Category Archives: Woodlands

Upright Spurge in the Wye Valley

Yesterday I paid a visit to Ravensnest Wood in the Wye Valley, to see one of the rarest plants found in this area, Upright Spurge (Euphorbia serratula). As a native species, Upright Spurge is found in Britain only in an area centred on the Wye Valley and the Forest of Dean. It is also naturalised in scattered locations, mainly in southern England. Although a rare plant in Britain, globally, it is found eastwards to central Asia.

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Upright Spurge’s habitat is woodland on limestone, but not the dense dark parts: instead, it is found in the open, and does best on disturbed ground. Newly created forestry tracks and clearings are where it does best, particularly if limestone chippings are laid. Ravensnest wood held 500 plants in 1997, presumably when the access track there was very new. Yesterday I counted a much more modest 17 plants: along much of the track, grassland had become established, crowding the spurge out, and it was only present in areas where there was still very sparse vegetation. Here is a map of the location:

According to Sell and Murrell’s Flora of Great Britain and Ireland, the most authoritative reference work on Britain’s flowering plants, Upright Spurge occurs in only about 24 British localities. The densest concentration is around Tintern and so, predictably, it has acquired the local name “Tintern Spurge”. Other locations in the Wye Valley are spread throughout a 10km-long stretch from about Wynd Cliff in the south to around Whitebrook in the north. In the Forest of Dean, its main concentration is just to the west and north of Lydney. Much further east, it grows in Highnam Woods, just west of Gloucester. West of the Wye Valley, it occurs in Chepstow Park Wood and in Coed Wen Wood, east of Newport (note that the Grid Reference in Trevor Evans’ Flora of Monmouthshire for this last site is incorrect).

Seeds of Upright Spurge can lay dormant in the soil for years, possibly decades, and so if a site becomes overgrown, fresh disturbance can boost the population. At Highnam Woods, the RPSB does just that, using a rotavator, and so the population there is likely to be secure. At other sites, Upright Spurge has declined or even vanished, but could no doubt be encouraged to flower again if similar techniques were applied. How about it, Gwent and Gloucestershire Wildlife Trusts?

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Ancient Woodland Indicators

One of the good things about Bristol is that you’re never very far away from a wildlife-rich place within the city itself. Over time, I aim to introduce you to as many of these as possible on this blog.

This time of year is when our local woodland sites are at their best: I’ve been to several of them recently, including, this week, St Annes Wood, which is just to the south of the River Avon, between Brislington and St Annes, in the valley of the Brislington Brook, here:

This is a site with quite a number of Ancient Woodland indicator plant species. Here are some photos of one of them, Ramsons (Allium ursinum), also known as Wild Garlic, a very apt name given the smell it gives off. In some places in our local woodlands, Ramsons forms large single-species stands, as in the left hand photo.

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In the 1980s, the Nature Conservancy Council (one of the predecessor bodies of Natural England) produced lists of Ancient Woodland indicators (AWIs) for several English regions. There has also more recently been an attempt to draw up a specific list for Somerset. These lists were limited to the well-studied vascular plants, not including ‘lower’ plants such as mosses. The lists are intended as a simple heuristic method for measuring the ecological continuity of a woodland: they consist of species which thrive well in woodland which has been undisturbed for a long time, and are slow to colonise more disturbed ‘secondary’ woodlands. So, the more AWI list species you have at a woodland site, the greater the likelihood that this woodland has a long continuous history as woodland, and therefore the greater the likelihood that other species of plant, animal and fungi dependent on continuously managed woodland are present too.

See the Articles page for details of articles about the Nature Conservancy Council and Somerset AWI lists.