Exam #2

Natural Resources And The Environment 811 with Burdick at University of New Hampshire

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By: Em Troisi
Created: 2011-11-01
Size: 92 flashcards
Views: 15

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peatlands develop through ____ or ______

terrestrializaton (the infilling of shallow lakes)

paludification (the blanketing of terrestrial ecosystems by overgrowth of peatland vegetation)

quaking bog succession

plant cover gradually develops from the edges toward the middle of the lake

classification schemes for peatlands have (7) features

1) floristic 2)vegetation structure 3) geomorphology 4) hydrology 5) chemistry 6) stratigraphy and 7) peat characteristics

landscape classification for peatlands

1) raised bogs

2) Aapa peatlands

3) Paalsa bogs

4) Blanket bogs

raised bogs

peat deposits that fill entire basins, are raised above GW levels, and recieve major inputs of nutrients from precipitation.

blanket bogs

are a result of paludification. the peat literally blankets very large areas far from the site of the original peat accumulation.

chemistry-based classification

1) minerotrophic peatlands

2) mesotrophic pearlands

3) ombotrophic peatlands

minerotrophic peatlands

true fens that recieve water that has passed through mineral soil. Generally have a high GW level.

mesotrophic peatlands

intermediate between mineral-nourised and precipitation-dominated peatlands. Also called poor fens

ombrotrophic peatlands

these are the true raised bogs that have developed peat layers higher than their surroundings and receive nutrients exclusively by precipitation.

Canadian Wetland Classification System

1) bog

2) fen

3) swamp

bog

peatland recieving water exclusivly from precipitation and not influenced by groundwater; sphagnum-dominated vegetation

fen

peatland receiving water rich in dissolved minerals; vegetation cover composed dominantly of graminoid species and brown mosses.

swamp

peatland dominated by trees, shrubs, and forbs; waters rich in dissolved minerals

____ and _____ are most important factors in the development and structure of peatlands

soil

water chemistry

the pH of peatlands generally ______ as the organic content _____.....

decreases, increases

5 causes of low pH of bogs...

1) cation exchange by Sphagnum= sphagnum peats have high exchangeable hydrogen and thus lower pH

2) oxidation of sulfur compounds to sulfuric acid

3)atmospheric deposition

4)biological uptake of cations by plants

5) buildup of organic acids by decomposition

bogs are _____ in available plant nutrients

deficient

the productivity of bogs vs fens

nutrient-poor bogs is lower than that of nutrient-rich fens

Sphagnum

moss genus

peatland plant

Eriophorum vaginatum

cotton grass

peatland plant

Carex spp

sedge species

peatland plant

Ledum palustre

Labrador tea

peatland plant

Larix laricina

tamarack

peatland

peatland stressor: waterlogged/anaerobic environment, adaptation(s): ______

1) development of large intercellular spaces (aerenchyma) for oxygen supply

2) reduced oxygen consumption

3) oxygen leakage from the roots to produce a locally aerobic root environment

peatland stressor: nutrient deficiency, adaptation(s): ______

1) evergreenness

2) sclerophylly (thickening of plant epidermis to minimize grazing)

3) uptake of amino acids

4) high root biomass

5) carnivory- the ability of carnviorous plants to trap and digest insects

Sarracenia purpurea

pitcher plant

peatland plant

peatland stressor: overgrowth by peat mosses, adaptation(s):

raising shoot bases by elongating rhizomes or by developing adventitious roots

bogs are systems of _____ primary productivity

low

Sphagnum mosses often ______ bogs and other vegetation is often ______ in growth

dominate, stunted

peat contains a ____ amount of nutrients, but is often ____ the rooting zone, thus is ____

vast, below, unavilable to plant uptake.

cycling is slow in low-nutrient peatlands in cold climates because...

low tempreatures, the nutrient deficiency of the litter, and the watterlogging of the substrate

the accumulation of peat in bogs is determined by...

the production of litter (from primary production) and the destruction of organic matter (decomposition)

the rate of decomp. in peatbogs is generally ____, because...

low, because of waterlogged conditions, low temps, and acidic conditions.

features common in many peatlands include;

1) acidity caused by cation exchange with mosses

2) low nutrients and primary productivity

3) slow decomp

peatlands are known to be nutrient ______

sinks

bogs are... and support...

acid peat deposits with no significant inflow or outflow of surface or GW.

acidophillic (acid loving) vegetation, particularly mosses

fens are.... and support...

open peatland systems that recieve some drainage from surrounding mineral soils

grasses, sedges, or reeds

2 primary processes necesary for peatland development

positive water balance

peat accumulation

positive water balance

water input is greater than evapotranspiration

trees in forested wetlands have developed several unique adaptations to wetland environments including...

knees, buttresses, adventitious roots, fluted trunks, and gas transport to the rhizosphere.

forested swamp primary productivity is closely tied to________ conditions

hydrologic

Chamaecyparis thyoides

Atlantic white cedar

forested swamp spp

Acer rubrum

red maple

forest swamp spp

Ulmus americana

american elm

cypress domes

poorly drained to permanently wet depressions dominated by pond cypress.

