Relationship Notes: Graphs The student will investigate and understand relationships among populations and communities within an ecosystem Key concepts include: interactions within and among populations including carrying capacities, limiting factors, and growth curves; Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

Factors that affect population growth Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment. EX.- Amount of water Amount of food Temperature

Other factors that affect population growth Carrying Capacity- the maximum population size that can be supported by the available resources There can only be as many organisms as the environmental resources can support Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

J-shaped curve (exponential growth) Carrying Capacity Nu m b e r J-shaped curve (exponential growth) Carrying Capacity (k) S-shaped curve (logistic growth) Ok so Time

Graph #1: Competition Among the same species Regulated by limiting factors Exponential growth

Graph #2: Competition Between 2 Different Species

Predator-Prey Interactions The population of any species is normally limited by the amount of food available. If the population of the prey increases, then so will the population of the _______. However, as the population of predators increases, the number of prey _______. predators decreases Eg. More grass means more ______. More rabbits means more _____ But more foxes means less ______. Eventually, less rabbits will mean ____ foxes again. rabbits foxes rabbits less

Graph #3: Predator- Prey