Just did some searching for "Pitch Pine"...
Not growing overhere at all. but it seems to have the same "qualities"as the Pinus sylvestris overhere.
One ove the features of this pitch pine compare to the P . sylv. is the "open" structure ot the crown of the tree. You can see, it is obviously to see that the tree is growing under dry conditions.
To immitate/to modell this tree I think an approach wit long and smaller fibres added with a electrost. appl. could be usefull!
The trick will be what kind of fibres, : longer12 or 6 mm , shorter ones 2mm, which one first....the longer ones? and how to add, at the end, the "glue"on the ends of the longer fibres to add the smaller "needles"( 1mm or even 0,5 mm from Mini Natur/Silhouette) like small mini "tuffts of gras"
It should be something that makes small drops/pearls of glue in which some 1 mm fibres will stick together....
Easy to write, I know,....but you could give it a try...may be after 12-15 trees ?
Actualy that number is peanuts comparing the trees in a real forrest and made within a very short period of time: per tree about 2 hours.....in real: 20-30 years!
the attached tree is about 5-6 cm= 2 1/2 inch . It has to look like a pine tree that is growing in/on a rock....somewhere in Switserland....