Download The Conservation Paradox

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A8
Morphological Adaptation
Specialised Organs
In order to withstand extreme climatic conditions, each organ of the
Edelweiss has developed its own specialised characteristics, from
the seeds to the root system. and including the stems, leaves and
flowers.
– Anti-UV down (microstructure of hairs)
– Hairy leaves and stem to protect against evapotranspiration
– Cold-resistant thick sap
– Rosette of protective leaves at the crown
– Thick and resistant rhizome
There is significant variation in the Edelweiss within populations.
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The Conservation Paradox
B1
Over the past twenty years, the Edelweiss has
gone from the status of an extremely rare, mythical and ‘over-picked’ plant to that of a domesticated one, rendering useless any mass collecting
and permitting the popular commercialisation of
this once threatened alpine species. It can now
take pride of place on our balconies and in our
floral bouquets…
Fig. 28
Scanning Electron Microscope picture of
the filaments covering the Edelweiss hair
layer. The substructure of the filaments
consistes of parallel fibres of approximately 0.18 mm in diameter, which correspond to the absorption wavelength of
UV radiation.
Fig. 29
The different organs of the Edelweiss.
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B2
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B3
Protected Status
From Nature to Culture
As it is attractive and relatively rare, the picking of Edelweiss has
been strictly controlled throughout the Alpine arc since the end
of the 19th century, first in the Swiss Canton of Obwalden in 1878,
followed by Austria where the Edelweiss has been protected throughout the country since 1886, and then practically over the whole
distribution range of the two species, Leontopodium alpinum and
Leontopodium nivale.
The domestication and selection of plants represent two successive
stages in the long process following on from simple collecting.
Domestication (Lat. domesticus, from domus = house) consists of the
cultivation by Man of a wild plant, whereas selection (Lat. selectio =
choice, sorting) consists of improving the characteristics of a plant to
optimize its culture.
In the case of the Edelweiss, the advantage of domestication lies
firstly in the protection of this species in its natural habitat through
the reduction of wild harvesting. This initial stage of cultivation has
already been carried out on many occasions, either in alpine botanical gardens or in ornamental rockeries.
Fig. 31
Poster with information about the protection of plants, from around 1884
Fig. 32
The first official ban on the picking of
Edelweiss was decreed in 1878 in the
Canton of Obwalden (Switzerland).
(Source : Canton of Obwalden State
Archives)
Fig. 33
Written report on the specificity of
the situation in the touristic regions of
Switzerland that was given to the Swiss
Commission for the Protection of Nature
(1912)
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Fig. 34
The first field of Edelweiss ‘Helvetia’ production in Reppaz/Orsières in full bloom
at the harvesting stage
Fig. 35
Rockeries in the Botanical
Gardens, Geneva
Fig. 36
Rockeries in the Botanical
Gardens, Zürich
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B4
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B5
Edelweiss & Collections
An Herbarium
Why? For whom?
Contrary to popular belief, Edelweiss can be fairly easily grown in
garden rockeries. On the plain, it tends to lose a little of its allure.
An herbarium is a collection of dried and mounted plants.
According to Correvon, the first rockeries of alpine plants were created in England during the 16th century, while in continental Europe,
interest in alpine plants only began towards the middle of the 19th
century.
‘It is in beds at the summit, in full sun and swept by violent winds,
that the plant acquires its most velvety sheen.’
– Henry Correvon, 1901
One might wonder, in the age of computers, digital photography and
multimedia, if an herbarium is still useful? The answer is yes!
Professional botanists still create scientific herbaria in order to
prove, often in direct relation to a publication, the validity of their
discoveries. For systematicians and taxonomists, an herbarium is an
indispensable working tool, for, if well dried and preserved, the specimens (plants) can be consulted for decades, even centuries, with
no alteration. This is not the case with photography or other modern
techniques (CD, DVD, etc.). Herbaria permit the identification, comparison and historical monitoring of species and their localities. They
are sometimes the scientific guarantee for conservation decisions
(reintroduction, renovation of biotopes, etc.).
The Botanical Conservatories of Geneva and Zürich, as well as certain museums, keep their herbaria in good condition and make them
available for consultation by researchers.
Fig. 37
Rockeries in the Botanical
Gardens, Geneva
Fig. 38
Terraces of Medicinal and
Useful Plants
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Fig. 39
The herbarium of the Conservatory and
Botanical Gardens in Geneva is one of
the most important in Europe. It notably
contains numerous specimens of Leontopodium (photo : Conservatory and
Botanical Gardens, Geneva)
Fig. 40
Part of the Boissier herbarium of the
Botanical Conservatory of Geneva. On it
is written the name of the genus, the species, the variety of the plant, the place
and date (7.1895) of collection, the dried
plant, along with its different organs, and
botanical drawings to facilitate identification. The drawings are by Gustave
Beauverd.
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B6
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B7
Selection &
Commercial Culture
Seeds &
Commercial Culture
The Edelweiss, when cultivated on a larger scale, shows great variation in terms of its size and appearance, which reflects the initial
biodiversity of the wild plant in nature.
Since 2004, seeds of the variety ‘Helvetia’ have been marketed by
the Fribourg seed company DSP (Delley Semences Production) and
the first field of Edelweiss ‘Helvetia’ was planted in 2005 in Orsières
(Valais, Switzerland).
In order to respond to the growing interest in the agronomic production of Edelweiss, particularly from the companies Just and Weleda
for cosmetics, and then Ricola for the production of sweets, a selection programme was set up by Charles Rey at the Research Centre
Conthey d’Agroscope Changins-Wädenswil ACW in 1993, in order to
obtain a homogenous and characteristic culture.
