Responses of ectomycorrhizal fungi to changes in carbon and nutrient availability

Ectomycorrhizal (ECM) fungi may receive 20% of the total C fixed by their host plants and are essential components of host nutrient acquisition. As a consequence of the vast physiological diversity that exists among ECM fungi, changes in community structure may potentially alter C and nutrient allocation and turnover within forest ecosystems. Effects of atmospheric CO2 enrichment and balanced nutrient addition on the community structure of ECM fungi were investigated. Significant effects of elevated CO2 , as well as elevated nutrient levels were found. Daily nutrient additions for 10 years did not cause reductions in the density of ECM roots or the degree of root colonisation, in contrast to other studies. Some species became more common due to nutrient additions; Cenococcum geophilum, Amphinema byssoides, Tylospora fibrillosa, tomentelloid species, and others, Piloderma byssinum and P. croceum, became less common. High variability among samples made individual species responses difficult to distinguish. Data suggest that the same species may respond similarly to both elevated CO2 and nutrient additions. In laboratory experiments, CO2 enrichment increased the production of extraradical mycelium by Hebeloma crustuliniforme, increasing mycelial spread and root colonisation. Under field conditions such a response could enable species to increase in abundance. The natural abundance of the stable isotope 13 C in fruitbodies can be used as a tool to distinguish between the two functional groups ECM and saprotrophic fungi. However, some caution is neccesary in the interpretation since values overlap between the two functional groups. The 13 C values can also be used to reveal the host-origin of carbon in mycorrhizal fungi in mixed forests. Generalist fungi, which can be associated with several different tree species, were found to receive most of their C from overstorey trees, as indicated by their high d 13 C values. This implies that large trees which are able to fix more C potentially subsidise smaller trees via a common ECM mycelial netwo

Carbon availability affects already large species-specific differences in chemical composition of ectomycorrhizal fungal mycelia in pure culture

Although ectomycorrhizal (ECM) contribution to soil organic matter processes receives increased attention, little is known about fundamental differences in chemical composition among species, and how that may be affected by carbon (C) availability. Here, we study how 16 species (incl. 19 isolates) grown in pure culture at three different C:N ratios (10:1, 20:1, and 40:1) vary in chemical structure, using Fourier transform infrared (FTIR) spectroscopy. We hypothesized that C availability impacts directly on chemical composition, expecting increased C availability to lead to more carbohydrates and less proteins in the mycelia. There were strong and significant effects of ECM species (R-2 = 0.873 and P = 0.001) and large species-specific differences in chemical composition. Chemical composition also changed significantly with C availability, and increased C led to more polysaccharides and less proteins for many species, but not all. Understanding how chemical composition change with altered C availability is a first step towards understanding their role in organic matter accumulation and decomposition

Site-dependent relationships between fungal community composition, plant genotypic diversity and environmental drivers in a Salix biomass system

Soil fungi are strongly affected by plant species or genotypes since plants modify their surrounding environment, but the effects of plant genotype diversity on fungal diversity and function have not been extensively studied. The interactive responses of fungal community composition to plant genotypic diversity and environmental drivers were investigated in Salix biomass systems, posing questions about: (1) How fungal diversity varies as a function of plant genotype diversity; (2) If plant genotype identity is a strong driver of fungal community composition also in plant mixtures; (3) How the fungal communities change through time (seasonally and interannually)?; and (4) Will the proportion of ECM fungi increase over the rotation? Soil samples were collected over 4 years, starting preplanting from two Salix field trials, including four genotypes with contrasting phenology and functional traits, and genotypes were grown in all possible combinations (four genotypes in Uppsala, Sweden, two in Rostock, Germany). Fungal communities were identified, using Pacific Biosciences sequencing of fungal ITS2 amplicons. We found some site-dependent relationships between fungal community composition and genotype or diversity level, and site accounted for the largest part of the variation in fungal community composition. Rostock had a more homogenous community structure, with significant effects of genotype, diversity level, and the presence of one genotype (“Loden”) on fungal community composition. Soil properties and plant and litter traits contributed to explaining the variation in fungal species composition. The within-season variation in composition was of a similar magnitude to the year-to-year variation. The proportion of ECM fungi increased over time irrespective of plant genotype diversity, and, in Uppsala, the 4-mixture showed a weaker response than other combinations. Species richness was generally higher in Uppsala compared with that in Rostock and increased over time, but did not increase with plant genotype diversity. This significant site-specificity underlines the need for consideration of diverse sites to draw general conclusions of temporal variations and functioning of fungal communities. A significant increase in ECM colonization of soil under the pioneer tree Salix on agricultural soils was evident and points to changed litter decomposition and soil carbon dynamics during Salix growth

