LIMITING FACTORS

Levels of Organization Overview  Cells  Tissues Organs Organ Systems Organisms  Populations  Communities  Ecosystems  Biome

Organisms-Biomes terms to know  Organism  One individual of a single species.  Population  Groups of individuals that belong to the same species and live in the same area.  Community  Groups of different populations that live together in a defined area  Ecosystem  Collection of all the organisms that live in a particular place, together with their abiotic (non- living), or physical environment.  Biome  Multiple ecosystems with similar characteristics in the same geographical area.

Levels of Organization Examples  Organism  Beavers, cattails, frogs, cranes, deer, trees, owls, etc.  Population  Groups of beavers, cattails, kudzu, raccoons, frogs, trees, etc.  Community  The deer, trees, foxes, raccoons together.  Ecosystem  Owl, tree, kudzu, squirrel, along with the soil, air, temperature, rainfall, etc.

What is a population?  Population  all the individuals of a species that live together in one place at one time.  Carrying Capacity  The maximum population size that an environment can sustain.

How is population affected?  Factors affecting population density  Increase: The number of births Immigration  Decrease The number of deaths Emigration  Populations do not usually grow without limits.  Their growth is limited by things such as predation, disease and availability of resources.  These factors are grouped together as Density-Dependent and Density-Independent.

Density-Dependent Limiting Factors  A limiting factor that depends on population size is called a density- dependant limiting factor.  Examples of density- dependent limiting factors (DDLF) include competition, predation, parasitism/disease, crowding  Usually Biotic Factors Living things  Exs.  Competition for food, water, shelter  Spread of disease (bacterial or viral) and parasites  Predator/prey relationships

Examples of Density Dependent Factors  Crowding  Organisms need a certain amount of space to nest and hunt, when that space is limited it can cause stress to the immune system and hormone levels  Predation  Predator/Prey relationships  Parasitism and Disease  Caused by parasites ranging from microscopic bacteria to very large tapeworms.  Competition  When populations become crowded, organisms compete with one another for food, water, space, sunlight and other essentials of life.

Density-Independent Limiting Factors  A limiting factor that DOES NOT depend on population size is called a density- independant limiting factor.  Examples of density- dependent limiting factors (DILF) include things like natural disasters and human interactions  Usually Abiotic Factors Non-Living things  Natural disasters Weather; hurricanes, tornadoes, floods, drought. Earthquakes, volcanoes, avalanches, mudslides.  Fires  Human activity plowing, clear cutting, slash and burn, use of toxins on crops)