This variety is now produced by all the growers of the cooperative
Valplantes in Sembrancher, which supply the cosmetic and food
processing companies. Since 2009, the seeds have been marketed by
MediSeeds in Conthey.
A hybrid between entirely female flowers and hermaphrodite
flowers in 2003 led to the selection ‘Helvetia’ which is characterised
by :
– excellent germination,
– good agronomic performance at medium altitude (1000-1500 m),
– regular growth,
– good homogeneity and numerous inflorescences which retain
the typical appearance of the flowers in nature,
– a stable, high active ingredient content.
Fig. 41
Hermaphrodite inflorescence
Fig. 42
Female inflorescence : the visible bifid
styles (female organs) require pollen
from another plant in order for pollination to take place.
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Fig. 43
The production of Edelweiss in beds of
three rows permits partial mechanisation
of the work and rationalisation of the
production.
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B8
Pests & Diseases
In lowland culture, aphids (Aphis sp.) easily colonise Edelweiss
plants, particularly if they are cultivated under cover. When the
number of aphids becomes excessive, the growth and the quality
of the plants diminish. In greenhouses, other pests lead to losses :
whitefly (Trialeurodes vaporianum), two-spotted spider mite (Tetranychus urticae) and western flower thrips (Frankliniella occidentalis).
Biological control trials with the help of antagonistic insects (living as
parasites on the pest) are in progress. Promising results have been
achieved so far against aphids through the introduction of natural
predators like the micro-hymenoptera (Aphidius colemani) or the
seven-spot ladybird (Coccinella septempunctata).
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Cultivation
B9
Contrary to popular belief, it is relatively easy to grow Edelweiss on
a small scale. Its seeds germinate very readily with a little warmth
and humidity, without the need for a cold period (or vernalization)
to break dormancy as is the case for other alpine species (Gentian’s,
Alchemilla, etc.).
Edelweiss should be planted on sunny terrain at altitude (1000-1700
m), in soil that is well-drained, neutral to alkaline, moderately fertile,
with a plant density of approximately 10 plants/m2.
The fields, therefore, require hoeing to prevent competition between
weeds (undesirable flora) and the young Edelweiss plants.
The first crop is harvested in the second year, even though some
flowers might be produced in the first year. After being harvested,
the flowers must be moved rapidly to a hot air dryer at 35oC.
The dried flowers are then put into bags to be stored at a constant
temperature and protected from light and odours.
In contrast with rockery plants which can survive for several decades,
commercially-grown ones only live for three to five years.
Due to repeated cutting, the productivity of older plants tends to lessen while competition from hardy weeds increases. It is not advisable
to replant Edelweiss consecutively on the same area of ground (crop
rotation).
Fig. 44
By its scent and colour, the Edelweiss
attracts many useful insects such as the
flies which pollinate it, or ladybirds which
feed on aphids.
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Fig. 45
Edelweiss seedlings in small individual
containers before pricking out.
Fig. 47
Harvesting Edelweiss flowers manually is
a family affair
Fig. 46
Edelweiss rosettes six weeks after being
planted in the field.
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B10 Edelweiss Bouquets
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In vitro Culture
B11
Edelweiss and cut flowers
Edelweiss multiplied in the laboratory
In 2007, ACW initiated a programme aiming to offer innovative solutions for the Swiss production of cut flowers (Sigg, 2008). For energy-saving reasons, the emphasis of this diversification programme
was placed on the search for species which require little heat such
as Echinops (the Globe thistle), the Masterwort and… our Edelweiss.
In vitro culture (literally ‘in sterile conditions’) of the Edelweiss was
first carried out at Trinity College, Dublin, Ireland (Hook, 1993) and
then in Romania (Zăpârţan, 1996). In Switzerland, Lê Công-Linh
(ACW) put into in vitro culture the parents of the variety ‘Helvetia’ in
2004, for the careful preservation of this genetic resource.
A selection programme aiming to create a variety of Edelweiss
specially adapted for the production of cut flowers was started in
2008. For this, the principal criteria selected were the rigidity and
the length of the stem, the preservation of the typical appearance of
the Edelweiss and a prolonged flowering period.
Subsequently, in vitro culture permitted the rapid multiplication of
a large number of Edelweiss ‘Helvetia’ for commercial production.
For in vitro culture, the seeds are disinfected and germinated on an
appropriate medium maintained at 25°C.
The young shoots, each with an axillary bud, are then pricked out into
glass tubes on a sterile culture medium, to which specific nutrients
have been added. The tubes are then placed in culture chambers
where the plantlets grow.
This technique permits the rapid reproduction of Edelweiss plants
to meet the urgent needs for the basic materials necessary for plant
breeding work.
Fig. 48
A shimmering bouquet of Edelweiss ‘Helvetia’, Masterwort (Astrantia major) and
Echinops (Echinops bannaticus). These
lowland-cultivated alpine flowers retain
all their attractiveness.
Fig. 49
Edelweiss is associated with Pelargonium
(incorrectly called geranium’s) to decorate the balconies of chalets, as seen
here in Zermatt.
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Fig. 50
Planting young Edelweiss plants in a
coconut fibre brick.
Fig. 51
Young Edelweiss plant in vitro, rooted
and ready to be weaned.
Fig. 52
Soil-less culture, three weeks after planting. The black tubes provide the plants
with water and the nutrient solution
necessary for their growth.
Fig. 53
Soil-less culture of Edelweiss, two and a
half months after planting. The inflorescences are ready to be harvested.
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