Ecology ReviewBy Denise M. Green

•Population•Community•Biosphere•Habitat•Niche

Population Review•Size of population = N•Density•Dispersion•Age•Survivorship

POPULATIONS

Survivorship Types•I – most individual survive to middle age with high mortality rate after that : humans•II- likelihood of death is the same at any age: invertebrates•III- most individuals die young with a few surviving to reproductive age and beyond: oysters and other free swimming larvae

POPULATIONS

Population growth•Biotic potential•Carrying capacity•Limiting factors

•Density dependent-disease, food•Density independent-natural disasters

POPULATIONS

Growth of a population•r = reproductive rate or growth rate•N = population size•r = births – deaths / N•Two patterns: exponential growth and logistical growth

POPULATIONS

A population of 265 swans was introduced to Circle Lake. The population’s birth rate is 0.341 swans/year per capita, and the death rate is 0.296 swans/year per capita. What is the rate of the population growth per capita, and is it increasing or decreasing? Round to the nearest thousandth.

r = b – d = 0.341 – 0.296 = 0.045 increasing

Exponential growth

Simulation: http://bcs.whfreeman.com/thelifewire/content/chp54/5402001.html

POPULATIONS

Logistical GrowthAs the size of the population increases, the reproductive rate increases until carrying capacity is reached.

K = carrying capacity http://bcs.whfreeman.com/thelifewire/content/chp54/5402002.html

POPULATIONS

Changes in population size.

POPULATIONS

Community Ecology•Competitive exclusion principle•Resource partitioning•Character displacement•Realized niche

Predation•True predator•Parasite•Parasitoid•herbivore

Symbiosis•Mutualism•Commensalism•Parasitism

Coevolution•Secondary compounds•Camouflage (cryptic coloration)•Aposemastic coloration- a conspicuous coloration to warn predators that they sting, bite, are poisonous•Mimicry

•Mullerian- several animals all with the same defense mimic each other in coloration•Batesian mimicry- animal without a defense mimics an animal with a defense in coloration

Ecological succession•Primary succession•http://bcs.whfreeman.com/thelifewire/content/chp55/55020.html

•Secondary succession

Ecosystems trophic levels•Primary producers•Primary consumers•Secondary consumers•Tertiary consumers•Dendritivores

Only 10% of energy from one level passes on to the next trophic level due to use at first trophic level.

Ecosystems and Energy Flow•Primary productivity is amount of light energy converted to chemical energy by autotrophs

•GPP- total energy•NPP- net productivity•Rs- respiration

NPP = GPP – RsBiomass = primary productivity reflected as dryWeight of organic materialSecondary productivity = rate at which consumers convert chemical energy of food to their own biomass

Biogeochemical Cycles

Terrestrial and Aquatic Biomes

Human Impact•Increase of Greenhouse effect•Ozone layer depletion•Acid rain•Desertification•Deforestation•Pollution•Reduction in species diversity

B

D

C

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D

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C

B

B

A

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C