Ecosystems can be classified as terrestrial or aquatic, with aquatic further divided into marine and freshwater. Land ecosystems are often categorized into biomes, such as tropical forests or …

This unit explores the Earth as a system with interdependent components, processes, and relationships. Learn about ecosystems, terrestrial and aquatic biomes, natural climate change, …

Ecosystems can be classified as terrestrial or aquatic, with aquatic further divided into marine and freshwater. Land ecosystems are often categorized into biomes, such as tropical forests or …

Apply your understanding of ecosystems and biomes in this set of free practice questions aligned to AP standards

Key points An ecosystem consists of a community of organisms together with their physical environment. Ecosystems can be of different sizes and can be marine, aquatic, or terrestrial. …

Learn about the levels of organization in the biosphere, including biomes, ecosystems, communities, and populations.

Review your understanding of the taiga, tropical rainforest, temperate forest, shrubland, grassland, savanna, desert, and tundra biomes in this free article aligned to AP standards.

Community structure & diversity Learn Ecosystems and ecological networks Community structure Introduced species and biodiversity Invasive species

The distribution and abundance of organisms on Earth is shaped by both biotic, living-organism-related, and abiotic, nonliving or physical, factors. Ecology is studied at many levels, including …

Unit 17: Ecosystems Populations, Communities and Ecosystems Learn Ecosystems and biomes