COMPONENTS OF UNCERTAINTY IN SPECIES DISTRIBUTION ANALYSIS: A CASE STUDY OF THE GREAT GREY SHRIKE

Ecology ◽  
2008 ◽  
Vol 89 (12) ◽  
pp. 3371-3386 ◽  
Author(s):  
Carsten F. Dormann ◽  
Oliver Purschke ◽  
Jaime R. García Márquez ◽  
Sven Lautenbach ◽  
Boris Schröder
Keyword(s):  
Species Distribution ◽  
Distribution Analysis ◽  
Grey Shrike

scholarly journals Combining connectivity and species distribution modeling to define conservation and restoration priorities for multiple species: A case study in the eastern Amazon

2021 ◽  
Vol 257 ◽  
pp. 109148
Author(s):  
Leonardo de Sousa Miranda ◽  
Marcelo Awade ◽  
Rodolfo Jaffé ◽  
Wilian França Costa ◽  
Leonardo Carreira Trevelin ◽  
...  
Keyword(s):  
Species Distribution ◽  
Species Distribution Modeling ◽  
Distribution Modeling ◽  
Multiple Species

scholarly journals Practical Considerations for Implementing Species Distribution Essential Biodiversity Variables

2021 ◽  
Vol 5 ◽  
Author(s):  
Robin Boyd ◽  
Nick Isaac ◽  
Robert Cooke ◽  
Francesca Mancini ◽  
Tom August ◽  
...  
Keyword(s):  
Species Distribution ◽  
Biodiversity Indicators ◽  
The United Kingdom ◽  
Occupancy Detection ◽  
Essential Biodiversity Variables ◽  
The Uk ◽  
Species Occupancy ◽  
Very High ◽  
The Ideal

Species Distribution Essential Biodiversity Variables (SD EBVs; Pereira et al. 2013, Kissling et al. 2017, Jetz et al. 2019) are defined as measurements or estimates of species’ occupancy along the axes of space, time and taxonomy. In the “ideal” case, additional stipulations have been proposed: occupancy should be characterized contiguously along each axis at grain sizes relevant to policy and process (i.e., fine scale); and the SD EBV should be global in extent, or at least span the entirety of the focal taxa’s geographical range (Jetz et al. 2019). These stipulations set the bar very high and, unsurprisingly, most operational SD EBVs fall short of these ideal criteria. In this presentation, I will discuss the major challenges associated with developing the idealized SD EBV. I will demonstrate these challenges using an operational SD EBV spanning ~6000 species in the United Kingdom (UK) over the period 1970 to 2019 as a case study (Outhwaite et al. 2019). In short, this data product comprises annual estimates of occupancy for each species in all sampled 1 km cells across the UK; these are derived from opportunistically-collected species occurrence data using occupancy-detection models (Kéry et al. 2010). Having discussed which of the “ideal” criteria the case study satisfies, I will then touch on what are, in my view, two underappreciated challenges when constructing SD EBVs: dealing with sampling biases in the underlying data and the difficulty in evaluating the extent to which they bias the final product. These challenges should be addressed as a matter of urgency, as SD EBVs are increasingly applied in important settings such as underpinning national and international biodiversity indicators (see e.g., https://geobon.org/ebvs/indicators/).

Formation of disjunct plant distributions in Northeast Asia: a case study of Betula davurica using a species distribution model

Plant Ecology ◽  
2018 ◽  
Vol 219 (9) ◽  
pp. 1105-1115 ◽  
Author(s):  
Takuto Shitara ◽  
Yukito Nakamura ◽  
Tetsuya Matsui ◽  
Ikutaro Tsuyama ◽  
Haruka Ohashi ◽  
...  
Keyword(s):  
Species Distribution ◽  
Species Distribution Model ◽  
Northeast Asia ◽  
Distribution Model ◽  
Plant Distributions

Proppant Distribution in Newly Completed and Re-Fractured Wells - An Eagle Ford Shale Case Study

2021 ◽  
Author(s):  
Justin Allison ◽  
Glyn Roberts ◽  
Brad Hicks Hicks ◽  
Todd Lilly
Keyword(s):  
Oil And Gas ◽  
Treatment Effectiveness ◽  
Design Parameters ◽  
Distribution Analysis ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Video Footage ◽  
Final Consideration ◽  
Fractured Well

