2010 Vol. 20, No. 4

Display Method:
Biomass Carbon Sequestration by Planted Forests in China
XU Xinliang, LI Kerang
2010, 20(4): 289-297. doi: 10.1007/s11769-010-0401-9
The planted forest area and carbon sequestration have increased significantly in China,because of large-scale reforestation and afforestation in the past decades.In this study,we developed an age-based volume-to-biomass method to estimate the carbon storage by planted forests in China in the period of 1973-2003 based on the data from 1209 field plots and national forest inventories.The results show that the total carbon storage of planted forests was 0.7743 Pg C in 1999-2003,increased by 3.08 times since the early 1970s.The carbon density of planted forests varied from 10.6594 Mg/ha to 23.9760 Mg/ha and increased by 13.3166 Mg/ha from 1973-1976 to 1999-2003.Since the early 1970s,the planted forests in China have been always a carbon sink,and the annual rate of carbon sequestration was 0.0217 Pg C/yr.The carbon storage and densities of planted forests varied greatly in space and time.The carbon storage of Middle South China was in the lead in all regions,which accounted for 23%-36% of national carbon storage.While higher C densities (from 17.79 Mg/ha to 26.05 Mg/ha) were usually found in Northeast China.The planted forests in China potentially have a high carbon sequestration since a large part of them are becoming mature and afforestation continues to grow.
Spatial Structure and Land Use Control in Extended Metropolitan Region of Zhujiang River Delta, China
DAI Junliang, WANG Kaiyong, GAO Xiaolu
2010, 20(4): 298-308. doi: 10.1007/s11769-010-0402-8
The Zhujiang (Pearl) River Delta is one of the most developed Extended Metropolitan Regions (EMR) in China.With the rapid urbanization,the agglomeration of population and industries has emerged,which has led to dramatic changes of spatial structure and land use in this region.With data of high resolution TM remote sensing images and Google Earth maps,this paper identified and analyzed the spatial pattern of the Zhujiang River Delta EMR using Envy and ArcGIS tools.It was found that 1) the industrial land uses were expanding substantially,particularly on the bank sides of the Zhujiang River estuary;2) large-scale housing developments were concentrated in the fringe of metropolitan areas such as those of Guangzhou and Shenzhen;3) a regional transportation network with the spatial pattern of "1 circle +2 pieces + 3 axes" had significantly affected the location choice of manufacture enterprises.At the same time,both highly specialized land use and severely mixed land use patterns were identified.As a consequence of the latter,land use efficiency of the whole EMR areas was reduced.Moreover,ecologic and environmental problems were severe.Based on the above analysis,suggestions were given from the viewpoint of spatial safety,land use efficiency,and the reorganization of spatial structure in the Zhujiang River Delta EMR.
Effects of Plant Types on Physico-chemical Properties of Reclaimed Mining Soil in Inner Mongolia, China
FU Yao, LIN Changcun, MA Jianjun, ZHU Tingcheng
2010, 20(4): 309-317. doi: 10.1007/s11769-010-0403-7
A field experiment was conducted in Jungar Banner,Inner Mongolia,China to study the effects of plant types on the physical structure and chemical properties of open-cast mining soils reclaimed for 15 years,and to analyze the triggering factors of the soil formation.Results indicate that plant types affect soil-forming process especially in the upper layer (0-20 cm),and the spatial structure of reclaimed plant is the main reason for variability of the soil-forming process.In the upper soil layer at the site reclaimed with mixed plants,the concentrations of soil organic matter (SOM) and soil organic carbon (SOC) are the highest,and they were significantly higher at the sites reclaimed with Leymus chinensis,Caragana sinica,which is mainly due to a large amount of litter fall and root exudation in herbages and shrubs.However,the concentrations of SOM and SOC in the soils at the reclaimed sites are quite low comparing with those in local primary soil,which indicates the importance of using organic amendments during the ecological restoration in the study area.
