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    10 October 2014, Volume 33 Issue 10
    Long-term effects of harvest intensity on forest above-ground biomass and landscape pattern of Changbai Mountain.
    WANG Min1,2, HE Hong-shi1**, LIANG Yu1, WU Zhi-wei1
    2014, 33(10):  2581-2587. 
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    Harvest is the key factor driving Changbai Mountain forest landscape changes. This paper used spatially explicit models (LANDIS PRO 7.0) to simulate the longterm dynamic changes of forest above-ground biomass and landscape pattern of Lushuihe Forestry Bureau in Changbai Mountain under five levels of harvest intensity scenarios. The results showed that: 1) harvest led to different degrees of fragmentation of tree species; 2) harvest intensity had a significant effect on forest above-ground biomass. With the increase of the harvest intensity, the above-ground biomass decreased. Harvest also significantly reduced above-ground biomass of different tree species. Moreover, harvest had a greater effect on Fraxinus mandshurica, Picea koraiensis, and Tilia amurensis. Therefore, in the early simulation period (2003-2103), when a higher harvest intensity was carried out, Betula platyphylla and Populus davidiana could be harvested firstly, followed by F. mandshurica, P. koraiensis, and T. amurensis. When a lower harvest intensity was performed, tree species
     of B. platyphylla, P. davidiana, F. mandshurica, P. koraiensis, and T. amurensis could be harvested equally. In the late simulation period (2103-2203), harvest intensity should be reduced because forest aboveground biomass showed a trend of decrease, and B. platyphylla, P. davidiana, F. mandshurica, P. koraiensis and T. amurensis can also be harvested equally. The harvest strategies can provide help for the forest administrative department to develop reasonable measures.
     
    Seasonal variations of sap flow and transpiration water consumption of introduced tree species Acacia auriculaeformis and Eucalyptus citriodora.
    SUN Zhen-wei1,2, ZHAO Ping1**, NIU Jun-feng1, NI Guang-yan1, ZHU Li-wei1, GAO Jian-guo1, ZHAO Xiu-hua1,2, ZHANG Zhen-zhen1,2, ZHOU Juan1,2
    2014, 33(10):  2588-2595. 
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    By the method of Granier’s thermal dissipation probe, the sap flow density of two exotic tree species (Acacia auriculaeformis and Eucalyptus citriodora) in South China was continuously measured in 2013, and the environmental factors including photosynthetically active radiation (PAR), soil water content (SWC), air temperature (T) and air relative humidity (RH) were measured simultaneously, aiming to characterize the seasonal variations of water use in the two tree species. Obvious diurnal variation patterns of sap flow for both species were observed in any season, yet the average and maximum flow rates were consistently higher in A. auriculaeformis than in E. citriodora. Crosscorrelation analysis showed that the time lag was correlated with tree species and seasons, and sap flow rates were significantly correlated with PAR, T, RH and water vapor pressure deficit (VPD). PAR and VPD were the dominant factors in winter and summer, respectively. With similar sapwood area and diameter in breast height, water consumption of A. auriculaeformis was significantly higher than that of E. citriodora. Seasonal variation of transpiration in A. auriculaeformis was more significant than that in E. citriodora. Sapwood depth in E. citriodora decreased rapidly with age, which resulted in its lower transpiration rate. Thus, the trees of E. citriodora planted in the mid1980s senesced earlier than their peers of A. auriculaeformis.

     
    Population dynamics and growth of Juglans cathayensis seedlings of different slope aspects in the west Tianshan valley in Xinjiang, China.
    ZHANG Wei1,2, JIA Feng-qin1, NA Sen-bate1, YANG Yun-fei2**
    2014, 33(10):  2596-2602. 
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    On the basis of the non-destructive determination of seedling age and survey one by one in plots, the static life table of Juglans cathayensis of different slope aspects in the west Tianshan valley in Xinjiang was established, and the quantitative characteristics of seedling height and the growth patterns were analyzed. Results showed that the seedling life expectancy of different slope aspects was longest in the 1st age class, being 2.018 on the sunny slope and 1.766 on the shady slope. The seedling life expectancy was generally higher on the sunny slope than on the shady slope in the 1st to 6th age classes. The proportions of the seedling population number of different slope aspects were largest in the 1st age class, being 39.7% on the sunny slope and 44.2% on the shady slope. The mortality rates of the seedlings were highest in the 3rd age class, with 82.0% on the sunny slope and 78.3% on the shady slope. The age structure of the seedling population was of an expanding type, and the survival curve tended to be of Deevey-Ⅱ type regardless of slope aspects. The seedlings could survive only 3.3% on the sunny slope and 1.1% on the shady slope from 1st to 7th age class. The seedling heights followed an allometry of the exponent function with the age classes, and the growth rate (b value) of the model was substantially the same regardless of slope aspects.
     
    Density and diversity of plant seeds in yak and sheep dung in cold season pasture of alpine meadow.
    JING Yuan-yuan, XU Chang-lin, CHEN Lu-jun, YU Xiao-jun**, YANG Hai-lei, ZHANG Jian-wen, XIAO Hong
    2014, 33(10):  2603-2609. 
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    In order to identify the features of plant seeds in dung of yak and Tibetan sheep grazing at different grazing stages of winter pasture (alpine meadow) on Eastern Qilian Mountain, the number of species, the seed diversity index, the seed number and density were studied. The results showed that in the same grazing stage, the number of seed species in yak dung was higher than in Tibetan sheep dung. The seed density in yak dung was lower than in the Tibetan sheep dung, but the difference was significant only at the middle grazing stage. At the initial and final grazing stages, the seed diversity index in yak dung was significantly higher than that in Tibetan sheep dung. The seed species number and seed density (grains·kg-1) in yak dung at the different grazing stages were both in order of final grazing stage > initial grazing stage > middle grazing stage, and those in Tibetan sheep dung were in order of initial grazing stage > final grazing stage > middle grazing stage and of middle grazing stage > final grazing stage > initial grazing stage, respectively. The seed number of sedge was the highest in yak dung, while the seed number of forbs was the highest in Tibetan sheep dung. The different conditions of winter pasture at the different grazing stages made the seed distribution different in each synusia of plant community, together with the differences in grazing habit, forage intake per bite and digestibility of yak and Tibetan sheep, causing the differences in seed density, seed species and seed diversity of their dung.
    Plant diversity and soil physicochemical properties under different aged Pinus massoniana plantations.
    CUI Ning-jie1, ZHANG Dan-ju1, LIU Yang1, ZHANG Jian1,2**, OU Jiang1, ZHANG Jie1, DENG Chao1, JI Tuo-wei1
    2014, 33(10):  2610-2617. 
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    Plant species diversity, soil properties and their interactions of Masson pine (Pinus massoniana) plantations with different stand ages in the upper reaches of the Yangtze River were investigated in this study. The results showed that: (1) There were more lightrequiring plants in the 3-year-old Masson pine forest, while the stand canopy density and the abundance of shading plants increased along with increasing the stand age. (2) The species richness index was highest in the midstage Masson pine plantations, and then dropped slightly but higher than that in the young stands. Both of the Simpson and Shannon indexes of shrubs and herbs showed a fluctuation in the early stage, declined in the mid-stage, and then increased in the later stage. (3) Soil organic matter, total nitrogen and total phosphorus contents increased significantly along with the stand age. (4) There were significant correlations between plant species diversity and soil factors such as soil pH, soil water content and total phosphorus content. The results suggested that soil physicochemical properties affected the species regeneration and succession, meanwhile, the community succession led to changes in soil water and nutrient contents, providing facilitative conditions for survival, colonization and growth of more species.
