Ecology 102 Answers

Limiting factors such as food, water, space, and shelter restrict population growth. Their availability determines the maximum population size, or carrying capacity, that an ecosystem can support over time.

A prolonged drought reduces water availability, causing plants to grow less or die. This can reduce food and habitat for animals, leading some organisms to migrate or die and causing populations and food webs to change.

Scientists need to study nonliving factors such as water, soil, sunlight, and climate as well as organisms because these factors affect which organisms can survive and how they interact. Together, living and nonliving parts determine how an ecosystem functions.

Primary succession begins on bare surfaces without soil. Pioneer organisms help form soil and a community develops. If a later disturbance removes the organisms but leaves the soil, secondary succession can begin as the ecosystem regrows.

With less shelter, organisms may be more exposed to predators and harsh conditions, and competition for the remaining shelter may increase. Some populations could decline or move to another area.

Greater biodiversity generally makes an ecosystem more stable and resilient because many species contribute to ecosystem functions, and some may be able to fill similar roles if another species declines. Low biodiversity can make the ecosystem more vulnerable to disturbances.