Maarja Opik

Maarja Opik
University of Tartu · Department of Botany

PhD

About

205
Publications
78,720
Reads
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8,937
Citations
Additional affiliations
October 2011 - present
University of Tartu
Position
  • Senior Researcher
March 2006 - March 2008
James Hutton Institute
Position
  • PostDoc Position
January 2003 - September 2011
University of Tartu
Position
  • Research Associate

Publications

Publications (205)
Preprint
Sustainable agriculture is essential to address global challenges such as climate change and biodiversity loss. Hedgerows enhance aboveground biodiversity and provide ecosystem services, but little is known about their impact on soil biota. Arbuscular mycorrhizal (AM) fungi are one of the key components of belowground biodiversity. We compared the...
Article
Knowledge about the distribution and local diversity patterns of arbuscular mycorrhizal (AM) fungi are limited for extreme environments such as the Arctic, where most studies have focused on spore morphology or root colonization. We here studied the joint effects of plant species identity and elevation on AM fungal distribution and diversity. We sa...
Article
Classical theory identifies resource competition as the major structuring force of biotic communities and predicts that: (i) levels of dominance and richness in communities are inversely related, (ii) narrow niches allow dense ‘packing’ in niche space and thus promote diversity, and (iii) dominants are generalists with wide niches, such that locall...
Article
Full-text available
Analyzing diversification dynamics is key to understanding the past evolutionary history of clades that led to present‐day biodiversity patterns. While such analyses are widespread in well‐characterized groups of species, they are much more challenging in groups which diversity is mostly known through molecular techniques. Here, we use the largest...
Preprint
Full-text available
Fungi play pivotal roles in ecosystem functioning, but little is known about their global patterns of diversity, endemicity, vulnerability to global change drivers and conservation priority areas. We applied the high-resolution PacBio sequencing technique to identify fungi based on a long DNA marker that revealed a high proportion of hitherto unkno...
Article
Full-text available
Wetland soils are the greatest source of nitrous oxide (N2O), a critical greenhouse gas and ozone depleter released by microbes. Yet, microbial players and processes underlying the N2O emissions from wetland soils are poorly understood. Using in situ N2O measurements and by determining the structure and potential functional of microbial communities...
Article
Full-text available
Arbuscular mycorrhizal (AM) fungi are a ubiquitous group of plant symbionts, yet processes underlying their global assembly — in particular the roles of dispersal limitation and historical drivers — remain poorly understood. Because earlier studies have reported niche conservatism in AM fungi, we hypothesized that variation in taxonomic community c...
Article
Organisms on our planet form spatially congruent and functionally distinct communities, which at large geographical scales are called “biomes”. Understanding their pattern and function is vital for sustainable use and protection of biodiversity. Current global terrestrial biome classifications are based primarily on climate characteristics and func...
Article
Fungi influence agricultural production due to their key roles in soil biotic and abiotic processes. However, there is limited knowledge of their status at scales relevant for farm management and policymaking. We examined the relationships between commonly applied agricultural practices and soil fungal diversity in 78 arable fields in Estonia. We u...
Article
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Root-associating arbuscular mycorrhizal (AM) fungi foster vegetation recovery in degraded habitats. AM fungi increase nutrient availability for host plants; therefore, their importance is expected to be higher when nutrient availability is low. However, little is known about how small-scale variation in nutrient availability influences plant and AM...
Article
Full-text available
This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Abstract Ecologists have long debated the properties that confer stability to complex, species-rich ecological networks. Species-level soil food...
Article
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Phenotypic plasticity is essential for organisms to adapt to local ecological conditions. It is expected that mutualistic interactions, such as arbuscular mycorrhizal (AM) symbiosis, mediate plant phenotypic plasticity, although it is not clear to what extent this plasticity may be heritable (i.e. transgenerational plasticity). We tested for plant...
Article
Knowledge of forest functioning is important for sustainable forest management and conservation. The growth variation of standardised plants (phytometers) can serve as a measure of ecosystem functions and provide a link with soil biotic and edaphic conditions. We aimed to test experimentally how forest edaphic conditions and different soil symbioti...
Article
Full-text available
Woody plant encroachment affects dry grasslands globally. To predict changes in biodiversity and ecosystem processes, it is important to understand how this process affects the functional composition of grassland organism groups. In this context, seminatural wooded meadows represent a form of experimental manipulation—where open grassland and woody...