    Monthly variation in soil moisture under Caragana intermedia stands grown in desert steppe.
    SONG Nai-ping1,2**, YANG Ming-xiu1,2, WANG Lei1,2, WANG Xing1,2, XIAO Xu-pei1,2, QU Wen-jie1,2
    2014, 33(10):  2618-2624. 
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    Caragana shrub has been widely planted to prevent ecological deterioration in desert steppe. However, water capacity is the most important factor limiting the development of Caragana in this area. Annual variations of soil moisture in Caragana stands with different ages (9, 16 and 26 years old) and natural grassland in April, August, October in 2012 and March, April in 2013 were studied. The results showed that: (1) Similar soil moisture dynamic pattern was observed in the different Caragana stands in an annual cycle. Soil moisture was dramatically depleted from May to August and recovered in September. Soil water underwent slight depletion from October in 2012 to February in 2013. The depleting process of soil moisture was accelerated from March to April. (2) There was no significant difference in soil moisture between grassland and Caragana stands, while a significant difference in soil moisture was found between the Caragana stands with different ages. (3) The annual closure errors of soil moisture for the different Caragana stands were under deficit. The least soil water deficit was recorded for the 26-year-old Caragana stand, indicating its low water consumption and strong ability to keep soil water balance. (4) The precipitation distribution, soil texture and rooting character had profound effects on the soil moisture in desert steppe.
    Effects of nitrogen and phosphorus nutrients on the nutritive organ phenotypic plasticity of invasive Chromolaena odorata.
    QUAN Guo-ming1,2, XIE Jun-fang1, ZHANG Jia-en1**, MAO Dan-juan1
    2014, 33(10):  2625-2632. 
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    The effects of different nitrogen and phosphorus levels on the nutritive organ phenotypic plasticity of invasive Chromolaena odorata were studied by a greenhouse pot experiment. The results showed that branch number, branch length, total leaf number, total leaf area, total biomass, stem biomass and leaf biomass of C. odorata increased significantly with the increase of nitrogen and phosphorus levels. The ratio of root biomass to aboveground biomass decreased significantly with the increasing nitrogen and phosphorus levels, while the stem biomass fraction increased notably at 0.05 g·kg-1 of nitrogen or phosphorus treatments and remained stable thereafter. Leaf mass fraction reduced first and then increased remarkably with the increasing nitrogen level, but it was less affected by the phosphorus levels. Leaf area ratio, the ratio of leaf area to root mass, specific leaf area and relative growth rate of C. odorata increased significantly with the increasing nitrogen and phosphorus levels, but had no differences when the phosphorus levels were ≥0.05 g·kg-1 except the relative growth rate. Phenotypic plasticity indexes of branch number, branch length, total leaf number, total leaf area, total biomass, stem biomass, leaf biomass, root mass fraction, the ratios of root biomass to aboveground biomass and leaf area to root biomass of C. odorata were higher than that of other parameters, and the phenotypic response to nitrogen nutrient was also stronger than that to phosphorus. The results indicated that nitrogen and phosphorus levels had significant effects on the growth of C. odorata. C. odorata could modify its morphology, structure, biomass accumulation and allocation to adapt to the changing nutrient conditions, and thus demonstrated a strong phenotypic plasticity in response to different nitrogen and phosphorus nutrient levels.
    Ecological characteristics of Phragmites australis vegetation at different water table levels and their relation to environmental factors in the Yellow River Delta.
    GUAN Bo1,2, LI Yun-zhao1, XIA Jiang-bao2, DONG Hong-fang3, LU Zhen-bo4, YU Jun-bao1**
    2014, 33(10):  2633-2639. 
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    The ecological characteristics of Phragmites australis wetlands at different water table levels in the Yellow River Delta and the related soil environmental factors were studied. The results showed that soil electrical conductivities (EC) of P. australis wetlands were significantly different at different water table levels. The lowest EC value occurred in the highest water table area. The ecological characteristics of P. australis wetlands showed great differences at different water table levels. The maximum values of plant height, shoot diameter, vegetation coverage and plant biomass occurred at the highest water table level. The plant biomass at the highest water table level was 10 t·hm-2. The contents of soil nutrient elements in the study area were at relatively low levels, and also showed significant differences among the different soil layers. The correlation analysis showed that the soil nutrient elements had various correlations with the contents of soil clay, coarse clay, fine silt, and coarse silt. The content of soil available phosphorus showed highly significant positive correlation with plant height, shoot diameter, vegetation coverage, and plant biomass. Therefore, it can be concluded that the soil available phosphorus is a limiting nutritional factor of plant growth in the coastal wetland of the Yellow River Delta.
    T-RFLP analysis of cucumber rhizosphere microbial communities in different cropping seasons.
    QIAO Peng-lei, ZHOU Xin-gang, WU Feng-zhi**
    2014, 33(10):  2640-2649. 
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    In this paper, the dynamic changes in bacterial and fungal community structures in the rhizosphere of cucumber in different cropping seasons were analyzed with the terminal restriction fragment length polymorphism (T-RFLP) method. Results showed that the diversity index of bacterial community decreased from the first to the seventh cropping season, and then increased in the ninth cropping season. At 50 days after sowing, the diversity index of fungal community increased from the third to the seventh cropping season, and then decreased in the ninth cropping season, which was in contrast with the trends observed at 30, 40 days after sowing. The number of predominant bacterial species decreased from the first to the seventh cropping season and then increased in the ninth cropping season, and the predominant species mainly included classes such as Clostridia, γ-Proteobacteria, α-Proteobacteria and unknown bacteria. The number of predominant fungal species increased from the first to the seventh cropping season, then decreased in the ninth cropping season, and the predominant species mainly included Hyphomycetes, ectomycorrhizal fungi, Zygomycete, Agaricomycetes, Basidiomycetes and unknown fungi. Moreover, the influence of cucumber growth stages on soil bacterial and fungal community structures was stronger than that of cropping seasons. In conclusion, continuous cropping changed the cucumber rhizosphere bacterial and fungal community structures and diversities. Especially, the bacterial and fungal community structures in the seventh cropping season were obviously different from those in the other cropping seasons.
    Effects of planting density on soil moisture and corn yield under plastic film mulching in a rain-fed region of northeast China.
    SUN Shi-jun**, FAN Yu-miao, XU Zhi-hao, ZHANG Xu-dong, CHI Dao-cai
    2014, 33(10):  2650-2655. 
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    High-yielding cultivation techniques such as plastic film mulching and high density planting are being used widely in northeast China in recent years, especially in those rain-fed agricultural regions. In this paper, the effect of plastic film mulching and planting density on corn yield and field soil moisture was studied in a rainfed agricultural region of Shenyang, Liaoning Province. The dynamic changes of soil moisture and corn yield were investigated in fields at three planting densities (60000, 67500, and 75000 plants·hm-2) with/without film mulching. Consistent trends in soil moisture were observed for the different planting densities through the whole growth period, i.e., an increase in soil moisture with the rainfall and a decrease in the drought time, especially during jointing stage and filling stage of corn. The corn yield was greater in the film mulching fields than that in the unmulching fields at a same planting density, and the greatest increment of yield appeared at the density of 60000 plants·hm-2 (by 14.3%). The influence of planting density on plant water use efficiency was more sensitive in the film mulching fields, compared to the un-mulching fields. Collectively, both increasing corn density and applying plastic film mulching can increase the corn yield, but lead to the decrease in soil water storage.
     
    Microclimate characteristics of sunlight greenhouse in Dawa, Liaoning Province.
