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Klippning och bortföring av biomassa i spår som en del av vegetationsröjningen av spårområdet
Get PDFVegetation i spår kräver röjning eftersom vegetationen påverkar bankroppens livslängd, försämrar dräneringen, resulterar i spårhalka, minskar sikt, skymmer signaler och attraherar vilt till spårområdet. Normalt sker röjning med kättingslagning, men även motormanuella metoder förekommer. Intervjuer med entreprenörer och projektledare visade att det fanns intresse av att samla upp den avklippta biomassan för att säkerställa banvallens kvalitet.Vi har i praktiska försök noterat att mängden biomassa (avklippt) kan vara så hög som 19 ton per spårkilometer. Prov med uppsugning av olika typer av biomassa har utförts på Forshem driftplats varvid en snösug använts. Tekniken visade sig fungera, men kräver ombyggnad för att kunna användas utanför slipersbredden och för att kunna samla in den uppsugna biomassan. Det finns färdig kommersiell utrustning att tillgå för samtidig avklippning och uppsugning, bl a från det Schweiziska företaget Müller, som redan idag används i Mellaneuropa.Förslagsvis genomförs prov i spår i södra Sverige med utrustning från Müller för att undersöka tekniken under svenska förhållanden. Omhändertagande av avklippt biomassa kan ske genom rötning till biogas, förkolning (biokol) eller kompostering. Samtliga dessa tekniker är väl undersökta och beprövade. Logistiken kring omhändertagandet behöver klargöras
Sustainable Spinning of Artificial Spider Silk Fibers with Excellent Toughness and Inherent Potential for Functionalization
Get PDFDespite impressive progress in the field, there are still several major bottlenecks in producing fibers from recombinantly produced spider-silk-like proteins to replicate the extraordinary mechanical properties of spider major ampullate silk. The conventional artificial fiber spinning processes rely primarily on organic solvents to coagulate proteins into fibers and require complex post-treatments to obtain fibers with valuable properties. This is due to challenges in obtaining soluble silk proteins, but also because the native silk spinning process leading to the hierarchical organization of the silk proteins is not fully understood and is hard to replicate in a manner applicable to industrial settings. Here, recombinant spider-silk fusion proteins are efficiently produced and processed into as-spun fibers with a toughness modulus of 120 MJ m-3 and extensibility of 255% using solely aqueous solutions. The spider-silk fusion proteins assemble in a manner similar to that reported for native spider silk: they phase separate induced by salting out, followed by alignment and a secondary structure transition triggered by shear forces and dehydration. Finally, the design of the fusion silk proteins enables straightforward functionalization of the fibers under mild all-aqueous conditions via a simple biomolecular click reaction both pre- and post-spinning.A sustainable aqueous wet spinning method enables an efficient production of artificial spider silk fibers which show excellent extensibility and remarkable toughness. A highly specific and efficient biomolecular click reaction is employed to functionalize these fibers under mild conditions, which offers a promising method to construct multi-functional 1D materials. imag
Estimating Leopard population sizes in western Mozambique using SNP-based capture-mark-recapture models
Get PDFReliable population size estimates are imperative for effective conservation and management, but are notoriously difficult to obtain for rare, cryptic species such as large carnivores. Genetic capture-mark-recapture (CMR) models can provide robust population size estimates and may be conducted noninvasively during a single sampling period. African leopards (Panthera pardus) are listed as vulnerable, with declining populations. However, population size estimates are rare for much of their range. Here, we provide population size estimates for leopards in the Limpopo (LNP) and Banhine (BNP) national parks and the Lebombo Conservancy (LC), in western Mozambique. We estimate population sizes using SNP-based CMR models derived from genetic information acquired noninvasively from scats collected across the sites. Additionally, we compare our density estimates with those derived from trophic scaling to provide inferences on the drivers of Leopard density in the region. We estimate populations of 87, 15, and 13 leopards in LNP, BNP, and LC, respectively. Population size estimates derived from trophic scaling suggest that leopards are limited by bottom-up prey resources in LNP and LC, but there is evidence for top-down regulation in BNP. Given the precariousness of Leopard populations in the region, we urge use of population monitoring using genetic CMR models to inform conservation and management.Few estimates of Leopard population sizes exist for Mozambique, hampering conservation efforts. We estimated 87, 15, and 13 leopards in Limpopo (LNP), Banhine (BNP), and the Lebombo Conservancy (LC), respectively. Populations in LNP and LC are limited by prey availability, and in BNP by poaching
