Population ecology is the study of how populations of organisms interact with their environment and how they change over time. It focuses on factors such as birth rates, death rates, immigration, and emigration, which influence the size and structure of populations. Understanding these dynamics helps scientists predict how populations respond to environmental changes and human activities. Researchers in population ecology often use models to analyze population growth and decline. These models can help in conservation efforts by identifying endangered species and assessing the impact of habitat loss. Key concepts include carrying capacity, population density, and species interactions, which all play a role in shaping ecosystems.