    ZHAO Xian-li1, ZHANG Shu-jie1**, CHEN Yan-qiu2, CAI Fu1, LI Jun-he3, ZHANG Mei-ling3
    2014, 33(10):  2656-2663. 
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    Using the microclimate data of inside and outside greenhouse in Dawa of Liaoning Province from April 2012 to May 2013, this paper analyzed the characteristics of microclimate and temperature and humidity effects of inside and outside greenhouse under different weather conditions. The results showed that the maximum temperatures inside greenhouse on sunny, cloudy, overcast and rainy days were 28.9-29.6, 23.8-27.5, 14.6-22.9 and 10.3-21.4 ℃, being 5.5-33.5 ℃ higher than that of outside. Under the abovementioned weather conditions, the minimum temperatures inside greenhouse were 5.3-9.0, 6.8-9.9, 5.8-11.0 and 4.0-7.9 ℃, respectively, being 2.5-20.8 ℃ higher than that of outside, and the minimum humidity  inside greenhouse were 44.8%-67.7%, 59.4%-78.3%, 74.7%-91.8% and 82.4%-99.9%, respectively, being 0.8%-27.1% higher than that of outside, while the maximum humidity inside was slightly higher or equal to outside. The temperature difference between inside and outside greenhouse was larger at daytime, especially around noon, but smaller at nighttime. The humidity difference was lager at night, less or no difference at daytime. The warmer and wetter effects were more often observed on sunny days than under other weather conditions and in winter than in autumn and spring. The total solar radiation was 0 W·m-2 before sunrise and after sunset, and the maximum value appeared around noon.
     
    Effects of timed soil warming on photosynthetic characteristics of cucumber seedlings in greenhouse.
    GAO Qing-hai**, WANG Ya-kun, LU Xiao-min, MIAO Yong-mei
    2014, 33(10):  2664-2669. 
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    Effects of soil temperature variation on photosynthesis of cucumber seedlings were studied in greenhouse by using timed soil warming with heating lines. The results showed that, compared with the control, soil warming at 6:00-8:00 significantly increased soil temperature. Especially at 7:00-12:00, higher soil temperature not only reduced the stomatal limit of cucumber leaves, increased the stomatal conductance and intercellular CO2 concentration, but also significantly increased ФPSII, Pn, AQY and CE of cucumber leaves. When soil was warmed at 12:00, Pn and ФPSII of cucumber leaves were 62.3% and 19.67% higher than those of the control, respectively, while soil temperature had little effect on Fv/Fm of cucumber leaves. Soil warming in solar greenhouse significantly promoted the growth of cucumber seedlings by increasing the plant height, stem diameter, and fresh weight; the shoot fresh weight was 113.8% higher than that of the control. In short, soil warming improved the utilization capability of CO2 and light energy by cucumber seedling leaves, improved photosynthesis of cucumber seedlings and promoted the growth of cucumber seedlings through increasing soil temperature. The results can serve as a theoretical basis for cucumber cultivation in cold seasons.
     
    Effects of inoculating microbes on composting of green wastes.
    LI Wen-yu, LUAN Ya-ning, SUN Xiang-yang**, XU Yu-kun, YANG Xiang, ZOU An-long, WU Xuan-yun
    2014, 33(10):  2670-2677. 
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    The effects of two kinds of inoculating microbes (white rot fungi, actinomycetes) on composting of green wastes using a high temperature aerobic composting system were studied. The results indicated that inoculating white rot fungi plus actinomycetes resulted in a higher temperature for a longer duration compared to the other treatments. However, the pH and EC were not affected by inoculating microbes. Inoculating white rot fungi plus actinomycetes shortened the time of composting to 35 days (GI>80%) to reach compost maturity, 5-15 days less than the control. The root length of inoculating white rot fungi treatment was longer than that of the other treatments. The results of scanning electron microscopy showed that the structure of lignin and cellulose clearly changed with the inoculation of white rot fungi plus actinomycetes, and the degree of their degradation was more thorough than in the other treatments.
    Screening of virulence-attenuated strains for Fusarium oxysporum f. sp. cucumerinum treated by extracts of the rotten root of the parsley.
    LI Jie, WANG Yong, GAO Xiao-min, QIAN Cheng, YUN Xing-fu**
    2014, 33(10):  2678-2686. 
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    In order to select the virulence-attenuated strains for Fusarium oxysporum f. sp. cucumerinum, the allelopathy and changes of pathogenicity of cucumber plants were detected after treatment by different parsley rotten root extracts on F. oxysporum f. sp. cucumerinum. The F. oxysporum f. sp. cucumerinum were treated from the first generation to fifth generation with parsley rotten roots extracted by ethanol, acetone and aqueous respectively in medium conditions. The results showed that the allelopathy effects of parsley rotten root ethanol extracts of each generation after 144 h treatment were 55.5%, 45.5%, 49.8%, 53.7%, and 44.0% respectively, and the pathogenicity dropped from 43.0% to 4.2% from the first generation to fifth generation. The allelopathy effects of acetone extract treatments were 23.1%, 28.2%, 24.3%, 23.3%, and 19.3% for the first to fifth generation respectively, and the disease index pathogenicity dropped from 35.0% to 3.3%. Both ethanol and acetone treatments had significant difference compared with their corresponding control. The allelopathy effects of aqueous extract treatments were 9.7%, 5.1%, 7.4%, 3.3%, and 2.8% for the first to fifth generation after 144 h treatment, showing no significant difference with their corresponding control, and the disease index dropped from 57.0% to 19.2%. Therefore, it was considered that virulenceattenuated F. oxysporum f. sp. cucumerinum strains could be screened after 5-generation treatment with ethanol or acetone extracts of parsley rotten roots, and they showed a good pathogenicity stability in cucumber plants.
    Analysis of fungal community structure during the Fahua-fermentation process of Fuzhuan Brick Tea by DGGE technology.
    LIU Shi-quan1,2, ZHAO Yun-lin1**, HU Zhi-yuan1
    2014, 33(10):  2687-2693. 
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    To explore fungal community structure and species composition in Fahua-fermentation process of Fuzhuan Brick Tea, the fungal variable region of 18S rDNA was amplified during different periods of Fahuafermentation process. Amplified products were separated by denaturing gradient gel electrophoresis (DGGE) and the bands were cloned, sequenced and aligned. The results show that two distinctive kinds of fungal communities, correlating to the fermentation periods, 0-8 d and 10-14 d respectively, were found. The dominant fungi of the former band include Wallemia muriae, Pichia kudriavzevii, Candida sp., and that of the latter include Eurotium amstelodami and W. muriae. The results of variable regions of 18S rDNA alignment showed that W. sebi, W. muriae, Debaryomyces hansenii, Saccharomyces cerevisiae, Candida sp., C. tropicalis, Lodderomyces sp., P. kudriavzevii, Rhodotorula graminis, Rhizomucor pusillus, Cryptococcus sp., E. amstelodami, Aspergillus penicillioides, R. miehei, C. ontarioensis, Trichosporon dermatis, Penicillium decumbens, Galactomyces geotrichum, A. glaucus, E. herbariorum were detected. The 18S rDNA alignment results also confirmed that there were 3 strains of W. sebi and 5 strains of E. amstelodami, displaying a wide variety of ecotypes within the dominant fungi. This study for the first time shows a detailed spectrum of fungi during the Fahuafermentation process. DGGE fingerprint is an important technique to analyze the comprehensive, detailed fungal community structure and diversity dynamics of Fuzhuan Brick Tea during this process.
    Effects of low-temperature stress on root system characteristics and electric conductivity of maize seedlings.
