Niche & Community Interactions

I. Niche Describes what an organism does and how it interacts with the biotic and abiotic factors of its environment.

Niche Resources refer to any necessity of life, such as water, nutrients, food, or space.

Niche The Physical Aspects of the Niche are the abiotic factors that are required for survival. An example would be water. The Biological Aspects of the Niche involve the biotic factors that are required for survival. An example would reproduction and food.

Niche There are two conditions that help define where and how organisms live. Tolerance Is the ability to survive and reproduce under a range of environmental conditions. All organisms have an upper and lower limit of tolerance for every environmental factor. Habitat Is the general place where an organism lives.

Competition Occurs when organisms attempt to use the same limited ecological resource in the same place and time. Can be intraspecific or interspecific.

Competition Competitive exclusion principle states that no two species can occupy exactly the same niche in exactly the same habitat at exactly the same time.

Competition Division of resources By causing species to divide resources, competition helps determine the number and kind of species in a community and the niche each species occupies.

Competition Division of resources Species usually divide similar resources instead of competing for them.

Predation, Herbivory, and Keystone Species Predation-prey relationships Predation occurs when one animal captures and feeds on another animal. Predators can affect the size of prey populations in a community and determine the places prey can live and feed.

Predation, Herbivory, and Keystone Species Herbivore- Plant Relationships Herbivory is an interaction in which one animal feeds on producers. Herbivores can have major effects on plant survival.

Predation, Herbivory, and Keystone Species Keystone species is a single species that can cause dramatic effects in the structure of a community. Examples: wolf and sea otter.

Symbiosis Means “living together.” Is any relationship in which two species live closely together. Biologist recognize three main classes of symbiotic relationships: mutualism, parasitism, and commensalism.

Symbiosis Mutualism is a relationship in which both species benefit. Example: sea anemone and clown fish.

Symbiosis Parasitism is a relationship in which one organism lives inside or on another organisms and harms it.

Symbiosis Commensalism is relationship in which one organism benefits and the other neither harmed nor helped. Examples: whale and barnacles, shark and remora.

Assignment Write a sentence that demonstrates your understanding of the vocabulary terms on page 99 of your M&L biology textbook. Do not write the definitions of the terms.