Guide to Common Urban Lichens 1 (O Trees and Wood). This item is unavailable.Guide to Common Urban Lichens 1 (O Trees and Wood)

• Identification guide to 49 lichens found on trees and wood
• Also includes an easy-to-use visual key
• Designed to be used outside: lightweight, rucksack-sized, splash-proof

WildID Urban lichens 1 guide features 49 lichens found growing on trees and wood, including sawn wood (like fences, gates and park benches).

This is a good time to look at urban lichens, as levels of sulphur dioxide, air pollution and acid rain have been falling rapidly. Indeed many leafy lichens are growing in sites in central London where they have been present for 200 years.

Lichens are highly sensitive to subtle changes in environmental conditions. So they are useful as natural indicators of the health of our environment. In the past sulphur dioxide from coal burning and industry was the main pollutant. It was a major cause of acid rain. But today nitrogen compounds from intensive farming and motor vehicle exhausts are becoming the main pollutant. Although pollutants can kill many lichens, other lichens tolerate, or even depend on them.