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    Resources Utilization and Management
  • Resources Utilization and Management
    Research on the Long-term and Short-term Dynamic Relationship Between Carbon Forestry Development and Economic Growth—Based on the Provincial Panel Data of China in 1998－2010
    LI Peng, ZHANG Jun-biao
    2013, 28(11): 1835-1845. https://doi.org/10.11849/zrzyxb.2013.11.001
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    Forests are important terrestrial ecosystems, researching on the long-term and short-term dynamic relationship between carbon forestry and economic growth is an effective way to promote the balance of forest ecosystem and sustainable economic growth. This study measures forestry carbon of China's 30 provinces in 1998-2010 (not including Chongqing, Hong Kong, Macao and Taiwan due to no data), and adopts the panel data unit root test, cointegration test, error correction model of causality test, and impulse response measurement technology to inspect and forecast the dynamic relationship between the ecological contribution of forestry carbon and the economic growth. The empirical results show that there exists a cointegration relationship between the forestry carbon and economic growth, and a short-term correction effect as well. When economic growth deviates from the long-term equilibrium, adjustment will be made to an equilibrium state with 19% of power, and Granger causality test and VAR panel model results verify the interactive relation. Impulse response function displays economic growth produces weak positive impact on the stability of carbon forestry development, and carbon forestry development produces positive significant ecological impact on the stability of economic growth in the short term. According to the above analysis, countermeasures and suggestions were proposed for increasing financial policy support, tree species and forestation pattern combination, establishing and improving the carbon measurement and monitoring mechanism, perfecting investment and financing channels, strengthening forest management, etc, so as to promote China's forest ecosystem sustainable economic development.
  • Resources Utilization and Management
    An Analysis of Influencing Factor on the Increase of CO2 Emission Because of Energy Consumption in Beijing—Based on Three-level Nested Method of I-O SDA Technique
    ZHANG Wang, XIE Shi-xiong
    2013, 28(11): 1846-1857. https://doi.org/10.11849/zrzyxb.2013.11.002
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    An extension model of buys in and import-competition economy-energy-CO2 emission input-output model was designed using three-level nested method of Structural Decomposition Analysis to decompose CO2 emission increase in Beijing during 1997-2007 from three aspects as integral, industries and industrial sectors. The research results are following: The main factors for CO2 emission increase were the effect of economic scale expansion such as consumption, investment, export and sell, their contribution rate was 272.46%; the dominant factor for reducing CO2 emission is the changing effect of energy consumption intensity, its contribution rate was-237.13% ; in effect of economic scale expansion, sell and consumption became the main contributors for carbon emissions increase with over investment and export reaching 8403.38×104 t; since the new round industrialization with "high carbon" features, the increase of CO2 emissions in 2002-2007 was 86.41% of the total emissions of 1997-2007; service industry was the first large sector of carbon emissions increase, its contribution rate was 75.93%, but industrial carbon emissions increase had surpassed service industry by 1036.40×104 t during 2002-2007; as for industrial branch aspects, heavy manufacturing was the key industry of carbon emissions increase, and its contribution rate was 1030.76%; energy industrial was the major industry of carbon emission reduction, and its contribution rate was-992.81% ; the effects played different roles and were not stable enough in different industries or different industrial sectors in each period.
  • Resources Utilization and Management
    Is the Quality of Economic Growth in Concordance with Energy Efficiency?
    CHEN Xi-hong, LI Chang-qing, ZHANG Guo-rong, JI Hui-lin, BAI Shuang-zhu
    2013, 28(11): 1858-1868. https://doi.org/10.11849/zrzyxb.2013.11.003
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    This paper proposes the concept of society-wide energy efficiency from the perspective of society-wide energy conservation, and constructs the index system in the quality of economic growth. Based on a panel data at the provincial level from 1997 to 2007, we employ the method of Malmquist DEA to measure and factorize the general index of technology progress, and analyze the mechanism of interaction between the quality of economic growth and energy efficiency. The empirical results suggest that the quality of economic growth and energy efficiency do not always change in the same direction. Specifically, improving environmental quality, technology progress and upgrading industrial structure may promote energy efficiency; but increasing the proportion of exports and improving the quality of life may embarrass energy efficiency. The effects of technical progress, technical efficiency, pure technical efficiency and scale efficiency on energy efficiency are positive. The contribution of technical progress to energy efficiency is smaller than that of technical efficiency. Pure technical efficiency and scale efficiency declined from 1997 to 2007, which weakened the positive effect of technological progress. The national energy efficiency growth slowdown is mainly due to the decline of the national pure technical efficiency, which is caused by the decrease of pure technical efficiency of the central and western regions.
