The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Erika Micheli - One of the best experts on this subject based on the ideXlab platform.
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“Black Soils” in the Russian Soil Classification system, the US Soil Taxonomy and the WRB: Quantitative correlation and implications for pedodiversity assessment
CATENA, 2021Co-Authors: Alexey Sorokin, Erika Micheli, Vince Lang, Phillip R. Owens, Zhuo-dong Jiang, Pavel KrasilnikovAbstract:Abstract “Black Soils” recently proposed by the FAO Global Soil Partnership, include fertile Soils, characterized by a thick, dark-colored Soil horizon rich in organic matter. This study addressed the proposed concept of “black Soils”, in terms of taxonomic relationship of their corresponding Soil types of existing Soil classifications. Similarity studies were based on the calculation of taxonomic distances between selected Soil groups with organic matter–enriched horizons of the Russian Soil Classification System, the United States Soil Taxonomy and the World Reference Base for Soil Resources. In the process, we used the so called ”centroids”, which are the calculated mean values of several Soil properties for each of the Soil groups using legacy data derived from national and international databases. The results indicated that the Great Groups of the Mollisol Order in the US Soil Taxonomy had small taxonomic distances within the order, except some Soils with shallow depth to the hardpan or permafrost. Dark-colored Vertisols and Andisols were found to differ from the Mollisols and similar Soils found in similar environments mainly under grasslands. We recommend excluding Vertisols and Andisols from the “black Soils” cluster due to the peculiarity in their properties, potential use and management. While the Vertisols and Mollisols of the Soil Taxonomy were completely dissimilar in properties, the WRB Vertisol Reference group and Russian dark-humus compact Soils fitted well the Mollisols cluster, presumably due to the different concept of the Vertisols in the studied system. The Soil types of the “black Soils” of the Russian Soil classification had a short distance to the corresponding Reference Groups of the World Reference Base. Also, the similarity was high with the Great Groups of the US Soil Taxonomy for all Soil types except of Kastanozems, but the relationship in places was not well interpreted from a pedogeographic point of view. We ascribed the phenomenon to the geographical bias of the databases. Though “black Soils” form a distinct cluster that roughly corresponds to the Mollisols Order of the US Soil Taxonomy, the taxonomic distance within the group may be significant, contributing to the pedodiversity of Soilscapes of “black Soils”.
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A nomenclature algorithm for a potentially global Soil Taxonomy
Geoderma, 2018Co-Authors: Philip Hughes, Erika Micheli, Jingyi Huang, Budiman Minasny, Alexander B. Mcbratney, Jonathan HempelAbstract:Abstract Previous work has been put into the creation of a global Soil Taxonomy using a harmonised dataset of 23 Soil properties at 18 depth intervals. The Taxonomy consisted of selected Soil taxa from the US Soil Taxonomy, World Reference Base for Soil Resources, the Australian Soil Classification, and the New Zealand Soil Classification. In this paper, a nomenclature algorithm was proposed for this established comprehensive Taxonomy. Firstly, a Ward dendrogram was calculated from a weighted distance matrix determined from principal components of the taxa. This dendrogram was then cut at three levels, creating 15 groups, 86 subgroups, and 493 sub-subgroups at tiers 1, 2 and 3, respectively. A sequence of consonants was used to name the taxa at each tier alphabetically with “A” and “E” inserted between the consonants of tiers 2 and 3 and “OZEM” appended after the consonants of tier 1. In addition, a distance-based algorithm was used to allocate and name 10 unknown Soil profiles to the comprehensive Soil Taxonomy. It was concluded that the nomenclature algorithm can be easily disaggregated by computer and can be used to understand the inter-relationships between Soil profiles from different classification systems. In the future, there is a need to include other Soil classification systems to the comprehensive system and assign different weights to the Soil properties and depths used to construct the comprehensive Soil classification system.
