Our community ecology group at University of Bern (led by Eric Allan) works on two interlinked questions: what maintains diversity within plant communities? And what effects do changes in community diversity have on the functioning of ecosystems and the services they provide?
We try to understand the biodiversity of plant communities from several different angles and we do experiments in the field and greenhouse and use statistical modelling to test these questions in large datasets.
On our website you can find more information on the major projects we are involved in, together with updates on our activities and interests.

Allan Ecology Group at INTECOL2022

After a few years of postponements and delays due to the Covid pandemic, INTECOL2022 was finally held in Geneva in September, bringing together ecologists from across the globe to share research on applied and fundamental questions in many areas of ecology. This breadth of research was demonstrated in the 50 sessions held at INTECOL including topics such as biodiversity, ecological mechanisms across scales, climate change, restoration, plant-enemy interactions and more.

It was great to be able to attend an in-person conference again! INTECOL 2022 had some really interesting talks, I especially enjoyed the theoretical discussions with the plenary talk by Peter Chesson and also the talk on eco-evolutionary effects on species coexistence by Vasco Lepori. Discussions around experimental results were also enriching, especially the impressive presentation from Zoe Xirocostas on how introduced plant change their interactions with enemies in their new ecosystem. – Caroline

I really enjoyed having a chance meeting and talking to many people at the INTECOL 2022 conference who are working in different aspects of ecology. The talks in the “Plant-enemy interactions in a changing world” and “Land use and biodiversity” sections were the ones I liked the most and therefore it would be difficult to pick one or two. It was very nice to not only share our work but also have a social life with other people in different countries called pandemic PhD. Thu Zar Nwe

For me, the best experience was the sheer wealth of inspiration, the opportunity to meet so many creative and enthusiastic but also busy researchers, in an environment where we all finally had time to share. I can’t remember how many times I thought “Ecology is just great!” I was especially deeply impressed by the work of several female early-career scientists, so many great role models for the future! The only downer was the question of how many colleagues stayed away from Switzerland for financial reasons. Wishing them the same feeling of being part of a large research community. – Noëlle Schenk

The Allan Ecology group was very involved in the conference including the organisation of a session by Eric, Anne, Gemma and Suz titled Plant Enemy Interactions in a Changing World. This session drew a number of big names in plant-enemy ecology as well as many emerging early and middle career researchers. All in all, it was a really interesting session to attend with new information, methods, data and a lot of interesting discussion. We finished the session with a dinner and drinks with all the speakers from the session which was a great time to keep chatting about ecology after many years of not seeing our international colleagues in person! You can see a thread that summarises all of the talks from this session on Suz’s twitter, complete with pictures of all the fantastic speakers!

The title for our exciting session on plant-enemy interactions
Dinner and drinks in Geneva with so many wonderful ecologists, some of whom we hadn’t seen in years!

Our team also contributed 5 talks to the conference. Eric and Anne presented an overview on the current state of knowledge of plant-enemy interactions and what the next big questions in this important ecological area may be. Suz presented preliminary results from the BugNet project in the same session (Plant Enemy Interactions in a Changing World) where many BugNet collaborators were in attendance and could see their data contributing to this exciting global study.

Eric and Anne giving their joint talk on the current field of plant-enemy interactions and what future research is needed

Suz presenting preliminary research on the BugNet

Thu Zar presented research from her PhD on how collembola communities and their functioning eg. mandible traits are driven by variable factors, which are altered by nitrogen addition directly and indirectly. Caroline also presented research from her PhD on how nitrogen and fungicide addition impact plant species competition networks, a study using competition matrices parametrized with data sampled on the PaNDiv experiment. And finally, Noëlle gave an excellent talk on her research from the Biodiversity Exploratories on how beta-diversity of multiple trophic groups and land-use intensity drive different grassland locations to provide distinct sets of ecosystem functions.

Thu Zar presenting research from her PhD that looks at Collembola in the PaNDiv Experiment
Caroline presenting her PhD research on plant competition in the PaNDiv experiment
Noëlle presenting in the big auditorium! Sharing results from her research in the Biodiveristy exploratories

The group also had time to attend field trips at the conference including an excursion to the mountain pasture of Chênex (Salève, France).

Enthusiastic poster presentation by Ralph Bolliger about his work on the effect of land-use intensity on grassland plant communities.

Fondue night!

