Table of Content

18 October 2014, Volume 25 Issue 10

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Spatiotemporal variation characteristics and related affecting factors of actual evapotranspiration in the Hun-Taizi River Basin, Northeast China.

FENG Xue1,2, CAI Yan-cong1,2, GUAN De-xin1, JIN Chang-jie1, WANG An-zhi1, WU Jia-bing1, YUAN Feng-hui1

2014, 25(10):  2765-2771. 

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Based on the meteorological and hydrological data from 1970 to 2006, the advection-aridity (AA) model with calibrated parameters was used to calculate evapotranspiration in the HunTaizi River Basin in Northeast China. The original parameter of the AA model was tuned according to the water balance method and then four subbasins were selected to validate. Spatiotemporal variation characteristics of evapotranspiration and related affecting factors were analyzed using the methods of linear trend analysis, moving average, kriging interpolation and sensitivity analysis. The results showed that the empirical parameter value of 0.75 of AA model was suitable for the HunTaizi River Basin with an error of 11.4%. In the Hun-Taizi River Basin, the average annual actual evapotranspiration was 347.4 mm, which had a slightly upward trend with a rate of 1.58 mm·(10 a^-1), but did not change significantly. It also indicated that the annual actual evapotranspiration presented a singlepeaked pattern and its peak value occurred in July; the evapotranspiration in summer was higher than in spring and autumn, and it was the smallest in winter. The annual average evapotranspiration showed a decreasing trend from the northwest to the southeast in the HunTaizi River Basin from 1970 to 2006 with minor differences. Net radiation was largely responsible for the change of actual evapotranspiration in the Hun-Taizi River Basin.

Aboveground biomass and nutrient distribution patterns of larch plantation in a montane region of eastern Liaoning Province, China.

YAN Tao1,2,3, ZHU Jiao-jun1,2, YANG Kai1,2, YU Li-zhong1,2

2014, 25(10):  2772-2778. 

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Larch is the main timber species of forest plantations in North China. Imbalance in nutrient cycling in soil emerged due to single species composition and mono system structure of plantation. Thus it is necessary to grasp its biomass and nutrients allocation for scientific management and nutrient cycling studies of larch plantation. We measured aboveground biomass (stem, branch, bark and leaf) and nutrient concentrations (C, N, P, K, Ca, Mg, Fe, Mn, Cu and Zn), and analyzed the patterns of accumulation and distribution of 19-year-old larch plantation with diameter at breast height  of 12.8 cm, tree height of 15.3 m, and density of 2308 trees·hm^-2, in a montane region of eastern Liaoning Province, China. The results showed that aboveground biomass values were 70.26 kg and 162.16 t·hm^-2 for the individual tree of larch and the stand, respectively. There was a significant difference between biomass of the organs, and decreased in the order of stem > branch > bark > leaf. Nutrient accumulation was 749.94 g and 1730.86 kg·hm^-2 for the individual tree of larch and the stand, respectively. Nutrient accumulation of stem was significantly higher than that of branch, bark and leaf, whether it was macronutrient or micronutrient. Averagely, 749.94 g nutrient elements would be removed from the system when a 19-year-old larch tree was harvested. If only the stem part was removed from the system, the removal of nutrient elements could be reduced by 40.7%.

Prediction of spatial distribution of forest carbon storage in Heilongjiang Province using spatial error model.

LIU Chang, LI Feng-ri, ZHEN Zhen

2014, 25(10):  2779-2786. 

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Based on the data from Chinese National Forest Inventory (CNFI) and Key Ecological Benefit Forest Monitoring plots (5075 in total) in Heilongjiang Province in 2010 and concurrent meteorological data coming from 59 meteorological stations located in Heilongjiang, Jilin and Inner Mongolia, this paper established a spatial error model (SEM) by GeoDA using carbon storage as dependent variable and several independent variables, including diameter of living trees (DBH), number of trees per hectare (TPH), elevation (Elev), slope (Slope), and product of precipitation and temperature (Rain_Temp). Global Moran’s I was computed for describing overall spatial autocorrelations of model results at different spatial scales. Local Moran’s I was calculated at the optimal bandwidth (25 km) to present spatial distribution residuals. Intrablock spatial variances were computed to explain spatial heterogeneity of residuals. Finally, a spatial distribution map of carbon storage in Heilongjiang was visualized based on predictions. The results showed that the distribution of forest carbon storage in Heilongjiang had spatial effect and was significantly influenced by stand, topographic and meteorological factors, especially average DBH. SEM could solve the spatial autocorrelation and heterogeneity well. There were significant spatial differences in distribution of forest carbon storage. The carbon storage was mainly distributed in Zhangguangcai Mountain, Xiao Xing’an Mountain and Da Xing’an Mountain where dense forests existed, rarely distributed in Songnen  Plains, while Wanda Mountain had moderatelevel carbon storage.

Remote sensing estimation of urban forest carbon stocks based on QuickBird images.

XU Li-hua1, ZHANG Jie-cun1, HUANG Bo1, WANG Huan-huan1, YUE Wen-ze2

2014, 25(10):  2787-2793. 

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Urban forest is one of the positive factors that increase urban carbon sequestration, which makes great contribution to the global carbon cycle. Based on the high spatial resolution imagery of QuickBird in the study area within the ring road in Yiwu, Zhejiang, the forests in the area were divided into four types, i.e., parkforest, shelterforest, companyforest and others. With the carbon stock from sample plot as dependent variable, at the significance level of 0.01, the stepwise linear regression method was used to select independent variables from 50 factors such as band grayscale values, vegetation index, texture information and so on. Finally, the remote sensing based forest carbon stock estimation models for the four types of forest were established. The estimation accuracies for all the models were around 70%, with the total carbon reserve of each forest type in the area being estimated as 3623.80, 5245.78, 5284.84, 5343.65 t, respectively. From the carbon density map, it was found that the carbon reserves were mainly in the range of 25-35 t·hm^-2. In the future, urban forest planners could further improve the ability of forest carbon sequestration through afforestation and interplanting of trees and low shrubs.

Carbon density and production in  valley spruce-fir forest in Xiaoxing’an Mountains, China.

CAI Hui-ying1, DI Xue-ying2, JIN Guang-ze1

2014, 25(10):  2794-2802. 

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The carbon density and production were measured using both forest inventory and allometry approaches in the declining valley sprucefir  forest in Xiaoxing’an Mountains. Results showed that the total carbon density of the forest was 268.14 t C·hm^-2 in 2011, and carbon densities of the vegetation, detritus and soil were 74.25, 16.86 and 177.03 t C·hm^-2, respectively. From 2006 to 2011, tree layer carbon density decreased from 80.86 t C·hm^-2 to 71.73 t C·hm^-2. The average decrease proportions per year of carbon density were 0.5%, 1.2%, 2.7% and 3.7% for Abies nephrolepis, Betula platyphylla, Picea spp., and Larix gmelinii, respectively. However, carbon densities were increased by 2.9%, 3.9% and 7.2% per year for Alnus sibirica, Pinus koraiensis and Acer ukurunduense, respectively. Net primary production (NPP) of the forest was 4.69 t C·hm^-2·a^-1. The ratio of belowground NPP to aboveground NPP was 0.56. Litterfall accounted for the largest proportion of the NPP of forest with a value of 34.5%. As the two most important carbon output approaches of forest ecosystems, the fluxes of heterotrophic respiration and coarse woody debris decomposition were 293.67 and 119.29 g C·m^-2·a^-1, respectively. Net ecosystem production (NEP) of the forest was 55.90 g C·m^-2·a^-1. The results indicated that the  valley sprucefir forest in the declining state still had a certain carbon sink capacity.


