Archive

  • Select all
    |
    Articles
  • Articles
    LI Wenhua
    Download PDF ( )   Knowledge map   Save
    Ecology has been recognized as an independent discipline since 1869, when Ernest Haeckel first used this terminology and defines it as a branch of science for studying the interactions between organisms and their environment. The modern ecology expanded the subject and scope of the study; broke throw the limitation of pure naturalism tendency and was actively involved in solving the urgent task of world-concerned global development problem. While equipped by modern methodology and equipments, it becomes a bridge between science and development. Although a wealth of knowledge with deep ecological thought has been accumulated in the long course of China’s development, it has not developed into a science until the 1950s. The development of ecology in China may roughly be divided into four phases (i.e. primitive embryonic phase, fundamental ecological study phase, ecosystem study phase, and the phase for sustainable development. This paper gives a general review of the development of ecology in China and introduced the progress in several selected areas. These include: biodiversity conservation, ecological research related to global change, restoration of degraded ecosystems, desertification control, ecosystem study on the Qinghai-Tibetan Plateau, promotion of sustainable development from concept to action, and evaluation of ecosystem services and eco-compensation, etc. Based on the current development status of ecological science in China and the needs of the country, six priority areas for development of Ecology in the future were recommended.
  • Articles
    CHENG Shengkui, XU Zengrang, SU Yun, LIU Xiaojie, SHEN Lei, XIE Gaodi, ZHEN Lin, LI Xiaojuan, LONG Xin
    Download PDF ( )   Knowledge map   Save
    In the 21st century, China is facing some challenges, e.g. population growth, rapid economy development, resources limitation and environmental vulnerability. Resource-use efficiency and the environmental impacts associated with growing resource utilization is a new challenge for both scientists and politicians, especially. In this paper, the concepts of resources and resource products flow is presented in order to analyze the environmental impacts that occur as a result of the resource flow process. We focus on forest resources, coal products and oil flows as these the main resources and products that are produced continuous severe and increasing environmental pressure. The data for domestic yield and exploitation, importation, exportation, and consumption, for various industries come from China’s forest statistical yearbooks for the period 1949 to 2001, and China’s energy statistical yearbooks for 1980 to 2006. We divided the resources flow process into key stages, such as harvest, exploitation, process or conversion and end consumption. Resources efficiency and environmental performance for each stage were evaluated. This study showed: resource-use efficiency improved and the structure of resources consumption has been optimized markedly in the past decades in China. However, the absolute quantities of resources consumption are still increasing, and the environment pressures originating from resource use became more severe.
  • Articles
    HE Chansheng, Thomas E. Croley II
    Download PDF ( )   Knowledge map   Save
    “Hydrological resource shed” is defined as a geographic area that contributes material (e.g. water, nutrients, and sediments) over one time interval, passing through a location of interest over another time interval. While similar to the concept of watershed, this relatively new concept has some unique features. First, the boundary of a watershed is delineated by topography and relatively more stable.  The boundary of a hydrologic resource shed, however, is delineated by the contributing sources of water and materials to a river or lake during hydrologic events, and changes over both space and time. Second, the concept of watershed emphasizes temporal distribution of water and materials within a given space, and the hydrologic resource shed focuses on both temporal and spatial distribution of water and materials within a changing space. Third, the concept of hydrologic resource shed incorporates the space-time variability in studying watershed patterns and processes. Taking advantage of current tracing, remote sensing, mapping, and modeling technologies, hydrologic  resource shed  provides a new way of discovering, understanding, and simulating the transport and distribution of water and materials across multiple space and time scales. An example is presented for computing the hydrologic resource shed distributions using a hydrologic model, Distributed Large Basin Runoff Model (DLBRM)  in the Maumee River watershed in western Lake Erie Basin of the U.S.
  • Articles
    XIA Jun, CHENG Shubo, HAO Xiuping, XIA Rui, LIU Xiaojie
    Download PDF ( )   Knowledge map   Save
    Potential impacts of climate change on water quality and ecosystem, as a newly emerged problem and challenge, is of great concern by scientists and governments. However, scientific researches and practices are still facing big challenges in these issues because of their complexity and uncertainty. This paper reviews the most recent literatures on this topic at first, and proposes some research gaps between published results and what needs to be known in practice. Additionally, basing on our knowledge and results of some recent case studies of the two representative rivers which are Huai River and Hanjiang River in China, it should be addressed that if the impact of climate change on the water quality and ecosystem has been taken concern, water pollution and related water environmental problem caused by human activities and economic development must be addressed firstly. It has also been recognized that water quality and ecosystem can be significantly impacted by climate change under the condition of human activities. Climate change can alter water temperature and hydrological regimes and thus influence the water quality and ecosystem. Then, the contents and principles of adaptation options and adaptability construction are discussed. The present study is expected to make clear of conceptions and to give directions for further relevant researches.
