Shared Flashcard Set


Wetlands Exam 3
Exam 3
Environmental Studies
Undergraduate 4

Additional Environmental Studies Flashcards




1. What conditions all need to come together to get a “big night” for spotted salamander migration?
The first night in the spring that it rains heavily and it has been consistently 40F long enough and through the night to loosen frozen soil. It can span hours and can happen multiple times
2. What are vernal pools and why are they so important for amphibians?
Ephemeral wetlands that due to their isolated-ness and inconsistent water presence, fish predators cannot survive there so juvenile amphibians and invertebrates can live survive there. Thus major spawning area for amphibians.
3. List four Massachusetts amphibians that are considered vernal pool obligates (almost completely dependent on vernal pools for breeding).

  • Wood frog (Lithobates sylvatica)
  • Spotted salamander (Ambystoma maculatum)
  • Jefferson salamander (Ambystoma jeffersonianum)
  • Bluespotted salamander (Ambystoma laterale)
  • Marbled salamander (Ambystoma opacum)
4. What invertebrate taxon is considered an obligate indicator of vernal pools?

  • Fairy shrimp (Order Anostraca)
5. What are the factors that have contributed to the decline in waterfowl numbers from about 1900 through 1985?

  • Used to be a major food source til the 30s
  • Dust Bowl decimates pop numbers due to dry conditions.
  • Unregulated hunting and habitat destruction until the 80s.
6. Explain the need for an adaptive approach to waterfowl management and how it is addressed by the concept of “Adaptive Management.”

• Understanding there are significant gaps that remain in collecting scientific data on abundance, ecology and population trends

• Highly variable and continually changing abiotic and biotic conditions of the environment

• Improving strategies and planning accordingly will be more cost effective.

• Taking in to account uncertainty as to their consequences of actions taken

• Monitoring and assessment of population dynamics

• Using these monitoring and assessment data  in future decision making

7. Explain how the U.S. and Canadian governments determine how many waterfowl are likely to be available for the fall hunting season.

• Breeding population & habitat surveys:

         • Conducted in May and June

• Aerial surveys along transects with a sample of ground/helicopters counts to estimate visibility bias

• Count number of ducks and ponds

• Production & habitat surveys

         • Conducted in July • Aerial & ground surveys              (not concurrent)

• Only a portion of strata surveyed

• Number of duck broods (brood index) & number of ponds

8. Explain how the US Fish and Wildlife Service determines how many waterfowl are harvested each year.

Annual Waterfowl Harvest Surveys – (2 parts) Part I.  

HIP Harvest Information Program FWS selects a random sample of migratory bird hunters & asks them for information

– Kind and number of migratory birds hunted

– Used to estimate total harvest

Part II: Cooperative Parts Collection Survey

Sample of successful hunters asked to mail in 1 wing from each duck & tail from each goose harvested.

9. Why is the extent of arctic snow and ice cover in early June relevant to goose populations?

  • Geese will only nest where there isn’t ice and snow so you can use snow amount to determine extent of available geese habitat and thus geese numbers.
10. Explain how the Migratory Bird Treaty Act of 1918 affects the way hunting regulations are set for waterfowl in the U.S.

• MBTA made it unlawful to hunt, kill, or possess migratory birds except as permitted by regulations set by the Secretary of the Interior.

• MBTA authorizes the Secretary to determine when, if at all, to allow the hunting of  birds.  SEASON IS CLOSED UNTIL OPENED

• MBTA does not prohibit States from making or enforcing regulations, provided such regulations are not more liberal than those approved by the Secretary

12. How were prairie potholes formed? Describe the hydrology of prairie potholes.

  • As glaciers receded, left behind dense till (sediment not sorted by size) and unevenly distributed across landscape. Their bottoms are impervious so they hold water creating shallow depressions that hold water.
  • Water primarily from snowmelt, some from rain. This means water amount very variable creating boom and bust periods for vegetation wildlife that depend on them.
13. What relevance does the Supreme Court’s SWANCC decision have for prairie pothole wetlands?