Estimation of Ecological Water Requirements Based on Habitat Response to Water Level in Huanghe River Delta, China
CUI Baoshan, HUA Yanyan, WANG Chongfang, LIAO Xiaolin, TAN Xuejie, TAO Wendong
2010, 20(4): 318-329. doi: 10.1007/s11769-010-0404-6
In recent years,wetland ecological water requirements (EWRs) have been estimated by using hydrological and functional approaches,but those approaches have not yet been integrated for a whole ecosystem.This paper presents a new method for calculating wetland EWRs,which is based on the response of habitats to water level,and determines water level threshold through the functional integrity of habitats.Results show that in the Huanghe (Yellow) River Delta water levels between 5.0 m and 5.5 m are required to maintain the functional integrity of the wetland at a value higher than 0.7.One of the dominant plants in the delta,Phragmites australis,tolerates water level fluctuation of about ± 0.25 m without the change in wetland functional integrity.The minimum,optimum and maximum EWRs for the Huanghe River Delta are 9.42×106 m3,15.56×106 m3 and 24.12×106 m3 with water levels of 5.0 m,5.2 m and 5.5 m,corresponding to functional integrity indices of 0.70,0.84 and 0.72,respectively.A wetland restoration program has been performed,which aims to meet these EWRs in attempt to recover from losses of up to 98% in the delta's former wetland area.
Distribution of Methyl Mercury in Rana chensinensis and Environmental Media in Gold-mining Areas of Upper Reaches of Songhua River, China
WANG Ning, ZHANG Gang, LIU Te, CAI Qingxiang
2010, 20(4): 330-336. doi: 10.1007/s11769-010-0405-5
The distribution characteristics of methyl mercury in Rana chensinensis and water,sediment and soil in gold-mining areas of the upper reaches of the Songhua River,China were studied by field sampling and laboratory testing.The results show that the methyl mercury contents in water,sediment and soil in gold-mining areas are much higher than those in the control site,indicating that gold-mining activities intensify the methyl mercury pollution in the study area.Methyl mercury contents are in a descending order of sediment > soil > water in the environment,and in a descending order of brain > viscera > muscle > skin in Rana chensinensis.There are significant correlation between methyl mercury contents in Rana chensinensis and those in water and sediment.In particular,the methyl mercury content in the skin of Rana chensinensis is positively correlated with those in water and sediment in spring.Therefore,skin is one of main intake pathways for methyl mercury due to its high permeability.
Application of Multivariate Model Based on Three Simulated Sensors for Water Quality Variables Estimation in Shitoukoumen Reservoir, Jilin Province, China
JIANG Guangjia, LIU Dianwei, SONG Kaishan, WANG Zongming, ZHANG Bai, WANG Yuandong
2010, 20(4): 337-344. doi: 10.1007/s11769-010-0406-4
This study applied a multivariate model based on three simulated sensors to estimating water quality variables in Shitoukoumen Reservoir,Changchun City,Jilin Province,China,including concentration of total suspended matter,concentration of chlorophyll-a and non-pigment matter absorption.Two field campaigns for spectra measurements with a total of 40 samples were carried out on June 13 and September 23,2008.The in-situ spectra were recalculated to the spectral bands and sensitivities of the instruments applied in this paper,i.e.Landsat TM,Alos and P6,by using the average method.And the recalculated spectra were used for estimating water quality variables by the single model and multivariate model.The results show that the multivariate model is superior to the single model as the multivariate model takes the combined effects of water components into consideration and can estimate water quality variables simultaneously.According to R2 and RMSE,Alos is superior to other sensors for water quality variables estimation although the precision of non-pigment matter absorption inversion performed the second.
