosses, humans

** r-selected species **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Short life <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Rapid growth <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Early maturity <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Many small offspring <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Little parental care or protection <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Little investment in individual offspring <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Adapted to unstable environment <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Pioneers, colonizers <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Niche generalists <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Prey <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Regulated mainly by external factors <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Lower trophic level <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l13 level1 lfo9; tab-stops: 45.0pt; text-indent: -9.0pt;">· Examples: annual plants, flour beetles, bacteria

** K-and r-selected species are extremes of a continuum. Many species are mixture of both characteristics. **

** Demographics – **study of the dynamics of the population change. ** Human Development Index ** – measure: <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l16 level1 lfo10; tab-stops: 45.0pt; text-indent: -9.0pt;">1. Life expectancy <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l16 level1 lfo10; tab-stops: 45.0pt; text-indent: -9.0pt;">2. Well being <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l16 level1 lfo10; tab-stops: 45.0pt; text-indent: -9.0pt;">3. Standards of living <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l16 level1 lfo10; tab-stops: 45.0pt; text-indent: -9.0pt;">4. GDP

** MEDC **- industrialized nations with high GDPs. ** LEDC **- less industrialized nations with lower GDP

** Population growth effects on the environment ** More people- more recourses- more waste- greater impact

** Factors that affect population size: **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l20 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Crude birth rate ** – number of births per thousand individuals in population per year <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l20 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Crude death rate ** – the number of deaths per thousand individuals in a population per year. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l20 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· Immigration <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l20 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· Emigration <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l20 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Natural increase rate ** – ** (crude birth rate – crude death rate) / 10 **, which, gives the natural increase rate as a percentage. It excludes the effects of migration. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l20 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Total fertility rate ** – the average number of children each woman has over her lifetime. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l20 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Fertility rate ** – the number of births per thousand women of childbearing age. In reality, ** replacement fertility ** ranges from 2.03 in MEDCs to 2.16 in LEDCs because of infant and childhood mortality. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l20 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· (Fertility is sometimes considered a synonym for the birth rate)

** Human population growth ** Demography is the study of the statistical characteristics of human populations, e.g. total size, age and sex composition ad changes over time with variations in birth and death rates.

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l7 level1 lfo12; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Carrying capacity ** – the maximum number of a species or “load” that can be sustainably supported by a given environment, without destroying the stock <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l7 level1 lfo12; tab-stops: 45.0pt; text-indent: -9.0pt;">· Populations remain ** stable when birth rate = death rate ** <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l7 level1 lfo12; tab-stops: 45.0pt; text-indent: -9.0pt;">· The size of the population is depended on the wealth of the population <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l7 level1 lfo12; tab-stops: 45.0pt; text-indent: -9.0pt;">· Demand for and the exchange of the resources effects the size <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l7 level1 lfo12; tab-stops: 45.0pt; text-indent: -9.0pt;">· All of the above ** differs in MEDCs and LEDCs **

** Population growth and food shortages **

There are two main theories relating to population growth and food supply, from Malthus and Boserup

** Malthusian theory **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l22 level1 lfo13; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Thomas Malthus ** – English clergyman and economist (1766 to 1834) <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l22 level1 lfo13; tab-stops: 45.0pt; text-indent: -9.0pt;">· Published an essay on the principle of population in 1798 <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l22 level1 lfo13; tab-stops: 45.0pt; text-indent: -9.0pt;">· Claimed that food supply was the main limit to population growth <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l22 level1 lfo13; tab-stops: 45.0pt; text-indent: -9.0pt;">· Believed that human population increases geometrically, whereas food supplies grows arithmetically, and as a result, there are much more humans than food supplies

** Limitations of Malthusian theory **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l10 level1 lfo14; tab-stops: 45.0pt; text-indent: -9.0pt;">· Too simplistic <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l10 level1 lfo14; tab-stops: 45.0pt; text-indent: -9.0pt;">· Shortage of food is just one possible explanation for the slowing in population growth <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l10 level1 lfo14; tab-stops: 45.0pt; text-indent: -9.0pt;">· It is only poor who go hungry <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l10 level1 lfo14; tab-stops: 45.0pt; text-indent: -9.0pt;">· Globalization is something Malthus could not have expected

** Boserup’ theory **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l21 level1 lfo15; tab-stops: 45.0pt; text-indent: -9.0pt;">· Ester Boserup, a Danish economist (1965) <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l21 level1 lfo15; tab-stops: 45.0pt; text-indent: -9.0pt;">· Increase in population would stimulate technologists to increase food production <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l21 level1 lfo15; tab-stops: 45.0pt; text-indent: -9.0pt;">· Rise in population will increase the demand for food and so act as an incentive to change agrarian technology and produce more food <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l21 level1 lfo15; tab-stops: 45.0pt; text-indent: -9.0pt;">· Belief that “necessity is the mother of invention”

** Limitations of Boserup’s theory **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l11 level1 lfo16; tab-stops: 45.0pt; text-indent: -9.0pt;">· Too simplistic view <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l11 level1 lfo16; tab-stops: 45.0pt; text-indent: -9.0pt;">· Like Malthus, his idea is based on the assumption of a “closed” community. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l11 level1 lfo16; tab-stops: 45.0pt; text-indent: -9.0pt;">· Emigration and immigration are not considered <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l11 level1 lfo16; tab-stops: 45.0pt; text-indent: -9.0pt;">· Overpopulation can lead to unsuitable faming

