chapter 49 - intro to ecology

Question 1

what 4 key factors affect organisms in aquatic biomes? how so?

Answer 1

distribution and abundance of organisms

1) salinity
2) water depth
3) water flow
4) nutrient availibility

Question 2

explain how salinity effects aquatic organisms

Answer 2

affects water balance of organisms (osmosis)

Question 3

explain how water depth effects aquatic organisms

Answer 3

• light -> productivity (eg photosynthesis in coral reefs)
• water absorbs and scatters light, turbidity (cloudiness)

Question 4

name and describe function of distinctive zones in oceans

Answer 4

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

Question 5

name and describe function of distinctive zones in lakes

Answer 5

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

Question 6

explain how water movement affects phenotype and resources available to organisms

Answer 6

• body shape/behavioural adaptations
• flow rate determines O2 availability

Question 7

how do nutrients flow through ocean/lake zones?

Answer 7

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

Question 8

explain lake turnover

Answer 8

• 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

Question 9

ecology

Answer 9

study of how organisms interact with each other and the environment

Question 10

name levels of ecological study

Answer 10

• organismal
• population
• community
• ecosystem
• global

Question 11

organismal ecology

Answer 11

asks how does shape, physiology and behaviour allow organisms to live in a particular habitat

Question 12

population ecology

Answer 12

asks how and why do # of individuals in a population change over time

Question 13

community ecology

Answer 13

• focus on consequences of interactions between species
• asks how/why communities maintain themselves
• how groups of species respond to natural disturbances (flood, fire etc)

Question 14

ecosystem ecology

Answer 14

• 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’

Question 15

global ecology

Answer 15

• investigates biosphere
• focus on human impact on the biosphere

Question 16

different ways of asking ecological questions

Answer 16

look at…
- behavioural ecology
- psychological ecology
- evolutionary ecology
- population ecology

Question 17

biogeography

Answer 17

study of how species are distributed geographically

Question 18

abiotic factors of biogeography

Answer 18

• range
• niche

Question 19

biotic factors of biogeography

Answer 19

• distribution of species can be limited or expanded by biotic factors
  eg competition, parasitism

Question 20

continental drift

Answer 20

causes radical change in shapes and positions of continents and oceans over time
- effects in population range and distribution

Question 21

Wallace line

Answer 21

divides species with asian v Australian affinities
- ocean trench impeded dispersal, making species and ecosystems evolve independently (allopatric speciation by vicariance)

Question 22

multidimensional niche models

Answer 22

predict the outcome of interacts between species (especially invasive and non-invasion)

Question 23

niche

Answer 23

suite of conditions a species can tolerate

Question 24

factor interaction

Answer 24

when one factor depends on another
eg moisture (factor 1) and ant presence (2) combined to affect activity of the invader ant

Question 25

why are the tropics warm and poles cold?

Answer 25

in general, areas that revise more sunlight per unit area are warmer (equator)
poles are cold because they receive less light per unit area

Question 26

factors that effect rainfall, explain

Answer 26

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

Question 27

cause of seasons

Answer 27

earth’s tilted axis
- less solar radiation per unit area at different time of year

Question 28

coriolis effect

Answer 28

air molecules…
- lag behind when they move pole to equator
- speed ahead when they move equator to pole

Question 29

how do mountains affect climate

Answer 29

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

Question 30

temperature + coriolis effect =

Answer 30

gyre

• water movement patterns based on temperature
• warm water moves to poles, speeding ahead
• cold water moves to equator, lagging behind

Question 31

main cause of differences between biomes

Answer 31

temperature and moisture
- effect net primary productivity (NPP)

Question 32

net primary productivity (NPP)

Answer 32

= carbon fixed - carbon used for cell respiration
basically says everything else reacts to what plants do!
- effected by temperature and moisture

Question 33

7 major biomes

Answer 33

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

Question 34

biome

Answer 34

regions defined by distinct abiotic characteristic and dominant vegetation

BIOME ≠ECOSYSEM

Question 35

anthropogenic biomes

Answer 35

human altered biomes
75% of earths surface impacted

Question 36

methods of predicting climate change

Answer 36

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)

Question 37

how will climate change effect terrestrial biomes

Answer 37

N biomes more N
S biomes more S

Question 38

explain ocean upwelling and its purpose

Answer 38

1) wind blows
2) surface water moves
3) upwelling
- as surface water leaves, it’s replaces by nutrient rich water from bottom