#22 Wetlands

Question 1

Why are wetland biomes so much more decoupled from climate?

Answer 1

the dominant influence is the presence of shallow water

Question 2

do mangroves have high or low salt content?

Answer 2

the highest salt content in mangroves and salt marches in coastal regions

Question 3

what are tidal freshwater marshes?

Answer 3

located in rivers upstream from salt marshes, where tides further downstream result in the freshwater of the river backing up and flooding, so do not directly see salt water

Question 4

Where are tidal freshwater marshes found?

Answer 4

large temperate estuaries that experience significant tides
e.g., St. Lawrence River and the Severn of Great Britain

Question 5

What are intertidal flats?

Answer 5

the last coastal wetland that experiences seawater. Flat areas subjected to tides that are too unstable in sediments so remain unvegetated

Question 6

Define Freshwater Marshes

Answer 6

Large non-forested flat areas that are continuously or frequently flooded but have water flowing through them.

Question 7

Why doesn’t acidity build up in freshwater marshes

Answer 7

continuous water circulation, acidity does not build up in the decomposing dead plant material, so it does not form peat.

Question 8

what is the largest freshwater marsh

Answer 8

The Everglades of Southern Florida - the worlds most famous wetland

Question 9

How do Freshwater Forested Swamps differ from freshwater marshes

Answer 9

primary vegetation is trees instead of grasses and sedges. amazon river basin

Question 10

What are Riparian Wetlands?

Answer 10

“of a river bank” - wetlands centre around a river which regularly burst its banks for part of the year

Question 11

what happened to the Mississippi river

Answer 11

towns and rivers created Levees (protective embankments from floods), which kept the water in and led to the draining, where soils were converted into farmland.

Question 12

what is the Pantanal?

Answer 12

the largest wetland, located at the tripoint of Brazil, Bolivia, and Paraguay. One of the richest ecosystems in the world, largest tropical wetland area and the largest flooded grassland

Question 13

how is peat formed

Answer 13

dead plant material (mostly moss) falls to the bottom and becomes compressed as further layers accumulate. As the water obstructs the oxygen flow and as acids form, normal bacterial processes are inhibited and so decomposition is very slow
As a result, most of the original carbon is preserved

Question 14

what percentage of carbon in the biosphere is trapped in peat?

Answer 14

30%, peatlands are known as carbon sinks

Question 15

Bogs vs Fens

Answer 15

Bogs
- no water flow
- highest acidity
- greatest peat production

Fens
- Some water flow
- Lower acidity
- Reduced peat production

Question 16

what is the largest wetland in North America

Answer 16

Hudson Bay Lowland

Question 17

The prairie pothole region runs from ______ to _______?

Answer 17

Alberta to Iowa. formed by uneven deposition of glacial till during the last ice age

Question 18

After video

Question 19

Define Wetlands

Answer 19

Open-water habitats and seasonally or permanently waterlogged areas, ranging along a gradient from permanently flooded to periodically saturated soil and supporting hydrophytic vegetation at some time during the growing season.

Question 20

wetlands cover ____ percent of the Earths surface

Answer 20

6% (most local)

Question 21

what are the four most significant wetlands in the world

Answer 21

• Pantanal (Brazil)
• Everglades (Florida)
• Okavango (Southern Africa)
• Fens (England)

Question 22

wetlands occur in which three topographic situations?

Answer 22

• Basin wetlands: shallow basins, from upland depressions to filled in lakes and ponds; water flow is vertical
• Riverine wetlands: shallow and periodically flooded river banks; un-directional water flow
• Fringe wetlands: Along the coast of large lakes, bi-directional water flow

Question 23

Marshes vs swamps vs riparian woodlands

Answer 23

• Marshes: Dominated by emergent herbaceous vegetation
• Swamps: Forested wetlands
• Riparian: Occasionally or seasonally flooded by river waters.

Question 24

What are peatlands or mires?

Answer 24

accumulation or organic matter.
- Peatlands (mires) are fed by groundwater to form fens dominated by sedges
- mires are dependent on precipitation for their nutrient supply

Question 25

List some characteristics of peatlands

Answer 25

• Organic matter rate exceeds rate of decomposition, accumulating OM as peat
• Associated with boreal forests, but can be found in tropical and subtropical regions
• Low production due to low temperatures, acidity, and nutrient immobilization
• low herbivore utilization due to unpalatability of plants
• Low abundance of decomposer organisms
• contribute to regional hydrology (basin wetlands function as natural resevoirs)
• act as water-infilatration systems: vegetation takes up excessive N, P, S, Cu, Fe and other metals, incorporates them into plant biomass and deposits them into anaerobic bottom muds

Question 26

what are the two components or hydrology?

Answer 26

• Physical aspects of water and its movement: precipitation, surface and subsurface flow, direction and kinetic energy of water, chemistry of the water
• Hydroperiod involves: duration, frequency, depth, and season of flooding

Question 27

How does hydroperiod influence plant composition?

Answer 27

Affects germination, survival and mortality at various plant stages.

Question 28

What part of the world is the effect of hydroperiod most pronounced and why?

Answer 28

Prairie Pothole Region
- Deep basins (potholes): standing water throughout periods or drought, dominant plants will be submergents
- Drought: tall or mid-height emergent species will dominate (cattails)
- Shallow pothole: flooded briefly in the spring - grasses/sedges/forbes dominate a wet-meadow community

Question 29

how do long hydroperiod differ from short hydroperiod?

Answer 29

Long hydroperiod - supports submerged and deep water emergents
- Short hydroperiod - Shallow water emergents and wet-ground plants

Question 30

Obligate vs facultative or amphibious plants

Answer 30

Obligate: pondweeds, floating pond lily, baldcrypress
Facultative or amphibious: Grown in standing water or saturated soil

Question 31

How do facultative plants grow in wetlands?

Answer 31

50:50 probability of growing in wetlands or non wetlands.
Facultative upland plants have a 1-30% probability of growing in a wetland.

Question 32

Why is it so obvious that coastal wetlands are threatened and disappearing rapidly?

Answer 32

70% of people live within 80km of the coastline.
this causes drainage for development and contamination of sites