The members of the county weed district board shall be paid a per diem of not less than twelve dollars for each day actually and necessarily engaged in the performance of their official duties as members of such board and shall be allowed mileage reimbursement on the same basis as provided in section 81-1176. The chairperson of the county board may appoint one additional member from the county board to serve as an ex officio member of the county weed district board to provide coordination between such boards, except that the county board member or commissioner so appointed shall not be entitled to the expense reimbursement allowed county weed district board members. The ex officio member shall possess the same authority as other members, including the right to vote.