The Allan Ecology Lab had a lovely Fall social event this October with a group outdoor fondue night. Loads of delicious swiss cheese, bread, potatos were devoured and of course paired with some lovely wines!

Lab Quiz

At the Allan Lab we have regular social events, for example we have dinner together or go to collect mushrooms. However, due to Covid-19 restrictions we could not meet in person anymore – but we did not let this stop us! Virtual meetings can be great fun if combined with trivia quiz (kahoot!) or drawing and guessing (skribbl.io). We even have a (non-virtual) trophy 🙂

The Allan Lab quizzing away… (can you find how many have the “thinker pose” 😉 )
Its “root exudate” – obviously 😀

The Bug-Network (BugNet)

We proudly present – the Bug-Network!

We are starting a new collaborative research network that aims to assess the impact of above- and belowground invertebrate herbivores and pathogenic fungi on plant communities and ecosystems.

We just started to search for collaborators all around the globe! If you are interested in contributing to our understanding of the importance and context-dependency of biotic interactions, and would like to contribute data or set-up an exclusion experiment in your area, contact us, and have a look at our website:


The PaNDiv experiment in the media

The PaNDiv experiment has been featured on the radio twice recently.
Noémie Pichon spoke about the experiment and her recently published work on decomposition on the Swiss French radio station RTS. Listen to the interview (in French) here.
And Seraina Cappelli gave an interview on the experiment and her recently published work on foliar pathogens for the Swiss German radio station SRF. Listen to the interview (in Swiss German) here.

The experiment was also featured in the “Berner Zeitung”, read the report on the experiment and first published results here (in German).

The first two PaNDiv-ers successfully emerged!

On the 21st of January in 2020, the first two PhD students of the PaNDiv project successfully defended their PhD.

Congratulations to Dr. Pichon and Dr. Cappelli!

Noémie investigated the effect of nitrogen enrichment and found that the direct and indirect effects of nitrogen enrichment were of similar importance in affecting ecosystem functioning. She found that species richness increased multifunctionality, as did functional diversity, while added nitrogen dampened these positive effects. The most functionally diverse communities were even slightly better at providing multiple functions than the low diversity fertilized communities. This suggests that managing for diversity can not only increase in productivity, but also provide multiple benefits compared to intensive systems. bioRχiv publication, Functional Ecology article, Functional Ecology blogpost

Seraina looked at the effect of removing plant pathogens (by applying fungicide) and found support for the growth-defense trade-off hypothesis, which states that fast growing species are less defended. Growth strategy (specific leaf area) was the main driver of infection. Surprisingly, there was no direct effect of nitrogen enrichment on fungal infection. She also found consistent negative selection effects and neutral to positive complementarity effects for all functions. The mechanisms underlying the diversity effects varied between the functions highlighting the importance of a high species diversity for the maintenance of multiple ecosystem functions. bioRχiv publication

The PaNDiv project now goes into its second phase and continues to explore new and exciting questions about the direct and indirect effects of global change drivers on above- and belowground invertebrate, fungal and plant communities and functioning.

Dr PichonDr. Pichon
with Prof. Matthias Erb (chair), Prof. Jasper van Ruijven (external examiner) and Prof. Eric Allan (supervisor)


Dr CappelliDr. Cappelli
with Prof. Matthias Erb (chair), Prof. Jasmin Joshi (external examiner) and Prof. Eric Allan (supervisor)


PaNDiv cake 1

The amazing PaNDiv cake by @debi.schaefer

British Ecological Society Conference 2019

This year’s British ecological society (BES) conference was the largest ever hosted (not counting the joint meetings with other societies), with more than 1200 participants. This large number was reflected in many parallel sessions and topics, ranging from microbial ecology to macroecology and biogeography, from very specific species interactions to whole ecosystems and from theoretical or computational ecology to very applied conservation and restoration ecology. There was plenty of food for thought for everyone’s taste, but at times it was difficult to keep the overview. Fortunately, the plenary lectures helped keeping things a little bit more general, by discussing important issues in ecology, for example communicating research, contextualizing, i.e. explicitly mentioning scales for biodiversity studies and considering in parallel above-ground and below-ground communities.

