Coming to this 13 years late (prompted by daily email).
I live in the UK and moved house recently to a 1960's build which had a predominantly evergreed garden dominated by a massive multi-stemmed Blue Cedar tree. It was clearly planted in the 70's when there was a big fashion here for evergreens, but then left to consume the garden.
I was in two minds to remove it or not - the environmentalist in me said no, the gardener said yes. The gardener won and the environmentalist found out he was wrong. It's been only down a year (we saved all the wood on site, chipped and logged and some planked for future use (not sure what yet!), but the change in the garden has been immense. The light has of course transformed the growth of other plants, but what's struck me most is the wildlife that has thrived out of the intense pine shade.
When we were having it cut a neighbour came round in tears telling us off for cutting such a large tree down - it affected me at the time, but I now realise how the loss of one tree can promote so much more. I've also learnt that cedars have a different symbiotic relationship with fungi and as such, combined with the dark and dryness, has killed or limited the growth of other native species which are now able to grow again.