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Volume 38,Issue 3
  • Driving forces behind ecosystem spatial changes in the Yangtze River Basin
  • Authors:KONG Lingqiao, ZHANG Lu, ZHENG Hua, XU Weihua, XIAO Yi and OUYANG Zhiyun
  • Abstract:There are obvious differences among the upper, middle, and lower reaches in the natural environment in the Yangtze River Basin. The regional topography and climatic conditions are significantly distinct, and economic development is unbalanced. The impacts of various socioeconomic factors, policies, and natural factors on land use stimulate changes in the ecological environment. Therefore, knowledge of the ecosystem's patterns, characteristics, and driving forces is the basis for studying the ecosystem services, ecological environmental problems, and ecological risk assessments. The ecosystem patterns, changing characteristics, and primary driving forces were analyzed from 2000 to 2015 in the Yangtze River Basin. During the 15-year period, about 6.4×104 km2 of the ecosystem changed, including a 67.5% increase in urban land, 2.1% increase in forest growth, and 7.5% reduction in croplands. These dramatic changes were concentrated in the lower reaches, big cities in the upper and the middle reaches, urban agglomerations, and reforested cropland areas. Ecosystem patterns and compositions in the upper, middle, and lower reaches were different. Forests and wetlands in the upper reach and urban land in the lower reach increased significantly, whereas croplands and wetlands in the lower reach decreased substantially. Through the analysis of landscape patterns, the degree of landscape fragmentation, as well as landscape diversity, increased. Between the years 2000 and 2015, the change in ecosystem patterns in the Yangtze River Basin was influenced by urbanization, ecological conservation and restoration, water resource development, agricultural development, geological hazards, and climate change. The contributions of the primary driving forces to ecosystem changes varied for the upper, middle, and lower reaches. The first important driving force was urbanization, with a contribution rate of 48.0% and up to 64.5% in the lower reach. The second important driving force was ecological conservation projects, with a contribution rate of 32.8% and up to 47.8% in the upper reach. Water resource development and agricultural development contributed 8.5% and 9.9%, respectively. In addition, the area of plateau lakes increased due to climate change. To sustainably protect the ecosystem in the Yangtze River Basin, the design of the ecological conservation redlines, reasonable land use planning in urbanization, conservation of high quality cropland, and the prohibition of development on important wetlands are necessary.
  • DownLoad:Driving forces behind ecosystem spatial changes in the Yangtze River Basin.PDF
  • Landscape pattern change in Beijing fringe area and its impact on the ecosystem services: a case study in Niulanshan-Mapo town
  • Authors:WANG Liqun, ZHANG Zhiqiang, LI Ge, MA Fengwei and CHEN Lixin
  • Abstract:Cities in China have been continuously expanding in recent years. This process has been affected by the country's rapid socio-economic development and urbanization, especially in large metropolises like Beijing. Because urban fringe areas are now undergoing rapid economic development, human activity has come to have a significant impact on landscape patterns and has led to changes in the ecosystem service function. For this reason, it is crucial to study the changes occurring in Beijing. The town of Niulanshan-Mapo is a representative of many urban fringe areas. It is located outside the sixth ring road, 50 km from the urban center of Beijing. Considering the town's important role in forming the Beijing fringe area, we undertook a case study of Niulanshan-Mapo. In this study, we investigated the changes in landscape patterns and ecosystem service value in Niulanshan-Mapo town during 1992 and 2015. We analyzed and identified changes in the trends and dynamics driving the changes in landscape patterns and corresponding ecosystem service value under the background of rapid socio-economic development. The Fragstats 4.2 spatial analysis tool was used to establish the landscape pattern index, and SPSS statistical software was used to analyze the relationship between the landscape pattern index according to land use data from 1992, 2001, and 2015. An ecosystem services equivalent factor table was constructed based on the actual grain production and price in Beijing. The results showed that the landscape pattern changed dramatically in Niulanshan-Mapo town. Fragmentation and heterogeneity were also greatly increased in this area. The dominant landscape types changed from farmland to built-up areas, and the ecosystem service value increased from 116.09 million yuan in 1992 to 149.92 million yuan in 2015. The forest ecosystem service value increased from 1109.67 million yuan in 1992 to 8940.98 million yuan in 2015, accounting for the largest contribution to the increase in ecosystem service value of all landscape types. According to the analysis of the relationship between the landscape pattern index and ecological system, it was beneficial to increase the ecosystem service value through improving the largest patch index, patch density index, and diversity index. However, as the landscape pattern varied among different regions, the relationship of landscape pattern index and ecosystem service value also changed. Hence, it was essential to analyze the degree of influence of the ecosystem service on each landscape pattern index. In conclusion, this study not only analyzed the temporal and spatial changes of land use, but also the structural change of ecosystem service value change in the rapid development of an urban fringe region. We determined the main land use type responsible for a change in ecosystem service value. An important finding of this study was that the interference of the landscape pattern might not necessarily lead to the degradation of ecosystem service function in the context of rapid urbanization. However, the scientific and reasonable planning and conservation policy on ecological environment constitute the main reasons for an increase in land ecosystem service value in Niulanshan-Mapo town. This study also provides the strategies and theoretical basis for the improvement of ecosystem service value of other similar urban fringe areas.
  • DownLoad:Landscape pattern change in Beijing fringe area and its impact on the ecosystem services: a case study in Niulanshan-Mapo town.PDF
  • Study on ecological footprint distance of fruit consumption in Beijing
  • Authors:CHEN Wenhui, XIE Gaodi, ZHANG Changshun, LU Chunxia, XIAO Yu, ZHANG Caixia, ZHANG Yinjun and WANG Hao
  • Abstract:The ecological footprint method was proposed in 1992 and improved later, and is widely applied in the assessment of sustainable development by its balance comparison to the bio-capacity. The ecological footprint is an area indicator demonstrating the human impact on natural capitals. Although the indicator of ecological footprint distance is established on the basis of ecological footprint, it describes the ecologically dependent distance of a city, which might be a valuable supplement and improvement to the ecological footprint and bio-capacity theory system. This study analyzed the ecological footprint distance of Beijing's fruit consumption. Population data and resident fruit consumptions were collected from the "Beijing Statistical Yearbook" and "Chinese Migrants Development Report" from 2008 to 2012. Additionally, a market investigation was carried out. There was an overall increasing trend of Beijing's fruit ecological footprint distance, imported fruit mass, and fruit ecological footprint distance per capita. From 2009 to 2012, the distance of imported fruit mass increased by 47.91% (to 17.01 billion t km); the fruit ecological footprint distance fluctuated smoothly between 8.87 hundred km and 1.07 thousand km; and the average fruit ecological footprint distance (per capita) increased by 26.42% (to 55.5 thousand km). From the aspect of category, the maximum annual average fruit ecological footprint distance was recorded for banana (2.07 thousand km), and the minimum for apple (4.76 hundred km); the maximum average annual imported mass of bio-capacity was observed for water melon (497.8 billion kg km), and the minimum for banana (51.8 billion kg km); and the maximum average annual ecological footprint distance of the four years was observed for water melon (177 thousand km), and the minimum for banana (192 thousand km). The result showed that the rapid urbanization of Beijing metropolis area had led to an enlarged ecological cost in fruit consumption, and led to a more wide-scope bio-capacity suppliers as well. Even more, this enlargement has exceeded the speed of population growth. The following limitations existed in this study:first, due to the limitation of data, fruit product was chosen as the representative of all kinds of ecological resources; second, an appropriate weight should be given to each type of fruit while calculating the indicator of fruit ecological footprint distance. It is recommended that the follow-up studies on the ecological footprint distance should improve in several ways:By collecting different types of industrial, agricultural, and service industrial products data as much as possible; by creating a model that could determine the distance weight set of all products and could provide an appropriate weight to each type of product; by choosing more cities of different population or economic scale as research targets. These improvements might be helpful in obtaining a more comprehensive and convinced indicator of a city's ecological footprint distance.
  • DownLoad:Study on ecological footprint distance of fruit consumption in Beijing.PDF
  • A study on urban ecosecurity pattern of island city: a case study of Pingtan Island
  • Authors:JIANG Yuantong, TIAN Ye and ZHENG Shuanning
  • Abstract:The world is undergoing the largest wave of urban growth in history. More than half of the world's population now lives in towns and cities, and the proportion of the global population in urban areas has increased conspicuously from 30% in 1950 to 54% in 2014. Urbanization is projected to increase even further to 60% in 2030. Though the process of urbanization provides comfortable and convenient living conditions for human beings, it also makes our country face a series of serious urban ecological security issues (such as environmental pollution and diminishing resources) because of the high-intensity of human activities and unreasonable land use. Nowadays, urban ecological security brought by the rapid urbanization is posing a serious threat to urban sustainable development. Against this background, constructing the urban ecological security pattern is the basic guarantee and important way to realize regional and urban ecological security. Based on the eco-environmental background conditions of Pingtan Island, this study first investigated the perspective of urban ecological security and considered the overall plan of Pingtan Comprehensive Pilot Zone to better understand six key ecological sensitive factors that were closely related to the urban ecological security of Pingtan Island. These six key ecological sensitive factors were drinking water resources, coastal shelterbelt, scenic spots and forest parks, natural mountain, cultivated land, and coastline resources. Thereafter, a comprehensive evaluation model was established by the analytical hierarchy process (AHP) and geographical information system (GIS) spatial overlay method to comprehensively evaluate the ecological sensitivity of Pingtan Island. The specific analysis process was as follows:First, an evaluation index system of Pingtan Island's ecological sensitivity by means of data collection, field investigation, remote sensing image interpretation and analysis, and expert reviews was established. These indices were classified according to their sensitivity. Second, the judgment matrix was constructed and consistency checks were performed in accordance with the AHP method, then the weight of each index was calculated according to the square root method. Finally, considering that scenic spots covered with natural mountain forest have the highest ecological sensitivity, and that other areas may not be ecologically sensitive or may be insensitive, the Pingtan Island was divided into five grades (extreme sensitivity, high sensitivity, moderate sensitivity, low sensitivity, and insensitive grades) according to their respective ecological sensitivity indices. We propose an ecological security pattern for Pingtan Island in order to adapt to the new round of large-scale urban development boom, and this pattern is mainly composed of ecological security barrier ring, ecological water system, ecological conservation area, ecological coastal zone, urban construction area, and the ecological promotion area. These components play different roles in maintaining ecological safety on Pingtan Island, and they must be rationally developed and utilized on the basis of their respective functions. Generally, the results of this study would help to provide decision support for urban planning, and could be of great theoretical and practical significance to maintain Pingtan Island's ecological security and promote the sustainable development of Pingtan Island. Moreover, these results may also be useful for ecosecurity pattern research on other island cities.
