20 research outputs found
Land Use and Host Neighbor Identity Effects on Arbuscular Mycorrhizal Fungal Community Composition in Focal Plant Rhizosphere
No full textArbuscular mycorrhizal fungi (AMF) provide a number of ecosystem services as important members of the soil microbial community. Increasing evidence suggests AMF diversity is at least partially controlled by the identities of plants in the host plant neighborhood. However, much of this evidence comes from greenhouse studies or work in invaded systems dominated by single plant species, and has not been tested in species-rich grasslands. We worked in 67 grasslands spread across the three German Biodiversity Exploratories that are managed primarily as pastures and meadows, and collected data on AMF colonization, AMF richness, AMF community composition, plant diversity, and land use around focal Plantago lanceolata plants. We analyzed the data collected within each Exploratory (ALB Schwäbische Alb, HAI Hainich-Dün, SCH Schorfheide-Chorin) separately, and used variance partitioning to quantify the contribution of land use, host plant neighborhood, and spatial arrangement to the effect on AMF community composition. We performed canonical correspondence analysis to quantify the effect of each factor independently by removing the variation explained by the other factors. AMF colonization declined with increasing land use intensity (LUI) along with concurrent increases in non-AMF, suggesting that the ability of AMF to provide protection from pathogens declined under high LUI. In ALB and HAI mowing frequency and percent cover of additional P. lanceolata in the host plant neighborhood were important for AMF community composition. The similar proportional contribution of land use and host neighborhood to AMF community composition in a focal plant rhizosphere suggests that the diversity of this important group of soil microbes is similarly sensitive to changes at large and small scales. [ABSTRACT FROM AUTHOR
Time-to-detection in culture of Mycobacterium tuberculosis: performance for assessing index cases contact-positivity
No full textObjectives: Time-to-detection (TTD) in culture on liquid media is inversely correlated to bacillary load and should be a contributing factor for assessing tuberculosis transmission. We wanted to assess if TTD was a better alternative than smear status to estimate transmission risk. Methods: From October 2015 to June 2022, we retrospectively studied a cohort of index cases (IC) with pulmonary tuberculosis (tuberculosis disease [TD]) from which samples were culture-positive before treatment. We studied the correlation between TTD and contact-positivity (CP) of IC contacts: CP was defined as CP = 1 (CP group) in case of TD or latent tuberculosis infection (LTI) in at least one screened contact of an IC, and CP = 0 otherwise (contact-negativity [CN] group). Univariate and multivariable analyses (logistic regression) were done. Results: Of the 185 IC, 122 were included, generating 846 contact cases of which 705 were assessed. A transmission event (LTI or TD) was identified in 193 contact cases (transmission rate: 27%). At day 9, 66% and 35% of the IC had their sample positive in culture for CP and CN groups, respectively. Age and TTD ≤9 days were independent criteria of CP (odds ratio 0.97, confidence interval [0.95-0.98], P = 0.002 and odds ratio 3.52, confidence interval [1.59-7.83], P = 0.001, respectively). Conclusion: TTD was a more discriminating parameter than smear status to evaluate the transmission risk of an IC with pulmonary tuberculosis. Therefore, TTD should be considered in the contact-screening strategy around an IC
Analysis of microbial populations in plastic–soil systems after exposure to high poly(butylene succinate-co-adipate) load using high-resolution molecular technique
No full textBackground: Bio-based and biodegradable plastics are considered as plastics of the future owing to their ability to decompose under various environmental conditions. However, their effects on the soil microbiome are poorly characterised. In this study, we aimed to investigate the effects of an important bio-based and biodegradable plastic, polybutylene succinate-co-adipate (PBSA), on soil microbial diversity and community composition using high-resolution molecular technique (Illumina sequencing) targeting all three microbial domains: archaea, bacteria, and fungi. Results: Adding high load of PBSA to soil (6% (w/w)) caused a significant decline in archaeal (13%) and fungal (45%) richness and substantial changes in both bacterial (Proteobacteria, Actinobacteria, and Acidobacteria) and fungal (Eurotiomycetes, Sordariomycetes, Leotiomycetes, and Dothideomycetes) community composition compared with no PBSA addition to soil. The combined effects of PBSA and (NH4)2SO4 fertilisation on the soil microbiome were much greater than the effects of PBSA alone. We only detected opportunistic human pathogens in low abundance on PBSA and in the surrounding soil. However, some plant pathogenic fungi were detected and/or enriched on the PBSA films and in surrounding soil. Apart from plant pathogens, many potential microbial control agents and plant growth-promoting microorganisms were also detected/enriched owing to PBSA addition. Adding high load of PBSA together with (NH4)2SO4 fertilisation can either eliminate some plant pathogens or enrich specific pathogens, especially Fusarium solani, which is economically important. Conclusions: We conclude that high load of bio-based and biodegradable PBSA plastic may negatively affect soil microbiome. © 2021, The Author(s)
