Loading...
Welcome to Chinese Journal of Ecology! Today is Share:

Table of Content

    10 March 2013, Volume 32 Issue 3
    Restrictive regulation of stand density on aboveground biomass allocation and allometric pattern of Oligostachyum lubricum. 
    GUO Zi-wu, YANG Qing-ping, LI Ying-chun, CHEN Shuang-lin**
    2013, 32(3):  515-521. 
    Asbtract ( 1803 )   PDF (721KB) ( 511 )  
    In order to provide a theoretical basis for establishing a high-productive Oligostachyum lubricum stand, this paper studied the aboveground biomass accumulation, allocation and the allometric pattern of 1-3 yearold O. lubricum at four stand densities (24600-29800 stems·hm-2, D1; 37500-42600 stems·hm-2, D2; 46500-52800 stems·hm-2, D3; and 76500-85500 stems·hm-2, D4) with basically the same DBH. The allocation proportion of the O. lubricum modular biomass was in the order stem>branch>leaf. With the increasing age of the O. lubricum, the modular biomass and aboveground biomass as well as the leaf/branch, leaf/stem, and branch/stem ratios at the four stand densities all had an increasing trend, and were significantly higher for 2 and 3-year-old O. lubricum than for 1-year-old O. lubricum. The allocation proportion of the branch and leaf biomass presented an increasing trend, while that of the stem biomass was in adverse. With the increasing stand density, the modular biomass and aboveground biomass of 1-3-year-old O. lubricum were overall in “∧” shape, i.e., increased gradually at stand densities D1-D3 but decreased significantly at stand density D4. The allocation proportion of the leaf and branch biomass of 1-3-year-old O. lubricum decreased, while that of the stem biomass increased. The leaf/branch, leaf/stem, and branch/stem ratios of 1-year-old O. lubricum were in inverse “N” shape, while those of 2- and 3-year-old decreased on the whole. The leafbranch biomass accorded with near-constant growth model, and the allometric index decreased slightly with increasing stand density; whereas the leaf-stem biomass and the branch-stem biomass accorded with simple allometric model, and their allometric indices presented a trend of increasing and of decreased after an initial increase with the increase of the stand density, respectively. All the results indicated that when the stand density was higher than 37500-42600 stems·hm-2, more biomass was tended to allocate in stem to promote the longitudinal growth to obtain more light resource, and the suitable stand density for the high-efficient biomass accumulation and allocation was 46500-52800 stems·hm-2.
    Coupling relationships between soil microbe and soil nutrient under different ecosystems in depression between karst hills.
    LU Cheng-yang1,2,3, PENG Wan-xia1,3, SONG Tong-qing1,3**, ZENG Fu-ping1,3, YANG Gai-ren2, ZHANG Hao1,3, LU Shi-yang1,3, DU Hu1,3
    2013, 32(3):  522-528. 
    Asbtract ( 1839 )   PDF (469KB) ( 410 )  
    Based on the analysis of soil microbe and soil nutrients in different ecosystems of depression between karst hills, i.e., cropland, plantation forest, secondary forest, and primary forest, this study explored the characteristics of soil microbe and revealed the coupling relationships between soil microbe and nutrients. The composition of microbial population differed in the four ecosystems, where the ratio of fungi was lower in the four ecosystems. The ratio of actinomycetes in cropland, plantation and primary forest was larger than that of bacteria, while the reverse was true in the secondary forest. In the four ecosystems, the microbial biomass carbon (Cmic) was significantly correlated with the microbial biomass nitrogen (Nmic) and phosphorus (Pmic). The relationship between soil microbial factors and soil nutrients differed in the four ecosystems, among which the soil microbial biomass was closely with soil nutrients, while the amount of soil microbial population was weakly related with soil nutrient in the four ecosystems. This indicated that soil microbial populations such as bacteria, fungi and actinomycetes was randomly disturbed, instead of controlled by sole nutrient factor. The coupling relationships between soil microbe and soil nutrient factors were different in the four ecosystems. In the cropland, soil organic matter (SOM), pH, and total phosphorus (TP) played a greater role and mainly affected on Cmic, bacteria and fungi. In the plantation forest, soil water content, SOM, total nitrogen (TN), and TP had a greater effect on soil microbial biomass C, N, and P. In the secondary forest, pH, SOM, TP, available nitrogen (AN), and available potassium (AK) mainly influenced soil microbial biomass C, N, P, and fungi. In the primary forest, pH, TP, and AN proudly affected on soil microbial biomass C, N, P, and bacteria.
    Impacts of wind erosion on the distribution patterns of soil organic carbon and total nitrogen in Horqin Sandy Land, China.
    LIAN Jie1,2**, ZHAO Xue-yong1, WANG Shao-kun1, WANG Xin-yuan1,2, YUE Xiang-fei1,2, HAN Juan-juan1,2, YUN Jian-ying1, HUANG Wen-da1
    2013, 32(3):  529-535. 
    Asbtract ( 2036 )   PDF (1952KB) ( 384 )  
    Taking the severely desertified region (S) in central Naiman County and the region with potential desertification (P) in Shelihu Lake basin of Horqin Sandy Land as test objects, a comparative study was made on the topsoil physical and chemical properties and the 0-100 cm soil layer’s organic carbon and total nitrogen contents and particle size fractions. In the regions S and P, three plots were installed, respectively, i.e., control (MS and MC), winderoded (TS and SC), and particulate-deposited (LS and NC). From northwest to southeast, the soil texture in the study area varied from coarse and fine sand to silt and clay and very fine sand. With the density of silt and clay decreased by 1 kg·m-2, the soil organic carbon and total nitrogen contents decreased by 10 and 1.1 g·m-2, respectively. In 0-20 cm soil layer, the bulk density was averagely 1.322-1.651 g·cm-3 and in the order of TS>MS>LS>NC>SC>MC, silt and clay fraction varied in a reverse order, and pH was in the order of NC>SC>MC> region S. As compared with those in the control plots MS and MC, the soil organic carbon and total nitrogen contents in winderoded plots TS and SC decreased to different extent. In the particulatedeposited plots LS and NC, the soil organic carbon and total nitrogen contents had an obvious increase in LS than in TS and MS, but a sharp decrease in NC than in SC and MC. The soil organic carbon and total nitrogen contents in silt and clay fraction were much higher in region S than in region P, but the impact of wind erosion-induced silt and clay loss and particulate deposition on soil quality was more significant in region P than in region S. It was suggested that under the natural conditions of Horqin Sandy Land, inappropriate land use and management could increase the wind erosion risk of potentially desertified soil, and the sustained impact of wind erosion could induce the different changes of soil organic carbon and total nitrogen storage.
    Long-term changes of soil fertility factors and their relationships with NDVI.
    LI Yan-li1,2, PAN Xian-zhang1**, ZHOU Rui1,2, WANG Chang-kun1,2, LIU Ya1,2, SHI Rong-jie1,2, CHEN Dong-feng1, ZHAO Qi-guo1
    2013, 32(3):  536-541. 
    Asbtract ( 2216 )   PDF (461KB) ( 456 )  
    Taking the Nanning and Chongzuo of Guangxi Province, South China as test areas, and by using the time-series NDVI of AVHRR and MODIS sensors and the soil data in 1981 and 2011, this paper analyzed the relationships between the normalized difference vegetation index (NDVI) and soil fertility factors, and the correlations between the longterm changes of the NDVI and soil fertility factors. In recent 30 years, the soil pH in test areas declined significantly, while the soil total nitrogen, available phosphorus, and available potassium contents had a significant increase. Meanwhile, the NDVI presented an overall slowincreasing trend, and the changes of the NDVI had significant positive relationships with those of the soil organic matter and total nitrogen, suggesting that the timeseries NDVI could be used to indicate the changes of soil organic matter and total nitrogen to some extent, and hence, provide a feasible method for monitoring the long-term change of soil fertility.
