Table of Content

18 June 2015, Volume 26 Issue 6

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Soluble nitrogen and soluble phosphorus dynamics during foliar litter decomposition in winter in alpine forest streams.

ZHANG Chuan1, YANG Wan-qin1, YUE Kai1, HUANG Chun-ping1,2, PENG Yan1, WU Fu-zhong1

2015, 26(6):  1601-1608. 

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In order to understand the dynamic pattern of soluble nitrogen and soluble phosphorus in the headwater streams during the process of litter decomposition in winter, a field experiment using litterbag method was conducted in an alpine forest in Western Sichuan, China. The foliar litter of two dominant canopy trees (Sabina saltuaria, and Larix mastersiana) and two shrubs (Salix paraplesia and Rhododendron lapponicum) were selected. The litterbags were placed in a headwater stream, river, riparian zone and closed canopy, and sampled in different freezingthawing periods of winter (prefreezing period, freezing period and thawing period). The results indicated that the soluble nitrogen content of foliar litter showed little changes over a whole winter decomposition regardless of species. In contrast, the soluble phosphorus content displayed the order as river < stream < riparian zone < closed canopy, and showed a decrease tendency in stream, river and riparian, although little changes under closed canopy over a whole winter decomposition. Correlation analysis suggested that the dynamics of soluble phosphorus content significantly correlated to the average temperature, positive accumulated temperature, negative accumulated temperature and flow velocity during the decomposition in winter. The dynamics of soluble nitrogen content only exhibited significant correlations with positive accumulated temperature. Additionally, litter quality (species) also controlled the dynamics of soluble nitrogen and soluble phosphorus content as litter decomposition proceeded. The results implied that soluble phosphorus could be more liable to loss in streams and rivers during litter decomposition compared with soluble nitrogen, which could further provide some new ideas in understanding nitrogen and phosphorus cycling in this alpine forest.

Community stability for sprucefir forest at different succession stages in Changbai Mountains, Northeast China.

ZHANG Meng-tao1, ZHANG Qing1, KANG Xin-gang1, YANG Ying-jun2, XU Guang2, ZHANG Li-xin3

2015, 26(6):  1609-1616. 

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Based on the analysis of three forest communities (polar-birch secondary forest, sprucefir mixed forest, sprucefir near pristine forest) in Changbai Mountains, a total of 22 factors of 5 indices, including the population regeneration, soil fertility (soil moisture and soli nutrient), woodland productivity and species diversity that reflected community characteristics were used to evaluate the stability of forest community succession at different stages by calculating subordinate function values of a model based on fuzzy mathematics. The results that the indices of population regeneration, soli nutrient, woodland productivity and species diversity were the highest in the sprucefir mixed forest, and the indices of soil moisture were the highest in the sprucefir nearpristine forest. The stability of three forest communities was in order of  natural sprucefir mixed forest > sprucefir near pristine forest > polarbirch secondary forest.

Spatial point pattern analysis of Abies georgei var. smithii in forest of Sygera Mountains in southeast Tibet, China.

XIE Chuan-qi1,2, TIAN Min-xia1,2, ZHAO Zhong-rui1,2, ZHENG Wei-lie2, WANG Guo-yan2

2015, 26(6):  1617-1624. 

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In this study, based on a 4 hm² stemmapping plot, we analyzed spatial distributions of Abies georgei var. smithii, the dominant species in forest of Sygera Mountains in southeast Tibet, China. Paircorrelation function was used to characterize univariate spatial point patterns of three size classes of the population and bivariate spatial patterns between those and different sizes of dead wood. A. georgei var. smithii population was characterized by reverse Jshaped DBH distribution, indicating an increasing population. Saplings of the population were spatially obviously aggregated at the small scales (0-7 m), and midsized trees and largesized trees of the population were randomly or uniformly distributed. The aggregation intensities of A. georgei var. smithii decreased with the increasing diameter classes and spatial scales. Saplings and midsized trees were significantly and negatively associated with largesized trees at the small scales (0-35 and 0-30 m), but the associations reversed at the large scales (45-100 and 80-100 m). In addition, with the increasing age difference between diameter classes of the population, the intensities of positive or negative correlations increased. Spatial associations between saplings and dead largesized trees, and between midsized trees and dead largesized trees were negative at the small scales (0-34 and 5-27 m), but positive at the large scales (49-100 and 73-100 m). This suggested that released niche space due to dead largesized trees is not enough to weaken their negative impacts on saplings. We concluded that selfthinning effect and Janzen-Connell hypothesis may be the main mechanisms for the spatial pattern formation of A. georgei var. smithii population.

Characteristics of surface energy fluxes over a sparse shrubland ecosystem in the farming-pastoral zone of the Loess Plateau, Northwest China.

GONG Ting-ting, LEI Hui-min, JIAO Yang, YANG Han-bo, YANG Da-wen

2015, 26(6):  1625-1633. 

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Based on the energy flux and meteorological data during 2011-2012 over a sparse shrubland ecosystem in the farming-pastoral zone of the Loess Plateau, this study investigated the diurnal and seasonal variations of the energy balance components, and discussed the responses of the latent and sensible heat fluxes to different intensities of rainfall events. In addition, we identified the major environmental controlling factors on latent and sensible heat fluxes via correlation analysis. The results showed that the diurnal and seasonal variations of net radiation (R_n), sensible heat flux (H), latent heat flux (LE) and soil heat flux (G) all showed single-peak curves. The annual mean values of R_n, H, LE and G were 78.19, 33.32, 24.91 and 2.65 W·m^-2, respectively. The ratios of energy budget components to net radiation were 43% (H/R_n), 32% (LE/R_n), and 3% (G/R_n), which indicated that sensible heat flux was the major form of energy loss at this site. In the growing season, the ratios of sensible heat flux and latent heat flux to net radiation were nearly the same (36%); while in the non-growing season, sensible heat flux accounted for 54% of net radiation. Latent heat flux increased sharply after heavy and weak rainfall events, while sensible heat flux decreased sharply at the same time. Continuous rainfall events would lead to fluctuations in latent and sensible heat fluxes. There were significant correlations between latent heat flux and net radiation, vapor pressure deficit and vegetation parameter, while remarkable correlations were found between sensible heat flux and net radiation, and air temperature gradient.

Impact of canopy structural characteristics on inner air temperature and relative humidity of Koelreuteria paniculata community in summer.

QIN Zhong1,2,3,4, LI Zhan-dong1,2,3,4, CHENG Fang-yun1,2,3,4, SHA Hai-feng5

2015, 26(6):  1634-1640. 

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To investigate  the diurnal variation of the correlations between the cooling and humidifying effects and canopy structural characteristics of the Koelreuteria paniculata community, the measurements of air temperature, relative humidity, canopy density, leaf area index (LAI) and mean leaf angle (MLA) were performed on calm sunny summer days in the community in Beijing Olympic Forest Park, China. There were significant correlations between the canopy density, LAI and MLA, which affected the cooling and humidifying effects together. The cooling effect reached its maximum by 12:00, whereas the humidifying effect reached its peak at 10:00. Compared with the control open space site, the community appeared to lower the air temperature by 0.43 to 7.53 ℃ and to increase the relative humidity by 1%-22% during the daytime. However, the cooling and humidifying effects seem to be not effective during the night. The canopy density and LAI were better for determining the cooling and humidifying effects from 9:00 to 12:00. However, these effects were largely controlled only by the canopy density from 12:00 to 14:00 and were significantly correlated with the canopy density and LAI afterwards until 18:00.

 

Effects of fertilization method and nitrogen application rate on soil nitrogen vertical migration in a Populus ×euramericana cv. ‘Guariento’ plantation.