 

Effects of topography on the diversity and distribution pattern of ground plants in karst montane forests in Southwest Guangxi, China.

YUAN Tie-xiang1,2,3, ZHANG He-ping1, OU Zhi-yang2,3, TAN Yi-bo2,3

2014, 25(10):  2803-2810. 

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Covariance analysis, curvefitting, and canonical correspondence analysis (CCA) were used to explore the effects of topographic factors on the plant diversity and distribution patterns of ground flora with different growth forms in the karst mountains of Southwest Guangxi, China. A total of 152 ground plants were recorded. Among them, 37 species were ferns, 44 species herbs, 9 species lianas, and 62 species shrubs. Covariance analysis revealed that altitude significantly correlated with the individual number and richness of ground plants, and slope aspect had a significant effect on richness. Statistical analyses showed a highly significant nonlinear correlation between the individual number or richness of ground plants and altitude. Results of CCA revealed that slope aspect had a significant effect on the distribution pattern of ferns, and slope had a significant effect on the distribution patterns of herbs, lianas and shrubs. Ferns were more sensitive than herbs, lianas and shrubs to changes in heat and soil water caused by aspect. The effect of slope was stronger than that of elevation on soil water and nutrients, and it was the most important topographic factor that affected the distribution patterns of herbs, lianas and shrubs in this region.

Change of vegetation net primary productivity in Yellow River watersheds from 2001 to 2010 and its climatic driving factors analysis.

CHEN Qiang1,2, CHEN Yun-hao1,2, WANG Meng-jie1,2, JIANG Wei-guo2, HOU Peng3, LI Ying3

2014, 25(10):  2811-2818. 

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Based on the MODIS-NDVI remotely sensed imagery, this paper analyzed the spatial distribution of vegetation net primary production (NPP) calculated by CASA model in Yellow River watersheds from 2001 to 2010. Associated with the temperature and precipitation data in the same period, this article respectively analyzed the change trends of vegetation NPP in six ecosystems with different spatial and temporal scales, and the relationship between NPP and climate factors. The results indicated that in terms of spatial scale, the vegetation NPP gradually reduced from northwest to southeast, the average of annual NPP was 108.53 Tg C, and the spatial distribution of vegetation NPP was highly related with the land cover types. In terms of temporal scale, the vegetation NPP gradually increased from 2001 to 2010, but this change trend had large differences in these regions. On annual level, the vegetation NPP had no significant correlation with climate factors, but precipitation and temperature had considerable impacts on the vegetation NPP on monthly level. The correlations between NPP and climate factors were different in different ecosystems, so did the time lag effect of the climate factors. The air temperature response of the NPP variation was relatively sensitive in forest ecosystem and the precipitation response was significant in grassland and wetland ecosystems. Additionally, the precipitation response of the NPP variation in grassland ecosystem had time lag effect and so did the air temperature response in desert ecosystem.

Soil humus differentiation and correlation with other soil biochemical properties in pure forests in semiarid lowhilly area of Inner Mongolia, China.

ZHANG Xiao-xi1, LIU Zeng-wen2,3, BING Yuan-hao4, ZHU Bo-chao2, HUANG Liang-jia2

2014, 25(10):  2819-2825. 

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Whether the content and composition of soil humus in pure forest change due to its simple component of litter and specificity of singlespecies dominant community is a key problem for forest sustainable management. In this study, soils from 6 kind of pure forests in semiarid lowhilly area of Inner Mongolia were collected and their humus and other biochemical properties were measured to investigate the differentiation of soil humus and the impact factors. The results showed that the soil of Picea asperata and Betula platyphylla pure forests had the highest contents of humus and better condensation degrees and stabilities, followed by that of Populus simonii, Larix principisrupprechtii and Ulmus pumila pure forests, while the soil of Pinus tabuliformis pure forest had the lowest content of humus, condensation degree and stability. There were significant positive correlations between soil microorganism biomass, activity of phosphatase and the content and stability of soil humus. In contrast, the soil peroxidate, dehydrogenase activity and soil humus content showed significant negative correlations with each other. Furthermore, the enhancement of dehydrogenase activity might decrease the stability of humus. There were significant positive correlations between available N and the content and stability of soil humus, but total Cu, Zn and Fe had negative correlations with them, and total Cu and Fe might reduce the stability of humus as well. The particularity of pure forest environment and litter properties might be the key inducement to soil humus differentiation, thus reforming the pure forest through mixing with other tree species or planting understory vegetation would be the fundamental way to improve the soil humus composition and stability.

Effects of light intensity contrast on clonal integration of Spartina anglica.

JIANG Xing-xing, DONG Bi-cheng, LUO Fang-li, ZHU Rui, XU Xi-yi, LI Hong-li, YU Fei-hai

2014, 25(10):  2826-2832. 

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We conducted a greenhouse experiment to test how clonal integration affected the growth responses of Spartina anglica to light intensity heterogeneity in light availability and whether such effects depended on contrast light intensity. The experiment had three homogeneous treatments and two heterogeneous treatments. In the homogeneous treatments, both ramets of a connected ramet pair were unshaded (high light intensity), moderately shaded (medium light intensity, 70% of the high light intensity) and deeply shaded (low light intensity, 30% of the high light intensity). In the heterogeneous treatments, one ramet of a pair was unshaded, but its connected ramet was either moderately shaded (low light intensity contrast) or deeply shaded (high light intensity contrast). In the homogeneous treatments, biomass of S. anglica was significantly higher in the high light intensity treatment than in the medium and low light intensity treatments. Number of leaves, root length, and total biomass were significantly higher in the shaded ramet in the heterogeneous treatment with low light intensity contrast than in the ramet in the homogeneous treatment with medium light intensity. Final size and mass were not significantly different between the unshaded ramet in the heterogeneous treatment with low light intensity contrast and the ramets in the homogeneous high light intensity treatment. These results suggested that clonal integration  benefitted a shaded ramet with little cost to an unshaded ramet when contrast in light intensity was low. However, effects of clonal integration were not significant when contrast was high. It therefore appeared that effects of clonal integration on the growth of S. anglica did not increase with increasing light intensity contrast. In natural habitats, clonal integration might improve growth of S. anglica when its ramets are moderately shaded by other plants but not when they are deeply shaded.

 

Variation of soil respiration and its underlying mechanism in grasslands of northern China.

HOU Jian-feng1,2, LU Xiao-tao1, WANG Chao1, WANG Peng1

2014, 25(10):  2840-2846. 

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Soil respiration is one of the most important variables in terrestrial ecosystem progresses and global carbon cycle, and determines the CO2 flux from soil to atmosphere. Soil respiration also has great implications for predicting regional and even global carbon cycle changes under the background of global climate change. We measured respiration rates of soil samples collected from northern China grassland transect by short term incubation experiment in laboratory. Results showed that soil respiration rates increased with mean annual precipitation (MAP) from west sites to east sites, ranging from 0.35 to 2.09 μg CO₂C·g^-1·h^-1. The variation range of soil respiration rates were 0.35-0.73 μg CO₂C·g^-1·h^-1 with MAP＜100 mm, 0.57-0.98 μg CO₂C·g^-1·h^-1 with MAP between 100 mm and 200 mm and 0.83-2.10 μg CO₂C·g^-1·h^-1 with MAP>300 mm, respectively. Soil respiration had a significant positive relationship with MAP, aboveground biomass, soil organic carbon and nitrogen content, while had a negative relationship with mean annual temperature and soil pH. Analysis of boosted regression tree showed that the predictors accounted for the explained variation included MAP (25.5%), aboveground biomass (23.6%), soil organic carbon content (18.3%) and soil organic nitrogen content (12.5%), and soil pH and mean annual temperature only explained 10.8% and 9.2% of the total variation, respectively.

