-Group of Interacting Populations in a specific area

-Richness

      >Number of species

-Abundance

      >Number per species

      >Community of Dominance

-Influenced by

-Latitude

      >Gradient from tropics to poles

-Could be influenced by size of community and proximity to source of species

-Ex. Tropics

      >Enviormental Heterogeneity (structural complexity)

      >Stable Climate

      >Warmer, Wetter

      >Most Productive

Dominant Species

-Most numerous

-Greatest Biomass

-Controls Nature/Stability of community

      >Shade

      >Light

      >Humidity

      >Habitats

-Controls structure, stability without being the most numerous

-Has more effect than expected based on numbers alone

-Ex. top predators, grazing herbivores, terriotorial birds, bison

      >Bison

-Presence or absence tells something about the enviorment

-Ex. Presence of insect larvae indicate health of stream water

-Have extensive requirements that if met protect many other species

-Large charasmatic species whose protection raises public awareness of conservation

-Predator/Prey

      >Herbivore/Plant

      >Parasite/Host

          *Plant Holoparasites: All nutrients from host

          *Endoparasites: Live within host

          *Ectoparasites: Live ON host

-Mechanical: Thorns

-Crypsis

      >Ex. Lithops

-Secondary Metabolites

      >Inedible Compounds

          *Alkaloides

          *Terpenoids

          *Phenolics

          *Ex. Nicotine in Tobacco, Tannins in Tea

      >Some herbivores have developed resistance (Detoxify)

-Cryptic appearance or Coloration (Camoflage)

      >Lizard

-Mechanical

      >Thorns

-Chemical

      >Toxic Compounds

      >Noxious Taste

          *May have vivid coloration

          *Ex. Monarch Butterfly, Poison Arrow Frog

Mimicry

(Animal Defense against Predation)

-Organism resembles (mimic) another one (model)

-Batesian

      >Model is distasteful or toxic to predators, Mimic is not

      >Ex. Coral Snake mimics the King Snake (Model)

-Mullerian

      >Two or more species which are both harmful to predators mimic each other so predators stay away from both

      >May show bright (aposematic) coloration

Intimidation

(Animal Defense against Predation)

-Porcupine Fish

-Ruffled Lizard

-Each species occupies its own niche

      >For species to produce and survive the must have role in community, condition, and resources required

      >Competitive Exclusion Principle: No 2 species can occupy same niche if resources are limited

          *Results in exclusion of one species

      >Ex. Exotic (Introduced) Vs. Native Species

-Plant Exclusion

-Toxic compounds from roots, leaves, or bark restrict growth of other plants

      >Ex. Black Walnut produces toxic juglones toxic to many trees and plants

-Caused by Niche Overlap/Competition

-5 species of Warblers in New England spruces

      >Different birds at different hights of spruce tree

-Exaggerated divergence of character (trait) in sympatric populations to avoid competition

-An interaction that benefits one species and leaves the other unaffected

-Ex. Barnacles on whales, Epiphytes on plants

-A Interaction in which both species benefit

-Ex. Flowers/Pollinators

      >Dispersive Mutualist

-Ex. Plant/Fruit Eater

      >Dispersive

-Ex. Ants protecting aphids

      >Defensive

-How fast can it recover from a disturbance?

      >Such as a fire, storm, and overharvesting

-Stabilitys link to richness

      >Intermediate disturbance produces greatest richness

      >Rich communities are most resistant to/recover best from disturbances

-Primary Succesion

      >succesion on newly exposed sites that were not previously occupied by soil and vegetation

      >Ex. Glacier Moraine

-Secondary Succesion

      >Succesion on a site that has supported life but has experienced a disturbance

      >Happens more quickly

      >Ex. Mt St. Helens