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Severe abrasive wear is an unwanted phenomenon which occurs widely during hot stamping processes due to extreme process conditions like high temperatures and the absence of lubrication. Abrasive wear is a form of tool wear in which material is removed from the tools, changing the geometrical characteristics of the tools. In a longer term, abrasive wear can negatively affect the shape of formed parts and can influence the heat transfer between the tools and the sheet. Therefore, it is important to develop advanced tools to predict and control abrasive wear during hot stamping processes. More recently an advanced friction model for hot stamping processes has been introduced to accurately describe frictional behavior of 22MnB5-AlSi. This study aims to further extend the advanced friction model of 22MnB5-AlSi into an abrasive wear prediction tool by evaluating a number of abrasive wear models. Three dimensional tool scans of an industrial part are used to calibrate the abrasive wear models. This resulted in a multi-dimensional abrasive wear model as a function of temperature, pressure, strain and the cumulative sliding distance in contact between the tool and the sheet. The abrasive wear distribution and tool lifetime predictions are evaluated based on an industrial part from Volvo Cars. The abrasive tool wear locations are properly identified on the dies and a good correlation in tool wear severity could be made. However, the evolution of abrasive wear in less severe areas should be further investigated to increase the prediction capability of the proposed tool wear model. © CHS2 2024 . All rights reserved.

Dominance often indicates one or a few species being best suited for resource capture and retention in a given environment. Press perturbations that change availability of limiting resources can restructure competitive hierarchies, allowing new species to capture or retain resources and leaving once dominant species fated to decline. However, dominant species may maintain high abundances even when their new environments no longer favour them due to stochastic processes associated with their high abundance, impeding deterministic processes that would otherwise diminish them. Here, we quantify the persistence of dominance by tracking the rate of decline in dominant species at 90 globally distributed grassland sites under experimentally elevated soil nutrient supply and reduced vertebrate consumer pressure. We found that chronic experimental nutrient addition and vertebrate exclusion caused certain subsets of species to lose dominance more quickly than in control plots. In control plots, perennial species and species with high initial cover maintained dominance for longer than annual species and those with low initial cover respectively. In fertilized plots, species with high initial cover maintained dominance at similar rates to control plots, while those with lower initial cover lost dominance even faster than similar species in controls. High initial cover increased the estimated time to dominance loss more strongly in plots with vertebrate exclosures than in controls. Vertebrate exclosures caused a slight decrease in the persistence of dominance for perennials, while fertilization brought perennials' rate of dominance loss in line with those of annuals. Annual species lost dominance at similar rates regardless of treatments. Synthesis. Collectively, these results point to a strong role of a species' historical abundance in maintaining dominance following environmental perturbations. Because dominant species play an outsized role in driving ecosystem processes, thei

In dit artikel berichten we over twee verschillende experimenten: een strooiseltransplantatie-experiment op de Johannahoeve (Arnhem) met data over diverse groepen bodemorganismen waaronder aaltjes, en een verteringsexperiment op Nieuw Dennenlust (Beekbergen) met een uitgebreide analyse van voedselgildes (soorten met een overeenkomstig dieet, bijvoorbeeld planteneters, schimmelzuigers, et cetera) van bodemmicroarthropoden.

Is de veerkracht van onze bomen en bossen toereikend om hetere endrogere periodes en aanhoudende bodemverzuring in de toekomst teoverleven? Welke bosbeheermaatregelen zijn mogelijk en nodig om deverschillende bosfuncties te behouden? Om deze vragen te beantwoordenen de gevolgen van klimaatverandering en bodemverzuring in kaart tebrengen zijn wij – een consortium van wetenschappers en bosgebruikers –een bosexperiment gestart. Het doel is om de reacties van bomen, bodemsen uiteindelijke hele bossen op verschillende beheeringrepen te begrijpenin relatie tot veranderingen in bodem en klimaat. Dit artikel geeft eenintroductie van het experiment.

