While the term ‘ecosystem’ might be unfamiliar, we are all familiar with a woodland, a lake, or even a city park. These are all examples of different types of ecosystems. In more specific terms, an ecosystem can be defined as a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit (Convention of Biological Diversity, Article 2).

The interactions between species, and between species and their physical environment, allow an ecosystem to function as a unit to produce goods and services upon which human activities and well-being may rely. In the case of peatlands for instance, numerous ecosystem goods and services can be derived from them. Until recently, peat has been extracted to produce energy in the form of briquettes, or horticultural substrate in the form of peat-based compost¹. In terms of services, peatlands have important roles in carbon sequestration, water filtration and regulation, as well as in the enjoyment and well-being we get from walking in a peatland landscape¹.

Human and economic well-being relies on ecosystems and the goods and services they provide. How would life exist without water and clean air? Both depend on ecosystem services for their continuous renewal, regulation and filtration. Likewise, we depend on ecosystems for food, e.g. the grassland ecosystems on which cattle graze or the marine ecosystems that provide fish. The provision of these goods and services arises from a series of biophysical processes and ecological functions whose maintenance and balance are dependent on the biological diversity (i.e. biodiversity) of the ecosystem².

Ecosystems are subject to a number of pressures including climate change, ocean acidification, habitat fragmentation, and air pollution. The conservation of biodiversity is important to ensure ecosystem resilience, thereby enabling ecosystems to withstand these pressures and keep producing goods and services. Policies aimed at protecting and conserving ecosystems and their biodiversity also ensure the continuing provision of essential goods and services. Developing effective environmental policies and monitoring their outcomes requires information in three areas:

1. Ecosystem extent: What types of ecosystem are present? How much of each type? Where are they?
2. Ecosystem condition: How well is the ecosystem functioning?
3. Ecosystem services: What services are provided? Who benefits?

 To address these information needs, a framework of Ecosystem Accounting has been developed.

1. National Parks and Wildlife Service. National Peatlands Strategy. (Department of Arts, Heritage and the Gaeltacht, 2015).

2. Balvanera, P. et al. Quantifying the evidence for biodiversity effects on ecosystem functioning and services. Ecol. Lett. 9, 1146–1156 (2006).

Go to the next chapter: Ecosystem Accounting