 

Carbon and nitrogen distributions and microbial characteristics in the soils of four types of wetlands in Sanjiang Plain, Northeast China.

XIAO Ye1,2, HUANG Zhi-gang3, WU Hai-tao1, LU Xian-guo1

2014, 25(10):  2847-2854. 

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Four typical wetlands in the Honghe Wetland Reserve of Sanjiang Plain (i.e. wetlands with the following dominant plant species: Calamagrostis angustifolia+Salix brachypoda, Calamagrostis angustifolia, Carex lasiocarpa, and Phragmites australis) were selected to analyze the changes of soil organic carbon (SOC) and total nitrogen (TN) contents and various indices of microbial characteristics including soil sucrose, catalase, cellulase, microbial biomass carbon/nitrogen (MBC/MBN), microbial respiration (MBR), microbial quotient (q_MB), and metabolic quotient (qCO₂), as well as the correlations among them. The results showed that SOC and TN contents decreased with increasing the soil depth, and varied significantly (P<0.01) in the different wetland types. Soil enzyme activities (except catalase), MBC, MBN and MBR also decreased significantly with increasing the soil depth in the wetlands with the greatest activities being detected in surface soil (0-10 cm). In soil layer of 0-30 cm, several parameters (including SOC, TN, soil enzyme activities, MBC, MBN, MBR, q_MB and qCO₂) were higher in the wetlands dominated by C. angustifolia+S. brachypoda and C. angustifolia, compared with those with C. lasiocarpa and P. australis as dominant plant species. Statistical analyses revealed significant correlations (P<0.01) between major microbial indicators (except qCO₂) with SOC and TN contents in the soils. It demonstrated that the microbial characteristics were the major indicators, and played an important role in the changes of SOC and TN in wetland soils.

Comparison of light response models of photosynthesis in Nelumbo nucifera leaves under different light conditions.

LENG Han-bing, QIN Jun, YE Kang, FENG Shu-cheng, GAO Kai

2014, 25(10):  2855-2860. 

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The light responses of Nelumbo nucifera ‘Boli Furen’, a local N. nucifera species was investigated under full light and 50% shading conditions in Shanghai. The net photosynthetic rate-light response curves of N. nucifera leaves were fitted and analyzed through four light response models to identify the bestfit models of different light conditions and explore the adaptability of N. nucifera to shading environment. The results showed that the sequence of fitting effect of the four light response models was in descending order of modified rectangular hyperbola model > exponential model > nonrectangular hyperbola model > rectangular hyperbola model. The latter three models had no extreme values, and could not directly and accurately provide values of light saturation point (LSP) and maximum net photosynthetic rate (P_{n max}). In contrast, the modified rectangular hyperbola model showed the best fit for LSP, P_{n max}, dark respiration rate (R_d) and LCP resulting in the minimum relative errors  between the measured and fitted values. Light response parameters of N. nucifera declined with the decreasing light. There were no significant differences between full light and shade treatments except for R_d. It was indicated that N. nucifera had good photosynthetic adaptive response and adjustment to weak light to maintain normal growth.

Effects of wheat root exudates on cucumber growth and soil fungal community structure.

WU Feng-zhi, LI Min, CAO Peng, MA Ya-fei,WANG Li-li

2014, 25(10):  2861-2867. 

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With wheat as the donor plant and cucumber as the receptor plant, this study investigated the effects of root exudates from wheat cultivars with different allelopathic potentials (positive or negative) and companion cropping with wheat on soil fungal community structure by PCR-DGGE method and cucumber growth. Results showed that the wheat root exudates with positive allelopathic potential increased height and stem diameter of cucumber seedlings significantly, compared to the control seedlings (W) after 6 days and 12 days treatment, respectively. Also, wheat root exudates with both positive and negative allelopathic potential increased the seedling height of cucumber significantly after 18 days treatment. The wheat root exudates with different allelopathic potentials decreased the band number, Shannon and evenness indices of soil fungal community significantly in cucumber seedling rhizosphere, and those in the soil with the control seedlings (W) were also significantly higher than that in the control soil without seedlings (Wn) after 6 days treatment. The band number, Shannon and evenness indices in all the treatments were significantly higher than those in the control soil without seedlings (Wn) after 18 days treatment. Companion cropping with negative allelopathic potential wheat decreased the Shannon and evenness indices of soil fungi community significantly in the cucumber seedling rhizosphere, suggesting the wheat root exudates and companion cropping with wheat changed soil fungal community structure in the cucumber seedling rhizosphere. The results of DGGE map and the principal component analysis showed that companion cropping with wheat cultivars with different allelopathic potentials changed soil fungal community structure in cucumber seedling rhizosphere.

Effects of nitrogen management on maize nitrogen utilization and residual nitrate nitrogen in soil under maize/soybean and maize/sweet potato relay strip intercropping systems.

WANG Xiao-chun1, YANG Wen-yu1, DENG Xiao-yan1, ZHANG Qun1, YONG Tai-wen1, LIU Wei-guo1, YANG Feng1, MAO Shu-ming2

2014, 25(10):  2868-2878. 

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A large amount of nitrogen (N) fertilizers poured into the fields severely pollute the environment. Reasonable application of N fertilizer has always been the research hotpot. The effects of N management on maize N utilization and residual nitrate N in soil under maize/soybean and maize/sweet potato relay strip intercropping systems were reported in a field experiment in southwest China. It was found that maize N accumulation, N harvest index, N absorption efficiency, N contribution proportion after the anthesis stage in maize/soybean relay strip intercropping were increased by 6.1%, 5.4%, 4.3%, and 15.1% than under maize/sweet potato with an increase of 22.6% for maize yield after sustainable growing of maize/soybean intercropping system. Nitrate N accumulation in the 0-60 cm soil layer was 12.9% higher under maize/soybean intercropping than under maize/sweet potato intercropping. However, nitrate N concentration in the 60-120 cm soil layer when intercropped with soybean decreased by 10.3% than when intercropped with sweet potato, indicating a decrease of N leaching loss. Increasing of N application rate enhanced N accumulation of maize and decreased N use efficiency and significantly increased nitrate concentration in the soil profile except in the 60-100 cm soil layer, where no significant difference was observed with nitrogen application rate at 0 to 270 kg·hm^-2. Further application of N fertilizer significantly enhanced nitrate leaching loss. Postponing N application increased nitrate accumulation in the 60-100 cm soil layer. The results suggested that N application rates and ratio of base to top dressing had different influences on maize N concentration and nitrate N between maize/soybean and maize/sweet potato intercropping. Maize N concentration in the late growing stage, N harvest index and N use efficiency under maize/soybean intercropping increased (with N application rate at 180-270 kg·hm^-2 and ratio of base to top dressing = 3:2:5) and decreased nitrate leaching loss with yield reaching 7757 kg·hm^-2 on average. However, for maize/sweet potato, N concentration and use efficiency and maize yield increased significantly with N application rate at 180 kg·hm-2 and ratio of base to top dressing=5:5 than that under other treatments with yield reaching 6572 kg·hm^-2. Under these circumstances, it would be possible to realize maize high yield, high efficiency and safety of N management under maize/soybean and maize/sweet potato relay strip intercropping systems.

