Chp. 37 - 40 Flashcards
Plants in general are inefficient in converting light into E.
How much light is absorbed, used, and then converted?
~1-5% is absorbed
Of that ~2% is used by the chlorophyll
Of that ~0.1-1% is converted into food E
What is Gross Primary Production?
Amount of light E converted into chem E by a group of plants over a given period of time.
GPP - (E used in maintenance & reproduction) = Net Primary Production
Net Primary Production is used for growth &/or stored
What is Gross Secondary Production?
2nd TL
GSP - (E used in maintenance & reproduction) = Net Secondary Production
Net Secondary Production is used for growth &/or stored
What does an Ecological Pyramid represent?
Demonstrates changes in #s of indv, biomass, and E as we move from the producers to the consumers TL
How much E is transferred from one TL to another in an Ecological Pyramid?
~10% E is transferred from TL to TL
~90% is lost as heat into the environment
Energy Definition is?
What are the two Laws of Thermo?
What kind of system is Earth?
Energy - The ability to do work
1st Law - E cant be created/destroyed only converted, Total amount of E in the universe is constant
2nd Law - The Entropy of the universe always increases for every transfer/transformation
Earth is an open system
Why are food chains relatively short?
2 Hypothesises
Energetic Hypothesis - Length of the food chain is limited by the inefficiency of E transfers along the chain
Dynamic stability Hypothesis:
- Long food chains are not as stable as short ones
- Pop fluctuations from environmental disturbances at lower TL are amplified at higher TL
- Longer the FC the harder for top predators to recover from disturbances
- the more unstable the environment the shorter the FC
What is a Food Web
Food Web - 2+ TL provide E for 2+ other TL
What is the definition of Population Ecology?
What are the three parts of Pop Ecology?
Population Ecology - branch of Ecology that studies the activities of populations
Density, Movement, & Population growth & #s
What are the three types of Population Density Distributions?
Random - chance
Clustered - school, herd, flock
Uniform - regularly, territories
What are the three types of movement?
Their definitions?
Emigration - Indv leaves a pop/habitat, We know where it is going
Immigration - Indv enters a pop/habitat, We know where it came from
Migration - Indv leaves a pop/habitat & returns to that pop/habitat
Population Growth & #s:
What is the Biotic Potential?
What is Environmental Resistance?
Biotic Potential (rmax) - the max rate at which a pop increases that results when all the females breed as often as possible & all indv survive beyond reproduction age under ideal conditions
Environmental Resistance - Sum of all environmental factors that collectively inhibit the growth of a pop’s #s
What is the equation for Environmental Resistance?
What do the variables represent?
What does the value mean?
ER = (K-N)/K
K: carrying capacity
N: Number of indv in pop
Meaning - a rate of increase.
- The larger the # the more indv can be added to the pop
What is Carrying Capacity?
Carrying Capacity - The average # of indv in a species pop that can be supported by a particular environment
Describe the ways to measure/estimate a pop density.
2 Ways
Direct count - Count all the indv in the habitat as long as there are defined boundaries
Estimate pop density
- Count indv in boundaries/areas
- Indirect indicators - # of burrows, nests, etc.
- Mark & Recapture
- N = (AB)/C
N: Estimated pop #
A: # first collected and marked
B: # indv caught second time (marked & unmarked)
C: # of marked indv recaptured
