Week 2 Flashcards
(24 cards)
Definition of stressor (environmental factor)
Any factor that inhibits the growth and reproduction of individuals
Definition of stress (environmental factor)
The physiological resultant of demands that exceed an organisms regulatory capacity
What process contains the need for balance?
Homeostasis
Give an example of stress
The availability of water in a hot summer and how it effects the local population
What is the definition of tolerance?
The range of conditions that an organism can withstand
What is shelford’s law of tolerance?
The distribution of a species is controlled by the environmental factor the organism has the lowest tolerance for
What are the three A’s of ecophysiology?
Acclimation= a response by an individual that allows it to tolerate a change in its environment
Acclimatization= a reversible adaptive response that helps tolerate several environmental factors, it may effect both physiological and behavioural factors eg. hibernation
Adaptation= This is an evolutionary process and through a mutation the tolerances of a species can change
What causes environmental variation?
Abiotic-
Physical barriers
Climate
Biotic-
Food insecurity
Disease
What is the species geographical range?
This is the area in which a species covers
What effects a species geographical range?
Species individual size
Currents
Landmasses
Mostly abiotic factors but recently human expansion has come into this as well
What is the definition of a biome?
This is the largest geographical biotic communities, this subdivision recognises differences in climate, vegetation and biotic factors
What are the seven terrestrial biomes?
Tundra
Boreal forest
Temperate forest
Temperate forest
Desert
Tropical savannah
Tropical rainforest
Tropical dry forest
How are the seven terrestrial biomes categorised?
Through a correlation between both temperature and precipitation
Low temp, Low precipitation= tundra
High temp, Low precipitation= Desert
High temp, High precipitation= Tropical forest
What causes higher precipitation at latitudes 0* and 45* but not at 30*
Due to atmospheric circulation cells, the more hot air rising the more rain that gets produced
0* is where hot air rises on both sides to feed the Hadley cells
30* Both the Hadley and Ferrell cells are descending so the area only receives cold air
45* The Ferrell cell has air rising and the polar cell is falling
How does global precipitation distribution change during the year?
In NH summer the sun is closer to the tropic of cancer so precipitation distribution shifts north
Autumn and spring means the sun is centred over the equator
In NH winter the sun is closer to the tropic of Capricorn so precipitation shifts south
What is another factor that dictates a biomes atmosphere?
Evapotranspiration- This is the amount of moisture that gets transpired from the plant community, it is dependent on available water and temperature
What are the 8 different aquatic biomes?
Rivers
Lakes
Open ocean
Coral reefs
Kelp forests
Mangrove forest
Salt marshes
Estuaries
What are the three factors that differentiate the oceanic biomes
Temperature
Salinity
Light intensity
What are the three layers of ocean density called?
Epilimnion= warm, low-density, surface waters
Thermocline=zone of rapid temperature change
Hypolimnion= cold, high-density, deep waters
How does each ocean density layer vary during the year?
In winter surface temperature is cooler and remains at about 3* as you go deeper
In fall temperature remains mostly at 5*
In summer surface waters are about 20* and switch drastically in the thermocline to become closer to the fall temperature in the hypolimnion
How do we use salinity to differentiate biomes?
Water is an excellent solvent so as it travels through the water cycle it picks up nutrients so we know how inland a source is by its salinity
Freshwater: rivers and lakes
Marine: open ocean, coral reefs, kelp forests etc
Why is ocean temperature so important?
Species in the ocean are highly adapted to certain temperature so have a low tolerance to sudden variation because they hinder their metabolic pathways
What is an example of a selection pressure and how do species adapt to it?
A lack of water
Terrestrial: lack of rain
E.g Kangaroo rat= they have a long loop of Henle so they have very concentrated urine
Aquatic: loss of water due to osmosis
E.g. Bony fish= drink more sea water, active transport of salt across the gills
What impact will climate change have on biomes
Temperature will increase
Precipitation patterns will differ and storms will become more frequent and violent
