Table of Content

18 October 2013, Volume 24 Issue 10

Previous Issue    Next Issue

Effects of selective cutting on the carbon density and net primary productivity of a mixed broadleaved-Korean pine forest in Northeast China.

LIU Qi, CAI Hui-ying, JIN Guang-ze

2013, 24(10):  2709-2716. 

Asbtract ( 1996 )   PDF (699KB) ( 587 )  

To accurately quantify forest carbon density and net primary productivity (NPP) is of great significance in estimating the role of forest ecosystems in global carbon cycle. By using the forest inventory and allometry approaches, this paper measured the carbon density and NPP of the virgin broadleaved-Korean pine (Pinus koraiensis) forest and of the broadleaved-Korean pine forest after 34 years selectivecutting (the cutting intensity was 30%, and the cutting trees were in large diameter class). The total carbon density of the virgin and selectivecutting broadleaved-Korean pine forests was (397.95±93.82) and (355.61±59.37) t C·hm^-2, respectively. In the virgin forest, the carbon density of the vegetation, debris, and soil accounted for 31.0%, 3.1%, and 65.9% of the total carbon pool, respectively; in the selectivecutting forest, the corresponding values were 31.7%, 2.9%, and 65.4%, respectively. No significant differences were observed in the total carbon density and the carbon density of each component between the two forests. The total NPP of the virgin and selectivecutting forests was (36.27±0.36) and (6.35±0.70) t C·hm^-2·a^-1, among which, the NPP of overstory, understory, and fine roots in virgin forest and selectivecutting forest accounted for 60.3%, 2.0%, and 37.7%, and 66.1%, 2.0%, and 31.2%, resp〖JP2〗ectively. No significant differences were observed in the total NPP and the contribution rate of each component between the two forests. However, the ratios of the needle and broadleaf NPPs of the virgin and selectivecutting forests were 47.24:52.76 and 20.48:79.52, respectively, with a significant difference. The results indicated that the carbon density and NPP of the broadleaved-Korean pine forest after 34 years selective-cutting recovered to the levels of the virgin broadleaved-Korean pine forest.

Variation characteristics of CO₂ flux in Phyllostachys edulis forest ecosystem in subtropical region of China

SUN Cheng1, JIANG Hong1,2, ZHOU Guo-mo1, YANG Shuang1, CHEN Yun-fei1

2013, 24(10):  2717-2724. 

Asbtract ( 1566 )   PDF (989KB) ( 633 )  

By using eddy covariance technique, this paper studied the CO₂  flux in a Phyllostachys edulis forest ecosystem with high-efficiency management in Zhejiang Province of China from December, 2010 to November, 2011, and analyzed the variations of net ecosystem exchange (NEE), ecosystem respiration (RE), and gross ecosystem exchange (GEE). During the study period, the monthly NEE was always negative, with the maximum (-99.33 g C·m^-2) in July and the minimum (-23.49 g C·m^-2) in November, and the seasonal change showed a bimodal shape. The average diurnal change of the monthly CO₂ flux varied greatly from -0.30 g CO₂·m^-2·s^-1(January) to -0.60 g CO₂·m^-2·s^-1(September). The NEE at the time point of positive and negative conversion had obvious seasonal characteristics. The yearly RE changed in unimodal shape, with the maximum in summer and the minimum in winter. The RE at nighttime had significant negative correlation with soil temperature. The yearly NEE, RE, and GEE were -668.40, 932.55, and -1600.95 g C·m^-2·a^-1, respectively, among which, the NEE occupied 41.8% of the GEE. As compared with other ecosystems, P. edulis forest ecosystem had a strong capability in carbon sequestration.

Spatial distribution patterns of soil organic carbon under Elacagnus angustifolia-Achnatherum splendens community in an arid area of Northwest China.

CHI Ting1, XU Chi1, LIU Mao-song1, ZHANG Ming-juan2, YANG Xue-jiao1

2013, 24(10):  2725-2730. 

Asbtract ( 1547 )   PDF (653KB) ( 529 )  

An  investigation was conducted to study the relationships of soil organic carbon (SOC) content with root biomass and soil moisture content as well as the accumulation mechanisms of SOC under the Elacagnus angustifolia-Achnatherum splenden community in Ningxia Hui Autonomous Region of Northwest China. The results showed that the SOC content decreased gradually with increasing soil depth, and changed gently in both horizontal and vertical directions. The correlations of the SOC content and its affecting factors varied with soil depth. In 0-30 cm layer, the SOC content was significantly negatively correlated with soil moisture content; in 60-150 cm layer, the SOC content was significantly positively correlated with soil moisture content and root biomass. Partial regression analysis indicated that the root biomass density in 0-30 cm soil layer contributed significantly to the variance of SOC content. In 60-150 cm layer, the SOC content was mainly affected by root system and soil moisture content; in 30-60 cm layer, no significant correlations were observed between the SOC content and the root biomass and soil moisture content. There was an obvious difference in the accumulation mechanism of SOC in different soil layers and at different locations of E. angustifolia-A. splendens community.

Effects of elevated ozone on Pinus armandii growth: A simulation study with open-top chamber.

LIU Chang-fu1, LIU Chen1, HE Xing-yuan2, RUAN Ya-nan4, XU Sheng2, CHEN Zhen-ju1,2,3, PENG Jun-jie2, LI Teng2

2013, 24(10):  2731-2736. 

Asbtract ( 1595 )   PDF (668KB) ( 498 )  

By using open-top chamber (OTC) and the techniques of dendrochronology, this paper studied the growth of Pinus armandii under elevated ozone, and explored the evolution dynamics and adaptation mechanisms of typical forest ecosystems to ozone enrichment. Elevated ozone inhibited the stem growth of P. armandii significantly, with the annual growth of the stem length and diameter reduced by 35.0% and 12.9%, respectively. The annual growth of treering width and the annual ring cells number decreased by 11.5% and 54.1%, respectively, but no significant change was observed in the diameter of tracheid. At regional scale, the fluctuation of ozone concentration showed significant correlation with the variation of local vegetation growth (NDVI).

Effects of harvest disturbance on soil CH₄ flux in a secondary hardwood forest in Northeast China.

SUN Hai-long, ZHANG Yan-dong

2013, 24(10):  2737-2745. 

Asbtract ( 1445 )   PDF (967KB) ( 463 )  

From June, 2007 to October, 2009, a measurement with static chamber / gas chromatograph techniques was conducted on the soil CH₄ flux in a typical secondary hardwood forest in Northeast China under the effects of different harvest disturbances, i.e., uncut (control), clear cutting (including both farming and reforestation after clear cutting), 50% stand volume removed, and 25% stand volume removed. In all of the four treatments, the soil was the sink of atmospheric CH₄, but cutting decreased the soil CH₄ uptake flux, with the order of uncut (-85.03 μg CH₄·m^-2·h^-1) > 50% stand volume removed (-80.31 μg CH₄·m^-2·h^-1) > 25% stand volume removed (-70.97 μg CH₄·m^-2h^-1) > farming after clear cutting (-65.57 μg CH₄·m^-2·h^-1) > reforestation after clear cutting (-62.02 μg CH₄·m^-2·h^-1). During the study period, the seasonal patterns of the soil CH₄ uptake flux in all treatments were similar, with a higher value in growth season and a lower one in winter. After the harvest disturbance, the soil temperature, humidity, and NO₃^--N, and NH₄⁺-N contents were all increased, and the soil CH₄ flux had a significant quadratic correlation with soil temperature, and a negative linear correlation with soil moisture content. It was suggested that the increase of the soil moisture, NO₃^--N, and NH₄⁺-N contents after the forest harvest was the main cause of the decrease of the soil CH₄ uptake flux.

Simulation of water and carbon fluxes in Harvard forest area based on data assimilation method.

ZHANG Ting-long1,2,3,4, SUN Rui2,3, ZHANG Rong-hua2,3,ZHANG Lei2,3

2013, 24(10):  2746-2754. 

