Earth Environment - Chapter 4 Flashcards

1
Q

describe the terrestrial environment from an integrated physical, biological and chemical perspective .

A
  • increase O.matter, H2O and nutrients = increased microbial activity
  • surface area affects ration : adsorptions and retention of H2O
  • air pockets/porous envi and H2O carrier nutrients needed for aerobic microbial growth
  • Cation exchange: bac = -, charged metal (PB2+)= +, soil=- charge
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2
Q

Why might water move so quickly into the saturated zone?

A
  • pores

- mineral particles are layer, therefor, doesn’t hold up H2O

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3
Q

What are some sources of increased acidity in the soil?

A
  • microbes metabolite(fermentation–> acid)
  • increased nitrogen(anthropogenic)–> nitracficiation (add lime to neutralize)
  • increase with time
  • acid rain
  • base cation(Ca2+, K+, Na+) are more easilu released than acid cation
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4
Q

Define surface soil

A
  • weathered end product

- high O Carbon content

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5
Q

Define vadose zone

A
  • low O.carbon content

- decreased H2O movement

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6
Q

Define saturated zone

A
  • shallow or intermediate/ deep aquifers
  • porous parent materials
  • wetlands
  • oligotrophic condition
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7
Q

Id components of soil as it related to microbial activity

A
  • texture: size of mineral particles
  • pore size distribution:
  • organic matter
  • soil structure: aggreigate/size
  • interaggregrate pore
  • intra-aggregrate pore
  • cation exchange
  • soil H2O potential
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8
Q

How can the components of soil vary?

A
  • O matter varies

- pores can vary based on mineral type (sand/small space vs. clay/large spores)

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9
Q

explain how microbial activity can influence the soil atmosphere

A
  • bac attach to porous media
  • leaching: micro-pore exclusion, competitive affinity
  • precipitation of minerals/pesticides–> affect soil solution chem
  • microbial alters N2, O2 and CO2 gases [ ] in saturated levels
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10
Q

soil properties

A
  • texture: size mineral particles
  • structure: aggrigate /size
  • porosity: H2O movement
  • chemistry: cation exchange capacity
  • colour:O..contents, minerals
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11
Q

Soil forming factores

A
  • parent material: rock/mineral that is weathered
  • climate: precipitation +temp
  • Organisms
  • Topography: slide angle and length
  • Time
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12
Q

Weathering created what? and what is released

A
  • sand, silt, clay
  • releases:
    1. minerals in solution
    2. oxides of Fe and Al (negative charge)
    3. silica
    4. stable waste
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13
Q

Phases of typical soil

A
  • pore space
  • mineral
  • organic material
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14
Q

Phases of typical soil

A
  • pore space
  • mineral
  • organic material
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15
Q

Distinguish b/n soil particles and soil aggregrate

A
  • particles: makes up pore

- Aggregrate: inter/intra aggregrate pores

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16
Q

Why do bogs have low microbial activity

A
  • high acidity levels (decrease cation exchange)
  • high O.matters b/e of low microbial activity
  • little H2O movement
17
Q

Why do bogs have low microbial activity

A
  • high acidity levels (decrease cation exchange)
  • high O.matters b/e of low microbial activity
  • little H2O movement
18
Q

Cation exchange capacity

A
  • sum of exchangeable based on soil
  • isomorphic sub
  • Ionization (pH dependent)
19
Q

field Capacity ?

A
  • # of H2O in sol w/ natural saturation

- h2o held naturally with sufficient O2

20
Q

field Capacity ?

A
  • # of H2O in sol w/ natural saturation
  • h2o held naturally with sufficient O2
  • wilt point, h2o films thin around particles (opposite to field capacity )
21
Q

water potential

A
  • work responsible to move a H2O
  • water bound by matric forces, gravity, surface tension, osmosis
  • predicts the ability of env. to move microbes and nutrients
22
Q

Biotic stress

A

competition
predation
parasatism
antibiotice production

23
Q

Abiotic stress

A
light
moisture
Temp
pH
redox potential (not enough E from terminal e-, maintenance not growth
24
Q

Redox potential @ 800

A

O2 to h2o

aerobes

25
Q

Redox potential @ 740

A

no3 to n2 or n2o

facultative anaerobes, nitrate reductions

26
Q

Redox potential @ -220

A

so4 to s

anaerobes, sulfate reduction

27
Q

Redox potential @ -300

A

co2 to ch4

anaerobes, methanogenesis