Term
| Why does ammonium accumulate in wetland soils? |
|
Definition
| Because nitrifiers never occur in anoxic zones (wetland soils) so the ammonium cannot be oxidized |
|
|
Term
|
Definition
| Complete decomposition of plant detritus by heterotrophic aerobes |
|
|
Term
| Is peat harvesting sustainable? Why or why not? |
|
Definition
| No, it may cause drainage or bring in water, which increases decomposition, eliminating some or all peatland. It often involves drainage and heavy equipment. Also, mining can lead to release of CO2, N2O, and CH4 into the atmosphere with more decomposition. Also peat accumulates very slowly so is not really renewable. |
|
|
Term
| How are marshes and wet meadows distributed and why? |
|
Definition
Located in tropics, sub-tropics, and temperate regions.
Not at higher latitudes because must be in a place where decomposition can keep up with plant productivity (to prevent peat accumulation), which only happens in warmer regions. |
|
|
Term
|
Definition
Aerobic and most anaerobes are heterotrophs.
They reduce the organic content of the soil over time and recycle nutrients |
|
|
Term
Chemoautotrophs/
Chemolithotrophs |
|
Definition
Use organic substances as electron donor, and many of these substances are the end products of anarobic repiration; electron acceptor is O2
These add to organic content |
|
|
Term
Mn and Fe oxidizers:
reaction and products |
|
Definition
Mn2+ (D) + O2 (A) --> Mn4+ (P)
Fe2+ (D) + O2 (A) --> Fe3+ (P)
Bog ore is made of these reactions |
|
|
Term
|
Definition
| Plates or nodules of Fe & Mn oxides and hydroxides formed at oxic-anoxic interfaces. There is sometimes enough present to mine |
|
|
Term
Sulfide Oxidation
process |
|
Definition
H2S (D) + O2 (A) -->SO4-2
Makes yellow deposits; and makes a lot of H+, along with other chemotrophs, making it acidic |
|
|
Term
|
Definition
CH4+ + O2 --> CO2
Some bypasses for CH4 into atmosphere:
ebullition (bubbles), and passage up aerenchyma |
|
|
Term
|
Definition
Detrital N --> NH4+ -> NO2- ->NO3- --> N2
Decomposition Nitrification.... Denitirification
NH4+ is not an anaerobic end product, so strict aerobes. Nitrification speeds up denitrification because aerobic heterotrophs are cloe to denitrifiers. |
|
|
Term
| Plant Participation in nutrient cycling |
|
Definition
Plants fix CO2 for org. compounds and take up nutrients from the soil. This initiates the food web with heterotrophs. Plants create O2 microzones in the soil by sending air down aerenchyma.
Decrease water flow rate, absorbed nutrients are buried within the sediment |
|
|
Term
| How do constructed wetlands remove P, N, and bacteria? |
|
Definition
| Plant uptake, sediment settling, adsorption of nutrients, denitrification |
|
|
Term
| Phosphorous Cycle in soil |
|
Definition
| PO4-3 in soil-->Plant uptake-->Plant dies, detritus mineralized to PO4-->PO4 adsorbed to metallic oxides and hydroxides-->released on mineral dissolution in anoxia |
|
|
Term
| Nitrogen path in wetlands |
|
Definition
| Plant uptake of NH4 and NO3-->N2 fixation, death and mineralization to NH4+-->Nitrification in oxic zones-->Denitrification in anoxic soil--> Ammonia volatilization |
|
|
Term
| Wetlands are hotspots for: |
|
Definition
| Nutrient and sediment trapping, anaerobic processing, greenhouse gas production, chemolithotrophy, production of humic acid, peat storage |
|
|
Term
How are bogs distributed globally
and why? |
|
Definition
High latitudes b/c decomp << primary production:
1) Low mean temperature (decreased decomp)
2) Low dissolved O2 (decreased water renewal)
3) Low pH (helps promote peat growth once already begun) |
|
|
Term
| What are floating bogs and what vegetation are they composed of? |
|
Definition
| They occur lake and bay edges. They float because of the airfilled and intertwined roots of Carex sedge. Mosses grow on top and soak up water, and they can grow there even with a lot of water because lakes are nutrient-poor, relative to soil |
|
|
Term
| How fast does decomposition occur in bogs and what does/ doesn't dissolve in them? |
|
Definition
In top 2cm, rates are 1/2-1/4 those of other wetlands.
