Thanks everybody. It's a labour of love, that's for sure!
(Figure painting takes a back seat whilst terrain building!)
what is the flock you used for the grass effect?
First a layer of Woodland Scenics turf - I mixed fine grade and medium grade - in burnt grass colour. This is sprayed with scenic cement (watered down PVA glue) to seal it, and then a second layer is sprinked on top of that in patches. This time, for the second layer, add some medium green static grass and a little lighter coloured flock. Then pray again with sealer. This gives the effect of of lush patches of grass here and there amongst the grassy areas.
The low level vegetation / scrub, is formed from Woodland Scenics 'clump foliage' or 'bushes' (it's all the same stuff, just dyed fragments of broken up foam) in olive green and light green, some little bits and pieces of lichen, and grass tufts in various colours. These items are all just attached with a touch of superglue.
Here are a couple more pics which show some close up detail of the surface textures...