On the combined effect of soil fertility and topography on tree growth in subtropical forest ecosystems—a study from SE China
No full textAims
The aim of our research was to understand small-scale effects of topography and soil fertility on tree growth in a forest biodiversity and ecosystem functioning (BEF) experiment in subtropical SE China.
Methods
Geomorphometric terrain analyses were carried out at a spatial resolution of 5×5 m. Soil samples of different depth increments and data on tree height were collected from a total of 566 plots (667 m2 each). The soils were analyzed for carbon (soil organic carbon [SOC]), nitrogen, acidity, cation exchange capacity (CEC), exchangeable cations and base saturation as soil fertility attributes. All plots were classified into geomorphological units. Analyses of variance and linear regressions were applied to all terrain, soil fertility and tree growth attributes.
Important Findings
In general, young and shallow soils and relatively small differences in stable soil properties suggest that soil erosion has truncated the soils to a large extent over the whole area of the experiment. This explains the concurrently increasing CEC and SOC stocks downslope, in hollows and in valleys. However, colluvial, carbon-rich sediments are missing widely due to the convexity of the footslopes caused by uplift and removal of eroded sediments by adjacent waterways. The results showed that soil fertility is mainly influenced by topography. Monte–Carlo flow accumulation (MCCA), curvature, slope and aspect significantly affected soil fertility. Furthermore, soil fertility was affected by the different geomorphological positions on the experimental sites with ridge and spur positions showing lower exchangeable base cation contents, especially potassium (K), due to leaching. This geomorphological effect of soil fertility is most pronounced in the topsoil and decreases when considering the subsoil down to 50cm depth. Few soil fertility attributes affect tree height after 1–2 years of growth, among which C stocks proved to be most important while pHKCl and CEC only played minor roles. Nevertheless, soil acidity and a high proportion of Al on the exchange complex affected tree height even after only 1–2 years growth. Hence, our study showed that forest nutrition is coupled to a recycling of litter nutrients, and does not only depend on subsequent supply of nutrients from the mineral soil. Besides soil fertility, topography affected tree height. We found that especially MCCA as indicator of water availability affected tree growth at small-scale, as well as aspect. Overall, our synthesis on the interrelation between fertility, topography and tree growth in a subtropical forest ecosystem in SE China showed that topographic heterogeneity lead to ecological gradients across geomorphological positions. In this respect, small-scale soil–plant interactions in a young forest can serve as a driver for the future development of vegetation and biodiversity control on soil fertility. In addition, it shows that terrain attributes should be accounted for in ecological research
Community assembly during secondary forest succession in a Chinese subtropical forest
No full textSubtropical broad-leaved forests in southeastern China support a high diversity of woody plants. Using a comparative study design with 30330 m plots (n=27) from five successional stages (<20, <40, <60, <80, and ≤80 yr), we investigated how the gradient in species composition reflects underlying processes of community assembly. In particular, we tested whether species richness of adult trees and shrubs decreased or increased and assessed to which degree this pattern was caused by negative density dependence or continuous immigration over time. Furthermore, we tested whether rare species were increasingly enriched and the species composition of adult
trees and shrubs became more similar to species composition of seedlings during the course of succession. We counted the individuals of all adult species and shrubs >1 m in height in each plot and counted all woody recruits (bank of all seedlings ≤1 m in height) in each central 10310 m quadrant of each plot. In addition, we measured a number of environmental variables (elevation, slope, aspect, soil moisture, pH, C, N, and C/N ratio) and biotic structural variables (height and cover of layers). Adult species richness varied from 25 to 69 species per plot, and in
total 148 woody species from 46 families were recorded. There was a clear successional gradient in species
composition as revealed by nonmetric multidimensional scaling (NMDS), but only a poor differentiation of different