** Family sizes **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l6 level1 lfo17; tab-stops: 45.0pt; text-indent: -9.0pt;">· Appears that decision to have children is not correlated with GNP of a country nor personal wealth: <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l6 level1 lfo17; tab-stops: 45.0pt; text-indent: -9.0pt;">· High infant and childhood mortality <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l6 level1 lfo17; tab-stops: 45.0pt; text-indent: -9.0pt;">· Security in old age <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l6 level1 lfo17; tab-stops: 45.0pt; text-indent: -9.0pt;">· Children are an economic asset in agricultural societies <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l6 level1 lfo17; tab-stops: 45.0pt; text-indent: -9.0pt;">· Status of women <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l6 level1 lfo17; tab-stops: 45.0pt; text-indent: -9.0pt;">· Unavailability of contraception

** The ways to reduce the family size are to: **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l8 level1 lfo18; tab-stops: 45.0pt; text-indent: -9.0pt;">· Provide education <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l8 level1 lfo18; tab-stops: 45.0pt; text-indent: -9.0pt;">· Improve health <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l8 level1 lfo18; tab-stops: 45.0pt; text-indent: -9.0pt;">· Provide contraception <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l8 level1 lfo18; tab-stops: 45.0pt; text-indent: -9.0pt;">· Increase family income <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l8 level1 lfo18; tab-stops: 45.0pt; text-indent: -9.0pt;">· Improve resource management

** Population Pyramids **

These pyramids show how many individuals are alive in different age groups (five-year cohorts) in a country for any given year. They also show the frequency of males and females. In the pyramids, population numbers are on the x-axis and the age groups on the y-axis.

** The shapes of the pyramids are following **:

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l5 level1 lfo19; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Expanding (stage 1) – ** high birth rates; rapid fall in each upward age group due to high death rates; short life expectancy.

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l5 level1 lfo19; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Expanding (stage 2) – **high birth rates; fall in death rates as more living to middle age; slightly longer life expectancy.

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l5 level1 lfo19; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Stationary (stage 3) – **declining birth rate; low death rate’ more people living to old age.

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l5 level1 lfo19; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Contracting (stage 4) – **low birth rate; low death rate; higher dependency ratio; longer life expectancy.

** Demographic transition model: **

Demographic transition model describes the pattern of decline in mortality and fertility (natality) of a country as a result of social and economic development.

This model can be described as a five-stage population model, which can be linked to the stages of the sigmoid growth curve. The stages are: ** Pre- industrial society: ** <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l15 level1 lfo20; tab-stops: 45.0pt; text-indent: -9.0pt;">· High birth rate due to no birth control; <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l15 level1 lfo20; tab-stops: 45.0pt; text-indent: -9.0pt;">· High infant mortality rates; <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l15 level1 lfo20; tab-stops: 45.0pt; text-indent: -9.0pt;">· Cultural factors encouraging large families. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l15 level1 lfo20; tab-stops: 45.0pt; text-indent: -9.0pt;">· High death rates due to disease, famine, poor hygiene and a little medicine. ** LEDC **: <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l4 level1 lfo21; tab-stops: 45.0pt; text-indent: -9.0pt;">· Death rate drops as sanitation and food improve, <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l4 level1 lfo21; tab-stops: 45.0pt; text-indent: -9.0pt;">· Disease is reduced so lifespan increases. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l4 level1 lfo21; tab-stops: 45.0pt; text-indent: -9.0pt;">· Birth rate is still high so population expands rapidly <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l4 level1 lfo21; tab-stops: 45.0pt; text-indent: -9.0pt;">· Child mortality falls due to improved medicine. ** Wealthier LEDC: ** <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l17 level1 lfo22; tab-stops: 45.0pt; text-indent: -9.0pt;">· Birth rats fall due to access to contraception. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l17 level1 lfo22; tab-stops: 45.0pt; text-indent: -9.0pt;">· Improved health care, education and emancipation of women. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l17 level1 lfo22; tab-stops: 45.0pt; text-indent: -9.0pt;">· Population begins to level off and desire for material goods and low infant death rates mean that people have smaller families. ** MEDC **: <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l19 level1 lfo23; tab-stops: 45.0pt; text-indent: -9.0pt;">· Low birth rates <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l19 level1 lfo23; tab-stops: 45.0pt; text-indent: -9.0pt;">· Low death rates <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l19 level1 lfo23; tab-stops: 45.0pt; text-indent: -9.0pt;">· Industrialized countries <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l19 level1 lfo23; tab-stops: 45.0pt; text-indent: -9.0pt;">· Stable population sizes ** MEDC: ** <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l23 level1 lfo24; tab-stops: 45.0pt; text-indent: -9.0pt;">· Population may not be replaces as fertility rate is low. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l23 level1 lfo24; tab-stops: 45.0pt; text-indent: -9.0pt;">· Problems of aging workforce.


 * Food Resources**

Undernourishment, malnourishment – Lack of essential nutrients like proteins, vitamins, minerals.

Agriculture

Types of farming systems

Subsistence farming – the provision of food by farmers for their own families or the local community

Cash cropping- growing the food for the market

Commercial farming- large, profit- making scale maximizing yields per hectare. (monoculture) One type of crop or animal is produced.

Extensive farming – more land with lower density of stocking or planting and lower inputs and corresponding outputs.

Intensive farming – using the land more intensively with high levels of input and output per unit area.

Pastoral farming – raising animals on a land which is not suitable for crops.

Arable farming is sowing crops on good soils to eat directly or to feed to animals

Mixed farming – has both animals and crops and is a system in itself where animals waster is used to fertilize the crops and improve soil structure.

