Table of Content

18 April 2014, Volume 25 Issue 4

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Water use of re-vegetation pioneer tree species Schima superba and Acacia mangium in hilly land of South China.

ZHANG Zhen-zhen1,2, ZHAO Ping1, NI Guang-yan1, ZHU Li-wei1, ZHAO Xiu-hua1,2, ZHAO Pei-qiang1,2, NIU Jun-feng1

2014, 25(4):  931-939. 

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The xylem sap flows of two pioneer tree species, i.e., Acacia mangium and Schima superba, in degraded hill lands of South China, were continually monitored with Granier’s thermal dissipation probes during 2004-2007 and 2008-2012, respectively, and their seasonal transpiration changes at different tree age levels were compared. The results showed that the annual transpiration of both species increased with tree ages, and S. superba demonstrated a higher value than A. mangium. The average annual wholetree transpiration of S. superba (7014.76 kg) was higher than that of A. mangium (3704.97 kg). A. mangium (511.46-1802.17 kg) had greater seasonal variation than S. superba (1346.48-2349.35 kg). The standard regression coefficients (β) of transpiration (E_h), photosynthetically active radiation (PAR) and vapor pressure deficit (VPD) for both species increased with soil moisture, suggesting the increase of soil moisture generated a greater sensitivity of plants to environmental factors. Partial correlation analysis revealed that soil moisture played an important role in the seasonal variation of transpiration of both species. The optimum soil moistures of S. superba and A. mangium were 0.22-0.40 and 0.29-0.30 (V/V), respectively, indicating the native pioneer species S. superba better adapted to water deficit compared with exotic pioneer species A. mangium.

Characteristics of carbon storage and its allocation in Erythrophleum fordii plantations with different ages.

MING An-gang1,2,3, JIA Hong-yan1,3, TIAN Zu-wei1,3, TAO Yi1,3, LU Li-hua1,3, CAI Dao-xiong1,3, SHI Zuo-min2, WANG Wei-xia2

2014, 25(4):  940-946. 

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Carbon storage and its allocation of 7-, 29- and 32-year-old  Erythrophleum fordii plantation ecosystems in Guangxi were studied on the basis of biomass survey. The results showed that the carbon contents in different organs of E. fordii, ranging from 509.0 to 572.4 g·kg^-1, were in the order of stem > branch > root > bark > leaf. No significant differences in carbon content were observed among the shrub, herb and litter layers of the E. fordii plantations with different ages. Carbon content in the soil layer (0-100 cm) decreased with increasing the soil depth, but increased with increasing the stand age. The carbon storage of the arbor layer was 21.8, 100.0 and 121.6 t·hm^-2  for 7-, 29- and 32-year-old stands, respectively, and the order of carbon storage allocation in different organs was same as the order of carbon content. The 7-, 29- and 32-year-old E. fordii plantation ecosystems stored carbon at 132.6, 220.2 and 242.6 t·hm^-2, respectively. The arbor layer and soil layer were the main carbon pools, accounting for more than 97% of carbon storage in the ecosystem. Carbon storage allocation increased in arbor layer but decreased in soil layer with increasing the stand age. The influence of stand age on carbon storage allocation in shrub, herb and litter layers did not show a obvious regular pattern.

Stoichiometric characteristics of plant and soil C, N and P in different forest types in depressions between karst hills, southwest China.

YU Yue-feng1,2,3, PENG Wan-xia1,2, SONG Tong-qing1,2, ZENG Fu-ping1,2, WANG Ke-lin1,2, WEN Li1,2,3, FAN Fu-jing1,2,4

2014, 25(4):  947-954. 

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The stoichiometric properties of plant carbon (C), nitrogen (N) and phosphorus (P) and their relationships with soil were studied in six dominant plant communities in three forest types, i.e., plantation forest, secondary forest and primary forest in depressions between karst hills, southwest China. The C, N and P contents of both plant and soil had significant differences among the different forest types. Soil C and N contents were the highest in the secondary forest and the lowest in the plantation forest. Soil P content was the highest in the plantation forest and the lowest in the primary forest. Plant C and P contents were in the order of plantation forest > primary forest >secondary forest, and plant N content was the highest in the plantation forest and the lowest in the primary forest. Soil N:P,C:P and plant C:P ratios were significantly higher in the primary forest than in the other two forest types. There were no significant difference for the soil C:N ratio among the three forest types. Plant N:P ratio was the highest in the secondary forest and the lowest in the plantation forest. Plant C:N ratio was in the order of primary forest > plantation forest > secondary forest. There were significantly positive linear correlations between N and P contents, C:N and C:P ratios, C:P and N:P ratios of arbor leaves in the different forest types, and significant negative linear correlations between plant C:N and N:P ratios, and between soil C:N and N:P ratios. There were no significant correlations between plant and soil C, N, P contents and C:P ratio, suggesting that the supply of C, N and P from soil had little influence on plant C, N and P contents.

Soil carbon and nitrogen storage of different land use types in northwestern Shanxi Loess Plateau.

2014, 25(4):  955-960. 

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The soil organic carbon (SOC) and total nitrogen (TN) storage under five different land use patterns, i.e., poplar and Caragana microphylla plantation, C. microphylla artificial shrubland, poplar plantation, bare land and cropland were studied in the hilly Loess Plateau of northwestern Shanxi. The results showed that the contents, densities and storage of SOC and TN varied remarkably under the different landuse patterns. Soil carbon and nitrogen contents and storage in the 0-20 cm soil layer were significantly higher in the 20-40 cm and 40-60 cm soil layers under each of the five land use patterns. In the same soil layer, the contents and densities of SOC and TN under the five land use patterns were in the order of poplar and C. microphylla plantation > C. microphylla artificial shrubland > poplar plantation > bare land > cropland. The SOC storage in the 0-60 cm soil layer was in the order of poplar and C. microphylla plantation (30.09 t·hm^-2) > C. microphylla artificial shrubland (24.78 t·hm^-2) > poplar plantation (24.14 t·hm^-2) > bare land (22.06 t·hm^-2) > cropland (17.59 t·hm^-2). Soil TN storage had the same trend as SOC storage, and TN storage in the 0-60 cm soil layer was the highest (4.94 t·hm^-2) in poplar and Caragana microphylla plantation, followed by  C. microphylla artificial shrubland (3.53 t·hm^-2), poplar plantation  (3.51 t·hm^-2), bare land  (3.40 t·hm^-2), and cropland (2.71 t·hm^-2). Poplar and C. microphylla plantation and C. microphylla artificial shrubland were the good land use patterns in the process of vegetation construction and ecological restoration in the hilly Loess Plateau of northwestern Shanxi.

Responses of Manglietia glauca growth to soil nutrients and climatic factors.

LU Li-hua, HE Ri-ming, NONG Rui-hong, LI Zhong-guo

2014, 25(4):  961-966. 