Asbtract ( 2301 )   PDF (841KB) ( 489 )  

Model simulation and in situ observation are the two most important means in studying the water and carbon cycles of terrestrial ecosystems, but have their own advantages and shortcomings. To combine these two means would help to reflect the dynamic changes of ecosystem water and carbon fluxes more accurately. Data assimilation provides an effective way to integrate the model simulation and in situ observation. Based on the observation data from the Harvard Forest Environmental Monitoring Site (EMS), and by using ensemble Kalman Filter algorithm, this paper assimilated the field measured LAI and remote sensing LAI into the Biome-BGC model to simulate the water and carbon fluxes in Harvard forest area. As compared with the original model simulated without data assimilation, the improved BiomeBGC model with the assimilation of the field measured LAI in 1998, 1999, and 2006 increased the coefficient of determination R² between model simulation and flux observation for the net ecosystem exchange (NEE) and evapotranspiration by 8.4% and 10.6%, decreased the sum of absolute error (SAE) and root mean square error (RMSE) of NEE by 17.7% and 21.2%, and decreased the SAE and RMSE of the evapotranspiration by 26.8% and 28.3%, respectively. After assimilated the MODIS LAI products of 2000-2004 into the improved Biome-BGC model, the R² between simulated and observed results of NEE and evapotranspiration was increased by 7.8% and 4.7%, the SAE and RMSE of NEE were decreased by 21.9% and 26.3%, and the SAE and RMSE of evapotranspiration were decreased by 24.5% and 25.5%, respectively. It was suggested that the simulation accuracy of ecosystem water and carbon fluxes could be effectively improved if the field measured LAI or remote sensing LAI was integrated into the model.

Fine root biomass and carbon storage in surface soil of Cinnamomum camphora plantation in Rainy Area of West China.

WEI Peng1, LI Xian-wei1,2, FAN Chuan1, ZHANG Teng-fei1, LIU Yun-ke1, SU Yu1, YANG Zheng-ju1

2013, 24(10):  2755-2762. 

Asbtract ( 1580 )   PDF (783KB) ( 737 )  

Fine root in forest ecosystems plays an important role in global C cycle. In this study, a measurement was made on the fine root biomass and carbon storage in the surface soil (0-30 cm) of a 31 yearold Cinnamomum camphora plantation in the Rainy Area of West China in November, 2010-December, 2011. The total biomass and carbon storage of the fine roots (living and dead) in the surface soil were 1592.29 kg·hm^-2 and 660.68 kg C·hm^-2, in which, living fine roots accounted for 91.1% and 91.8% respectively. The total biomass and carbon storage of the first five order living roots and dead roots decreased significantly with increasing soil depth, and the living root biomass and carbon storage increased significantly with root order. The sum of the biomass and carbon storage of living and dead fine roots was the largest in autumn and the smallest in winter, but the biomass and carbon storage of the dead fine roots were the largest in winter and the smallest in summer. The biomass and carbon storage of the first two order roots were the largest in summer and the smallest in winter, while those of the last three order roots were the largest in autumn and the smallest in winter. The spatial heterogeneity of soil moisture and nutrients was the main factor affecting the fine root biomass and carbon storage.

Effects of drought stress on the root growth and photosynthetic characters of Dactylis glomerata seedlings.

JI Yang1,2, ZHANG Xin-quan1, PEN Yan1, LIANG Xiao-yu1，2, HUANG Lin-kai1, CHEN Ling-zhi1, LI Zhou1, MA Ying-mei1

2013, 24(10):  2763-2769. 

Asbtract ( 2191 )   PDF (796KB) ( 662 )  

Taking the droughtsensitive Dactylis glomerata line “01998” and droughttolerant cultivar “Baoxing” as test materials, a pot experiment was conducted to study the effects of drought stress on the seedlings root growth, physiological characteristics, and leaf photosynthesis, aimed to approach the differences in the droughttolerance mechanism of different D. glomerata lines (cultivars). Under drought stress, the root vitality and root number of “01998” and “Baoxing” presented a trend of increased first and decreased then. When the soil relative moisture content decreased to 30%, the root vitality and root number of “01998” and “Baoxing” increased significantly and reached the maximum. Drought stress decreased the relative water content, leaf chlorophyll content, net photosynthesis, transpiration, and stomatal conductance, but increased the electric conductivity and intercellular CO₂ concentration of “01998” and “Baoxing”. Under drought stress, the leaf area per plant of both “01998” and “Baoxing” decreased, and the underground and aboveground plant biomass of “01998” decreased while that of “Baoxing” had less change.

Effects of different water harvesting modes on alfalfa planting in semi-arid areas of Northwest China.

2013, 24(10):  2770-2778. 

Asbtract ( 1304 )   PDF (1075KB) ( 593 )  

A field experiment with complete random design was conducted to investigate the effects of different mulching materials \[common plastic film (CMR), biodegradable mulch film (BMR), and soil crust (SR)\] and different ratios of furrow to ridge (60 cm：30 cm, 60 cm：45 cm, and 60 cm：60cm) on the runoff efficiency, soil water storage, soil water content, and hay yield and water use efficiency of alfalfa in semiarid areas of the Loess Plateau. The runoff efficiency in treatments SR, BMR, and CMR was 32.0%, 90.7%, and 96.4%, respectively. In the early growth period of alfalfa (from April to June), the soil water storage between the treatments had no significant difference, but in the late growth period (from July to September), the soil water storage in CMR and BMR was significantly higher than that in SR. The soil water storage in SR was significantly higher than that in traditional planting (TP). At budding stage, the soil water storage in TP, SR, BMR, and CMR was 223.27, 248.56, and 277.81, and 284.16 mm, respectively. In the whole growth period, the hay yield of alfalfa in TP, SR, BMR, and CMR was 4112.1, 3397.5, 4317.8, and 4523.8 kg·hm^-2, and the water use efficiency was 11.08, 10.48, 14.56, and 1495 kg·mm^-1·hm^-2, respectively. The ratio of furrow to ridge had no significant effects on the water use efficiency in the same treatments. When the ratio of furrow to ridge was 60 cm：44 cm, the hay yield in CMR and BMR reached the maximum.

Runoff process in forested basin of Hun River-Taizi River, Northeast China: A simulation study.

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

2013, 24(10):  2779-2786. 

Asbtract ( 1587 )   PDF (1920KB) ( 365 )  

Based on the hydrological data from the Beikouqian and Nandianyu stations in the upstream of Hun River and Taizi River as well as the meteorological data from the Qingyuan, Xinbin, and Benxi County stations, Northeast China in 1998-2007, a distributed hydrological model (DHSVM) was applied to simulate the hydrological process in Hun-Tai basin. The scientific applicability of the model was validated, and the reference values of the most sensitive model parameters were provided. The simulated monthly runoff NashSuttclife coefficient (E _value) for the source region of Hun River in calibration period (1998-2002) and validation period (2003-2007) was 0.9675 and 0.8957, respectively, which could better reappear the monthly runoff process in this source region. The simulated monthly and annual runoff E_values for the upstream of Taizi River were greater than 0.6, indicating that this model had good applicability in Hun-Tai basin, and the calibrated parameter scheme had a good reliability. This paper established a solid framework for the hydrological study over ungauged basin, and constructed a reasonable parameter scheme.

 

Relationships between Dendrobium quality and ecological factors based on partial least square regression.

LI Wen-tao, HUANG Lin-fang, DU Jing, CHEN Shi-lin

2013, 24(10):  2787-2792. 

Asbtract ( 1676 )   PDF (712KB) ( 292 )  

A total of eleven ecological factors values were obtained from the ecological suitability database of the geographic information system for traditional Chinese medicines production areas (TCMGIS), and the relationships between the chemical components of Dendrobium and the ecological factors were analyzed by partial least square (PLS) regression. There existed significant differences in the chemical components contents of the same species of Dendrobium in different areas. The polysaccharides content of D. officinale had significant positive correlation with soil type, the accumulated dendrobine in D. nobile was significantly positively correlated with annual precipitation, and the erianin content of D. chrysotoxum was mainly affected by air temperature. The principal component analysis (PCA) showed that Zhejiang Province was the optimal production area for D. officinale, Guizhou Province was the most appropriate planting area for D. nobile, and Yunnan Province was the best production area of D. chrysotoxum.