Farming’s energy budget

A system with inputs, outputs, storages and flows = marketable product sold by weight

Energy balance in farming = fuel, labor, any other energy, soil, sow the seed, harvest the crop, prepare and package, transport, energy cost of dealing with waster products.

Grain equivalent – the quantity of wheat grain that would have to be used to produce one kg of that product.

Rice Production in Borneo

- Low inputs of energy and chemicals, high labor intensity and a low productivity. - No fertilizers and pesticides used - Rice yield is only output (no pollution)
 * Traditional, extensive rice production in Indonesian Borneo

- high inputs of energy and chemicals, low labor intensity and a high productivity - diesel and petrol - fertilizers (N, P) Pesticides (insecticides and herbicides) - More energy input than output - More pollution
 * Intensive rice production in California

Fisheries – industrial hunting

According to FAO more than 70% of the world’s fisheries are fully exploited, in decline or seriously depleted. The global fish catch is in decline even though technology has improved. Demand is high and rising but fisherman cannot find or catch enough fish because they are no longer there

The tragedy of the commons - Tension between the common good and the needs of the individual and how they can be in conflict.

Exploitation of the oceans is the tragedy of the commons

The Grand Banks off the coast of Newfoundland were once among the richest fishing grounds on Earth. Since 1400s it’s been depleted by various countries.

The United Nations Convention on Law of the Sea (UNCLOS) – international agreement written over decades that attempts to define the rights and responsibilities of nations with respect to the seas and marine resources.

Maximum Sustainable Yield (MSY)

Sustainable Yield – increase in natural capital

Sustainable yield of the aquifer is the amount that can be taken each year without permanently decreasing the amount of water stored.

SY = annual growth and recruitment – annual death and immigration

Harvesting MSY leads to population decline and thus loss of resource base and an unsustainable industry or fishery.

Optimal Sustainable Yield (PSY) – half the carrying capacity. Safety margin than MSY ut still may have an impact on population size with other environmental impacts.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Resources- Natural Capital <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Natural Capital - Natural resources, services that support life, natural processes. The Goods and services that are not manufactured but have value to humans.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;"> Natural Income – (yield, harvest, services) Yield from the natural capital. <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Renewable Resources – living resources that can replace or restock themselves. (Alternative energy resources) <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Non-renewable resources- exist in finite amounts on Earth and are not renewed or replaced after they have been used or depleted. (Minerals and fossil fuels) <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Replenishable Resources – replaceable but take long period of time. (Groundwater) <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Sustainability – living within the means of nature, on the “interest” or sustainable natural income generated by natural capital.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;"> “Tragedy of commons”- many individuals who are acting in their own self-interest to harvest a resource may destroy the long-term future of that resource so there is none for anyone. __<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Resource Values __ <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Urbanization – the drifts from the countryside to urban life. Urbanization might eventually encroach on or degrade natural habitats of the cities. <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Globalization- Every society on Earth is connected and unified into a single functioning entity. (Global trade) Globalization often leads to westernization. Globalization has facilitated the process of global agreements on global issues. <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Human Carrying Capacity – Maximum number or load of individuals that an environment can sustainably carry or support. <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Ecocentric - reduce the use of non-renewable resources and minimize their use of renewable ones.
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Economic – marketable goods and services
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Ecological- life-support services
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Scientific/technological - applications
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Intrinsic – aesthetic, cultural, spiritual

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;"> Technocentric – human carrying capacity can be expanded continuously through technological innovation and development.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;"> Conventional Economists – trade and technology increase the carrying capacity. <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Ecological Economists – technological innovation can only increase the efficiency with which natural capital is used. <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Reuse- object is used more than once. (Drink bottles, secondhand cars) <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Recycling – objects material is used again to manufacture a ne product. (Aluminum) <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Remanufacturing – object’s material is used to make a new objects of the same type. (Plastic bottles) <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Absolute Reductions – use fewer resources (energy, paper) <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Ecological footprint – area of land that would be required to sustainably provide all of a particular population’s resources and assimilate all its wastes.

** Population dynamics **

** Exponential growth or geometric growth ** When the population is growing, and there are no limiting factors slowing the growth.

** Density-dependent limiting factors (biotic factors when effects depend on the population density) ** · Negative feedback mechanism- lead to stability of the population <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l10 level1 lfo1; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Internal **– factors act within species 1. Limited food supply lead to intraspecific competition 2. Lack of suitable territory 3. Survival of the fittest <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l10 level1 lfo1; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** External ** – factors act between different species (predation and disease) 1. Predation – pray animals increase, predators increase -> pray decreases and the predators decrease 2. Disease – at high populations spreads fast ** S-curves ** ** The visual picture of the curves **

· Start with exponential growth · Then the growth slows down · Finally constant size ** Other facts: ** · Consistent with carrying capacity of the environment · Environmental resistance

** Density-independent limiting factors (abiotic factors when effects do not depend on the population density) ** · Climate · Weather · Volcanic eruptions · Floods

** J- curves ** · “Boom and bust” – population grows exponentially and suddenly collapses · The collapse is referred to as overshoot · The sudden collapse usually caused by abiotic factors · The J-curves usually occur in: 1. Microbes 2. Invertebrates 3. Fish 4. Small mammals

** K-and r-selected species ** ** K-selected species **

· Long life · Slower growth · Late maturity · Fewer large offspring · High parental care and protection · High investment in individual offspring · Adapted to stable environment · Later stages of succession · Niche specialists · Predators · Regulated mainly by internal factors · Higher trophic level · Trees, albatrosses, humans

