How much water for an individual plant of corn does cost? There is no conclusion so far worldwide. Many literatures have frequently cited the number of "200kg" as the whole water consumption for an individual plant of corn in entire growth period. In the monograph of "Corn Cultivation in China", the water consumption of corn by transpiration is 80kg/plant, which is two and half times difference with the former number mentioned. By analyzing the data collected at the Yucheng Comprehensive Experimental Station, CAS, the author studied the water consumption for an individual plant of corn and the average total water consumption (including transpiration and evaporation among plants) under the natural growth condition. The following results were concluded: 1) Water consumption for an individual plant of spring corn is about 100kg/plant and transpiration is about 60kg/plant. 2) Total water consumption for summer corn in North China Plain is 50-80 kg/plant and transpiration is 30-40 kg/plant. 3) Water condition in soil has no great influence on water consumption for an individual plant of corn unless the long-term drought happening. 4) The density of corn planting impacts the water consumption greatly. When the density of corn planting increased from 50,000 plants/ha to100,000 plants/ha, the total water consumption increased only 13.18%. Meanwhile the water consumption for an individual plan decreased by 44.48%.

Owing to the effects of changing environment,such as human activities and climate,the natural annual runoff series for water resources evaluation calculation lost their consistency.In order to adapt to a changing environment demand for inconsistent annual runoff forecast,multi-level recursive method is applied.Different from previous mathematical statistic method with fixed-parameters,the multi-level recursive method is the one just dealing with the time-space variation system.The dependability of forecasted results will be enhanced because the regime of runoff is forecasted based the time-varying parameters forecasted in the model.The paper will illustrate the method by taking Zhuqi station of Minjiang River as an example,and the results will provide scientific basis for planning water use in the future.

通过农田样方观测与实验分析获得主要农作物的含碳率、经济系数、果实水分系数，再根据盐亭县近55年来(1949~2004年)农作物产量与耕地面积的相关数据，估算了该区农田生态系统植被碳储量与碳密度的动态变化。结果表明，近55年来该区农田植被碳储量和植被碳密度都有一定程度的提高，具有碳汇效应；但植被碳储量和碳密度很不稳定。植被碳储量以大春作物为主(占总碳储量的70.80%)；近期大春作物的比重略有下降，而小春作物所占比重则略有上升。今后该区应加强农田基本建设，维持农业生产和农田植被碳储量的稳定；改进农业生产技术和管理水平，提高作物单产、农田植被碳储量和碳密度；适度扩大水稻、马铃薯和油菜等作物的种植面积，稳定小麦播种面积。

Grassland is worldwide common pool resource. Existing studies on grassland degradation focuses in particular on technical solutions, with little attention to the institutional and policy driving factors of herders' behavior and the resulting in environmental effects. This may explain why the degraded grassland area is still expanding at a rate of about 2 million ha per year, despite the huge efforts made by the Chinese government at different levels to control grassland degradation. By analyzing data from 231 households from 17 counties of 6 provinces in western China and field survey information around Qinghai Lake collected in 2006 and 2007, this paper gives some interesting insights into how the institutional, policy and market factors drive the main and basic decision-makers on rangeland management in western China, and what the resulting environmental consequences are from the herders' activity choices under the prevailing rangeland property rights. Based on the main findings, policy implications can be suggested: when managing rangelands towards degradation alleviation, government's support on financing fencing, shed construction and forbidden grazing are very needed by the micro decision-makers. Policies that can help herders to be more likely involved in off-farm employment and to increase their income are desirable. In addition, to reduce the population pressure on rangelands is undoubtedly an effective way of alleviating degradation.

Three types of modern blowouts including simple blowout,compound blowout on level grassland and simple blowout on stabilized dune are identified in sandy grassland of Hulun Buir.We investigate the morphology and vegetation distribution of sand deposit of blowouts and the results indicate that the distribution of plant species has a characteristic of zonation and species vary with the morphology and scales of sand deposit.The projected configuration of sand deposit of individual blowout on level grassland is tongue-shaped.From the edge of blowout to primary grassland there are three regular crescent-shaped plant zonations that were sequentially dominated by the species of Agriophyllum pungens,Agropyron cristatum and Thymus mongolicu with sand transport direction.The depositional area of combined blowout are dismembered by the dune with slip-face,bare tongue-shaped sandy zonation,crescent-shaped plant zonation of Calamagrostis epigejos following wind and stripped zonation dominated by Agropyron cristatum which are distributed in the two-sides of the two zonations on level grassland.On stabilized dune the bare depositional area of blowout that is tongued-shaped passes through the zonations of Rosa davurica and Caragana microphylla that grew on dune before the appearance of blowout and extends to primary grassland.The leeward of bare depositional area is occupied by crescent-shaped zonation of Calamagrostis epigejos.Analyzing the factor of vegetation zonation,we found there is a cubic equation correlation between Shannon-Wiener index and burial depth of sand,which suggests that the depth of deposition may be the major factor in zonation.These results demonstrate that the vegetation zonation is induced by sand-wind activity on sandy grassland.With the expanse of temporal and spatial scales of sand deposit of blowout,the primary grassland vegetation will degrade to sand vegetation in converse succession.

