Del|The loss of biodiversity
has not stopped in any of the nine Danish
ecosystems. This is the conclusion in a
new report from The National Environmental
Institute (NERI) at Aarhus University, based
on the examination of a large variety of
species, habitats and processes.
Old grassland with lichen-covered granite
boulders in Mols Bjerge. Stop of grazing
is one of the major problems for our open
and bright landscape – heaths, commons,
meadows, costal slopes, etc. Photo: Henriette
Bjerregaard.
Biodiversity, i.e. biological
variety, is enormous. In Denmark alone we
are believed to have more than 30,000 different
species. A large group of scientist from
NERI and from The Natural History Museum
in Aarhus has therefore taken up a tremendous
challenge by dividing the Danish landscape
into nine ecosystems. Here they have chosen
a total of 139 elements of biodiversity:
65 species and groups of species (a total
of more than 600 species), 43 habitats and
31 processes.
The result of the efforts
of this large group of scientists has now
been published in the report (in Danish)
”Danmarks biodiversitet 2010 – status, udvikling
og trusler” ("Denmark's biodiversity
2010 – present state, development and threats").
Historic low
The report shows that
biodiversity continues to decline in all
ecosystems. Out of the 139 elements included
in the research, 47 % are declining, 25
% are stable or progressing and for the
remaining 28 % the scientists know too little
to be able to form an estimate of the development.
So more than twice as many elements are
declining than elements being stable or
progressing.
But why is the situation
this serious? Senior scientist and project
manager Rasmus Ejrnæs explains:
"We can see that
even if the best landscape is protected
by laws and regulations, there is no protection
against stop of grazing or atmospheric nitrogen
deposition. This leads to overgrowing of
meadow, grassland and costal habitats, and
eventually to the loss of stress-tolerant
plants, butterflies, bumblebees and beetles.
Another major problem is that our landscape
is under pressure. We have seen that the
protection of meadows, heaths, mires and
grasslands is weak; we can see that the
small biotopes in the arable land disappear
or are reduced, and we can see that towns
and roads keep spreading at the expense
of natural habitats."
The report also shows
that once species have been lost, they will
not automatically return if the habitat
is restored. The fact is that - contrary
to the white-tailed eagle - many species
are dispersal limited so they will only
return very slowly. In addition to that,
the destruction of habitats has been so
comprehensive that a small increase in habitat
availability will not be enough to stop
the decrease in species. In addition to
this delay in recovery time, we also experience
a damage delay, i.e. species that disappear
in response to historical habitat losses.
The scientists demonstrate in the report
that several threatened habitats in forests
increase whereas the corresponding species
continue to decrease.
In the light of the
large, historical decrease in species and
habitats, the scientists find no ecosystems
without continued loss of biodiversity.
Rasmus Ejrnæs:
”The characteristic
feature is that the occasional progress
we have detected is found in areas that
had reached a historic low. This is for
instance the case of our large lakes which
have typically been seriously loaded by
nutrients during the previous century and
are now slowly recovering. And it is the
case in our forests where we have never
before found so little dead wood, old deciduous
trees, forest glades and wetlands as today."
Summary of the estimate
of the development for all 139 examined
elements. The elements are divided into
species (or species groups), habitats and
processes, and into the nine examined ecosystems.
The first column corresponds to a decrease
in the biodiversity, the middle column corresponds
to stability or increase and the last column
corresponds to an unknown development.
Action wanted
The report shows that
there is a need for evidence-based actions
to stop the loss of biodiversity. The comprehensive
scientific documentation of the report provides
a solid professional basis for future strategies
and action plans in the field of biodiversity.
In his preface to the
report, Director General Henrik Sandbech
writes:
”The Minister for the
Environment has announced a national strategy
for biodiversity to follow up on the international
agreement made in Japan. This UN agreement
has given us ten years more; but in the
light of the prevailing political agenda
for economic growth, we cannot permit ourselves
to lean back. Biodiversity will continue
its decline if we do not act now. The effort
must be applied, evidence-based and long-term.
This will not be the case until the day
when nature and biodiversity are part of
the government basis - on equal terms with
other important goals for our welfare society".
About the report
Nature's diversity is
on the decline all over the world. Species
become extinct at unnaturally great speed
because man monopolizes more and more of
the natural resources of our planet. The
concern for the loss of biodiversity has
led to the biodiversity convention of 1992
and to EU's 2010 aim to stop the loss of
biodiversity. The target was missed and
the world society therefore set up new targets
at the UN Biodiversity Conference in Japan,
and the year 2020 was set as deadline for
a stop to the biodiversity decline.
