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110 Cards in this Set
- Front
- Back
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Age of Earth? Age of Solar System? Age of the Universe? |
4.54 x 10^9 a 4.57 x 10^9 a 13.8 x 10^9 a |
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Diameter of Universe? Number of stars in Milky Way? Number of galaxies in Universe? Number of atoms in Universe? |
93 x 10^9 light years or 4.3 x 10^23 km 4 x 10^11 5 x 10^11 10^78 - 10^82 |
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The sun is a [blank] type main sequence star with [blank] surface temperature? |
G-type and 5500C |
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List the 3 key properties of a habitable Earth |
1. presence of liquid water over extended (evolutionary) period of time 2. continuous protection from cosmic radiation 3. sufficiently low rate of highly disruptive impacting bodies (comets, asteroids, etc) |
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Describe the Milankovitch cycles |
Eccentricity: Earth encounters more variation in energy it receives when orbit is elongated than when it is circular Tilt: Greater the tilt, the more solar energy the poles receive Precession: Gradual change, or wobble, in orientation of Earth's axis affects relationship b/w tilt and eccentricity |
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What determines concentration of CO2 in Earth's atmosphere? |
CO2 pumped into atmosphere through terrestial and submarine volcanism |
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Deterministic Chaos and it's equation |
Behavior exhibited by a system that is infinitely sensitive to initial conditions Examples: turbulence in fluid flows, meteorology, insect populations xnext = rx(1-x) x is population in particular year, r is growth rate |
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What are implication of deterministic chaos? |
Complex patterns of change do not necessarily arise from complex causes Complex effects can arise from simple non-linear relationships Some natural systems may be inherently 'unpredictable' |
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What is the concept of the exposome? |
Developed to draw attention to critical need for more complete environmental exposure assessment in epidemiological studies Complements the genome by providing a comprehensive description of lifelong exposure history |
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What is the Anthropocene Concept? |
Captures the quantitative shift in the relationship between humans and the global environment. Used as a synonym for the Quaternary for several decades |
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What is temperature? |
Determines which way heat flows and is a manifestation of the amount of heat a body contains. Response of an object to the heat it contains Measures typical speed of motion of the molecules in an object Mass of objects determine how it absorbs heat and also different material |
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What is Heat (energy)? |
Quantity of energy required to give an object its temperature. Form of energy measured in joules |
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What is (Heat) Flow / Flux? |
Rate of energy transfer (between objects) possibly per unit area. Stronger the light, the more energy is transferred in a given time |
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What determines temperature of a planet? |
Heating by incident sunlight. As distance from the Sun increases, the power of the incident light weakens. Variation in heating due to orbit of Earth around Sun (which is elliptical). Net power absorbed by sun is incident power x (1-albedo) |
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What is infrared? What is Earthshine? |
Form of light, but at wavelengths longer than our eyes can see. Planet cools to space by radiating electromagnetic radiation |
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What is the calculation for Earth? |
T^4 = (340 Wm^-2 / 5.67x10^-8 Wm^-2k^-4) x 0.7 = 4.2 x 10^9 K^4 |
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Where Earthshine comes from |
Clouds and greenhouse gases absorb radiation from surface, impeding the surface cooling to space Radiate up and down, adding additional heating to the surface Surface temp is warmer so that it radiates more in order to balance the heating by sunlight and downward IR |
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Describe Troposphere, Tropopause and Stratosphere |
Troposphere is heated from below (rising warm air, descending cool air) Tropopause is the height where vertical mixing stops (temp stops decreasing with height) Stratosphere is heated by absorbing UV light, heated directly and warms with increasing height |
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Describe pressure in the atmosphere |
Pressure always decreases with increasing altitude. Density follows pressure quite closely |
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What is the radiation constant? |
5.67 x 10^-8 Wm^-2K^-4 |
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What is climate forcing? |
Perturbation of the climate Change that is externally imposed on the climate system, as measured by the impact the change has on the top-of-atmosphere radiation balance |
