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  • Articles
    WANG Dai, LIN Xueqin YU Jianhui, SI Yuefang
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    To date, theories of eco-compensation and biological restoration have been popular, and some models in developed countries are treated as good examples. Here, we not only focus on Japan, but also pay more attention to challenges during this process. Based on a long-term field study on Sado Island, a less developed region in Japan, we attempt to describe how the government carries out environmental remediation towards the reintroduction of ibis (Species name) into the wild, and the conflict between ibis habitat restoration and farm management. We discuss the underlying reasons for this conflict and the negative effect on regional development. We follow policy improvements of the local government and related supplementary help carried out to fix the mismatch between the payment for ecological benefits and that lost by farmers in the pre-period. We conclude that the coordination of interest among different social groups is the key for success in ecological restoration and compensatory measures have to be made to meet the actual needs of the local groups. This case study in Japan can be applied to similar regions with poor environments and urgent environment restoration needs in China.
  • Articles
    TANG Chengcai, ZHONG Linsheng, CHENG Shengkui
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    Some Tibetan villages in Shenzha county, Tibet were chosen as typical Tibetan communities in China. Attitudes and perceptions towards Tibetan community participation in ecotourism were analyzed using face to face interviews. Most residents supported the development of ecotourism. They are willing to engage in ecotourism projects and accept ecotourism education and training, and expect that the government provides opportunities for them to participate in making ecotourism decisions. Most residents believed that ecotourism promotes local economies and social development, and enhances the ability and quality of local residents while improving their environmental consciousness. However, some residents were concerned that ecotourism may destroy local natural environments and Tibetan folk customs and culture. The level of community participation in ecotourism development is only in its infancy in Shenzha, but there is strong potential. The chief participatory approaches of ecotourism development for most residents were providing labor and catering services and commodities for tourism, and Tibetan performance singing and dancing. Limiting factors include language, a shortage of knowledge and skills, and poor ecotourism infrastructure. Most residents had little confidence that the government was willing to support them to participate in ecotourism. We put forward some mechanisms to enhance the level of community participation in ecotourism in this important region.
  • Articles
    Siegfried FLEISCHER
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    Energy-yielding processes in the N-cycle form important links with the global C-cycle. One example is demonstrated with the supply of nitrogen to soils, initially resulting in lowered CO2 emissions. This well known effect has mostly been interpreted as hampered or delayed soil respiration. When added in surplus, however, nitrogen supply does not stabilize the minimum emissions initially obtained, but gradually results in increased CO2 emissions. Specific inhibition of the CO2 consuming process nitrification in soils, with surplus ammonium supply or with acetylene, mostly results in additional CO2 emissions. The difference between this disclosed gross heterotrophic respiration (GHR) and the net CO2 emission (NHR) is the result of a within-soil CO2-sink. Soil respiration solely determined as CO2 emitted as NHR (the common situation) therefore may lead to misinterpretations of the function of the soil system, especially in areas with high N-deposition. As a consequence, the interpreted’acclimation’ of the soil respiration response in a warmer world should be reconsidered. The concept of respiration inhibition by nitrogen supply may also be questioned. Disregard of these processes, including the indicated N-driven within-soil CO2-sink, may prevent adequate measures counteracting climate change.
  • Articles
    LU Chunxia, XIE Gaodi, XIAO Yu
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    The cost of ecological and environmental protection is a core part of ecological compensation standards and consists of direct costs, opportunity costs and development. This paper uses Naqu, a section of the Chang Tang Nature Reserve, Tibet as a case study to assess direct and opportunity costs of wildlife conservation to herdsmen. A standard sheep unit has been established for determining the animal carrying capacity of grasslands across China, and we used this to convert wild animals into standard sheep units. This approach links the grassland ecosystem, herbivorous wild animals and their valuation together. Our results show that the total cost of wildlife conservation reached 5.69 billion Chinese Yuan (CNY). The opportunity cost was 4.5 billion CNY, accounting for 79% and direct cost. The biggest economic loss to herdsmen was the opportunity cost in Chang Tang Nature Reserve and means that herdsmen have to give up economic income from livestock husbandry when grazing is banned. Opportunity cost assessment is integral to establishing ecological compensation. The average value of wildlife conservation was 1482 CNY per capita and 57 CNY per hectare according to population and the area of moderately and seriously degraded grassland. The period of ecological compensation should last five to ten years after grazing is banned.
  • Articles
    ZHANG Wei, WANG Xiuhong, ZHANG Hongye
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    How to coordinate arid eco-environmental protection and oasis agricultural development and avoid desertification is a key problem in achieving the sustainable development of oasis humanearth systems. We analyzed the temporal characteristics and overall tendency of an arid oasis agricultural production system in Yining County, China by means of emergy methods and ternary diagrams theory. From 1989–2008, total emergy input and output of the oasis agricultural system in Yining County had a trend of sustainable development. According to the sustainability analysis with emergy indices, the agricultural production systems in Yining County were still at a sustainable status. However, the emergy-based sustainability index (ESI) followed a decreasing trend. Scenario analysis of the sustainability lines based on ternary diagrams showed that both the F (input from economic component) and N (input from nonrenewable resource) leading modes had limitations in the study case. The agricultural production of Yining County should adopt the R leading mode, in which the percentage of non-renewable resources in the local system will be kept roughly unchanged, while the fraction of purchased inputs and renewable resources will be decreased in synchronism. In this way, the contribution from local renewable resources to agricultural production will be increased, and sustainable development ensured.