  • DownLoad:A study on urban ecosecurity pattern of island city: a case study of Pingtan Island.PDF
  • Urban fringe area ecological vulnerability space-time evolution research: the case of Ganjingzi District, Dalian
  • Authors:YANG Jun, GUAN Yingying, LI Xueming and XI Jianchao
  • Abstract:Based on the land use data of 1998 and the remote sensing data of 2003, 2007, and 2013 SPOT5, the Ecological Vulnerability Index (EVI) value of the communities was calculated using the Exposure Susceptibility Coping Capacity (ESC) model combined with spatial analysis and linear weighting, and the ecological vulnerability of the Ganjingzi area was divided into five grades. To establish the evaluation index system, the change slope was calculated using the multiplication method. When the F value was significant, the change slope and significance were divided into four grades. Temporal distribution of ecological fragility in Ganjingzi District of Dalian, from 1998 to 2013, was also studied. The results were as folloes:(1) From the perspective of the distribution characteristics of ecological vulnerability in urban fringe areas, the ecological environment of the urban fringe area showed the same level of aggregation, and the neighborhood adjacent to the Shahekou District showed a distinct radial pattern, with obvious differences between the east and the west. (2) From the perspective of the ecological vulnerability of the communities, the ecological status of the communities within Ganjingzi District was significantly different. The ecological vulnerability of the communities adjacent to the urban area was remarkable, and the ecological environment was rapidly deteriorating. The mean EVI increased from 0.62 to 0.73. The change index, for significant differences, was 2.26. The ecological environments of some communities distant from the urban areas did not change remarkably, and were maintained in a good condition. In some communities, changes in EVI showed negative growth and the ecological environments gradually recovered. (3) From the urban fringe ecological vulnerability of the overall trend of change, the change of ecological vulnerability in Ganjingzi District between 1998 and 2013 was closely related to the speed of urbanization. With 2007 as the node, the average change or slope index in 1998-2007 was 0.51 and that in 2007-2013 was 0.19, showing a slow down after the first slow trend.
  • DownLoad:Urban fringe area ecological vulnerability space-time evolution research: the case of Ganjingzi District, Dalian.PDF
  • Virtual water analysis for the Jing-Jin-Ji region based on multiregional input-output model
  • Authors:CAO Tao, WANG Saige and CHEN Bin
  • Abstract:The optimization of regional water resources via regulation of trade and consumption has been considered as an alternative to alleviate the severity of water shortage. The multiregional input-output (MRIO) analysis makes it possible to explore virtual water trade among regions. This study established a virtual water accounting model for the Jing-Jin-Ji region based on the MRIO, combining the economic input-output table and sectoral water consumption in 2012. The import and export of virtual water for different regions and sectors were analyzed by calculating the direct water use coefficient, total water use coefficient, the final consumption of virtual water, and virtual water trade volume. The results show that the Jing-Jin-Ji region is a net virtual water exporter. Main net exporters of virtual water include the service and transport sector in Beijing and the manufacturing and agricultural sector in Hebei. From the perspective of the driving coefficient, manufacturing, construction, services, and transport in Jing-Jin-Ji region have high cumulative water input, but low direct water input, implying they need more indirect water inflow from other sectors for production. Moreover, it is evident that the agricultural and manufacturing sector in Hebei has high virtual water outflow, indicating that these should be the key sectors for water-saving management through reducing water consumption from both direct and indirect perspectives. By investigating direct water consumption, indirect water consumption, water use coefficients, driving coefficients, and the virtual water trade among sectors in the Jing-Jin-Ji region, we could identify the key sectors and pathways for water consumption and thus provides a solid foundation for virtual water trade strategies to alleviate water resource pressure in the Jing-Jin-Ji region.
  • DownLoad:Virtual water analysis for the Jing-Jin-Ji region based on multiregional input-output model.PDF
  • A method of delimiting urban ecological red line protection area based on bayesian network
  • Authors:LI Bin, HE Jianhua, QU Sai, HUANG Junlong and LI Yihui
  • Abstract:Delimiting ecological red lines is the key to answering spatial-allocation questions for land resources. At present, most studies on the delimitation of ecological red lines have been based on the evaluation of suitability conditions of ecological land, without considering the process of historical change. Therefore, it cannot be guaranteed that the zoning results will adapt to the trends in ecological land change in the area, leading to frequent designation and adjustment of ecological red lines. In this study, to guarantee the stability of ecological red lines, we examined a delimitation method for ecological red lines based on a Bayesian network model, which included both factors concerning ecological suitability conditions and dynamic change of the land. Next, the proposed model was applied to E-Zhou, a city near the mid-reaches of the Yangtze River. In this proposed model, ecological suitability factors, which represented the quality of the ecological land, and dynamic change factors, which illustrated the history of the ecological land, were obtained. Using the ecological land potential value as the target variable, we defined the structure of the network using expert knowledge. The Bayesian network was trained by the maximum likelihood method with 20000 random sample points. The results showed that only 65.5% of ecological land remained stable from 2004 to 2013 in E-Zhou City. For the two dynamic factors, the influence of farmland occupancy was the greatest, and accounted for 43.6%, whereas the influence of urban encroachment accounted for 10.2%. The results of the sensitivity analysis also indicated that farmland occupancy had the greatest influence on the potential value of the ecological land, with the highest variance reduction of 29.5%, followed by eco-environmental sensitivity, and the importance of ecosystem services, which exhibited variance reductions of 8.55% and 1.84%, respectively. The variance reductions for the distance to a water body and the ecological protection of a forest were greater than that of the distance to a road or a railway, change in traffic facilities, and urban construction, which all had little effect on the ecological land potential. A causal link between influence factors and the target variable was obtained during backward propagation in diagnostic analysis. Under the condition that the value of ecological land potential was "yes", the probability of the "extremely important" factors of ecosystem services and water conservation increased by 6% and 2.7%, respectively. This indicated that the contributions of ecosystem service values of a forest ecosystem and aquatic ecosystem increased. Furthermore, the probabilities of "highly sensitive" and "extremely sensitive" factors of ecological sensitivity decreased by 13.4% and 1.8%, respectively. This verified the improvement of the natural condition of the land by ecological land protection. Then, using the values for the ecological suitability factors in 2013, we obtain the relative potential value of each ecological land parcel as the ecological red lines through forward reasoning of the trained network, and delimiting ecological land with the potential value of the target variable. The results showed that this delimiting method worked in accordance with the trends in urban development in the area and spatial distribution of ecological land in E-Zhou City. This method can improve the stability of ecosystem services, as well as ensure the quantity and quality of ecological red lines. This new and effective model could serve as a support for other cities.
  • DownLoad:A method of delimiting urban ecological red line protection area based on bayesian network.PDF
  • Multi-objective linear programming-based trade-off and optimization of the ecosystem services in Jiajiyu small watershed in the Loess Plateau, China
  • Authors:BAO Rui, LIU Feng, ZHANG Jianping, DUAN Yinglin, ZHAO Shuai, YAN Xiaoya and LIU Ying
  • Abstract:The Loess Plateau is one of the most serious soil-erosion areas with ecosystem service degradation in China. Small watersheds are the main place of soil erosion; therefore, it is important to evaluate various ecosystem services when promoting their water and soil conservation. This paper took Jiajiyu, a typical small watershed in the Loess Plateau, as the study area using 2012 as the base year and 2022 as the target year. Based on the Statistical Yearbook and investigation data, the ecosystem service values of different land-use types were evaluated by the methods of market value, shadow price, shadow project, alternative cost, and opportunity cost. The ecosystem services were evaluated and optimized based on the adjustment of land-use structure by multi-objective linear programming through adjusting land-use types. The supply service, water and soil conservation service, and other services values were taken as the trade-off sub-objectives and the total ecosystem service value as final objective, with 17 constraint equations developed by 35 decision variables. The constraint equations included the land-area control, grain and oil security, and suitability of land-use types on the slope. The results showed that the ecosystem service values of slope farmlands and waste grasslands were much lower than most of other land-use types, and both of them took a relatively higher proportion of small watershed area, which restricted the ecosystem service values of Jiajiyu. The land-use structure was obviously improved by the trade-off and optimization of ecosystem services, with most of the slope farmlands and waste grasslands adjusted to arbor forest or terrace, both of which have much higher ecosystem service values. The total ecosystem service value increased by 9.23%, and the value of supply service, water and soil conservation service, and other services also increased by 6.24%, 9.81%, and 17.35%, respectively. Increases in the three sub-objects of ecosystem service values were dominated by the total increase in ecosystem service values by 25.96%, 54.42%, and 19.62%, respectively. Compared with the optimization results, which only took supply service, water and soil conservation service, other services or total ecosystem service values as the objective function, the optimization results of the three objective sub-functions were more coordinated, and all three benefits increased significantly. Significant differences were observed in the growth rates of ecosystem service values in different reaches, with the highest growth rates observed in the other service values of upper reaches, water and soil conservation service values of middle reaches, and supply service and total service values of lower reaches, which were confomed to the ecological orientation of upper, middle, and lower reaches of Jiajiyu, respectively. In this paper, the suitability of land use was fully considered. Under the guarantee of supply service, the water and soil conservation service was highlighted, other ecosystem services were optimized, and the evaluation indices of comprehensive management were improved at the same time. Our results were consistent with the actual conditions of the small watershed in the Loess Plateau.
  • DownLoad:Multi-objective linear programming-based trade-off and optimization of the ecosystem services in Jiajiyu small watershed in the Loess Plateau, China.PDF
  • An evaluation index system of vulnerability of the desertification reversion process based on the socio-ecological systems theory
  • Authors:WANG Ya, ZHOU Lihua and WEI Xuan
  • Abstract:Sandy desertification is one of the most severe ecological and environmental problems worldwide. Desertification reversion, as the reverse process of desertification expansion, has some instability and vulnerability due to disturbances by numerous socio-ecological factors. We call this phenomenon vulnerability of the desertification reversion process, and define it as the possibility and tendency of a reversion trend decline or reversal. Socio-ecological systems theory is a new form of ecological systems research. Based on this theory, we selected the driving-pressure-status-impact-response (DPSIR) framework and a typical reversed desertification area in Yanchi County as the study area. In this area, human activities have obviously interfered with natural processes and the expansion and reversal of desertification contrast sharply. We constructed an evaluation index system to assess the vulnerability of the desertification reversion process. This system includes four levels, five groups, and forty-one concrete indexes, including a moisture index, an ecological governance index, and sandy proportion. Finally, we explore the logical causality between drivers, pressure, status, impact, response, meanwhile discuss the quantitative calculation method of vulnerability. The objective of this study was to scientifically assess the vulnerability of the desertification reversion process, and to provide support and a scientific basis to make decisions, manage, and regulate the desertification problem in the pastoral transitional zone.
  • DownLoad:An evaluation index system of vulnerability of the desertification reversion process based on the socio-ecological systems theory.PDF
  • Ecological niche-based competition and cooperation relationships among county-level cities in Hexi Corridor
  • Authors:NIE Xiaoying, SHI Peiji, LÜ Rui, ZHANG Xuebin, LIANG Bianbian and WEI Wei
  • Abstract:Domestic and international scholars have paid considerable attention to research on intercity co-opetition relationships. Based on the systematic examination and analysis of previous research results, the article, starting with the theory of the ecological niche, regards the modern city as special life system with ecosophy from the perspective of phytocoenology. Cities in certain regions may have various relationships. Co-opetition between cities usually plays an essential role in whether the cities can achieve continuous development together in the same city group. The percentage of a particular city's resource occupation in its group is reflected by its comprehensive development level, the utilisation of resources is represented by the niche breadth, and the co-opetition of 20 cities in county areas of the Hexi Corridor is clarified by cluster analysis and the structural division of the eco-system. Finally, a realistic strategy for co-opetition is put forward by virtue of the ecological niche, aiming to provide theoretical suggestions for coordinated and continuous development in city groups of the Hexi Corridor. It is concluded that all the cities in the region have made mixed progress in terms of their comprehensive development levels, with their ecological niches experiencing mixed ups and downs. The positive correlation observed between a city's comprehensive development level and its ecological niche width shows that the occupation and utilisation of resources are two supplementary coefficients. Among the 20 county-level cities in the region, Jiayuguan and Jin Chuan District have always been categorised as Tier I, as they always top the list of cities with highest ecological niche; Liang Zhou District, Su Zhou District and Gan Zhou District are Tier Ⅱ cities; Akesai, Yumen, Dun Huang and Su Bei are Tier Ⅲ; and the remaining 11 cities are Tier IV. Based on the analysis of the eco-system structure in the cities of the Hexi Corridor, together with theories such as niche dislocation, expansion, coordinated development, the following corresponding co-opetition strategies are proposed:Jiayuguan District and Jinchuan District need to play a radiating and exemplary role, with coordinated development in the Liangzhou District, Suzhou District and Ganzhou District. This activity will drive other cities' development, reaching a balance for the ecology niche in the city system of the Hexi Corridor.
