TEPaul,
GCGC was not a tree less site in the late 1800's early 1900's. but I doubt it was as densely populated with trees as Clementon, N.J.., If you look through the book, you will see plenty of mature, specimen trees in the early photos.
The 1897 diagram shows substantial tree and shrub areas
I don't think seperation was the intent at GCGC, I just think it happened slowly until it reached the point where the trees became invasive to play.
With respect to LuLu and other early courses, I would think, with 20 players on the course, safety was a minor issue, but with 150 players on the course, concerns were heightened, and in some instances, trees were introduced as the solution.
As time distanced the game from its Scottish roots, openness became less popular or less remembered, and the desire for isolation, seperation, from the other golfers on the course more desireable, and the method employed to achieve that was the planting of trees.
Today, a new fad is responsible for the addition of more trees to golf courses. Beautification committees are planting flowers, shrubs and trees at an alarming pace, with few people visualizing the impact on maintainance budgets, and playability in the future.
How sad, that we look back in admiration at these old photos of courses like LuLu and many others. What has taken 70-80 years to do, may never be undone, although there are, almost immediate remedies.