The board may:
(a)
Employ, or authorize the city forester to employ, as many assistants as it deems necessary to carry on the work.
(b)
Fix the compensation of the assistants.
(c)
Purchase the necessary machinery, tools and implements, for the proper conduct of the work, such purchases to be made in the manner provided by law or ordinance, and only out of funds available for expenditure by the board for that purpose.
(d)
Incur such other expenses as it deems necessary for the conduct of the work.