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
why can't plants take milk
- Fat from milk coats the seed and prevents water from coming into the seed
26
why is manure good for plants
- it acts as a natural fertilizer, providing essential nutrients like nitrogen, phosphorus, and potassium
- Also improves soil structure by adding organic matter
27
macronutrients vs micronutrients
- 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
fertilizer
- a chemical or natural substance added to soil or land to increase its fertility
29
Phytoliths
- 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
organic matter
- 2-6% in a fertile soil
- Originates from living organisms, including plant and animal remains in various stages of decomposition
31
Humus
- 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
why are wetland soils mostly organic matter?
- 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
bogs
- 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
law of the minimum
- 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
limiting factors
- environmental conditions or resources that restrict the growth of a population
36
total vs available (limiting factor)
- "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
Interactions between minerals (serpentine)
- Interacts with other minerals through a process called "serpentinization"
38
serpentinization
- ultramafic rocks react with water to create serpentinite rock
- Can occur in the seafloor, continental margins, and subduction zones
39
cations vs anions
- 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
cation exchange
- 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
Calciphiles vs calciphobes
- Calciphile-plant that thrives in calcium rich soil
- ex: skunk cabbage
- Calciphobe- plants that can’t thrive in calcium rich soil
- magnolia
42
colloids
- 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
young vs old soils
- 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
root uptake
- The process by which a plant's roots absorb water and mineral nutrients from the soil
45
mass flow
- a gravity-driven movement of a mixture of fluid and debris down a slope
46
interception
- the process by which precipitation is captured by vegetation or other surfaces before it reaches the ground
47
diffusion
- The natural movement of particles from an area of higher concentration to an area of lower concentration, due to random molecular motion
48
Mid-Atlantic ridge
- an underwater valley that tears more and more as the continents slowly move apart
49
continential crust
- The outermost layer of Earth's land, made of igneous, metamorphic, and sedimentary rocks
50
isostacy
- the state of gravitational equilibrium where the Earth's crust "floats" on the denser mantle
- reason why mountains don't collapse
51
Asthenosphere
- a semi-solid layer of Earth's upper mantle that's located beneath the lithosphere
- "rock soup"
52
magma (lava)
- 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
rifting
- Occurs when the Earth's lithosphere thins and stretches, separating tectonic plates
54
subduction
- 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
collision
- 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
Mt. Everest: Limestone
- 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
hot spots
- A volcanic region that sits over a plume of hot mantle material
- fueled by heat deep within the Earth
58
igneous rock
- composed of primary minerals (not been chemically altered since they formed as molten lava solidified)
- intrusive and extrusive
59
intrusive igneous rock
- forms when magma is trapped deep inside the Earth
- Lava solidifies while it’s trying to come up to the surface
- Ex: Granite
60
extrusive igneous rock
- 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
Sedimentary
- 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
metamorphic rock
- formed when existing rocks are transformed by heat and pressure
- Ex: Granite to gneiss, shale to slate (sidewalks), Limestone to marble
63
Disintegrate
- just break up
- Physical breakdown
- Same minerals we had originally (primary)
64
decompose
- 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
surface area with rocks breaking up
- As a rock breaks up, we get more surface area
66
exfoliation
- type of physical weathering that causes rocks to break apart in flat or curved sheet
- ex: granite
67
abrasion
- geological process that occurs when particles wear away a surface through:
- Friction
- Fire
- Temperature change
- Pressure release
68
dissolution
- the process by which solid materials, like minerals, dissolve into a liquid, usually water
- ex: salt NaCl to Na+ + Cl-
69
Oxidation and reduction (Ox-Redox)
- 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
acidification
- 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
caliche
- A layer of soil or sediment that has been cemented together by minerals
- same as a hardpan
72
Hydrolysis
- water molecule gets added but gets split
- ex: A-B + H20 -> A-H +B-OH
73
hydration
- add a water molecule
- CaSO4 + 2H2O → CaSO4·2H2O
74
secondary minerals
