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78 Cards in this Set
- Front
- Back
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A4 - Hydrogen Sulfide |
Hydrogen Sulfide odor indicates anaerobic conditions long enough for iron reduction to take place |
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A5 - Stratified Layers |
frequent deposition on floodplains leads to many different layers as seen in this indicator |
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A11 - Depleted below Dark Surface |
3/2 dark surface 15 cm thick depleted starts within 30 cm |
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A12 - Thick Dark Surface |
30cm Black surface Dark transition 15cm thick depleted/gleyed |
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S1/F1 - Mucky Mineral |
5cm thick sand 10cm thick fine Starting within 15cm |
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S4/F2 - Gleyed Matrix |
60% or more gleyed matrix within diagnostic zone |
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S5 - Sandy redox |
10cm thick 60% depleted 2% mottles within diagnostic zone |
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S7 - Dark Surface |
3/1 or darker 10cm thick within diagnostic zone dark or depleted below |
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F3 - Depleted Matrix |
60% depleted 5/15cm thick starts within 10/25 cm |
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F6 - Redox dark surface |
3/2 Dark with concentrations 10cm thick Starts within 20cm |
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F7 - Depleted dark surface |
3/2 or darker 20% Depletions starting within 20cm |
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F8 - Redox depressions |
5% concentrations 5cm thick within 10cm |
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Histosol |
40cm+ organic |
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Histic epipedon |
20cm+ organic, aquic or drained |
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Reduction (3) |
Loss of oxygen Gain of hydrogen Gain of electrons |
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Oxidation (3) |
Gain of oxygen Loss of hydrogen Loss of electrons |
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Differences between headslope, sideslope and noseslope |
Headslope - concave, collects Sideslope - straight, transports Noseslope - convex, spreads Hydric soil boundary will be higher in a headslope, lower on a noseslope. |
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Definition of hydric soil |
A soil developed under saturated, flooded or ponded conditions long enough during the growing season to develop anaerobic conditions in the upper part |
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Order of reduction |
O2, NO3, Mn4, Fe3, SO4, CO2 |
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Nitrogen Reduction |
NO3 > NO2 > NO > N2O > N2 NO2 - deadly to babies/wildlife N2O - GHG |
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Manganese reduction |
Mn4+ > Mn2+ Manganic > Manganous Insoluble > Soluble |
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Iron Reduction |
Fe3+ > Fe2+ Ferric > Ferrous Insoluble > Soluble |
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Sulfur reduction |
SO4 > H2S Sulfate > Sulfide Solid > Gas Rotten egg odor |
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Carbon reduction |
CO2 > CH4 Methane - GHG |
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Conditions for redox |
Above biological zero (>5C) Carbon source pH |
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0- 50 cm; Black (N 2/0) loam; weak, fine, granular structure. 50-60 cm; Very dark brown (10 YR 3/1) loam to clay loam; weak, medium, subangular blocky structure. 60-100 cm; Light gray (10YR 7/1) loam with common, medium, prominent red (2.5Y 4/4) mottles; structureless, massive |
Hydric Black, Transition, Depleted |
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0-20 cm; Black (N 2/0) loam; weak, fine, granular structure. 20-50 cm; Pale brown (10YR 6/3) loam with few, fine, distinct strong brown (7.5YR 5/6) mottles; weak, fine, subangular blocky structure. |
Non hydric
6/3, chroma too high |
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0- 25 cm; Dark brown (10YR 3/2) fine sand; weak, fine, granular structure. 25-35 cm; Light gray (10YR 7/2) fine sand with common, medium, distinct light gray 10YR 7/2 and yellowish red (5YR 5/6) mottles; structureless, massive. 35-70 cm; Gray (5YR 5/1) fine sand with few, medium, distinct yellowish red (5YR 5/6) mottles; structureless, massive
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Non-Hydric
Surface not Black Depletions start below diagnostic zone (sand) |
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0- 40 cm; Very Dark Brown (10 YR 2/2); loam; weak, fine, granular structure 40-70 cm; Light gray (10YR 7/2) loam with common, medium, distinct light gray 10YR 7/2 and yellowish red (5YR 5/6) mottles; moderate, medium, subangular blocky structure |
Non-Hydric
Surface not black Depletions outside of diagnostic zone |
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0-100 cm; Black (N 2/0) silt loam, moderate, fine and medium, granular structure. 100-125 cm; Very Dark Brown (10YR 3/1) loam, moderate, medium, granular structure 125-150 cm; Light gray (10YR 7/2) loam with few, medium, distinct light gray 10YR 7/2 and yellowish red (5YR 5/6) mottles; weak, medium, subangular blocky structure. |
Hydric Black, transition, depleted |
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Piezometer vs Well |
Wells let water enter throughout the length, piezometers only allow water to enter at the bottom allowing more detailed data |
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Recharge hydrology |
Gains: Precipitation Surface water Losses: Infiltration Evapitranspiration |