  • Resources Utilization and Management
    Decomposition of Factors Contributed to the Increase of China’s Chemical Fertilizer Use and Projections for Future Fertilizer Use in China
    LUAN Jiang, QIU Huan-guang, JING Yue, LIAO Shao-pan, HAN Wei
    2013, 28(11): 1869-1878. https://doi.org/10.11849/zrzyxb.2013.11.004
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    Intensive use of chemical fertilizer has largely contributed to the increase of China's agricultural production in the last 30 years, while in the same time, the excessive use of chemical fertilizer has also led to serious negative impacts on environment. There is a lot of debate on what causes continuous growth of fertilizer use in China and what would be the trend of future fertilizer use in China. Using the official statistical data of fertilizer use, this paper decomposed the factors that led to the increase of chemical fertilizer in China in the past 20 years. The results showed that the growth of fertilizer intensity is the major contributor to the overall growth of fertilizer use. But since 2007, the contribution from fertilizer intensity has decreased, while the expansion of cultivated area has begun to play a big role. On the basis of decomposition results and CHINAGRO model, this paper projects the national and provincial levels of fertilizer use in 2020. The results showed that in the next 10 years, China's total fertilizer use and per unit sown area of fertilizer use will continue to increase, and keep higher than the international limited standard which is 225 kg/hm2 in a long period. The total fertilizer use and per hectare of cultivated land fertilizer usage in 2020 are expected to increase by 2% and 4.3% respectively compared with 2010. Per hectare of fertilizer use in Guangdong, Fujian, Tianjin and Beijing will be close to or more than 600 kg/hm2 in 2020, which will exert great pressures on environment of these regions.
    • Resources Economics
  • Resources Economics
    Negative External Effect of Farmers and Herdsmen’ Response to Government Leading Ecological Construction Projects：A Comparative Analysis of Mountain-River-Lake of Jiangxi and Three-River Headwaters of Qinghai
    SHAO Jing-an, SHAO Quan-qin, LU Qing-shui, HUANG Lin, KUANG Wen-hui
    2013, 28(11): 1879-1890. https://doi.org/10.11849/zrzyxb.2013.11.005
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    This paper selected two typical ecological construction projects as the object, i.e., Mountain-River-Lake of Jiangxi and Three-River Headwaters of Qinghai, to identify the negative external effect induced possibly by farmers and herdsmen' participation under the different ecological construction periods, using participatory rural appraisal method from farmers and herdsmen cognitive perspective. These results showed: 1) The direct negative externality resulted from farmers' behavior was easily adjusted in Mountain-River-Lake area, while that induced by herdsmen' participation was difficult to control and regulate in Three-River Headwaters area. 2) The potential negative externality of farmers' behavior was mainly driven by exogenous variable in Mountain-River-Lake area, e.g., migrant workers resulted in the increase of wild boar and forest fire, and the mountain trees suffered massive damage due to an increase of rats induced by snake hunting. Although herd structure and adult female ratio were also affected by grassland degradation in Three-River Headwaters area, the relationship between them and grassland degradation presented stronger endogenous. 3) Farmers could understand more clearly strong probability negative externality resulted from farmers' management behavior intervention, and evaluate it scientifically and qualitatively in Mountain-River-Lake area. Strong probability negative externality caused by herdsmen' engagement in secondary and tertiary industries could become income gap in Three-River Headwaters area, via to the differences of herdsmen' culture, ability, customs, and so on. Under such environment, it was easy to return herd for herdsmen. 4) Small probability negative externality induced by farmers' behavior adjustment in Mountain-River-Lake area was determined by forest which was a disadvantaged industry. Namely, it was driven by climate change, and possessed irresistible features. But, to some extent, the disaster losses caused by it could be relatively reduced, if appropriate management behavior was applied in the early stage. In Three-River Headwaters area, it was brought by herdsmen' behavior adjustment and was affected by the external economic environment or introduced industrial status. And, to a certain degree, it could be regulated. The policy implication of this paper aimed at identifying the references of farmers and herdsmen' adaptability behavior adjustment, in order to reduce or mitigate negative external effect, in the process of two major ecological construction projects.
