Profiles

Pil Rasmussen

Pil Rasmussen

Forskningsassistent

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Arbetar vid Institutionen för ekologi miljö och botanik
Telefon 08-16 34 15
E-post pil.rasmussen@su.se
Besöksadress Svante Arrhenius väg 20 A
Rum N 402
Postadress Institutionen för ekologi miljö och botanik 106 91 Stockholm

Om mig

I recently finished my PhD at the Department of Ecology, Environment and Plant Sciences, where I now work as a researcher.

My work focuses on the linkage between above- and belowground organisms, with a main focus on root-associated fungi. Specifically, I look into spatial patterns of soil microbes; dispersal abilities of soil microbes; how abiotic (e.g. climate, soil pH and nutrients) and biotic  factors (e.g. plant genotype and root-associated fungi) can affect soil microbes; and what consequences belowground microbes can have on aboveground communities.  

In my group is Ayco Tack (my supervisor), Maria FaticovLaura van DijkAlvaro Gaytan, Etsuko Nonaka and Ahmed Abdelfattah.

 

Teaching

I've been teaching on the Ecology I (BSc) and Molecular Plant Microbe Interactions (MSc level) courses.

 

Other activities

I was chairman of the PhD council and a science communicator in our communication group, but stopped to focus on writing my thesis which I defended on 30th November 2018.

 

Publikationer

I urval från Stockholms universitets publikationsdatabas
  • 2018. Pil Uthaug Rasmussen, Ayco J. M. Tack, Martijn Bezemer.

    Soil contains a wealth of diversity – bacteria, fungi, nematodes, arthropods and earthworms are just some of the many organisms found belowground. These organisms play an important role in shaping the soil environment and they strongly influence plant fitness, diversity and community composition. Their impact even cascades up to affect aboveground species interactions. Ultimately, belowground organisms are a vital part of ecosystem functioning. Nevertheless, most of the diversity and ecology of belowground organisms are to this day unknown, and increasing our insights into the role and ecology of soil organisms is of importance for natural and agricultural systems.

    The main goal of this thesis was to investigate spatial patterns of plant-associated soil communities (I, II), to identify the drivers of such spatial patterns (I, II, III), and to study some of the consequences of belowground spatial patterns for aboveground species interactions (IV). To answer these questions, I used both observational studies and multifactorial experiments in combination with microscopy and metabarcoding. I focused on the plant Plantago lanceolata (ribwort plantain) and its root-associated soil microbes, with a strong emphasis on arbuscular mycorrhizal fungi, an important group of root symbionts.

    I found that in natural environments arbuscular mycorrhizal fungal communities frequently show high small-scale variation (I). In the following work I showed that the pattern of high small-scale heterogeneity may be due to dispersal limitation (II), abiotic conditions such as pH, soil nutrients and climate (I, III), and biotic conditions, such as interspecific community composition and genetic variation (I, II). The high variation at small spatial scales (I) in combination with genetic variation of plants and insects (IV) may help maintain high local heterogeneity in aboveground plant-associated communities, thereby influencing aboveground diversity and dynamics.

    The insight gained here has increased our general knowledge on the distribution of soil microbes and the interactions taking place above and belowground. It has furthermore laid a foundation for future work on the world of soil microbes and their implications aboveground.

  • 2018. Pil U. Rasmussen (et al.). New Phytologist 220 (4), 1248-1261

    Arbuscular mycorrhizal (AM) fungi form diverse communities and are known to influence above‐ground community dynamics and biodiversity. However, the multiscale patterns and drivers of AM fungal composition and diversity are still poorly understood.

    We sequenced DNA markers from roots and root‐associated soil from Plantago lanceolata plants collected across multiple spatial scales to allow comparison of AM fungal communities among neighbouring plants, plant subpopulations, nearby plant populations, and regions. We also measured soil nutrients, temperature, humidity, and community composition of neighbouring plants and nonAM root‐associated fungi.

    AM fungal communities were already highly dissimilar among neighbouring plants (c. 30 cm apart), albeit with a high variation in the degree of similarity at this small spatial scale. AM fungal communities were increasingly, and more consistently, dissimilar at larger spatial scales. Spatial structure and environmental drivers explained a similar percentage of the variation, from 7% to 25%. A large fraction of the variation remained unexplained, which may be a result of unmeasured environmental variables, species interactions and stochastic processes.

    We conclude that AM fungal communities are highly variable among nearby plants. AM fungi may therefore play a major role in maintaining small‐scale variation in community dynamics and biodiversity.

  • 2017. Pil U. Rasmussen (et al.). Ecological Entomology 42 (6), 793-802

    1. While both arbuscular mycorrhizal (AM) fungi and plant and insect genotype are well known to influence plant and herbivore growth and performance, information is lacking on how these factors jointly influence the relationship between plants and their natural herbivores. 2. The aim of the present study was to investigate how a natural community of arbuscular mycorrhizal fungi affects the growth of the perennial herb Plantago lanceolata L. (Plantaginaceae), as well as its interaction with the Glanville fritillary butterfly [Melitaea cinxia L. (Nymphalidae)]. For this, a multifactorial experiment was conducted using plant lines originating from multiple plant populations in the angstrom land Islands, Finland, grown either with or without mycorrhizal fungi. For a subset of plant lines, the impact of mycorrhizal inoculation, plant line, and larval family on the performance of M. cinxia larvae were tested. 3. Arbuscular mycorrhizal inoculation did not have a consistently positive or negative impact on plant growth or herbivore performance. Instead, plant genetic variation mediated the impact of arbuscular mycorrhizal fungi on plant growth, and both plant genetic variation and herbivore genetic variation mediated the response of the herbivore. For both the plant and insect, the impact of the arbuscular mycorrhizal community ranged from mutualistic to antagonistic. Overall, the present findings illustrate that genetic variation in response to mycorrhizal fungi may play a key role in the ecology and evolution of plant-insect interactions.

Visa alla publikationer av Pil Rasmussen vid Stockholms universitet

Senast uppdaterad: 16 april 2019

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