  • Articles
    LI Shaojuan, HUANG Ying, TU La
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    Based on daily mean temperature records from 1961 to 2007 at 20 meteorological sites in Southwest Yunnan, and the surface temperature simulated by IPCC AR4 Climate Models, a quantitative examination was undertaken into the characteristics of multi-timescale temperature (AMT, DMT and WMT) variation in Southwest Yunnan. The simulation abilities of the models were also evaluated with the normalized root mean square error (NRMSE) and Mann-Kendal test statistic methods. Temperatures show remarkable increasing trend from 1961 to 2007, with the Mann-Kendall test statistic passing 95% confidence verification. The result of the NRMSE analysis shows that the simulated temperature anomaly variations are more similar to observed ones especially for AMT and DMT, and the projected result (anomalies) of IPCC AR4 climate models can be used for predicting the trends in multi-timescale temperature variation in Southwest Yunnan in the next 40 years under the three emission scenarios, which has better simulating effect on AMT and DMT than WMT. Over the next 40 years the temperature will continue to rise, with annual mean temperature showing a more remarkable rising trend than that of the dry and wet seasons. Temperature anomalies exhibit different increasing rates under different emission scenarios: During the 2020s the rising rates of multi-timescale temperature anomalies in a high greenhouse gases emissions scenario (SRESA2) are smaller than those under a low emission scenario (SRESB1). Except that, the rate of increase in temperature anomalies are the highest in the intermediate emissions scenario (SRESA1B), followed by those in SRESA2, and those in low emissions scenario (SRESB1) are the lowest. The reason of different simulating effects on WMT from AMT and DMT was also discussed.
  • Reports
  • Reports
    ZHANG Jinghua, JIANG Luguang, FENG Zhiming, LI Peng
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    The severest drought on record occurred in southwestern China from September 2009 until March 2010. In order to measure the impact the drought imposed on vegetation, we developed an evaluation indicator called the Vegetation Index Anomaly (VIA) based on MODIS/EVI. The tempospatial pattern of this impact was analyzed. Given that this impact may be modulated by many factors, the responses of different vegetation types (woodland, grassland and cropland), and the spatial pattern of meteorological drought were also analyzed. Results show that more than 50% of vegetation suffered because of this drought event, but there was significant tempo-spatial variability in the range and intensity of impact. This variability may be caused by many factors. Of the three major vegetation types, cropland was the most sensitive to drought, followed by grassland and then woodland. In addition, meteorological factors (precipitation and air temperature) also played a role; however, obvious differences exist between the spatial distribution pattern of drought-stricken vegetation and that of meteorological drought, which further demonstrates the intervention of other factors besides meteorological factors. So compared to meteorological drought, the vegetation index may be more useful for measuring the actual intensity, duration and impact of drought events. The limitations of vegetation indices are also considered.
  • Reports
    ZHANG Canqiang, LI Wenhua, ZHANG Biao, LIU Moucheng
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    Water yield calculation and mapping are of great importance to water resource planning and management and hydropower station construction. A water yield model based on InVEST was employed to estimate water runoff in the Xitiaoxi River basin. The data included land use and land cover, average annual precipitation and potential evapotranspiration, soil depth, and plant available water content. In order to test model accuracy the natural runoff of Xitiaoxi River was estimated based on linear regression relation of rainfall-runoff in a ‘reference period’. After repeated validation, when the Z value was 6.5 the water yield was 8.30 E+8 m3 and this was a smaller difference with natural runoff. From the distribution of water yield, south and southwestern areas of the watershed had higher water yield volumes per hectare.
  • Reports
    YANG Hailong, LV Yao, FENG Zhiming
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    Considering energy security and greenhouse gas emission, many governments are developing bio-liquid fuel industries. The Chinese Government advocates the development of a fuel ethanol industry with non-food crops such as cassava. However, scientists debate the carbon emission of these bio-liquid fuels. The focuses are the influence of soil carbon pool destruction and by-product utilization. This study built a carbon balance analysis model, and assessed carbon emission of cassava fuel ethanol across its life cycle. The results show that the carbon emission of cassava fuel ethanol per kilogram in its life cycle was 0.457 kg under new technical conditions and 0.647 kg under old technical conditions. Carbon emission mainly came from the use of nitrogen fertilizer (9% of total emissions), the destruction of the soil carbon pool (29%) and fossil energy inputs (50%). Taking gasoline as a reference, the carbon emission of cassava fuel ethanol was 90% of that of gasoline. This percentage would drop to 64% if soil carbon pool destruction was avoided. Therefore, in order to promote the development of cassava fuel ethanol in China, farms should apply fertilizer properly, grow cassava on marginal land, and not alter land use patterns of woodland, grassland and other environments. In addition, we should exploit efficient fuel ethanol conversion technologies and strengthen the use of by-products.