  • DownLoad:Ecological niche-based competition and cooperation relationships among county-level cities in Hexi Corridor.PDF
  • Analysis of landscape ecological security and cultivated land evolution in the Karst mountain area
  • Authors:PENG Wenjun and SHU Yingge
  • Abstract:The ‘No. 1 Central Document’ issued in 2016 pushed the ‘three rural issues’ to the cusp. As an important component of the agricultural landscape, the features of the farmland landscape would directly affect the inside ecological processes and productivity of cultivated land, so as to finally decide whether the food problem of the 1.3 billion people in China can be solved or not. In order to investigate changes in the ecological environment of cultivated land in the Karst mountain area on the basis of landscape ecological security theory, the farmland of Chishui City (Guizhou Province, China) was selected as the research object in this essay. Firstly, datas like patch density, patch shape index, patch fractal dimension and patch stability factor were picked out and be used in order to analyse the characteristics of landscape patch evolution and spatial distribution of landscape pattern in the Karst mountain area. Secondly, a landscape ecological security evaluation model for farmland in the Karst mountain area should be constructed to analyze the evolution of the cultivated land's landscape ecological security from 2000 to 2004. In this step, ecological security index, patch proximity index, patch fragmentation, patch boundary fragmentation, landscape type patch dominance index, separation index, and landscape fragile index were used. Thirdly, on this basis of the past two steps, the centroid method commonly used in geography and economics was introduced to calculate the gravity center of the landscape ecological security of cultivated land. In the same time, both the gravity transfer distance model and the moving direction model were used to measure the distance and direction of the ecological safety center of cultivated landscapes. Finally, to explore the driving factors of ecological safety evolution and center of gravity shifts based on regional characteristics, 10 indices were selected, namely, population density, proportion of agricultural population, rate of regional construction land, grain yield, unit of cultivated land fertilizer, arable area, gross output value of agriculture, per capita disposable income of farmers, crop sown area, and number of rural practitioners, and a grey correlation analysis was performed for changes in the indices and changes in the ecological security indices of the cultivated landscape. The results showed as follow. Firstly, in the recent 15 years, the ecological security center of gravity of cultivated land landscape in Chishui moved to the Northwest. Meanwhile the patch density, fractal dimension, and fragmentation decreased, the patch shape index and connection degree increased. The shape of the cultivated land gradually changed to a complex state, and the distribution tended to be homogeneous, whereas the patches became increasingly clustered. Secondly, arable land continued to decline, ecological safety decreased. According to the landscape ecological security index of cultivated land calculated results, it could be seen that the ecological security zone of dry land landscape was expanding to the southeast, and the safe areas was changed to the the relatively safe areas, and the relatively safe areas was changed to the dangerous areas; The relatively safe areas of paddy field landscape changed from a centralized distribution to a divergent distribution, the safe areas transformed the relatively safe areas and hazardous areas. The ecological security of dry land and paddy field landscape was not optimistic. Thirdly, the gray analysis results indicated that the driving factors that affect the evolution of landscape ecological security and the transfer of gravity in dry land of the study area were obtained, and the maximum was the total agricultural output value, followed by grain yield and crop sown area. Grain yield was the most important factor affected by the evolution of landscape ecological security and gravity transfer in paddy fields, followed by the level of fertilizer application and population density.
  • DownLoad:Analysis of landscape ecological security and cultivated land evolution in the Karst mountain area.PDF
  • Spatial management zoning based on the water eco-health: A case study of the areas around Chaohu Lake
  • Authors:ZHAO Haixia, JIANG Xiaowei and LIU Yan
  • Abstract:The water eco-health has become an important goal of regional environment management and a new trend of eco-environmental fields in China and abroad. In the areas around Chaohu Lake of China, the rapid industrialization and urbanization have led to ecological health problems, such as water quality deterioration, vegetation degradation and ecosystem degeneration. This paper aims to give some advices on achieving the healthy development of water ecosystem based on spatial development and regulation zoning in the areas around Chaohu Lake. After building the evaluation index system composed of water ecological sensitivity and water ecological pressure, this paper discusses the methods of spatial zoning which is related to both regional development and ecological environment protection, based on 500 m×500 m grid units and ArcGIS software, as well as the comprehensive evaluation of single factor and multifactor analysis. The areas around Chaohu Lake, serving as a case study, are divided into four types by the method of two-dimensional quadrant analysis, namely, high-sensitivity and high-pressure area, high-sensitivity and low-pressure area, low-sensitivity and high-pressure area, and low-sensitivity and low-pressure area, representing 2.66%, 20.46%, 13.01 and 63.87% of the total area respectively. Different measures are put forward according to different types of areas. Firstly, the areas around Chaohu Lake generally should adopt a policy on low density development prioritizing the ecological and cultural protection. As an important drinking water source and ecological barrier areas in Chaohu and Hefei city, the areas around Chaohu Lake is expected to give a strict protection of the natural reserve, existing mountain, water and wetland landscape, forest parks, scenic areas, lake shelterbelts and so on. Secondly, learning from previous lessons on the development models of lakeside districts in other regions and countries, the development model in the areas around Chaohu Lake should adopt appropriate measures suiting local conditions:the belts along the main rivers into Chaohu Lake have the higher sensitivity to water environment, are not suitable for large-scale development and construction, and need to strengthen the ecological restoration and environmental protection. Thirdly, the northern Binhu new district of Hefei city, Chaohu city and their towns have higher pressures on water ecosystem from high-density development activities, is in urgent needs of the model transformation and structure upgrade in industrial and urban development, and implements strict access standards to environmental and pollution emissions. Lastly, although some regions with lower ecological sensitivity and pressure can adopt different measures and development models relying on local resources and their own advantages, a strict control of new emissions of pollutants and maintenance of healthy development of ecological water are of prime importance.
  • DownLoad:Spatial management zoning based on the water eco-health: A case study of the areas around Chaohu Lake.PDF
  • Impact of land use on the water quality of inflow river to Erhai Lake at different temporal and spatial scales
  • Authors:XIANG Song, PANG Yan, DOU Jiashun, LÜ Xingju, XUE Liqiang and CHU Zhaosheng
  • Abstract:Relationships between land use and water quality of rivers flowing into lake vary spatially and temporally. These variations were analyzied using spatial analysis and mathematical statistical methods for the inflow rivers and their subcatchments on the western side of the Lake Erhai basin. The results indicated that the land use types influencing river water quality significantly were construction and vegetation land at four spatial scales (subcatchment, and 30m, 60m, and 90m riparian buffer zones). Vegetable land included forest, grassland and shrub land. The greatest impact occurred at the subcatchment scale, followed by the 30m riparian buffer zone. At the subcatchment scale, the amount of construction land was positively correlated with COD and TP concentrations of the inflow rivers. The amount of vegetation land was negatively correlated with NH4+-N concentration, and the main water quality indexes corresponding to land use were TN and TP, with 0.624 and 0.579 adjusted regression coefficients, respectively. Seasonal correlation analysis suggested that the regression relationships between construction land and COD, NH4+-N, and TP concentrations during the wet season were stronger than those in the dry season, and the regression relationships between vegetation land and COD and TP concentrations were also stronger during the wet season than those in the dry season. COD concentration change caused by variation in construction land and vegetation land variation occurred more rapidly during the wet season than those in the dry season. During river basin management, particular attention should be paid to land use control during the wet season for the Baihe and Zhonghe Rivers, whose watersheds have a lower proportion of vegetation land and a higher proportion of construction land. Vegetation coverage should be increased, whereas the effects of land development should be studied adequately before implementation.
  • DownLoad:Impact of land use on the water quality of inflow river to Erhai Lake at different temporal and spatial scales.PDF
  • Forest ecological security evaluation based on ecological location coefficient and gravity center transfer analysis in Hubei Province
  • Authors:TANG Xu, FENG Yan, LU Shasha and ZHANG Dahong
  • Abstract:Forest ecosystems are important but fragile, and the rapid development of economy and society can affect the sustainable development of human beings. Therefore, the study of forest ecological security has a strong significance. Based on the date of forest panel from 1999 to 2014 in Hubei Province, this paper used the entropy method and fuzzy matter-element method to calculate the forest ecological security index, which was adjusted according to the ecological location coefficient obtained from the meteorological and terrain indices. Moreover,combined use of the ArcGIS software and the gravity analysis model in the present study revealed that:(1) the area with the highest ecological location coefficient was mainly distributed in the western and the central regions of Hubei Province. Futher,the area with the lowest ecological location coefficient was mainly distributed in the west,and the coefficient was correlated to a certain extent with economic development. (2)From the perspective of forest cover change in the 16-year study period, the counties with the worst forest ecological security grade increased 100%,reflecting that the overall situation of forest ecological security in Hubei is not optimistic. (3)The forest ecological security index of Danjiangkou and Songzi maintained an increasing trend during the study period. (4)The foest ecological security gravity center moved from the northwest to the southeast from 1999 to 2007,and thereafter from east to west at a high speed until 2014.
  • DownLoad:Forest ecological security evaluation based on ecological location coefficient and gravity center transfer analysis in Hubei Province.PDF
  • Mapping of wetland reserve boundary in coastal zone utilizing spatial constraints assessment
  • Authors:CHEN Yang, YUE Wenze and ZHANG Liang
  • Abstract:The delineation of wetland reserve boundary is essential not only to the functional sustainability of wetland, but also to the coordination of land resource configuration and spatial distribution among wetland protection, farmland utilization and urban construction. This paper is conducted to analyze wetland reserve boundary in light of the theory of source and sink landscape interaction by using a case study of the southern bank of Hangzhou Bay. The spatial differentiation of wetland protect source and sink landscape including ecological bound and spatial constraints assessment were analyzed respectively. And wetland reserve boundary and its type were delineated by using the minimum cumulative resistance model. The case study demonstrated the applicability of research strategy by using minimum cumulative resistance model based on spatial constraints assessing and ecological bound zoning in delineating wetland reserve boundary. While accounting for 52.69% is of the ecological bound, high constraint district or medium constraint district, only percent of 34.53%, 12.79% are low constraint district and none constraint district, showing an intensive constrained trend of spatial pattern. The area of wetland reserve boundary and buffer zone have the area of 49.11km2, 24.07km2 respectively, taking the percentage of 5.47% in the southern bank of Hangzhou Bay, revealing that the space of wetland reserve is limited. In addition to ecological bound, wetland reserve boundary can be classified into three types including preserved forest area, farmland expansion and water sources.
