5.2: biogeographic concepts Flashcards
(31 cards)
describe migration.
seasonal movement of organisms from one place to another. usually for feeding or breeding.
what does migration do to biodiversity?
changes it as animals leave or appear
migration results from…
the push from the lack of resources or the pull from an abundance in another area
what are the two different types or migration?
- latitudinal migration: migration north or south of a position
- altitudinal migration: migration from one elevation to another
what is the concept of island biogeography?
larger islands tend to have more species than smaller ones.
define to term “island”
any habitat surrounded by an inhabitable area
define speciation.
creation of new species through evolution
what are the 2 different types of evolution?
- convergent: 2 or more unrelated species evolve in a similar way due to similar pressures
- divergent: population or one species disperses and evolves differently than the rest
what is dispersal?
movement of an organism away from where it originated. decreases competition and allows more resources to be available.
what are the different types of dispersal?
- intra-range dispersal: organisms disperses within its current geographic range
- extra-range dispersal: organism disperses outside its current geographic range. (often lethal)
- active dispersers: organisms that disperse under their own power
- passive dispersers: organisms that disperse due to an external force
in terms of dispersal, define/describe the following:
- corridor
- biogeographic filter
- colonization
- invasion
- corridor: allow unrestricted movement between habitats
- biogeographic filters: barriers that allow certain types of organisms to disperse across them and other not
(climatic {deserts and icecaps} and biological {predation and competition) - colonization: successful establishment of a population in a new geographic region without human intervention
- invasion: successful and unwanted establishment of a population in a new geographic region as a result of human activity
what is an ecological disturbance?
sudden event that disrupts an ecosystem
what is succession?
the series of changes in an ecosystem that follow a disturbance
what are the two different types of succession?
- primary: when life is completely removed form a landscape. soil and plants develop at the same time
- secondary: life survives the disturbance and ecosystems rebuild. (more common)
what is a sere?
stage of ecological development
what is a niche?
resources and environmental conditions that a species requires from an area.
what is a habitat
exists within a niche; physical environment in which a species lives
what are limiting factors?
prevent organisms from reaching reproductive or geographic potential; controls species niche.
what are the various physical limiting factors?
- light: the amount of light that is needed by plants in order to grow
- temperature: extremes in temperature affect biological processes
- water: required by all organisms on earth
what are various biological limiting factors?
- predation: consumption of one organism by another
- competition: interaction between organisms that require the same resources or anything that organisms needs to survive.
- mutualism: relationship between 2 species that benefits both of them
what are ecosystems?
unit that includes living and non-living components within an environment.
what is biodiversity?
number of living species in a region
what is the difference between biomass and phytomass?
total living organic matter produced in a given area versus the total amount of plant matter only.
what is the latitudinal gradient in biodiversity?
biodiversity is greatest at equator and smallest at poles