 

Effect of shorttime drought process on denitrifying bacteria abundance and N₂O emission in paddy soil.

LU Jing1,2,3, LIU Jin-bo4, SHENG Rong1,2, LIU Yi1,2, CHEN An-lei1,2, WEI Wen-xue1,2

2014, 25(10):  2879-2884. 

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In order to investigate the impact of drying process on greenhouse gas emissions and denitrifying microorganisms in paddy soil, wettingdrying process was simulated in laboratory conditions. N₂O flux, redox potential (Eh) were monitored  and narG and nosZcontaining denitrifiers abundances were determined by realtime PCR. N₂O emission was significantly increased only 4 h after drying process began, and it was more than 6 times of continuous flooding (CF) at 24 h. In addition, narG and nosZ gene abundances were increased rapidly with the drying process, and N₂O emission flux was significantly correlated with narG gene abundance (P<0.01). Our results indicated that the narGcontaining deniteifiers were the main driving microorganisms which caused the N₂O emission in the short-time drought process in paddy soil.

Effects of straw incorporation on rice carbon sequestration characteristics and grain yield formation.

PEI Peng-gang1, ZHANG Jun-hua1,2, ZHU Lian-feng1, YU Sheng-miao1, HU Zhi-hua1, JIN Qian-yu1

2014, 25(10):  2885-2891. 

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A field experiment was conducted to study the effects of straw incorporation on rice dry matter accumulation and transportation, rice carbon sequestration and grain yield formation. The experiment included four levels of straw incorporation: 0 (control), 4000, 6000 and 8000 kg·hm^-2. Hybrid rice cultivar Zhongzheyou 1 was used in this experiment. The results showed that the average rice dry matter accumulation amount of the three straw incorporation treatments was increased by 63.03 g·m^-2 compared with the control, and that of straw incorporation of 6000 kg·hm^-2 showed the most favorable result, which was 154.40 g·m^-2 higher than the control. Effects of straw incorporation on rice dry matter accumulation showed the best performance from the maximum tillering stage to the full heading stage, and the dry matter accumulation at this stage was 71.25 g·m^-2 higher than the control. Compared with the control, the average dry matter exportation rate and apparent transformation rate from rice stem and leaf in the straw incorporation treatments were increased by 4.2% and 3.7%, respectively. The highest dry matter exportation rate and apparent transformation rate from rice stem and leaf were observed in the straw incorporation treatment of 6000 kg·hm^-2, which were increased by 12.8% and 11.1% compared to the control, respectively. The average rice carbon sequestration from the straw incorporation treatments was increased by 55.38 g·m^-2 compared with the control, and straw incorporation of 6000 kg·hm^-2 performed best with an increase of 17.8% compared with the control. Straw incorporation played a positive role in regulating the carbon sequestration of stem and leaf at the early growth stage and carbon sequestration of spike at the late growth stage. The average grain yield from the straw incorporation treatments was increased by 794.59 kg·hm^-2 (9.5% higher) compared with the control. Rice grain yields from the straw incorporation treatments of 6000 and 4000 kg·hm^-2 were significantly higher than the control, while rice grain yield from the straw incorporation treatment of 8000 kg·hm^-2 did not show a significant increase compared to the control. The rice grain yield was closely related to the yield components, and the increase of effective panicles may be the main reason for the higher grain yields in the straw incorporation treatments. Effective panicles in the straw incorporation treatments was averagely 8.41 spikes·m^-2 more than the control.

Effects of climate change on flax development and yield in Guyuan of Ningxia, Northwest China.

LI Shu-zhen1, SUN Lin-li2,3, MA Yu-ping3, XU Yu-dong3, E You-hao3

2014, 25(10):  2892-2900. 

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Based on variations of the annual mean temperature and precipitation analyzed using observation data in Guyuan of Ningxia, the effects of climate change on the local flax developmental process and yield were investigated. The results showed that the annual mean temperature had an increasing trend (0.3 ℃·(10 a)^-1) and the annual precipitation had a decreasing trend (-20 mm·(10 a)^-1) from 1957 to 2012. While the increasing trend of mean temperature during growing season of flax was more obviously than that of the annual temperature, the decreasing trend of precipitation during growing season was similar to that of annual precipitation. With temperature increasing and precipitation decreasing, the flax development rate was accelerated, resulting in the reduced growing period. Seedling stage was advanced 0.7 d with 1 ℃ increase in temperature during the period from sowing to seedling emergence. The duration from seedling emergence to two pairs of needles was shortened by 0.8 d with 1 ℃ increase in temperature and 0.1 d with 1 mm decrease in precipitation. Maturity stage was advanced 1.8 d with 1 ℃ increase in temperature and 0.1 d with 1 mm decrease in precipitation during the period from technical maturity to maturity. The flax development was accelerated because of temperature increasing and precipitation decreasing in the vegetative growth phase, which was one of the main causes of flax yield reduction year by year. Meanwhile, flower bud differentiation and pollination of flax were influenced by temperature increasing in the reproductive growth phase, which would affect the number of capsules and the seed setting rate per plant and lead to the decrease of flax yield. Therefore, adjusting plant structure and enlarging the planting area of late or middlelate variety were the important measures to reduce the effects of climate change on local flax production.

 

Effects of different nitrogen regulators on nitrogen transformation in different soil types.

LIU Jian-tao1,2, XU Jing1, SUN Zhi-mei1, CUI Shao-xiong1,2, WANG Xue1,2

2014, 25(10):  2901-2906. 

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Laboratory incubation experiments were conducted to compare the inhibitory effects of dicyandiamide (DCD) and 3,5-dimethylpyrazole (DMP) on nitrification in meadowcinnamon soil and fluvo-aquic soil, the main soil types of North China Plain. The synergistic effect of DMP combined with urease inhibitor hydroquinone (HQ) on nitrogen transformation in fluvo-aquic soil was further studied. The results indicated that, in contrast to DCD, DMP had a stronger inhibitory effect on the nitrification in the two tested soils. In comparison with the treatment without any inhibitor, the soil NH₄⁺-N content in the treatment with DMP increased significantly by 149.5%-387.2% at the peak of nitrogen transformation stage, and the soil NO₃^--N content reduced by 22.3%-55.3%. The inhibitory effects of DCD and DMP in fluvo-aquic soil were both stronger than in meadow-cinnamon soil. In addition, the application of DMP combined with HQ had a significantly synergistic effect on soil nitrogen transformation.

Effects of nitrogen application and winter green manure on soil active organic carbon and the soil carbon pool management index.

YANG Bin-juan, HUANG Guo-qin, LAN Yan, CHEN Hong-jun, WANG Shu-bin

2014, 25(10):  2907-2913. 

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Based on a copping system of “winter green manuredouble rice”, the 4× 4 twofactor test was used to study the effects of different nitrogen (N) application levels and winter green manure application on soil active organic carbon (AOC) and the C pool management index. The aim was to explore the ecological effects of winter green manure on soil improvement and determine the appropriate application levels of N fertilizer and winter green manure for improved rice yield. Results were as follows: 1) Compared with the control, the SOC and AOC contents increased by 22.2% and 26.7%, respectively, under the green manure only treatment, but the SOC contents decreased by 0.6%-3.4% under the single N fertilizer treatment. Compared with the control, the soil C pool management index increased by 24.55 and 15.17 under the green manure only and green manure plus N fertilizer treatments, respectively, and reduced by 2.59 under the single N fertilizer treatment. Compared with no fertilization, the average microbial biomass carbon (MBC)  increased by 54.0%, 95.2% and 14.3% under the green manure, green manure plus N fertilizer and single N fertilizer treatments, respectively. 2) The soil AOC content was significantly positively correlated with the C pool management index (P<0.01), and had a significant correlation with dissolved organic C and MBC (P<0.05). Rice yield was significantly positively correlated with AOC contents and the C pool management index, and the correlation coefficient was significantly greater than that with the total organic C. These results suggested that application of winter green manure at proper rates with inorganic fertilizer could increase SOC contents and the soil C pool management index, improve soil quality and fertility.