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Comparisons between USDA Soil Taxonomy and the Australian Soil Classification system II: Comparison of order, suborder and great group taxa
Geoderma, 2018Co-Authors: Philip Hughes, Jonathan Hempel, Erika Micheli, Jingyi Huang, Budiman Minasny, Alexander B. Mcbratney, Edward J. JonesAbstract:Abstract Soil taxonomies over the world are incongruent- based on different tiers and different sets of properties. This second paper is concerned with understanding the relationships of each tier (Order, Suborder and Great Group) in both Soil Taxonomy (ST) and the Australian Soil Classification system (ASC) using mean nearest neighbour distances and convex hull areas in two principal component dimensions. It is determined that in most instances, convex hull comparisons using only two principal components, representing 30% of the variation in the data describe much of the variability between and within the orders, suborders and great groups of each classification system. These are useful for visual comparisons of taxa at various levels. Mean nearest-neighbour distances can include all 414 variables if necessary, which is more rigorous but complex. Both distance calculations and convex hulls highlight the same associations between taxa from ASC and ST. Both these methods demonstrate the robust Soil classification capability of the ST and the ASC, but with convex hull sizes and nearest-neighbour distances that are smaller, the ASC proves to be slightly more coherent. The two systems occupy somewhat different areas in PC space, and ST covers a larger overall area, demonstrating that ASC is a purpose-built classification for Australian conditions while ST Is a more general system that can cover a wider variety of Soils and management issues. We also show that great groups in ST are at about the same level of taxonomic generalization as great groups of the ASC. Combining the best elements and taxa of both these systems would be a positive step in the creation of a comprehensive system.
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comparisons between usda Soil Taxonomy and the australian Soil classification system i data harmonization calculation of taxonomic distance and inter taxa variation
Geoderma, 2017Co-Authors: Philip Hughes, Erika Micheli, Jingyi Huang, Budiman Minasny, Alexander B. Mcbratney, Jonathan HempelAbstract:Abstract Soil classification as a world exercise consists of predominantly individual organizations, creating locally meaningful categories for regional Soils. This process has inevitably created a recognized disconnect between classification systems, and a push for a universal classification has been proposed. In this paper, as a way of standardization between systems, Soil taxa at the great group level from two separate regions and Soil classification systems, Australia and the United States of America were represented by separate databases of Soil profile descriptions (SPDs) comprising the same 23 properties at 18 depth intervals. Taxa centroids from Soil Taxonomy (ST) and the Australian Soil Classification System (ASC) were calculated via principal component analysis. Convex hulls of each Soil order of both systems were created and the associations each taxon had with other individuals in the same taxon discussed, as well as the variance. We determined that ASC orders have smaller overall dispersion compared with the ST. The influence of each property to the overall taxonomic distances was also explored. It was concluded that this analysis opened the way for the possibility of comparing differing taxonomies and could pave the way for a more comprehensive classification method.
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testing the pedometric evaluation of taxonomic units on Soil Taxonomy a step in advancing towards a universal Soil classification system
Geoderma, 2016Co-Authors: Erika Micheli, Vince Lang, Phillip R. Owens, Alexander B. Mcbratney, Jon HempelAbstract:Abstract Most existing Soil classification systems were developed to understand and provide information on Soils, their natural properties and potential use for certain purposes. The conceptual developments of the systems took place before the recent boom of observation technologies, data storage and data processing achievements that can support to determine or predict Soil differences. Until the recent past Soils under agricultural or forestry use received more attention than other Soils, such as anthropogenically modified or urban Soils, or Soils of the cold regions. The broader view of Soil functions and the understanding of global environmental processes require a better understanding and description of all Soils. Precisely recorded and harmonized data is needed to serve the new era of modern agricultural practices, other land uses as well as different scientific applications. The Soil science community is challenged to apply the accumulated knowledge on Soil formation, Soil differences and functions, as well as, new tools of robust data processing to evaluate current systems and define objective relationships for better future classification systems. The evaluation of existing Soil classification systems may help the understanding of taxonomic relationships of differentiated Soil groups and improve our methods of classifying Soils. This paper is summarizing the approaches and methods of evaluation that was applied for the great group and higher levels of Soil Taxonomy. Simple statistical and pedometric methods were applied on centroids and, calculated on the basis of properties commonly used to define the classification units. The centroids provide an objective tool to evaluate the concepts of taxa and the taxonomic relationships between them. Examples of conceptual evaluations and detailed discussions of the taxonomic distance calculations between the great groups within their orders and members of other orders are provided. The presented methods and relationships were found very useful for the evaluation purpose. The extension of the methods for other systems, other data bases and the combination of those is in progress. The initial results suggest that the objective, pedometric approaches can support the development of an envisioned Universal Soil Classification System.
