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Autumn Newsletter 2001 |
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To Manage, or Not to Manage?
Faced with land which one is responsible for, the first question is usually "What
should I do with it, if anything?" Habitat management is an extremely complex
subject, which means that the answer to that question is very variable. It will depend
both on the type of habitats involved and on the intended use of the land.
The most basic point to understand is that habitats don't stay the same. They constantly
alter. Lack of management will result in inevitable changes in the habitat. As a
consequence, the habitat will contain different mixes of species.
This constant change is most often brought about by a process called 'succession'.
Through succession, one group of plants and their associated animals is gradually replaced
by different ones, as conditions in the habitat subtly alter. This may occur for a variety
of reasons. Short plants will become shaded out as taller ones grow above them and cut out
their light. Wet areas will gradually dry up through siltation, favouring different
species, or dry areas may become wet through weather, natural causes or land drainage
changes.
Management is largely, although not exclusively, concerned with either controlling, or
modifying succession.
Deciding whether to manage a habitat or not therefore depends on whether you wish to
maintain it in the same state, or whether you want to try and create something different.
Of course not all habitats are of equal value in conservation terms. Habitats such
as heaths and wetlands are far more valuable than the woodlands which would take over in a
natural succession, because they are rarer than woodland. Each habitat will have
particular plant and animal species associated with them, some exclusively. Loss of
habitat area results in a total loss of the populations of the species which live
there.
Therefore if the habitat is a rare one, or contains populations of rare or threatened
species, it should be managed in order to maintain the current conditions, or even improve
them for specific species.
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However specific
management for specific species requires first and foremost, an understanding of the often
astonishingly complex interactions involved in the lifecycles of the species.
This may be easier said than done, as our knowledge of these interactions is often
extremely sketchy, or even non-existent. However, as long as we have a reasonably good
idea of what conditions are necessary, then careful management can be applied to enhance
those conditions.
Alternatively, management may be more general and may be aimed at maintaining a specific
habitat to benefit a wide range of associated species, rather than just for one or two
particular species. Controlling the amount of silt being laid down in a wetland would fall
into this category. Inevitably, sometimes these two different objectives may clash and
decisions have to be made based on which is the most important objective.
If you are aiming to restore, or create a different habitat from land which is degraded,
then it is essential to work with the environmental conditions which are already present,
rather than against them.
In other words, work out what kind of habitat the area would tend towards naturally and
then facilitate that through management.
Whatever management you decide to implement needs to be sensitively timed to avoid
disturbing major breeding periods.
Management creates very specific effects and so needs to be monitored and be flexible. If
it is not having the desired effect, then it will need to be changed. |
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