2023-2028 trial participants: observations start on 1 September

Results

12/2025 – Results from the pilot trials of MyGardenOfTrees: variation in early regeneration across sites

10/2025 – You make the difference: Citizen Science in MyGardenOfTrees

10/2025 – Different responses of fir and beech to heat and drought in their early life stages

06/2023 – Trials 2021-2023: Germination rates results

07/2022 – Estimating germination rates: continuation of the climate chamber experiment with new provenances

06/2022 – Trials 2021-2023: preliminary results

04/2022 – Estimating germination rates using a climate chamber experiment

11/2021 – Summer trials 2021

12/2025 – Results from the pilot trials of MyGardenOfTrees: variation in early regeneration across sites

Each tree icon indicate a provenance of Abies or Fagus seeds. The provenance name is composed of the species (AA = Abies alba, AN = Abies nordmanniana, FS = Fagus sylvatica and FC = Fagus caspica), the country (e.g., DE = Germany, PL = Poland, etc.) and a number in case of multiple provenances from one country. Diamond icons indicate the location of the pilot micro-gardens. In the background, the natural distribution of Abies spp (orange) and Fagus spp (blue).

Read the full article here!

During our pilot phase (2021–2023), we developed and tested the protocols for establishing the very first micro-gardens. 18 pioneering foresters across Europe participated, laying the foundation for the network we have today.

The map below shows the locations of seed origins and micro-gardens spanning from France to the Caucasus. In this initial phase, we purchased—not collected—12 provenances of Abies alba, 9 of Fagus sylvatica, plus one each of their eastern relatives Abies nordmanniana and Fagus caspica. Because of its uniqueness and availability in sufficient quantity, the Fagus caspica provenance from Iran is the only seed source used both in the pilot phase and in the current 2023–2028 trials.

To understand what drives germination success, we tested seeds under both controlled and natural conditions. First, we conducted climate chamber experiments with standardized temperature, light, and moisture conditions (Figure 3). Then, the same provenances were sown directly in forest micro-gardens under natural conditions, following very similar protocol to what you have been using. This approach allowed us to answer a critical question: do laboratory tests predict real-world performance?

Climate chamber set up. Left panel: overview of one of the climate chambers with multiple trays sown with seeds from various provenances and families. Right panel: close-up of one tray taken during an observation protocol. Some Fagus seeds, such as in row J and K, are already germinating.

Heat maps showing seed germination success across micro-gardens. The left panel shows Abies and the right panel Fagus. Columns represent seed sources (provenances) and rows represent test micro-gardens. Darker colors indicate higher germination success. Rows and columns are ordered from lowest to highest germination rates. Hatched cells indicate combinations that were not tested, and X marks indicate no germination. Gray margin bars show average germination per seed source (top) and per garden (right). Site 21 appears twice because seeds were planted in two contrasting environments, treated as separate gardens with two blocks each.

Abies spp

For fir, we found modest correlation between lab and field performance, though field germination averaged only 21% of laboratory rates. More surprising: some provenances that struggled in controlled conditions (<10% germination) rebounded to respectable rates in certain forests. The heatmaps (Figure 4, left panel) reveal substantial site-to-site variation, with germination ranging from near zero to over 50% for the same provenance depending on garden location.

Fagus spp

For beech, laboratory and field germination results diverged strongly. Caspian beech from Iran topped laboratory tests at 60% germination but managed only 4.6% average in the field. Meanwhile, Italian beech that barely germinated in the lab (<1%) reached over 30% in some forests (Figure 4, right panel).

Takeaway

Forest environment matters as much as seed origin. Laboratory tests provide useful information on seed viability, but they cannot reliably predict regeneration success in specific forest sites. The same provenance may perform very differently depending on local conditions.

The first summer: a critical filter

For both species, mortality peaked during the first summer (Figure 5), with additional losses during the first winter. Seedlings that survived through the second growing season generally persisted into year three, suggesting that early establishment is the most critical phase. By autumn 2024, 55 fir seedlings and 42 beech seedlings remained alive across all micro-gardens, highlighting just how challenging natural regeneration can be under real forest conditions.

Clear differences between species emerged. Several fir provenances showed moderate initial germination but excellent persistence, meaning they were slow to start but resilient once established. For beech, one Slovenian provenance stood out, combining high initial germination with above-average survival after three years—a rare winning combination.

