Det lysåbne landskab - DCE - Nationalt Center for Miljø og Energi

ehov for kontinuitet. Selv i større naturområder er en dynamisk naturforvaltning
vanskelig. Der findes således ikke mange større naturområder
i Danmark, hvor naturen ikke er påvirket direkte eller indirekte
af klitdæmpning, kystsikring, vandløbsregulering, dræning
eller inddæmning.
5. Globale forandringer
Vores atmosfære og klima er under forandring med temperaturstigning
og vandstandshævning i havet til følge. Konsekvenserne for naturen
kendes ikke, men kystnære naturtyper som klitter og strandenge
er naturligvis særligt udsatte. Hurtige klimaforandringer vil især gå
ud over arter med lav spredningsevne tilknyttet de mest fragmenterede
naturtyper, som derfor ikke kan nå at ’vandre’ til nye levesteder.
6. Mangel på viden
Selvom udviklingstendenserne for de terrestriske naturtyper er veldokumenterede,
medfører mangel på terrestrisk forskning og overvågning,
at vi ikke kan kvantificere den dokumenterede tilbagegang, og at
vi ikke kan forudsige, hvor stor en indsats der skal til for at vende udviklingen
English Summary
The entire documentation of the development of Denmark’s open natural
and semi-natural habitats and their species is sporadic. Nevertheless,
the studies available clearly depict a vulnerable nature under
heavy stress. The trends particularly affecting the development of
these habitat types will be described in the following sections. Some of
these development trends are mutually enforced.
1. The debt from the past
During the last 200 years all open natural and semi-natural habitats
have been reduced to a fraction of their previous range. Many Danish
flora and fauna species are associated with the open natural habitat
types and a great part of these species are nowadays red-listed. Even
if the number of habitats is stabilised, a further reduction of a wide
range of red-listed species is to be expected, as there may be a considerable
time delay between the damage of habitats and the consequential
extinction of populations. Many species can survive for quite
some time in non-sustainable habitats where the final local extinction
will only occur at a later stage – typically caused by coinciding instances
of natural and man-made fluctuations. Despite the enhanced protection
of the remaining nature, the decline has continued for the last
20 years and a further decline in Denmark’s biological diversity must
be expected before this development is reversed.
2. Progress of the few – at the cost of the many
At present, the open natural and semi-natural habitats are reasonably
safeguarded at area level (quantitatively). The core of the present pro-
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