  • DownLoad:Mapping of wetland reserve boundary in coastal zone utilizing spatial constraints assessment.PDF
  • Spatial variation analysis of biodiversity in the Bohai region coastal wetland
  • Authors:XIAO Yang, ZHANG Lu, ZHANG Liyun, XIAO Yi, ZHENG Hua and OUYANG Zhiyun
  • Abstract:Unreasonable use of biological resources by humans and climate change have negative impacts on biodiversity at a global scale. As a consequence of the rapid population growth, with its associated further demands, along the east coast of China in recent years, biodiversity protection is facing enormous challenges, which have huge impacts on the sustainable development of the regional economy and ecological environment. Coastal wetlands, with their highest biodiversity, are among the most important ecosystems. Human activities are major contributors to biodiversity loss and degradation of biological community structure. Wetland development and reclamation and its dynamics have an important impact on species habitat, population distribution, and biodiversity. Many researchers have attributed biodiversity loss in coastal wetlands to long-term human interference and widespread changes in land use and cover. However, recent studies have shown that human activities may improve the level of biodiversity in selected study regions across China. It is necessary to investigate current regional costal wetland status and its response to human activities, which will promote a better understanding of their accumulated consequences. On the basis of the biodiversity status in Bohai region costal wetland, we used an index of habitat quality and species richness as evaluation factors to calculate an index of biodiversity, and to analyze the hotspots or cold spots of biodiversity change via the method of spatial correlation. The results obtained were as follows. (1) The dominant ecosystem type in Bohai region costal wetland is reservoir and water pits, followed by grass swamp. There was almost no change in the total area of wetland ecosystem. However, internal change occurred in the form of transformation between reservoir and grass swamp from 2000 to 2010. (2) High biodiversity areas are mainly distributed in central Liaodong Bay, southeast of Bohai Bay, and northwest of Laizhou Bay. Because of the increasing rate of urbanization, and the growing interference of human activities in recent years, biodiversity in the Bohai region costal wetland is facing gradual deterioration, which has huge impacts on sustainable development of the regional economy and ecological environment. (3) The hotspots of biodiversity change are mainly distributed in the southeast of Bohai Bay and northwest of Laizhou Bay. The cold spots of biodiversity change are mainly concentrated in the north-central region of Bohai Bay. A trend of improvement in biodiversity was found in the southeast of Bohai Bay and northwest of Laizhou Bay, indicating that efficient ecosystem transformation together with establishment of wetland reserves could yield a win-win result.
  • DownLoad:Spatial variation analysis of biodiversity in the Bohai region coastal wetland.PDF
  • Quantifying the climatic and hydrological effects of land use/cover change based on Weather Research and Forecasting model
  • Authors:LIAN Lishu, LI Baofu, CHEN Zhongsheng, CHEN Yaning and SUN Xiaoyin
  • Abstract:Currently, most studies have been conducted to determine the impact of land use/cover change (LUCC) on the runoff yield and conflux (Direct Hydrological Effect), while only a few studies have been conducted to determine the runoff change caused by the LUCC-induced regional climate change (Indirect Hydrological Effect). In this study, the Weather Research and Forecasting (WRF) model and elasticity method were used to investigate the indirect hydrological effect caused by LUCC in the Yihe River from 1990 to 2010. The results suggested that the WRF model simulated the temperature of the study area well with high correlation coefficients (0.86-0.97, P<0.001) between the modeled and measured values. Although the simulation precision of model in precipitation was lower than that in temperature, the correlation coefficients ranged from 0.41 to 0.91 with P<0.05 statistically significant level. The main land use in the study area was farmland (including dry and paddy lands), representing approximately 80% of the total area. In the recent 20 years, the land use in the study area transformed gradually from the dry land to the urbanized land (747.3km2) and bare/sparse vegetation (132.4km2). The temperature increased by 0.2℃ in January and October and decreased by 0.2℃ in July, which was caused by the LUCC, while the temperature in April was basically stable. The LUCC caused the largest temperature changes, i. e., 0.4-1.3℃ in the mixed forests and water bodies, and the smallest temperature changes, i. e., <0.1℃ in the deciduous broadleaf forests and wetlands. The LUCC showed a weak impact on the precipitation change in January, April, and October, while substantially affecting the precipitation in July with a decrease of 23.7mm. Therefore, the LUCC significantly affected the summer precipitation because of the abundant precipitation in summer, thus changing the moisture fluxes in the study area. The results also indicate that the spatial variations in precipitation due to the LUCC were weakly associated with the underlying surface. Elastic analysis showed that the annual temperature and precipitation changed by 1% during 1960-2013, which can induce runoffs to change by 1.8% and 2.4%, respectively. During 1990-2010, the LUCC-induced changes of precipitation and temperature led runoffs to change by 18.4% and 1.7%, respectively.
  • DownLoad:Quantifying the climatic and hydrological effects of land use/cover change based on Weather Research and Forecasting model.PDF
  • Dynamic changes in population size and habitat distribution of wintering red-crowned crane in northern Jiangsu Province
  • Authors:LIU Ling, LIU Hongyu, LI Yufeng, WANG Juan and XIE Fufu
  • Abstract:The red-crowned crane (Grus japonensis), a globally endangered species, is under first-grade state protection in China. There are about 3050 individuals of wild red-crowned crane in the world. Recently, the western flyway subpopulation of red-crowned crane has sharply decreased. Previous studies have primarily focused on population size, distribution and habitat selection of red-crowned crane, and several studies have further examined the effects of human disturbance on these factors. However, the majority of such studies concentrated on the coastal regions of Yancheng, Jiangsu Province, over short time; few studies focus on historical tracking of wintering red-crowned crane populations and wintering behaviors over long time. Using trace data and land-use data available over a comparatively long period, the study systematically analyzed the dynamic changes in population size and habitats distribution of wintering red-crowned crane since 1982. Thus the study reveals the effects of land use changes to the wintering habitats of the red-crowned crane. These results can include three conclusions. First, the population of wintering red-crowned crane has changed substantially from 1982 to 2015; the current population size is 50% lower than that recorded in the 1990s. Second, the range of wintering habitats has gradually reduced, and the remaining habitats have been severely fragmented. The red-crowned crane prefers various types of wetlands in winter. During the 1980s, the red-crowned crane was widely distributed in the northern Jiangsu, particularly in the swamps around island lakes in the middle and lower reaches of the Yangtze River, as well as in the coastal wetlands of Jiangsu. Over following decades, wintering habitats gradually shifted to coastal areas, primarily distributed in Sheyang County, Yancheng. However, with increasing development of the coastal economy at the beginning of the twenty-first century, wintering habitats in coastal areas were further reduced and fragmented. At present, wintering red-crowned cranes are concentrated in the central area of the Yancheng National Nature Reserve. Third, according to the Pearson correlation analysis, the habitat distribution points of wintering red-crowned crane are significantly related with the land use types and the socio-economic development. The rapid development of the Chinese economy, accompanied by the rapid expansion of land use for construction and industry directly decreased the area of habitat of wintering red-crowned crane. Additionally, changes in the distribution and intensity of land use and human disturbance caused existing habitats to be fragmented, reducing their suitability for use as of wintering habitats by red-crowned crane.
  • DownLoad:Dynamic changes in population size and habitat distribution of wintering red-crowned crane in northern Jiangsu Province.PDF
  • Relationships between environmental factors and the distribution of Indo-Pacific humpback dolphins (Sousa chinensis) in the western Pearl River Estuary, China
  • Authors:WANG Xinxing, CHEN Tao, LI Min, WANG Xuehui and WANG Yuezhong
  • Abstract:The Indo-Pacific humpback dolphin (Sousa chinensis) is a small odontocete species that is widely distributed throughout inshore waters of the Indian and western Pacific oceans. This species is currently classified as "Near Threatened" by the IUCN in its red list of threatened species. The effective conservation of this species requires an understanding of the relationship between its populations and their habitats. The Pearl River Estuary contains one of the world's largest-known populations of this dolphin species; however, commercial development is extensively modifying the surrounding environment. Moreover, the region is densely populated, and the intensity of human activities, such as shipping and reclamation, are all increasing. The habitat of the Indo-Pacific humpback dolphin throughout the Pearl River Estuary is changing and life for the dolphins within it is becoming more complex. We used data collected during vessel-based line-transect surveys in 2012, augmented by data from nekton sampling by bottom trawls and environmental variables, to identify relationships between the environment and the distribution of S. chinensis in the western Pearl River Estuary. A total of 200 nekton species belonging to 81 families and 19 orders were collected during the four surveys. On the basis of humpback dolphin encounter rates, generalized additive models (GAM) were used to assess the relationships between dolphin encounters and nine environmental variables:Beaufort Sea state, depth, bottom water temperature, salinity, pH, dissolved oxygen, nekton density, prey species density, and distance to the shore. Nekton density, depth, prey species density, distance to the shore, and bottom water temperature were all significantly associated with dolphin encounter rate, and collectively explained 64.7% of the observed variance. GAM models revealed the habitat preferences of these dolphins. Along with an increase in nekton density, dolphin encounter rate fluctuated, initially increasing and then decreasing and increasing again. The reason for this observed pattern may be the proportion of dolphin prey in the nekton, indicating that prey density was not positively correlated with nekton density. Humpback dolphin distribution and prey density were closely related, although any effect of prey density decreased above a threshold level, suggesting that foraging time decreases in times of prey abundance. Water depth is considered to be a factor limiting the offshore distribution of humpback dolphins. We noted that humpback dolphins were more frequently observed in water depths of 10m, and this preference shown by dolphins for a certain water depth is the same as that recorded in other survey years. We also identified a relationship between dolphin encounter rates and bottom water temperature, with the encounter rates decreasing markedly when the bottom water temperature exceeded 19.5℃. It is likely that bottom temperature affects the distribution of prey species, which in turn influences the nature of dolphin distribution. Offshore distance is also an important factor determining dolphin distribution. With an increase in the offshore distance from 0.1 to 3km, the dolphin encounter rate increased monotonically with increasing distance. Thereafter, the encounter rate decreased monotonically when the offshore distance exceeded 3km. Because the preferred habitat of humpback dolphins occurs at a distance of less than 3km offshore, prioritized conservation of this environment would better protect and improve management of this increasingly threatened dolphin species.
  • DownLoad:Relationships between environmental factors and the distribution of Indo-Pacific humpback dolphins (Sousa chinensis) in the western Pearl River Estuary, China.PDF
  • Effects of artificial riverbanks on distribution of the Yangtze finless porpoise in the Anqing section of the Yangtze River main stem
  • Authors:CHEN Minmin, LIU Zhigang, HUANG Jie, LIAN Yuxi, YANG Xiaoge and YU Daoping
  • Abstract:The critically endangered Yangtze finless porpoise inhabits areas in the near-shore shallow waters, and particularly prefers areas with natural muddy or sandy riverbanks. However, a considerable stretch of the natural riverbank of the Yangtze main stem has been replaced by artificial riverbanks since the 1990s, such as rocky and dock banks. Artificial riverbanks appear to cause destructive effects on the ecological environment of the Yangtze river. However, the effects of artificial riverbanks on the Yangtze finless porpoise remain largely unknown. In this study, twelve consecutive surveys were conducted in two nature reaches of the Yangtze River (~57 km) from March 2016 to January 2017. The data recorded included abundance and distribution patterns of the Yangtze finless porpoise, and the styles of the riverbank. A total of 215 porpoises were sighted during the twelve surveys, with a range of 9-32 per survey. The average number of porpoises was 17.92±7.09 individuals per survey. No significant difference was found in the number of porpoises observed in different seasons (P>0.05). The total the artificial riverbank per 3 km (r=-0.639, P<0.01). In the natural riverbank, 31.8% of the porpoises were sighted within 50 m in-shore. However, in the artificial riverbank, only two porpoises were sighted within 50 m in-shore. These findings may suggest that the artificial riverbank has caused habitat loss and fragmentation for the Yangtze finless porpoise. This factor should be considered when drawing up measures to conserve and restore the continuity of the Yangtze finless porpoise habitat.
