Wetlands Exam 2
1. Be prepared to list and briefly describe how the following processes are involved in wetland formation.

a.     Tectonic processes- faulting, subsidence


b.     Glacial processes-Moraine dams, Kettle depressions, Compact glacial till , Stratified drift


c.     Eolian processes – Winds may erode, transport, and deposit materials in regions with sparse vegetation, a lack of soil moisture.


d.     Marine processes-Long shore deposits isolate embayments, inlets and estuaries.


e.     Fluvial processes- Rivers meander to displace energy, results in uneven deposition of sediments that change the landscape and course of the river over time.


f.      Lacustrine deposits-pingo scars


g.     Subsurface dissolution- Rain is naturally acidic because of CO2 content (carbonic acid) which dissolves certain sediments over time making caves and sink holes.

2. What are the hydrologic pathways for water to enter or leave wetlands?

Precipitation,

Surface runoff,

Groundwater,

Tides,

Flood waters (rivers, lakes),

Evaporation/Transpiration

3. What are the hydrological characteristics of wetlands that affect wetland physiochemical conditions that, in turn, strongly influence the biota and ecology of wetlands?

Water depth

Flow patterns

Duration of flooding

Frequency of flooding

Physiochemical conditions –Biota

4. What are the principle physiochemical conditions that are affected by wetlands hydrology?

-Nutrient availability

• Degree of substrate anoxia

• Soil salinity

• Sediment properties

• pH

*Water inputs are a major source of nutrients to wetlands

 

*Water outflows remove biotic & abiotic material from wetlands

5. Define hydroperiod.

hydroperiod=seasonal pattern of the water level fluctuation

*The integration of all inflows & outflows of water, but influenced by physical features of terrain & proximity to other water bodies.

Flood duration?amount of time water is standing in a wetland

Flood frequency?avg.number of times a wetland is flooded in a given period.

Hydroperiod affected by:

Surface contours of the landscape

Subsurface soils & geology

Groundwater conditions

Balance between inputs and outputs (water budget)

Capacity to store water

6. Define and describe “spring tide” and “neap tide.”

“Spring tide”= When the tide is at its highest possible extreme range due to the alignment of the gravity of the earth, sun, and moon.

“Neap tide”= When the tide changes by the smallest degree because the sun and moon are inflicting opposing gravitational forces due to their positions around earth.

7. What stresses and benefits are associated with tidal influence in coastal wetlands?

Stresses-

  • Flooding

  • Anaerobic soil conditions

  • Salinity

Benefits-

 

  • Flushing of salts

  • Re-establishment of aerobic conditions

  • Source of nutrients

8. What is a “seiche” and how do they form?
seiche= Occurs on enclosed bodies of water (lakes or ponds) where the wind is strong and consistent enough to “push” the water to one side above its normal level. Once the wind stops, the water sloshes back to the other side flooding it also until equilibrium is reached and normal levels return.
9. Describe how biological organisms influence the hydrology of wetlands

 

  • Peat & sediment accumulation

  • Effects frequency & depth of flooding

  • Paludification

  • Shading > evaporation

  • Transpiration > evaporation

  • Sediment binding > erosion

  • Interruption of water flow (plants, beavers) • Undermining banks (muskrats, beavers)

  • Excavation (alligators)

10. With regard to soils what differentiates between:
a. The A-horizon and the O-horizon
b. The B-horizon and the A-horizon
c. The C-horizon and the B-horizon

a.     The A-horizon and the O-horizon- The O horizon is the organic material layer, The A horizon is the topsoil layer that has a lot of organic material, but is a mineral layer

b.     The B-horizon and the A-horizon- The A horizon is the topsoil, the B horizon is the subsoil, it is the zone of illuviation (deposition and weathering)

c.     The C-horizon and the B-horizon?- The B-horizon has a lot of weathering, The C-horizon has little weathering, and it consists of mostly parent material (decomposition of bedrock)

11. Why are wetland soils so much duller (low chroma) than upland soils?
Known as gleization, wetland soils rich with organic matter, are inundated for long enough periods that the anaerobic conditions result in a reduction of iron, the loss of which results in the lack of reddish color iron usually creates.
12. What are the three types of organic soils (histosols) found in wetlands?

 

  • peats(fibrist)

  • Mucky peats & peaty mucks (hemists)

  • Mucks (saprists)

13. What is redox potential? How does it relate to chemical processing in wetland soils?

Redox potential is the potential for a chemical to gain electrons and get reduced.

 

  • Under prolonged anaerobic condition, iron becomes soluble and is stripped from the soil grains.

  • When dissolved iron encounters oxygen in the soil, it becomes oxidized and precipitates out as rusty mottles

14. What is another name for carbon fixation?
photosynthesis
15. What is another name for the oxidation of carbon?
respiration
16. What are the mechanisms in wetlands that returns dissolved inorganic phosphorus to surface water?