Ectomycorrhizal necromass turnover is one-third of biomass turnover in hemiboreal Pinus sylvestris forests

Societal Impact Statement Efficient mitigation of climate change requires predictive models of forest ecosystems as sinks for atmospheric carbon. Mycorrhizal fungi are drivers of soil carbon storage in boreal forests, yet they are typically excluded from ecosystem models, because of a lack of information about their growth and turnover. Closing this knowledge gap could help us better predict future responses to climate change and guide policy decisions for sustainable management of forest ecosystems. This study provides new estimates of the production and turnover of mycorrhizal mycelial biomass and necromass. This information can facilitate the integration of mycorrhizal fungi into new predictive models of boreal forest soils. Summary center dot In boreal forests, turnover of biomass and necromass of ectomycorrhizal extraradical mycelia (ERM) are important for mediating long-term carbon storage. However, ectomycorrhizal fungi are usually not considered in ecosystem models, because data for parameterization of ERM dynamics is lacking. center dot Here, we estimated the production and turnover of ERM biomass and necromass across a hemiboreal Pinus sylvestris chronosequence aged 12 to 100 years. Biomass and necromass were quantified in sequentially harvested in-growth bags, and incubated in the soil for 1-24 month, and Bayesian calibration of mathematical models was applied to arrive at parametric estimates of ERM production and turnover rates of biomass and necromass. center dot Steady states were predicted to be nearly reached after 160 and 390 growing season days, respectively, for biomass and necromass. The related turnover rates varied with 95% credible intervals of 1.7-6.5 and 0.3-2.5 times yr-1, with mode values of 2.9 and 0.9 times yr-1, corresponding to mean residence times of 62 and 205 growing season days. center dot Our results highlight that turnover of necromass is one-third of biomass. This together with the variability in the estimates can be used to parameterize ecosystem models, to explicitly include ERM dynamics and its impact on mycorrhizal-derived soil carbon accumulation in boreal forests

Variation in hyphal production rather than turnover regulates standing fungal biomass in temperate hardwood forests

Soil fungi link above‐ and belowground carbon (C) fluxes through their interactions with plants and contribute to C and nutrient dynamics through the production, turnover, and activity of fungal hyphae. Despite their importance to ecosystem processes, estimates of hyphal production and turnover rates are relatively uncommon, especially in temperate hardwood forests. We sequentially harvested hyphal ingrowth bags to quantify the rates of Dikarya (Ascomycota and Basidiomycota) hyphal production and turnover in three hardwood forests in the Midwestern United States, where plots differed in their abundance of arbuscular (AM)‐ vs. ectomycorrhizal (ECM)‐associated trees. Hyphal production rates increased linearly with the percentage of ECM trees and annual production rates were 66% higher in ECM‐ than AM‐dominated plots. Hyphal turnover rates did not differ across the mycorrhizal gradient (plots varying in their abundance of AM vs. ECM trees), suggesting that the greater fungal biomass in ECM‐dominated plots relates to greater fungal production rather than slower fungal turnover. Differences in hyphal production across the gradient aligned with distinctly different fungal communities and activities. As ECM trees increased in dominance, fungi inside ingrowth bags produced more extracellular enzymes involved in degrading nitrogen (N)‐bearing relative to C‐bearing compounds, suggesting greater fungal (and possibly plant) N demand in ECM‐dominated soils. Collectively, our results demonstrate that shifts in temperate tree species composition that result in changes in the dominant type of mycorrhizal association may have strong impacts on Dikarya hyphal production, fungal community composition and extracellular enzyme activity, with important consequences for soil C and N cycling