气候变化的影响导致发展投资的效率和效益产生风险，其潜在的影响会阻碍中国经济和社会的发展。论文开发了一个综合评估工具，旨在评估气候变化对工程项目的影响以及适应性措施的经济效益，并将这一分析框架运用密云水库水供给项目的评估。 结果显示未来气候变化情景下，密云水库水供给量将会受到极大影响。而收益-成本分析和多目标分析结果显示，采用水田改旱地、引滦入潮、污水处理等适应性措施，在技术上和经济上将是可行的。图4表3参22

文章提出了利用搭载在欧洲第二代静止气象卫星上（MSG）的SEVIRI传感器数据估算裸土区热惯量及地表热通量的方法。首先，文章根据Jiang(2006)提出的方法，结合MSG－SEVIRI可见光及热红外数据，获得了间隔15分钟的地表温度数据；其次，利用日出与日落间的时间段及相应的地表温度和平均夜晚净辐射，估算了热惯量。在热惯量估算过程中，考虑到在整个夜晚，只能够获取两条大气廓线，所以作者用两种方法估算了平均净辐射。一种是以18时和24时的平均净辐射作为整个夜晚的净辐射；另一种是假定夜晚净辐射是时间的线性函数，通过这个函数关系得到各个时刻的净辐射，进一步得到不同时段的平均净辐射。基于两种估算夜晚净辐射的方法，文中分别计算了固定时间段及变化时间段的热惯量。最后，结合地表温度的余旋周期函数和前面所估算的热惯量，估算了地表热通量。通过三个试验点的两天数据对此方法的验证表明，变化时间段方法估算的热惯量比固定时间段方法估算的热惯量更为稳定，同时，这3个位置的地表热通量较高，最高达到了300W/m2。图2表5参12

The sea area is an essential basic resource of China just the same as the land, furthermore, the sea area is also of great significance to the economy, environment, national defence and so on. Because of the lack of virtual monitoring of the sea area usage in the past, the sea area managers could not accurately know the trends of the sea area usage, so it was very difficult for them to make reasonable management decisions, this problem has resulted in lots of natural disasters relating to marine resources and environment. Taking the speciality analyse of the sea area usage as basis and the correlative monitoring pattern as reference, this paper discussed the pattern of the sea area usage monitoring system in China in both aspects of technology and operation. For the first time, the primary conceptual framework of the dynamic sea area usage monitoring system was formed in China.

Lying between 80.33°-94.93°E and 28.76°-36.49°N, the alpine pastoral area of northwestern Tibet is known as the ridge of the roof of world with a mean elevation of 4500 m. As an alpine pastoral area, the animal husbandry faces the dual pressures of both gaining the yield and protecting the pasture. The environmental condition of this area has significant effect on the main rivers, climate and eco-environment of Tibet and the whole country, even on the globe for its rigorous natural condition and fragile ecosystem.This study selected vegetation cover as the main evaluation index, and analyzed the present situation of grassland degradation and it’s mechanism of the alpine pastoral area in northwestern Tibet, based on the remote sensing data such as NDVI data derived from NOAA/AVHRR with a spatial resolution of 1 km of 1992-2005 and from MODIS with a spatial resolution of 0.5 km of 2002-2005 respectively in this area, in combination with investigation data of the actual condition of grassland resources completed according to the background material of the end of the 1980’s. The grassland degradation processes and their response to climate change during 1971-2005 were discussed and analyzed systematically in the study using meteorological data.The results show that grassland coverage rank degree presents normal distribution with ground vegetation being sparse as a whole in this region. According to the present degenerated situation, the total degenerated grassland area is 14.19×10⁴km² , occupying 39.64% of the region’s total natural pasture area. Of which light degenerated area is most extensive, being 65.96%, moderate and heavy degenerated areas are 25.20% and 8.84% respectively of the total degenerated grassland area.From the analysis, we can conclude that the direct factors related to grassland degeneration in the study area are climate change for the annual temperature increasing with cess precipitation in recent years in Naqu county. The indirect factors are over-grazing and human activities. For example, the overload rate reaches 59.18% as a result of domestic animal’s massive increase, thus bringing increasing pressure on part of pasture, and causing grassland degeneration and more and more serious desertification phenomenon. In addition, population increase and frequent human activities also bring serious damage to the grassland.