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Tree height and diameter of breast height (DBH) as growth characteristics of Manglietia glauca introduced from Vietnam were measured at many sites in south China and responses of M. glauca growth to soil nutrients and climatic factors were analyzed in this study. Annual average increments of tree height and DBH among different planted sites had significant differences. Annual average increments of tree height and DBH had significant positive correlation with soil total N and P, available N and P, but no significant correlation with soil organic matter, total K, available K, indicating that soil N and P contents could be the main affecting factors for the growth of M. glauca. Annual average increment of tree height had significant difference, but annual average increment of DBH had no significant difference at different altitudes. Annual average increment of tree height increased with the altitude from 150 to 550 m, the maximum was at the altitude of 550 m, and then it decreased. It indicated that the most appropriate altitude for M. glauca introduction is 550 m. Annual average increments of tree height and DBH had significant negative correlation with annual average temperature and ≥10 ℃ accumulated temperature, and significant positive correlation with annual average precipitation, suggesting that annual mean temperature, ≥10 ℃ accumulated temperature and annual average precipitation could be the main climatic factors influencing the growth of M. glauca.

Climate suitability for tea growing in Zhejiang Province.

JIN Zhi-feng1,2, YE Jian-gang3, YANG Zai-qiang2, SUN Rui4, HU Bo1, LI Ren-zhong1

2014, 25(4):  967-973. 

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It is important to quantitatively assess the climate suitability of tea and its response to climate change. Based on meteorological indices of tea growth and daily meteorological data from 1971 to 2010 in Zhejiang Province, three climate suitability models for single climate factors, including temperature, precipitation and sunshine, were established at a 10-day scale by using the fuzzy mathematics method, and a comprehensive climate suitability model was established with the geometric average method. The results indicated that the climate suitability was high in the tea growth season in Zhejiang Province, and the three kinds of climate suitability were all higher than 0.6. As for the single factor climate suitability, temperature suitability was the highest and sunshine suitability was the lowest. There were obvious inter-annual variations of tea climate suitability, with a decline trend in the 1970s, less variation in the 1980s, and an obvious incline trend after the 1990s. The change tendency of climate suitability for spring tea was similar with that of annual climate suitability, lower in the 1980s, higher in the 1970s and after the 1990s. However, the variation amplitude of the climate suitability for spring tea was larger. The climate suitability for summer tea and autumn tea showed a decline trend from 1971 to 2010.

Spatial pattern of forest biomass and its influencing factors in the Great Xing’an Mountains, Heilongjiang Province, China.

WANG Xiao-li1,2, CHANG Yu1, CHEN Hong-wei1, HU Yuan-man1, JIAO Lin-lin1,2, FENG Yu-ting3, WU Wen1,2, WU Hai-feng1,2

2014, 25(4):  974-982. 

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Based on field inventory data and vegetation index EVI (enhanced vegetation index), the spatial pattern of the forest biomass in the Great Xing’an Mountains, Heilongjiang Province was quantitatively analyzed. Using the spatial analysis and statistics tools in ArcGIS software, the impacts of climatic zone, elevation, slope, aspect and vegetation type on the spatial pattern of forest biomass were explored. The results showed that the forest biomass in the Great Xing’an Mountains was 350 Tg and spatially aggregated with great increasing potentials. Forest biomass density in the cold temperate humid zone (64.02 t·hm^-2) was higher than that in the temperate humid zone (60.26 t·hm^-2). The biomass density of each vegetation type was in the order of mixed coniferous forest (65.13 t·hm^-2) > sprucefir forest (63.92 t·hm^-2) > Pinus pumila-Larix gmelinii forest (63.79 t·hm^-2) > Pinus sylvestris var. mongolica forest (61.97 t·hm^-2) > Larix gmelinii forest (61.40 t·hm^-2) > deciduous broadleaf forest (58.96 t·hm^-2). With the increasing elevation and slope, the forest biomass density first decreased and then increased. The forest biomass density in the shady slopes was greater than that in the sunny slopes. The spatial pattern of forest biomass in the Great Xing’an Mountains exhibited a heterogeneous pattern due to the variation of climatic zone, vegetation type and topographical factor. This spatial heterogeneity needs to be accounted when evaluating forest biomass at regional scales.

Evaluation of root and bud cold hardiness of wine grape varieties based on temperatureinjury relation.

GAO Zhen, ZHAI Heng, SUN Lu-long, MA Yan-chun, DU Yuan-peng

2014, 25(4):  983-990. 

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A system for differential thermal analysis (DTA) was applied for low temperature exotherms (LTE) analysis of roots and buds of eight wine grape varieties, and the temperatureinjury (LT-I) regression functions of buds, phloem and xylem of roots were established to evaluate the cold hardiness of roots and buds of the different varieties. The order of phloem 50% lethal temperature of the eight grapevines was Marselan > Cabernet Franc > Cabernet Sauvignon > Petit Manseng > Chardonnay > Cabernet Gernischt > Italian Riesling > Xiongyuebai. The xylem 50% lethal temperature of the different cultivars was in the order of Marselan > Chardonnay > Cabernet Sauvignon > Petit Manseng > Cabernet Franc > Cabernet Gernischt > Italian Riesling > Xiongyuebai. The order of bud 50% lethal temperature was Cabernet Sauvignon > Petit Manseng > Cabernet Gernischt > Cabernet Franc > Chardonnay > Italian Riesling > Marselan > Xiongyuebai. A comprehensive evaluation on cold hardiness of the different varieties was conducted by fuzzy membership function. For roots, Marselan was the poorest, and Xiongyuebai was the best. For buds, Cabernet Sauvignon, Cabernet Franc, Petit Manseng and Cabernet Gernischt were poorer, while Italian Riesling and Xiongyuebai were better.

Citrus boron nutrient level and its impact factors in the Three Gorges Reservoir region of Chongqing, China.

ZHOU Wei1,2, PENG Liang-zhi1, CHUN Chang-pin1, JIANG Cai-lun1, LING Li-li1, WANG Nan-qi2, XING Fei2, HUANG Yi2

2014, 25(4):  991-996. 

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To investigate the level of boron nutrient in citrus and its impact factors, a total of 954 citrus leaf samples and 302 soil samples were collected from representative orchards in the 12 main citrus production counties in the Three Gorges Reservoir region of Chongqing to determine the boron content in citrus leaves, as well as the relationships between leaf boron content with soil available boron content, soil pH value, cultivar, rootstock and the age of tree. Results indicated that the leaf samples from 41.6% orchards (<35 mg·kg^-1) and the soil samples from 89.4% orchards (<0.5 mg·kg^-1) were boron insufficient. The correlation of leaf boron content and soil available boron content was not significant. The soil pH, cultivar, rootstock and the age of tree did affect the leaf boron content. The leaves from the orchards with soil pH of 4.5-6.4 demonstrated significantly higher boron contents than with the soil pH of 6.5-8.5. The leaf boron contents in the different cultivars was ranged as Satsuma mandarin > pomelo > valencia orange > sweet orange > tangor > navel orange. The citrus on trifoliate orange and sour pomelo rootstocks had significantly higher leaf boron contents than on Carrizo citrange and red tangerine rootstocks. Compared with the adult citrus trees (above 8 year-old), 6.6% more of leaf samples of younger trees (3 to 8 year-old) contained boron contents in the optimum range (35-100 mg·kg^-1).