    LUO Ning1,2, WEI Shi1,2**, LI Jing1,2, GU Wan-rong1,2, HE Dan1, QU Tian-ming1, QIAO Tian-chang1, YANG Zhen-fang1
    2014, 33(10):  2694-2699. 
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    Low temperature during the seedling period is one of the main limiting factors for high and stable yield of maize in Heilongjiang Province. To address the effect of low temperature on the growth of seedling root, three maize cultivars Zhengdan 958 (cold resistance type), Xianyu 335 (middle type), and Fenghe 1 (sensitivity type) were investigated at diurnal temperature of 20 ℃/11 ℃ (CK), 18 ℃/9 ℃, 16 ℃/7 ℃, 14 ℃/5 ℃ for 2, 4, 6, 8, 10 days. The root characteristics and root electric conductivity after low temperature treatment were studied. The results showed that with increasing the temperature stress, the growth rates of root dry weight, length, surface area, and dry weight density decreased, the electric conductivity increased, and the roots almost stopped growing at 5 ℃. The inhibitory effects of low temperature on the growth and cell membrane permeability of roots of the three cultivars were in order of Fenghe 1 > Xianyu 335 > Zhengdan 958. The results indicated that low temperature could inhibit the growth of roots, while increase the cell membrane permeability of roots. Cold resistance cultivars showed better root growth, more stable root plasma membrane system with a lower permeability.
     
    Effects of rifampicin on population parameters of two color morphs of Acyrthosiphon pisum Harris.
    LU Ning, LIU Chang-zhong**
    2014, 33(10):  2700-2705. 
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    The objective of this study was to clarify the effects of rifampicin (antibiotics) on the growth, development and population parameters of two color morphs (red and green) of Acyrthosiphon pisum Harris. In laboratory, four treatments were set up: control (CK), spraying rifampicin on plant surface and aphid body at the same time (Ⅰ), spraying rifampicin on aphid body (Ⅱ) and spraying rifampicin on plant surface (Ⅲ). Biological parameters (the average weight, weight difference, mean relative daily weight growth rate during the developmental period, and the mean fecundity per female) were measured. The results showed that: 1) nymph and generation durations of the two color morphs in the three rifampicin treatments were significantly longer than those of the same color type in the control (P<0.05). Adult longevity of either treatment Ⅰ or treatment Ⅲ was obviously longer than that of the same color type in the control (P<0.05), while the adult longevity of treatment Ⅱ showed no significant difference compared to the same color type in the control (P<0.05). In treatment Ⅰ, the development durations, adult longevity and generation durations of the red and green morphs were 9.46, 19.40 and 28.22, and 9.84, 18.47 and 28.29 days, respectively. 2) The average weight, weight difference and relative growth rate of the two color morphs in the three rifampicin treatments were all significantly reduced compared with the same color morph in the control (P<0.05), while the reproductive rate of each of the two color morphs was lower than that of the same color type in the control (P<0.05). 3) The net reproductive rate, mean generation duration, intrinsic rate of increase, finite rate of increase and double population time of the two color morphs in the three rifampicin treatments were significantly different from the same color morph in the control (P<0.05). However, all the population parameters were not significant between the two color morphs (P>0.05).
    The diversity of autumn weed community in tea gardens in southern hilly regions of Jiangsu Province.
    ZHANG Hai-yan1, JI Min1, SUN Guo-jun1,2**, LI Fen-hua1, HAN Min1, YUAN fang1, XU Ying-lian3, WAN Yu-cheng1
    2014, 33(10):  2706-2713. 
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    In order to reveal the species composition, biodiversity and harmfulness of autumn weeds in tea gardens of different natural environments, management practices, and tea planting time, a survey on species number, density and weed height were conducted in October 2011 and 2012 in hilly regions of southern Jiangsu Province. Based on the survey data and habitat characters, all sampling tea gardens were classified into five habitat groups through cluster analysis. The results showed that significant differences in family, genera and species composition, and in weed community structure and ratios of annual to perennial species were found among the different groups, due to the influence of habitat and management practices. In Groups Ⅲ and Ⅳ, Eleusine indica + Echinochloa crusgalli var. austrojaponensis + Digitaria sanguinalis weed community and D. sanguinalis + Rostellularia procumbens + Acalypha australis + Eleusine indica + Erigeron annus + Conyza canadensis + Oxalis corniculata weed community occurred respectively. In these two groups, main species were more than the other groups, and species composition and community structure were stable and complicated, which may allow the communities to buffer from disturbance and environmental fluctuation. Groups Ⅱ and Ⅴ, Leptochloa panicea + C. canadensis + Euphorbia humifusa + Erigeron annus weed communities and Ophiopogon japonicus + C. canadensis + Pieris multifida + Phyllanthus urinaria + Rostellularia procumbens weed communities, had unstable structures and caused little harmfulness. Group Ⅰ had Digitaria sanguinalis + Erigeron annuus + Echinochloa crusgalli var. austrojaponensis +Eleusine indica +Oxalis corniculata + Acalypha australis weed communities, with biodiversity index values contrary to those of the other groups, while the dominant species predominated the community structure, often causing serious harmfulness.
    Control of Spartina alterniflora by integrated technique of mowing plus shading.
    ZHAO Xiang-jian1, LIU Xiao-yan1, GONG Lu1, DENG Zhen-zhen1, BAI Jia-de2, LI Jun-sheng1, ZHAO Cai-yun1**
    2014, 33(10):  2714-2719. 
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    Spartina alterniflora is native to the Atlantic and Gulf coasts of North America, and it was introduced to many coastal areas of the world. Recently, this species was found threading the native ecosystems and was considered as a noxious invasive plant in many countries. Integrated physical control techniques were proved more effective on controlling S. alterniflora than single physical control techniques. For example, cutting plus waterlogging was proved to be more effective than cutting, but it was usually expensive. In this study, an integrated technique of mowing plus shading method (MS) was conducted to investigate its effectiveness for controlling S. alterniflora. The results showed that although mowing alone significantly decreased the node number, plant height and aboveground biomass after six months (P<0.05), no significant changes were found on the node length, basal item diameter, population density, fruiting ratio or inflorescence length of S. alterniflora (P>0.05). It was indicated that mowing only slow down the vegetative growth of S. alterniflora but had little effect on controlling its population. After six months using MS treatment, plant height, node number, node length, basal item diameter, aboveground biomass and population density of S. alterniflora were all significantly decreased than the mowing group and control group (P<0.05), and clonal growth and sexual reproduction of S. alterniflora were absolutely inhibited in the whole growth season. Moreover, no seedlings of S. alterniflora were found in MS treatment after six months. Our results demonstrated that MS technique was more effective on controlling S. alterniflora than single mowing, and was especially suitable for controlling small S. alterniflora communities at their early invasive stage.
    The current status and disease occurrence of captive forest musk deer (Moschus berezovskii) in Shaanxi Province.
    WANG Yong-qi1, MENG Xiu-xiang2**
    2014, 33(10):  2720-2726. 