DAI Teng-fei, XI Ben-ye, YAN Xiao-li, JIA Li-ming

2015, 26(6):  1641-1648. 

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A field experiment was conducted to investigate the effects of fertilization methods, i.e., drip (DF) and furrow fertilization (GF), and nitrogen (N) application rates (25, 50, 75 g N·plant^-1·time^-1) on the dynamics of soil N vertical migration in a Populus ×euramericana cv. ‘Guariento’ plantation. The results showed that soil NH₄⁺-N and NO₃^--N contents decreased with the increasing soil depth under different fertilization methods and N application rates. In the DF treatment, soil NH₄⁺-N and NO₃^--N were mainly concentrated in the 0-40 cm soil layer, and their contents ascended firstly and then descended, reaching their maximum values at the 5th day (211.1 mg·kg^-1) and 10th day (128.8 mg·kg^-1) after fertilization, respectively. In the GF treatment, soil NH₄⁺-N and NO₃^--N were mainly concentrated in the 0-20 cm layer, and the content of soil NO₃^--N rose gradually and reached its maximum at the 20th day (175.7 mg·kg^-1) after fertilization, while the NH₄⁺-N content did not change significantly after fertilization. Overall, N fertilizer had an effect within 20 days in the DF treatment, and more than 20 days in the GF treatment. In the DF treatment, the content and migration depth of soil NH₄⁺-N and NO₃^--N increased with the N application rate. In the GF treatment, the NO₃^--N content increased with the N application rate, but the NH₄⁺-N content was not influenced. Under the DF treatment, the hydrolysis rate, nitrification rate and migration depth of urea were higher or larger than that under the GF treatment, and more N accumulated in deep soil as the N application rate increased. Considering the distribution characteristics of fine roots and soil N, DF would be a better fertilization method in P. ×euramericana cv. ‘Guariento’ plantation, since it could supply N to larger distribution area of fine roots. When the N application rate was 50 g·tree^-1each time,  nitrogen  mainly distributed in the zone of fine roots and had no   risk of deep leaching, consequently improving the fertilizer utilization efficiency.

Spatial interpolation of soil organic matter using regression Kriging and geographically weighted regression Kriging.

YANG Shun-hua1, ZHANG Hai-tao1, GUO Long2, REN Yan1

2015, 26(6):  1649-1656. 

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Relative elevation and stream power index were selected as auxiliary variables based on correlation analysis for mapping soil organic matter. Geographically weighted regression Kriging (GWRK) and regression Kriging (RK) were used for spatial interpolation of soil organic matter and compared with ordinary Kriging (OK), which acts as a control. The results indicated that soil organic matter was significantly positively correlated with relative elevation whilst it had a significantly negative correlation with stream power index. Semivariance analysis showed that both soil organic matter content and its residuals (including ordinary least square regression residual and GWR residual) had strong spatial autocorrelation. Interpolation accuracies by different methods were estimated based on a data set of 98 validation samples. Results showed that the mean error (ME), mean absolute error (MAE) and root mean square error (RMSE) of RK were respectively 39.2%, 17.7% and 20.6% lower than the corresponding values of OK, with a relative improvement (RI) of 20.63. GWRK showed a similar tendency, having its ME, MAE and RMSE to be respectively 60.6%, 23.7% and 27.6% lower than those of OK, with a RI of 59.79. Therefore, both RK and GWRK significantly improved the accuracy of OK interpolation of soil organic matter due to their incorporation of auxiliary variables. In addition, GWRK performed obviously better than RK did in this study, and its improved performance  should be attributed to the consideration of sample spatial locations.

Estimating forest canopy cover by combining spaceborne ICESat-GLAS waveforms and multispectral Landsat-TM images.

WANG Rui, XING Yan-qiu, WANG Li-hai, YOU Hao-tian, QIU Sai, WANG Ai-juan

2015, 26(6):  1657-1664. 

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The spatial distribution of forest canopy cover is a critical indicator for evaluating the forest productivity and decomposition rates. With the Wangqing Forest Region in Jilin Province of China as the study area, this study first estimated the forest canopy cover using spaceborne LiDAR ICESat-GLAS waveforms and Landsat-TM multispectral images, respectively, and then GLAS data and TM images were combined to further estimate forest canopy cover by using multiple linear regression and BP neural network. The results showed that when the forest canopy cover was estimated with single data source, the determination coefficient of model was 0.762 for GLAS data and 0.598 for TM data. When the forest canopy cover was estimated by combining GLAS data and TM data, the determination coefficient of model was 0.841 for multiple linear regression, and the simulation precision was 0.851 for BP neural network. The study indicated that the combination of ICESat-GLAS data and Landsat-TM images could exploit the advantages of multisource remote sensing data and improve the estimating accuracy of forest canopy cover, and it was expected to provide a promising way for spatially continuous mapping of forest canopy cover in future.

 

An object-based information extraction technology for dominant tree species group types.

TIAN Tian, FAN Wen-yi, LU Wei, XIAO Xiang

2015, 26(6):  1665-1672. 

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Information extraction for dominant tree group types is difficult in remote sensing image classification, howevers, the objectoriented classification method using high spatial resolution remote sensing data is a new method to realize the accurate type information extraction. In this paper, taking the Jiangle Forest Farm in Fujian Province as the research area, based on the Quickbird image data in 2013, the objectoriented method was adopted to identify the farmland, shrubherbaceous plant, young afforested land, Pinus massoniana, Cunninghamia lanceolata and broadleave tree types. Three types of classification factors including spectral, texture, and different vegetation indices were used to establish a class hierarchy. According to the different levels, membership functions and the decision tree classification rules were adopted. The results showed that the method based on the objectoriented method by using texture, spectrum and the vegetation indices achieved the classification accuracy of 91.3%, which was increased by 5.7% compared with that by only using the texture and spectrum.

Further reduction of nitrogen fertilizer application in paddy field under green manuring of Taihu Area, China.

ZHAO Dong1,2,3, YAN Ting-mei1, QIAO Jun1,3, YANG Lin-zhang1, TANG Fang4, SONG Yun-fei4

2015, 26(6):  1673-1678. 

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This study focused on the nitrogen loss via runoff, change of nitrogen in different forms in surface water in paddy field, and grain yield, through further reduction of nitrogen fertilizer application rate under green manuring without basal dressing. Results showed that with 150 kg·hm^-2 inorganic N fertilizer input after return of green manure to soil, no basal dressing could not only sharply reduce N concentration in surface water and decrease 17.2% of N loss, but also increase 2.8% of grain yield in comparison with basal dressing. It was a worthwhile farming method that inorganic nitrogen fertilizer was not used for basal dressing but for topdressing after return of green manure to soil in Taihu Area. However, the grain yield would decrease if the rate of topdressing nitrogen was excessively reduced or increased. After all, it was feasible to realize harmonization of grain yield and environmental benefits in Taihu Area, with 133 kg·hm^-2 inorganic N fertilizer input after return of green manure to soil as well as no application of basal dressing, which could greatly reduce N fertilizer input and N loss as well as ensure rice yield.

Low-temperature response and cold tolerance at spike differentiation stage of winter wheat varieties sowed in spring.

XU Lan1,2, GAO Zhi-qiang1, AN Wei3, YUAN Ya-qi2, LI Yan-liang3

2015, 26(6):  1679-1686. 

