RNR 4013
areas inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, under natural conditions, a prevalence of vegetation typically adapted for life in saturated soil conditions
definition of a wetland
geologic history
major factor influencing location and abiotic characteristics of wetlands
hydrogeomorphic method
system that classifies wetlands based on geomorphic setting, dominant water source, and hydrodynamics; also used for functional assessment
scroll topography/ ridge and swale
meander scars left behind as a river changes course across a floodplain
deflation
removal of loose fine-grained material through wind action
cutbank
area on the outside of a curve in a river where higher velocity causes more erosion
point bar
sandbar that forms on the inside of river curves where lower velocity allows for greater sediment deposition
hydroperiod, water budget, connectivity, variability
four components that make up hydrology
hydroperiod
seasonal pattern of the water level of a wetland
V/t = Pn + Si + Gi - ET - So - Go ± T
water budget equation
watershed
total area drained by a river system
sand
sediment that drains the best (highest infiltration)
forest
land use category with lowest runoff
urban
land use category with highest runoff
water table
uppermost surface of saturated soil zone
less than, greater than
soil porewater pressure is ___________ atmospheric pressure above saturated zone and ____________ atmospheric pressure within saturated zone
discharge wetland
surface water level is lower than water table of surrounding land and grounwater inflows to wetland
recharge wetland
water table of wetland is higher than surrounding water table and groundwater outflows from wetland into aquifer
perched wetland
wetland that is situated well above the goundwater of the area; often separated from water table by an impermeable layer such as rock or clay hardpan
discharge, arid
____________ wetlands and ________ regions are generally more saline
open basin wetland
has hydrologic outlet in the form of rivers/ streams
closed basin wetland
evaporation is the only hydrologic outlet, common in arid saline regions
hydrologic connectivity
linkage between groundwater, surface water, and biotic communities
gaining stream
river captures groundwater
losing stream
river replenishes grounwater
longitudinal connectivity
connects upstream to downstream
lateral/ vertical connectivity
connects river surfacewater to groundwater
horizontal connectivity
connects river to floodplain
temporal connectivity
flooding variability from year to year
alluvial fan
fan-shaped sediment deposition left behind when ephemeral stream slows as it moves from mountain/ canyon to valley
soil matrix
dominant soil color
mottle
contrasting colors/ spotted areas within soil
Munsell color system
classifies soil color in terms of hue, value, and chroma (saturation)
parent material, Fe & Mn presence, organic matter content
factors influencing soil color
loess
highly erodable windborne sediment deposits
bulk density
dry mass / volume
porosity
air + water volume / total volume
inversely
bulk density and porosity are ___________ related
clay
negatively charged (colloid) soil particles which can bind to water or positively charged ions (nutrients) and take longer to settle out
cohesion
the attractive force of water to itself
adhesion
the attractive force of water to solid surfaces
capillary fringe
layer above saturated zone where porewater is pulled up (rather than down, by gravity), also constitues main water available to plants
gravitational water
free water draining downwards through soil profile, found in macropores
hydroscopic water
thin film of water tightly bound to soil particles by adhesion, not available to plants
episaturation
perched water table on surface above some unsaturated zone
endosaturation
water table is saturated all the way down to aquifer
cation exchange capacity
measure of how well soil particles can hold onto nutrient cations (for plant uptake) via total negative charge
basic
more __________ soils are more negatively charged
NPK
three limiting nutrients in plants
ferric iron (Fe 3+)
oxidized iron state that has a rusty hue and is insoluble in water
ferrous iron (Fe 2+)
reduced iron state that is gray in color and water soluble
O
surface organic material horizon
A
surface mineral horizon
E
optional lighter colored horizon caused by leaching
B
subsoil horizon with greater structural development and clay accumulation
C
underlying parent material (rock) horizon
R
bedrock horizon
histosol
highly organic (>20% OM) soil
entisol
miscellaneous, geographically young soil
vertisol
clay rich soil that shrinks and swells with changes in moisture
A species
annuals with 1 year lifespan
P species
perennials with 2-3 year lifespan
V species
vegetatively reproducing perennials with indefinite lifespan
D species
dispersal-dependent species with short lived seeds
S species
seedbank species with long lived seeds and vegetative propagules
Type I species
requires drawdown for propagule establishment/ germination, emergents
Type II species
requires flooding/ standing water for germination, submergents and floating leaf aquatics
lifespan, propagule longevity, germination requirements
three life history conditions in Van der Valk model of wetland succession
emergent plants
roots and base are in wet soil, vegetative parts (leaves/ stem) extend above
floating-leaf plants
root in deep water and send broad floating leaves to surface
submergent plants
root in substrate, vegetative parts float in water column, low in lignin b/c do not require much structural support
basal meristem
plant grows from the base, found in monocots
apical meristem
plant grows from the tip, found in dicots
aerenchyma
cells that diffuse oxygen from aerial stems to roots, stimulated by ethylene and cellulase production which breaks down cell walls
hydrochory
the dispersal of seeds by water
disturbance
an event that disrupts ecosystem community structure and changes the physical environment (EX fire, flood, muskrats/ herbivory, humans, hurricane, droughts, etc.)
transient seeds
germinate within a year
persistent seeds
can remain in soil for over a year
carbohydrates, protein
waterfowl obtain ___________ from plant matter (seeds/tubers) and ___________ from invertebrates
10,000
oxygen diffusion is _________ times slower in water than in air
2.7 ppt
average sulfate concentration in seawater, as opposed to 0.1 ppt in freshwater
bulk density
saltmarshes store more soil carbon despite lower OM% b/c of higher _________________
nutrients, aeration, salinity
three soil components that predominantly determine plant zonation
fermentation
a form of anaerobic respiration where organic matter is reduced into other organic products that produces very little energy
reduced, oxidizing
specially adapted microbes can use ___________ forms as their energy source by ___________ them
negative
the reduced form of a substance has a more _________ charge
FeS
the product that forms when sulfide binds with ferrous iron; the substance is a black-colored solid which is nontoxic
elemental sulfur
the oxidation of sulfide into _____________ can produce a solid white film sometimes observed on the surface water of a wetland
sulfate
the oxidation of sulfide into ___________ when wetland soils are drained can cause highly acidic conditions
methanogenesis, long hydroperiod
the presence of a floating/ pop-up wetland, caused by _______________, is indicative of a _________ _______________
freshwater, salt
methanogenesis is more common in ____________ marshes while sulfide reduction is more common in __________ marshes (because they have higher sulfide concentrations)
oxygen, nitrate, manganese, iron, sulfate, carbon dioxide
order of terminal electron acceptors in soil microbes
detritus
broken down organic material that serves as the main substrate for invertebrates
decomposition cycle
leaching of loosely bound nutrients, microbial colonization peaks in a few days, conditioning into coarse and fine particulate organic matter, incorporated into soil to become substrate for new plants (to die and decompose)
palatable/ nutritious
microbial colonization makes litter more _________ to invertebrates
breeding season
time of life cycle when waterfowl consume the most invertebrates
longer
predatory inverts tend to have _______ life cycles
shredders
feed on vascular plant tissue (EX crustaceans)
collectors
feed on detritus (EX chironomids)
scrapers
feed on algae on plants (EX snails)