Assessment of Norway maple

Background and Objective

The aim of the project is to assess the adaptability and growth performance of Norway maple in forests in Germany. Therefore, a series of trial plots under different site conditions will be established to evaluate selected population seed samples as well as single tree progenies from the whole natural range. Such field trials are necessary to be able to give well-founded recommendations for the use of suitable seed and plant material for forestry practice. Furthermore, criteria for a genetically sustainable seed production should be developed based on population genetic analyses. This includes analyses of the within-population gene flow, and it also examines whether there is any evidence of pollen flow from horticultural varieties into natural populations of Norway maple. In order to answer these genetic questions, a suitable marker set for Norway maple will be developed.

Target Group

forest administration, forest owner, forest tree nursery, research stations

Approach

1. Material selection and seed harvest
2. Plant cultivation for nursery and field trials
3. Nursery experiment (establishment, evaluation of phenological and physiological variation)
4. Development of a strategy for sustainable seed harvesting based on population genetic knowledge
5. Planning and establishing of field trials

Our Research Questions

see above

Results

The main findings are:

• 12 trial sites were established in 3 series with 185 individual tree progenies from 22 populations or harvests. For the cultivation of the test plants, container cultivation proved to be more suitable than bare-root cultivation, as the soil substrate could be better controlled.

Even though there are about 1000 entries for basic material in the EU database FOREMATIS, it is difficult to obtain foreign FRM.

• Mycorrhisation had a positive effect on plant development during cultivation. The Norway maple goes through several flowering phases in spring.
• Species-specific nuclear microsatellite markers (SSR markers) for Norway maple were adapted and optimised. 15 SSR markers were combined into 2 new marker sets. More than 5000 samples were genotyped. The marker sets have been established in the laboratories of the Thünen Institute of Forest Genetics in Waldsieversdorf and Großhansdorf and have been made available to other research institutions and state institutes.
• The results of the population genetic analyses (SSR markers) show (a) that forest reproductive material from seed sources of the category “source identified” is not recommended for the cultivation of forest plants; (b) that the minimum number of trees to be harvested in a stand should be increased and (c) that a high number of components (clones), which is higher than the minimum number of trees for the approval of stands, is used for the establishment of seed orchards.