Lecture 3 climate Flashcards
Ecophysiology
adaptation of organisms physiology to environment
Plant ecophysiology
Mechanisms - sensing and responding to env. changes
Integration of responses to variable conditions
- radiation
- temp
- water …
phenotypic plasticity [change within lifetime]
animal ecophysiology
endocrine system
metabolism
thermoregulation
abiotic env.
Radiation Temperature Air Water Soil Chemicals
Climate
earth spherical = latitudinal variation in solar radiation absorption
Teperature and precipitation = vary with latititude
proportion of land or ocean = affects temp
totation around axis = air and water movment = wind and ocean currents
tilt of earths axis and orbit = seasons
altitude = surface uneven
climate involves
radiation [solar]
temperature
humidity
precipitation
Albedo effect
fraction of solar radiation reflected from earth back into space
measure of the reflectivity of earths surface (ice and snow reflect. forests and water absorb0
northen hemisphere greater proportion of land vs southern
northern warmer.
land radiates more heat to air above it
oceans absorb it more
circulation and precipitation
solar radiation determines atmospheric air circulation and percipitation patterns
air warmed. expands. becomes less dense. rises. cools. releases moisture (precipitation)
rising warm air replaced by surface air flowing in setting up atmospheric circulation cells
Coriolis effect
earths rotation = wind and ocean currents
prevailing wind meeting continents = large circular ocean currents called gyres
ocean currents transport heat
primary production and climate
primary production varies with latitude
primary production influences community diversity
Solar radiation
4 points
- Solar radiation drives global climate patterns
- 70% absorbed by atmosphere and earths surface
- Much of energy radiated from earths surface in form of heat
- Greenhouse gases e.g. CO2 trap most of radiated heat in atmosphere
Solar radiation
Albedo effect
5 points
- Albedo is fraction of solar radiation reflected from earth back into space
- Measure of reflectivity of earths surface
- Ice and snow reflect
- Water and forests absorb
- (high albedo = high reflection)
Solar radiation
Coriolis effect
5 points
- Earth rotation generates global wind and ocean currents
- Rotation fastest at equator
- Prevailing wind patterns drive ocean circulation patterns or currents
- Prevailing winds meeting continents set up large circular ocean currents called gyres
- Ocean currents affect earths climates by transporting heat
Solar radiation
Determines atmospheric air circulation and precipitation patterns
2 points
- Air warmed, expands, becomes less dense, rises, cools, releases moisture (precipitation)
- Rising warm air replaced by surface air flowing in, setting up atmospheric circulation cells
Temperature
Northern hemisphere slightly warmer and more variable in temperature than southern hemisphere
2 points
- North (greater proportion of land) - land radiates more heat to air above it
- South - Oceans absorb more heat
Earths climate
involves
- Radiation
- Temperature
- Humidity
- Precipitation
- Global circulations
Earths climate
involves
4 points
- Radiation
- Temperature
- Humidity
- Precipitation
- Global circulations
Earths climate
Global variation in climate
2 points
- Biomes: grouping of ecologically similar organisms shaped by environment
- affects primary production which influences community diversity
Scales of Spatial variation in climate
Variation across climatic zones
§ Latitudinal variation in climate
§ Biomes
§ Climate affects which species present in community e.g. tropicl forrests, arctic tundra
§ Strongest effect for species with low powers of dispersal
Scales of Spatial variation in climate
Variation across climatic zones
4 points
- Latitudinal variation in climate
- Biomes
- Climate affects which species present in community e.g. tropical forests, arctic tundra
- Strongest effect for species with low powers of dispersal
Scales of Spatial variation in climate
Variation within a region
2 points
- Spatial variation affects species distribution
- Saguaro cactus -
killed when temp below freezing for 36 hours.
Daily thaw no problem. Arizona northern and eastern limits correspond to places where on occasional days it fails to thaw
Scales of Spatial variation in climate
adaptations to temperature
4 points
- Organisms can modify heat exchange
- Fixed properties e.g. reflective cuticle of desert plants
- Behavioural responses e.g. shade seeking or sun basking
- Physiological response e.g. shivering (bumble bees)
All have costs and limits
microclimate
3 points
- Trapped moisture
- trees and forests create microclimates
- Bottom of valley may be much colder at night
What varies with Latitude
temperature
precipitation
why does amount of solar radiation received on earth vary with latitude
4 points
Earth:
- Is a sphere
- Orbits sun
- Spins on tilted axis
- Both land and water
Seasons
4 points
- Tilt of earths axis and orbit create seasons
- Tilt of earths axis relative to sun causes greater seasonal variation in temperature at higher and lower latitudes
- Near equator day length and seasonal temperatures change only slightly
- Tilt explains why northern and southern hemisphere have opposite seasonal patterns
adaptation to seasons
5 points
- Tolerance
- Dormancy
- Migration
- Seasonal shedding of leaves by plants
- Seasonal lifecycles in animals
topography
4 points
- Altitude
surface of earth uneven mountains have altitudinal gradients
Climate varies with altitude - Ocean floor topography affects water depth
- Human infrastructure and agriculture have transformed half of the earths area
- ocean floor topography affects
mountain topography affects
5 points
- Temperature decreases with elevation
- Precipitation increases with elevation
- Rain shadow on windward side of mountains
- Temperature inversion in valleys
- Environmental conditions vary over relatively short distances
ocean floor topography affects
5 points
- Water depth
- Light penetration
- Water temperature
- Water pressure
- Water movement
Adaptation to diurnal (day time) variation in climate
2 points
- Circadian rhythm - 24 hour cycle in physiological processes of plants, animals, fungi and bacteria
- Response to external cues such as sunlight and temperature
e. g. birds sing in morning, slugs active at night and mosquitoes bite at night
Plants differ in their capacity to photosynthesise
2 points
- Highest photosynthetic capacity
plants from env where nutrients water and light are seldom limiting - Lower photosynthetic capacity
plants from resource poor env
annual variation in radiation -
animals
- may affect life cycles of animals
E.g. birds migrate, hedgehogs hibernate
Animal adaptation to temperature
endotherms
5 points
- regulate temperature by producing heat within bodies (birds and mammals)
- Regulate temperature
- Constancy of performance
- Large expenditure of energy
- Large requirement for food
Animal adaptation to temperature
ectotherms
- rely on external sources of heat (other animals, plants, microorganisms)
- Killed by extreme temp
- Lower optimum temp perform slowly
- On either side of optimum temp show reduced viability
- Temp affects whole life cycle
Animals and moisture
3 points
- Availability linked to temperature
- Great microclimatic variation
- Adaptations to retain moisture and limit desiccation
Environmental change
3 points
- Predicted change in global temperature
- Warming not uniform
- more marked in arctic than southerly latitudes 2-5 C in next 100 yrs
plant adaptations to radiation
3 points
- Phenotypic plasticity e.g. growing leaves differently
- Daily movement of leaves
- Some species avoid competition for light by growing early in season - vernal species e.g. bluebell.
But may be exposed to temperature stress
environmental change
arctic aphid
6 points
- Overwintering eggs = females
- Females produce daughters without mating
- Several generations a sexual generation is produced (males and females which lay overwintering eggs)
- Cue is environmental (day length or temp)
- Control is genetic
- Raised temperature = population increase.
… How might this affect food and predators