    Point pattern analysis of Pteroceltis tatarinowii population at its different development stages in limestone mountain area of north Anhui, East China.
    ZHANG Xing-wang1**, ZHANG Xiao-ping2, GUO Chuan-you1, ZHANG Qiang1
    2013, 32(3):  542-550. 
    Asbtract ( 1548 )   PDF (772KB) ( 450 )  
    Based on the investigation data from the sampling plots of Pteroceltis tatarinowii secondary forest in limestone mountain area of north Anhui, and by the methods of space substituting time and Oring statistics, this paper studied the diameter-class structure and the spatial distribution pattern and association of the P. tatarinowii population at its different development stages. In the plots, the diameter-class structure of P. tatarinowii population presented an invert “J” shape, and the individuals, mainly seedlings and saplings but fewer medium and mature trees, were distributed in each diameter-class, showing a stablegrowth type of the population in different habitats. The seedlings, saplings, and medium trees exhibited an obvious clumped distribution at some small spatial scales, and the aggregate intensity of Huangcangyu population was significantly higher than that of Xiangshan population. With the increase of spatial scale, the individuals tended to distribute randomly. The individuals at mature stage all exhibited random or approximately uniform distribution. The spatial association of the population at different development stages was mainly at medium and small scales, and, with the increase of the scale, the spatial association turned to be not significant. It was suggested that the diameter-class structure and spatial distribution of the P. tatarinowii population were mainly affected by the habitat heterogeneity, population’s itself biological properties (especially clonal reproduction), and human disturbances.
    Spatial patterns of dominant species in secondary evergreen broad-leaved forest in central Yunnan, Southwest China.
    LIU Bao-shuang1, FU Deng-gao1,2, WU Xiao-ni1, WANG Hong-jiao1, WANG Qi1, DUAN Chang-qun1**
    2013, 32(3):  551-557. 
    Asbtract ( 1605 )   PDF (607KB) ( 470 )  
    By using Ripley’s point pattern analysis, the spatial patterns of the dominant species Cyclobalanopsis glaucoides and Keteleeria evelyniana in the secondary evergreen broadleaved forest in central Yunnan of Southwest China as well as the spatial associations among the individuals of the two species with different DBH classes were analyzed. Overall, the individuals of the two species with different DBH classes were in uniform distribution, indicating that the growth of the two populations was in stable period. The two species and their individuals with different DBH classes had a clumped distribution. With the increase of DBH class, the aggregation degree of C. glaucoides had a decreasing trend, while that of K. evelyniana decreased first, increased then, and decreased at last. A positive or no significant spatial association was observed among the saplings, juvenile trees, and adult trees of the two species. At different spatial scales, the two species of different DBH classes had less association, possibly because of the greater differences in the survival strategies of the two species. It was suggested that in the restoration of the forests in central Yunnan, it would be essential to control the plant population density and attend to the interspecific interaction to build an appropriate structure of the community.
    Stability of Platycladus orientalis mixed forest communities at different successional stages.
    MA Hong-jing, LI Rui-xia, YUAN Fa-yin, SHI Long-yan, GUAN Qing-wei**
    2013, 32(3):  558-562. 
    Asbtract ( 1715 )   PDF (424KB) ( 443 )  
    Stability is a comprehensive indicator of community structure and function, and has been the focus of ecological research. To further understand the variation trend of the stability of volcanic rock mountain forest communities at  different succession stages, three typical forest communities at different succession stages (Platycladus orientalis and Quercus variabilis mixed forest, P. orientalis mixed forest, and Q. variabilis and Pistalia chinensis mixed forest) in a typical volcanic rock mountainous region of Jiangsu Province, East China were taken as the study objects, four indicators (population regeneration, species diversity, Gordon stability value, and community structure) and eleven factors were chosen as the parameters to build an evaluation model, aimed to evaluate the stability of the communities by using the membership function values. With the development of succession, the stability of the forest communities was increasing, which was in line with the traditional succession theory, namely, the succession was from unstable to stable. Though the overall richness index and Whittaker’s diversity index of the three communities had definite differences, the two indices presented the same variation trend, i.e., P. orientalis mixed forest > Q. variabilis and P. chinensis mixed forest > P. orientalis and Q. variabilis mixed forest. P. orientalis mixed forest had the highest diversity, while Q. variabilis and P. chinensis mixed forest had the highest stability, i.e., the diversity could not fully represent the stability. The density of P. orientalis and Q. variabilis mixed forest was too large, and thus, appropriate tending should be made to promote the positive succession of the forest.
    Present situation and configuration evaluation of aquatic plants in landscape waters in Shanghai.
    TANG Li-hong1,2, MA Ming-rui1,2, HAN Hua1,2, WANG Hao-bin1,2, YOU Wen-hui1,2**
    2013, 32(3):  563-570. 
    Asbtract ( 2031 )   PDF (652KB) ( 575 )  
    From March to October 2012, a sampling plot investigation was conducted on the aquatic plants in the Dianshan Lake, Yuandang, and seven parks landscape waters in Shanghai. The analytic hierarchy process method was also applied to establish an evaluation model of the aquatic plants in landscape waters, aimed to evaluate the aquatic plants configuration in the typical landscape waters in Shanghai. In the study areas, a total of 31 aquatic plant species belonging to 18 families were recorded. The dominated species were of emergent plants, and the complementary species were of floating plants and submerged plants, with the common species being Phragmites australis, Thalia dealbata, and Canna indica. The configuration pattern of the aquatic plants in Dianshan Lake and Yuandang was excellent, with the configured composite index (CI) being 0.93, which was obviously higher than that of the parks landscape waters in Shanghai. Among the seven parks, Shanghai Botany Garden had the CI of 0.89, and its aquatic plants configuration pattern was also at excellent level. Caoyang Park and Xuhui Park were in good level in aquatic plants configuration pattern, Jing’an Park, Jinqiao Park, and Zhabei Park were in medium level, whereas Tianshan Park only had a CI of 0.22, indicating that its aquatic plants configuration pattern was the worst.
    Soil labile organic carbon in different types of moso bamboo (Phyllostachys edulis) stands.
    DU Man-yi1, FAN Shao-hui1**, QI Liang-hua1, LIU Guang-lu1, TANG Xiao-lu1, XIAO Fu-ming2
    2013, 32(3):  571-576. 
    Asbtract ( 1537 )   PDF (469KB) ( 442 )  
    Taking the Phyllostachys edulis forest, P. edulis and broadleaved mixed forest, and P. edulis and Cunninghamia lanceolata mixed forest in Anfu County, Jiangxi Province of China as test objects, this paper studied the variations of soil labile organic carbon in different types of moso bamboo stands. The contents of soil total organic carbon (TOC) and readily oxidizable carbon (ROC) were the highest in P. edulis forest (13.1 and 2.15 g·kg-1, respectively), while the soil microbial biomass carbon (MBC) and hot waterextractable carbon (HWC) were the highest in P. edulis and C. lanceolata mixed forest (123.3 and 349.0 mg·kg-1, respectively). The soil labile organic carbon contents in the three types of moso bamboo stands all decreased with soil depth, indicating that surface soil layer could significantly enrich soil labile organic carbon. The soil TOC, MBC, HWC, and ROC contents were significantly correlated with each other (P<0.01), and the MBC, HWC, and ROC could be used to evaluate the contents of soil active labile organic carbon.
    Decomposition dynamics of the litters from three dominant plant species in Taxodium ascendens forest in Dalian Lake of Shanghai.
    WANG Bin, ZHENG Si-jun, ZHU Yi, JU Bo, ZHAO Hui-juan, ZHANG Qun, CUI Xin-hong**
    2013, 32(3):  577-582. 
