Ectomycorrhizal fungal mycelial dynamics and its role in forest soil carbon cycling

Most boreal tree species rely on root-associated ectomycorrhizal fungi for nutrient acquisition, in exchange the trees allocate part of their photosynthetically fixed carbon (C) to these fungi. This has a feedback on soil C dynamics as mycorrhizal fungi are important in regulating soil C cycling and storage. However, mycorrhizal fungi are often not included in C dynamics models, as mechanistic understanding of their contribution to mycorrhiza-mediated processes are largely lacking. The aim of the work described in this thesis was to address this knowledge gap by studying the contribution of mycorrhizal fungi in regulating soil C fluxes. This was done by quantifying C fluxes associated with the extraradical mycelium (ERM) of mycorrhizal fungi, and examining how the ERM contributes to variations in soil C cycling along a nemoboreal chronosequence of managed Pinus sylvestris forests. Production and turnover of ERM was quantified by determining ERM biomass in sequentially harvested ingrowth mesh bags and by mathematical modelling. Respiration of ERM was measured as CO2 efflux from mesh bags, and carbon use efficiency (CUE) was calculated from ERM production and respiration rates. We assessed soil fungal communities along the chronosequence and investigated correlations between taxonomic composition and enzyme activities. The ERM standing biomass increased despite decreased production along the chronosequence. This contradiction was explained by a drastic decline in biomass turnover, from seven times to one time per year. The CUE decreased with forest age, but increased tenfold from summer (0.019) to autumn (0.200). This seasonal increase in CUE was associated with a decline in gross photosynthetic production, suggesting that variation in photosynthetic C supply regulates seasonal variations in CUE. Relative abundance of ectomycorrhizal taxa increased with forest age, and was dominated by Atheliaceae species in young forests, and by Cortinarius and Russula species in mature forests. Enzyme activities were related to community composition, and seem to be important for maintaining forest productivity, by facilitating organic nutrient mobilisation. This thesis is a first step in parameterizing mycorrhizal mycelial C fluxes to enable explicit inclusion of ERM parameters in forest ecosystem C models

Climate change mitigation potential of biochar from forestry residues under boreal condition

Forest harvest residue is a low-competitive biomass feedstock that is usually left to decay on site after forestry operations. Its removal and pyrolytic conversion to biochar is seen as an opportunity to reduce terrestrial CO2 emissions and mitigate climate change. The mitigation effect of biochar is, however, ultimately dependent on the availability of the biomass feedstock, thus CO2 removal of biochar needs to be assessed in relation to the capacity to supply biochar systems with biomass feedstocks over prolonged time scales, relevant for climate mitigation. In the present study we used an assembly of empirical models to forecast the effects of harvest residue removal on soil C storage and the technical capacity of biochar to mitigate national-scale emissions over the century, using Norway as a case study for boreal conditions. We estimate the mitigation potential to vary between 0.41 and 0.78 Tg CO2 equivalents yr−1, of which 79% could be attributed to increased soil C stock, and 21% to the coproduction of bioenergy. These values correspond to 9–17% of the emissions of the Norwegian agricultural sector and to 0.8–1.5% of the total national emission. This illustrates that deployment of biochar from forest harvest residues in countries with a large forestry sector, relative to economy and population size, is likely to have a relatively small contribution to national emission reduction targets but may have a large effect on agricultural emission and commitments. Strategies for biochar deployment need to consider that biochar's mitigation effect is limited by the feedstock supply which needs to be critically assessed.acceptedVersio

Soil microclimate changes affect soil fungal communities in a Mediterranean pine forest

Soil microclimate is a potentially important regulator of the composition of plant‐associated fungal communities in climates with significant drought periods. Here, we investigated the spatio‐temporal dynamics of soil fungal communities in a Mediterranean Pinus pinaster forest in relation to soil moisture and temperature. Fungal communities in 336 soil samples collected monthly over 1 year from 28 long‐term experimental plots were assessed by PacBio sequencing of ITS2 amplicons. Total fungal biomass was estimated by analysing ergosterol. Community changes were analysed in the context of functional traits. Soil fungal biomass was lowest during summer and late winter and highest during autumn, concurrent with a greater relative abundance of mycorrhizal species. Intra‐annual spatio‐temporal changes in community composition correlated significantly with soil moisture and temperature. Mycorrhizal fungi were less affected by summer drought than free‐living fungi. In particular, mycorrhizal species of the short‐distance exploration type increased in relative abundance under dry conditions, whereas species of the long‐distance exploration type were more abundant under wetter conditions. Our observations demonstrate a potential for compositional and functional shifts in fungal communities in response to changing climatic conditions. Free‐living fungi and mycorrhizal species with extensive mycelia may be negatively affected by increasing drought periods in Mediterranean forest ecosystems.info:eu-repo/semantics/acceptedVersio

