Wetland Final Exam

Wetlands are highly productive because

high organic primary production and have alrge amounts of both animal and plant biomass

Wetlands regulate the climate through

carbon storage, methane production, and coal production

Nitrogen is abundant in ____ but scarce in ____

air, organisms

Nitrogen fixation

done by Cyanobacteria that converts atmospheric N₂ to NH₄

Denitrification

removal of N in plant tissues or organic material and is converted back to atmospheric N₂

Nitrogen is limiting in _____ and phosphorus is limiting in ___

land, water

Sediment can store nutrient such as

N and P leading to peat build up

Wetlands can act as storage for

rare species, biologial diversity, and genetic diversity

Wetland services and management

individual species, large amounts of biodiversity, water purification, and huge economic value

Causes of flooding

rain, melting snow, natural rising and falling of water, natural or man-made disasters

Wetlands ____ flooding

reduce

Wetlands can record historical data including

climate data, organisms, succession, contaminates, and depostition rates

Flooding causes variations

within years and among years

Biological consequences of flooding

water fluctuations, breeding and maturing of offspring, behavior and life cycle of fish, macroinvertebrate composition, and endangering rare plants

Water level fluctuations depending on sources of water

Rivers → seasonal flooding

Lakes → rising and falling shorelines

Beaver ponds → dab building and collapse

Potholes/vernal pools → rain and snowmelt

Peatlands → more stable water tables

Flooding in swamps

zone woody plants at high elevation and occasional flooding allows vegetation to survive

Flooding in wet meadows

kills woody plants, plants can establish more rapidly, and requires occasional flooding

Flooding in Marshes

flooded for most of the growing season and plants are tolerant of flooding

Hydrological effects of dams

stabilized water levels, shifted food timing, increased flooding (levees concentrate flow), and decreased flooding (reduced floodplain area)

Upstream effects of flooding

water levels depend on dam purpose, extreme flucations are possiblem and reversed or extreme cycles can cut vegetation

Downstream effects of flooding

reduced spring floods (global loss of wetlands), conversion of wet meadows to woody vegetations), and loss of biodiversity and habitat

Predicting consequences of flooding

Stablizied water levels reduces plant diversity and marsh area

Six elements make up all organisms

CHOPNS

__ and __ are loved by plants and can be used to determine habitat suitability, also called ___

P and N, fertility

Fertility controls ___. Thus __ and __ supplies limit plant growth.

primary productivity, N, P

Infertile wetlands include ___ and are characterized by …

Pocosin (sandy peat soils and wood shrubs), relying on rain water( low nutrients), sensitivty to increase nutrient availability, and strong gradients in plant compostion

Infertile habitats have unique species including plants

that can tolerate nutrient shortages, have slow growth, evergreen foilage, nutrient storage, anti-herbivory defenses, and mycorrhizae

____ is the limiting factor is fertile habitats leading to plants that are tall and fast growing

light

Fertility varies in ____ in wetlands that can be used to explain the patterns of a wetland

gradients

Peatlands (fertility)

low in nutrients, pH and calcium concentrations play a major role, water supply, water level, and location play a role in species composition and growth

Mycorrhizae

fungi with a symbiotic relationship to plants roots, Mycorrhizae recieve sugars and plants recieve nutrients in return

Most plants products contain less than ___ N which is ___ for herbivores

5%, bad

Animal strategies for increasing Nitrogen

synchronzining life cycles with food availability, selecting tissues with higher N, eating quickly and digesting more efficiently, supplementing plant food with animal protein, and territoral and social behavior

Four general consquences of nutrient accumulation in wetlands

1. decreased biodiversity due to increased biomass causes by alleviation of nutrient limiations

2. increased nutrients cause plants to become more palatable to herbivore, increasing herbivory and herbivore numbers

3. increased floating algae can kill aquatice macrophytes

4. decomposition of algae and macrophtyes lead to increased O₂ consumption and hypoxic conditions

Sources of nutrients

urband areas (point source), rural areas (diffuse source), and rainfall

Solutions to excess nutrients

Urban: wastewater treatment, reduce lawn fertilizer, clean up after pets

Rural: change agriculture and forestry practice and reduce road building

Precipitation: stricter environmental regulations of buring fossil fuels and reduce car usage

Calcium in Wetlands

reduces acidity, binds with P to form calcium phosphates lowering amount of P available to plants, and calcium concentrates and pH are very important for determing wetland type (Bogs: low pH and sphagnem moss)

Calciphilous

species restricted to calcium-rich soils

Disturbance

a short lived event that removes biomass and causes measurable change in the properties of an ecological community

Common distrubance examples

fire, ice scour, storms, herbivory

Distrubance can alter

biomass, substrate, and nutrients

4 properties of disturbance

1. duration (how long)

2. intensity (severity of the event)

3. frequency (higher intensity of disturbance =less frequent)

4. area (amount of land effected by distrubance)

Seed banks

buried reserves of viable seeds

Fire can

remove biomass inceasing light availability and ash contains P

Marshs and wet meadow species can only regenerate in ___ provided by ___

gaps, disturbance

Seeds can detect disturbace through

fluctuations in soil temp, increased light, and changes in the quality of light

Highest intensity disturbance is equals

highest species richness

Saline environments have ___ seed densities

lower

Colonization patterns from erosion and deposition

Herbaceos pioneer plants → small pioneer trees → mixed pioneer and successional species (closed canopy forms) → mature plant community

