Wednesday 21 February 2018

A focus on the future... flora and fauna

My 12 months of Letterboxing challenges is over.  I've challenged myself, and I feel more motivated than ever.  I've thought a great deal, and considered the hobby and it's place in my life a lot.  I've seen places, people, and 'boxes in a new and refreshing light.  I can focus firmly on the future.  I'm planning new series and new blog posts.

But what of this future?  What is Dartmoor going to look like?  What do the experts and the authorities say?  First up:

A changing climate

In the latest minutes of the Dartmoor Steering Group (from last November's meeting) the question was raised on how a changing climate was affecting vegetation on the Moor.  Vegetation which can both help and hinder Letterboxers and Letterboxing in equal measure.  Just witness how Wistman's Wood has doubled in size in the last 100 years.  See how the flora and fauna of Tavy Cleave has become impenetrable in places.  How gorse is flourishing in more favourable conditions.  

A Climate Strategy document produced by Devon County Council in 2005 shows trends for temperature and rainfall for years between 1920 and 2000.  A mean average temperature rise of 0.8 degrees since 1900 and a significant rise in precipitation since the 1970s are shown.  Does this information appear a little out of date?  Whilst no further charts have been produced by the council, the upward trends have continued, with local, national and international records being broken on an almost annual basis, according to the NOAA.

According to Met Office projections: by 2050, even when using the most optimistic greenhouse gas emission estimates, Western Dartmoor will experience around a further 20% increase in Winter precipitation, though Summer precipitation will decrease by a similarly large amount.  Summer and Winter mean temperatures will increase by between 1.8 and 2.5 degrees respectively.  In summary, this will result more droughts, more flooding, and inevitable changes to levels of vegetation.  Ferns and grasses will see considerable growth under these circumstances.

Bracken is one plant which will spread extensively in a changing climate.  The DNPA has tried (and generally failed) to use aerial photography since the turn of the 21st century to witness how climatic change (reduced late frosts and extended growing seasons) has aided Bracken's spread.  Bracken does have it's benefits: it is great as a wildlife habitat.  Ring ouzel, High brown fritillary butterflies and 11 unique invertebrates are among some of the key species that rely on bracken on Dartmoor.  However, on the down-side, it is a carcinogenic plant, it can be poisonous to livestock, is associated with tick numbers and Lyme disease.  It reduces grazing land, reduces access to the Moor in Summer and Autumn, damages archaeological sites, and crowds out other vegetation, such as heather.

The Park authority have admitted that the distribution of bracken on Dartmoor is little studied.  The last study was in 1994.  A briefing document in 2009 coincided with the 2008 release of Natural England technical documents.  None of these provided data on the extent of bracken's spread, the condition of which remains unsubstantiated. 

As a general principle, Natural England affirm that it is unlikely that bracken could ever be eradicated from a site.  Chemical treatment often poisons watercourses, and never lasts longer than 10 years.  Mechanical treatment is difficult in rocky, uneven terrain.  Cutting or rolling bracken reduces it's density but doesn't tackle it's vigour.  Ploughing is often impossible, leaving just trampling as the only remaining control tactic.

Bring on the Letterboxers!

I mentioned that the subject was raised in the latest Steering Group minutes.  The Steering Group - you'll remember - is a working party of stakeholders who annually review the impact of the military on the Moor.  The Duchy of Cornwall's Bailiff (of 12 years) David Marino was asked what steps were being taken to monitor changes in Dartmoor vegetation.  In reply, he indicated that he "had been looking into the matter and had come to the conclusion that although some areas had changed [he] did not consider it too serious to require monitoring".  Lt Col Crispin d'Apice, new Ten Tor's chief, and Training Safety Officer for the MOD in the South West, "suggested that the Dartmoor training estate had not identified any impacts from the changing climate".  Apart from - one presumes - the rapid pace of erosion repair, improving conditions for Ten Tor's weekend, and the MOD-funded breeding bird surveys which he mentioned earlier in the Steering Group meeting.  A case right there that an opinion or conclusion formed on the basis of incomplete information is merely a statement lacking rigorous proving.

What will rigorous proof require?  There's a contentious subject.  Next up in my future of Dartmoor focus: Money.

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