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165 Cards in this Set
- Front
- Back
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Haeckel's definition of ecology
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the study of all of the complex interrelations referred by Darwin as the struggle for existence
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Why are greek philosophers credited with origins of modern science?
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Aristotle and Threophrastus studied the "balance of nature" they wrote about intterelationships between organisms and their environment.
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Which of the following is a focus of modern ecological science
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- Distribution and abundance of organisms
- Flow of energy and matter through the biosphere - Physiological adaptation of oranisms to abiotic factors |
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Branches of Ecology
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-Plant Ecology
-Animal Ecology -Physiological Ecology -Population -Ecosystem |
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Reductionist
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the ecosystem is a sum of its parts. by understanding how each part-the species, characteristics-functions, we can discover how the whole system operates. Rather than guiding the evolution of species, the nature of ecosystems results from the evolution of species
(parts of the clock) |
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Holistic
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studying the total behavior or attributes of a complex system. (pointless to study the parts of the clock, only when they are put together can the clock function)
-emphasis on emergent properties |
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synergystic effect
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It is not uncommon for the effect of two chemicals on an organism to be greater than the effect of each chemical individually, or the sum of the individual effects. The presence of one chemical enhances the effects of the second. This is called a synergistic effect or synergy, and the chemicals are sometimes described as showing synergism.
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Who coined the term ecology?
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Haeckel
"home," "place to live" |
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Darwin
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creattionism can not be right.
fossil record, extinctions, competition, selective pressures "struggle for existence" "descent with modification" |
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Population genetics
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combination of Darwins "survival of the fittest" and Mendels inheritance mechanisms
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inductive method
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Goes from specific to general.
Descriptive/observational science. "natural experiments" |
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deductive method
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general to specific. experimental science. Investigator develops hypothesis then collects data.
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dependent/independent variables
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experimentation involves the determination of the resoponse of one variable, THE DEPENDENT VARIABLE, to variations in an independent variable or variables, manipulated by treatments. The association of the dependent to independent cariables assesses the nature of the response of the dependent cariable and teslls something about the relationship between the two.
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replication, controls
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The experimental approach involves replicates of treatments and controls that do not receive the treatment. Replicates allow the scientist to account for uncontrolled cariations among experimental units; controls form the basis of comparison
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model
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abstraction and simplification of a natural phenomenon developed to predicta new phenomenon or to provide insights into existing ones
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statistical model
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mathematical descriptions of data. predict calue of the dependent variable based on mathematical functions (however not all mathematical models are statistical)
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stimulation model
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take on a variety of forms, including differential equations. Because they can not be solved analytically , simulation models require the use of a computer to arrive at a solution
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abiotic factors
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non-living. ie geological structures, weather, temperature
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climate
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summation of weather over time. A combination of temperature, moisture, precipitation, and winds
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weather
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air in motion driven by unequal heating.
air in motion, results from differential heating and global heat transfer |
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_____ is the major source of thermal energy for earth.
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solar radiation
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solar constant
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amount of solar radiation that reaches the earth's atmosphere. about 2 calories/cm^2
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How much solar light makes it to the earths surface?
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50%
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What happens to solar light that doesnt make it to earths surface?
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25% is reflected from clouds, atmosphere
5% reflected from earth's surface 25% absorbed by dust, water vapor, CO2 in atm |
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___ % of solar radiation is absobed by earth as SHORT WAVE RADIATION
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45
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29% of absorbed radiation is returned to atomsphere by
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thermals and evaporation of surface water
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earths radiation is ____ wave.
88% reflected back to earth by: |
long wave.
CO2, water vapor (greenhouse effect) *provides some stability to surface structures |
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spectrum of radiation changes as it reaches earth.
UV- |
almost all is removed
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atm gasses scatter ___ wave lengths
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short: blue color
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water vapor scatters ___ wave lengths
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all: white + shadow = grey clouds
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dust scatters ___ wave lengths
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long: reds/yellows
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because of the scattering of solar radiation by dues and water vapor, part of it reaches earth as diffuse light from the sky, called...
