14. Habitat management
Malcolm Ausden
14.1 Introduction
Habitat management is the manipulation of habitats to provide suitable conditions
for species of interest, or in some cases to reduce the number of species considered
as pests. Habitat management is most commonly used to:
- provide suitable conditions for species where these are no longer created by
natural processes; - maintain characteristic assemblagesof species, where persistence of the
assemblageis dependent on continuation or re-instatement of particular
land-management; - maximize the harvestable surplus of game species (Chapter 13).
Most habitat management involves preventing or reversing the direction of vegeta-
tion succession. In some cases it is also used to create suitable vegetation structure,
increase food availability, and provide suitable nesting areas for birds.
The successional stage of an area, and hence its suitability for a given species, is
influenced by processes such as grazing by large herbivores and disturbance by fire,
floods, and storms. In many remaining fragments of semi-natural habitat, the key
natural processes influencing succession either no longer operate, or if they do, they
operate at an inappropriate scale or frequency to maintain suitable conditions for
the species of interest. The absence of suitable natural processes is most acute in
small and isolated patches of habitat. For example, small patches of semi-natural
habitat are rarely grazed by large wild herbivores, let alone by their full complement
of native species. Large-scale disturbances caused by fire or flood are largely pre-
vented as a matter of policy. If they do occur, they are likely to affect the whole of
the remaining small fragment of habitat, and so make it temporarily unsuitable for
most of its associated species. If the fragment of habitat is isolated from sources of
re-colonization, the less mobile species lost because of the disturbance are unlikely