    Asbtract ( 1745 )   PDF (481KB) ( 313 )  
    By using litterbag method, a 190day incubation experiment was conducted to study the decomposition rates and the release dynamics of C, N, and P of the litters from three dominant species (Taxodium ascendens, Echinochloa cruspavonis, and Alopecurus japonicas) in T. ascendens forest in Dalian Lake, Shanghai. In the meantime, the quantity of the litters in the T. ascendens forest was measured by using collection container. In the forest, the annual production of T. ascendens litters was 5.70 t·hm-2, being the primary source of the litters in the forest. The litter decomposition rate (dry mass loss rate) was in the order of A. japonicus > E. cruspavonis > T. ascendens. During the experimental period, the C content of the three species litters decreased significantly, while the N and P contents had somewhat increase in T. ascendens litters but not in E. cruspavonis and A. japonicus litters.
    Effects of different soil moisture contents on root growth characteristics of Tamarix austromongolica seedlings.
    WANG Tong-shun, SUN Bao-ping**, FENG Lei, HU Sheng-jun, YU Ming-han
    2013, 32(3):  591-596. 
    Asbtract ( 2082 )   PDF (603KB) ( 378 )  
    Taking 1-year-old Tamarix austromongolica seedlings as objects, an experiment was conducted to study the seasonal variation of root characteristics of T. austromongolica seedlings under different water treatments by artificial trench digging method. The water treatments included dry treatment, moderate irrigation, and sufficient irrigation, respectively. The results showed that water treatments significantly affected the root growth of T. austromongolica seedlings. Depth and growth rate of vertical roots increased with the decreasing of irrigation. Increasing surface irrigation led to root distribution in the upper soil layer and gradual decrease of root extinction coefficient. Root biomass had a significant negative logarithmic relationship with soil depth. The average values of the root/shoot ratios were 0.43, 0.60, 0.90, and 1.12 from July to October, respectively, suggesting an allometric relationship between shoots and roots under different water treatments. Root/shoot ratio increased with decreasing soil moisture content, especially in the later growing season.
     
    Seasonal dynamics of Albizia kalkora stem sap flow in Yunmou dryhot valley of Southwest China.
    WANG Xiao-fei1,2, SUN Yong-yu1**, LI Kun1, ZHANG Chun-hua1, LI Bin1
    2013, 32(3):  597-603. 
    Asbtract ( 1893 )   PDF (894KB) ( 368 )  
    By using thermal dissipation probe (TDP), the sap flow of Albizia kalkora in Yunmou dryhot valley of Southwest China was continuously measured in the typical months of dry and wet seasons in 2011-2012, and the soil moisture content and some meteorological factors such as photosynthetic active radiation (PAR), air temperature (T), atmospheric relative humidity (RH), water vapor pressure deficit (VPD), and wind speed were synchronously measured. The sap flow of the A. kalkora displayed an obvious variation pattern of high at day and low at night. In wet season, the stem flow velocity had obvious difference, with the mean value and peak value in sunny days being 2.8 and 2.4 times of those in cloudy days, and 7.5 times and 7.8 times of those in rainy days, respectively. The starting time of the sap flow in sunny days was about 3 hours earlier than that in cloudy days, and about 4 hours earlier than that in rainy days. In sunny days, the sap flow velocity was obviously higher in south side than in north side; while in cloudy days or rainy days, the sap flow velocity in south side was nearly the same as that in north side. As compared with those in dry season, the starting time of the sap flow in wet season was about 1.5 hours earlier, the peak hours of the sap flow were longer, the mean value and peak value of the sap flow velocity were 1.9 and 2.3 times higher, respectively, and the sap flux was about 2-3 times higher. The sap flow velocity was significantly positively correlated with the PAR, T, VPD, and wind speed, and negatively correlated with atmospheric RH, with the correlation coefficient in the order of PAR > VPD > T > atmospheric RH > wind speed.
    Photosynthesis light response curves of four rice varieties and model fitting.
    YAN Xiao-hong1,2**, YIN Jian-hua3, DUAN Shi-hua1, ZHOU Bing1, HU Wen-hai1, LIU Shuai1
    2013, 32(3):  604-610. 
    Asbtract ( 4678 )   PDF (522KB) ( 524 )  
    Four typical models of photosynthesis light response curve (rectangular hyperbolic model, nonrectangular hyperbolic model, exponential function, and modified rectangular hyperbolic model) were adopted to fit the photosynthesis light response curves of four rice varieties (02428, Ganxin688, JR8892-1, and JR8892-2). All the four models could well fit the photosynthesis light response curves of the four rice varieties (R2>0.99), but only the modified rectangular hyperbolic model could well fit the light response curves of photoinhibition part, and directly calculate their saturation irradiance (Isat). The rectangular and nonrectangular hyperbolic models overestimated the Pn max, while the exponential function and the modified rectangular hyperbolic model presented more realistic values. The Isat values estimated by rectangular hyperbolic model, non-rectangular hyperbolic model, and exponential function were significantly different from the measured data. The Isat values of the rice varieties except JR8892-1 estimated by the rectangular hyperbolic model, nonrectangular hyperbolic model, and exponential function were lower than the measured data, and only the Isat values estimated by the modified rectangular hyperbolic model were consistent with the measured data. The estimated values of the low irradiance part parameters such as light compensation point (Ic) and dark respiration (Rd) by the modified rectangular hyperbolic model were most close to the measured values. As for the photosynthesis characteristics, the Isat and Pn max values of JR8892-1 were obviously higher than those of the variety 02428 with high photosynthetic efficiency. The JR8892-2 at tillering stage also presented higher Isat and Pn max, while the super rice Ganxin688 presented a lower Rd, with a lower consumption of photosynthetic products than the other rice varieties.
    Effects of brassinolide on the polyamines, ATPase activity, and inorganic ion content in roots of cucumber seedlings under hypoxia stress.
    LU Xiao-min1,2, GUO Shi-rong1**
    2013, 32(3):  611-614. 
    Asbtract ( 1641 )   PDF (432KB) ( 346 )  
    A laboratory experiment was conducted to study the effects of 24-epibrassinolide (EBR) on the polyamines
    (PAs), inorganic ion content, and ATPase activity in roots of cucumber seedlings under hypoxia stress. Hypoxia stress induced the significant increase of PAs, the decrease of (Spd+Spm)/Put ratio, and the significant decrease of K+, Ca2+, Mg2+, and Zn2+ contents and of ATPase activity. EBR could increase the Spm and Spd contents and the (Spd + Spm)/Put ratio under hypoxia stress, and in addition, significantly increase the Ca2+, Mg2+, Fe3+, and Mn2+ contents and the ATPase activity. It was suggested that EBR could regulate the PAs content, increase the ATPase activity, enhance the inorganic ion content, and thereby, alleviate the damage of hypoxia stress.
     
    Effects of enhanced UV-B radiation on physiological metabolism and photosystem-related protein expression of Didymodon vinealis (Brid.) Zand crust.
    HUI Rong1, LI Xin-rong1**, CHEN Cui-yun1, ZHAO Rui-ming2, ZHAO Xin1, LI Pei-guang1
    2013, 32(3):  583-590. 
    Asbtract ( 1784 )   PDF (811KB) ( 380 )  
    Taking the Didymodon vinealis (Brid.) Zand crust from an artificial vegetation area of Shapotou Desert Research and Experiment Station in Northwest China as test object, a 10-daylaboratory simulation experiment was conducted to study the effects of enhanced UVB on the physiological metabolism and photosystemrelated protein expression of the crust. Four UV-B treatments were installed, i.e., 2.75 (CK), 3.08, 3.25 and 3.41 W·m-2. With the increasing UV-B radiation, the malondialdehyde (MDA) content presented an increasing trend, while the chlorophyll a fluorescenceinduced kinetics parameters and the watersoluble protein and thylakoid membrane proteins expression showed a continuous decrease, and the decrement was negatively proportional to the intensity of the UV-B radiation. The enhanced UV-B radiation accelerated the reactive oxygen species (ROS) metabolism rate, induced the lipid peroxidation, decreased the watersoluble protein content, and further, reduced the activity of the reaction center of photosystem II (PSII), leading to the decline of photosynthesis. This study would help us to further understand the response mechanisms of biological soil crust (BSC) under UV-B radiation, and have academic and practical significances for the BSC application in
    desertification areas.
