423 midterm new Flashcards
1
Q
soil
A
- dirt plus organic matter
- Ideally 50% pores of which 50% air
- Nutrients supplied to plants in solution
- Supplies us with nearly all of our food
- all plant nutrients come from the soil except for CO2
2
Q
why is it important to study soil?
A
- they are the medium for plant growth
- nutrient and waste cycling
- habitat for soil organisms
- water supply and purification
3
Q
soil profile
A
- a vertical cross-section of soil that shows the different layers, or horizons, that make up the soil
- Water comes from above,so it flows into the profile, seeps down, dissolves minerals, and moves some minerals downward
- erosion from top, but also from leaching
4
Q
leaching
A
- the process by which water carries nutrients and contaminants out of the soil and into groundwater or surface water
- bad for soils
5
Q
zone of loss
A
- A layer where materials like clay, nutrients, and iron are removed by water percolation
- in A horizon
6
Q
zone of accumulation
A
- The layer of soil where minerals and other materials build up from the A and E horizons above
- in the B horizon
7
Q
o horizon
A
- The organic layers at the soil surface
- Typically at the top of the soil structure
- Referred to as forest floor because they usually occur in forested areas
- Contains humus
8
Q
A horizon (topsoil)
A
- the layers nearest the surface that are dominated by mineral particles but have been darkened by the accumulation of organic matter
9
Q
E horizon
A
- A mineral horizon in the upper part of the soil
- Typically present only in forested areas it underlies an O or A horizon
- Zones of maximum leaching, or eluviation, of clay, iron,and aluminum oxides, which leaves a layer of resistant materials like quartz
10
Q
B horizon
A
- a soil layer that is characterized by an accumulation of minerals like clay, iron, and aluminum that have been leached from the layers above
- Illuviation happens here (when materials come from the layers above)
- Less organic matter and more subsoil (small particles like sand, silt, and clay)
11
Q
C horizon
A
- formed from when plant roots and microorganisms extend below the B horizon and cause chemical changes in the soil water
- This is the least weathered part of the soil profile
- Little or no humus accumulation or soil structure development
12
Q
R horizon
A
- The layer of partially weathered or unweathered bedrock at the base of the soil profile
- Continuous masses of hard rock (bedrock)
13
Q
CLORPT
A
- Climate Organisms Relief Parent Material Time
- what contributes to soil formation
14
Q
C-Climate
A
- Weather you get leaching or not has to do with evaporation vs precipitation
- If there is more precipitation than evaporation, then you get leaching
- Minerals stay around longer, and less translocation, in a dry climate
15
Q
weathering (physical vs chemical)
A
- Any minerals exposed to the surface/ the weather will get broken down; change in the particles mostly from larger to smaller
- Physical weathering- the rock breaks into smaller pieces with no chemical change; primary
- Ex: frost wedging, abrasion from wind or water, river currents rounding pebbles
- Chemical weathering- you change the minerals; secondary
- ex: oxidization (rust formation), , the dissolution of limestone through carbonation, and acid rain
16
Q
O-organism
A
- Evergreen trees, also known as conifers, keep their needles or scales all year, while deciduous trees lose their leaves annually
- Earthworms have high Calcium requirement, so they are not in acid soils
17
Q
R- Relief
A
- topography
- Affects erosion, leaching
- Shape of the earth’s surface affects how soil thrives
18
Q
P- Parent material
A
- usually rock, but not always
- Sandstone vs shale
- Sandstone is derived from larger sand-sized particles and shale is made of fine clay particles
- Soil texture: sand, silt, clay
- Limestone vs. serpentine
- Limestone parent material is a sedimentary rock, while serpentine parent material is a metamorphosed igneous rock
19
Q
T-time
A
- Why aren’t all soils old?
