In the beginning of December, professor Martin Zobel and senior researcher Mari Moora had an opportunity to visit Brasil and its species-rich grasslands. They collaborated professor Valerio De Patta Pillar (Federal University of Rio Grande do Sul) and collected root samples from plant species representing different functional types. It was a pilot study aiming to understand variation of the diversity of arbuscular mycorrhizal fungal (AMF) communities in different soil conditions, including phosphorus deficient latosols.

Plant Ecology Lab is proud to congratulate two of its members for earning PhD degree. On 17^th, Annika Uibopuu defended her thesis titled "Communities of arbuscular mycorrhizal fungi in spruce forest ecosystem and their effect on performance of forest understorey plant species",dr. Miroslav Vosátka (Institute of Botany, Academy of Sciences of Czech Republic) acting as an opponent. On 19^th, Ülle Saks defended her thesis titled "Arbuscular mycorrhizal fungal diversity patterns in boreonemoral forest ecosystems" with dr Concepción Azcón González de Aguilar, (Estación Experimental del Zaidín, CSIC, Spain) acting as an opponent. Dr Concepción Azcón González de Aguilar gave also a seminar introducing her work in the Department of Botany on the following day.

Kadri Koorem was granted a post-doctoral fellowship from Plant Fellows Programme to work at Netherlands Institute of Ecology (NIOO). During the next two years, Kadri will work with Prof. van der Putten and study the association between plants and arbuscular mycorrhizal fungi during the range expansion of the plants. 

We welcome new visiting PhD students Valentina Ciccolini and Laetitia Hermann. During stay with plant ecology laboratory they are supervised by Maarja Öpik.

Valentina studies molecular diversity of arbuscular mycorrhizal fungi in a restored peatland ecosystem in Italy. Her supervisor is Dr. Elisa Pellegrino (Scuola Superiore Sant’Anna, Pisa, Italy).

Laetitia studies molecular diversity of arbuscular mycorrhizal fungi in a chronosequence of rubber tree plantations in Thailand. Her supervisors are Dr. Didier Lesueur (CIRAD-UMR Eco&Sols, Montpellier, France / Land Development Department, Bangkok, Thailand) and Dr. Lambert Brau (Deakin University, Melbourne, Australia).

Mari Moora is asked to be a keynote speaker of the first international symposium on Ecological Networks, which will be held in Coimbra, Portugal on 23rd-25th October. The syposium provides insights into the importance of food-webs and the use of network theory to advance Ecology and Conservation. Mari will be introducing the role of mycorrhizal networks in plant coexistence.  

Identification of arbuscular mycorrhizal fungi is nowadays commonly performed on the basis of DNA sequences. Species-level identification is possible if a reference database containing sequences originating in expert-identified specimens. However, majority of sequences obtained from environmental studies do not match such reference sequences, being apparently “new” species. The paper introduces the concept of virtual taxonomy which aims to classify such data, stored and systematized in the database MaarjAM. Virtual taxa are phylogenetically defined sequence groups which are based on a type sequence to make them consistent in time, but they also evolve as new data becomes available. Virtual taxonomy standardises the original sequence designations, and allows comparison and consistency between studies, much like traditional binomial taxonomic nomenclature. Virtual taxonomy has been used in our team since 2009, and is increasingly used by other research groups. 

Jaak-Albert Metsoja, Lena Neuenkamp and Martin Zobel studied the restoration potential of the persistent soil seed bank (SB) in abandoned flooded meadows in central Estonia. Although SB similarity to locally defined target vegetation was <20%, the proportion of typical flooded meadow species in SB remained high (up to 42%) even after 50-yr abandonment. SB could thus play an important role in the restoration of abandoned meadows. Read the full article.

Senior Research Fellow of Plant Ecology Lab, Maarja Öpik is now an editor in the journal New Phytologist. Congratulations for the new and exciting task! Read also the article addressing mycorrhizas and the journal New Phytologist. 

Our lab is happy to welcome new members: PhD student Maret Gerz and master student Siim-Kaarel Sepp!

Ülle Saks, John Davison, Maarja Öpik, Martti Vasar, Mari Moora and Martin Zobel published a paper in Botany where they analyzed arbuscular mycorrhizal fungal (AMF) communities in plant root samples from a natural forest ecosystem – a primeval forest at Järvselja, Estonia. All together they identified seventy-six AMF sequence groups (virtual taxa, VT) from plant roots. Taken together with seven further VT recorded in an earlier investigation of soil AMF communities at the site (Davison et al., 2012), this represents the highest number of AMF reported from a single ecosystem to date. The six study plant species hosted similar AMF communities. However, AMF community composition in plant roots was significantly different from that in soil and considerably more VT were retrieved from roots than from soil. AMF VT identified from plant roots as a whole and from individual plant species were frequently phylogenetically clustered compared random subsets of the local (from Järvselja forest) and global taxon pools, suggesting that nonrandom assembly processes, notably habitat filtering, may have shaped fungal assemblages. By contrast, the phylogenetic dispersion of AMF communities in soil did not differ from random subsets of the local or global taxon pools. Read more.

