Abundant on sand dunes
No interactions present.
I agree with R.pimpinellifolia for the white flowered one - especially as it is noted for growing in dunes. I think the pink one is R.rugosa.
I agree with Vinny, both of these are common species here on Portland as well. R. pimpinellifolia is, I believe, a native species whereas R.rugosa is definitely introduced and commonly planted by developers and councils etc.
Lat/Lng: 54.8, -3.4
OS grid ref: NY1353