Crucially, high germination does not guarantee establishment. Some top-germinating fir provenances experienced dramatic first-summer mortality, losing most seedlings despite promising starts. Others with lower initial germination rates showed better long-term survival, suggesting different life-history strategies. Environment dominated this early stage: spring precipitation at garden sites significantly boosted germination success, but surviving that first summer depended heavily on local moisture availability and microsite conditions.

What we have learned so far

The pilot trials show that regeneration success is determined by strong interactions between seed origin and local forest conditions—patterns that cannot be reliably captured by laboratory tests alone.

Laboratory tests are informative but not predictive. Climate chamber experiments reliably assess seed viability and reveal genetic differences among provenances, but correspondence with field establishment was weak, particularly for beech. Field performance depended largely on site-specific conditions absent from controlled settings.

Local conditions matter as much as provenance. Variation in germination and survival among micro-gardens was comparable to variation among seed sources. The same provenance performed very differently across sites, indicating strong provenance-by-environment interactions and no universally superior seed source.

Early life stages are the main bottleneck. Most mortality occurred during germination and the first summer. Of approximately 18,000 seeds sown, only 97 seedlings remained after three years. High germination did not guarantee establishment, while some provenances with lower initial germination showed higher post-establishment survival.

Multi-year field monitoring is essential. Seedling performance in the first year did not predict longer-term survival. Only continued monitoring allows identification of seed sources that combine adequate germination with sustained survival under local forest conditions.

These results demonstrate that your observations across diverse real-world conditions generate insights that controlled experiments alone cannot provide. Your continued monitoring is building the evidence base we need to understand adaptation potential under changing climate conditions

Read the full article here!

10/2025 – You make the difference: Citizen Science in MyGardenOfTrees

When we talk about citizen science, we mean research that relies on data collected by people outside traditional scientific institutions. It is a way of opening science to society, while also reaching scales of observation that would be impossible for researchers alone.

Citizen science has deep roots. In some countries, these efforts began more than two hundred years ago. For example, the ladybird beetle observation network in Belgium started in 1800, and has ammassed over 80'000 records since then! Similarly, the phenology observation network in Austria has been active intermittently since 1851. In these early projects, citizens followed demanding protocols, repeated observations, or even manipulated specialized equipment. However, the geographic reach of their observations remained limited.

Over time, technological advances such as the internet and smartphones, have transformed what citizens science can do. Today, many projects reach thousands of people across countries or even continents, asking for simpler data or even just photographs - think about the famous iNaturalist network.

From local projects involving a handful of engaged volunteers, citizen science has evolved into large-scale initiatives that gather valuable yet straightforward data from thousands of participants across countries and professions — often with nothing more than a smartphone. What about MyGardenOfTrees?

MyGardenOfTrees is different.

What is next-generation citizen science?

MyGardenOfTrees brings citizen science to the realm of coordinated distributed experiments (CDEs) where collaborating teams run experiments across multiple locations while following the same protocol. Achieving such broad temporal and spatial scale while managing complex experiments is challenging, but MyGardenOfTrees meets this challenge by engaging professionals who contribute meaningfully to research and help translate findings into policy and action. This collaborative approach is built on several key strengths:

Next-generation citizen science: when citizens and scientists co-create sustainable solutions. NGCS proposes highly engaging work to citizens that aligns with their profession. For example, in MyGardenOfTrees, foresters and forest scientists cooperate to perform an Europe-wide experiment to advise assisted migration decisions.

Sustained participation: MyGardenOfTrees participants return to their micro-gardens repeatedly, monitoring seed germination, survival, and growth across seasons and years.
Active experimentation: Participants don’t just observe nature — they conduct experiments by sowing seeds from different provenances under controlled conditions.
Protocol fidelity and complexity: participants follow standardized protocols for data collection, ensuring that results are directly comparable across hundreds of sites.
Spatial diversity: With micro-gardens spread across Europe the project captures plant responses across a broad climatic and environmental gradient.
Temporal depth: Because observations are repeated over multiple years, the data offers rare insight into early forest dynamics under climate change.

All this is possible thanks to the engagement of a very special group of participants: foresters. They bring both practical experience and professional knowledge allowing them to carry out complex experimental tasks while having a genuine stake in the outcomes. This collaboration places MyGardenOfTrees within what we call next-generation citizen science (NGCS), initiatives where participants bring specialized expertise and take an active role in structured, hypothesis-driven research. As the figure above illustrates, MyGardenOfTrees sits at the interface between traditional citizen science and fully coordinated distributed experiments conducted by scientists, pushing the boundaries of what participatory science can achieve.

