Charakteristik der polnischen Norm fuer Baumpflanzen aus Folienzelten fuer Forstkulturen und Plantagen : Actual Problems of the Legislation of Forest Reproductive Material and the Need for Harmonization of Rules at an International Level

1992

S. 129-134

Unselbständiges Werk

200065059

Before 1960, one applied in Poland norms for individual tree species. In 1967 and then in 1976, new improved versions of the norms were established. The last one is still operative, it involves 123 species (15 coniferous and 108 deciduous ones). The development of plant production in controlled environment (plastic tunnels, glasshouses, frames) necessitated the elaboration in 1982 of a new norm for reproductive material - tree plants from controlled conditions for forest plantations and tree-plantings. The norm involves only 26 tree species from generative reproduction, therefrom 11 coniferous and 15 deciduous species.