14 Feb 2014

Tree Lichens

Colin Miles

When Bruce first suggested that survey for Tree Lichens, the first questions I asked were, what do they do and what function do they perform in the eco-system?  We didn’t really know, so we did what we always do, we Googled.  And this is what we found.

‘Lichens account for approximately 8 percent of the vegetation covering Earth’s surface. In certain environments, such as regions of tundra, they cover vast areas of land. Lichens delay global warming by consuming significant amounts of carbon dioxide (CO2) during photosynthesis. When they cover the ground, they prevent soil from drying out. In desert areas they are able to capture and conserve the moisture present in fog and dew. Lichens release nutrients, such as nitrogen and phosphorus, which are important in regions with nutrient-poor soils as the nutrients aid tree growth. Lichens are also an important food source for many species of animals, including wild turkeys and reindeer of the Arctic tundra. Birds such as the olive-headed weaver of Madagascar and the goldfinch of Europe use lichens to build their nests.’

Ok – but what are Lichens?  Another Google came up with this which I have precised.

‘Lichens are made up of two or three different organisms from different Kingdoms. These form a symbiotic relationship with each other for their mutual survival. The dominant member, which is the bit you see, is a fungus capable of making it’s own food inside of which, and protected by it are cells of an algae and/or cyanobacteria. The algae provide nutrients via photosynthesis in the same way as green plants do.’

So on yet another glorious sunny Tuesday morning we set out to discover just how much we didn’t know about Lichens.  Indeed the first question was, how do you pronounce it?  But I will leave that one for the reader to decide!

First stop was at the trees by the fountains in Millenium Square where all 9 of us gathered round the trunks of one tree peering at the Lichens there.  Obviously a very peculiar sight to the curious young Robin perched just above us.  Then there was the Beech tree covered in a white Lichen, not to mention all the various ones that we found on the Birch Trees and on the walls all around.  And the more we looked the more we realised how many there were.

Up in the Spring Woods and a chance to examine the trees there – and to admire the Snowdrops which were now in full bloom and to listen to the birds.  Lauren, a welcome new addition to our group, spotted a jelly-like Lichen.  But was it really a Lichen or a Fungus?  We didn’t really know.  And Spring Woods is changing as there has been a lot of clearance and planting with Rhodendrons, Camellias and one particular plant which bore the label,’unknown’.  Should be interesting to see in a few years time.
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On past Bee corner – no sign of bees despite the sunshine – and the fallen Boar is looking decidedly forlorn and the worse for wear, but the Derwydd Daffodils are showing signs of flowering soon.  Should be plenty for St. David’s day, unlike last year.

As for Tree Lichens, we were finding them everywhere and not just singly but sometimes in groups intermingling with each other.  And, as you can see from John’s photos, some of them are really rather beautiful.
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Finally on to the Ghost Forest to see what Lichens they harboured.  Not that many really, and indications that perhaps the hardwoods had less than then softwoods.  But time will tell.

Thanks  to John for the photos and if any volunteer or member is interested in joining us please  send an email to Colin Miles  – you DON’T have to be an expert in anything, just interested.   If you click on any of the images in these blogs, or anywhere else you will see a larger picture. And if you click on the Wildlife Walks heading on the left-hand side under News you will see a list of the last 10 Wildlife Survey blogs

If you find an injured bird, hedgehog or other wild animal and want help and advice then phone the Gower Bird hospital. on 01792 371630.