April 2022

Estimating germination rates using a climate chamber experiment

Master thesis by Johannes Alt

Part of the seeds provenances used in the trials 2021-2026, have been tested in our climate chamber at WSL by master student Johannes Alt. Johannes' objective was to assess the germination rate of the provenances under a dry and moist water regime. The germination test was done in a climate chamber using a cycle of 16h night and 8h day at 5 – 15°C for eight weeks and 10 – 20°C for additional two weeks.

European beech reached a mean germination rate of 38.2% (ranging from 29% to 59% between provenances) while for silver fir it was 25.4% (9% to 39%). The different water regimes had no significant effect on the germination rate. Nevertheless, for both European beech and silver fir Johannes found a significant provenance effect on the germination rate, indicating that not all origins are equally suitable for the conditions tested.

The second germination experiment with the rest of the provenances is currently ongoing. The combined results from all provenances will provide a solid baseline for comparison with germination in the micro-gardens. This will help us generate information on the suitability of the different provenances and their potential for assisted migration!

Germination curves obtained from the germination data for silver fir (A), and European beech (C); dotted line indicates higher temperature cycle (10-20°C); line defines the end of the experiment; day 72 equals absolute germination rate

November 2021

Summer trials 2021

The very first trials of MyGardenOfTrees!

Enthusiastic citizens and NGOs from Scotland, France, Italy, Switzerland and Hungary helped us develop different steps of the project. Together, we tested the first version of the experimental design and particularly the effect of seed predation by rodents (using mesh cages) and competition (using weed exclusion sheets).

While competition from other seedlings seemed not to have a strong effect, seeds and seedlings predation from mice and snails was a clear issue. Because of these results, we designed a new kind of seed protector that we used for the following trials.

Citizen science is a beautiful way to do research which benefits both the scientific community and the public. Thanks to our early participants, we could go through the different steps of engaging and working with citizens and prepare us for the large-scale participation of the next trials!

Check out this great video from our participants in Scotland to learn more about the summer trials 2021!