Low intensity fire disturbance

removes above ground biomass and shift species composition and wetland type

High intensity fire disturbance

burn organic soil, create new species composition, often create open water

The everglades are a ___ of different vegetation types due to ___ disturbance

mosaic, fire

Fire disturbance in peatlands can record history of disturbance and system response in ____ and ____ layers

charcoal, macrofossil

Feedback loops in peatlands with fire

fire → carbon release → higher temperatures → more frequent fires

Types of ice disturbance

ice foot formation, spring ice, riparian effects, and ice scour

Ice scour

large chunks of ice driven by wind and currents can rip out sediment and vegetation, removes fine sediment, lowers OM conten, and increases habitat without shrub coverage

Effects of wave action

moderate exposure: expand wet meadows and marshes

high exposure: sand or gravel shorelines

chronic exposure: removal of fine sediments

amplify ice effects: increase movement and erosion during freeze and thaw conditions

Animals ___ biomass by ___

remove, herbivory

Types of animal disturbance

gator holes (biodiverse), prairie potholes, muskrats (eat outs), beavers (alter water flow and levels)

Important disturbances in praire potholes

grazing, mowing, and natural disturbance

Peat-cutting

cutting out peat from a watland to enhance plant biodiversity and peat is used as fuel, however must continually remove peat

Logging

created by removing biomass from a forested system, however secondary effects are greater (ruts, roads, and canals)

Logging can also have …

permanent hydrological changes

Hurriance disturbance has 4 main components

felling of trees (wind), saltwater pulses (storm surge), freshwater pulses (rain), and sediment redistribution (waves)

Frosts can convert ____ to ___

mangrove swamp, salt marshes

Patches in wetlands are formed by …

fires, prolonged flooding, muskrat herbivory, ice scour, floating mats of litter, buried alluvial deposits

Invertebrates are ___ to disturbances and when they are at ___ densities there is ___ food for waterfowl

senstive, high, more

What are the disturbances that cause high invertebrate densities (highest to lowest)

cutting cattails → buring → mowing → flooding

Ways to measure and determine effects of disturbances

1. Measure relative changes in species compostition and biomass

2. Determine how the effects of disturbance varies between habitats or groups of species

Competition

negative effects that one organism has on another, examples consumption and resource limitation

Competition takes ____ studies over a ___ period of time

multiple, long

Ghost of competition past

species that use to overlap (over a resource) divereged characteristics to partion resources and aviod competition; past competition shapes current morphology and behavior

Competition is often _____ causing ___ competition, one species ___ another

one-sided, asymmetric, out competes

Assymetric competition is the greatest and least in which habitats

greatest: fertile and flooded

least: unfertilized and moist

Competition for ____ produces ____ hierarchies through processes such as

light, competitive, rates of vegetative reproduction, antagonism (competition), and dense canopies suggest that the competition is for light

Prescence of canopy has ___ effects on growth

negative

____ plants are often larger than ____ plants

Dominant, subordinate

Survival of the weak competitor can be due to

patches, disturbance, and gradients

Centrifugal organization

links high competition with low diversity, with the ocre habitats as fertile, undisturbed, and have high biomass

Peripheral habitats are at risk due to

stablized hydrology, high amounts of nutrients, lowered herbivory, fire suppression, and genetic changes (including hybridization)

Natural disturbance regimes help these species …

bog turtles, box turtles, spotted turtles, wood turtles, baltimore checkerspot butterflies, bog buck moths, sedge wrens, and rare sedges and orchids

Allogenic burial

sediment and OM from external areas (deltas)

Autogentic

OM produced locally (peat bogs)

Sediment arrives in ___ and may not remain in the same location

single pulses

Sediment loads

increase with rainfall and deforestation AND produces a diverse array of wetland types AND decrease when dams are constructed

Natural levees

built by the river as it deposits new layers of sediment along the banks

Artifical levees (embankments)

Concrete walls put up to stop flooding

Rain-fed bog formation

peat accumulates across a broad area with no lateral expansion, peat can begin at multiple individual points and eventually fuse together, or peat could accumulate at one site and increase in depth and area

Burial may happen from ___ and reduces _____ and ___ . It can cover ___ and growing points. Controls which species survive and drives _____ in plant communities.

flooding, runoff, or storms; light and oxygen; shoots; changes

Rhizomes

store energy, allow lateral spread, push shoots through sediment

Which wetlands are most and least sensitive to burial

Most senstive: alpine

Tolerant: freshwater and coastal wetlands

How does burial depth affect plants

survival decreases as depth increases, deeper burial prevents emergence, and can lead to plant death

cm of sedi is sufficient to reduce emergence by more than how much? 2cm burial?

50%, near 0 emergence

Seedlings are senstive to burial because

burial reduces species diversity, sediment may contain contaminants, and only tolerant species persist

3 leading threats ot freshwater aquatic ecosystems

sedimentation, exotic species, impoundments

with 20% fish are extinct of declining

Primary sources for alter sediment loads and it consquences

agricultural non-point pollution and road construction, aquatice invert and fish eggs are suffocated and nutrients in sedi causes summer growth then after winterkill the O levels are reduces

When urban land increases ther should be an ___ in ____ to compensate

increase, riparian

Sediment cores indicate changes in vegetation in what pattern

open water → floating-leaved plants → reeds → bog

Counter succession factors

fire, flooding, erosion, burial, and climate change

Short term effects of burial

immediate death