  • Reports
    LI Miao, XIA Jun, MENG Dejuan
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    A comprehensive precipitation trend and periodic analysis at the seasonal scale on a 286- year data series (1724-2009) for Beijing are presented using linear regression, 11-year moving averages, Mann-Kendall test and continuous Morlet wavelet analysis. We found that in the past 300 years precipitation has increased except during winter. There were strong increasing trends after the 1780s in both summer and annual precipitation data series and the trend was significant for a longterm period. The abrupt points of summer and annual data series of precipitation are 1764 and 1768 respectively, after that, the trend changed from decreasing to increasing. It shows different periodic traits in four seasons respectively: 30–170 years, 80–95 years, 75–95 years and 55–65 years are considered to be the strongest period in spring, summer, autumn and winter. One hundred and fiftythree years, 85 years, 83 years and 59 years are the first order main periods in spring, summer, autumn and winter, respectively. The trend and period of annual precipitation are mainly impacted by rainfall in summe. According to the first main period of 85 years in both summer and annual precipitation data series, Beijing will experience a time period of less precipitation in 2009–2030.
  • Reports
    SUN Zhenzhong, OUYANG Zhu, LI Fadong, WU Lanfang
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    The major function of clover in a winter wheat–white clover intercropping system is to supply nitrogen (N) for the wheat. A field experiment was conducted at Yucheng Comprehensive Station of the Chinese Academy of Sciences, to evaluate the effect of cutting white clover on N fixation and the transfer of fixed N to the associated winter wheat. A method of 15N natural abundance was used to determine the nitrogen dynamics in the intercropping system. The results showed that the amount of N transferred from the clover to the wheat, throughout the growing season, varied between 34.4 and 57.5 kg ha-1. Compared to leaving the clover standing, cutting the clover increased the amount of N that accumulated in the soil and also resulted in reduced N concentrations in the leaves and stems of the wheat. Using the cut clover as mulch between wheat rows led to decreased N concentrations in the wheat plants’ leaves and stems. The present study provides preliminary information on the amount of N transferred from clover to wheat in an intercropping system.
  • Reports
    YANG Dingding, ZHOU Caiping, OUYANG Hua, CHEN Chuanyou
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    Using annual nature runoff data from 1961–2000 for the Qinghai-Tibet plateau Nyangqu River, the Mann-Kendall method and wavelet transform were adopted to analyse runoff variation characteristics for the Nyangqu River. The results show that the annual change in runoff is relatively stable and that the intra-annual distribution of the runoff is extremely uneven. The disparity in runoff between wet seasons was significant. The runoff for June-September accounted for 65% of the whole year and the highest monthly runoff accounted for 24.56%. From 1961-2000, runoff showed a significant increasing trend with an abrupt increase in 1985. The 5-8 years oscillation period of the runoff was most notable and the 10-15 years period was relatively notable. The principal periods of annual runoff for Shigatse station and Gyantse station were 5a and 7a. The second were 13a and 12 years. Increasing glacial melt water caused by rising temperatures may be the main reason for increased runoff in the Nyangqu River.
  • Reports
    LIU Junwei, LV Huijin
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    Estimating the value of water resources not only forms the basis of water rights transactions between upstream and downstream and eco-compensation standards, but also provides scientific data for the reasonable establishment of local water prices and promotes sustainable use and efficient management. Here, we estimate the economic value of the water resources of the upper reaches of the Xin’an River basin. Our purpose is to establish theoretical support for eco-compensation standardization and provide data for the protection of water resources and water price reform.
  • Reports
    ZHANG Qiuying, LI Fadong, TANG Changyuan
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    Nitrate contamination has become one of the most important issues for surface water and groundwater. N2O, with an increasing contribution to global warming, has been more and more attention by the IPCC recently. As well known, denitrification plays a major role in nitrogen cycle of aquatic ecosystems and operates at rates far below its potential under proper conditions. Sediments are the single largest pool of nitrogen in wetland ecosystems. During this process, facultative anaerobic bacteria transform nitrite into nitrogen gas which dissolves in the groundwater and diffuses into the atmosphere finally when it shows up with seepage or spring in the wetland. To seek a mechanistic understanding of N removal in natural wetland ecosystem, a case study was carried in terms of denitrification rate at the Ochi catchment, Chiba, Japan. In this study, samples of intact soil cores in 0–20cm were taken along the groundwater flow path, which including 2 samples in the unsaturated zone and 2 in saturated wetland ecosystem. Denitrification capacity of soil was quantified using acetylene (C2H2) inhibition/gas chromatography ECD method with time intervals of 0, 2, 6, 12, 24 h. Total-N and Total-C contents and amount of denitrifying bacteria were also analyzed. It is found that denitrification ability is low for all 2 samples in the unsaturated zone and high in saturated zone. Results show that N2O emission flux after C2H2-inhibition ranges from 0 to 1.17 gN m-2h-1, with an increase value prior 6 hours and slow down after that.