This chapter is directed at ecosystem management on a local (in particular the UK) rather than a global scale. There has been considerable development in the understanding of ecosystem structure and functioning over the last few decades, particularly in the field of vegetation change. In many ecosystems and habitat types it is possible to be reasonably confident about the consequences of management interventions, thus achieving the objectives of management aims. There are a number of important principles which emerge from the problems that face environmental managers.

Problems of ecosystem management

Ecosystems are in a constant state of flux, but the degree to which and the speed with which changes occur relate to the ecosystem's successional stage. Succession is a more or less predictable change in vegetation type. In most of the UK it progresses from bare soil, through annual and biennial weed and grassland communities, to low and then tall scrub. Tall scrub then gives way to pioneer woodland species (e.g. birch (Betula spp.), ash (Fraxinus excelsior), pine (Pinus spp.) and alder (Alnus glutinosa)), but the exact nature varies according to environmental factors such as soil and climate. Finally the pioneer canopy species are replaced by tall oak (Quercus spp.) forest, the so-called climax type. The stable vegetation types found in fully developed ecosystems (the climax stage) change relatively little apart from local variations arising from death and replacement of their constituents.