Into the Valley of Flowers …

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I can safely say that our hotel in Ghangharia was one of the worst in which I have ever stayed.  The rooms were draughty, dirty and damp, there was no hot water and the cheerful Nepali kitchen staff had a very limited grasp of health and safety.  This is one of the downsides of being a Guinea pig for a tour party: we stayed in two excellent hotels and three perfectly adequate ones but, occasionally, we have to suffer so that next year’s paying guests don’t have to.   The tented camp, just outside the village, looks like a much better bet for next year.

On the plus side, the low cloud disappeared overnight and we awoke to blue skies with just a few puffy cumulus clouds and gulped lungfuls of cool mountain air in order to banish the fetid atmosphere of the hotel.   The track out of Ghangharia was quiet: the Sikh pilgrims have to walk further and climb higher than those of us heading to the Valley of Flowers, so had made earlier starts.   We paid our 600 rupee entrance fees at a hut beside the path just after our route diverged from the path that the Sikhs took, and followed the track through a fir forest overhung by enormous vertical cliffs of much-folded ancient rocks.

The Valley of Flowers is a hanging valley – a glacial valley which ends in an abrupt drop as it joins with the valleys below.  This meant another stiff climb along a path that zig-zagged up a hillside and across the site of recent landslides.  We were now walking at about 3500 metres, and I was reminded of the limitations of my acclimatisation programme with every step.  But we had reached the tree line and the valley had broadened out to give us our first views of the valley that Smythe had first seen in 1931.   From where we stood at the western end, the valley extended for about five km due west before reaching the foot of the Tipra glacier. Behind these, peaks (several climbed for the first time by Smythe and his associates) rose to 6600 metres although, during our visit, most were hidden by clouds.  On either side of the valley there were lateral moraines deposited by the glacier in colder times whilst the Pushpawti river, carrying the glacier’s meltwater, has gouged out a V-shaped notch along the mid-line of the valley.

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Looking west up the Valley of Flowers towards Tipra glacier with stands of balsam in the foreground.  The photograph at the top of the post shows our first view of the Valley on arrival from Ghanghria.

There was a profusion of flowers but, to our mutual surprise, the most abundant by far, especially close to the mouth of the valley, was Himalayan balsam, scourge of British river banks (see “The politics of pests”).  After a while, however, we started seeing more diversity, especially in areas where the balsam was less prevalent and as we pushed further into the valley.  Everyone has to leave the valley by nightfall, which limits the distance that visitors can penetrate to a couple of kilometres, so there were many areas that Smythe described but which we could not visit.  Nonetheless, Heather, the real botanist in the family, photographed about 100 different species (her own accounts will follow) at a time of year when important groups such as Primula and the orchids are long past their best.

The prevalence of balsam was intriguing.  This is its native habitat, and we don’t have enough knowledge of the plant communities in this part of the world to know how typical these extensive stands of balsam are at these altitudes.  Smythe reported its presence but also commented that it was ruining pastures in the area.  However, he only made a couple of visits so his opinion, too, may not be definitive.  We did learn from a park ranger that the cover of balsam had increased in recent years.  When the valley was declared as a World Heritage Site grazing was banned and though this was at a very low level (a single family), we did wonder whether this had a role in maintaining habitat.   On the other hand, the balsam here is much more varied than the monocultures of Impatiens glandulifera that we are used to seeing in the UK, where it was introduced and perhaps we are approaching it with minds pre-conditioned by negative attitudes at home?   I. glandulifera is found in the valley, but I. sulcata, the Giant Himalayan balsam, is more common here.   There is no doubt that the splashes of pink-purple flowers across the floor of the valley were a dramatic fulfilment of many peoples’ expectations as they first entered the valley.

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Valley of Flowers, looking west at about 1.5 km from the foot of Tilpri glacier.   The plants in the foreground are (probably) Campanula latifolia (bellflower) and Selinum wallichianum (milk parsley), one of several umbellifers that are found in the valley.

By now, the sun was sinking and we needed to start retracing our steps back down to Ghanghria.   Our personal odyssey was over; we had seen the Valley of Flowers. For Heather, at least, it is probably “au revoir” rather than “goodbye” as there is a strong chance that she will bring a tour party back here next year or the year after.   For me, who knows?

And, yes, I did collect some diatoms from a stream whilst I was in the Valley of Flowers.  I’ll write more about those at some point.  Somehow, too, I must have communicated my interest in the diversity of the microbial world to the kitchen staff of our hotel, as they kindly sent me back down the track to civilisation with a payload of grumbly enteric bacteria.  But you don’t want me to write too much about that …

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The Valley of Flowers, showing abundant stands of Persicaria polystachya, a very common plant along river banks (i.e. in the habitat where we would expect to find Himalayan balsam, Impatiens glandulifera, in the UK).

