Wetlands Exam 2

Define the following. Neustonic Nektonic Benthic

Neustonic (water surface) = the collection of microscopic & small organisms that inhabit the region on or just below the surface of a body of water Nektonic (water column) = the collection of marine & freshwater organisms that can swim freely and are generally able to move independent of currents, ranging in size from microscopic organisms to whales Benthic = (Surface sediments) organisms that live in and on the bottom of the ocean floor

Describe the marsh cycle of prairie pothole wetlands and the role of muskrats play in that cycle

1) Dry marsh: stimulates germination of upland & semi-wet annuals, stimulates vegetative sprouting of perennial emergent plants, creates a diverse community of plants 2) Dense marsh: dense & diverse vegetation at first, re-flooding drowns out intolerant plants, cattails gradually crowd out other plants 3) Hemi-marsh: openings created in dense marsh (floatation, muskrat activity - feeding & house building), interspersion of vegetation & water at its best for wildlife 4) Open marsh: Muskrat "eat-outs" create more larger openings, sustained flooding inhibits germination, interspersion & cover become generally unfavorable for wildlife, decreased vegetation = decreased invertebrates 5) Open water marsh: Mostly open water with vegetated fringe (germination zone), little change until next dry period (about a 20 year cycle)

What is a catadromous fish? Provide an example of a catadromous fish that lives in Massachusetts.

A catadromous fish is born in saltwater, spends most of its life in freshwater, and returns to saltwater to spawn. Ex. American eel

What is an anadromous fish? Provide an example of an anadromous fish that lives in Massachusetts

An anadromous fish is born in freshwater, spends most of its life in salt water, and returns to freshwater to spawn. Ex. American Shad

How do the shells of terrestrial turtles differ from those of aquatic turtles?

Aquatic turtles usually have a very reduced plastron on their bellies. Terrestrial turtles need to be able to retract into their shell for safety.

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

Autogenic processes: Vegetation community changes are caused by the biota (i.e. succession) The accumulation of organic material from plant production was seen to build up the surface until it was no longer flooded and could support flood-tolerant terrestrial forest species Allogenic processes: Distribution of plant species caused by its response to its environment The vegetation found at the wetland site consists of species adapted to the particular environmental conditions of that site

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

Barriers to salt entry • Endodermis • Especially in roots • Ex. mangroves Salt excretion • Specialized cells • Ex. Spartina

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

Beavers provide a lot of habitat for many different species such as otters, kingfishers, fish, and frogs. The flooded areas they create can be opportunistic to some events: if a tree gets flooded, then snags get created which creates nesting habitats for bird and even some mammal species like the Great Blue Heron. Snags formed in these areas also create opportunities for cavity nesters such as Wood Ducks, Hooded Mergansers, and Tree Swallows. When a dead tree falls over, it becomes accumulated in the muck and sediment. This allows marsh plants to establish themselves and create emergent marshes. Even if a beaver dam fails and drains, it can create wet meadows or otherwise grasslands which can convert to forests quickly, creating a completely new landscape for other forested species to thrive. Overall, the dynamic of these habitats created by the beaver can shift overtime, and there are a vast majority of species that are dependent on the beavers work.

Why are wetland soils so much duller (low chroma) than upland soils?

Because they are hydric

Describe the unusual foraging techniques used by black skimmers.

Black Skimmers fly along the surface of the water dragging their long lower bill in the water and when it comes into contact with a fish the bird scoops it up and swallows it quickly.

Why do so many carnivorous plants occur in bogs?

Bogs are some of the most nutrient poor wetlands and so carnivorous plants live there because they can get nutrients by eating insects, instead of the soil

Describe how invertebrates use the boundary layer as a microhabitat in fast-flowing streams.

Boundary layer Roughness of rock traps water layer that doesn't move so bugs can get real flat and just stay there even through running water

What are the three major groups (orders) of amphibians?

Caudata - salamanders Anura - frogs & toads Apoda - caecilians

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 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.

