For the scenic aspects of my wargaming I use - pretty much exclusively - very old Merit trees. These were made by J & L Randall Ltd, whose range of HO/OO railway accessories is legendary, and I have a lot of them, in the three known varieties, some dating back to the late 1950s, I would guess. Some of my oldest fir trees of this type were among the very earliest trackside scenic add-ons for my first model railway (if anyone cares, my first loco was the Hornby Dublo LMS "Duchess of Atholl", which was prehistoric even when I first got it).
The definitive posting on Merit is in Clive's wonderful Hinton Hunter blog, here. I love these trees. I'm not completely sure why - they don't look especially realistic, to be sure, but they are part of that old black-and-white tradition in Terry Wise's early books and elsewhere, they are clean and practical, and I have come to take them for granted as part of my own arrangements. I have also owned much more expensive and exotic trees from all sorts of specialist makers, and they have come and gone - literally - like the withering leaves. Storage is never satisfactory with the de-luxe jobs, and I have a lifelong hatred of foliage flock detritus - no doubt a symptom of a heavily anal upbringing, but also of the permanent need to have wargaming co-exist pleasantly and harmoniously with the other activities of formal dining-rooms etc. So all the fancy stuff has passed on, yet I still have the Merit trees, augmented now and then by finds on eBay and elsewhere. The prices have become a bit silly - especially for someone like me who doesn't even keep the original boxes.
Shock horror. My world is now threatened by the gradual deterioration of my trees. The plastic, over all this time, has started to change. The rot is uneven, but some of them now have the structural properties of spun sugar, and are extremely delicate. I try to glue damage as it occurs, but I can see that my HO/OO plastic ecosphere is showing signs of sliding into history. This is not a trivial matter - I really don't know what I shall do if I have to replace them. No-one has ever made a direct equivalent and - very sadly indeed - the re-issue of almost the entire Merit range by Modelscene has specifically excluded the trees. I gather that the moulds were beyond redemption, and it has been suggested to me that they are unlikely to reappear, since modern flocked trees are so good now, and only a crazed nostalgist would want the Merit items.
I can almost feel the tears welling up as I write this. I shall continue to look after the trees I have left, but this is beginning to feel like a real ecological issue - does no-one care if, along with the red squirrel, my silly old trees disappear? I have to stop now - can't go on...