chapter 49 - intro to ecology Flashcards
what 4 key factors affect organisms in aquatic biomes? how so?
distribution and abundance of organisms
1) salinity
2) water depth
3) water flow
4) nutrient availibility
explain how salinity effects aquatic organisms
affects water balance of organisms (osmosis)
explain how water depth effects aquatic organisms
- light -> productivity (eg photosynthesis in coral reefs)
- water absorbs and scatters light, turbidity (cloudiness)
name and describe function of distinctive zones in oceans
INTERTIDAL
- shoreline (submerged @ high tide)
NERITIC
- gently sloping space before CONTINENTAL SHELF
OCEANIC
- deepwater beyond CONTINENTAL SHELF
BENTHIC
- bottom of ocean @ all depths
sunlight zones: PHOTIC
deep zones: APHOTIC
name and describe function of distinctive zones in lakes
LITTORAL
- shoreline
- shallow enough for plants to take root
LIMNETIC
- offshore
- enough light to photosynthesize, too deep for plants to take root
BENTHIC
- bottom of lake @ all depths
sunlight zones: PHOTIC
deep zones: APHOTIC
explain how water movement affects phenotype and resources available to organisms
- body shape/behavioural adaptations
- flow rate determines O2 availability
how do nutrients flow through ocean/lake zones?
PHOTIC
3 types of water flow
- coastal runoff
- ocean upwelling (nutrients to surface)
-lake turnover
APHOTIC
- when organisms from photic zone die, they sink to photic zone
- aphotic zone organisms feed
explain lake turnover
- happens each spring and fall
- based on water density (colder water to top, warm to bottom)
WINTER
- 0º at top (high O2 concentration)
- 4º at bottom (high nutrients)
SPRING
- water turnover:
- high O2 surface water warms, sinks
- high nutrient, cold water to top
SUMMER:
- warm high O2 at top
- cold high nutrient at bottom
FALL
- water turnover:
- high O2 surface water cools, sinks
- high nutrient, cold water to top
ecology
study of how organisms interact with each other and the environment
name levels of ecological study
- organismal
- population
- community
- ecosystem
- global
organismal ecology
asks how does shape, physiology and behaviour allow organisms to live in a particular habitat
population ecology
asks how and why do # of individuals in a population change over time
community ecology
- focus on consequences of interactions between species
- asks how/why communities maintain themselves
- how groups of species respond to natural disturbances (flood, fire etc)
ecosystem ecology
- considered ALL organisms in a region (biotic and abiotic)
- how nutrients and energy move among organisms and natural environment
- what keeps the whole system ‘ticking’
global ecology
- investigates biosphere
- focus on human impact on the biosphere
different ways of asking ecological questions
look at…
- behavioural ecology
- psychological ecology
- evolutionary ecology
- population ecology
biogeography
study of how species are distributed geographically
abiotic factors of biogeography
- range
- niche
biotic factors of biogeography
- distribution of species can be limited or expanded by biotic factors
eg competition, parasitism
continental drift
causes radical change in shapes and positions of continents and oceans over time
- effects in population range and distribution
Wallace line
divides species with asian v Australian affinities
- ocean trench impeded dispersal, making species and ecosystems evolve independently (allopatric speciation by vicariance)
multidimensional niche models
predict the outcome of interacts between species (especially invasive and non-invasion)
niche
suite of conditions a species can tolerate
factor interaction
when one factor depends on another
eg moisture (factor 1) and ant presence (2) combined to affect activity of the invader ant
why are the tropics warm and poles cold?
in general, areas that revise more sunlight per unit area are warmer (equator)
poles are cold because they receive less light per unit area
factors that effect rainfall, explain
air circulation patterns
HADLEY CELLS (3 north, 2 south)
- most air air warms near equator, rises
- air cools, water condenses, causing rainfall (tropics)
- cool air pushed to poles, density increases, begins to sink
- air pushed towards earth’s surface, warms, picks up moisture (dessert zone)
- warms, moves to equator and cycle starts again
cause of seasons
earth’s tilted axis
- less solar radiation per unit area at different time of year
coriolis effect
air molecules…
- lag behind when they move pole to equator
- speed ahead when they move equator to pole
how do mountains affect climate
rain shadow
- moist air blows up mountain
- as air rises, it cools, creating rain
- when air crests mountain its very dry, creating desert conditions on other side
heat capacity + seasons
- water’s high heat capacity
- absorbs heat in summer, releases it in winter
- places closer to ocean more moderate climates
temperature + coriolis effect =
gyre
- water movement patterns based on temperature
- warm water moves to poles, speeding ahead
- cold water moves to equator, lagging behind
main cause of differences between biomes
temperature and moisture
- effect net primary productivity (NPP)
net primary productivity (NPP)
= carbon fixed - carbon used for cell respiration
basically says everything else reacts to what plants do!
- effected by temperature and moisture
7 major biomes
tundra
- low total + average rain
- high variation + very low avg temp,
boreal forest
- low volume/variation rain
- lower seasonal temperatures with high variation
temperate forest
- more constant rain
- moderate avg + variation in temperatures
temperate grassland
- low volume seasonal rain
- moderate average + variation in seasonal temperatures
subtropical desert
- low volume + variation rain
- high avg + moderate variation seasonal temperatures
tropical wet forest
- high volume + variation rain
- high constant temperature
biome
regions defined by distinct abiotic characteristic and dominant vegetation
BIOME ≠ECOSYSEM
anthropogenic biomes
human altered biomes
75% of earths surface impacted
methods of predicting climate change
1) simulation studies (weather pattern models)
2) observational studies (long-term monitoring)
3) historical studies (reconstructing prehistorical trends)
4) experiments (simulate climate change to gauge organism response)
how will climate change effect terrestrial biomes
N biomes more N
S biomes more S
explain ocean upwelling and its purpose
1) wind blows
2) surface water moves
3) upwelling
- as surface water leaves, it’s replaces by nutrient rich water from bottom