 

Variation characteristics of maize yield and fertilizer utilization rate on an upland yellow soil under long term fertilization.

LUO Long-zao1,2, LI Yu1,2, ZHANG Wen-an1,2, XIAO Hou-jun1,2, JIANG Tai-ming2,3

2013, 24(10):  2793-2798. 

Asbtract ( 1375 )   PDF (564KB) ( 518 )  

An analysis was made on the 16-year experimental data from the long term fertilization experiment of maize on a yellow soil in Guizhou of Southwest China. Four treatments, i.e., no fertilization (CK), chemical fertilization (165 kg N·hm^-2, 82.5 kg P₂O₅·hm^-2, and 82.5 kg K₂O·hm^-2, NPK), organic manure (30555 kg·hm^-2, M), and combined application of chemical fertilizers and organic manure (NPKM), were selected to analyze the variation trends of maize yield and fertilizer use efficiency on yellow soil under effects of different long term fertilization modes, aimed to provide references for evaluating and establishing long term fertilization mode and promote the sustainable development of crop production. Overall, the maize yield under long term fertilization had an increasing trend, with a large annual variation. Treatment NPKM had the best yieldincreasing effect, with the maize yield increased by 4075.71 kg·hm^-2 and the increment being up to 139.2%. Long term fertilization increased the fertilizer utilization efficiency of maize. In treatment M, the nitrogen and phosphorus utilization rates were increased significantly by 35.4% and 18.8%, respectively. Treatment NPK had obvious effect in improving potassium utilization rate, with an increment of 20% and being far higher than that in treatments M (8.7%) and NPKM (9.2%). The results showed that long term fertilization, especially the combined application of chemical fertilizers and organic manure, was of great importance in increasing crop yield and fertilizer use efficiency.

Effects of phosphorus fertilization on leaf area index, biomass accumulation and allocation, and phosphorus use efficiency of intercropped maize.

CHEN Yuan-xue1, LI Han-han1, ZHOU Tao1, CHEN Xin-ping2, HUANG Wei1, LIU Jing1, ZHANG Chao-chun2, XU Kai-wei1

2013, 24(10):  2799-2806. 

Asbtract ( 1669 )   PDF (695KB) ( 568 )  

A 2year field experiment was conducted in 2011 and 2012 to investigate the effects of phosphorus (P) fertilization on the leaf area index (LAI), dry matter accumulation (DMA), and P use efficiency (PUE) of maize in wheat/maize/soybean intercropping system. Five P fertilization rates were installed, i.e., 0, 45, 90, 135, and 180 kg P₂O₅·hm^-2 for wheat, marked as WP₀, WP₁, WP₂, WP₃, and WP₄, respectively, and 0, 37.5, 75, 112.5, and 150 kg P₂O₅·hm^-2 for maize, marked as MP₀, MP₁, MP₂, MP₃, and MP₄, respectively. During the coexisted growth periods of wheat and maize, P fertilization increased the LAI, leaf area duration (LAD), and stem and leaf DMA of maize significantly. After the jointing stage of maize, the maize LAI, LAD, DMA, and crop growth rate (CGR) all decreased after an initial increase with the increasing P rate, with the maximum growth in treatment MP₂ or MP₃. During the reproductive stage of maize, the maize dry mass translocation from vegetative to reproductive organ increased with increasing P fertilization rate, and the grain yield of both maize and whole cropping system increased firstly and decreased then, with the maximum grain yield of maize and whole cropping system being 6588 and 11955 kg·hm^-2 in treatment P₃, respectively. The P apparent recovery efficiency of maize was the highest (26.3%) in treatment MP₂, being 82.6%, 38.4%, and 152.9% higher than that in MP₁ (14.4%), MP₃ (19.0%), and MP₄ (10.4%), respectively. In sum, for the wheat/maize/soybean intercropping system, applying appropriate amount of P fertilizer could promote maize growth, alleviate the impact of wheat on maize, and consequently, increase the P apparent recovery efficiency of maize. In this study, the appropriate P fertilization rate was 75-112.5 kg P₂O₅·hm^-2.

Effects of rape cropping in summer fallow period on dryland soil moisture content and winter wheat yield.

ZHAO Gang1, FAN Ting-lu2, LI Shang-zhong1, ZHANG Jian-jun1, WANG Yong1, DANG Yi1, WANG Lei1

2013, 24(10):  2807-2813. 

Asbtract ( 1362 )   PDF (636KB) ( 419 )  

Taking the fallow land with wheat stubble after harvesting as the control, a 4-year field experiment was conducted in a dryland of east Gansu, Northwest China to investigate the effects of rape cropping in summer fallow period on the soil moisture content, wheat yield, and water use efficiency (WUE). The rape was sown at 6 dates. There was a significant difference (P<0.05) in the soil moisture content in summer fallow period when the rape was sown at different dates. When the rape was sown on August 5, the soil water storage efficiency was 58.5%, and the wheat yield and WUE were increased by 7.5% and 5.9%, respectively, as compared with the control. Averagely, cropping rape in fallow period could increase the wheat yield by 16.1% in dry year and 6.8% in normal year. It was suggested that rape cropping in summer fallow period would benefit the wheat yield and drought resistance of drylands in Northwest China.

Experiment precision and comprehensive environmental evaluation of regional wheat trials in rainfed regions of China.

CHANG Lei1, HAN Fan-xiang2, CHAI Shou-xi1, YUE Yun3, YANG De-long2, YANG Chang-gang1, HUANG Cai-xia4, CHENG Hong-bo2

2013, 24(10):  2814-2820. 

Asbtract ( 1313 )   PDF (419KB) ( 383 )  

Based on the grain yield data of regional trials with 233 winter and spring wheat cultivars (lines) in rainfed farmlands at 82 locations in four subregions of China in 2003-2009, this paper studied the experiment precision (EP), variety comparison precision (VCP), and testingsite discrimination ability and representativeness of national regional trials, and comprehensively evaluated the trial environment. The results showed that in onelocationoneyear experiments, the average coefficient of variation (CV) and the relative least significant difference (RLSD) were 6.1% and 10.5%, respectively, and in multilocationoneyear experiments, the CV was all within 8.2%, and the CV and RLSD were mostly well controlled, indicating that the trials had a high precision. The testingsite discrimination ability was the highest in the northwest spring wheat subregion, but showed less difference in the other subregions. The testingsite representativeness was the best in the northeast spring wheat subregion, and the worst in the northwest spring wheat subregion. On the basis of the comprehensive consideration of the testingsite discrimination ability and representativeness, and by using the parameters of the environmental comprehensive assessment (r_g-h) of GGE model, it was shown that the proportion of the ideal trial locations for wheat in our rainfed farmlands was only 32.4%. Among the wheat production regions, the proportions of the ideal trial locations were in the order of northwest spring wheat subregion (40.9%) > northeast spring wheat subregion (33.3%) > Huang-Huai winter wheat subregion (30.4%) > north winter wheat subregion (21.4%).

Screening of  wild barley genotypes with high phosphorus use efficiency  and their rhizosphere soil inorganic phosphorus fractions.

XU Jing, ZHANG Xi-zhou, LI Ting-xuan, YU Hai-ying, JI Lin

2013, 24(10):  2821-2830. 