A Method for Surface Roughness Parameter Estimation in Passive Microwave Remote Sensing
ZHENG Xingming, ZHAO Kai
2010, 20(4): 345-352. doi: 10.1007/s11769-010-0407-3
Surface roughness parameter is an important factor and obstacle for retrieving soil moisture in passive microwave remote sensing.Two statistical parameters,root mean square (RMS) height (s) and correlation length (l),are designed for describing the roughness of a randomly rough surface.The roughness parameter measured by traditional way is independence of frequency,soil moisture and soil heterogeneity and just the "geometric" roughness of random surface.This "geometric" roughness can not fully explain the scattered thermal radiation by the earth's surface.The relationship between "geometric" roughness and integrated roughness (contain both "geometric" roughness and "dielectric" roughness) is linked by empirical coefficient.In view of this problem,this paper presents a method for estimating integrated surface roughness from radiometer sampling data at different frequencies,which mainly based on the flourier relationship between power spectral density distribution and spatial autocorrelation function.We can obtain integrated surface roughness at different frequencies by this method.Besides "geometric" roughness,this integrated surface roughness not only contains "dielectric" roughness but also includes frequency dependence.Combined with Q/H model the polarization coupling coefficient can also be obtained for both H and V polarization.Meanwhile,the simulated numerical results show that radiometer with a sensitivity of 0.1 K can distinguish the different surface roughness and the change of roughness with frequency for the same rough surface.This confirms the feasibility of radiometer sampling method for estimating the surface roughness theoretically.This method overcomes the problem of "dielectric" roughness measurement to some extent and can achieve the integrated surface roughness within a microwave pixel which can serve soil moisture inversion better than the "geometric" roughness.
Field Modeling Method for Identifying Urban Sphere of Influence: A Case Study on Central China
DENG Yu, LIU Shenghe, WANG Li, MA Hanqing, WANG Jianghao
2010, 20(4): 353-362. doi: 10.1007/s11769-010-0408-2
With rapid development of urbanization and regional interaction and interdependence,regional urban agglomeration planning becomes more and more important in China,in order to promote integrated development of various cities with close interrelationship.However,it is still arguable academically on how to define the boundary or which cities to be included for the urban agglomeration of a region.This paper aims to shed lights on how to identify urban spheres of influence scientifically by introducing field modeling method and by practicing a case study on 168 cities in Central China.In our field modeling method,the influence intensities of cities were measured by a comprehensive index and urban spheres of influence were represented spatially by field intensity.Then,their classification and spatial distribution characteristics of study area in 2007 were identified and explored by using GIS and statistical methods.The result showed that:1) Wuhan is the absolute dominant city in Central China;2) the provincial capital cities dominate their own provinces and there are no other lower grade agglomeration centers;and 3) the basic types of organization form of urban sphere of influence are single-polar type,agglomeration type,close-related group type and loose-related group type.
Microhabitat Effect on Iron Distribution and Transfer in Carex pseudocuraica in Sanjiang Plain Wetlands
ZOU Yuanchun, LU Xianguo, JIANG Ming, YU Xiaofei
2010, 20(4): 363-371. doi: 10.1007/s11769-010-0409-1
Ten clonal units of Carex pseudocuraica growing in four different microhabitats (perennial flooded ditch water,perennial flooded ditch sediment,seasonal flooded ditch sediment and perennial flooded soil) of the Sanjiang Plain,Northeast China,were collected randomly for phenotypic plasticity analysis.Iron content,chemical and physical properties of substrates and the total Fe of nine plant modules were measured as well.The results show that the performance of the C.pseudocuraica is affected by the microhabitat,with the greatest performance score in perennial flooded ditch water,and the lowest in perennial flooded soil.The biomass allocation indexes indicate that much more mass is allocated to stems and roots to expand colonization area.The distribution of the total Fe in plant modules appears as pyramids from the tip to the root,while marked differences are observed in the distribution proportion of stems,tillering nodes and roots that are allometrically growing.Iron transfer from substrates to the plant is mainly controlled by the substrate type.The differences of iron distribution and transfer in the plant in different microhabitats are attributed to the iron contents of the substrates as well as the phenotypic plasticity of the plant.
Expansion Strategies and Evolution Paths of Hotel Groups in China
ZENG Guojun
2010, 20(4): 372-380. doi: 10.1007/s11769-010-0410-8
The organizational structure change of enterprises should be subject to the change of strategy,and strategy change is the reaction to the environment change.This paper studied the expansion strategies and evolution paths of hotel groups in China by a survey in 2007,in which the research objects were 91 hotel groups listed by China Tourist Hotels Association.The conclusions are drawn:based on the two dimensions of unification management function scope and the unification management degree,hotel groups can be divided into four strategic types,including strategically concentrated group,close function group,widespread alliance group and loose union group.Simultaneously there are three different expansion paths:stability path,growth path and undulation path.About 72.5% of Chinese hotel groups have a stability or growth expansion path.