The ongoing climate change may strongly impact soil biodiversity with cascading effects on the processes they drive. Thus, it is of prime interest to improve our knowledge about responses by soil ...organisms such as collembolans to expected shifts in environmental conditions by considering communities comprising both detritivores and predators.
The aim of the present study was to evaluate how simulated climate change and predation under laboratory conditions alter a collembolan community.
To infer the impact of climate change, we applied a decreased level of soil moisture (60% vs. 30% soil water holding capacity) and an increasing air temperature (15°C vs. 25°C) to a collembolan community constituted by four species (Folsomia candida, Protaphorura fimata, Proisotoma minuta and Mesaphorura macrochaeta) exhibiting distinct functional traits, for example, body size and furca presence, in the presence or absence of a predatory gamasid Acari Stratiolaelaps scimitus during 2 months in a microcosm experiment.
We observed that decreasing soil moisture altered the collembolan community with species‐specific responses. Interaction between soil moisture, temperature and predation indicates that low soil moisture reduced total collembolan abundance especially (a) by suppressing the positive effect of increasing temperature and (b) by increasing the predatory control on collembolan abundance.
These results highlight that soil moisture is the major driver of Collembola community and by consequence, a shift in climatic parameters with the ongoing climate change should strongly modify the Collembola community structure and the predator–prey interaction. Our findings are highly important since a strengthening of predation impact on Collembola prey could have major consequences on the whole soil food web being able to lead to a slowdown of key ecosystem processes they drive (e.g. litter decomposition and nutrient recycling). Finally, our study promotes the need to study more complex systems considering distinct soil‐dwelling species, their functional traits and their trophic interactions to better predict the ecosystem responses to the ongoing climate change.
A free Plain Language Summary can be found within the Supporting Information of this article.
A free Plain Language Summary can be found within the Supporting Information of this article.
Mapping earthworm communities in Europe Rutgers, Michiel; Orgiazzi, Alberto; Gardi, Ciro ...
Applied soil ecology : a section of Agriculture, ecosystems & environment,
01/2016, Letnik:
97
Journal Article
Recenzirano
•Existing earthworm data were collected from 3838 sites in 8 European countries.•Habitat–response relationships were developed for earthworm community attributes.•Digital Soil Mapping was used to ...predict earthworm distributions across Europe.•These earthworms maps can be used for raising awareness, e.g. in the Global Soil Biodiversity Atlas.
Existing data sets on earthworm communities in Europe were collected, harmonized, collated, modelled and depicted on a soil biodiversity map. Digital Soil Mapping was applied using multiple regressions relating relatively low density earthworm community data to soil characteristics, land use, vegetation and climate factors (covariables) with a greater spatial resolution. Statistically significant relationships were used to build habitat–response models for maps depicting earthworm abundance and species diversity. While a good number of environmental predictors were significant in multiple regressions, geographical factors alone seem to be less relevant than climatic factors. Despite differing sampling protocols across the investigated European countries, land use and geological history were the most relevant factors determining the demography and diversity of the earthworms. Case studies from country-specific data sets (France, Germany, Ireland and The Netherlands) demonstrated the importance and efficiency of large databases for the detection of large spatial patterns that could be subsequently applied at smaller (local) scales.
Effects on soil Collembola of Cu, Zn, Pb, and Cd pollution from Cu smelters over 40 years were investigated in paddy fields from an area of Eastern China. We compared the field effects to those ...observed in single-species laboratory tests employing the hemiedaphic collembolan
Folsomia candida
and the epedaphic
Sinella curviseta
obtained from laboratory cultures and exposed to field-collected polluted soil. The results indicated that different collembolan species responded differently to the pollution in the fields and could be divided into sensitive, indifferent, and tolerant types accordingly. The abundance of sensitive species decreased as the pollution increased, but this was not the same for indifferent and tolerant species. The dominant species changed from sensitive to tolerant species as the pollution increased. The reproduction of
F. candida
and
S. curviseta
was most sensitive to the contaminated soil compared to growth and survival; the sensitivity of the two species was similar. The growth was more sensitive than the survival for
F. candida
but not for
S. curviseta
. The growth and survival of
F. candida
were much more sensitive than those of
S. curviseta
. Sensitivity of field populations of
F. candida
(EC
10
31 15–46) and hemiedaphic species
Folsomia quadrioculata
(EC
10
52 0.7–102) were comparable with sensitivity of the reproduction of
F. candida
in the single-species tests (EC
10
21 14–27), suggesting that single-species test based on laboratory cultures and field soil could be used to link laboratory and field data and then reflect the field situation.
S. curviseta
could be used as an epedaphic species in single-species tests and
F. quadrioculata
as an indicator species for assessment of field effect.