Article
Mycorrhizal symbiosis, comprising functionally distinctive plant‐fungus associations, mediates key plant population and community processes, and ultimately the functioning of terrestrial ecosystems (Tedersoo et al., 2020). It is estimated that about 90% of the world’s vascular flora forms mycorrhizal symbioses with soil fungi (Smith & Read, 2008; B...
Article
The identification and proper naming of microfungi, in particular plant, animal and human pathogens, remains challenging. Molecular identification is becoming the default approach for many fungal groups, and environmental metabarcoding is contributing an increasing amount of sequence data documenting fungal diversity on a global scale. This include...
Article
Full-text available
Plants involved in the arbuscular mycorrhizal (AM) symbiosis trade photosynthetically derived carbon for fungal‐provided soil nutrients. However, little is known about how plant light demand and ambient light conditions influence root‐associating AM fungal communities. We conducted a manipulative field experiment to test whether plants’ shade‐toler...
Article
Elevated atmospheric CO2 concentration (eCO2) effects on plants depend on several factors including plant photosynthetic physiology (e.g. C3, C4), soil nutrient availability and plants’ co-evolved soil-dwelling fungal symbionts, namely arbuscular mycorrhizal (AM) fungi. Complicated interactions among these components will determine the outcomes for...
Article
The introduction of temporary grassland into an annual crop rotation is recognized to improve soil ecosystem services, and resulting legacies can be beneficial for the following crops. In this context, the aim of the present study was to evaluate legacy effects of introducing temporary grassland into an annual crop rotation on five ecosystem servic...
Article
Full-text available
Dispersal is a critical ecological process that modulates gene flow and contributes to the maintenance of genetic and taxonomic diversity within ecosystems. Despite an increasing global understanding of the arbuscular mycorrhizal (AM) fungal diversity, distribution and prevalence in different biomes, we have largely ignored the main dispersal mecha...
Article
High‐throughput sequencing (HTS) of multiple organisms in parallel (metabarcoding) has become a routine and cost‐effective method for the analysis of microbial communities in environmental samples. However, careful data treatment is required to identify potential errors in HTS data, and the large volume of data generated by HTS requires in‐house ex...
Article
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There were errors in the name of author László G. Nagy and in affiliation no. 31 in the original publication. The original article has been corrected.
Article
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The arbuscular mycorrhizal (AM) fungi are a globally‐distributed group of soil organisms that play critical roles in ecosystem function. However, the ecological niches of individual AM fungal taxa are poorly understood. We collected >300 soil samples from natural ecosystems worldwide and modelled the realized niches of AM fungal virtual taxa (VT; a...
Article
Full-text available
Deserts cover a significant proportion of the Earth’s surface and continue to expand as a consequence of climate change. Mutualistic arbuscular mycorrhizal (AM) fungi are functionally important plant root symbionts, and may be particularly important in drought stressed systems such as deserts. Here we provide a first molecular characterization of t...
Article
Abstract Aim Plants that host root‐symbiotic nitrogen‐fixing bacteria have an important role in driving terrestrial ecosystem processes, but N‐fixing ability is unequally distributed among plant taxa and ecosystems. Here we explore the large‐scale distribution of N‐fixing plant species worldwide. Location Global. Time period Present. Major taxa...
Article
Full-text available
The cryptic lifestyle of most fungi necessitates molecular identiication of the guild in environmental studies. Over the past decades, rapid development and afordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats. Yet, in spite of the progress of molecular methods, knowledge about f...
Article
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The soil fungal community plays an important role in determining plant growth and health. In this study, we investigated the fungal diversity and community composition in the roots and soil of 21 potato (Solanum tuberosum L.) cultivars using high-throughput sequencing at three different time points across the growing season. In soil and roots, the...
Article
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The relatively poor simulation of the below-ground processes is a severe drawback for many ecosystem models, especially when predicting responses to climate change and management. For a meaningful estimation of ecosystem production and the cycling of water, energy, nutrients and carbon, the integration of soil processes and the exchanges at the sur...
Preprint
Full-text available
Arbuscular mycorrhizal fungi (AMF) are widespread microfungi that provide mineral nutrients to most land plants and form one of the oldest terrestrial symbioses. They have often been referred to as an "evolutionary cul-de-sac" for their limited ecological and species diversity. Here we use a global database of AMF to analyze their diversification d...
Preprint
Full-text available
Phenotypic plasticity is essential for organisms to adapt to local ecological conditions. Little is known about how mutualistic interactions, such as arbuscular mycorrhizal (AM) symbiosis, mediate plant phenotypic plasticity and to what extent this plasticity may be heritable (i.e. transgenerational effects). We tested for plant plasticity within-...
