Das Samenplantagenprogramm der Bayerischen Staatsforstverwaltung

1989

3 Abb., 12 Lit. Ang.

Unselbständiges Werk

4223

200020992

Due to the varied topography found in Bavaria the establishment of tree-seed- orchards for high-elevation provenances is of special importance. Presently 32 tree species have been established on 65 hectares in Bavaria. They not only serve in maintaining site adapted genetic material but also in providing provenance specific forest seed of high quality. The maintenance of genetic diversity is of special importance during the selection process as well as during the establishment and tending of the seed-orchards. Most of the seed-orchards are established by grafting. The plus-tree selection criteria depend upon the species and provenance. Grafting is generally done during winter in greenhouses. Larger container plants of the same species and provenance serve as understock. We strive to concentrate seed-orchards in specific locations. Finding sufficiently large areas and pollen isolation is difficult in Bavaria. The clones are distributed randomly in a final spacing of generally 10 x 10 m and a initial, pre-thinning spacing. Thus we hope to attain sufficient and variable pollination between the clones and thus a high genetic diversity. Keeping the seed-orchards free of competing vegetation is done mechanically. The additional function of the seed-orchard area as a biotope is taken into consideration. To prevent frost damage the stems of decidous trees are painted with a white silicate paint. Pruning methods as developed for fruit trees and ornamentals can only be adapted to forest trees to a limited extend. The seed-orchard program is planned by the Bavarian Ministry for Nutrition, Agriculture and Forestry in coordination with the forest-regional offices and the Bavarian Institution for Seeding and Planting at Teisendorf (LASP). In carring out the seed-orchard program the LASP works closely with the responsible forest districts.