Assessing the effects of pesticide hazards on microbiological processes in the soil is currently based on analyses that provide limited insight into the ongoing processes. This study proposes a more ...comprehensive approach. The side effects of pesticides may appear as changes in the expression of specific microbial genes or as changes in diversity. To assess the impact of pesticides on gene expression, we focused on the amoA gene, which is involved in ammonia oxidation. We prepared soil microcosms and exposed them to dazomet, mancozeb or no pesticide. We hypothesized that the amount of amoA transcript decreases upon pesticide application, and to test this hypothesis, we used reverse-transcription qPCR. We also hypothesized that bacterial diversity is affected by pesticides. This hypothesis was investigated via 454 sequencing and diversity analysis of the 16S ribosomal RNA and RNA genes, representing the active and total soil bacterial communities, respectively.
Treatment with dazomet reduced both the bacterial and archaeal amoA transcript numbers by more than two log units and produced long-term effects for more than 28 days. Mancozeb also inhibited the numbers of amoA transcripts, but only transiently. The bacterial and archaeal amoA transcripts were both sensitive bioindicators of pesticide side effects. Additionally, the numbers of bacterial amoA transcripts correlated with nitrate production in N-amended microcosms. Dazomet reduced the total bacterial numbers by one log unit, but the population size was restored after twelve days. The diversity of the active soil bacteria also seemed to be re-established after twelve days. However, the total bacterial diversity as reflected in the 16S ribosomal RNA gene sequences was largely dominated by Firmicutes and Proteobacteria at day twelve, likely reflecting a halt in the growth of early opportunists and the re-establishment of a more diverse population. We observed no effects of mancozeb on diversity.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Thermal gasification of straw is a highly efficient technology that produces bioenergy and gasification biochar that can be used as a soil amendment, thereby returning non-renewable nutrients and ...stable carbon, and securing soil quality and crop productivity.
A Danish on-farm field study investigated the impact of traditional straw incorporation vs. straw removal for thermal gasification bioenergy production and the application of straw gasification biochar (GB) on soil quality and crop production. Two rates of GB were applied over three successive years in which the field was cropped with winter wheat (Triticum aestivum L.), winter oilseed rape (Brassica napus L.) and winter wheat, respectively, to assess the potential effects on the soil carbon pool, soil microorganisms, earthworms, soil chemical properties and crop yields.
The application of GB did not increase the soil organic carbon content significantly and had no effect on crop yields. The application of straw and GB had a positive effect on the populations of bacteria and protists, but no effect on earthworms. The high rate of GB increased soil exchangeable potassium content and soil pH indicating its potassium bioavailability and liming properties.
These results suggest, that recycling GB into agricultural soils has the potential to be developed into a system combining bioenergy generation from agricultural residues and crop production, while maintaining soil quality. However, future studies should be undertaken to assess its long-term effects and to identify the optimum balance between straw removal and biochar application rate.
•Gasification biochar (GB) increased soil exchangeable potassium content and pH.•The application of GB did not increase the soil organic carbon content.•The application of GB did not have any effect on crop grain yields.•The straw and GB increased the populations of bacteria and protist.•The GB had no negative effect on earthworm abundance.
Zusammenfassung
Die vorliegende Studie basiert auf einer quantitativ-qualitativen Erhebung der Arbeitsbedingungen und -zufriedenheit des religionswissenschaftlichen Nachwuchses (d. h. ohne ...unbefristete Anstellung als Professor*in). Die Erhebung wurde von Mai bis Juli 2022 vom Arbeitskreis Mittelbau und Nachwuchs (AKMN) der Deutschen Vereinigung für Religionswissenschaft (DVRW) durchgeführt. Sie ist eine erweiterte Variante einer Erhebung von 2015. Auf der Grundlage der Umfrageergebnisse werden die Arbeitsbedingungen und ihre Auswirkungen auf berufliche Perspektiven und persönliche Lebensumstände der Betroffenen beschrieben und mit denen von 2015 verglichen. Zudem werden die speziellen Herausforderungen während der Corona-Pandemie dargestellt. Die Studie ist nicht nur eine aussagekräftige Untersuchung der Entwicklung der Arbeitsbedingungen des religionswissenschaftlichen Nachwuchses, sondern auch ein Beitrag zur derzeit intensiv geführten Debatte um Beschäftigungsverhältnisse an deutschen Universitäten.
Normalization of target gene expression, measured by real-time quantitative PCR (qPCR), is a requirement for reducing experimental bias and thereby improving data quality. The currently used ...normalization approach is based on using one or more reference genes. Yet, this approach extends the experimental work load and suffers from assumptions that may be difficult to meet and to validate.
