State nurseries shall be maintained under the management of the department for all of the following purposes:
(a) Operation of a state seed bank to provide facilities for the processing and storage of adequate supplies of high-quality seed necessary to protect the genetic integrity and diversity of forest tree and plant species, giving emphasis to those native species threatened with extinction.
(b) Reforestation of public and private lands, giving preference to forest land which has been substantially damaged by fire, flood, insects, disease, or other natural causes.
(c) Production for sale of tree seedlings planted for purposes of meeting resource conservation standards required pursuant to Section 4561 and the rules and regulations of the board. For this purpose, the department shall take whatever steps are necessary to ensure to the maximum degree feasible that the seedlings are adapted to the planting site, and represent an appropriate diversity of forest species.
(d) Propagation and distribution of tree seedlings of the species Taxus brevifolia (Pacific yew) for research related to taxol in the treatment of cancer.