- Initially assumed it gets better and better over time
- It does tend to get deeper (except hardpans)
- BUT, in wet climates fertility declines eventually (Australia and tropical rainforests)
20
Q
hardpans
A
- a cemented or compacted and often clayey layer in soil that is impenetrable by roots
21
Q
karst
A
- landscape underlain by limestone, where the dissolving of the bedrock has created sinkholes, sinking streams, caves, springs, and other characteristic features
22
Q
Serpentine barrens
A
- occur as small, one to two acres or larger, openings surrounded by serpentine conifer or woodland communities
- represent the harshest serpentine community
23
Q
thorns
A
- Jesus was crowned with thorns as he was being crucified
- Christ’s thorn (ziziphus spina-christi) is a plant from which these thorns came from, according to legends
- thistles have prickles and they are a symbol of desolation or wilderness
24
Q
Tropical savanna climate (wet season and dry season)
A
- The dry season lasts 5 to 6 months, usually from May to October
- The wet season lasts 5 to 6 months and
lasts from December to March - Consists of small, thorny trees that shed their leaves seasonally
25
Q
why can’t plants take milk
A
- Fat from milk coats the seed and prevents water from coming into the seed
26
Q
why is manure good for plants
A
- it acts as a natural fertilizer, providing essential nutrients like nitrogen, phosphorus, and potassium
- Also improves soil structure by adding organic matter
27
Q
macronutrients vs micronutrients
A
- Macronutrients- essential elements used by plants in relatively large amounts
- plants need plenty of them
- Ex: carbon, hydrogen, nitrogen, oxygen
- Micronutrients- essential elements used in smaller amounts
- Plants don’t need much of them
- Ex: chlorine, iron, Manganese
28
Q
fertilizer
A
- a chemical or natural substance added to soil or land to increase its fertility
29
Q
Phytoliths
A
- A microscopic silica body found in plants
- Act as a physical barrier that can wear down the mouthparts of herbivores when they try to eat the plant
30
Q
organic matter
A
- 2-6% in a fertile soil
- Originates from living organisms, including plant and animal remains in various stages of decomposition
31
Q
Humus
A
- Improves structure
- source of nitrogen, Phosphorus, and sulfur for soils
- a dark, organic material in soil that is formed when plant and animal matter decays
32
Q
why are wetland soils mostly organic matter?
A
- the waterlogged and anaerobic conditions in wetlands significantly slow down the decomposition of plant and animal debris
- This allows organic material to accumulate over time
33
Q
bogs
A
- wet, muddy ground too soft for supporting a heavy body
- Mammoths were buried here because the meat would be preserved
- Anaerobic and have a lot of acidity that make decomposition slow
34
Q
law of the minimum
A
- The growth of an organism is primarily limited by the scarcest essential resource available to it, even if all other resources are abundant
- created by Liebig, the father of artificial fertilizer
35
Q
limiting factors
A
- environmental conditions or resources that restrict the growth of a population
36
Q
total vs available (limiting factor)
A
- “total” refers to the entire amount of a resource available
- “Available” refers to the portion of that resource that is actually accessible and usable
37
Q
Interactions between minerals (serpentine)
A
- Interacts with other minerals through a process called “serpentinization”
38
Q
serpentinization
A
- ultramafic rocks react with water to create serpentinite rock
- Can occur in the seafloor, continental margins, and subduction zones
39
Q
cations vs anions
A
- In order for the plants to take up nutrients, they have to be dissolved (ions)
- Cations-positive charge (ex: calcium, potassium, magnesium)
- Anions- negative charge (ex: chloride (CL-))
40
Q
cation exchange
A
- the process by which positively charged ions (cations) like calcium, magnesium, and potassium, are attracted to and held by negatively charged soil particles like clay and organic matter
41
Q
Calciphiles vs calciphobes
A
- Calciphile-plant that thrives in calcium rich soil
- ex: skunk cabbage