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The future is pink …

It occurred to me, as I walked along a local river bank with a friend a couple of weeks ago, that anyone under the age of about 30 probably has little idea why ecologists make such a fuss about Himalayan balsam (see The Politics of Pests).   I was explaining how different this place was now compared to when I first visited but for her, the pink flowers of Himalayan balsam were something that she always associated with river banks. Himalayan balsam was as much a feature of the British countryside for her as rabbits – introduced here by the Romans.

I also wrote recently about the barriers that public perceptions create (see “To Constable country, via a blog on fracking …”).   Environmental improvements are expensive and we need to justify expenditure yet, with the passing of time, Himalayan balsam and other invasive plants will become part of people’s experience of rivers, not as intrusive aliens. Their impact on the native vegetation will be something that only a few specialists appreciate.   There is, in fact, a big literature on how public perceptions are important in environmental management, but this has an inherent limitation as even our earliest memories do not extend far enough into the past to give reliable insights into the natural state of lakes and rivers.   In theory, of course, applying the scientific method allows a more objective, less biased evaluation of what we mean by a “natural” ecosystem.   But we ignore public perception at our peril: the case for environmental restoration beyond a state that lay people regard as desirable will need to be made very clearly in order to justify the costs.   An absence of Himalayan balsam is not, itself, a benefit that a lay person will automatically appreciate.

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Himalayan balsam growing beside Smallhope Burn, a tributary of the River Browney, near Lanchester, County Durham.

I end this short thread of posts about Himalayan balsam on a pessimistic note.   The river banks we were walking around were part of a country park managed by the local council.   Their budgets have been cut so much that the prospect of manual control of Himalayan balsam is out of the question. Indeed, there is so much Himalayan balsam that any effort to remove it from a single location would have to be an ongoing campaign as it would constantly re-invade from outside.   It may be possible for Wildlife Trusts to marshal volunteers to keep Himalayan balsam at bay on nature reserves, but the co-ordinated regional and national control programmes that I mentioned in The Politics of Pests belong to the world of fantasy, not reality. I have seen the future … and it is pink.

Reference

Valinia, S., Hansen, H.-P., Futter, M.N., Bishop, K., Srisskandarajah, N. & Fölster, J. (2012). Problems with the reconciliation of good ecological status and public participation in the Water Framework Directive. Science of the Total Environment 433: 482-490.

Coda

A colleague read my blog and passed on a recent press release from CABI announcing the start of a trial release of a rust fungus to control Himalayan balsam.   Laboratory-based trials have established that the fungus damages the Himalayan balsam plants whilst not infecting native species. The field trials are taking place in Berkshire, Middlesex and Cornwall and it will be interesting to see how these perform.   If it is as successful – and cost-effective – as the project team hopes, then maybe the future will not be so pink after all …

The politics of pests …

My training for the Great North Run takes me along the banks of the River Wear and, since writing about Himlayan balsam recently (see “An Indian summer on our riverbanks …”) I have had plenty of opportunities to both observe and ponder the biology of this plant.   I remembered, just after posting my piece on Himalayan balsam, that some former colleagues at Durham University had done some research on this species just after I had left.   Another colleague had commented wryly that they had managed to prove that Himalayan balsam lives by river banks though, on reading their work, it is clear that this was a rather unfair judgement.  It is also wrong, as I noticed this morning as I pushed through stands of Himalayan balsam that were encroaching on the path I was running along, some distance from the river.   I have run along this path for several years but this year is the first when I have noticed Himalayan balsam in such abundance.

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Coiled seed pods of Himalayan balsam, photographed on the Durham river banks, July 2014.

If you look closely at the seed pods you can see that they are tightly coiled, like springs. And, when you brush against a mature seed pod, these springs are capable of catapulting the seeds for several metres.   This characteristic, in fact, is the reason why the Latin name of the genus is “Impatiens” (“impatient”).   Each plant can produce many seeds, so all it takes is for a few of these to land in suitable conditions and the stand of Himalayan balsam will, by the next year, have extended itself by a few metres.   The predilection for river banks is partly because these are associated with fertile, moist, often shaded, soils where the seeds are able to thrive, but also because the natural flooding of the river can transport the seeds rapidly between locations.   However, my former colleagues at Durham also noted that Himalayan balsam was also strongly associated with roadsides and, indeed, Frank Smythe, in Valley of Flowers, does not record Himalayan balsam in its natural habitat as being so strongly associated with rivers.

