When this book was first published in 1973 the idea that ecologically valuable sites could be found in the waste lands and dumps of our urban areas must have been rather novel. Today it seems remarkable that people could have missed the diversity and vigor that can spring from waste-lands.
However, such a change of perspective does not render this either an old fashioned or irrelevant book - far from it. In his sensible, lucid prose Mabey explores many sites in England's SE and finds wildlife to be abundant - often short lived, but still abundant.
He calls such areas the Unofficial Countryside, in clear contrast to the Official Countryside of national parks, nature reserves and ANOB's and such like.
Some of the things that he identified have been overtaken by time, - urban foxes, squirrels, Japanese Knotweed and such like, but the central message remains the same - given a chance, some form of natural ecosystem will form in most places over time.
This is still an important message. The official countryside, for all its protection (assuming it does not get sold off to the highest bidder!) is almost certain to lose species over time, that's what islands do. Other areas - the unofficial bits - are needed to connect these high value sites together. But beyond that the Unofficial Countryside has value of its own - but we may need to change our perspective to see it.
This is an excellent and insightful book which is worth reading in the light of modern habitat change, as well as being a historical insight into the development of the urban ecology movement.