Alexander B. Mcbratney - One of the best experts on this subject based on the ideXlab platform.
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A nomenclature algorithm for a potentially global Soil Taxonomy
Geoderma, 2018Co-Authors: Philip Hughes, Erika Micheli, Jingyi Huang, Budiman Minasny, Alexander B. Mcbratney, Jonathan HempelAbstract:Abstract Previous work has been put into the creation of a global Soil Taxonomy using a harmonised dataset of 23 Soil properties at 18 depth intervals. The Taxonomy consisted of selected Soil taxa from the US Soil Taxonomy, World Reference Base for Soil Resources, the Australian Soil Classification, and the New Zealand Soil Classification. In this paper, a nomenclature algorithm was proposed for this established comprehensive Taxonomy. Firstly, a Ward dendrogram was calculated from a weighted distance matrix determined from principal components of the taxa. This dendrogram was then cut at three levels, creating 15 groups, 86 subgroups, and 493 sub-subgroups at tiers 1, 2 and 3, respectively. A sequence of consonants was used to name the taxa at each tier alphabetically with “A” and “E” inserted between the consonants of tiers 2 and 3 and “OZEM” appended after the consonants of tier 1. In addition, a distance-based algorithm was used to allocate and name 10 unknown Soil profiles to the comprehensive Soil Taxonomy. It was concluded that the nomenclature algorithm can be easily disaggregated by computer and can be used to understand the inter-relationships between Soil profiles from different classification systems. In the future, there is a need to include other Soil classification systems to the comprehensive system and assign different weights to the Soil properties and depths used to construct the comprehensive Soil classification system.
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Comparisons between USDA Soil Taxonomy and the Australian Soil Classification system II: Comparison of order, suborder and great group taxa
Geoderma, 2018Co-Authors: Philip Hughes, Jonathan Hempel, Erika Micheli, Jingyi Huang, Budiman Minasny, Alexander B. Mcbratney, Edward J. JonesAbstract:Abstract Soil taxonomies over the world are incongruent- based on different tiers and different sets of properties. This second paper is concerned with understanding the relationships of each tier (Order, Suborder and Great Group) in both Soil Taxonomy (ST) and the Australian Soil Classification system (ASC) using mean nearest neighbour distances and convex hull areas in two principal component dimensions. It is determined that in most instances, convex hull comparisons using only two principal components, representing 30% of the variation in the data describe much of the variability between and within the orders, suborders and great groups of each classification system. These are useful for visual comparisons of taxa at various levels. Mean nearest-neighbour distances can include all 414 variables if necessary, which is more rigorous but complex. Both distance calculations and convex hulls highlight the same associations between taxa from ASC and ST. Both these methods demonstrate the robust Soil classification capability of the ST and the ASC, but with convex hull sizes and nearest-neighbour distances that are smaller, the ASC proves to be slightly more coherent. The two systems occupy somewhat different areas in PC space, and ST covers a larger overall area, demonstrating that ASC is a purpose-built classification for Australian conditions while ST Is a more general system that can cover a wider variety of Soils and management issues. We also show that great groups in ST are at about the same level of taxonomic generalization as great groups of the ASC. Combining the best elements and taxa of both these systems would be a positive step in the creation of a comprehensive system.
