• Assignment 3: Friday, 5/3
• Make-Up Lab: Friday, 5/3
• Final Exam: Tuesday, 5/7, 11:00 - 1:00
Thursday, April 25, 2013
Ecology
• Study of the structure, function and behavior of the environment.
• Population - all individuals of the same species living in the same place
• Community - all living organisms in the same area
• Ecosystem - all living and non-living components of a particular area
Thursday, April 25, 2013
Energy Flow (One Way)
Producer ConsumerSunlight
Decomposer
Detritus
Heat Heat
Heat
Photosynthesis
Respiration
Biomass Biomass
BiomassThursday, April 25, 2013
Biodiversity
• Refers to the variety of life
• Includes:
• Species richness - number of species
• Species diversity - measure of number and relative abundance of species
Thursday, April 25, 2013
Biodiversity
Ecosystem I
Species A = 33Species B = 33Species C = 34
Ecosystem II
Species A = 90Species B = 5Species C = 5
Species Richness = 3 Species Richness = 3
Higher Diversity Lower Diversity
Thursday, April 25, 2013
Niche
• Role each species plays in its ecosystem
• Habitat - area where it lives
• Interactions with other organisms (interspecific relationships)
Thursday, April 25, 2013
Predator-Prey
• One organism (predator) kills and eats another organism (prey).
• Predator larger (usually)• Predator benefits, prey harmed
Thursday, April 25, 2013
Animal eats Animal
• Frog eating insect• Snake eating bird egg• Lynx and snowshoe hare - figure in text
Thursday, April 25, 2013
Predatory Plants• these photosynthesize to make food
but need to get N and P from insects since it is low in areas they live
• Venus Fly Trap• Pitcher Plant
Thursday, April 25, 2013
Parasite-Host• One organism (parasite) lives in or on
another (host) and feeds off host.• Parasite usually smaller • Parasite benefits, host harmed.
Thursday, April 25, 2013
Endoparasite
•Parasite inside host•e.g. Heartworms on Dog (see figure in text)
Thursday, April 25, 2013
Lichens
•Mutualism between Green Algae and Cup Fungus•Algae makes food by photosynthesis•Fungus absorbs water and nutrients from substrate
Thursday, April 25, 2013
Root Nodules
•Mutualism between plant root of legumes and blue-green bacteria•Roots provides bacteria with food (made in leaves in transported to root)•Blue-green bacteria perform nitrogen fixation to provide root with ammonia and nitrate
Thursday, April 25, 2013
Leaf-Cutting Ant/Fungus
•Mutualism •Ants deliver food to fungus•Fungus digests leaves for ant to eat
Thursday, April 25, 2013
Commensalism
• One species benefits, other unaffected.
• Plants such as orchids and bromeliads live in branches of large trees to be nearer to sunlight, tree unaffected
• Clownfish hides in tentacles of sea anemone for protection against predators, anemone unaffected.
Thursday, April 25, 2013
Competition• Two or more species use the same resource.• Both harmed if resource is limited.
• Dandelions and grass on lawn
Thursday, April 25, 2013
Competitive Exclusion Principle
• No 2 species can indefinitely occupy the same niche at the same time
• Leads to resource partitioning - different species use different parts of resources
• e.g. 5 species of warblers (birds) live in different parts of tree (fig. in text.)
• e.g. 2 species of barnacles live at different heights on sea edge. (fig. in text.)
Thursday, April 25, 2013