Rutland Water is not just important for birds, as Wildlife Recorder Ivan Pedley explains…
Not even the most blinkered birder, whilst scanning the hedgerows for migrants, or the woodland backdrop when looking far out across the water for wildfowl, will have failed to have seen these remarkable sights. They come in to focus as trees and bushes ablaze with yellow and orange, and in the spring sunshine of late afternoon appear almost to be on fire. I am speaking, of course, of trees with their twigs and branches clothed in leafy lichens. Usually these trees are basic bark species, ash, willows and elder, and the lichens on closer examination are seen to consist of several species, not only the leafy ones of yellow and orange but also more delicate tufted forms of grey and white. About ten species are constantly associated with these trees and are collectively known as “The Xanthorion Community” after the dominant, most noticeable and attractive species, Xanthoria parietina.
A quarter of a century ago lichens would have been absent from the trees in the area—inhibited by a drizzle of sulphuric acid whenever it rained. Now, at least in terms of sulphur dioxide, air quality is superb throughout the Midlands and lichens are flooding back in to reclaim lands lost to industrial pollution 200 years ago.
Lichenologists, however, are a pessimistic lot and many are not completely overjoyed by the Xanthorion Community. Whilst these lichens are lovely to behold and can be spectacular they also indicate a darker truth—an environment awash with nitrogen compounds, mainly ammonia. This community is the “vegetable patch” of the lichen world; offer it more nitrogen and, like a plot of prize cabbage, it flourishes to the point where all other lichens may be excluded from the twigs and branches. For an optimist like me, however, the glass is half full. The Midlands has been a lichen desert for many years, so I rejoice to see them returning, I marvel at their beauty and I stand in awe of their resistance to everything the elements can throw at them (other than acid rain!). And I also giggle at the collective name for this community which is so dependent on nitrogen compounds-“ornithocoprophilous species”-which, if you know a little Greek, translates as “Lovers of bird poo”—always a useful phrase to trot out in a crowded hide when bird life is minimal and spirits are low!