Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Overexploitation wikipedia , lookup
Habitat conservation wikipedia , lookup
Introduced species wikipedia , lookup
Island restoration wikipedia , lookup
Occupancy–abundance relationship wikipedia , lookup
Renewable resource wikipedia , lookup
River ecosystem wikipedia , lookup
Flow of Energy and Relationships The Structure of Ecosystems • Trophic categories • Trophic relationships: food chains, food webs, trophic levels. • Nonfeeding relationships: symbiosis • Abiotic factors Autotrophs = Producers = Self feeders Consumers = Heterotrophs • Primary consumers = herbivores = rabbit: eat plant material • Secondary consumers = carnivores = predators = coyotes: prey are herbivores and other animals. • Detrivores – feed on dead material (detritus) Consumers = Heterotrophs • Parasites = predator = either plant or animal: prey are plants or animals. Detritus Food Web Trophic Relationships: Food Chain Third-order Consumer Secondary Consumer Primary Consumer Producer Match Organisms with Trophic Level(s) Trophic Levels Organisms Secondary Consumer ThirdOrder Consumer Snakes X X Owls X X X X Plants Producer X Rabbits Bacteria Primary Consumer X X X Match Trophic Categories with Trophic Level(s) Trophic Levels Category Autotrophs Producer Primary Consumer Secondary Consumer Third-Order Consumer X X X X X X X X X Herbivores X Carnivores Omnivores Parasites X Trophic Relationships Among Producers and Consumers Food Webs = Food Chain Interrelationships Keystone Species • Role in the community is critical to the community’s survival • Importance can be greater than their abundance suggests • Can be predators, prey, producers, or mutualistic species Keystone Species • Are often involved in predator-mediated competition – Predators thin the numbers of highly competitive species, allowing other species to survive – Removal of a predator can cause a trophic cascade • Lower levels of the food chain grow out of control then crash • Can be ecosystem engineers – Alter and create habitat for other organisms Trophic Level Energy Flow Third-order Consumer 1Kcal Secondary Consumer 10 Kcal Primary Consumer 100 Kcal Producer 10,000 Kcal Biomass Pyramid Trophic Levels: Pyramid of Biomass 5 4 3 2 1 Which level is occupied by: producers? primary consumers? secondary consumers? third-order consumers? Trophic Levels: Pyramid of Energy 5 4 3 2 1 Which level is occupied by: producers? primary consumers? secondary consumers? third-order consumers? Nutrient Cycles and Energy Flow Nonfeeding (Symbiotic) Relationships • + And + = Mutualism. Both species benefit by the interaction between the two species. Honey bee and flower • + And 0 = Commensalism. One species benefits from the interaction and the other is unaffected. Remora fish and shark Nonfeeding (Symbiotic) Relationships • + And - = One species benefits from the interaction and the other is adversely affected. Examples are predation, parasitism, and disease. • - And - = Competition. Both species are adversely affected by the interaction. Resource Partitioning: Reducing Competition