A forest reservation shall contain not less than two hundred growing forest trees on each acre. If the area selected is a forest containing the required number of growing forest trees, it shall be accepted as a forest reservation under this chapter provided application is made or on file on or before February 1 of the exemption year. If any buildings are standing on an area selected as a forest reservation under this section or a fruit-tree reservation under section 427C.7 , one acre of that area shall be excluded from the tax exemption. However, the exclusion of that acre shall not affect the area’s meeting the acreage requirement of section 427C.2 . [S13, §1400-d; C24, 27, 31, 35, 39, § 2607; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §161.3 ] 84 Acts, ch 1222, §1 C93, §427C.3 2001 Acts, ch 150, §16, 26