Biogeography Flashcards
What is biogeography?
Studying the spatial distribution of biodiversity
What are the core influences upon species distribution?
Climate
Topography (linked to climate through altitude)
Other species (competition, prey, predators)
Anthropogenic factors
What allows for there to be so many ecosystems in the world?
The fact that the earth is so large
What is a biome?
A distinct biological community of plants, animals and bacteria
What are the key influences upon biome distribution?
Climate (Precipitation, Temperature, Net Radiation) Bioclimatic Variables (lots)
What are bioclimatic variables?
Key biological processes and cycles within an environment that are determined by climate
Give 5 examples of bioclimatic variables?
Evapotranspiration, Soil Moisture content, Runoff/water surplus, Seasonality, Photosynthesis active radiation
What is photosynthesis active radiation?
Incoming solar radiation that is in the correct wavelength for plants to absorb and subsequently use in photosynthesis
What is island biogeography theory and who developed it?
Developed by McArthur and Wilson in the 1960s this theory states that following the removal or killing of a species within a biome, eventually that species would recolonize back to its original number. They also explored how island size and distance from the mainland would affect the rate of recolonization
How do island size and distance from the mainland affect the rate of recolonization?
A larger island means that there is a greater amount of space and resources available which allows for more of that species to colonise. The closer the island to the mainland then the easier it is for the main species to assist with recolonizing
What factors affect biodiversity and what is the correlation?
Temperature = positive Precipitation = positive Altitude = negative Latitude = normal distribution (peak at tropics)
What causes the tropics to be so biodiverse?
Area: Largest area on earth’s surface
Age: They were able to best resist glacial periods
History: Pangea originally located in the tropics so the species on continents that drifted away have to adapt and restart
Productivity: GPP of tropics is higher due to favourable conditions that transcends through ecosystem
Climate: Temperature in the tropics increases the rate of processes in the biome
What threat is posed to the tropical biomes?
The species are so immensely tailored to such unique conditions, relative to other more versatile species, means they are weak and in the event of a perturbation may be outcompeted.