Deeper than .5m, decomp is essentially stopped.
Organics are well preserved, calcium carbonates and phosphates dissolve in acid. |
|
|
Term
| How are peatlands conditions maintained? |
|
Definition
Precipitation >> Evapotranspiration:
Mosses need increased water; they have no cuticle so lose water quickly. For the short term, they can draw water up via capillary action.
With high humidity, there is low evapotranspiration, so need less precip, allowing for raised/ blanket bogs |
|
|
Term
| What are the main limits to peat buildup? |
|
Definition
Drought (increased O2 allowed),
Altered hydrology,
Biomass removal by people (peat mining) |
|
|
Term
|
Definition
| Peat mounds above a basin, and is kept moist by rainfall, fog, &/or capillary action. Makes a dome shape because edges can decompose, but moss and plants grow on top. Water can run off the dome and accumulate around the edges, creating a lagg (aka moat). Trees grow inside the lagg. |
|
|
Term
|
Definition
| The water run off from a raised/ concentric bog dome, that has accumulated around its edges, creating a moat. Trees grow inside the lagg where roots can access the mineral soil. |
|
|
Term
|
Definition
| Massive bogs formed through the fusion of >2 concentric bogs. They grow out of more than one filled bains, and rise above the landscape. They have an irregular shape, and are so large, that peat compresses, and makes pools of water on top. |
|
|
Term
|
Definition
| Blankets of moss or peat covering the country side. They start in depressions and spread outwards. Moss and peat compress to initiate water pooling, anoxia, and acid accumulation. Paludification occurs: forest turns into a wetland because is smothered. |
|
|
Term
String bogs/
Patterned Fens/
Aapa Peatlands |
|
Definition
| Formed as thawed gound slides down a slope. Flow produces ridges of rolled peat alternating with water-filled depressions (flarks). Ridges contain moss and heaths (string), pools have sedges (fen), steeper slopes make closer spacing. Common in permafrost regions (Alaska, Yukon, N.E. Territories, Scandanavia). |
|
|
Term
|
Definition
| Mesas or plateaus of peat that rise above the landscape. At the core of the plateau is a chunk of ice, often a pingo: a lake or pond that has frozen solid and expanded to rise out of its basin. Typically in the tundra. |
|
|
Term
| Mosses and common type in bogs |
|
Definition
Dominant veg in bogs, and co-dom with sedges in fens.
Sphagnum moss is especially abundant: grows from the top while the bottom dies and decomposes. It holds 20X is dry weight in waterm keeping the bog moist; absorbs atmospheric water or from capillary action. Its CEC is 2X that of other mosses. |
|
|
Term
|
Definition
| Primitive non-vascular plant that grows on mosses in moister areas, giving bogs a dark cast where abundant |
|
|
Term
|
Definition
| algal-fungal associations, grows on drier mounds of moss; adds many different colors like pinks, yellows, turquoise, white, etc. |
|
|
Term
|
Definition
Emergent plants with stems that are generally triangular and "solid"; very common in fens, but also in bogs.
