Section 13. If there are trees upon or structures affixed to the land taken which are not included in the taking, the owner may remove the same, but the damages shall include the value thereof, so far as they enhance the value of the land, and the value thereof for purposes of removal shall be deducted from the damages. If part of a parcel to which structures are affixed is taken, the damages shall include the value of all structures upon such parcel so far as they enhance the value of the land, deducting therefrom the value of all structures or parts thereof left standing on the part not taken, and, if the taking did not include the structures, the value for purposes of removal of the structures upon the part taken. If the owner of trees upon land taken refuses or neglects to remove them within the time specified in the order of taking, he shall be deemed to have relinquished his rights thereto. If the owner of structures upon land taken refuses or neglects to remove them within the time specified in the order of taking, the officers having the direction and control of the public improvement in connection with which the taking was made shall sell such structures at public auction, after five days' notice of such sale, and hold the proceeds for the benefit of such owner, and the expenses of such sale shall be deducted from the owner's damages; but if such property is of less value than the estimated expense of such sale no sale need be made. In that case, or if at the sale no person bids for such property, the owner thereof shall be held to have relinquished his right thereto. If the owner of personal property lying upon land taken refuses or neglects to remove it after reasonable notice in writing from the officers having the direction and control of the public improvement in connection with which the taking was made, he shall be held to have relinquished his right thereto.