This discussion document is part of a consultation process to arrive at consensus on
practical definitions for ecological structure and function that can guide UK marine
monitoring. It presents an overview of the different definitions in use and how they differ
in approach (as illustrated in the diagram below). At one end of the spectrum there are the
bottom-up approaches where each element of the ecosystem is described in detail, and due
to the level of detail is most often used at the local scale. At the other end of the spectrum
there are a range of top-down approaches that attempt to integrate elements of the
ecosystem into a reduced number of parameters, or group attributes under broader headings
or categories. Some of these approaches are more synthetic than others, for example
grouping attributes into categories that cover large regional scales may still allow
considerable detail within each category. In contrast some modelling approaches synthesize
all ecosystem processes into one or two measures, such as energy flow.