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    As an important way for exsitu conservation and musk production, musk deer (Moschus spp.) farming was initiated in China in 1958. This study focused on investigating farming pattern and disease occurrence of the main farmed deer species (i.e. forest musk deer, M. berezovskii) in Shaanxi Province of China during 2001-2012. In Shaanxi Province, farmed musk deer are distributed in the core habitats of wild musk deer, which is the QinglingBashan mountainous area including Baoji, Hanzhong and Ankang. There were 4725 captive forest musk deer in Shaanxi Province, the population growth rates reached 25.06%, and fitted the exponential model well. Generally, the provincial musk deer farms increased rapidly with the average annual rate of 27.92%. The average population size, however, tended to decrease. The average population sizes were 20.53 and 19.45 individuals in 2005 and 2010, respectively. There were 53 commonly occurring diseases in captive musk deer, falling in 10 categories. Among them, the digestive system diseases, parasitic disease and respiratory system diseases occurred most frequently. For captive musk deer, the death rate of males (54.28%) was significantly higher than that of females (45.72%) (P< 0.05), indicating that male-biased death existed in farmed forest musk deer. Moreover, the death rate for adults (35.99%) was significantly higher than that for subadults (31.86%) (P< 0.01) or the young (32.15%) (P< 0.05), but no significant differences existed between the two latter age classes. In order to ex situ conserve the endangered forest musk deer in Shaanxi Province and ensure sustainable musk production, the growth rate of captive forest musk deer population must be enhanced significantly, and the disease occurrence should be controlled and prevented in musk deer farming.
    Response of Misgurnus anguillicaudatus to feed with transgenic Cry1Ab/Ac rice pollen added.
    LI Fei1, LIU Yu-fang1**, SUN Yuan-dong1, MO Shu-yin1, XIAO Lu1, TAN Shu-hua1, LIU Wen-hai1, GUI Fang-yan1, GE Feng2
    2014, 33(10):  2727-2732. 
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    As an additive, the pollen of transgenic Cry1Ab/Ac insectresistant rice (HH1) was added to the normal feed of Misgurnus anguillicaudatus, which made the artificial feed containing 1%, 5%, 10% and 20% pollen, respectively. M. anguillicaudatus were cultured in laboratory for 100 days fed on one of the artificial feeds mentioned above. Feed with the pollen of nonCry1Ab/Ac parent rice (MH63) added was used as a control, while the regular feed without any pollen was used as a negative control. The ecological safety of transgenic Cry1Ab/Ac rice pollen on M. anguillicaudatus was evaluated by testing the growth performance and activities of physiological enzymes in liver of M. anguillicaudatus. The results showed that no significant differences were found in the weight gain rate, viscera somatic index and liver somatic index of M. anguillicaudatus feeding transgenic Cry1Ab/Ac rice pollen compared to that in the control groups. The activities of two antioxidant protective enzyme, SOD and CAT, and detoxification enzyme GST of M. anguillicaudatus had no significant difference either. With up to 20% pollen content of transgenic Cry1Ab/Ac rice in feed, no obvious influences on the growth performance and physiological metabolism of liver function of M. anguillicaudatus were found after feeding 100 days. The results suggested that the pollen of transgenic Cry1Ab/Ac rice would have no obvious ecological risk on M. anguillicaudatus.
    Ecological characteristics of phytoplankton community in Guangxi coastal area.
    XU Shan-nan, LIN Hua-jian, DAI Ming, XIAO Ya-yuan, CHEN Zuo-zhi**
    2014, 33(10):  2733-2739. 
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    Based on the data collected from the ecological investigation on Guangxi coastal waters in both wet season (September 2009) and dry season (January 2010), the species composition, dominant species, abundance and community diversity of phytoplankton were analyzed. The results showed that a total of 134 species from 40 genera belonging to 4 phyla were identified in the surveyed area. Of all the phyla, diatom was the predominant group, which accounted for 87.3% of the total species. There were 84 common species in both wet and dry seasons and the species similarity index between the two seasons was 81.4%, suggesting no significant seasonal variations in the species composition. During the wet season, there were many dominant species, and the major ones were Chaetoceros curvisetus and Pseudonitzschia delicatissima. The dominant species was relatively simple during the dry season, and Phaeocystis globosa accounted for the absolute majority with a dominance index of 96.1%. The abundance of phytoplankton cells showed significant spatial and seasonal differences. During the wet season, the phytoplankton density decreased from the eastern to western coastal waters, and the density in coastal area was generally higher than that of the offshore waters. In general, the average Shannon diversity index (H′) was 2.79, and the average evenness index (J) was 0.58, suggesting a high diversity of the phytoplankton community. Both H′ and J of phytoplankton showed no clear seasonal variation, whereas the spatial pattern showed an obvious single peak that was higher in central area but lower in the eastern and western areas. Correlation analysis demonstrated that the density of phytoplankton community had definite correlations with environment factors. During the wet season, phytoplankton density displayed a significant negative correlation with water temperature (P<0.05); during the dry season, it showed a significant positive correlation with the dissolved inorganic nitrogen (P<0.01), and significant negative correlations with biochemical oxygen demand (P<0.01) and salinity (P<0.05).
     
    Community characteristics of ciliates and water environment evaluation in Lhalu wetland during summer and autumn.
    Basang1, HUANG Xiang2, Pubu1, MA Zheng-xue3**
    2014, 33(10):  2740-2748. 
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    To understand the variation characteristics of ciliate community and aquatic environment quality of Lhalu wetland in Tibet during summer and autumn, the ciliate species diversity and community structure were investigated by using site sampling, direct observation (in vivo) and fixedstaining methods in July and October of 2011 and 2012. A total of 110 ciliate species were identified, including 15 uncertain species, belonging to 53 genera, 44 families, 13 orders and 3 classes. Hypotrichida and Prostomatida were the dominant groups; Karyorelictida and Synhymeniida were occasional groups; the others were common groups. Coleps hirtu, Cinetochilum margaritaceum, and Strobilidium gyrans were the dominant species in summer. There were no dominant species in autumn. The distribution of ciliate species in the Lhalu wetland showed high heterogeneity temporally and spatially. The average species diversity index was higher in autumn (3.3) than in summer (2.7). The analysis of correlation between the community structure and major water environmental variables suggested that water temperature was the major factor controlling the variations of ciliate community structure in summer. Evaluation of water quality showed that the water quality of the Lhalu wetland was slightly disturbed by human activities.
    Age structure and growth characteristics of Pseudobagrus truncatus in Minjiang River.
    ZOU Yuan-chao, YUE Xing-jian, WANG Yong-ming, QIN Chuan-jie, XIE Bi-wen, LI Bin, TAO Min, WANG Yu, QI Ze-min**
    2014, 33(10):  2749-2755. 
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    The age structure and growth characteristics of Pseudobagrus truncatus were studied based on 436
     specimens collected from Minjiang River, a Yangtze River’s tributary in November-December 2012 and April-May 2013. The results showed that asteriscus was a good material for determining the age of  P. truncatus. The ages of the specimens ranged from 1-6 years.  The dominated age ranged from 2-3 years, accounting for 81.82% of the total specimens. With the growth of age, the male appeared to grow at a faster rate and there were significant differences in growth patterns between males and females. The relationship between the body length (L) and the body weight (W) appeared as a power function relation, which could be expressed by formula W= 2×10-4L2.3822 (n=193, R2=0.904, P<0.01) for females and W =2×10-4L2.4322 (n=225, R2=0.884, P<0.01) for males, respectively. The Gompertz growth function was especially suited to describe the growth patterns. The growth of body length and body weight of the female and male can be described by the Gompertz growth equation as follows: ♀: Lt=785.78e-1.36e-0.59t, ♂: Lt=926.35e-1.84e-0.42t; ♀: Wt=438.62 e-5.61e-0.45t, ♂: Wt=559.64e-5.49e-0.41t. The inflection points of body length growth were 4.18 years and 4.75 years, and the inflection points of body weight growth were 3.09 years and 2.21 years for the female and male, respectively. Our results indicated that P. truncatus was at younger ages in the study area. In order to sustainably utilize the P. truncatus population, we suggest that only fish larger than 100 mm (10 g) could be harvested.
    Effect of starvation on swimming performance of juvenile crucian carp.
