Research in the Soil Ecology Workgroup

Soil fungi in the farming landscape (FUNFARM, Personal Research Grant PRG PRG1789; Maarja Öpik)

Duration: 2023-2027

Healthy soil is a strategic natural resource. In the light of European Green Deal, UN Sustainable Development Goals, and current global challenges, we need to: 
(1) assess and model soil biota diversity in farming landscapes;
(2) understand functioning of farmland soil biota in landscapes of different complexity;
(3) incorporate the meaning of soil biota for people involved in and impacted by green transition in diversity-based management guidelines. 
Focusing on a key soil organism group, plant beneficial arbuscular mycorrhizal fungi (AMF), we will model their occurrence in Estonia as a consequence of landscape complexity and farm management; clarify the mechanistic roles of AMF in soil N2O emissions and N cycle; and involve farmers as co-creators and co-communicators in living lab trials and action groups. 
We will develop regionally informed evidence-based soil biota management guidelines aiming at biodiversity preservation with no compromise on agricultural productivity.

Project participants: Maarja Öpik, Tanel Vahter, Inga Hiiesalu

Funding: Estonian Research Council

Arbuscular mycorrhizal fungi along altitudinal gradients: relationships with evolutionary and ecological processes at multiple spatial scales (Personal Research Grant, Starting project PUT1170; Inga Hiiesalu)

Duration: 2016-2023 (temporarily on hold during 2019-2022 due to maternity leave)

Although altitudinal diversity patterns of macroorganisms are relatively well studied, diversity patterns in microorganisms, such as arbuscular mycorrhizal fungi (AMF) remain largely unknown. This project aims to examine the diversity of AMF and plants along altitudinal gradient in the arid Ladakh in NW Himalayas. This is one of the world's most extreme environments where vascular plants grow as high as 6150 m and is affected by global change. We propose a framework integrating information on the diversity and distribution of high-mountain plant and AMF communities in a phylogenetic and functional context. We aim to describe new patterns of AMF communities and reveal the underlying mechanisms by using molecular methods, large available datasets of AMF diversity, plant traits and climatic conditions combined with extensive soil sampling. This project will provide novel insights into the diversity and distribution of AMF in one of the most unique and threatened environments in the world.

Project participants: Inga Hiiesalu

Funding: Estonian Research Council

Interactive effects of local and landscape scale restoration of semi-natural grasslands and agricultural fields on species interactions and ecosystem functions (Interrest, Aveliina Helm)

Duration: 2022-2025

Calcareous grasslands were created by traditional land use in European cultural landscapes and are one of the most species-rich habitat types. They harbour many rare and highly endangered species, but are nowadays often threatened, mainly by abandonment and eutrophication. Hence, restoration measures are urgently needed. However, transnational restoration approaches are missing and evaluations within regional restoration schemes focus usually only on indicator species or species richness and ignore their biotic interactions, ecosystem functions and the landscape context. Especially species interactions are important indicators of restoration success as they are often more sensitive to environmental changes and determine vital functions that are necessary to stabilize ecosystems. In this project we will investigate species interactions across different trophic levels including (1) plant-soil, (2) plant-pollinator and (3) bird-food resource interactions, in restored and degraded calcareous grasslands that are embedded in different socio-ecological and landscape contexts in three countries (Germany, Spain and Estonia). Additionally, we will measure ecosystem functions including soil functions, pollination and predation. We hypothesize that local restoration measures will lead to more complex and stable interactions and improved ecosystem functions compared to degraded sites. Moreover, we will investigate whether landscape-scale restoration with agri-environment schemes can make local restoration more effective through additive or synergistic effects. We will also analyse the social contexts of the restoration programs and identify key actors who are necessary to achieve local and landscape restoration goals. The results of our project will contribute to several Aichi targets by focussing on habitats with extremely high conservation value. They will inform the European Habitats Directive on the effects of restoration measures on species interactions and ecosystem functions and how they are linked to social networks. Knowledge on the contribution of agri-environment schemes at the landscape scale to the restoration of calcareous grasslands can be integrated in the Common Agricultural Policy. The project will contribute to safeguard the precious biodiversity in calcareous grasslands, their interactions and functions and promote resilient ecosystems in European cultural landscapes.

Project participants: Tanel Vahter, Inga Hiiesalu

Funding: Estonian Research Council


Test battery for the effect determination of chemicals in soils: Suitability of test systems with mycorrhiza fungi for the risk assessment (ERAMYC, Mari Moora)

Duration 2021-2023

Due to their recognized ecological relevance in supporting key soil functions, and their sensitivity to chemicals, namely Plant Protection Products, Arbuscular Mycorrhizal Fungi (AMF) have been indicated as a potential group of non-target test organisms to be included in a test battery to assess the effects of different chemicals on soil organisms. The main objectives of this research proposal are: (i) to improve the existing test protocol for the pre-symbiotic phase not only by the inclusion of other test species and testing conditions, but mainly by the development and inclusion of test procedures embracing the symbiotic phase of AMF species; (ii) to standardise the developed protocol via the performance of a ring-test with different chemicals; (iii) to develop a draft OECD Test Guideline to be submitted for scrutiny under the remit of an OECD expert group and to evaluate the experimental results against the existing framework for the risk assessment of soil organisms exposed to chemicals.

Participants: Tanel Vahter