  • SWANCC said intrastate, isolated, non-navigable waters not protected under Clean Water Act solely because of Migratory Bird Rule even though their crucial to waterfowl.
  • Are protected under Swamp Buster though meaning they cant be converted for agriculture.
14. Be prepared to describe or identify the various classes of prairie potholes. Which classes are most important for waterfowl?

  • Class 1: Ephemeral Pond • Surface water for only a short period of time in early spring • Vegetation dominated by prairie grasses and forbs
  • Class 2: Temporary Pond • Periodically covered by surface water for a few weeks after snowmelt • Vegetation dominated by wet meadow grasses, sedges, and forbs
  • Class 3: Seasonal Pond • Surface water in spring and early summer; dry by late summer/early fall • Vegetation dominated by shallow marsh plants (grasses, sedges, & rushes)
  • Class 4: Semi Permanent Pond • Surface water in spring and summer and usually into fall and winter • Vegetation dominated by marsh plants & submerged aquatics
  • Class 5: Permanent Pond • Surface water throughout the year in most years • Central zone devoid of vegetation except submerged plants
  • Class 6: Alkali Pond • Deep water is typically not permanently present • Characterized by a pH above 7 and a high concentration of salts • Dominated by salttolerant plants.
  • Class 7: Fen Pond • Fen vegetation dominates the deepest portion of the wetland • Low Prairie vegetation on the edges • Soils normally saturated by alkaline groundwater • Often have quaking or floating mats of emergent vegetation.
15. Why is it so important to have many different types of prairie pothole wetlands in close proximity to each other?

  • Need different types to accommodate different life stages (moulting, breeding, , feeding, etc.), ever changing conditions (one dries up, move to another), and multiple species differing needs (shorebirds like high salinity, dabbling ducks like shallower water, etc.)
  • Close proximity helps increase success of these moves. Farthe rin crease risk of predators, lack of resources, etc.
16. Describe the marsh cycle of prairie pothole wetlands and the role of muskrats play in that cycle.

Dry Marsh

• Drought conditions Stimulates germination of            upland and semi wet annuals

• Stimulates vegetative sprouting of perennial              emergent plants

• Creates a diverse community of plants

Dense Marsh

• Dense & diverse vegetation at first

• Reflooding drowns out intolerant species

• Cattails gradually crowd out other plants


• Openings created in dense marsh –

Floatation – Muskrat activity (feeding and house building)

• Interspersion of vegetation and water at its                 best for wildlife (50:50)

Open Marsh

• Muskrat “eatouts” create more and larger                  openings

• Sustained flooding inhibits germination

• Interspersion and cover become generally                unfavorable for wildlife

• ↓vegetation → ↓invertebrates

Open Water Marsh

• Mostly open water with vegetated fringe –                  Germination zone

• Little change until next dry period – ~ 20 year             cycle


17. Be prepared to describe or identify the various zones of bottomland hardwood swamps. Which zones are most important for waterfowl?

Zone I - No major veg, too wet.

Zone II - Bald cypress and water tupelo

Zone III to V - Oak mast producing species that waterfowl can eat so most important for them.

• Invertebrates and acorns are important foods for overwintering and breeding waterfowl, as well as other wildlife

• Dense cover

• Shade and cooler temperatures in summer

• Riparian travel corridors[image]

18. Why are bottomland hardwoods important for waterfowl and other wildlife?

• Historically, vast areas of flooded forest served as highquality habitat for waterfowl

• Invertebrates and acorns are important foods for overwintering and breeding waterfowl, as well as other wildlife

• Dense cover

• Shade and cooler temperatures in summer

• Riparian travel corridors

• Cypress, blackgum, and Sycamore produce cavities some waterfowl nest in.

19. What has happened to bottomland hardwood forests in the Mississippi Alluvial Valley? What current stresses are affecting bottomland hardwoods?

