The ONS and Defra released a scoping study: "Developing UK Mountain, Moorland and Heathland ecosystem accounts" which can be found at this link.
This methodological paper is part of the Department for Environment, Food and Rural Affairs and Office for National Statistics (Defra-ONS) Natural Capital Project. An imperitive objective of the project is the development of eight habitat-based ecosystem accounts, one of which being Mountains, Moorlands and Heathlands (MMH). This paper will look into ecosystem accounting techniques concerning MMH, available data sources and the recommended approach to developing the initial account.
For more information about ONS-Defra work on measuring natural capital and ecosystems, see the following link.