Lecture 26: Ecology
Biology 1009 with I Dont Know at University of Minnesota - Twin Cities
About this deck
By: Nancy Feist
Textbook:
Biology (Custom edition for University of Minnesota)
Created: 2010-04-29
Size: 38 flashcards
Views: 13
Textbook:
Biology (Custom edition for University of Minnesota)Created: 2010-04-29
Size: 38 flashcards
Views: 13
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what is ecology?
the study of interactions of organisms with their environment?
What is biotic and abiotic?
- biotic-living
- abiotic-chemical, physical
What are the levels of organization in a living thing?
- molecule
- cell
- tissue
- organ
- organism
What is a population?
interbreeding group of individuals (same species, same area)
What is a community?
interacting populations (different species) in the same area.
What is an ecosystem?
A community along with its abiotic environment.
What are some emergent properties of populations?
- dispersion (clumped, uniform or random)
- density
- growth or decline (birth/mortality rates)
What is a metapopulation?
small isolated populations
What can reestablish subpopulations that have gone extinct?
Migration
Why do populations increase or decrease?
- immigration
- births
- deaths
- emmigration
What are the assumptions for an ideal population?
- stationary population
- no migration
- stable age dist.
- no predation
- no parasitism
- no competition (interspecies or intraspecific)
- environment of unlimited resources
How is population growth calculated?
if (b+i) > (d +e), population increases
if (b+i) < (d + e), population decreases
if (b+i) < (d + e), population decreases
- b: births
- i: immigration
- d: deaths
- e: emmigration
What is a closed population?
a population that experiences no immigration or emigration.
In a closed population, when will population increase?
if b -d > 0
In a closed population, when will population decrease?
if b - d < 0
What is the rate?
# of individuals (born, dying, ect) per individual (per capita) per unit of time.
When will populations grow exponentially?
if r remains positive and constant over time.
What will tell you how much the population will grow during the next interval?
multiplying the per capita rate of incr (r) by the current population size (N)
What is population growth a function of?
r (rate of increase) and N (population size)
When will r (rate of increase) assume maximum possible (rmax)?
- ideal environmental conditions for population
- low population densities
When does rmax occur?
When birth rates are at a maximum and death rates are at a minimum.
What is logistical growth?
growth rate approaches zero as population approaches carrying capacity.
What is the carrying capacity (K)?
max stable population size that environment can support over an extended time period.
What type of curve is a logistical growth curve?
What is the logistical equation?
dN/dt=rN [(K-N)/K)]
When does dN/dt (rate of increase) decline?
- death rate (d) increases
- birth rate (b) increases
- or both
What are density-dependent factors?
influence per individual increases as population density increases.
What are examples of density-dependent factors?
- food supply
- shelter
- disease, parasitism
- predation
What are density independent factors?
influence per individual is independent of population density.
What are examples of density independent factors?
- fire
- storms
- cold
- floods
- drought
What are life history strategies?
traits that affect schedule of reproduction and survival.
What are examples of life history strategies?
- age at first reproduction
- number of offspring
- size of offspring
- frequency of reproduction
- parental care
- longevity
what are typical traits of r-selected species?
- short life span
- high mortality
- type III survivorship
- low competition
- small body size
- semelparous reproduction
- many small offspring
What are typical of K-selected species?
- long life span
- low mortality
- types I, II survivorship
- high competition
- large body size
- iterparous reproduction
- few larger offspring
What is semelparity?
one-time reproductive effort
What is iteroparity?
repeated reproductive efforts.
Why is it that the longer the human population delays stabilizing the human population, the more difficult it will be to do so?
dN/dt=N
What happens when a population exceeds the carrying capacity K?
over-exploitation permanently lowers the carrying capacity.
About this deck
By: Nancy Feist
Textbook: Biology (Custom edition for University of Minnesota)
Created: 2010-04-29
Size: 38 flashcards
Views: 13
Textbook:
Biology (Custom edition for University of Minnesota)Created: 2010-04-29
Size: 38 flashcards
Views: 13
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
Think of it as a digital backpack™: access to all of your study materials online and on your phone.
STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.
“I have been getting MUCH better grades on all my tests for school. Flash cards, notes, and quizzes are great on here. Thanks!”
Kathy
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