Lichens, an indicator of clean air, on the top of a drystone wall, alongside a beech wood, at Mill Gill, Askrigg, Wensleydale

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Lichens are generally associated with clean air

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Size: 7360px × 4912px
Location: Askrigg, North Yorkshire, United Kingdom
Photo credit: © Neil Wilmore / Alamy / Afripics
License: Royalty Free
Model Released: No

Keywords: agriculture, air, aperture, askrigg, beech, boundary, clean, dales, differential, drystone, farming, focus, footpath, gill, hill, indicator, large, lichen, lichens, limestone, march, mill, pasture, pennines, pollution, stone, trees, wall, wensleydale, yorkshire