Interactions with Ecosystems Notes for Test

Abiotic: a non-living factor that affects an ecosystem (ie. rain, water, sunlight) Biotic: a living factor that affects an ecosystem (ie. the population of producers) Adaptation: a special feature that an organism has that aids in survival (ie. camouflage, mimicry)

Organization of Life Organism: a single living thing (a tiger) Population: all of the organisms of one species in an area (all of the tigers in the jungle) Community: all the populations in an ecosystem (tigers, lions, monkeys, trees) Ecosystem: the community AND all the abiotic factors interacting (community plus wind, rain, temperature) Biome: a series of related ecosystems (jungles, rivers, swamps) Biosphere: all of the ecosystems in the world (every single living and non-living thing in the world)

Producer: an organism that can make it’s own food using photosynthesis (tree) Consumer: an organism that can’t make it’s own food and therefore must eat plants or animals that eat plants in order to get the sun’s energy (dog) Decomposer: an organism that breaks down matter in to simple nutrients so that it can be recycled (earthworm)

Herbivore: an organism that eats only plants (deer) Carnivore: an organism that eats only animals (lion) Omnivore: an organism that eats both plants and animals (bears)

Food Chains Food chain: a diagram that shows energy transfer Coyote Rabbit Grass

Food Webs A food web is a group of many intersecting food chains. They are better than food chains because they are a more realistic view of energy transfer in an ecosystem (ex. Coyotes don’t only eat rabbits and rabbits get eaten by more than just coyotes).

The Matter Cycle ( the use and reuse of matter on earth) Producer (grass) Consumer (deer) Consumer (wolf) Decomposer (maggot)

The Matter Cycle The matter cycle shows how energy is transferred and matter is reused. Energy is transferred from the producer to the herbivore and the herbivore to the carnivore. When the producers, herbivores and carnivores die the energy is transferred to the decomposers The decomposer breaks down the dead matter into nutrients so that new plants (producers) can grow. Energy is transferred from the producer to the herbivore and the herbivore to the carnivore.

Ecological Pyramids An ecological pyramid is a graphical way to show the effects of loss of energy at each higher level in the food chain. The base of the pyramid holds producers. At each level above the producer the amount of energy available is less (the organism uses some of it’s energy before it’s consumed). That explains why in an ecosystem you will always have more producers than herbivores and more herbivores than carnivores.

At each higher level there are fewer organisms and less energy. Higher Carnivores Carnivores Herbivores Producers

Biological Amplification When pesticides are sprayed in an ecosystem it is not only the pest that is affected. At each level of the food chain the effect is greater. For example, if a mosquito was sprayed with 1 measure of pesticide, a dragonfly would have 50 (after it ate 50 mosquitoes), a frog would have 250 (after it ate 5 dragonflies) and a snake would have 500 (after it ate 2 frogs). This is called biological amplification.

Succession Succession is how ecosystems change over time. Primary succession is when an ecosystem begins where there was none before. Secondary succession occurs after the complete or partial destruction of an ecosystem.

The first species to appear in succession is called the pioneer species (always a producer). Once the pioneer species (ex. lichen) has a chance to live, die, decompose and make new soil (*), some rich soil will be produced. This will allow larger producers to grow (ex. moss) and this producer will also *. This will allow larger producers to grow (ex. grass) and this producer will also *. Consumers that depend on these producers will arrive and *. This will allow larger producers to grow (ex. shrubs) and this producer will also *.

Consumers that depend on these producers will arrive and *. This will allow larger producers to grow (ex. trees) and this producer will also *. Consumers that depend on these producers will arrive and *. As larger producers put smaller producers in the shade those producers will die out. Once the ecosystem reaches it’s final community (the climax community) it will remain unchanged for many years.