Midterm Flashcards
1
Q
soils
A
- crucial to life on Earth
- the upper layer of earth in which plants grow
- typically consisting of a mixture of organic remains, clay, and rock particles
2
Q
Phytotoxic substances
A
- chemicals that damage plants, and may result from human activities, or they may be produced by plant roots, by microorganisms, or by natural chemical reactions
- good soil will protect plants by decomposing or absorbing organic toxins, or by suppressing toxic-reducing organisms
3
Q
mineral nutrients
A
- soils supply plants with these
- A fertile soil will provide a continuing supply of dissolved mineral nutrients in amounts and relative proportions appropriate for optimal plant growth
4
Q
essential elements
A
- Of the 92 naturally occurring chemical elements, 17 have been shown to be essential elements
- plants can’t grow and complete their life cycle without them
5
Q
macronutrients/micronutrients
A
- essential elements used by plants in relatively large amounts are called macronutrients
- those used in smaller amounts are known as micronutrients
6
Q
humus
A
- Soils have the capacity to assimilate great quantities of organic waste, turning it into beneficial humus
- created when plant and animal matter decays
7
Q
hydroponics
A
-plants grown in nutrient solutions without soil
8
Q
anoxic conditions
A
- Micro-zones of good aeration may be only millimeters from areas of anoxic conditions
- occur when there is little to no oxygen in the soil
9
Q
soil exists as an interface between these four worlds
A
- the worlds of rock (the lithosphere)
- air (the atmosphere)
- water (the hydrosphere)
- and living things (the biosphere)
10
Q
pedosphere
A
- the soil mantle of the Earth
11
Q
parent material
A
- soil is a soils’s parent material
- the underlying geological material in which the soil horizon forms
- Two different parent materials give you different fertility and texture of the new soil
12
Q
O-horizons
A
- The organic layers at the soil surface
- typically at the top of the soil structure
- refered to as forest floor because they usually occur in forested areas
13
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
14
Q
plow layer
A
- the top layer of soil that has been turned over by a plow
- typically rich in organic matter and nutrients, making it ideal for plant growth
15
Q
E horizons
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
16
Q
B horizon
A
- a soil layer, typically located beneath the A horizon (topsoil), 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)
17
Q
C- horizons
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
18
Q
sand
A
- particles that are large enough to be seen by the naked eye and feel gritty when rubbed between the fingers
19
Q
silt
A
- particles that are too small to see without a microscope or to feel individually, so silt feels smooth but not sticky, even when wet
20
Q
clay
A
- particles that are the smallest mineral particles and adhere together to form a sticky mass when wet and hard clods when dry
21
Q
colloidal properties
A
- too small for the naked eye to see
- The smaller particles of clay have colloidal properties and can be seen only with the aid of an electron microscope
22
Q
soil texture
A
- The proportion of particles in these different size ranges
23
Q
high-activity clays
A
- have a great capacity to retain and supply large quantities of nutrients
- Soils containing certain high-activity clays make very unstable material on which to build because they swell when wet and shrink when dry
24
Q
low-activity clays
A
- can be very stable and easy to work with
25
Q
soil structure
A
- the way that sand, silt, and clay particles are put together to form soil
26
Q
soil biomass
A
- a measure of the mass of the living component of soil organic matter
- Soil organic matter consists of a wide range of organic substances, including living organisms (soil biomass)
27
Q
soil solution
A
- soil water, but called this because soil water is never pure water, but contains hundreds of dissolved organic and inorganic substances,
28
Q
buffering capacity
A
- the ability for soil to resist change
- Is dependent on many chemical and biological factors, including the attraction and release of substances by colloidal particles
29
Q
pH of the soil
A
- determines the relative levels of hydrogen ions and hydroxyl ions in the soil solution
30
Q
what do negative/positive charged absorb/attract?
