Ecosystems

Ecosystem = all the organisms that live in a particular place, AND their nonliving and living environment Ecosystems are made and shaped by both living (biotic) and nonliving things (abiotic)

Biotic Factors The living influences on an organism. plants animals fungi bacteria Abiotic Factors The physical, or nonliving, factors that shape an ecosystem. moisture temperature wind sunlight soil Biotic and abiotic factors determine survival and growth of an organism and productivity of the ecosystem in which the organism lives.

Sunlight Plants moisture sand

Energy in an Ecosystem * Life in an ecosystem requires a source of energy Producers = organisms that make their own food from the sun or inorganic chemical compounds Provide energy for other organisms in an ecosystem This image uses chlorophyll abundance to show the distribution of producers

Producers Producers are called Autotrophs “auto” = self “troph” = feeder Photoautotroph = Autotrophs who use energy from the sun (through photosynthesis) to make their food Chemoautotroph = Autotrophs who use energy from inorganic chemical compounds to make their food

Chemosynthesis is the process by which organisms form carbs using chemicals, rather than use light, as an energy source. This is found in sulfur rich salt marsh flats and in hydrothermal pools in Yellowstone National Park. carbon dioxide + water + hydrogen sulfide + oxygen sugar + sulfuric acid

Consumers Consumers = organisms that get energy by eating other living or once-living resources. Heterotrophs “Hetero” = other “troph” = feeder

There are different types of heterotrophs based on what they eat. Herbivores eat plants. Carnivores eat animals. Omnivores eat both plants and animals. Detritivores eat detritus (dead organic matter) ex. millipede Decomposers are detritivores that break down organic matter into simpler compounds. This is important to an ecosystem b/c it returns vital nutrients back into the environment. Ex. fungi decomposer carnivore ominvore detritivore

Feeding Relationships Food Chain = series of steps in which organisms transfer energy by eating and being eaten. Food chains follow the connection between one producer and a single chain of consumers in an ecosystem

Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers). Feeding Relationships

energy transferred energy lost Each step in a food chain is called a trophic level. Trophic levels are the nourishment levels in a food chain. Primary consumers are herbivores that eat producers. Secondary consumers are carnivores that eat herbivores. Tertiary consumers are carnivores that eat secondary consumers. Omnivores, such as humans that eat both plants and animals, may be listed at different trophic levels in different food chains.

Energy Transfer Only 10% of energy is transferred from one trophic level to the next WHY? Because organisms use much of the energy they consume for life processes (respiration, movement, reproduction)

Energy Transfer The amount of energy available at each trophic level can be identified using an energy pyramid 100% 10% 1%.1%

A food web shows a complex network of feeding relationships. Emphasizes complicated feeding relationships and energy flow in an ecosystem. An organism may have multiple feeding relationships in an ecosystem. Producers Primary consumers Secondary consumers Tertiary consumers