  • Articles
    DONG Jinwei, LIU Jiyuan, SHI Wenjiao
    Download PDF ( )   Knowledge map   Save
    The largest ecological restoration project in the form of Sloping Land Conversion Program (SLCP) been implemented for about ten years in China since 1999. Nationwide research on Sloping Land Conversion (SLC) policy needs to examine especially at the beginning of 21st century, because the project has been implemented on unprecedented scale in this period. This study tried to monitor the spatial pattern of ecological SLC using land use change dataset from human-aided interpretation of Landsat TM images. Quantity and spatial pattern of SLC (2000-2005) including two types of conversion, namely “converting cultivated land into forest” and “converting cultivated land into grassland” was analyzed. A case study of Middle and Northern Shaanxi Province, which is one of the most typical region of Loess Plateau, was investigated to analyze the rationality of the project implementation based upon the two types of conversion. The model of habitat suitability for cropping was used for the rationality evaluation of SLCP. The results showed that: (1) SLCP was concentrated mainly in the central regions of China, especially in the middle reaches of Yangtze River and Yellow River, and SLC covered nearly a half of the total cropland loss; the soil erosion zone of Loess Plateau had a large area of sloping lands which was estimated about 1162.50 km2, and more than half of them for forestation; (2) the spatial location of the projects was rational on the whole, and the cropland with lower suitability levels had a higher area proportion convered. The proportion of sloping lands conversion in marginal suitability level was the largest and covered 77.35 % of all the SLCP area, of which 603.32 km2 was converted into forest lands and 528.94 km2 of that into grasslands. There was more croplands converted into forest than into grassland. The converted cropland area with moderate suitability still had a percentage of 19.38, and the possible reason was due to the management factor and target allocation of SLCP. Furthermore, local farmers set aside cropland, and then worked in cities for more subsides. There was still a large areas of cropland unsuitable and marginally suitable, which should be considered to be converted first of all in the future.
  • Articles
    HE Xiahong, ZHU Shusheng, WANG Haining, XIE Yong, SUN Yan, GAO Dong, YANG Jing, LIU Lin, LI QiXin, ZHANG Shaobo, ZHAO Gaohui, HU Mingcheng, JIANG Kaimei, LI Chengyun, ZHU Youyong
    Download PDF ( )   Knowledge map   Save
    Aiming at the difficulties of controlling on potato late blight, maize northern and southern leaf blight diseases caused by the overlapping of rainfall and peak of these diseases in mountainous area of Southwest China, intercropping of potato with maize by adjusting planting time and spacing to avoid rainfall and disease occurrence was assessed. The results showed that early or late planting of potato, avoiding rainfall peak from potato vigorous growth and increasing light and air diffusion in space, alleviated potato late blight disease. The average severities decreased by 44.3% for potato late blight, 14.8% for maize northern leaf blight and 22.5% for maize southern blight, compared with the monocropped controls. Moreover, this kind of intercropping pattern improved the output significantly. The crop yields were increased and reached a land equivalent ratio (LER) of 1.738 for early planting pattern and 1.766 for late planting. This approach can be practical significance for ecological control of crop disease and food production increase. The agroecological structure in harmony with the natural environment results in ecological and cycle agriculture with high yield, high quality and high efficiency.
  • Articles
    XIE Gaodi, ZHEN Lin, LU Chunxia, XIAO Yu, LI Wenhua
    Download PDF ( )   Knowledge map   Save
    Valuation of global ecosystem services by R. Costanza(1997)has attracted attention of the Chinese ecological researchers over the years. Many Chinese scientists have been using the methods to valuate the ecosystem services for forest, grassland and farmland ecosystems. However, it has been turned out that there are several shortcomings in direct adaptation of the methods, for instance, some ecosystem services have been insufficiently valuated or even ignored. To meet this gap, we have used a “unit value” based method for assessment of ecosystem services. Expert interviews with structured questionnaire have been contacted in 2002 and 2007 respectively; altogether 700 Chinese ecologists have been involved in the interviews. It has been found that the values of ecosystem services from expert knowledge based unit value method and biomass based method are comparative. Therefore, expert knowledge based assessment of ecosystem services could be used as a method for the assessment with known land use areas, and a good result could be generated within a short time period. However, for scientifically sound and concrete results, a long term simulation of ecosystem service flux curve via experimental research is required, and spatial and temporal disparity of ecosystem services should be taken into account.
  • Articles
    LONG Hualou, ZOU Jian
    Download PDF ( )   Knowledge map   Save
     In China, the pattern of farmland use has been greatly changed due to the rapid development of the economy, since economic reform in 1978. Variations in available farmland, in terms of both quantity and quality, have brought about changes in grain production. This paper analyzes the spatiotemporal pattern of China’s level of farmland use for the period 1978 to 2004, and develops a “farmland-grain elasticity coefficient” (FGEC) to reflect the interrelationship between changes in farmland use and levels of grain production, using agricultural statistical data from local governments. The outcome of this study indicates that since 1978 the effect of farmland loss on grain security has been somewhat abated, due to increased investments and the subsequent improvements on farmland. Since the initiation of economic reform, China’s level of farmland use has been generally improved. These improvements are mainly due to rapid economic development and constitute a move across a gradient from the southeast coast of China to the Chinese inland areas, following the same path as that of economic development. However, continuous improvements in the level of farmland use may not always bring about sustainable and steady growth in grain output. Therefore, considering the law of diminishing marginal utility, in developing countries, the area of available farmland will play a key role in maintaining security in grain production. This will also constitute a practical scientific basis for strict farmland protection objectives and strategies for China.