  • DownLoad:Effects of artificial riverbanks on distribution of the Yangtze finless porpoise in the Anqing section of the Yangtze River main stem.PDF
  • Group coverage of burrow entrances and distribution characteristics of desert forest-dwelling Rhombomys opimus based on unmanned aerial vehicle (UAV) low-altitude remote sensing: A case study at the southern margin of the Gurbantunggut Desert in Xinjiang
  • Authors:MA Tao, ZHENG Jianghua, WEN Amin, CHEN Meng and LIU Zhongjun
  • Abstract:Grassland rodents are an important community component affecting the ecological balance of grasslands. Grassland rodent monitoring is also an important part of pest control. Unmanned aerial vehicle (UAV) low-altitude remote sensing is a new pest monitoring method, which has high spatial resolution, high efficiency, low cost, and low potential for loss. A demonstration project was conducted in Xinjiang to assess its potential as a rodent monitoring and control method. This project was conducted in October 2015 and May 2016 in a desert forest, which is the typical habitat of Rhombomys opimus in Xinjiang, near the southern edge of the Gurbantunggut Desert. A UAV low-altitude aerial survey was conducted in October 2015 and May 2016, 0.02m and 0.024m, respectively, to obtain ultra-high resolution images of the experimental area. The experimental area was divided into two sections for visual interpretation to determine the distribution and conduct a buffer analysis of gerbil holes, and to add a trend line to the gerbil-hole distribution map based on spatial distribution trend analysis and the relationship between the holes and topography in the mountain shadow map overlay. Using GIS grid and GIS overlay analysis, a coverage map of all gerbil holes was created. Based on the results, it was concluded that:UAV low-altitude remote sensing can provide highly accurate distribution information for Rhombomys opimus; the group coverage rate for Rhombomys opimus holes in the southern Gurbantunggut Desert forest zone was 19.4%, where 18.8% has been considered a high density; the research area for Rhombomys opimus exhibited accumulation and zonal distribution characteristics; characteristics of the distribution of Rhombomys opimus holes leading to burrows was obtained for the study area; the zonal distribution of Rhombomys opimus holes and topography were closely related; spatial distribution characteristics could be used for scientific planning of rodent control; and UAV low-altitude remote sensing has broad applications for rodent monitoring and control.
  • DownLoad:Group coverage of burrow entrances and distribution characteristics of desert forest-dwelling Rhombomys opimus based on unmanned aerial vehicle (UAV) low-altitude remote sensing: A case study at the southern margin of the Gurbantunggut Desert in Xinjiang.PDF
  • Relationship between the spatial distribution of the mounds of plateau zokor (Eospalax baileyi) and environmental factors in eastern Qilian Mountain
  • Authors:CHU Bin, MA Sujie, ZHOU Yanshan, JI Chengpeng, ZHOU Jianwei, ZHOU Rui, TIAN Yongliang and HUA Limin
  • Abstract:Plateau zokor (Eospalax baileyi) is a subterranean rodent endemic to the Tibetan Plateau, and it plays an important role in the alpine rangeland system because of the ecosystem function in terms of substance circulation and energy exchanges. However, at high population density, zokors are regarded as pests aggravating the degradation of rangelands. As zokors live underground, they dig tunnels in the soil for foraging or mating. In digging tunnels, the soil is pushed out on the ground as mounds, which reduce the grazing area and cover the forages. However, the mounds made by zokors create environmental heterogeneity, which increases the species diversity and nutrient recycling in soil. Therefore, the mounds have an important impact on the alpine rangeland ecosystem. Studying the spatial distribution of plateau zokor mounds and its correlation with environmental factors can reveal its role in habitat use and selection, which is the basis for controlling zokor damage and protecting biodiversity in the place. The variables of traditional statistics must be random variables, and the traditional statistics can not clarify the relationship between the variables and geographic location. As a result, the traditional statistics can not explain the reasons that influence the spatial distribution patterns in population studies. Currently, the geostatistical analysis methods are often used to study population spatial distribution patterns. In our study, we selected the small habitat of plateau zokor (140m×100m) in eastern Qilian Mountain because a small habitat can eliminate the heterogeneity of climate and geography. We used the semivariogram and ordinary kriging of geostatistical analysis methods to analyze the spatial heterogeneity of zokor mounds and the environmental factors that influence the distribution of mounds. The purpose of this study was to determine the relation between the distribution of zokor mounds and environmental factors, including soil bulk density, soil moisture, aboveground biomass, underground biomass, root's water-soluble sugar, crude protein, crude fat, richness of grass, and richness of forbs and sedges. The results of semivariogram and ordinary kriging indicated that the mounds of plateau zokor presented clumped distribution with medium variation level, and all environmental factors had spatial heterogeneity in the studying site. The results of a crossvariogram analysis showed that the distribution of zokor mounds had a positive spatial correlation with soil moisture and aboveground as well as underground biomass at the same studying scale (10.74-71.85m). The distribution of zokor mounds had a positive spatial correlation with forage nutrients, such as root's crude protein and water-soluble sugar at the studying scale (10.74-30.82m), as well as root's crude fat at the studying scale (10.74-44.01m). Besides, the distribution of zokor mounds had a positive spatial correlation with forbs at all studying scales. The mantel test indicated that the distribution of zokor mounds had a significant negative spatial correlation with soil bulk density and richness of sedge and a significant positive spatial correlation with richness of forbs and the contents of root's fat. In conclusion, the plateau zokors prefer to select the alpine meadows with softer soil, more forbs as well as plants with higher root's fat in this studying site.
  • DownLoad:Relationship between the spatial distribution of the mounds of plateau zokor (Eospalax baileyi) and environmental factors in eastern Qilian Mountain.PDF
  • Geostatistical analysis of the spatial distribution of Arhopalus rusticus larvae and adults
  • Authors:CHEN Qian, XU Zhichun, ZHANG Liansheng, LU Pengfei and ZHANG Yongfu
  • Abstract:Arhopalus rusticusis an important wood-boring pest that can cause considerable damage to species of the genera Pinus,Cunninghamia,and Cupressus,mainly in weak conifers and dry wood after fires, which have the strongest likelihood of supporting Bursaphelenchus mucronatus and Monochamus alternatus. To effectively control this insect, and to confirmthe spatial distribution of its population, spatial characteristics were analyzed using Go-statistical methods for A. rusticus larvae and adults in three Pinustabulaeformis woodlands with different levels of damage. The results showed that the degree of damage caused by A. rusticus differed significantly in the three woodlands. In lightly infested woodland, 30.8% of trees were infested, whereas 44.3% and 78.3% of trees were infestedin moderately and heavily infested woodlands, respectively. Isotropic variogr amanalysis indicated that Gaussian models were suitable for simulation of the spatial distribution of A. rusticus larvae in lightly andmoderately infested forests, while, the Exponential modelswere suitable for heavily infested forests. In contrast, linear models were suitable for simulation of the spatial distribution of A. rusticus adults in lightly, moderately, and heavily infested forests. The quantity of larvae showed evident spatial dependence in the three woodlands, with the distances of larval spatial dependence for lightly, moderately, and heavily infested forests being 19.10, 11.97, and 61.98m, respectively, and the related intensities of local spatial continuity being 0.646, 0.784, and 0.500, respectively. The distances of adult spatial dependence for lightly, moderately, and heavilyinfested forests were 43.08, 43.23, and 44.17m, respectively,and the corresponding intensities of local spatial continuity were 0.044, 0.021, and 0.171, respectively. The number of adults was, however, randomly distributed in space, and did not show spatial dependence. Analysis of the vertical distribution of A. rusticus indicated thatlarvae and adults preferred to congregate at a certain height in Pinus, whereas above and below this height, the density decreases. In lightly infested woodland, the largest number of larvae were found at a height of 24-25cm, whereas the largest number of adults was found at a height of 4-5cm; in moderately infested woodland, the largest number of larvae were found at 9-10cm and the largest number of adults at 26-27cm;and in heavily infested woodland, the largest numberof larvae were found at 13-14cm, and the largest number of adults at 5-6cm. The spatial distribution pattern generated by Kriging interpolation showed thatthere was intensivespatial aggregation of larvae in all three types of woodland, and that the aggregation was primarily centered in the center of the woodland and spread from there into the entire woodland. In contrast, adults showed a random distribution.
  • DownLoad:Geostatistical analysis of the spatial distribution of Arhopalus rusticus larvae and adults.PDF
  • Characteristics of soil fauna communities in the Karst region, Southwest China, based on meta-analysis
  • Authors:SONG Lihong, WANG Kehong and YAN Xiumin
  • Abstract:The karst area in Southwestern China is regarded as one of the most vulnerable ecological zones, characterized by low environmental capacity, high sensitivity of environmental variation, and low resilience of ecosystems to catastrophic variations. Soil fauna are important components of terrestrial ecosystems and play significant roles in maintaining the functions and stability of ecosystems. Based on meta-analysis, the present study evaluated the community characteristics of soil fauna in the Karst region, Southwest China, by analyzing the soil fauna species composition, their vertical distribution, and the influence of rocky desertification on soil fauna density and group numbers. Publications related to studies of soil fauna ecology studies carried out in the Karst region of Southwest China, which were published between January 1, 1990 to October 31, 2016, were retrieved from the Web of Science and China Knowledge Resource Integrated Database (CNKI) by using key words of soil fauna, soil animal, soil invertebrates, soil micro-arthropods, and karst both in Chinese and English. A total of 34 publications were selected for meta-analysis after literature filtering and quality evaluation. Results of meta-analysis, using R langue for statistical analysis, showed that soil fauna belonged to 5 phyla, 15 classes, and 31 groups (classes or orders) in the Karst region of Southwest China. Soil macro-fauna were dominated by Hymenoptera and Coleoptera. Soil micro-fauna and soil meso-fauna were dominated by soil mites and collembolan. The density of soil micro-fauna and meso-fauna ranged from 6.0×103 to 1.9×104 individuals m-2. Soil fauna density and group numbers in summer and autumn were significantly higher than those in winter and spring. Rocky desertification in the Karst region, Southwest China, significantly decreased soil fauna density (P < 0.01, MD=-7799.6, 95% CI:-10822.24——4776.99) and group numbers (P < 0.01, MD=-1.9, 95% CI:-2.89——1.09). Soil fauna individuals significantly decreased with soil depth (P < 0.01, MD=-23.4, 95% CI:-0.31——0.16), showing an obvious phenomenon of soil surface layer accumulation. These results indicate that soil fauna group numbers were high, while the density was low. Nevertheless, soil fauna density was possibly underestimated because of the lack of soil nematodes data in most of the retrieved original publications. Because of the importance of soil fauna in ecosystems, greater attention should be paid to the soil fauna communities and their ecological functions, especially for biodiversity protection and the recovery of vulnerable ecosystems in the Karst region, Southwest China.