Exploring the Integration Between Colour Theory and Biodiversity Values in the Design of Livning Walls

Designing green infrastructure in cities requires vegetation that has multiple outcomes and functions, particularly using plants that have both attractive visual or aesthetic features and high biodiversity values. Plantings that have high visual appeal are more highly valued by people and increase their feeling of wellbeing. Increasing biodiversity in cities is one of the major challenges facing urban planning and design. However, balancing biodiversity and aesthetic outcomes in urban planting design is complex, and to date there are few methods that can be used to guide plant selection. To address this knowledge gap, we investigated the use of a colour theory framework for planting arrangements to see if we could design vegetation that is highly aesthetic and has high biodiversity. We did this by configuring planting combinations for living walls in Malmö, Sweden, using principles based on Johannes Itten’s colour theories. The plant combinations on each wall were graphically arranged using (1) colour analysis of each plant and (2) design of the plant species into two colour schemes: light-dark colour concept and a complementary colour concept. For each species used in the compositions we created a biodiversity classification, based on its pollination value, “nativeness” and conservation value as a cultivar; and a plant visual quality classification, based on the performance from living walls studies. The graphical colour composition and interlinked biodiversity value were then compared to designs created with randomly selected plant species. The results showed that it is possible to design a living wall based on colour theory without compromising with biodiversity outcomes, namely species richness, pollination and the nativeness of the species. The results also indicate the potential application of this design approach to deliver greater aesthetic appreciation and enjoyment from plantings. While more work is needed, this study has shown that a theoretical colour framework can be a useful tool in designing green infrastructure to improve delivery of both cultural and regulatory ecosystem services

Ericaceous dwarf shrubs contribute a significant but drought-sensitive fraction of soil respiration in a boreal pine forest

Boreal forests often have a dense understorey of ericaceous dwarf shrubs with ecological adaptations that contrast those of the canopy-forming trees. It is therefore important to quantify contributions by understorey shrubs to ecosystem processes and disentangle shrub- and tree-driven responses to climatic factors. We quantified soil respiration driven by the pine canopy and the ericaceous shrub understorey over 3 years, using a factorial pine root exclusion and shrub removal experiment in a mature Pinus sylvestris forest. Soil temperature and moisture-related responses of respiration attributed to autotrophs (shrubs, pine roots) and heterotrophs were compared. Additionally, we assessed effects of interactions between these functional groups on soil nitrogen availability and respiration. Understorey shrubs accounted for 22% +/- 10% of total autotrophic respiration, reflecting the ericaceous proportion of fine root production in the ecosystem. Heterotrophic respiration constituted about half of total soil respiration. Shrub-driven respiration was more susceptible to drought than heterotrophic- and pine-driven respiration. While the respiration attributed to canopy and understorey remained additive, indicating no competitive release, the plant guilds competed for soil N. Synthesis. Ericaceous understorey shrubs accounted for a small, yet significant, share of total growing season soil respiration. Overlooking understorey respiration may lead to erroneous partitioning and modelling of soil respiration mediated by functional guilds with contrasting responses to soil temperature and moisture. A larger contribution by heterotrophs and pine root-associated organisms to soil respiration under drought conditions could have important implications for soil organic matter accumulation and decomposition as the climate changes in boreal forests

