1,720,983 research outputs found
Pinon-Juniper Dendrometer, Height, and Crown Area Measurements at Cerro Montosa, Sevilleta National Wildlife Refuge, New Mexico (2006-2009)
No full textAllometry is a standard method of determining biomass and Net Primary Production of many trees. One of the standard variables used in such allometric regressions is bole diameter. On straight trunk trees measurements at breast height (DBH) taken using a DBH tape is adequate for quantifying changes in diameter over time. However, in scrub forests such as the Pinon Juniper PJ woodlands, common on the Sevilleta, both the pinon and particularly the junipers are relatively short and multi-trunked so that measurements must be taken near the ground and the consistency between measurements often lead to erroneous growth analysis. To reduce such discrepancy in readings, dendrometer bands were installed on 20 pinons and 20 junipers in the Cerro Montoso area where understory ANPP has been measured for some time. These dendrometers quantify the expansion (and contraction) of the tree bole through time. The beginning diameter at the time of installation was also measured and recorded. Heights of the 40 trees were also measured. The diameter of the foliage was measured across these trees at the widest point and then again on an axis perpendicular to this first reading. Readings of the dendrometers are repeated on about a monthly basis through the growing season. Heights of the trees are done on an annual basis. Measurements are collected to quantify the increase in bole diameter for a set of Pinons and Junipers in this area over time
Pinon-Juniper Overstory Density, Cover and Biomass Data from Cerro Montosa, Sevilleta National Wildlife Refuge, New Mexico (2006-2009)
No full textIn 2006, to obtain a measure of pinon and juniper biomass in the Cerro Montosa area, belt transects were superimposed on transects along which understory net primary producitivy (NPP) is sampled. All trees rooted within 5 m to the north of each belt were tagged, although some shorter belts exist on which all trees within 5 m to either the north or south were tagged. The height of each tagged tree was measured, as was the diameter-at root-crown (DRC). Crown diameters both parallel and perpendicular to the belt transect were also measured. Trees were re-measured in 2007, 2008, and 2009
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
Pinon-Juniper (Core Site) Quadrat Data for the Net Primary Production Study at the Sevilleta National Wildlife Refuge, New Mexico (2003-present )
No full textThis dataset contains pinon-juniper woodland quadrat data and is part of a long-term study at the Sevilleta LTER measuring net primary production (NPP) across four distinct ecosystems: creosote-dominant shrubland (Site C, est. winter 1999), black grama-dominant grassland (Site G, est. winter 1999), blue grama-dominant grassland (Site B, est. winter 2002), and pinon-juniper woodland (Site P, est. winter 2003). Net primary production is a fundamental ecological variable that quantifies rates of carbon consumption and fixation. Estimates of NPP are important in understanding energy flow at a community level as well as spatial and temporal responses to a range of ecological processes. Above-ground net primary production is the change in plant biomass, represented by stems, flowers, fruit and and foliage, over time and incoporates growth as well as loss to death and decomposition. To measure this change the vegetation variables in this dataset, including species composition and the cover and height of individuals, are sampled twice yearly (spring and fall) at permanent 1m x 1m plots within each site. A third sampling at Site C is performed in the winter. The data from these plots is used to build regressions correlating biomass and volume via weights of select harvested species obtained in SEV157, Net Primary Productivity (NPP) Weight Data. This biomass data is included in SEV182, Seasonal Biomass and Seasonal and Annual NPP for Core Research Sites
Pinon-Juniper Dendrometer, Height, and Crown Area Measurements at Cerro Montosa, Sevilleta National Wildlife Refuge, New Mexico (2006-2009)
No full textThis dataset was originally published on the Long Term Ecological Research (LTER) Network Data Portal, https://portal.lternet.edu, and potentially via other repositories or portals as described. The Digital Object Identifier (DOI) of the source data package is
