Natural resources plan. This plan shall show existing and proposed wooded areas, buffer areas including the intended screening devices and buffers, grading at two (2') foot contour intervals inside the tract and within fifty (50') feet of its boundaries, seeded and/or sodded areas, ground cover, retaining walls, fencing, signs, recreation areas, shrubbery, trees, and other landscaping features. These plans shall show the location and type of man-made improvements and the location, species, and caliper of plant material and trees to be located on the tract. All portions of the property not utilized by buildings or paved surfaces shall be landscaped utilizing combinations such as landscaped fencing, shrubbery, lawn area, ground cover, rock formations, contours, existing foliage, and the planting of coniferous and/or deciduous trees native to the area in order to maintain or re-establish the tone of the vegetation in the area and lessen the visual impact of the structures and paved areas. The established grades and landscaping on any site shall be planned for aesthetic, drainage, and erosion control purposes. The grading plan, drainage facilities, and landscaping shall be designed to prevent erosion and siltation as well as assuring that the capacity of any natural or man-made drainage system is sufficient to handle the water from the site and contributing upstream areas.