 

Effects of field border length for irrigation on photosynthetic characteristics, dry matter accumulation and water use efficiency of wheat.

MA Shang-yu1, YU Zhen-wen1, SHI Yu1, ZHAO Jun-ye2, ZHANG Yong-li1

2014, 25(4):  997-1005. 

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With the high-yielding winter wheat cultivar Jimai 22 as test material, a three-year field experiment was conducted to examine the effects of border length for irrigation on flag leaf water potential, photosynthetic characteristics, dry matter accumulation and distribution of wheat. In the 2010-2011 growing season, six treatments were installed, i.e., the field border length was designed as 10 m (L₁₀), 20 m (L₂₀), 40 m (L₄₀), 60 m (L₆₀), 80 m (L₈₀) and 100 m (L₁₀₀). In the 2011-2012 and 2012-2013 growing seasons, the field border length was designed as 40 m (L₄₀), 60 m (L₆₀), 80 m (L₈₀) and 100 m (L₁₀₀). The results showed that the average relative soil water content of the 0-200 cm soil layer was presented as L₈₀, L₆₀>L₁₀₀>L₄₀>L₂₀>L₁₀ at anthesis in the 2010-2011 growing season and as L₈₀, L₆₀>L₁₀₀>L₄₀ in the 2011-2012 and 2012-2013 growing seasons. At 11 d and 21 d after anthesis, the water potential, net photosynthetic rate and transpiration rate of flag leaf were presented as L₈₀, L₁₀₀>L₆₀>L₄₀>L₂₀, L₁₀, and as L₈₀>L₆₀, L₁₀₀>L₄₀, L₂₀, L₁₀ at 31 d after anthesis. The coefficients of variability both of the dry matter accumulation at anthesis and maturity and of grain yield in different regions of L₈₀ field were lower than those of L₁₀₀. The average dry matter accumulation, dry matter accumulation after anthesis and the contribution to grain of L₈₀ were dramatically higher than those of L₁₀₀, L₄₀, L₂₀ and L₁₀. L₈₀ had the highest average grain yield and water use efficiency, being the best treatment for irrigation in our study.

Effects of plant polysaccharides-containing compound agents on yield and matter accumulation and transportation of winter wheat.

BAI Wen-bo1, LU Guo-hua1, ZHANG Yuan-cheng2, SONG Ji-qing1, LIU Xing-hai1, LI Ji-hui1

2014, 25(4):  1006-1012. 

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A field experiment was conducted to study the effects of foliar spraying of three kinds of compound agents \[plant polysaccharides (P₁), plant polysaccharides plus 5-aminolevulinic acid (P₂), and plant polysaccharides plus 5-aminolevulinic acid and dimethylpiperidinium chloride (P₃)\] at the initial flowering stage of winter wheat on its yield components, sucrose content, soluble sugar content, the accumulation and translocation of dry matter, nitrogen and phosphorus. The grain number per spike and kilograins mass of winter wheat increased with the spray of the compound agents. The grain yield increased by more than 8.5% compared with the control. Within 20 days after spraying the three compound agents, the sucrose content of flag leaf had an obvious increase. Compared with the control, P₁ and P₃ increased the soluble sugar content by more than 4.5% and 11.0%, respectively. P₃ enhanced the accumulations of postanthesis dry matter, nitrogen and phosphorus by 48.5%, 116.9% and 18.1%, respectively. Correspondingly, contributions of accumulated postanthesis dry matter and nutrient to grain yield increased significantly. Whereas, the contribution of translocated preanthesis nutrient to grain yield in P₃ treatment was smaller than in the other treatments. The high yield of winter wheat was related to the regulation of photosynthetic product supply in vegetative organ, the increased soluble sugar content in grain, and the accumulation of postanthesis dry matter and nutrient regulated by the plant polysaccharidescontaining compound agent.

Characteristics of ammonium N and nitrate N accumulation in dryland soil in relation with wheat yield.

MlAO Yan-fang1, LI Sheng-xiu2, FU Yan-yan1, WANG Zhao-hui2, XU Xiao-feng1, LUO Lai-chao1

2014, 25(4):  1013-1021. 

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A total of eleven field trials in Yongshou, Shaanxi Province and seven in Luoyang, Henan Province were conducted with two treatments (without N as control and with 150 kg N·hm^-2 addition). The wheat biomass and seed yield were determined, and so were the nitrate and ammonium N concentrations in five layers (0-20, 20-40, 40-60, 60-80, 80-100 cm) at each trial site. Results showed that soil ammonium concentrations in the two provinces were very low while nitrate N concentrations were relatively high. Soil nitrate N occupied 91% of the total mineral N, and exhibited the same trend as the total mineral N in reflecting soil N supplying capacity. Without N application, the cumulative nitrate N amounts in the 0-40, 0-60, 0-80 and 0-100 cm layers in Yongshou  were significantly correlated with wheat biomass and seed yield while no such correlation existed in Luoyang.  With N addition, the relations of cumulative nitrate N of the different layers to wheat biomass and yield were greatly declined in Yongshou whereas those of Luoyang were changed to be negative. The yield increases were significantly correlated with the amount of nitrate N accumulated in the 0-80 and 0-100 cm layers of the two sites under N addition. Wheat mainly depended on nitrate N from the 0-20 cm layer at seedling stage, 0-40 cm at reviving, and 0-60 cm at elongation stages, and could utilize 0-100 cm nitrate N at maturity. After wheat harvest, the concentration of ammonium N was not significantly different from the initial value while that of nitrate N greatly decreased.

Effect of waterlogging on leaf senescence characteristics of summer maize in the field.

REN Bai-zhao, ZHANG Ji-wang, LI Xia, FAN Xia, DONG Shu-ting, ZHAO Bin, LIU Peng

2014, 25(4):  1022-1028. 

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Taking two summer maize hybrids Zhengdan 958 (ZD958) and Denghai 605 (DH605) as experimental materials, a field experiment was conducted to explore the effects of waterlogging for different durations (3 and 6 days) on leaf senescence characteristics of summer maize at the three-leaf stage (V3), six-leaf stage (V6), and 10 days after the tasseling stage (10VT). Results showed that superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities and soluble protein content decreased significantly after waterlogging. However, the content of malondialdehyde (MDA) increased significantly by 35.3% and 34.1% for DH605 and ZD958, respectively. The leaf chlorophyll content and grain yield of summer maize decreased significantly after waterlogging. The grain yields of DH605 and ZD958 after waterlogging for 6 days at V3 were most seriously affected, which were decreased by 32.1% and 35.2%, respectively. Overall, the summer maize was most susceptible to the effect of waterlogging at V3, followed by V6 and 10VT, and the influence extent increased with the increase of waterlogging duration.

Impact of different tillage practices on soil organic carbon and water use efficiency under continuous wheat-maize binary cropping system.

JI Qiang1, SUN Han-yin1, Taraqqi AK1, WANG Xu-dong1,2

2014, 25(4):  1029-1035. 