successional stages with respect to particular species. Adult richness per 100 individuals (rarefaction method)
increased with successional stage. None of the measured abiotic variables were significantly correlated with adult
species richness. We found no evidence that rare species were responsible for the increasing adult species richness, as richness of rare species among both adults and recruits was independent of the successional stage. Furthermore, the
similarity between established adults and recruits did not increase with successional stage. There was a constant
number of recruit species and also of exclusive recruit species, i.e., those that had not been present as adult
individuals, across all successional stages, suggesting a continuous random immigration over time
Designing forest biodiversity experiments : general considerations illustrated by a new large experiment in subtropical China
No full textFunded by German Research Foundation. Grant Number: DFG FOR 891/1 and 2 National Natural Science Foundation of China. Grant Numbers: NSFC 30710103907, 30930005, 31170457 , 31210103910 Swiss National Science Foundation (SNSF) Sino-German Centre for Research Promotion in BeijingPeer reviewe
Jesuit collegiate education in England, 1794 1914
No full textIn 1773 the Society of Jesus was formally suppressed and the Fathers of the English Province entered a period of limbo which their school at St. Omers survived in a variety of guises. The first chapter of this thesis describes the arrival of the teachers and pupils of this school in England; and examines the manner in which the College and Order were reconstituted on English soil. The nature of the curriculum, finances and social class composition are considered -inter alia. The second and third chapters relate the way in which the work undertaken at the founding College, Stonyhurst, was expanded. These chapters describe the revival of day Colleges by the Society, and analyse the way in which the new Colleges, both day and boarding, were managed. An important feature examined, is the extension of educational provision for middle class pupils coupled with the curricular and financial adaptations undertaken. One element which is common to all chapters is an analysis of the relationship of the Order to the Hierarchy. In Chapter 4 this becomes a central concern of the study as the attempts by the Jesuits to begin a College in Manchester resulted in a direct confrontation with the local Bishop and ultimately with the whole English Hierarchy, The attitude and machinations of the Cardinal Archbishop, Henry Edward Manning, led to the defeat of the Order in a canonical dispute in Rome, a result which blighted the Jesuits' work for more than a decade. The chapter also examines the educational circumstances and effects of this dispute, the case in canon law awaits exploration. Chapters 5 and 6 examine the work of the Order in the light of the Bull Romanos Pontifices which followed the defeat in Rome. The former considers the Fathers' efforts to improve their educational service to Catholic youth while effectively prevented from opening new schools. The latter examines the revitalisation of the English Province's Colleges in the Archiepiscopate of Cardinal Vaughan, but also demonstrates the inexorable financial difficulties facing the opening and conduct of schools. In the penultimate chapter, a departure is made to examine the progress made by the Jesuits in boarding education in the Stonyhurst tradition. The opening and evolution of Beaumont College and the assimilation of the Order's schools into the community of Public schools are important factors under scrutiny. The final chapter considers the relationship of the Jesuit day Colleges to the State. As the State expanded its role and the Jesuit schools sought additional finance, they were ineluctably drawn together. The evolutionary nature of this relationship and its political ramifications are considered as they moved to a position of mutually agreed neutrality, if not satisfaction, an appropriate point, before the overwhelming cataclysm of the First World War, to terminate this thesis. The foundations upon which this thesis was constructed lie in the study of much manuscript material. Like many of the sources for Catholic history, these records are widely dispersed and have had to be correlated. As the study makes clear, there are few secondary guides. University theses have often contained the only indications of the work of the Bishops, or other Catholic educators. It is hoped that this thesis will, in its turn, serve to guide others in a terrain where there are many areas yet unexplored
Steering Taste: Ernest Marsh, a study of private collecting in England in the early 20th Century
No full textThe primary aim of this thesis is to focus attention on the bourgeois, 'un-named' collector. The driving force behind most museum and art gallery collections of the Victorian and Edwardian period. British museum and art gallery records of gifted collections, bequests and loans usually note their donors. However, with a few notable exceptions, little is known about the collectors, their activities and motivation in making such presentations.
