Ecological Succession
what is the main difference between primary and secondary succession
primary starts with bare rock, secondary starts with soil
When comparing 2 islands of the same size, one 5 km from the mainland and one 30 km from the mainland, which is predicted to have more different species and why?
CLOSER - because MIGRATION rates are higher.
Portion of the range of tolerance graph in which older, weaker organisms fail to thrive
What is the Zone of Stress
Beavers are this type of keystone species
Ecosystem (or habitat) engineer
Similar traits acquired by unrelated species
Convergent Evolution
What is a lichen?
Algae & fungus, living together symbiotically.
When comparing 2 islands both 5 km from the mainland, one small and one large, which is predicted to have more different species (greater biodiversity) and why?
LARGER: Lower EXTINCTION rates.
when an organism is pushed outside its range of tolerance, what are it's three options?
migration, adaptation, extinction
What are examples of natural disturbances?
wildfires, hurricanes, tornadoes and flooding
Key difference among the different species of Darwin's finches and the "Selective pressure" (reason) driving this evolution
Beak size & shape differ; due to type of food (e.g. nuts vs. seeds vs. nectar)
Pioneer Species for secondary succession
Examples: Purple lupine (flowers) - Mt St Helens; Aspen - boreal forests; burned areas; Jack pine - northeast US after fires
How does biodiversity affect the resiliency of an ecosystem?
more biodiverse= more likely to survive bc variety of species
less biodiverse= not likely to survive due to low species variation
Define ecological tolerance
a set of abiotic conditions that an organism can endure before injury or death
plant or animal species that has a disproportionally large effect on its environment relative to its abundance
keystone species
A species evolves into a group of new species after entering a new habitat with unoccupied niches
What is adaptive evolution (or divergent evolution)
what do you call species that first colonize rock and turn it into soil?
pioneer species
Change over time, in a population's gene pool
evolution
Region of an ecological tolerance graph that has the highest population
"Optimal Zone" - The center portion
In the Pacific, loss of otters (due to hunting by man OR whales) caused what direct effect and what indirect effect on the ecosystem?
DIRECT: large increase in sea urchins
INDIRECT: loss of kelp forests.
Adaptations that are more helpful for survival and reproduction
what is "fitness"
What is it called when a community reaches its most productive state. Give 3 examples of typical species.
climax community
EXAMPLES: White oak/hickory (Eastern US); Cactus (Desert SW); White Spruce (northern latitudes)
The maximum number of species on an island is controlled by what 2 factors
extinction rate and immigration rate
Example of abiotic conditions that affect the ecological tolerance of a species
temperature, salinity, flow rate and sunlight
Wolves introduced into Yellowstone prey on elk; now the willows (favorite food of elk) have regrown extensively. This is an example of a
trophic cascade
3 types of adaptations and an example of each.
physical - e.g. coloration
behavioral - e.g. migration
Physiologic e.g. skin tanning -- occurs at cellular level.