26- intro to biodiversity Flashcards
3 components of biodiversity
genetic
ecosystem
species
what is genetic diversity?
variation among individuals within the same population and species
factors that determine the genetic diversity in a population
-mode of reproduction
-population size
-chance events
-gene flow
-mutation rate
-natural selection
-sexual selection
populations that have high genetic diversity…
have a greater chance of surviving changes in the environment and climate
are less likely to be wiped out by diseases
what is ecosystem diversity?
the number, size and variation of different ecosystems and habitats within an area or region
what factors determine ecosystem diversity?
-topography
-climate
-disturbance
-species diversity (size and structure and function of those species)
areas with high ecosystem diversity…
-provide habitats for more species
-are often more resilient to environmental changes, natural disasters, changes in climate, and other disturbances
-are often more productive, more efficient nutrient cycling, water storage, decomposition and soil formation -> more producers -> more consumers
what is species richness
the number of species in an area
what is species evenness?
the relative abundance of a species in an area
what factors determine species diversity?
immigration + speciation - emigration - extinction = the number of species in an area
what factors determine immigration?
-distance to source populations (mainland)
-the nature of the matrix (the non-habitat area between source population and the island)
-the dispersal ability of a species
what factors determine speciation?
- same factors that affect reproductive isolation
which factors determine emigration?
-distance to other suitable habitats
-the nature of the matrix
-resources
-dispersal ability
what factors determine extinction?
-available resources
-predators
-competitors
-climate
-disturbance
-natural disasters