Article
Full-text available
True fungi (Fungi) and fungus-like organisms (e.g. Mycetozoa, Oomycota) constitute the second largest group of organisms based on global richness estimates, with around 3 million predicted species. Compared to plants and animals, fungi have simple body plans with often morphologically and ecologically obscure structures. This poses challenges for a...
Preprint
The rhizosphere fungal community can play an important role in determining plant growth and health. In this study, using high-throughput sequencing, we investigated the fungal diversity and community composition in the roots and rhizosphere soil of 21 potato (Solanum tuberosum L.) cultivars. The samples were collected at three different sampling po...
Article
Full-text available
The present study aimed to investigate the effects of arbuscular mycorrhizal (AM) fungal communities originating from organic and conventional agriculture on wheat growth and yield. Six different spring wheat cultivars released in different years in north and central European countries were considered. We hypothesised that AM fungal inoculum collec...
Book
Full-text available
This Handbook of methods aim to provide the different techniques and methodologies to obtain a minimum data set of variables, from soil biodiversity assessment to SOM dynamics, including, isotope analysis, bioturbation assessment and metagenomics. With the knowledge gathered in forthcoming projects and studies, researchers (biogeochemists and soil...
Article
Grasslands are among the most threatened terrestrial biomes, and habitat conservation alone will be insufficient to meet biodiversity goals. While restoration of indigenous grasslands is a priority, conflict with economic objectives means that incorporation of alternative habitats is necessary to offset grassland loss. With up to 800,000 km2 of lan...
Conference Paper
Traditionally, soil quality has been assessed through physical, chemical and biological properties without paying attention to soil biota and the different associated ecosystem services provided (Tyler, 2019). To fill that gap, the european BiodivERsA "SoilMan" project (Ecosystem services driven by the diversity of soil biota - understanding and ma...
Article
Full-text available
While mutualistic interactions are widespread and essential in ecosystem functioning, the emergence of uncooperative cheaters threatens their stability, unless there are some physiological or ecological mechanisms limiting interactions with cheaters. In this framework, we investigated the patterns of specialization and phylogenetic distribution of...
Article
Benefits of the arbuscular mycorrhizal (AM) symbiosis for associating plants and fungi are modulated by the functional characteristics of both partners. However, it is unknown to what extent functionally distinct groups of plants naturally associate with different AM fungi. We reanalysed 14 high‐throughput sequencing data sets describing AM fungal...
Article
Full-text available
This study explores the relationships of AM fungal abundance and diversity with biotic (host plant, ungulate grazing) and abiotic (soil properties, precipitation) factors in the Serengeti National Park, Tanzania. Soil and root samples were collected from grazed and ungrazed plots at seven sites across steep soil fertility and precipitation gradient...
Article
This study aimed to analyze spatial patterns of soil ectomycorrhizal fungal (EMF) communities at the local scale in a subtropical pine-oak forest located in the Nearctic-Neotropical transition in central Mexico, to underpin biodiversity conservation strategies in forest fragments of this region. We used a spatially-explicit nested square sampling d...
Article
Full-text available
Although the roles of mycorrhizal fungi in different vegetation types are widely acknowledged, it is still largely unknown how the diversity and frequency of different symbiotic partners vary among plant assemblages globally. We asked (i) how the global distribution of vascular plants correlates with the diversity (i.e. number of species) and frequ...
Article
Ecosystem biomass, soil conditions and the diversity of different taxa are often interrelated. These relationships could originate from biogeographic affinity (varying species pools) or from direct ecological effects within local communities. Disentangling regional and local causes is challenging as the former might mask the latter in natural ecosy...
Article
Full-text available
Manioc (Manihot esculenta Crantz) is an important tropical crop that depends on arbuscular mycorrhizal (AM) association for its nutrition. However, little is known about the richness and species composition of AM fungal communities associating with manioc and possible differences across soils and manioc landraces. We studied the diversity and compo...
Poster
Arbuscular mycorrhizal fungi (AMF) form a mutualistic relationship with 71% of the known plant species. This relationship called arbuscular mycorrhiza (AM), positively and directly influences plants and AMF fitness and have an indirect effect on diversity and community composition of both integrant of the association. The Chilean matorral is a biod...