 

  • Nutrient pump

  • Diffusion

  • Turbulent mixing

  • Sediment inhabiting animals

17. Understand and know the names of all the important transformations in the nitrogen cycle?

 

  • Decomposition, Processing-Plants to organic N (SON, POM)

  • Nitrogen fixation-atmospheric N_2_ to Organic N

  • Storage/accumulation-organic N to Peat/Muck

  • Mineralization-organic N to NH_4_+

  • Immobilization-NH_4_+ to sediments

  • Nitrification (oxidation)- NH_4_+ to NO_3_-

  • Reduction- NO_3_- to NH_4_+

  • Denitrification- NO_3_- to N_2_(gas) or N_2_O (gas)

  • Uptake-NH_4_+ or NO_3_- to Plants & Microorganisms

18. Why do bogs become acidic over time?
Mainly because of the sphagnum moss that grows there uses the export of hydrogen ions (which increase acidity) in its process of uptaking other nutrients resulting in a net increase in acidity over time because bogs are only fed water by rain so there is “flushing” of the water quality.
19. What plant adaptations were discussed in class for dealing with the anaerobic conditions encountered in wetlands?

Leaves: • Aerial leaves • Floating leaves • Submersed leaves • Heterophylly (always submerged plants)

Stems and Roots: • Aerenchyma (air pockets within stems/leaves)  • Lenticels • Adventitious roots • Pneumatophores (Root projections sticking up out of the water)

Growth of most of theses special structures stimulated by the hormone ethylene.

20. What leaf adaptations are typically found in floating leaved plants?

 

  • Round shape

  • Tough and leathery

  • Waxy upper surface or dense hairs

  • Stomates on top

21. What leaf adaptations are typically found in plants with submerged leaves?

Leaf is shaped to increase surface area

 

  • Long, thin leaves

  • Compound leaves

  • Disected leaves

  • Thin & pliable texture

  • Lacks supportive tissue

Heterophylly

 

more than one leaf type, uses ethylene, found in emergent/submergent plants

Aerenchyma (air cells)-
porosity of land plants (2-7% volume), wetland plants (up to 60% volume), ethylene
Adventitious roots-
aka prop routes, roots that emerge above the anaerobic soil, abundant lenticels, ethylene
Pneumatophores

 

root projections sticking up out of the water, abundant lenticels, cypress and black mangrove

lenticels
openings for gas exchange on stems & roots and are often hypertrophied on wetland plants
23. How do oxidized rhizospheres (oxidized pore linings) serve to improve environmental conditions in anaerobic soils?
Anaerobic soils are toxic to most plants due to the presence sof iron, magnesium, sulfer in dissovled forms plants can uptake. When roots “leak” oxygen around them, the iron immediately around them is oxygenated and creates a physical barrier to the toxins.
24. What are the general types of plant adaptations for reproduction in wetlands?

 

  • Aerial flowers

  • Floating flowers

  • Submerged flowers

  • Floating seeds

  • Vivipary-seeds germinate before they fall

  • Vegetative reproduction (fragmentation)

26. What are the plant adaptations discussed in class for the saline conditions encountered in coastal wetlands?

Barriers to salt entry:  • Endodermis (specialized cells that physically block salt, especially in the roots)

Salt excretion: • Specialized cells called Spartina excrete salt that has been taken up. Salt crystals will form outside of plant.

a. Ecological succession

 

the replacement of plant species in an orderly sequence of development

Sere (seral coomunity)

 

an intermediate stage found in ecological succession

Climax community

 

a stable community that represents the final stage of ecological succession

28. Explain Autogenic and Allogenic processes and how they can effect vegetation community change.

Autogenic processes- vegetation community changes are caused by the biota (i.e. succession)

 

Allogenic processes-distribution of plant species caused by its response to its environment

29. Compare and contrast the Classical Model of Succession with the Continuum Concept of vegetation community change.

Classical Model of Succession-

  • Vegetation occurs in recognizable and characteristic communities

  • Community change through time is brought about by biota (autogenic)

  • Changes are linear and directed toward a climax ecosystem

Continuum Concept of vegetation community change-

 

  • Distribution of a species is governed by its response to its environment (allogenic succession)

    • Each species responds differently to its environment

    • Replacement sequence is influenced by chance occurrence of propagules

    • Results in a continuum of overlapping sets of species, each responding to subtly different environmental cues.  