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Describe Ocean warming |
Most absorbed near surface (20 m) Heated from above Stabilize oceans Ocean deeps are the coolest Convection (downward) happens when surface is cooled and saline |
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Describe Thermal Radiation |
1. Overall behavior: hotter objects radiate a more intense flux 2. Idea that the fundamental scale of temperature is kelvin 3. Dependence is steep |
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Recipe for Planetary Temperature |
Calculate solar heating at planet using distance from sun (incident heating) Multiply by (1-albedo) to get flux into planet's climate system Find temperatur that gives a matching flux using CONST x (t + 273C)^4 where CONST = 5.67x10^-8WM^-2K^-4 |
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Characteristic Timescale |
t = C/F where F is flux and C is reservoir If F is one component of a balanced flux, t is an average residence time in the reservoir If F is the net flux (imbalance b/w influx and efflux), t is the time-scale for change in the reservoir |
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Describe Climate Feedback |
Climate system is highly interconnected Various components that affect the global temp in themselves depend on temperature (i.e. water vapor, cloud cover and ice/snow) |
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Water Vapor Feedback |
If output of initial forcing (here temp rises) can initiate a chain of events that leads to an additional forcing in same direction, then feedback is POSITIVE |
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What is the effect of extra GHG |
Increase the altitude pegged to -18degC, thus, assuming the atmospheric lapse rate is unchanged the surface temperature increases Increases the mean height of radiation to space |
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Describe Water Vapor |
Determined by the fast processes of meteorology Human activity has tiny direct control on WV globally Involved in an efficient, fast acting feedback on climate Feedback is positive if any changes (warming or cooling) get amplified Humans do not affect directly |
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What is pressure? |
Enormous numbers of air molecules hitting a surface. These molecules exert a force. More mass -> more molecules -> more force -> greater pressure Warmer -> molecules hit faster -> more force -> greater pressure Measured in Pascals |
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Describe pressure gradient force |
Air tends to flow from high to low pressure Pressure falls with height, so air accelerates vertically Pressure forces balanced by gravity = hydrostatic equilibrium |
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Describe Convergence |
Low pressure - air is flowing inwards Generates vertical motion which then diverges aloft |
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Describe the Coriolis effect |
Overall effect of rotating Earth is, in Northern Hemisphere, deflecting motion to the right Southern Hemisphere to the left Behaves like a force and is proportional to the speed and directed at right angles to motion Arises because we want to measure things relative to rotating Earth |
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Describe some climatic features |
Troposphere air cools as it rises As air cools it can hold less water vapor. The excess water vapor precipitates as rain or snow. Rain happens when air rises |
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Name the three cell zones |
Hadley Ferrel Polar |
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Describe the Hadley Cell (Equatorial Circulation) |
Sun overhead -> lots of solar heating and surface air rises giving convergence Water condenses as air cool so lots of cloud and rain Convergent flow, if over oceans, brings in moisture Dry air diverges aloft and flows away from equator Air descends around 30deg away from upflow and then flows equatorwards ("trade" winds) |
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Describe Polar circulation |
Poles are very cold - little incoming radiation from sun and most energy provided by atmosphere Cold air is dense and sinks -> high pressure and divergent flow at the surface and convergent flow aloft |
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Describe the Ferrel Cell (Mid Latitudes) |
Mid latitudes have warm descending air on the equatorial side and cold air on polar side Cell is weak and discernible with much averaging Flow through Coriolis effect, generates flow that south westerly (from SW) |
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Describe Anticyclones |
Hidden dangers: cold, extreme temps and air pollution High pressure gives low pressure gradients so winds are weak High pressure = diverging air = descending air descending air is dry, so little clouds Winds low so little mixing and air stays where it is for a long time |
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Describe mid-latitude flow |
Gradients give rise to pressure gradients and thus flow Strong temperature gradients exist Speed increases with height - pressure gradient is larger and is Westerly (low pressure on left, wind on back in NH) |
