1. Ecology and Ecosystems What is Ecology

2. Ecology and Biospheres  Ecology= Interactions among organisms AND between organisms and their environment.  Biosphere= Contains the combined portions of the planet in which all life exists including:  Land  Water  Air or Atmosphere

3. Species, Populations & Communities  Species= Group of organisms so similar to one another that they can breed & produce fertile offspring  Populations= Groups of individuals that belong to the same species  Communities= Groups of different populations that live together in a defined area  Also the simplest grouping of more than one kind of organism in the biosphere

4. Ecological Methods  Observing= First step in asking ecological questions EX: What are species like here? How many individuals of each species are here?  Experimenting= Used to test hypotheses. EX: setting up artificial ecosystem or conduct experiments in natural ecosystem  Modeling= Used to look at large scale ecological phenomena. Many consist of mathematical formulas. EX: A mathematical formula used to look at population fluctuations in a community

5. Energy Flow  Sunlight is the main energy source for life  Some types of organisms rely on energy stored in inorganic chemical compounds EX: chemosynthetic bacteria  Autotrophs=Capture energy from sunlight and or chemicals and use that energy to produce food. EX: Plants, some algae, and certain bacteria  Producers= Organisms that produce their own food

6. Energy Sources  Photosynthesis: Autotrophs use sunlight to convert carbon dioxide and water into energy (Sugars and Carbohydrates) Releases oxygen into the air. EX: Trees, grasses, algae  Chemosynthesis: Autotrops use chemical energy to produce carbohydrates and oxygen EX: Bacteria that live in volcanic vents & hot springs

7. Consumers  Heterotrophs= Organisms that rely on other organisms for their energy and food supply  4 Types of Heterotrophs: Herbivores: Eat plants EX: Caterpillars, deer Carnivores: Eat meat EX: snakes, dogs, owls Omnivores: Eat plants & meat: EX: Humans, bears Detrivores: Eat plant & animal remains EX: Worms, crabs, snails, mites Decomposers: Break down organic matter EX: Bacteria and fungi **HETEROTROPHS ARE ALSO CALLED ** CONSUMERS

8. Feeding Relationships  Energy flows through an ecosystem in one direction  From the sun or inorganic compound to autotrops and then to heterotrophs Food Chain= Series of steps in which organisms transfer energy by eating & being eaten EX: Shark eats squid which eats small fish, which eats zooplankton, which eats algae. Food Web= ecological model of relationships that form a network of complex feeding interactions among organisms in a community from producers to decomposers.  EX: feeding relationships in a salt marsh community

9. Feeding Relationships Cont..  Trophic Level= Each step in a food chain or food web Producers= 1 st trophic level Consumers= 2 nd, 3 rd, and higher trophic levels

10. Ecological Pyramids  Ecological Pyramid= Diagram showing the transfer of energy or matter in each trophic level of a food chain or web  Biomass= The total amount of living tissue within a given trophic level