Published : Jul 23,
2013
Grassland butterflies have declined dramatically
between 11000 and 2011. This has been caused
by intensifying agriculture and a failure
to properly manage grassland ecosystems,
according to a report from the European
Environment Agency (EEA).
This dramatic decline
in grassland butterflies should ring alarm
bells – in general Europe’s grassland habitats
are shrinking. If we fail to maintain these
habitats we could lose many of these species
forever.
The fall in grassland
butterfly numbers is particularly worrying,
according to the report, because these butterflies
are considered to be representative indicators
of trends observed for most other terrestrial
insects, which together form around two
thirds of the world’s species. This means
that butterflies are useful indicators of
biodiversity and the general health of ecosystems.
Seventeen butterfly
species are examined in 'The European Grassland
Butterfly Indicator: 11000–2011’, comprising
seven widespread and 10 specialist species.
Of the 17 species, eight have declined in
Europe, two have remained stable and one
increased. For six species the trend is
uncertain.
Butterflies examined
in the report include the Common Blue (Polyommatus
icarus), which has declined significantly,
the Orangetip (Anthocharis cardamines),
which seems to be stable since 11000, and
the Lulworth Skipper (Thymelicus acteon),
which shows an uncertain trend over the
last two decades.
Hans Bruyninckx, EEA
Executive Director, said: “This dramatic
decline in grassland butterflies should
ring alarm bells – in general Europe’s grassland
habitats are shrinking. If we fail to maintain
these habitats we could lose many of these
species forever. We must recognise the importance
of butterflies and other insects – the pollination
they carry out is essential for both natural
ecosystems and agriculture.”
Why are butterflies
disappearing?
Intensifying agriculture
and abandoned land are the two main trends
affecting the populations of grassland butterflies.
Agriculture has intensified where the land
is relatively flat and easy to cultivate,
and, on the other hand,large areas of grasslands
have been abandoned in mountainous and wet
regions, mainly in eastern and southern
Europe. Both intensification and abandonment
result in the loss and degradation of habitat
for grassland butterflies.
Agricultural intensification
leads to uniform grasslands which are almost
sterile for biodiversity. In addition, butterflies
are also vulnerable to pesticides, often
used in intensively managed farming systems.
Farmland is often abandoned
for socio-economic reasons. When farming
on low-productivity land brings only a small
amount of income, and there is little or
no support from the Common Agricultural
Policy (CAP), farmers give up their enterprises
and the land is left unmanaged. The grassland
becomes overgrown and is soon replaced by
scrub and woodland.
In some regions of north-western
Europe, grassland butterflies are now almost
restricted to road verges, railway sidings,
rocky or wet places, urban areas and nature
reserves. Areas using traditional low-input
farming systems, known as High Nature Value
Farmland, are also important habitats.
Monitoring Europe’s
butterflies
The report is based
on the European Grassland Butterfly Indicator,
compiled by De Vlinderstichting (Dutch Butterfly
Conservation), Butterfly Conservation Europe
and Statistics Netherlands, using data from
11000 to 2011. The indicator brings together
information from national butterfly monitoring
schemes in 19 countries across Europe, most
of them European Union Member States. Thousands
of trained professional and volunteer recorders
count butterflies on approximately 3 500
transects scattered widely across Europe.
This volunteer fieldwork is essential for
understanding the state and trends of Europe’s
butterflies.
While the report is
based on data from 11000 to 2011, it should
be noted that in many areas of Europe the
current changes in land use began before
11000. The report therefore suggests that
the recent halving of butterfly numbers
may be the most recent development in a
much bigger long-term decline.
The EU Biodiversity
Strategy recognises the poor conservation
status of grasslands. Grasslands should
be properly managed, the report states,
both within Natura 2000 protected areas
and on HNV farmland. A new system of payments
under the Common Agricultural Policy could
help support better management, the report
says.
The European Grassland
Butterfly Indicator could be used as a measure
of success of agriculture policies. Sustainable
funding of butterfly indicators would help
validate and reform a range of policies
and help achieve the goal of halting the
loss of biodiversity by 2020.