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skylight
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skylight enables...
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us to see in shaded areas and in twilight
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infrared radiation absorbed..
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IR that reaches earth and is sensed as heat is absorbed and a portion is reradiated back as far infrared
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humidity
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water content of air
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relative humidity
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Relative humidity is defined as the ratio of the partial pressure of water vapour in a parcel of air to the saturated vapour pressure of water vapour at a prescribed temperature.
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absolute humidity
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Absolute humidity is the quantity of water in a particular volume of air
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albedo
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Earth's surface reflects back a percentage of solar radiation impinging on it, called albedo. Varies from region to region
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albedo percentages
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water 2%
snow and ice 45-90 forest/grasslands 5-30 global: poles 50-60 tropics 20-30 |
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vapor pressure
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amount of pressure water vapor exerts
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latent heat of evaporation
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heat absorbed by evaporative processes
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saturation of water in air is ____ dependent
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temperature (warm air holds more water than cold air)
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rain shadow
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air is forced to go over a mountain. As it rises, the air mass cools and loses its moisutre as precipitation on the windward side. The descending air, already dry, picks up moisture from the leeward side
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coriolis effect
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effects of rotation on objects in motion
northern hemisphere: deflection to the right southern hemisphere: defclection to the left |
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hadley cells
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direct circulation cells near equator
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convergence zones have ___ rainfall
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high
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circulation of air:
hight pressure |
(clockwise, downward) dry, clear
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circulation of air:
low pressure |
(counterclockwise, downward)
wet, cloudy |
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ground positions of sun:
t/f all points on earth receive the same amount of light and dark |
true but photoperiod changes with latitude and ground position of sun
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intensity changes with...
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latitude
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gyres
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each ovean is dominated by 2 great circular water motions, each centered on a subtropical high-pressure area north and south of the equator
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polar deep water flow
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carries warm water
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upwellings
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areas in oceans where currents force water from deep within the ocean into the euphotic zone
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climograph
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depicts seasonal climate change in a region by plotting mean monthly tempreatures against mean monthly precipitation
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microclimates
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(not regional climate) the actual climatic conditions under which organisms live. Litter, logs, rocks, and vegetative cover provide microclimatic habitat for organisms
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urban climate and heat islands
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compared with surrounding rural areas, a city has a higher average temp, particularly at night, more cloudy days, more fog, more precipitation, lower rate of evap, lower humidity
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north/south facing slopes
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in the northern hemisphere, south facing slopes recieve the most solar energy
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Corliolis
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rotational effect on paths taking by objects in motion that are not firmly attached to earth
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seasonal change in tropics
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hadley cells, thermal circulation of air, ground position of sun
ITCZ! convergence zone |
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visible light
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part of electromagnetic spectrum btween wavelengths of 400-740
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PAR
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photosynthetically active radiation (visible light)
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UVlight
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seen by bees and fish, short (280-380)
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fate of light
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absorbed, reflected, transmitted
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plants reflect...absorb...
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plants reflect green light most strongly and absorb red wavelenths used in photosynthesis
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light in plant communities
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light passing through a canopy of vegetation becomes attenuated. certain wavelengths drop out before others. in a forest, green and far red wavelengths pass through unaltered
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light in water
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in pure water, red and IR light are absorbed first, followed by yellow, green, and violet; blue penetrates the deepes. natural water is rarely clear, and attenuation is strongly affected by shit in water
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leaf area index
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ratio of area of canopy foilage to ground area
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light extinction coefficient
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k, a measure of the degree to which leaves absorb and reflect light
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photic zone determined by light penetration in water
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blue penetrates furthest in clear water
clays- yellowish, green and red penetrates furthest |
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sunlight penetration in forests:
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may determine distribution of plants based on their shade adaptations
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which wavelength of light penetrates furthest
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blue
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a leaf area index measures
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amount of leaf area per ground area
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heat manifests itself as
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- brownian motion
- kinetic energy - rate of chemical rxns - rate of dissolution |
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absolute zero
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absence of heat, no movement (0 kelvin)
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temperature
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heat content and propensity to give off heat
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thermal limit for animals
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52 c
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thermal limit for plants
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+- 60
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algae thermal limit
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73 c
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thermal limit bacteria
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above 100 c
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radiation
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form of thermal energy exchnage....energy propogated in waves
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conduction
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direct transfer of heat from one object to another
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comvection
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transfer of heat by circulation of fluids, liquids, or gas
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evaporation
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cools a subject bc changing from liquid to vapor
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How does kinetic energy affect rate of chemical reactions
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Temperature is a measure of the kinetic energy of a system, so higher temperature implies higher average kinetic energy of molecules and more collisions per unit time
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rain shadow
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decreasing in abs humidiity with increasing elevation, and decreasing relative humidity with decreasing elevation
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photic zone
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is the depth of the water in a lake or ocean, that is exposed to sufficient sunlight for photosynthesis to occur. The depth of the photic zone can be greatly affected by seasonal turbidity.