Asbtract ( 1701 )   PDF (1037KB) ( 481 )  

A pot experiment was conducted to investigate the differences of 16 wild barley genotypes in phosphorus (P) uptake and use efficiency under the same P supply levels and the characteristics of inorganic P fractions in rhizosphere and non-rhizosphere soils of high P use efficiency genotypes. There existed greater differences in the P use efficiency for dry matter production at jointing stage (CV=11.6%) and flowering stage (CV=12.4%), and in the P use efficiency for grain yield at maturing stage (CV=13.7%) among the genotypes. The biomass, P accumulation amount, and P use efficiency for dry matter production of high P use efficiency genotypes (IS-22-30 and IS-22-25) were significantly higher than those of low P use efficiency genotype (IS-07-07), and the grain yield of IS-22-30 and IS-22-25 was 3.10 and 3.20 times of that of IS-07-07, respectively. When supplied 0 and 30 mg·P kg^-1, the concentrations of available P and water soluble P in rhizosphere soils were significantly lower than those in non-rhizosphere soils, especially for the water soluble P. The concentrations of inorganic P fractions in the rhizosphere and non-rhizosphere soils were in the order of Ca₁₀-P>O-P>Fe-P>Al-P>Ca₂-P>Ca₈-P. When supplied 30 mg·P kg^-1, the Ca₈-P concentration in high P use efficiency genotypes rhizosphere soils at jointing and flowering stages was significantly lower than that in low P use efficiency genotype rhizosphere soil, but the Ca₂-P concentration was in adverse. When no P was supplied, the concentrations of Ca₂-P and Ca₈-P in high P use efficiency genotypes rhizosphere soils were significantly higher than those in low P use efficiency genotype rhizosphere soil, and the Ca₁₀-P concentration in the rhizosphere soils of all genotypes decreased. When supplied 30 mg·P kg^-1, the Fe-P and O-P concentrations in high P use efficiency genotypes rhizosphere soils were significantly higher than that in low P use efficiency genotype rhizosphere soil, but the Al-P concentration presented an opposite trend. Under no P supply, the Al-P, Fe-P, and O-P concentrations in high P use efficiency genotypes rhizosphere soils were significantly lower than those in low P use efficiency genotype rhizosphere soil. It was suggested that under low P stress, the capabilities of high P use efficiency genotypes in activating and absorbing soil Al-P and Ca₂-P were stronger than those of low P use efficiency genotype.

Yield formation of different single-season rice (Oryza sativa L.) types and its relationships with meteorological factors in Yunnan Province of Southwest China.

ZHONG Chu1, ZHU Ying-mo2, ZHU Yong1, ZHU Bin1, ZHANG Mao-song1, XU Meng-ying1

2013, 24(10):  2831-2842. 

Asbtract ( 1436 )   PDF (1612KB) ( 394 )  

By using the 1994-2010 observation data of paddy rice growth period and yield from 14 agro-meteorological stations at different altitudes in Yunnan Province, this paper studied the rice yield formation and the effects of meteorological factors on low-yield rice yield components. According to the systematic cluster analysis of rice yield components and the rice types at the 14 stations, the rice was divided into 4 types, i.e., lowyield japonica rice, low-yield indica rice, high-yield japonica rice, and high-yield indica rice. The analysis of the yield components of the 4 rice types showed that there was a significant positive correlation between the spikelet number per square meter (sqm) and the rice yield. The yield of low-yield japonica was mainly affected by the seed setting rate and the spikelet number per sqm. For the other three rice types, the spikelet number per sqm had greater effects on the rice yield. The low-yield japonica rice was mainly affected by low temperature. At booting stage, low temperature decreased the spikelet number and the productive panicle number of unit sqm. At booting and flowering stages, low temperature increased the empty grain rate, and the effects of average temperature, average maximum temperature, and cold accumulated temperature were greater. At pre-milk stage, low temperature increased the unfilled grain rate, and meanwhile, decreased the 1000-grain mass. The yield components of low-yield indica rice were obviously affected by multiple meteorological factors. A certain degree of warming at tillering and jointing stages was not beneficial to the increase of productive panicle number per sqm of low-yield indica rice, but the more sunshine hours and the greater average diurnal temperature range at tillering stage was beneficial to the increase of the productive panicle number per sqm. There was a parabolic relationship between the temperature and sunshine hours at tillering and jointing stages and the spikelet number per panicle. The low temperature at flowering stage affected the empty grain rate of low-ield indica rice to a certain extent, while the high temperature and less rain at pre-milk stage not only increased the unfilled grain rate, but also distinctly reduced the 1000-grain mass.

Responses of winter wheat seedling growth and allelochemical content to elevated CO₂ and O₃ concentrations.

ZHANG Xiao-ying1,2, WANG Peng1, ZHOU Bin1,2

2013, 24(10):  2843-2849. 

Asbtract ( 1333 )   PDF (780KB) ( 544 )  

By using open-top chamber (OTC), a pot experiment was conducted to study the effects of elevated CO2 (550 μL·L^-1), O₃ (60 μL·L^-1), and their interaction (CO₂ 550 μL·L^-1 plus O₃ 60 μL·L^-1) on the seedling dry mass and allelochemical DIMBOA content of seven winter spring cultivars. Under elevated CO₂, there existed significant differences in the shoot dry mass and DIMBOA content among  the test wheat cultivars. As compared with the control (CO₂ 370 μL·L^-1; O₃ 40 μL·L^-1), the shoot and root dry mass of cultivar Bima-1 under elevated CO₂ increased by 36.8% and 24.7%, respectively, and the DIMBOA content increased by 5.7%-184.6%. Elevated O₃ decreased the seedling dry mass except for Bima-1 and Shan-139, but increased the DIMBOA content of all the cultivars, with an increment of 0.5-3 folds. Under the interaction of elevated CO₂ and O₃, the root dry mass of all cultivars decreased, and the shoot dry mass, root dry mass, and DIMBOA content of Changwu-134 had the greatest decrement of 8.2%, 27.9%, and 35.5%, respectively. In contrast to the decrease of the DIMBOA content of Changwu-134, Yuanfeng-175 and Lankao-217, the DIMBOA content of Shan-139 increased by 84.6%. The cluster analysis indicated that both the treatments and the cultivars had significant effects on the DIMBOA content, the cultivars Shan-139, Lankao-217, and Changwu-134 under the elevated CO₂ or O₃ could be grouped together, whereas the DIMBOA content of Shan-139 in all treatments increased. These findings suggested that DIMBOA could be used as a specific indicator for resistance breeding under climate change, especially under elevated O₃ and CO₂.

Effects of paclobutrazol on the yield, quality, and related enzyme activities of different quality type peanut cultivars.

ZHANG Jia-lei1，2, WANG Yuan-yuan1, SUN Lian-qiang1, WEI Tong-tong1, GU Xue-hua1, GAO Fang3, LI Xiang-dong1

2013, 24(10):  2850-2856. 

Asbtract ( 1930 )   PDF (521KB) ( 441 )  

Selecting high-protein peanut cultivar KB008, high-fat cultivar Hua17, and high O/L cultivar Nongda818 as test materials, a field experiment was conducted in 2011 and 2012 to study the effects of foliar spraying paclobutrazol (PBZ) at late flowering stage on the kernel yield and quality and the activities of leaf carbon and nitrogen metabolism enzymes of the cultivars. Spraying PBZ increased the pod yield of the cultivars significantly via increasing the pod number per plant, decreasing the pod number per kilogram, and increasing the percentage of double kernel. Spraying PBZ also increased the kernel fat and soluble sugar contents but decreased the kernel protein content to varying degrees, and increased the O/L ratio of high-fat cultivar Hua17 significantly. PBZ increased the kernel fat content while decreased the kernel protein content of Nongda818 significantly, but had little effects on the kernel protein or fat content of the other two cultivars. Spraying PBZ decreased the leaf nitrate reductase  activity of the three cultivars at their pod setting stage, and the leaf glutamine synthetase  and glutamate dehydrogenase  activities at pod setting and filling stages, with the largest decrement for Nongda818 and the smaller one for KB008 and H17. Spraying PBZ decreased the leaf glutamate oxaloacetic transaminase  and glutamate pyruvate transaminase  activities of the three cultivars at their pod setting and filling stages, illustrating that the decrease of the nitrogen metabolism enzyme activities after spraying PBZ was the main reason of the decreased kernel protein content of the cultivars. PBZ increased the leaf sucrose synthase and sucrose phosphate synthase  activities at pod setting and filling stages, being significant for Nongda818. PBZ improved the leaf phosphoenolpyruvate carboxylase  and ribulose bisphosphate carboxylase activities of the three cultivars at their pod setting and filling stages, being most significant for Nongda818. It was suggested that the increase of the carbon metabolism enzyme activities was the physiological basis of the improvement of kernel fat content after spraying PBZ.