In the regions short of water, the adjustment of cropping structure is also an important measure to save water in agriculture besides water-saving irrigation techniques and cultivation techniques. Considering the harmonious development of economy, society and ecology, the thesis established a multi-objective fuzzy optimization model for regional water-saving cropping structure which conquers the limitation that economic benefit is regarded but social and ecological benefits are ignored in the previous studies. The multi-objective fuzzy optimization model is applied in the study for water-saving cropping structure adjustment in North China where the water scarcity is very serious. The result of calculation presents an optimized schedule of water-saving cropping structure in 2010 and 2030. The planting proportion of crops with high water consumption is reduced and that of low water consumption was increased in the schedule, and water use efficiency is improved gradually.

After eight-year study on effects of soil and water conservation measurements which were alley cropping,cross channel and cross planting on sloping land in Guizhou,the results showed soil erosion on the bared sloping farmland was very serious.The runoff reached 4044.4 m³/ha·a and the soil loss reached 172.4t/ha·a on it.The topsoil (15cm) will be eroded and the productivity of soil will be lost after 12 years in case of such erosion.Cross channel measurement on sloping land could reduce runoff by 702.6m³/ha·a and soil loss by 19.2t/ha·a compared with cross planting measurement,but the crop yield and income were low since the cross channel occupied much more area of land.Alley cropping measurement could reduce runoff by 345.3 m³/ha·a and soil loss by 21.0t/ha·a in comparison with cross planting measurement.Although parts of land were occupied by alley crops,the crop yield did not reduce.Soil pH,soil texture and nutrition contained in top soil were enhanced and the soil erosion rate was further lower than soil weathering rate under alley cropping measurement.Combined with land cultivation, the sloping land could be terraced at a speed of 17.5cm per year and slow down the sloping at a speed of 1.1°.The sloping land to be terraced and to be cultivated sustainably can be achieved under the alley cropping measurement finally.

The Ecological Footprint (EF) is a valid method for measuring sustainable development through ecological impact. It has gained much attention in academic, policy-oriented and popular literature since its introduction in the mid-1990s. However, only few studies have addressed the problem of EF in the realm of long time series prediction with nonlinear dynamic model. The fluctuant cycles of China's per capita ecological footprint and biocapacity from 1961 to 2005 are decomposed and picked-up based on the empirical mode decomposition (EMD) method in this paper. Nonlinear dynamic prediction models are presented with the cycles, and per capita EF and BC in China are predicted from 2006 to 2015. This research could be meaningful for predicting regional sustainable development status; at the same time, we hope it would provide new access to effective methodology in predicting and interpreting the EF in long time series.Over last 44 years, the obvious undulation cycles of per capita EF growth in China are 4.3 years, 14.3 years and 17 years. Per capita BC growth in China is 3.5 years, 8.8 years, 17.7 years and 44 years. Per capita EF would decrease from 1.636gha in 2005 to 1.366gha in 2015 and per capita BC in China would increase from 0.925gha in 2005 to 1.108gha in 2015 if their average annual change rates are constant. Per capita ED in China would be 0.258gha in 2015. Therefore, China could denote sustainability at the global level with the growth of economic development, technology advancement, and standard of living enhancement.