doi:10.6073/pasta/07dfedda2bac49fb6b6a6a04dcddf702, and may be accessed at http://dx.doi.org/10.6073/pasta/07dfedda2bac49fb6b6a6a04dcddf702. Metadata and files included in this record mirror as closely as possible the source data and documentation, with the provenance metadata and quality report generated by the LTER portal reproduced here as '*-provenance.xml' and *-report.html' files, respectively.Allometry is a standard method of determining biomass and Net Primary Production of many trees. One of the standard variables used in such allometric regressions is bole diameter. On straight trunk trees measurements at breast height (DBH) taken using a DBH tape is adequate for quantifying changes in diameter over time. However, in scrub forests such as the Pinon Juniper PJ woodlands, common on the Sevilleta, both the pinon and particularly the junipers are relatively short and multi-trunked so that measurements must be taken near the ground and the consistency between measurements often lead to erroneous growth analysis. To reduce such discrepancy in readings, dendrometer bands were installed on 20 pinons and 20 junipers in the Cerro Montoso area where understory ANPP has been measured for some time. These dendrometers quantify the expansion (and contraction) of the tree bole through time. The beginning diameter at the time of installation was also measured and recorded. Heights of the 40 trees were also measured. The diameter of the foliage was measured across these trees at the widest point and then again on an axis perpendicular to this first reading. Readings of the dendrometers are repeated on about a monthly basis through the growing season. Heights of the trees are done on an annual basis. Measurements are collected to quantify the increase in bole diameter for a set of Pinons and Junipers in this area over time
Pinon Juniper Net Primary Production Quadrat Data from the Sevilleta National Wildlife Refuge, New Mexico: 1999-2001
No full textThis three-year study at the Sevilleta LTER was designed to monitor net primary production (NPP) across two distinct ecosystems: pinon/juniper woodland (P) and juniper savannah woodland (J). Net primary production (NPP) is a fundamental ecological variable that measures rates of carbon consumption and fixation. Estimates of NPP are important in understanding energy flow at a community level as well as spatial and temporal responses of the community to a wide range of ecological processes. While measures of both below- and above-ground biomass are important in estimating NPP, this study focused on estimating above-ground biomass production (ANPP).To measure ANPP (i.e., the change in plant biomass, represented by stems, flowers, fruit and foliage, over time), the vegetation variables in this dataset, including species composition and the cover and height of individuals, were sampled twice yearly (spring and fall) at permanent 1m x 1m plots. The data from these plots was used to build regressions correlating biomass and volume via weights of select harvested species obtained in SEV157, Net Primary Productivity (NPP) Weight Data. In addition, volumetric measurements were obtained from permanent plots to build regressions correlating biomass and volume.Spring measurements were taken in April or May when shrubs and spring annuals reached peak biomass. Fall measurements were taken in either September or October when summer annuals reached peak biomass but prior to killing frosts. Winter measurements were taken in February before the onset of spring growth
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Pinon-Juniper (Core Site) Seasonal Biomass and Seasonal and Annual NPP Data for the Net Primary Production Study at the Sevilleta National Wildlife Refuge, New Mexico
No full textThis dataset was originally published on the Long Term Ecological Research (LTER) Network Data Portal, https://portal.lternet.edu, and potentially via other repositories or portals as described. The Digital Object Identifier (DOI) of the source data package is
doi:10.6073/pasta/175b978efeffdfdba73d9fce52f02751, and may be accessed at http://dx.doi.org/10.6073/pasta/175b978efeffdfdba73d9fce52f02751. Metadata and files included in this record mirror as closely as possible the source data and documentation, with the provenance metadata and quality report generated by the LTER portal reproduced here as '*-provenance.xml' and *-report.html' files, respectively.This dataset contains pinon-juniper woodland biomass data and is part of a long-term study at the Sevilleta LTER measuring net primary production (NPP) across four distinct ecosystems: creosote-dominant shrubland (Site C, est. winter 1999), black grama-dominant grassland (Site G, est. winter 1999), blue grama-dominant grassland (Site B, est. winter 2002), and pinon-juniper woodland (Site P, est. winter 2003). Net primary production is a fundamental ecological variable that quantifies rates of carbon consumption and fixation. Estimates of NPP are important in understanding energy flow at a community level as well as spatial and temporal responses to a range of ecological processes.Above-ground net primary production is the change in plant biomass, represented by stems, flowers, fruit and and foliage, over time and incoporates growth as well as loss to death and decomposition. To measure this change the vegetation variables in this dataset, including species composition and the cover and height of individuals, are sampled twice yearly (spring and fall) at permanent 1m x 1m plots within each site. A third sampling at Site C is performed in the winter. Volumetric measurements are made using vegetation data from permanent plots (SEV278, "Pinon-Juniper (Core Site) Quadrat Data for the Net Primary Production Study") and regressions correlating species biomass and volume constructed using seasonal harvest weights from SEV157, "Net Primary Productivity (NPP) Weight Data.
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