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comparisons between usda Soil Taxonomy and the australian Soil classification system i data harmonization calculation of taxonomic distance and inter taxa variation
Geoderma, 2017Co-Authors: Philip Hughes, Erika Micheli, Jingyi Huang, Budiman Minasny, Alexander B. Mcbratney, Jonathan HempelAbstract:Abstract Soil classification as a world exercise consists of predominantly individual organizations, creating locally meaningful categories for regional Soils. This process has inevitably created a recognized disconnect between classification systems, and a push for a universal classification has been proposed. In this paper, as a way of standardization between systems, Soil taxa at the great group level from two separate regions and Soil classification systems, Australia and the United States of America were represented by separate databases of Soil profile descriptions (SPDs) comprising the same 23 properties at 18 depth intervals. Taxa centroids from Soil Taxonomy (ST) and the Australian Soil Classification System (ASC) were calculated via principal component analysis. Convex hulls of each Soil order of both systems were created and the associations each taxon had with other individuals in the same taxon discussed, as well as the variance. We determined that ASC orders have smaller overall dispersion compared with the ST. The influence of each property to the overall taxonomic distances was also explored. It was concluded that this analysis opened the way for the possibility of comparing differing taxonomies and could pave the way for a more comprehensive classification method.
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testing the pedometric evaluation of taxonomic units on Soil Taxonomy a step in advancing towards a universal Soil classification system
Geoderma, 2016Co-Authors: Erika Micheli, Vince Lang, Phillip R. Owens, Alexander B. Mcbratney, Jon HempelAbstract:Abstract Most existing Soil classification systems were developed to understand and provide information on Soils, their natural properties and potential use for certain purposes. The conceptual developments of the systems took place before the recent boom of observation technologies, data storage and data processing achievements that can support to determine or predict Soil differences. Until the recent past Soils under agricultural or forestry use received more attention than other Soils, such as anthropogenically modified or urban Soils, or Soils of the cold regions. The broader view of Soil functions and the understanding of global environmental processes require a better understanding and description of all Soils. Precisely recorded and harmonized data is needed to serve the new era of modern agricultural practices, other land uses as well as different scientific applications. The Soil science community is challenged to apply the accumulated knowledge on Soil formation, Soil differences and functions, as well as, new tools of robust data processing to evaluate current systems and define objective relationships for better future classification systems. The evaluation of existing Soil classification systems may help the understanding of taxonomic relationships of differentiated Soil groups and improve our methods of classifying Soils. This paper is summarizing the approaches and methods of evaluation that was applied for the great group and higher levels of Soil Taxonomy. Simple statistical and pedometric methods were applied on centroids and, calculated on the basis of properties commonly used to define the classification units. The centroids provide an objective tool to evaluate the concepts of taxa and the taxonomic relationships between them. Examples of conceptual evaluations and detailed discussions of the taxonomic distance calculations between the great groups within their orders and members of other orders are provided. The presented methods and relationships were found very useful for the evaluation purpose. The extension of the methods for other systems, other data bases and the combination of those is in progress. The initial results suggest that the objective, pedometric approaches can support the development of an envisioned Universal Soil Classification System.
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Testing the pedometric evaluation of taxonomic units on Soil Taxonomy — A step in advancing towards a universal Soil classification system
Geoderma, 2016Co-Authors: Erika Micheli, Vince Lang, Phillip R. Owens, Alexander B. Mcbratney, Jon HempelAbstract:Abstract Most existing Soil classification systems were developed to understand and provide information on Soils, their natural properties and potential use for certain purposes. The conceptual developments of the systems took place before the recent boom of observation technologies, data storage and data processing achievements that can support to determine or predict Soil differences. Until the recent past Soils under agricultural or forestry use received more attention than other Soils, such as anthropogenically modified or urban Soils, or Soils of the cold regions. The broader view of Soil functions and the understanding of global environmental processes require a better understanding and description of all Soils. Precisely recorded and harmonized data is needed to serve the new era of modern agricultural practices, other land uses as well as different scientific applications. The Soil science community is challenged to apply the accumulated knowledge on Soil formation, Soil differences and functions, as well as, new tools of robust data processing to evaluate current systems and define objective relationships for better future classification systems. The evaluation of existing Soil classification systems may help the understanding of taxonomic relationships of differentiated Soil groups and improve our methods of classifying Soils. This paper is summarizing the approaches and methods of evaluation that was applied for the great group and higher levels of Soil Taxonomy. Simple statistical and pedometric methods were applied on centroids and, calculated on the basis of properties commonly used to define the classification units. The centroids provide an objective tool to evaluate the concepts of taxa and the taxonomic relationships between them. Examples of conceptual evaluations and detailed discussions of the taxonomic distance calculations between the great groups within their orders and members of other orders are provided. The presented methods and relationships were found very useful for the evaluation purpose. The extension of the methods for other systems, other data bases and the combination of those is in progress. The initial results suggest that the objective, pedometric approaches can support the development of an envisioned Universal Soil Classification System.