- Calciphobe- plants that can’t thrive in calcium rich soil
- magnolia
42
Q
colloids
A
- Particles in soil that are less than 1 micrometer in diameter
- Made up of clay and organic matter
- Most chemically active part of the soil
- Dissolved mineral ions are attracted to the surface of tiny colloidal particles and essentially “stick” to them
43
Q
young vs old soils
A
- older soils are usually poorer soils
- Few places where there are really really old soils because:
1. rivers change where they’re flowing
2. Erosion - A young soil has a thin A horizon and often no B horizon
- young soils have higher nutrient content due to less weathering and leaching
44
Q
root uptake
A
- The process by which a plant’s roots absorb water and mineral nutrients from the soil
45
Q
mass flow
A
- a gravity-driven movement of a mixture of fluid and debris down a slope
46
Q
interception
A
- the process by which precipitation is captured by vegetation or other surfaces before it reaches the ground
47
Q
diffusion
A
- The natural movement of particles from an area of higher concentration to an area of lower concentration, due to random molecular motion
48
Q
Mid-Atlantic ridge
A
- an underwater valley that tears more and more as the continents slowly move apart
49
Q
continential crust
A
- The outermost layer of Earth’s land, made of igneous, metamorphic, and sedimentary rocks
50
Q
isostacy
A
- the state of gravitational equilibrium where the Earth’s crust “floats” on the denser mantle
- reason why mountains don’t collapse
51
Q
Asthenosphere
A
- a semi-solid layer of Earth’s upper mantle that’s located beneath the lithosphere
- “rock soup”
52
Q
magma (lava)
A
- Magma is molten rock that’s stored beneath the Earth’s surface, while lava is molten rock that reaches the surface through a volcano
53
Q
rifting
A
- Occurs when the Earth’s lithosphere thins and stretches, separating tectonic plates
54
Q
subduction
A
- a convergent plate boundary where one tectonic plate slides beneath another
- During ocean-continent plate boundary, the denser oceanic plate sinks beneath the continental plate, forming a deep trench
- Creates a volcanic arc
- During Ocean-ocean plate boundary, one is pushed under the other (subduction), and this creates a volcanic island arc
55
Q
collision
A
- a place where two or more tectonic plates move towards each other and collide
- During Continent-continent plate boundary, they crumple and uplift, creating large mountain ranges due to neither plate being able to subduct beneath the other because of their similar densities
56
Q
Mt. Everest: Limestone
A
- Mount Everest is located at a continental-continental convergent plate boundary
- The limestone that makes up Mount Everest’s summit was originally deposited on the continental shelf of India
57
Q
hot spots
A
- A volcanic region that sits over a plume of hot mantle material
- fueled by heat deep within the Earth
58
Q
igneous rock
A
- composed of primary minerals (not been chemically altered since they formed as molten lava solidified)
- intrusive and extrusive
59
Q
intrusive igneous rock
A
- forms when magma is trapped deep inside the Earth
- Lava solidifies while it’s trying to come up to the surface
- Ex: Granite
60
Q
extrusive igneous rock
A
- Rocks that form at erupting volcanoes
- The magma erupts at the surface, becomes lava, then solidifies when it is exposed to the relatively cool temperatures of the atmosphere
- Ex: Basalt- formed when lava cools and hardens
- gives rise to good soils
- Main rock of the ocean floor
61
Q
Sedimentary
A
- Rocks broken up into smaller pieces (sediments) that come together and form a new rock
- Happens right off shore where sediments accumulate and then compress into sedimentary rocks
- Sand turns to sandstone, clay goes to shale, limestone forms several different ways
62
Q
metamorphic rock
A
- formed when existing rocks are transformed by heat and pressure
- Ex: Granite to gneiss, shale to slate (sidewalks), Limestone to marble
63
Q
Disintegrate
A
- just break up
- Physical breakdown
- Same minerals we had originally (primary)
64
Q
decompose
A
- chemical reactions/breakdown; secondary minerals
- As a rock breaks up, we get more surface area