Changes of organic soil substrate properties with different cultivation years and their effects on cucumber growth in solar greenhouse.

SONG Wei-jiao, HE Chao-xing, YU Xian-chang, ZHANG Zhi-bin, LI Yan-su, YAN Yan

2013, 24(10):  2857-2862. 

Asbtract ( 1476 )   PDF (465KB) ( 309 )  

This paper studied the changes of organic soil substrate properties with increasing cultivation years and their effects on the cucumber growth in  solar greenhouse. The results showed that with increasing cultivation years, the physical and chemical properties of organic soil substrate deteriorated, which was manifested in the increase of bulk density and the decrease of total porosity, pH, and available nutrient contents. The numbers of bacteria and actinomycetes in the substrate decreased with increasing cultivation years, while that of fungi was in reverse. The cucumber growth was also affected to a certain extent, manifesting in the decrease of plant height and leaf area, the decline of photosynthetic efficiency, and the decrease of yield and quality. It would be necessary to restore the fertility of organic soil substrate after 3-year cultivation.

Satellite remote sensing retrieval of canopy nitrogen nutritional status of apple trees at blossom stage.

WANG Ling, ZHAO Geng-xing, ZHU Xi-cun, WANG Rui-yan, CHANG Chun-yan

2013, 24(10):  2863-2870. 

Asbtract ( 1656 )   PDF (1196KB) ( 440 )  

Taking Qixia City of Shandong, China as the study area, and based on the Landsat-5 TM and ALOS AVNIR-2 images, the canopy retrieval reflectance of apple trees at blossom stage was acquired. In combining with the measured reflectance of sample trees, the nitrogensensitive spectral indices were constructed and selected. By using the sensitive spectral indices as the independent variables, the nitrogen retrieval models were established, and the model with the best accuracy was used for spatial retrieve. The correlations between the spectral indices and the nitrogen nutritional status were in the order of canopy > leaf > flower. The sensitive indices were mainly composed of green, red, and near infrared bands. The accuracy of the retrieval models was in the order of support vector regression > multi-variable stepwise regression > one-variable regression. The retrieval results based on different images were similar, and showed that the leaf nitrogen content was mainly of grades 3-4 (27-33 g·kg^-1), and the canopy nitrogen nutrient indices were mainly of grades 2-4 (TM: 38-47 g·kg^-1; ALOS: 32-41 g·kg^-1). The spatial distribution of the retrieval nitrogen nutritional status based on different images also showed the similar trend, i.e., the nitrogen nutritional status was higher in the north and south than that in the middle part of the study area, and the areas with the high grades of leaf nitrogen and canopy nitrogen were mainly located in Sujiadian Town and Songshan subdistrict in the northwest, Zangjiazhuang Town and Tingkou Town in the northeast, and Shewopo Town in the south, which were consistent with the distribution of the key towns for apple production in Qixia City. This study provided a feasible method for the acquisition of  nitrogen nutritional status of apple trees on macroscopic scale, and also, provided reference for other similar remote sensing retrievals.

Effects of elevated rhizosphere CO₂ concentration on the photosynthetic characteristics, yield, and quality of muskmelon.

LIU Yi-ling1, SUN Zhou-ping1, LI Tian-lai1， GU Feng-ying2, HE Yu3

2013, 24(10):  2871-2877. 

Asbtract ( 1494 )   PDF (783KB) ( 388 )  

By using aeroponics culture system, this paper studied the effects of elevated rhizosphere CO₂ concentration on the leaf photosynthesis and the fruit yield and quality of muskmelon during its anthesis-fruiting period. In the fruit development period of muskmelon, as compared with those in the control (350 μL CO₂·L^-1), the leaf chlorophyll content, net photosynthetic rate (P_n), stomatal conductance (G_s), intercellular CO₂ concentration (C_i), and the maximal photochemical efficiency of PSⅡ(F_v/F_m) in treatments 2500 and 5000 μL CO₂·L^-1 decreased to some extents, but the stomatal limitation value （L_s） increased significantly, and the variation amplitudes were larger in treatment 5000 μL CO₂·L^-1  than in treatment 2500 μL CO₂·L^-1. Under the effects of elevated rhizosphere CO₂ concentration, the fruit yield per plant and the Vc and soluble sugar contents in fruits decreased markedly, while the fruit organic acid content was in adverse. It was suggested that when the rhizosphere CO₂ concentration of muskmelon during its anthesis-fruiting period reached to 2500 μL·L^-1, the leaf photosynthesis and fruit development of muskmelon would be depressed obviously, which would result in the decrease of fruit yield and quality of muskmelon.

Water productivity of apple orchards with different planting densities in semiarid mountainous regions of Loess Plateau, Northwest China: A simulation study.

ZHANG Li-na1, LI Jun2, FAN Peng1, CAO Yu2, GUO Zheng1, YANG Xiao-li3

2013, 24(10):  2878-2887. 

Asbtract ( 1547 )   PDF (1235KB) ( 379 )  

By adopting the revised WinEPIC model, a simulation study was conducted to investigate the responses of the apple yield and deeper soil moisture content to 7 planting densities in the apple orchards in Yan’an of Shaanxi and in Jingning of Gansu in 1965-2009. Under the 7 planting densities, the annual yields of the 4-45 years apple orchards increased rapidly at early growth stage, and then decreased with fluctuation after reached the maximum. The higher the planting density, the higher the annual yield was obtained at early growth stage, but the yield at late growth stage fluctuated dramatically with annual precipitation. The orchards with different planting densities had the similar soil water stress process, i.e., no water stress at early growth stage, and water stress occurred and fluctuated dramatically with increasing planting years. The days of water stress at late growth stage changed oppositely to annual precipitation. At early growth stage, the soil available moisture content in 0-15 m layer under the 7 planting densities all decreased rapidly with strong fluctuation, ranged in a low level of 0-600 mm after 17-22 years in Yan’an and after 13-20 years in Jingning. The soil moisture content in 0-15 m layer changed similarly under different planting densities, i.e., decreased gradually with the deepening of soil desiccation, and the stable depth of drying layer could reach 12 m. Considering the apple yield and the soil available moisture content in 0-15 m layer, the reasonable planting density of apple orchard was 650-800 plants·hm^-2 in Yan’an and 550-700 plants·hm^-2 in Jingning.

 

Sizes of soil macropores and related main affecting factors on a vegetated basalt slope.

GUAN Qi1, XU Ze-min2, TIAN Lin2

2013, 24(10):  2888-2896. 

Asbtract ( 1477 )   PDF (792KB) ( 403 )  

The landslide on vegetated slopes caused by extreme weather has being increased steadily, and the preferential flow in soil macropores plays an important role in the landslide. By using water breakthrough curve and Poiseuille equation, this paper estimated the radius range, amount, and average volume of soil macropores on a vegetated basalt slope of Maka Mountain, Southwest China, and analyzed the distribution of the soil macropores and the main affecting factors. In the study area, the radius of soil macropores ranged from 0.3 to 1.8 mm, mainly between 0.5 and 1-2 mm. The largeradius  macropores (1.4-1.8 mm) were lesser, while the small-radius  macropores (<1.4 mm) were more. With the development of soil profile, soil macropores were more in upper layers and lesser in deeper layers. The average volume of the macropores contributed 84.7% to the variance of steady effluent rate. Among the factors affecting the average volume of the large macropores, vegetations root mass had a linear relationship, with the correlation coefficient being 0.70, and soil organic matter content also had a linear relationship, with the correlation coefficient being 0.64.

Effects of land use change on soil labile organic carbon in central Jiangxi of China.

DU Man-yi1, FAN Shao-hui1, LIU Guang-lu1, QI Liang-hua1, GUO Bao-hua1, TANG Xiao-lu1, XIAO Fu-ming2

2013, 24(10):  2897-2904. 

