Factors that Impact Factors that Impact EcosystemsEcosystems

AP Biology

Unit 1

Abiotic vs. Biotic Factors

• Abiotic factors = non-living components that affect living organisms – Ex. Temperature, sunlight, rocks

• Biotic Factors = all living things or their materials that directly or indirectly affect organisms in its environment (includes interactions)

Affect of Biotic and Abiotic Factors• Interactions with biotic and abiotic factors

can have an effect on several different levels: cellular, organismal, population, ecosystem

• Cellular Level: ex. temperature, water availability can affect a cell’s function.

• Organismal level: ex. interactions (such as mutualism, predation) as well as abiotic factors (water, temperature)

Affect of Biotic and Abiotic Factors

• Population, Ecosystem, Community Level: – ex. Water availability, availability of nesting

materials and sites, species diversity, can all contribute to the stability of these groups.

Biomes• Ecosystem types that are classified

according to the dominant vegetation

• Locations are closely tied to abiotic factors such as temperature and rainfall

• Ex. Desert, tropical rain forest, tundra

Geological & Meteorological Events

• Impact ecosystem distribution

• Biogeographical studies – Studies that determine the distribution of

species

• Ex. Continental drift – Marsupials fill ecological roles in Australia

similar to those filled by placental mammals on other continent

Species-specific events• Keystone species =

have a strong influence on other species in the ecosystem

• Loss of keystone species can result in drastic changes to or the collapse of the ecosystem.

Human Activities • Occurs on a local,

regional, and global scale

• Speeds up changes to ecosystems locally and globally

• Ex. Urbanization, global climate change, introduced species