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Base on an 8year field experiment, the effects of tillage practices coupled with or without straw return on the soil organic carbon (SOC) and water use efficiency (WUE) were investigated in Guanzhong Plain during the growing seasons from 2008 to 2009. The results showed that conservation tillage practices (sub-soiling, SS; rotary tillage, RT; notill, NT) improved the SOC, WUE and crop yield compared with conventional tillage (CT), among which, SS coupled with straw return had the highest increment, with increase in SOC content of the 0-30 cm soil layer, WUE and crop yield by 19.5%, 16.9% and 20.5%, respectively. The NT practice effectively increased the SOC content of the 0-10 cm soil layer. Conclusively, under the current soil and climatic conditions in Guanzhong Plain, subsoiling coupled with straw return is the most efficient tillage practice for promoting SOC accumulation, increasing water-use efficiency and yield.

Characteristics of distribution and transportation of rice genotype with high nitrogen utilization efficiency at the late growth stage.

JI Lin1, LI Ting-xuan2， ZHANG Xi-zhou2, YU Hai-ying2, ZHENG Zi-cheng2

2014, 25(4):  1036-1042. 

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Taking a high nitrogen utilization efficiency rice genotype (NUE_H) as test material and a low nitrogen utilization efficiency genotype (NUE_L) as control, a pot experiment was carried out with nitrogen treatments of 100 (low) and 200 mg·kg^-1 (normal), to analyze the differences in nitrogen accumulation distribution, translocation and transport efficiency between the two genotypes. The results showed that NUE_H could still maintain a high yield and a high nitrogen utilization efficiency at the low rate of nitrogen fertilization, with the grain yield being 1.75 times of that of NUE_L, and the nitrogen recovery efficiency of 50.9% compared with 36.4% for NUE_L. Compared to the normal nitrogen fertilization rate, the low nitrogen fertilization rate promoted the nitrogen accumulation by 34.2%, 2.5% and 0.5% in NUE_H at the flowering, filling and mature stages, while decreased by 23.5% and 15.6% in NUE_L at filling and mature stages, respectively. Nitrogen accumulation distribution in organs of NUE_H was in the order of leaf > stem > root > spike, spike > leaf > stem > root, and spike > stem > leaf > root at the flowering, filling and mature stages, respectively. With the advancement of growth period, the nitrogen accumulation in spike increased obviously. At the two nitrogen fertilization rates, nitrogen transfer was ordered as leaf > stem> root for NUE_H, and stem> leaf > root for NUE_L, and nitrogen transfer efficiencies of NUE_H were 60.8%, 60.3%, which were as 1.67 and 1.55 times as that of NUE_L, respectively. It could be concluded that the higher nitrogen transport efficiency of NUE_H leaves laid a good foundation for the construction of grain after heading.

Dynamics simulation on plant growth, N accumulation and utilization of processing tomato at different N fertilization rates.

WANG Xin1, MA Fu-yu1,2, DIAO Ming1,2, FAN Hua1, CUI Jing1, JIA Biao1, HE Hai-bing1, LIU Qi1

2014, 25(4):  1043-1050. 

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Three field experiments were conducted to simulate the dynamics of aboveground biomass, N accumulation and utilization of drip-irrigated processing tomatoes at different N fertilization rates (0, 75, 150, 300, 450, or 600 kg·hm^-2). The results showed that Logistic models best described the changes in aboveground biomass, N accumulation, and utilization of accumulated N efficiency with the physiological development time (PDT). Rapid accumulation of N began about 4-6 d (PDT) earlier than the rapid accumulation of aboveground biomass. The momentary utilization rate of N (NMUR) increased after emergence, reached a single peak, and then decreased. The N accumulation, aboveground biomass and yield were highest in the 300 kg·hm^-2 treatment. The quadratic model indicated that application rate of 349 to 382 kg N·hm^-2 was optimum for dripirrigated- processing tomatoes in northern Xinjiang.

Effects of bamboo biochar addition on temperature rising, dehydration and nitrogen loss during pig manure composting. 

HUANG Xiang-dong1,2, XUE Dong1

2014, 25(4):  1057-1062. 

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Composting is an effective way to realize the treatment and recycling of livestock manure. However, traditional composting process has the problems of slow temperature rising, poor dehydration effect and serious nitrogen loss. Composting experiments of pig manure were carried out to investigate the influence of different rates of bamboo biochar addition on the temperature rising speed, dehydration effect and nitrogen loss during the composting process. The results showed that the addition of bamboo biochar could shorten the temperature rising time of the pile by 24-48 h, increase the dehydration rate by 13.6%-21.4%, and prolong the lasting time of the thermophilic phase by 216-264 h. The NH₄⁺-N, NO₃^--N, and total nitrogen contents in the pile were higher under the treatments with bamboo biochar amendment than under the control, and moreover, the nitrogen fixation percentage increased by 28.3%-65.4% as compared to the control.

 

Characteristics of phosphorus adsorption and desorption of soils from wetlands recovered from farmlands in Caizi Lake.

YANG Yan-fang1, KONG Ling-zhu2, ZHENG Zhen2, LIU Shuang2, LIU Wen-jing2, ZHANG Ping-jiu2

2014, 25(4):  1063-1068. 

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In this study, topsoil samples were collected from wetlands recovered from farmlands respectively for 3, 5, 9 and 11 years around Caizi Lake, Anhui, China. Their characteristics of adsorption and desorption of phosphorus were examined with comparison to soils sampled from an adjacent vegetable farmland and a noncultivated wetland. Phosphorus adsorption curves of all studied soils could be modeled by Langmuir and Freundlich equations (P<0.01). The maximum P adsorption (X_m), adsorption constant K and  maximum buffer capacity (MBC) of all the 6 soil samples were in the ranges of 478-1074 mg·kg^-1, 0.14-0.61 and 68.6-661.5 mg·kg^-1, respectively. These three parameters all tented to increase with the recovered years but did not reach the values of the noncultivated wetland. However, the P desorption rate ranging from 6.2% to 14.6%, increased first and then decreased with the recovered years and was significantly higher than that of the non-cultivated wetland. It was concluded that the P immobilization would increase with the recovery years of cultivated wetlands, which could be affected by the soil organic carbon and clay contents of the wetland soil.

Effects of long-term fertilization on evolution of S forms in a red soil and a black soil.

XU Chuang1,2, WANG Song-shan2, LI Ju-mei3, MA Yi-bing3, SUN Wen-tao1, LUO Lei2, ZHANG Shu-zhen2

2014, 25(4):  1069-1075. 

