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Su S.,Zhejiang University | Jiang Z.,Minjiang University | Zhang Q.,Zhejiang University | Zhang Y.,CAS Changchun Northeast Institute of Geography and Agroecology
Applied Geography | Year: 2011

This paper analyzed the spatiotemporal dynamics of agricultural landscapes within Hang-Jia-Hu region (China) from 1994 to 2003 using a set of metrics that relate closely with sustainability. Considerable urban expansion was identified with the total built-ups increasing by 224.7% from 6.99 × 104 ha to 22.7 × 104 ha. The outcomes indicated that, at the whole region scale, agricultural landscapes became lost, fragmented, transformed and isolated as urbanization intensified. Global Moran's I statistics and Local Indicators of Spatial Association (LISA) analysis were employed to characterize the spatial dependence and hotspots for intra-level agricultural landscape changes at two grid scales. Generally, isolation of agricultural patches was a localized problem, while shape transformation of agricultural landscapes was a more regionalized problem; hotspots for lost, fragmentation and irregularity of agricultural landscapes concentrated around urban centers, while those for isolation of agricultural patches appeared in rural mountain areas. Spatial regression models further revealed that changes of agricultural landscapes showed diverging relationships with urbanization indicators for each landscape metric. The character and strength of relationships for each landscape metric were different and changed with scale. While our results of agricultural landscape changes consisted with some theoretical predictions in the literature, they also showed different spatiotemporal signatures of urbanization. Resolving these differences will certainly contribute to the ongoing landscape transformation and sustainability debate. This study demonstrated complexities of relationships between urbanization and agricultural landscape changes, and highlighted the importance of selected variables, spatial and temporal scales and incorporation of spatial dimensions when quantifying these relationships. © 2010 Elsevier Ltd. Source


Liu D.,CAS Changchun Northeast Institute of Geography and Agroecology | Zhang Z.-Q.,Landcare Research
Zootaxa | Year: 2013

The genus Austrophthiracarus (Acari: Oribatida: Phthiracaridae) was represented in New Zealand by four species prior to this work. In this paper, two new species of Austrophthiracarus are described from the South Island, New Zealand: Austrophthiracarus cronadun sp. nov. collected near Cronadun, Buller and Austrophthiracarus tawhai sp. nov. from Catlins State Forest, Otago. A key to all known species of Austrophthiracarus in New Zealand is provided. Copyright © 2013 Magnolia Press. Source


Su S.,Zhejiang University | Xiao R.,Zhejiang University | Zhang Y.,CAS Changchun Northeast Institute of Geography and Agroecology
Applied Geography | Year: 2012

Scientific interpretation of the relationships between agricultural landscape patterns and urbanization is important for ecological planning and management. Ordinary least squares (OLS) regression is the primary statistical method in previous studies. However, this global regression lacks the ability to uncover some local-specific relationships and spatial autocorrelation in model residuals. This study employed geographically weighted regression (GWR) to examine the spatially varying relationships between several urbanization indicators (urbanization intensity index, distance to urban centers and distance to road) and changes in metrics describing agricultural landscape patterns (total area, patch density, perimeter area ratio distribution and aggregation index) at two block scales (5 km and 10 km). Results denoted that GWR was more powerful than OLS in interpreting relationships between agricultural landscape patterns and urbanization, since GWR was characterized by higher adjust R2, lower Akaike Information Criterion values and reduced spatial autocorrelations in model residuals. Character and strength of the relationships identified by GWR varied spatially. In addition, GWR results were scale-dependent and scale effects were particularly significant in three aspects: kernel bandwidth of weight determination, block scale of pattern analysis, and window size of local variance analysis. Homogeneity and heterogeneity in the relationships between agricultural landscape patterns and urbanization were subject to the coupled influences of the three scale effects. We argue that the spatially varying relationships between agricultural landscape patterns and urbanization are not accidental but nearly universal. This study demonstrated that GWR has the potential to provide references for ecological planners and managers to address agricultural landscapes issues at all scales. © 2011 Elsevier Ltd. Source


Liu D.,CAS Changchun Northeast Institute of Geography and Agroecology | Zhang Z.-Q.,Landcare Research
Systematic and Applied Acarology | Year: 2013

The genus Oribotritia (Acari: Oribatida: Oribotritiidae) was represented in New Zealand by six species prior to this work. In this paper, three species of Oribotritia from New Zealand are described, including two new species, Oribotritia mangamuka sp. nov. and Oribotritia bilaminae sp. nov., and a known species with some variation. A key to all known species of Oribotritia in New Zealand is also provided. © 2013 Systematic & Applied Acarology Society. Source


Zhou D.W.,CAS Changchun Northeast Institute of Geography and Agroecology
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban | Year: 2011

Field survey and site study were conducted to approach the process and causes of salinization-alkalization of Leymus chinensis grassland in Songnen Plain, and to examine the hypothesis of soil disturbance-bareness. In the grassland, surface soil (0-30 cm) had a lower salt content, while deeper soil (> 30 cm) was in adverse. Thereby, the grassland was defined as soil-salted grassland. There was an increasing salt content in surface soil. This process was called as soil salinization-alkalization, and the grassland under the salinization:alkalization was named as alkali-salinized grassland. The leading reason for the surface soil salinization-alkalization was that the surface soil originally with low salt content was disturbed and lost away, subsurface soil rich in salt emerged as new surface soil, and the salt in deeper soil layers accumulated in the new surface soil and other soil layers. Secondary halophyte communities formed on the surface-soil-disturbed new bare land, but the communities had no succession sequence. The degradation process of the grassland was soil degradation first, followed by vegetation degradation, halophyte invasion, and successive evolution from nearly primitive condition. Source

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