Using the interests and activities of the Quaker miller and collector Ernest Marsh (1843-1945) as a case study, this thesis explores how in the period 1890-1945 a collector came to be a key agent in the construction and manifestation of taste in British Applied Arts and to a lesser degree in the Fine Arts. Through primary visual and documentary evidence of the Marsh home, and reference to contemporary and later commentaries it considers the relative influences of husband and wife on decorating and furnishing the domestic interior, the evolution of taste, and, for Ernest Marsh, its impact upon his artistic interests within the public arena.
By examination of private papers, metropolitan and provincial art gallery and museum archives it also considers evidence of the inter-relationships between donors and curators, and the mutual advantages and disadvantages accruing to both, particularly focussing on the processes in bringing about changes in individual and institutional collecting policy. Further, by review of records of, in particular, the Contemporary Art Society and the Greenslade archive, it examines the degree to which private benefactors and those in public or semi-public office, acting as fund-raisers and spenders exercise influence through patronage of particular practitioners, choice of works and initiating new designs
Global Soil Biodiversity Atlas
No full textSPE EA Pôle BIOME The Atlas is divided in 8 chapters covering all the aspects of soil biodiversity: - Chapter I: The soil habitat - Chapter II: Diversity of soil organisms - Chapter III: Geographical and temporal distribution - Chapter IV: Ecosystem functions and services - Chapter V: Threats - Chapter VI: Interventions - Chapter VII: Policy, education and outreach - Chapter VIII: Conclusions Soil biodiversity experts from all over the world are involved in the project aiming at the creation of a reference publication not only for soil biodiversity researchers but also policy makers and general public.International audienceThe Global Soil Biodiversity Initiative (GSBI) and the Joint Research Centre (JRC) of European Commission announce the writing of the Global Soil Biodiversity Atlas (GSBA) in the frame of the Global Soil Biodiversity Assessment. The Atlas is a series of amazing photos, maps, charts, statistics, and shared information that scientists, educators, policy makers, and non-specialists alike can use as a toolkit for knowing and understanding soil biodiversity globally
Global Soil Biodiversity Atlas
No full textSPE EA Pôle BIOME The Atlas is divided in 8 chapters covering all the aspects of soil biodiversity: - Chapter I: The soil habitat - Chapter II: Diversity of soil organisms - Chapter III: Geographical and temporal distribution - Chapter IV: Ecosystem functions and services - Chapter V: Threats - Chapter VI: Interventions - Chapter VII: Policy, education and outreach - Chapter VIII: Conclusions Soil biodiversity experts from all over the world are involved in the project aiming at the creation of a reference publication not only for soil biodiversity researchers but also policy makers and general public.International audienceThe Global Soil Biodiversity Initiative (GSBI) and the Joint Research Centre (JRC) of European Commission announce the writing of the Global Soil Biodiversity Atlas (GSBA) in the frame of the Global Soil Biodiversity Assessment. The Atlas is a series of amazing photos, maps, charts, statistics, and shared information that scientists, educators, policy makers, and non-specialists alike can use as a toolkit for knowing and understanding soil biodiversity globally
