BIOL 2170 Midterm Review (copied from old acc)

ecology

the scientific study of the interactions between organisms and their environment

interaction

a relationship where each party influences & is influenced by the other party

environment

the biotic & abiotic factors of the habitat that interact with the organisms

stochastic events

periodic physical events (fires, floods, hurricanes)

commensal

relationship where 1 party benefits and the other is indifferent

ecosystem

sum of the biological community and the abiotic factors with which it interacts

climate

range of extremes over months, years, decades

weather

day to day conditions

PAR

photosynthetically active radiation

solar radiation

incoming shortwave radiation from the sun (ultraviolet, PAR, infrared)

earth radiation

outgoing longwave radiation (far infrared)

incoming shortwave radiation

30% reflected by clouds
19% reflected by earth's surface
51% absorbed

cloud cover

dampens variation in temperature

energy variation over time

days, seasons, elliptical orbit

energy variation over space

curved surface of planet means that some areas receive more rays/area

albedo

the proportion of energy reflected by a surface

coriolis effect

deflection of objects moving northwards and southwards, due to the counterclockwise rotation of the earth

large scale airflow patterns

as air warms it rises and is replaces by cold air in its old position, as it travels away from the equator it cools/sinks

hadley cell

directly on either side of the equator. most powerful cells. create the NE/SE trade winds

ferrel cells

on the outer side of the tropics. direction of flow controlled by hadley cells. create the westerlies

polar cells

closest to the poles. direction of flow controlled by ferrel cells. create the polar easterlies.

intertropical convergence zone

also called doldrums. pocket of still air between the hadley cells

barometric/atmospheric pressure

weight (mass) of the air column above a given position on the earth's surface

air column

a tube surrounding a given area that extends from the ground to the limit of the atmosphere (~180km)

low pressure system

warmer air

high pressure system

colder air

adiabatic process

temperature change that occurs due to a change in density, without a energy gain or loss

dry adiabatic lapse rate

if water vapour is not condensing, air temp decreases at a rate of 1C/100m rise in elevation

moist adiabatic lapse rate

if water vapour within a rising air mass is condensing, air temp decreases at a rate of ~0.6C/100m rise in elevation

horizontal currents - wind

surface winds push water in directions according to their movement

horizontal currents - topography

continents deflect water and change movement

horizontal currents - coriolis

water deflected by coriolis effect (N - E, S - W)

gyre

cycle of water movement (cw in nh, ccw in sh)

vertical currents - temp

water cools and becomes more dense as it travels to the N pole and sinks

vertical currents - salinity

salt water denser than fresh water
water at surface becomes more saline due to evaporation
sinks

vertical currents - topography

underwater topography deflects and controls the movement of water

thermohaline circulation

pattern of global water movement that takes 500 - 1000 years
down at N pole
up in Indian Ocean and W coast of NA

precipitation

water falling to earth at various temperatures

conditions for precipitation

1. air mass must contain water 2. air mass' capacity to contain water must decrease

evotranspiration

water vapour picked up from plants and the soil

relative humidity

the actual amount of water vapour per unit volume of air over the max amount if water that can be held as vapour per unit volume of air times 100

dewpoint

temperature at which condensation of water vapour in the atmosphere begins

aspect

the direction that a slope is facing

air deflection

the deflection of air due to a physical obstacle ex mountain

generation of wind due to aspect

as sun warms air on southern aspects air from colder aspects replaces it. only daylight hours

rain shadow effect

the increase in precipitation on the incoming side of a mountain due to air being forced higher and the subsequent drop in precip on the other side

regional climates - albedo

albedo lower in more vegetated areas, more energy is retained (opposite in areas with more precip, esp snow)

microclimate

climate varies across scale. larger distances mean larger variations in climate

greenhouse atmosphere

atmo a lot of UV radiation, lets most PAR through, bounces longwave radiation back

greenhouse effect

warming caused by the retention of longwave radiation by greenhouse gasses in the atmosphere

greenhouse gasses

H2O, CO2, CH4 (methane), N20 (nitrous oxide), SO2 (sulphur dioxide), O3 (ozone)

GG - Air Temp

temp changes across entire planet and across seasons

GG - Precip

drier areas will get drier, wetter areas will get wetter

polar ice melting

summer sea ice expected to disappear soon
add to sea level rise

sea level rise

rising due to melting glaciers and THERMAL EXPANSION

psu

practical salinity units
freshwater <4
brackish 4 - 25
seawater 25

lentic

standing water, lakes and ponds

lotic

flowing water, rivers and streams

epilimion

surface layer of freshwater in summer, greatest variation in temp over time

thermocline

narrow intermediate layer in summer, quick change in density, very little variation in temp over time
accumulation of

hypolimnion

bottom layer in summer, 4C, very little variation in temp over time

lake turnover

complete cycling of water in spring and fall

winter kill

die off of orgs due to low oxygen levels bc ice prevents reoxygenation

incident

amount of sunlight available very close to the surface

euphotic zone

surface layer year-round, high light intensity (100% - 1%)
photosynthesis > respiration

compensation level

depth at which light intensity is 1% of incident
photosynthesis = respiration

aphotic zone

bottom layer year-round, <1% incident
cannot sustain primary producers

littoral zone

perimeter of lake, euphotic zone extends to the bottom
high primary production (rooted plants), structural complexity, species diversity

limnetic zone

open water, above comp lvl
moderate-low primary production (phytoplankton), very low structural complexity, moderate species diversity

profundal zone

deep water, below comp lvl
no primary production, moderate structural complexity (water-sediment interface), moderate species diversity

pond

body of water that does not occur below the comp lvl

lake

body of water with a comp lvl and a profundal zone

saltwater thermocline

much more diffuse - several meters thick

saltwater density

densest at around 1.7C

marine euphotic zone

0 - 200m, where all photosynthetic activity takes place

marine comp lvl

200m, 1% of incident

marine dysphotic zone

200 - 1000m, minimal light

marine aphotic zone

>1000m, no light

vertical nutrient gradient

0-200m, low nutrient concentrations
>200m, high nutrient concentrations

marine depth of bottom

most of ocean floor below 3km, below comp lvl

horizontal nutrient gradient

nutrients most abundant close to shoreline due to upwelling (wind/conveyor belt) and river runoff
availability becomes highly limited 20-200km from shore

upwelling

wind pushing surface water away from coast to be replaced with deeper, more nutrient rich water

intertidal zone

also called littoral zone, region below low & high tide, very specific population
high nutrient levels, light intensity, primary production (macroalgae)

neritic zone

region overlaying the continental shelf (down to about 200m)
high-moderate nutrient levels, high light intensity, high-moderate primary production (macroalgae, phytoplankton)

oceanic zone

region beyond continental shelf
low nutrient levels at surface, high light intensity at surface, decreasing gradient with deepness, low primary production

pelagic zone

open water in neritic and oceanic zones (photic - aphotic)
moderate-low species diversity
orgs here never see land

benthic zone

ocean bottom
intense biological activity (orgs on/in bottom), high species diversity