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Orchid conservation
An uncertain future
High up in the tree canopy, the comet orchid (Angraecum sesquipedale)
with its waxy white flowers awaits its moth pollinator. When Charles
Darwin received a specimen from Kew he predicted that the flower,
with its 30 cm long nectar-producing spur, would be pollinated by
a moth with a sucking tongue of the same length. Subsequently, just
such a moth was discovered. The intimate and highly specific relationship
between orchids and their pollinators is one factor contributing
to the uncertain future that these complex plants face in the wild.
If the moth disappears, the orchid will vanish too.
Of the world's 25,000 orchid species, some 10% are believed to
be endangered in their native habitats. Clearance of natural vegetation
for crop cultivation or forestry, or for industrial or urban development
is the prime threat. It not only affects the orchids directly, but
also impacts on their insect partners and the other plants and fungi
that they depend on. Another threat is the unsustainable harvest
from the wild of prized species, primarily for the collections of
unscrupulous orchid growers.
Orchids - going, going, gone
After its discovery in Vietnam in the 1920s, the slipper orchid
Paphiopedilum delenatii was brought into cultivation and successfully
propagated. However, for over 70 years it was thought to be extinct
in the wild. Then, in 1995, a single specimen was found in a consignment
of other orchids sent to Taiwan for the trade in traditional Chinese
medicine. Within a matter of months, large populations of the species
had been identified, but over 6 tonnes of wild plants, representing
between 60,000 and 120,000 individual plants, had been collected
and Paphiopedilum delenatii was once again deemed to be
on the verge of extinction.
Like many other tropical orchids that can be successfully cultivated,
this species has suffered needlessly from over-exploitation in its
natural habitat. With modern propagation and culture techniques
capable of producing large numbers of healthy plants, it should
not be necessary to harvest wild orchids in such huge quantities.
Orchids from tropical mountains and temperate fields
Cloud forests, as their name suggests, are cool moist environments.
They occur on tropical mountains at altitudes where cloud and fog
form at night. The high humidity is ideal for many epiphytic orchids,
including the tropical American masdevallias and draculas. These
plants cling to tree trunks or branches where the light is stronger
than at ground level. They absorb the water they need from the damp
atmosphere or from rainfall. Large areas of these mountain forests
are being logged or transformed to pasture or crop plantations.
Other orchids which thrive in the cool conditions of this zone
are those from the world's temperate regions. The majority of these
are ground-living, many of them occupying habitats that were created
or modified by the farming activities of early people. Today, those
habitats are being changed or destroyed at such a rate that the
local orchid species are often unable to adapt quickly enough to
survive.
More plants
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On to: Kew's orchid research
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