Oppdatering av kunnskapsgrunnlag for klimatiltak i skog: Gjennomgang av 11 utvalgte tiltak i bestandsskogbruket

På oppdrag fra Miljødirektoratet og Landbruksdirektoratet har vi gått gjennom kunnskapsstatus på 11 ulike tiltak utvalgt av direktoratene. Alle tiltakene ligger innenfor det tradisjonelle bestandsskogbruket. Tiltakene er vurdert ut fra hvordan de kan øke skogens netto CO2-opptak (karbonlagring), men for noen tiltak også betydning for andre klimagasser og for biogeofysiske effekter som albedo. Utvalget er ikke uttømmende, og også andre tiltak gjennom omløpet vil ha effekt på skogens CO2-opptak. Potensielle substitusjonseffekter gjennom tilgang på mer tømmer eller tømmer med høyere kvalitet er ikke inkludert. Klimatilpasning har vært med i vurderingen av alle tiltak. Det er korte omtaler av tiltakenes effekter på naturmangfold.Oppdatering av kunnskapsgrunnlag for klimatiltak i skog: Gjennomgang av 11 utvalgte tiltak i bestandsskogbruketpublishedVersio

Interoperabilitet, administration och ledning av radiosambandssystem TARAS relativt JTIDS/MIDS

Det svenska taktiska radiosystemet (TARAS) bygger på en tekniskt liknande arkitektur som NATOs system JointTactical Information Distribution System/Multifunctional Information Distribution System (JTIDS/MIDS). JTIDS/MIDShuvudsakliga tjänst är den taktiska datalänken link 16. En avsikt med uppsatsen är att visa på vilka likheter ocholikheter som finns mellan dessa två radiosambandssystem ur ett tekniskt perspektiv. På grundval av dessa likheteroch olikheter studeras hurvida det finns någon internationell anpassningsförmåga av TARAS-systemet motJTIDS/MIDS-systemet. En anpassningsförmåga som syftar till interoperabilitet för svenska flyg- och sjöstridskraftergentemot NATO. En annan avsikt är att utgå från den uppenbara likheten att båda systemen är ytterst komplexa till sinnatur och kräver därför en kompetent organisation för adminstration och ledning. Vald metod är att studera hur enutvald nations, Storbritanniens, ledningsorganisation för JTIDS/MIDS arbetar. Syftet är att analysera huruvidaslutsatser kan dras rörande hur en svensk lednings-, planerings- och driftorganisation för nyttjande av TARASsystemeti Sverige skall verka i framtiden. Avseendet är då att studera organisatorisk nivå inom försvarsmakten,uppgifter i stort för densamma samt övergripande kompetensfrågor hos personalen. Slutsatserna i uppsatsen innebäratt någon interoperabilitet inte föreligger mellan TARAS och JTIDS/MIDS. Sverige måste därför lämna TARASsystemetoch gå över till JTIDS/MIDS-systemet om interoperabilitet på den högsta nivån, i uppsatsen benämndhumannivån, skall uppnås. Slutsatserna från diskussionen rörande administration och ledning av TARAS-systemetpekar på att endast en övergripande slutsats kan dras genom att jämföra med Storbritannien. Slutsatsen är att ensvensk ledningsorganisation för TARAS bör vara försvarsmaktsgemensam och organiseras inom Opil/FTK ram. Närdet gäller uppgifter i stort och kompetensfrågor är skillnaderna för stora för att slutsatser skall kunna dras. Orsaken tilldetta är olika nyttjandefilosofier mellan TARAS och JTIDS/MIDS samt olikheten mellan det svenska enbefälssystemetoch Storbritanniens tvåbefälssystem.The Swedish tactical radiosystem (TARAS) has a similar architecture from a technical point of view as the NATOsystem Joint Tactical Information Distribution System/Multifunctional Information Distribution System (JTIDS/MIDS).The prime service offered by JTIDS/MIDS is the tactical datalink Link 16. One purpose with this thesis is to describesimilarities and dissimilarities between the two radio systems from a technical point of view. According to thesesimilarities and dissimilarities this thesis studies whether there is any ability to adapt the TARAS-system toJTIDS/MIDS or not. An adaptation which has the ultimate goal of interoperability between Swedish air and seaforcesand NATO. Another purpose is to use the flagrant similarity between the systems regarding complexity, andconsequently the demand to ensure the efficient and co-ordinated use of data links in any operational theatre cell as abasis for discussion on how a Swedish data link planning and management cell, supporting TARAS, should beorganised. By using a selected nation’s, The United Kingdom’s, data link management cell as a basis for discussion itis examined if any conclusions can be drawn as to how a Swedish data link planning and management cell should beorganised and working in the future. The issues regarding organisational level within the Swedish Armed Forces, majortasks and competency of the crew is examined. The conclusions in the thesis is that there is no interoperabilitybetween the two systems TARAS and JTIDS/MIDS. Consequently, Sweden must leave the TARAS-system and adaptthe JTIDS/MIDS-system if any interoperability at the highest level, between on the human level (brain-to-brain), is tobe achieved. Regarding the data link planning and management cell, the only general conclusion that is possible todraw in the comparison with the U.K. cell is that the Swedish analogue should be organised in a joint way and withinthe framework of the organisation of the Air Component Commander’s organisation. When it comes to tasks andcompetency of the crew, the dissimilar philosophies for using the systems and the use of NCOs, a category thatdoesn’t exists in Sweden, makes further comparisons impossible.Avdelning: ALB - Slutet Mag 3 C-upps.Hylla: Upps. ChP T 00-0

