Ecology

Population Ecology

Dispersion

• Clumped-individuals in patches

• uniform- result of antagonistic(hostile interactions)

• random- unpredictable spacing

Demography

TYPE I - shows low death rates during early and midlife; then the death rate decreases sharply for older groups.

TYPE II- shows a constant death rate over the organisms life span.

TYPE III- shows very high early death rates early, then a flat rate for the few surviving to older age groups

Population Growth

• Exponential population growth- growth under ideal conditions

• Logistic growth model- per capita rate of increase declines as a carrying capacity is reached

• Carrying capacity- maximum population size that a certain environment can support at a particular time with no degradation

Exponential equation- dN/dt=r(max)NLogistic equation- K: dN/dt= r(max)N (K-N)/K

Density Independent Factors

What is Density independent factors?

• things that are unaffected by population size

• Damages affect everyone in a population regardless of the size

Examples Of Density independent factors

• Weather• Natural disasters• Climate• Pollution • Seasonal cycle (ex.-

monsoons, el Niño, La Nina

Density-dependent factors

a death rate that rises as the population density rises and a birth rate that falls as the population density rises

Predation Competition Diseases

Community Ecology

Ecological Succession

Primary succession- plants and animals gradually invade a region that was virtually lifeless where soil has not yet formed

Secondary succession- occurs when an existing community has been cleared by a disturbance that leaves the soil intact.

Relationships

Parasitism- symbolic interaction in which the parasite derives its nourishment from its host. Parasites may have a significant effect on the survival, reproduction, and density of their host.

Mutualism- interspecific interaction in which both species benefit

Commensalism- a process in which one species benefits and the other species is neither harmed or benefited.

KEYSTONE SPECIES

• exert control on community structure by their important ecological niches.

• disappearance would start a domino effect

Restoration & Conservation Ecology

Flow of Energy

Primary Consumers - herbivores that eat the primary consumers

Secondary Consumers- carnivores that eat the herbivores

Tertiary Consumers- carnivores that eat the secondary consumers

Decomposers( Detritivores)- consumers that get their energy from nonliving organic material

traced through the trophic levels of a food chain and food web

Energy cannot be recycled

Primary Production

the amount of light energy converted to chemical energy by autotrophs

is known as the Gross Primary Production(GPP)

GPP is not the amount

of energy available to consumers

Energy

energy is lost at each level of transfer as heat

3 Types of Ecological Pyramids a biomass pyramid an energy pyramid a pyramid of

numbers

Nitrogen Cycle

moves nitrogen from the atmosphere through the living world

a common limiting factor for plant growth

most of earth's nitrogen is in the form of N2

is unusable by plants

Carbon Cycle

is a balance between the amount of CO2 removed from ecosystem by photosynthesis and cellular respiration

The burning of fossil fuels adds significant amounts of Co2 to the atmosphere

CO2 effects on global warming

Resources

• www.biologycorner.com • www.southtexascollege.edu • www.laney.edu • www.nanotechproject.org • www.clas.ufl.edu