Ecosystems
What is an Ecosystem? Ecosystem – A community of organisms in a given area and the abiotic factors that affect them.
Habitat and Niche Habitat – A place where animals and plants naturally live and grow. Niche – A habitat that supplies the factors necessary for existence. Also, the ecological role of an organism in its community.
Abiotic vs. Biotic Factors Abiotic – All the nonliving factors in an area. Examples: water availability, amount of sunlight, temperature, precipitation, etc. Also includes Nitrogen and Carbon Cycles Biotic – All the living factors in an area. Examples: plants, animals, bacteria, etc.
Populations in Ecosystems Population – A group of organisms belonging to the same species that live in a particular area. What kinds of things influence a Population? What makes Population Numbers increase? What makes Population Numbers decrease?
Competition The relationship between living things that depend on the same resources in the same place at the same time.
Cooperation Type of animal behavior in which social animals live and work together for the good of the group.
Population Factors Things that effect a population… Density-Dependent Factors – Factors triggered by overpopulation or overcrowding. Examples: Competition (food, water, shelter), Predation, Parasitism, and Disease. Density-Independent Factors – Factors that occur regardless of the population. Examples: Weather or climate change, Natural disasters, and Human activities (pollution)
Population Simulation Watch the Simulation and observe how the bunny population changes when Biotic and Abiotic Factors are introduced. Answer the questions on your paper. http://phet.colorado.edu/en/simulation/natural-selection
Symbiotic Relationships Species may form relationships with other species to increase the chance of survival Symbiosis - a close relationship between organisms of different species in which at least one organism benefits.
Commensalism: a symbiotic relationship in which one species benefits and the other is unaffected. Ex: Spanish moss and a tree Mutualism: a symbiotic relationship in which both species benefit. Ex: Ants and acacia trees Ex: Teeth cleaner birds
Parasitism: a symbiotic relationship in which one species benefits and the other is harmed. Ex: Ticks, tapeworms, tree fungus
Food Web Animal Name Clarification Large Fish Gulls and Terns Wading Birds Bivalves Small Fish Benthic Invertebrates Herbivorous Ducks