Planting a native tree is almost as important as planting a tree in the first place.
It's no good just getting any old tree, plonking it down somewhere and thinking "that's one tree planted!" There's more to it than that.
For a start, if you are having to transport trees and seeds that have been sourced in Europe or elsewhere, just think of the unnecessary transport costs and pollution that would be generated.... kind of defeats the object somewhat of planting a tree in the first place! And planting a native tree means that the tree can easily adapt to the local conditions and is therefore more likely to thrive and survive. Then there's the business of keeping the landscape and woodlands that are unique to our country going, so that we can preserve our local natural heritage.
So... that's why Trees for Hosting only ever plant native trees.... it's important.