Ecosystems Limiting Factors

Let’s suppose…. We have two mice…: and they produce the standard 56 “pups” (baby mice) each year. and each of these mice goes on to have 56 babies each year….

Soon….. We’d be over-run with mice on the planet!! Why doesn’t this occur?

Limiting Factors A limiting factor is an abiotic or biotic factor that restricts the number of individuals in a population.

Limiting Factors Limiting factors can include: Competitors

Limiting Factors Limiting factors can include: Competitors Disease and parasites

Limiting Factors Limiting factors can include: Competitors Disease and parasites Weather

Limiting Factors Limiting factors can include: Competitors Disease and parasites Weather Fires

Limiting Factors Limiting factors can include: Competitors Disease and parasites Weather Fires Available habitat

Limiting Factors Limiting factors can include: Competitors Disease and parasites Weather Fires Available habitat Predators

1. Competitors-competition results when organisms struggle to survive in a habitat with limited resources Birds of prey: live in forests on the edge of fields Eat mice and other rodents Nest in trees Live in same habitat, use same resources, so they compete with each other Red-Tailed Hawk Barred Owl

2. Disease and Parasites Diseases and parasites can be dependent on population size and habitat Larger population = more parasites and disease = limit how big population gets

3. Weather Storms Drought Flooding Heat/cold

4. Fires Fires lead to succession which is a predictable change in the community over time.

5. Available Habitat Human activities play a large role Development (homes, buildings, parking lots), damming rivers, clear cutting forests, hunting. Parts of the habitat can also be limiting: amount of food(prey), available nesting sites

6. Predators Predator-prey relationship can be a delicate balance between the two populations.

Predators As the prey population increases, the predator population increases. As the prey population decreases, then so does the predator population.

Example: Lynx and Hare:

What is Carrying Capacity? Because of these limiting factors, each ecosystem has a finite capacity for growth connected to its carrying capacity.

What is Carrying Capacity? Carrying capacity is the maximum number of individuals of a species that an ecosystem can support.

Limiting Factors of the Cedar Glade Activity In nature, populations of organisms rarely grow uncontrolled. Each ecosystem has a carrying capacity (or number of organisms it can sustain/support). Remember, limiting factors are biotic and abiotic factors that prevent the continuous growth of a population. Because of limiting factors, the number of organisms in a population is often well below carrying capacity.

Limiting Factors of the Cedar Glade Activity This activity will look at limiting factors found in the Cedar Glade ecosystem, and their impact on population growth.

The details of the activity…