topic 2.1

biodiversity

variety of life across all levels of biological organization

• varies based on location

• the more biodiverse, the more stressors an ecosystem can handle

genetic diversity

variety of different genes and alleles (different versions of a gene) within a population of a species

• the less genetically diverse a population is, the more likely they are to suffer inbreeding

• high genetic diversity = higher chance that some individuals will have a trait that make them more resistant to environmental stressors

bottleneck effect

when genetic variation is reduced due to a sudden decline in population from habitat loss, natural disaster, etc

• makes surviving species less able to adapt to future changes

• the resulting low genetic diversity from this event often leads to extinction

species diversity

the number or variety of species found in an area

• species richness - number of species in an ecosystem (maple tree, oak tree, redwood tree)

• species evenness - number of individuals of each species (30% maple tree, 50% oak tree, 20% redwood)

• high species diversity = more likely that a species will be able to fill another’s ecological role

ecotones

“transition” habitats such as creeks connecting forests and lakes

• typically have high species diversity

ecosystem diversity

the number and variety of ecosystems / habitats in an area

• loss of ecosystem diversity leads to a loss of specialist species (particularly those with large territorial requirements), followed by a loss of generalist species

generalist species

tolerate a wide range of abiotic / biotic conditions

• ex: rat

  • lives on every continent, eats a lot of different food, has a quick reproduction rate

specialist species

can only tolerate a narrow range of conditions / feed on a very small group of species

• ex: giant panda

  • only lives in china, very selective diet, very slow reproduction rate and long period of parental care