Asbtract ( 1939 )   PDF (533KB) ( 476 )  

Selecting the 15-year abandoned land (AL) and three forest lands ［Phyllostachys edulis plantation (PE), Schima superba secondary forest (SS), and Cunninghamia Lanceolata plantation (CL)］ in Anfu County of Jiangxi Province as test objects, this paper studied the effects of land use change on the soil organic carbon (SOC) pool and soil labile organic carbon (SLOC) contents. The soil organic carbon (SOC), microbial biomass carbon (MBC), hot water extractable carbon (HWC), and readily oxidizable carbon (ROC) contents in the test lands were all in the order of PE>CL>SS>AL. As compared with those in AL, the SOC content, soil carbon stock, and soil labile organic carbon (SLOC) contents in the three forest lands all decreased with increasing soil depth, and had an obvious accumulation in surface soil. The proportions of different kinds of SLOC to soil total organic carbon differed markedly, among which, ROC had the highest proportion, while MBC had the smallest one. There existed significant relationships between SOC, MBC, HWC, and ROC. The MBC, HWC, and ROC contained higher content of active carbon, and were more sensitive to the land use change, being able to be used as the indicators for evaluating the soil quality and fertility in central Jiangxi Province.

Characteristics of rain season atmospheric PM_2.5 concentration and its water-soluble ions contents in forest parks along an urban-rural gradient in Guangzhou City of South China.

XIAO Yi-hua1, XI Dan2, TONG Fu-chun3, KUANG Yuan-wen2, LI Jiong2, CHEN Bu-feng1, SHI Xin1, PEI Nan-cai1, HUANG Jun-biao1, PAN Yong-jun1

2013, 24(10):  2905-2911. 

Asbtract ( 1872 )   PDF (464KB) ( 311 )  

During the rainy season (April-September) of 2012, the atmospheric particulate matter with a diameter less than 2.5 mm (PM_2.5) were sampled from the forest parks in the urban area, suburban area, and rural area of Guangzhou City.  The  mass concentration of PM_2.5 and its watersoluble ions (SO₄^2-, NO₃^-, NO₂^-, Cl^-, F^-, Na⁺, NH₄⁺, Ca²⁺, K⁺, and Mg²⁺) contents were also measured. In the forest parks in the urban area, suburban area, and rural area, the diurnal variation of PM_2.5 mass concentration was 21.8-161.7, 19.4-156.3, and 17.2-66.5 μg·m^-3, with an arithmetic average being 55.9, 49.8, and 44.4 μg·m^-3, respectively. SO₄^2-, Na⁺, and NH₄⁺ were the main components of watersoluble ions in the PM_2.5, and the SO₄^2- had the highest content and decreased gradually from urban to rural forest parks. The contribution of the SO₂ and NO_x in the PM_2.5 from coal combustion to the forest parks was larger than that from vehicle exhaust, but presented a decreasing trend from urban to rural forest parks, indicating that vehicle exhaust had a greater contribution to the atmospheric SO₂ and NO_x in the urban forest park. In the sampling period, the contribution of sea salt to the water soluble fractions (especially K⁺) of the PM_2.5 was greater for the suburban forest park than for the other two parks. The equivalent concentration of the NH₄⁺ in the PM_2.5 was far less than those of the SO₄^2- and NO₃^-, with a neutralization ratio being much lower than 1.0, which suggested that the PM_2.5 had a higher acidity. The PM_2.5  acidity had an increasing trend from rural to urban forest parks.

Assessment of groundwater vulnerability to nitrate in He’nan Province of China based on principal component regression.

KOU Chang-lin1, GUO Zhan-ling1, MA Zheng-hua1, LI Li-dong2, WANG Shou-gang1, SHEN Alin1, ZHAO Li-jun1

2013, 24(10):  2912-2916. 

Asbtract ( 1905 )   PDF (923KB) ( 383 )  

According to the hydrological and morphological characteristics, He’nan Province was divided into mountainous region and plain region. The level of rich water, infiltration modulus of precipitation, fertilization level per unit area, proportions of vegetable planting area, and soil texture were selected as the common indices, and the slope and groundwater depth were selected as specific indices to assess the groundwater vulnerability to nitrate. Principal component regression analysis was adopted to determine the index weights, and the spatial distribution of groundwater vulnerability to nitrate in He’nan Province was assessed with ArcGIS 9.2. In the Province, the groundwater vulnerability to nitrate was mainly at low and medium level, and the region with this vulnerability level accounted for 68.4% of the total. The high vulnerability region accounted for 19.8%, and the extremely high vulnerability region occupied 11.8%. The main factors affecting the groundwater vulnerability to nitrate in plain region were soil texture, fertilization level, and infiltration modulus of precipitation, while those in mountainous region were fertilization level, soil texture, and slope. This study provided a theoretical basis for reasonable fertilization and agricultural environment management.

 

Characteristics and adaptation of seasonal drought in southern China under the background of climate change. Ⅴ. Seasonal drought characteristics division and assessment in southern China.

HUANG Wan-hua1,2, SUI Yue2,3, YANG Xiao-guang2, DAI Shu-wei4, LI Mao-song5

2013, 24(10):  2917-2925. 

Asbtract ( 2991 )   PDF (1234KB) ( 527 )  

Zoning seasonal drought based on the study of drought characteristics can provide theoretical basis for formulating drought mitigation plans and improving disaster reduction technologies in different arid zones under global climate change. Based on the National standard of meteorological drought indices and agricultural drought indices and the 1959-2008 meteorological data from 268 meteorological stations in southern China, this paper analyzed the climatic background and distribution characteristics of seasonal drought in southern China, and made a threelevel division of seasonal drought in this region by the methods of combining comprehensive factors and main factors, stepwise screening indices, comprehensive disaster analysis, and clustering analysis. The firstlevel division was with the annual aridity index and seasonal aridity index as the main indices and with the precipitation during entire year and main crop growing season as the auxiliary indices, dividing the southern China into four primary zones, including semiarid zone, subhumid zone, humid zone, and superhumid zone. On this basis, the four primary zones were subdivided into nine secondlevel zones, including one semiarid area-temperatecold semiarid hilly area in SichuanYunnan Plateau, three subhumid areas of warm subhumid area in the north of the Yangtze River, warmtropical subhumid area in South China, and temperatecold subhumid plateau area in Southwest China, three humid areas of temperatetropical humid area in the Yangtze River Basin, warmtropical humid area in South China, and warm humid hilly area in Southwest China, and two superhumid areas of warmtropical superhumid area in South China and temperatecold superhumid hilly area in the south of the Yangtze River and Southwest China. According to the frequency and intensity of multiple drought indices, the secondlevel zones were further divided into 29 thirdlevel zones. The distribution of each seasonal drought zone was illustrated, and the zonal drought characteristics and their impacts on the agricultural production were assessed. Accordingly, the drought prevention measures were proposed.

Characteristics of soil denitrifying enzyme activity in riparian zones with different land use types in Chongming Island, Shanghai of China.

CHEN Gang-liang, LI Jian-hua, YANG Chang-ming

2013, 24(10):  2926-2932. 

Asbtract ( 2204 )   PDF (629KB) ( 507 )  

By using acetylene inhibition method, this paper studied the soil denitrifying enzyme activity (DEA) and its affecting factors in the riparian zone with different land use types (cropland riparian, forested riparian, and grassy riparian zones) in Chongming Island, Shanghai of China. The riparian soil DEA was (0.69±0.11) - (134.93±33.72) μg N·kg^-1·h^-1, which differed obviously among different land types, with a decreasing trend of forested riparian zone > cropland riparian zone > grassy riparian zone. The soil DEA was significantly (P<0.05) higher in 0-10 cm in 10-30, 30-50, and 50-70 cm layers. There were significant positive relationships between soil DEA and soil TOC, TN, and NO₃^--N (P<0.01). Land use change mainly altered the soil natural structure and soil physical and chemical properties, decreased the accumulation of soil organic carbon, and affected the soil nitrogen transformation, and thus, inhibited the occurrence of riparian soil denitrification.