Soil pH buffer capacity of tea garden with different planting years.

SU You-jian1,2, WANG Ye-jun1, ZHANG Yong-li1, LUO Yi1, SUN Li1, SONG Li1, LIAO Wan-you1

2014, 25(10):  2914-2918. 

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In order to investigate the effects of longterm tea planting on soil pH buffer capacity (pHBC), the variation of  pHBC and its influence factors were investigated in tea gardens of 10, 15, 20, 25 and 30 years in Langxi and Qimen of Anhui Province. The results showed that the acidbase titration method was suitable for the determination of soil pHBC of tea gardens. The amount of acidbase added had approximate linear relationship with soil pH value in specific section (pH 4.0-6.0) of acidbase titration curves, so the soil pHBC could be calculated by linear regression equation. Soil pHBC in the tea gardens from the two regions showed a downward trend with increasing the planting years, which decreased at rates of 0.10 and 0.06 mmol·kg^-1·a^-1 in Langxi and Qimen tea gardens, respectively. Soil pHBC had significant positive correlation with CEC, soil organic matter, base saturation and physical clay content, and significant negative correlation with exchangeable acid and exchange H⁺.

 

Effect of 5-aminolevulinic acid on photosynthetic characteristics of tomato seedlings under NaCl stress.

ZHAO Yan-yan, YAN Fei, HU Li-pan, ZHOU Xiao-ting, ZOU Zhi-rong

2014, 25(10):  2919-2926. 

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In this research, the possibility of exogenous application of 5-aminolevulinic acid (ALA) on photosynthetic characteristics of tomato seedlings under NaCl stress was investigated. Five leaves seedlings of tomato (Solanum lycopersicum cv. Jinpeng No.1) were used as starting materials, applied with 50 mg·L^-1 ALA by foliage spray or 10 mg·L^-1 ALA by root soaking to study the changes in their photosynthesis and fluorescence parameters under 100 mmol·L^-1 NaCl. The result showed that, photosynthetic gas exchange parameters (net photosynthetic rate P_n, stomata conductance g_s, intercellular CO₂ concentration C_i,
transpiration T_r) and chlorophyll fluorescence parameters (F_v′/F_m′, F_m′, Φ_PSⅡ, ETR, q_P, Pc) were severely reduced under NaCl treatment and ALA application by foliage spray or root soaking with proper concentrations exerted positive influences on tomato seedlings under salt stress, while there were some differences between foliage spray and root soaking in the influence on chlorophyll content, photosynthesis and chlorophyll fluorescence. Both foliage spray with 50 mg·L^-1ALA and root soaking with 10 mg·L^-1ALA significantly increased  P_n, C_i, g_s and  T_r of tomato seedlings under NaCl stress, alleviated photosynthetic inhibition. Root application of ALA had a better effect on the chlorophyll content than foliage application. However, the photosynthetic parameters showed that foliage application of ALA had a better effect than root application, and both treatments had no difference in the influence on chlorophyll fluorescence parameters of tomato seedlings. It could be deduced that the regulating effect of ALA on enhancing salt tolerance of tomato seedlings is attributed to its effect on improving chlorophyll biosynthesis and metabolism, increasing stomatal conductance and reducing stomatal limitation, thus, enhancing the photosynthetic capacity and PSⅡ photochemical efficiency of tomato leaves under NaCl stress.

Effects of cold-shock on tomato seedlings under high temperature stress.

LI Sheng-li, XIA Ya-zhen, LIU Jin, SHI Xiao-dan, SUN Zhi-qiang

2014, 25(10):  2927-2934. 

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High temperature stress (HTS) is one of the major limiting factors that affect the quality of intensively cultured seedlings in protected facilitates during hot season. Increasing the cross adaptive response of plant induced by temperature stress is an effective way to improve plant stress resistance. In order to explore the alleviating effect of coldshock intensity on tomato seedlings under HTS, tomato seedlings were subjected to cold-shock treatments every day with 5 ℃, 10 ℃, and 15 ℃ for 10 min, 20 min, and 30 min, respectively, in an artificial climate chamber. The effect of single appropriate cold-shock on the gene expression of small heat shock proteins LeHSP23.8 and CaHSP18 was investigated. The results showed that hypocotyl elongation and plant height of tomato seedlings were restrained by coldshock treatment before HTS was met. The alleviating effect of tomato seedlings under HTS by coldshock varied greatly with levels and durations of temperature. The membrane lipids in the leaf of tomato seedlings were subjected to peroxidation injury in the cold-shock treatment at 5 ℃, in which the penetration of cell membrane was increased and the activities of antioxidant enzyme was inhibited. The alleviating effect to HTS by cold-shock was decreased with the increasing cold-shock duration at 10 ℃, however, a reverse change was found at 15 ℃. The results indicated that cross adaptive response of tomato seedling could be induced with a moderate cold-shock temperature for a proper duration before HTS was met. The optimum cold-shock treatment was at 10 ℃ for 10 min per day, under which, the dry mass, healthy index, activities of protective enzymes (including SOD, POD and CAT) in leaves of tomato seedlings were significantly increased, the contents of proline and soluble protein were enhanced, relative conductivity and malondialdehyde concentration were significantly decreased, and the expression levels of LeHSP23.8 and CaHSP18 were increased compared with that under normal temperature condition.

Effects of irrigation threshold on soil temperature in blossom and fruit-set periods of muskmelon under mulching-drip irrigation in greenhouse.

GONG Xue-wen1, LIU Hao1, SUN Jing-sheng1, ZHANG Hao1, LI Yong1, WU Xiao-lei1, CUI Jia-xin2

2014, 25(10):  2935-2943. 

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It is very significant for muskmelon growth and production to maintain optimal conditions of soil moisture and temperature, especially during blossom and fruitbearing periods. The object of this study was to analyze the effects of different soil water thresholds (T₁: 55% of the field capacity, T₂: 65% of the field capacity, T₃: 75% of the field capacity, CK: 85% of the field capacity) on soil temperature  under mulchingdrip irrigation in greenhouse. Moreover, effects of the ratio of soil moisture to heat in the plough layer (0-20 cm) on muskmelon growth and fruit setting were investigated. Results indicated that during the flowering and fruit bearing periods, the order of mean soil temperature in the plough layer for the different treatments was T₁＞T₂＞T₃＞CK. There was an inverse correlation between soil temperature in the plough layer and moisture. The maximum oneday variations for soil temperature on sunny day, rainy day and after irrigation were observed in the soil surface under the plastic film mulch, while the minimum happened in the soil layer of 20 cm outside the mulch. The soil temperature extreme was closely related with soil depth, and the difference in the extreme soil temperature between the soil surface and the soil layers of 10 and 20 cm was significant. The treatment T₃, with the fastest plant growth rate, the minimum duration of fruit bearing and the maximum fruit setting rate, could be selected as the optimal treatment, and the ratio of soil moisture to heat in T₃ was 1.62 mm·℃^-1. Therefore, taking into consideration the relationship between soil moisture and temperature during flowering and fruit bearing periods of muskmelon under mulchingdrip irrigation, the ratio of soil water to heat in the plough layer should be kept at 1.62 mm·℃^-1. The result would be very meaningful for drip-irrigated muskmelon production and management in greenhouse in North China.