It is generally assumed that the dependence of conventional agriculture on artificial fertilizers and pesticides strongly impacts the environment, while organic agriculture relying more on microbial functioning may mitigate these impacts. However, it is not well known how microbial diversity and community composition change in conventionally managed farmers’ fields that are converted to organic management. Here, we sequenced bacterial and fungal communities of 34 organic fields on sand and marine clay soils in a time series (chronosequence) covering 25 years of conversion. Nearby conventional fields were used as references.We found that community composition of bacteria and fungi differed between organic and conventionally managed fields. In the organic fields, fungal diversity increased with time since conversion. However, this effect disappeared when the conventional paired fields were included. There was a relationship between pH and soil organic matter content and the diversity and community composition of bacteria and fungi. In marine clay soils, when time since organic management increased, fungal communities in organic fields became more dissimilar to those in conventional fields. We conclude that conversion to organic management in these Dutch farmers’ fields did not increase microbial community diversity. Instead, we observed that in organic fields in marine clay when time since conversion increased soil fungal community composition became progressively dissimilar from that in conventional fields. Our results also showed that the paired sampling approach of organic and conventional fields was essential in order to control for environmental variation that was otherwise unaccounted for.

As a response to the increased pressure of global climate change on most ecosystems, national and international agreements aim at creating forests that are productive, resilient to climate change, and that store carbon to mitigate global warming. However, these aims are being challenged by increased tree mortality rates and decreased tree growth rates in response to increased incidence of extreme drought events. These phenomena make us aware of a lack of crucial insights into the effects of forest management on the growth and survival of trees, and on carbon storage in both trees and forest soils under increased incidence of drought. Here we compile current knowledge on how forest management and drought impact on tree growth and survival, and above- and belowground carbon storage in forest ecosystems. Based on this, we propose that climate-smart forestry may benefit from controlling stand density at intermediate levels (>60%, e.g.∼80%) by applying low levels of tree harvest intensity on a regular base. Furthermore, we propose that the actual optimal density will depend on the tree species, site conditions and management history. As a next step, studies are needed that take an above- and belowground approach and combine forest experiments with mechanistic models on water, carbon and nutrient flows in trees and soils within forests in order to transform current results, which focus on either soil or trees and are often highly-context dependent, to a more generic forest framework. Such a generic framework would be needed to enhance understanding across forest ecosystems on how forest management may promote forest resilience, productivity and carbon storage with increasing drought.

Soil bacteria and fungi are key drivers of carbon released from soils to the atmosphere through decomposition of plant-derived organic carbon sources. This process has important consequences for the global climate. While global change factors, such as increased temperature, are known to affect bacterial- and fungal-mediated decomposition rates, the role of trophic interactions in affecting decomposition remains largely unknown. We designed synthetic microbial communities consisting of eight bacterial and eight fungal species and tested the influence of predation by a model protist, Physarum polycephalum, on litter breakdown at 17 and 21 °C. Protists increased CO2 release and litter mass loss by ~35% at 17 °C lower temperatures, while they only had minor effects on microbial-driven CO2 release and mass loss at 21 °C. We found species-specific differences in predator–prey interactions, which may affect microbial community composition and functioning and thus underlie the impact of protists on litter breakdown. Our findings suggest that microbial predation by fast-growing protists is of under-appreciated functional importance, as it affects decomposition and, as such, may influence global carbon dynamics. Our results indicate that we need to better understand the role of trophic interactions within the microbiome in controlling decomposition processes and carbon cycling.

Plant–soil feedback (PSF) results from the net legacy effect that plants leave in the composition of soil communities and abiotic soil properties. PSF is induced by the rhizosphere and by litter inputs into the soil, however, we have little understanding of their individual contributions. Here, we examine feedback effects from the rhizosphere of living plants, decomposing litter and their combination. We used four pairs of climate warming-induced range-expanding plant species and congeneric natives, and examined PSF effects on plant biomass production, as well as on decomposition in their new range. We tested the hypothesis that the plant rhizosphere provides less negative feedback to range-expanders than to the congeneric natives, and that feedback mediated by litter decomposition does not provide such a difference because decomposers might be less specialized than pathogens. To determine PSF, we used soil from the congener species within each pair as an ‘away’ soil to indicate whether range-expanders may have lost their specialized soil biota upon arrival in the novel range. Our results show that although range-expanding plant species and their congeneric natives developed neutral PSF in both rhizosphere- and litter-conditioned soils, two of the four range-expanders produced more biomass than natives in soils conditioned by litter, that is, soils with high nutrient content. Shoot litter from two out of four range-expanding species decomposed more than that of natives, but decomposition was unaffected by soil conditioning. Synthesis. We compared PSF effects of range-expanders and congeneric natives mediated via both the rhizosphere and litter using the congeneric species as a control. Under those conditions, PSF effects were neutral and not affected by plant origin. Therefore, we conclude that studies not comparing within plant genera may overestimate the impact of plant origin on PSF. Still, even under those conditions range-expanders appeared to benefit more from