    Effects of exogenous nitric oxide on the growth and osmotic regulation substances of Cichorium intybus L. under salt stress.
    GU Wen-ying1, LI Xing-zheng1, QI Xin-mei1, GAO Hong-wen2**
    2013, 32(3):  615-620. 
    Asbtract ( 1894 )   PDF (522KB) ( 345 )  
    A sand culture experiment was conducted in a growth chamber to study the responses of the growth and osmotic regulation substances of Cichorium intybus L. cv. Commander seedlings to the exogenous NO donor, sodium nitroprusside (SNP, 0.2 mmol·L-1), under salt stress (140 and 280 mmol·L-1 of NaCl). As compared with the control, the leaf area, length, width, and relative water content (RWC) of seedlings  under the salt stress had an obvious decrease whereas the leaf proline content increased significantly (P<0.05), and the decrement and increment were timedependent. The highperformance liquid chromatography (HPLC) analysis further indicated that the fructose, glucose and sucrose contents in the seedling’s roots under salt stress decreased after an initial increase, and the root 1-kestose and nystose contents decreased sharply under the stress of 140 mmol·L-1 of NaCl but increased somewhat under the stress of 280 mmol·L-1 of NaCl. Pretreatment with SNP not only alleviated the inhibitory effects of salt stress on the leaf growth and RWC, but also made the leaf proline and nystose contents increased significantly (P<0.05) and the leaf fructose, glucose and sucrose contents decreased. It was suggested that exogenous NO could enhance the resistance of C. intybus seedlings against salt stress by increasing the seedling’s water retention capacity and promoting the synthesis of osmotic regulation substances proline and fructan, especially nystose.
    Acaricidal activity of different ultrasonic wave extracts from Phytolacca americana roots against Tetranychus cinnabarinus.
    DING Li-juan, DING Wei**, ZHANG Yong-qiang
    2013, 32(3):  621-626. 
    Asbtract ( 1609 )   PDF (510KB) ( 325 )  
    Two ultrasonic wave extracts (n-butarol and ethyl acetate as solvents) of Phytolacca americana acetone extract and residues after extracting were investigated for acaricidal activities against Tetranychus cinnabarinus. Results showed that the n-butarol extract exhibited the highest acaricidal activity among all treatments. The corrected mortalities of n-butarol extract were 74% and 97% after 24 h and 48 h of treatment at 2.5 mg·mL-1, and its LC50 and LC90 were 1.787 and 7.272 mg·mL-1 for 48 h, respectively. Meanwhile, the repellent rates were 62%, 82% and 84% against the mite for 24 h and oviposition inhibition rates (48 h) were 39%, 81% and 93%, at concentrations of 4, 2 and 1 mg·mL-1, respectively. The nbutarol extract was further separated by the silica gel column and monitored by thinlayer chromatography (TLC) with UV detection, and 14 fractions were obtained. The 11th fraction showed highest acaricidal activity with a corrected mortality of 98% at the concentration of 2 mg·mL-1 and its LC50 and LC90 were 0.932 and 3.110 mg·mL-1, respectively after 48 h of treatment.
    Morphological diversity of four Dendrolimus species in relation to environmental factors.
    NANGONG Zi-yan1, YANG Jun2, XU Xiu-ping3, GAO Bao-jia4**
    2013, 32(3):  627-633. 
    Asbtract ( 1663 )   PDF (829KB) ( 284 )  
    A genetic diversity analysis was made on the morphological characteristics (pupa weight, pupa length, female weight, female wing length, female body length, male weight, male wing length, and male body length) of Dendrolimus punctatus punctatus Walker, D. superans Butler, D. houi Lajonquiere, and D. kikuchii Matsumura. Significant differences were observed in the test morphological characteristics among the four Dendrolimus species, with the largest coefficient of variation (CV=51.99%) of pupa weight. D. superans population had the largest morphological diversity, while D. houi population had the smallest one. The principal component analysis showed that pupa length, female weight, and female wing length contributed most to the morphological diversity. Based on the UPGMA clustering, the first branch included D. punctatus punctatus and D. superans, and the second one included D. houi and D. kikuchii. There exited close correlations between the morphological diversity of the Dendrolimus species and the ecoenvironmental factors.
    Ciliate species diversity and its relationships with environmental factors in plateau swamp wetlands of southern Gansu Province, Northwest China in autumn.
    NING Ying-zhi1**, WANG Fang-guo1, DU Hai-feng2, WANG Hong-jun3, SU Chang1
    2013, 32(3):  634-640. 
    Asbtract ( 1849 )   PDF (871KB) ( 335 )  
    By using non-flooded Petri dish method, live observation, and protargol dyeing, this paper studied the ciliate species diversity in the plateau swamp wetlands of southern Gansu Province in autumn, with the relationships between the ciliate community’s structural parameters and environmental factors analyzed by grey relational analysis. At six sampling sites, a total of 157 ciliate species were collected, belonging to 53 genera, 34 families, 11 orders, and 3 classes, among which, 1 species was new, 24 species were uncertain, and 4 species were newly recorded in China. Among the species identified, Hypotrichida was the most predominant group, followed by Prostomatida, while Oligorichida and Bursariomorphida were of rare groups. The common groups included Colpodida,  Nassulida, Cyrtophorida, Hymenostomatida, Scuticociliatida, Heterotrichida, and Peritrichida. Due to the habitat peculiarity in the plateau swamp wetlands, the ciliate species diversity and community complexity were high, rare and endemic species had greater proportion, while cosmopolitan species occupied smaller proportion. Grey relational analysis showed that the abundance of ciliate species at the sampling sites had close correlations with the microhabitat environmental factors, among which, organic matter and ammonium nitrogen contents were the major factors affecting the ciliate community stability in the plateau swamp wetlands.
    Morphometrics differences between the populations of endangered species Onychostoma rara from Yuanjiang River and Xijiang River systems, Southwest China.
    DAI Ying-gui**, YUE Xiao-tong, YIN Bang-yi
    2013, 32(3):  641-647. 
    Asbtract ( 1725 )   PDF (943KB) ( 353 )  
    By the methods of coefficient of difference, variance analysis, discriminant analysis, and principal component analysis (PCA), this paper studied the morphometrics differences, including 10 countable characteristics and 31 proportional characteristics, between the 142 and 92 specimens of endangered species Onychostoma rara collected from the Yuanjiang River and Xijiang River systems, respectively. The variance analysis showed that a total of 6 countable characteristics and 27 proportional characteristics had significant differences between the populations of O. rara from the Yuanjiang River and the Xijiang River systems, respectively (P<0.05). The discriminant analysis revealed that there were 9 proportional characteristics being important to differentiate the two populations from each other, and the discriminant functions for the two populations were established, respectively. Based on the results of PCA, there were 16 proportional characteristics along the dorsalventral axis, 6 proportional characteristics along the anteriorposterior axis, and 2 proportional characteristics along the caudal peduncle of fish body among the individuals of O. rara presenting obvious differences. As a result, the morphometrics of the two populations had shown obvious differentiation, probably due to the longterm segregation of the two populations and their adaptive evolution in different river systems. However, the coefficient of difference demonstrated that the morphometrics differences between the two populations were still under subspecies level.
    Toxicity effect of chromium on the growth and development of Rana chensinensis tadpoles.