Ecological function evaluation and related management strategies of river ecosystem in Taizi River basin, North China.

WAN Jun1, LIU Hong-yan2, ZHANG Yuan1, MA Shu-qin1, MENG Wei1

2013, 24(10):  2933-2940. 

Asbtract ( 1592 )   PDF (2660KB) ( 608 )  

By the method of index evaluation at reach scale, this paper evaluated the ecological functions of aquatic biodiversity maintenance, habitat maintenance, water quality sustainment, and hydrological support of the river system in Taizi River basin of North China. The dominant ecological functions and the total ecological function were determined after sorting and summing. All the reaches in the basin were divided into four hierarchies of ecological functions. Overall, the total ecological function showed a spatially degrading trend from the mountainous region to the plain. Based on the evaluation results of the total function and dominant functions, six ecosystem management strategies were proposed. For the reaches with the functions of aquatic biodiversity and habitat maintenance, the primary ecological management strategies included ecological conservation, ecological maintenance, and ecological restoration; for the reaches with the functions of water quality sustainment and hydrological support, the primary strategies of ecological management included limited development, development optimization, and exploitation.

Effects of biochars produced from different sources on arsenic adsorption and desorption in soil.

GUAN Lian-zhu, ZHOU Jing-jing, ZHANG Yun, ZHANG Guang-cai, ZHANG Jin-hai, CHAN Zhong-xiang

2013, 24(10):  2941-2946. 

Asbtract ( 4611 )   PDF (961KB) ( 409 )  

By using OECD Guideline 106 batch equilibrium method, this paper studied the characteristics of As (Ⅴ) adsorption and desorption in brown soil as affected by the biochars produced from dairy manure, pine needle, and corn straw. When the addition amount of the biochars was 0.5%, the maximum adsorption amount of As (Ⅴ) was decreased in the order of dairy manure biochar > pine needle biochar > corn straw biochar, which was related to the basic characteristics of the biochars. The adsorption isotherm of As (Ⅴ) could be well fitted by Langmuir model (R²= 0.997). In comparing with CK, both the adsorption capacity (lgK_f=1.99-2.10) and the adsorption intensity (1/N=0.413-0.449) of As (Ⅴ) were low, and the main adsorption mechanism was physical adsorption. The desorption rate of As (Ⅴ) (14.5%-18.7%) was decreased in the order of dairy manure biochar > pine needle biochar > corn straw biochar. The addition of the biochars decreased the adsorption of As (Ⅴ) by brown soil, which could induce the increase of the bioavailability of As, and strengthen the toxicity of As in soil.

Responses of functional diversity of aquatic insect community to land use change in middle reach of Qiantang River, East China

ZHANG Lian-bo1, LIU Dong-xiao1, LIU Shuo-ru1, ZHANG Yong1, TONG Xiao-li2, WANG Bei-xin1

2013, 24(10):  2947-2954. 

Asbtract ( 2692 )   PDF (939KB) ( 515 )  

Based on the biological traits such as life history, resistance ability against environmental disturbance, and physiological characteristics of aquatic insects, and by using the fourthcorner statistical method, this paper studied the responses of the functional diversity of aquatic insect community to land use change in the middle reach of Qiantang River, Zhejiang Province of East China. For the test aquatic insect community, some of its biological traits were sensitive to land use change, and altered along human disturbance gradients as expected. With the increasing intensity of human disturbance, the maximal insect body length decreased gradually, the dominant respiration pattern evolved from gill respiration to tegument respiration, and the abundance of burrowers increased significantly. At the same time, the functional diversity measured as Rao’s quadratic entropy was significantly higher in reference sites than in disturbed sites (P<0.001), demonstrating that the changes in the functional diversity of the aquatic community were mainly induced by the land use change caused by human activities, which resulted in the decline of stream water quality and habitat quality and the variations of aquatic insect community composition and biological traits. The aquatic insect biological traits and functional diversity could be the potentially effective indicators in the stream health assessment in the future.

Parasitic and lethal effects of Trichoderma longibrachiatum on Heterodera avenae: Microscopic observation and bioassay.

ZHANG Shu-wu1,2,3,4, LIU Jia1,4, XU Bing-liang1,2,3,4, GU Li-jun1,2, XUE Ying-yu1,4

2013, 24(10):  2955-2960. 

Asbtract ( 1411 )   PDF (888KB) ( 545 )  

A laboratory experiment was conducted to study the parasitic and lethal effects of Trichoderma longibrachiatum conidia suspension on Heterodera avenae cysts. Different concentrations (1.5×10⁵-1.5×10⁷ cfu·mL^-1) of T. longibrachiatum conidia suspension had strong parasitic and lethal effects on H. avenae cysts, and the effects differed significantly among the different concentrations. When treated with the T. longibrachiatum conidia suspension at a concentration of 1.5×10⁷ cfu·mL^-1, 96.7% of the H. avenae cysts were parasitized by the conidia at the 18th day, and the hatching rate of the cysts was inhibited by 91.2% at the 22nd day. The microscopic observation showed that at the initial parasitic stage, T. longibrachiatum conidia suspension adhered or parasitized on the cyst surface, germinated a large number of hyphae, and grew on the cyst surface, making the development of cyst embryo stopped and the contents in cysts flocculated, and even, some cysts started to deform, and small dark brown vacuoles formed on the cyst surface. At the later parasitic stage, the cysts were penetrated by dense mycelium, cysts were broken, their contents exosmosed, and the mycelium on the integument of some cysts produced conidiophores, on which, conidium were adhered or parasitized. It was considered that T. longibrachiatum could be used as a potential high-efficient bioagent to control the occurrence and damage of H. avenae.


Effects of Trichoderma longbrachitum and Streptomyces jingyangensis combination on the growth and disease resistance of tobacco seedlings.

ZHANG Liang1,2, LIU Hao-bao1, GU Jin-gang3, SONG Yu-feng1,2,DONG Lian-hong1,2, SU Yu-long1,2, LI Shi-gui3, LEI Qiang4, WU Ren-jun4, YIN Ying4, QU Jian-kang4, WANG Yong5

2013, 24(10):  2961-2969. 

Asbtract ( 2442 )   PDF (797KB) ( 425 )  

An agar plate antagonism experiment in combining with in vivo screening experiment was conducted to study the affinity and bacteriostasis spectrum of the combination of biocontrol agents Trichoderma longbrachitum and Streptomyces jingyangensis to Nicotiana tabacum seedlings, with the effects of each agent and their combination on the N. tabacum seedlings growth, induced resistance, and resistance to Phytophthora nicotianae analyzed. The two agents had no interactive inhibitory effect and showed higher affinity to N. tabacum, and the agents themselves as well as their metabolites had higher bacteriostasis activities and wider bacteriostasis spectrum to P. nicotianae, Pythium aphanidermatum, and Alternaria alternate in different habitats. The combination of the two agents affected the morphological characteristics of the seedlings underground and aboveground parts, promoted the growth of root, stem, and leaf, and increased the root volume, total surface area, length, and average diameter as well as the stem height and size and the leaf length, width, and biomass, with these promotion effects being superior than those of the singleagent treatment. The combination of the two agents also increased the activities of the defensive enzymes superoxide dismutase, catalase, phenylalanine ammonia lyase, and peroxidase  in the seedlings root significantly, with the relative control efficiency against P. nicotianae reached 69.3%, as compared to the conventional treatment. This study showed that the combination of T. longbrachitum and S. jingyangensis was a compatible combination with higher affinity and efficiency. This combination showed a synergistic effect of the two agents in plant disease control and in promoting plant growth, being able to promote the tobacco seedlings growth and control the P. nicotianae effectively.

 

Effects of nano-selenium on antioxidant capacity and histopathology of Cyprinus carpio liver under fluoride stress.

CHEN Jian-jie1, CAO Jin-ling1, LUO Yong-ju2, LI Ju-yin3

2013, 24(10):  2970-2976. 

