Pedogenetic soil horizons are one of the fundamental building blocks of modern soil classification; however, in soils of urban areas which are often strongly disturbed by human activities, horizons are difficult to di...Pedogenetic soil horizons are one of the fundamental building blocks of modern soil classification; however, in soils of urban areas which are often strongly disturbed by human activities, horizons are difficult to distinguish but substitutive morphological layers may be identified. To identify the characteristic soil layers in an urban environment, 224 soil layers of 36 in-situ pedons were examined and described in urban and suburban Nanjing, and 27 variables were extracted for multivariate analysis. Three groups and six subdivisions were identified by TwoStep cluster analysis combined with hierarchical cluster analysis based on factor scores. Soil forming factors and soil forming processes could be interpreted from the principal component analysis （PCA） of variables, cluster analysis of soil layers, and discriminant analysis of soil layer groups and their subdivisions. Parent materials, moisture regimes, organic matter accumulation, and especially nutrient accumulation were the main causes of characteristic soil layer formations. The numerical approaches used in this study were useful tools for characteristic soil layer identification of urban soils.展开更多
Based upon 134 rel関es, the vegetation of the forests with Mongolian pine (Pinus sylvestris var. mongolica) of the Great Xingan Mountains in the northeast China was classified into 3 communities, 7 types and 4 subtype...Based upon 134 rel関es, the vegetation of the forests with Mongolian pine (Pinus sylvestris var. mongolica) of the Great Xingan Mountains in the northeast China was classified into 3 communities, 7 types and 4 subtypes by numerical cluster analysis. 1) The Pinus sylvestris var. mongolica-Populus davidiana-community was found on relatively dry sites. It was subdivided into a Quercus mongolica-type, consisting of a Adenophora tetraphylla subtype, a Pulsatilla dahurica subtype, and a pure type; 2) The Pinus sylvestris var. mongolica-Rhododendron dauricum-community occurred on medium dry sites. It included a Calamagrostis angustifolia type, consisting of a Cladonia arbuscula subtype, a pure subtype, and a Rubus idaeus-type; 3) The Pinus sylvestris var. mongolica-Ledum palustre-community was found on periodically wet sites. It included a Picea koraiensis type, a Vaccinium uliginosum type, and a pure type.展开更多
基金the National Natural Science Foundation of China (No40625001)the Knowledge Innovation Program of the Chinese Academy of Sciences (NoKZCX2-YW-409)
文摘Pedogenetic soil horizons are one of the fundamental building blocks of modern soil classification; however, in soils of urban areas which are often strongly disturbed by human activities, horizons are difficult to distinguish but substitutive morphological layers may be identified. To identify the characteristic soil layers in an urban environment, 224 soil layers of 36 in-situ pedons were examined and described in urban and suburban Nanjing, and 27 variables were extracted for multivariate analysis. Three groups and six subdivisions were identified by TwoStep cluster analysis combined with hierarchical cluster analysis based on factor scores. Soil forming factors and soil forming processes could be interpreted from the principal component analysis （PCA） of variables, cluster analysis of soil layers, and discriminant analysis of soil layer groups and their subdivisions. Parent materials, moisture regimes, organic matter accumulation, and especially nutrient accumulation were the main causes of characteristic soil layer formations. The numerical approaches used in this study were useful tools for characteristic soil layer identification of urban soils.
文摘Based upon 134 rel関es, the vegetation of the forests with Mongolian pine (Pinus sylvestris var. mongolica) of the Great Xingan Mountains in the northeast China was classified into 3 communities, 7 types and 4 subtypes by numerical cluster analysis. 1) The Pinus sylvestris var. mongolica-Populus davidiana-community was found on relatively dry sites. It was subdivided into a Quercus mongolica-type, consisting of a Adenophora tetraphylla subtype, a Pulsatilla dahurica subtype, and a pure type; 2) The Pinus sylvestris var. mongolica-Rhododendron dauricum-community occurred on medium dry sites. It included a Calamagrostis angustifolia type, consisting of a Cladonia arbuscula subtype, a pure subtype, and a Rubus idaeus-type; 3) The Pinus sylvestris var. mongolica-Ledum palustre-community was found on periodically wet sites. It included a Picea koraiensis type, a Vaccinium uliginosum type, and a pure type.