** r-selected species **

· Short life · Rapid growth · Early maturity · Many small offspring · Little parental care or protection · Little investment in individual offspring · Adapted to unstable environment · Pioneers, colonizers · Niche generalists · Prey · Regulated mainly by external factors · Lower trophic level · Examples: annual plants, flour beetles, bacteria

** K-and r-selected species are extremes of a continuum. Many species are mixture of both characteristics. **

** Demographics – **study of the dynamics of the population change. ** Human Development Index ** – measure: 1. Life expectancy 2. Well being 3. Standards of living 4. GDP

** MEDC **- industrialized nations with high GDPs. ** LEDC **- less industrialized nations with lower GDP

** Population growth effects on the environment ** More people- more recourses- more waste- greater impact

** Factors that affect population size: **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l56 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Crude birth rate ** – number of births per thousand individuals in population per year <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l56 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Crude death rate ** – the number of deaths per thousand individuals in a population per year. · Immigration · Emigration <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l56 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Natural increase rate ** – ** (crude birth rate – crude death rate) / 10 **, which, gives the natural increase rate as a percentage. It excludes the effects of migration. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l56 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Total fertility rate ** – the average number of children each woman has over her lifetime. <span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l56 level1 lfo11; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Fertility rate ** – the number of births per thousand women of childbearing age. In reality, ** replacement fertility ** ranges from 2.03 in MEDCs to 2.16 in LEDCs because of infant and childhood mortality. · (Fertility is sometimes considered a synonym for the birth rate)

** Human population growth ** Demography is the study of the statistical characteristics of human populations, e.g. total size, age and sex composition ad changes over time with variations in birth and death rates.

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l23 level1 lfo12; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Carrying capacity ** – the maximum number of a species or “load” that can be sustainably supported by a given environment, without destroying the stock · Populations remain ** stable when birth rate = death rate ** · The size of the population is depended on the wealth of the population · Demand for and the exchange of the resources effects the size · All of the above ** differs in MEDCs and LEDCs **

** Population growth and food shortages **

There are two main theories relating to population growth and food supply, from Malthus and Boserup

** Malthusian theory **

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l59 level1 lfo13; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Thomas Malthus ** – English clergyman and economist (1766 to 1834) · Published an essay on the principle of population in 1798 · Claimed that food supply was the main limit to population growth · Believed that human population increases geometrically, whereas food supplies grows arithmetically, and as a result, there are much more humans than food supplies

** Limitations of Malthusian theory **

· Too simplistic · Shortage of food is just one possible explanation for the slowing in population growth · It is only poor who go hungry · Globalization is something Malthus could not have expected

** Boserup’ theory **

· Ester Boserup, a Danish economist (1965) · Increase in population would stimulate technologists to increase food production · Rise in population will increase the demand for food and so act as an incentive to change agrarian technology and produce more food · Belief that “necessity is the mother of invention”

** Limitations of Boserup’s theory **

· Too simplistic view · Like Malthus, his idea is based on the assumption of a “closed” community. · Emigration and immigration are not considered · Overpopulation can lead to unsuitable faming

** Family sizes **

· Appears that decision to have children is not correlated with GNP of a country nor personal wealth: · High infant and childhood mortality · Security in old age · Children are an economic asset in agricultural societies · Status of women · Unavailability of contraception

** The ways to reduce the family size are to: **

· Provide education · Improve health · Provide contraception · Increase family income · Improve resource management

** Population Pyramids **

These pyramids show how many individuals are alive in different age groups (five-year cohorts) in a country for any given year. They also show the frequency of males and females. In the pyramids, population numbers are on the x-axis and the age groups on the y-axis.

** The shapes of the pyramids are following **:

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l17 level1 lfo19; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Expanding (stage 1) – ** high birth rates; rapid fall in each upward age group due to high death rates; short life expectancy.

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l17 level1 lfo19; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Expanding (stage 2) – **high birth rates; fall in death rates as more living to middle age; slightly longer life expectancy.

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l17 level1 lfo19; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Stationary (stage 3) – **declining birth rate; low death rate’ more people living to old age.

<span style="margin-left: 9.0pt; mso-add-space: auto; mso-list: l17 level1 lfo19; tab-stops: 45.0pt; text-indent: -9.0pt;">· ** Contracting (stage 4) – **low birth rate; low death rate; higher dependency ratio; longer life expectancy.

** Demographic transition model: **

Demographic transition model describes the pattern of decline in mortality and fertility (natality) of a country as a result of social and economic development.

This model can be described as a five-stage population model, which can be linked to the stages of the sigmoid growth curve. The stages are: ** Pre- industrial society: ** · High birth rate due to no birth control; · High infant mortality rates; · Cultural factors encouraging large families. · High death rates due to disease, famine, poor hygiene and a little medicine. ** LEDC **: · Death rate drops as sanitation and food improve, · Disease is reduced so lifespan increases. · Birth rate is still high so population expands rapidly · Child mortality falls due to improved medicine. ** Wealthier LEDC: ** · Birth rats fall due to access to contraception. · Improved health care, education and emancipation of women. · Population begins to level off and desire for material goods and low infant death rates mean that people have smaller families. ** MEDC **: · Low birth rates · Low death rates · Industrialized countries · Stable population sizes ** MEDC: ** · Population may not be replaces as fertility rate is low. · Problems of aging workforce.


