Ecology

Ecology-study of organisms and their interactions with the environment Biotic factorsAbiotic- 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 Exponential Logistic

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.