Open Space. When a subdivision meeting the density and parcel area requirements of Secs. 8-4.4, 8-8.2(c), 8-8.4, 8-8.6, 8-9.2(b) and 8-9.2(c), results in the designation of areas within the subdivision for open space use, the areas shall be designated on the final subdivision map and Zoning Map as open space, and, in that case, upon approval of the final subdivision map the areas shall automatically be transferred to the "Open District, Special Treatment-Open Space" for zoning purposes.