31. What are the invertebrate adaptations discussed in class for the anaerobic conditions encountered in wetlands?

 

  • Integument gas exchange

  • Gills

  • Lungs (pulminate snails)

  • Siphons

  • Physical gill

  • Air chambers (diving spiders)

  • Oxygen-binding pigments

  • ventilation

33. What are the general types of invertebrate adaptations for dealing with wet-dry cycles in wetlands?

 

  • Seasonal life cycles (e.g. fairy shrimp)

  • Drought-resistant life stages (eggs, cysts)

  • Bio-magnification (cladocerans)

  • Anti-desiccation adaptations

  • Highly sclerotized gills

  • Behavioral adaptations (e.g. burrowing)

  • Internal biological rhythms

  • mobility

a. Neustonic-

 

water surface mobility

b. Nektonic-

 

water column mobility

c. Benthic-

 

surface sediments

35. Describe how invertebrates use the boundary layer as a microhabitat in fast-flowing streams.
The boundary layer is the unmoving thin layer of water immediately next to a rock or piece of debris which some invertebrate flatten themselves down enough to be in this “layer so that they avoid being washed away.
36. What are the functional feeding groups for wetland and aquatic invertebrates?

 

  • Gleaners

  • Scrapers

  • Shredders

  • Filter feeders

  • predators

37. Why is the decline in horseshoe crabs along the Atlantic coast of the U.S. such a big concern in terms of shorebird populations?
The Red Knot population relies on the consumption of horseshoe crab eggs as a main food source in the spring.
38. Why is the maintenance of natural hydrology in wetland important for fisheries?

 

  • Life cycles tied to annual cycles of flooding

  • Flood control results in loss of floodplain habitat

  • Disruption of natural hydrology can desynchronize breeding cycle and hydrological coditions

39. In what ways are estuarine wetlands stressful environments for fish?

 

  • 80% of commercially harvested fisheries are dependent on coastal wetlands

    • Spawning habitat

    • Nursery habitat

    • Foraging habitat

    • Food chain support

40. What basic strategies have fish evolved for dealing with fluctuating salinity in estuarine wetlands?

 

  • Movers: avoid stressing conditions

  • Euryhaline species: tolerate stressful conditions

    • Able to tolerate rapid changes in blood chemistry

  • Physiological shifts

    • Anadromous fish undergo major changes in kidney and gill function and internal chemistry

41. What is a catadromous fish? Provide an example of a catadromous fish that lives in Massachusetts.
Lives in fresh water and enters salt water to spawn. Ex: American Eel
42. What is an anadromous fish? Provide an example of an anadromous fish that lives in Massachusetts.
Born in fresh water, spends most of its life in the sea and returns to fresh water to spawn. Ex: Blueback herring
42. What is an anadromous fish? Provide an example of an anadromous fish that lives in Massachusetts.
Born in fresh water, spends most of its life in the sea and returns to fresh water to spawn. Ex: Blueback herring
43. What are the three major groups (orders) of amphibians?

  • Salamanders and newts (Urodela)

  • Caecillians (Apoda)

  • Frogs & toads (Anura)

 

44. Why are amphibians so tied to freshwater (i.e., vulnerable to dry conditions and salt water)?
They need access to freshwater to survive due to their permeable skin, they would dry up in salt water. The skin provides little resistance to evaporative water loss, their eggs require wet or moist environment because they are unshelled.
45. What general adaptations do amphibians have for avoiding or coping with dry conditions?

  • Behavior

    • Largely nocturnal

    • Burrowers

    • Posture- to reduce surface area available for water loss

  • Cocoon-like structures
  • Waxy coatings
  • Aestivation- summer dormancy

46. What general adaptations do amphibians have for moving in wetlands/water?

 

  • Tail fins

  • Webbed feet

  • Eel-like bodies

  • Flattened body shape

  • “claws”

47. What are the three general methods used by amphibians for fertilizing eggs?

 

  • External fertilization

  • Spermatophores

  • Intromittent organs (phallodeum)

48. What general strategies do amphibians use for protecting their eggs from predators?

 

  • wide use of ephemeral wetlands (vernal pools, bromeliads)

  • eggs deposited out of water positioned to allow larvae to drop or wriggle into water

  • brooding

  • direct development

  • ovovivipary

  • vivipary

49. Which of the following are more closely related?

a. Crocodiles and turtles
b. Turtles and snakes
c. Crocodiles and snakes
d. Crocodiles and birds

D. Crocodiles and Birds
50. How is it that a basilisk can run along the surface of water?
It’s webbed-feet are oriented in a way that they hook off sideways as it runs that minimizes pressure and creates pocket of air underneath it. If it stops running at  any point, it will fall in. There’s a video on it online you can watch too that explains it.
51. Why are American alligators so important to the ecology of the Florida Everglades?

 

  • Used to be on the brink of extinction, but it’s super common now. Fish rely on periodical flooding to ensure their eggs stay wet. Alligators create huge compost pile nests that they build to a specific height so that their eggs don’t get inundated by water.

