Wetlands 1

Wetland Big 3

1. Water present on surface/in root zone at some point in the growing season (inundated)

2. Soils inundated long enough to develop anaerobic conditions (hydric soils)

3. Biota is adapted to saturated conditions, particularly vegetation (hydrophytic vegetation)

Hydric soils

soil that has been inundated with water long enough that is has developed anoxic conditions

Hydrophytic Vegetation

vegetation adapted to wet/saturated conditions, adapted to survive in harsh/unstable conditions, evolved special structures to survive extreme conditions

Marine

salt water, deep, open ocean, typically no/microscopic vegetation

Estuarine

Fresh and salt water, shallower water, typically with emergent and submerged vegetation, macro-vegetation

Riverine

Fresh water, channelized flowing water (rivers, streams), emergent vegetation on banks (riparian)

Lacustrine

Fresh water, non-flowing, deep, large, closed systems of water (lakes), submerged vegetation + emergent veg on banks, not much vegetation

Palustrine

Fresh water, ponds, vernal pools, non-flowing, typically small, lots of vegetation of all kinds

Bogs

peat accumulating wetlands, no in or outflows, dominated by Sphagnum, acidophilic mosses

Marshes

Frequently or continually inundated wetland, emergent herbaceous vegetation adapted to saturated soil conditions (graminoid (grasses), forbs, woody)

Swamps

wetland dominated by trees or shrubs

Upland (UPL)

• plant almost never occurs in wetlands

• 1% occurrence in wetlands

• rarely hydrophyte, found in uplands

(Artemisia vulgaris)

Facultative Upland (FACU)

• Plant usually occurs in non-wetlands, may occur in wetlands

• 1-33% occurrence in wetlands

• sometimes hydrophytes, found in uplands

(Annual ragweed)

Facultative (FAC)

• Plants usually occur in wetlands and non-wetlands

• 34-66% occurrence in wetlands

• Sometimes hydrophytic, sometimes not hydrophytic

(rough-leaf dogwood, American hornbeam)

Facultative Wetland (FACW)

• Plant usually occurs in wetlands

• 67-99% occurrence in wetlands

• usually hydrophytic

• predominates in hydric soil

(broom sedge, silky dogwood)

Obligate (OBL)

• Plant almost always found in a wetland

• 99% occurrence in wetlands

• almost always hydrophytic

• usually in standing water/seasonally saturated soils

(cypress trees)

Submerged

OBL plant that conduct virtually all their growth and reproductive activity under water (water milfoil, water-nymph, pondweed)

Floating

OBL plants that often grow with leaves + vegetative material/other reproductive organs floating on the water’s surface, roots float in the water column

(duckweed, water shield, northern watermeal)

Floating Leaved

OBL plants that are rooted in the sediment but their leaves float on the surface of the water

(hairy water clover, yellow pond lily)

Emergent

OBL plants that are herbaceous or woody and rooted in soil that is inundated, upper portions of the vegetation are above water level

Wetland Delineation

deems that the dominant species must be more than 50% OBL, FACW, or FAC to be considered a wetland

Aerenchyma Tissue

adaptation of super spongy material/air pockets in roots and stems of wetland plants, helps with positive buoyancy and oxygen diffusion into the root system (Nymphaea odorata)

Adventitious Roots

adaptation of roots coming out of the stem, stability/support, oxygen diffusion to help maintain oxygen levels below soil surface, grows above water line

Stem Hypertrophy

adaptation of buttressing of tree roots (widening of roots closer to soil), cells have gotten larger and less dense here, support in inundated conditions

Fluted Trunks

adaptation for widening at the bottom of woody plants with concave parts in between roots, support in inundated conditions

Rapid Vertical growth/growth dormancy

low metabolism at times with low water, rapid growth at times with high water/nutrients

Lenticels

adaptation of pores allowing for gas exchange

Pneumatophores

root adaptation, roots stick up and out of the water, roots full of aerenchyma (very squishy and flexible), covered in lenticels, diffuse oxygen in air and bring it to root level

Pressurized gas flow

adaptation that diffuses oxygen to roots and keeps plants standing up

Anaerobic Respiration

plants can have aerenchyma too

Decreased salt water uptake, excrete salt, altered nutrient absorbance

helpful for coastal plants

Timing of seed production

wet vs dry seasons, seed produced in wet season

Buoyant seeds and seedlings

longer dispersion area, less competition with progeny

Viviparous seedlings

germination can happen on the plant (mangroves), progeny has head start in harsh conditions

Persistant seed banks

seeds stay dormant for a long time then come back

Succession

process of directional change; species composition of a community changes over time; proceeds through series of changes that remains mostly stable through ecological time

Pioneer Species

the earliest species to arrive at a site

Climax community

the final seral stage in the process of succession

Autogenic succession

self generated, vegetation in communities, community changes through time by the biota, changes are linear and directed toward a mature, stable climax ecosystem (linear and predictable)

