1,721,021 research outputs found
Plant community data from burned peat soil on the Stalybridge estate (UK), October 2018
No full textThis dataset is a compilation of results obtained from vegetation surveys in the Stalybride estate moorlands (commonly known as the Saddleworth moors) following a wildfire in 2018. Ten plots were established in October 2018 at the post-fire site which were 10 m x 10 m in size. Five plots were identified as suffering a less severe (shallow) burn. The other 5 plots were in areas where a more severe (deep) burn. In all plots the surface vegetation had been removed by the fire exposing the bare peat. The data file contains: (1) On-site post-fire vegetation data – species ID and coverage, and (2) species presence in the one-year post-fire seed bank. The dataset is the result of research in the light of an NERC Urgency grant entitled 'RECOUP-Moor: Restoring Ecosystem CarbOn Uptake of Post-fire Moorland' (NE/S011943/1, led by Dr. Bjorn Robroek of the University of Southampton (now Radboud University Nijmegen, the Netherlands).,We performed a series of vegetation surveys in these plots to track the composition of the recovering vascular plant community. Vegetation surveys were performed using a 1 m x 1 m point quadrat with 1 cm intervals. We performed two surveys at random positions within each plot. The results of the two survey were then combined to give one overall community for each plot at each time of survey.</span
Post-fire microbial data (16S DNA) from burned peat soil on the Stalybridge estate (UK), October 2018
No full textThis dataset contains information on the Bacterial Amplicon Sequence Variant (ASV) abundance from peat soil sampled following a wildfire on the Stalybridge estate (UK) in June 2020. Samples were taken in 10 established plots at three time periods following the fire: approximately 3 months, 10 months and 12 months post-fire. This was taken at two depths: 0 – 5cm from the surface (top) and 5 – 10 cm from the surface (bottom). The 10 plots were divided into two groups of five, one that was observed to have suffered a light burn (termed shallow burn) and one that received a more severe burn (termed deep burn). Five additional plots were sampled at the same time as the 3-month samples from a neighbouring unburned site (termed control plots). Samples where no ASVs were observed were removed from the dataset.,DNA was extracted from the peat soil using the QIAGEN DNeasy powersoil kit, following standard manual specifications. The extracted DNA was then sequenced through the use of high-throughput sequencing, using 515F/806R primers that target the V4 region of the 16S rRNA. Results from the sequencing were then cleaned and prepared using the DADA2 pipeline to produce the ASV table.</span
Biogeochemical and edaphic data from burned peat soil on the Stalybridge estate (UK), October 2018
No full textThis dataset contains biogeochemical and edaphic information from burned peat soil on the Stalybridge estate located near Manchester (UK), commonly referred to as Saddleworth moor. This study was conducted after a wildfire fire on the Saddleworth moor in June 2018. The sample plots included areas with deep and shallow peat burn. The data includes geographical information (location, elevation and slope), soil temperature and soil chemical composition (carbon, nitrogen and 22 other elements). The dataset is the result of research funded by a NERC Urgency grant entitled 'RECOUP-Moor: Restoring Ecosystem CarbOn Uptake of Post-fire Moorland' (NE/S011943/1, led by Dr. Bjorn Robroek of the University of Southampton (now Radboud University Nijmegen, the Netherlands).,We established 10 plots in October 2018 at the post-fire site. Each plot was 10 m x 10 m in size. We identified 5 of these plots as suffering a less severe (shallow) burn. The other 5 plots were in areas where a more severe (deep) burn was identified. In all plots the surface vegetation had been removed by the fire exposing the bare peat. We determined the geographical properties of each plot. This included their geographical location, elevation and slope. We also measured soil temperature at each location at multiple time points over the following 24 months. On July 23rd 2019 we extracted small peat samples from the surface of each plot. Each sample was 5 cm x 5 cm in diameter and 2 cm in depth. The samples were homogenized and kept at c. 5oC until further analysis was completed to determine their chemical composition. In preparation for the chemical analysis of each sample we dried the peat at 70 oC for 72 hours. This was then crushed forming a fine homogenous powder. To determine the carbon and nitrogen content of each sample we extracted three sub-samples of the fine peat powder. Each sample was then combusted at 1800 oC and the percentage of carbon and nitrogen released was quantified. This was performed using a Vario Micro Cube (Elementar). For each plot, the content of each sub-sample was compared to ensure that the observed values were consistent, and the samples were homogenous. An average of the three sub-samples was then taken to provide one value per plot. To determine the composition of other elements within the samples, we extracted two sub-samples from each plot sample and performed Inductively Coupled Plasma-Mass-Spectrometry (ICP-MS) analysis on each of the sub-samples. This was used to determine the relative composition of 22 elements. For each plot, an average of the two sub-samples was taken.</span
How nitrogen and sulphur addition, and a single drought event affect root phosphatase activity in Phalaris arundinacea