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A total of 10 winter wheat varieties were imported from the middle and lower reaches of the Yangtze River region in China. Those varieties were sowed in spring in Xinding basin area of Shanxi Province, and the field trials were performed for two years (2013-2014). The traits and physiological characteristics under low temperature stress including grain yield, total content of chlorophyll, osmotic adjustment, membrane system, ion leakage rate, contents of soluble sugar and soluble protein were investigated, and the cold tolerance levels of the wheat varieties were assessed. The results showed that low temperature stress led to increases in wheat leaf ion leakage rate, soluble sugar and protein contents, but obvious reduction of chlorophyll content. According to principal component analysis and cold tolerance (D _value), Yumai 10, Yangmai 20, and Yunmai 42 were classed as cold sensitive wheat varieties. Yangmai 13, Yumai 12, and Ningmai 13 were classed as stronger coldresistant wheat genotypes, and showed stability through twoyear field trials, with the D _values being 0.665-0.659, 0.493-0.495, and 0.471-0.583, respectively, while the D _values for the controls Ning 2038 and Xinchun 30 were 0.368-0.397, and 0.328-0.330, respectively. The grain yields of the cold resistant wheat varieties were significantly higher than that of the other varieties tested. Therefore, Yangmai 13, Yumai 12 and Ningmai 13 could be imported and used as the cold tolerant wheat varieties for North Plain of China.

Effects of sub-low temperature and drought stress on characteristics of photosynthetic and fluorescence kinetics in tomato leaves.

DU Qing-jie1, DAI Kan-ren2, LI Jian-ming1, LIU Guo-ying1, PAN Tong-hua1, CHANG Yi-bo1

2015, 26(6):  1687-1694. 

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By using tomato as material potted in climatic chamber, the photosynthetic characteristics and allocation of energy and electron flow were studied under sublow temperature (8-15 ℃) and drought (55%-65% of field moisture capacity) conditions. The results showed that the photosynthetic pigment content declined under sublow temperature stress, but increased under drought stress. Both sublow temperature stress and drought stress significantly decreased the intercellular CO₂ concentration, stomatal conductance and photosynthetic rate, and increased the stomatal limitation, which further decreased or increased under simultaneous treatment of sublow temperature and drought stress. The photorespiration significantly increased under separate treatment of sublow temperature and drought stress, but decreased under simultaneous treatment. The stress declined the F_o, F_v/F_m and F_v′/F_m′, which showed the damage of photosystem. It increased the distribution of energy to PSⅡ and declined the photochemical efficiency, total electron flow and alternating electron flow. Thermal dissipation and the ratio of alternating electron flow were elevated to dissipate the excess energy. Compared with separate treatment of sublow temperature and drought stress, the simultaneous treatment made thermal dissipation higher, but did not make alternating electrons flow further increase.

Effect of  climatic mean value change on the evaluation result of rice delayed cold damage in Liaoning Province, Northeast China.

JI Rui-peng, YU Wen-ying, WU Jin-wen, FENG Rui, ZHANG Yu-shu

2015, 26(6):  1695-1703. 

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The anomaly of mean temperature summation from May to September (ΔT_5-9) was commonly used to assess delayed cold damage of rice in Northeast China, but whether the change of statistics years for climatic mean value (∑T_5-9) would affect the evaluation results of Liaoning rice under cold damage needed to be further studied. By using the meteorological industry standard of the People’s Republic of China “technical standard on rice cold damage evaluation” (QX/T 182-2013) and the supplemental indices (ΔT_5-9), the index (∑T_5-9) was calculated in four periods 1961-1990 (S₁), 1971-2000 (S₂), 1981-2010 (S₃) and 1961-2010 (S₄), and the spatial and temporal changes of cold damage in Liaoning Province were analyzed based on the ratio between cold damage stations and total stations (IOC) and the occurrence frequency. The results showed that the heat condition (∑T_5-9) in rice growing season increased obviously and the spatial and temporal changes were significant from 1961 to 2010. The original meteorological index of rice cold damage was improved by using quadratic polynomial model. The identification results were similar between S₂ and S₄. The variation coefficient of IOC in S₃ was lower than that of the other three. Compared with the typical rice yield reduction years, the evaluation results accorded better with the actual situation in evaluating the rice delayed cold damage in Liaoning during study period by using the S₃ climate mean value. The results could provide evidence for accurately evaluating the variation of rice cold damage in spatial and temporal distribution in Liaoning Province under the background of global climate change.

Simulation of instantaneous light transmission in wheat/maize intercropping canopy in Hetao region, China.

WANG Zi-kui1,2, WU Pu-te1,2, ZHAO Xi-ning1,2, CHEN Xiao-li2,3, LI Zheng-zhong4, CHAI Rong-hua4

2015, 26(6):  1704-1710. 

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The leaf distribution in intercropping canopy is usually laterally and vertically heterogeneous, which makes continuous measurement of light interception very difficult. In order to quantify the light interception by wheat/maize intercropping during different growth stages, a geometrical model was developed in this study to simulate photosynthetically active radiation (PAR) transmission in this system. Measured PAR values in field experiments were used to validate the geometrical model. Results showed that the geometrical model efficiently simulated the PAR transmitted on soil surface under intercropping canopy. The determination coefficients of linear regression between estimated and measured values were 0.947 and 0.950 for 6:2 intercropping (I62) and 12:4 intercropping (I124), respectively. The values of PAR intercepted by I62 intercropping system in 2012 and 2013 were 1061.4 and 924.3 MJ·m^-2, respectively, which were the highest among all cropping systems. The radiation caption ratios (RCRs) of I62 and I124 relative to sole crops were 1.29 and 1.19 during 2012 growing season, and 1.21 and 1.16 during 2013 growing season, respectively.

Dimensional fractal of post-paddy wheat root architecture.

CHEN Xin-xin1, DING Qi-shuo, LI Yi-nian, XUE Jin-lin, LU Ming-zhou, QIU Wei

2015, 26(6):  1711-1717. 

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To evaluate whether crop rooting system was directionally dependent, a field digitizer was used to measure postpaddy wheat root architectures. The acquired data was transferred to Pro-E, in which virtual root architecture was reconstructed and projected to a series of planes each separated in 10° apart. Fractal dimension and fractal abundance of root projections in all the 18 planes were calculated, revealing a distinctive architectural distribution of wheat root in each direction. This strongly proved that postpaddy wheat root architecture was directionally dependent. From seedling to turning green stage, fractal dimension of the 18 projections fluctuated significantly, illustrating a dynamical root developing process in the period. At the jointing stage, however, fractal indices of wheat root architecture resumed its regularity in each dimension. This   wheat root architecture recovered its dimensional distinctness. The proposed method was applicable for precision modeling field state root distribution in soil.

Effects of exogenous α-naphthaleneacetic acid on the antioxidation system in soybean leaves subjected to long-term drought stress during flowering.

JIANG Hong-qiang1, XING Xing-hua1, ZHOU Qin1, JIANG Hai-dong1

2015, 26(6):  1718-1726. 

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Two different drought tolerance soybean (Glycine max) varieties (Nannong 99-6 and Kefeng 1) were used to study the effects of α-naphthaleneacetic acid (NAA) on the antioxidation system under longterm drought stress after flowering with pot experiment, which lasted for 110 days at Pailou Experiment Station, Nanjing Agricultural University, in 2012. The results showed that longterm stress decreased the shoot dry mass significantly, however, increased the level of reactive oxygen species (ROS) and malondialdehyde (MDA) content. It also obviously increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), glutathione reductase (GR) and glutathione peroxidase (GPX). The contents of ascorbic acid (AsA) and glutathione (GSH), and the ratios of AsA/DHA (dehydroascorbic acid) and GSH/GSSG (L-glutathione oxidized) were obviously enhanced. Kefeng 1 showed a higher antioxidation ability than Nannong 99-6, and could consequently maintain lower ROS and MDA levels. NAA distinctly enhanced the activities of APX, POD, CAT, MDHAR, GPX, and ratios of AsA/DHA and GSH/GSSG, while decreased the levels of ROS and MDA. The AsA content and dehydroascorbate reductase (DHAR) activity were significantly increased in Kefeng 1.