    LI Bo1,2, WANG Wei-jun1, LI Xin-yi1, ZHANG Yu-hui1**
    2013, 32(3):  648-654. 
    Asbtract ( 1872 )   PDF (603KB) ( 464 )  
    In order to evaluate the acute toxicity of chromium (Cr) on amphibian larvae, the Rana chensiensis tadpoles at the stages 28-29 were exposed to the water contaminated by 30-35 mg·L-1 of Cr(III) and 10-45 mg·L-1 of Cr(VI), with the death rate of the tadpoles and the sublethal concentration (LC50) of Cr(III) and Cr(VI) for 24, 48, 72, and 96 h determined, respectively. Both the Cr(III) and the Cr(VI) had obviously acute toxicity on the tadpoles. The LC50 of Cr(III) for 24, 48, 72, and 96 h was 34.09±1.06, 33.47±0.65, 32.58±0.11, and 32.05±0.20 mg·L-1, and the LC50 of Cr(VI) was 91.97±5.32, 51.19±4.62, 35.79±1.40, and 28.81±1.87 mg·L-1, respectively. The safe concentration (SC) of Cr(III) and Cr(VI) was 3.21±0.02 and 2.88±0.19 mg·L-1, respectively. The acute toxicity of Cr(III) was from its combination with the skin secretion of the tadpoles, forming a complex compound sticking on the gill chamber, and then, causing the tadpoles dead from breath obstacle; whereas the acute toxicity of the Cr(VI) was due to its strong oxidizing property, causing the tadpoles skin fester, gill atrophy, and ultimately, the mortality of the tadpoles. The assessment of the sublethal concentrations of Cr(III) and Cr(VI) on the growth and development of R. chensiensis tadpoles showed that Cr was a teratogenic substance which could restrain the growth and development of the tadpoles. This effect also had a doseeffect relationship with the Cr concentrations, but the time cumulative effect was irregular.
    Effects of water velocity on the swimming behavior of Anabarilius grahami.
    ZHONG Jin-xin, ZHANG Qian, LI Xiao-rong, KANG Bin**
    2013, 32(3):  655-660. 
    Asbtract ( 1246 )   PDF (579KB) ( 342 )  
    A specially built installation was adopted to determine the swimming performance, swimming speed, rheotaxis frequency, and tail beat frequency of Anabarilius grahami at the water velocities 0, 0.1, 0.2, and 0.25 m·s-1 at 25 ℃, aimed to understand the effects of water velocity on the swimming behavior of A. grahami. The rheotaxis frequency of the A. grahami was significantly higher at the water velocities 0.1, 0.2, and 0.25 m·s-1 than at 0 m·s-1, but no significant differences at 0.1, 0.2, and 0.25 m·s-1. At the water velocity increased from 0 to 0.2 m·s-1, the tail beat frequency increased significantly; but at 0.25 m·s-1, the tail beat frequency was significantly lower than that at 0.2 m·s-1 after 40 min. With the increase of water velocity, the swimming performance of the A. grahami changed from countercurrent swimming to countercurrent static. At the water velocities 0.1, 0.2, and 0.25 m·s-1, the percentage of downstream swimming was lower than that of the other swimming states. In the states of countercurrent swimming, the swimming speed increased with increasing water velocity, while in the states of downstream swimming, the swimming speed had no significant correlation with water velocity. There existed significant linear correlations among the swimming speed, tail beat frequency, and flow velocity.
    Effects of topography and tidal current of sand ridge and tidal creek system in North Jiangsu shoal of East China on the distribution of shrimps.
    QUE Jiang-long1,2, KE Chang3**, XU Zhao-li1, SUN Lu-feng1, CHEN Jia-Jie1
    2013, 32(3):  661-667. 
    Asbtract ( 1808 )   PDF (6198KB) ( 392 )  
    Based on the data from two oceanographic surveys in North Jiangsu shoal in November 2010 and May 2011, this paper analyzed the shrimp density, population composition, and dominant species in the shoal, and, in combining with the unique topography of the sand ridge and tidal creek system in the shoal, studied the effects of the topography and tidal current on the quantitative distribution of the shrimps. A total of 15 shrimp species were identified, among which, Leptochela gracilis and Acetes chinensis were the dominant species in spring and autumn, respectively, according to the index of relative significance (IRI). As compared with those in autumn, the biomass and individual density of the shrimps were relatively high in spring, being 35.64 vs. 9.24 kg·km-2, and 35.42×103  vs. 25.92×103 ind·km-2, respectively. According to the β value, there was a close correlation between the variations of the total shrimp density and the main dominant species density, and the two had the same horizontal distribution pattern. Due to the unique topography of the sand ridge and tidal creek system in the shoal, in addition to the forward wave of East China Sea and the rotating wave of Yellow Sea, the tidal current concentrated centripetally from north, east, and south, which was consistent with the direction of the tidal creeks. The flow rate of the tidal current was faster in tidal creeks than on sand ridges, which made the shrimp biomass and individual density be far greater in tidal creeks than on sand ridges, and slightly higher in the deep grooves between sand ridges and intertidal fords than on the sand ridges, no matter in spring or in autumn.
    Contents of mineral elements of hair, serum, feces and urine from grazing sheep.
    ZHONG Jin-feng1,2, ZHANG Li3,4**
    2013, 32(3):  668-674. 
    Asbtract ( 1694 )   PDF (461KB) ( 350 )  
    In order to explore the change pattern of mineral elements from hair, serum, feces and urine on grazing sheep of Qinghai-Tibet Plateau, the contents of Cu, Mn, Zn, Mg, Se and Mo in hair, blood, feces and urine collected in spring, summer and autumn from sheep on the southern shore of Qinghai Lake were measured, and the correlations of different elements in the same samples and the same elements in different samples were calculated. All elements showed no significant difference except the Mn and Se in serum among seasons, and all elements in urine, hair and feces showed significant difference except Se in hair and Zn in feces (P<0.05). These results showed that the content of each element in serum was much easier to keep constant than that in hair, feces and urine. From the correlation of different elements in the same samples, the positive relationship in spring was more than that in summer or autumn, and the related degree of each element in feces was higher than others, and the Mg had more synergic effect with other elements while the Se had less. From the correlation of the same element in different samples, the correlation of each element between urine and other sample was of significance. Zn and Se had a tight relationship with other elements while Mo did not. In conclusion, the urine is recommended as an index to monitor the grazing sheep minerals and Se should be separated from other elements to avoid antagonism when adding minerals in spring.
    Health risk assessment of polycyclic aromatic hydrocarbons in soils of the Tiexi relocated old industrial area, Shenyang, China.
    YANG Ming-ming1, SUN Li-na1**, LUO Qing1, Bing Long-fei2
    2013, 32(3):  675-681. 
    Asbtract ( 1985 )   PDF (1785KB) ( 418 )  
    The health risk assessment of soil PAHs in soils of the Tiexi relocated old industrial area (TROIA), Shenyang was evaluated by the RBCA model of USEPA. ∑PAHs in soil samples from TROIA were 290.9-8492.37 μg·kg-1 dry weight. The noncancer hazard index was from 6.39×10-6 to 3.04×10-4, which was less than the threshold defined by USEPA and indicated that soil PAHs in the TROIA had little risk on human health. The cancer risk index was from 2.08×10-7 to 7.52×10-6, which was evidently less than upper threshold of cancer risk (10-4), but was a little more than low threshold of acceptable cancer risk (10-6). These indicated that the cancer risk of soil PAHs was acceptable in the TROIA, but great attention to the benzo(a)pyrene pollution in the soil should be paid because their contribution rates to the total cancer risk was 61.0%. The personal exposure of soil PAHs was mainly by direct ingestion and dermal contact pathways, which contributed to the noncancer hazard index and cancer risk by 99% and 100%, respectively.