  • And they create “gator holes” that are excavated low spots to trap water for themselves during the dry season which is a refuge for fish, birds, and other things that require water.

52. What unusual adaptation does the alligator snapping turtle have for capturing prey?
Their tongue is bright red and worm-like that they will wiggle around while lying still at the bottom with their mouth open until a fish comes along and tries to eat it.
53. How do the shells of terrestrial turtles differ from those of aquatic turtles?
The underside of aquatic shells are far less developed and are reduced. This is so they can swim away faster as opposed to just sealing itself in it’s shell for protection.
54. What unusual reproductive strategy is used by Northern Long Neck Turtles?
It is the only turtle known to lay it’s eggs in water. It lays it’s eggs in teh flooded areas of rivers and then stay dormant until water levels drop and go dry for long periods of time. They wont hatch until the next major flood. People couldn’t find their nests for a super long time until a biologist stuck a transmitter in a female before she did. Turns out native knew the whole time, but biologists wouldn’t listen to them.
55. Why are roads such serious threats to turtle populations?

 

  • Turtles move long distances over land to mate, lay eggs, and just get to new habitat. They have slow reproduction and long lives (60-100 yrs) so they dont reach sexual maturity for many years and have low reproductive capacity. So one loss to the population results in huge loss to next generation. Nearly all turtle populations are threatened because of this.

56. Why do moose feed in wetlands in the spring and summer?

 

  • Because the rest of the year their diet if exclusively browse (twigs and buds) which have high potassium levels as a defense mechanism which the liver needs to dispose off but loses sodium as a byproduct. Wetlands are first to get green vegetation with low sodium allowing their sodium levels to recover.

57. To what purpose does a star-nosed mole use its unusual nose appendages?
The tentacles have many touch receptors that can identify edible material in milliseconds. It’s not necessarily a good smell, except it can sniff underwater by blowing bubbles first.
58. List three characteristics of the duck-billed platypus that distinguish it from most other mammals.

 

  • They lay eggs

  • The males are venomous

  • They sense electromagnetic signals from the muscle movement of their prey

60. Describe how beavers maintain a mosaic of habitats in the landscape that support a diversity of wetlands wildlife.

 

  • Create ponds by damming up rivers/streams. Ponds are habitat for other species of fish, otter, and birds (king fishers).

  • Flooded area can also create dead snags which many birds nest in.

  • Can fill with rich substrate over time and become a marsh or fill completely (or drain after dam breach) and become critical meadow land habitat. (Mostly lost to developement now).

  • Essentially, they create a dynamic landscape of changing habitat type availabilities whic makes the area more diverse.

61. What general adaptations of feet and legs do birds have for life in wetlands?

 

  • Webbed (palmate) ex. Blue-footed boody

  • Lobed (lobate)-grebe

  • Elongated toes-for lily pads, ex. Jacana-lives in the tropics, have long toes for lilypad walking

  • Roughened feet-osprey

  • Long legs-black-winged stilt

62. What general adaptations of bills/beaks do birds have for life in wetlands?

  • Sieve-like (lemellate) ex. Northern shoveler, flamingo,

  • Saw-toothed (serrate) elongated bills-red-breasted merganer

  • Pouched-white pelican,

  • Spear-like-anhinga

  • Hooked-snail kite for eating snails out of their shells

    • -american avocet, yellowlegs, whimbrel-curved shape reflects their foraging styles

  • Skimmers-black skimmer-different sized upper and lower bills for skimming along water surface

63. Given a list of bird species discussed in class (and included in the class notes) be able to identify for each in which feeding guild it belongs.

 

  • Grazers-feeds on herbaceous vegetation- canada goose, snow goose

  • Surface foragers- dabbling ducks(don’t dive)-black duck, trumpeter swans, coots, white pelicans, fulvous whistling duck

  • Diving foragers-diving ducks- completely underwater- red head, ruddy duck, canvasbacks

  • Diving piscivores-eating fish, not invertebrates- mergansers (common merganser, hooder merganser), cormorants, grebes, loons, anhinga

  • Aerial piscivores-dive from air to hunt fish- herring gull, belted kingfisher, least terns, brown pelicans, northern gannet, osprey(uses its feet, not beak)

  • Wading piscivores-snowy egret, great blue heron, wood stork

  • Tall wading

64. Describe the unusually foraging techniques used by black skimmers.
Skimmers-black skimmer-different sized upper and lower bills for skimming along water surface. Lower bill larger than upper and super sensitive. Lower dragged through water and claps instantly when fish is felt.
65. Where does the expression “skinny as a rail” come from?

 

  • Virginia rail, small water bird in dense vegetation, walks among dense vegetation, compresses its body size to avoid wiggling the vegetation as it walks through

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