Countrystride #106: The LICHENS of Borrowdale

...in which we take a deep dive into the miniature world of lichens with Cumbria Lichens & Bryophytes expert Pete Martin. Embarking from the car park at Seatoller – and not wandering much further - we ask what a lichen is (a question not easily answered) and why lichens matter. Wandering up-dale towards Seathwaite, we stop at trees and walls to encounter five of the county's most recognisable lichens and observe a remarkable world of elf ears, maps, jam tarts and wine gums. Deep in the Borrowdale rainforest we consider the expansive 'second skin' lichen and bryophyte ecosystems that form on older pollarded trees, and the key role lichens play in fixing both carbon and nitrogen. Taking a long view of land use in the valley, our journey ends at the famous Borrowdale Yews, where we learn why Wordsworth's 'Fraternal Four' were never four at all, and why, in ecology, things are often more complex than they first seem.

• You can find Pete on Twitter twitter.com/onLoughrigg

• The Cumbria Lichen & Bryophyte Group can be found at bumbrialichensbryophytes.org.uk

Bessyboot

Base Brown as we enter Seathwaite.

Xanthoria parietina- “Sunburst lichen”- thrives where there’s lots of nitrogen pollution (so doing well at the moment).

Rhizocarpon geographicum- “Map lichen”- forms mosaics on acid rocks.

Normandina pulchella- “Elf ears”- expanding its range with the decline in sulphur dioxide pollution as less coal is burnt.

Peltigera praetextata- a “Dog lichen”- big leafy lobes, can grow quite quickly (for a lichen).

Lobaria pulmonaria- “Tree lungwort”- a translocated example, fixed to its new home with mesh.

Lobaria pulmonaria- “Tree lungwort”- the charismatic “rainforest” species- this is what it is hoped the translocations will grow to look like, standing out from the tree like brackets

Lichen drawing out the iron in the rock.

Our guest for the day: Pete Martin.

Following the infant Derwent.

One of the remaining 'Fraternal Two'.