  • Resources Economics
    Farm Households’ Adoption Behavior of Environment Friendly Technology and the Evaluation of Their Environmental and Economic Effects in Taihu Basin—Taking Formula Fertilization by Soil Testing Technology as an Example
    LUO Xiao-juan, FENG Shu-yi, SHI Xiao-ping, QU Fu-tian
    2013, 28(11): 1891-1902. https://doi.org/10.11849/zrzyxb.2013.11.006
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    Based on the data collected from 221 rice producing households located in the upper reaches of the Taihu Basin, this paper firstly analyzed driven forces that affect the farm households' adoption of formula fertilization by soil testing technology using the Probit model, and then evaluated their environmental and economic effects by estimating input demand and output supply functions, respectively. Research results indicate that younger households and households with better durable asset conditions and contacting more frequently with extension staffs last year are more likely to adopt formula fertilization by soil testing technology. While less and highly educated households are reluctant to adopt this technology. Formula fertilization by soil testing technology can indeed reduce chemical fertilizer use and increase rice yield. Keeping other variables constant, each 1% increase of the formula fertilization by soil testing technology adoption possibility may lead to 0.09% reduction of fertilizer use amount (about 0.45 kg/hm2) and 0.04% growth of rice yield (around 2.91 kg/hm2). In our research area, if all the households can apply this technology, the use of chemical fertilizer will further reduce 34.91 kg/hm2 and the yield of rice will increase 223.98 kg/hm2, indicating very good environmental and economic effects. However, the promotion of formula fertilization by soil testing technology processes slowly in reality, what's worse, the implementation of this project management is not standard enough either. It is therefore necessary to increase the technical research investments and strengthen the propaganda and training of formula fertilization by soil testing technology, meanwhile fully exert the role of the demonstration households, in order to promote thorough extension and proper implementation of formula fertilization by soil testing technology.
  • Resources Economics
    A Quantitative Study of Urban Economic Scale Constrained by Water Environmental Carrying Capacity
    LIU Chen-hui, SHEN Yu-tong, ZHOU Ming-yao, XU Hai-gang, YU Long
    2013, 28(11): 1903-1910. https://doi.org/10.11849/zrzyxb.2013.11.007
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    Environmental carrying capacity is an important constraint to regional sustainable development. It is the thresholds of the population size and economic scale that make the system of a regional environment support. In this article, a new method is proposed to study the threshold of urban economic scale constrained by water environmental carrying capacity. Regional water environmental carrying capacity can be quantitatively represented by the value of Gross Domestic Product (GDP), if the population size can be predictable in this region. This new method is primarily based on the Water Environmental Threshold Value Model, which is proposed for the first time in this article, as well as some statistical techniques. In this mathematical model, the threshold value of GDP constrained by water environmental carrying capacity at a regional level is a function of five independent variables: G=[(P + C)×kI + 0.1WI]/[kI×(1-RT)], where G denotes the threshold value of GDP at a regional level, P is the value-added in primary, C is the value-added in construction, WI is the goal of the total amount control of industrial pollutants, RT is the proportion of the tertiary industry in GDP, and kI is the amount of pollutant emissions per 104 yuan of industrial value-added. The statistical methods applied here include regression analysis, which is used for the computation of the parameters P, C, WI, RT, kI, and interval estimation, which is used for the analysis of the sensitivity and reliability of the model. Yangzhou City is taken as a case to compute the economic scale constrained by the water environmental carrying capacity in 2015. COD is chosen as a total amount control factor (COD≤56845 t/a). The values of P, C, WI, RT, and kI are 229.02×108 yuan, 228.45×108 yuan, 18132 t, 39%, and 0.39 (1.38) kg/104 yuan per unit of industrial value-added, respectively. The result of computation indicates that: 1) Taking into account the continuity of the policy of pollutant reduction (kI=0.39), the annual water environmental carrying capacity of Yangzhou City can achieve 8372×108 yuan in GDP, with a confidence level of 90% and a confidence interval of 7881×108 to 9030×108 yuan; 2) without considering the pollutant emission reduction policy (kI =1.38), the annual GDP at the regional level can reach only 2904×108 yuan; 3) When the total amount control goal is determined, the main limiting factors of economic growth are the pollutant emission intensity and the proportion of the tertiary industry. If the regional economic growth target touches 5070×108 yuan, then the COD emission intensity should be controlled to below 0.69 kg/104 yuan per unit of industrial value-added.
