APES unit 2 (biodiversity)

biodiversity

diversity of life forms in ecosystems

ecosystem Diversity

the number of different habitats in a given area

species diversity

the number of different species in an ecosystem and the balance of evenness of the pop. sizes of all species in the ecosystem

genetic diversity

how different the genes and genomes (set of genes) are of individuals within a pop.

species richness (r)

total number of different species found in an ecosystem

species evenness

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

high r is generally a good sign of ___

ecosystem health (more species means more quality resources like H2O and soil)

evenness indicates if ____

there are one or two dominant species, or if pop. sizes are well balanced

genetic diversity benefits

enhances population response to environmental stressors like drought, disease or famine

bottleneck event

an environmental disturbance that drastically reduces population size and kills organisms regardless of their genome; they reduce genetic diversity

inbreeding depression

reduces fitness from mating among closely related individuals

ecosystem resilience

ecosystem's ability to recover after major disturbances like wind storm, fire flood, clear-cutting, etc

higher species diversity =

higher ecosystem resilience

ecosystem services

goods and services provided by natural ecosystems that are beneficial to humans (often monetarily or life-sustaining)

provisioning services

goods taken directly from ecosystems or made from natural resources

examples of provisioning services

wood, paper, food, fish, hunting animals, medicine, rubber, etc.

ways provisioning services are disrupted

overharvesting, water pollution, clearing land for agriculture and urbanization, etc.

regulating services

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

examples of regulating services

trees in a forest store CO2 through photosynthesis which reduces rate of climate change and lessens damage caused by rising sea level and reduces crop failure from drought; trees filter ari by absorbing air pollutants which reduces health care cost for treating diseases like asthma and bronchitis

ways regulating services are disrupted

deforestation and other things

supporting services

natural ecosystems support processes we do ourselves, making them cheaper and easier

examples of supporting services

wetland plant roots filter pollutants, leading to cleaner groundwater that we don;t have to pay as much to purify with expensive water treatment plants; bees and other insects pollinate or ag. crops, leading to more crop production and higher profits

cultural services

money generated by recreation or scientific knowledge

examples of cultural services

beautiful landscapes draw tourist who pay to enter parks, spend money at local stores/restaurants, or camping fees; fishermen pay for fishing licenses to catch fish in clean rivers; scientist learn about plant compounds that can lead to creation for new medicines which are sold for profit

ways cultural services are disrupted

deforestation, pollution, urbanization, etc

examples of humans disrupting ecosystem services

clearing land for agriculture/cities removes trees that store CO2 (more CO2 in atmosphere= more climate change= more storm damage and crop failure); overfishing leads to fish pop. collapse (lost fishing jobs and lower fish sales in the future)

island biogeography

study of ecological relationships and community structure on islands

two basic "rules" of island biogeography

larger islands support more total species and islands closer to the "mainland" support more species

larger islands=

higher ecosystem diversity, more available roles, larger pop. sizes, lower extinction rate, positive correlation between island size and species richness

closer to mainland=

higher species richness (easier for more species to migrate to the island)

the further away from mainland

the fewer species

ecological range

range of conditions such as temperature, salinity, pH, or sunlight that an organism can endure before injury or death results

optimal range

range where organisms survive, grow, and reproduce

zone of physiological stress

range where organisms survive, but experience some stress such as infertility, lack of growth, decreased activity, etc.

zone of intolerance

range where the organism will die (ex: thermal shock, suffocation, lack of food/water/oxygen, etc.)

natural disturbances

a natural event that disrupts the structure and or function of an ecosystem (ex: tornadoes, hurricanes, asteroids, forest fires, drought, etc.)

periodic (natural disturbances)

occurs with regular frequency (ex: dry-wet seasons)

episodic (natural disturbances)

occasional events with irregular frequency (ex: hurricanes, droughts, fires)

random (natural disturbances)

no regular frequency (ex: volcanoes, earthquakes, and asteroids)

natural climate change

earth's climate has varied over geologic time for numerous reasons like slight changes in earth's orbit and tilt

why have sea levels varied over geological time?

glacial ice on earth melts and forms due to natural climate change

enviroment change=

habitat disruption, major environmental disturbances result in widespread habitat changes and/or loss

effects on migration due to natural disruptions

wildlife may migrate to a new habitat as the result of natural disruptions

why genetic diversity exists

random mutations in DNA and crossing over in parent chromosomes

adaptation

a new trait that increases an organism's fitness

fitness

ability to survive and reproduce

natural selection

organisms that are better adapted to their environment survive and reproduce more offspring, passing off adaptations

selective pressure/force

the environmental condition that kills individuals without the adaptation (ex: predation)

what determines which traits are adaptations?

the environment an organism lives in

pace of evolution

the more rapidly and environment changes, the less likely a species in the environment will be able to adapt to those changes

the more genetic diversity in a pop. ____

the better they're able to adapt to environmental change (higher chance that some individuals have good mutations)

ecological succession

a series of predictable stages of growth that a forest goes through (2 types)

primary succession

starts from bare rock in an area with no previous soil formation, moss and lichen spores carried by the wind grow directly on rocks, breaking them down to form soil

secondary succession

starts from already established soil, in an area where a disturbance (fire, tornado/human land clearing) cleared out the majority of plant life

stages are characterized by___

which types of plant species dominate the ecosystem; different species are adapted to teh conditions of the different stages

pioneer/early succession species

appear first, when the ground is simply bare rock, or bare soil after a disturbance

characteristics of pioneer/early succession species

seeds spread by wind or animals, fast growing, tolerant of shallow soil and full sunlight

examples of pioneer/early succession species

moss, lichen (for bare rock), wildflowers, raspberries, grasses/sedges

mid-successional species

appear after pioneer species have helped develop deeper soil with more nutrients by their cycles of growth/death

characteristics of mid-successional species

relatively fast growing, larger plants that need deeper soils with more nutrients than pioneers, sun tolerant

examples of mid-successional species

shrubs, bushes, fast-growing trees like aspen, cherry, and pine

late successional/climax community species

appear last, after soil is deepened and enriched with nutrients by cycles of growth and death by early and mid successional species

characteristics of late successional/climax community species

large, slow-growing trees that are tolerant of shade and require deep soils for large root networks

examples of late successional/climax commmunity species

maples, oaks, other large trees

moss and lichen

(spores dispersed by wind) are able to grow directly on rock by secreting acids that break down rock & release minerals containing nutrients they need (N/P/K)

pioneer species in secondary succession

wind-dispersed seeds of plants that are fast-growing and sun tolerant, but grasses/wildflowers/weeds instead of moss/lichen