Download Population Density

http://www.gdargaud.net/Antarctica/Life/WeddellSeal.j
pg
Mitch Lange
Jack Connor
Kelly Goehring
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Studying populations in relation to the environment…
 Environmental influences, on population density, distribution, age structure, and
population size
With more of these guys…
There will be less of these guys
http://4.bp.blogspot.com/fsV4PsAeGIo/TaTBsK4pY9I/AAAAAAAAAjE/hbD
sJ0IRVik/s1600/lone%2Bseal2_for%2Bblog720230.jpg
http://2.bp.blogspot.com/lI0g2NzaOJ8/Tf4udjOH9oI/AAAAAAAAAFo/
CTZ0kaz0DAA/s1600/utah-hunting.jpg
Population size can be determined in a number of ways:
Like number of nests, burrows, tracks, or poop
Additions to population occur from :
Births
http://www.scotlandincolour.com/finch/fin
ches-flying01ll.jpg
Population Size
http://4.bp.blogspot.com/_2V1Yi84pHb8/SW
wtF8KmDWI/AAAAAAAAAak/xfpC4cpyqTU/s
400/il_fullxfull_52550225.jpg
Immigration
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Animals leave because of:
Deaths
http://laudyms.files.wordpress.com/2010/03/hawk_eating_prey.
jpg
&
Emigration: Movement of animals
out of a population
http://www.ect.coop/wp-content/uploads/2010/08/Osprey-Leaving-Nest.jpg
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3 types:
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Clumped: Most common, with individuals in separate patches
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Uniform: Evenly spaced, with patterns resulting from interactions
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Random: Unpredictable Spacing
http://bio1903.nicerweb.com/Locke
d/media/ch53/53_04cRandomDispe
rsion-L.jpg
http://mycozynook.com/36_02aClumped
Dispersion-L.jpg
http://bio1903.nicerweb.com/Locked/media/ch
53/53_04bUniformDispersion-L.jpg
Vital Statistics of populations and their change over time
 Particularly looking at birth rate and death rates
 Life Table
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Age that a person/animal is expected to live to
Cohort= group of individuals of same age. Used to follow the fate from birth to death
Survivorship Curve
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http://bealbio.wikispaces.com/file/view/survivorshi
p.gif/104532503/survivorship.gif
Plot to see which data points in a cohort
are still alive
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Some species reproduce in a one shot chance called semelparity
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Others reproduce in the annual cycle called iteroparity
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If offspring survival rate is low, this is favored
More favorable when there is dependable environment and might be competition for resources
There are many trade-offs between reproduction and survival:
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High mortality rates in offspring often exhibit large number of small offspring
High predation rates also factor into large numbers of offspring
http://scienceblogs.com/tetrapodzoology/killi
n_ur_biodiversiteh.jpg
Per Capita Rate of Increase is the amount a population goes up over time
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Deaths>Births is declining population
Births>Deaths is growing population
Births=Deaths is zero population growth
Intrinsic rate of increase or rmax is when the per capita rate of increase is at its maximum
http://2.bp.blogspot.com/_hpxaqo7FS9c/TRKQgN9
1moI/AAAAAAAAC8E/IYtb9e0wgE/s1600/maps%2B-%2Bcensus%2B%2BUS%2Bpopulation%2Bgrowth%2Bsince%2B17
90.png
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With more population density, each individual has access to fewer resources
The carrying capacity is the max population an environment can support
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In this model, the per capita rate of increase declines as carrying capacity is reached
The graph of most real populations is like an S shape
When the population increases to it there is a lag in time where the population can resettle
http://www.nabt.org/blog/wpcontent/uploads/2009/05/logistic.jpg
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Density Dependency
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Death rate rises as population density rises
Also a birth rate falling with rising density
Density Independency
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Birth rate or death rate does NOT change with population density
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Competition for Resources
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Territoriality
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Transmission rate of a disease can wipe out a population
Predation
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Territory space is what the animals compete for i.e: nesting sites
Health
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More population more competition
More food captured means lowered population
Toxic Wastes
Intrinsic Factors
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http://www.grguy.net/Q2_30Y3399-Cheetahmarking-300.jpg
Physiological effects of things like over-reproduction
http://recyclingewaste.files.wordpress.com
/2011/09/toxic-waste.jpg
Population Dynamics
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Metapopulations
Population Cycles = predictable intervals
http://ipmworld.umn.edu/chapters/Radcl
iffeSlide1.gif
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1962-no longer y^x
Demographic Transition
Developed countries: reproduction rates about = replacement level
Population growth in Developing countries
http://www.mongabay.com/images/pop.gif
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Relative number of individuals at each age
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Some say a billion, some say a trillion
Ecological Footprint( EF)
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Ecological Capacity( EC)
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Produce all resources, absorb all wastes
Actual resource base of their country
U.S. EF= 8.4 ha, EC= 6.2 ha
World EF= 1.7 ha
http://sunhomedesign.files.wordpress.com/2009/04/cc-graphic1.gif
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Space
Nonrenewable Resources
Renewable Resources
Earth’s Capacity to Absorb Wastes