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Discharge hydrology |
Gains: Groundwater Precipitation Surface water
Losses: Evapotranspiration |
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Tensiometer: +30 @ 50cm |
Saturation at 20cm deep |
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Tensiometer: -33kPa @ 50cm |
Field capacity at 50 cm deep |
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Tensiometer: -1500 kPa @ 50cm |
Permanent wilting point at 50 cm deep |
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Consociation |
Dominated by a single soil series |
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Complex |
Dominated by multiple series in a repeating pattern |
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Recharge vs Discharge morphogy |
Recharge = Leeching Discharge = Accumulating |
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Reasons floodplains may not develop Redoximorphic features |
Moving water is rich in oxygen Soils are young due to constant deposition of sediment |
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Typic Medisaprist |
Hydric - sapric histosol |
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Mollic Endoaqalf |
Hydric Aq = aquic Endo = from below |
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Lithic Dystrochrepts |
Non-Hydric Not a histosol/histel Not aquic |
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Alfic Udipsamments |
Non-Hydric Not a histosol/histel Not aquic |
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Typic fluvaquents |
Hydric Aq = aquic Fluv = fluvial (moving water) |
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Lithic Cryofolist |
Non-hydric Histosols EXCEPT Folists |
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Folist |
Organic soil developed due to low temperatures rather than anaerobic conditions |
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Derranged drainage |
Low connectivity Primarily depressional wetlands |
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Dendritic drainage |
High connectivity Primarily riparian wetlands |
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Redox potential definition |
Tendency of a substance to accept (+) electrons and become reduced Used to quantify degree of reduction |
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Influence of pH on redox potential |
Redox potential decreases as pH increases |
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Redox potential of O2 |
320 - 380 mV |
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Redox potential of NO3 |
220 - 280 mV |
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Redox potential of Fe3 |
150 - 180 mV |
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Redox potential of SO4 |
-120 - -180 mV |
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Redox potential of CO2 |
-200 - -280 mV |
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Problems with redox potential |
Multiple couples occur simultaneously giving an average reading Rate of electron donation varies with decay of organic matter Concentration of electron acceptors in constant flux |
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Electrode readings |
Negative means soil is reduced, positive soil is oxidized Lower potential = more available electrons because less are being used |
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Carbon pools (gigatonnes) |
Plants 450 Atmosphere 750 Soil 2 000 Ocean 39 000 Rocks 65 000 000 |
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Soil carbon pool vs atmosphere vs peatlands |
Soils = 3x atmosphere Peat = atmosphere |
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Carbon release from soil |
Drainage Fire Methanogenesis |
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Sulfur cycle |
Sulfate reduction Sulfide lost to atmosphere Returns as acid rain |
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Nitrogen mobility |
NH4 binds to exchange complex, not mobile NO3 is water soluble, highly mobile |
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Peatlands with climate chage or drainage |
Become a carbon source due to increased decomposition |
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Hanging Fen |
Caused by seepage from groundwater |
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Wetland Hydrology |
Timing (growing season) Frequency (50% of years) Duration (morphology) |
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Limnic materials |
Materials deposited in ancient lake beds Marl Coprogenous earth Diatomaceous earth |
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Lakefill |
Vegetation builds from outside in until lake becomes a fen/bog |
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Paludification |
Expansion of peatlands on low gradient land Associated with rising water table |
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Lagg |
Zone of water between bog and upland Higher DOC, bioactivity, nutrients, pH |
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Acrotelm |
Surface aerobic during periods hydrologically active |
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Catotelm |
Bottom Anaerobic Hydrologically inactive |
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Peatland subsidence |
Compression of peat after drainage |
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Neap tide |
Lowest high tide |
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Spring tide |
Highest high tide |
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Flood tide |
Rising Depositional |
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Ebb tide |
Falling Erosional |
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Storm surge |
Higher tide during incoming storms |