    Variation characteristics of water-soluble inorganic ions in size-segregated atmospheric particles in Chengdu in winter.
    YANG Zhou1,2, LI Xiao-dong1**, YU Jing3, SHI You-xiang3, DU Feng3
    2013, 32(3):  682-688. 
    Asbtract ( 1606 )   PDF (614KB) ( 368 )  
    By means of the Andersen stage sampler, size-segregated atmospheric particles were collected in Chengdu City in winter, 2010. The size distribution spectra of major water-soluble inorganic ions (SO42-, NO3-, Cl-, F-, NH4+, Ca2+, Mg2+, K+, and Na+) were determined. Mass contents of SO42-, NO3-, NH4+, Cl-, K+ and Na+ mainly concentrated in the fine particles within the size range of 3.3-0.65 μm, and those of Ca2+ and Mg2+ concentrated in the coarse particles (11.0-4.7 μm). SO42-, NO3-, NH4+ and Ca2+ were the major inorganic ions in the collected atmospheric particles. Under different weather conditions, mass concentrations of SO42- and NO3- decreased in sequence of foggy day, cloudy day and rainy day, and their contents in the foggy day were about 2.5 and 5 times higher than that in cloudy day and rainy day, respectively. Accordingly, the other ions were also about 2 times higher. In the all sizesegregated particles, the ratios of \[NO3-\]/\[SO42-\] were less than 1.0, indicating that the air pollution in  Chengdu City are still dominated by stationary source (coal combustion) while the mobile pollution source (main as vehicle exhaust) is becoming increasingly important.
    Characteristics and evolution of settlement size structure in Suzhou, Wuxi, and Changzhou area of East China.
    LU Jun-yu1, LIU Mao-song1**, XU Chi1, YANG Xue-jiao1, ZHANG Yan1, ZHANG Ming-juan2
    2013, 32(3):  689-695. 
    Asbtract ( 1780 )   PDF (4589KB) ( 327 )  
    By using the Landsat TM/ETM+ images acquired in 1987, 1993, 1999, 2005, and 2010, the spatial distribution patterns of the settlements in Suzhou, Wuxi, and Changzhou area (including 3 prefecturelevel units and 9 countylevel units) of East China were extracted, the settlement patches were classified into 8 size classes (<5, 5-20, 20-80, 80-320, 320-1280, 1280-5120, 5120-20480, and ≥20480 hm2), and the characteristics and evolution process of the settlement size structure in the prefecture and countylevel units were comparatively analyzed. In 1987-2010, the settlements in the study area expanded 5 times in size, but the settlement growth varied with administrative units, showing different growth rhythms. The settlement size class was promoted by 1-2 levels, with the proportion of the lowest size class decreased greatly while that of the highest size class increased continuously. In addition, the second-highest size class presented very small proportions (even 0) in 3 prefecture-level units and some countylevel units. The equilibrium distribution degree of the prefecture-level units decreased continuously, but that of most county-level units showed an increasing trend. The comparison of the location conditions of equilibrium and nonequilibrium distribution types administrative units and of the landscape resource patterns within the units showed that the resource distribution pattern should be the important factor affecting the settlement size structure and its evolution trend.
    Landscape dynamics of aggradational coastal wetland in Jiangsu Province in the past three decades.
    ZHANG Ming-juan1**, WANG Lei2, LIU Mao-song3, XU Chi3
    2013, 32(3):  696-703. 
    Asbtract ( 1581 )   PDF (899KB) ( 405 )  
    The landscape dynamics of the aggradational coastal wetland in Jiangsu Province in the past three decades were studied by using Landsat images acquired in four periods (1975, 1990, 2002 and 2010). The results showed that the area of the aggradational coastal wetland in Jiangsu Province increased from 2100.18 km2 to 3686.31 km2 (increased by 75.52%). The artificial wetland (including agricultural/aquatural land and salina) increased from 514.97 km2 to 1795.18 km2 (increased 2.46 times); while the natural wetland (halophyte communities dominated by Pragmites communis, Saueda spp., Aeluropus littoralis and Spartina spp., and bare intertidal mud flat) only increased a little, and the area percentage of natural wetland relative to the total wetland decreased from 74.59% to 50.30%. In the past three decades, the average wetland width increased from 8.64±1.64 km in 1975 to 13.89±2.86 km in 2010; the artificial wetlands extended to the sea in most locations, while the natural wetland extended and retreated in different periods and locations. The succession series of wetland landscape was intertidal mud flat→ halophyte communities→ agricultural/aquatural lands. The agricultural lands were mainly reclaimed from the P. communis communities, while the aquacultural lands were mainly reclaimed from the Saueda spp. communities.
    Variation characteristics of annual and spring standardized precipitation index and Z index in different climate regions of Gansu Province, Northwest China in 1960-2010.
    CHEN Li-li, LIU Pu-xing**, YAO Yu-long, ZHU Xiao-juan, ZHAO Min-li
    2013, 32(3):  704-711. 
    Asbtract ( 1471 )   PDF (1634KB) ( 360 )  
    Based on the 1960-2010 daily precipitation data from 26 meteorological stations in Gansu Province of Northwest China, and by using standardized precipitation index (SPI) and Z index, this paper analyzed the variation characteristics of the annual and spring drought in different climate regions of the Province in recent 51 years. Overall, the annual SPI and Z index in the Province presented an increasing trend in the cool and warm climate regions of Hexi and in the Qilian Mountains, with the greatest increment in the arid areas of western warm temperate zone in Hexi, and the change tendency rate of both SPI and Z index being 0.13·(10a)-1, and a decreasing trend in the semi-humid region of southern cold temperate zone of Longzhong, semi-arid region of northern cold temperate zone of Longzhong, and humid region of alpine Gannan, with the greatest decrement in the semihumid region of southern cold temperate zone of Longzhong, and the change tendency rate of SPI and Z being -0.13·(10a)-1 and -0.14·(10a)-1, respectively. The drought degree in early spring showed a decreasing trend, with the greatest decrement in the semihumid region of southern cold temperate zone of Longzhong, and the change tendency rate of SPI and Z being -0.12·(10a)-1 and -0.06·(10a)-1, respectively. The annual and spring SPI and Z index had the same variation trends. Severe drought occurred in Hexi in the 1960s and in Hedong in the 1990s. In the cool and warm climate regions of Hexi and in the Qilian Mountains, the change rate of drought index was positive, the drought degree decreased, and the change degree of spring drought was smaller than that of annual drought; whereas in the semi-humid region of southern cold temperate zone of Longzhong, semiarid region of northern cold temperate zone of Longzhong, and humid region of alpine Gannan, the change rate of drought index was negative, the drought degree exacerbated, and the change degree of spring drought was greater than that of annual drought. In the Province, there was an obvious difference in the spatial distribution of drought, with an increasing trend from northwest to southeast.
    Spatiotemporal variations of vegetation NPP and related driving factors in Shiyang River basin of Northwest China in 2000-2010.
    LI Chuan-hua, ZHAO Jun**
    2013, 32(3):  712-718. 
    Asbtract ( 1738 )   PDF (1754KB) ( 481 )  
    By using MODIS remote sensing data, this paper studied the spatiotemporal distribution and variation characteristics of vegetation net primary productivity (NPP) and their relationships with climate change and human activity in the Shiyang River basin of Northwest China in 2000-2010, with the human effect model of NPP established. In 2000-2010, the total vegetation NPP in the basin decreased after an initial increase, with the peak in 2002 and a periodical fluctuation in the decreasing process. Overall, the NPP had a significant positive correlation with precipitation, but less correlation with air temperature; whereas in some areas, the NPP had significant correlation with precipitation, and also, stronger correlation with air temperature. The related division lines for the annual precipitation were 380 mm and 170 mm. In the areas with the annual precipitation greater than 380 mm, air temperature was the dominant factor affecting the NPP; in the areas where the annual precipitation was 170-380 mm, precipitation was the dominant factor; and in the areas with the annual precipitation less than 170 mm, precipitation and human activity were the primary factors.  Under the effects of human activity, the annual increment of the NPP in the basin in 2000-2010 was averagely 2353.86 g C·m-2·a-1, suggesting that the vegetation coverage in the basin was improved to some extent after the eco-environment management project was implemented. From the view point of vegetation type, grassland was most acutely positively and negatively affected human activity, cropland was also very obviously affected by human activity, and the cropland NPP was increased by the improvement of cultivation and management measures, whereas the Gobi, saline and alkaline land, sand land, and forestland in the oasis edges were basically positively affected by human activity, their vegetation coverage and quality being somewhat increased.