Essential oils are mixtures of different volatile aromatic compounds extracted from plants. Since the discovery of their antifungal and antimicrobial properties, preparations of essential oils have been applied in pharmacology, medical microbiology, phytopathology and food preservation. Nowadays, the problem of environmental pollution and ecological environment destruction has been more and more serious. The study of how to utilize the plant resources' environmental effect has become an important field of the plant-resources utilization, and it also has been an important subject in academic field. With the increasing public concern on the level of their effects about environment, Fortunella calamondin Rutaceaei was used as an example by examining its anti-bacterial and anti-tumor activity in this paper. As the oil’s antifungal activity is a basic research work for the application of its environmental functions of essential oils, the study concerning the composition of essential oil from Fortunella calamondin is very limited. At first the volatile oil form its leaves was obtained by steam distillation, then its chemical constituents were analyzed by GC-MS. After that biological activity of the volatile oil was screened with microbiological method and Alamar Blue method. With the analysis of its constituents and biological activity of volatile oil from the leaves of the Fortunella calamondin, 23 compounds were identified, showing 99.578% of the total contents; the tested Escherichia coli, Staphylococcus aureus and Rhodotorula glutinis showed great sensitivity to the volatile oil, and the volatile oil could also obviously inhibit the growth of cultured tumor cells. And the inhibitory effects on the cell viability were obviously dose-dependent with a inhibition rate of 82.56% at a volatile oil concentration of 0.1g/L.

Based on the analysis of nearly thirty years meteorological and hydrological data (1970-2002) and remote sensing data of the 1980s and the 1990s, SWAT model (Soil and Water Assessment Tool) developed by USDA Agricultural Research Service (ARS) was adopted to study the change of the eco-hydrological characteristics in the Jinghe River Basin under the conditions of climatic warming-drying trend and aggravated human activities. After model validation and field verification, our results showed that the model SWAT could precisely predict the eco-hydrological processes in the Jinghe River Basin. Results showed that from the 1980s to the 1990s the mean annual precipitation decreased, especially in July, August and September. Affected by climate warming-drying trend and land-use change, the mean annual runoff reduced 8.92 m³s^-1. By respectively fixing the climatic factors and the land-use factors in the Jinghe River Basin, and putting the simulated scenarios into the SWAT model, the effects of climate change and land-use change on the mean annual runoff in the Jinghe River Basin were obtained. From the 1980s to the 1990s, the climatic warming-drying alone could reduce the mean annual runoff by 28.08 m³s^-1, which is about 314.80% of the actual runoff reduction. Meanwhile, the land-use change alone could increase the mean annual runoff by 26.57 m³s^-1, which is about 297.87% of the actual runoff change from the 1980s to the 1990s. Both the climate and land use changes significantly affect the runoff in the Jinghe River Basin.

Using the data of remote sensing of lakes from EOS-MODIS satellite and climate,frozen earth by monitoring from 2001 to 2006 in the headwaters of the Yellow River, this study analyzed the dynamic change of the high and chill lakes in the concerned region since the 21st century, described the developing background of the climate and frozen earth since the observation with apparatus, and then revealed the response to changes of the climate and frozen earth environment in terms of the area and the number of the lakes. The results indicated: the latest fluctuation coming from the headwaters of the Yellow River was an unanimous indication of the increase in area and quantity, which was more remarkable in the earlier flood period than in the later, and the change of the lakes in quantity was most obvious; the large background appeared in the last 52 years, including the increase in temperature, precipitation and evaporation, but the chief climatic characteristic was warm and moist since 2001,at the same time, the evaporation had been lessened apparently, and the thickness of the frozen earth had been decreased and the frozen time shortened due to the warmer climate; the lakes expanded and the number increased, at this time, the precipitation increased, evaporation decreased and the frozen earth deteriorated, which reinforced the melting of groundwater, all of these were the direct result of the changes of climate and frozen earth environment.

With the subscription on the Convention Concerning the Protection of the World Cultural and Natural Heritage and going deep into the conservation and management, China’s natural heritage movement flourished. But the conservation is not ideal. On the basis of the extensive information collecting, the principle of integrity for the conservation of the natural heritage sites was put forward and the studies on the threats of worldwide natural heritage sites were carried out. It is confirmed that there is difference between the OECD and Non-OECD countries in the threats for those of the Non-OECD countries mainly include hunting, logging and poor management while the OECD countries are introduced species. Tourism pressure, mining and road construction are the common threats. Dam construction, natural disaster, and surrounding pollution may be the potential threats. The conservation status of China’s nine world natural heritage sites (five natural sites and four mixed sites) are also discussed. Among China’s threats of natural heritage sites, tourism pressure ranks first, and then management constrains, dam construction, road construction and natural disaster. The countermeasures for conserving China’s natural heritage sites are put forward: (1) from the point of theory, the theory on natural conservation should be reconstructed based on the principle of integrity;(2) from the point of practice, the threats of tourism development, dam construction and introduced species should be dealt with urgently;(3) from the point of institution, the authenticity and responsibility of the central government should be strengthened, the management system be consolidated, laws and regulations be formulated, etc.