- Basically anything small
- clay
- very susceptible to weathering
75
resistance to chemical weathering
- Varies with climate
- quartz is the most resistant material
- Large mineral grains disintegrate more but decompose less
76
inert gases
- no charge, they do not ionize or react
- last group vertically on periodic table
- ex: He, Ne
77
glacial till
- a mixture of unsorted sediments that glaciers deposits
- can include clay, sand, gravel, or boulders
78
erosion vs weathering
- Erosion is just the movement of rocks and broken down rock material
- weathering is the process of breaking down rocks
79
deposition
- Dropping materials that were moved (through erosion) off in a new location
80
lakes vs wetlands
- lakes fill in, wetlands are temporary
81
moraine
- ridges of till that are deposited by glacial sheets
- Masses of sediments deposited by a glacier
- landfill made of glacial till
82
outwash plain
- Plain made of glacial sediments depsited by meltwater
83
Residual soil
- 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
transported soil
- Formed from weathered material that has been moved from its original location
- ex: colluvial, alluvial
85
Differential soil
- Different parts of a soil mass settle at varying rates, causing uneven settlement
86
anticlines
- an arch of rock arranged in layers that bend downward in opposite directions from the top
87
Alluvial
- 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
colluvial
- Loose, weathered material that has accumulated at the base of hillside
- movement on slopes; gravity and water are big helpers
89
floodplains
- Land that is prone to flooding, such as when a river overflows its banks
90
deltas
- at the mouth of a river
91
fans
- A landform created by the deposition of sediment from a fast-moving stream
92
marine parent material
- 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
glacial parent material
- glaciall till is a type
- these are materials that are transported and deposited directly by ice
94
aeolian soil
- soil that has been deposited by wind, usually made of silt or sand
- sand dunes and loess are types
95
sand dune
- 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
distribution of sand dunes
- covers 6% of global surface area
- occurs mostly in deserts and arid regions, but also along coasts of seas and rivers
97
loess
- 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
loess plateau
- Chinese loess plateau
- surrounded by the yellow river, which is yellow because of the loess that enters through the loess plateau
99
folding under compression
- the process where rock layers bend and form folds due to compressive stress
100
colluvium
- material that accumulates at the foot of a steep slope
- loose and poorly sorted debris
101
clod
- lumps of clay
- clay sticks to itself and absorbs a lot of water
102
soil structure
- refers to how clay, silt, and sand are arranged in the soils
- tilthing manipulates the soil structure to get plants to grow well
103
tilth
- 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
plowing
- removes horizontal clods from the soil
105
pros of plowing
- 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
cons of plowing
- Overplowing can cause soil loss
- It can remove vegetation and cause higher erosion rates
107
soil texture
- 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
sand
- .05 to 2 mm
- never sticky
- cannot be molded
- anything over 2 mm is gravel
109
silt
- from .002 mm to .05 mm
- creates thick choking dust
- essentialy micro sand
110
clay
- smallest of the three
- sticky when wet, hard and cloddy when dry
- less than .002mm
111
Atterberg Limits
- 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
soil texture types/orders
- 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
bearing resistance
- The pressure or resistance that soil exerts when a load is applied to it
- Aka soil bearing capacity
114
slumps
- 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
diagnostic horizons
- a layer of soil that is used to classify soils
- histic, mollic, umbric, and ochric
116
gley and blanket bogs
- 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
peat
- found in wetland areas
- A natural, organic material that forms from partially decomposed plant matter
118
pygmy
- These soils are highly acidic, low in nutrients, and hydrophobic
- found in California and Sweeden
- bad for plants
119
microfauna
- less than .1 mm
- invisable
- ex: protists and rotifiers
120
mesofauna
- between .1 and 2 mm
- ex: mites and springtails
121
macrofauna
- can be seen by naked eye
- ex: earthworms, termites
122
Autotrophs
- make their own food, usually through photosynthesis
- ex: plants, algae
123
Heterotrophs
- have to eat organisms to survive
- ex: humans, dogs
124
food webs and food pyramids
- 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
mafic minerals
- more dense because they have iron
- weather faster than felsic minerals
- have more fertile soil because of Ca and Mg
126
felsic minerals
- less fertile soils, less dense, and weather slower
- light colored
- rich in silica and aluminum