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Sulfur (S) forms in two contrasting soils (a red soil and a black soil) under different long-term fertilization treatments (from 1990 to 2011) from the National Long-term Monitoring Network of Soil Fertility and Fertilizer Effects of China were investigated using a fractionation scheme in order to explore the distribution and transportation of S with different forms in the soils. The soil samples were collected from the topsoil (0-20 cm) and subsoil (20-40 cm) horizons that were treated with no fertilizers (CK), nitrogen, phosphorus, and potassium fertilizers (NPK), or NPK plus organic manures (MNPK) since 1990. The results indicated that when compared with the CK, total S contents in the topsoil layers treated with NPK and MNPK were increased by 42% and 33% for the red soil, and by 6% and 76% for the black soil, respectively, while the total S in the subsoil layer was less affected by the fertilization treatments and obviously lower than in the topsoil layer except for the red soil treated with NPK. The main forms of inorganic S in the red soil and black soil were found to be available S and HClextracted S, respectively. The application of NPK and MNPK increased the available S by 447% and 102% in the topsoil layer of the red soil compared with CK, and facilitated the transportation of available S into the lower depth. In contrast, NPK and MNPK only increased the available S by 54% and 93% in the topsoil layer of the black soil, and showed a slight influence on available S in the subsoil. The organic S forms were predominantly composed of ester S and residual S in the two soils. Under longterm fertilization, the residual S significantly increased over 32% and 55% in the topsoil and subsoil layers, respectively, compared with CK. The ester S and carbonbonded S, which were relatively active, were less affected by the fertilization treatments, but positively related to the level of organic carbon in each soil (P<0.05). In addition, the results from the long-term experiments indicated that the contribution of S input from atmospheric deposition was significant and should not be neglected.

Ecological risk assessment of human activity of rapid economic development regions in southern Jiangsu, China: A case study of Dantu District of Zhenjiang City.

FANG Guang-ling1,2, XIANG Bao1,2, WANG Bao-liang1,2, JIN Xia3, HU Yu1,2,4, ZHANG Li-kun1,2

2014, 25(4):  1076-1084. 

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This article investigated the spatiotemporal variation of landscape ecological risk in Dantu District of Zhenjiang City with statistical method based on the ETM remote sensing data in 2000 and 2005, and the TM remote sensing data in 2010, and quantitative index of regional ecological risk assessment was established with the employment of landscape index, so as to enhance the ecosystem management, prevent and reduce the regional ecological risk in southern Jiangsu with rapid economic development. The results showed that the fragmentations, divergence, and ecological losses of natural landscape types, such as forestland, wetland, waters, etc., were deteriorated with the expansion of builtup lands from 2000 to 2010. The higher ecological risk zone took up 5.7%, 9.0%, and 10.2% of the whole region in 2000, 2005, and 2010, respectively, which mainly distributed in the plain hilly region. During the study period, the area aggravating to the higher ecological risk zone was approximately 296.2 km², 48% of the whole region. The ecological risk rose up in most of the region. The interference of rapid economic development to landscape patterns was even more intensive, with obvious spatial differences in ecological risk distribution. The measures of exploiting resources near the port, utilizing natural wetlands, constructing industrial parks, and rapid urbanization, etc., intensified the ecological risk and accelerated the conversion rate. Prompt strategies should be established to manage the ecological risk of this region.

The Chinese urban metabolisms based on the emergy theory.

SONG Tao1,2,3, CAI Jian-ming1, NI Pan4， YANG Zhen-shan1

2014, 25(4):  1085-1092. 

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By using emergy indices of urban metabolisms, this paper analyzed 31 Chinese urban metabolisms’ systematic structures and characteristics in 2000 and 2010. The results showed that Chinese urban metabolisms were characterized as resource consumption and coastal external dependency. Non-renewable resource emergy accounted for a higher proportion of the total emergy in the inland cities’ urban metabolisms. The emergy of imports and exports accounted for the vast majority of urban metabolic systems in metropolises and coastal cities such as Beijing and Shanghai,  showing a significant externallyoriented metabolic characteristic. Based on that, the related policies were put forward: to develop the renewable resource and energy industry; to improve the non-renewable resource and energy utilization efficiencies; to optimize the import and export structure of services, cargo and fuel; and to establish the flexible management mechanism of urban metabolisms.

Evaluation of ecosystem service value and strategies for ecological design in land consolidation: A case of land consolidation project in Da’an City, Jilin Province, China.

WANG Jun1, YAN Shen-chun1,2, YU Li3, ZHANG Ya-nan1

2014, 25(4):  1093-1099. 

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Land consolidation, as one of the major driving forces for the changes of land use/cover, has significant impacts on landscape patterns, ecological functions, and ecosystem services. In this paper, a land consolidation project conducted in Da’an City, Jinlin Province, China, was selected to evaluate the ecosystem service values before and after land consolidation at three spatial scales, i.e., village, town, and county. The results indicated that the land consolidation with the goal to increase the area of cultivated land might cause the decrease of the saline and alkaline land, grassland, and wetland. In addition, land consolidation resulted in the reduction of the total ecosystem service values at varying degree at the three scales. Compared to the preconsolidation status, the total postconsolidation ecosystem service values at the village, town and county scales were 7.96, 843.01 and 1205.86 million yuan, and reduced by 10.5%, 14.2% and 33.1%, respectively. Based on the evaluation of ecosystem service value, strategies of landscape ecological design were discussed to improve the ecological functions and to provide the guidance for the sustainable development of land consolidation.

Forest lighting fire forecasting for Daxing’anling Mountains based on MAXENT model.

SUN Yu1, SHI Ming-chang1, PENG Huan1, ZHU Pei-lin1, LIU Si-lin1, WU Shi-lei1, HE Cheng2, CHEN Feng1

2014, 25(4):  1100-1106. 

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Daxing’anling Mountains is one of the areas with the highest occurrence of forest lighting fire in Heilongjiang Province, and developing a lightning fire forecast model to accurately predict the forest fires in this area is of importance. Based on the data of forest lightning fires and environment variables, the MAXENT model was used to predict the lightning fire in Daxing’anling region. Firstly, we studied the collinear diagnostic of each environment variable, evaluated the importance of the environmental variables using training gain and the Jackknife method, and then evaluated the prediction accuracy of the MAXENT model using the max Kappa value and the AUC value. The results showed that the variance inflation factor (VIF) values of lightning energy and neutralized charge  were 5.012 and 6.230, respectively. They were collinear with the other variables, so the model could not be used for training. Daily rainfall, the number of cloudtoground lightning, and current intensity of cloudtoground lightning were the three most important factors affecting the lightning fires in the forest, while the daily average wind speed and the slope was of less importance. With the increase of the proportion of test data, the max Kappa and AUC values were increased. The max Kappa values were  above 0.75 and the average value was 0.772, while all of the AUC values were  above 0.5 and the average value was 0.859. With a moderate level of prediction accuracy being achieved, the MAXENT model could be used to predict forest lightning fire in Daxing’anling Mountains.

Effects of phytase transgenic corn planting on soil nematode community.

GUO Wei-wei1, ZHAO Zong-chao1, SU Ying1, MOU Wen-ya1, LIU Man-qiang2, CHEN Xiao-yun2, CHEN Fa-jun1

2014, 25(4):  1107-1114. 

