Natural Resource - Exam 1: Section 2 (soils, wetlands, and sttreams)

is soil a renewable resource?

yes but not in a humans life time

if used properly soils are…

reusable and growing more fertile overtime

formation of soils

weathered parent material

chemical weathering

physical weathering

chemical weathering

chemical breakdown of rocks and minerals due to natural processes

physical weathering

breakdown of material through mechanical processes

biofuels

fuel made from plants; hypothetically if it were done right it would be a net zero carbon emission

O horizon

the organic layer

Oi

recognizable organic material

ex. freshly fallen leaves, pine needles, a recently dead animal

Oe

moderately decayed material but still recognizable

ex. leaves from a few months ago that have rotted but you can still tell what they are

Oa

completely unrecognizable decayed material (humus layer)

A horizon

the most organic mineral layer (5% organic) very dark in color

E horizon

zone of Elluviation

materials are leeching out of this layer and going into the next (irons, clays, oxides, etc.)

B horizon

zone of illuviation

materials are coming into this layer

This layer is very dense

C horizon

regolith/parent material bedrock

b (soils)

buried soil horizon (important for historical studies bc it is a buried landscape)

f (soils)

frozen soil (permafrost)

k (soils)

accumulation of calcium carbonate; this occurs in arid environments and creates a white layer in the soil

p (soils)

soil has been plowed

t (soils)

accumulation of silicate clays (the older the clay the more silicate clay it has)

soil texture

soils ability to retain water relies on

sand

largest grain size (clay, sand, and silt)

silt

middle sized grain

clay

smallest grain size (among clay, sand, silt)

gravel

bigger than sand

colloid

smaller than clay (carries electrical currents very well)

Sandy soils

low matric tension - does not hold onto water very well but plants can access it very easy

• not great for ag because water leaves the system so fast

matric tension

ability for sediment to hold water

clayey soils

High matric tension - water is held extremely tightly within these soils which means plants cant even access it. The water is there but it is unusable

silty and loamy soils

soils with the best matric tension for fertility and agriculutre

pressure gradient force

water moves from high pressure (wet) to low pressure (dry) places within the soils which is how plants are able to uptake the water. The water is constantly moving towards the roots as the roots take in the water.

loam

a mixture of all three soil types

Wind Erosion Prediction sysetem

WEPS - GIS computer model that shows things like soil wetness, depth, weather patterns, structure, etc.

RUSE - Revised universal soil equation

used to create a soil prediction model using things like aspect, slope, crop management, conservation practices, hydrology, etc.

sheet flow

when water flows down a slope at a uniform depth

sheet erosion

when sheet flow drops eroded sediment at the bottom of the slope which can lead to rills

rills

cm deep x cm wide in a slope caused by water erosion, as they flow they get deeper and wider

master rill

rill that is 10 cm wide x 10 cm deep

gully

meters wide x meters deep

these can destroy ecosystems and are important to stop from happening

formation of these is dependant on how we manage our land

a gully becomes a stream when…

it meets the water table

stream bank erosion (lateral erosion)

natural process that creates cutbanks

cutbanks are…

eroded

point bars are…

deposited

RipRap

the stuff that is put onto cutbanks to stabilize it and stop it from eroding more

ex. people often put old cars in stream banks to stop erosion

deflation

the general lowering of a landscape by wind erosion

this takes the A horizon

Threshold Entrainment Velocity (TEV)

velocity that is required to move particles

sand, silt, and clay have different TEVs

highest TEV

clays have the highest because they flocculate (stick together) which makes it harder for them to move

lowest TEV

silt has the (blank) TEV and they are the most important for fertility (biodiversity and farming rely on silts)

Bernoulli effect

results in lift of particles and is exceptionally strong near the boundary layer

Loess

wind blown depostited silt

saltation

when a grain bounces on the ground before it has become suspended

suspension

particle is fully in the air and no longer touching any ground

Impact threshold

once something is in motion it is easier to keep it in motion (momentum)

TEV is lower in already moving particles

T-Value

USDA value determining how much top soil is okay to lose

production is always changing so this number is often changing depending on development rates

ranges from 1-5 tons depending on the soil (5 on richest soils)