The 56th Symposium of the International Association for Vegetation Science (IAVS 2013) was held in Tartu on 26–30th June. Members of Plant Ecology Group were privileged to contribute to the organization of the event and it was a pleasure to host 450 delegates from 41 countries. The days of the symposium were filled with interesting presentations and exiting discussions from best known and most cited researchers from the world. Among others, several members of our group had a great opportunity to present and discuss their most recent research. 

From Plant Ecology Lab, Maret Gerz defended her master thesis and Rahel Valdmaa her bachelor thesis. Congratulations!

Lena Neuenkamp, Jaak-Albert Metsoja, Martin Zobel and Norbert Hölzel published a new article about “Impact of management on biodiversity-productivity relations in Estonian flooded meadows“ in Plant Ecology.

This paper focussed on the effect of management on species richness-productivity relations in productive floodplain meadows. In particular, they addressed the relative importance of biomass cutting, hay removal and nutrient impoverishment on species richness and growth form structure. They conducted fieldwork in flooded meadows, which were dominated by sedges or forbs, in Alam-Pedja Nature Reserve, central Estonia. The main result of this study was that management—mowing and hay removal—reduced the amount of litter but not aboveground biomass. The effect of nitrogen supply was significant, but explained less variation. Management increased the proportion of sedges in the sedge meadow and of small herbs in the tall forb meadow. They conclude that litter removal is the most important management means to support biodiversity. On highly productive sites, reducing nutrients via hay removal is of secondary importance within a timeframe of 10 years.

Lars Götzenberger successfully applied to be funded by the PLANT FELLOWS fellowship program and has already started his new position at the Institute of Botany of the Czech Academy of Science. Together with Jitka Klimesova and Francesco de Bello, he will be exploring the role of functional diversity for community assembly across different scales. Within the framework of this project and beyond, Lars will continue to collaborate with researchers from our working group. 

This years seminar of Plant Ecology Lab took place on February 21-22 in Kubija near Võru. Participants of the seminar gave talks about their current as well as forthcoming projects, new ideas and conferences, where the lab members have recently participated. In addition to the members of Plant Ecology Lab, several collaborators from other workinggroups from University of Tartu also participated in the seminar. Sandra Varga, a visitor from Jüväskylä University, presented a very interesting talk about the relationships between mycorrhizal fungi and sexually dimorphic plants and discussed opportunities for further collaborations. 

Information about the global distribution of microscopical organisms is limited, and this is also the case with soil- and root-dwelling arbuscular mycorrhizal (AM) fungi. Several members of our team and Department of Botany (Maarja Öpik, Martin Zobel, John Davison, Inga Hiiesalu, Teele Jairus, Jesse M. Kalwij, Kadri Koorem, Jaan Liira, Jaanus Paal, Sergei Põlme, Ülle Reier, Ülle Saks, Odile Thiéry, Martti  Vasar, Mari Moora) have participated in global fieldworks and analysis of the collected samples in order to improve the dataset of AM fungal distribution. The collected data are published in a recent paper, which describes the molecular (DNA-based) diversity of AM fungi in roots of 96 host plant species collected from total of 25 sites from six continents. This study detected a total of 204 AM fungal phylogroups (virtual taxa, VT), which increases the described number of AM fungal VT from 308 to 341 globally. These data improve considerably our knowledge about which AM fungi are associated with which plant species and in which regions they are distributed.

Molecular Ecology announces Maarja Öpik as one of its best reviewers! See the full list.

In a collaboration with colleagues from Germany, Mari Moora, Martin Zobel and Lars Götzenberger have been working on a paper entiteld "Mycorrhizas in the Central European flora - relationships with plant life history traits and ecology", which can now be accessed as preprint version and will be published in Ecology. Using a large comparative dataset, the study investigates the associations between the ability of plant species to form mycorrhizal symbiosis and their biological and ecological attributes. While confirming some previously reported and hypothesized relationships, the study also found new patterns that open up further research in plant-mycorrhizal ecology

Estonian Public Bradcasting has a TV series which introduces Estonian top sciences and it reverberated the activities of Plant Ecology Lab. Look at the program (in Estonian).

Odile Thiéry, Mari Moora, Martti Vasar, Martin Zobel and Maarja Öpik published a paper entitled “Inter- and intrasporal nuclear ribosomal gene sequence variation within one isolate of arbuscular mycorrhizal fungus, Diversispora sp.” in Symbiosis.

In this paper, they reported nucleotide variation within one spore (intrasporal) and among spores (intersporal) of a Diversispora sp. (Glometomycota) within a ca 4960 bp fragment of the nuclear ribosomal operon. Data for each marker region (SSU, ITS and LSU) originated from the very same spores. Highest variation was observed in ITS region, particularly in ITS1, at both the inter- and intrasporal levels. LSU showed more intersporal variation than SSU. The SSU and the LSU genes had relatively similar evolutionary divergence per spore. Sequence variant richness was not exhaustive for any of the marker regions, indicating that multiple sequences per spore from multiple spores are needed when characterizing a species. This paper provides reference sequences for ecological studies, permitting identification of AMF in environmental samples using any of the ribosomal regions or primer systems amplifying these regions. Read more.