论文提出了一个基于高时间分辨率静止卫星的陆面区域蒸散模型(a Land Regional Evapotranspiration Model based on High Temporal Resolution Geostationary Satellite Data, LREMHT)，该模型基于对地表温度日过程的傅立叶拟合计算感热通量，进而地面实测潜在蒸发的日总量及其空间分布对模型结果进行了验证，表明模型计算合理，可用于区域耗水模拟。利用该模型计算分析了春旱季节（2005年4月份）淮河流域蚌埠以上农业区的区域耗水时空分布格局，结果表明：①日内：耗水最低值出现在日出前后，最高值出现在正午能量交换最活跃的时刻；②月内：一日耗水最高值出现时刻逐步往后推移：上旬出现在11：00前后，中旬出现在13：00前后，而下旬出现在14：00前后；日总量呈现递增趋势；③区域耗水月总量在空间上呈现北高南低、西高东低的趋势，由东南向西北递增，西北农业区耗水量最高。图7表1参33

在气候变化对水资源影响评价研究中，统计降尺度方法通常用来解决空间尺度不匹配问题。在本文中，预报量采用海河流域上典型区域的11个气象站点1961~2000共40年的日降水资料，预报因子选自NCEP/NCAR的再分析资料，以及英国Hadlay 中心GCM模型在a2情景和b2情景下的大气变量，主要采用Statistical Down-Scaling Model（SDSM模型）进行海河流域日降水的降尺度研究。结果表明：①使用逐步线性回归方法(SMLR)，可以在广阔的空间范围内优选出具有一定物理意义的预报因子；②使用统计降尺度方法SDSM，采用不同的GCM资料，都可以较准确模拟降水的季节变化特征；③使用NCEP/NCAR再分析资料的降尺度结果优于Hadlay中心a2和b2情景下的，观测和模拟降水的相关系数分别可以达到93%和85%左右；④与现状年(1984~1993年)相比，未来(2011~2040年)的年降水总量大约会减少4％；降水峰值略滞后；降水时间更加集中；极端降水事件的强度加大；最大干天持续天数也变长。图3表5参32

Due to poverty in economy, serious soil erosion and shortage of rural household energy in loess hilly region of Gansu Province, excessive consumption of biofuel becomes an important driving factor of eco-environmental of degeneration. Data on rural household energy use was obtained by questionnaires in this research, and based on substitutable analysis, environmental and economic costs under different energy consumption structures were estimated by the quantitative model. Results show that one family consumes 2112.44 kgce and per capita 428.59kgce per year at present, an indication of a lower level of energy consumption. The total energy consumption cost of per household is 1925.65yuan/a, in which the environmental cost is 621.13 yuan/a and the economic cost is 1304.52 yuan/a. Commercial energy has been used widely. The per household cash payment is 536.51yuan/a that is 8.69% of the household net income. The full use of solar energy and biogas can obviously decrease the above-mentioned cost of energy consumption. Cash payout and gettable capacity of energy are the main reasons for the rural households to choose energy categories. To compare with the actual structure of energy usage, there are obvious differences on the total cost, the environment cost, economic cost and cash payout for households among the four substitutable structures. Each item of cost is lower when biogas and solar energy are used, so this structure is the primary direction for the future development of rural energy.

生态系统服务研究是当前国际上科学研究的热点和前沿。近年来我国生态系统服务研究取得了较快进展。为了全面认识与介绍国内生态系统服务研究的状况与成果，促进国际生态系统服务研究的交流与合作，论文首先回顾了我国生态系统服务研究的4个时期，并简要概括了所取得的成就和存在的问题，最后指出，中国生态系统服务的研究应该尽快由当前的概算式研究转向更深层次的研究，尤其要重点关注生态系统功能的基础理论研究、评估指标与方法的标准化、生态服务价值动态评估模型研究、评估结果在决策过程中的应用研究以及生态系统服务的市场化机制研究。

Glacier is an important kind of fresh water resources. The glacier change not only affects obviously water resources in and around mountain area, but also contributes greatly to sea level rise. Thus, it becomes the focus of attention. Reviewing international and domestic studies, this article puts forward that there is still a big gap between native research and foreign ones in scope and depth. Especially, there are few studies on the process and mechanism of melt-water production and forecast models are lagging behind in types, conceptual framework and technical means. The impact of west glacier water resources change on socioeconomy and ecological environment must be taken into consideration in the process of Western Development, and it is urgent to strengthen related monitoring and researches.