Riparian buffer/corridor

creates a corridor for wildlife and a place where ag and ranching does not take place to preserve the health of the soil

contour plowing on slopes

this catches water because the contours are perpendicular to the slope and slows erosion

• this stops rills and gulleys

strip farming

10 meter rows with varrying crop types between rows

cover crops

nitrogen fixing plants and plants that cover the ground so it is protected from sun and elements

grassed waterways

planting natural grasses where water natrually flows to hold down the soil

terraces

farming technique that slows down the flow of water by pooling

check dams

putting temporary dams using rocks, plants, or some kind of material to slow the flow of water (slows down gulleys)

Food Security Act (1985)

established conservation reserve program (CRP)

conservation reserve program (CRP)

program where government pays farmers to not farm portions of land if they are doing it in the name of conservation. Over 20 million acres of US land is in this program they are the largest private land program in the US

They focus on highly erodible land

Tillage

act of breaking up the soil to make planting easier

conventional tilling

exposes soil to erosion and uses lots of energy

reduced tiling

less tilling

No till

there are a lot of weeds and it requires much more manual labor and often uses more herbicides to deal with the weeds.

Not necessarily better

NRCS (originally SCS)

provides assistance to farmers and creates land capability classification for land

Class 1 NRCS land classification

you can pretty much do anything on this land; agriculture, ranch, whatever…

Class 4 NRCS land classification

moderate cultivation can occur on this land, nothing too crazy bc it is not the healthiest land

Class 8 NRCS land classification

can’t do anything on this land, its besaiclly just an ecosystem for conservation at this point

important NRCS program caveat

private landowners don’t have to take their advice, they can do whatever they want on their private land because it is PRIVATE

rangeland

a source of froage/food for domestic and wild free ranging animals

types of praire

savannah, steppe, tall grass praire

what is the most fertile and productive soils in the world

tall grass praire! but it is endangered bc we farm too much of it

metabolic reserve

amount of the plant (the stalk) that needs to be left after grazed so that the plant can grow back

Bison

low risk grazers: they bite high on the stalk so there is enough reserve for the plant to grow back and they are naturally roaming so they do not stay in the same place for long

Cattle

moderate risk grazers: have an intermediate bite but they do not roam naturally so they need to be moved around to no degrade the land

Sheep

high risk grazers: group very tightly together and bite very low so the plants do not grow back

Horses

high risk grazer: extremely low bite because they pull their lips back when biting so when there are a lot in one place it is a huge problem

Decreaser plant

these plants are highly nutritious so animals eat them first and they are the first to decrease in number

increaser plants

these plants increase in number over highly grazed land and are less nutritious so animals do not eat them until they have to

invader plants

these would not naturally be there but invade once all of the other plants are gone

hydric soils

soils that form in fully saturated in environments: they have iron oxide rings

hydrophytic plants

fully saturated plants that pull in oxygen from the water and create oxidized root casts where the oxygen is pulled in

3 characteristics qualifies something as a wetland

hydric soils

hydrophytes

has to be saturated

Marine wetland

shallow water over the continental shelf; shorelines and tide pools

Estuarine

where freshwater and saltwater meet; tidal salt marshes, bays, mangrove swamps

riverine

riparian wetlands; constant inputs and outputs so it is a constantly open system

riparian vegetation

this causes river meandering (natural), slows down flow, creates pools and traps organic material

beavers and water table

they increase water table because they slow down the flow of the water

Palustrine

upland wetlands; fens (mountain springs), marshes, swamps, and bogs in mountains

discharge

total amount of water flowing through a stream

aquifer

permeable rock that can hold water

aquiclude

impermeable rock that water can not move through

Clean water act (1972)

first time that the government protected wetlands; 1985 addition to the bill with a no net loss policy

mainly has happened on public lands not private lands

Swamp Buster Provision (on the farm bill)

farmers and ranchers receive subsidies from gov but if they destroy any wetlands then they no longer will receive the subsidies

Wetland easements

similar to CRP, gov will come in and help restore wetlands on private lands

what 5 agencies share responsibility for wetland management

USACE: US army corp of engineers, EPA, USFWS, NOAA, NRCS

idea of “hungry water”

water wants to carry a certain amount of sediment and if it does not have enough then it will find it elsewhere (erosion)

when it has too much sediment then it will drop it (deposition)

high turbidity =

= high sediment load