 * Energy** **Resources**

· Source – sun. · Fossil fuels are sources of stored energy from the sun · Oil is the economy’s largest source at the moment, supplying 37% of all the energy we use. · Coal is the next largest, supplying 25% · Natural gas supplying 23%


 * How much longer for fossil fuels? **

· Oil – 50 years · Natural gas – 70 years · Coal - 250 years · Will eventually run out, as they are non-renewable energy sources.
 * The common estimates include: **

· Our rate of use · Technologies · Efficiency of humans · How successful humans are at finding new sources · How successful humans are at finding and extracting more. · If the wealth of humans increase · The population of humans · Demand increase or decrease
 * Depends on: **


 * Evaluation of energy sources and their advantages and disadvantages **


 * Non-renewable **


 * Coal (fossil fuel) **

· Fossilized plants laid down in the carboniferous period · Mined from seams of coal which are in strata between other types of rock · May be open cast mined (large pits) or by tunnels underground. · Burnt to provide heat directly or electricity by burning to turbines in power stations.
 * From **

· Plentiful supply · Easy to transport and solid · Needs no processing · Relatively cheap to mine and convert to energy by burning · Up to 250 years of coal left ** Disadvantages **
 * Advantages **

<span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l21 level1 lfo30; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Non-renewable energy source <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l21 level1 lfo30; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Cannot be replaced once used (same for oil and gas) <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l21 level1 lfo30; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Burning releases carbon dioxide which is a greenhouse gas <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l21 level1 lfo30; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Some coals contain up to 10% sulfur. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l21 level1 lfo30; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Burning sulfur forms sulfur dioxide which causes acid deposition <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l21 level1 lfo30; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Particles of soot from burning coal produce smog and lung disease. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l21 level1 lfo30; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Coal mines leave degraded land and pollution. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l21 level1 lfo30; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Lower heat of combustion than other fossil fuels (less energy released per unit mass) ** Oil (fossil fuel) ** ** From ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l12 level1 lfo32; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Fossilized plants and micro-organisms that are compressed to a liquid and found in porous rocks <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l12 level1 lfo32; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Crude oil is refined by fractional distillation to give a variety of products from lighter jet fuels and petrol to heavier diesel and bitumen. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l12 level1 lfo32; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Extracted by oil wells. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l12 level1 lfo32; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Many oil fields are under the oceans so extraction is dangerous <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l12 level1 lfo32; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Pipes are drilled down to the oil-bearing rocks to pump the oil out. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l12 level1 lfo32; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Most of the world economy runs on oil either burnt directly in transport and industry or to generate electricity ** Advantages ** <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l30 level1 lfo33; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· High heat of combustion <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l30 level1 lfo33; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Many uses <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l30 level1 lfo33; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Once found is relatively cheap to mine <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l30 level1 lfo33; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Easily converted into energy ** Disadvantages ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l7 level1 lfo34; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Only a limited supply <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l7 level1 lfo34; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· May run out in 20-50 years <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l7 level1 lfo34; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Gives off carbon dioxide when burned <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l7 level1 lfo34; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Oil spill danger from tanker accidents. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l7 level1 lfo34; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Risk of terrorism in attacking oil pipes <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l7 level1 lfo34; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Greenhouse gas effect ** Natural gas (fossil fuel) ** ** From ** <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l15 level1 lfo35; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Methane gas and other hydrocarbons trapped between seams of rock <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l15 level1 lfo35; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Extracted by drilling like crude oil <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l15 level1 lfo35; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Often found with crude oil <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l15 level1 lfo35; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Used directly in homes for domestic heating and cooking ** Advantages ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l33 level1 lfo36; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Highest heat of combustion <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l33 level1 lfo36; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Lot of energy gained from it <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l33 level1 lfo36; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Ready- made fuel <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l33 level1 lfo36; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Relatively cheap form of energy <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l33 level1 lfo36; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Cleaner fuel than coal and oil ** Disadvantages ** <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l41 level1 lfo37; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Only limited supply of gas but more than oil <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l41 level1 lfo37; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· About 70 years left (according to current usage) <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l41 level1 lfo37; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Gives off carbon dioxide but only half as much per unit of energy produced as coal ** Nuclear fission ** ** From ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l58 level1 lfo38; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Uranium is the raw material. This is a radioactive and is split in nuclear reactors by bombarding it with neutrons <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l58 level1 lfo38; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· As it splits into plutonium and other elements, massive amounts of energy are also released <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l58 level1 lfo38; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Uranium is mined <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l58 level1 lfo38; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Australia has the most known reserves <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l58 level1 lfo38; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Canada exports the most <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l58 level1 lfo38; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Other countries have smaller amounts <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l58 level1 lfo38; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· About 80 years worth left to mine at current rates <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l58 level1 lfo38; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Could be extracted from sea water ** Advantages ** <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l45 level1 lfo39; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Raw materials are relatively cheap once the reactor is built and can last quite a long time <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l45 level1 lfo39; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Small mass of radioactive material produces a huge amount of energy <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l45 level1 lfo39; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· No carbon dioxide released nor other pollutants (unless there are accidents) ** Disadvantages ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l38 level1 lfo40; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Extraction costs high. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l38 level1 lfo40; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Nuclear reactors are expensive to build and run <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l38 level1 lfo40; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Nuclear waste is still radioactive and highly toxic <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l38 level1 lfo40; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Big question of what to do with it <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l38 level1 lfo40; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Needs storage for 1000s of years <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l38 level1 lfo40; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· May be stored in mine shafts or under the sea <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l38 level1 lfo40; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Accidental leakage of radiation can be devastating. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l38 level1 lfo40; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Accidents are rare but worst nuclear reactor accident at Chernobyl, Ukraine was in 1986 <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l38 level1 lfo40; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Risk of uranium and plutonium being used to make nuclear weapons ** Renewable ** ** Hydroelectric power (HEP) ** ** From ** <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l4 level1 lfo41; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Energy harnessed from the movement of water through rivers, lakes and dams to power turbines to generate electricity <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l4 level1 lfo41; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Pumped-storage reservoirs power turbines ** Advantages ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l13 level1 lfo42; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· High quality energy output compared with low quality energy input <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l13 level1 lfo42; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Creates water reserves as well as energy supplies. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l13 level1 lfo42; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Reservoirs used for recreation, amenity <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l13 level1 lfo42; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Safety record is good. ** Disadvantages ** <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l20 level1 lfo43; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Costly to build <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l20 level1 lfo43; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Can cause the flooding of surrounding communities <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l20 level1 lfo43; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Dams have major ecological impacts on local hydrology <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l20 level1 lfo43; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Silting of dams <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l20 level1 lfo43; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Downstream lack of water <span style="display: block; margin-left: 1.25in; mso-add-space: auto; mso-list: l20 level1 lfo43; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Risk of flooding if dam bursts ** Biogas ** ** From ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l40 level1 lfo44; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Decaying organic plant or animal waste are used to produce methane in biogas generators or burnt directly as dung/plant material <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l40 level1 lfo44; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· More processing can give oils which can be used as fuel in vehicles instead of diesel fuel = biofuels ** Advantages ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l31 level1 lfo45; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Cheap <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l31 level1 lfo45; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Available <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l31 level1 lfo45; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· If the crops are replanted, biogas can be a long-term, sustainable energy source ** Disadvantages ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l32 level1 lfo46; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· May be replacing food crops on a finite crop land and lead to starvation <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l32 level1 lfo46; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· When burnt, it still gives off atmospheric pollutants, including greenhouse gases. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l32 level1 lfo46; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· If crops are not replanted, biomass is a non-renewable resource. ** Wood ** ** From ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l42 level1 lfo47; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Felling or copping trees. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l42 level1 lfo47; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Burnt to generate heat and light ** Advantages ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l22 level1 lfo48; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Cheap <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l22 level1 lfo48; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Available <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l22 level1 lfo48; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· If the crops are replanted, biogas can be a long-term, sustainable energy source ** Disadvantages ** <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l48 level1 lfo49; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Low heat of combustion <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l48 level1 lfo49; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· Not much energy released for its mass <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l48 level1 lfo49; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· When burnt, it gives off atmospheric pollutants, including greenhouse gases <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l48 level1 lfo49; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· If trees are not replanted wood is a non-renewable resource. <span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l48 level1 lfo49; text-align: justify; text-indent: -.25in; text-justify: inter-ideograph;">· High cost of transportation as high volume. ** Solar photo volcanic cells **