Effects of plant density and nitrogen level on nitrogen uptake and utilization of winter wheat.

ZHANG Juan1,2,WU Tong-hua2, DAI Xing-long1, WANG Xi-zhi2, LI Hong-mei2, JIANG Ming-yang2, HE Ming-rong1

2015, 26(6):  1727-1734. 

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A two-year (2011-2012 and 2012-2013) field experiment was conducted on one winter wheat cultivar supplied with two levels of nitrogen (180 and 240 kg N·hm^-2) under three plant densities (135×10⁴, 270×10⁴, and 405×10⁴ plants·hm^-2) . The ¹⁵Nlabeled urea was injected into 20, 60 and 100 cm soil depths, respectively, aiming to investigate the effect of nitrogen and plant density and their interaction on the N uptake, utilization and nitrate nitrogen contents at different soil depths. The results showed that increasing the plant density from 135×10⁴ to 405×10⁴ plants·hm^-2 significantly increased the ¹⁵N uptake at depths of 20, 60 and 100 cm averagely by 1.86, 2.28 and 2.51 kg·hm^-2, respectively, and increased the above ground N uptake (AGN), N uptake efficiency (UPE) averagely by 12.6% and 12.6%, respectively, but decreased the N utilization efficiency (UTE) by 5.4%. Compared to the N input of 240 kg N·hm^-2, the 180 kg N·hm^-2 significantly reduced the ¹⁵N uptake at depths of 20 and 60 cm averagely by 4.11 and 1.21 kg·hm^-2, respectively, and significantly increased the ^15N uptake at depths of 100 cm averagely by 1.02 kg·hm^-2. Reducing the N input decreased the AGN averagely by 13.5%, but significantly increased the UPE and UTE by 9.4% and 12.2%, respectively. Equivalent grain yield was observed among N input of 180 kg N·hm^-2 with plant density of 405×10⁴ plants·hm^-2 and N input of 240 kg N·hm^-2 with plant densities of 270×10⁴ and 405×10⁴ plants·hm^-2. Increasing the plant density or reducing the N input could encourage the N uptake at deep soil profile and increased UPE and UTE by 13.4% and 11.9%, respectively. Meanwhile, both the nitrate nitrogen contents in 0-200 cm soil layers at maturity and the ratio of the nitrate nitrogen in 100-200 cm soil layers to that in 0-200 cm were significantly decreased. Therefore, properly decreasing the N input with increasing the plant density of winter wheat was efficient in absorbing N at deep soil, synergistically obtaining high grain yield, UPE and UTE, and reducing the pollution of residual soil nitrate.

Effects of irrigation amount and various fertigation methods on yield and quality of cucumber in greenhouse.

FANG Dong-ping1, ZHANG Fu-cang1,2, LI Jing1, WANG Hai-dong1, XIANG You-zhen1, ZHANG Yan1

2015, 26(6):  1735-1742. 

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Taking cucumber as experimental plant, an experiment was conducted to study the effects of irrigation amount and fertigation methods on growth, yield and quality of cucumber in greenhouse. The experiment had designed two irrigation levels, i.e. 100% ET₀〖KG*3〗(W₁) and 75% ET₀ (W₂), and four fertigation fertilization ratios, i.e. 100%, 66.6%, 33.3% and 0% (Z₁₀₀, Z₆₆, Z₃₃, Z₀) fertigation of a total amount of (360:180:540 kg·hm^-2) (N:P₂O₅:K₂O) by 8 times with the corresponding remainders (0%, 33.3%, 66.6% and 100%) were applied to soil as basic fertilization before the planting according to the recommended fertilization rate, and no fertilizer treatment was set up as the control (CK). Results showed that irrigation and fertilization levels had positive correlations with plant height, leaf areas, dry mass, yield and quality of cucumber. Yield at W₁Z₁₀₀ was the highest, reaching 67760 kg·hm^-2. W₂ treatment increased the mean water use efficiency (WUE) by 9.4% compared to W₁. W₂Z₁₀₀ treatment had the highest WUE, reaching 47.13 kg·m^-3. Yield at W₂Z₁₀₀ was only 3.4% lower than the maximum, but saved 25% of water. Yield and dry matter at Z₁₀₀ were 15.3% and 16.8% higher than at Z₀, respectively, the cucumber fruit vitamin C, soluble protein and soluble sugar contents were increased, and the water use efficiency was increased by 19.1%. W₂Z₁₀₀ treatment was the best treatment which could enable cucumber to obtain both the high-yield and the high-quality.

 

Effects of different LED light qualities on photosynthetic characteristics, fruit production and quality of strawberry.

LIU Qing, LIAN Hai-feng, LIU Shi-qi, SUN Ya-li, YU Xin-hui, GUO Hui-ping

2015, 26(6):  1743-1750. 

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Taking ‘Miaoxiang No.7’ strawberry as material, full red light, full blue light, full yellow light, full white light, red/blue/yellow (7/2/1), red/blue (7/2) light generated by light emitting diode (LED) was applied to accurately modulate with white light generated as control. The indicators of photosynthetic and fluorescence parameters, pigment content, fruit production and quality, root activity were investigated. The effects of light quality under the light intensity (500 μmol·m^-2·s^-1) on the photosynthetic characteristic, fruit production and quality of strawberry were studied. The results showed that the red light could increase photosynthetic parameters (P_n, T_r), while blue light had inhibitory effect. Intercellular CO₂ concentration (C_i) and conductance (g_s) were the highest under blue light. The fluorescence parameters were significantly affected by light quality, F_o, F_m and Φ_PSⅡ the highest under red light, but values of the maximal photochemical of PSⅡ (F_v/F_m), F_v/F_o and F_m/F_o highest under red/blue/yellow (7/2/1). In addition, the soluble solids content and vitamin C were highest under red light, the blue light could increase protein and titratable acid, sugaracid ratio was the highest under red/blue/yellow (7/2/1). Comprehensive analysis indicated that red/blue/yellow (7/2/1) was more beneficial to the increase of pigment contents of leaves, fruit production and some qualities of strawberry.

Effect of plant density on population yield and economic output value in maize-soybean intercropping.

ZHU Yuan-gang1,2, GAO Feng-ju1， CAO Peng-peng1, WANG Le-zheng1

2015, 26(6):  1751-1758. 

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The effects of plant density on population yield and economic output value in maize and soybean intercropping were studied with the design of the double saturated Doptimal regression. A mathematical model was developed, in which the densities of maize and soybean were independent variables, and population grain yield, dry matter accumulation and economic output value were dependent variables, respectively. The result showed that the plant density significantly affected the population grain yield, dry matter accumulation and economic output value, and the effects of density of maize on population indices were greater than those of density of soybean. Under the low level conditions of density, the population grain yield, dry matter accumulation and economic output value increased with the density of maize and soybean. The maximum population grain yield was 8101.31 kg·hm^-2 with the optimized combination of 72023 plant maize·hm^-2 and 99924 plant soybean·hm^-2, while the maximum population dry matter accumulation was 15282.45 kg·hm^-2 with the optimized combination of 75000 plant maize·hm^-2 and 93372 plant soybean·hm^-2, and the maximum population economic output value was 23494.50 Yuan·hm^-2 with the optimized combination of 73758 plant maize·hm^-2 and 87597 plant soybean·hm^-2. The optimum combination of densities of maize and soybean calculated by computer were 58554-71547 plant·hm^-2 for maize and 82217-100303 plant·hm^-2 for soybean in order to obtain grain yield greater than 7500 kg·hm^-2, dry matter accumulation greater than 14250 kg·hm^-2 and economic output value greater 22500 yuan·hm^-2 under the condition of this experiment.

