Great piece! 
I can see many battles will be fought over the control of this fuel depot.
What is planned next? 
Thanks all for the nice comments!
Well, I had done a nice game mat using faux leather with some spraypaint depth added, only to find out recently that one of the sprays must have prompted a chemical reaction, leaving the whole mat sticky to the touch. Essentially unusable, luckily "only" 20 Euros down the drain, but a shame for the nice texture already on the sheet. I'll probably resort to doing some flat PVC plates with sand and paint added to experiment with new texturing methods.
The trees turned out quite nicely, though! Unfortunately at the moment, if it isn't raining around here, it's wuthering like a flatulent Brontesaurus, and I would prefer to photograph them outside as they cover quite a bit of tablespace by now and I would like to capture the effect straight away.
Further plans focus on a bit of aerodrome terrain. I've pretty much finished off a copy of the Airfix Control Tower and will do up the baseplate that came with the Italeri airbase set (from which the watchtower and barrels originate) as a helicopter pad, plus maybe a concrete or steel matting runway. Possibly concrete, as the work required for steel matting will be awful, but it does look quite nice in my imagination - maybe a reason to break out the tracing wheel!