California Code, Government Code - GOV § 1304

(a) The Speaker of the Assembly or the Senate Committee on Rules may appoint a Member of the Legislature or legislative staff to serve as an alternate for a Member of the Legislature appointed to a state board or commission within the Natural Resources Agency in the Member's absence.

(b) An alternate designated pursuant to this section shall exercise all of the rights, privileges, and powers that are available to the Member with respect to serving on the board or commission within the Natural Resources Agency.  The alternate designated pursuant to this section may not vote and shall adhere to the same rules of conduct as a voting member and serve at the pleasure of the Speaker of the Assembly or the Senate Committee on Rules.

(c) An alternate designated pursuant to this section shall serve on the board or commission within the Natural Resources Agency only during the period for which the Member may serve on the board or commission.