A
- oppositely charged ions from the soil solution and hold them as exchangeable ions
31
Q
root interception
A
- comes into play as roots continually grow into new undepleted soil
32
Q
mass flow
A
- Nutrient ions must travel some distance in the soil solution to reach the root surface
- mass flow is when dissolved nutrients are carried along with the soil water flowing toward a root that is actively drawing water from the soil
33
Q
soil quality
A
- a measure of the ability of a soil to carry out particular ecological functions
34
Q
sustainable soil management
A
- using soils in ways that will provide current benefits without jeopardizing capacity of the soil resources to satisfy the needs of future generations
35
Q
soil resiliance
A
- soil’s ability to recover from minor degradation if left to revegetate on their own
36
Q
restoration ecology
A
- rapidly evolved to guide managers in restoring plant and animal communities to their former level of productivity and diversity
37
Q
soil restoration
A
- requires in-depth knowledge of all aspects of the soil system
38
Q
hard water
A
- has built up white deposite from the magnesium
- usually found from people who get water from wells
39
Q
different parts of soil
A
- Dirt- tiny rock
- Organic matter- not a lot in soil
- Nitrogen, phosphorus ,and sulfur
- In a good soil, there’s 2-6% and it’s in the upper part of the soil usually
- Pore spaces- ideally, 50% air and 50% water
- Fill with water after rain, but air eventually comes back to the big pore spaces
- Water stays in the small pore spaces for a long time
- Minerals - Lots of minerals in dirt
- CaCO2 (100% calcium carbonate)
- Not all minerals on the planet
- Carbon dioxide plants get from the air
40
Q
when do plants get minerals from soil?
A
- if the minerals are dissolved in water
41
Q
soil profile
A
- Water comes from above,so it flows into the profile, seeps down, dissolves minerals, and moves some minerals downward
- This is why we get the horizons (also because of the organic matter on top)
What dissolves depends on temperature, etc
42
Q
additions
A
- input of materials to the developing soil profile from outside sources
43
Q
losses
A
- losses from the soil profile occur by leaching to groundwater, erosion of surface materials, or other forms of removal
44
Q
translocation
A
- movement from upper to lower level in the soil profile
45
Q
CLORPT
A
- CL- Climate
- O-Organisms
- R- Relief
- P- Parent Material
- T-time
46
Q
Cl-Climate
A
- less translocation in a dry climate
- Weather you get leaching or not has to do with evaporation vs precipitation
- If there is more precipitation than evaporation, they you get leaching
Minerals stay around longer in a dry climate - effective precipitation and temperature influence the climate and therefore, soil formation
47
Q
weathering
A
- Weathering- 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
- Ex: When weather goes from below, to above, to below freezing: causes potholes in the roads
- Chemical weathering- you change the minerals; secondary
- Physical weathering- the rock breaks into smaller pieces with no chemical change
48
Q
erosion
A
- the movement of soil
- by wind, water, ice, or gravity
49
Q
O-Organism
A
- If you want a compost, or to make a garden=worms
- Improve the soil
- Can’t grow in every environment (too sandy is bad, places that are too acidic, etc)
- many years of falling pine needle can make the soil acidic (low pH)
50
Q
R-Relief
A
- topography
- shape of the earth’s surface affects how soil thrives
51
Q
P-Parent material
A
- the kinds of rocks or transported sediments that the soil formed in
- ex: limestone is high calcium so it can give good soils
- genesis- the formation of a soil from parent material
52
Q
T-time
A
- age of the surface where the soil is from
- few places where there are really really old soils because:
1. rivers change where they’re flowing
2. erosion
53
Q
igneous rocks
A
- composed of primary minerals (not been chemically altered since they formed as molten lava solidified)
54
Q
sedimentary rocks
A
- form when weathering rocks released from other, older rocks collect under water as sediment and eventually reconsolidate into new rocks
55
Q
metamorphic rock
A
- formed by other rocks by a process of change termed metamorphosis
- Usually harder and more strongly crystalline than the sedimentary rocks when they were formed
56
Q
exfoliation
A
- the peeling away of outer layers
- some rocks may be weathered by exfoliation
