biogeography Flashcards
what percentage of species is predicted to go extinct by 2050
15-37%
what is the species response function (3 answers)
- a way to quantify how well a species is performing along an environmental gradient
- shows parts that are unsuitable/suitable for species
- shows how species interact with one another
what does a narrow environmental gradient mean for the species
they are specialised
what does a broad environmental gradient mean for the species
able to handle different environmental conditions
what is a condition
- not consumed or used up by organisms
eg temp, moisture, light
what is a resource
- quantities that can be used up or reduced by activity of species
eg food, water
what is a niche
set of environmental states in which a species is able to survive
what is the fundamental niche
set of environmental states in which a species can survive WITHOUT interaction of other organisms
what is the realised niche
set of environmental states in which a species can survive and resporduce in the presence of other organisms
what are the speices distribution patterns
- cosmopolitan
- disjunct
- endemic
what is cosmopolitan pattern
species occurring all over the world - broad and wide range
what is disjunct pattern
species occurring in 2 or more seperated regions - closely related species but large range
what is endemic pattern
species occuring in only one area
what is difference between species NICHE and species RANGE
niche = environmental conditions
range = spatial distribution
what is an alien species
species whose presence in an area is due to human activity
what is a naturalised species
alien species that manage to sustain viable populations
what is an invasive species
naturalised species with lots of offspring dispersing away from site of introduction
what is an introduced species
species that has been transported by humans across a geographical barrier
what are the 4 stages of the invasion process
- transport
- introduction
- establishment
- spread
how does niche -> range -> biodiversity
- realised niche determines its range
- overlapping ranges at a location makes up its biodiversity
what is biodiversity a measure of
number of species (species richness) and genetic diversity
how many global KNOWN species are there
1.7 mill
how many global ESTIMATED species are there
9 mill
how many species in nz are there
56k
what is speciation
process by which populations of same species evolve into 2 distinct species
what is allopatric speciation
geographic seperation of population into disjunct populations
what is sympatric speciation
speciation without geographic seperation
- something happens in environment
what happens to extinction when spcies richness increases
higher chance for species to go extinct
- more species sharing limited resources
what is maccarthur and wilsons theory for small and large islands (extinction)
more likely for species to go extinct on a small island
- small area
- low in resource
what is maccarthur and wilsons theory for distant and near islands (extinction)
higher chance for extinction on distant islands
- nearby other individuals = less likely to go extinct
what happens to immigration rates as number of species increases
immigration decreases as species increases
what are biomes
regions with similar climates and functionally similar species
what are the 4 examples of ecosystem services
- provisioning - physical attribute that people can harvest/use
- regulating - not physical attribute
- cultural - important for wellbeing
- supporting -
what are the 4 main processes of NATURAL environmental change
- tectonic seperation
- tectonic drowning
- land uplift
- climate change
what are the 3 main processes of ANTHROPOGENIC (HUMAN) environmental change
- land use
- forest fragmentation
- climate change
what are the 3 ways species respond to environmental change
- adapt
- move
- die