** From ** · Conversion of solar radiation into electricity via chemical energy

** Advantages ** · Infinite energy supply · Safe · Low quality energy converted to high.

** Disadvantages ** · Manufacture and implementation of solar panels can be costly. · Need sunshine, do now work in the dark

** Solar-passive **

** From ** · Using buildings or panels to capture and store heat

** Advantages ** · Minimal cost if properly designed.

** Wind **

** From **: · Can be found singly, but usually many together in wind farms

** Advantages ** · Clean energy and supply once turbines made · Little maintenance required

** Disadvantages ** · Need the wind to blow · Often windy sites not near highly populated areas · Manufacture and implementation of wind farms can be costly · Noise pollution · Some local people object to on-shore wind farms, arguing that it spoils countryside · Question of whether birds are killed or migration routes disturbed by turbines

** Tidal **

** From **: · The movement of sea water in and out drives turbines · A tidal barrage is built across estuaries, forcing water through gaps · In future underwater turbines may be possible out at sea and without dam

** Advantages ** · Should be ideal for an isolated country such as the UK · Potential to generate a lot of energy this way · Tidal barrage can double as bridge, and help prevent flooding

** Disadvantages ** · Very costly · Few estuaries are suitable · Opposed by some environmental groups as having a negative impact on wildlife · May reduce tidal flow and impede flow of sewage out to sea

** Wave **

** From ** · The movement of sea water in and out of cavity on the shore compresses trapped air, driving a turbine

** Advantages ** · Should be ideal for an island country · These are more likely to be small local operations · Can be done on a national scale

** Disadvantages ** · Construction can be costly · May be opposed by local or environmental groups. · Storms may damage them

** Geothermal **

** From ** · It is possible to use the heat inside the Earth in volcanic regions. · Cold water is pumped into the Earth and comes out as steam · Steam can be used for heating or to power turbines creating electricity.

** Advantages ** · Infinite energy supply · Is used successfully in some countries, such as New Zealand.

** Disadvantages ** · Can be expensive to set up · Only works in areas of volcanic activity · Geothermal activity might calm down, leaving power station redundant · Dangerous underground gases have to be disposed carefully

** Nuclear fusion **– energy can be released by the fusion of two nuclei of light elements

=__** TOPIC 4: Biodiversity and Conservation **__= <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">To see all 6 mass extinctions refer to the Table on page 95
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Background and Mass Extinctions **
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">background extinction rate- natural extinction rate for species
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">E. O. Wilson- a biologist at Harvard, thinks that the current rate of extinction is 1000 times the background rate and is caused by human activities
 * //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">hotspots //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">- areas where species are more vulnerable to extinction
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Biologists thing: we are the sixth mass extinction called the //Holocene extinction event//
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">The Sixth Mass Extinction **
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">far greater than any in the past
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">already wiped out many large mammal and flightless bird species
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">humans alter the landscape on an unprecedented scale
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">previous mass extinctions were due to physical (abiotic) causes over long time spans
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">current mass extinction is caused by humans (biotic causes) and is accelerating
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">humans:
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">transform the environment
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">overexploit other species
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">introduce alien species
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">pollute the environment