57
Q
biogeochemical weathering
A
- chemical weathering is enhanced by geological (presence of water and oxygen) and biological (acids produced by microbial and plant–root metabolism) agents
58
Q
lithosequence
A
- a series of soils that differ from each other due to the changing composition of the rocks and minerals beneath them
59
Q
climosequence
A
- a series of soils that differ from each other due to variations in climate
60
Q
biosequence
A
- series of soils that have different horizons due to the influence of vegetation on the soil’s development
61
Q
toposequence
A
- a series of soils that occur in different positions on a slope and have distinctive characteristics due to topography
62
Q
chronosequence
A
- a series of soils that are genetically related and differ in age
63
Q
terraces
A
- if there is a change in grade for a stream, over time, it might cut down through it’s already well-formed alluvial deposits, which leaves terraces above the floodplain on one or both sides
64
Q
drift
A
- the movement of sediment by glaciers or ocean currents, or the movement of surface water by wind
65
Q
till
A
- a type of glacial sediment that is deposited by glaciers and is made up of unsorted rocks, clay, silt, and sand
66
Q
moraines
A
- ridges of till that are deposited by glacial sheets
67
Q
terminal moraine
A
- a ridge of rocks, soil, and sediment that forms at the end of a glacier, marking the furthest point it reached
68
Q
recessional moraine
A
- a ridge of till that forms when a glacier temporarily stops moving and then retreats again
69
Q
outwash plains
A
- formed by the sediment on valleys and plains where the glacial waters were able to flow away freely
70
Q
lacustrine deposits
A
- sedimentary rock formations that form at the bottom of lakes
71
Q
eolian materials
A
- materials that travel by wind
72
Q
dune sand, loess, and aerosolic dust
A
- from largest to smallest particle size
- wind-transported as parent materials for soil formation
73
Q
peat
A
- organic deposits
- a type of soil that forms in wet areas, like river valleys and wetlands, when plants die and decompose in low-oxygen conditions
74
Q
carbocentrism
A
- the belief in the superiority of carbon based life forms
75
Q
karst
A
- landscape underlain by limestone which has been eroded by dissolution, producing ridges, towers, fissures, sinkholes and other characteristic landforms
76
Q
tropical dry forest
A
- open woodlands in tropical regions that have long dry seasons and short wet seasons
77
Q
thorn scrub
A
- the types of forests or areas with an average rainfall of less than 70 cm
78
Q
shrub savanna
A
- made when the soil isn’t fertile enough to make trees
79
Q
macronutrients
A
- plants need plenty of it
- ex: nitrogen, phosphorus, potassium, calcium
80
Q
micronutrients
A
- plants don’t need to much of it
- ex: manganese, iron, copper
81
Q
phytoliths
A
- a microscopic silica body found in plants
- in grass, makes it so we can’t eat it because it’s bad for our teeth
82
Q
liming
A
- treat (soil or water) with lime to reduce acidity and improve fertility or oxygen levels
83
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
84
Q
the 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
85
Q
cations vs anions
A
- Cations-positive charge
- Anions- negative charge
86
Q
calciphile
A
- plant that thrives in lime and calcium rich soil
- ex: skunk cabbage
87
Q
calciphobes
A
-a plant that is unable to grow in soil that is high in calcium
- grab any calcium that they can
- ex: blueberries
88
Q
cation exchange
A
- the process where positively charged ions (cations) like calcium, magnesium, and potassium, which are held onto negatively charged soil particles (mainly clay and organic matter), can be readily exchanged with other cations in the soil solution, making them available for plant uptake
89
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
90
Q
mass flow
A
- rate at which mass of a substance changes over time
91
Q
interception
A
- the process by which precipitation is captured by vegetation or other surfaces before it reaches the ground
92
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
93
Q
arid region soils vs wet (humid) region soils
A
- way more ions in arid region soils bc of leeching in the wet climate
- more plant growth in wet region climate
- arid region soils hold onto the minerals more
94
Q
rock cycle
A
- a model that describes how rocks change over time, from one type to another
- there is melted rock below us
