mikem said:Abandoned mine sites tend to be great for wildlife in the medium term, but often mature into something less productive because there are no large mammals tending the environment (like bison etc would have done after the ice age).
That reminds me of another regular task I did with the conservation volunteers. The Devil's Dyke north of Cambridge is an SSSI and an SAC. It's chalk grassland, supporting, amongst other flora, pasqueflowers. It used to be grazed by sheep, but that became uneconomical, it's over 11km long but only about 40m wide. We used to go and mow the banks (tricky on such a steep slope) and rake the grass into the ditch, to keep hawthorn, etc from growing and turning into scrubland.