Yingui Cao

Effects of soil and topographic factors on vegetation restoration in opencast coal mine dumps located in a loess area.

Vegetation plays an important role in improving and restoring fragile ecological environments. In the Antaibao opencast coal mine, located in a loess area, the eco-environment has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation of the soil, topography and vegetation in 50 reclamation sample plots in Shanxi Pingshuo Antaibao opencast coal mine dumps was performed. Statistical analyses in this study included one-way ANOVA and significance testing using SPSS 20.0, and multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA) using CANOCO 4.5. The RDA revealed the environmental factors that affected vegetation restoration. Various vegetation and soil variables were significantly correlated. The available K and rock content were good explanatory variables, and they were positively correlated with tree volume. The effects of the soil factors on vegetation restoration were higher than those of the topographic factors.

Forces Driving Changes in Cultivated Land and Management Countermeasures in the Three Gorges Reservoir Area,China

The Three Gorges project accelerates economic development in the Three Gorges Reservoir Area. This paper aimed to investigate the distribution, changes and features of cultivated land in this area, analyze the forces driving the changes in cultivated land area, and propose the countermeasures for cultivated land management. Transition matrix was used to analyze the features of cultivated land changes, and quantitative analysis and qualitative analysis were adopted to research the driving forces according to the features of cultivated land changes. Cultivated land in the Three Gorges Reservoir Area mainly lay to the northwest of the Yangtze River, especially the upper reaches. The areas of cultivated land increased from 1996 to 1999, then decreased from 2000 to 2006, and finally increased again from 2007 to 2009. The important forces driving changes in cultivated land included government policies, employment and food security, increasing construction land, agriculture structure adjustment, land rearrangement, inundation. During cultivated land management, firstly, it is necessary to insist on the principle of cultivated land protection, standardize land exploitation and strictly restrict the transformation of cultivated land into non-farming land. Secondly, land rearrangement must be implemented, which can not only increase the area of the cultivated land, but also improve the quality of the cultivated land. Thirdly, it is feasible to intensify eco-agriculture construction to increase the quantity and quality of cultivated land. Fourthly, it is helpful to improve the traditional agriculture production methods to promote cultivated land quality. Lastly, it is important to propagandize cultivated land protection and realize the enormous pressure of cultivated land shortage, making more people obligated to protect cultivated land.

Characteristic analysis and pattern evolution on landscape types in typical compound area of mine agriculture urban in Shanxi Province, China

The compound area of mine agriculture urban is a community of resource, economy and society. In this study we took the compound area of mine agriculture urban in Pinglu District, Shuozhou City, Shanxi Province, China as the study object in order to discover the landscape type changing characteristics and pattern and analyze the driving forces from 1986 to 2013. We found that: (1) although farmland was the primary landscape type, construction land had increased obviously and destruction land also increased linearly; (2) cultivated land decreasing was mainly impacted by de-farming, construction occupation and mining destruction; (3) landscape changing types differed remarkably at different period, but generally increased, mainly from bidirectional farmland conversion to the coexistence of bidirectional farmland conversion, farmland to construction land and farmland to destruction land. Lastly, we proposed some management measures to direct landscape type changes.

Polycyclic aromatic hydrocarbons in the soil profiles (0–100 cm) from the industrial district of a large open-pit coal mine, China

Mining and industrial activities are the primary sources of soil pollution in the open-pit coal mine. The concentrations of PAHs in 11 sampling sites in the industrial district and 9 sampling sites with different land use types in Pingshuo open-pit coal mine, China, were measured to investigate the distributions of PAHs and possible sources in soil profiles (0–100 cm). In the topsoil layer (0–20 cm), concentrations of 16 PAHs ranged from 2.15 to 33.51 mg kg−1, with a mean value of 11.93 mg kg−1. PAHs were more variable in the middle soil layer (20–50 cm), ranging from 0.199 to 36.888 mg kg−1 with the average value of 9.21 mg kg−1. Comparable extreme concentrations were detected from the samples in the subsoil layer (50–100 cm). Compared with those in topsoil, the average concentrations of the most individual PAH species were less in the middle soil and subsoil layers. The concentrations of most of the individual PAHs in the topsoil were higher than those in the middle soil and subsoil. Distribution patterns of PAHs in the three soil layers correlated well with each other. The high concentration hotspots were concentrated around the old coal washery, reaching about 30 mg kg−1. The average concentrations of PAHs with different rings in the industrial district exceeded those in the other land use types. However, only the concentrations of 5-ring PAHs in topsoil showed difference with different land use types (P < 0.05). Diagnostic ratios and the total index showed that petroleum combustion was the main source of PAHs.

