Environ 303 Wetlands Exam Review

wetlands

high diversity of wetland ecosystems. continuum of genesis, geomorphologic setting, shape, and form, water supply source, etc. can be inundated seasonally or never. transition areas between aquatic ecosystems and uplands

depth and flow rate determine:

dissolved oxygen availability

5 materials soil is composed of

minerals, organic matter, living organisms, gas, water

hydric soils

soil that formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part

hydrophytic plants

plants adapted to grow in water or on soil that is periodically anaerobic because of excess water.

soil horizons

distinct layers differ in color, thickness, and chemical content

soil profile

vertical arrangement of horizons

peat

surface organic layer of a soil that consists of partially decomposed organic matter, derived mostly from plant material which has accumulated under conditions of waterlogging, oxygen deficiency, high acidity, nutrient deficiency

muck

technical term for organic soil, dead plant material is highly decomposed. form and are maintained where the hydrological regime allows some soil aeration

Ramsar Convention on Wetlands (canada)

mission: conservation/use of wetlands through local and national actions and international cooperation

major categories: marine/costal, inland, human-made wetlands

Cowardin Wetlands and Deepwater Habitats System

classified by landscape position, vegetation cover and hydrological regime.

5 main wetland types: marine, riverine, slope, depressional, flat, and fringe

hydrogeomorphic approach

classified by geomorphic setting, dominant source, hydrodynamics

peatlands and peat

- plant material does not fully decay in wet, acidic, anaerobic conditions.

- rate of organic matter production > rate of decomposition

composition of peat

temperate, boreal, sub-arctic regions. lowland humid tropics

peat formation stages

1. water is retained in the depression from nearby river flows and rainfall

2. development of marsh vegetation, organic matter accumulates

3. development of freshwater swamp forest, peat layer forms after 2.5-4.5 years

(depression -> marsh vegetation -> freshwater swamp forest)

acrotelm

active peat layer with aerobic conditions, upper portion of peat profile

catotelm

thick layer of peat disconnected from system, permanently below water table

functions of peat

atmospheric carbon sink, nutrient recycling, trap eroding soil, filter out polluting chemicals

bogs

- ombrotrophic (rainfall source, not groundwater, no inflow or outflow)

- water depth: variable

- peat depth: thick

- pH: acidic (3.1-4.5)

- oxygen and productivity: low

- microclimate: extreme

raised bogs

originate on level ground, center of bog higher than edges, ombrotrophic

valley bogs

in hollows and valleys, rheotrophic: water enters from surrounding land bringing in minerals

blanket bogs

blankets the landscape, ombrotrophic, perched water table

how do bogs form?

terrestrialization (develop via infilling of a water body), paludification bogs (develop directly on mineral soils by expansion into upland forests. GRADUALLY FILLS UP LOW-LYING LAND

fens

- minerotrophic (supplied by water from surrounding or underlying mineral soil)

- water depth: deep, variable

- peat depth: thick

- nutrients: higher than bogs

- pH: moderate acidity

- oxygen and productivity: low, but higher than bogs

- microclimate: low temperatures and short growing seasons (high precip, high temp)

wooded wetlands

- minerotrophic: riparian -> inflow and outflow

- common types in US: red maple, atlantic white-cedar, bald cyprus

vernal pools

- naturally occurring, seasonal wetland in a shallow depression that lacks fish

- seasonal depressional wetlands

water source: isolated, no continuous surface water connection to permanent water (precipitation, runoff, flooding)

- hydrology: temporary

- usually underlain by bedrock or clay to hold in water

emergent marshes

- frequent or seasonal flooding, typical depth of 8ft

- occur along shores of lakes and streams

- distinct vegetation zones, water-tolerant plants that grow from the soil

- seasonal dry periods

wild rice (manoomin) marshes

- annual aquatic grain is the dominant macrophyte

- manoomin: critical part of great lakes ecosystem

- cultural significance to native peoples

- critical habitat for migratory birds, wolves, lynx

- challenges/threats: development (rapid habitat loss), recreational use (habitat loss from shoreline erosion), climate change, pollution

wet meadows

- seasonally wet, high water table year around

- MUCK, not peat because alternate between between inundation and exposure

- grasses, sedges, herbaceous

beaver ponds/meadows

support diverse plant life, benefits for fish and amphibians

wetland function and productivity are primarily driven by

basin geomorphology, soil composition, hydrologic regime, disturbance

ecosystem services

nutrient cycling, water storage and infiltration, groundwater, recharge, flood/erosion control, improve water quality, carbon storage, habitat structure for animals, nutrient/oxygen source