 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Worldwide Fund for Nature produces periodic report called the Living Planet Report
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">measures trends in the Earth’s biological diversity


 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">two phases to the sixth mass extinction
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">1. when modern humans spread over the Earth about 100 000 years ago
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">2. when humans became farmers 10 000 years ago


 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Hotspots **
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">some regions have more biodiversity than others
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">in hotspots there are unusually high numbers of //endemic species//- those only found in that place
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">tend to be nearer the tropics and are often tropical forests
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">tend to have large densities of human habituation nearby
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Keystone Species **
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">species that have a bigger effect on their environment than others
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">act as keystone in an arch, holding the arch together
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">their disappearance can have an impact far greater than and not proportional to their numbers or biomass
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">could destroy the ecosystem or imbalance it greatly


 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Example: elephants in the African savanna act as engineers, removing trees, after which grasses can grow
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Types of Diversity **
 * //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Biodiversity- //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;"> the numbers of species of different animals and plants in different places
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">can be considered at three levels:
 * § //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Genetic diversity- //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">the range of genetic material present in a species or a population
 * § //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Species diversity- //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">the number of different species within a given area or habitat
 * § //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Habitat diversity- //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;"> the number of different habitats per unit area that a particular ecosystem or biome contains
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Simpson’s diversity index- measure species diversity in an area
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Simpson’s reciprocal index- in which 1 is the lowest diversity
 * <span style="font-family: Calibri,sans-serif; font-size: 11pt;">[[image:livingearth/04050305.jpg caption="04050305.jpg"]] <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">where //N =// the total number of organisms of all species and //n =// the total number of organisms of a particular species


 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">How New Species Form **
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Charles Darwin proposed the theory of evolution which is outlined in The Origin of Species, published in 1859
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">The theory is summarized bellow
 * o //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Speciation- //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">when species are formed by gradual change over a long time
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">when populations of the same species become separated, they cannot interbreed and may start to diverge if the environments they inhabit change
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">separation may have geographical or reproductive causes; humans speed up speciation by artificial selection of plants and animals and by genetic engineering
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">over time the population gradually changes= //natural selection//
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">“the survival of the fittest”


 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Physical Barriers (examples of species and speciation)
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Large flightless birds (e.g. emu, ostrich, rhea, cassowary) only found in Africa, Australia, South America
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">cichlid fish in the lakes of East Africa, Lake Victoria, Lake Tanganyika, Lake Malawi
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Llamas and camels (llamas in South America and camels in Africa and central Asia)


 * //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Land bridges: //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">allow species to invade new areas
 * //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Continental drift: //<span style="font-family: Sylfaen,serif; font-size: 12pt;">the movement of tectonic plates
 * //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Plate tectonics: //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">the study of the movement of plates (continental drift)
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Plates may either slide past each other, diverge, or converge
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Factors that help to maintain the biodiversity **
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">complexity of the ecosystem
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">stage of succession
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">(lack of) limiting factors
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">inertia
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Factors that lead to loss of biodiversity **
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Natural hazards
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">loss of habitat
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">fragmentation of habitat
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">pollution
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">overexploitation
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">introducing non-native (exotic species)
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">spread of disease
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">modern agricultural practices
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">What makes a species prone to extinction? **
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">narrow geographical range
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">small population size of reclining numbers
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">low population densities and large territories
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">few populations of the species
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">a large body
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">low reproductive potential
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">seasonal migrants
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">poor dispersers
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">specialized feeders or niche requirements
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">hunted for food or sport
 * //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">minimum viable population size: //<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">that is needed for a species to survive in the wild is a figure that scientists and conservationists consider
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Species Examples (recovered, extinct, endangered) **
 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Recovered Species
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Australian saltwater crocodile
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">18 out of 23 were once endangered
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">listed as protected species in Australia in 1971
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">overexploited for skin (leather), meat and body parts through illegal hunting, poaching and smuggling
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">restored through ranching and closed-cycle farming
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Golden lion tamarin (GLT) recovered or not?
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">small monkey
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">endemic to Atlantic coastal rainforests of Brazil
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">omnivores
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">only 2% of their native habitat is left
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">poachers earn US$20 000 for skin
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">captive breeding program
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">some re-introduced to the wild but with only 30% of success
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">their future uncertain


 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Extinct Species
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Thylacine (Tasmanian tiger)
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">life expectancy of 12-14 years
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">habitat: open forests and grassland
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">competed with dingoes on the mainland of Australia
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">hunted by farmers whose stock of sheep was the species’ prey
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">hunting, poisoning, and trapping
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">shooting parties organized for tourists’ entertainment
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">last one has been killed in 1930
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">now introduced dogs have taken over the ecological role of the thylacine
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Dodo
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">large flightless bird endemic to the island of Mauritius
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">ground-nesting bird
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">1505 Portuguese sailors ate dodo as a source of fresh meat
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">new species introduced that ate dodo
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">humans killed the birds for sport
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">destruction of habitat
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">extinct by 1681
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">fauna impoverished by its loss
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">became an icon due to its apparent stupidity


 * <span style="background-color: #ffffff; font-family: 'Times New Roman',serif; font-size: 12pt;">Endangered species
 * o <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Rafflesia
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">tropical parasitic plant in the forests of South-East Asia
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">single sexed
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">pollination must be carried out when the plant in bloom
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">vulnerable because they need specific conditions to survive
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">deforestation and logging destroy their habitat
 * § <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">now there are Rafflesia sanctuaries