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What are the three types of air streams? |
Warm conveyor Cold conveyor Dry conveyor |
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Describe the Warm Conveyor Belt |
Rises over the cold air (warm air being less dense than cold air) Provides warm wet air which drive the clouds/rain on the cold front |
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Describe the Cold Conveyor Belt |
Runs parallel to the warm front and spirals into the center. Provides the center of the system with wet air |
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Describe the Dry Conveyor Belt |
High air (thus dry) being pulled down Sometimes get cloud clear areas in a depression because of Dry Belt - so called dry slots |
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What is the ITCZ? |
Inter-tropical Convergence Zone. Warm wet air converges here, convects and rises all to the tropopause Air drives the Hadley Circulation with descending air at 30deg |
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Describe the Life Cycle of a Tropical Cyclone |
Need some upper level divergence Divergence generates upwelling and convergence which generates convection (move slowly west) some patches grow to tropical depression - low pressure with organized convection |
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What windspeed is needed for a tropical depression to grow to a storm? cyclone? |
16ms^-1 and 33ms^-1 |
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Describe New Orleans in relation to Hurricane Katrina |
City is vulnerable Located in the delta of the Mississippi Largely below sea level Surrounded by "levees" Area vulnerable to flooding from rain, hurricanes or Mississippi |
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Describe the Fatality Rate of Hurricane Katrina |
80% of New Orleans population evacuated outside the risk area 10% evacuated to shelters 10% remained in flood zone Fatality rate was about 1% similar to other flooding events |
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What are some criticisms? |
Trend in some climate observation doesn't mean it is due to human activities Could be due to natural drivers rather than human induced warming Data records are not homogenous Human driven increase in TCs is not proven |
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Heat Wave Human Impacts |
Excess mortality throughout all of Summer 2003 Big peak in early August Total excess deaths was about 70,000 (7% of "normal" summer death rate) No evidence of "harvesting" as death rate later in year are slightly elevated |
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Describe Eccentricity |
"Stretch" of Orbit Large values correspond to more elliptical orbit More insulation at Perihelion (when Earth is closest to the Sun) and less at Aphelion Average radiation over a year is about the same Northern summers colder when eccentricity large and occurs at Aphelion |
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Describe Obliquity |
Tilt of Axis High (low) obliquity gives more (less) extreme summers and winters |
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Describe Precession |
Where the axis points Changes the dates of the equinoxes, perihelion and aphelion effect to change amplitude of seasonal cycle - modulated by eccentricity |
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CO2 during Glacial/ Interglacials |
Methane (CH4) thought to be a proxy for wet tropics. When the tropics are wet then there is a larger emission of CH4 and so larger atmospheric concentrations |
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Describe some Early Anthropocene Mechanisms |
CH4 has short lifetime in the atmosphere so concentration largely reflects source rate CO2 has long lifetime but on 100 to 1000 year timescales is taken up by deep ocean Early farming caused considerable deforestation and CO2 emissions Rice farming causes large CH4 emissions |
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Describe how Parameterization works |
Many processes occur below the grid resolution These need to have their effects represented in terms of the large-scale (resolved) flow Since there is uncertainty in how these processes are represented it leads to uncertainty in model feedbacks and climate sensitivity |
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What are the types of fluxes? |
Evaporation Transpiration (release of water vapor to the atmosphere from plants, largely through pores (stomata) on leaves Evapotranspiration (combined effect of evaporation and transpiration) Precipitation Lateral atmospheric transport |
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What are the factors controlling mean annual runoff? |
R = P - E R is mean annual runoff from drainage basin P is mean annual precipitation across drainage basin E is mean annual evapotranspiration across drainage basin |
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Describe Evaporation |
Kinetic energy of molecules Direction of movement - can be away from surface Increase of kinetic energy with temperature Loss of molecules lowers temperature (evaporative cooling) Balance of molecules into and out of water surface produces water vapor layer that is saturated Availability of water to be evaporated |
