ecology. ecology-study of organisms and their interactions with the environment biotic...
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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
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.
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