Scientists and foresters co-create sustainable solutions

The strength of scientific conclusions depends directly on the quality and consistency of the data behind them. In MyGardenOfTrees, every observation you record contributes to building a unique, continent-wide dataset on seed germination and seedling growthunder different environmental conditions. The observations originated in the coordinated network of micro-gardens will be essential to test how silver fir and beech respond to climate variation – information that will ultimately support decisions about forest adaptation and assisted migration.

What can we learn from this for citizen science in general?

Structure matters – Clear, standardized protocols and training materials make sure that data collected across hundreds of sites remain comparable.
Community matters – People stay engaged when they feel part of a shared scientific journey, not just when submitting a single measurement.
Feedback matters – Sharing updates and early insights (like in this blog or in the results page of this website) strengthens motivation and reminds participants that every observation has value.

These principles show that citizen science is most powerful when it becomes a collaboration between citizens and researchers built on shared purpose and trust.

Your engagement has already demonstrated that citizen science can reach a new level of rigor and commitment. As data collection continues, your observations will form the foundation for understanding how trees establish, grow, and survive under different climates. This knowledge will be critical for addressing one of the most pressing questions in modern forestry:

How can we use scientific evidence to guide assisted migration and help forests adapt to the conditions of the future?

Together, we are proving that citizen science is not just about participation — it’s about co-creating the science that will help sustain our forests.

Read the full article here

10/2025 – Different responses of fir and beech to heat and drought in their early life stages

Climate change is making natural regeneration increasingly uncertain. In our climate chamber experiments – using the same seed lots later sent to participants — we tested two key stress factors: shorter, warmer winters that reduce seed chilling, and warmer, drier springs that increase evaporative stress when seedlings. Analyses by our PostDoc researcher, Leo Zeitler, show that fir seedlings are more resilient under these conditions, while beech struggles to establish when faced with climate stress.

In the climate chambers we tested over 34,000 seeds collected from 32 fir and beech populations across Europe, including around 10 seed families per population. Seeds were exposed to two types of winter chilling or stratification (long vs. short) and two spring conditions (cool vs. warm/dry). We then followed seedling development every few days for three months — roughly the length of a natural first growing season. We looked at the very first stages of tree development — from seed to young seedling.

Short stratification delayed germination in both species, while dry/warm germination conditions accelerated it (see figure below). Fagus showed reduced germination rates (i.e., the proportion of seeds that emerged with a shoot) under warm winter conditions, Abies maintained high germination rates even with reduced chilling and dryer, warmer spring conditions. However, the effects of reduced stratification emerged later in development: in both species, seedlings from some provenances exhibited halted growth under warmer conditions, revealing interactions between the genetic background of provenances and the environment where they grow. Abies development was more influenced by provenance, suggesting stronger adaptive divergence, while Fagus showed more consistent growth across provenances, indicative of a greater colonization potential.

Overall, life history strategies differ greatly between Abies and Fagus: while Abies seeds germinated well, both in terms of capacity and speed, we observed a plastic response to stress later in the development through reduced developmental speed under stress. Contrary to this, Fagus sensed stress already during germination, producing fewer seedlings that grow at a steady rate but face higher mortality later.

Our findings show that early seedling development is shaped by both genetic background and environmental conditions, including winter chilling, spring water and heat accumulation. Using predictive provenancing could help maintaining fir populations that regenerate naturally even under shorter winters and warmer/dryer springs and summers expected in the future. In contrast, natural regeneration in beech could be further reduced under future climate change scenarios, a finding that is largely confirmed by recent research on adult beech trees.

06/2023 – Trials 2021-2023: Germination rates results

We continue to analyse the data from the pilot trials 2021-2023! In these trials, 18 participants from 7 different countries (100 to 1400 m a.s.l.) planted seeds of 13 provenances of Abies spp and 10 provenances of Fagus spp. Participants monitored germination, phenology and survival during the 2022 growing season. The observations continue in 2023 and will be analysed after the end of this growing season.

