1,721,113 research outputs found
Greenhouse Gas Data ( collected in lab)
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Greenhouse gas data collection and measurement in 2018. A detailed description of methods used to derive the data is below. Further questions can be directed to [email protected]
Methods: Soil preparation, incubation, gas sampling, and analysis
Water holding capacity of sieved soils at different matric potentials was determined using the pressure-plate method [41]. Sub-samples of air-dried soils were first placed in O-rings on porous ceramic plates and saturated for 24 h. Saturated soils were then pressurized at 0.1, 0.5, 1.0, 5.0, and 15.0 bars for 72 h, after which the moisture content at each pressure level was quantified by drying at 105 ºC for 27 h to a constant mass and reweighing. Water content at 15 bar was considered the permanent wilting point (PWP), while 0.1 bar was the field capacity (FC) of sandy soils [42] and 0.33 bar the FC of clayey soils [41]. Water content at 0.33 bar was estimated by linear extrapolation of water contents at 0.1, 0.5, and 1.0 bar. The moisture content of air-dried sieved soil was also determined following the oven-dry method (described above) to help maintain the desired soil moisture level throughout the subsequent incubation experiment.
For each grassland investigated, 100 g of oven-dry equivalent air-dried soil was placed in each of six 500 mL Mason jars for the incubation experiment. Sufficient water was added (with a dilute 0.005 M CaSO4 to protect micro-aggregates from disruption) to bring these soils to a moisture level of either FC, 40% FC, or PWP [43]. One set of Mason jars with soil from each moisture treatment was placed in an incubator at 5 ºC, while the other set was placed in another incubator at 25 ºC. The tops of all jars were covered with perforated aluminum foil for five consecutive days to stabilize microbial activity. On the fifth day (collection day 0), initial GHG samples were collected from the headspace air of the jars immediately after closing them using a lid equipped with a rubber septum. Soils were further incubated for 24 h with the lids closed, and then headspace samples were collected again to determine the change in GHG concentrations. Subsequent sampling of GHGs occurred on days 1, 2, 4, 7, 10, 13, 18, 23, 28, 35, 42, 52, 62, 72, 82, 92 and 102. The change in gas concentration between the 0 and 24 h headspace samples on each sampling day was used to calculate daily GHG flux per unit dry mass of soil. Soil moisture levels were maintained throughout the incubation period by tracking water loss by weighing the jars and replenishing the water at least 3 days prior to each gas sampling event. Headspace air samples were collected with an air-tight 20 mL syringe (Norm-Ject, Henke Sass Wolf, Tuttlingen, Germany) and injected into 12 mL pre-vacuumed soda glass Isomass Exetainers (Labco Limited, Lampeter, Wales, UK).
Greenhouse gas samples were analyzed with a Varian CP 3800 gas chromatograph (Varian Canada, Mississauga, Canada) containing three detectors. A thermal conductivity detector (TCD) and flame ionization detector (FID) simultaneously determined the concentration of CO2 and CH4, respectively [44], while the electron capture detector (ECD) determined the concentration of N2O [45]. Standard curves were generated using mixtures of gases at standard concentrations of CO2 (360 ppm), CH4 (1.6 ppm) and N2O (1.0 ppm) (Praxair) and used to calculate the headspace concentrations of respective gases
Cougar telemetry and road data in Southwestern Alberta, 2010 - 2011
No full textGPS locations from collared cougars in Southwestern Alberta, and nearest road information.
Please see the second tab in the file for descriptive metadat
Plant Composition and Biomass Data
No full textSummary: Vascular plant composition and biomass data collected for the AGGP AMP project. Detailed description of methods available within https://doi.org/10.1111/1365-2664.14181 and below. Composition data collected during 2017-2018, biomass data collected during 2018.
To capture plant community responses to AMP grazing relative to regionally typical management, we established 0.5 × 0.5 meter quadrats in which we identified plant community abundances and biomass estimates. As outlined in Grenke et al. (2022), due to our prioritization of sampling many pairs of ranches rather than conducting intensive sampling within each ranch, rarefaction curves for each of our study sites did not saturate. Therefore, plant community measures should be considered on a relative rather than an absolute basis.