  • DownLoad:Characteristics of soil fauna communities in the Karst region, Southwest China, based on meta-analysis.PDF
  • Relationship between the growth of phytoplankton and the distribution of nutrients in the Fenhe water storage area of Taiyuan
  • Authors:LIU Yang, LÜ Junping, LIU Qi, XIE Shulian and FENG Jia
  • Abstract:Physicochemical factors and nutrients are important factors affecting aquatic ecosystems. Differences in physicochemical and nutrimental factors determine variation in phytoplankton community structure. Therefore, evaluation of water quality and nutrient status is necessary. Since 2015, we have studied the phytoplankton, and the physicochemical and nutrimental factors of the Fenhe water storage area. The results showed that (1) Cyanophyta and Chorophyta constituted the majority of the plankton community in the regions studied. Throughout the year, Cyanophyta was the most abundant phylum of planktonic algae. The dominant species, including Chroococcus minutus, Merismopedia tenuissima, Oscillatoria tenuis, and Microcystis aeruginosa, all of accounted for 42.95% and 59.24% of the algal community during the wet season and the dry season, respectively. Simultaneously, the concentration of chlorophyll-a revealed strong temporal and spatial variation in the Fenhe water storage area of Taiyuan, (annual mean:38.13mg/L; range:17.04-84.60mg/L). The chlorophyll-a concentration during the wet season was significantly higher than that in the dry season. During the wet season and the dry season, the spatial distribution patterns of chlorophyll-a were similar, increasing from upstream to downstream. (2) The water quality indicated eutrophication in the studied area. With rapid socio-economic development, increase in population and industrial enterprises, and urban-scale expansion, multiple test sites near the city center revealed that high levels of household-generated garbage, sewage, and industrial waste discharge into the Fenhe water storage area, owing to the lack of strict control measures. Total phosphorus and the other indicators were on the higher side, indicating that the water body is in mild or moderate eutrophic state (Chaicun Bridge, Shengli Bridge, Yingze Bridge, and Changfeng Bridge areas). In addition, at one point, some sites reached a severe eutrophic state (Nanneihuan Bridge, Jifen Bridge, Nanzhonghuan Bridge, and Jiuyuanshahe Bridge), which resulted the destruction of the ecological environment. (3) Chlorophyll is essential for photosynthesis. Measuring chlorophyll-a concentration could reflect the phytoplankton biomass and water quality status. The species composition of the phytoplankton community was closely correlated with chlorophyll-a content, dynamic variation of the physical and chemical index, and comprehensive index of water body. The correlation and principal components analyses revealed significant positive correlation of chlorophyll-a concentration with temperature, total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD), and permanganate index (CODMn). Further, phosphorous might be a limiting factor, as indicated by its strong effect on phytoplankton abundance.
  • DownLoad:Relationship between the growth of phytoplankton and the distribution of nutrients in the Fenhe water storage area of Taiyuan.PDF
  • Relationship between flowering phenology and phylogeny in 31 woody plants of Urumqi, Xinjiang
  • Authors:YANG Xiaodong, JI Panpan, RE Yisha and LI Hongxia
  • Abstract:Environmental factors, i. e. precipitation, temperature, and sunshine duration, are considered the determinate factors of variation in plant phenology. However, whether environmental factors singly affect phenological change is still unknown. Phylogenetic structure refers to a developmental sequence of plants along evolutionary time; however, there is no consensus regarding whether phylogenetic structure affects plant phenology. In this paper, the initial flowering time, falling flower times, and duration of the flowering period of 31 woody plants, were investigated in Urumqi, Xinjiang. Subsequently, the distribution pattern in flowering phenology, the differences in flowering phenology between trees and shrubs, and the regression relationships between flowering phenology and phylogenetic structure were analyzed to explain the relationship between flowering phenology and phylogeny in woody plants. The results showed that:(1) the initial flowering time, falling flower time, and the duration of the flowering period was April 18th±9 days, May 5th±12 days, and 16 days±8 days, respectively, for 31 woody plants of Urumqi; (2) standard deviations of the initial flowering time and falling flower time of trees were higher than those of shrubs, indicating that trees have a greater stability of flowering phenology than shrubs; (3) the initial flowering time and falling flower time of trees were significantly earlier than those of shrubs (P<0.05), whereas the duration of flowering period was not significantly different (P>0.05); (4) the time interval of the initial flowering time, the falling flower time, and the duration of the flowering period had a significantly positive linear relationship with the phylogenetic distances between different species (P<0.05). In conclusion, the differentiation between trees and shrubs in the vertical space changed the flowering phenology across plant life types. Additionally, although environmental factors change flowering phenology, phylogenetic structure also may play an important role in variation in flowering phenology among species, among biotypes, and along temporal and spatial scales.
  • DownLoad:Relationship between flowering phenology and phylogeny in 31 woody plants of Urumqi, Xinjiang.PDF
  • Population structure and dynamics of Torreya fargesii Franch., a plant endemic to China
  • Authors:JIANG Bo, ZHOU Xianrong, SHANG Jin, WANG Jianhua, SONG Hang, QIN Mingyi, LIU Xuening and WANG Qing
  • Abstract:Torreya fargesii is an endangered species that is endemic to China and under second-class state protection. Our previous studies indicated that T. fargesii is distributed from the Qinling, Dabashan, Qionglaishan, and Daloushan mountains to the Wushan, Wulingshan, and Dabieshan mountains, which are located in subtropical regions 800-2700m above sea level. Although T. fargesii has a wide distribution and occurs in many different locations, most populations have only a few individuals and occupy a small area. To better understand the status of T. fargesii populations and propose a protection strategy, we investigated the population structure and dynamics of stands across the region. Plots that covered a total of 18000m2 were established at 15 sites in Chongqing, Sichuan, Shaanxi, Hubei, Anhui, Henan, and Gansu. Diameter-and height-class structure diagrams and a static life table were created, and the mortality and disappearance rates, as well as survivorship curves, were determined. Spectral analysis was used to analyze dynamic changes in population quantity. The findings showed that T. fargesii has a low population density, averaging 5.33 plants/100m2. Population density was highest in Shennongjia (9.58/100m2) and lowest in Chengkou (2.75/100m2). The diameter-class structure of T. fargesii showed an expanding age structure, with a higher percentage of younger age-class individuals. There were variations in the diameter-class structure among the different populations and the diameter-class distributions of all populations were incomplete (i. e., all size classes were not represented), except in the Baoxing population. Within the height-class distribution of the T. fargesii populations, individuals of less than 6m accounted for 88.74% of all trees, and most individuals were within the shrub layer at their respective sites. The populations' life expectancy rates varied greatly among the different age classes, and the life expectancy of the third and seventh age classes were relatively low. The survivorship curve of the T. fargesii populations tended to correspond to the Deevey-Ⅲ type curve, whereas the mortality and disappearance rate curves exhibited the same trend of having peaks in the third and seventh age classes. Spectral analysis showed that the population dynamics of T. fargesii followed one major trend, and there were a few clear fluctuations in smaller cycles of growth and death. T. fargesii is an old and long-lived plant with patchy isolated distribution, small population sizes, and poor natural regeneration. Thus, T. fargesii is in danger of extinction and should be protected before it is too late.
  • DownLoad:Population structure and dynamics of Torreya fargesii Franch., a plant endemic to China.PDF
  • Multi-scale responses of vegetation changes relative to the SPEI meteorological drought index in North China in 2001-2014
  • Authors:YANG Siyao, MENG Dan, LI Xiaojuan and WU Xinling
  • Abstract:In recent years, the decrease in precipitation and the effect of global warming have resulted in the increase in the degree of drought in the North China, affecting vegetation growth, and leading to the deterioration of the regional ecological environment. In this paper, based on the data of TRMM (Tropical Rainfall Measuring Mission) and MODIS (Moderate-resolution Imaging Spectroradiometer), Standardized Precipitation Evaporation Index (SPEI) was extracted to characterize meteorological drought status, while Normalized Difference Vegetation Index (NDVI), Net Primary Production (NPP), and Vegetation Condition Index (VCI) were used to characterize the vegetation status. Temporal and spatial variation of meteorological drought and vegetation, as well as the multi-scale response of vegetation changes relative to meteorological drought index in North China during 2001-2014 were comprehensive examined. The results indicated that drought showed a increasing trend in the southwestern region, whereas a decreasing trend in the northeastern region of North China. There were drought and wet alternating characteristics by month scale SPEI, and with the increase of time scale, a more obvious trend of drought characterized by SPEI were observed. In addition, the spatial distribution trends of NDVI and NPP in North China were slightly different, but generally, vegetation conditions have been improved in North China, while deteriorated in the central and coastal areas. Finally, the vegetation condition index were positively correlated with SPEI in most areas of North China. The degree of correlation was high in the grassland areas and middle-high altitude areas, whereas the response of forest land to drought was not sensitive relatively. The response of each vegetation type to SPEI-3 was most obvious in vegetation growing season, especially in the summer, and SPEI-12 mainly affected the early growth stage during the vegetation growing season. The results of meteorological drought on vegetation would assists on drought research in north China.
  • DownLoad:Multi-scale responses of vegetation changes relative to the SPEI meteorological drought index in North China in 2001-2014.PDF
  • Variation in basic properties and carbon sequestration capacity of an alpine sod layer along moisture and elevation gradients
  • Authors:SU Peixi, ZHOU Zijuan, SHI Rui and XIE Tingting
  • Abstract:The alpine sod layer is spongy, tough, and resistant to the shifting surface soil layer formed under natural vegetation in the alpine cold region. Understanding the ecological functions of this layer is necessary to promote sustainable methods of grass production and animal husbandry that can restore and protect existing grasslands, and to suggest new projects to implement these goals. After conducting extensive preliminary investigations regarding the alpine vegetation on the Zoige Plateau on the Eastern Qinghai-Tibetan Plateau, China, we established community sample plots along the existing soil moisture gradient:swamp, degraded swamp, swampy meadow, wet meadow, dry meadow, and degraded meadow. We also established community sample plots along the existing elevation gradient:subalpine meadow, subalpine shrub meadow, alpine shrub meadow, and alpine meadow. We determined sod layer thickness, bulk density, soil particle composition, and soil organic carbon (SOC) content in the community plots to compare carbon sequestration capacity along the moisture and elevation gradients. The results indicated that the average thickness of the sod layer was 30cm. The bulk density of swamp soil was the lowest among the communities studied, and the SOC content of swamp soil was greater than 300g/kg. The bulk density of degraded meadow soil was the highest among the communities studied, and the SOC content of degraded meadow soil was significantly lower than that of the other communities. The SOC density of the different communities ranged from 10 to 24kg C/m2, and decreased with decreasing soil water availability. Degraded meadow soil had significantly lower SOC storage in the sod layer. The SOC density of alpine shrub meadow soil was 15% higher than that of alpine meadow soil. The minimum mass water content needed to maintain a stable sod layer was 30%, and the minimum SOC was 30g/kg. In alpine vegetation regressive succession, the bulk density and compactness of the sod layer became increased. SOC content, density, and storage decreased along the soil moisture gradient from swamp to degraded meadow. The higher the gravel content of swamp soil, the more easily it was degraded. Similarly, the higher the sand content of meadow soil, the more easily it was degraded. The carbon sequestration capacity of alpine shrub meadows was greater than that of alpine meadows; however, the productivity of shrub meadows was lower. To maintain sustainable development of grassland production and protect the carbon sequestration function of the alpine sod layer, it is necessary to prevent degradation of the sod layer and prevent succession from meadows to shrub meadows.