 

Responses of stomata and Kranz anatomy of maize leaves to soil water shortages.

LI Zhen-zhen, ZHANG Li, LI Si, DONG He, WANG Qiao-yan, LIU Xi-ping, YAO Ya-qin

2014, 25(10):  2944-2950. 

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Seedlings of the popular maize cultivar “Zhengdan-958” growing in pots individually were exposed to suitable soil water conditions as control, light water shortage, moderate water shortage, and severe water shortage, corresponding to soil water contents between 75%-85%, 65%-75%, 55%-65%, and 45%-55% of field water capacity, respectively. Responses of stomatal aperture, Kranz anatomy, and vascular bundle structure to different water contents of maize leaves were investigated. Results showed that under increased water shortages, the levels of H₂O₂ in both guard cells and subsidiary cells were enhanced, also the fluorescence intensity of H₂O₂ labeled with fluorescent dye increased, while stomatal aperture and conductance decreased gradually. Moreover, Kranz cells were messily arranged and the cell size became smaller and smaller, and the structure of bundle sheath cells went irregular; and the sectional area of the big bundle and xylem, the cell number of phloem, and the thickness of whole leaf and of upper and lower epidermis reduced. In addition, the number of chloroplasts in mesophyll cells and vascular bundle sheath cells decreased, particularly under the moderate water deficit, chloroplasts in Kranz cells which located in the inside of cytoplasmic membrane and cling on the cell wall spread to the direction of cell center. It demonstrated that stomatal closing of maize could be regulated by H₂O₂ in guard cells and subsidiary cells together, and H₂O₂ in subsidiary cells maybe played a cooperative role. In conclusion, under increased soil water shortages, droughtinduced H₂O₂ accumulations in both guard cells and subsidiary cells of maize leaves participated in the regulation of stomatal closing. And, the size of Kranz cells and bundle sheath cells, the cell number of phloem, and the area of the xylem and phloem reduced, thereby, reducing water shortageinduced damage.

Analysis on accessibility of urban park green space: The case study of Shenyang Tiexi District.

LU Ning, LI Jun-ying, YAN Hong-wei, SHI Tuo, LI Ying

2014, 25(10):  2951-2958. 

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The accessibility of urban park green space is an important indicator to reflect how much the natural service supplied by parks could be enjoyed by citizens conveniently and fairly. This paper took Shenyang Tiexi District as an example to evaluate the accessibility of urban park green space based on QuickBird imagery and GIS software, with four modes of transportation, walking, nonmotor vehicle, motor vehicle and public transport being considered. The research compared and analyzed the distribution of the accessible area and the accessible people of park green space. The result demonstrated that park green space in Shenyang Tiexi District was not enough and the distribution was not even. To be precise, the accessibility in southwest part and central part was relatively good, that in marginal sites was worse, and that in east part and north part was the worst. Furthermore, the accessibility based on different modes of transportation varied a lot. The accessibility of motor vehicle was the best, followed by nonmotor vehicle and public transport, and walking was the worst. Most of the regions could be reached within 30 minutes by walking, 15 minutes by nonmotor vehicle and public transport, and 10 minutes by motor vehicle. This paper had a realistic significance in terms of further, systematic research on the green space spatial pattern optimization.

 

Land use change dynamics and driving forces of the vulnerable ecological region in northwestern Shanxi Province, China.

LI Xiu-fen1, LIU Li-min1, QI Xin2, ZHANG Jin-xin3, ZHAO Tong-bin1, WANG Yi1, LIU Xue-feng1, ZHOU Yong-bin1

2014, 25(10):  2959-2967. 

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By using remote sensing and GIS technology, this paper collected land use information of 1980, 1990, 2000 and 2010 and the relevant statistical data, and analyzed the characteristics of land use change and its driving forces in northwestern Shanxi Province, the typical ecological fragile area. The results showed that there were significant changes in land use patterns in the past 30 years. During 1980-1990, 1990-2000 and 2000-2010 periods, the area of farmland decreased continuously, while the areas of grassland and woodland experienced increasedecreaseincrease and decreaseincreasedecrease patterns of change, respectively. The areas of industrial and resident lands increased continuously, but the water body and unused land decreased. The farmland was mainly transformed to grassland and woodland, and the areas of industrial and resident lands increased from the farmland. The lost area of water body was transformed to grassland and farmland. The decrease of unused land was due to the implementation of ecological engineering and urban expanding. In general, the changes of land use types were significantly higher before 2000 than after 2000. The industrial and resident lands, unused land and grassland changed drastically. The relationships between land use types and driving forces indicated that population pressure and economic development led to the changes of industrial land and farmland; policy of forestry ecological engineering drove the changes of woodland and grassland; the droughtcharacterized climate was the major cause inducing the decrease of water area and hindering the restoration of forest.

Adaptability assessment of economic and environmental development of Tangshan, Hebei, China.

HAN Rui-ling, ZHU Shao-hua, ZHANG Qiu-luan

2014, 25(10):  2968-2974. 

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It is vital to explore whether the economic system adapts to the environmental system as the relationship between economy and environment becomes a gradually concerned problem. Tangshan, a typical resourcebased city, was chosen to study the adaptabilities and performances of economic developments in response to environmental changes from 1992 to 2011. It was found that the economicenvironmental adaptation curve of Tangshan City had an overall fluctuating and increasing tendency. The systematic adaptability kept advancing, reflecting Tangshan paid much attention to environmental development in addition to economic performances, and the two aspects became more and more coordinated. Filtering analysis of the adaptive curve with Eviews software revealed that the potential systematic coordinating index was rising continuously, however, the sum of resilience gap for 20 years was still negative, which implied that fundamental contradictions between high economic development and high energy consumption and high pollutant emission still existed. Carrying out adaptive researches not only helps people to adapt to climate changes better, but also has significances for economic and environmental coordination and sustainability research.

Evaluation of comprehensive capacity of resources and environments in Poyang Lake Eco-economic Zone.

SONG Yan-chun, YU Dun

2014, 25(10):  2975-2984. 

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With the development of the society and economy, the contradictions among population, resources and environment are increasingly worse. As a result, the capacity of resources and environment becomes one of the focal issues for many countries and regions. Through investigating and analyzing the present situation and the existing problems of resources and environment in Poyang Lake Eco-economic Zone, seven factors were chosen as the evaluation criterion layer, namely, land resources, water resources, biological resources, mineral resources, ecologicalgeological environment, water environment and atmospheric environment. Based on the single factor evaluation results and with the county as the evaluation unit, the comprehensive capacity of resources and environment was evaluated by using the state space method in Poyang Lake Eco-economic Zone. The results showed that it boasted abundant biological resources, quality atmosphere and water environment, and relatively stable geological environment, while restricted by land resource, water resource and mineral resource. Currently, although the comprehensive capacity of the resources and environments in Poyang Lake Eco-economic Zone was not overloaded as a whole, it has been the case in some counties/districts. State space model, with clear indication and high accuracy, could serve as another approach to evaluating comprehensive capacity of regional resources and environment.

Phylogenetic relationships of seabuckthorn based on ITS sequences.