Physiological response of the distribution of non-structural carbohydrates to water stress in wheat.

SU Li-wei, LI Sheng, MA Shao-ying, WANG Ya-mei, CAO Bao-chen

2015, 26(6):  1759-1764. 

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In this paper, the spring wheat (cv. Xihan No. 2) was taken as research material to investigate the dynamic changes of the nonstructural carbohydrates （NSC） in flag leaves, stems and leaf sheaths and activities of carbonmetabolizing enzymes (SSS, GBSS) in grains during wheat development process under various water stresses by water stress and rewatering treatment methods. The results indicated that various water stresses had no significant effects on the sucrose contents in flag leaves, stems, leaf sheaths and other organs of wheat. With the increase of water stress, the content of starch in flag leaves was significantly increased within 12-18 d after flowering. Water stress shortened the starch accumulation period in stems and sheaths after flowering and inhibited the transformation and distribution of starch in wheat stems. The accumulation of starch in sheath also gradually increased, which was early terminated under moderate water stress. At the beginning of the water stress, the contents of NSC in vegetative organs were listed as: flag leaves > stems > leaf sheaths. With the increase of water stresses, the NSC contents in vegetative organs were listed as: stems > flag leaves > leaf sheaths. We could conclude that the changes in main NSC (sugar, starch) distribution and carbon-metabolism enzyme activities was a kind of physiological regulation response of wheat to water stresses.

Effects of different straw recycling and tillage methods on soil respiration and microbial activity.

LI Xiao-sha, WU Ning, LIU Ling, FENG Yu-peng, XU Xu, HAN Hui-fang, NING Tang-yuan, LI Zeng-jia

2015, 26(6):  1765-1771. 

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To explore the effects of different tillage methods and straw recycling on soil respiration and microbial activity in summer maize field during the winter wheat and summer maize double cropping system, substrate induced respiration method and CO₂ release method were used to determine soil microbial biomass carbon, microbial activity, soil respiration, and microbial respiratory quotient. The experiment included 3 tillage methods during the winter wheat growing season, i.e., notillage, subsoiling and conventional tillage. Each tillage method was companied with 2 straw management patterns, i.e., straw recycling and no straw. The results indicated that the conservation tillage methods and straw recycling mainly affected 0-10 cm soil layer. Straw recycling could significantly improve the microbial biomass carbon and microbial activity, while decrease microbial respiratory quotient. Straw recycling could improve the soil respiration at both seedling stage and anthesis, however, it could reduce the soil respiration at filling stage, wax ripeness, and harvest stage. Under the same straw application, compared with conventional tillage, the soil respiration and microbial respiratory quotient in both subsoiling and no-tillage were reduced, while the microbial biomass carbon and microbial activity were increased. During the summer maize growing season, soil microbial biomass carbon and microbial activity were increased in straw returning with conservation tillage, while the respiratory quotient was reduced. In 0-10 cm soil layer, compared with conventional tillage, straw recycling with subsoiling and no-tillage significantly increased soil microbial biomass carbon by 95.8% and 74.3%, and increased soil microbial activity by 97.1% and 74.2%, respectively.

Regulation of biochar on matrix enzyme activities and microorganisms around cucumber roots under continuous cropping.

ZOU Chun-jiao, ZHANG Yong-yong, ZHANG Yi-ming, GUO Xiao-ou, LI Ming-jing, LI Tian-lai1

2015, 26(6):  1772-1778. 

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The effects of addition of biochar on the matrix enzymes activity, microorganisms population and microbial community structure were evaluated under cucumber continuous cropping for 6 years (11 rotations). Cucumbers were grown in pots in greenhouse with 5% or 3% of medium (by mass) substituted with biochar. The control consisted of medium alone without biochar. The results showed that the activity of peroxidase was significantly improved to the level of the first rotation crop form 30 to 120 d after planting in both biochar treatments, with the effect of 5% biochar being more significant than that of 3% biochar. However, the neutral phosphatase activity was markedly reduced after biochar treatment. The addition of 5% biochar had significant regulation effect on the activities of invertase and urease from 30 to 90 d after planting, while the addition of 3% biochar had little effect. The populations of bacteria and actinomycetes were increased and the fungi population was reduced in both biochar treatments from 30 to 90 d after planting, and the effect of 5% biochar was more significant than that of 3% biochar. Meanwhile, the addition of biochar significantly increased the diversity of the bacterial community structure. In summary, biochar had obvious regulation effect on soil enzyme activity, microorganism quantity and microbial community in continuous cropping nutrition medium.

Effects of crop rotation and bioorganic manure on soil microbial characteristics of Chrysanthemum cropping system.

XIAO Xin1, ZHU Wei1, DU Chao1, SHI Ya-dong2, WANG Jian-fei1

2015, 26(6):  1779-1784. 

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We conducted a field experiment to evaluate the effects of rotation system and bioorganic manure on soil microbial characteristics of Chrysanthemum cropping system. Taking Chrysanthemum morifolium Ramat and wheat as experimental plants, treatments under Chrysanthemum continuous cropping system (M₁), conventional Chrysanthemumwheat rotation system (M₂), and Chrysanthemumwheat rotation system receiving bio-organic manure application of 200 kg·667 m^-2 (M₃) were designed. Soil chemical properties, soil microbial biomass carbon (MBC) and nitrogen (MBN), and the amounts of different types of soil microorganisms were determined. Results showed that compared with M₁, treatments of M₂ and M₃ significantly increased soil pH, organic matter, available N, P, and K, MBC, MBN, and the amounts of bacteria, fungi and actinomycetes, but decreased the ratio of MBC/MBN, and the relative percentage of fungi in the total amount of microorganisms. Treatment of M3 had the highest contents of soil organic matter, available N, available P, available K, MBC, MBN, and the amounts of bacteria, fungi and actinomycetes, with the values being 15.62 g·kg^-1, 64.75 mg·kg^-1, 83.26 mg·kg^-1, 96.72 mg·kg^-1, 217.40 mg·kg^-1, 38.41 mg·kg^-1, 22.31×10⁶ cfu·g^-1, 56.36×10³ cfu·g^-1, 15.90×10⁵  cfu·g^-1, respectively. We concluded that rational crop rotation and bioorganic manure application could weaken soil acidification, improve soil fertility and microbial community structure, increase the efficiency of nutrition supply, and have a positive effect on reducing the obstacles of continuous cropping.

Effects of tillage and straw returning on microorganism quantity, enzyme activities in soils and grain yield.

ZHAO Ya-li1,2,3, GUO Hai-bin1,4, XUE Zhi-wei1, MU Xin-yuan1, LI Chao-hai1,2,3

2015, 26(6):  1785-1792. 

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A two-year field study with split plot design was conducted to investigate the effects of different soil tillage (conventional tillage, CT; deep tillage, DT; subsoil tillage, ST) and straw returning (all straw retention, AS; no straw returning, NS) on microorganism quantity, enzyme activities in soil and grain yield. The results showed that, deep or subsoil tillage and straw returning not only reduced the soil bulk density and promoted the content of organic carbon in soil, but increased the soil microbial quantity, soil enzyme activities and grain yield. Furthermore, such influences in maize season were greater than that in wheat season. Compared with CT+NS, DT+AS and ST+AS decreased the soil bulk density at 20-30 cm depth by 8.5% and 6.6%, increased the content of soil organic carbon by 14.8% and 12.4%, increased the microorganism quantity by 45.9% and 33.9%, increased the soil enzyme activities by 34.1% and 25.5%, increased the grain yield by 18.0% and 19.3%, respectively. No significant difference was observed between DT+AS and ST+AS. We concluded that retaining crop residue and deep or subsoil tillage improved soil microorganism quantity, enzyme activities and crop yield.