Jon Hempel - One of the best experts on this subject based on the ideXlab platform.
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testing the pedometric evaluation of taxonomic units on Soil Taxonomy a step in advancing towards a universal Soil classification system
Geoderma, 2016Co-Authors: Erika Micheli, Vince Lang, Phillip R. Owens, Alexander B. Mcbratney, Jon HempelAbstract:Abstract Most existing Soil classification systems were developed to understand and provide information on Soils, their natural properties and potential use for certain purposes. The conceptual developments of the systems took place before the recent boom of observation technologies, data storage and data processing achievements that can support to determine or predict Soil differences. Until the recent past Soils under agricultural or forestry use received more attention than other Soils, such as anthropogenically modified or urban Soils, or Soils of the cold regions. The broader view of Soil functions and the understanding of global environmental processes require a better understanding and description of all Soils. Precisely recorded and harmonized data is needed to serve the new era of modern agricultural practices, other land uses as well as different scientific applications. The Soil science community is challenged to apply the accumulated knowledge on Soil formation, Soil differences and functions, as well as, new tools of robust data processing to evaluate current systems and define objective relationships for better future classification systems. The evaluation of existing Soil classification systems may help the understanding of taxonomic relationships of differentiated Soil groups and improve our methods of classifying Soils. This paper is summarizing the approaches and methods of evaluation that was applied for the great group and higher levels of Soil Taxonomy. Simple statistical and pedometric methods were applied on centroids and, calculated on the basis of properties commonly used to define the classification units. The centroids provide an objective tool to evaluate the concepts of taxa and the taxonomic relationships between them. Examples of conceptual evaluations and detailed discussions of the taxonomic distance calculations between the great groups within their orders and members of other orders are provided. The presented methods and relationships were found very useful for the evaluation purpose. The extension of the methods for other systems, other data bases and the combination of those is in progress. The initial results suggest that the objective, pedometric approaches can support the development of an envisioned Universal Soil Classification System.
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Testing the pedometric evaluation of taxonomic units on Soil Taxonomy — A step in advancing towards a universal Soil classification system
Geoderma, 2016Co-Authors: Erika Micheli, Vince Lang, Phillip R. Owens, Alexander B. Mcbratney, Jon HempelAbstract:Abstract Most existing Soil classification systems were developed to understand and provide information on Soils, their natural properties and potential use for certain purposes. The conceptual developments of the systems took place before the recent boom of observation technologies, data storage and data processing achievements that can support to determine or predict Soil differences. Until the recent past Soils under agricultural or forestry use received more attention than other Soils, such as anthropogenically modified or urban Soils, or Soils of the cold regions. The broader view of Soil functions and the understanding of global environmental processes require a better understanding and description of all Soils. Precisely recorded and harmonized data is needed to serve the new era of modern agricultural practices, other land uses as well as different scientific applications. The Soil science community is challenged to apply the accumulated knowledge on Soil formation, Soil differences and functions, as well as, new tools of robust data processing to evaluate current systems and define objective relationships for better future classification systems. The evaluation of existing Soil classification systems may help the understanding of taxonomic relationships of differentiated Soil groups and improve our methods of classifying Soils. This paper is summarizing the approaches and methods of evaluation that was applied for the great group and higher levels of Soil Taxonomy. Simple statistical and pedometric methods were applied on centroids and, calculated on the basis of properties commonly used to define the classification units. The centroids provide an objective tool to evaluate the concepts of taxa and the taxonomic relationships between them. Examples of conceptual evaluations and detailed discussions of the taxonomic distance calculations between the great groups within their orders and members of other orders are provided. The presented methods and relationships were found very useful for the evaluation purpose. The extension of the methods for other systems, other data bases and the combination of those is in progress. The initial results suggest that the objective, pedometric approaches can support the development of an envisioned Universal Soil Classification System.