• Originally 10 million ha

• Flood control beginning in the late 1800s eventually eliminated virtually all mainstem flooding and reduced tributary flooding by 90%

• Extensive drainage for agriculture

• 80 % loss of bottomland hardwoods in the MAV

• Remaining bottomlands are fragmented and disconnected

• Most forested wetlands outside the mainstem levees of the Mississippi River no longer are connected to floodplain processes – hydrology has been severely altered

• Croplands receive heavy treatments of insecticides and herbicides that run off into remaining bottomlands

20. What is Moist Soil Management?

  • The use of water level manipulation (drawdowns and flooding)
  • promote the growth of “moist soil” plants (plants that germinate on exposed mudflats)...
  • ...that provide food (primarily seeds) for waterfowl
21. What is accomplished by water drawdowns in wetlands that are managed for waterfowl?

  • Concentrate prey
  • Create habitat conditions that can be exploited by a variety of wildlife
  • Provide soil and water conditions that promote the germination and growth of a wide variety of plants
22. What are the benefits of Moist Soil Management?

  • Impoundments also support invertebrates, amphibians and reptiles
  • Provide habitat (food and cover) for raptors, herons and other wildlife
  • MSM is a useful technique where several wetlands are available for water-level manipulations
  • A wetland complex can be managed to maximize the availability of habitat for a variety of waterfowl and other wildlife throughout the annual cycle
23. Explain how muskrats can create problems for Moist Soil Management operations.

  • They burrow and can burrow through a dyke or levee and weaken it.
  • *remember the marsh cycle
24. What are Green Tree Reservoirs and how are they used?

  • Forested areas are leveed and flooded
  • Flooded in fall and winter so as not to kill trees
  • Initially started in Arkansas to attract waterfowl for hunting
  • Provides waterfowl with access to acorns, soft mast and invertebrates
  • Compensates for variable fall precipitation and provides more flooded forest habitat early in the season for ducks
25. What are some important management issues associated with Green Tree Reservoirs?

*don’t flood during the growing season, trees will die under lack of oxygen

  • Long-term productivity compromised as a result of modifications in natural flooding regime
  • Early and prolonged flooding to greater depths associated with vegetation changes
  • To minimize shift in tree species composition variations in water manipulations are essential within and among years
26. Explain how beavers can create problems for Green Tree Reservoirs.

  • Beavers have access to trees that they might not have had access to
  • You are creating a wet area around trees that may not have been there
  • They screw up the water management that you may have set up by damming and flooding areas that are sensitive
27. What are the management goals recommended by Weller (1987)?

  • long -term productivity under the most natural conditions possible
  • Maintain natural values through the use of natural processes
  • Long term over short term benefits
  • Conservation programs that serve the greatest range of public interests
28. What are the general principles recommended by Baldassarre & Bolen (2006) relative to wetland conservation?

  • Protect wetland complexes
  • Protect small wetlands (most vulnerable to loss)
  • Consider all wetland-dependent wildlife when actively managing wetlands
  • Large wetlands are needed to maintain area-dependent species
  • Protected sites will likely require direct management to maintain their habitat value
  • Protect or restore adjacent upland habitats
29. Describe and distinguish high marsh and low marsh components of salt marsh wetlands in terms of hydrology and vegetation.
30. What are salt marsh Pannes and how are they formed?

  • Water retaining areas of the high marsh that hold water even after spring tides receed.
  • Mat of organic debris (known as wrack) is deposited upon existing vegetation, killing it. This creates a slight depression in the surrounding vegetation which retains water for varying periods of time.
31. Be prepared to list wildlife species that typically use salt marshes.

  • Ribbed mussel
  • Fiddler crab
  • Blue crab
  • Spotfin killifish
  • Rainbow smelt
  • Weakfish
  • Striped bass
  • Black seabass
  • Butterfish
  • Salt marsh watersnake
  • Diamondback terrapin
  • Willet
  • Clapper rail
  • Seaside sparrow
  • Egret
  • osprey
32. Why is the hydrology of a typical monthly tide cycle important for spawning mummichogs and spotfin killifish?