=__** TOPIC 5: Pollution Management **__=

· Pollution: the addition of substances to the biosphere by human activity, at a rate greater than could be rendered harmless by the env-t

- __Major sources of pollution (table on p. 277)__ · Combustion of fossil fuels · Domestic waste · Industrial waste · Agricultural waste

- __Point source pollution__ · the release of pollutants from a single, clearly identifiable site(e.g factory chimney, waste disposal pipe) · easier to locate à easier to manage

- __Non-point source pollution__: the release of pollutants from numerous, widely dispersed origins (e.g. vehicles, chemical spreads on fields) · Difficult to locate · General restrictions could be put to control it

__ Detection and monitoring of pollution __

· Indicator species: species that are only found if the conditions are either polluted or unpolluted

- __Biochemical oxygen demand (BOD)__ · The measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity · Indirect pollution measurement · Higher BODà more pollution

- __Biotic index__ · A 1 to 10 scale · Gives a measure of the quality of an ecosystem by the presence and abundance of the species living in it · Indirect method · Used at the same time as BOD measurements

- __Three-level model of pollution management__ · a model for reducing the impact of pollutants · “replace, regulate, restore” model · Refer to figure 15.3 on page 282 · Pollution management strategies (refer to case study on p282-283)

- __Domestic Waste (Solid domestic waste or municipal solid waste)__ · Makes up about 5% of total waste · 3kg of solid waste per capita in USA · solid waste production has risen from 300kg per year in 1985 to 500


 * Strategies to minimize waste **

- __Recycling__ · Collecting and separating waste materials and processing them for reuse · E.g. aluminum cans o Only 5% of energy needed to recycle it o Can be recycled indefinitely

- __Disposal of waste: Landfill__ · Waste buried in a suitable site · Lined with special plastic liner to prevent leachate (liquid waste) from seeping out · Produced methane could be used to generate electricity

- __Disposal of waste: Incinerators__ · Burning of waste at high temperatures · Heat produced is used (heat-to-energy incineration) · Smaller land area used than in landfill · Ash from incinerators could be used in road building · Expensive

- __Disposal of waste: organic waste__ · Could be composted or put into anaerobic digesters · Produced methane could be used as fuel

__ Eutrophication __

· The addition of excess nutrients to a freshwater ecosystem · Could be a natural process · Usually nitrates and phosphates from: detergents, fertilizers, sewage etc.

- __The process of eutrophication__ · Fertilizers wash into a river or lake · High levels of phosphate allow faster algae growth · Algal blooms block the sunlight · More algaeà more food for zooplanktonàmore food for fishàless zooplankton · Algae die and are decomposed · Not enough oxygen in wateràfood chains collapseàorganisms die · Dead organic material forms sediments on the river bed and turbidity increases · A clear blue lake is left Reduces biodiversity in slow-moving water bodies, temporary reduction in biodiversity in fast-moving waters

- __Eutrophication management strategies (refer to table 15.4 on p. 287)__

- __Impacts of eutrophication__ · Bad smell · Rivers/lakes covered by green algal scum and duckweed · Anaerobic water (oxygen-deficient) · Loss of biodiversity and shortened food chains · Death of higher plants · Death of aerobic organisms – invertebrates, fish and amphibians · Increased turbidity

__ Introduction to ozone __

Found in stratosphere, where it blocks UV radiation, and troposphere

- __Depletion of stratospheric ozone__ · // The ozone layer // o Reactive gas mostly found between 20 and 40km altitude o Made from oxygen (O2) o UV radiation is absorbed in its formation and destruction o The ozone layer absorbs more than 99% of UVC radiation · // Damaging effects of UV radiation // o Mutation o Damage to photosynthetic organisms o Damage to consumers of photosynthetic organisms o C

- __The action of ozone depleting substances__ · Liming lakes: adding powdered limestone raises the pH but the effects are short-lived · Reducing emissions: reducing combustion of fossil fuels o Precombustion: removing sulfur from the fuel before combustion o “end of pipe measures”

= = =__** TOPIC 6: The Issue of Global Warming **__= = = =__** TOPIC 7: Environmental Value Systems **__=

**Environmental philosophies** o Ecocentric: life-centered, respects rights of the nature and the dependence of humans on nature o Technocentric/Anthropocentric: human-centered, humans are not dependent on nature, but nature is there to benefit the human kind

**Technocentric worldviews** o Cornucopians: people who see the world having infinite resources to benefit humanity. Believe that the env-tal problems could be solved with technologies, improving our living standards o Env-tal managers(stewardship): believe that we have an ethical duty to protect the nature. Support limited limiting resource exploitation. Believe that if we look after the planet, it looks after us = = **Ecocentric worldviews** o Biocentric: all life has an inherent value, not just for humans. Some philosophies believe that humans aren’t any more important than other species. o Soft technologists: believe in small-scale local community action and emphasize the role of individuals making a difference o Deep ecologies: put more value on nature than humanity. Believe in biorights – universal rights of all species and ecosystems; advocate strong policy and population change
 * · Nurturing vs. intervening or manipulative approaches= environmental vs. technocentric worldviews

**Various environmental worldviews** o Communism and capitalism in Germany - disregarding value of the environment and exploiting resources o Native American - Use low impact technologies and respect nature - Polytheistic religion believes that animals and plants have a spirituality o Modern Western - view earth as a resource for humanity. - Ecofeminists · argue that it is the rise of male-dominated species that has led to our view of nature as a foe o Buddhism’s view - believe that we are all dependent on each other and preaches that all being are equal - believe that all living organisms share the conditions of birth, old age, suffering and death