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| 455726862 | Key Concepts | 1. how a system is connected to the rest of the environment 2. how mater and energy flow between parts of a system 3. whether a system is static or dynamic 4. average residence time 5. feedback 6. linear and nonlinear flows | |
| 455726863 | static system | has a fixed condition and tends to remain in that exact condition | |
| 455726864 | dynamic system | changes, continuously, over time | |
| 455726865 | classical stability | static system; constant condition, has disturbing factors but always returns once factor is removed | |
| 455726866 | Equilibrium | "rest point" | |
| 455726867 | Steady-state system | the inputs are equal to the outputs so the amount stored within the system is constant | |
| 455726868 | Equation 1 | I=O+/-DeltaS; I is the input; O is output; DeltaS is change in storage | |
| 455726869 | Average Residence Time | ART=S/F S=the size, F=rate of transfer | |
| 455726870 | Negative feedback | is self-regulating, or stabilizing, the way that steady-state systems can remain in a constant condition | |
| 455726871 | positive feedback | when an increase in output leads to a further increase in output; ex: erosion | |
| 455726872 | flow | an amount transferred | |
| 455726873 | flux | the rate of transfer per unit time | |
| 455726874 | linear process | if you add the same amount of anything to a compartment in a system, the change will always be the same no matter how much you have added before and no matter what else has changed about the system and its environment | |
| 455726875 | nonlinear process | the effect of adding a specific amount of something changes on how much has been added before | |
| 455726876 | lag time | is the delay between a cause and the appearance of its effect | |
| 455726877 | biosphere | the planetary system that includes and sustains life | |
| 455726878 | Curves on a graph | show: 1. a straight line (linear) 2. the positive exponential 3. neg. exponential 4. logistic curve 5. the saturation (Michaelis-Menton) curve | |
| 455726879 | Form of Positive Exponential curve | y=ax^b; a=y-intercept, and b=slope | |
| 455726880 | exponential growth | change is exponential when it increases or decreases at a constant rate per time period rather than by a constant amount (j-curve)..starting out nearly flat then rising steeply | |
| 455726881 | Two important qualities of exponential growth | 1. the rate of growth measured as a % 2. the doubling time in years (70/annual%growthrate) | |
| 455726882 | Growth rate equation | k=R/100; if R=the % change per unit of time | |
| 455726883 | Equation for exponential growth | N=Ne^kt; N=future value, N=present value, e=the base of logs, k=the equality of something increasing or decreasing at a fixed fraction per unit of time | |
| 455726884 | overshoot | exceed graph | |
| 455726885 | collapse | when one decreases greatly in a graph due to the overshoot | |
| 455726886 | Environmental Unity | it is impossible to change only one thing, everything affects everything else | |
| 455726887 | uniformitarianism | that geological and biological processes that occur today are the same kinds of processes that occurred in the past and vice versa; James Hutton | |
| 455726888 | James Hutton | believed earth to be a super organism and he compared the cycling of nutrients from souls and rocks in a stream or river to the cirulation of blood in an animal | |
| 455726889 | Gaia Hypothesis | that life manipulates the environment for the maintenance of life communication among these parts, and the ability to self-generate | |
| 455726890 | Series of Hypothesis | 1. life, since inception, has greatly affected the planetary environment (few scientists would agree) 2. that life has altered earth's environment in ways that have allowed life to persist 3. that life deliberately controls global environmetn (few scientists accept this) | |
| 455726891 | environmental resistance factors | control of pop., disease, lack of food,water,resources,loss of habitat,fires,natural disasters,climate change, competition, predators | |
| 455726892 | vectors | the rats that carried/transferred the bubonic plague | |
| 455726893 | yersinia pestice | causes bubonic plague, got into a flee, didnt affect the flee but flee transported it | |
| 455726894 | West Nile Virus | spread by mosquitos, whos bite infected birds then bit people' quick speed | |
| 455726895 | acute respiratory system | showed that modern transportation and the world's huge human pop. ould lead to the rapid speed of sprea | |
| 455726896 | Concerns that pandemics may increase due to: | 1. as the human pop. grows, people live in new habitats, where previous diseases were 2. strains of the diseased organisms have developed resistance to antibiotics and other modern methods of control | |