We developed a data driven normalization algorithm (NORMA-Gene). An analysis of the performance of NORMA-Gene compared to reference gene normalization on artificially generated data-sets showed that the NORMA-Gene normalization yielded more precise results under a large range of parameters tested. Furthermore, when tested on three very different real qPCR data-sets NORMA-Gene was shown to be best at reducing variance due to experimental bias in all three data-sets compared to normalization based on the use of reference gene(s).
Here we present the NORMA-Gene algorithm that is applicable to all biological and biomedical qPCR studies, especially those that are based on a limited number of assayed genes. The method is based on a data-driven normalization and is useful for as little as five target genes comprising the data-set. NORMA-Gene does not require the identification and validation of reference genes allowing researchers to focus their efforts on studying target genes of biological relevance.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Circumpolar Biodiversity Monitoring Programme (CBMP) provides an opportunity to improve our knowledge of Arctic arthropod diversity, but initial baseline studies are required to summarise the ...status and trends of planned target groups of species known as Focal Ecosystem Components (FECs). We begin this process by collating available data for a relatively well-studied region in the Arctic, the North Atlantic region, summarising the diversity of key terrestrial arthropod FECs, and compiling trends for some representative species. We found the FEC classification system to be challenging to implement, but identified some key groups to target in the initial phases of the programme. Long-term data are scarce and exhibit high levels of spatial and temporal variability. Nevertheless, we found that a number of species and groups are in decline, mirroring patterns in other regions of the world. We emphasise that terrestrial arthropods require higher priority within future Arctic monitoring programmes.
Context:
Due to current operational requirements, elite soldiers deploy quickly after completing arduous training courses. Therefore, it is imperative that endocrine and inflammatory mediators have ...fully recovered.
Objective:
Our objective was to determine whether a short-term (2–6 wk) recovery period was sufficient to restore endocrine and inflammatory homeostasis after sustained energy deficit.
Design:
Before and immediately after the course, serum concentrations of inflammatory and endocrine markers were taken along with anthropometric measures prior to and immediately after the Army Ranger course. In addition, nine soldiers were assessed between 2 and 6 weeks after the course.
Setting:
This research occurred in a field setting during an intensive 8-week military training course characterized by high-energy expenditure, energy restriction, and sleep deprivation (U.S. Army Ranger School).
Participants:
Twenty-three male soldiers (23.0 ± 2.8 y; 177.6 ± 7.9 cm; 81.0 ± 9.6 kg, 16.8 ± 3.9% body fat) participated in this study.
Interventions:
There were no interventions used in this research.
Outcome Measures and Results:
Significant changes occurred in circulating total testosterone (−70%), brain-derived neurotrophic factor (−33%), total IGF-1 (−38.7%), free IGF-1 (−41%), IGF binding protein (IGFBP-6; −23.4%), sex-hormone binding globulin (+46%), thyroid stimulating hormone (+85%), IGFBP-1 (+534.4%), IGFBP-2 (+98.3%), IGFBP-3 (+14.7%), IL-4 (+135%), IL-6 (+217%), and IL-8 (+101%). Significant changes in body mass (−8%), bicep (−14%), forearm (−5%), thigh (−7%), and calf (−2%) circumferences, sum of skinfolds (−52%), and percentage body fat (−54%). All anthropometric, inflammatory, and hormonal values, except T3, were restored to baseline levels within 2–6 weeks after the course.
Conclusions:
Endocrine markers and anthropometric measures were degraded, and inflammatory mediators increased after an extended energy deficit. A short-term recovery of 2–6 weeks was sufficient to restore these mediators.
Abstract Objective To investigate the efficacy and underlying mechanisms of β-hydroxy-β-methylbutyrate (HMB) on body composition, muscle mass and physical performance under catabolic versus normal ...training conditions. Materials/Methods Mice were divided into four groups (n = 10/group): 1) ALT = ad libitum + trained (1 h/d for 3 d/wk); 2) ALTH = ALT + HMB (0.5 g/kg BW/d); 3) C = calorie restricted (− 30%) + trained (6 h/d, 6 d/wk); and 4) CH = C + HMB. Repeated in vivo assessments included body composition, grip strength and sensorimotor coordination before and after the experimental protocol, while in vitro analyses included muscle wet weights, expression of selected genes and proteins regulating muscle mass, and myofiber cross-sectional area. ANOVAs were used with significance set at p < 0.05. Results ALTH had greater lean mass than ALT and sensorimotor function increased in ALTH, but decreased in ALT under normal training conditions. Grip strength decreased only in C, but was maintained in CH. Gastrocnemius mass and myofiber CSA were greater in CH than C following catabolic conditions. Gastrocnemius atrogin-1 mRNA expression was elevated in C but not in CH compared to all other groups whereas atrogin-1 protein levels showed no significant changes. Conclusion HMB improves body composition and sensorimotor function during normal training and attenuates muscle mass and strength loss during catabolic conditions.
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