Class Notes (1,100,000)
CA (640,000)
McMaster (50,000)
BIOLOGY (3,000)
Lecture 31

BIOLOGY 1M03 Lecture Notes - Lecture 31: Bromus Tectorum, BiogeographyPremium


Department
Biology
Course Code
BIOLOGY 1M03
Professor
Jon Stone
Lecture
31

This preview shows half of the first page. to view the full 2 pages of the document.
BIOLOGY1M03Lecture31IntroductiontoEcology(Continued)
Biogeography:
● AbioticFactors:
○ Becauseoffitnesstradeoffs,organismstendtobeadaptedtoa
limitedsetofphysicalconditionstoaparticulartemperatureand
moistureregimeonlandoraparticularwaterdepthandmovement
regimeinwater.
○ Tounderstandaspeciesdistributionthoroughly,biologistsexamine
historicalandbioticfactorsinadditiontothephysicalconditions
present.
TheRoleofHistory:
● Dispersalisthemovementofanindividualfromitsplaceoforigintothe
locationwhereitlivesandbreedsasanadult.
● Thebiogeographicaldemarcation,knownastheWallaceline,separates
specieswithAsianandAustralianaffinities.
ForestFires:
● Ifafiregetsstarted,itdoesnotaffectcheatgrassfortworeasons:
○ Cheatgrassisannual,sonolivingtissueexposedoncegrowing
seasonisover
○ Cheatgrassseedssproutreadilyinsoilsthathavebeendepletedof
organicmatter
KeyConcepts:
● Climatechangesrapidlyaroundtheglobeandvarieswith:
○ Latitude
○ Elevation
○ Mountains
○ Oceans
● Waterdepthisacrucialfactorinaquaticecosystemsbecausesunlight
wavelengthsrequiredforphotosynthesisdonotpenetratewaterefficiently.
○ Thus,onlycertainzonesinalakeoroceancansupport
photosynthesis
■ Organismsinotheraquaticzonesmustdependonfoodthat
rainsoutofthesunlitareasnearthesurface
● Distinctclimaticregimesareassociatedwithdistincttypesofterrestrial
vegetationorbiomes.
○ Biomesrepresentmajortypesofenvironmentsavailabletoterrestrial
organisms.
You're Reading a Preview

Unlock to view full version

Subscribers Only