Biogeography Flashcards
Describe a basic cycle which includes autotrophs and heterotrophs
Sunlight gives energy to plant Plant takes in CO2 and gives out O2 Plants are eaten by fish/plants die Fish are eaten by bears Animals die Dead animals and plants are decomposed by microbes CO2 returns to the environment
What are the 4 essential inputs of an ecosystem?
Carbon
Nutrients
Water
Energy
Give the definition of metabolism and two examples
Converting inputs to outputs
Eg. Photosynthesis - solar energy to glucose
Respiration - burns glucose to make energy
Compare photosynthesis and respiration
Photosynthesis
- stores energy as sugar
- uses CO2 and H2O
- increases weight
- produces oxygen
Respiration
- releases energy from sugar
- releases CO2 and H2O
- decreases weight
- consumes oxygen
Name and define the 6 types of distribution
Cosmopolitan - species or taxonomic group that is distributed widely throughout the world
Primary endemic - s or t group in a particular region native only to that region
Secondary endemic - s or t group in a particular region whose distribution has contracted so that it is now native only to the region in which it’s found
Rare - restricted geographically or is widespread but never found anywhere in abundance
Disjunct - occupies areas that are widely separated and scattered
Indigenous or native - originates in a particular place or has arrived there independently of human activity
What factors control patterns of species distribution?
Climate - heavily influenced by light and moisture availability
Geological factors - tectonic movement ie. Wallace’s line
Ecological factors - habitat conditions
What are the controlling physical factors in an environment?
Temperature
Moisture availability
Zonal factors - regional macroclimate (Equatorial, monsoonal)
Atonal factors - no zonal organisation or structure
Where is Wallace’s line?
Between Borneo and Sulawesi
Between Bali and Lombok
Who came up with the theory of continental drift?
Wegener
What is vicariance and dispersal?
Vicariance - species range is divided even though the species has remained in place. May happen through tectonic action, geologic action (rise of mountain, change in course of river) or other processes
- eg species B evolves from species A after plate tectonic split and isolation
Dispersal - species range changes because of some or all individuals moving to a new location (possibly crossing a barrier)
- eg species C migrates to another island and evolves into species E on the new location
Name some biomes
Tundra Taiga Steppe grasslands Temperate deciduous forests Temperate grasslands Tropical forests Savanna region Hot deserts
Define the biome - tundra
A vegetation of mosses, grasses and low shrubs developed in Arctic and alpine regions
Cold mean temp of warmest month
Describe the biome - taiga
Northern ‘boreal’ coniferous forest (Alaska, Canada, northern Scandinavia, Siberia)
Dominated by spruce
Characterised by severe and relatively dry winters
Define the biome - steppe grasslands
Areas of permanent grassland
Winters relatively cold, though the steppes may be hot in summer, precipitation less than 50cm a year
Precipitation-evapotranspiration too low to support continuous forest
Define the biomes - prairie grasslands and Savannah
Prairie grasslands are warmer than the steppes but still have a low precipitation-evapotranspiration ratio
Savannah - open grassland with scattered trees, coldest month averaging over 18 degrees Celsius
