2011 Vol. 21, No. 3

Display Method:
Mollisols Properties and Changes in Ukraine and China
Yuri S KRAVCHENKO, ZHANG Xingyi, LIU Xiaobing, et al.
2011, 21(3): 257-266.
Soils are the foundation of civilizations and the basis for human food production. Mollisols in Ukraine and Northeast China are two out of the four major Mollisol regions in the world. The natural areas from which Mollisols developed are the prairies and steppes that experience temperate and freezing conditions. This review paper introduces the general climate, vegetation, and topography of Mollisols regions in Ukraine and Northeast China, analyzes their properties, including soil texture, soil organic matter content, soil bulk density, pH, cation exchange capacity and other chemical properties, and compares the property changes and management practices of Mollisols in relation to sustainable grain production.
Geomorphological Evolution Revealed by Aeolian Sedimentary Structure in Badain Jaran Desert on Alxa Plateau, Northwest China
BAI Yang, WANG Nai′ang, LIAO Kongtai, Patrick KLENK
2011, 21(3): 267-278.
The Badain Jaran Desert, located in the Alxa Plateau, Northwest China, features mega-dunes and a unique dune-lake alternation landscape. This paper presented the aeolian sediment structures of three representative dunes in the Badain Jaran Desert using ground-penetrating radar (GPR). We processed and analyzed the GPR data and investigated the feasibility of using integrated GPR and sedimentological data to reconstruct dunes structure, sedimentary environment and geomorphological evolution. The results show that the internal structures of star dune and transverse dune represent various stages of mega-dune evolution: the main deposition processes of mega-dune are similar to those of transverse dunes but have a more complicated mechanism of sand transport and deposition because of the superimposition of dunes; the upper section of the mega-dune has a structure similar to that of star dune, with vertical aggradations on top. Diffraction hyperbolae in the GPR profile indicates that the presence of ancient dunes characterized by calcareous cementation layers is involved in the maintenance of mega-dunes, and water levels, shown by continuous, sub-horizontal GPR reflections, are supposed to be closely related to mega-dunes and the interdune lakes. Outcrop of wet sand and horizontal stratifications on the GPR image indicate moisture potentials with different levels inside mega-dunes. The multiplex geomorphology in the Badain Jaran Desert is the result of global climatic undulation, the unique geographical location, the geological structural features, etc.
Carbon Sequestration in Forest Vegetation of Beijing at Sublot Level
XIAO Yu, AN Kai, XIE Gaodi, LU Chunxia, ZHANG Biao
2011, 21(3): 279-289.
Based on forest inventory data (FID) at sublot level, we estimated the carbon sequestration in forest vegetation of Beijing, China in 2009. In this study, the carbon sequestration in forest vegetation at sublot level was calculated based on net biomass production (?B) which was estimated with biomass of each sublot and function relationships between ?B and biomass. The biomass of forested land was calculated with biomass expansion factors (BEFs) method, while those of shrub land and other forest land types were estimated with biomass, coverage and height of referred shrubs and shrub coverage and height of each sublot. As one of special forested land types, the biomass of economic tree land was calculated with biomass per tree and tree number. The variation of carbon sequestration in forest vegetation with altitude, species and stand age was also investigated in this study. The results indicate that the carbon sequestration in forest vegetation in Beijing is 4.12 × 106 tC/yr, with the average rate of 3.94 tC/(ha•yr). About 56.91% of the total carbon sequestration in forest vegetation is supported by the forest in the plain with an altitude of < 60 m and the low mountainous areas with an altitude from 400 m to 800 m. The carbon sequestration rate in forest vegetation is the highest in the plain area with an altitude of < 60 m and decreased significantly in the transitional area from the low plain to the low mountainous area with an altitude ranging from 200 m to 400 m due to intensive human disturbance. The carbon sequestration of Populus spp. forest and Quercus spp. forest are relatively higher than those of other plant species, accounting for 25.33% of the total. The carbon sequestration in vegetation by the forest of < 40 years amounts to 45.38% of the total. The carbon sequestration rate in forest vegetation peaks at the stand age of 30–40 years. Therefore, it would be crucial for enhancing the capability of carbon sequestration in forest vegetation to protect the forest in Beijing, to limit human disturbance in the transitional area from the plain to the low mountain area, and to foster the newly established open forest.
Assessing Adaptability of Planted Trees Using Leaf Traits: A Case Study with Robinia pseudoacacia L. in the Loess Plateau, China
JIN Tiantian, LIU Guohua, FU Bojie, DING Xiaohui, YANG Lei
2011, 21(3): 290-303.