There is a certain impact and influence on the ecological environment when human utilizes natural resources and obtain access to the ecological services function nature provides. Ecological footprint indicator is such an integrated indicator to measure the use of human resources and the effects on the ecological environment. The ecological footprint is not only a means to record the process of the survival and development of mankind’s ecological resources of changing history, but also embodies the scale of economic development and the evolution of consumption levels for each stage. Through building the decomposition model of ecological footprint, variable of ecological footprints of China during the period from 1990 to 2004 was decomposed to three different changing effects, namely GDP, structure of industry economy and ecological footprint identity of industries, and each decomposition effect was measured and analyzed in this study.The results show that: 1) Varied factors impacted together on variation of ecological footprints and these factors exerted different effects on the variable of general ecological footprints in different periods of time. From 1990 to 2004 the total footprint changes always show an increasing trend. Inter-annual change’ mean of ecological footprint is 2.1082×10⁸ha, thereinto, the scale of economic development, the industrial structure and the identity of industries ecological footprint have different contributions to the change, being 2.1082×10⁸ha, -0.6029×10⁸ha and -0.4398×10⁸ha respectively. 2) Growth of GDP is a drive to the increase of the general ecological footprints, while the change in industrial structure and increase of ecological footprint identity of industries constrain the growth of the general ecological footprints variation on the contrary. 3) It is a key in depression periods of time to reduce growth of ecological footprints by adjusting structure of industry economy and improving identity of ecological footprint. This research will promote understanding the theory about harmonous development stratagem and development occasions, and possess reference value by all means to the adjustment of policy of industrial development and the study of sustainable development relatively.

根据番茄的生长发育特点，分别以50%、60%、75%田间持水量作为苗期、花期、结果期的土壤水分下限，按照不同的土壤水分上限设置不同的灌水量处理。对番茄不同生育期的灌水量、耗水量、产量、水分利用效率及其关系进行了研究。结果表明，灌水控制上限和下限之间存在交互效应，番茄灌水量、耗水量与其具有显著的正相关性；当灌水控制下限一定时，耗水强度和耗水模数随灌水控制上限的减小呈降低趋势；番茄苗期、花期和结果期的灌水控制上、下限(占田持)分别控制在50%～65%、60%～75%和75%～85%为宜。

利用构建的石油安全评估指标体系，结合统计数据，对中国1992~2002年的石油安全态势进行了定量评估。评估结果表明：中国在1992年至2002年评价期内的石油安全态势处于一般状态，得分大致在5.04（1993年）到5.66（2002年）之间（总分在0~10之间），变化幅度为0.62，不超过1，石油安全程度基本处于略有上升态势。

Global warming affects regional sustainable development but there has been lacking in an appropriate approach to assess the impacts. By applying Arc/GIS and Visual Foxpro technologies, this study performs systematical simulation and analysis of the variations in the monthly cropland water balance for 12 major crops in Northwest China over the last 40 years (1960-2000). For 313 counties in the region, it shows that the precipitation and soil water are generally unable to meet the water requirements of the crops. The deficit of cropland water tends to increase from the southeast to the northwest and from mountains to lower basins. By analyzing the anomaly percentage of cropland water balance, this study shows that during the last 40 years, the western part of Northwest China, mainly the Xinjiang Uygur Autonomous Region, has shown a moderate increase both in temperature and precipitation, a slight shift to a warm-wet pattern in climate, and a moderate decrease in water deficit. In contrast, the central and eastern parts of the region have encountered a moderate increase in temperature, a relatively significant decrease in precipitation (especially in recent 10 years), and a moderate increase in water deficit. Furthermore, this study classifies the region into 13 agro-ecological zones and examines the variance of cropland water balance over the last 40 years through analyzing the variation of C_v in these zones. It is shown that in Hexi Corridor of Gansu and Xinjiang Uygur Autonomous Region, C_v is the lowest (<0.10), while in hilly areas around Sichuan Basin C_v takes the highest value of 2.1. In most parts of Northwest China, a significant positive correlation between cropland water balance and precipitation can be identified (r=0.85), indicating that precipitation has been a dominant factor affecting cropland water balance. The correlations of cropland water balance with the maximum and minimum temperature are less significant, particularly the latter. Cropland water balance is also closely related with evapotranspiration (r=-0.88), demonstrating the impact of climate change on cropland water balance.

