The flight instructor reported that during the student pilot's first night flight, the lesson was to familiarize the student with flying at night, and included takeoffs and landings. The flight instructor reported that during landing, the student pilot held the approach path "for a while" then drifted below the approach path, as indicated by the visual approach slope indicator. The flight instructor told the student that he needed to climb and reestablish the airplane on the approach path. The flight instructor reported that subsequently he (the instructor) "became confused" and could not determine the airplane's position relative to the runway. The flight instructor reported that he "snapped out of the condition", but the airplane collided with trees and impacted the ground short of the runway before a recovery could be made. The airplane sustained substantial damage to the left wing. The pilot reported no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.