Abstract Fracture treatments and stage designs for new wells have evolved considerably over the past decade contributingto significant production growth. For example, in the acreage discussed hererecently used higher intensity fracturing methods provided an ~80% increase in recovery rates compared with legacy wells. Older wells completed originally with less efficient techniques can also benefit from these more up-to-date designs and treatments using re-fracturing methods. These offer the prospect of economically boosting production in appropriately selected wells. While adding in-fill wells has often been favored by Operators as a lowerrisk option the number of wells being re-fractured has grown every year for the last decade. In this case study two adjacent Eagle Ford wells, comprising a newly completed and a re-fractured well, allow both methods to be considered and compared. Completion design and fracture treatment effectiveness are evaluated using the uniformity of proppant distribution at cluster and stage level as the primary measure. Perforation erosion measurements from downhole video footage is used as the main diagnostic. Novel data acquisition methods combined with successful well preparation provided comprehensive and high-quality datasets. The subsequent proppant distribution analysis for the two wells provides the highest confidence results presented to date. Clear, repeatable trends in distribution are observed and these are compared across multiple stage designs for both the newly completed and re-fractured well. Variations in design parameters and how these effects distribution and ultimately recovery are discussed. These include changes to perforation count per cluster, cluster spacing, cluster count per stage, stage length, perforation charge size and treatment rates and volumes. As a final consideration production records for the evaluated wells are also discussed. Historical industry data shows that the number of wells being re-fractured increases relative to the number of newly drilled wells being completed during periods of low oil and gas prices. With the industry again facing harsh economic realities an increasing number of decisions will be made on whether new or refractured wells, or a combination of both, provide the best solution to replace otherwise inevitable production decline. This paper attempts to provide a detailed understanding of how proppant distribution, as a significant factor in production for hydraulically fractured wells, can be evaluated and considered in these decisions.

scholarly journals Combining Deforestation and Species Distribution Models to Improve Measures of Chimpanzee Conservation Impacts of REDD: A Case Study from Ntakata Mountains, Western Tanzania

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1195
Author(s):  
Rebecca Dickson ◽  
Marc Baker ◽  
Noémie Bonnin ◽  
David Shoch ◽  
Benjamin Rifkin ◽  
...  
Keyword(s):  
Biodiversity Conservation ◽  
Species Distribution ◽  
Carbon Emissions ◽  
Species Distribution Models ◽  
Cost Effective ◽  
Climate Mitigation ◽  
Suitable Habitat ◽  
Distribution Models ◽  
Western Tanzania

Projects to reduce emissions from deforestation and degradation (REDD) are designed to reduce carbon emissions through avoided deforestation and degradation, and in many cases, to produce additional community and biodiversity conservation co-benefits. While these co-benefits can be significant, quantifying conservation impacts has been challenging, and most projects use simple species presence to demonstrate positive biodiversity impact. Some of the same tools applied in the quantification of climate mitigation benefits have relevance and potential application to estimating co-benefits for biodiversity conservation. In western Tanzania, most chimpanzees live outside of national park boundaries, and thus face threats from human activity, including competition for suitable habitat. Through a case study of the Ntakata Mountains REDD project in western Tanzania, we demonstrate a combined application of deforestation modelling with species distribution models to assess forest conservation benefits in terms of avoided carbon emissions and improved chimpanzee habitat. The application of such tools is a novel approach that we argue permits the better design of future REDD projects for biodiversity co-benefits. This approach also enables project developers to produce the more manageable, accurate and cost-effective monitoring, reporting and verification of project impacts that are critical to verification under carbon standards.

Regulation of intestinal lipid metabolism by fusion-induced fatty liver based on graphene oxide nanopore DNA

2020 ◽  
Vol 10 (6) ◽  
pp. 802-811
Author(s):  
Gemin Xiao ◽  
Hong Shi ◽  
Jiongshan Zhang ◽  
Mei Liao ◽  
Wenhai Guo ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Lipid Metabolism ◽  
Fatty Liver ◽  
Relative Abundance ◽  
Species Distribution ◽  
Normal Population ◽  
Fat Metabolism ◽  
Intestinal Flora ◽  
Alpha Diversity ◽  
Distribution Analysis

The regulation of glucose and lipid metabolism by intestinal microorganisms is closely related to the occurrence of fatty liver. In order to explore the relationship between the distribution of intestinal flora and the occurrence of fatty liver, we extracted fecal DNA from normal people (group C) and patients with fatty liver (group D), sequenced the collected samples with graphene oxide (GO) nano-solid nanopore, and sequenced the V3 and V4 regions of 16S. After screening the sequencing data, all tag sequences of all samples were clustered according to operational taxonomic units (OTUs) using UPARSE 9 software. After determining abundance of OTUs and species annotation of the sequencing results, alpha diversity was analyzed based on an OTU abundance table. Krona (V2.6) 18 software displayed the results of species annotation in an interactive and visual way, and species distribution among groups was compared. The LEfSe method was used to analyze the differences of species distribution among components. After cluster analysis, the number of OTUs in the normal population was 512, the number of intestinal species in fatty liver patients was 541, of which 262 were common species. Alpha diversity analysis revealed reduced relative abundance in the fatty liver patients. The abundance of phylum, class, order, family, genus, and species in each group were compared. The abundance of Pachytene and Proteus increased abnormally and the relative abundance of Clostridium decreased. In addition, the abundance of Enterobacteriaceae in Enterobacteriaceae and Fusobacteria in Fusobacteria decreased. The relative abundance of Bacteroidea, Bacteroideae, and Lachnospiraceae increased. The results of species distribution analysis confirmed that the difference of Fusicantibacter distribution in Lachnospiraceae was significant. Functional analysis of the distribution of the flora revealed the principle role of the flora in fat metabolism. Therefore, it was concluded that Fusicantibacter was the dominant flora in patients with fatty liver, which promoted the formation of fatty liver by enhancing fat metabolism. The findings also demonstrated that GO nanopores can be used for DNA sequencing.

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