I must say, I really enjoyed the whole conference. There were so many great contributions by great scientists. Personally, I really liked the talks of Alexandra Wright, James Buckley and Kimberley Simpson, who spoke about the effects of living plant diversity on the microclimate, herbivore pressure and plant defense along an environmental gradient and growth-strategies respectively. – Seraina

It was great to meet ecologists working on different topics like marine ecology, or theoretical ecology. I could discuss with many people and had some really relevant insights for my project. There were many great talks, and it’s difficult to choose, but I think my favorites were the presentations of  Ian Donohue on ecosystems stability, Jakob Assmann on remote sensing of the Greenland flora and  Korinna Allhoff on competition in seabeds. – Caroline

I am feeling particularly inspired after this conference, especially to explore energy fluxes in grasslands thanks to Andrew Barnes and to link metabolite variation to growth defence trade-offs thanks to a great talk by Tom Walker. I’m looking forward to the BES conference next year already! – Tosca  

It had been some years since I last attended a BES Meeting but I enjoyed every moment there. I met all friends and I made new ones that hopefully will lead to some sort of collaboration in the future. I really enjoyed plenary talks by Jonathan Chase and Esther Ngumbi, truly inspiring for ecologists in any stage. I also liked the presentation by Korinna Allhoff about Bryozoa coexistence and Ainhoa Magrach’s adventures pursuing hummingbirds. Finally, I must say that lab members dancing skills are on point! – Hugo S.

The BES 2019 has been a fantastic event to reconnect with some of my favorite Soil Ecologists working on soil organisms and the ecosystem processes they drive; with no specific order Nicolas Fanin, Ciska Veen, Paul Kardol, Karina Clemmensen and Franciska De Vries. I also think that the BES meeting was great to know better my colleagues as we went there as a group! Overall, it was a good place to make stronger bounds between us and plant seeds for future research projects! – Nadia

The Allan group contributed three posters and four talks to the conference in different sessions. Tosca, Thu Zar and Caroline showed posters about primary results and planned analysis about collembola, plant-herbivore interactions and plant species coexistence in the PaNDiv experiment. Anne presented her work about top-down and bottom-up regulation of herbivores in David Wardles island study system. Nadia talked about how saprotrophic and mycorrhizal fungi decompose litter in the face of nutrient deposition. Hugo used the large data sets of the biodiversity exploratory to show that there are two main thresholds of land use intensity (one for taxa and one for functions), which once crossed cause rapid ecological changes and likely hysteric behavior. And Seraina showed that even though diversity causes comparable patterns in different ecosystem functions, different species contributed to these patterns and likely also different mechanisms.


Tosca, Caroline and Thu Zar


Hugo, Seraina, Nadia and Anne

The many social activities throughout the conference promoted a relaxed and friendly atmosphere and gave the conference a touch of “school camp” for grown-ups to meet old and new friends. We drank wine and chatted at the welcome mixer, discussed about work-life balance in a workshop and danced ceilidh folk dances at the conference dinner. Overall, the conference was very inspiring, and we all came home with a pile of notes and lists of soon-to-be-out studies we must read. We are definitely looking forward to the 2020 meeting in Edinburgh!


Thu Zar, Eric, Seraina, Anne and Tosca

Mushroom picking

Autumn time is mushroom time so on 18th of October 2019 the Allan Lab went on a mushroom-picking adventure in the Bremgartenwald near Bern. We were amazed by how many different species we saw and we even found a huge amount of edible ones – many Xerocomellus (Rotfussröhrlinge), some Boletus badius (Maronen-Röhrlinge), some Cantharellus (Eierschwämme), various puffball species and a few Suillus grevillei (Goldröhrling)!

We also visited the famous “Glasbrunnen” and in the evening we enjoyed a delicious meal and wine together at Provisorium 46.

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New preprint about sick plants in grassland communities

Slowly but steadily the results of the PaNDiv experiment start to be available. With many helping hands we piled up data about fungal infection, plant traits, community composition, biomass etc. and are now putting the pieces of the puzzle together. In the latest preprint we show that the functional composition of a plant community is a main driver of fungal infection and that the consequences of fungal infection are context dependent.

Sick plants in grassland communities, Cappelli et al. 2019 (preprint)


Figure 1 Overview over the main hypotheses which we tested. Growth-defense trade-off hypothesis: Plant species adapted to resource-rich environments and able to compete well under nutrient rich conditions are often less defended against natural enemies. Nitrogen disease hypothesis: Higher nutrient content of the plant material following nitrogen fertilization should promote disease. Host dilution hypothesis: Many pathogens are dependent on the availability and density of host plants. At high plant diversity the abundance of each host plant is in average lower than in species poor communities, which is suggested to be the underlying mechanism of observed negative diversity-disease relationships.