MA Yu-hua, YE Gui-sheng, XIANG Qian-sheng, GAO Ying, YANG Chun-jiang, WEI Guo-liang, SONG Wei-xiu

2014, 25(10):  2985-2990. 

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Sequences of the internal transcribed spacer (ITS) was compared in three seabuckthrons (Hippophae rhamnoides subsp. sinensis, H. tibetana and H. neurocarpa) distributed in Qinghai Province, then the systematic positions of 15 seabuckthron samples were analyzed with Elaeagnaceae angustifolia being outgroup. The results showed that ITS sequences in three seabuckthron species varied in length from 600 to 605 bp. ITS-1, 5.8S and ITS2 varied from 201 to 203 bp, 166 to 167 bp and 232 to 236 bp, respectively. The sequence divergence among three seabuckthorn species was also remarkably high. Cluster analysis based on ITS indicated that H. gonicocarpa subsp. litangensis and H. gonicocarpa subsp. goniocarpa were distinct and could be classified as H. gonicocarpa and H. litangensis. H. gyantsensis had the closest genetic relationship with H. salicifolia and the distant relationship with H. rhamnoides subsp. sinensis. The positions of nine subspecies of H. rhamnoides based on morphological classification were different from the results of ITS.


 

Effect of silicon on translocation and morphology distribution of lead in soiltobacco system.

YAN Yi-hua1, ZHENG Zi-cheng1, LI Ting-xuan1, ZHANG Xi-zhou1, WANG Yong2

2014, 25(10):  2991-2998. 

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Taking tobacco as test material, a pot experiment was conducted to study the effect of silicon on translocation of lead (Pb) form soil to tobacco in order to explore effective measures for reducing Pb concentration in tobacco leaf. The results showed that silicon application promoted the transformation of exchangeable Pb into Fe-Mn oxide-bound Pb in nonrhizospheric soil, and into Fe-Mn oxide-bound Pb and residual Pb in rhizospheric soil, which decreased the availability and mobility of Pb in the soil. Silicon application significantly reduced the Pb uptake of tobacco, with the content of Pb being decreased by 6.5% to 44.0% in tobacco, and 3.1% to 60.4% in leaf. Silicon application promoted the transformation of ethanolextractable, H₂Oextractable Pb and NaClextractable Pb into HClextractable Pb and residual Pb in root, stem and leaf of tobacco, which reduced the toxicity and mobility of Pb in tobacco. Silicon restricted the transportation of Pb from soil to tobacco leaf by reducing the mobility index of Pb from soil to root  and the mobility index of Pb from root to stem  in soiltobacco system. Meanwhile, the mobility index of Pb from stem to leaf  in soil-tobacco system showed a risingandfalling trend with the increase of Pb application. Silicon inhibited the Pb migration from soil to tobacco leaf by reducing availability of Pb, mitigating toxicity of Pb to tobacco, and changing the distribution of Pb forms in tobacco, consequently reducing Pb concentration of tobacco leaf. These results demonstrated silicon application could be effective in reducing translocation of Pb from soil to tobacco.

Enhancement of GA₃ and EDTA on Lolium perenne to remediate Pb contaminated soil and its detoxification mechanism.

WU Qiu-ling1, WANG Wen-chu2, HE Shan-ying1

2014, 25(10):  2999-3005. 

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A pot experiment was conducted to study the effects of plant growth regulator GA₃ and metal chelate EDTA on enhancing the remediation of Pb contaminated soil, and the detoxification mechanism of Lolium perenne grown on Pb contaminated soil at 250 and 500 mg·kg^-1. The results showed that cell wall deposition and vacuolar compartmentalization played important roles in the detoxification of Pb in L. perenne shoot. The addition of EDTA alone increased Pb concentration in plants and Pb proportions in soluble fraction and organelles fraction, and enhanced the toxicity of Pb to plant, leading to the significant reduction of the plant biomass (P<0.05). Foliar spray of lower concentration of GA₃(1 μmol·L^-1 or 10 μmol·L^-1) alone significantly increased Pb accumulation by L. perenne (P<0.05), but Pb proportions in soluble and organelles fraction were decreased, which alleviated the adverse effects of Pb on plant, thus improving the growth of plants (P<0.05), with 1 μmol·L^-1 GA₃ being the most effective. In contract, the addition of 100 μmol·L^-1 GA₃ decreased Pb concentration in L. perenne, but increased the proportions of Pb in soluble fraction and organelles fraction, resulting in the reduction of plant biomass. Lower concentration of GA₃ might alleviate the adverse effects of Pb and/or EDTA on plant, since the biomass amounts in the different treatments were in order of GA₃ alone of lower concentration > GA₃ of lower concentration+EDTA > EDTA alone. The combination application of low concentration of GA₃ and EDTA showed a synergistic effect on the Pb accumulation in L. perenne (P<0.05). Especially, Pb concentration in shoot and Pb extraction efficiency reached 1250.6 mg·kg^-1 and 1.1%, respectively, under the treatment of EDTA+1 μmol·L^-1 GA₃ on the Pb 500 mg·kg^-1 soil. Therefore, the application of 1 μmol·L^-1 GA₃ along with EDTA appeared to be a potential approach for phytoremediation of Pb contaminated soil.

Ecological responses of brown planthopper, Nilaparvata lugens, to triazophos and deltamethrin on transgenic Bt rice lines and their nonBt parental rice.

LI Xiang-dong1,2, YANG Ya-jun1, TIAN Jun-ce1, XU Hong-xing1, ZHENG Xu-song1, LU Zhong-xian1，2

2014, 25(10):  3006-3010. 

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In this study, the brown planthopper (BPH), Nilaparvata lugens (Hemiptera: Delphacidae), cultured on Bt rice lines (T1C-19 with cry1C gene and T2A-1 with cry2A gene) and their parental rice MH63, were treated with a series of concentrations of triazophos and deltamethrin when they developed up to the third instar for the evaluation of the effects of Bt rice on BPH resurgence induced by pesticides. The results indicated that BPH nymphal duration decreased with the increasing concentration of deltamethrin, while no significant differences of BPH nymphal duration were observed on the same rice variety treated with the different concentrations of triazophos. Furthermore, the survival rate of BPH significantly declined and their fecundity significantly increased with the increasing concentration of insecticides. However, ecological fitness parameters of BPH including nymphal duration, survival rate, female adult mass, fecundity and egg hatchability were not significantly different among Bt and nonBt rice varieties when they treated with the same concentration of insecticide. These results implied that no significant difference in the BPH resurgence induced by pesticides was observed among the two tested Bt rice varieties and their nonBt parental rice variety.

Electrophysiological and behavioral responses of male Apamea apameoides (Draudt) (Lepidoptera: Noctuidae) to sex pheromone components.

ZHANG Ai-liang1, ZHOU Zhang-ting2, ZHANG Ya-bo3, ZHOU Zhi-feng2, SHEN Zhi-lian4, WANG Hao-jie3, SHU Jin-ping3

2014, 25(10):  3017-3022. 