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Describe Transpiration |
Water movement from soil -> root -> stem -> leaf -> atmosphere, due to root pressure, capillary action and transpirational pull Leaf area, density of stomata, light (affects opening of stomata), temp, relative humidity, wind, water supply to plant, fine hairs on leaf surface to create high humidity layer |
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Describe potential and actual evapotranspiration |
Potential evapotranspiration: rate of evapotranspiration that would occur under a specific set of conditions given a limitless supply of water Actual: rate of evapotranspiration under a specific set of conditions (rate that actually occurs) |
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What is the Water Balance equation |
P = Q + E + Delta(I + M + G + S) Where p is precipitation, Q is river discharge, E is evapotranspiration, I is interception and biological water storage, M is soil water storage, G is groundwater storage and S is channel/surface storage |
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How was the Salton Sea formed? |
In 1905, heavy rain and snowmelt in the Colorado catchment led to poorly constructed canal system being swamped Lake did not disappear even though it should've. Identified as a useful repository |
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Hoover Dam |
Used to tame the Colorado River |
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What has been the impact on the Grand Canyon? |
Geomorphological impacts: 'beaches' of the Grand Canyon Ecological impacts: habitat changes for fish species and vegetation |
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What were the key impacts in the river regime? |
1. removal of annual spring/early summer snowmelt flood 2. much lower magnitude diurnal flood regime related to HEP generation 3. water flow erosive as 'under-charged' with sediment (clear-water erosion) |
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Why did the 1983 flood occur? |
Water released at the Glen Canyon Dam in 1983 due to risk of overtopping (level of Lake Powell reached just 1.8m below the dam crest) and potential dam collapse Arose b/c inadequate lowering of the lake level in the previous season, long winter and rapid snowmelt, inaccurate weather forecasts and late decision to release water |
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Response to the 1983 flood |
Appreciation of the role of 'natural' flooding in maintaining the geomorphological and ecological characteristics of the Colorado River in the Grand Canyon Prompts move to an approach to river management that attempts to incorporate ecological processes High flow experiments involved controlled flooding |
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Consequence of decline in Arctic sea ice extent |
1. Reduction in albedo (radiation reflected back into space) 2. Change in heat budget through absorption of energy by sea water resulting in changes to patterns of atmospheric pressure 3. Weakening of pressure difference b/w Arctic and mid-latitudes which encourages movement of Arctic air to lower latitudes |
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What are some possible implications for climate of norther Europe? |
Southerly displacement of jet stream in summer associated with wetter summers Higher frequency and persistence of large meanders in jet stream associated with longer periods of similar weather Impact in terms of temp and precipitation of persistent patterns of weather depends on precise location of jet stream meanders |
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Describe the Subak irrigation |
Water irrigation system for rice paddy fields comprising dams, channels, tunnels and flow dividers Water is distributed equally b/w farmers (topographically) higher up and lower down |
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Why is cheating rare at the Subak? |
Everyone belongs to the Subak organization Decisions are made by consensus about irrigation schedule (relates to planting schedule and pest control) Those who do not attend are subject to fines Water supplies can be cut off depending on responsibilities met |
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What is regolith? |
unconsolidated material found overlying bedrock may have formed in situ or been transported by water, wind or ice soil is part of the regolith, and is usually the top part which contains a high concentration of organic material and is affected by weathering |
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Describe O, H, A and E soil profiles |
O: unsaturated organic layer at surface H: saturated organic layer at surface A: mineral horizon at or near surface with humified organic matter associated with mineral E: mineral horizon just below the surface which has lost clay, organic material or iron by downward movement |
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Describe B, C and R soil profiles |
B: subsurface mineral horizon resulting from the change in situ of soil or the washing in of materials from above C: unconsolidated or weakly consolidated mineral horizon which has evidence of rock structure and lack properties of A, E or B R: continuous hard or very hard rock |
