Saturday, March 02, 2019

Scotland's Ancient Woodlands #Allt Broighleachan

The wood of Allt Broighleachan - a remnant Caledonian Forest Reserve 
Tèarmann na Coile Cailleannaich – Allt Broighleachan 


Glen Orchy is well known for its roaring falls and kayaking challenges, and in spate the dramatic Eas Urchaidh boils through a narrow gorge, which in quieter conditions reveals great swirl-holes full of pebbles. The bedrock schist geology of Glen Orchy here peeps through, the cliffs smoothed along layered lines which are the tortuous echoes of our Caledonian Orogeny, when ancient sandstones were metamorphosed into a glittering rock, uplifted and finally eroded to the twinkling mica sand we see today in the river’s gravel banks. Whilst the river is the audible and visible focus of the glen, the quiet hills on each side are steep and cloaked in a noise-cancelling patchwork of Sitka spruce – trees which are often characterised (unfairly?) as a vegetal form of vermin, their pernicious seedlings sprouting everywhere by the roads and tracks, creeping up the hills amongst the moor-grass clumps. These close-packed and claustrophobic trees dominate the lower slopes of Glen Orchy and from the river the remnants of the older Caledonian forest cannot be seen, as they lie hidden in the bowls and gorges of the higher corries. Hogging the slopes of the glen, the Sitka finally gives way to the natural alder, birch and Scots pines of an older, higher ecosystem. 
A steep but short hike up the gorge of the Allt Broighleachan (‘the breasting burn’) leads to a pleasant clearing by the river with a picnic table provided by the Forestry Commission. A short walk through the last of the Sitka plantation leads to the fenced-off reserve, with the remnant pines in various states of youth, maturity and decline, spread generously over the slopes around the Allt Coire Thoraidh (originally this was spelled Allt Coire Ghoridh, meaning ‘the brief corrie’). At some points through the old pines you can sense how Scotland may once have been experienced in the typical ‘open-plan’ airiness of a Scots pine forest. 
Just before the exit gate at the top of the reserve, about 100m to the left of the track, stands a three-pronged sentinel pine, centuries old, keeping watching over her flock below, though gendering a Scots pine is anthropomorphic and pointless, as pines bear both male and female parts (the male pollen-bearing catkins are low on the tree, so they do not self-fertilise the higher female cones). A lone pine in these remnant forests is always a poignant spot to absorb the generational fragility of an old pine forest – lone pines sit like exiled elders, whereas younger trees huddle round mineral-rich ‘morainic mounds’, in which the wind-borne seeds love to germinate. It is invigorating to imagine an earlier, post-glacial landscape of moraine piles and gravelly scrub, with the forest spreading quickly over the mineral soils, perfect ground for seeds caught in ancient winds. 

The higher reaches of the Broighleachan reserve exhibit some of these colonised glacial humps which have caught the downwind spread from this mother pine. From its higher stance it seems to have generated stands of younger kin and some lonesome, rebel pines. How it got so high above the others is invisible history, likely a bird or mammal ingested a seed and excreted the resilient nut further uphill to begin the process of upwards colonisation. Then this pine cast its winged pollen to regenerate further trees, and so the Caledonian forest grew. The older ‘hill-climbing’ generations are often in senescence and the ‘younger’ remnant forests fill themselves in with density and kinship, perhaps one day to reclimb the hills, if only they could exist beyond the enclosure they require from the inquisitive lips of red deer.
 





No comments:

Post a Comment