Ecological properties of earthworm burrows in an organically managed grass-clover system

Earthworms have long been recognized for their soil engineering capacities. Since the creation of the ecosystem service concept the utilitarian perception of nature has gained a lot of attention and funding for research. Hence, we selected earthworms and their burrowing activities to enable an assessment of their influence on water movement and nutrient release. The study went on in autumn where earthworm population densities and their burrowing activities were quantified in plots of third year clover-grass crops differing in fertilisation and the manner of removing the biomass either by grazing or cutting. We found very high biomasses as expected for clover-grass about 200 g wet earthworm weight m-2. The common earthworm association typical to our region was: Aporrectodea tuberculata, Aporrectodea rosea, Aporrectodea longa and Lumbricus terrestris, i.e. two endogeic and two anecic species. We present our results on the burrow size distribution down the soil profile and link it to the species and species traits. The results are further put into perspective in our present research on macropores related to soil ecosystem services and pesticide leachin

Injuries from trending active play products in children and adolescents

INTRODUCTION. Trend products such as trampolines and roller skates may result in child injuries. This study aimed to describe the development of product-related injuries and the pattern of lesions associated with six different trend products among children and adolescents in an urban Danish population from 1980 to 2021. METHODS. We included all children and adolescents aged 0-17 years treated for injuries associated with bouncy castles, play stands, roller skates, scooters, skateboards and trampolines from 1980 to 2021. From the emergency departments at Odense University Hospital, Denmark, we extracted information on the date of injury, diagnosis and severity. We estimated annual incidence rates (IRs) for each product. RESULTS. We included a total of 19,207 cases. The overall injury IRs per 10,000 population/years were 68.3 (95% confidence interval (CI): 67.0-69.6) for play stands, 21.9 (95% CI: 21.2-22.7) trampolines, 13.1 (95% CI: 12.5-13.6) roller skates, 8.0 (95% CI: 7.6-8.5) for skateboards, 7.0 (95% CI: 6.6-7.4) for scooters and 5.5 (95% CI: 5.2-5.9) for bouncy castles. Play stands had a high IR during the entire study period, whereas a significant peak in IR of trampoline injuries of 61.0 (95% CI: 57.6-64.6) and scooters of 18.5 (95% CI: 16.6-20.5) occurred in the 2017-2021 period. For skateboard, roller skate, scooter and play stand injuries, most lesions were located to the upper limbs. The lower limbs were the most frequently injured body region for the remaining products. CONCLUSION. The study provides useful information for the planning of preventive campaigns. FUNDING. None. TRIAL REGISTRATION. Not relevan

Collembola Communities, 20 Years After the Establishment of Distinct Revegetation Treatments in a Severely Eroded Area in South Iceland

