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.

 Ramsons for blog 2 Ramsons for blog

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.


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