Wildflowers Vs. Sedum

So much of our native wildlife is in decline that almost every week we hear or read reports from ecologists and biologists alike that yet another native species is in decline.  2010 is the year of biodiversity which has caught the imagination of architects, garden designers and TV presenters across the nation.  From Chelsea to Gardeners World Live, Landscape Man to Grow your Own Drugs we have been doused with a veritable downpour of glorious solutions guaranteed to appease our consciences. Even in our towns and cities we are encouraged to cover those unsightly flat roofs with something living and green.
So should you decide to have a green roof which will you go for?  Wildflowers of Sedum?  Which green roof will be the most bio-diverse?  A tricky question you might say, given that both are accepted as being ecologically friendly.
This year, it was decided to put the theory to the test.  What was needed was an Entomology survey.  Entomology being the study of insects.
In June and July this year two surveys were carried out on two very different roofs, one wildflower and one sedum.  The results speak for themselves really.