Usual suspects meet mission impossible: Nutrient losses and effects of mitigation measures on a coastal catchment in the Baltic Sea region
Get PDFEutrophication of coastal areas is a global problem. A full-scale coastal remediation project was initiated in Bj & ouml;rn & ouml;fj & auml;rden bay in the Stockholm archipelago in 2011. Measures to reduce external nutrient inputs from the surrounding catchment (15 km2) targeted agriculture, on-site wastewater treatment facilities, and horse keeping. The effects were evaluated at 22 water quality monitoring stations over 11 years (2012-2022) to determine temporal trends in nutrient concentrations, spatial correlations within and between monitored sub-catchments, and effects of individual mitigation measures at local and catchment scale. The effect of individual measures varied from no significant effect to significant nutrient decreases (21% reduction in dissolved P concentrations in one lime filter) or increases (11% higher concentrations in total P in one constructed wetland). However, few significant trends were detected at sub-catchment outlet stations. Tailored placement, design, dimensioning, and maintenance of implemented mitigation measures are needed to improve their nutrient retention effect
Identification and characterisation of temporal abundance of microRNAs in synovial fluid from an experimental equine model of osteoarthritis
Get PDFBackgroundMicroRNAs, a class of small noncoding RNAs, serve as post-transcriptional regulators of gene expression and are present in a stable and quantifiable form in biological fluids. MicroRNAs may influence intra-articular responses and the course of disease, but very little is known about their temporal changes in osteoarthritis.ObjectivesTo identify miRNAs and characterise the temporal changes in their abundance in SF from horses with experimentally induced osteoarthritis. We hypothesised that the abundance of miRNA would change during disease progression.Study designIn vivo experiments.MethodsRNA extracted from synovial fluid obtained sequentially (Day 0, 28 and 70) from nine horses with experimentally induced osteoarthritis was subjected to small RNA sequencing using the Illumina Hiseq 4000 sequencing platform. Differentially abundant miRNAs underwent further validation and mapping of temporal abundance (Day 0, 14, 17, 21, 28, 35, 42, 49, 56, 63 and 70 days after osteoarthritis induction) by microfluidic reverse transcription quantitative real-time PCR. Bioinformatic analyses were performed to predict potential biological associations and target genes of the differentially abundant microRNAs.ResultsSmall RNA sequencing revealed 61 differentially abundant microRNAs at an early osteoarthritis stage (Day 28), and subsequent reverse transcription quantitative real-time PCR analysis validated 20 of these. Significant biological functions of the differentially abundant microRNAs were apoptosis, necrosis, cell proliferation and cell invasion. Following validation, four microRNAs (miRNA-199b-3p, miRNA-139-5p, miRNA-1839 and miRNA-151-5p) were detected in more than 50% of the synovial fluid samples and had higher abundance in osteoarthritic than in control joints.Main limitationsLimited sample size.ConclusionThis is the first study to determine longitudinal changes in synovial fluid microRNA abundance in an equine model of osteoarthritis. Larger studies are needed in naturally occurring osteoarthritis to interrogate putative changes identified by this study
A global dataset of experimental agricultural management on soil carbon accrual, its synergies and trade-offs
Get PDFMaintaining and enhancing soil organic carbon (SOC) in agricultural soils is proposed as a key practice to mitigate climate change. While there is agreement on the co-benefits of SOC accrual on other agroecosystem services, its potential trade-offs in terms of greenhouse gas emissions and nutrient losses are still under debate. We present a global dataset compiling the results of 232 articles that experimentally compare the effects of agricultural management practices with a potential to preserve or enhance SOC against conventional practices. The dataset reports 570 experimental effects of practices to minimise soil disturbance, diversify cropping systems, or increase organic inputs in 254 experiments across 38 countries. The dataset further reports the qualitative (positive, neutral or negative) effects of these management practices on SOC accrual, crop yield, and other response variables related to soil structure, soil biota, CO2 and N2O emissions, and nitrogen and phosphorus losses. This dataset helps understanding the synergies and trade-offs of SOC accrual practices with other ecosystem services, detect current knowledge gaps, and guide future agricultural policies