  • DownLoad:Variation in basic properties and carbon sequestration capacity of an alpine sod layer along moisture and elevation gradients.PDF
  • Community structure characteristics of saxicolous lichens in the Bogda Mountains of Xinjiang, China
  • Authors:Anwar Tumur, Reyim Mamut and Abdulla Abbas
  • Abstract:In this investigation of saxicolous lichen communities in the Bogda Mountains using 20 quadrats (20m×20m), the data were classified based on species coverage using two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DCA). Community structure characteristics, species diversity, and similarity index were analyzed. The relationship between species distribution of saxicolous lichens and six different environmental factors was examined by canonical correspondence analysis (CCA). The results showed that the saxicolous lichen community can be divided into five associations according to the TWINSPAN analysis and DCA ordination:Association 1 (Lecidea tessellata Florke+Peltula euploca (Ach.) Poelt+Xanthoparmelia durietzii Hale), including 25 species with the total coverage of 30.145% and diversity of 4.025; Association 2 (Hypogymnia physodes (L.) Nyl. +Aspicilia sublaqueata (H. Magn.) J. C. Wei+Collema subconveniens Nyl.), including 17 species with the total coverage of 15.885% and diversity of 3.196; Association 3 (Lecanora accumulata H. Magn. +Xanthoria elegans (Link) Th. Fr. +Aspicilia asiatica (H. Magn.) Yoshim.), including 30 species with the total coverage of 37.87% and diversity of 4.357; Association 4 (Endocarpon sinense H. Magn. +Physconia muscigena (Ach.) Poelt. +Rhizoplaca melanophthalma (DC.) Leuckert & Poelt), including 24 species with the total coverage of 30.458% and diversity of 3.912; and Association 5 (Collema flaccidum (Ach.) Ach. +Dermatocarpon vellereum Zschacke+Rhizocarpon viridiatrum (Wulfen) Korber.), including 18 species with the total coverage of 19.331% and diversity of 3.515. The CCA ordination results showed that the species composition and distribution pattern of saxicolous lichens were most strongly influenced by altitude, then light intensity, rock pH, and human disturbance; the distribution pattern of the lichen communities did not significantly correlate with aspect and rock size.
  • DownLoad:Community structure characteristics of saxicolous lichens in the Bogda Mountains of Xinjiang, China.PDF
  • Research on vertical zonation of soil physical properties in Sygera Mountain, Tibet
  • Authors:WAN Dan, LIANG Bo, NIE Xiaogang, YU Wu and ZHANG Bo
  • Abstract:Soil and water loss in the southeastern plateau of Tibet, particularly in Sygera Mountain has become an important problem in regional ecological environment. The soil physical properties of Sygera Mountain at different altitude gradients were analyzed. The results showed that:(1) soil bulk density increased with the increase in soil depth at different elevations, except for 3600m and 4200m. The total porosity and capillary porosity decreased with soil depth at different elevations. The non-capillary porosity was not significantly related to the soil layer. The saturated soil water content, capillary water content, and field capacity decreased with the increase in soil depth at different elevations. (2) The soil bulk density, total porosity, capillary porosity, and non-capillary porosity at different elevations ranged from 0.58-1.10g/cm3, 57.00%-72.47%, 53.33%-67.59%, and 3.20%-4.87%,respectively. The saturated water content, capillary water content, and permeability followed a similar trend, with the maximum values at an elevation of 3800m and 3400m, minimum values at 3200m and 3600m, and intermediate values in the summit area (4000-4600m). Field capacity plotted against altitude revealed an M-shaped trend. (3) The soil physical properties at different elevation had a strong spatial heterogeneity, and the indices revealed spatial auto-correlation with each other. Significant differences in soil physical properties were present among different soil layers and elevations. Moreover, human disturbance was an important reason underlying the spatial heterogeneity of soil physical properties. (4) In general, physical properties of surface soil (0-10 cm) at Sygera Mountain were better than that of deeper soil layers (10-30cm or more). However, physical properties of surface soil at the foot of the mountain (3200m) and 3600m were the worst, whereas those in the summit area (4000-4600m) were intermediate, and those in the hillside areas (3400,3800m) were the best. The present study indicated that soil structure was vulnerable in the virgin forest areas of Sygera Mountain, southeast Tibet. Therefore, tourism, and forest industrial production and management, should be better managed in order to maintain the ability of this forest to conserve water and soil.
  • DownLoad:Research on vertical zonation of soil physical properties in Sygera Mountain, Tibet.PDF
  • Soil heavy metal pollution and ecological risk warning assessment of pepper field in Yanqi Basin, Xinjiang
  • Authors:Mamattursun EZIZ, Ajigul MAMUT and Anwar MOHAMMAD
  • Abstract:Heavy metals have long been recognized as pollutants that are potentially harmful to human health. In recent decades, research on heavy metals in soil environments has become a hotspot in environmental research. Under normal conditions, heavy metal concentrations in soils are several orders of magnitude higher than that in the background value of soils. Thus, the concentrations and potential ecological risks of heavy metals in farmland soils are important reference indicators for evaluating farmland soil environmental quality. Human activities are known to result in heavy metal pollution of farmland soils. Recent research in this field in China has focused on the sources, distribution, pollution, and ecological risk of heavy metals in farmland soils in the eastern or central parts. However, there has been limited research on soil contamination of farmland, particularly pepper fields, in the arid regions of northwest China. Therefore, we collected a total of 105 soil samples from pepper field in the main pepper production area (Yanqi Basin) in Xinjiang, China, and determined the content of eight heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn) by standard methods. The heavy metal pollution of pepper field soils was analyzed based on pollution load index (PLI), potential ecological risk index (RI), and ecological risk warning index (IER). The results indicated that the average content of Cd, Cr, Ni, Pb, and Zn exceeded 1.65, 1.40, 1.32, 3.21, and 6.42 times, respectively, that of the background values for irrigation soil in Xinjiang. High levels of Pb, and Zn pollution, low levels of Cd, Cr and Ni pollution, and no As, Mn, or Cu pollution were detected in pepper field soils. The average value of PLI was 1.40, which showed a light pollution level; the average RI for each heavy metal in decreasing order was as follows:Cd, Ni, As, Cu, Pb, Cr, and Zn. The average value of RI of soil was 18.40, which indicated light ecological risk. The average value of IER of soil was -4.78, which indicated a no warning situation. The pollution level, potential ecological risk, and ecological risk warming of Bahrash county were the highest, whereas those of Hejing county were the lowest in Yanqi Basin. As, Cd, Pb, and Zn pollution in pepper field soil were mainly affected by the human activities, and Cr, Cu, Mn, and Ni pollution were mainly affected by the geochemical background of soils. Cd was the main pollutant of farmland soil with strong influence on the PLI, RI, and IER. The pollution risk of Cd should be a major concern during the process of agricultural production in Yanqi Basin.
  • DownLoad:Soil heavy metal pollution and ecological risk warning assessment of pepper field in Yanqi Basin, Xinjiang.PDF
  • Short-term effects of forest gap size on soil microbial biomass carbon and nitrogen in the Platycladus orientalis plantation
  • Authors:FEI Fei, XIAO Wenya, DIAO Jiaojiao, GUAN Yunyun, CHEN Bin and GUAN Qingwei
  • Abstract:To investigate the short-term effects of forest gap size on soil microbial biomass carbon and nitrogen in Platycladus orientalis plantations, we conducted a study in a 50-year P. orientalis plantation in Xuzhou. The effects of three levels of forest gap size (S, M, and L, with a radius of 4, 8, and 12m, respectively) and position (inside, edge, and outside the gap) on soil microbial biomass, carbon (MBC), and nitrogen (MBN) were analyzed two years after the creation of gaps. The results showed that (1) L gaps had significantly higher soil MBN content at the outside position in spring (207.1mg/kg) and summer (169.5mg/kg) than that in the control plots. The M gaps had significantly larger soil MBC content at the inside and edge positions (2959.3 and 3008.8mg/kg, respectively), soil MBN content at the edge position in spring (207.7mg/kg), and soil MBN content at the inside position (144.4mg/kg) in summer than those in the control plots. The S gaps had significantly reduced soil MBC (2159.2 and 1955.1mg/kg) and MBN (153.1 and 131.3mg/kg) content at the outside and edge positions in spring, respectively, than those in the control plots. (2) Soil MBC content was positively correlated with soil total organic carbon and dissolved organic carbon (DOC) content, but negatively correlated with soil temperature; soil MBN content was positively correlated with soil water content, DOC content, and soil total carbon. MBC content was not significantly correlated with MBN content in soil and litter. We recommend the M gap size as an efficient management practice for increasing soil microbial biomass, promoting soil carbon and nitrogen cycling, and improving soil fertility and tree growth in P. orientalis plantations.
  • DownLoad:Short-term effects of forest gap size on soil microbial biomass carbon and nitrogen in the Platycladus orientalis plantation.PDF
  • Effects of different human disturbances on soil water conversation and fertility of natural secondary shrub
  • Authors:YOU Yujie, WANG Yixiang, ZHANG Huafeng, QIU Wanting and WU Minjuan
  • Abstract:It is difficult for the natural secondary shrub originated from subtropical evergreen broad-leaved forest by repetitive disturbance to recover to the arbor forest without protective measures. To explore the response of soil water storage capacity and fertility quality of shrub to different disturbance, moderate human disturbance and protective human disturbance(PHD) were taken in typical natural secondary shrub with high human disturbance as control during the period 2012-2015 in Lin'an, Zhejiang Province, China. No protective measures were taken in high human disturbance stands, but artificial interference activities such as wood chopping and herb gathering occurred occasionally. As for the protective interference, no one was permitted entry. Target trees in the natural secondary thickets were selected and tended in moderate human disturbance stands. The integrated soil fertility was determined by Nemero index, and correlation methods were used to estimate the comprehensive evaluation index of soil. Compared with the control, the soil total storage, retention storage and short term storage in protective disturbance and moderate disturbance plots increased by 12.41%, 5.33%,17.37% and by 29.13%,33.23%, 26.24%, respectively. Compared with control, soil maximum water-holding capacity, capillary water holding capacity, and minimum water-holding capacity in protective disturbance and moderate disturbance plots increased by 23.35%, 9.51%, and 17.55% by 48.63%, 56.08%, 71.05%, respectively. Comprehensive soil fertility of protective disturbance and moderate disturbance plots increased by 15.43% and 58.94% respectively when compared with control. Available nitrogen, organic carbon and soil organic matter of protective disturbance plots increased by 12.11%, 38.91% and 38.94%. Moreover, available nitrogen, available phosphorus, organic carbon and soil organic matter of moderate disturbance plots increased by 61.97%, 90.57%, 130% and 130.04%. The integrated soil quality index of protective disturbance and moderate disturbance plots increased by 15.43% and 58.94%, respectively. Bivariate correlation analysis indicated that there were strong positively correlation between the comprehensive soil fertility, soil water storage and soil organic carbon. The results showed that protective disturbance treatment decreased soil density, increased the total soil porosity, total water storage, available nitrogen and organic matter, which could be attributed to the faster growth rate of the trees and increasing amount of litterfall owing to the prohibiti on of firewood chopping and collection. Moderate disturbance not only banned firewood chopping and collection, but also selected and tended the target trees, releasing their competition. It accelerated the closure and biomass of the secondary shrub and enhanced the capability of vegetation interception on precipitation, thus, lessening precipitation on soil erosion. Tending biomass was kept inside leading an increase amount of litter. Compared to the high disturbance and protective disturbance, moderate disturbance decreased soil density, increased soil capillary, noncapillary, total porosity, total water storage, available nitrogen and organic matter. Protective disturbance and moderate disturbance reversed the retrogressive succession of the secondary shrub, accelerated the trees growth and improved the stand structure, resulting in improved soil nutrient cycling, increased soil organic matter and integrated fertility, forming a better status of tree growth and soil recovery, which promoted each other. In conclusion, MDH is better than PDH in leading the secondary shrub community to achieve the desired goal of soil water storage and water conservation, fertility and carbon sequestration. Thus, in the presence of favorable operating conditions, moderate human disturbance could be selected to accelerate the soil restoration of shrub.