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A healthy soil ecosystem is essential for nutrient cycling and energy conversion, and the impact of exogenous genes from genetically modified crops had aroused wide concerns. Phytase transgenic  corn (i.e., the inbred line BVLA430101) was issued a biosafety certificate on 27 September 2009 in China, which could improve the efficiency of feed utilization, reduce environmental pollution caused by animal manure. In this study, the abundance of trophic groups, community structure and ecological indices of soil nematodes were studied over the growing cycle of phytase transgenic corn (ab. transgenic corn) and control conventional parental corn (ab. control corn) in the field. Totally 29 and 26 nematode genera were isolated from transgenic corn and control corn fields, respectively. The abundances of bacterivores and omnivorespredators, the total number of soil nematodes, and the Shannon index (H) were significantly greater under transgenic corn than under control corn, while the opposite trend was found for the relative abundance of herbivores and the maturity index (∑MI) of soil nematodes. Repeatedmeasures analysis of variance (ANOVA) did not detect any significant effects of transgenic corn on the composition and abundance of nematode trophic groups and ecological indices of soil nematodes. Furthermore, the StudentT test showed that the abundances of bacterivores and omnivorespredators and the total number of soil nematodes during the milk-ripe stage were significant higher in the transgenic corn field than in the control corn field. The effects of transgenic corn planting on soil nematodes might be related to the increase in the nitrogen content of field soil under transgenic corn compared to control corn.

Effects of vegetable cultivation years on microbial biodiversity and abundance of nitrogen cycling in greenhouse soils.

WANG Ya-nan1, ZENG Xi-bai1, WANG Yu-zhong2, BAI Ling-yu1, SU Shi-ming1, WU Cui-xia1, LI Lian-fang1, DUAN Ran1

2014, 25(4):  1115-1124. 

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The effects of facility vegetable cultivation years (three, nine, fourteen or seventeen years) on biodiversity and abundance of soil microorganisms, such as bacteria, ammonia oxidizing bacteria (AOB) and nirK type denitrifying bacteria, in the greenhouse soils in Wuwei of Gansu Province, China were determined by the combined analyses of terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR. The results showed that the dominant population structure and abundance of bacteria, AOB, nirK type denitrifying bacteria in the soils were significantly different from those in the farmland fields. The dominant population also changed with the cultivation years. With the increase of vegetable cultivation years, the abundance of 16S rRNA and nirK gene in the 0-20 cm soil layer first increased and then decreased, with the maximum values of 9.67×10⁹ and 2.30×10⁷ copies·g^-1 soil at year 14 and year 9, being as 1.51 and 1.52 times of that of the 3year, respectively. However, the abundance of amoA gene showed an opposite trend. The amoA gene copy number in the 14-year sample was 3.28×10⁷ copies·g^-1 soil, which was only 45.7% of that of the 3-year. These results illustrated that the ecological adaptation mechanisms of the different functional microorganisms involved in nitrogen cycling had significant differences in the facility vegetable soils, and provided a base for further researches on exploring and explaining the characteristics and adaptation mechanisms of microorganisms in greenhouse soil.

Effects of arbuscular mycorrhizal fungi on root system morphology and sucrose and glucose contents of Poncirus trifoliata.

ZOU Ying-ning, WU Qiang-sheng, LI Yan, HUANG Yong-ming

2014, 25(4):  1125-1129. 

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The effects of inoculation with Glomus mosseae, G. versiforme, and their mixture on plant growth, root system morphology, and sucrose and glucose contents of trifoliate orange (Poncirus trifoliata L.) were studied by pot culture. The results showed that all the inoculated treatments significantly increased the plant height, stem diameter, leaf number, and shoot and root biomass. In addition, the mycorrhizal treatments significantly increased the number of lst, 2nd, and 3rd lateral roots. Inoculation with arbuscular mycorrhizal fungi significantly increased the root projected area, surface area, volume, and total root length (mainly 0-1 cm root length), but decreased the root average diameter. Meanwhile, G. versiforme showed the best effects. Mycorrhizal inoculation significantly increased the leaf sucrose and root glucose contents, but decreased the leaf glucose and root sucrose contents. Owing to the ‘mycorrhizal carbon pool’ in roots, inoculation with arbuscular mycorrhizal fungi resulted in high glucose content and low sucrose content of roots, which would facilitate the root growth and development, thereby the establishment of better root system morphology of host plants.

Inhibition effects and mechanisms of the entophytic fungus Trichoderma harzianum LH-7 from Aloe barbadensis.

WANG Li-heng1, KE Yang2, QIANG Yi3, MA Yu2

2014, 25(4):  1130-1136. 

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Inhibition spectrum and antagonistic mechanism of an endophytic fungus Trichoderma harzianum LH-7, isolated from wild medicinal plant Aloe barbadensis, were investigated by in vitro culture methods against 9 kinds of plant pathogens. The results showed that nutrient competition and hyper-parasitism were the two primarily antagonist approaches that strain LH-7 adopted to inhibit the tested plant pathogens with a significant inhibition rate of 62.4%-88.4%. Moreover, the active compound from metabolites of LH-7 could cause pathogen mycelial deformities, cell wall rupture and conidial malformation, leading to the effective inhibition on pathogens growth and reproduction.

Biotypes and phylogenetic analysis of Bemisia tabaci (Hemiptera: Aleyrodidae) in China.

XU Li-li, CAI Li, SHEN Wei-jiang, DU Yu-zhou

2014, 25(4):  1137-1144. 

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Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) is considered taxonomically as a species complex and could cause serious damages to crops by directly feeding on phloem and/or indirectly transmission of plant viruses. In this study, biotypes and phylogenetic relationships of 33 geographic populations of B. tabaci collected from nine provinces of China in 2010 and 2011 were studied based on the mitochondrial COI gene. The results showed there were a total of six biotypes of B. tabaci (B, Q, ZHJ-1, ZHJ-3, An and Nauru) recovered in China and the geographical distribution of these six biotypes was uneven. Phylogenetic analysis showed that biotype An B. tabaci from Taiwan clustered together with Hainan biotype An populations, indicating these two geographic populations might originate from a same ancestor. In addition, biotype B B. tabaci in China had a 99% genetical similarity compared to that from France and Uganda. However, relationships of biotype Q on the phylogenetic tree were divided into two different clusters. One was occupied with the population from China and Western Mediterranean Sea countries (France and Morocco) and the other contained biotype Q populations from Eastern Mediterranean Sea countries (Israel and Turkey). Overall, the results suggested that biotype Q B. tabaci in China was genetically similar to that from Western Mediterranean Sea countries and it could be highly possible that Chinese biotype Q B. tabaci originated from Western Mediterranean Sea areas.

Accumulation of lead in Spodoptera exigua (Hübner) and its impact on the population.

HU Meng-meng, CAI Wen-chen, SU Hong-hua, YANG Yi-zhong

2014, 25(4):  1145-1150. 

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The heavy metals pollution is one of the ecological problems which have been paid close attention to Spodoptera exigua Hübner, one of the key pests on vegetables and cotton in the Yangtze River and its southern area in China, has broken out more frequently in recent years. In this study, accumulation of Pb²⁺ in S. exigua and its excretion were detected when fed with artificial diets with different Pb²⁺ concentrations (0.3, 1.2, 4.8, 19.2 and 76.8 mg·kg^-1, respectively). Life table was constructed according to the survival and growth of different stages of S. exigua. The effect of lead on three successive generations of beet armyworm was studied using the life table in the laboratory. It was found that the Pb²⁺ contents were significantly different when S. exigua was reared at different Pb²⁺ concentrations in the same generation in a significant dosedependent manner. The concentration of Pb²⁺ increased with prolonging the stress time at the same time. The Pb²⁺ concentrations at the three developmental stages of beet armyworm followed the order of larvae > adult > pupa. The beet armyworm could excrete heavy metals by means of faeces, prepupa exuviate and puparium, and the concentrations of Pb²⁺ in faeces and prepupa exuviate were far higher than in puparium. According to the survival rates of different developmental stages, the female ratios and the egg numbers, the laboratory population life table was constructed. It showed that low doses of Pb²⁺ promoted the growth of the population, and high doses inhibited the growth, and the index of population trend (I) declined more rapidly with the increase of stress time. The study could provide references for longterm and objective assessment of heavy metal hazard and its effect on the populations of important agricultural pests.

