FSX SEASONABLE

Dear friends.I'm talking about the seasonality of FSX's ADDED scenarios.That is the question:Trees by default become full of snow in winter.The same trees that I add with ADE remain without snow.From AVSIM I downloaded textures from a file created by a Frenchman, a certain Leclerq, which I then overlaid on the default textures (in FSX>texture>world>texture).It did not work.What I don't really understand is the mechanism of this seasonality and here maybe if you can help me... maybe thinking about an example:- With ADE I create a very simple airport made up of a grass runway and a single tree.- I draw the track with the ADE tools, while I insert the tree from the ADE "object library". For this example I will call it “Tree”.- Here the library makes me choose between 2 types: "Tree" without suffixes and "Tree wi" where the suffix stands for "winter". I choose the first, convinced that it is the ...seasonable one.Could you tell me why in winter the green track turns white (like the whole scenery) while the tree remains green?The tree I chose is exactly the one present in the default scenarios....Where does FSX go to get the instruction to make the snow white slope? THANK YOU, if you can...Gulliver.