Nya spelregler En kvalitativ studie om migrerade mäns upplevelser av att vara pappa i Sverige

Studien handlar om migrerande mäns upplevelser av att vara pappa i Sverige och syftar till att undersöka hur den svenska kontexten bestående av strukturer, ideal och normer påverkar föräldraskapet hos dessa. Som ingång till detta ämne har föräldraskapet ställts i relation till de resonemang som förts mellan föräldrarna kring fördelning av föräldradagar. Empirin har samlats in genom sex kvalitativa semistrukturerade intervjuer med män som är födda utanför norden och som har barn under åtta år. I studien framkom det att vissa av respondenterna kunde känna sig bevakade i sitt föräldraskap då de som utlandsfödda pappor kunde förväntas agera annorlunda av majoritetssamhället. Det visade sig även att pappans roll i föräldraskapet till viss del kunde ha förändrats efter migrationen till Sverige. Detta då de fick ta på sig ett större ansvar i hemmet då släkten efter migrationen inte var i närheten och kunde ta den centrala roll som de hade i födelselandet. Enligt tidigare forskning är Sverige dessutom ett land med hög grad av defamilialisering där sociala förmåner är utformade så att de ska vara som mest effektiva i tvåförsörjarfamiljer. Detta har bidragit till att ideal skapats kring jämn ansvarsfördelning mellan könen vilket ytterligare kan ha påverkat det rollskifte som några av våra respondenter har upplevt. Föräldraförsäkringssystemet har visat sig inte vara ett tillräckligt verktyg för att åstadkomma likafördelning mellan föräldrarna utan andra faktorer så som förväntningar på könen och traditionella maktstrukturer spelar in. Det görs en tydlig uppdelning mellan könen när det kommer till vilka roller som tas i föräldraskapet som följer en traditionell uppdelning men detta är inte något utmärkande för ”invandrarfamiljen” utan enligt tidigare forskning går dessa tendenser även att finna i Sverige generellt

Framskrivninger for arealbrukssektoren (LULUCF) under FNs klimakonvensjon: Sensitivitets- og usikkerhetsanalyser

Arealbrukssektoren (engelsk: Land Use, Land-Use Change and Forestry, LULUCF) omfatter arealbruk og arealbruksendringer, med tilhørende utslipp og opptak av CO2, CH4 (metan) og N2O (lystgass), og er en del av det nasjonale klimagassregnskapet under FNs klimakonvensjon. I oktober 2022 ble det publisert oppdaterte, nasjonale framskrivninger for sektoren (Mohr mfl. 2022), basert på data og metodikk fra Norges siste rapportering til FNs klimakonvensjon (Miljødirektoratet mfl. 2022). Som en oppfølging av det arbeidet presenteres her et utvalg sensitivitets- og usikkerhetsanalyser som illustrerer følsomheten og usikkerheten i framskrivningene for noen parametre. Dette er klima (RCP4.5 versus 8.5 og et gjennomsnitt av disse to), to utvalgte typer arealbruksendring (avskoging, og overgang fra myr og skog på organisk jord til annen arealbruk), samt inndata brukt i Yasso07.Framskrivninger for arealbrukssektoren (LULUCF) under FNs klimakonvensjon: Sensitivitets- og usikkerhetsanalyserpublishedVersio

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