Effects of host stage of Phenacoccus solenopsis Tinsley on the fitness of the offspring of Aenasius bambawalei Hayat.

ZHANG Juan1, HUANG Jun1, LU Yao-bin2

2014, 25(4):  1151-1155. 

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To understand the effects of host stage on the fitness of the offspring Aenasius bambawalei Hayat, the sex ratio and body size of their offsprings parasitizing Phenacoccus solenopsis Tinsley of different stages (3^rd instar nymph and adult)were determined under the laboratory conditions of (27±1) ℃, RH (70±5)% and 14L∶10D. Sex ratio, body length and hind tibia length of the offsprings of A. bambawalei parasitizing the P. solenopsis adult females were significantly higher compared to those parasitizing the 3^rd instar mealybugs. The hind tibia length of the offspring wasp was closely related to the body length. The body size of the parasitised 3^rd instar mealybugs affected the size of the offspring wasp of A. bambawalei significantly, while such relationship was not found between the adult female of mealybugs and the offspring wasp.

Effect of locomotion and feeding on metabolic mode of juvenile lenok, Brachymystax lenok (Pallas) under different water temperatures.

XU Ge-feng1,2, WANG Yu-yu2, HAN Ying2, LI Xiang3, MA Bo1, LIU Yang1, MOU Zhen-bo1

2014, 25(4):  1156-1162. 

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To investigate the effect of locomotion and feeding on the metabolic mode of juvenile lenok, Brachymystax lenok (Pallas) under different water temperatures, the preexercise oxygen consumption rate (MO_2p), active oxygen consumption rate (MO_2a), metabolic scope (MS), critical swimming speed (U_C) and swimming metabolic rate of both fasting and fed fish were measured at five temperature levels (4 ℃, 8 ℃, 12 ℃, 16 ℃ and 20 ℃) and ten flow velocities with saturated dissolved oxygen (>8.0 mg·L^-1). The results showed that the MO_2p and MO_2a  of the feeding group were significantly higher (P<0.05) than the fasting group under different temperatures, and the increases in MO_2p and MO_2a at 4 ℃, 8 ℃, 12 ℃, 16 ℃and 20 ℃ were 15%, 47%, 30%, 43% and 8%, and 12%, 23%, 21%, 36% and 7%， respectively. No significant differences were observed for U_C  and MS between the fasting and the feeding groups (P>0.05), but the MS showed a trend of decline with increase in water temperature. Swimming metabolic rate of fish was increased with increasing the flow velocity, and further increase of flow velocity resulted in a decline in swimming metabolic rate, and the swimming metabolic rate of the feeding group was significantly higher than that of the fasting group (P<0.05). The metabolic rate increased with increasing the swimming speed up to 70% U_C, and then decreased with increasing the swimming speed up to U_C. It was concluded that, under certain temperature, the maximum metabolic rate was induced by exercise and feeding; the metabolic rate exhibited the additive metabolic mode before increasing to the maximum and thereafter, the metabolic rate induced by feeding reduced with decreasing the swimming metabolic rate, exhibiting the locomotion prioritized mode.

Anaerobic biodegradation of phthalic acid esters (PAEs) in municipal sludge.

LIANG Zhi-feng1, ZHOU Wen1, LIN Qing-qi1, YANG Xiu-hong1,2, WANG Shi-zhong1，2, CAI Xin-de3, QIU Rong-liang1，2

2014, 25(4):  1163-1170. 

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Phthalic acid esters (PAEs), a class of organic pollutants with potent endocrinedisrupting properties, are widely present in municipal sludge. Study of PAEs biodegradation under different anaerobic biological treatment processes of sludge is, therefore, essential for a safe use of sludge in agricultural practice. In this study, we selected two major sludge PAEs, i.e. di-n-butyl phthalate (DBP) and di-(2 enthylhexyl) phthalate (DEHP), to investigate their biodegradation behaviors in an anaerobic sludge digestion system and a fermentative hydrogen production system. The possible factors influencing PAEs biodegradation in relation to changes of sludge properties were also discussed. The results showed that the biodegradation of DBP reached 99.6% within 6 days, while that of DEHP was 46.1% during a 14-day incubation period in the anaerobic digestion system. By comparison, only 19.5% of DBP was degraded within 14 days in the fermentative hydrogen production system, while no degradation was detected for DEHP. The strong inhibition of the degradation of both PAEs in the fermentative hydrogen production system was ascribed to the decreases in microbial biomass and ratios of grampositive bacteria/gramnegative bacteria and fungi/bacteria, and the increase of concentrations of volatile fatty acids (e.g. acetic acid, propionic acid and butyric acid) during the fermentative hydrogenproducing process.

 

Aquatic ecological risk assessment of microcystins and nitrogen pollution based on species sensitivity distribution.

CHEN Jin1,2, LIU Yi-mei3, ZHANG Jian-ying1,2

2014, 25(4):  1171-1180. 

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Species sensitivity distributions (SSDs) methods in both forward and reverse modes were used to evaluate the ecological risk and determine the contaminant concentration threshold for the protection of aquatic species and ecological quality. In this study, the existing toxicity data of freshwater organisms were fitted to SSD functions to estimate the hazardous concentrations for 5% of the species (HC₅) for microcystins, ammonia and nitrite, and the ecological risk of their mixtures. The potentially affected fractions (PAFs) of various concentrations of microcystins, ammonia and nitrite were also calculated. Results showed that microcystins exhibited a higher ecological risk than ammonia and nitrite. The HC₅ value for microcystins exposure was 19.22 μg·L^-1 whereas the HC₅ values for ammonia and nitrite exposure were 6583.94 μg·L^-1 and 334.33 μg·L^-1, respectively. The sensitivity of freshwater organisms varied with exposed concentrations of microcystins, ammonia and nitrite. Crustaceans were more sensitive than fishes to microcystins, and less sensitive than fishes to nitrite when the concentrations of microcystins and nitrite were below 125.04 μg·L^-1 and 2989.40 μg·L^-1, respectively, and vice versa when exposed to higher concentrations of microcystins and nitrite. No significant difference was observed for the sensitivities of fishes and crustaceans exposed to ammonia. In studies with selected lakes in China, our results showed that the ecological risk in both Tai and Hongfeng lakes exceeded the permissible HC₅ threshold, and the multiple substance potentially affected fractions (msPAFs) of microcystins, ammonia and nitrite were 2.6%-5.6%, indicating that the ecological risk of their mixtures was more threatening than each individual contaminant being investigated.

