Limiting Factors Lecture What are Limiting factors s

Limiting Factors Lecture

What are Limiting factors? s Any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.

Abiotic Factors s s Temperature Climate Biome/Ecosystem Wind p. H

Biotic Factors s s s Food Availability Parasites Predators Symbiosis Competition Habitat Destruction

Situation/Example s Think Grassland where grass, seeds, and mice live. s If there was a drought, what would happen to the mice? s Answer: Think about the grass. . s Grass dies, produces less seeds. s Mice get fewer seeds to eat. s Mice population decreases. s What about the hawks that eat the mice?

Tolerance s Sometimes, organisms may survive but may not reproduce because of limiting factors. s I. E. Corn needs lots of sun for 2 months to make seeds and reproduce. s If grown in shade for most of that time… it will survive, but not make new plants. s Tolerance is the ability to withstand fluctuations in abiotic and biotic factors.

Range of Tolerance s Tolerance varies among species

Density dependent vs. density independent Factors s Density Dependent means… s It depends on the density (or how cramped) the population is. s Density Independent means… s It does not matter how dense the population is.

Density Independent variables s s s Some Include: Temperature Storms Floods Drought Habitat Disruption (Cutting trees)

Density Dependent variables s Some Include: s Water Source (competition) s Disease (outbreak) s Food Source (starvation) s Shelter s Parasites

Predation as a factor