Thresholds of environmental sustainability: the case of woodlands

As a result of its commitment to sustainable development, society will have to face substantial costs for the protection and restoration of environmental systems. An understanding of the constraints or thresholds of sustainability is therefore required. To do this we must know the limits beyond which the integrity of ecological systems will be damaged in relation to the output of goods and services they provide for people. In this paper we examine the concept of sustainability thresholds in the context of the notion of 'ecosystem functions'. We show that a functional approach to landscape ecology is one which can help us define the concept of sustainability thresholds at the landscape scale more easily. An example is provided based on the analysis of patterns of recent woodland planting and the uptake of woodland management agreements in England. Such case studies illustrate that, for the future, landscape ecology needs to develop better methods of combining information about the biophysical constraints that apply in real landscapes, with the social and economic values held by different stakeholder groups. These types of analysis will enable us to both identify the limits associated with individual landscape functions and, more importantly, the tradeoffs that needs to be considered in the management of multifunctional landscapes.