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What factors control soil formation? |
Pedological processes: climate biological activity relief parent material (e.g. rock) time S = f(Cl, o,r, p, t) S is any soil property, Cl is climate, o is organism, r is relief/topography, p is parent material, t is time and f is function |
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What is the influence of climate on soil |
Rainfall: lower -> salt crusts/lime layer higher -> leaching of soluble salts, more clays, organic matter, cation exchange and nutrients increase Temp: heavy rain and high temp lead to rapid breakdown of organic material small increase in clay minerals with temp evaporation (impact depends on rainfall) weathering (temp and rainfall) |
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What is the influence of biological activity on soil (micro-organisms) |
Micro-organisms (bacteria, fungi, algae, protozoa) Anaerobic and aerobic bacteria Nitrifying bacteria Denitrifying bacteria Fungi - break down organic material |
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What is the influence of biological activity on soil (macro-organisms) |
Earthwords mix organic and mineral matter arthropods also mix soil slugs and snails breakdown organic material small animals loosen and mix soils |
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What is the influence of biological activity on soil (plants) |
litter and roots supply soil with nutrients and organic matter different types of tree produce different soils seasonal vegetation Rhizosphere around roots important site for exchange nutrients Symbiotic relations with fungi and bacteria |
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What is the influence of relief? |
Altitude: in UK, colder and wetter conditions lead to accumulation of organic material Aspect: warmth of soil Slope: mass movement, overland flow, throughflow, creep Catena: Relationship of soils of similar age with varying characteristics due to variation in relief drainage |
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What is the influence of time? |
Young soils: tend to share features with parent material Pedological begin to mask parent material with time Older soils (mature): in equilibrium with environment often very different from parent old soils can be nutrient poor |
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What are Histosols, Anthrosols and Vertisols? |
Histosol: more than a defined amount of organic material, organic soils Anthrosols: influence of human activities dominates soil formation Vertisols: Clayey soils which crack widely when dry and swell when moist |
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What are Fluvisols, Gleysols, Andosols and Podzols? |
Fluvisol: Soils developed on river deposits showing alluvial stratification Gleysol: Soils dominated by the effects of poor drainage and anaerobic conditions Andosols: Soils composed of volcanic materials, often with a dark colored surface horizon Podzols: Soils with a bleached, ashy colored horizon immediately beneath the surfacce and a spodic B horizon |
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What are Chernozoms and Cambisols? |
Chernozems: Dark colored, deep soils rich in organic matter, and calcareous lower in the profile, associated with prairie/steppe Cambisols: Moderately developed soils with lower horizons and a cambic B horizon |
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Describe Peats (Histosols) |
Form in areas with poor drainage Paludification: organic material undergoes limited decomposition, builds up to form peat deposit Blanket bog: high rainfall, high water table, low temps, acidic Basin bog: low lying damp area, ponds can become bogs as they fill in Raised bog (ombrogenous): domed shape bog which grows above water table, acid, brown peat, maintained solely by rainfall Progressions: basin peats can become raised bogs, blanket bogs can grow to cover landscape Importance: wildlife habitats, carbon reservoirs |
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Describe Gley Soils |
Mineral soils characterized by waterlogging Little water movement and bioturbation Anaerobic conditions lead to iron changing from red/brown to greys Base of slopes, hollows and often have a high clay content Range from all mineral to peaty gley Common on poorly drained ground |
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Describe Podzols |
Formed on acid, coarse grained, well drained materials Surface organic material not broken down (coniferous and heather vegetation difficult to decompose) Iron, Al, nutrients and organic matter are leached from upper horizons and deposited in B horizon (spodic horizon) |
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Describe Brown (Earths) Forest Soils |
Fertile deep soils Deciduous woodland Bioturbation leads to organic material being rapidly broken down Not very acidic or slightly alkaline Important agricultural land (artificially fertilized, aberdeenshire, fife, lothians, SE Scotland) |
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What are the four constituents of soil? |
Mineral (45%) Organic Matter (5%) Water (20-30%) Air (20-30%) |