Long-term population dynamics of an insect in a simple food web under a changing environment
Get PDFWeather conditions are important for the population dynamics of "cold-blooded" animals like insects, with both direct and indirect effects (via the food web). How weather, in combination with other factors, generates population change, and how such effects change over time, are important questions in times of climate change. We monitored an insect seed predator population during a 36-year period of changing weather patterns. The insect is part of a simple food web dominated by seed consumption and lacking natural enemies. Environmental conditions were relatively stable during the first half of the study, but patterns changed during the latter half. Areas of host plant patches increased and seed production entered a strong bi-annual pattern. Insect abundance was measured twice during the yearly life cycle, before and after summer reproduction, and seed resources and competitor densities were measured at the end of the summer. We fit a population model to abundance data to investigate the population dynamics of the insect in relation to changing patterns in weather conditions and food resources. There were both direct and indirect effects of weather, operating at multiple time scales. Abundant sunshine during summer resulted in increased population growth during the same period, but it also resulted in increased survival the following winter. Population growth further depends on seed set the previous summer, which in turn depends on summer rainfall and is likely affected by climate change. This implies indirect weather effects at both short-term and decadal time scales. The new pattern of seed production seems to have led to increased average insect abundance but did not otherwise lead to clear changes in the dynamics of the population. This can be explained by weak regulation of the dynamics of the insect such that short-term environmental variation leads to long unstable population fluctuations. Our study illustrates how insect responses to drastic changes in their environment can be subtle, slow, and hard to detect, manifested by long-term fluctuations. This highlights the importance of long-term data and mechanistic understandings of population dynamics to assess the consequences of changing weather and climate on insects
Life at the (h)edge-Multidiversity in shrub ecotones is driven by habitat quality and shrub foliage cover
Get PDFShrub ecotones, the species-rich transitional zones between grasslands and forests, serve as important refuges for biodiversity but are often confined to small and degraded areas due to prevailing management practices that prioritise either grasslands or forests. This loss of habitat area and quality threatens and impoverishes biodiversity reliant on shrub ecotones. Despite their importance for biodiversity, shrub ecotones were rarely considered in ecological studies, and the drivers affecting their biodiversity across taxa remain unknown. We assessed the effects of multiple shrub ecotone habitat and landscape characteristics for five taxa and their combined multidiversity in 45 sites in Germany. These taxa vary in habitat requirements and dispersal capacities, inhabit different strata and represent multiple trophic levels: herbaceous plants, orthopterans, true bugs, carabids and spiders. The shrub ecotones differed in (i) type (open vs. half-open), (ii) ecotone area, (iii) habitat quality and (iv) surrounding semi-natural habitat cover as potential drivers of diversity (species richness, Hill-Shannon diversity and Hill-Simpson diversity) and multidiversity. Shrub ecotone type and habitat quality were the most important drivers of multidiversity, which peaked in open shrub ecotones of high habitat quality. Open ecotones of high quality contained the highest species richness of herbaceous plants, orthopterans and true bugs, while ecotone area and semi-natural habitat cover were less important. Spiders had the highest Hill-Shannon and Hill-Simpson diversity in open ecotones, while carabids were most speciose in half-open ecotones of lower quality. Synthesis and applications. Our multi-taxa assessment is the first comprehensive study of diversity across taxa and multidiversity in shrub ecotones. By combining multiple diversity metrics, our findings provide a more nuanced understanding of biodiversity patterns, which can better inform conservation strategies. To maximise biodiversity benefits across taxa, we recommend managing shrub ecotones at the landscape scale, maintaining a mosaic of open and half-open shrub ecotones. Designated shrub transition zones with reduced management should be established around suitable habitats to promote the formation of new shrub ecotones.Geb & uuml;schs & auml;ume, die artenreichen & Uuml;bergangszonen zwischen Wald und Offenland, dienen als wichtige R & uuml;ckzugsr & auml;ume f & uuml;r die Biodiversit & auml;t. Allerdings sind sie aufgrund & uuml;blicher Bewirtschaftungspraktiken, die entweder Offenland oder Wald priorisieren, h & auml;ufig auf kleine und degradierte Fl & auml;chen beschr & auml;nkt. Dieser Fl & auml;chenverlust und die abnehmende Habitatqualit & auml;t gef & auml;hrden die auf Geb & uuml;schs & auml;ume angewiesene Biodiversit & auml;t und f & ouml;rdern ihre Verarmung. Trotz ihrer Bedeutung f & uuml;r Flora und Fauna wurden Geb & uuml;schs & auml;ume in & ouml;kologischen Studien bisher selten ber & uuml;cksichtigt, und Einflussfaktoren auf die Biodiversit & auml;t, die sie beherbergen sind weitgehend unbekannt. Wir untersuchten die Auswirkungen verschiedener Habitat- und Landschaftseigenschaften auf f & uuml;nf Taxa sowie deren Multidiversit & auml;t in 45 ausgew & auml;hlten Geb & uuml;schs & auml;umen in Bayern. Die untersuchten Taxa unterscheiden sich in ihren Habitatanspr & uuml;chen und ihrer Ausbreitungsf & auml;higkeit, besiedeln verschiedene Vegetationsschichten und repr & auml;sentieren unterschiedliche trophische Ebenen: krautige Pflanzen, Heuschrecken, Wanzen, Laufk & auml;fer und Spinnen. Die Geb & uuml;schs & auml;ume wiesen Unterschiede in (i) dem Deckungsgrad der Strauchvegetation (offen vs. halboffen), (ii) der Fl & auml;chengr & ouml;ss e, (iii) der Habitatqualit & auml;t und (iv) dem Anteil naturnaher Habitate in der umgebenden Landschaft auf. Diese Faktoren wurden als potenzielle Einflussfaktoren auf die Diversit & auml;t (Artenreichtum, Hill-Shannon-Diversit & auml;t und Hill-Simpson-Diversit & auml;t) sowie auf die Multidiversit & auml;t untersucht. Der Deckungsgrad der Strauchvegetation und die Habitatqualit & auml;t erwiesen sich als die wichtigsten Einflussfaktoren f & uuml;r die Multidiversit & auml;t, die in offenen Geb & uuml;schs & auml;umen mit hoher Habitatqualit & auml;t am h & ouml;chsten war. Offene Geb & uuml;schs & auml;ume von hoher Qualit & auml;t wiesen den h & ouml;chsten Artenreichtum an krautigen Pflanzen, Heuschrecken und Wanzen auf, w & auml;hrend die Fl & auml;chengr & ouml;ss e und der Landschaftskontext eine geringere Rolle spielten. Spinnen erreichten die h & ouml;chste Hill-Shannon- und Hill-Simpson-Diversit & auml;t in offenen Geb & uuml;schs & auml;umen, w & auml;hrend Laufk & auml;fer in halboffenen Geb & uuml;schs & auml;umen von geringerer Habitatqualit & auml;t am artenreichsten waren. Synthese und Anwendungen. Wir pr & auml;sentieren die erste umfassende Analyse der Biodiversit & auml;t & uuml;ber verschiedenen Taxa in Geb & uuml;schs & auml;umen sowie deren Multidiversit & auml;t. Durch die Kombination mehrerer Diversit & auml;tsma ss e liefern unsere Ergebnisse ein differenzierteres Verst & auml;ndnis von Biodiversit & auml;tsmustern zur Optimierung von Naturschutzstrategien. Um die Biodiversit & auml;t & uuml;ber verschiedene Taxa hinweg zu maximieren, empfehlen wir, die Pflege der Geb & uuml;schs & auml;ume auf Landschaftsebene zu organisieren. Diese sollte die Erhaltung eines Mosaiks aus offenen und halboffenen Geb & uuml;schs & auml;umen als Ziel haben. Zudem sollten & Uuml;bergangszonen mit extensiverer Bewirtschaftung um geeignete Habitate ausgewiesen werden, um die Ausbildung neuer Geb & uuml;schs & auml;ume zu f & ouml;rdern
Swift adjustment of biomass allocation strategies in Scots pine after thinning
Get PDFOur study aimed to evaluate the short-term effects of thinning in Scots pine (Pinus sylvestris L.) forests, with focus on above-ground biomass and allocation patterns within trees to compare between treatments. We have established four treatments: one control (unthinned), two moderate thinnings (from above and from below) and one heavy thinning from below, which were properly replicated across four blocks located at two sites in central Sweden. In addition to tree measurements in the field, we performed two destructive samplings, one before thinning in 2020 and another one three years after thinning (2023). We created above-ground biomass functions for each assessment and tree compartment, as well as leaf area and sapwood area functions, which were used for prediction of those variables for treatment effect comparisons on stand level. We found that, within three years after thinning, the dominant trees in the heavily thinned plots presented a significantly higher diameter at breast height (dbh) and leaf area increment, in addition to an increased leaf area-to-sapwood area ratio, than the control. These results indicate that Scots pine trees were able to quickly adjust their allocation strategies under intensive forest management, at least in the short-term, which further suggests that thinning can be a useful strategy in times of climate change and future extreme droughts, when adaptations would be necessary for retaining vital forests