1. Plant-soil feedback (PSF) results from the net legacy effect that plants leave in the composition of soil communities and abiotic soil properties. PSF is induced by the rhizosphere and by litter inputs into the soil, however, we have little understanding of their individual contributions. Here, we examine feedback effects from the rhizosphere of living plants, decomposing litter, and their combination. 2. We used four pairs of climate warming-induced range-expanding plant species and congeneric natives, and examined PSF effects on plant biomass production, as well as on decomposition in their new range. 3. We tested the hypothesis that the plant rhizosphere provides less negative feedback to range-expanders than to the congeneric natives, and that feedback mediated by litter decomposition does not provide such a difference because decomposers might be less specialized than pathogens. To determine PSF, we used soil from the congener species within each pair as an “away” soil to indicate whether range-expanders may have lost their specialized soil biota upon arrival in the novel range. 4. Our results show that although range-expanding plant species and their congeneric natives developed neutral PSF in both rhizosphere- and litter-conditioned soils, two of the four range-expanders produced more biomass than natives in soils conditioned by litter, i.e. soils with high nutrient content. Shoot litter from two out of four range-expanding species decomposed more than that of natives, but decomposition was unaffected by soil conditioning. 5. Synthesis. We compared PSF effects of range expanders and congeneric natives mediated via both the rhizosphere and litter using the congeneric species as a control. Under those conditions, PSF effects were neutral and not affected by plant origin. Therefore, we conclude that studies not comparing within plant genera may overestimate the impact of plant origin on PSF. Still, even under those conditions range-expanders appeared to benef

A key challenge is to increase sustainability in agriculture without yield loss. Organic agriculture uses no chemical fertilizers and pesticides. Instead, yield depends on nutrients released from organic inputs, and thereby on soil communities that drive soil carbon and nutrient cycling. However, these soil communities may need time to establish, resulting in lower yields during the beginning of this conversion. How carbon and nutrient cycling change during the conversion from conventional to organic agriculture is not well understood, but it may help us to understand, and eventually reduce, the yield gap. Here, we studied how carbon and nitrogen cycling change when converting conventional agricultural systems into organic agricultural systems. We used a hronosequence approach, where we collected soil samples from 37 organic fields, on both sand and clay soils, that have been converted from conventional to organic agriculture between 1 to 40 years ago and from neighboring conventional fields. Under controlled conditions we measured potential rates of carbon and nitrogen mineralization. Potential carbon mineralization and substrate induced respiration were higher in organic soils, but there was no effect of time since conversion. This might be explained by variation in abiotic factors such as soil organic matter content. We use our data to unravel how fast ecosystem processes change after the conversion of conventional into organic farming systems. Our findings will yield important insights how the performance of soil communities is changed during transition and this will help us to understand changes in crop yield.

1. It is increasingly recognized that interactions between plants and soil (a)biotic conditions can influence local decomposition processes. For example, decomposer communities may become specialized in breaking down litter of plant species that they are associated with, resulting in accelerated decomposition, known as ‘home-field advantage’ (HFA). Also, soils can vary inherently in their capacity to degrade organic compounds, known as ‘ability’. However, we have a poor understanding how environmental conditions drive the occurrence of HFA and ability. 2. Here, we studied how HFA and ability change across three types of successional gradients: coastal sand dunes (primary succession), inland drift sands (primary succession), and ex-arable fields (secondary succession). Across these gradients, litter quality (i.e., nutrient, carbon and lignin contents) increases with successional time for coastal dunes and decreases for the other two gradients. 3. We performed a 12-month reciprocal litter transplant experiment under greenhouse conditions using soils and litters collected from early-, mid-, and late-successional stages of each gradient. 4. We found that HFA and ability did not consistently shift with successional stage for all gradients, but were instead specific for each type of successional gradient. In coastal dunes HFA was positive for early-successional litter, in drift sands it was negative for mid-successional litter, and for ex-arable fields, HFA increased with successional time. Ability of decomposer communities was highest in mid-successional stages for coastal dunes and drift sands, but for ex-arable fields ability decreased throughout with successional time. High HFA was related to high litter C content and soil and organic matter content in soils and to low litter and soil nutrient concentrations. Ability did not consistently occur in successional stages with high or low litter quality. 5. Synthesis: Our findings show that specific environmental conditions