Which of the following are more closely related? a. Crocodiles and turtles b. Turtles and snakes c. Crocodiles and snakes d. Crocodiles and birds

Crocodiles and birds

Be able to define the following terms. Ecological succession Sere-Seral Community Climax Community

Ecological succession = The replacement of plant species in an orderly sequence of development Sere- Seral Community = An intermediate stage found in ecological succession Climax community = A stable community that represents the final stage of ecological succession

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

External fertilization - male releases sperm over female's eggs as they are laid Spermatophores - capsule or mass containing spermatozoa created by males & transferred in entirety to the female's ovipore during reproduction Intromittent organs (phallodeum) - long tube like organ that is inserted into the female's cloaca (internal insemination - caecilians are the only order of amphibians to do this)

What are the functional feeding groups for wetland and aquatic invertebrates?

Gleaners Scrapers Shredders Filter Feeders Predators

List three characteristics of the duck-billed platypus that distinguish it from most other mammals.

Have a bill Have webbed feet Lay eggs Electroreception - locate prey by detecting electric fields generated by muscle contractions Venomous

Define the following: Heterophylly Aerenchyma Adventitious roots Pneumatophores

Heterophylly = The presence of differently shaped leaves on the same shoot or different shoots of the same plant. In terms of aquatic plants, the leaves most likely differentiate above and below ground. Finely divided leaves below the surface of the water are better for gas exchange (ex. Mermaid weed) Aerenchyma = Spongy tissues form air channels, which allow for gas exchange between stems (above water) and roots (below water). Hormonal changes, increased concentration of ethylene, which encourages production of adventitious roots (ex. Burred) Adventitious roots = Roots that emerge above the anaerobic soil, abundant in lenticels for gas exchange (ex. Red mangrove, willow) Pneumatophores = Root projections sticking up out of the water, "knees", abundant lenticels for gas exchange (ex. Cypress and Black mangrove)

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

High sodium & protein content of aquatic plants Reduces overall energy expenditure Safe from predators (?)

To what purpose does a star-nosed mole use its unusual nose appendages?

It uses its highly sensitive nose to feel for food (invertebrates) in the damp soil around wetlands since it lives underground and has poor vision its nose is comparable to eyes. The nose is composed of raised papillae and they are Elmer's sensory organ's. It's nose can identify what is edible and what is not so quickly that the species holds the title of fastest forager in the world. It can also blow bubbles and then breathe them in which allows it to smell underwater.

How is it that a basilisk can run along the surface of water?

Its long webbed toes allow to have more surface area hitting the water and the sideways movement of its legs help to create friction between its feet and the water which gives enough resistance to propel the lizard forward for the next step.

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

Leaf shaped to increase surface area Long thin leaves Compound leaves Disected leaves Texture Thin & pliable Lack supportive tissue

What plant adaptations were discussed in class for dealing with the anaerobic conditions encountered in wetlands?

Leaves: • Aerial leaves- out of the water, normal • Floating leaves- round shape, tough and leathery, waxy upper surface or dense hairs, stomates on top • Submersed leaves- Leaf shape to increase surface area like long thin leaves, compound leaves, disected leaves -Texture- thin and pliable, lack supportive tissue • Heterophylly Stems and Roots • Aerenchyma (air cells) • Lenticels (openings for gas exchange on stems & roots, often hypertrophied on wetland plants) • Adventitious roots (have abundant lenticels) • Pneumatophores (root projections sticking up out of water) Others Fluted or buttressed trunks- large cells and abundant lenticels, promotes gas exchange Shallow root system

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

Long bills for catching fish/probing mud Hooked bills for catching fish, sucking in water Lamellae helps filter debris from water

Why is the maintenance of natural hydrology in wetland important for fisheries?

Many life cycles are tied to the annual cycles of flooding, flood control results in loss of floodplain habitat, and disruption of natural hydrology can desynchronize breeding cycle and hydrological conditions

What unusual reproductive strategy is used by Northern Long Neck Turtles?

Northern Long Neck Turtles lay eggs in mud underwater during the wet season and when everything dries out there is no evidence of the nest above ground. When it becomes wet again the eggs have now developed and hatch.

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

Nutrient availability Degree of substrate anoxia Soil salinity Sediment properties pH

With regard to soils what differentiates between: - The A-horizon and the O-horizon - The B-horizon and the A-horizon - The C-horizon and the B-horizon?

O-Horizon: • Varying states of decay • Thick in wetlands • Low strength • Darker color A-Horizon: • Mineral layer enriched with organic matter • Usually dark brown in color from accumulated humus B-Horizon • Also known as subsoil • Zone of illuviation & weathering, usually reddish/brown in color C-Horizon: • Substratum • Relatively unweathered parent material

What are the three types of organic soils (histosols) found in wetlands?

