Healthy lichen, healthy air.

Lichen has long been understood by scientists as an indicator-species for air pollution, and it is my understanding that the more frail-looking and leafy a lichen is, the more it is susceptible to air quality. 

So it brings great satisfaction (and not a little relief!) to discover that despite the flight path for Bristol airport and the A36 in relatively close proximity, our lichen are telling us they're happy with an explosion in the growth on the old cherry tree on the great terrace, amongst others.

So... if you need a gulp of fresh air, you know where to come!

p.s. Starter for 10:  can anyone name the lichen pictured?