    • Resources Evaluation
  • Resources Evaluation
    The Inter-Intra Annual Climatic Pattern of Potential Evaporation in Beijing and Attribution
    ZHAO Ling-ling, XIA Jun, WANG Zhong-gen, LI Zong-li
    2013, 28(11): 1911-1921. https://doi.org/10.11849/zrzyxb.2013.11.008
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    Based on the metrological data in Beijing station during 1951-2009, this paper firstly uses the Penman-Monteith formula to estimate the potential evaporation. Then the climatic character istics in inter-and intra-annual potential evaporation are analyzed. The results show that at 95% confidence level, the trend in annual potential evaporation during 1951-2009 increases significantly. The trends of relativity humidity and solar radiation decrease, temperature increases, and wind speed shows no trend in Beijing station. The sensitivity to potential evaporation (ET0) from strong to weak is relativie humidity, temperature, solar radiation and wind speed. Considering the fluctuation variation pattern of climatic variables, the contribution of temperature, VDP, wind speed and solar radiation is 13%, 58%, 17% and 11% respectively. This suggests the fluctuation of climatic variables have great effect on the change pattern of ET0, especially the wind speed. In order to detect how climatic variables affect ET0, this paper uses the detrend method considering the inter-annual change pattern combined with sensitivity of climatic variables. The detrend analysis demonstrate that the increasing temperature and decreasing relativie humidity are the main cause for increasing potential evaporation. As to the decreasing shortwave radiation, the ET0 slightly decreases, but no change in its increasing trend.
  • Resources Evaluation
    Precipitation Variations and Its Impact on Water Level in the Lower Reaches of Jianghuai Basin：A Case Study in the Inner Lixiahe Region
    YE Zheng-wei, XU You-peng, PAN Guang-bo
    2013, 28(11): 1922-1934. https://doi.org/10.11849/zrzyxb.2013.11.009
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    Methods of precipitation concentration period and precipitation concentration degree analysis, classification analysis and wavelet coherence analysis are applied to explore the variations and relationship between precipitation and water level from 1957 to 2006 in the inner Lixiahe region, an area located in the lower reaches of Jianghuai basin. Results show that decreasing trends can be detected both in precipitation concentration period and precipitation concentration degree for the annual precipitation, it experienced an in-phase to anti-phase switch in 1980. Maximum days and contribution rate of higher grades of precipitation appeared in 1980s. Decreasing trend can be observed in the days of lower, middle and higher precipitation grades. However, precipitation contribution rate tends to be significantly higher in flooding years implying an increasing in precipitation intensity. Decreasing trend can be observed for the lower and the higher grades of water level days, but that it turns out to be increasing and decreasing trend for the lower and higher grades of water level contribution rate respectively. However, a significant increasing tendency can be identified for the middle grades of water level days and contribution rate with an implication that there might be an enhanced accumulation impact of middle precipitation grade on water level, this could be resulted from the negative hydrological effect of enhanced human activities. Precipitation contribution rate has more important impact on water level change compared to the precipitation days. A positive correlation can be examined between higher precipitation grade and water level days, while negative and positive correlation can be detected between lower and middle grade days of precipitation and water level respectively, and a similar phase relation can be found in grade total precipitation and contribution rate of water level. Furthermore, higher, lower and middle grade total precipitation exhibits an in-phase, anti-phase and weak phase relation with the corresponding water level respectively.