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land gradient
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xeric (dry ) -->mesic-->hydric (wet)
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aquatic gradient
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freshwater (hydric) to saltwater (xeric)
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water gradient in estuaries
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vertical and horizontal gradient. salty bottom fresh top. ocean side salty river side fresh.
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properties of water
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polar (cohesion/adhesion), high specific heat, high heat of fusion/evaporation, high viscosity
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distribution of water
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97% ocean
only 3% of global water is freshwater |
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solar energy in evaporated water released as
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1. heat from condensation
2. work as water moves back to sea level |
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what is the driving force of water cycle
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precipitation
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Because of ____, various amounts of water evaporate into the atmosphere without ever reaching the soil surface
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interception
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precipitation moves into soil by...
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infiltration/percolation
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where is most drinking water
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in the aquifer below sand and gravel but above clay layer
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what layer is recharged by rain
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surfical aquifer
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soil-
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results from a combination of abiotic and biological processes acting on sediment or rock
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soil (abiotic)
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weathering, leaching, mechanical breakdown
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soil (biotic)
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accumulation of organic material, acid production
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Horizons
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o, a, e, b, c, r
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o horizon
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surface, litter, duff, no mineral component
greatest change in temp, moisture may fluctuate seasonally most decomposition occurs here |
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A horizon
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first mineral layer, contains organic matter,
mostly DOM Gradient of POM to attenuated DOM leaching of minerals, clays, from water percolation |
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E Horizon
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zone of max leaching of minerals, little organic matter
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B Horizon
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zone of accumulation
silicates, clay, iron, aluminum may be above a solide clay layer |
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C Horizon
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unaltered parent material: marine, alluvial sediment
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R Horizon
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unaltered bedrock
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rock fragments
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greater than 2.0mm
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sand
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.05-2.0 mm
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silt
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.002-.05 mm
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clay
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< 0.002 mm
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well sorted
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only one type (only sand or only clay for example)
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pore/ interstitial space
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determined by texture, 50% pore space is best
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____ is important to soil chemistry/nutrient availability
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clay
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clay mineral structure
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layers of aluminum or silica, net negative charge
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cation exchange in order of binding strength
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al 3+, H+, Ca2+, Mg, k, NH, Na
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cation exchange capacity
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number of cation binding sites per unit soil
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percent base saturation
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% of binding sites occupied by Ca, Mg, K, NA
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soil fertility depends on
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CEC, %BS, salinity, metals
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field capacity
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amount of water held 2-3 days post rain
-consists of capillary and hygroscopic water |
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capillary water
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water help between soil particles
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hygroscopic water
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water ionically bound to particles (not available to plants)
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wilting point
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inability of plants to extract water from the soil
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AWC
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available water capacity....the amount of water retained by the soil between field capacity and wilting point....highest in intermediate clay loam soils
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drainage dependent on
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soil texture
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saturated soils:
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anaerobic, accumulated organic matter, histosols
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histosol
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soil with high organic matter content
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POM
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particulate organic matter
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photosynthesis
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process by which autotrophs use the energy of the sun to convert carbon dioxide and water into carbohydrates
two processes: light and dark rxns |
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light reaction
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initial photochemical rxn where light energy is trapped in chlorophyll and excites it
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what traps light in light rxn
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absorbing pigments called chlorophyll within the cholorplasts
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The absorption of a photon light raises the energyl level of the cholorophyll molecule and makes it unstable...
