1. Populations and Ecosystems

2. Resources and exponential growth A population: a group of organisms of one species that lives in the same place and the same time and can successfully reproduce. Growth occurs at a rate higher than what is needed to replace individuals that have left or died. Exponential growth in populations: –Typically short term, in new habitat with lots of resources, or when pressures are removed such as species protection

3. Exponential Growth. protection

4. Exponential Growth and re-introduction Cases where habitat has been destroyed in the past can deplete a species. Ex. Deforestation When the habitat is reinstated it is possible to reintroduce the species and as long as the resources remain available exponential growth will occur. Ex. Wild turkeys went from 4400 to 70,000 in 20 years.

6. Limiting Factors Exponential growth cannot be sustained naturally As the population increases the individuals have access to fewer resources Abiotic factors also play a huge role

7. Carrying Capacity Carrying capacity is the size of the population that can be supported indefinitely but the available resources and services of an ecosystem. When a population is maintained at carrying capacity it is at an equilibrium (Balanced) When a resource is being used at a rate that exceeds carrying capacity the population will drop in relation. This resource could be food, but may also be abiotic.

8. Human Activity and Carrying Capacity Urban Sprawl-the spreading of city area across natural habitats results in habitat loss. This affects the carrying capacity of many species. Intensification, building up as opposed to out is one solution to prevent habitat loss.

9. Interactions Among Species Ecological Niche –The way that an organism occupies a position in an ecosystem, including all the necessary biotic and abiotic factors. –Ex. Biotic niche of brown bat Insects it eats Competitors (common Nighthawk) Predators –Abiotic niche of brown bat Places for roosting and hibernation Time of night it hunts Airspace it flies Temperature range it can tolerate