  • Resources Evaluation
    Spatial Distribution of Night Rainfall in Summer over China
    DUAN Chun-feng, CAO Wen, MIAO Qi-long, LIU Ke
    2013, 28(11): 1935-1944. https://doi.org/10.11849/zrzyxb.2013.11.010
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    Diurnal variability of rainfall is an important aspect of regional climates to fully understand the climate systems. When precipitation occurs regularly during particular time periods of the day the atmospheric system usually is characterized by conditions and physical processes that suggest strong convection during the favored periods. As one of the special characteristics of daily variation in precipitation, night rainfall is an unique and valuable agricultural climate resource. In this paper, the hourly precipitation data for 2046 automatic weather stations all over China from 2005 to 2007 provided by the National Meteorological Information Center was used to study the diurnal variations of precipitation in summer (from June to August) during 2005 to 2007. The temporal and spatial distribution of the night rainfall in summer over China was analyzed. Differences in diurnal variation of precipitation between the typical and the atypical rainfall regions were also compared. Results showed that the night rainfall occurred widely over China. The precipitation peaked mostly at afternoon (eastern China) and midnight (western China). The night rainfall appeared most obviously in the Tibetan Plateau, the Sichuan Basin, the Yunnan-Guizhou Plateau as well as the mountains and surrounding areas in the northern part and western part of China. The percentage of the hourly average precipitation in the nighttime for most parts of the Tibetan Plateau and the Sichuan Basin reached 60%, even up to 80% for individual stations. The percentage for most parts of the Yunnan-Guizhou Plateau was above 50%. However the night rainfall occurred rarely in areas south of the middle-lower Yangtze River. The percentage of the hourly average precipitation in the nighttime for such areas was mostly below 40%, especially only 20% for many areas of Guangdong and Hainan provinces. Nine typical regions were selected to further study the diurnal variation of precipitation in the night rainfall area. The precipitation occurred frequently in late night than in early night over most parts of China, except eastern part of the Tibetan Plateau and the Sichuan Basin. The diurnal variation of precipitation was also affected by topography. The precipitation peaked both at afternoon and night. Night rainfall in mountainous areas was related to mountain-valley wind circulation caused by thermal contrast, while precipitation peaked at afternoon due to thermal convection caused by solar radiation. The difference of night rainfall between plateaus and mountains may be related to large amount of cumulus cloud in summer.
  • Resources Evaluation
    Variations of Precipitation Stable Isotope and Vapor Origins Revealed by Deuterium Excess in Changsha
    HUANG Yi-min, ZHANG Xin-ping, TANG Fang-yu, WU Hua-wu, ZHANG Jian-ming
    2013, 28(11): 1945-1954. https://doi.org/10.11849/zrzyxb.2013.11.011
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    Variations of both stable isotope and deuterium excess (denoted as d) in precipitation as well as their relationship with precipitation, temperature and humidity were analyzed by using daily precipitation stable isotope data from January 1, 2010 to May 31, 2012. The results show that both stable isotopes and d in precipitation indicate obvious seasonal variation in the monsoon system, high value in the summer half year and low value in the winter half year. There are precipitation amout effect and humidity effect, in addition, anti-temperature effects in the summer half year and temperature effect in the winter half year. Considering both d and δD in precipitation with atmospheric humidity, we deduced that the main causation of stable isotopic variations in precipitation is related to the property of rainfall air mass. In the summer half year, the water vapor is transported by the southwest and southeast monsoon from low latitude oceans, with high humidity, low stable isotopic ratios and d owing to the rainout of vapor on the transport way. Then, in the winter half year, the vapor is primarily from the westerly transportation and the replenishment of reevaporated vapor in inland, with low humidity, high stable isotopic ratios and d values in precipitation.
