What is Ecology? Defined: Studying how life interacts within the biosphere is called Ecology All life interacts within the biosphere – Area within the deepest ocean trenches to the highest mountains

Defined: Group of one species living in the same area Population changes based on: – Births, Deaths, Immigration, Emigration, Available resources Click on information box Populations

Population Patterns Populations go through 3 stages: 1)Slow growth Population is slowly adapting to particular environment 2) Exponential growth High birth rates due to abundant resources 3) Carry capacity Defined: greatest number of individuals that the environment can sustain Birth & death rates eventually balance What stage is the human population in?

After Carrying Capacity? Some populations stabilize for the long term Some populations experience a sharp decline called a “crash” Which will humans experience?

Communities Defined: Populations of many species living in the same area at the same time Each organism has it own HABITAT – Habitat: Place where an organism lives Each species has its own NICHE – Niche: The role/needs of a species – Ex: Termites return nutrients to the soil

Ecosystems Defined: Communities of species interacting with the living & non-living Biotic (living) Factors: o Animals: Mice, Reptiles, Insects o Plants: Cactus, Flowers, Shrubs Abiotic (non-living) Factors: o Sand, rocks, sunlight, climate, soil, water, etc… Ecosystem changes affect biodiversity o Keystone species greatly alter ecosystems

The Biosphere Defined: All organisms and the part of the Earth where life exists Biosphere changes can affect life Ex: More CO2 in the atmosphere… causes warmer temps

What is a Biome? Defined: Large area with distinct climate, plant, and animal life Climate factors: sun, rain, topography Climate determines life

Review 1) What is ecology? 2) What are two reasons that populations will increase? 3) What are two reasons that populations will decrease? 4) What are factors that control population growth called? 5) How does a population, community, ecosystem, biome, and biosphere differ? 6) What is a keystone species? 7) Place the levels of ecology in order from smallest to largest. – Ecosystem, Population, Biosphere, Community, Biome