Community Interactions Remember…it’s the INTERACTIONS that are important in ecology!

Compare and Contrast Species Species Population Population Community Community

Definitions Species: A class of individuals having common characteristics (ex. Mankind, cats etc.) Species: A class of individuals having common characteristics (ex. Mankind, cats etc.) Population: the number of individuals that occupy a certain area. (ex. People in Wilmington) Population: the number of individuals that occupy a certain area. (ex. People in Wilmington) Community: Different species interacting together in a certain environment (ex. Plants, squirrels, and fox) Community: Different species interacting together in a certain environment (ex. Plants, squirrels, and fox)

Competition Same or different species attempt to use an ecological resource in the same place at the same time Same or different species attempt to use an ecological resource in the same place at the same time resource = necessity of life (water, nutrients, light, food, space) resource = necessity of life (water, nutrients, light, food, space)

Community Interactions No two species can occupy No two species can occupy the same niche the same niche in the same habitat in the same habitat at the same time at the same time Direct competition in nature often results in winner and loser – losing organism fails to survive Direct competition in nature often results in winner and loser – losing organism fails to survive

Food Chain A food chain is a food pathway that links different species in a community. A food chain is a food pathway that links different species in a community. In a food chain, energy and nutrients are passed from one organism to another. In a food chain, energy and nutrients are passed from one organism to another. A series of steps in which organisms transfer energy by eating and being eaten. A series of steps in which organisms transfer energy by eating and being eaten. i.e. Wheat  mouse  snake  hawk i.e. Wheat  mouse  snake  hawk

Food Chain Example

Food Chains rarely contain more than six species because amount of energy passed on diminishes at each stage, or trophic level. Food Chains rarely contain more than six species because amount of energy passed on diminishes at each stage, or trophic level. The longest chains usually involve aquatic animals. The longest chains usually involve aquatic animals. In a food chain, an animal passes on only about 10 percent of the energy it receives. The rest is used up in maintaining it's body, or in movement, or it escapes as heat. In a food chain, an animal passes on only about 10 percent of the energy it receives. The rest is used up in maintaining it's body, or in movement, or it escapes as heat.

Food Chain

Food Web A community of living things may contain hundreds or even thousands of different species. A community of living things may contain hundreds or even thousands of different species. Each species is usually involved in several different food chains. Each species is usually involved in several different food chains. Different food chains often interconnect to form a large network, called a food web. Different food chains often interconnect to form a large network, called a food web.

Food Web

Trophic Levels A trophic level of an organism is the position it holds in a food chain. A trophic level of an organism is the position it holds in a food chain. 1. Trophic level 1are primary producers or autotrophs 2. Trophic level 2 is herbivores (organisms that eat primary producers) - organisms at this level are also called primary consumers.

3. Trophic level 3 is predators that eat herbivores - organisms at this level are also called secondary consumers. 4. Trophic level 4 is predators that eat secondary consumers. Tertiary consumers 5. Trophic level 5 is predators that eat secondary consumers/tertiary consumers Decomposers (such as bacteria) start the cycle again.

Trophic Levels Each step in a food chain or food web Each step in a food chain or food web 1 st level = producers 1 st level = producers 2 nd, 3 rd, or higher levels = consumers 2 nd, 3 rd, or higher levels = consumers Usually no more than 5 levels because 90% of energy is lost at each level. Usually no more than 5 levels because 90% of energy is lost at each level.

PREDATOR An animal that hunts and kills animals for food An animal that hunts and kills animals for food The term predator usually refers to animals that catch and kill. The term predator usually refers to animals that catch and kill. They have special adaptations to help them find and catch their food. These include good vision, a keen sense of smell, or strong legs for rapid movement. They have special adaptations to help them find and catch their food. These include good vision, a keen sense of smell, or strong legs for rapid movement.

PREY Prey are animals that are lower on the food chain that are eaten by predators. Prey are animals that are lower on the food chain that are eaten by predators. Prey also have special adaptations to help them survive the attack of their predators. Camouflage helps them blend in, sharp senses warn them of attack, and speed allows them to escape. Prey also have special adaptations to help them survive the attack of their predators. Camouflage helps them blend in, sharp senses warn them of attack, and speed allows them to escape.

Write if the organism is a producer, consumer or decomposer. Tell what trophic level they are at as well. OrganismType Trophic Level Human Deer Pine Tree Bear Rabbit Bacteria

OrganismType Trophic Level Mouse Snake Wheat Maggot Bluegrass Hawk

OrganismType Millipede Trout Sparrow Cat Frog Algae

Draw a Food Chain Draw a food chain with the organisms you worked with above. Try to make your food chain with at least 5 organisms. Draw a food chain with the organisms you worked with above. Try to make your food chain with at least 5 organisms. If you want to you can also work with other animals you can think of to make your food chain If you want to you can also work with other animals you can think of to make your food chain

Example of a Food Chain

Biotic Are living things in an environment that interact with non-living. Are living things in an environment that interact with non-living. What are some biotic things that could be an environment? What are some biotic things that could be an environment? Plants and animals Plants and animals Why are these important to have an environment? Why are these important to have an environment?

Abiotic Are the non-living factors in an environment. Are the non-living factors in an environment. What are some non-living things that should be in an environment? What are some non-living things that should be in an environment? Temperature, rocks and minerals, water Temperature, rocks and minerals, water How could these factors affect the environment? How could these factors affect the environment?

Biological Interactions Symbiosis-is a close ecological relationship between the individuals of two (or more) different species. Symbiosis-is a close ecological relationship between the individuals of two (or more) different species. Sometimes a symbiotic relationship benefits both species, sometimes one species benefits at the other's expense, and in other cases neither species benefits. Sometimes a symbiotic relationship benefits both species, sometimes one species benefits at the other's expense, and in other cases neither species benefits.

Biological interaction types Mutualism Mutualism -- both species benefit -- both species benefit Commensalism Commensalism -- one species benefits, the other is unaffected -- one species benefits, the other is unaffected Parasitism Parasitism -- one species benefits, the other is harmed -- one species benefits, the other is harmed

Aquatic Food Web

Energy & Matter in an Ecosystem

Other Community Interactions Predation Predation Symbiosis Symbiosis Parasitism Parasitism Mutualism Mutualism Commensalism Commensalism

Predation One organism captures and feeds on another organism One organism captures and feeds on another organism Predator – the one killing and eating Predator – the one killing and eating Prey – the food Prey – the food

herbivory is a form of predation

Symbiosis When two species live close together. When two species live close together. Three types: Three types: Parasitism – one is harmed (host), one benefits (parasite) Parasitism – one is harmed (host), one benefits (parasite) Mutualism – both benefit Mutualism – both benefit Commensalism – one is neutral, one benefits Commensalism – one is neutral, one benefits

Parasitism

Mutualism

Commensalism

Mutualism Parasitism Commensalism