Monday, 22 August 2016

Kingdom of the wind - where plants walk

On the high plateaux of the Cairngorms, the wind rules everything. The great open areas of ground above 1100m / 3600ft are exposed to the full force of weather from every direction and are often swept by gales and winds of hurricane force, especially in winter. Gusts of over 170mph/280kph have been recorded and sustained wind speeds in excess of 100mph/160kph are common. Given these sorts of speeds, it's hardly surprising that the wind exerts influence over everything which lives on the high arctic-like plateaux, limiting possibilities and even determining landforms.

When planning walks on the high ground here, the wind is a primary consideration with strength and direction factored into the day's plan. After a run of windy days in mid July abated, I took a long walk on Ben Avon (pronounced "A'an" and named for the river at the mountains foot -the bright one). 

Any day out on Ben Avon will be a "big day"; this is the largest of the Cairngorm hills by area, some 12 kilometres NE to SW and 9 kilometres N to S - really a hill-range rather than a single mountain.  In addition to the large extent of the hill, the starting points for walks are at some distance from the summit.  The most logical starting point from my home is at Cock Bridge to the north east of the hill, and my route would be some 40 kilometres.  The wind was forecast to remain light until evening, when it would once again begin to increase.  Fortunately, a mountain bike can be used on the track leading from Cock Bridge past the source of the River Don and on to Inchrory and the Linn of Avon, meaning that I'd do around 20km on the bike and 20km on foot.

Above Inchrory, this dry ravine cuts steeply down through lime-rich rock, an unusual rock type for the Cairngorms and visible from quite a distance as a bright green patch among the more muted colours.  Ahead, the outlying slopes of Ben Avon beyond the river were still cloud-capped.  The MWIS forecast was for the cloud to lift gradually during the day; I hoped that it would be as accurate as it usually is.

The bike was left near the Linn of Avon and I headed uphill on a stalkers path past grouse butts.....

...towards the start of one of the ridges of Ben Avon at Carn Fiaclach (toothed (or notched) Cairn).  Beyond  and above the wood surrounding the lodge at Inchrory, my route of approach already seemed quite distant, the green slope leading down to the estate track and across the hills to Cock Bridge.

The bald summit of Meall Gaineimh (sandy hill) is passed on a path which winds through gravelly ground and past some of the distinctive granite tors which are such a feature of Ben Avon.  The walking is a delight, fast movement on small mountain paths once the initial ascent is done.

My route took me up to the granite ridge of East Meur Gorm Craig before descending slightly to the wide sweep of the appropriately named Big Brae (slope).  Even in mid summer there are significant snow patches in most years, and this is in part due to the wind.  Snow is either compacted by gales into any depression on a windward slope.....

.....or deposited on lee slopes and in corries to immense depths.  The snow patches irrigate the ground through the summer and give a foothold to alpine grasses and plants.

Up to around 1000 metres / 3300ft there's a mix of plants such as Alpine Lady's Mantle (Alchemilla alpina), a relative of the larger plant commonly seen in gardens.  A combination of grazing by deer and the scouring of the wind keeps the plant low-growing.

Higher up, and only the hardiest of plants can survive the harsh conditions.  Alternately frozen, baked, flooded and subject to drought and gale, plants need to be tough up here.  The Three-leaved Rush (Juncus trifidus) is a real Cairngorm plateau specialist, able to survive on the most exposed ground where few other plants are able to apart from mosses and lichens.  Talking of "trifid", the 1951 Sci-Fi book by John Wyndham, later made into a classic 1962 movie - "Day of the Triffids" - features a species of plant capable of "walking" locomotion.  Here on the Cairngorm plateau, there are species of plants which can do just that, albeit slowly.

This Crowberry (Empetrum nigrum sp) started life in the lee of the small boulder at the bottom of the image.  It has grown away from the prevailing wind, putting out small roots as it goes seeking a more sheltered spot, curving around the boulder near the top of the image.  The original rootstock and stem are now dead and completely detached from the ground.  In some examples of this sort of downwind movement, the track of individual plants over decades and perhaps centuries can be traced by the absence of lichens on the rocks over which they have moved. 

This Crowberry also has a reproductive trick to help it survive the harsh environment, it is of the sub-species hermaphroditum which has bisexual flowers to increase the chances of fertilisation, and smaller, stubbier foliage to resist the hostile weather.  A real life "Triffid" !

A gentle rise to the SW now took me to the highest plateau of Ben Avon, a broad ridge leading towards the tor which forms the summit.  I emulated the plants and sheltered behind a large boulder to rest and eat, there wwas still plenty of walking ahead....


  1. A nice post Ian. One of the delights of the Cairngorm plateau, apart from the tors, when I was young was the large carpets of pink Moss Campion growing between the boulders. Amazing such delicate little cushions of tiny cluster flowers can survive 100 plus wind speeds and months of deep snow.

    1. Thanks Bob, Moss Campion is a favourite of mine too, but I didn't see any of it on this walk...the wildflowers along the track beside the River Avon were brilliant though...

      Kind Regards

  2. Sounds like a "massive day", Ian. As in Bob's comment above, the juxtaposition of delicate flora and unforgiving, and at times, ferocious weather is incredible. We see that here in the tiny alpine flowers, high up in the windswept and snowbound Rockies. Once again, nature's message to us to never give up hope...even against all odds. Another great adventure! Warm wishes.

  3. It was certainly a bit of a long day Duncan, but typical of hill days in the Cairngorms and a really good day out. Like you, I'm constantly amazed by the way that seemingly delicate plants can survive and thrive in harsh environments

    Warm wishes to you both