Allogenic succession

influenced by environmental factors, create wetlands to transition

Total water budget

change in volume over time (amnt of water stored in wetland) = net precipitation + surface inflow + groundwater inflow - evapotranspiration - surface outflow - groundwater outflow +- tidal flow

Bankful Discharge

when water overtops banks and flows into floodplain

Soil

combination of sand, silt and clay (soil matrix)

Field capacity

amount of water soil can hold against the force of gravity

Wilting Point

point at which plants can no longer uptake water from the soil (pore size of the sediment is too small (clay) and water is trapped and adheres to the sediment grains too well)

Saturation

all pores between sediment grains is filled with water

Organic layer

top layer of soil that is primarily dead/organic litter (very large layer in wetlands because decomposition is slowed)

Mineral Layer

gleyed soil, grey/muted colors due to anaerobic conditions; less than 20-30% organic content

Sapirists (muck)

greater than 2/3 decomposition, less than 1/3 plant fibers are identifiable; more watery and gritty soil

Fibrists (peat)

less than 1/3 decomposition, greater than 2/3 plant fibers are identifiable; dense soil

Hemists (peaty muck/mucky peat)

have characteristics of both peat and muck

Redoximorphic features

nodules and concretions, masses, pore linings

Biogeochemical cycling

transportation and transformation of chemicals; major role in nitrogen, carbon, phosphorus, sulfur cycles

Intrasystem

chemical cycling and transformations within the wetland (within the system)

Intersystem

transportation and exchange of chemicals between adjacent systems; influence and is influenced by both aquatic and upland systems

Oxidation

loss of electrons; reducing agent (those that are oxidized)

Reduction

gain of electrons; oxidizing agent (those that are reduced)

Methanogenesis

bacteria breaking down organic material in anaerobic conditions and releasing methane gas, more efficient in warmer temperatures (more CH4 produced)

Redox potential

quantitative measure of tendency of soil to oxidize or reduce substances; more positive redox potential = more oxidized soil and more aerobic processes; more negative redox potential = more reduced soil and more anaerobic processes; around 300 mv is where aerobic switches to anaerobic; much higher redox potential at soil surface

Oxygenic Photosynthesis

oxidized layer, CO2 is reduced to organic compounds, major pathway

Anoxygenic photosynthesis

reduced layer, CO2 is reduced to organic compounds without oxygen, in bacteria

Oxic Respiration

oxidized layer, oxygen is biological oxidation of organic material

Anaerobic Respiration

reduced layer, biological oxidation of organic matter without oxygen

Fermentation

reduced layer, carbohydrates are broken down to dissolved organic carbon, provides substrate for other microbes, can lead to methanogenesis

Nitrogen fixation

reduced layer, N2 (dinitrogen) fixing bacteria, nitrogenase (enzyme) is inhibited by oxygen

Mineralization

oxidized layer, conversion of organic nitrogen (reduction of organic material) into ammonium (NH4+), ammonification (could happen in reduced layer)

Nitrification

oxidized layer, conversion of ammonium (NH4+) to nitrite (NO2-), to nitrate (NO3-), most biologically accessible form, aerobic process

Denitrification

Reduced layer, conversion of nitrate to nitrite, to nitric oxide, to nitrous oxide to dinitrogen (N2), anaerobic process

Anamox

reduced layer, anoxic, convert reduced ammonium into dinitrogen gas

Phosphorus cycle

very slow cycle, hard to recycle, sinks into ocean and only comes up when mountains are formed, phosphorus runs into water from weathering/erosion of phosphorus rocks

Sedimentation

PO4-3 binds to sediment grains and enters wetlands through runoff

Phosphorus mineralization

conversion of organic phosphorus into inorganic form

Sulfur oxidation

oxidized layer, reducing sulfur compounds to sulfate (H2S (hydrogen sulfide) > S (sulfur) > SO4-2 (sulfate)), releases energy that can be used by microbes

Sulfate Reduction

reduced layer, anoxic, converting sulfate into hydrogen sulfide, form of anaerobic respiration, releasing energy through breakdown of organic compound

Sulfate Absorption/Leaching

reduced layer, absorption is minimal and can be higher in clay layers; leaching: sulfate is highly reactive and moves out of wetlands through water in soil pores (happens more in sandy/coastal wetlands; can lead to sulfate deficiency in plants)

Iron Sulfide Production (FeS2, FeS)

reduced layer, takes a lot of heat to react iron and sulfide, usually done by microbes, anoxic conditions

Hydrogen Sulfide Emissions

reduced layer, rotten egg smell, happens when not being oxidized or reduced, can be toxic in high quantities, high in salt water

Source

Wetland is a source of a material if the outflow of that material is larger than the inflow

Sink

wetland is a sink of a material if the inflow of that material is larger than the outflow

Factors influencing nutrient budget

• seasonality nutrient uptake

• adjacent ecosystems

• temporal and spatial variability

• Anthropogenic influence 

Point Source

one single point that can be attributed to a pollutant’s origin

Non-point source

when a pollutant’s source cannot be pin pointed to one single source; pollution comes from a sheet (general area)