| 455726897 | population dynamics | the general study of pop. changes | |
| 455726898 | species | all individuals that are capable of interbreeding and so a species is composed of 1 or more pop. | |
| 455726899 | demography | the statistical study of human pop. | |
| 455726900 | Five Key Properties of any Pop | 1. abundance:size of pop. 2.birth rates 3.death rates 4.growth rates 5.age structure 6. the growth | |
| 455726901 | exponential rate | the annual growth rate is a constant % of the pop. | |
| 455726902 | our history in phases | 1. hunters/gatherers 2. rise of agriculture 3. industrial revolution 4. modernization | |
| 455726903 | logistic growth curve | how the pop. growth will follow a smooth s-shape; discovered by P.F. Verhulst | |
| 455726904 | logistic carrying capacity | assumes a constant environment and a homogeneous pop., constant carrying capacity (unrealistic) | |
| 455726905 | inflection point | the point at which the curve changes (pop. curve; s-shape) | |
| 455726906 | logistic projections assume that: | 1. mortality will fall everywhere and level off when female life expectancy reaches 82 years 2. fertility will reach replacement levels everywhere between 2005 and 2060 3. there will be no worldwide catastrophe | |
| 455726907 | population age structure | the proportion of the pop. of each age group | |
| 455726908 | 4 shapes of age structure | pyramid, a column, an inverted pryamid | |
| 455726909 | pyramid age structure | occurs when a pop has many young people and a high death rate at each age; rapidly growing pop and also a pop with relatively short average lifetime | |
| 455726910 | column shape age structure | occurs when the birth rate and death rate are low and a high % of pop is elderly | |
| 455726911 | bulge structure | occurs if some event in the past caused a high birth rate or death rate for some age group but not others | |
| 455726912 | Inverted pyramid structure | occurs when a pop has more older than younger people | |
| 455726913 | Malthus argument | the power of pop growth is infinitely greater than the power of Earth to produce subsistence | |
| 455726914 | Demographic Transition stages | 1. a decline in death rate 2. high growth rates 3. birth rates drop towards death rates and the growth rate declines eventually to lower or 0 growth 4. birth rate would remain the same while death rate fell 5. a stable phase of low or 0 growth; only when the birth rate declined even further to match the decline in death rate | |
| 455726915 | acute disease/epidemic disease | appears rapidly in the pop affects a comparatively large % of it and then declines or almost disappears for awhile, only to reappear later | |
| 455726916 | chronic disease | always present in a pop, typically occurring in a relatively small but relatively constant % of the pop. ex: heart disease, cancer, and stroke | |
| 455726917 | Total impact of human pop. equation | T=PxI; P=pop size; I=average environmental impact per person | |
| 455726918 | human carrying capacity | how many people can live on earth at the same with, depends on the equality of life people desire and are willing to accept | |
| 455726919 | short term factors | affect a pop during the year in which they become limited ex: disruption of food from drought | |
| 455726920 | intermediate-term factors | those whose effects are apparent after one year but before ten years ex: desertification | |
| 455726921 | long-term factors | those whose effects are not apparent for ten years ex: soil erosion | |
| 455726922 | Methods of Estimating carrying capacity | 1. extrapolate from past growth 2. "the packing problem approach" considers how many people might be packed onto earth; "standing-room-only approach" led to high expectations 3. deep ecology-sustaining biosphere primary moral imperative; says that the whole earth is necessary to sustain life | |
| 455726923 | Two roles science plays with carrying capacity | 1. leading to new knowledge, which inturn leads to new technology 2. scientific methods can be used to forecast a probable carrying capacity once a goal for the average quality of life is chosen; can tell us the implications of our value judgements, but cant provide those value judgements | |
| 455726924 | zero pop growth | a condition in which the human pop on average, neither increases or decreases | |
| 455726925 | Possible Appraoches of Achieving Zero pop growth | -age of first childbearing-simple and effective 2. birth control-breast feeding can delay resumption of ovulation after childbirth 3. national programs to reduce birth rates: requires a change in attitude, knowledge of the means of birth control, and the ability to afford these means | |
| 455726926 | environmental unity | every ecosystem is intertwined and they all affect each other |
