ecosystem

An ecosystem is a complex and dynamic network of living organisms and their physical environment in a defined area, interacting to exchange energy and cycle nutrients. It comprises biotic components—plants, animals, fungi, and microorganisms—and abiotic factors such as sunlight, temperature, water, air, soil, and minerals. Through processes like photosynthesis, respiration, predation, decomposition, and symbiotic relationships, ecosystems transform energy and move it through food webs, while nutrient cycles such as carbon, nitrogen, and phosphorus recycle essential elements.

Ecosystems are organized by trophic structure and bounded by boundaries that affect the flow of energy and materials. They exhibit resilience, the ability to absorb disturbances and still maintain function, and they may undergo successional change as species arrive, disappear, or adapt.

Ecosystem types vary widely and include terrestrial systems such as forests, grasslands, deserts, and wetlands, as well as aquatic systems like rivers, lakes, and oceans. Each type supports characteristic biodiversity and functions, from primary production to pollination to decomposition.

Ecosystem services are the benefits that people obtain from ecosystems, including provisioning services like food and water, regulating services such as climate regulation, flood control, and disease management, supporting services like nutrient cycling and soil formation, and cultural or recreational services.

Human activities threaten ecosystems through habitat loss, pollution, introductions of invasive species, overexploitation, and climate change, leading to declines in biodiversity and service provision. Conservation and restoration efforts, including protected areas, sustainable management, restoration ecology, and ecosystem-based approaches, aim to maintain or recover ecosystem structure and function.