 

Topographical and pedological factors adapted to the growth of domestic truffles (Tuber indicum).

QING Yuan1,3, JI Lin2, LI Ting-xuan2, LI Xiao-lin4, LIU Cheng-yi5, YANG Mei5, ZHENG Lin-yong 1,4 

2015, 26(6):  1793-1800. 

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Topographical and pedological factors at 9 sites of Tuber indicum in Yunnan, Sichuan and Tibet were studied by using principal component analysis in order to determine the connection between trufflegrowth with topographic factors and soil factors. Results showed that: 1) The 5 principal components selected from 15 topographical and pedological factors had a great cumulative contribution, up to 87.5%. Among the topographical factors, the slope position was the most important ecological factor affecting truffles growth. The higher the slope position was, the less conducive to truffles growth. In the middle and lower parts of the slope, T. indicum grew best. 2) As for the
pedological factors, the bulk density, silt content, pH, total nitrogen content, exchangeable calcium and magnesium contents were the important factors restricting T. indicum growth. Under the condition of bulk density 0.65-0.82 g·cm^-3, silt content 30.0% and sand content about 55.0%, T. indicum grew well. Too high bulk density or clay content was not conducive to its growth. The soil with pH 6.40 or so, total nitrogen content of 2.29-3.70 g·kg^-1, exchangeable calcium content of
22.91-37.17 cmol·kg^-1 and exchangeable magnesium content of 1.85-2.59 cmol·kg^-1 were favorable for growth of T. indicum. 3) The comprehensive evaluation showed that the site at Shaoshang Village in Kunming, Yunnan and Jiangsegang Village in Linzhi Prefecture, Tibet had higher scores, which meant these two sites had the most favorable conditions for truffles growth. However, the site at Ershijiuliangzi Village in Panzhihua, Sichuan and the Mt. Wuding in Chuxiong Prefecture, Yunnan had lower scores, which meant these two sites were not fit for truffles growth regarding the topographical and soil conditions.

Effects of different salt and alkali stresses on ion distribution in Red globe/Beta grapevines.

DU Yuan-peng, JIN Xue-juan, GUO Shu-hua, FU Qing-qing, ZHAI Heng

2015, 26(6):  1801-1806. 

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The potted Red globe/Beta grapevines were selected to irrigated with NaCl, Na₂SO₄, NaHCO₃, NH₄Cl， (NH₄)₂SO₄ . Hence, the ions which induced leaf etiolation were screened and the impacts of different salt and alkali on ion distribution in different organs of grapevines were investigated. It was found that NaHCO₃ exerted the greatest effects on grapevines, leaf etiolation at 14 days after treatment. By contrast, NaCl and NH₄Cl treatments induced leaf etiolation at 28 days after treatment. The Na⁺ content in all the detected organs were significantly increased under NaHCO₃ and NaCl treatment, and Na⁺ content in root under NaHCO₃ treatment was 6.4 times as that in control root. NaHCO₃ and NaCl treatments significantly decreased K⁺ content in the organs with the exception of leaf. NaHCO₃ treatment significantly decreased K/Na in different organs, which declined to 0.1 in root. By contrast, NaCl treatment significantly decreased K/Na in the detected organs with exception of stem. Besides, the transport of Ca²⁺, Mg²⁺, Fe²⁺ to aboveground organs was significantly decreased by NaHCO₃ and NaCl treatments. K/Na ratio in the detected organs were decreased under NH₄Cl, (NH₄)₂SO₄ and Na₂SO₄ treatments, especially under NH₄ Cl treatment. Taken together, NaHCO₃ was the primary factor resulting in leaf etiolation, followed by NaCl and NH₄Cl, while
(NH₄)₂SO₄ and Na₂SO₄ produced impacts.

Effects of long-term fertilization on bacterial and archaeal diversity and community structure within subtropical red paddy soils.

YUAN Hong-zhao1,2, WU Hao2,3, GE Ti-da1,2, LI Ke-lin3, WU Jin-shui1, WANG Jiu-rong1

2015, 26(6):  1807-1813. 

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Paddy soils not only function as an important sink for “missing carbon” but also play an important role in the production of greenhouse gases such as N₂O and CH₄. Dynamic changes in greenhouse gases in the atmosphere are closely related to microbially mediated carbon and nitrogen transformation processes occurring in soil. Using soil samples collected from a longterm fertilization experimental site in Taojiang County, subtropical China (established in 1986), we determined the effects of longterm (>25 years) nonfertilization (CK), chemical fertilization (NPK), and NPK combined with rice straw residues (NPKS) on soil bacterial  and archaeal community structures. The 16S rRNA genotypes from the three differently treated soils were divided into 9 bacterial phylotypes, mainly including Proteobacteria, Acidobacteria, Chloroflexi, and archaea of Crenarchaeota and Euryarchaeota. The relative abundance of Proteobacteria, Acidobacteria and Crenarchaeota increased in the soils under NPK and NPKS treatments, with the increase being greater in the latter treatment. LUBSHUFF statistical analyses also demonstrated that there was significant difference among the microbial community compositions in CK, NPK and NPKStreated soils. The abundance of bacterial and archaeal 16S rRNA genes ranged from 0.58 × 10¹⁰ to 1.06 × 10¹⁰ copies·g^-1 dry soil and from 1.16 × 10⁶ to 1.72 × 10⁶ copies·g^-1 dry soil, respectively. Application of fertilizers increased the bacterial and archaeal abundance and diversity in the treated soils, with NPKS>NPK. Longterm chemical and organic applications significantly affected the abundance, diversity and composition of bacterial and archaeal communities in paddy ecosystems.

Effects of GA₃ and CPPU on grape fruit adjacent leaf photosynthesis and fruit quality.

XIN Shou-peng1, LIU Shuai1, YU Yang1, NIE Song-qing2, GAO Zhi-hong1, TAO Jian-min1

2015, 26(6):  1814-1820. 

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Taken the grape cultivar ‘Shine Muscat’ as the material, the effect of the combination of GA₃ and CPPU on the lightresponse curves in the fruit adjacent leaves and fruit quality were investigated two weeks after blossoming. The results showed that nonrectangular hyperbolic model was more suitable for grape fruit adjacent leaf light response curve fitting. P_n and g_s of fruit adjacent leaves among all treatments increased with the increasing light intensity under the combination treatments of 25 mg·L^-1 GA₃ and 5, 10, 15, 20 mg·L^-1 CPPU, respectively, but C_i decreased. Fruit quality increased with the increasing CPPU concentration under the combination treatments of 25 mg·L^-1 GA₃ and 5, 10, 15 mg·L^-1 CPPU, respectively. Grape fruit adjacent leaf photosynthesis under the 25 mg·L^-1 GA₃ + 20 mg·L^-1 CPPU treatment was higher than  the other treatments. The fruit quality under the 25 mg·L^-1 GA₃ + 20 mg·L^-1 CPPU treatment was lower than  the 25 mg·L^-1 GA₃ + 15 mg·L^-1 CPPU treatment. It indicated that reasonable CPPU treatment concentration could improve fruit adjacent leaf photosynthetic ability and fruit quality. Too high concentration made the fruit quality lower instead. The 25 mg·L^-1 GA₃ +15 mg·L^-1 CPPU treatment was most appropriate in two weeks after blossoming.

Environmental efficiency evaluation under carbon emission constraint in Western China.

RONG Jian-bo1, YAN Li-jiao1, HUANG Shao-rong2, ZHANG Ge3

2015, 26(6):  1821-1830. 