Knowing where Himalayan balsam grows was, however, only the start, as they were able to use their knowledge of the plant’s distribution to build a mathematical model that described how Himalayan balsam spreads and then to manipulate the model to simulate various options for controlling the spread.   They concluded that, once established, Himalayan balsam would be very difficult to eradicate, regardless of strategy.   That’s no big surprise, given what we know about the biology of the plant and also from knowledge of efforts to control other invasive weeds. But that, too, got me thinking …

We are, now, less than 10 months away from a general election.   Expect many fine words about the environment to be spoken between now and then.   But, as is often the way, it will be the economy, health and education which will dominate the campaigns.   Politicians will look for environmental policies that will either give a quick and demonstrable benefit or Grand Gestures with maturation times that extend well beyond the term of the next parliament.   Control of invasive weeds fails on both counts.   The paper on control strategies concludes: “If eradication is a serious goal of control programmes then they must be co-ordinated at a regional or national scale, involve greater investment and extend over a longer duration”. In other words, they will need a bigger slice of the budget that the environment is likely to be allocated.   Moreover, how can regional or national co-ordination be achieved in governments committed to reducing the size of the public sector?   No, I’m afraid that control of Himalayan balsam is very unlikely to feature on any politician’s to-do list in the immediate future.

References

Collingham, Y.C., Wadsworth, R.A., Huntley, B. & Hulme, P.E. (2000).   Predicting the spatial distribution of non-indigenous riparian weeds: issues of spatial scale and extent.   Journal of Applied Ecology 37 (Suppl. 1) 13-27.

Wadsworth, R.A., Collingham, Y.C., Willis, S.G., Huntley, B. & Hulme, P.E. (2000). Simulating the spread and management of alien riparian weeds: are they out of control?   Journal of Applied Ecology 37 (Suppl. 1) 28-38.

 

An Indian summer on our riverbanks …

One of my favourite places in County Durham is, paradoxically, also one of the most polluted.   When I first visited, over thirty years ago, the stretch of the River Team pictured below was heavily polluted from several sources, including sewage works, abandoned coal mines and a large battery factory, just a couple of kilometres upstream. The latter made the river an ideal open-air laboratory for work that we were doing at the time on the effect of heavy metals.   The River Team, like many other rivers in this part of County Durham, flowed through a gorge incised into the landscape. The steep slopes of the gorge made agriculture and settlement impractical so locations such as this are blessed by beautiful wooded valleys (the incised meander at Durham City is the most famous example of these – see “The River Wear in summer”).

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Causey Arch crossing the River Team in County Durham, July 2014.

Causey Arch, the bridge in my picture dates from 1726 and is the oldest surviving single-arched railway bridge in the world and is a reminder of the region’s industrial heritage. George Stephenson is a local lad and the Stockton and Darlington Railway, the first public railway to use steam locomotives, is just 50 km to the south. So do not be deceived by the idyllic view of the wooded gorge around Causey Arch: the surrounding area has a high population density and a long history of water-polluting industries.

Although the battery factory that polluted the river in the 1970s and 80s has now closed, the river is still heavily polluted, particularly from a sewage works about a kilometre upstream from where this photograph was taken.   There has, however, been one other change since my first visits in the early 1980s: the banks of the river are now thick with the pink-flowered plants of Himalayan Balsam, Impatiens glandulifera.   The riverbanks do not just look different, they are also heavy with Himalayan Balsam’s sweet, pungent odour.  Ironically, these changes have taken place as the water quality itself has gradually improved.

As the name suggests, Himalayan balsam is not a native plant; it was introduced here in the 19th century for its attractive pink flowers but has escaped from gardens to become a nuisance over much of the country.   You can read more about this in Heather’s blog, written in preparation for her trip to the Himalayas later this year.   She refers back to Frank Smythe’s classic book “Valley of Flowers” in which he notes that, even in the Himalayas, this plant is often a nuisance weed.

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Himalayan balsam, Impatiens glandulifera, growing at Causey Arch, County Durham, July 2014.

My own private gripe with Himalayan balsam is that the tall plants grow just far enough apart to allow nettles to thrive in the gaps. I’ve struggled to get into rivers to collect my samples several times this year already and suffered multiple stings as a result.   I have slowly realised that my chest waders, though very hot to wear on a sunny day, are much preferable to bare legs.

Postscript

There is more about invasive plants in the Plant Invaders episode of Plants: from Roots to Riches on the BBC iPlayer. Curiously, Himalayan balsam is not mentioned in this programme but it is worth a listen nonetheless.