    An integrated assessment model of county level eco-environmental quality based on RS and GIS: A case study of Huidong County, Guangdong Province of South China.
    FAN Chen1,3, XIA Bei-cheng1**, QIN Jian-qiao2
    2013, 32(3):  719-725. 
    Asbtract ( 2276 )   PDF (2654KB) ( 403 )  
    Based on the GIS data, statistical yearbook data, and the idea of “classifying indices first and weighting each index then”, by adopting Kruskal-Wallis (χ2) test to confirm index weight, and in combining with RS/GIS software, this paper evaluated the ecoenvironmental quality of Huidong County, Guangdong Province of South China, aimed to approach the construction method of eco-environmental quality assessment index system and the method of confirming weight, and to establish an easily transplanted eco-environmental quality assessment model at county, town, and raster scales. The assessment at county scale showed that the overall eco-environmental quality of Huidong County was good, with the eco-environmental quality index (EQI) being 3.6. The assessment at town scale showed that Gaotan Town had the best eco-environmental quality (EQI=4.26), while Port Management Committee had the worst one (EQI=2.64). The assessment at raster scale showed that the eco-environmental quality of the economically developed region in southwest coast of Huidong County was fair or poor, with an area accounting for 21% or 23% of total area, respectively, while that of the economically undeveloped region in northeast mountains of Huidong County was good, with an area accounting for 56% of the total.
    Spatial patterns of vegetation net primary productivity in Jiangxi Province of China in relation to climate factors.
    DING Qing-fu1,2, WANG Jun-bang2**, QI Shu-hua3, YE Hui3, HUANG Mei2, XU Yue-tong1, YING Tian-yu4, TAO Jian2
    2013, 32(3):  726-732. 
    Asbtract ( 2154 )   PDF (3564KB) ( 482 )  
    By using GLOPEMCEVSA model, the net primary productivity (NPP) of terrestrial vegetations in Jiangxi Province in 2000-2006 was simulated, and the spatial patterns of the NPP in relation to climate factors were analyzed. The simulated NPP had a significant linear correlation with the surveyed NPP, and the multiple correlation coefficient was 0.85 (P< 0.001). Among the main vegetations in the Province, evergreen needleleaf forest had the highest NPP (1091.38 g C·m-2·a-1), followed by evergreen broadleaf forest (846.09 g C·m-2·a-1), shrub (596.62 g C·m-2·a-1), and grass (325.50 g C·m-2·a-1). The analysis of the NPP along the climate gradient showed that in the areas with the precipitation less than 1900 mm, the NPP increased with increasing precipitation, but the increment was small and had a greater fluctuation. In the areas with the precipitation being 1900-1950 mm, the NPP increased significantly with increasing precipitation; while in the areas with the precipitation >1950 mm, the NPP decreased with increasing precipitation. In the areas with the air temperature lower than 17 ℃, the NPP increased with increasing temperature; while in the areas with air temperature higher than 17 ℃, the NPP decreased with increasing temperature. The further analysis on the relationships between the NPP and precipitation in the areas with lower air temperature (< 17.25 ℃), medium air temperature (17.25-18.55  ℃), and higher air temperature (>18.55 ℃) showed that in the areas with lower and medium air temperature, the dominant vegetation was evergreen needle-leaf forest, which had higher NPP, while in the areas with higher air temperature, crop and shrub were the main vegetations, whose NPP was lower and had greater variability.
    Responses of reference crop evapotranspiration in Loess Plateau of Northwest China to climate change in 1961-2010 and estimation of future trend.
    ZHANG Bo, ZHANG Tiao-feng**
    2013, 32(3):  733-740. 
    Asbtract ( 1577 )   PDF (1650KB) ( 474 )  
    It is essential to accurately estimate the reference crop evapotranspiration (ET0) in semiarid areas where the water resources are limited and excessively explored, which would be greatly helpful for planning the irrigation water supply and understanding the effects of climate change on hydrological processes. Based on the 1961-2010 daily meteorological data from 67 meteorological stations in the Loess Plateau of Northwest China, and by using PenmenMonteith equation, the reference crop evapotranspiration (ET0) in the Plateau was calculated, and, in combining with the many years’ variations of various meteorological factors, the causes of the past years ET0 change in the Plateau were analyzed. On these bases, the future trend of the ET0 was estimated by the rescaled range analysis method. In the study area, the sensitivity of ET0 to mean air temperature was relatively low. However, due to its great variation, the mean air temperature was the dominant factor inducing the ET0 change, with a contribution rate of 6.37%. Solar radiation and wind speed also had greater contribution rate to the ET0 change. Actual vapor pressure, due to its smaller variation, had minor effects on the ET0, only with a contribution rate of 1.36%. Spatially, air temperature had positive contribution to the ET0 change, wind speed and solar radiation had negative contribution in most regions, whereas actual vapor pressure had positive contribution in northern part and but negative contribution in southern part. Within a definite period in the future, the ET0 would keep the same change trend as the past. This study provided a basis for developing appropriate measures to reduce the losses from drought in the Loess Plateau.
    Driving mechanisms of spatial differentiation in the growth rate of urban fringe area of Nanjing, East China.
    SHI Yun-feng1, LIU Mao-song1**, XU Chi1, YANG Xue-jiao1, ZHANG Ming-juan2, ZHANG Yan1, CHI Ting1
    2013, 32(3):  741-747. 
    Asbtract ( 1754 )   PDF (933KB) ( 414 )  
    To better understand the driving mechanisms of urban growth, a multiscale analysis was made on the changes of the settlements in the urban fringe area of Nanjing and the driving mechanisms of the spatial differentiation in the urban growth rate, by using the spatial analysis and generalized linear models and based on the Landsat TM images in 1998, 2003, and 2008. In 1998-2008, the settlement coverage in the urban fringe area of Nanjing had a continuous increase, and there existed significant differences in the settlement distribution and its growth rate among different locations and time periods. The settlement growth in the urban fringe area was affected by a variety of factors, which depended on the spatial and temporal scales of interest. In 1998-2003, the main affecting factors were the water body’s coverage, bus stop number, nearest distance to main roads, and forest coverage. In 2003-2008, the affecting factors included nearest distance to main roads, public green land, and bus stop number. Overall, the transportation accessibility and the quality of living environments affected the urban growth rate at all studied scales, but the specific factors were scaledependent. Transportation accessibility generally had the highest relative importance in affecting urban growth. The negative effects of urban infrastructure and public green land reflected the constraint of growing space, and the constraining effect only occurred at a small scale in 1998-2003 but turned to be significant at both small and large scales in 2003-2008.
    Landscape pattern change and its driving forces in agricultural oasis of Sangong River basin in Xinjiang, Northwest China in recent 30 years.
    LU Qing1,2, LIU Li-juan1, WANG Yu-gang1**, LI Yan1
    2013, 32(3):  748-754. 