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This research used the SBM model based on undesirable outputs to measure the static environmental efficiency of Western China under carbon emission constraint from 2000 to 2012. The researchers also utilized the Malmquist index to further analyze the change tendency of environmental efficiency. Additionally, Tobit regression analysis was used to study the factors relevant to environmental efficiency. Practical solutions to improve environmental quality in Western China were put forward. The study showed that in Western China, environmental efficiency with carbon emission constraint was significantly lower than that without carbon emission constraint, and the difference could be described as an inverse U-shaped curve which increased at first and then decreased. Guangxi and Inner Mongolia, the two provinces met the effective environmental efficiency levels all the time under carbon emission constraint. However, the five provinces of Guizhou, Gansu, Qinghai, Ningxia and Xinjiang did not. Furthermore, Ningxia had the lowest level of environmental efficiency, with a score between 0.281-0.386. Although the environmental efficiency of most provinces was currently at an ineffective level, the environmental efficiency quality was gradually improving at an average speed of 6.6%. Excessive CO₂ emission and a large amount of energy consumption were the primary factors causing environmental inefficiency in Western China, and energy intensity had the most negative impact on the environmental efficiency. The increase of import and export trade reduced the environmental efficiency significantly in Western China, while the increase of foreign direct investment had a positive effect on its environmental efficiency.

Net anthropogenic nitrogen input to Huaihe River Basin, China during 1990-2010.

ZHANG Wang-shou1,2, SU Jing-jun1, DU Xin-zhong1,2, LI Xu-yong1

2015, 26(6):  1831-1839. 

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Social economy in Huaihe River Basin had undergone enormous changes during 1990-2010. The grain yield had increased by 58%, from 64.14 million tons to 101.21 million tons, and the urbanization rate had increased by 22%, from 13% to 35%. Assessing the negative impacts of these high intensive human activities caused by rapid social development on terrestrial ecosystem would serve as a scientific basis for quantitative management of regional ecology. This paper estimated the spatial and temporal distribution of net anthropogenic nitrogen input (NANI) in Huaihe River Basin during 1990-2010. The results showed that there was an increasing trend in NANI in the period of 1990-2001, and after that this trend was slower. The NANI increased from approximately 17232 kg N·km^-2·a^-1 in 1990 to a peak of 28771 kg N·km^-2·a^-1 in 2003, and then declined to 26415 kg N·km^-2·a^-1 in 2010. Chemical fertilizer and atmospheric deposition were the largest two sources of NANI, followed by food & feed import and biological nitrogen. Contributions from both chemical fertilizer and atmospheric deposition had been increasing continuously, respectively from 64% and 16% in 1990 to 77% and 19%. Our findings implied that the shift from fertilizersupported agriculture and fossil fuelsupported industry to scitech lead economic development is urgently needed.

Spatial-temporal evolution of urban thermal environment based on spatial statistical features.

ZHANG Wei1,2,3, JIANG Jin-gang3, ZHU Yu-bi 4

2015, 26(6):  1840-1846. 

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A new method which aims to determine the area of urban heat island (UHI) was proposed in this paper based on spatial statistical features by means of remote sensing and GIS spatial analysis tools, and was applied in the spatialtemporal evolution analysis of UHI in Hangzhou, China. The results showed that the area of UHI in Hangzhou increased 8.66 times from 1984 to 2010. During the 26 years, the spatial structure of UHI in Hangzhou had become more and more complex, and its spatial distribution changed from singlecenter to multicenter. Generally speaking, the change trend of thermal environment in Hangzhou was turning from lowtemperature spatial equilibrium to hightemperature spatial equilibrium. The major cause for the development of UHI in Hangzhou was urban expansion as it showed in the results of dynamic change detection. This  new method considered the spatial correlation of urban land surface temperature (LST), and reflected the global statistical features of LST. It was more objective and accurate than the conventional methods, and could provide more information, which would help us to resolve the problem of being lack of generality and comparability in the current research.

Evaluation of ecosystem service and emergy of Wanshan Waters in Zhuhai, Guangdong Province, China.

QIN Chuan-xin1,2,3, CHEN Pi-mao1,2,3, ZHANG An-kai1, YUAN Hua-rong1,2,3, LI Guo-ying1,2,3, SHU Li-ming1,2,3, ZHOU Yan-Bo1,2,3, LI Xiao-guo1,2,3

2015, 26(6):  1847-1853. 

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The method for monetary value and emergy value analysis of ecosystem service was used in this paper to analyze the change in value of marine ecosystem service of Wanshan District, Zhuhai from 2007 to 2012. The result showed that the monetary value and emergy value of marine ecosystem service of Wanshan District, Zhuhai rose to 11512840000 yuan and 1.97×10²² sej from 7721630000 yuan and 1.04×10²² sej, respectively. Both monetary value and emergy value could forecast the change in the value of marine ecosystem service, but they reflected different value structures and ecological energy, which could be used to more objectively evaluate the ecosystem service. Ecological civilization development, as an inherent driving force to impel the development of marine ecosystem service structure, was important for rational exploitation of marine resources and optimization of marine ecosystem service.


 

Ecological security early-warning in Zhoushan Islands based on variable weight model.

ZHOU Bin1,2, ZHONG Lin-sheng2, CHEN Tian2, ZHOU Rui2,3

2015, 26(6):  1854-1862. 

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Ecological security early warning, as an important content of ecological security research, is of indicating significance in maintaining regional ecological security. Based on driving force, pressure, state, impact and response (D-P-S-I-R) framework model, this paper took Zhoushan Islands in Zhejiang Province as an example to construct the ecological security early warning index system, test degrees of ecological security early warning of Zhoushan Islands from 2000 to 2012 by using the method of variable weight model, and forecast ecological security state of 2013-2018 by Markov prediction method. The results showed that the variable weight model could meet the study needs of ecological security early warning of Zhoushan Islands. There was a fluctuant rising ecological security early warning index from 0.286 to 0.484 in Zhoushan Islands between year 2000 and 2012, in which the security grade turned from "serious alert" into "medium alert" and the indicator light turned from “orange” to “yellow”. The degree of ecological security warning was “medium alert” with the light of “yellow” for Zhoushan Islands from 2013 to 2018. These findings could provide a reference for ecological security maintenance of Zhoushan Islands.

Impact of artificial reef on community of macrobenthos in Jincheng area of Laizhou Bay, China.

REN Bin-bin1,2, YUAN Wei2, SUN Jian-qiang2, CHEN Rui-sheng2, WANG Jun2

2015, 26(6):  1863-1870. 

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In order to evaluate the impact of artificial reef on the communities of macrobenthos, from 2009 to 2012, samples were collected in four seasons at the artificial reef area and the control area in Jincheng area of Laizhou Bay from 9 cruises. A total of 35 macrobenthos species (4 phyla, 30 families) were recorded in the two areas, with 30 species in the artificial reef area, and 27 species in the control area. Results suggested that the two macrobenthos communities with different  species composition could be discriminated. One community was located in artificial reef area, the other  outside the reef area. Planktophagous group was the most dissimilaritycontributing species. The species similarity (Jaccard) of the two areas increased from 37.5% in the first year to 58.6% in the second year. The biomass and abundance of macrobenthos in the artificial reef area respectively increased from 1.00 g·m^-2 and 540 ind·m^-2 in the first year to 1.55 g·m^-2 and 622 ind·m^-2 in the second year, which were both higher than those in the control area. Compared with the control area, the Shannon index and abundance index of the artificial reef area were increased, while the evenness index was decreased. The abundance biomass comparison (ABC) curve showed that the macrobenthos communities were more heavily disturbed in the second year than that in the first year after artificial reef set. It was considered that the macrobenthos community was unsteady at the early stage after artificial reef construction (1-2 years). The physical, chemical, biological and human activities were the main factors influencing macrobenthos community in Jincheng area of Laizhou Bay.