Here we summarize the success and pace of germination in the climate chambers (at the WSL) and in the micro-gardens followed by foresters in different countries. We chose to show the cumulative percentage of germinated seeds as a function of the Growing degree days, or GDD, which is a measure of heat accumulation. Indeed, in order for the seeds to germinate and to develop into healthy seedlings, they need to be exposed to cold during the winter (chilling), and then to heat and humidity during the growing season. GDD indicates how much heat had been accumulated since the daily mean temperature reached the 5°C. Using GDD, instead of the date, is not only biologically meaningful, but also allow us to compare the development of seedlings across different environments. The lines indicate the performance of different provenances and the dots indicate when the were observations performed.

Regular observations are precious and necessary. The success and development of different provenances across different environments can only be understood by regular observations! We thank all our participants for their time and work! We also encourage future participants to observe even when the germination rate is low because these data can help us identify the limiting conditions for seedling development.

Important differences between provenances and micro-gardens. Differences between provenances in tree growth are known to foresters. However, it has been less known that provenances may differ also in early life-stages and consistently across environments! For example, the Abies nordmanniana from Georgia and the beech from Slovenia, performed well at most sites and in the climate chambers. For some provenances, the environment played a more important role: beech from Iran, performed very well in the climate chambers but less well in the field.

Germination in the field can be as high as in the climate chamber! For example, the fir from Corsica and beech from the Massif Armoricain showed equally high germination in the chamber and in the field, and beech from Slovenia and fir from Romania had higher germination in the field compared to the climate chamber.

Abies alba and Abies nordmanniana

Fagus sylvatica and Fagus orientalis

07/2022 – Estimating germination rates: continuation of the climate chamber experiment with new provenances

Our student Mert Celik continued the climate chamber experiment started by Johannes Alt (see below results from April 2022) and finished testing all provenances used for the trials 2021-2023. This includes provenances of Abies alba, Abies nordmanniana, Fagus sylvatica and Fagus orientalis.

Using the same dark-light cycle (16 h dark, 8 h light), this time the experiment was maintained for 16 weeks to see if germination rates reached a plateau. Ambient temperature was kept at 5-15 oC for the first nine weeks, and it was increased to 10-20 oC for the rest of the experiment duration. For all species and provenances, germination rates reached the plateau in 80 to 85 days after the beginning of the experiment.

Once concluded, Mert combined the results of the first and the second experiment and showed that germination rates of the species belonging to the Abies genus ranged between 9% and 65% with a mean germination rate of 33%. Caucasian fir (Abies nordmanniana) outperformed all other silver fir provenances with a germination rate of 65%. In the Fagus genus, the oriental beech from the Iranian Alborz Mountains reached the highest germination rate of 72%. Across provenances, germination rates ranged between 0% and 72%, with a mean rate of 29%. Beech from Romania (SE Carpathians) and Switzerland (Salenstein) did not germinate at all during the experiment.

These results partly reflect what is happening in the micro-gardens in the field (check the preliminary results in the section below!).

In a nutshell: Germination rates of the Abies genus ranged between 9% and and 65% with a mean germination rate of 33%. In the Fagus genus,germination rates ranged between 0% and 72%, with a mean rate of 29%.

Germination curves obtained from the germination data for silver fir and caucasian fir (top graph), and European and oriental beech (bottom graph); dotted lines indicate moist treatments, solid lines indicate dry treatment.

06/2022 – Trials 2021-2023: preliminary results

Our participants from the trials 2021-2023 have been collected data for an entire growing season already, starting in spring 2022. Have a look at the graphs below to find out what happened in each micro-garden installed, which provenance performed better where and more.

In the dropdown menu, you can select different variables. Depending on what you choose, you can explore :

the percentage of germinated seeds in each garden ("Micro-garden")
the number of germinated seeds for each germination stage ("Germination stage")
the percentage of germinated seeds for each provenance ("Provenances-Abies" or "Provenances-Fagus")
the evolution of the percentage of germinated seeds in each garden ("Evolution-Abies" or "Evolution-Fagus")
the number of germinated seeds for each provenance and in each garden ("Heatmap-Abies" or "Heatmap-Fagus")

NOTE: In the heatmaps you can compare the results from the micro-gardens with the results from the climate chamber experiments. Please keep in mind that not all provenances were tested in the climate chamber so some information is missing. Similarly, some provenances were planted in only some micro-gardens and we have fewer data on them.

04/2022 – Estimating germination rates using a climate chamber experiment

Master thesis by Johannes Alt

Part of the seeds provenances used in the trials 2021-2023, 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!

Download the full thesis here!

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

11/2021 – 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!

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