Sunday 25 March 2012

Snowdrops in the Czech Republic


The River Labe rises in the Krkonoše Mountains of the northern Czech Republic and flows south for about a hundred miles before turning west and north and flowing through the Czech Republic and Germany, where it is known as the Elbe, to its mouth at Cuxhaven on the North Sea. Over its 1,100 kilometre length it drains 148,000 square kilometres of industrial central Europe, the fourth largest catchment on the continent.

Some stretches of the river are flanked by floodplains several to tens of miles wide formed of a series of sedimentary terraces, all recent in geological terms. Deposition of the oldest, most elevated terrace, which lies between 4 and 4.5 metres above current river level, began only 9,500 years ago and the lowest terrace was deposited during the Little Ice Age of the 16th century. Buried tree trunks provide evidence of occasional catastrophic flooding, interspersed with periods when the river was at equilibrium, meandering across a stable floodplain. We live in such a time today (the evidence for these claims is presented in this interesting paper).

Human settlement of the floodplain has waxed and waned since Neolithic times, when humans started developing agriculture. Deciduous forests, dominated by oak, have reclaimed the deep, fertile soil whenever man has been driven from the floodplain by periods of severe flooding. At Mělník, north west of Prague, where the Labe and the Vltava meet, the river is a fat, lazy, silt-laden waterway, navigable by the huge barges that once carried most of the trade in and out of central Europe but which have now all but vanished from the rivers and canals. Human engineering has erased the river’s meanders, reinforced its banks and contained its flow within a dependable channel.

The River Labe near Mělník, Czech Republic

The oak forests have largely disappeared, replaced by cabbage and hop fields, subsidised since the Czech Republic’s accession to the European Union by the taxpayers of western Europe. The hops, at least, go into some of the world's best beer, but a Eurosceptic need spend only a day driving across the Labe floodplain to have his worst fears confirmed[1].

Here and there, however, small patches of woodland remain alongside the Labe. They are currently protected from brassica encroachment by the same people whose election prospects depend upon their standing with cabbage farmers. In mid March each year these little patches of woodland light up with millions-upon-millions of snowdrops. I’ve seen some extraordinary floral spectacles in my time but I think that March in the woods flanking the Labe is up there with South Africa’s Cape Province in spring for sheer jaw-dropping awesomeness. The fact that a single plant species – Galanthus nivalis – is responsible for the spectacle somehow makes it more, not less, impressive. Astonishingly, at least to me, this annual extravaganza seems to come and go almost un-observed by human eyes. I was there for three days at peak flowering this year and, other than a few dog walkers, I did not see another soul in the woods.




So far as I could tell, the Galanthus colonies are all on the lowest, most recently deposited terrace of the Labe floodplain. An interesting implication of this is that the populations are, at most, 500 years old. Conservationists - I consider myself one but disown the tainted label - often claim to be attempting to save 'natural' habitats from destruction but it is rare to hear the youth or transience of some of these habitats discussed. Especially in the temperate northern hemisphere, where cycles of glaciation dramatically alter the natural vegetation at a particular site over periods of a few millennia, attempting to conserve a natural habitat is like trying to find the east pole.

A galanthophile in paradise immediately notices a problem. Life (even in paradise) is too short to examine every plant. The only possible solution is to stumble, drunk on the beauty of the plants one is crushing underfoot, on a random walk through the colonies. The snowdrop colonies along the Labe are the most variable so far discovered. Every aspect of the plants’ morphology varies wildly. Stature, flower size, pedicel length, the shape and size of the outer segments, the size and shape of the marking on the inner segments, the presence or absence of virescence, the occurrence of poculiforms, the colour of the ovary and the occasional outright freak.





Each colony is slightly different from its neighbours. Two in particular stand out for the superabundance of unusual varieties. In one of these colonies plants with green marks on the outer segments are particularly common (perhaps one in 1,000 plants is marked in this way) and in the other poculiforms are similarly abundant. The images below give an impression of the diversity present in the populations.





Although I have seen snowdrop colonies elsewhere in Europe, for example in Montenegro, with a small proportion of unusual plants, I have never encountered variation on anything like the scale of the populations in the Czech Republic. The question arises why these colonies are so variable. An obvious explanation presents itself, namely that the floodplain of the Labe has been inundated repeatedly in recent decades with water laced with a cocktail of various industrial effluents. It is quite conceivable that some of these pollutants are mutagenic and are responsible for many of the oddities but this hypothesis needs careful testing. Alternatively, or as well, founder effects may have had a role to play.

It quickly becomes clear, when walking through these woods, that the unusual traits that galanthophiles admire are heritable. This is particularly clear in the case of virescent snowdrops. If one’s eye is caught by a particularly fine virescent plant, the natural tendency is to squat on one’s haunches and look more closely. It soon becomes apparent that several of the clones within a few yards of the central plant are also virescent, to a greater or lesser extent. I tried to photograph this phenomenon but could not achieve sufficient depth of field to illustrate it well. The same is true of poculiforms. One ‘purple patch’ I encountered must have contained a hundred or more different poculiform clones within an area of about half an acre.



As any fule kno, the self-appointed guardians of wildlife conservation have arranged for trade in Galanthus to be regulated by CITES, thereby driving the international trade in horticulturally desirable snowdrops underground while making no difference whatsoever to the fate of wild populations, which is determined by the unholy alliance between developers and politicians, not by plant enthusiasts. How, then, is one to rescue some of this genetic goldmine before it is turned over to cabbage cultivation or, on a slightly longer timescale, inundated in a new period of catastrophic flooding?

Seed. I think the answer must be to collect and sow an enormous quantity of seed. It is not currently illegal to send Galanthus seed outside the EU from within it. Of course, as soon as the relevant bureaucrats spot this loophole, they’ll close it, thereby sealing the fate of the species they will loudly proclaim they are trying to save.


[1] It has been noted that, whereas the ten commandments contain 179 words and the US declaration of independence 1300, EU cabbage legislation runs to nearly 27,000. I need hardly add that although the first two tracts are also horseshit of the stinkiest variety, at least they are concise horseshit.

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