Hi in a review of the Small Operation, Storming Ashi-Shima a question was asked about the presence of trees on the Atoll of Wake:
Wake, as it appeared to the Marines of the 1st Defense Battalion, was a V-shaped atoll composed of three islands: Wake Island proper,[7] the body of the V; and Wilkes and Peale, the two tip-ends. Its land-mass consisted of some 2,600 acres of sand and coral, a substantial part of which was, in 1941, covered by very dense low brush. An excellent vignette of Wake[8] in 1941 was given by Colonel Bayler:
"Wake is by no means the bare sandy spit one thinks of when atolls are mentioned. Considerable areas of it are covered by woods, and though the trees are small, their thick foliage and the scrubby tangled underbrush provided admirable cover. * * * Walking in these jungles was difficult but not impossible. * * *
http://www.pacificislandtravel.com/micronesia/about_destin/wake_history1.html