Leaf trait patterns and their variations with climate are interpreted as an adaptive adjustment to environment. This study assessed the adaptability of planted black locust (Robinia pseudoacacia L.) based on the analysis of leaf traits and the comparison of its leaf traits with inter-specific ones existing in the same area. We measured some water and N use related leaf traits: leaf dry mass per unit area (LMA) and N, P and K concentrations based on both leaf area (Narea, Parea and Karea) and leaf mass (Nmass, Pmass and Kmass) of R. pseudoacacia at 31 sites along a water stress gradient in North Shaanxi Province, China. The results show that leaves of R. pseudoacacia have high Nmass and low LMA in the study area. High Nmass and low LMA are usually representative of luxurious resource use, and will advance plant resource competitiveness in high-resource conditions. As a whole, LMA-nutrient relationships of R. pseudoacacia display patterns that are fairly similar to the inter-specific relationships in both direction and intensity. The tendency for LMA and Narea to increase with decreasing water availability and the positive correlation between LMA and Narea reflect the trend for R. pseudoacacia to enhance water use efficiency (WUE) at the expense of down-regulated photosynthetic N use efficiency (PNUE) and high construction cost in dry conditions. However, the positive relationship between LMA and Narea in high mean annual precipitation (MAP) area is either unremarkable or reversed with decreasing water availability. This implies a lower photosynthetic capacity and a higher construction cost for high-LMA leaves. The inter-specific relationship between LMA and Narea is positive and does not change with water availability. This difference between inter-species and intra-species may be due to more diversified anatomies and more specialised structures for inter-species than intra-species. The failure of R. pseudoacacia adaption to dry conditions reflected by LMA-Narea relationship may be partially responsible for the emergence of rampike and dwarf forms found frequently in dry conditions. Incorporating intrinsic characteristics of planted trees into vegetation restoration project will be instructive and meaningful for species selection.
Extracting Vegetation Phenology Metrics in Changbai Mountains Using an Improved Logistic Model
LI Ming, WU Zhengfang, QIN Lijie, MENG Xiangjun
2011, 21(3): 304-311.
Remotely sensing images are now available for monitoring vegetation dynamics over large areas. In this paper, an improved logistic model that combines double logistic model and global function was developed. Using this model with SPOT/NDVI data, three key vegetation phenology metrics, the start of growing season (SOS), the end of growing season (EOS) and the length of growing season (LOS), were extracted and mapped in the Changbai Mountains, and the relationship between the key phenology metrics and elevation were established. Results show that average SOS of forest, cropland and grassland in the Changbai Mountains are on the 119th, 145th, and 133rd day of year, respectively. The EOS of forest and grassland are similar, with the average on the 280th and 278th, respectively. In comparison, average EOS of the cropland is relatively earlier. The LOS of forest is mainly from the 160th to 180th, that of the grassland extends from the 140th to the 160th, and that of cropland stretches from the 110th to the 130th. As the latitude increases for the same land cover in the study area, the SOS significantly delays and the EOS becomes earlier. The SOS delays approximately three days as the elevation increases 100 m in the areas with elevation higher than 900 m above sea level (a. s. l.). The EOS is slightly earlier as the elevation increases especially in the areas with elevation below 1200 m a. s. l. The LOS shortens approximately four days as the elevation increases 100 m in the areas with elevation higher than 900 m a. s. l. The relationships between vegetation phenology metrics and elevation may be greatly influenced by the land covers. Validation by comparing with the field data and previous research results indicates that the improved logistic model is reliable and effective for extracting vegetation phenology metrics.
Land Cover Classification with Multi-source Data Using Evidential Reasoning Approach
LI Huapeng, ZHANG Shuqing, SUN Yan, GAO Jing
2011, 21(3): 312-321.
Land cover classification is the core of converting satellite imagery to available geographic data. However, spectral signatures do not always provide enough information in classification decisions. Thus, the application of multi-source data becomes necessary. This paper presents an evidential reasoning (ER) approach to incorporate Landsat TM imagery, altitude and slope data. Results show that multi-source data contribute to the classification accuracy achieved by the ER method, whereas play a negative role to that derived by maximum likelihood classifier (MLC). In comparison to the results derived based on TM imagery alone, the overall accuracy rate of the ER method increases by 7.66% and that of the MLC method decreases by 8.35% when all data sources (TM plus altitude and slope) are accessible. The ER method is regarded as a better approach for multi-source image classification. In addition, the method produces not only an accurate classification result, but also the uncertainty which presents the inherent difficulty in classification decisions. The uncertainty associated to the ER classification image is evaluated and proved to be useful for improved classification accuracy.