- We get potholes as the temperature goes under, above, and then under freezing
65
Q
surface area with rocks breaking up
A
- As a rock breaks up, we get more surface area
66
Q
exfoliation
A
- type of physical weathering that causes rocks to break apart in flat or curved sheet
- ex: granite
67
Q
abrasion
A
- geological process that occurs when particles wear away a surface through:
- Friction
- Fire
- Temperature change
- Pressure release
68
Q
dissolution
A
- the process by which solid materials, like minerals, dissolve into a liquid, usually water
- ex: salt NaCl to Na+ + Cl-
69
Q
Oxidation and reduction (Ox-Redox)
A
- describes the balance between oxidized and reduced forms of elements, like iron, manganese, and sulfur, within a geological environment
- Weakens crystal structure when Fe2+ is oxidized
- Soil color and climate: orange in tropics, not in deserts
70
Q
acidification
A
- a process that increases acidity in the environment, which can impact soil, water, and ecosystems
- ex: carbonation
- CaCO3 + H2CO3 (rainwater) to Ca2+ + 2HCO3- (bicarbonate)
71
Q
caliche
A
- A layer of soil or sediment that has been cemented together by minerals
- same as a hardpan
72
Q
Hydrolysis
A
- water molecule gets added but gets split
- ex: A-B + H20 -> A-H +B-OH
73
Q
hydration
A
- add a water molecule
- CaSO4 + 2H2O → CaSO4·2H2O
74
Q
secondary minerals
A
- Basically anything small
- clay
- very susceptible to weathering
75
Q
resistance to chemical weathering
A
- Varies with climate
- quartz is the most resistant material
- Large mineral grains disintegrate more but decompose less
76
Q
inert gases
A
- no charge, they do not ionize or react
- last group vertically on periodic table
- ex: He, Ne
77
Q
glacial till
A
- a mixture of unsorted sediments that glaciers deposits
- can include clay, sand, gravel, or boulders
78
Q
erosion vs weathering
A
- Erosion is just the movement of rocks and broken down rock material
- weathering is the process of breaking down rocks
79
Q
deposition
A
- Dropping materials that were moved (through erosion) off in a new location
80
Q
lakes vs wetlands
A
- lakes fill in, wetlands are temporary
81
Q
moraine
A
- ridges of till that are deposited by glacial sheets
- Masses of sediments deposited by a glacier
- landfill made of glacial till
82
Q
outwash plain
A
- Plain made of glacial sediments depsited by meltwater
83
Q
Residual soil
A
- a soil formed from, or resting on, consolidated rock of the same kind as that from which it was formed, and in the same location
84
Q
transported soil
A
- Formed from weathered material that has been moved from its original location
- ex: colluvial, alluvial
85
Q
Differential soil
A
- Different parts of a soil mass settle at varying rates, causing uneven settlement
86
Q
anticlines
A
- an arch of rock arranged in layers that bend downward in opposite directions from the top
87
Q
Alluvial
A
- a fan-shaped deposit of sediment (like gravel, sand, and silt) formed when a stream or river flows out of a narrow channel onto a flatter area and slows down, depositing the materials it was carrying
88
Q
colluvial
A
- Loose, weathered material that has accumulated at the base of hillside
- movement on slopes; gravity and water are big helpers
89
Q
floodplains
A
- Land that is prone to flooding, such as when a river overflows its banks
90
Q
deltas
A
- at the mouth of a river
91
Q
fans
A
- A landform created by the deposition of sediment from a fast-moving stream
92
Q
marine parent material
A
- a collection of sediments that have settled to the bottom of the ocean
- the south had marine sediments that aren’t good for soil
93
Q
glacial parent material
A
- glaciall till is a type
- these are materials that are transported and deposited directly by ice
94
Q
aeolian soil
A
- soil that has been deposited by wind, usually made of silt or sand
- sand dunes and loess are types
95
Q
sand dune
A
- mound or ridge of sand or other loose sediments, formed by the wind, especially on the sea coast or in a desert
- Not fertile
- Good aquifers usually come with sand dunes
- made up of larger sand grains than loess
96
Q
distribution of sand dunes
A
- covers 6% of global surface area