M. H. Farpoor - One of the best experts on this subject based on the ideXlab platform.
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Comparing the ability of Soil Taxonomy (2014) and WRB (2015) to distinguish lithologic discontinuity and an abrupt textural change in major Soils of Iran
CATENA, 2018Co-Authors: I. Esfandiarpour-borujeni, Z. Mosleh, M. H. FarpoorAbstract:Abstract A “considerable increase in clay content within a very short distance” and “significant change of particle size distribution or mineralogy” are diagnostic Soil properties defined as “abrupt textural change” and “lithologic discontinuity” in the most Soil classification systems, i.e., Soil Taxonomy (ST) and World Reference Base for Soil Resources (WRB). This study investigates the ability of the latest versions of ST (2014) and WRB (2015) to classify Soils that have an abrupt textural change and lithologic discontinuity. Six study sites were selected from different regions (north, middle north, central, south, southeast and west) of Iran. One representative pedon was selected, described, and sampled in each study site. The physicochemical properties of the different genetic horizons of each pedon were determined and the Soils were classified according to the ST (2014) and WRB (2015) systems. In the ST system, the abrupt textural change characteristic was only used for some of the great groups or subgroups. Furthermore, the “Abruptic” qualifier was not considered for all of the reference Soil groups (RSGs) in the WRB system. Although, the presence of lithologic discontinuity at taxon name was totally neglected by the ST system, the WRB system showed this property with the “Raptic” qualifier. This seems to be a limitation for both of the Soil classification systems, thus the management of Soils with abrupt textural change and lithologic discontinuity still faces an important challenge. To overcome this problem and to harmonize both the classification systems, defining new great groups such as Palegypsids and new subgroups including Lithic Calcixerepts, Calcic Palexerolls, Abruptic Argigypsids, Calcic Argigypsids, Calcic Paleustalfs, and the “Raptic” subgroup for all taxa in the ST system is highly recommended. The addition of “Abruptic” qualifier for the RSGs such as Chernozems, Calcisols, and Gypsisols seems necessary in the WRB system.
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Comparing Soil Taxonomy (2014) and updated WRB (2015) for describing calcareous and gypsiferous Soils, Central Iran
CATENA, 2016Co-Authors: Masoomeh Sarmast, M. H. Farpoor, Isa Esfandiarpour BoroujeniAbstract:Abstract Soil classification is a useful tool for understanding and managing Soils. Latest editions of Soil Taxonomy (2014) and WRB (2015) were compared for classification of calcareous and gypsiferous Soils of southern Kerman in the present research. Soils along Jiroft-Kahnooj transect with ustic and hyperthermic moisture and temperature regimes were selected. Eleven pedons were described and sampled. Routine physical and chemical analyses were performed and Soils were classified according to Soil Taxonomy (2014) and WRB (2015) systems. Calcic, gypsic, anhydritic, salic, argillic (argic), and cambic diagnostic horizons were investigated after field and laboratory work. Based on the findings of the research, it is recommended that new Calciustalfs and Saliustepts great groups and Salic Anhydritic Calciustepts, Salic Calciustepts, Anhydritic Calciustepts, and Anhydritic Saliustepts subgroups are added to Soil Taxonomy (2014) classification system. Anhydritic diagnostic horizon, property, or material and paralithic qualifier were also suggested for WRB (2015) classification system. Calcium carbonate equivalent percentage needed for calcic horizon in WRB (2015) system is suggested to be re-defined as the 2.c required characteristics of calcic horizon in Soil Taxonomy (2014) system. Results of the study showed that WRB (2015) classification system using various qualifiers and specifiers could classify Soils of the area, especially saline Soils, more efficiently than Soil Taxonomy.
Jonathan Hempel - One of the best experts on this subject based on the ideXlab platform.