  • These species lay their eggs in the high marsh that they only have access too during less frequent spring tides. This means eggs up out of water where predators can reach them. When high marsh refloods, eggs rehydrate and hatch and babies can leave.
  • If regular tide cycles disrupted could be too long before eggs rehydrated and they die or rehydrate too soon and they dont fully develop and die.
33. Be prepared to discuss the various threats to salt marsh ecosystems discussed in class.

  • Coastal development
  • Invasive species (nutria, phragmites)
  • Freshwater intrusion
  • Tidal restrictions
  • Sea level rise
  • Nutrient enrichment
  • Sediment starvation
  • Crab herbivory/trophic cascade
  • Salt marsh die back
34. Describe how a “trophic cascade” may be affecting Cape Cod salt marshes via native purple marsh crabs.

  • Commercial and recreational overfishing has removed the predator of the purple marsh crab, thus there are more crabs just eating the tops of vegetation causing “die backs” (areas lacking vegetation resulting in no sediment trapping resulting in lose of marsh land).
  • Loss of predator “cascades” negative effects of increased crabs, causing increased vegtaion loss, then causing decreased sediment retention.
35. How does nutrient enrichment (particularly nitrogen loading) undermine salt marsh ecosystems?

  • Nitrogen a common pollutant now when marshes naturally nitrogen starved.
  • Results in increased plant growth, BUT growth focused in upper portion, not roots like they naturally do.
  • Means net loss in peat production that raises ground level of marsh to combat sea level rise.
36. Over long periods of time how do salt marshes adjust their elevation to match changing sea levels? What will be necessary for salt marshes to survive sea level rise associated with global warming?

  • When water levels rise, marsh plants increase productivity to produce more biomass that doesnt decompose cause of anoxic conditions in water which also works to trap sediment too and help build up mass. Called Accretion.
  • When sea level drops again, biomass exposed to air can decompose and ground drops to lower sea level.
  • Marshes also can also “migrate” where they just shift back inland to where ever appropriate water level is.
  • Seal levels need to rise slow enough for plants to Accretion to happen. Also dams people build to prevent water getting to developments also prevent marshes from migrating back far enough to exist.
37. Recount the history of grid ditching of salt marshes along the Atlantic coast of the U.S.

  • People were worried about mosquito born diseases
  • Was done when the U.S. had a surplus workers during the 1920’s
  • Wasn’t necessarily done well, they had a motivation to make the environment better for business
38. Apart from comfort, why is mosquito control such an important issue worldwide?

  • Mosquito bourn diseases
    • Malaria
    • Dengue
    • Yellow fever
    • West nile virus
    • Zika fever
    • Filariasis
    • Western Equine Encephalitis
    • EEE
39. Why does a lot of mosquito control tend to focus on wetlands?

  • Wetlands are where you get large concentrations of mosquitoes when they breed/lay eggs and when they are larvae.
  • Means you can use more targeted control techniques as opposed to less effective, broad-scale treatments that can be more damaging to other wildlife.
40. Be prepared to discuss each of the four broad categories of mosquito control that were discussed in class.
  • Adulticides-typically applied by aircraft or trucks
    • Organophosphates
      • Malathion
      • Naled

  • Larvicides
    • Application targeted at the immature mosquitoes
    • Applied to bodies of water that contain larvae
    • Biological larvicides
    • Chemical larvicides
  • Biological control
    • Fish: e.g. mosquito fish(gambusia)
    • Dragonflies
    • Notonecta
    • Turbellarian flatworms
    • Copepods
  • Source reduction-most effective and economical mosquito control technique
    • ditching/draining wetlands
    • Open marsh water management
    • Rotational impoundment management (RIM)
41. How are monomolecular films used in mosquito control? How do they work?

