Factors that Limit Population

Population Size Can change over time As a population grows it puts more demands on the ecosystem’s resources. Ex: large population of lions will need more food than a small population If there’s not enough food, some will die. Size of the population is thus limited by available food.

Limiting Factors Environmental factors that limit the size of a population Available water, oxygen, food, and sunlight.

Density-Dependent Factors Limit growth of a population Occurs when population density reaches a certain area Predation and competition Predator/prey populations  if predator pop. Is too large, there won’t be enough prey so some will die off. As pred. pop. decreases, prey pop. increases

Density-Independent Factors Limit growth of pop. Regardless of size Ex: extreme temperatures, tidal wave, volcano, flooding, etc.

Carrying Capacity The largest population an environment can support.

Cycling Matter Photosynthesis and cellular respiration are a continuous cycle called the carbon cycle. Nutrients flow between organisms and their environment.

Plant and Animal Effects Plants remove CO2 from the atmosphere to make food and release O2 into the atmosphere Animals remove O2 from the atmosphere and release CO2

Decomposer Effects Break down dead/decaying matter Return energy and nutrients to the ecosystem Ex: fungi and bacteria

Human Impact on Environment Humans place stress on the environment by constantly changing resources. Human population: Stayed stable for many years, then grew significantly.

Effects of Population Running out of resources and energy. Increase in pollution In water can cause algal blooms which use up all the oxygen. Urbanization: clearing of land causes other organisms to relocate. Deforestation: clearing of trees

Resource Depletion Trees being removed are renewable resources but if they are not being replaced as quickly as they are cleared resource depletion.

Climate Change Global warming  increased burning of fossil fuels.