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Comparisons between USDA Soil Taxonomy and the Australian Soil Classification system II: Comparison of order, suborder and great group taxa
Geoderma, 2018Co-Authors: Philip Hughes, Jonathan Hempel, Erika Micheli, Jingyi Huang, Budiman Minasny, Alexander B. Mcbratney, Edward J. JonesAbstract:Abstract Soil taxonomies over the world are incongruent- based on different tiers and different sets of properties. This second paper is concerned with understanding the relationships of each tier (Order, Suborder and Great Group) in both Soil Taxonomy (ST) and the Australian Soil Classification system (ASC) using mean nearest neighbour distances and convex hull areas in two principal component dimensions. It is determined that in most instances, convex hull comparisons using only two principal components, representing 30% of the variation in the data describe much of the variability between and within the orders, suborders and great groups of each classification system. These are useful for visual comparisons of taxa at various levels. Mean nearest-neighbour distances can include all 414 variables if necessary, which is more rigorous but complex. Both distance calculations and convex hulls highlight the same associations between taxa from ASC and ST. Both these methods demonstrate the robust Soil classification capability of the ST and the ASC, but with convex hull sizes and nearest-neighbour distances that are smaller, the ASC proves to be slightly more coherent. The two systems occupy somewhat different areas in PC space, and ST covers a larger overall area, demonstrating that ASC is a purpose-built classification for Australian conditions while ST Is a more general system that can cover a wider variety of Soils and management issues. We also show that great groups in ST are at about the same level of taxonomic generalization as great groups of the ASC. Combining the best elements and taxa of both these systems would be a positive step in the creation of a comprehensive system.
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A nomenclature algorithm for a potentially global Soil Taxonomy
Geoderma, 2018Co-Authors: Philip Hughes, Erika Micheli, Jingyi Huang, Budiman Minasny, Alexander B. Mcbratney, Jonathan HempelAbstract:Abstract Previous work has been put into the creation of a global Soil Taxonomy using a harmonised dataset of 23 Soil properties at 18 depth intervals. The Taxonomy consisted of selected Soil taxa from the US Soil Taxonomy, World Reference Base for Soil Resources, the Australian Soil Classification, and the New Zealand Soil Classification. In this paper, a nomenclature algorithm was proposed for this established comprehensive Taxonomy. Firstly, a Ward dendrogram was calculated from a weighted distance matrix determined from principal components of the taxa. This dendrogram was then cut at three levels, creating 15 groups, 86 subgroups, and 493 sub-subgroups at tiers 1, 2 and 3, respectively. A sequence of consonants was used to name the taxa at each tier alphabetically with “A” and “E” inserted between the consonants of tiers 2 and 3 and “OZEM” appended after the consonants of tier 1. In addition, a distance-based algorithm was used to allocate and name 10 unknown Soil profiles to the comprehensive Soil Taxonomy. It was concluded that the nomenclature algorithm can be easily disaggregated by computer and can be used to understand the inter-relationships between Soil profiles from different classification systems. In the future, there is a need to include other Soil classification systems to the comprehensive system and assign different weights to the Soil properties and depths used to construct the comprehensive Soil classification system.
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comparisons between usda Soil Taxonomy and the australian Soil classification system i data harmonization calculation of taxonomic distance and inter taxa variation
Geoderma, 2017Co-Authors: Philip Hughes, Erika Micheli, Jingyi Huang, Budiman Minasny, Alexander B. Mcbratney, Jonathan HempelAbstract:Abstract Soil classification as a world exercise consists of predominantly individual organizations, creating locally meaningful categories for regional Soils. This process has inevitably created a recognized disconnect between classification systems, and a push for a universal classification has been proposed. In this paper, as a way of standardization between systems, Soil taxa at the great group level from two separate regions and Soil classification systems, Australia and the United States of America were represented by separate databases of Soil profile descriptions (SPDs) comprising the same 23 properties at 18 depth intervals. Taxa centroids from Soil Taxonomy (ST) and the Australian Soil Classification System (ASC) were calculated via principal component analysis. Convex hulls of each Soil order of both systems were created and the associations each taxon had with other individuals in the same taxon discussed, as well as the variance. We determined that ASC orders have smaller overall dispersion compared with the ST. The influence of each property to the overall taxonomic distances was also explored. It was concluded that this analysis opened the way for the possibility of comparing differing taxonomies and could pave the way for a more comprehensive classification method.