Bsci106 Exam 1

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August 31, 2012—LECTURE 1
·      What is ecology?
o   interactions of organisms with each other and with their environment §  biotic environment
§  abiotic environment
·      why is ecology important?
o   Context for evolution
o   Management of resources
o   Evaluation of human impacts
Levels of study (ECOLOGY)
·      Organismal: individual interactions with their environment ·      Population: factors regulating population growth rates and population size ·      Community: interactions among different species in an area ·      Ecosystem: interactions between communities and their environments o   Biotic/abiotic

·      Landscape ecology
·      Global ecology
 
ABIOTIC FACTORS
·      Some predictable attributes of communities that are based on large scale abiotic factors o   (ex: light/latitude/energy input/temperature)
o   global air circulation (Hadley cells: air circles)
§  –predictable patterns where deserts are due to winds (all around 30 degrees North and South of equator) o   seasonality/tilt of earth axis
§  —seasonality is due to how the earth is tilted on an axis §  effects climate in a big way
·      (Green Sahara: ~8000 years ago the Sahara was lush and wet environment, since then the earth’s axis tilt has changed slightly—profound effects) o   bodies of water
§  water can retain a lot of heat (warm bodies of water give land masses milder climates) §  water currents circle around the equator which influences climate on land o   earth is round—effects air/water patterns

o   local geography—huge effect on planet
§  “rain shadows” –when there’s a lot of rain in a certain area (normally coastal), it can produce a dry area on the opposite side o   terrestrial ecosystems are heavily influenced by temperature/precipitation o   aquatic ecosystems—water depth and rate of water movement are key o   biomes: major life zones characterized by vegetation type or physical environment  

·      if the abiotic factors change, then the biotic(ecosytems) change o   global climate change-> documented and predicted changes in organism distributions  
BIOTIC FACTORS
·      Dispersal capabilities
·      Behavior
·      Interactions with other organisms ****
Study figure 52.20 on your own

LECTURE2 september 5 

mastering biology course id: MBBELYFALL2012 
 
how do populations grow? 

models can be very useful in projecting population growth into the future  * population: group of individuals of single species living in same general area characteristics?
1number (N)
* important for assessing potential for increase in absolute numbers  * particular importance in conservation 
2density (N/per area or volume) 
* many ecological factors influenced by density of a population, not the absolute number  3dispersion
* pattern of spacing among individuals
* ex. clumped/uniform/random
* want to see how the population# changes over time
1. new additions (births)
2. loss (death)
3. immigrate (come in)
4. emigate (leave) 
4potential for change in #s 
* in absolute numbers:
* B/Δ T
* D/Δ T
* Δ N/Δ T = (B-D)/Δ T   ---(change in N per unit time)  * per capita-----
* births;
* b- the per capita #births/time
* B/Δ t= bN         (B/N)/Δ t=b
* deaths;
* d- the per capita #deaths/time 
* D/Δ t=dN           (D/N)/Δ t=d
* per capita growth rate
* r-the per capita growth rate of population
* r=b-d 
5life history characteristics
* individuals in a population are not all equivalent * ex. age can have a big impact on survival/reproduction * life table: age-specific summary of survival & reproduction patterns in a population  * survivorship (lx) curves 

* may vary dramatically with age/gender
* may change over time --droughts/famine/ect.
* varies among...
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