LT 1.2 Carrying Capacity

Limiting Factor

Biotic or abiotic factor that limits the numbers of a species.  Food, water, shelter, predation

Range of Tolerance

For any environmental factor (biotic or abiotic), there is always an upper & lower limit that any species can live between.

Ecological Succession

Ecosystems may change, so that one community may replace another because of changes in biotic and abiotic factors.

Primary Succession

A community is established on exposed rock that does not have any soil. 

Pioneer Species

 break down rock, make soil.

Climax Community

A stable, mature ecological community at balance, Remains stable until disrupted by external factors.

Secondary Succession

A disturbance destroys the community, which slowly reestablishes itself on the remaining topsoil.

Biomes

Zones classified by plant communities; determined by Latitude, Altitude, and Climate.

Variates in: temperature, sun exposure, and water to grow plants.

Koppen Climates

A: Moist Tropical: high temp and large rain
B: Dry: little rain and daily temp range
C: humid middle latitude: dry summers cool winters

D : continental - seasonal temps vary
E: Cold: Ice always present

Species Richness

The number of species a community contains. 

Varies with latitude.If you are closer to the equator more species, farther from equator less species.

Species Area Effect

Larger areas generally contain more species than smaller ones.

greater habitat supports more species, reducing habitat supports less species.

Species interactions

Predators prevent competitive exclusion among their prey.  Superior competitors cannot become dominant if subject to predation.

Community Stability

Species-rich areas are more resistant to change; in a disturbance, less species are lost, and recovery time is faster.  

Resistant

Remains mostly unchanged by disturbances until large impact shatters community

Resilient

If changed, it recovers quickly

Population Density

The number of individuals of a population in a defined space.

Dispersion

How organisms distribute themselves in an environment.

clumped, uniform, or random

Population Size

How many individuals are in a population.

Range

Distribution of a species on our planet.

Limited by the ability to travel, abiotic factors, and adaptability. 

Growth Rates

The amount by which a population’s size changes over time.

Emigration

Organisms leave population

Immigration

Organisms join population

r-selected populations

generally exist as species that show exponential growth, and then crash. 

k-selected populations

generally exist as species that show logistic growth and are stable near their environment’s carrying capacity. 

exponential

constant birth and death rates for short periods of time; slow initial growth

logistic

levels off as the population grows, flattens when carry capacity reached.

carrying capacity

Limit for specific population’s size based on limiting factor.

Density independent factors

Weather, natural disasters,  & human activity reduce populations by same proportion

Density dependent factors

Resource limitations; water, food or shelter shortages.  Affect growing populations.

Explain why a population size fluctuates once carrying capacity is reached.

due to the balance between resource availability and population growth, where limited resources lead to increased life and decreased birth rates.