The terrestrial ecosystem is the supporting system for the biosphere as well as for human being’s survival and development. The research of net primary productivity will help in understanding the amount of carbon fixed by terrestrial vegetation and its influencing factors. The purpose of this paper was to find out the NPP spatial and temporal dynamic distribution in the Heihe Basin during 1998 to 2002, and analyze vegetation’s feedback on climatic conditions. The CASA (Carnegie Ames Stanford Approach) was selected to calculate NPP. The SPOT/VEGETATION, land use/land cover, meteorologic data and soil attribute were collected. The results validate the CASA’s applicability in inland watershed scale. The 5 years NPP variation in the Heihe Basin was monitored by the model. The upper, middle and lower reaches of the Heihe Basin contributed ~50％,~30％ and ~20％ to the total NPP of the basin respectively. From 1998 to 2000 the NPP decreased and then increased from 2000 to 2002. The NPP in the upper reaches of the basin was mainly controlled by heat because the vegetation seldom faced the problem of moisture shortage, and the NPP increased when temperature increased. The NPP in the middle reaches of the basin also had good relationship with heat. The reason was that the cropland plants could get adequate water supply when necessary because there were many reservoirs set up for irrigation system and factories. The NPP variation in the lower reaches of the basin was larger than upper and middle, and had weak relationship with meteorologic factors. The vegetation endured drought throughout the year and high temperature in summer. It seldom obtained water supply, even from the oasis along the river because of water interception by the middle reaches reservoirs. Desert plants mainly lived on groundwater to survive in case of drought.

East Chongming salt marsh,located in the east of Changjiang Estuary, is a large wetland, which exhibits a variety of macrobenthos. Understanding the food sources and trophic level of macrofauna is a foundation to study the material and energy flux in the ecosystem. In this paper, stable carbon and nitrogen isotope ratios of organic matter sources and consumers were investigated in the summer of 2005 in the differents living environments of East Chongming salt marsh. It is found that the δ¹³C and δ¹⁵N values of surface sediments vary in different tidal levels, with δ¹³C from-21.3‰ to-24.2‰ and δ¹⁵N from 4.6‰ to 5.6‰. These stable isotope values suggest that sediments not only contain the extraneous materials but also are influenced by the autochthonous organic matter. Our data displays that the dominant macrophytes Scirpus mariqueter and Phragmites australis are the main allochthonous sources of sedimentary organic matter and the extraneous source is suspended particulate organic matter. The dominant macrophytes Scirpus mariqueter and Phragmites australis are C₃ plants, and Spartina alterniflora is C₄ plant. The stable isotopes are variable among different tissues of plants, especially of Phragmites australis, which suggests that care must be taken and the isotope value of leaves may not be used as that of the whole plant when estimating the food sources. The macrofauna shows a wide range of δ¹³C, with overall δ¹³C values between -23.6‰ and -14.7‰, which suggests significant difference of food sources. As a whole, sedimentary organic matter seems to be food base for macrofauna, while the dominant macrophytes of salt marsh appears to play a negligible trophic role. The nitrogen isotope can reflect the trophic level of macrobenthos. It is calculated that trophic level of macrofauna in East Chongming salt marsh is between 2.0 and 3.7, and thus the invertebrates are primary and secondary consumers.

A spatial interpolation by combining the Barnes scheme and precipitation frequency is developed according to daily rainfall characteristics. With the interpolation, a daily grid precipitation dataset, which covers a domain ranging from 99° to 123°E and 24° to 36°N and has a 0.1 longitudinal and latitudinal resolution, is obtained by utilizing daily precipitation data of basic observation stations in China and ordinary observation stations in 15 provinces in the vicinity of the Changjiang valley during 1971 to 2005. The error estimation of the grid dataset is accessed through cross-validation statistics. The statistics show the combining scheme for daily precipitation interpolation is not only with small mean biased error, mean absolute error and mean square error as well as high correction coefficient, but also close to the observation variation and frequency. The primary analysis indicates that the datasets provide a finer precipitation distribution. And the years with the greatness (smallness) of the annual area precipitation, in particularly the summertime area precipitation, correspond to the distinguished flooding (drought) processes occurred in the Changjiang valley. So the daily precipitation datasets can be applied to meteorology and relative field with realistic, continuum grid data.