  • Resources Evaluation
    The Dynamic Characteristics of Carbon and Nitrogen Storage in Phyllostachys edulis Forest with Operating Time
    LIU Guang-lu, FAN Shao-hui, GUO Bao-hua, DU Man-yi
    2013, 28(11): 1955-1965. https://doi.org/10.11849/zrzyxb.2013.11.012
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    In order to understand the variation of carbon and nitrogen storage and the ration of carbon to nitrogen of Phyllostachys edulis forest with different modes of operation and operating duration, this study was designed to test the dynamic characteristics of carbon and nitrogen storage by typical sample method in Yongan city, Fujian Province and Anfu County, Jiangxi Province. The result showed that the carbon and nitrogen storage decreased in P. edulis forest with fertilization and increased in P. edulis forest with reclamation. The carbon and nitrogen storage of soil layer was the largest, followed by the vegetable layer for both the moso bamboo forests. The proportion of soil layer carbon storage was 63.25%-86.32% and the vegetable layer was 13.17%-35.15%. The nitrogen storage of soil layer was 94.44%-98.15% and the vegetable layer was 1.62%-5.12% . The carbon and nitrogen storage of moso bamboo system was affected by the carbon and nitrogen storage of soil layer. There was a significant difference for the moso bamboo carbon and nitrogen storage in different operating time. The carbon storage of moso bamboo with fertilization was in the order of control forest>moso bamboo forest with 13 years fertilization>moso bamboo forest with 5 years fertilization and the nitrogen storage was in the order of control forest >moso bamboo forest with 5 years fertilization >moso bamboo forest with 13 years fertilization. The carbon and nitrogen storage of moso bamboo forest with reclamation was in the order of moso bamboo forest with 3 years reclaim>moso bamboo forest with 10 years reclamatiom >control forest. The change of carbon storage was not compatible with the nitrogen storage. Thus the value of C:N was amplitude largely. The ratio of C:N was from 18 to 39 in forest with fertilization and was from 13 to 16 in forest with reclamation. The amplitude was more violently in forest with fertilization. Those changes may damage the site sustained productivity. The carbon and nitrogen storage increased due to treatment of fertilization and reclamation. However, the carbon and nitrogen storage of vegetation layer distribution pattern was different for different types of moso bamboo. The difference of the carbon and nitrogen storage implied the exclusive management measures can be designed for the P. edulis forest.
  • Resources Evaluation
    Spatial Distribution and Evaluation of Nutrients in Surface Sediments of Zhalong Wetland
    YE Hua-xiang, ZANG Shu-ying, XIAO Hai-feng, ZHANG Li-juan, JIA Xiao-dan
    2013, 28(11): 1966-1976. https://doi.org/10.11849/zrzyxb.2013.11.013
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    A total of 271 sediments samples from Zhalong Wetland were analyzed for concentration and distribution of nutrients (TOC, TN and TP). It was followed by the evaluation of their pollution level. Then the linkages of C/N and C/P were discussed so as to find out the pollution sources. The results can be summarized as follows: The average values of TOC, TN and TP were 21047.2, 1961.9 and 404.4 mg·kg-1 respectively. Their spatial distributions were distinctly different. The concentration of nutritive salt in the north was higher than that in the south and the west was higher than the east. In southwest, the values of TOC and TN were relatively high, and in northeast and southwest, the value of TP was high. The average accumulation indexes of TOC, TN and TP were 2.3, 6.7 and 1.3 respectively with the sequence of TN>TOC>TP. The average pollution index of TOC, TN and TP were 2.1, 3.6 and 0.7, meaning that the sediments had been polluted, but still within the standing point for most benthos. The average value of C/N was 11, indicating that the organic matter in sediments had double sources. The organic matter was mainly distributed in the north and east, followed by the west. The value of C/P was higher than that of C/N. The organic matter in sediments dominated the change of C/P value.