Several restoration methods have been developed to aid ecosystem development from highly degraded Icelandic deserts into fully vegetated functional ecosystems. Despite the critical role of soil biota in many key ecosystem processes, the effect of restoration efforts on soil biota has rarely been explored. We took advantage of a large-scale restoration field experiment, to study the effect of distinct revegetation treatments on the taxonomic and functional composition of Collembola communities. Soil samples were taken from plots (one ha. each), that had received functionally distinct revegetation treatments; i: grass + fertilizer, ii: birch seedlings, iii: willow cuttings, iv: lupine and v: control. We were able to show that different revegetation treatments led to the establishment of distinct collembola communities in terms of density and taxonomic and functional composition, 20 years after the revegetation process had started. Life-forms were responsive to revegetation treatment, which suggests that the treatments had induced successional trajectories that lead to distinct habitat conditions, especially with respect to abiotic stress. In contrast to literature, eu-edaphic species were dominating in plots, which were exposed to high levels of disturbance and fluctuations in abiotic conditions. Further research is needed to unravel, to which extent resource supply and abiotic habitat conditions steer Collembola community development across successional trajectories.Several restoration methods have been developed to aid ecosystem development from highly degraded Icelandic deserts into fully vegetated functional ecosystems. Despite the critical role of soil biota in many key ecosystem processes, the effect of restoration efforts on soil biota has rarely been explored. We took advantage of a large-scale restoration field experiment, to study the effect of distinct revegetation treatments on the taxonomic and functional composition of Collembola communities. Soil samples were taken from plots (one ha. each), that had received functionally distinct revegetation treatments; i: grass + fertilizer, ii: birch seedlings, iii: willow cuttings, iv: lupine and v: control. We were able to show that different revegetation treatments led to the establishment of distinct collembola communities in terms of density and taxonomic and functional composition, 20 years after the revegetation process had started. Life-forms were responsive to revegetation treatment, which suggests that the treatments had induced successional trajectories that lead to distinct habitat conditions, especially with respect to abiotic stress. In contrast to literature, eu-edaphic species were dominating in plots, which were exposed to high levels of disturbance and fluctuations in abiotic conditions. Further research is needed to unravel, to which extent resource supply and abiotic habitat conditions steer Collembola community development across successional trajectories.Szereg metod rekultywacji zostało opracowanych w celu przyspieszenia procesu przekształcania mocno zdegradowanych pustyń islandzkich w porośnięte roślinnością ekosystemy lądowe. Wpływ rekultywacji na organizmy glebowe jest rzadko badany, mimo że odgrywają one decydującą rolę w wielu kluczowych procesach zachodzących w ekosystemach. Celem przeprowadzonego na dużą skalę eksperymentu było zbadanie wpływu różnych zabiegów rekultywacyjnych na skład taksonomiczny i funkcjonalny zespołów skoczogonków Collembola. Próbki gleby pobrano z poletek (każde o powierzchni 1 ha), na których zastosowano różne zabiegi; i: trawa + nawóz, ii: sadzonki brzozy, iii: sadzonki wierzby, iv: łubin i v: kontrola. Uzyskane wyniki wykazały, że po 20 latach od rozpoczęcia rekultywacji, poszczególne zabiegi przyczyniły się do powstania zróżnicowanych pod względem zagęszczenia, składu taksonomicznego i funkcjonalnego zespołów skoczogonków. Stwierdzono wyraźną zależność udziału form życiowych skoczogonków od metody rekultywacji, co daję podstawę sądzić, że zastosowane zabiegi zainicjowały różne trajektorie sukcesji, prowadzące do powstania odmiennych zwłaszcza pod względem czynników abiotycznych warunków siedliskowych. Inaczej niż we wcześniejszych badaniach, wykazano, że gatunki euedaficzne dominowały na poletkach narażonych na wysoki poziom zakłóceń i wahania czynników abiotycznych. Zwrócono uwagę, że konieczne są dalsze badania, które pozwolą określić w jakim stopniu zasoby i warunki abiotyczne siedliska wpływają na kształtowanie się zespołów Collembola w różnych przebiegach sukcesji.Several restoration methods have been developed to aid ecosystem development from highly degraded Icelandic deserts into fully vegetated functional ecosystems. Despite the critical role of soil biota in many key ecosystem processes, the effect of restoration efforts on soil biota has rarely been explored. We took advantage of a large-scale restoration field experiment, to study the effect of distinct revegetation treatments on the taxonomic and functional composition of Collembola communities. Soil samples were taken from plots (one ha. each), that had received functionally distinct revegetation treatments; i: grass + fertilizer, ii: birch seedlings, iii: willow cuttings, iv: lupine and v: control. We were able to show that different revegetation treatments led to the establishment of distinct collembola communities in terms of density and taxonomic and functional composition, 20 years after the revegetation process had started. Life-forms were responsive to revegetation treatment, which suggests that the treatments had induced successional trajectories that lead to distinct habitat conditions, especially with respect to abiotic stress. In contrast to literature, eu-edaphic species were dominating in plots, which were exposed to high levels of disturbance and fluctuations in abiotic conditions. Further research is needed to unravel, to which extent resource supply and abiotic habitat conditions steer Collembola community development across successional trajectories