Enrichment of Cd²⁺ and Hg²⁺ in Phascolosoma esculenta and their effects.

WU Hong-xi1,2,3, GAO Ye-tian4, HUANG Zhen-hua2,3, JIANG Xia-min1

2015, 26(6):  1871-1876. 

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The accumulation of Cd²⁺ and Hg²⁺ in Phascolosoma esculenta and its effects on its growth and main nutrient components were investigated using atomic absorption spectrometer analysis and atomic fluorescence spectrometer examination. The results showed that within the experimental heavy metal concentrations, the amounts of Cd²⁺ and Hg^2+ accumulated in the somatic muscles increased with increasing exposure time and reached their saturated levels at the end of the experiment. Exposure of higher heavy metal concentrations speeded up the accumulation of Cd²⁺ and Hg²⁺ and subsequently took less time to reach their saturated levels, which were greater than those of lower concentration groups. The rate of mass gain of P. esculenta decreased with increasing the heavy metal exposure concentrations. The combination exposure of Cd²⁺ and Hg²⁺ led to a significantly lower mass gain rate compared to those exposed to Cd²⁺ or Hg²⁺. The protein content of somatic muscles increased with the increase of exposure concentration and reached the maximum values at 0.05 and 0.02 mg·L^-1 for Cd²⁺ and Hg²⁺, respectively. After that, the protein content of somatic muscles began to decrease. The combined exposure of the two heavy metals showed similar effect trends but more significant impacts on the protein content of somatic muscles. The lipid content of somatic muscles decreased with increasing the concentration of Cd²⁺ or Hg²⁺ exposure, and the combination of Cd²⁺ and Hg²⁺ led to lower lipid content.

Interspecies diet relationship of Coreius from Yinbin reach of Yangtze River, China.

LI Lei2, WEI Qi-wei1,3, GUO Wei1,3, LIN Dan-qing1,4, WU Jin-ming1

2015, 26(6):  1877-1882. 

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This study investigated the diet compositions of Coreius heterodon and C. guichenoti in Yibin reach of Yangtze River from April to May, 2012 by carbon and nitrogen stable isotopes technique, and analyzed their diet relationship by the multivariate statistical technique, which covered the diet similarity index, overlap coefficient, and the influence of morphological differences in feeding organ between the two species on diet compositions. The results showed that, 1) the δ¹³C and
δ¹⁵N of C. heterodon was from -21.15‰ to -20.31‰ and 9.67‰ to 10.21‰, respectively, which indicated that the fish had an omnivorous possessing carnivorous preference. The δ¹³C and δ¹⁵N of C. guichenoti was from -23.30‰ to -21.18‰ and 7.40‰ to 9.21‰, respectively, which had an omnivorous possessing phytophagous preference. There were some differences in the results between the stable isotopes and the traditional intestinal contents analysis. 2) The diet similarity index and the overlap coefficient was 78.7% and 55.6%, respectively. 3) The principal component analysis (PCA) result showed that the morphological characters of the feeding organs in the two fishes were different. In conclusion, the interspecies competition was not intense between the C. heterodon and C. guichenoti, and as the last investigation of the diet composition and food relationship of the two species before the impoundment of the Xiangjiaba Reservoir, the results could provide reference for analyzing the influence of impoundment on the fish trophic structure in Yibin reach of Yangtze River.

Heavy metal pollution characteristics and ecological risk analysis for soil in Phyllostachys praecox stands of Lin’an.

FANG Xiao-bo1, SHI Jian2, LIAO Xin-feng2, LOU Zhong3, ZHOU Lyu-yan2, YU Hai-xia2, YAO Lin2, SUN Li-ping1

2015, 26(6):  1883-1891. 

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An investigation was carried out in an attempt to reveal the characteristics of heavy metals contamination in the soils of Phyllostachys praecox forest in Lin’an. Based on the concentrations of Hg, As, Cu, Pb, Zn, Cd, Cr, Ni, Co and Mn in 160 topsoil samples, the pollution status and ecological risks of heavy metals in the soils were assessed by single factor pollution index, Nemerow integrated pollution index and Hankanson potential ecological risk index. The spatial variability of heavy metal concentrations in the soils closely related to the distribution of traffic, industrial and livestock pollution sources. The average concentrations of Hg, As, Cu, Pb, Zn, Cd, Cr, Ni, Co and Mn in the soils were 0.16, 7.41, 34.36, 87.98, 103.98, 0.26, 59.12, 29.56, 11.44 and 350.26 mg·kg^-1, respectively. Pb, Cd, Zn and Cu concentrations were as 2.89, 1.70, 1.12 and 1.12 times as the background values of soil in Zhejiang Province, respectively. But their concentrations were all lower than the threshold values of the National Environmental Quality Standard for Soil (GB 15618-1995). The average single factor pollution index revealed that the level of heavy metal pollution in the soils was in order of Pb＞Cd＞Cu= Zn＞Hg＞As＞Ni＞Co＞Cr＞Mn. Pb pollution was of moderate level while Cd, Cu and Zn pollutions were slight. There was no soil pollution caused by the other heavy metals. However, the Nemerow integrated pollution index showed that all the 160 soil samples were contaminated by heavy metals to a certain extent. Among total 160 soil samples, slight pollution level, moderate pollution level and heavy pollution level accounted for 55.6%, 29.4% and 15.0%, respectively. The average single factor potential ecological risk index (E_i^r) implied that the potential ecological risk related to Cd reached moderate level, while the others were of slight level. Furthermore, Cd and Hg showed higher potential ecological risk indices which reached up to 256.82 and 187.33 respectively, indicating Cd and Hg had a strong ecological risk and therefore might pose the most serious ecological risk in the soils of P. praecox standsin Lin’an. In addition, the integrated factor potential ecological risk analysis suggested a slight risk to local ecosystem originated from heavy metal contamination in the soils of P. praecox stands in Lin’an.

Research progress of cover crop in Chinese orchard.

WHANG Yan-ting1, JI Xiao-hao1, WU Yu-sen1, MAO Zhi-quan1, JIANG Yuan-mao1, PENG Fu-tian1, WANG Zhi-qiang2, CHEN Xue-sen1

2015, 26(6):  1892-1900. 

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Grass growing in orchard is implemented in most fruit cultivation advanced countries, but only China carries out grass weeding. To effectively resolve the puzzle on harmful or beneficial effect on fruit production imparted by grass growing, and promote grass growing management in orchard in China, more and more domestic research was reported in recent years. Combined the results of our research and domestic related research, we reviewed the latest research progress about the effect of growing grass on soil, microclimate, fruit tree diseases and insect pests, tree growth and fruit quality, etc. in this paper. We pointed out that grass growing in orchard must consider the local conditions, economic efficiency, the critical period, and the supporting technique.

 

Advances in low impact development technology for urban stormwater management.

LIU Wen, CHEN Wei-ping, PENG Chi

2015, 26(6):  1901-1912. 

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Low impact development (LID), as an innovative technology for stormwater management, is effective to mitigate urban flooding and to detain pollutants. This paper systemically introduced the LID technology system, and summarized the reduction effects of three typical LID facilities (i.e., bioretention, green roof and permeable pavement) on stormwater runoff and main pollutants in recent literature, as well as research outcomes and experiences of LID technology on model simulation, cost-benefit analysis and management system. On this basis, we analyzed the problems and limitations of current LID technology studies. Finally, some suggestions about future research directions, appropriate design and scientific management were put forth. This work intended to provide scientific basis and suggestions for widespread use and standard setting of LID technology in China by referencing overseas studies.