- occurs mostly in deserts and arid regions, but also along coasts of seas and rivers
97
Q
loess
A
- material transported and deposited by wind and consisting with of predominantly silt-sized particles
- loess is made up of finer particles than sand dunes
- found in the mid-latitude regions of North America, Asia, and Europe
98
Q
loess plateau
A
- Chinese loess plateau
- surrounded by the yellow river, which is yellow because of the loess that enters through the loess plateau
99
Q
folding under compression
A
- the process where rock layers bend and form folds due to compressive stress
100
Q
colluvium
A
- material that accumulates at the foot of a steep slope
- loose and poorly sorted debris
101
Q
clod
A
- lumps of clay
- clay sticks to itself and absorbs a lot of water
102
Q
soil structure
A
- refers to how clay, silt, and sand are arranged in the soils
- tilthing manipulates the soil structure to get plants to grow well
103
Q
tilth
A
- turning soil over so it has a good arrangement of aggregates and clumps so you gave a good mixture of small pores where the water is, and big pores for air to go through
104
Q
plowing
A
- removes horizontal clods from the soil
105
Q
pros of plowing
A
- Used to get the organic matter on top, to work down into the soil
- Destroys weeds, so you can plant in the area where the weeds were
- Breaks crust up
106
Q
cons of plowing
A
- Overplowing can cause soil loss
- It can remove vegetation and cause higher erosion rates
107
Q
soil texture
A
- refers to the relative proportions of sand, silt, and clay particles in a soil
- a soil texture pyramid is used for this
- 12 of them
108
Q
sand
A
- .05 to 2 mm
- never sticky
- cannot be molded
- anything over 2 mm is gravel
109
Q
silt
A
- from .002 mm to .05 mm
- creates thick choking dust
- essentialy micro sand
110
Q
clay
A
- smallest of the three
- sticky when wet, hard and cloddy when dry
- less than .002mm
111
Q
Atterberg Limits
A
- a set of measurements that indicate the water content at which a fine-grained soil changes from one state to another
- Categories are solid, semi-solid, plastic, and liquid
- changes between these stages are called the Attenberg limits:
- shrinkage, plastic, and liquid limit
112
Q
soil texture types/orders
A
- main ones are sandy, silty, clay, and loamy
- 12 in total, because you can combine them, plus silty clay loam and sandy clay loam
- tell us CLORPT info
113
Q
bearing resistance
A
- The pressure or resistance that soil exerts when a load is applied to it
- Aka soil bearing capacity
114
Q
slumps
A
- type of landslide
- When slope gets saturated and there’s less friction,so things (including houses) fall down the slope
- Happens particularly for clays that shrink and swell
115
Q
diagnostic horizons
A
- a layer of soil that is used to classify soils
- histic, mollic, umbric, and ochric
116
Q
gley and blanket bogs
A
- soils that are waterlogged, either periodically or permanently
- blanket bogs a type of peatland found in only a few parts of the world with cool, wet and, usually, oceanic climates
117
Q
peat
A
- found in wetland areas
- A natural, organic material that forms from partially decomposed plant matter
118
Q
pygmy
A
- These soils are highly acidic, low in nutrients, and hydrophobic
- found in California and Sweeden
- bad for plants
119
Q
microfauna
A
- less than .1 mm
- invisable
- ex: protists and rotifiers
120
Q
mesofauna
A
- between .1 and 2 mm
- ex: mites and springtails
121
Q
macrofauna
A
- can be seen by naked eye
- ex: earthworms, termites
122
Q
Autotrophs
A
- make their own food, usually through photosynthesis
- ex: plants, algae
123
Q
Heterotrophs
A
- have to eat organisms to survive
- ex: humans, dogs
124
Q
food webs and food pyramids
A
- A food web is a network of interconnected food chains, while a food pyramid shows the energy distribution within those chains
- the arrows in a food web show transfer of energy
125
Q
mafic minerals
A
- more dense because they have iron
- weather faster than felsic minerals
- have more fertile soil because of Ca and Mg
126
Q
felsic minerals
A
- less fertile soils, less dense, and weather slower
- light colored
- rich in silica and aluminum