Warming shifts the biomass distribution of soil microarthropod communities

Climate warming is often more detrimental to large body sized organisms than small body sized organisms. Yet, how such differential effects of warming at organismal levels affect aggregate community properties, such as community biomass, remains little understood. Here, using geothermally warmed sub-Arctic grassland soils, we investigate how total biomass (product of density and individual body mass) of two major groups of soil microarthropods (Collembola and mites), which are composed of both large and small body sized species, shift in warmed soils when warmed by ∼3–∼6 °C. Our results show that total biomass of Collembola significantly decreased in warmed soils predominantly due to a decline in the density of large body sized species. In contrast, total mite biomass showed a unimodal response to warming. As a result, there was a shift towards mite biomass dominated microarthropod communities in warmed soils. Within Collembola, the deep soil living eu-edaphic functional group declined the most in total biomass, whereas the unimodal response in mites was most pronounced in oribatid mites. Our study highlights that warming induced shifts in total community biomass of soil microarthropods are likely due to greater detrimental effects of warming on several large body sized Collembola

Population resistance and recovery after an extreme heat event are explained by thermal effects on life-history traits

Extreme heat events lower the fitness of organisms by inducing physiological stress and increasing metabolic costs. Yet, little is known about the role of life-history traits in elucidating population responses to extreme heat events. Here, we used a trait-based approach to understand population resistance and recovery using four closely related species of soil-dwelling Collembola. We measured thermal reaction norms of life-history traits (survival and reproductive traits) and used this information to identify ecological mechanisms linked to population responses after an extreme heat event (i.e. one week at 26–30°C, representing + 10°C above ambient conditions). Furthermore, we investigated potential shifts in the body size distribution of recovering populations to better understand if extreme heat events can restructure body size spectra within populations. While resistance remained unaltered across species in our study, the recovery response of the most heat-sensitive species (Protaphorura pseudovanderdrifti, predominantly a boreal species) was strongly affected by the extreme heat event (−54% population change compared to ambient conditions). Given that the fecundity (linked to recovery) of P. pseudovanderdrifti was more sensitive to heat than their survival (linked to resistance), we detected a decoupling between population resistance and recovery to an extreme heat event in this species. In addition, the detrimental effects of heat on fecundity were largely responsible for a drop in the proportion of small-sized (juvenile) individuals in the recovering populations of P. pseudovanderdrifti. Thermally insensitive resistance and recovery in the other three species (P. armata, P. fimata, P. tricampata; predominantly temperate species) can be explained by their high survival and fecundity at warmer temperatures. We highlight that life-history trait responses to warming can help explain population resistance and recovery after extreme heat events

Temperature-dependent trade-offs in maternal investments: An experimental test with two closely related soil microarthropods

Organisms face trade-offs in their reproductive investment due to energetic constraints. Yet, little is known about how such investments may change at different temperatures, and particularly so in soil invertebrate organisms. Here, we studied two Collembola species (Folsomia candida and Proisotoma minuta) using a long term (several generations) temperature incubation experiment (separately at 15 and 20 ◦C) to investigate how egg size and egg numbers and the trade-off between the two are affected in two temperature regimes. Both species are known to grow at these temperatures, but the variation in their reproductive strategies are little known. Our results show that egg sizes of F. candida were larger in colder temperature whereas no such patterns were found in P. minuta. By contrast, we found no effect of the two temperatures on egg numbers (per clutch) in any of the species. Moreover, we observed a negative correlation (indication of a potential trade-off) between egg size and egg numbers (per clutch) at colder temperature in F. candida, which disappeared in warmer temperature in the same species. No such trade-offs were found in P. minuta. Our results highlight that temperature effects on maternal investments are both trait- and species-specific, particularly when Collembola species are within their optimal thermal niches