Ex: Carex, cotton grass |
|
|
Term
|
Definition
| Evergreen shrubs with schlerophyllus leaves (leaves designed to minimize water loss); have thick cuticles, sunken stomata, some have rolled margins and hairs underneath. Major habitat: mountain meadows and bogs. |
|
|
Term
| Why are heaths designed to conserve water in a bog? |
|
Definition
1) Adaptation to physiologically dry winters: Heaths grow yr round, and liquid water is scarce in winter
2) Acid uptake is minimized by low water uptake
3) Selection was for evergreeness: Peatlands are nutrient poor and leaf retention reduces nutrient demand |
|
|
Term
|
Definition
| Alders and sweet gale, often thrive in bogs and have N-fixing symbionts in their nodules. N-fixing is crucial in N-cycling in wetlands because there is not other N source |
|
|
Term
| What form of bog vegetation gives a dark cast when abundant? |
|
Definition
|
|
Term
Examples of common peatland vegetation
|
|
Definition
Mosses, liverworts, lichens, sedges, heaths, N-fixing shrubs, trees, carnivorous plants, orchids
(in order of most to least dominant, relatively) |
|
|
Term
| How do orchids and other flowers deal with low nutrients in bogs? |
|
Definition
| They root on trees or moss and use nutrients in rain water |
|
|
Term
How do carnivorous plants deal with low nutrients in bogs?
|
|
Definition
| They obtain nutrients through the consumption of insects and other animal prey |
|
|
Term
| What problems exist in bogs for animals? |
|
Definition
Herbivory is constrained by low nutrient quality and vegetation toughness.
Bacteria dislike low pH, so conditioned detritus is scarce, discouraging detritivory.
Waterfowl can't find many places to take off or land. |
|
|
Term
|
Definition
| Plant biodiversity (many of its spp dont grow elsewhere), high nutrient retention, high water retention in storms, cranberry growing, peat mining, sequestering CO2 from atmosphere, raw material for coal formation, paleoecology (preserves organics well), anthropology |
|
|
Term
Wet meadows and
Inland Marshes
and the difference between them |
|
Definition
Palustrine Emergent Wetlands
little to no peat accumulation because decomp keeps up with primary productivity; dominated by herbaceous, emergent vegetation; ususally freshwater, non-tidal.
Marshes: have standing water most of the time
Wet meadows: normally just damp with occassional flooding and drying out |
|
|
Term
Wet meadow/ marsh distribution globally,
and where are they located there |
|
Definition
Tropics, sub-tropics, temperate regions, NOT high latitudes; where decomp keeps up with PP.
Occur: along rivers and lakes, on river deltas, coastal plains, in depressions made by glaciers or wind. |
|
|
Term
|
Definition
| Grasses (cattails), sedges (Carex), Broad-leaved flowering (forbs) (pickerlweed), non-flowering plants (ferns), deeper pool plants (water lily, lotus) |
|
|
Term
| Are grazers more common in marshes than bogs? why? |
|
Definition
| Yes, grazers (eat live veg) are more important/common in marshes; the veg is softer and nutrient rich; insects geesem and muskrats are important. Detrital food chains are also important to this. |
|
|
Term
| Threats to amphibians and their solutions |
|
Definition
Egg loss (to dessication, diseas, predation),
Larval predators (frogs/ salamanders: wading birds, ducks, snakes, fish; toads secrete toxins so no),
Drought (aestivate to slow down metabolism),
Winter (hibernate and produce antifreeze),
pollutants (not well adapted) |
|
|
Term
| What characteristics reflect a snake's history of burrowing? |
|
Definition
| no legs,no external ears (inner ear detects ground vibrations), no eyelids (just nictitating membranes) |
|
|
Term
| How do snakes detect their prey? |
|
Definition
All have at least 2 systems:
1) Nostrils opening into organs like humans
2) Jacobsen system: pits in the roof of mouth that snake inserts its tongue into
3) only pit vipers also sense infrared radiation to locate warm-blooded prey with the loreal pit (between the nostril and the eye) |
|
|
Term
| Why do most waterfowl live in marshes? |
|
Definition
| High abundance of high energy/ protein foods (seeds, tubers, submerged plants), good animal food, good for avoiding predators (extensive cover, mud and veg are hard to run through, islands in open water provide good viewpoints and resting spots |
|
|
Term
|
Definition
| Harvest submerged/ floating-leaved plants from floating position b/c of long necks. Bad walkers because far back legs |
|
|
Term
|
Definition
| Grazers eating shoreside veg with modified bill for clipping veg, further forward legs fo better walkers, heavily hunted because considered good game and health hazard (from poop) |
|
|