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Describe Minerals (inorganic content of soil) |
Produced by weathering of parent material In situ or transported from elsewhere Important size ranges from 2mm to < 0.002mm Variations in particle size lead to soil texture |
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What are some primary minerals? |
Quartz, micas and feldspars Sand and slit fraction of soil Persistent products of physical weathering |
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What are some secondary minerals? |
Silicate clays, iron oxides - clays (colloidal organic material) Formed by breakdown and weathering of minerals in soil Clays - kaolinite, smectite and hydrous micas Fine platey minerals which swell when wet Important sites for exchanging (ions) cations and anions |
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Describe Soil Organic Matter |
Living organisms (soil biomass) Remains of organisms Organic compounds Generally only forms 1-6% of mineral soil Forms granular loose soil structure, source of phosphorous, sulphur and nitrogen, Increase amount of water the soil can hold Important part of carbon cycle twice as much carbon stored in soil as vegetation |
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Describe Soil Organic Matter as an Active Pool |
Microbial biomass and easily decomposed compounds Small % of total C, but major role in Carbon Cycle Active fraction declines rapidly when vegetation is cleared |
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Describe Soil Organic Matter as a Passive Pool |
Most of the organic carbon (60-90%) Stable, can remain in soil for 10^3 or 10^4 years Cation exchange sites and water retention |
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Describe Clay-Humus Complex |
Colloidal organic material Complex organic compounds Resistant to decay Important sites for exchanging ions and cations Attract and hold nutrient ions and water Contain hormone-like compounds with aid plants Crucial to soil structure |
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Describe soils influence on organic content |
Climate: Organic content high in cool moist conditions Drainage: Organic content high in poorly drained soil Biomass: Organic content high where root biomass is high |
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Describe soil water |
Moisture regime of soils depends on climate, vegetation, organic content, texture of soils Water held in pores: gravitational water - freely drains, capillary water in fine pores, water molecules attached to minerals, not all soil water is available to plant Soil solution: dissolved compounds and elements |
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What is a biome? |
An intercontinental formation of similar climate and vegetation Characteristic animal and plant adaptations Contains functionally distinct biota Land and water |
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Is it only climate that determines Why What Where? |
No. Soils (nutrients, texture), species (physiology, ecology), history and chance (fire, volcano, humans) |
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Why is it useful to think about WWW and natural systems? |
Classify the biosphere to identify key properties so that we can start to: Identify and analyze causes of change Predict Change |
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How do we classify the biosphere? |
Ecosystem concept: exchange as well as organisms Relationships among organisms (biota) in a given area and their interactions with the physical (abiotic) environment |
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What is Biodiversity? |
Diversity of plant and animal life, as represented by the number of extant species Functional and taxonomic diversity of organisms across all spatial and temporal scales |
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What are the 3 types of species patterns? |
1. Historical factors determine regional pool of species (evolution, climate change) 2. Abiotic factors govern distribution and abundance within the region (pH, rainfall) 3. Biotic factors further govern distribution and abundance within the community |
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What came before the Pleistocene? |
Tectonic movements affecting climate, ocean currents, marine and land area, biotic interactions |
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What are some changes in species patterns? |
Historical processes affecting present patterns Future patterns: possible impacts of change during the 21st century Impact of climate change History a guide to the future Human impacts |
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Biogeographic dynamics in the Pleistocene |
Environment: location, extent, configuration of habitat Changes in nature of climatic zones Formation/ dissolution of dispersal routes Biotic responses: move remain: tolerate or adapt reduction in range, eventual extinctions |
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Predicted rates of change from IPCC? |
Boreal zone: loss or gain in total area Temperate zone: overall gain in area Tropical mountains: upwards by 2-5m/ yr, loss in area Rates of migration larger than Pleistocene changes Scenarios of initial losses: different migration, migrate through fragmented landscapes |
