Module 3.1 — Population Growth Models & Density Dependence

What abiotic or biotic conditions promote population growth by increasing birth rates or decreasing death rates?

Abundant resources, favorable environmental conditions, available mates, low competition, low predation, and low disease increase birth rates and decrease death rates, allowing populations to grow rapidly.

Why can't populations grow exponentially forever?

Resources such as food, water, and space become limited. Competition, disease, and predation increase, causing population growth to slow and stabilize near carrying capacity.

Contrast negative and positive density dependence.

Negative density dependence occurs when population growth decreases as density increases due to competition, disease, and limited resources. Positive density dependence occurs when growth increases as density increases because individuals can more easily find mates and avoid predators.

What is carrying capacity?

The maximum population size an environment can support indefinitely with available resources.