  • MMFs are lighter than water and do not mix particularly well with it. As their name implies, MMFs produce an extremely thin film on the water’s surface. form an ultra-thin film that is about one molecule in thickness. They act by significantly reducing the surface tension of the water and wetting mosquito structures, which leads to drowning.
  • do not kill by toxic action. Mosquito adults, eggs, larvae, and pupae utilize the surface tension of water in various aspects of their life cycle. With the surface tension reduction, mosquito larvae, pupae, and emerging adults cannot properly orient at the air-water interface and will eventually drown.
42. What’s the downside of using biological control for mosquitos?

  • Risks intended control species become invasive due to unforseen interactions and impossible to eradicate after that pretty much.
  • Takes a lot of careful study before implementation and can still go really wrong.
43. Describe Open Marsh Water Management and discuss why it is preferable to the grid ditching approach for source reduction.

  • Rotary ditching
    • Shallow ditches to allow fish access to water
    • Broadcast spoil evenly across the marsh
    • Use of sills to prevent dewatering of the marsh
  • Central pond and radial ditching
    • Pond provides permanent water for fish survival
    • Ditches allow fish access to marsh surface and pannes
44. What is Rotational Impoundment Management (RIM) and what can be done to limit the negative consequences of this source reduction technique on the ecology of estuarine marshes?

  • Use of impoundment dikes and culverts to regulates to regulate water levels on the high marsh
  • Culverts are typically open for most of the year and contain water at low tide
  • Culverts are close from late spring to early fall flooding the high marsh
  • Water levels on the high marsh are carefully controlled to avoid killing vegetation
  • Fish can enter and leave the flooded high marsh during high tides
45. Why is the lower Mississippi valley subsiding?

  • Built up sediments naturally subside over time as they settle more densely and thus ground sinks.
  • Oil development processes and diversion of sediment deposition away from natural area to ocean drop off areas instead mean the settling settlement not replenished.
46. Explain why the Mississippi River “wants” to change its course to the Atchafalaya basin.

• As delta forms the river segment lengthens

• River gradient is reduced over time

• River seeks fastest route to the sea = highest gradient

• Atchafalaya route to the sea is 145 miles

• Less than half the distance of the Mississippi’s current channel

• Long overdue for a course change

47. Recap the history of the Mississippi River’s relationship with the Red and Atchafalaya Rivers and the creation of the Old River Control Structure.

  • Mississippi river used to just be parallel to the red river until it meandered  to connect to it over time. Red river then become tributary to Mississippi river and part extending below attachment point became Atchafalaya distributary from mississippi.
  • Not much water went down the Atchafalaya cause there was a giant log jam. People wanted to use the water way though so they worked to break it up.
  • Another dude Henry Shreve decided to just cut through the meander and left over small streams act as tributaries from mississippi to atchafalaya that has been cleared.
  • Control structures built to supress flow of mississippi in to these tributaries to the atchafalaya. They checked on one (Old River Control Structure, biggest one) after a while and the whole bottom had been scoured out and it was shaking and was gonna go any second. So they built a bigger one and are hoping for the best.
  • Long overdue for a course change and mississippi “wants” to go through atchafalaya which would change entire area.
49. What are the primary causes of wetland loss in the Mississippi River delta?

Causes of Wetland Loss in the Mississippi Delta

• Natural subsidence

• Oil and gas extraction → subsidence

• Diversion of sediment

• NavigaƟon channels → salt water intrusion

• Coastal erosion and hurricanes

50. Discuss how the current sediment dynamics in the Mississippi river and the Mississippi delta affect the extensive wetlands of this region.

• Natural subsidence

• Oil and gas extraction → subsidence

• Diversion of sediment

• Navigation channels → salt water intrusion

• Coastal erosion and hurricanes

51. Discuss the importance of Mississippi delta wetlands for protecting human settlements and infrastructure from storm damage.

         o Reduce wave energy and trap sediments, slowing shoreline retreat and anchoring.