  • DownLoad:Effects of different human disturbances on soil water conversation and fertility of natural secondary shrub.PDF
  • Effects of simulated warming on soil phosphorus availability in subtropical Chinese fir plantation
  • Authors:BEI Zhaoxian, ZHANG Qiufang, ZHENG Wei, YANG Liuming, CHEN Yuemin and YANG Yusheng
  • Abstract:Phosphorus (P), one of the most important nutrients in soil, is essential for plant growth, and plays a significant role in maintaining the balance of forest ecosystems. Furthermore, soil P availability is controlled mainly by geochemical and biological processes and can be vulnerable to global climate change. Warming, which has become one of the most important topics of current study, directly and indirectly alters soil P cycling in terrestrial ecosystems; however, to date, most studies have focused on nitrogen deficiency in temperate ecosystems, and have produced inconsistent results regarding the responses of soil P dynamics. Few relevant studies have been conducted in P-deficient tropical and subtropical forest ecosystems. In order to study the potential impacts of warming on soil P fractions related to P availability, we simulated warming in a subtropical Chinese fir plantation, and undertook sampling after one and a half years of short-term warming. The result showed that soil acid phosphatase in the warming treatment was 1.5 times higher compared to that in the control treatment, and that soil available P had increased by 25%, whereas soil total P, microbial P, and organic P had declined by 6%, 34%, and 12%, respectively. The increased soil P availability after short-term soil warming is mainly attributed to an increase in acid phosphatase activity that can promote mineralization of soil organic P, and to the reduced P immobilization of microbe. Despite the increase in soil available P after short-term warming, the significant decrease in microbial P, which is potentially available for plants, is likely to exacerbate P limitation in subtropical Chinese fir plantations. The findings of this study indicate that more attention should be paid to the responses of soil P to climate warming in the subtropical zone and highlight the need for further research.
  • DownLoad:Effects of simulated warming on soil phosphorus availability in subtropical Chinese fir plantation.PDF
  • Relationship between spatial distribution pattern and factors affecting weight per thousand seeds of cultivated barley in Qinghai-Tibet Plateau
  • Authors:WANG Jianlin, FENG Xibo, FU Gang, HOU Weihai, WANG Gaihua, Dacizhuoga and ZHONG Zhiming
  • Abstract:Weight per thousand seeds (WTS) is an important quality character of barley grain. In recent years, some researchers have shown that WTS is affected by genetic factors, as well as by its cultivation and environmental conditions. However, the effects of different environmental factors on barley WTS remain unclear. In addition, although previous studies have mostly been conducted at several sites, large-scale studies have not systematically addressed the relationship between cultivated barley WTS and environmental factors. Moreover, with a large number of hull-less barley varieties or resources being required on an urgent basis for modern agriculture development in an environment of high radiation, low temperature, and drought, Qinghai-Tibet Plateau is an important region for growing hull-less barley in China. However, until now, the relationship between barley WTS and environmental factors in Qinghai-Tibet Plateau has not been reported. Therefore, the present study investigated the distribution of cultivated barley WTS characteristics in Qinghai-Tibet Plateau using geography, climate, soil, and agronomy data from 83 sampling sites. The aim of this study was to identify the relative effects of different environmental factors on WTS, to clarify the relationship between the distribution of barley WTS and environmental factors, and to explicitly assess acclimation of WTS of barley varieties planted in different areas to the environment. The results showed that (1) WTS exhibited a macrocosm pattern of spatial distribution along the horizontal direction in Qinghai-Tibet Plateau, with staggered patches of different values and an N-shaped tendency. In addition, two regions of higher WTS (south-western and north-eastern) included the counties of Qushui, Duilongdeiqin, Naidong, Shigatse, Zhanang, Gongga, Jiacha, Dazi, Qiongjie, Lazi, and Dingri in Tibet and Haiyan, and Mengyuan and Gangcha in Qinghai Province. (2) Along the vertical direction, GSC distribution exhibited a pattern with double peaks, with two higher value zones between the altitudes from 3600.0 m to 3900.0 m and that above 4500.0 m with average WTS values of (49.6815±10.0764) g and (47.9500±0.1732) g, respectively. (3) The effect of the magnitude of environmental factors on WTS followed an order of precipitation during the growth period from heading to maturation > soil available K content > sunshine hours during the growth period from tillering to elongation > average temperature during the growth period from heading to maturation > sunshine hours during the growth period from heading to maturation > average diurnal temperature range during the growth period from elongation to heading > longitude.
  • DownLoad:Relationship between spatial distribution pattern and factors affecting weight per thousand seeds of cultivated barley in Qinghai-Tibet Plateau.PDF
  • Dynamics of shade tolerance, biomass, and individual growth of five understory plant species in Eucalyptus urophylla plantations
  • Authors:GONG Xuyun, RAO Xingquan, ZHOU Lixia, WANG Xiaoling, ZHU Xiaolin and CAI Xi'an
  • Abstract:In order to investigate the ecophysiological characteristics and growth adaptability of different understory plants in Eucalyptus urophylla plantations, five understory species with high economic and medicinal values, including Ilex asprella, Gardenia jasminoides, Melastoma candidum, Rhodomyrtus tomentosa, and Litsea cubeba, were selected to measure leaf characteristics, chlorophyll content, and photosynthetic light response curves. In addition, the dynamics of biomass and individual number were analyzed based on field sampling survey data in 2006 and 2011. Comparative analysis and cluster analysis revealed that:(1) the leaf width, thickness and, area of M. candidum were the largest, whereas those of I. asprella were the smallest. Overall, the net photosynthetic rate of the selected understory plants increased with increasing light intensity. However, the net photosynthetic rate of I. asprella and G. jasminoides increased more rapidly than that of M. candidum and L. cubeba, and reached the light saturation point more quickly. R. tomentosa, M. candidum, and L. cubeba had higher light saturation points than that of I. asprella and G. jasminoides. The selected understory plants could be classified into two groups in terms of shade-tolerance ability, based on hierarchical cluster analysis. I. asprella and G. jasminoides were assigned to the strong shade-tolerant group, whereas M. candidum, L. cubeba, and R. tomentosa were assigned to the low shade-tolerant group. (2) Biomass of the five selected understory species increased with stand age, but the range of increment varied. The greatest increase was observed in M. candidum (74 fold), followed by R. tomentosa (18 fold), and the least was observed in L. cubeba (1.3 fold). The increase in biomass of M. candidum, R. tomentosa, and L. cubeba was mainly caused by the increase in individual height and basal diameter, whereas the increase in biomass of I. asprella and G. jasminoides was mainly attributed to the increase in individual number, height, and basal diameter. (3) I. asprella, a shade-tolerant understory species with high economic value, dominated the shrub community with increasing stand age of the Eucalyptus plantations, mainly owing to the increase in density, individual height, and basal diameter. G. jasminoides showed lower dominance over the shrub community owing to lesser increase in individual height and basal diameter than those of I. asprella. The density of L. cubeba, R. tomentosa, and M. candidum showed an overall decline with minor increase in individual height, basal diameter, and biomass. L. cubeba, R. tomentosa, and M. candidum can only survive in forest gap and edge owing to light limitation. In conclusion, we suggested that I. asprella and G. jasminoides should be protected and re-introduced during Eucalyptus plantation management for biodiversity conservation. Under the short-rotation management regime, M. candidum, L. cubeba, and R. tomentosa should be retained and re-introduced in the forest gap and edge.
  • DownLoad:Dynamics of shade tolerance, biomass, and individual growth of five understory plant species in Eucalyptus urophylla plantations.PDF
  • Research progress on the thermal environment of the urban surfaces
  • Authors:YAO Yuan, CHEN Xi and QIAN Jing
  • Abstract:The dramatic changes in the thermal environment of urban surfaces could not only affect human health and well-being in terms of increased mortality and morbidity, but also alter components of the eco-environment, such as air and water quality, biodiversity, and net primary production. Over the last 50 years, within the context of rapid urbanization and human population density increases, ever-expanding impervious surfaces have triggered various environmental challenges in developing countries like China. Concerns related to environmental degradation, traffic jams, air pollution, and shortages of resources are expected to become more serious in conjunction with dramatic changes in the urban surface thermal environment. In light of this, studies on the urban surface thermal environment using quantitative research methods have become a hot topic for scientists in China, as well as worldwide. Hence, understanding the current progress in studies related to the urban surface thermal environment has importance and practical significance on the quantitative evaluation of the urban thermal environment and the promotion of sustainable urban development. In this paper, we first introduce the concepts of the urban surface thermal environment and urban heat island, main research methods, and data acquisition techniques. Secondly, we review the progress of research on the urban surface thermal environment considering the following aspects:the spatial temporal characteristics of the urban surface thermal environment and its changes, driving forces and mechanisms, urban surface radiation and energy balance, the relationship between urban surface heat islands and urban atmospheric heat islands and its evolution, urban greenbelt and water-body alleviation of the urban heat island effect, and scaling transformation of remote sensing temperature products. Finally, the difficulties, shortcomings, and existing bottlenecks in current research are discussed. Future research directions are equally proposed to provide a reference for future researchers interested in quantitative analysis of the urban surface thermal environment.
  • DownLoad:Research progress on the thermal environment of the urban surfaces.PDF
  • Effect of reclamation activity on coastal ecological environment: progress and perspectives
  • Authors:XU Caiyao, PU Lijie and ZHU Ming
  • Abstract:Coastal wetland ecosystems are among the most productive yet highly threatened systems in the world. Being typical ecologically vulnerable zones, coastal wetland ecosystems are not only the most active area on earth's surface and are affected by anthropogenic activities. Therefore, the severity of anthropogenic pressure on the environment is increasing. In recent decades, the reclamation of coastal wetland for agricultural and architectural land use has been a common practice worldwide. It has become an important method of meeting the increasing demand of space for living and development in China. This paper summarized the history and status quo of coastal reclamation briefly, analyzed the effects of reclamation activity on coastal eco-environment from the aspects of soil properties, biodiversity, land use and landscape pattern, ecological security, and ecosystem services. The present study showed that with the increase in time after reclamation, 1) tidal flat soil accumulated nutrient in the process of desalinations and tended to become fertile; 2) plant species diversity increased, whereas terrestrial insects and soil animals gradually replaced macrobenthos and waterfowl, which constituted the typical biological communities in coastal wetlands; 3) land use transformed from natural land use to artificial land use, and the landscape pattern appeared to increase fragmentation and dominance index, while decreasing diversity; 4) during the transition of natural wetland ecosystem to terrestrial ecosystem, the provisioning value increased and provisioning was the only growth ecosystem service, but its increment was lower than the reduction from regulating, cultural and supporting, leading to the loss of total value of ecosystem service; 5) reclamation could increase ecological risk in terms of land and water resource security, biological invasion, natural hazard and other factors. Therefore, the trade-off between resource utilization and environmental conservation to realize the harmony between man and nature has been a key problem in coastal reclamation activity. Consequently, in the future, we should study the mechanisms underlying the effects of reclamation based on long-term stationary experiments for developing the meta-synthetic framework and integrated countermeasures system. In addition, further research on the effects of reclamation and exploitation on coastal eco-environment would be necessary.
  • DownLoad:Effect of reclamation activity on coastal ecological environment: progress and perspectives.PDF

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