It seems fairly obvious that Shakespeare intends audiences to view the pastoral, bucolic quality of the forest as an idealized setting. Here is where all the lovers finally come together. As Orlando says when approached by Rosalind/Ganymede, "there is no clock in the forest" and this statement indicates a timelessness that allows romance to proliferate. One interesting plot element is Phebe's infatuation with Ganymede: she seems to reject the shepherd Silvius in favor of the more refined Ganymede, being unaware that Ganymede is Rosalind in disguise. This suggests that the forest may be seen symbolically as the realm of the "male" which manifests in physicality, brash talk and bumbling courtship; while the court (Rosalind/Ganymede) is the "feminine" expression, being concerned with appearances, verbalization and a calculating, worldly view of love (Ganymede lectures Phebe on her sharp-tongued rebuke of Silvius, thereby making the gullible shepherdess reject her suitor and fall in love with her).
This book is a satire of the romance genre, and the author already knows that his audience would like humor at the cost of watching agrarian pretensins and country bumpkins.