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The sex pheromone gland extracts collected from calling females of Apamea apameoides (Lepidoptera: Noctuidae) were analyzed with GC-MS, the electrophysiological and behavioral responses of the male adults to serial dilutions of sex pheromone components and their synthetic blends were investigated with Ytube olfactometer in laboratory and in bamboo forest field. The results indicated that (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol were the functional components in the sex pheromone gland extracts. Electroantennogram (EAG) recordings showed that sex pheromone gland extracts, (Z)-11-hexadecenyl acetate, (Z)-11-hexadecen-1-ol and the mixture of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol all could elicit strong EAG responses, and the average EAG values increased with the increasing concentration of the sex pheromone. The blends of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol at the ratio of 57:43 elicited a higher EAG value than each singular component did. The results of behavioral assay by Y-tube olfactometer accorded with those of EAG responses on the whole, and the mixture of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol at the ratio of 57:43 was more attractive than each component alone. In field tests with silicone rubber as pheromone dispensers (concentration=10⁴ ng·uL^-1), the average number of male adults captured per trap by the mixture was (48.5±6.7).

Effects of sewage discharge on abundance and biomass of meiofauna.

HUANG De-ming, LIU Xiao-shou, LIN Ming-xian, CHEN Huai-pu, WEI Lian-ming, HUANG Xin, ZHANG Zhi-nan

2014, 25(10):  3023-3031. 

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In order to elucidate the effects of sewage discharge on abundance and biomass of meiofauna, a seasonal survey was carried out on meiofauna at stations with different distances to a sewage outlet in the middle intertidal zone of No.1 bathing beach in Huiquan Bay, Qingdao in spring (April), summer (August), autumn (October) and winter (December), 2011. The results showed that the annual average meiofaunal abundance was (1859.9±705.1) ind·10 cm^-2, with higher values of (2444.9±1220.5) ind·10 cm^-2 at Station S₂ (20 m to the sewage outlet) and (2492.2±1839.9) ind·10 cm^-2 at Station S₃ (40 m to the sewage outlet), while the lowest value of (327.9±183.2) ind·10 cm^-2 was observed at Station S₁(0 m to the sewage outlet) in terms of horizontal distribution. The annual average biomass was (1513.4±372.7) μg·10 cm^-2. Meiofaunal abundance and biomass varied seasonally with the highest values in spring and the lowest values in summer. A total of 11 meiofaunal groups were identified, including nematodes, copepods, polychaetes, oligochaetes, tardigrades, halacaroideans, planarians, ostracods, isopods, crustacean nauplii and others. Free-living marine nematodes were the dominant group constituting 83.1% of the total abundance, followed by benthic copepods, accounting for 12.8% of the total abundance. In terms of vertical distribution, most of the meiofauna concentrated in the top 0-2 cm, and the meiofauna abundance decreased with increasing the sediment depth. Meiofauna was also noted to migrate deeper into the sediment in the winter. Pearson correlation analysis showed that meiofaunal abundance and biomass had highly significant negative correlations with sediment median particle diameter and organic matter content. In addition, tourisminduced activities affected meiofaunal abundance and distribution. A comparison with historical data from similar studies was carried out, and the applicability of the ratio of abundance of nematodes to copepods  in monitoring organic pollution was discussed.

Estimation and experiment of carbon sequestration by oysters attached to the enhancement artificial reefs in Laizhou Bay, Shandong, China.

GONG Pi-hai1,2, LI Jiao2, GUAN Chang-tao2, LI Meng-jie1,2, LIU Chao1,2

2014, 25(10):  3032-3038. 

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Through sampling investigation of fouling organisms on the enhancement artificial reefs set up in Laizhou Bay, it was proved that oyster (Ostrea plicatula) was the dominant fouling species. Therefore the dry mass of shell (M_s), total fresh mass (M_t) and thickness (T) of oyster attached on the reefs were analyzed. The results showed that the M_t and M_s presented seasonal variation (P<0.01), that is, the values were the lowest in April and the highest in December. The reef age and the length of the time the enhancement reefs placed in the sea had significant effect on M_t, M_s and T. With the increment of reef ages, all indices increased obviously. The carbon sinks of oysters attaching to the tube enhancement reefs constructed in 2009, 2010 and 2011 in Laizhou Bay were 17.61, 16.33 and 10.45 kg·m^-3, respectively. The oysters on the enhancement reefs of Jincheng marine ranch with an area of 64.25 hm² had fixed carbon of 297.5 t C (equivalent to 1071 t of CO₂) from 2009 to 2013 in Laizhou Bay. To capture and store the same amount of CO₂ would cost about 1.6×10⁵-6.4×10⁵ US dollars. Therefore, oysters attaching to the enhancement reefs bring
about remarkable ecological benefits.


 

Research progress on carbon sink function of agroforestry system under climate change.

XIE Ting-ting1, SU Pei-xi2, ZHOU Zi-juan2, SHAN Li-shan3

2014, 25(10):  3039-3046. 

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As a land comprehensive utilization system, agroforestry system can absorb and fix CO₂ effectively to increase carbon storage, and also reduces greenhouse effect convincingly while reaching the aim of harvest. The regulatory role in CO₂ makes humans realize that agroforestry systems have significant superiority compared with single cropping systems, therefore, understanding the carbon sinks of different components in an agroforestry system and its influencing factors play an important role in studying global carbon cycle and accurate evaluation of carbon budget. This paper  reviewed the concept and classification of agroforestry system, and then the carbon sequestration potentials of different components in agroforestry systems and influencing factors. It was concluded that the carbon sequestration rate of plants from different agroforestry systems in different regions are highly variable, ranging from 0.59 to 11.08 t C·hm^-2·a^-1, and it is mainly influenced by climatic factors and the characteristics of agroforestry systems (species composition, tree density and stand age). The soil C sequestration of any agroforestry system is influenced by the amount and quality of biomass input provided by tree and nontree components of the system and the soil properties such as soil texture and soil structure. Overall the amount of carbon storage in any agroforestry system depends on the structure and function of its each component. The future studies should focus on the carbon sink functions of structurally optimized agroforestry systems, the temporal variation and spatial distribution pattern of carbon storage in agroforestry system and its carbon sequestration mechanism in a long time.

 

Research advances in ecological stoichiometry of marine plankton.

CHEN Lei1,2, LI Chao-lun1

2014, 25(10):  3047-3055. 

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Ecological stoichiometry can be simply defined as: The biology of elements from molecules to the biosphere, which spans all levels of the environment and of the life. It’s a new idea to build a unified theory and becomes an inevitable trend to develop the ecological science. Marine ecosystems, which contribute to 50% of the biosphere biomass, are the important component of the global biogeochemical cycles. Marine zooplankton plays an important role in the material circulation and energy flow of marine ecosystems and serves as a connecting link between the preceding and the following in a more precise understanding of the key elemental cycles. However, research on ecological stoichiometry of marine plankton is fragmentary and rare. This article summarized the ecological phenomena and mechanisms of limiting elements affecting marine plankton, the response of biochemical substances to nutrition limitation, and the food chain transmission and feedback of nutrition limitation. Meanwhile, we also put forward some perspectives for future research of ecological stoichiometry of plankton in China’s seas.

 

Applications of metaproteomics in the study of wastewater biotreatment process.

CHEN Shi-xia, WANG Lei, HAN Zhi-ying

2014, 25(10):  3056-3066. 

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With the advent of the postgenomic era, metaproteomics is gradually emerging as a new tool that has been successfully applied in life sciences and pharmacology, and has become one of the most popular methods in many research fields. Although application of metaproteomics in studying wastewater biotreatment is still in its infancy, its strong potential that contributes to basic research has already been well noticed. This paper reviewed the recent research advances  in using metaproteomics to biotreatment wastewater. It also reviewed and summarized the research strategies and application of metaproteomics, such as the identification of functional proteins or enzymes, understanding of the mechanisms of pollutant biodegradation, deduction of key metabolic pathways, and investigation of microbial ecosystems within different sludge of microbial habitats.