Evaluating relationships between soil chemical properties and vegetation cover at different slope aspects in a reclaimed dump

Conducting research about the relationships between soil chemical properties and vegetation coverage at different slope aspects is especially important in reconstructed ecosystems of vulnerable ecological regions. This study was conducted in the first reclaimed dump within the Pingshuo mining area of Shanxi Province, China, to analyze patterns of soil chemical properties (soil organic matter (SOM), soil total nitrogen (STN), soil available phosphorus (SAP) and soil available potassium (SAp) and vegetation coverage (NDVI) and their correlations at different slope aspects. In the reclaimed dump, 26 quadrats were established along four slope aspects (i.e., shady, semi-shady, sunny and semi-sunny slopes). There was no significant difference in SOM or STN among different slope aspects, while SAP differed between shady slopes compared to semi-shady, sunny and semi-sunny slopes; SAP differed significantly between semi-shady and semi-sunny slopes. The NDVI of semi-sunny slopes differed significantly from that of the other three aspects. There was variation in the relationships between NDVI and soil chemical properties, depending on the slope aspects. The logarithm of SOM and NDVI was related linearly on shady and semi-shady slopes, while NDVI was inversely related to the natural logarithm of the logarithm of SOM on sunny and semi-sunny slopes. STN and NDVI had a first-order function relationship on shady and semi-shady slopes, yet a quadratic function relationship on sunny and semi-sunny slopes. The relationships between SAP and NDVI were inverse on all types of slopes. On shady and semi-shady slopes, NDVI had a quadratic relationship with the logarithm of SAp, but it was well fitted by using a cubic function on sunny and semi-sunny slopes. The sensitivity coefficients of soil chemical properties and NDVI were different, and soil chemical properties changed differently depending on changes in NDVI at different slope aspects.

Analyses on Changes of Land Use in Three Gorges Based on Quantitative Research

Based on the MSS datum in 1975 and Landsite TM datum in 1987, 1995, 2000 and 2005, monitored the land use change in the Reservoir Area of three gorges was conducted with the support of several indexes to reflect the temporal-spatial changes during 30 years. The results as following, (1) The areas of cultivated land, forestry land, grass land decreased but the areas of construction land and water area increased during 30 years. (2) Used the indexes to indicate the trend of change. Making use of several indexes can reflect changes of land use absolutely, which is helpful for the land planning in Reservoir Area of Three Gorges.

ANALYSES ON REGIONAL CULTIVATED LAND CHANGEBASED ON QUANTITATIVE METHOD

Three Gorges Project is the great project in the world, which accelerates economic development in the reservoir area of Three Gorges Project. In the process of development in the reservoir area of Three Gorges Project, cultivated land has become the important resources, a lot of cultivated land has been occupied and become the constructing land. In the same time, a lot of cultivated land has been flooded because of the rising of the water level. This paper uses the cultivated land areas and social economic indicators of reservoir area of Three Gorges in 1990-2004, takes the statistic analyses and example research in order to analyze the process of cultivated land, get the driving forces of cultivated land change, find the new methods to stimulate and forecast the cultivated land areas in the future, and serve for the cultivated land protection and successive development in reservoir area of Three Gorges. The results indicate as follow, firstly, in the past 15 years, the cultivated land areas has decreased 200142 hm 2 , the decreasing quantity per year is 13343 hm 2 . The whole reservoir area is divided into three different areas, they are upper reaches area, belly area and lower reaches area. The trends of cultivated land change in different reservoir areas are similar to the whole reservoir area. Secondly, the curve of cultivated land areas and per capita GDP takes on the reverse U, and the steps between the change rate of cultivated land and the change rate of GDP are different in some years, which indicates that change of cultivated land and change of GDP are decoupling, besides that, change of cultivated land is connection with the development of urbanization and the policy of returning forestry greatly. Lastly, the precision of multi-regression is