Earth: A Living Planet Ecology - Study of the interactions of organisms with one another & their environment. Biosphere - Part of the Earth in which life exists. 1) Ecosystem- area of Earth that includes: biotic factors- living things AND abiotic factors- non-living things

2) Community - all organisms that live together in an ecosystem. 3) Population - a group of species. 4) Species/organism - an individual species in a population. Habitat- area where an organism lives Niche- an organism’s role in a habitat

Niche vs. Habitat 7 lizards same habitat 7 different niches divided by height

Organism’s Energy Roles 1) Producer - organisms that make their own food/energy. 2) Consumer - organisms that obtain food from producers. Ex.- Herbivores(plants), Carnivores(meat), Omnivores(plant & meat) 3) Decomposers - organisms that break down organic matter. *Energy flows from: sun→producers→consumers→decomposers

Energy Diagrams 1) Food Chain - illustrates a step-by-step feeding relationship - each step is a trophic level

- illustrates every feeding relationship 2) Food Web - illustrates every feeding relationship - more complex than a food chain

3) Energy Pyramids - illustrates amount of energy in the trophic levels of food chains & webs. -biomass- amount of living tissue in each level - 10% LAW - only 10% of energy is passed on to each level. - most energy is lost as heat.

Community Interactions 1) Competition - conflicts over resources * No two species can occupy the same niche in the same habitat at the same time. 2) Predation - one organism feeds on another organism

3) Symbiosis - organisms that form a relationship together Examples a) Mutualism - both organisms benefit - insects & flowers b) Commensalism - one organism benefits, the other gets no benefit & isn’t harmed. - barnacles on a whale c) Parasitism - one organism benefits, the other is harmed.

Nutrient Cycles 1) Water Cycle - movement of water between the land and air.

2) Nitrogen Cycle - Nitrogen Fixation - bacteria changing nitrogen gas into ammonia - ammonia is converted to soil nitrates(fertilizer) - producers absorb nitrates - consumers eat producers gaining nitrogen

3) Carbon Cycle - carbon moving between photosynthesis & respiration processes.

Ecological Succession - series of changes in a community over time 2 Types 1) Primary Succession - occurs in areas without soil - follows volcanic eruptions & glacier melts 2) Secondary Succession - occurs where soil is present - typically follows a wildfire

Biomes - area with a characteristic community Land Biomes 1) Tundra- cold, dry northern areas 2) Taiga- cold winters, mild summers, conifer trees 3) Temperate Forests- 4 seasons, deciduous trees 4) Grasslands- 4 seasons, moderate rainfall 5) Rain Forests- hot & wet all year, large % of life 6) Deserts- little rainfall, variable temperatures Aquatic Biomes 1) Freshwater- rivers & lakes 2) Marine- oceans & coastal areas

Population Growth Growth Curves 1) Logistic Growth Curve - growth with fluctuations at a certain level - most populations experience this growth 2) Exponential Growth Curve - rapid increase with no stopping * Carrying Capacity- max amount of organisms for a given habitat

Population Growth Curves

Paramecium Aurelia vs. Paramecium Caudatum Competition

Limiting Factors - factors that control population growth 2 Types 1) Density-dependent - only affect large populations Example: predation, competition, disease 2) Density-independent - affects any size population Example: natural disasters (hurricane, fire)

Demography - scientific study of human populations Growth Factors 1) Birth rate- # people born per year 2) Death rate- # people who die per year 3) Growth rate- birth rate – death rate = growth rate

History of Human Growth

Environmental Issues CLIMATE CHANGE - Increase in Earth’s temperature- Cause: - Due to increase in Carbon Dioxide - CO2 added by fossil fuels Effects: - Sea level rising - Melting ice caps - warmer seasons

2. DEFORESTATION - cutting down of forests- Cause: - creates farmland for poor countries - wood used for fire and building Effects: - increase in Carbon Dioxide(climate change) - increase in erosion - loss of habitats - decrease in available water(transpiration)

3. ACID RAIN - increase in the acidity of rain Cause: - rain combining with air pollution from coal Effect: - increases acidity of lakes harming wildlife - kills trees and plants sensitive to acidity

4. OZONE DEPLETION - caused by CFC’s (aerosol cans) - Ozone blocks UV light from the sun - less Ozone allows in excess radiation