No full textConservation and restoration of fens and fen meadows often aim to reduce soil nutrients, mainly nitrogen (N) andphosphorus (P). The biogeochemistry of P has received much attention as P-enrichment is expected to negatively impact on species diversity in wetlands. It is known that N, sulphur (S) and hydrological conditions affect the biogeochemistry of P, yet their interactive effects on P-dynamics are largely unknown. Additionally, in Europe, climate change has been predicted to lead to increases in summer drought. We performed a greenhouse experiment to elucidate the interactive effects of N, S and a single drought event on the P-availability for Phalaris arundinacea. Additionally, the response of plant phosphatase activity to these factors was measured over the two year experimental period. In contrast to results from earlier experiments, our treatments hardly affected soil P-availability. This may be explained by the higher pH in our soils, hampering the formation of Fe-P or Fe-Al complexes. Addition of S, however, decreased the plants N:P ratio, indicating an effect of S on the N:P stoichiometry and an effect on the plant's P-demand. Phosphatase activity increased significantly after addition of S, but was not affected by the addition of N or a single drought event. Root phosphatase activity was also positively related to plant tissue N and P concentrations, plant N and P uptake, and plant aboveground biomass, suggesting that the phosphatase enzyme influences P-biogeochemistry. Our results demonstrated that it is difficult to predict the effects of wetland restoration, since the involved mechanisms are not fully understood. Short-term and long-term effects on root phosphatase activity may differ considerably. Additionally, the addition of S can lead to unexpected effects on the biogeochemistry of P. Our results showed that natural resource managers should be careful when restoring degraded fens or preventing desiccation of fen ecosystems
Slash-and-burn agriculture and tropical cyclone activity in Madagascar : implication for soil fertility dynamics and corn performance
No full textOn the western coast of Madagascar, the dry tropical forest of Kirindy may disappear in the next 50 years because of its rapid conversion into agricultural land by slash-and-burn cultivation. The slash-and-burn fields are cultivated during 3 years in average and are further abandoned because of soil depletion, weed invasion and finally lower crop yields. As a consequence, new forest areas are regularly cleared from the primary forest, causing deforestation. In addition, Madagascar is situated in a region with high cyclonic activity. Violent storms hit the western coast every 3-4 years, leading to intense rainfalls and floods. These events may enhance soil physical degradation and nutrient leaching, thereby accentuating the soil depletion by slash-and-burn agriculture and with it, the forest conversion rate. Focusing on the combined effects of historic land management and prevailing climatic conditions, this paper investigates: (1) the temporal evolution of soil fertility along with crop performance from cultivation up to field abandonment, and (2) the relative effects of land use (crop cultivation) and extreme climatic events (heavy rain, cyclonic storms) on soil and crop properties. We used a space-for-time substitution approach in slash-and-burn corn (Zea mays L.) fields to describe dynamics of soil fertility and crop performance. We sampled soils and plants during two seasons: (a) a normal rainy season, in 2014, and (b) a cyclonic rainy season, in 2015. We found that under the cyclonic storm, soil becomes not only N and P deficient, but the K concentration also steeply drops. Overall, this leads to a dramatic reduction of corn performance. While a decrease in grain yield due to slash-and-burn agriculture reaches about 37.5% after three years of cultivation on the same field (from 4 to 2.5 t ha-1), it decreases up to 75% after a single cyclonic rainy season (from 4 to 1 t ha-1). On the sidelines of the study, a locust pest also damaged half of the corn fields in 2014, driving the corn yield down to zero on those particular fields. Given what precedes, the study points out the fragility of traditional agricultural techniques against natural hazards. Along with global warming, the frequency and intensification of natural disasters are expected to increase, impacting negatively and strongly the livelihoods of rural farmers. This raises the urgent need to increase farmer’s awareness to alternative and more sustainable agricultural practices
Competition between Sphagnum mosses in European raised bogs : the effect of a changing climate
No full textDe effecten van klimaatsveranderingen op ecosystemen domineren steeds vaker het nieuws. Toch is er nog maar weinig bekend over de effecten op hoogvenen, terwijl deze een grote rol spelen in het vastleggen van koolstof, een belangrijk element voor broeikasgassen. Veenmossen spelen daarin een cruciale rol. Bjorn Robroek toonde aan dat veranderingen in temperatuur, waterstanden en veranderende regenwater patronen, als gevolg van klimaatsveranderingen, een effect kunnen hebben op de veenmossamenstelling in hoogvenen. Als de huidige klimaatsscenario’s uit zullen komen, zullen vooral bultvormende soorten en soorten met een meer zuidelijke distributie gaan domineren. Maar ook dat de concurrentiekracht anders verandert bij verschuivingen in de beschikbaarheid van wate
Peatland plant functional type effects on decomposition factors are non-pervasive, but microhabitat dependent
No full textThis dataset contains information on the decomposition rate constant (k), the stabilisation factor (S), and the activity of five hydrolytic enzymes (ALA, BG, NAG, PHOS, SUL), as well as data on vascular plant communities sampled in July 2019 in the Store Mosse National Park, Sweden. Samples were taken in plant functional type removal plots (0.5 × 0.5 m) that have been established in 2011
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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