Crop Classification Using MODIS NDVI Data Denoised by Wavelet: A Case Study in Hebei Plain, China
ZHANG Shengwei, LEI Yuping, WANG Liping, et al.
2011, 21(3): 322-333.
Time-series Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data have been widely used for large area crop mapping. However, the temporal crop signatures generated from these data were always accompanied by noise. In this study, a denoising method combined with Time series Inverse Distance Weighted (T-IDW) interpolating and Discrete Wavelet Transform (DWT) was presented. The detail crop planting patterns in Hebei Plain, China were classified using denoised time-series MODIS NDVI data at 250 m resolution. The denoising approach improved original MODIS NDVI product significantly in several periods, which may affect the accuracy of classification. The MODIS NDVI-derived crop map of the Hebei Plain achieved satisfactory classification accuracies through validation with field observation, statistical data and high resolution image. The field investigation accuracy was 85% at pixel level. At county-level, for winter wheat, there is relatively more significant correlation between the estimated area derived from satellite data with noise reduction and the statistical area (R2 = 0.814, p < 0.01). Moreover, the MODIS-derived crop patterns were highly consistent with the map generated by high resolution Landsat image in the same period. The overall accuracy achieved 91.01%. The results indicate that the method combining T-IDW and DWT can provide a gain in time-series MODIS NDVI data noise reduction and crop classification.
Characterization of Water Constituents Spectra Absorption in Chagan Lake of Jilin Province, Northeast China
WANG Yuandong, LIU Dianwei, SONG Kaishan, et al.
2011, 21(3): 334-345.
Research on the optical characteristics of water color constituents in Chagan Lake of Jilin Province, Northeast China was carried out in order to investigate the variability of the spectra absorption parameters as inputs to bio-optical models and remote sensing algorithms for converting observed spectral signals into water quality information. Samples of total particulates, non-algal particles and colored dissolved organic matter (CDOM) were first prepared by quantitative filter technique (QFT) and then absorption coefficients of these color producing agents were determined by spectrophotometry. Spectral characteristics of absorption coefficients by total particulate matter, spectral specific absorption dependency on chlorophyll concentration (Chl-a) of phytoplankton, spectral absorption slopes variation for CDOM and non-algal particles and their corresponding reasons were examined and clarified over five months of 2009 and 2010 in this study. Results suggest that total particulate spectral absorption in Chagan Lake is mainly dominated by non-algal particles in most cases, but phytoplankton could be the dominant contributor when chlorophyll concentration is high (up to 84.48 mg/m3 in autumn 2010). The specific absorption coefficients of phytoplankton particulate (a*ph(λ)) dependency on Chl-a is significantly variable due to relative contributions of package effect and accessory pigments, and the parameters of power function are clearly biased on a long time span. The sources of variability in spectral absorption slopes of CDOM and non-algal particles are mainly attributed to the changing proportions of high molecular weight humic acids and mineral suspended sediments in waters, respectively.
A Spatio-temporal Data Model for Road Network in Data Center Based on Incremental Updating in Vehicle Navigation System
WU Huisheng, LIU Zhaoli, ZHANG Shuwen, ZUO Xiuling
2011, 21(3): 346-353.
The technique of incremental updating, which can better guarantee the real-time situation of navigational map, is the developing orientation of navigational road network updating. The data center of vehicle navigation system is in charge of storing incremental data, and the spatio-temporal data model for storing incremental data does affect the efficiency of the response of the data center to the requirements of incremental data from the vehicle terminal. According to the analysis on the shortcomings of several typical spatio-temporal data models used in the data center and based on the base map with overlay model, the reverse map with overlay model (RMOM) was put forward for the data center to make rapid response to incremental data request. RMOM supports the data center to store not only the current complete road network data, but also the overlays of incremental data from the time when each road network changed to the current moment. Moreover, the storage mechanism and index structure of the incremental data were designed, and the implementation algorithm of RMOM was developed. Taking navigational road network in Guangzhou City as an example, the simulation test was conducted to validate the efficiency of RMOM. Results show that the navigation database in the data center can response to the requirements of incremental data by only one query with RMOM, and costs less time. Compared with the base map with overlay model, the data center does not need to temporarily overlay incremental data with RMOM, so time-consuming of response is significantly reduced. RMOM greatly improves the efficiency of response and provides strong support for the real-time situation of navigational road network.