    Asbtract ( 1813 )   PDF (1310KB) ( 351 )  
    The imbalance utilization of water and land resources in oasis has resulted in serious desertification in inland river basin of arid area. Taking the agricultural oasis in the Sangong River basin of Xinjiang as a case, this paper studied the landscape pattern change and its driving forces at basin scale, based on the Landsat images data in 1978, 1987, 1998, and 2009, and by using the theories of landscape ecology and the methods of GIS, RS, and statistics. In the oasis, the increasing intensity of land exploitation under human activities increased the landscape diversity, and intensified the landscape fragmentation. The main landscape patch types changed from the grassland in natural landscape type to the cropland in artificial landscape type. Due to the increasing area of cropland, more volumes of water resources were needed for agriculture, which promoted the construction of irrigation works. The changes in the water resources utilization pushed forward the oasis landscape evolution, while the anthropogenic activities also accelerated the evolution processes of the oasis landscape.

     
    Mercury methylation bacteria and methyl mercury producing: A review.
    LIANG Xiao-bing**
    2013, 32(3):  755-761. 
    Asbtract ( 3999 )   PDF (768KB) ( 518 )  
    Mercury methylation bacteria change inorganic mercury to the highest toxic methylmercury (MeHg) under anaerobic conditions, which can result the human’s MeHg exposure by bioaccumulation and biomagnification. This article reviews the species and phylogeny of mercury methylation bacteria, methylation mechanism, spatial location of MeHg producing and the affecting factors in aquatic environments. In aquatic environments, mercury methylation occurs mainly in the anaerobic sediments of oceans, estuaries, rivers and lakes. Sulfate-reducing bacteria (SRB) and iron-reducing bacteria (IRB) are the main methylation bacteria. Their species, community structure and distribution control MeHg production and effects to human health. The studies on the biochemical mechanisms of mercury methylation show that MeHg may be produced from different metabolism pathways, but there still exist no consistent conclusions on mercury methylation mechanism. Spatial distribution of MeHg producing in sediments and the rate of mercury methylation are controlled by the distribution of mercury methylation bacteria, therefore the geochemical factors in aquatic environments affect the distribution of methylation bacteria, methylation rate and MeHg producing.
    Ecological significance and industrial application of extracellular polysaccharides from cyanobacteria: A review.
    REN Xin-xin1, JIANG Hao1,2, LENG Xin1, AN Shu-qing1**
    2013, 32(3):  762-771. 
    Asbtract ( 3075 )   PDF (623KB) ( 604 )  
    Cyanobacteria can produce extracellular polysaccharides (EPS) and release them to the environment, which is one of the adaptive mechanisms of cyanobacteria evolved to face complicated and variable environment. As a protective barrier between cell and environment, the EPS play a protective role against desiccation, ultraviolet radiation, biomineralization, or predation by protozoans. The EPS produced by cyanobacteria are a kind of complex anionic heteropolymer polysaccharides, more than 75% of which are composed of six or more monosaccharaides. Glucose is the most frequent kind of monosaccharaides. The characteristics of the EPS vary with cyanobacterial species. Most of the EPS show an anionic feature due to the charged groups, such as uronic acid and sulfate groups. Sulfate group is the basis of the anti-viral properties of polysaccharides, while hydrophobic groups such as ester-linked acetyl groups, peptides moieties, and deoxy sugars contribute to emulsifying properties. Therefore, the EPS produced by cyanobacteria have a broad application prospect in many industries, such as food additives, cosmetology, pharmacology, and wastewater treatment. The industrial application of the EPS can not only reuse the cyanobacteria bloom, bringing considerable economic benefits, but also provide a solution to the salvaging cyanobacteria distribution problem, avoiding its secondary pollution. Until now, there is no commodity from cyanobacterial EPS, and many technical problems are needed to be solved between the theoretical study and large batch industrial production.
     
    Best management practices of agricultural non-point source pollution in China: A review.
    SUN Qi-qi1,2, ZHANG Chun-ping3, YU Xing-xiu2**, LI Jian-hua1,2, ZHANG Yong-kun1,2, GAO Yan1,2
    2013, 32(3):  772-778. 
    Asbtract ( 1545 )   PDF (517KB) ( 581 )  
    Best management practices (BMPs) are of significance in controlling agricultural non-point source pollution. This paper reviewed the research progress of BMPs in China from the aspects of 1) the classification of BMPs types (source control, migration pathways interception, and terminal treatment) based on the position of key pollutants source, and 2) the assemblage of BMPs at spatial unit scales (watershed and administrative area) based on the environmental background of implementing BMPs. It was pointed out that the existing BMPs researches were mainly insufficient in theory, cost-benefit analysis, measurements optimal assemblage, and environmental effect evaluation. Accordingly, the issues that should be put into priority in the future would be the theory system construction, model simulation, measures research and development and technologies integration, spatialscale transformation, and benefit evaluation. This paper could benefit the improvement of BMPs construction level and research quality in China, and also, provide theoretical reference and scientific evidence for the prevention and control of agricultural non-point source pollution and the improvement of water quality in China.
    Screening of an efficient biosurfactant-producing bacterial strain and the structure and property of its surface-active metabolic product.
    XIAO Bing1,2, YANG De-yu1,2, SHI Rong-jiu2**, ZHANG Ying2, ZHANG Yang1, HAO Jin-sheng3, LI Guo-qiao3, ZHAO Jin-yi3
    2013, 32(3):  779-786. 
    Asbtract ( 1528 )   PDF (867KB) ( 415 )  
    By adopting blood-agar procedure combined with surface tension screening strategy, an efficient surfactant-producing bacterial strain DY-9 was successfully isolated from the produced water from low-permeability Gaotaizi oil reservoir, Daqing Oilfield of Northeast China. The comparison with the homoeologous 16S rDNA sequences deposited in the GenBank showed that the DY9 had a 99% sequence similarity with Bacillus licheniformis. When cultured on a medium with 20 g·L-1 of molasses as the sole carbon source at 180 r·min-1 and 45 °C, the DY-9 could grow well, and decrease the surface tension of culture broth from initial 69.3 mN·m-1 to 26.5 mN·m-1 within 24 h. After cultured for 48 h, the maximum raw biosurfactant yield of the strain reached 0.48 g·L-1, and the critical micelle concentration was 28 mg·L-1. The biosurfactant produced by the DY9 could keep stable under the conditions of high temperature (120 °C) for 1 h, high salinity (12% NaCl), and wide pH (2-12), and the surface tension of the zymotic fluid within 48h was lower than 30 mN·m-1. The analysis with infrared spectroscopy (IF-TR) and high-pressure liquid chromatographymass spectrometry (HPLC-MS) revealed that the surface-active product of the DY-9 was a cyclic structure lipopeptide biosurfactant.
    Effect evaluation of various protective systems in the Horqin Sand Land.
    ZHOU Quan-lai1**, YANG Hong1, JIANG De-ming1, ALAMUSA1, LI Xue-hua1, Toshio Oshid2
    2013, 32(3):  787-794. 
    Asbtract ( 1467 )   PDF (729KB) ( 409 )  
    We evaluated protection effects of ecological protection systems in six land use types at Wulanaodu village in the Horqin Sand Land. Analytic hierarchy process (AHP) was used with six evaluation indices by building AHP model. The evaluation scores of the six land use types were 0.263, 0.170, 0.206, 0.169, 0.103 and 0.088 in forest land, shrub land, grass land, fixed dune, semi-fixed dune and active dune, respectively. By using the ratio of areas of different land use types to the total area as weights of evaluation score of the six land use types, the overall score of protection effect in the study area was 0.133, only 50.6% of the score in forest land. Theoretically, the score of total area could be increased to 67.2% of score of forest land by forestation and sand dune stabilization. However, the protection effects of ecological protection systems in the Horqin Sand Land were low due to influences of climate, soil and human activities. Therefore, we have a long way to go in enhancing protective effects of the various systems when we are facing a serious contradiction between ecological construction and national policies and  economic development.