Peats (fibrist) Mucky peats & peaty mucks (hemists) Mucks (saprists)

Why do bogs become acidic over time?

Plants decay slowly in bogs because flooding prevents a healthy flow of oxygen from the atmosphere. Because of this bog soils are oxygen- and nutrient-poor, and are thus much more acidic than other soils

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

Precipitation Evaporation/Transpiration Surface runoff Tides Ground water Flood waters

Where does the expression "skinny as a rail" come from?

Rails are small slender birds that live in wetlands. They have a streaked coloration pattern that makes them look even more slender than they already naturally are.

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

Redox potential = quantitative measure of the tendency of the soil to oxidize or reduce substances Related to the concentration of oxidants & reductants

What is another name for carbon fixation?

Reduction

What is another name for the oxidation of carbon?

Respiration

What leaf adaptations are typically found in floating leaved plants?

Round shape, tough & leathery, waxy upper surface or dense hairs, stomates on top

In what ways are estuarine wetlands stressful environments for fish?

Salinity Temperature Dissolved oxygen Hydrologic fluctuations

What is a "seiche" and how do they form?

Seiche = a standing wave oscillating in a body of water Formed when strong winds and rapid changes in atmospheric pressure push water from one end of a body of water to the other. When the wind stops, the water rebounds to the other side of the enclosed area. The water then continues to oscillate back & forth.

Why is the decline in horseshoe crabs along the Atlantic coast of the U.S. such a big concern in terms of shorebird populations?

Some shorebird species rely heavily on horseshoe crab eggs for food during their spring migration.

Define and describe "spring tide" and "neap tide."

Spring tide = A tide in which the difference between high and low tide is the greatest. Spring tides occur when the Moon is either new or full, and the Sun, the Moon, and the Earth are aligned. When this is the case, their collective gravitational pull on the Earth's water is strengthened. Neap tide = A tide in which the difference between high and low tide is the least. Neap tides occur twice a month when the Sun and Moon are at right angles to the Earth. When this is the case, their total gravitational pull on the Earth's water is weakened because it comes from two different directions.

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

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

Tail fins Webbed feet Eel-like bodies Flattened body shape "Claws"

Define hydroperiod.

The seasonal pattern of water level fluctuation

Why are amphibians so tied to freshwater (i.e., vulnerable to dry conditions and salt water)?

They are mostly "skin breathers" & with this their skin is permeable to oxygen, carbon dioxide, water and salts. Their moist, scaleless skin causes them to be vulnerable to dehydration & without moist conditions, their skin dries out and they die In fresh water frogs have a body salt content much higher than the surrounding water and therefore tend to absorb water by osmosis & lose salts by diffusion through the skin. However they have a physiology that compensates for this and they survive. In seawater, they would be immersed in a medium much more concentrated than their body fluids, especially blood; they would lose water rapidly & gain salts, processes for which their physiology cannot compensate so they would die

What unusual adaptation does the alligator snapping turtle have for capturing prey?

They bury themselves in the substrate, open their mouths, and wiggle a growth on their tongue that looks like a worm. When a fish comes to eat it, they slam their jaws closed and eat the fish.

Among invertebrates how do "tolerators" differ from "regulators" in the manner in which they deal with salinity?

Tolerators evolved to tolerate a broad range of salinity concentrations in its blood, including high concentrations of salt. They have no control over what is happening in their body. Regulators either get rid of the excess salt or prevent it from coming in.

Why are roads such serious threats to turtle populations?

Turtles rely on a high adult survival rate because many species don't mature until 16 years or 18 years. They are slow at reproducing which means that for the population to be stable they need to have high adult survival.

What are the mechanisms in wetlands that returns dissolved inorganic phosphorus to surface water?

Via nutrient pump Diffusion Turbulent mixing Sediment inhabiting animals

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

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

Webbed & lobed toes Long legs for wading

Discuss the concept of Insularity related to wetlands as discussed in Mitsch and Gosselink. Pg. 244

Wetlands store nutrients in their system and a lot of them in the sediment mineralize, providing a steady source of organic fertilizer for plant growth, as a result much of the nutrient demand is satisfied by recycling. Growth in wetlands is limited by the mineralization rate, which in turn is strongly temperature and hydroperiod driven. Thus as wetland ecosystems develop they become insulated from the variability of the environment by storing nutrients.