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the electrons return rapidly to their ground state releasing the absorbed photon energy
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How is the absorbed photon energy released from the chlorophyll?
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1.thermal dissipation
2. flourescence 3. electron transfer |
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thermal dissipation
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released as heat
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flourescence
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emitted as a photon of lower energy content
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electron transfer
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results in ATP from ADP...triggers dark rxn
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Dark reactions
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carbon dioxide is made into chemical energy (reduction of carbon)
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stomata
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opening in leaves that take in carbon dioxide (driven by a diffusion gradient)
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transpiration
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loss of water through stomata opening, a cost associated with the uptake of carbon dioxide
dissipates excess energy |
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aquatic plants
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no stomata, can use bicarbonate
slow diffusion of carbon dioxide from water into leaf |
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rubisco
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carboxylation of ribulose bisphosphate
yields 2 3-pga (C3 plants) |
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C3 cycle
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calvin cycle. involves in fromation of 3-PGA from RuBP.
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Drawback of C3
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Photorespiration: rubisco oxygenates RuBP, releases carbon dioxide, competes with c3 respiration limiting efficiency
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dark respiration
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done in mitochondria, maintenance and growth (energy from carbs)
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C4 cycle
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use a four carbon process in which carbon dioxide taken into the leaf reacts to form malic or aspartic acid, stored in mesophyll cells. The carbon dioxide fixed in these compounds is then released and fixed once again using the calvin cycle in the bundle sheath cells
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c4 plants
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grasses, herbacious plants, sugarcane, etc
high efficiency, little discrimination to carbon isotopes |
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c3 plants
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trees, algae
less efficient, discriminate against 13C |
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CAM
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plants in deserts open stomata and fix carbon dioxide as malic acid at night. By day they close their stomata and use calvin cycle
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light response curve
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function relating the net exchange of carbon dioxide (net photosynthesis) for a plant to the recieved PAR
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light compensation point
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that calue of PAR at which the rate of carbon dioxide uptake in photosynthesis exactly offsets the loss of carbon dioxide in respiration
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light satruation point
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the value of PAR at which any further increase results in no further increase in photosynthesis
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photoinhibition
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slowing or stopping of a plant process by light
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adaptation to light levels
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the reduction of light directly reduces rates of photosynthesis through its impact on light reatctions. to compensate for reduced photosynthetic rate per unit leaf area, plants allocate more carbon to the production of thinner, broader leaves. this shift acts to compensate by increasing photosynthetic suface area
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shade tolerant plants
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low photosynthetic, respiratory, metabolic growth rates
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plants radiation net balance
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the net energy absorbed by a plant
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two ways plants disspate heat energy
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convection and evaporation
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R=
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Rn=M+S+(C+lE)
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R=
M= S= C= E= l= |
Rn=radiation balance
M=light converted to chemical energy S=Light converted to heat energy C= convection E= evaporation includes transpiration (dominates) and evaporation from surfaces l=latenet heat of vaporization |
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What keeps leaves from reaching critical temperatures
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dissipation
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thermal affects on photosynthesis and respiration
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as temps rise above freezing photo and resp rates increase. at higher temps photo rates decline and respiration rates increase
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why do c4 plants carry on photosynthesis at higher temp ranges than c3 plants?
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PEP functions at a higer temp than rubisco
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Net Primary Production, NPP
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is the net amount of primary production after the costs of plant respiration are included. Therefore, NPP = GPP - R
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Gross Primary Production, GPP
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is the total amount of CO2 that is fixed by the plant in photosynthesis.
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xeric adaptation
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Small Waxy leaves
Heavy cuticle Succulent Deep roots |
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hydric adaptations
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Shallow root systems
Kness and pneumatophores Aerenchymous tissue Hollow stems/roots |
