APES Unit 2: The Living World: Biodiversity

Key concepts and terms for AP Environmental Science Unit 2: The Living World: Biodiversity.

biodiversity

general term for diversity of life forms in an ecosystem, measured in 3 different levels: ecosystem, species, and genetic

ecosystem diversity

diversity in ecosystems available in a given area, to do with entire biomes

species diversity

diversity in species in an ecosystem and balance/evenness of the population sizes

genetic diversity

diversity in genes of individuals within a population (group of same species)

richness

term for total number of different species found in an ecosystem

evenness

measure of how all the individual organisms in ecosystem are balanced between different species

more genetic diversity equals…

better response to environmental stressors

higher richness equals…

healthy ecosystem, quality resources

bottleneck event

environmental disturbance that drastically reduces population and kills organisms regardless of genome

inbreeding

when organisms mate with closely related “family” members

inbreeding leads to…

higher chance of offspring having harmful genetic mutations

inbreeding depression

offspring suffering from harmful mutations caused by inbreeding

ecological resilience

ability of an ecosystem to return to its original conditions after major disturbance

higher species diversity equals…

higher ecosystem resilience

ecosystem services

general term for goods that come from natural resources, functions from ecosystems that have economic/financial value to humans

provisioning services

goods taken directly from ecosystems or made from natural resources (ex: apples, wood, green beans)

regulating services

natural ecosystems regulate climate/air quality, reducing storm damage and healthcare costs

supporting services

natural ecosystems support processes we do ourselves, making them cheaper and easier (ex: bees pollinate crops)

cultural services

natural ecosystems generate money from recreation or scientific knowledge (ex: payment for natural parks, tourism)

island biogeography

general term for study of ecological relationships and community structure on islands

island sizes and species richness have a ____ correlation

positive

island distance from mainland and species richness have a ____ correlation

inverse

adaptive radiation

single species rapidly evolving into several new species to use different resources and reduce competition

ecological range of tolerance

general term for range of conditions that an organism can endure before injury or death

optimal range

range where organisms survive, grow, and reproduce

zone of physiological stress

range where organisms survive, but experience stress (ex: infertility, lack of growth, decreased activity)

zone of intolerance

range where all organisms will die

natural disturbance

natural event that disrupts the structure and/or function of an ecosystem

periodic

occurs w/ regular frequency (ex: rainfall)

episodic

occurs occasionally, irregularly (ex: hurricanes)

random

occurs with no frequency (ex: volcanoes, asteroids)

crossing-over

parts of chromosomes from parents exchange information

adaptation

trait comes from genetic variability that benefits an organism, increases its fitness

fitness

ability to survive and reproduce

natural selection

idea that organisms that are better adapted to their environment survive and produce more offspring

selective force/pressure

environmental condition that kills off organisms that don’t have the adaptation

pace of evolution

ability of a population to adapt

the more rapidly an environment changes…

the less likely the species in that environment will be able to adapt to those changes

if pace of evolution is high…

organisms migrate elsewhere or die

if pace of evolution is slow…

organisms might be able to stay and adapt

the longer the lifespan of organism…

the less likely organisms adapt to environmental changes

ecological succession

series of predictable stages of growth that a forest goes through

primary succession

• starts from bare, exposed rock

• no soil formation

• moss and lichen spores grow

secondary succession

• previously established soil

• plants have been cleared by disturbance (ex: fire, tornado, human)

• grasses, sedges, wildflowers, and berry bushes

pioneer/early succession species

• appear first

• usually seeds spread by wind/animals

• fast-growing

• tolerant of shallow soil and full sunlight

mid-succession species

• appear after pioneers

• relatively fast-growing

• larger, need more deeper soil

• more sun tolerant

late succession species

• appear last

• large, slow growing trees

• deepest soils

• tolerant of shade

chemical weathering

acids from moss or lichen break down rocks and eat their nutrients