How do oxidized rhizospheres (oxidized pore linings) serve to improve environmental conditions in anaerobic soils?

When anoxia is moderate, the magnitude of oxygen diffusion through many wetland plants into the roots is apparently large enough not only to supply the roots but also to diffuse out, oxidize the adjacent anoxic soil, and produce an oxidized rhizosphere. Oxygen diffusion from the roots is an important mechanism that moderates the toxic effects of soluble reduced ions such as manganese in anoxic soil and restores ion uptake and plant growth. These ions tend to be reoxidized and precipitated in the rhizosphere, which effectively detoxifies them.

Why are alligators so important to the ecology of the Florida Everglades?

When the dry season starts, they dig out a hollow for themselves to stay in the water. This is called a gator hole. Fish use these as refuges during the dry season and birds hunt the now concentrated fish to feed their babies.

What are the general types of plant adaptations for reproduction in wetlands?

• Aerial flowers- Bladderwort sticks flower way up out of the water, based on a pontoon style of floating up there • Floating Flowers- Water lily, Wild celery (pushes down on the surface tension of the water) • Submerged flowers • Floating seeds- Arrowhead/Duck potato - float until they lodge themselves into a shallow area • Vivipary- Red mangrove- seeds germinate before they fall into the water for dispersal • Vegetative reproduction (fragmentation)

What general adaptations do amphibians have for avoiding or coping with dry conditions?

• Behavior (largely nocturnal, burrowers, posture) • Cocoon-like structures • Waxy coatings • Aestivation (similar to hibernation - inactivity, & lowered metabolic rate that is entered in response to high temperatures & arid conditions)

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

• Integument gas exchange- Get oxygen through diffusion through skin • Gills - high surface area, increase oxygen transfer • Lungs- Like in pulminate snails • Siphons- Snorkel tube, stick it up out of the water to get oxygen, mosquito larvae • Physical gills - captures bubbles up against skin • Air chambers (diving spiders) • Oxygen-binding pigments - blood worms • Ventilation - burrows, keeps water moving

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

• Movers: Avoid stressing conditions by moving to areas they can tolerate • 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 If adapted to freshwater you are trying to prevent saltwater from coming in, hold their osmotic concentration

Describe how biological organisms influence the hydrology of wetlands.

• Peat & sediment accumulation (effects frequency & depth of flooding, paludification) • Excavation (alligators) • Shading decreases evaporation • Transpiration increases evaporation • Sediment binding decreases erosion • Interruption of water flow (plants & beavers) • Undermining banks (muskrats, beavers)

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

• Seasonal life cycles • Drought-resistant life stages (eggs stay in sediment until flood) • Biomagnification (Ex. clodosterens go through asexual reproduction & only produce females, but when drying occurs they produce males & females) • Anti-desiccation adaptations • Highly sclerotized gills (stay in tact when in contact with air) • Behavioral adaptations (ex. burrowing) • Internal biological rhythms (ex. don't come out until certain temperatures) • Mobility

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

• Tectonic - Faulting & subsidence • Glacial -Creation of moraine dams, kettle depressions, compact glacial till, and stratified drifts • Eolian -Winds erode, transport, & deposit materials & shape the landscape • Marine - Long shore deposits isolate embayments, inlets, and estuaries - without a barrier beaches would be open water and tides would prevent wetlands formation • Fluvial - Deposits & landforms created by rivers and streams (relationship between elevation of river & sediment - high: source of sediment, middle: losing & gaining equal amount of sediment, low: sediment settles out) • Lacustrine - As lake beds thaw, parts of it sink creating another level of sediment - a persistent spot of ice creates a hill (lots of sediment lost due to erosion, when it finally thaws it subsides and creates shallow depression • Subsurface Dissolution - Ex. slightly acidic water carves away the underground, impermeable substrates

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

• Wide use of ephemeral wetlands (vernal pools) • Eggs deposited out of water positioned to allow larvae to drop/wiggle into water • Brooding • Direct development • Ovovivipary (embryos develop inside eggs & remain in mother's body until they are ready to hatch) • Vivipary (live birth)