Hurricanes & Storm Surge:

• 4.7 cm/km of marsh reduced storm surge

• Katrina surge reduced by 3.7 m with 80 km of marsh before reaching NOLA

52. Describe the original hydrology of the Everglades and how it has been altered by human activity.

Original Hydrology

• Primarily from rainfall: ~ 127 cm/yr. (48”/yr.)

• 80% of rain falls in summerfall

• Total runoff equivalent to ~ 19 cm/yr.

• Limited storage through the dry season (12 cm) mostly in lakes and rivers

• Nearly no carryover of water from one annual hydrological cycle to the next

• Peat forms a barrier to infiltration

• In southern reaches water passes out to sea under and through the coastal ridge

Anthropogenic Impacts

1880s: Dredging of Kissimmee Lakes and Lake Okeechobee

1921: Lake Okeechobee surrounded by earthwork levees, canals drain lake to east and gulf coasts bypassing everglades

19211947: Everglades Agricultural Area, 2,150 km2 drained and farmed; 65% of everglades drained

1947: Establishment of Flood Control Districts

1950s 1962: Formation of Water Conservation Areas (3,600 km2)

19611971: Channelization of Kissimmee River; 80% of basin’s wetlands lost

1962: Flow to South Everglades cut off by transverse levee

53. What have the ecological impacts been of the human alterations to the Everglades?

• 65% loss of original wetlands

• Rapid movement of water down gradient via canals

• No flow to Big Cypress or NE Shark River Slough

• Disruption of seasonal cycles

– Water levels rise higher in early wet season

– Water levels are lower in late fall

– Water levels fall more slowly in dry season

• Increased nutrient levels – increase in cattails

54. Describe how the disrupted hydrology of the Everglades affected American alligators?

  • Sometimes in order to take advantage of certain habitats, because of the delay between laying eggs and them hatching, the animal has to anticipate the water levels
  • Alligators create nests of composts before the high water period, they decide how high the nest must be. The eggs need to be above the high water mark.
  • If you artificially disrupt the water flowing into the everglades, this can lead to nest flooding that the alligators can’t adapt to
55. Describe how the disrupted hydrology of the Everglades affected wood storks?

• Wood storks prefer water depth of 0.3 m

• Feeding tactic is groping: require high densities of prey

• Feed in everglades as lower levels drop: “drying edge”

• Wood storks time nesting to take advantage of natural hydrological fluctuations

• Falling water levels concentrate prey at time when feeding demands of young are highest

• Disruption of hydrology forces storks to abandon the everglades (90% decline)

56. What is the Comprehensive Everglades Restoration Plan and what does it hope to accomplish?

  • Authorized by congress in 2000
  • Put more fresh and clean water into the “River of Grass”
  • Federal-State partnership: National Park Service and Army Corps of Engineers trying to restore natural historical hydrology. (Meaning sheet flow of water instead of current concentration into culverts and ditches due to roads that cut across original area.)
57. Explain the “terrifying new math” about climate change as described by Bill McKibben.

• Copenhagen (2009) Climate Conference: Limit global temperature increase to 2°C (3.6°F)

• 167 countries have signed on to this target

• Many scientists believe that 1°C is a better target

• 565 more gigatons of carbon in the form of C02 will result in temperature increase of 2°C

• Proven coal, oil & gas reserves: 2,795 gigatons

• 80% of these reserves need to stay in the ground…

• …but all are already economically above ground.

58. What are the four key greenhouse gases and how are they affected by wetlands?

• Carbon dioxide: Has increased 30% since the mid1700s

• Water vapor: No known trend or change

• Methane: 25 times more effective as a greenhouse gas than CO2 after 100 years

• Nitrous oxide: Has increased 20% since preindustrial times

59. What are the elements of climate change and give some examples of how each might affect wetlands in the future?

  • Rising temperatures
  • Sea level rise
  • Changing precip patterns
  • Changes in seasons
  • More severe storms
  • Acidification of the ocean
Supporting users have an ad free experience!