Omförhandlingar : Kropp, replik, etik

Renegotiations: Body, Line, Ethics departs from questions concerning authorship and agency for actors in institutionalised settings and moves towards a discussion on ethics, responsibility and possibilities in the body – text relationship. The question of how bodies can be renegotiated in and by the theatrical line is central to the work. Against a backdrop of previous and other stage productions in theatre institutions and independent constellations the staging of three texts by Elfriede Jelinek: Rosamunde, The Wall and Winterreise becomes the method for investigating and articulating the authorship of the actor. An investigation of the possible renegotiation of the (female) body from social objectivity to existential subjectivity has unfolded through the three works, partly in dialogue with the thematic content of the texts but mainly through the process of reflection and action spurred by the actor's translation of the dramatic line into bodily and oral specificity, in the labour of making poetry concrete. The ethics of ambivalence proposed by Simone de Beauvoir has emerged as an important artistic method in these processes, as her ethics not only suggests a conceptual and political framing of the work and authorship of the actor as inherently ambivalent and transcendent, but also offers a range of methodological approaches to agency coupled with rather than opposed to doubt and self-criticism, for a simultaneous construction and questioning of subjectivity. Photos and videos from the three performances are part of the final presentation of the dissertation, as are three freely articulated responses from Christina Ouzounidis, Annika Nyman and Hanna Hallgren, who each expose critical, methodological and thematic aspects in one of the works. Part of the presentation is also an essay in four chapters. Departures and conflicts in the project is discussed, in a topology extending from institutional critique to methodology and feminist theory. The work and position of the actor is articulated in relation to thinkers as Hannah Arendt and Virginia Woolf, together with a feminist reading of a dialectical theatre tradition and the historical and philosophical understanding of "the woman" as proposed by Simone de Beauvoir. With Beauvoir the essay moves into a discussion of the theatrical situation as constituted by body and time rather than by social circumstances. This discussion is further deepened by the psychoanalytical approach offered by Julia Kristeva's understanding of the relationship between language and the speaking subject, and then moves into a description of the methods used, using the staging of Rosamunde as example. Finally, an attempt at articulating the actor's work as an ethical practice is presented, as a consequence of the previous discussion but also informed by the postcolonial analysis of feminism and translation of Gayatri Chakravorty Spivak, Sara Ahmed's queer phenomenology and Judith Butler's approach to what constitutes "the possible." Rather than understanding the practice of the performing actor as a work aiming at communicating themes or ideas and bringing narratives to life, this dissertation suggests understanding it as a social and political becoming, where the performing body can create the possibility of observing itself and the possibility of renegotiating the creation of subjectivity; all in the moment of the performance. Thus the work concludes with an insisting on the body – text relationship as performative and potentially radically transformative: a becoming with the other and others where the body is exposed to the risk and possibility of change, a change in which desire, grief and insecurity are embraced as ethical resources

Migraine – A survey study on experiences of care and treatment

Introduktion: Migrän är en neurologisk sjukdom som påverkar cirka 15 % av befolkningen, orsakar omfattande påföljder, försämrar livskvalitet och arbetskapacitet samt driver upp vårdkostnader. Remiss till specialist kan hjälpa till att lindra symtom, men det finns fortfarande brister inom sjukvården gällande tillgången till adekvat vård och behandlingsalternativ. Syfte: Att undersöka upplevelser av vård och behandling bland vuxna som har migrän. Metod: Studien genomfördes som en tvärsnittsstudie med en kvantitativ ansats, data samlades in via en webbenkätundersökning på Facebook. Resultat: Utav 81 respondenter bekräftade 70,4% att migränen påverkade deras dagliga liv i stor utsträckning. Vidare svarande 5% att de upplevde att vårdpersonalen arbetade med en individuellt anpassad behandlingsplan. Resultatet visade att över hälften av respondenterna inte upplevde att de hade fått information om faktorer som potentiellt kan framkalla migrän. Cirka en tredjedel uttryckte att vårdpersonalen inte förstod deras beskrivna symptom. Respondenter som blivit remitterade till en neurolog uppgav oftare att deras behandling ökat deras livskvalitet. Slutsats: Resultatet belyser migränens inverkan på respondenternas vardag och påvisar behovet av en mer patientcentrerad vård samt brister inom vårdens kompetens att informera, behandla och erbjuda stöd. Det understryker vikten av utökad utbildning för både patienter och vårdpersonal gällande migränhantering. En central upptäckt är att tillgången till neurologisk expertis är betydelsefull för patienternas vårdupplevelse och livskvalitet, då de som erhållit sådan hjälp rapporterat om effektivare lindring. Studien bidrar till en fördjupad förståelse kring hur individer med migrän upplever sin vård och behandling och kan tjäna som bas för vidare forskning och utveckling inom hälso- och sjukvårdssektorn.Introduction: Migraine, a neurological condition, affects around 15% of the population, leading to substantial repercussions, diminished quality of life, decreased work capacity and increased healthcare costs. Specialist referrals can ease symptoms, yet healthcare still lacks in providing sufficient care and options. Objective: To explore the care and treatment experiences of adults with migraines. Method: A cross-sectional, quantitative study collected data via a web survey on Facebook. Results: Among 81 study respondents, 70,4% confirmed that migraines affected their daily lives extensively. Additionally, 5% felt that medical staff did not offer individualized treatment plans. Over half had not received information on potential migraine triggers, and about one-third felt their symptoms were misunderstood by healthcare providers. Those referred to neurologists often noted improved quality of life through their treatment. Conclusion: The findings illustrate the significant daily impact of migraines and the necessity for patient-focused care and deficiencies in healthcare's ability to inform, treat, and support. The importance of enhanced education on migraine management for both patients and professionals is emphasized. Access to neurological expertise appears crucial for patient care experiences and quality of life, with those receiving specialist care reporting better symptom relief. This study deepens the understanding of migraine sufferers' care experiences, potentially guiding future health sector research and development