Acute periodontal lesions

This is a review and update on acute conditions affecting the gingival tissues, including abscesses in the periodontium, necrotizing periodontal diseases, and other acute conditions that cause gingival lesions with acute presentation, such as infectious process not associated with oral bacterial biofilms, muco-cutanenous disorders, and traumatic and allergic lesions. A periodontal abscess is clinically important since it is a relatively frequent dental emergency, it can compromise the periodontal prognosis of the affected tooth, and because bacteria within the abscess have been identified, mainly by the type of etiology, and there are clear diffrences between those affecting a previously existing periodontal pocket ahd those affecting healthy sites. Therapy for this acute condition consists of drainage and tissue debridement, with individual evaluation of the need for systemic antimicrobial therapy. the definitive treatment of the pre-existing condition should be accomplished after the acute phase is controlled. Necrotizing periodontal disease (NPD) present three typical clinical features : papilla necrosis, gingival bleeding, and pain. Although the prevalence of these diseases is not high, their importance is clear, since they represent the most severe conditions associated with dental biofilm, with very rapid tissue destruction. In adittion to bacteria, the etiology of NPD includes numerous factors that alter the host response and predispose to these diseases, including HIV infection, malnutrition, stress, and tobacco smoking. The treatment consists of superficial debridement, careful mechanical oral hygiene, rinsing with chlorhexidine, and daily re-evaluation. Systemic antimicrobials may be used adjunctively in severe cases or in non-responding conditions and the best option is metronidazole.Once the acute disease is under control, definitive treatment should be provided, including the adequate therapy for the pre-existing gingivitis or periodontitis. Among other acute conditions affecting the periodontal tissues, but not caused by the microorganisms present in oral biofilms , are infectious diseases, muco-cutaneous diseases and traumatic or allergic lesions. In most cases, the gingival envolvement is not severe, though they are common and may prompt a dental emergency visit. These conditions may the direct result of a trauma or the consequence of the breaking of vesicles and bullae. A proper differential diagnosis is important for an adequate management of the case

Screening programmes for the early detection and prevention of oral cancer

Oral cancer is an important global healthcare problem, its incidence is increasing and late-stage presentation is common. Screening programmes have been introduced for a number of major cancers and have proved effective in their early detection. Given the high morbidity and mortality rates associated with oral cancer, there is a need to determine the effectiveness of a screening programme for this disease, either as a targeted, opportunistic or population-based measure. Evidence exists from modelled data that a visual oral examination of high-risk individuals may be a cost-effective screening strategy and the development and use of adjunctive aids and biomarkers is becoming increasingly common

Temperature responses in a subarctic springtail from two geothermally warmed habitats

Common-garden experiments with populations sampled along natural thermal gradients help to reveal local adaptation, disentangle environmental and genetic effects, and ultimately predict, by analogy, future biotic responses to climate change. In this regard, geothermal habitats are useful model systems as they exhibit dramatic changes in soil temperature. The springtail Protaphorura pseudovanderdrifti has apparently coped with such local geothermal warming in Iceland, as this species occurs along a more than half-century-old geothermal gradient in a grassland and persists along a newly emerged temperature gradient in a previously non-geothermal planted spruce forest. We measured thermal reaction norms for development and walking speed and acute cold shock tolerance of P. pseudovanderdrifti originating from the grassland and forest geothermal gradients. Temperature-dependent juvenile development showed little variation among subpopulations from the recently warmed forest, probably due to insufficient evolutionary time, but springtails from the warmed grassland plots had significantly steeper reaction norms than their counterparts from the corresponding unwarmed plot. In contrast, cold tolerance and locomotory activity showed no conclusive clinal pattern despite significant within-habitat variation. There appeared to be significant differences between habitats, as springtails from the forest had more temperature-sensitive developmental rate and locomotory activity, walked faster, and exhibited more variable cold tolerance than grassland springtails did. The planting of a forest, therefore, seems to have exerted a stronger effect on the thermal phenotype of P. pseudovanderdrifti than the emergence of a geothermal gradient. Thus, habitat properties may be no less important in shaping thermal reaction norms than the mean temperature. These local-scale findings suggest that, in addition to warming per se, global transformation of communities may drive the evolution of thermal phenotypes to an extent comparable with the effect of rising environmental temperature