As defined by the Convention on Biological Diversity, ecosystem is 'a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit'.

Source: EUROSTAT

An ecosystem is a system in which living things (plants, animals, bacteria, etc.) and their non-living surroundings interact as a functional unit.

Biodiversity plays a vital role in ecosystem services, the services that nature supplies and on which humans depend. These include pollination, climate regulation, flood protection, soil fertility and the production of food, fuel, fibre and medicines. Human consumption and behaviour have led both directly and indirectly to a rapid deterioration in biodiversity, resulting in ecosystem collapse.

Since the 2000s, the EU has been trying to address biodiversity loss by means of action plans and strategies, the latest of which is the 2030 biodiversity strategy, designed to put Europe’s biodiversity back on the path to recovery by 2030. The strategy, part of the European Green Deal, contains commitments and actions to protect and restore biodiversity and well-functioning ecosystems.

Source: EURO-Lex

A dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit.

Source: EEA Glossary

A community of organisms and their physical environment interacting as an ecological unit. 

Source: EEA Glossary

A dynamic complex of plant, animal, fungal, and micro-organism communities and their associated non-living environment interacting as a functional unit; the organisms living in a given environment, such as a tropical forest, a coral reef or a lake, and the physical part of the environment that impinges on them. - a complex of organisms and their environment, interacting as a defined ecological unit (natural or modified by human activity, e.g. agroecosystem), irrespective of political boundaries.- a community of organisms in their physical environment.

Source: EEA Glossary