  • Resources Evaluation
    The Characteristics of the Rare and Endangered Tibetan Medicinal Plant Resources in Shannan Region
    LU Jie, LAN Xiao-zhong
    2013, 28(11): 1977-1987. https://doi.org/10.11849/zrzyxb.2013.11.014
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    The rare and endangered plants are used more and more widely in Tibetan medicinal industry; however, there has been a lack of a clear understanding of these resources and their reasonable applications. In this study, the rare and endangered Tibetan medicinal plants in Shannan Region were investigated and analyzed by field work, interviews with local people, sample collection and laboratory bioassay. Results showed that there were 49 species of rare and endangered plants, belonging to 25 families and 43 genera in Shannan Region, accounting for 65.33% of the total distribute in Tibet. There were 53.06% of the endemic species in China, of which 20.41% were distributed in Tibet, and 73.47% were in Cuona County. The species living in hillside was 75.51%, of which 61.22% were distributed at altitude over 3000 m, the perennial herb accounted for 83.67% and the plants using entire grass as medicinal materials accounted for 55.10%. The mean biomass of individual plant of Rubus biflorus was the highest (1830.48 g) and the lowest one was only 0.31 g for Cordyceps sinensis. The root-shoot ratio of Asparagus filicinus was the maximum (5.31), the minimum was 0.04 for Przewalskia tangutica. The output and resource of Rubus biflorus were the highest, being respectively 36.61 kg/hm2 and 34040.78 t, followed by Berberis Agricola being 27.00 kg/hm2 and 10759.37 t and the lowest were 0.004 kg/hm2 and 2.37 t for Halenia elliptica. The output and resource of grade Ⅰ endangered Tibetan medicinal plants were ranked in the order of Rhodiola crenulata > Sinopodophyllum hexandrum > Mirabilis himalaica > Gentiana tibetica > Codonopsis convolvulacea > Corydalis boweri > Corydalis pygmaea > Aconitum gymnandrum > Meconopsis torquata > Gentiana urnula > Paraquilegia anemonoides > Veronica ciliata > Saxifraga umbellulata var. pectinata > Cordyceps sinensis. The resources reserves of the rare and endangered plants were 60959.12 t in Shannan Region, that of medicinal parts were 48663.97 t, 79.83% of the total. The reserves of Cordyceps sinensis with a great economic value was 9.30 t. In a word, there were abundant species with special characteristics, rich reserves and high economic value in Shannan. The main reason for the rareness and endangerment of the Tibetan medicinal plants were the unique biological characteristics, fragile ecological environment and human disturbance. Suggestions were provided for the management and sustainable utilization of the rare and endangered plants in Shannan Region.
    • Resources Research Methods
  • Resources Research Methods
    A Study on Regional Difference of Hydrological Parameters of SWAT Model
    LIN Bing-qing, CHEN Ying, CHEN Xing-wei
    2013, 28(11): 1988-1999. https://doi.org/10.11849/zrzyxb.2013.11.015
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    Discussing the parameter sensitivity in different regions and their regional difference for SWAT model would be helpful for reducing the uncertainty of hydrological process simulation and improving the application level in different regions. Based on the domestic articles related to application of SWAT model, firstly, different regions including humid, semi-humid, semi-arid, and arid regions were divided according to aridity index. Then the variation of sensitivity and values of hydrological parameters in different regions were investigated and its influencing factors were analyzed qualitatively for SWAT model. The results indicate that the parameters sensitivity and parameter value of SWAT model have some regional difference. During surface water process, runoff curve coefficient (CN2) and soil water availability (SOL_AWC) are sensitive in all regions, soil evaporation compensation coefficient (ESCO) is more sensitive in humid and semi-humid regions. Because influenced by soil texture, the value of CN2 is much bigger in humid region than in semi-humid region, and that of SOL_AWC is opposite. Because influenced by temperature and vegetation cover, the value of ESCO is much bigger in humid and arid regions. The groundwater parameters are more sensitive in humid and arid regions. Snow parameters only show sensitivity in arid region where melt water accounts for very great proportion of runoff. Moreover, the main reason for the difference of parameters is due to regional heterogeneities of climate, soil and vegetation. That spatial heterogeneities of several parameters sensitivity and values in the same region also exist, because the hydrological process is also affected by local meteorological conditions and underlying surface, and other factors of model which have not been revealed.