Climate warming was significant in recent 20 years in Heilongjiang province. Many researchers found that increase of heat was beneficial to agricultural production except for drought and meteorological disasters in this province. The existing researches neither fully considered the spatial difference nor the impact of economic factors. In order to disintegrate physical and economic factors in grain yields more reasonably and analyze their different impacts on changes of yields in Heilongjiang Province, we collected the data of agricultural production (labors input, power input, irrigation input, fertilizer input, agriculture output, grain yields, and sown area of crops)from 1986 to 2000 in 79 counties of Heilongjiang Province, based on which grain yield (Y) was divided into climatic yield (Yc) and economic yield (Yt) by the method of Cobb-Douglas Production Function. Daily temperature and precipitation of 30 weather stations were used to calculate accumulated temperature ≥10℃ and precipitation during growing season. EOF method was applied to analyze the spatial and temporal characteristics of grain yield, climatic impact index (Yc/Yt), accumulated temperature ≥10℃ and growing season precipitation whose relationships were also considered. The results showed that grain yields of the whole province steadily increased during the past 15 years. Fertilizer was the leading driving force of economy that influenced the economic yields. Labors and R&D Fund Input in agriculture were not as important as fertilizer input. At the same time, power and irrigation input played the relative less roles in so many economic factors. Climate warming was significant from 1986 to 2000 in Heilongjiang Province. Accumulated temperature ≥10℃ increased 21-27℃ per year, benefiting agricultural production in most parts of the province. However, no obvious precipitation trend of growing season was found, and the change of precipitation didn’t essentially affect crop yields. The climate impact index increased during 15 years with different temporal and spatial variations. From 1986 to 1993, accumulated temperature ≥10℃ increased more obviously in the northern and southwestern parts of the province than the northeastern and southeastern parts, which had greater impacts on crop yields. While the converse situation existed from 1993 to 2000. Accumulated temperature ≥10℃ increased much more obvious in the northeastern and southeastern parts than the northern and southwestern parts, so did crop yields.

The traditional land-use statistics based on districts can not represent the spatial differences of land use structure entirely. At first, the paper extends the algorithm of Statistical Information Grid-Based (STING) and then puts forward a kind of multi-grids land resources data structure according to the spatial difference of the regional land use structure. It’s theory and method can be generalized as follows:Because different land use researches and applications have different data requests, the land spatial data and other natural environment/socioeconomic data should be mutually matched conveniently. So according to a certain method the land resources data space needs to be divided non-uniformly into more layers which can be called multi-grids land data structure to satisfy the distribution of data items. Namely the region with crowded data (land use structure is fine) should contain the massive small grids, but the region with sparse data (land use structure is extensive) only includes a few big grids. Through analysis the landscape multiplicity is selected as a quantitative index for building such a multi-grids land data structure and the expression of landscape multiple index is:H=-∑(S_i/∑S_i) ×log₂(S_i/∑S_i) (i=1,2,…,m)where H is landscape multiple; m is the number of the type of landscape in the region; and S_i is the area of one land use/cover type. RS images contain rich land use/cover information, so the land classification results using RS images can be applied to figure out the value of 'H’ index. In the paper the experiment data are TM images of Wuhan district(1998-10), with an overall precision of land use/cover classification result being 89% and KP value 0.87. Taking the entire experimental land data space as the root point the quad tree division is done. In advance a threshold named N of 'H’ should be decided (for example taking one half of the H_max as a threshold) to judge whether a grid point continues to be divided or not. If the 'H’ value of a grid point is smaller than N, then the division stops otherwise continues. In the experiment a multi-grids structure with 16 layers and 2728 leaves was obtained. The multi-grids land resources data system provides a good data index structure for further data analysis and researches, so according to different applications it can be filled with many kinds of data and it’s structure can be changed conveniently. For example, the traditional statistics of population density is spot population density based on such a premise hypothesis that population in one administrative region is even, but in fact it is uneven because of natural/social resources’ uneven distribution. Based on the multi-grids land data structure, an experiment on simulation of surface population density in Wuhan district was made. Different saturated red colour was used to indicate the different population ranks and the simulation of population density spatial distribution in Wuhan district was obtained.The simulated population density shows that the multi-grids land data structure can integrate land use data with other socioeconomic statistics conveniently and neatly to complete some simple land data mining tasks such as the effective data computation or analysis, and can reflect the land use/cover status of one region.