Many grassland biodiversity experiments show a positive relationship between biodiversity and ecosystem functioning, however, in most these experiments plant communities are established by sowing and natural colonization is prevented by selective weeding of non-sown species. During ecosystem restoration, for example on abandoned fields, plant communities start on bare soil, and diversity is often manipulated in a single sowing event. How such initial plant diversity manipulations influence plant biodiversity development and ecosystem functioning is not well understood. We examined how relationships between taxonomic and functional diversity, biomass production and stability develop over 16 years in non-weeded plots sown with 15 species, 4 species, or that were not sown. We found that sown plant communities become functionally similar to unsown, naturally colonized plant communities. However, initial sowing treatments had long-lasting effects on species composition and taxonomic diversity. We found only few relationships between biomass production, or stability in biomass production, and functional or taxonomic diversity, and the ones we observed were negative. In addition, the cover of dominant plant species was positively related to biomass production and stability. We conclude that effects of introducing plant species at the start of secondary succession can persist for a long time, and that in secondary succession communities with natural plant species dynamics diversity-functioning relationships can be weak or negative. Moreover, our findings indicate that in systems where natural colonization of species is allowed effects of plant dominance may underlie diversity-functioning relationships.

Our basic understanding of plant litter decomposition informs the assumptions underlying widely applied soil biogeochemical models, including those embedded in Earth system models. Confidence in projected carbon cycle–climate feedbacks therefore depends on accurate knowledge about the controls regulating the rate at which plant biomass is decomposed into products such as CO2. Here we test underlying assumptions of the dominant conceptual model of litter decomposition. The model posits that a primary control on the rate of decomposition at regional to global scales is climate (temperature and moisture), with the controlling effects of decomposers negligible at such broad spatial scales. Using a regional-scale litter decomposition experiment at six sites spanning from northern Sweden to southern France—and capturing both within and among site variation in putative controls—we find that contrary to predictions from the hierarchical model, decomposer (microbial) biomass strongly regulates decomposition at regional scales. Furthermore, the size of the microbial biomass dictates the absolute change in decomposition rates with changing climate variables. Our findings suggest the need for revision of the hierarchical model, with decomposers acting as both local- and broad-scale controls on litter decomposition rates, necessitating their explicit consideration in global biogeochemical models.

Our basic understanding of plant litter decomposition informs the assumptions underlying widely applied soil biogeochemical models, including those embedded in Earth system models. Confidence in projected carbon cycle-climate feedbacks therefore depends on accurate knowledge about the controls regulating the rate at which plant biomass is decomposed into products such as CO2. Here, we test underlying assumptions of the dominant conceptual model of litter decomposition. The model posits that a primary control on the rate of decomposition at regional to global scales is climate (temperature and moisture), with the controlling effects of decomposers negligible at such broad spatial scales. Using a regional-scale litter decomposition experiment at six sites spanning from northern Sweden to southern France – and capturing both within and among site variation in putative controls – we find that contrary to predictions from the hierarchical model, decomposer (microbial) biomass strongly regulates decomposition at regional scales. Further, the size of the microbial biomass dictates the absolute change in decomposition rates with changing climate variables. Our findings suggest the need for revision of the hierarchical model, with decomposers acting as both local- and broad-scale controls on litter decomposition rates, necessitating their explicit consideration in global biogeochemical models.

Global warming has begun to have a major impact on the species composition and functioning of plant and soil communities. However, long-term community and ecosystem responses to increased temperature are still poorly understood. In this study, we used a well-established elevational gradient in northern Sweden to elucidate how plant, microbial and nematode communities shift with elevation and associated changes in temperature in three highly contrasting vegetation types (i.e. heath, meadow and Salix vegetation). We found that responses of both the abundance and composition of microbial and nematode communities to elevation differed greatly among the vegetation types. Within vegetation types, changes with elevation of plant, microbial and nematode communities were mostly linked at fine levels of taxonomic resolution, but this pattern disappeared when coarser functional group levels were considered. Further, nematode communities shifted towards more conservative nutrient cycling strategies with increasing elevation in heath and meadow vegetation. Conversely, in Salix vegetation microbial communities with conservative strategies were most pronounced at the mid-elevation. These results provide limited support for increasing conservative nutrient cycling strategies at higher elevation (i.e. with a harsher climate). Our findings indicate that climate-induced changes in plant community composition may greatly modify or counteract the impact of climate change on soil communities. Therefore, to better understand and predict ecosystem responses to climate change, it will be crucial to consider vegetation type and its specific interactions with soil communities.