Migraine – A survey study on experiences of care and treatment

Introduktion: Migrän är en neurologisk sjukdom som påverkar cirka 15 % av befolkningen, orsakar omfattande påföljder, försämrar livskvalitet och arbetskapacitet samt driver upp vårdkostnader. Remiss till specialist kan hjälpa till att lindra symtom, men det finns fortfarande brister inom sjukvården gällande tillgången till adekvat vård och behandlingsalternativ. Syfte: Att undersöka upplevelser av vård och behandling bland vuxna som har migrän. Metod: Studien genomfördes som en tvärsnittsstudie med en kvantitativ ansats, data samlades in via en webbenkätundersökning på Facebook. Resultat: Utav 81 respondenter bekräftade 70,4% att migränen påverkade deras dagliga liv i stor utsträckning. Vidare svarande 5% att de upplevde att vårdpersonalen arbetade med en individuellt anpassad behandlingsplan. Resultatet visade att över hälften av respondenterna inte upplevde att de hade fått information om faktorer som potentiellt kan framkalla migrän. Cirka en tredjedel uttryckte att vårdpersonalen inte förstod deras beskrivna symptom. Respondenter som blivit remitterade till en neurolog uppgav oftare att deras behandling ökat deras livskvalitet. Slutsats: Resultatet belyser migränens inverkan på respondenternas vardag och påvisar behovet av en mer patientcentrerad vård samt brister inom vårdens kompetens att informera, behandla och erbjuda stöd. Det understryker vikten av utökad utbildning för både patienter och vårdpersonal gällande migränhantering. En central upptäckt är att tillgången till neurologisk expertis är betydelsefull för patienternas vårdupplevelse och livskvalitet, då de som erhållit sådan hjälp rapporterat om effektivare lindring. Studien bidrar till en fördjupad förståelse kring hur individer med migrän upplever sin vård och behandling och kan tjäna som bas för vidare forskning och utveckling inom hälso- och sjukvårdssektorn.Introduction: Migraine, a neurological condition, affects around 15% of the population, leading to substantial repercussions, diminished quality of life, decreased work capacity and increased healthcare costs. Specialist referrals can ease symptoms, yet healthcare still lacks in providing sufficient care and options. Objective: To explore the care and treatment experiences of adults with migraines. Method: A cross-sectional, quantitative study collected data via a web survey on Facebook. Results: Among 81 study respondents, 70,4% confirmed that migraines affected their daily lives extensively. Additionally, 5% felt that medical staff did not offer individualized treatment plans. Over half had not received information on potential migraine triggers, and about one-third felt their symptoms were misunderstood by healthcare providers. Those referred to neurologists often noted improved quality of life through their treatment. Conclusion: The findings illustrate the significant daily impact of migraines and the necessity for patient-focused care and deficiencies in healthcare's ability to inform, treat, and support. The importance of enhanced education on migraine management for both patients and professionals is emphasized. Access to neurological expertise appears crucial for patient care experiences and quality of life, with those receiving specialist care reporting better symptom relief. This study deepens the understanding of migraine sufferers' care experiences, potentially guiding future health sector research and development