Hollow Villages and Rural Restructuring in Major Rural Regions of China: A Case Study of Yucheng City, Shandong Province
SUN Hu, LIU Yansui, XU Keshuai
2011, 21(3): 354-363.
The agricultural land resources of China are relatively limited because of its large population. Therefore, balancing the land use for industrialization, urbanization, and food security is a big challenge. In recent years, rural hollowing in China has resulted in numerous of abandoned rural houses, and the areas with abandoned houses need to be restored into agricultural land with effective land consolidation techniques. This study used the method of benefit-cost analysis and the data collected through field surveys conducted in Yucheng City in the northwest of Shandong Province in March 2009, to examine how hollow villages (HVs) to be created and how to solve the problem. The qualitative and quantitative analyses indicate following results. 1) The situation of HVs is becoming increasingly severe under rapid industrialization and urbanization in Yucheng City. 2) Poor infrastructure in rural areas and incomplete urbanization are the main factors that have led to the rural hollowing in many major rural regions of China. 3) In order to resolve the problem caused by HVs and increase agricultural land, reconstructing rural communities in the countryside is necessary. 4) A new mechanism in the provision of compensation funds by developed regions to the villages in less-developed regions must be established.
Relationships and Evolving Networks of Rural Manufacturing Clusters: A Case Study in Yucheng County, Henan Province of China
LI Erling, LI Xiaojian, LIU Zhigao
2011, 21(3): 364-376.
The evolution of networks in rural industrial clusters, in particular in the context of China has been paid more attention to in the world. Applying the theory and techniques of social network analysis (SNA), this study is with particular regard to the business network relationships and their evolutionary dynamics of steel measuring tape manufacturing clustered in Nanzhuang Village, Yucheng County of Henan Province, China, which is important for better understanding the industrial and regional development in less developed rural areas. From data collected by comprehensive questionnaire survey in 2002 and mass interviews with 60 enterprises and assembling families and several government authorities in 2002, 2003, 2004, 2005 and 2008, four types of networks are identified: spin-off, consulting, communication and cooperative. The characteristic of these networks is outlined in detail. Compared with the high-tech clusters of typical developed areas, the networks that have evolved in traditional manufacturing clusters are more affected by emotive linkages. The cluster networks are shown to exhibit a polycentric hierarchical structure. The family relationships are the dominate spin-off channels of enterprises, while the supply and demand relationships and the mobility of the skilled workers are also important paths of network learning, and the cooperation relationships are comparatively stable. Besides the root enterprises, the middle-sized enterprises are comparatively more active than small-sized enterprises, and the intermediary agencies and the service institutions act as bridges of the inter-enterprises cooperation. By analysis of the structure of networks and the interactions between the networks, the four stages of network evolution are also identified. The four stages are dominated by the family networks, the internal division production networks, the local innovation networks and the global supply networks respectively, and they play different roles in cluster development.
Influence of Tourists′ Environmental Tropisms on Their Attitudes to Tourism and Nature Conservation in Natural Tourist Destinations:
A Case Study of Jiuzhaigou National Park in China
CHENG Shaowen, ZHANG Jie, LU Shaojing, et al.
2011, 21(3): 377-384.
People′s environmental tropism has an effect on their understanding of tourism-nature relationship, and also influences their attitudes to natural resources utilization and environmental protection. Taking Jiuzhaigou National Park of China as a study case, the authors conducted some quantitative analyses with the tools of SPSS 16.0 and LISREL 8.7, to explore the influence of tourists′ environmental tropism on their attitudes to tourism and nature conservation in the natural tourist destination. Three hypotheses and the theoretic model of influences of tourists′ environmental tropism on their attitudes to tourism and nature conservation have been tested and accepted based on the Structural Equation Model analysis on survey data collected in Jiuzhaigou National Park of China. Some conclusions were drawn as follows: 1) tourists′ human-prioritized concept influences their cognition to tourism-nature relationship. This concept has a positive influence on their supportive attitudes to tourism, but a negative influence on their attitudes to nature conservation; 2) tourists′ human-nature coordination concept has a positive influence on their supportive attitudes to both tourism and nature conservation, especially to the latter. This paper generally proves that human′s environmental tropism does have an influence on their attitudes to tourism and nature conservation in natural tourist destinations.