Article
Arbuscular mycorrhizal fungi (AMF) are a key component of soil microbiota in natural and anthropogenic ecosystems. Even though soil type and climate conditioned land uses in the past, soybean cultivation has overrode such limitations and replaced the earlier diverse agro-and natural ecosystems in many countries of South America. We investigated whe...
Preprint
Full-text available
While mutualisms are widespread and essential in ecosystem functioning, the emergence of uncooperative cheaters threatens their stability, unless there are functional or evolutionary mechanisms limiting cheaters interactions. Here, we evaluated the constraints upon mycoheterotrophic (MH) cheating plants in the mutualistic interaction network of aut...
Article
Full-text available
Most studies consider aboveground plant species richness as a representative biodiversity measure. This approach inevitably assumes that the partitioning of total plant species richness into above‐ and belowground components is constant or at least consistent within and across vegetation types. However, with studies considering belowground plant ri...
Article
Arbuscular mycorrhizal (AM) fungi are obligate plant symbionts that have important functions in most terrestrial ecosystems, but there remains an incomplete understanding of host‐fungus specificity and the relationships between species or functional groups of plants and AM fungi. Here, we aimed to provide a comprehensive description of plant‐AM fun...
Conference Paper
Full-text available
More than 400 million years ago, before plants had leaves and roots, they had established intimate relationships with fungi. Fungi at that time may already have been key ecosystem players that recycled carbon, solubilized and redistributed minerals, and colonized plants and other organisms. We will assess fossil and phylogenetic evidence for the ki...
Conference Paper
The arbuscular mycorrhizal (AM) symbiosis is a key plant-microbe interaction in sustainable functioning ecosystems. AM fungi can directly benefit plant performance, and indirectly affect plant community structure by mediating biotic interactions. Furthermore, extra-radical hyphae production by mycorrhizal fungi influences soil physical characterist...
Preprint
Island biogeography theory is one of the most influential paradigms in ecology. That island characteristics, including remoteness, can profoundly modulate biological diversity has been borne out by studies of animals and plants. By contrast, the processes influencing microbial diversity in island systems remain largely undetermined. We sequenced ar...
Article
Island biogeography theory is one of the most influential paradigms in ecology. That island characteristics, including remoteness, can profoundly modulate biological diversity has been borne out by studies of animals and plants. By contrast, the processes influencing microbial diversity in island systems remain largely undetermined. We sequenced ar...
Article
Certain forestry and agricultural practices are known to affect arbuscular mycorrhizal (AM) fungal communities, but the effects of deforestation – including slash-and-burn management and other more severe disturbances – in tropical rain forests are poorly understood. We addressed the effects of anthropogenic disturbance on rain-forest AM fungal com...
Article
Full-text available
Arbuscular mycorrhizal (AM) fungal communities vary across habitat types, as well as across different land use types. Most relevant research, however, has focused on agricultural or other severely human-impacted ecosystems. Here, we compared AM fungal communities across six habitat types: calcareous grassland, overgrown ungrazed calcareous grasslan...
Article
Full-text available
Nitrogen (N) availability is increasing dramatically in many ecosystems, but the influence of elevated N on the functioning of arbuscular mycorrhizal (AM) fungi in natural ecosystems is not well understood. We measured AM fungal community structure and mycorrhizal function simultaneously across an experimental N addition gradient in an alpine meado...
Article
The arbuscular mycorrhizal (AM) symbiosis is a key plant‐microbe interaction in sustainable functioning ecosystems. Increasing anthropogenic disturbance poses a threat to AM fungal communities worldwide, but there is little empirical evidence about its potential negative consequences. In this global study we sequenced AM fungal DNA in soil samples...
Article
Arbuscular mycorrhizal (AM) symbiosis is a key plant-microbe interaction in sustainable ecosystems. Increasing land use intensity poses a threat to AM fungal communities, yet little is known of the impact of agricultural land use on AM fungal communities in many regions and cultivation types. The last few decades have witnessed increased cultivatio...
Preprint
Interactions between communities of plants and arbuscular mycorrhizal (AM) fungi shape fundamental ecosystem properties. Experimental evidence suggests that compositional changes in plant and AM fungal communities should be correlated, but empirical data from natural ecosystems are scarce. We investigated the dynamics of covariation between plant a...
Article
There is an urgent need to develop novel approaches to enhance sustainable agriculture while not reducing cr op yields. Arbuscular mycorrhizal (AM) fungi establish symbiotic associations with most crop plants improving plant performance and soil health. This study investigated the extent of colonisation of potato roots by indigenous AM fungi in the...