Saturday 31 March 2012

One month left...

Sorry for the hiatus.  I don’t have long left on Tristan. So I’ve been concentrating on completing the survey.  I’m due to leave on the 2nd of May on the MV Edinburgh to Cape Town - weather and sea conditions permitting.   You can never rely on departing and arriving on time, so I’ve re-arranged my return flight to allow for up to nine days over-run.  I just hope that is enough.  It has been known to  take two weeks longer than scheduled.  
Brilliant news - Simon is now flying to Cape Town and is due arrive at the same time as me - so if all goes to schedule we’ll have a week’s holiday in Cape Town before returning to the UK.  We plan to chill out in Cape Town and visit my cousins Sandy & Ali nearby.  BTW we are returning to an excellent B&B we stayed at on the way out called Black Heath Lodge.  If you are ever looking for accommodation in CT I can’t recommend it highly enough!  See www.blackheathlodge.co.za
I’m feeling a bit homesick today.  My sister, Catherine, and her family travelled over from the USA last weekend to help my brother, Peter, with the lambing on the family farm in Perthshire. They’ve been there all week – in glorious spring weather I hear.  Tonight there is a big family meal at Mum’s before they jet off tomorrow morning and I wish I could be there too!
I’ve had a busy morning in the kitchen – baking bread rolls & tea cake and making mince and Cape gooseberry jam. This afternoon I’ve been out visiting islanders.  And tonight I’m going to Steve’s 21st birthday party at the village hall.
I’m not long back from a camping trip to Stony Hill in the south of the island where I surveyed 15 coastal 1km squares.  After that we have 28 squares left to do – out of a total of 118. Some have been partially surveyed but need another visit.  Many are coastal and are relatively easy to pick off.  We are planning a trip round to Sandy Point at the eastern extremity of the island next week.  There are 12 squares to do there.  A few of the remaining squares are on the Base near the ponds.  But many are on the peak, where there isn’t much vegetation to survey, the ground is easy and you can do a lot in a day.  Good weather is vital for that – but becoming increasingly rare. 
 
To date we’ve made some 5000 individual plant species records across Tristan of approximately 132 non-native and 76 native species.  I say approximately because we are not entirely sure about the identity of several plant collections we’ve made and I’ll take those to experts at Kew or elsewher for examination.
Dmap 1km UTM square distribution of Yorkshire Fog, or Farm Grass on Tristan (to date).
The size of the dot is proportional to estimated abundance.

Recently I’ve installed Dmap and got it set up to display their distributions against a map of Tristan (thanks Alan).  It is fascinating to see the data mapped.  It’s amazing how widespread some of the non-natives are.  The most widespread is Holcus lanatus, Yorkshire Fog (known as Farm grass locally) which is found in 89 squares.  The most widespread natives are Empetrum rubrum (Island or Peak Berry), Blechnum penna –marina (a Fern) and the endemic Isolepis bicolor (Little Bog-grass).  All three are found in 91 squares from sea level to near the summit of the Peak.  So far the rarest native is Cardamine glacialis (known locally as Scurvy grass): just three widely separated populations with only a few plants in each.  It is fascinating to see how some plants prefer low ground, while others like high ground; some only occur on the Base and others prefer the coastal plains.  Dmap is giving us a new way to look at our data.  It is also proving invaluable in spotting errors and omissions.
Distribution of Island or Peak Berry on Tristan (so far).

2 comments:

  1. I am a latecomer to this blog but have been greatly inspired by your ventures. Thanks for sharing!

    ReplyDelete