NRC 260 Flashcards

epilimnion

epilimnion

upper layer, warmer, higher dissolved o2, circulation/mixing, photosynthesis

metalimnion

middle layer, temperature change

thermocline

temperature gradient in metalimnion

hypolimnion

bottom layer, colder, less dissolved o2, decomp of built up organic matter, little light, little mixing (in lakes)

water is most dense at

4 C

lotic system

continuously flowing water

low order river

lots of flow, rapid/steep

high order river

lots of water, less rapid, sediments settle, deltas

3 river shapes

straight, sinuous, meandering

headwaters

source, high order, rapids, swift, erosional

lower reaches

slower, depositional, low order

loosing stream

lower water table

gaining stream

higher water table

allochthonous

external, leaf litter

autochthonous

internal, photosynthesis

wind seiche

wind makes water surface uneven

oligotrophic

low nutrients, rocky, clear water, pine and birch

mesotrophic

moderate productivity, some algae, deciduous trees

eutrophic

shallow, murky water, prairie, very productive

average ocean salinity

35 ppt

strongest tide

new moon spring tide

tidal bore

swelling of water into an area by a tide; bay of fundy

coriolis

to the right in N, to the left in S

winds in N hemisphere

polar easterlies, westerlies, tradewinds, ITCZ

ekman spiral

dif layers move in dif directions basically

ecotone

transition zone, spatial and/or functional, possibly unstable

wetlands

soil is perm or seasonally saturated, impacted by groundwater and aboveground flow, not always w open water

bogs

precipitation dominated, no open water, peat and sphagnum moss, acidic, low nutrients, low biodiversity, higher elevations with permafrost under

vernal pools, wet meadows, wet prairies, prairie potholes

precipitation dominated, interannual variation in precip, depressions formed following glaciation, important habitat for 50% of NA migratory waterfowl

fens

groundwater dominated, gets water and nutrients from ground. less acidic, higher nutrients and biodiversity than bogs, mostly N hemisphere

marshes

usually surface water dominated, often open water w emergent vegetation, high nutrients, neutral ph, high biodiversity, tidal freshwater marshes levels are influenced by tides

wetland functions

reduce water flow (flood prevention), groundwater recharge, nutrient transformation (nitrification, removal of phosphates, carbon storage, etc)

emergent wetland flora

growing out from water

3 types of wetland flora

emergent, floating, submerged

wetland fauna

many niches, permanent and transient species

estuaries

semi enclosed coastal embayment w river discharge, where freshwater meets saltwater

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zonation factors

desiccation, competition/predation, salt spray, wave energy