Biogeography Flashcards
Define biogeography
the study and interpretation of plant and animal distributions in geographic space
Define taxonomy
the classification of something, especially organisms
Define ecosystems
communities together with the physical environment that sustains them
Describe the relationship between plant and animal communities
not separate entities
they share environments and interact in a variety of ways
Define a species
a population whose members are able to interbreed to produce fertile offspring
What is species richness?
number of species
What is species abundance?
number of individuals
How is species diversity calculated?
species richness + species abundance
What is a clade?
A group of organisms believed to comprise all the evolutionary descendants of a common ancestor.
Describe ecosystems as a system
An open system with inputs and outputs and flows of materials.
Define a producer
An autotrophic organism capable of producing complex organic compounds from simple inorganic molecules through the process of photosynthesis
Define a consumer
An organism that generally obtains food by feeding on other organisms or organic matter due to lack of the ability to manufacture own food from inorganic sources; a heterotroph
When is a population surplus reached?
Births + immigration > death + exportation
When is a population deficit reached?
Births + immigration < death + exportation
Name 2 abiotic factors that limits population?
Stenotopic and Eurytopic
Define stenotopic species
species adapted to a NARROW range of environmental conditions
Define eurytopic species
species are adapted to a WIDE range of environmental conditions
Name 4 biotic factors that limits population?
- competition
- predation
- dispersal
- habitat structure
Whats the key difference between abiotic and biotic factors?
Biotic factors = dependent variables
Abiotic factors = independent variable
What is the principle of competitive exclusion?
‘stable populations of 2 or more species cannot continuously occupy the same niche’
Define a niche
The role/function of an organism within an ecosystem
Give 3 examples of abiotic factors
Climatic factors e.g. temperature, soil ph, water availability
Define an endotherm
creates the heat it needs from internal chemical reactions
Define an ectotherm
an organism which derives the heat it requires from the environment
What does bergmanns rule state?
that within a broadly distributed taxonomic clade, populations of larger size are found in colder environments, and species of smaller size are found in warmer regions
Define a realised niche
the actual space that an organism inhabits and the resources it can access as a result of limiting pressures from other species
Why are tropical species more at risk from climate change?
they tend to have smaller ranges and narrower climatic tolerances
What is parasitism?
An interaction between species where one species gets nutrients by damaging the other
What is mututalism?
A positive interaction where both species benefit each other by their existence
Name 4 interactions between different species?
- competition
- predation
- parasitism
- mutualism
What is the neutral theory?
the view that species are functionally equivalent and it is chance that drives community structure
What are the main mechanisms of species distributions in the neutral theory?
- dispersal and variation as well as the evolution of new species
What does a species distribution model show?
- it models the relationship between abiotic variables and the presence of a given species
Name some limitations of SDMs
- don’t incorporate information on biotic interactions and dispersal ability
- scale dependency; different factors relevant at different scales
- data quality