    PENGHAN Liu-yi, CAO Zhen-dong, FU Shi-jian**
    2014, 33(10):  2756-2760. 
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    To investigate the effect of starvation on swimming performance of juvenile crucian carp (Carassius carassius), three different measures of swimming performance (critical swimming speed, Ucrit; constant acceleration speed, Ucat; maximum speed in faststart, Ufast) were measured after different periods of starvation (1, 14 and 28 days) at 20 ℃. The Ucat was 131%-152% that of Ucrit whereas Ufast was 368%-509% that of Ucrit with starvation. Starvation showed no significant effect on Ufast whereas significant decreases of 14%-32% in Ucat and of 24%-29% in Ucrit were observed after 14 and 28 days of starvation. The difference between Ufast and Ucrit(or Ucat) was aggravated after starvation. The difference between Ucrit and Ucat was also aggravated after shortterm starvation (14 days) since Ucrit was more sensitive to starvation than Ucrat. Starvation showed no significant difference in active oxygen consumption rate (MO2active), indicating oxygen  uptake capacity was not the reason for decrease in Ucrit after starvation. Furthermore, starved crucain carp showed higher MO2 at any given swimming speed and more profound MO2 increase with the increase of swimming speed compared to fish in control group, indicating that the decrease of Ucrit under starvation was mainly due to lower swimming efficiency and shortage of substrates.
    Diagnosis and evaluation of biological toxicity for main stream of Liaohe River protection area.
    GUO Wei1, FAN Qi-yang1, KE Xin2**, GUI Shao-feng2, YANG Yan-xi1, ZHAO Guo-qing1
    2014, 33(10):  2761-2766. 
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    The aquatic environment quality of Liaohe River protection area was diagnosed and evaluated by the aquatic comprehensive index and biological toxicity test. The results showed that the survival rates of adult and juvenile zebrafish and the hatching rate of eggs were all more than 50%, suggesting that the biological toxicity of water by acute and chronic toxicity tests was low. Furthermore, there were significant negative correlation relationships between pH, COD, BOD5 and the survival rates of adult and juvenile zebrafish or the hatching rate of eggs (P<0.05). Therefore, the pH, COD, and BOD5 had great effects on the development of adult and juvenile zebrafish and eggs. The aquatic quality comprehensive index showed that Yitong River reached grade V and the other rivers reached grade IV of China’s National Water Quality Standards.
     
    Ecotoxicological effects of tetracycline on the growth, antioxidant defense system and gene expression of earthworm Eisenia foetida in soil.
    JI Zhan-hua1,2, AN Jing1**, XIAO Ming-yue3, WEI Shu-he1, TAI Pei-dong1, LU Ze4
    2014, 33(10):  2767-2774. 
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    A simulated experiment in laboratory was conducted to study the ecotoxicological effects of tetracycline (TC) on the growth, antioxidant defense system and the gene expression of earthworm Eisenia foetida in soil. The results showed that, in the early exposure (≤14 d), the weight and soluble protein (SP) of earthworm stressed by 1-100 mg·kg-1 TC had no significant difference from the control. However, with the increase of TC concentration and the prolonging of exposure time, the weight of earthworm decreased and the content of SP increased. The balance of the antioxidant system was destroyed by 1-100 mg·kg-1 TC with the activities of SOD, POD and CAT increased to varying degrees after a 14 d exposure. Moreover, the results of DDRTPCR showed that 1-100 mg·kg-1 TC affected the gene expression of earthworm after a 28 d exposure. It was suggested that TC had chronic ecotoxicological effects on earthworm and the biomarkers such as antioxidant defense enzyme and the gene expression can be used to estimate the ecotoxicological effects of TC.
     
    Toxic effects of six typical antibiotics on seed germination and physiological characteristics of Chinese cabbage.
    XIAO Ming-yue1, AN Jing2**, JI Zhan-hua2,3, CUI Shuang1, LI Ping1
    2014, 33(10):  2775-2781. 
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    Chinese cabbage (Brassica chinensis L.) was selected to investigate the toxic effects of six antibiotics (tetracycline, oxytetracycline, chlorotetracycline, doxycycline, chloromycetin and sulfadimidine) on the seed germination, root (shoot) elongation, soluble proteins and antioxidant enzymes of the Chinese cabbage. The results showed that 0.5-5 mg·L-1 antibiotics did not inhibit the germination rate, while the seed germination was significantly inhibited with the increasing of antibiotics concentration. There was a good doseeffect relationship between the antibiotic concentration and the inhibition rate of root (shoot) elongation. According to the EC50 values of root inhibition of the Chinese cabbage stressed by the antibiotics, the toxicity of the antibiotics was in order of sulfadimidine > chloramphenicol > chlortetracycline > tetracycline > doxycycline > xytetracycline. The contents of soluble proteins of Chinese cabbage induced by the antibiotics were significantly different among the groups. Moreover, the balance of the antioxidant enzyme system of Chinese cabbage seedlings was destroyed by the tested antibiotics.
    Assessment of phytoremediation for magnesium-rich dust contaminated soil in a magnesite mining area.
    WANG Hong-quan1,2, ZHAO Qiong1**, ZHAO Xin-ran1,2, WANG Wei-wei1,2, WANG Ke-lin1,2, ZENG De-hui1
    2014, 33(10):  2782-2788. 
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    The magnesium (Mg)-rich dust from magnesite mining and calcination has damaged the soil and vegetation severely. However, the knowledge on remediation of Mg-rich dust contaminated soil is scarce. We conducted a pot experiment in the greenhouse to evaluate the remediation effects of Aneurolepidium chinense, Elymus dahuricus, Agrostis stolonifera and Puccinellia distans, combined with application of Ca(H2PO4)2·H2O, on soil contaminated by different amounts of Mg-rich dust (0, 2%, 5% and 10%). We found that: (1) A. chinense and E. dahuricus had a very strong tolerance to Mg-rich dust contamination and the tolerance of A. stolonifera and P. distans was moderate; (2) These plants did not hold a strong Mg enrichment capacity, as the concentration of total Mg in shoot  was 1.6-8.6 g·kg-1, the bioconcentration factor was less than 1 and the translocation factor was 0.5-3.1. These four plants had a good effect on the removal of Mg in the lightly contaminated soil (2%); (3) Application of Ca(H2PO4)2·H2O significantly enhanced the plant biomass and the removal of soil Mg, particularly in the 5% and 10% treatments. Our results suggested that planting A. chinense and P. distans with the application of Ca(H2PO4)2·H2O could not only restore vegetation, but also remove soil Mg effectively in lightly Mg-contaminated soil. In moderately and severely Mg-rich dust contaminated soil, planting A. chinense and E. dahuricus with the application of Ca(H2PO4)2·H2O could accelerate the vegetation restoration.
    Spatial distribution, source and regional difference of soil heavy metals in Yanqi basin, China.
    YIMIT Hamit1**, MAMT Zulpiya2, TAYIR Xiakure2
    2014, 33(10):  2789-2795. 