Asbtract ( 1615 )   PDF (2074KB) ( 418 )  

To evaluate the protection effect of nanoselenium (NSe) on the antioxidant capacity and histopathology of Cyprinus carpio liver under fluoride stress, a total of 750 C. carpio individuals were randomly divided into five groups, i.e., no fluoride stress and NSe addition (CK), fluoride (100 mg F^-·L^-1)stressed (FS), and fluoridestressed plus NSe added with a dosage of 0.1 mg Se·L^-1 (NSe L), 0.5 mg Se·L^-1 (NSe M), and 1.0 mg Se·kg^-1 (NSe H). The NSe was mixed with fish foods, and the fishes of FS and NSe groups were exposed to the fluoride stress for 30 days. As compared with CK, fluoride stress decreased the SOD, CAT, and GSHPx activities and increased the MDA content of C. carpio liver, and induced a definite damage on the histopathology of the liver. Compared with FS, NSe increased the liver SOD, CAT, and GSH-Px activities, decreased the liver MDA content, and mitigated the damage of fluoride stress on the histopathology of the liver. The results demonstrated that in some extent, the addition of NSe into fish foods could alleviate the decline of the antioxidant capacity of C. carpio liver and the damage on the liver histopathology caused by fluoride stress.

Toxic effect of nodularin on the apoptosis of grass carp (Ctenopharyngodon idellus) lymphocytes and related mechanisms.

ZHANG Hang-jun1,2, WU Yu-huan2, ZHAO Jing1, SHAO Jian-zhong1

2013, 24(10):  2977-2982. 

Asbtract ( 1829 )   PDF (901KB) ( 387 )  

Nodularin is a new kind of cyanobacterial toxins found in water blooms worldwide, and fish is very easily to suffer from the negative effects induced by this toxin. This study found that nodularin could induce the apoptosis of Ctenopharyngodon idellus lymphocytes in vitro. The observation of transmission electron microscopy showed that under the impacts of nodularin, the lymphocytes presented typical apoptosis features, such as obvious cytoplasm condensation and nuclear chromatin agglutination and marginalization. The DNA ladder fragmentation further confirmed the occurrence of the apoptosis of the lymphocytes. After incubated with 1, 10, and 100 μg·L^-1 of nodularin for 12 h, the percentages of apoptotic lymphocytes reached 19.4%, 31.6%, and 71.6%, respectively, suggesting a dosedependent manner. The nodularininduced apoptosis was related to the increase of intracellular reactive oxygen species (ROS), decline of mitochondrial transmembrane electric potential, upregulation of intracellular Ca²⁺, downregulation of Bcl₂, and upregulation of Bax. Meanwhile, the activation of Caspase-3 and Caspase-9 were involved in the process of apoptosis. These results strongly indicated that nodularin could induce the apoptosis of fish lymphocytes via mitochondria pathway.

Countyscale N₂O emission inventory of China’s manure management system.

WANG Chuan1, GAO Wei2, ZHOU Feng3, CHEN Qing3, YING Na4, XU Peng1, HOU Xi-kang4

2013, 24(10):  2983-2992. 

Asbtract ( 1919 )   PDF (4051KB) ( 505 )  

Manure is one of the two largest contributors to China’s N₂O emission. By using the countyscale activity data and the regional emission factors and related parameters with spatial differentiation in China in 2008, this paper assessed the N₂O emission loading, sources profile, spatial pattern, and uncertainty, aimed to establish a highresolution N₂O emission inventory of China’s manure management system in 2008. As compared with the research results based on the IPCC, EDGAR, and other works, the proposed emission inventory was more reliable and comprehensive. The total China’s N₂O emission from manure in 2008 was estimated as 572 Gg, among which, the emission from the manure except pasture/range/paddock was 322 Gg (56.3%), from the manure in pasture/range/paddock was 180 Gg (31.5%), and the indirect emission from atmospheric volatilized N deposition and leaching/runoff was 45.8 Gg (8.0%) and 1.23 Gg (0.2%), respectively. The spatial pattern of China’s N₂O emission from manure was more centralized, and mainly concentrated in Jilin, Shandong, Sichuan, Hunan, Henan, Heilongjiang, and Liaoning provinces, contributing 52.4% of the total emission, and more than 25% being from 84 counties (only <3% of the whole counties). The proposed emission inventory had a higher spatial resolution and accuracy. Different with this inventory, the IPCC underestimated the direct emission while overestimated the indirect emission, with the regions of higher emission rate being underestimated by -1.5%--6.0% and those of lower emission rate being overestimated by 1.6%-13%. As for the EDGAR, the regions of higher emission rate were underestimated by -18.8--5.0%, and those of lower emission rate were mostly overestimated by 25%-54.1%.

Horizontal transfer of antibiotic resistance genes in the environment.

YANG Feng-xia1, MAO Da-qing2, LUO Yi3, WANG Qing4, MU Quan-hua4

2013, 24(10):  2993-3002. 

Asbtract ( 2221 )   PDF (1250KB) ( 699 )  

The transfer of antibiotic resistance genes (ARGs), a new type of environmental pollutants, could have more adverse effects on the environment than the ARGs themselves, while the horizontal gene transfer (HGT) could be the most important propagation pathways of the ARGs, being one of the reasons for the growing pollution of ARGs in the environment. This paper systematically elaborated the molecular elements of the horizontal transfer of ARGs and the related affecting factors, which was of significance for investigating the molecular mechanisms of the horizontal transfer of the ARGs. In combining with the phylogenetic mechanisms of multiple antibiotic resistances, this paper also provided effective strategies to reduce the transfer and proliferation of ARGs in the environment. Based on the present contamination situations, the further researches on the horizontal transfer of ARGs in the environment were prospected.

Process and mechanism of plants in overcoming acid soil aluminum stress.

ZHAO Tian-long, XIE Guang-ning, ZHANG Xiao-xia, QIU Lin-quan, WANG Na, ZHANG Su-zhi

2013, 24(10):  3003-3011. 

Asbtract ( 2544 )   PDF (647KB) ( 572 )  

Aluminum (Al) stress is one of the most important factors affecting the plant growth on acid soil. Currently, global soil acidification further intensifies the Al stress. Plants can detoxify Al via the chelation of ionic Al and organic acids to store the ionic Al in vacuoles and extrude it from roots. The Al extrusion is mainly performed by the membranelocalized anion channel proteins Al³⁺activated malate transporter (ALMT) and multidrug and toxin extrusion (MATE). The genes encoding ABC transporter and zinc-finger protein conferred plant Al tolerance have also been found. The identification of these Alresistant genes makes it possible to increase the Al resistance of crop plants and enhance their production by the biological methods such as gene transformation and mark-associated breeding. The key problems needed to be solved and the possible directions in the researches of plant Al stress resistance were proposed.

Watershed water environment pollution models and their applications: A review.

ZHU Yao, LIANG Zhi-wei, LI Wei, YANG Yi, YANG Mu-yi, MAO Wei, XU Han-li, WU Wei-xiang

2013, 24(10):  3012-3018. 

Asbtract ( 3370 )   PDF (461KB) ( 1145 )  

Watershed water environment pollution model is the important tool for studying watershed environmental problems. Through the quantitative description of the complicated pollution processes of whole watershed system and its parts, the model can identify the main sources and migration pathways of pollutants, estimate the pollutant loadings, and evaluate their impacts on water environment, providing a basis for watershed planning and management. This paper reviewed the watershed water environment models widely applied at home and abroad, with the focuses on the models of pollutants loading (GWLF and PLOAD),  water quality of received water bodies (QUAL2E and WASP), and the watershed models integrated pollutant loadings and  water quality (HSPF, SWAT, AGNPS, AnnAGNPS, and SWMM), and introduced the structures, principles, and main characteristics as well as the limitations in practical applications of these models. The other models of  water quality (CE-QUAL-W2, EFDC, and AQUATOX) and watershed models (GLEAMS and MIKE SHE) were also briefly introduced. Through the case analysis on the applications of single model and integrated models, the development trend and application prospect of the watershed water environment pollution models were discussed.