  • Resources Research Methods
    Aboveground Biomass in the North Tibet and Estimate Model Using Remote Sensing Data
    CHU Duo, DEJI Yang-zong, PUBU Ci-ren, JI Qiu-mei, TANG Hong
    2013, 28(11): 2000-2011. https://doi.org/10.11849/zrzyxb.2013.11.016
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    Estimation of aboveground biomass (AGB) is necessary for studying productivity, carbon cycles, nutrient allocation, and fuel accumulation in terrestrial ecosystems. Remote sensing techniques allow scientists to examine properties and processes of ecosystems and their inter-annual variability at multiple scales since satellite observations can be obtained over large areas of interest with high re-visiting frequencies. In this study, AGB and its spatial distribution in the North Tibet are analyzed using in-situ measurements during August to September in 2004, and the regression models are established using in-situ AGB data and corresponding Terra MODIS NDVI and EVI. The results show that due to constraints of alpine climate, soil and moisture conditions, the average AGB in the North Tibet is very low, being 96.88 g/m2. Of the total AGB, the dry matter content of fresh grass (hereafter referred to as fresh AGB) is above 80% and the dry matter content of dead material is below 20% . AGB raries greatly at different sampling sites and for different grassland types, ranging from 37.1-589.12 g/m2. On an average, the largest AGB occurs in swampy meadow, being 356.84 g/m2, followed by temperate steppe (64.48 g/m2) and alpine meadow (61.61 g/m2); the lowest value occurs in alpine steppe (48.87 g/m2). The optimum regression models for the North Tibet by using MODIS NDVI and EVI are compound, growth, exponent and power models, which can be used to estimate AGB and fresh AGB in the study area and four models have same performance. The efficiency of regression models based on MODIS NDVI or EVI for fresh AGB is better than for total AGB, which reflects unique spectral response of green plant. At spatial level, both AGB and fresh AGB decrease from the southeast to the northwest in the study area, reaching above 100 g/m2 in some part of southeastern region while below 20 g/m2 in northwestern region.
    • Comprehensive Discussion
  • Comprehensive Discussion
    The Modeling Algorithms for the Effects of Nitrogen on Terrestrial Vegetation Carbon Cycle Process
    LI Lei, HUANG Mei, GU Feng-xue, ZHANG Li
    2013, 28(11): 2012-2022. https://doi.org/10.11849/zrzyxb.2013.11.017
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    Nitrogen is an important nutrient element for plant growth. Nitrogen deposition is increasing with the increasing human activities, and this will influence terrestrial ecosystem carbon cycle greatly. Expressing accurately and quantitatively the effects of nitrogen on carbon cycle is the key factor to predict the global carbon balance change. This paper systematically summarizes the mathematical algorithms for the effects of nitrogen on photosynthesis and respiration, assimilates allocation processes in the state-of-the-art biogeochemical models, and analyses the sources of uncertainties in the algorithms used in each process. The future trends of model approaches are: development of new algorithms for photosynthetic process which reflects nitrogen saturation phenomenon and describes explicitly the relationship between nitrogen and photosynthetic rate; development of new algorithms for respiration process which reflects the relationships between nitrogen and the respiration rate for each part of the plant components (such as root, stem and leaf); and development of dynamic assimilates allocation algorithms on the basis of mechanism research. Because most of the current models do not include the nitrogen saturation phenomenon in their photosynthesis algorithms, these models will overestimate the effects of nitrogen deposition on photosynthetic rate when used to predict the future global carbon balance. Our research results will benefit to further carbon and nitrogen interaction researches and to provide references for carbon and nitrogen coupled model researches.