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    In order to understand the status of heavy metal contents in Yanqi basin, a typical oasis basin in arid region, we collected soil samples and measured the contents of Pb, Mn, As, Zn, Ni and Hg. The multivariate statistical analysis and geostatistical analysis methods in combination with administrative division, land use types and the National Standard of Soil Quality (GB 15618-1995) were applied to study the spatial distribution characteristics, source, and regional differences of heavy metals in the soils of Yanqi basin. The results showed that the average contents of the six heavy metals in Yanqi basin was in order of Zn > Pb > Mn > As > Ni > Hg. The maximum contents of Zn, Pb, Ni and As exceeded the soil background values of Xinjiang, but were still within the second grade of the national standard. Geostatistical analysis showed that the contents of As, Pb, Hg and Zn were higher in the northwestern Yanqi county and Hejing county, while Mn and Ni had higher contents in southeastern and southwestern Heshuo county and Bohu county. The contents of As, Hg, Pb and Zn in different land use types were in order of cropland > grassland > bare land > wetland, while the contents of Mn and Ni were in order of bare land > grassland > wetland > cropland. According to the background of the sampling sites, As, Pb, Hg and Zn mainly originated from anthropogenic pollution, while Mn and Ni mainly originated from natural environment. Our results suggested that recent economic development had negative influences on heavy metal contents in the cropland and some other land use types of the west of the basin. Therefore, we should pay more attention on such influence and take measures to prevent the pollution of heavy metals in soils of Yanqi basin.
    Characteristics of soil heavy metals concentrations in the tailings of Guliku placer gold mine in the Greater Khingan Mountains.
    HU Ya-lin1**, WANG Cheng-yi2, WANG Hong-quan1,3, ZENG De-hui1
    2014, 33(10):  2796-2802. 
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    Mine tailings have become the potential sources of soil heavy metals contaminations. There are large areas of mine tailings in the Greater Khingan Mountains where is one of the most important distribution regions of placer gold mine in China because of nearly a century of mining activities. However, few studies have assessed the characteristics of soil heavy metals contaminations in the tailings of placer gold mine in this region. In this study, we investigated soil Hg, As, Pb, Cd and Cr concentrations and their distribution in the tailings of Guliku placer gold mine. Moreover, soil pollution risk was evaluated using Nemerow index. We found that: (1) soil As, Cd and Cr concentrations increased significantly by 83%, 78% and 101% in the tailings of placer gold mine as compared to natural forest soil. (2) soil Hg and Pb concentrations were different among sampling locations, but not for soil As, Cd and Cr. (3) soil Hg, As, Pb, Cd and Cr concentrations were all lower than the firstgrade environmental quality standards for soils (GB 15618-1995) of China. Our results implied that soil heavy metals contaminations in the tailings of placer gold mine in the Greater Khingan Mountains were not serious. Therefore, we should pay more attention to soil water or nutrient limit rather than soil heavy metals contaminations during ecological restoration of placer gold mine tailings in the Greater Khingan Mountains.
    Arsenic immobilization by gypsum during iron-arsenic coprecipitation process.
    LI Xiao-liang1,2, ZHANG Dan-ni1, WANG Shao-feng1, WANG Xin1, SONG Yu1,2, JIA Yong-feng1**
    2014, 33(10):  2803-2809. 
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    Iron(III)-arsenate coprecipitation is widely practiced for the removal and immobilization of arsenic from mineral processing solutions and effluents in hydrometallurgical industry. However, the role of gypsum in the fixation of arsenic in the coprecipitation process is still unknown. In this study, the gypsum generated during ironarsenate coprecipitation process was isolated by ascorbic acid leaching and the content of arsenic, the mass of the gypsum and the percentage of arsenic fixed by gypsum were determined. The effects of initial arsenic and sulfuric acid concentrations and Fe/As molar ratio were investigated. The results showed that the content and the percentage of arsenic fixed by gypsum increased significantly with the increase of coprecipitation pH. Raising the initial arsenic concentration of the starting solution would increase the arsenic content in gypsum. The generated gypsum contained lower content of arsenic at higher concentration of sulfuric acid or greater Fe/As molar ratios, but fixed higher percentage of arsenic from the starting solution. The findings in this work have important implications to a better understanding of the speciation of arsenic in the coprecipitates and their environmental risk assessments.
    Polycyclic aromatic hydrocarbons and their health risk assessment in urban surface dust from main roads of Guiyang, Southwest China.
    ZHANG Chun-hui1, GUO Jian-yang2**, SHI Shun-quan1, ZHANG Liang2, WU Yong-gui1,3, LI Jiang1,3, YANG Shao-bo1
    2014, 33(10):  2810-2816. 
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    Thirteen polycyclic aromatic hydrocarbons (PAHs) in 32 urban dust samples collected from the main roads of Guiyang City, Southwest China were measured using GCMS method, and their health risks were assessed using the methods proposed by US Department of Energy and US EPA. The results showed that PAHs in urban dusts were in the range of 1291-9215 μg·kg-1 (mean: 4006 μg·kg-1), which was modest at the global scale. These PAHs were mostly originated from vehicle emission and domestic coal combustion based on the principal component analysis. Health risk assessment suggested that the noncarcinogenic hazard and the cancer risks were mainly stemmed from the respiratory activities. The integrated noncarcinogenic hazard index was much less than one, while the integrated cancer risk was at least one magnitude higher than that of the acceptable cancer risk, indicating certain cancer risk cannot be avoided. Among the thirteen PAHs, BaP and DBA contribute the most to the integrated cancer risk, which deserve more concerns.
     
    Geographical distribution of risk factors on cold dew wind of late rice in southern China.
    WU Li1, HUO Zhi-guo1,2**, JIANG Yan3, ZHANG Lei4, YU Cai-xia1
    2014, 33(10):  2817-2823. 
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    Based on the industrial standard Technical specifications for evaluation of rice cold damage, the data of daily average temperature from 169 weather stations in doublecropping late rice growing areas in southern China during 1981 to 2010 were analyzed. Taking the occurrence risk of cold dew wind as the risk factor, the risk index was established on the basis of the occurrence probability and intensity of cold dew wind, and the characteristics of geographical distribution of the occurrence probability and integrated risk index for eachlevel cold dew wind of japonica rice and indica rice were analyzed by using GIS. The results showed that the occurrence probability and integrated risk index for eachlevel cold dew wind of japonica rice and indica rice presented in a trend of gradual reduction from northwest to southeast in the study area. The occurrence probability for cold dew wind of late rice in most of the study area was less than 50%. Meanwhile, the occurrence probability for eachlevel cold dew wind in the east and south of the study area for japonica rice and in the southeast coast for indica rice was below 5%. The areas with high values of probability were mainly located in Wanyuan and Dujiangyan of Sichuan, Hanzhong of Shaanxi and central Yunnan growing areas. The distribution characteristics of the integrated risk index and the occurrence probability of severe cold dew wind were basically the same. This study provided a scientific basis for the spatial arrangement of planting doublecropping late rice in southern China.
    Research progress and prospects of correlation between plant community modules.
    WANG Guo-xun1,2, YU Shun-li2**, FANG Wei-wei2, LI Dan-feng2, YUE Ming1
    2014, 33(10):  2824-2833. 
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    The vegetative modules such as roots, stems, leaves, and reproductive modules such as flowers, fruits and seeds of angiosperm, reflect the response and adaptation of plants to their abiotic environments. During the developmental processes of plants under various environmental stresses, these parts of plants are not independent, but have intrinsic connections both in structure and function. It means they may coevolve and operate with each other; correlations between these different organs can decide the life history strategy of plants, and further affect the plant species coexistence and biodiversity maintenance in a community or ecosystem. This paper review the research progress of coevolution of vegetative organs and reproductive organs of plants at community levels, and not only explores correlation of the macroscopic traits between plant organs, but also covers the research achievements in the field of microscope. The research scale is across species, across communities or ecosystems, even across regions. On the basis of morphological traits, this paper expands more traits in other disciplines, such as anatomy, cytology, physiology and genetics, etc. This paper also expounds some deficiencies in those relational studies and makes some prospects of future researches.
    Recent advances in leaf hydraulic traits.
    PAN Ying-ping1,2, CHEN Ya-peng1**
    2014, 33(10):  2834-2841. 