The so-called 2010 target
to stop the loss of biodiversity is one
of the most important goals for the Danish
environmental policy. In the spring of 2010,
NERI decided to start a science-based evaluation
of the 2010 goal, and the result of this
evaluation is the 148-page report.
The report was presented
at the first Danish biodiversity symposium
on 20 and 21 January in Aarhus.
The symposium assembled
more than 250 Danish scientists, administrators
and decision-makers in the field of nature
management and biological conservation.
The purpose of the symposium was to create
a Danish forum where people meet to discuss
new knowledge and topical problems related
to biodiversity and nature management in
Denmark.
Main results:
Forests
Habitat of the highest
number of threatened and vulnerable species.
Major decline in the number of beetles in
dead wood, butterflies in woodland meadows
and glades, epiphytic lichens.
Habitats connected to more natural forests
increasing.
Coasts
Denmark's most important
contribution to international biodiversity.
Seven out of nine species groups are declining.
Seals flourish, and the nitrogen deposition
is falling.
Grasslands, heaths, meadows and bogs
The area covered by
grassland, heath and bog as well as poor
and grazed meadows continues to decline.
Greatest decline of chafers, ground beetles,
butterflies and wax capsin grasslands and
heaths and for spiders in bogs.
Increase of heather; the nitrogen loading
in bogs and meadows has been stabilized.
Lakes and streams
The loss of biodiversity
in large lakes has been stopped, but continues
in other lakes and streams.
Greatest decline for amphibians in small
lakes; decline of pondweed, fish and thick-shelled
freshwater mussels in streams.
Sea
The less known ecosystem.
Decline for fish, birds and benthic invertebrates.
Arable land, roads and towns
Cover three quarters
of the terrestrial environment.
Most intensively exploited areas.
Urban areas provide new habitats for heat-demanding
species like lizards.
Basis of knowledge
Only 40 % of all evaluations
are based on empirical data. 60 % are based
on expert judgments. For 28 % of all elements
the development is unknown.
The inadequate data available reflects the
fact that society still lacks knowledge
about the present state and development
of the Danish biodiversity.
+ More
Kittiwakes’ trans-Atlantic
winter odyssey linked to breeding success
03 February 2011, Biodiversity
and Land Use, CEH
One of Britain's best
known seabirds winters on opposite sides
of the Atlantic depending on whether its
breeding attempt has been successful according
to new research published today in the journal
Proceedings of the Royal Society B. The
findings highlight previously unsuspected
links between summer breeding performance
and wintering distributions of kittiwakes.
Kittiwake on nest, Isle
of May Photograph - Mark Newell/CEHThe research
team was led by Dr Maria Bogdanova from
the Centre for Ecology & Hydrology (CEH)
in conjunction with colleagues from CEH
and the British Antarctic Survey (BAS).
The discovery of such
patterns of segregated winter distributions
is important for defining key wintering
areas in declining species such as the kittiwake
that are experiencing poor breeding seasons
with increasing regularity.
The results show kittiwakes
that experienced breeding failure left their
colony earlier than successful breeders.
Failed breeders then travelled over 3000km
and wintered off Canada while their successful
neighbours remained close to Britain. The
two groups did not differ in the timing
of return to the colony the following spring.
However, over half the males from both groups
made a previously undescribed long-distance
journey out into the central Atlantic before
the breeding season.
Lead author Dr Maria
Bogdanova, an animal population ecologist
at the Centre for Ecology & Hydrology,
said, “Our results demonstrate important
but previously poorly understood links between
breeding performance and winter distribution,
with significant implications for populations.
It is fascinating that successful and unsuccessful
pairs nesting only a few metres apart in
the colony can be separated by thousands
of kilometres in the winter.”
This study used a tiny
instrument (1.4g) known as a geolocator
for tracking animal migration. During the
2007 breeding season, the team fitted 80
kittiwakes on the Isle of May NNR off the
east coast of Scotland, with geolocators.
Geolocators were developed
by BAS and have so far been used on animals
such as geese, albatrosses, penguins and
seals. They make regular recordings of light
intensity, data which can be used to generate
two geographical positions per day.
Co-author Francis Daunt,
a seabird ecologist also from the Centre
for Ecology & Hydrology said, “Kittiwakes
have declined substantially in the last
25 years over much of their range. Conservation
efforts to protect wintering grounds should
consider that winter distributions may be
shifting as breeding failure is becoming
more common.”
