Land Manager's Diary: Read it here>

BOOK onto one our upcoming workparties>

We had an action packed and exciting day on Wednesday out with our volunteers at Greenbank Wood at Ambleside. Initially this wood looks just like a small piece of scratty woodland. But look a bit deeper and it has a character and value all of its own. Sitting within the edges of built up Ambleside, it plays a key role in the setting of Ambleside, links habitats going up the valleys towards Rydal and plays its part sequestering carbon and helping combat pollution in the town.

Our tasks for the day were to remove the invasive beech seedlings and to thin the holly so that the wood can remain an oak,ash and holly woodland. But we kept getting side tracked… A contractor popped in to discuss laying the old hedge alongside the road; Garnett from Westmorland Red Squirrel group popped in to discuss controlling the grey squirrels and let us have a go with his thermal imaging camera.

The Lichens of Sweden and Greenbank Wood

We also had a visit from Pete Martin, the fount of all knowledge of all things relating to lichens. Pete has generously been working his way around our woodlands carrying out lichen surveys for us. We're delighted to welcome Pete as our guest blogger this week as he tells us about the hidden and fascinating world of lichens and his discoveries in Sweden and Greenbank woodlands...

'Lichens, a symbiosis between a fungus and an alga or a cyanobacteria (or both), can be beautiful and informative, telling stories about woodland history and pollution among other things. In the last few weeks I’ve looked at the lichens in the Friends’ Greenbank and Sweden Woods. They are less than 600 metres apart. They’ve both got some old trees, a lot of young trees, and some intriguing history to unpick. But from a lichen perspective they are really rather different.

'Greenbank, where I found 29 species, is near the centre of Ambleside, so if there’s been any pollution this wood will have received it. There are some lovely old Beeches and a lot of Holly growth, both of which make the place quite dark. But most lichens quite like the light, as the alga or cyanobacteria in them has to photosynthesise. So that partly accounts for there being few things on the tree trunks.

Pictured: Greenbank Wood- the big old Beeches have relatively few lichens on them © Pete Martin

The trees themselves are an issue too. Different lichens like different kinds of bark, whether that’s the texture or the wetness or the chemistry, and Beech trees in Cumbria don’t normally have a lot  of lichens. The Beeches in Greenbank are lovely, but not from a lichen point of view.

'On the other hand, it wasn’t without interest: there were a couple of species that haven’t been recorded much in Cumbria before (there aren’t many of us who look at the silvery sheens on hazel bark); and some things that like dark places. There was also Pyrenula chlorospila, a waxy crust that I found on several young Ash trees. There’s plenty of it in North Wales and Galloway. But for some reason it’s only been found in Cumbria about ten times. And it was here!

Pictured: The waxy lichen Pyrenula chlorospila colonising the smooth bark of young Ash trees in Greenbank Wood © Pete Martin

'Sweden Wood (67 species) was a different story. The younger trees weren’t all crowded together, so the branches, particularly of the Oaks and Birches had leafy species like Parmelia sulcata and Parmotrema perlatum, and treebeards like Evernia prunastri and Usnea subfloridana.

Pictured: A lichen rich old Ash pollard at Sweden Wood © Pete Martin

The rocks and walls were covered in lichens too: Rhizocarpon geographicum, the Map Lichen;  white splats and crusts like “Crab’s Eye” Ochrolechia parella;  Cladonia species growing on the mossy parts. There was a bit of nitrogen pollution, which allows Xanthoria parietina and Physcia species to develop. You wouldn’t want too much of that, but if there’s a little bit it adds to the variety. There were also some older Oaks that had species like Ochrolechia androgyna and Flavoparmelia caperata, the things that grow on older acid-barked Oaks. And there were some older Ashes too. They can have a different (less acid) bark chemistry so I found things like Peltigera horizontalis and Acrocordia gemmata. There was a little bit of Pyrenula chlorospila as well.

Pictured: Peltigera horizontalis © Pete Martin

Pictured: Collema flaccidum; a jelly lichen on the base of an old Ash pollard © Pete Martin

'None of this is particularly rare, but these older trees had a lichen flora that you could imagine remaining from the days when this was just a field, and the trees were field trees; stretching back to Victorian times and beyond. It’s the continuity of habitat that’s important for some lichens, they can’t move very fast after all.  If you have a variety of different places and habitats for them to live in, then you’ll get more types of lichen. And light! Though even in a well lit wood you can often find the “dark lovers” hanging round the back of a Holly tree.'

Pete Martin