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    Leaf hydraulic traits represent the survival strategies of plant in leaf water transport when adapting to external environment. They constraint the whole plant’s water transport and affect its gas exchange and its response to drought. Therefore, studies on leaf hydraulic traits have been the research focus of plantwater relationship. In this paper, the basic indices of leaf hydraulic traits, i.e. wholeleaf hydraulic conductance (Kleaf), leaf xylem hydraulic conductance (Kxylem), and leaf out the xylem hydraulic conductance (Kout-xylem), and the five measuring methods of leaf hydraulic conductance are summarized. Meanwhile, the research progresses are introduced, including the effects of leaf venation traits as well as the environmental factors on leaf hydraulic traits, the tradeoff relations between leaf hydraulic traits and leaf functional traits (e.g. stomatal conductance, leaf water potential, leaf maximum photosynthetic rate), and the relations between leaf hydraulic traits and drought resistance of plants. Two suggestions on further study of leaf hydraulic traits are proposed: 1) combining the leaf hydraulic traits with gas exchange and anatomical structures of leaves, which is help for building a carbonwater coupling model on leaf scale, to further reveal the ecological strategies of leaves in response to the external environmental change and the plant watercarbon investment mechanism; 2) conducting the research on interactions between plant water transport systems (root-stem-leaf) in order to choose species with a safe and efficient water transport system.
    Some issues about the impacts of sea level rise on mangroves in China.
    FU Hai-feng, TAO Yi-jia, WANG Wen-qing**
    2014, 33(10):  2842-2848. 
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    It is universally acknowledged that global average sea level is rising and mangroves existing in coastal zones would suffer disturbance of sea level rise. Distributions of mangroves are controlled by main factors including temperature, wave, tide, substrate and salinity. Increased inundation caused by sea level rise would impact the transverse distribution of mangroves on the tidal flat, and mangroves are obliged to transgress inland. In China, sea level rise together with seawalls is threatening the survival of mangroves and small tidal range increases the susceptibility of mangroves to sea level rise. Mangroves of China are extremely sensitive to sea level rise. Presently, there exist several problems about the impacts of sea level rise on mangroves of China. (1) Little research concentrates on the impacts of sea level rise and seawalls on mangroves from the perspective of mangrove community structure. (2) Changes of mangrove ground elevation are poorly understood, which are usually compared with local rises in sea level to predict the effects of sea level rise on mangroves. (3) A monitoring network based on surface elevation table-marker horizon system is urgently needed to observe how mangroves of China respond to sea level rise.
     
    Simulation of ANPP in response to climate change in China’s desert steppe based on CENTURY model.
    ZHANG Cun-hou1,2, WANG Ming-jiu1**, ZHAO Xing-hua1, SUN Xiao-long2, CHEN Hai-jun3, WU Rong-sheng2
    2014, 33(10):  2849-2857. 
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    Desert steppe is one of the major community types of Inner Mongolia grassland, which becomes sensitive in response to climate change. CENTURY model applicability was tested using 50-year climate data, recent 5-year soil investigation information, and 7-year quadrat data on-ecological meteorological observation experimental station of Siziwang County. The correlations of aboveground net primary production (ANPP) simulation values and 26 meteorological factors in the past 50 years were analyzed. Based on the output data of climate emissions scenarios of SRES B2, A2 and A1B from the regional climate system of PRECIS, possible variation trends of ANPP were analyzed under three kinds of climate scenarios over the future 50 years in the study area. The results showed that CENTURY model can successfully simulate the seasonal dynamics and interannual variability in Siziwang County desert steppe. The correlation of monthly aboveground biomass between the simulated and observed values was good in growing season (R2=0.66, P<0.01). Increased air temperature, slightly increased precipitation, and increased ANPP were found in Siziwang County desert steppe in the past 50 years. With changes of temperature and precipitation, simulated ANPP presented obvious change patterns. Correlation analysis showed that ANPP was significantly positively correlated with precipitation, negatively correlated with annual extreme maximum temperature and annual evaporation, and not remarkably correlated with the other meteorological factors. Under the climate scenarios of SRES B2, A2 and A1B, the mean maximum temperature, minimum temperature and precipitation were all of increasing trends. The overall increasing trend of ANPP was evident though its inter-annual fluctuation was stronger. The increases of future ANPP under the three scenarios were 2.55%, 4.19% and 9.44% over the baseline period, respectively. Under the three climate scenarios, impact of climate change on ANPP would be positive in Siziwang County desert steppe in future. This research realized the application of CENTURY model on desert steppe in Inner Mongolia, and made up the lack of unrealizable dynamical evaluation and estimation for grassland productivity due to the shortage of continuous long-term field experiment data and the heterogeneity of ecosystem.
    Estimating leaf nitrogen content of Populus euphratica and P. pruinosa in the upper reaches of Tarim River using hyperspectral index.
    WANG Jia-qiang1, WU Wei-mo1,2**, LI Zhi-jun1,2, WEN Shan-ju1, NIU Jian-long1, CHI Chun-ming1
    2014, 33(10):  2858-2864. 
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    Hyperspectral reflectances of Populus euphratica and P. pruinosa leaves were obtained using field spectrometer in the upper reaches of Tarim River. Leaf nitrogen content was also determined. The bands of 657 nm and 689 nm could be used as sensitive bands to estimate leaf nitrogen content of P. euphratica and P. pruinosa, respectively. The determination coefficient of the linear model between reflectance and leaf nitrogen content of P. euphratica was higher than that of P. pruinosa. Highly significant linear relationships were also found between leaf nitrogen content and hyperspectral characteristic variables, vegetation index and red edge position, respectively. The determination coefficients of linear models between leaf nitrogen content and vegetation index were higher than those of other models. Therefore, inversion models based on vegetation index have good predictability. Significant relationships also existed between leaf nitrogen content and spectral areas. Therefore, spectral areas also can be used to estimate leaf nitrogen content. It was feasible to estimate nitrogen content of P. euphratica and P. pruinosa leaves based on hyperspectral reflectance and parameters transformed from hyperspectral reflectance.
    Assessment on water source stability of the Hani Terrace landscape based on river-ditch connectivity.
    WANG Da-qiong, JIAO Yuan-mei**, HE Li-ping, ZONG Lu-ping, XIANG Dong-fu, HU Zhi-xin
    2014, 33(10):  2865-2872. 
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    The stability of water supply is the key to the sustainability of the World Cultural Landscape Heritage of Honghe Hani Terraces. Taking the Quanfuzhuang River basin located within the core area of the heritage as the object, we obtained the spatial distribution and structural characteristics of rivers and ditches based on QuickBird image and field survey. We selected slope and the distance between rice terraces and rivers or ditches or river-ditches network as the two resistant factors, and analyzed the connectivity of riverditches based on the least-cost distance model in ArcGIS. The results showed that: (1) the ratio of line to node, connectivity and circuitry index of river-ditch network were bigger than those of rivers or ditches; (2) the irrigation resistance of the Hani Terraces by rivers and ditches was higher than by river-ditch network. 66.4% of the total terrace area got stable water irrigation by riverditch network. (3) Taking the self-irrigation and twoway irrigation terraces into account, the highest stable area and higher stable area of water irrigation of the Dayutang village increased by 3.9% and 5.7%, while those of the Xiaozhai village increased by 3.2% to 5.9%, respectively, which indicated the increased stability of water irrigation of Hani Terraces. (4) According to the field survey, the connectivity of river-ditches calculated through the least-cost model can be used for reasonable classification of water irrigation stability, and the results can be used for decision making of maintaining the terrace landscape.