Sunday, 26 February 2012

Deep Gulch

Looking up Deep Gulch towards the summit

Deep Gulch is one of the most remote and revered of gulches on Tristan.  There is no easy way to get to there and few people visit.  You can’t get from the bottom up (from sea level) so you have to approach it from above.  We’ve just returned from an expedition to the area involving the ascent of the 2,000m Peak followed by a 1,150m descent to our campsite.  A challenge – especially carrying food for 6 days, plus camping and survey equipment.  (Though we didn’t have to carry the tents and sleeping bags all the way; we’d previously left them at 1,900m.)

That's a blanket of moss on the ground (not snow!)
We set off early on a beautiful morning. A couple of hours later the clouds gathered and we were in mist and murk.  But near the summit we emerged into gloriously warm sunshine with deep blue skies, above the clouds.  Quite stunning. The only problem was that we then had to descend back into cloud, navigate to the right ridge and find a sheltered camp site. But not before encountering some lovely high-altitude springs.  They are like oases with water and vegetation amongst a desert of volcanic cinders.  Here moss dominates. There are patches of Empetrum rubrum (Island or Peak Berry) with few other higher plants.  Those that do occur such as Blechnum penna-marina, Lagenophora nudicaulis, Nertera depressa  and Agrostis magellanica are quite sparse. Interestingly all of them seemed to be flowering or fruiting.

Sunrise over the South Atlantic
Gamochaeta thouarsii,
Cow Pudding Grass
With five days of successful surveying complete we begin our return walk to the settlement.  Around the base this time, but keeping high to make gulch crossings easier. The route takes us through some amazing landscapes of volcanic rock eroded in bizarre shapes.  It is a long and tiring walk, especially with a detour to drop of tents and sleeping bags near our next major survey area – Big Gulch.  We survey as we walk, and that slows progress a little but makes it more interesting. The highlight on the return journey was another population of the little endemic rush, Rostkovia tristanensis – at a new altitudinal record of 1380m.

Late Christmas presents
We’ve had a week at base since then, waiting for the weather to settle before the next big adventure.  It’s been an exciting week as the MV Edinburgh arrived with some new people, fresh fruit and vegetables and lots of mail for me - well not just me!  Including two more Christmas presents from back home.  One of them via Vancouver and possibly New Zealand. Both full of lovely bits and pieces like chocolates, puzzle books, oatcakes, shortbread, fudge, a mini-calendar and a newspaper from November last year!   Many, many thanks to Dot and Den and Rob and Janet.  The last two editions of BSBI News and the New Journal of Botany also arrived this week – keeping me in reading material.  (Thank you Gwynn.)  Talking about mail, I gather the postcards I sent last October arrived this week!

The days are getting shorter and it is starting to feel like early autumn here now.  The fields have a good scattering of mushrooms. The Cape Gooseberry bushes are laden and the Peak berries are starting to blacken.  I’ve been collecting and busy in the kitchen making Peak Berry crumble, Cape Gooseberry jam and mushroom soup.

Tuesday, 7 February 2012

Camping on Tristan

Day 1:

We're camping on the base at 750m in a grassy gulch. It's 7.30pm and the sun has disappeared behind a thin sliver of silvery-edged cloud low on the horizon. Immediately below there is a gaping chasm, and the broad expanse of The Base covered with Phylica arborea (Island Tree) and Blechnum palmiforme (Bog Fern). In the distance and far below I can just make out and hear waves on the sea.  Behind me and above our sodden tents, the peak, tinged red by the setting sun.

We’ve had a 4 hour walk with heavy rucksacks in driving mist and drizzle. We arrived just before midday soaking wet and pitched the tents - and stayed there until the wind and rain eased off - four hours later. Unlike Scotland you can't survey in bad weather because of the complex landscape and vegetation. Maps are not detailed or accurate enough to navigate with safely. You must be able to see.

It's now a fantastic sunset. The clouds have turned red. The flow in the waterfall above our tents drops noticeably. There is not much flat sheltered ground for pitching tents. So we had to use this gulch. It was dry when we arrived but water soon began to flow and puddle perilously close to our tents. We cut drainage channels. The vegetation in the floor of the gulch is entirely non-native. Quite depressing really. It comprises of Holcus lanatus (Yorkshire Fog) and Agrostis capillaris (Common Bent), so I don’t feel bad about it. Lourens compliments me on my moat - which seems to work.  We used Island Tree branches as extra strong (and long) tent pegs.  So we're now secure for the night.  Silent but for the sound of trickling water and distant sea.

Day 2:

We had planned a first-light start. But it has been drizzling and misty since 5am. Now it's 10am and we're still in the tents. This hasn't happened often but it is very frustrating when it does. All the effort getting here wasted. A blink of sunshine. Maybe it's clearing... An hour later blue sky appears and we breakfast and set off and have a really good day despite the late start.  We happen across the right ridges and gulches for once and cover a lot of interesting ground without huge effort.  Our route to the edge of the base is enlivened with rare encounters with Radiovittaria ruiziana (Bootlace Fern). From there we walk along the exposed edge, where the vegetation is wind blasted and easier, into the next square.

We return at 7.30 – with just enough time to prepare dinner before dark.  Spaghetti and mince (again).  With enough saved for tomorrow’s lunch.  Pudding is a thick slice of home-made tea-cake.  The sun sets on a crystal clear Peak tonight.

The Peak in evening sunshine
Day 3:

The day does begin with blue sky, but I can’t see the peak or the sea and the mist quickly closes in.  We breakfast, break camp and return along the boggy path towards Burntwood.  It’s at the end of the only road on the island and where we parked the quad bike.  We don’t have to make a final decision on whether to survey for a couple kilometers.

It seems to clear and we decide to survey.  Over much of plateau the vegetation comprises of no more than 25 taxa. I hope we chance upon an interesting gulch.  But here the gulches are narrow, weedy and scrubby.  Progress is slow and the botanising disappointing. 

We reach the edge of The Base eventually and see waves crashing onto Anchorstock Point far below. There is an even scattering on non-natives amongst the vegetation on the escarpment.  Most noticeably Leucanthemum vulgare (Ox-eye Daisy) and Holcus lanatus (Yorkshire Fog) but less obviously Aira caryophyllea (Silver Hair-grass), Vulpia bromoides (Squirrelltail Fescue) and Cerastium fontanum (Common Mouse-ear).  On a landslip, there is a large population of the native Apium australe (Wild Celery) in flower.

The weather closes in again and our return is windy and wet.  We stop and monitor Deschampsia flexuosa (Wavy Hair-grass) by the path.  As far is known this is the one and only population on the island.  How it got here is a puzzle. 

Just before the final descent, I collect Empetrum rubrum berries for Peak Berry Crumble.  The berries are just beginning to blacken and sweeten. (I’ll let you know how it tastes).  The highlight of the Burntwood descent is a 700 foot scree run. For once easy ground!

(Written in the field)