Ecology

Ecology-study of organisms and their interactions with the environment

Biotic factors Abiotic- non-living

Climate vs. weather

• Climate- overall patterns of temperature, precipitation, sunlight, wind, etc. Mainly determined by distance from the equator.– Macroclimate- global or regional– Microclimate- Hazleton- colder than the rest of

the area• Weather- day to day

Succession• Primary succession-occurs where there is no

soil. It occurs on rock, such as volcanic rock. Lichens are the first organisms. They break down the rock and for soil. A succession of species then move in depending upon the biome. A climax community results.

• Secondary succession- occurs where a climax community is disturbed, such as deforestation. The soil remains. The organisms will be different and less diverse than the original species.

Biomes

• Savannas- grasses and some trees; think Africa• Desert- less than 25 cm of rainfall per year.

Deserts can be cold.• Chaparral- coastal areas with mild rainy

winters and long, hot, dry summers. Plants are adapted to fires. Ex. Corsica

• Temperate grasslands- grasses; large grazing animals.

More biomes

• Temperate broadleaf/deciduous forests- us• Coniferous forest/Taiga- cone-bearing trees,

cold; lots of snow• Tropical- most diversity. There is an entire

community in the canopy. Epiphytes live in many of the trees.

Aquatic biomes-oceans

• Photic- areas that get sunlight• Aphotic- no sunlight- the abyss• Coastal• Continental shelf- a lot of fish• Benthic zone- on the bottom of the ocean• Thermoclines- narrow areas that separate

warm upper water from cold lower water

Freshwater biomes- moving or standing water

• Littoral zone- shallow water near the edge; a lot of plants

• Limnetic zone- well let; not near edge• Oligotrophic lakes- deep, nutrient poor lakes• Eutrophic lakes- shallow with more nutrients; fill

in over time. Eutriphication• Streams and rivers- diversity depends upon

temperature, speed, and how clean the water is.

Estuaries

• Can be found where freshwater streams or rivers meet saltwater.

• There is a lot of life there. Great breading grounds.

Population Ecology

• Density- number of individuals per unit area.• Dispersion- clumped, uniform , random• Demography- the study of populations.

Demographic transition occurs in human pop.– Type I- low death early in life; older age groups dying.

U.S.– Type II- survivorship curves- constant death rate at all

ages. Ex. Squirrels, humans in India– Type III- high death rate of young, then flat for older

individuals. Ex. Clams, humans in Ethiopia

Survivorship Curves

2 types of growth rates

• Exponential- growth under ideal conditions with no limits due to food, shelter, etc.

• Logistic- shows carrying capacity. Limits due to resources

ExponentialLogistic

More Factors Affecting Populations

• Immigration, emigration, births, deaths• Availability of resources causes populations

to meet carrying capacity. What do you think that number is for humans?

• Complete analyzing data on page 123

Factors that regulate density

• What is a limiting factor?• Density dependent- competition, space,

disease, predation. The larger the population, the greater the effects.

• Density independent- natural disasters. population size is irrelevant.

Ecological footprint

• The effects organisms, especially humans, have on the environment.

Reproductive strategies

• K- strategy- organism takes care of young to insure survival.

• R- strategy- many offspring; no care. Large numbers insure some may survive.