Ecosystems are functional units comprising living organisms (biotic components) and their physical environment (abiotic components), interacting as a system through the exchange of energy and matter. The concept, rooted in the work of Arthur Tansley (1935), moves beyond biological communities by insisting that organisms and their environment co-constitute each other — a position that anticipates modern systems theory and social-ecological systems frameworks.
An ecosystem is not merely a collection of species but a network of feedback loops that regulate flows of energy, nutrients, and information. Primary producers capture solar energy; consumers redistribute it; decomposers return nutrients to the soil; the physical environment constrains all three. The stability of these loops — what C.S. Holling distinguished as resilience versus resistance — determines whether the ecosystem persists, transforms, or collapses under disturbance.
The ecosystem concept has become central to ecology precisely because it is scale-independent: a pond, a forest, and the biosphere are all ecosystems, differing in extent but sharing structural dynamics. This scale-independence is what enables the framework to connect to panarchy and adaptive governance, where the same feedback logic applies to institutions and economies.