dwarf cypress swamps

major areas in SW florida, where pond cypress is the dominant tree but it grows stunted and scattered in a herbaceopus understory marsh.

poor growing conditions result from lack of suitable sunstrate overlaying the bedrock limestone that is found in the region.

lake-edge swamps

bald cypress swamps often found as margins around lakes and sloughs.

slow-flowing cypress strands

are found primarily in S florida where rivers are replaced with slow flowing strands. substrate is primarily sand.

atlantic white cedar swamps

hydrologic regime can be classified as seasonally flooded, with flooding for an extended period during the growing season.

swamps are generally ___, depending on accumulation of peat and how much ______ dominates the hydrology

acidic to nuetral, preceipitation

nutrients conditions in swamps vary from...

nutrient/mineral poor on rainwater-fed swamps to

nutrient/mineral rich conditions in alluvial river swamps and GW discharge swamps

Taxodium distichum

bald cypress

Tsuga canadensis

eastern hemlock

Clethra alnifolia

sweet pepperbush

Vaccinium corymbosum

highbush blueberry

cedar swamps

redmaple swamps

Ilex verticillata

winterberry

red maple swamps

Scirpus cyperinus

wool grass

forested swamp

swamp stresser: waterlogging, adaptation(s):

knees/pnuemataphores

buttresses (swelling occurs at part of tree that is flooded atleast seasonally)

hydrochory

longevity

shallow or adventitious roots

gaseous diffusion

swamp productivity is tied to its ______

hydrologic regime

nutrient inflows are major _____

sources of influence on swamp productivity

swamps can be nutrient ____

sinks

decomp of woody and non-woody material in swamps is affected by_____

the water regime and the degree of anaerobiosis

pulsing hydrology supports _____ systems than does _______

more productive, permanent flooding or lack of flooding

The hydroperiod is the result of a balance between....

the water budget (inflows and outflows of water)

the wetland basin geomorphology,

and the subsurface conditions.

the major components of a wetlands water budget include;

precipitation, evapotranspiration, overbank flooding in riparian wetlands, other surface flows, GW fluxes, and tides in coastal wetlands.

hydrology affects...

species composition and richness

primary productivity

organic accumultion,

and nutrient cycling

in general, productivity is high in wetlands that have....

high flow-through of water and nutrients or in wetlands with pulsing hydroperiods

hydroperiod

the seasonal pattern of the water level of a wetland and is the wetland's hydrologic structure

flood duration

the amount of time that a wetland is in standing water

flood frequency

the average # of times that a wetland is flooded in a given period

hydropulses nourish the riverine wetland with...

additional nutrients and carry away detritus and waste products

the hydroperiod is the result of:

the balance btw inflows and outflows of water

the surface contours of the landscape

subsurface soil, geology, and GW conditions

the reccurence interval is...

the average interval between the occurance of floods a a given or greater stage (depth)

hydrology leads to a unique vegetation composition but can also...

limit or enhance spp richness

wetland biogeochemistry

a combination of chemical transformations and chemical transport processes

an ecosystem is considered biogeochemically open when...

there is an abundant exchange of materials with its surroundings, and closed where there is little movement of materials across the ecosystem boundary.

mineral soil is less than _____% OM

25-30%

peat

is a generic term for relativly undecomposed organic soil

compare organic to mineral soils in terms of bulk density/porostiy, hydraulic conductivity, nutrient availability, and cation exchange capacity

organic soils typically have;

lower bulk densities and higher porosity

both have wide ranges

more minerals tied up in organic forms unavailable to plants

greater cation exchange capacity

redox concentrations

accumulation of iron and manganese oxides

redox depletions

low chroma bodies with high values

reduced matrices

low chroma soils

redox potential

a measure of the electron pressure (or availability) in a solution used to further quantify the degree of electrochemical reduction of a wetland soil.

Autogenic succession (Clements)

1) vegetation occurs in recognizabe and characteristic communitites

2) community change through time is brought about by the biota (autogenic)

3) changes are linear and directed toward a mature, stable climax ecosystem.

Individualistic hypothesis (Gleason)

have developed into the continuum concept, which says that the distribution of species is governed by its response to its environment (allogenic succession).

In this view, no communitites exist in the sense used by clements.

classical hydrarch succession

says that wetlands are a transient stage of a terrestrial forested climax community from a shallow lake.

environmental sieve model (Van der Valk)

all plant spp are classified into life-history types, based on potential life span, propagule longevity, and propagule establishment requirements.

Cetrifugal organization concept (Keddy)

describes the distribution of species and vegetation types along a standing-crop gradient caused by combinations of environmental constraints.

-transition from core habitat to periphery habitat.

ecosystem engineer

organisms that have dramatic and important effects on an ecosystem.

Approx Redox Potential for Transformation: OXYGEN

o2-h20 @ >400

About this deck

By: Em Troisi
Created: 2011-11-01
Size: 92 flashcards
Views: 15

About StudyBlue

“I have used this website for three exams, and I see a huge difference in my test results.”
Naj