A comparative study of different sampling designs in fish community estimation.

ZHAO Jing1, ZHANG Shou-yu1,2, LIN Jun1, ZHOU Xi-jie1

2014, 25(4):  1181-1187. 

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The study of fishery community ecology depends on quality and quantity of data collected from welldesigned sampling programs. The optimal sampling design must be costefficient, and the sampling results have been recognized as a significant factor affecting resources management. In this paper, the performances of stationary sampling, simple random sampling and stratified random sampling in estimating fish community were compared based on computer simulation by design effect (De), relative error (REE) and relative bias (RB). The results showed that, De of stationary sampling (average De was 3.37) was worse than simple random sampling and stratified random sampling (average De was 0.961). Stratified random sampling performed best among the three designs in terms of De, REE and RB. With the sample size increased, the design effect of stratified random sampling decreased but the precision and accuracy increased.

 

Changes of non-structural carbohydrates and its impact factors in trees: A review.

ZHENG Yun-pu1，3, WANG He-xin1, LOU Xin1, YANG Qing-peng2, XU Ming3

2014, 25(4):  1188-1196. 

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Non-structural carbohydrates (NSCs) are an important energy source for the metabolism of plants. The size of the NSC pool is likely to mirror the overall carbon supply status and its dynamics strongly influences physiological processes in plants. In order to predict the response and adaptation of trees to climate change, this review summarized the current understanding of NSC pool in trees, and mainly focused on its seasonal and spatial variation for analyzing the relationships between environmental factors and NSC allocation. Moreover, the response and adaptation strategies of NSC pool in trees to climate change were also discussed. Finally, some suggestions were proposed for the potential study orientation of NSC pool in trees in future climate conditions.

Ecological function and application of toxin β-ODAP in grass pea (Lathyrus sativus).

XIONG Jun-lan, BAI Xue, BATOOL Asfa, KONG Hai-yan, TAN Rui-yue, WANG Ya-fu, LI Zhi-xiao, XIONG You-cai

2014, 25(4):  1197-1205. 

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Grass pea (Lathyrus sativus) is a legume with various adverse adaptability and rich nutrition. However, it can lead to the human and animal neurotoxicity after longterm consumption due to its neurotoxin, β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), limiting its utilization. This paper summarized the influences of β-ODAP on osmotic adjustment and growth regulation in grass pea under drought stress, the research progress in analysis methods, toxicological mechanisms and practical utility of β-ODAP, and the breeding strategies for low and zero-β-ODAP. β-ODAP synthesis was found to be abundant in grass pea under drought stress and its content was enhanced gradually with the increasing extent of drought stress. β-ODAP could supply nitrogen for plant growth and seed development, scavenge reactive oxygen species (ROS), involve in osmotic adjustment as a soluble amino acid, transport zincions as a carrier molecule, and impact nodule development. However, increasing the content of sulfurcontaining amino acids (methionine and cysteine) could decrease the level of toxicity of grass pea. There were a lot of investigations on collecting genetic resources, cross breeding, tissue culture, and gene manipulation for low and zerotoxin in grass pea in recent years. Although β-ODAP could induce excitotoxicity by damaging intracellular Ca2+ homeostasis and as glutamate analogues, it has medicinal value on hemostasis and antitumor.

Research advance in the function of quorum sensing in the biological aggregates.

DAI Xin1, ZHOU Jia-heng1, ZHU Liang1, XU Xiang-yang1,2

2014, 25(4):  1206-1212. 

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Quorum sensing is a microbial phenomenon that microorganisms use signal molecules to perceive environmental conditions and regulate specific gene expressions. As the communication function of quorum sensing is increasingly highlighted in the microbial field, researches on quorum sensing in the formation process of biological aggregates (biofilm and granules) attract wide attentions. The paper reviewed autoinducers (AI) classification and the corresponding regulation methods in quorum sensing, and provided an uptodate account on research progress of AIs regulating biological aggregates formation and structural stability. New territories and future of quorum sensing were also outlined.

Contribution of fungi to soil nitrous oxide emission and their research methods: A review.

HUANG Ying1,2, LONG Xi-en2

2014, 25(4):  1213-1220. 

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Nitrous oxide is an important greenhouse gas. Soil is one major emission source of N₂O, which is a byproduct of microorganismsdriven nitrification and denitrification processes. Extensive research has demonstrated archaea and bacteria are the predominant contributors in nitrification and denitrification. However, fungi may play a predominant role in the N transformation in a certain soil ecosystem. The fungal contribution to N₂O production has been rarely investigated. Here, we reviewed the mechanism of N₂O production by soil fungi. The mechanisms of denitrification, autotrophic and heterotrophic nitrification and their key microbes and functional genes were described, espectively. We discriminated the differences in denitrification between bacteria and fungi and discussed the methods being used to determine the contribution of fungi to soil N₂O emission, including selective inhibitors, ¹⁵N stable isotope probing, isolation and pure culturing and uncultured molecular detection methods. The existing problems and research prospects were also presented.

 

Copper in methane oxidation: A review.

SU Yao, KONG Jiao-yan, ZHANG Xuan, XIA Fang-fang, HE Ruo

2014, 25(4):  1221-1230. 

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Methane bio-oxidation plays an important role in the global methane balance and warming mitigation, while copper has a crucial function in methane biooxidation. On one side, copper is known to be a key factor in regulating the expression of the genes encoding the two forms of methane monooxygenases (MMOs) and is the essential metal element of the particulate methane monooxygenase (pMMO). On the other side, the content and fractionation of copper in the environment have great effects on the distribution of methanotrophs and their metabolic capability of methane and non-methane organic compounds, as well as on the copper-specific uptake systems in methanotrophs. Thus, it is meaningful to know the role of copper in methane bio-oxidation for comprehensive understanding of this process and is valuable for guiding the application of methanotrophs in greenhouse gas removal and pollution remediation. In this paper, the roles of copper in methane oxidation were reviewed, including the effect of copper on methanotrophic community structure and activity, the expression and activity of MMOs as well as the copper uptake systems in methanotrophs. The future studies of copper and methane oxidation were also discussed.

Application of microfluidics in aquatic environmental pollution analysis.

WANG Hu1,2, WEI Jun-feng1,2, ZHENG Guo-xia1,2

2014, 25(4):  1231-1238. 

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Recently, a new type of chip technology, microfluidics, has received global attention for its rapid analysis speed, low reagent consumption, small size and simple operation, etc. Based on a microchannel network and supported by a MicroElectroMechanic System (MEMS), this technology integrates all the functions of a laboratory into one small piece of chip, which is called “lab on the chip”. This paper presented a brief introduction about microfluidics and its representative developments. Future prospects in the aspects of instrument miniaturization, system integration, chip materials, and detection techniques, as well as the implementation of microfluidics in aquatic environmental pollutant analysis were thoroughly discussed. Some problems faced now were put forward. With the rapid progress in the microfluidics, a universal lowcost microchip capable of high speed multichannel detection and integrated with many kinds of detection methods would be the research focus in the future.