To determine the potential for specific components of the plant community to influence biomass production we assessed community composition. Composition was sampled by randomly placing five quadrats within each of three landscape positions, for a total of 15 quadrats per study site. Sampling was stratified by topographic landscape position in order to capture potential topographically sourced heterogeneity, with landscape designations representative of relative positioning within the context of each ranch pair. Areas were designated as “low” if they occurred within the bottom third of a local relief, “high” if they occurred within the top third of the local relief, and “medium” if they occurred within the middle third of the landscape relief.
To assess how vascular plant species composition may have influenced biomass production we recorded vascular plant species abundance (percent cover) at every site using a 0.5 meter × 0.5 meter quadrat. All non-senesced vascular plants within the quadrat were identified to species (USDA, NRCS 2021). Vascular plant species abundances were collected over two years, during the peak growing seasons of both 2017 and 2018, typically between June 15 and July 15. To reduce variance in our diversity estimates, we pooled data across the two years of sampling. Further details can be found in Grenke et al. (2022).
2.3.2. Plant community biomass estimates
We measured plant biomass (aboveground biomass, litter mass, and roots from soil cores) using three randomly selected quadrats from each of the three landscape positions within the ranch (9 quadrats per ranch). Biomass data were taken from a randomly determined half of the plant composition quadrat (0.25 meter × 0.5 meter total). Plant biomass measures were collected during the peak growing season of 2018 at the same time as vascular plant species abundance sampling (June 15-July 15). Litter mass was removed using hand raking, followed by clipping all standing plants to ground level (aboveground biomass). Two soil cores (6 cm diameter, 15 cm deep) were then taken within the same area and pooled within a quadrat, with roots later sieved out and washed. All biomass and litter mass was dried to constant weight at 70°C, weighed, and standardized to g/m². The resulting root biomass measures were lower than would be reasonably expected from these systems (e.g., see Bork et al., 2019). This was likely due to extensive fine-root degradation in transport as well as breakage during the washing process. As such, root biomass measures represent the within-study relative treatment effects, not absolute indicators of total root biomass present.
To measure aboveground biomass and biomass removal by livestock, we required approximate measures of plant growth with and without current-year grazing. The adaptive nature of ranch operations at our sites, as well as the geographic breadth of the sampling area, precluded us from systematically placing exclusion cages prior to grazing. Thus, at each plot, we installed an exclosure cage (1 × 1 meter) located 2 meters away from the non-exclosed plot a minimum of 2 weeks before plant community sampling. Biomass (aboveground, litter mass, and soil cores) and vascular plant species composition were sampled at the excluded and non-excluded sites within each pair. Subsequent analysis and discussion of biomass refer to those data collected from exclosure cages to mitigate the confounding influence of short-term grazing
PLFA and Microbial Biomass Data
No full textIn this study, grassland soils were collected from 15 ranch pairs located across the Canadian prairie, where, in each pair, one ranch practiced multi-paddock grazing while the other practiced conventional grazing (varying from continuous to slow to fast rotational grazing). Soil phospholipid fatty acid (PLFA) profiles were used to quantify microbial functional groups, and measured microbial biomass C and soil properties
Covariate raster data used for multi-scale cougar predation analyses in west-central Alberta
No full textThese covariate raster TIFFs were used as input data in generalized linear models (GLMs), which were developed to estimate cougar habitat and prey selection at multiple spatial scales in west-central Alberta, Canada. The study area for which these raster TIFFs were developed was in west-central Alberta, bounded to the west by Jasper National Park; to the north by Hinton, Alberta; to the south by Cadomin, Alberta; and to the east by Obed, Alberta. These raster TIFFs are being published in support of a multi-scale cougar predation analysis conducted by M Beale, S Widmeyer, and M Boyce. The manuscript associated with these data is currently being reviewed and will be included under 'Related Publications' upon acceptance
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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