What is Ecology?• Ecology- the study of relationships between organisms and their environment.
Levels of Ecological Organization• Biosphere- the entire planet: land air, water, atmosphere• Biome- a group of ecosystems that have the same climate & dominant communities.• Ecosystem- a collection of LIVING organisms AND the ENVIRONMENT of a particular area.• Community- all organisms that live w/in an ecosystem.• Population- all members of the same species in an area• Species- organisms that can interbreed reproduce fertile offspring
Diversity• The measure of the number of living things in an ecosystem.
What Determines Diversity?• 1)Size of ecosystem.• 2) Latitude of ecosystem. – a) more sunlight promotes growth – b) longer growing season=more producers – c) more producers = more consumers
Ways to Study Ecology? 1) Observation 2)Experimenting 3)Modeling
Energy in Ecosystems• Producers- take energy from surroundings & store it in complex molecules. – Photosynthetic- plants, (some) bacteria, algae – Chemosynthesis- bacteria, algae – AKA autotrophs – *Sunlight- main source of energy; source of – life.
• Consumers- consume/eat other organism – Animals, most protists, bacteria and fungi – AKA heterotrophs
3 Types of Consumers• 1) Herbivores• 2) Carnivores• 3) Omnivores• 4) Detritivores- organisms that feed on dead material. Mites, earthworms, snails, crabs, etc.
Who Eats Who…• Food web- – Shows complex relationship of ecosystem through overlapping food chains. – Network of feeding relationships• Keystone species- – Most important species in a food web – Cannot be easily replaced – Affects every other species
Energy Flow in an Ecosystem• Energy flows through an ecosystem from the sun to producers, to consumers. Each step in the series of organisms eating other organisms is called a trophic level (eating level)
Trophic Levels• Group of organisms whose energy source is the same number of steps from the sun.• Autotrophs- plants & other organisms that make their own food. (1st trophic level)• Herbivores- animals that eat plants (2nd trophic level)• Omnivores-eats both plants & animals• Heterotrophs- cannot make own food feed on other organisms waste (above
How many trophic levels are possible?• Few ecosystems have more than 4 or 5 trophic levels because energy diminishes at each level.• Energy pyramids- represent the energy present at each level of the food web.