  • Articles
    XU Yuqing, HE Jicheng, LI Linghao, CHENG Weixin
    Download PDF ( )   Knowledge map   Save
    Gaseous N losses via ammonia (NH3) volatilization were measured during the 2005 and 2006 growing seasons in a long-term (17 years) experiment with five grazing intensities (0.00, 1.33, 2.67, 4.00 and 5.33 sheep ha–1). We aim to understand the seasonal variations in ammonia production, the potential carry-over effects of previous grazing and the underlying regulating processes involved. It was found that rates of NH3 volatilization varied seasonally, ranging from 0.88 to 3.52 g N ha–1d–1 during the measurement period, with higher values in spring and early summer and lower values in late summer and autumn. Soil pH value, NH4+-N concentration, moisture and bulk density exerted controls on NH3 volatilization over the two growing seasons. However,?the constraining effect of bulk density on NH3 flux, driven by grazing, muted the supporting effect of above other three environmental factors. Even though no statistically significant effects of different grazing intensities on rates of NH3 volatilization were generally found, grazed treatments tended to result in relatively higher cumulative NH3 volatilization, and relatively lower soil N content, plant growth and productivity. It indicates that restoration of the degraded grazed grassland may be slower in comparison with the ungrazed grassland. The study on NH3 volatilization in grassland ecosystem is meaningful in terms of its contribution to advancing our understanding of the role of N loss in limiting grassland processes and to drawing up grazing guideline and fertilizing regime for utilizing the resources rationally.
  • Articles
    HE Chun E, LIU Xuejun, ZHANG Fusuo
    Download PDF ( )   Knowledge map   Save
    Atmospheric N deposition has become an environmental concern in the North China Plain (NCP), because of the large anthropogenic reactive N emissions in this region since the 1990s. A manually integrated total N input (ITNI) method was developed using 15N-labelled monitor plants grown in pots to obtain accurate measures of total N deposition to the agroecosystems in the NCP and to improve N-fertilizer recommendations. In the NCP, total airborne N input into the maize-wheat rotation system is 80-90 kg N ha–1 yr–1, and the plant available N from deposition for maize and wheat plants is c. 50 kg N ha-1 yr–1. While total airborne N input measures at almost 100 kg N ha–1 yr–1 when ryegrass is used as the monitoring plant the plant available N from deposition for ryegrass is c. 76 kg N ha-1 yr-1, accounting for 77% of the total N deposition. Dry deposition is likely to be the major contributor to the total N deposition during the wheat growing season in the dry and dusty NCP. In order to obtain reliable N deposition results, especially when the plant density in small area pots (0.57 m2) is different from the density in the field, we found that a correction factor (0.54 in this study) had to be used for maize to rectify values obtained from pot area.
  • Reports
  • Reports
    SHEN Lei, FANG Lan
    Download PDF ( )   Knowledge map   Save
    The international minerals market has seen a general weakening since the early 1970s and the late 1980s. In contrast, rapid economic growth, not least in China in the early 1990s, and then India in the early 2000s, has contributed to an increase in the growing demand for minerals market and trade in the world. The production, consumption and trade in minerals have played a crucial role in the growth and development of the Chinese economy over the past decades. This article presents an overview of the general changing characteristics of international minerals market and trade patterns, identifies the major theoretical determinates affecting minerals demand and supply in China, and empirically investigates the characteristics of China's mineral trade and future development. The authors argue that whether or not the great potential of China's minerals market become a major driver of the international minerals trade, and hence stimulate further economic growth in China remains to be seen. However, China is actively involved in the global minerals market and trade.
  • Synopsis
  • Synopsis
    LEE Xuhui
    2010, 1(1): 87-93.
    Download PDF ( )   Knowledge map   Save
    This commentary arises from a seminar course on China’s environment taught at Yale University. Emerged out of the seminar discussion are five themes, including: a) the balancing act of local interest and regional coordination in the fight against pollution dispersion, b) the creation of special environmental zones for experimenting bold, forward-looking ideas, c) new approaches to environmental education and capacity building, d) the need for international collaboration, and f) the unique situation of checks and balances in China’s environmental decision-making. This paper is not intended to provide an in-depth analysis of these topics; rather its goal is to emphasize the need for infusion of western environmental thinking with China’s reality.
  • Synopsis
    MIN Qingwen, SUN Yehong, SHI Yuanyuan
    2010, 1(1): 94-96.
    Download PDF ( )   Knowledge map   Save