Ch 36 Energy in Ecosystems. 36.1 Food Chains & Food Webs. 34.1 Biotic and Abiotic Factors. What are biotic and abiotic factors? The biological influences on organisms are called biotic factors. Physical components of an ecosystem are called abiotic factors. Biotic Factors.
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36.1 Food Chains & Food Webs
What are biotic and abiotic factors?
The biological influences on organisms are called biotic factors. Physical components of an ecosystem are called abiotic factors.
A biotic factor is any living part of the environment with which an organism might interact, including animals, plants, mushrooms and bacteria.
Biotic factors relating to a bullfrog might include algae it eats as a tadpole, the herons that eat bullfrogs, and other species competing for food or space.
An abiotic factor is any nonliving part of the environment, such as sunlight, heat, precipitation, humidity, wind or water currents, soil type, etc.
For example, a bullfrog could be affected by abiotic factors such as water availability, temperature, and humidity.
The difference between abiotic and biotic factors is not always clear. Abiotic factors can be influenced by the activities of organisms and vice versa.
For example, pond muck contains nonliving particles, and also contains mold and decomposing plant material that serve as food for bacteria and fungi.
In addition, trees and shrubs affect the amount of sunlight the shoreline receives, the range of temperatures it experiences, the humidity of the air, and even the chemical conditions of the soil.
A dynamic mix of biotic and abiotic factors shapes every environment.
Ex. Blue Sweet lip fish
Ecologists might ask, “How do Blue Sweet lip fish adapt to the challenges posed by the environment?”
Ex. A group of Blue Sweet lip fish
Ecologists might ask, “What factors limit the numbers of sweet lip fish living around this reef?”
Ex. Coral reef is home to many living things including fish, coral animals, microscopic algae….
Ecologists might ask, “How might a disease that strikes the coral animals affect the other species in the community?”
1.)Sunlight- provides light and warmth, powers photosynthesis.
2.)Water- essential for all life. (we are 70% water)
3.)Temperature- most life exists between a narrow range of temperatures.
(0 50 °C)
4.)Soil- the product of abiotic forces (such as ice, rain, and wind) and the actions of the living things (microorganisms, plants and earthworms) on the rocks and minerals of the earth’s crust.
5.)Wind-it can affect the distribution and organisms in several ways.
6.) Sever Disturbances- fires, hurricanes, tornadoes, droughts, floods, and volcanic eruptions.
consumers that feed on detritus, the wastes and remains of dead organisms.
Many consumers and decomposers have more than 1 food source
Movement of energy occurs in complex webs rather than in simple chains
Trophic Levels Each of the feeding organisms represents a trophic level in the ecosystem. Both energy and chemicals move from one organism to the next as organisms feed.
Primary consumers- 1st level
Secondary consumers- 2nd level
Tertiary consumers- 3rd level
Quaternary Consumers-4th level
eats another carnivore- tertiary consumers
Figure 36-2 Each of these food chains includes five trophic levels. The arrows indicate the direction of food transfer between trophic levels.
2. In the following food chain, identify the trophic levels: