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    10 July 2009, Volume 28 Issue 07
    Articles
    Responses of tobacco leaf photosynthetic parameters to illuminance under attenuated UV-B radiation.
    JI Peng1;WANG Yi2;CHEN Zong-yu1;ZHONG Chu1;DONG Chen-wen-hua1
    2009, 28(07):  1218-1223 . 
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    By the method of covering with different transparent plastic films to attenuate UV-B radiation, this paper studied the photosynthetic characteristics of tobacco cultivar K326 at its early maturity stage as affected by the illuminance at the heights 50 and 150 cm when the UV-B transmittance was 100% (CK), 75% (T1), 50% (T2), and 35% (T3). The change of tobacco leaf net photosynthetic rate in treatments T1 and T3 was mainly due to stomatal factor while in treatment T2 was mainly due to non-stomatal factors. Through the comparison of the average water use efficiency (WUE) in the four treatments, it was found that there could be a threshold of UV-B radiation intensity to WUE. The illuminance at height 150 cm had definite inhibitory effects on the photosynthetic parameters except the transpiration rate in all treatments and the stomatal conductance in treatment T2. For all treatments, the responses of tobacco leaf photosynthetic parameters to the illuminance at heights 50 cm and 150 cm were consistent but differed in sensitive degree.
    Canopy interception of tree and shrub plantations in a farming-pastoral zone of Loess Plateau.
    CHENG Xiang-rong1,2;HUANG Ming-bin2;SHAO Ming-an2;YU Mu-kui1
    2009, 28(07):  1213-1217 . 
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    A 2-year investigation was made on the characteristics of canopy interception of Pinus tabulaeformis, Robinia pseudoacacia, Caragana korshinskii, and Salix psammophila plantations in the Liudaogou watershed in a farming-pastoral zone of Loess Plateau. The canopy interception and the throughfall of the four plantations had significant positive correlations with precipitation, and the canopy interception could be expressed as a power function of precipitation. The average interception of the plantations was 167% for P. tabulaeformis, 116% for R. pseudoacacia, 112% for C. korshinskii, and 128% for S. psammophila. Simulation result showed that modified Wang’s model could more accurately estimate the canopy interception of the representative tree and shrub plantations in semiarid region of Loess Plateau.
    Growth response of Potamogeton crispus to water depth gradient.
    HE Wei1;WANG Guo-xiang1;YANG Wen-bin1,2;CHEN Qiu-min1;LU Yi-chao1
    2009, 28(07):  1224-1228 . 
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    In a pot culture experiment, Potamogeton crispus was planted at the water depths 30, 60, 90, 120, 150, and 180 cm, with its growth response to the water depth gradient was studied. The stem length of P. crispus had a significant correlation with water depth (P<001), and the appropriate water depth for P. crispus growth was 90〖KG-*2〗-〖KG-*7〗150 cm. Around May 7th, the leaf numbers of P. crispus in all treatments except at the water depth 180 cm decreased, indicating that the plant became senescent. The difference in water depth had no significant effects on the photosynthetic pigment content of P. crispus. At the water depths 30 and 60 cm, the Fv/Fm and photosynthetic electron-transport rate (ETR) of P. crispus were lower, illustrating that a water depth less than 60 cm had certain inhibitory effects on the photosynthetic electron-transport rate during the mid- or late growth period of P. crispus. It was suggested that water depth less than 60 cm or more than 150 cm was not beneficial to the P. crispus during its mid or late growth period.
    Effects of NaCl stress on seed germination and seedling growth of four Poaceae grass species.
    MA Hong-yuan1,2;LIANG Zheng-wei1,2;WANG Ming-ming1,2;GUAN Fa-chun1,2;KONG Xiang-jun1,2
    2009, 28(07):  1229-1233 . 
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    This paper studied the seed germination and seedling growth of four perennial drought-tolerant rhizome grasses Leymus chinensis, Agropygron elongatum, Festuca arundinacea and Elymus junceus under effects of 0, 50, 100, 150, 200, 300, 400, and 500 mmol NaCl·L-1. With increasing NaCl concentration, the seed germination rate of test grasses had a decreasing trend. L. chinensis had the lowest salt tolerance. Its seed germination rate was only 15% at 300 mmol NaCl·L-1, and no seeds germinated at >300 mmol NaCl·L-1. A. elongatum, F. arundinacea and E. junceus had higher salt tolerance. Their seed germination rate reached 173%, 20%, and 181%, respectively, at 500 mmol NaCl·L-1. The root length and shoot height of test grasses were significantly negatively correlated with NaCl concentration. With the increase of NaCl concentration, E. junceus had the greatest decrement of its root length while A. elongatum had the smallest one, and L. chinensis had the greatest decrement of its shoot length while A. elongatum had the smallest one. The root/shoot ratio of L. chinensis increased while that of the other three grasses decreased with increasing NaCl concentration, illustrating that for L. chinensis, the inhibitory effect of NaCl was stronger on root growth than on shoot growth, while for the other three grasses, it was in adverse. In sum, L. chinensis had the lowest salt tolerance during its germination and seedling stages, while the other three grasses had higher salt tolerance in their seed germination and seedling growth.
    Life table of natural Taiwania flousiana population in Leigong Mountain Nature Reserve of Guizhou Province.
    FENG Jin-chao;YUAN Fei;XU Gang
    2009, 28(07):  1234-1238 . 
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    An ecological investigation was made on the natural Taiwania flousiana population in Leigong Mountain of Guizhou Province by using checkerboard frame method, and the life table of the population was established by the method of spatial series substituting for time series. There was a fluctuation in the structure of T. flousiana population. The individuals at adult stage were abundant, and the survival curve of the population trended to the type of Deevey Ⅱ. The mortality rate curve and the disappearance rate curve in the lifespan had the similar variation trend, with the peaks in 6th and 12th age class periods. The survival rate of the population decreased monotonically, whereas the cumulative mortality rate was in adverse. Four survival functional curves showed that T. flousiana population grew stably in middle age period but declined in old age period.
    Anatomical characters of vegetative organs and ecological adaptability of new alien species Flaveria bidentis.
    REN Yan-ping;GU Song;JIANG Sha;ZHENG Shu-xin;ZHAO Na
    2009, 28(07):  1239-1244 . 
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    To better understand the ecological adaptability of alien species Flaveria bidentis, the anatomical characters of its vegetative organs were studied with scanning electron microscope and optical microscope. F. bidentis leaf was of isobilateral type, and had thicker epidermis cell wall and cuticle, obvious cryptopores, and highly developed palisade tissue, with typical C4-plant Kranz anatomy. The collenchymas and vascular tissue in stem and the aerenchyma in root were well developed. Secretory structure was found in all vegetative organs. According to the analyses of soil physical and chemical properties and relevant ecological factors, F. bidentis preferred to live under strong light and high temperature conditions, and exhibited strong tolerance against drought, saline/alkaline, and poor nutrients, being able to coexist with some drought- and salt-tolerant plants. It was suggested that the strong adaptability of F. bidentis to harsh environment had definite relations to the anatomical characters of its vegetative organs, being one of the causative factors responsible for the invasiveness of F. bidentis.
    Characteristics of remnant vegetation in isolated island-liked hilly fragment in urbanized area of Shanghai, China.
    LIN Ming-rui1,2;ZHANG Qing-fei2;ZHENG Si-jun2;XIA Lei2;ZHANG Zhi-shun1;HUI Guang-xiu1;ZHANG Hui-bo1
    2009, 28(07):  1245-1252 . 
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    The remnant vegetation in the isolated island-liked mountain fragment of conservation area of the Shanghai Chenshan Botanical Garden was inventoried to examine the features of species composition, flora composition, community structure, and species diversity after nearly five decades succession. There were only 94 vascular plant species, belonging to 50 family and 75 genera. The dominant species in the communities were deciduous broadleaf species Liquidambar formosana, Robinia pseudoacacia, Ailanthus altissima, Acer buergerianum, and Celtis sinensis, evergreen broadleaf species Cinnamomum camphora and Elaeocarpus glabripetalus, and Phyllostachys heterocycla. Robinia pseudoacacia+Cinnamomum camphora community had the highest Shannon-Wiener index (H) (1757) and Phyllostachys heterocycla+Acer buergerianum community had the highest Simpson index (D) (0163), but no consistency was observed between the curves of H and D. For vertical structure, most communities had no significant understory stratification. The regeneration insufficiency, development inadequacy, and low ecosystem stability in remnant forest were due to the lack of seedling recruitment by long-term isolation as well as the local and entire changes of the mosaic structure by human activities. It was suggested that deciduous broadleaf forest could be induced into evergreen and deciduous mixed forest through utilizing the suitable understory condition by introducing zonal evergreen species such as Castanopsis sclerophylla and Cyclobalanopsis glauca.
    Population structure and distribution pattern of dominant species in Tilia mandshurica forest in Dongling Mountain of Beijing.
    SURIGUGA;ZHANG Jin-tun;CHENG Jia-jia;ZHANG Bin
    2009, 28(07):  1253-1258 . 
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    The spatiotemporal variations in the population structure and distribution pattern of dominant species in Tilia mandshurica forest in Dongling Mountain of Beijing were studied in terms of importance value, size structure, survivorship curve, and point pattern analysis. In the forest, T. mandshurica population had a higher importance value, and belonged to growing population because of the greater proportion of T. mandshurica seedling individuals. Fraxinus rhynchophylla and T. mongolica populations were of stable populations. T. mandshurica population had significant negative correlations with F. rhynchophylla and T. mongolica populations on large scale, and was in clumped distribution.
    Relationship between phytoplankton community in summer and environmental factors in Shanghai park lakes.
    BO Fang-fang;YANG Hong;ZUO Zhuo;YOU Wen-hui
    2009, 28(07):  1259-1265 . 
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    In order to understand the phytoplankton community structure and the phytoplankton’s demands for environment in Shanghai park lakes, a field survey was conducted in 11 park lakes in Shanghai in July and September 2008, with the relationships between the distribution of phytoplankton species and the environmental factors analyzed. A total of 384 species were identified, belonging to 8 phyla. The phytoplankton density ranged from 201×105〖KG-*2〗-〖KG-*7〗5760×105 cells·L-1. The phytoplankton community was mainly composed of Cyanophyceae, Euglenophyceae, Bacillariophyceae, and Chlorophyceae, and the dominant species were Oscillatoria subtillissima, Dactylococcopsis irregularis, Euglena caudata, Melosira granulata, Cyclotella meneghiniana, Chlorella vulgaris, and Scenedesmus quadricauda. The main environmental factors affecting the distribution of phytoplankton species in July were ammonium-nitrogen, dissolved oxygen, water temperature, and total phosphorus, while those in September were pH, water temperature, dissolved oxygen, transparency, and total nitrogen. Water transparency and zooplankton were the main factors affecting the biomass of Cryptophyceae, Pyrrophyceae, and Bacillariophyceae; while nitrogen, phosphorous, and dissolved oxygen were the main factors affecting the biomass of Cyanophyceae, Euglenophyceae, and Chlorophyceae.
    Community composition of phytoplankton in controlled enclosure system at low salinity levels.
    ZHA Guang-cai
    2009, 28(07):  1266-1271 . 
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    Experimental enclosures were set up in prawn (Litopenaeus vannamei) culture pond to study the community composition and its dynamics of phytoplankton at low salinity levels (2‰-6‰). A total of 86 phytoplankton species were identified, belonging to 7 phyla and 58 genera. There were 50 species of Chlorophyta (581% in species abundance), 18 species of Cyanophyta (209%), 9 species of Bacillariophyta (105%), 4 species of Euglenophyta (47%), and 3 species of Cryptophyta (35%). Dictyosphaerium pulchellum, Ankistrodesmus angustus, Scenedesmu sp., Microcystis aeruginosa, Cylindrospermopsis raciborskii, Cyclotella meneghinian and Chroomonas acuta were the dominant species. In the early period of phytoplankton cultivation, the majority of the dominant species was of Chlorophyta, and its subrogation was rapid; while in the mid and late periods, Cyanophyta was in predominance, and M. aeruginosa was the dominant species in 60% of the enclosures. The average dominance of dominant species was 596%. The phytoplankton had an average density of 297×107 cells·L-1, and its Shannon-Wiener diversity index was 218. In the enclosures applied with organic manure, phytoplankton species were abundant, diversity and density were higher, and the community was stable, being favorable for prawn growth. Applying large amount of chemical fertilizers was liable to cause harmful M. aeruginosa bloom.
    Effects of methane stress on the ecophysiological characteristics of greenbelt plants.
    YANG Wen-jing1,2; DONG Shi-kui2;ZHANG Xiang-feng2;LIU Xiao-jing1
    2009, 28(07):  1272-1276 . 
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    Methane (CH4) stress is one of the main factors limiting the survival and growth of greenbelt plants on garbage landfill, while the selection of adaptive plants is of significance in the re-vegetation and recovery of the landfill. In this study, two greenbelt plants Medicago sativa and Festuca arundinacea were utilized to testify their adaptability to the CH4 stress in laboratory. The growth rate and net photosynthesis rate of test plants decreased under CH4 stress, but the plants could enhance their CH4-tolerance via the increase of proline accumulation in their organs. M. sativa could also resist the CH4 stress via decreasing its SOD activity. For the two test plants, their proline content could be used as a physiological indicator to judge their resistance to CH4 stress.
    Assessment of heavy metals pollution in abandoned lead-zinc mine tailings in Huize of Yunnan Province.
    FANG Hui1,2;CAO Min1
    2009, 28(07):  1277-1273 . 
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    Based on the analysis of the Pb, Zn, and Cd contents in the soil and plant samples from abandoned Pb-Zn mine tailings in Huize of Yunnan Province, Southwest China, the heavy metals pollution of the reclaimed and abandoned soils in this area was assessed by the methods of single factor pollution index and Nemerow integrated index, respectively. Compared with the Environmental Quality Standard for Soil of China (GB 15618〖KG-*2〗-〖KG-*7〗1995) (EQSSC), the heavy metals contents in the reclaimed and abandoned soils were higher than the Level 3 pollution defined by EQSSC. The total contents of Cd, Zn, and Pb in reclaimed soil were as 350, 280, and 113 times as Level 3 of EQSSC, whereas those in abandoned soil were as 407, 376, and 167 times as Level 3 of EQSSC, respectively. The assessment with single factor pollution index indicated that the severity level of heavy metals pollution was Cd>Zn>Pb, all in the heavy-pollution category, and the assessment with Nemerow integrated index also showed that the study area had been heavily polluted. The main causes of the pollution were the mine tailings and the local heavy metals-extracting techniques. As a result, the reclaimed soil might not be suitable for farming any more. In the polluted soils, there were certain kinds of wild plants still growing well, and some of them had strong capability to absorb and transmit heavy metals, being able to be used for the bioremediation of the polluted soils.
    Effects of cadmium, lead, and their combined pollution on some physiological indices of Brassia campestris.
    YANG Jin-feng1;BU Yu-shan2;DENG Hong-yan1
    2009, 28(07):  1284-1287 . 
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    A pot experiment was conducted to study the physiological responses of Brassia campestris to cadmium (Cd), lead (Pb), and their combined pollution. When treated with Cd alone, the plant nitrate reductase activity and root vigor all increased at lower Cd but decreased at higher Cd, suggesting that B. campestris had definite Cd-tolerance capability at lower concentration Cd but was damaged by higher concentration Cd. In treatments Pb alone and Pb + Cd, the nitrate reductase activity and root vigor all decreased with increasing concentrations of Pb and Cd. When treated with Cd or Pb alone, the free proline content in B. campestris roots increased with increasing concentrations of Cd and Pb, and was signi ficantly higher when treated with Cd than with Pb, which further confirmed the h igher toxicity of Cd. The root proline content was higher when treated with Pb + Cd than with Pb or Cd alone, suggesting that the combined pollution of Cd and P b promoted the accumulation of proline in roots, and Pb enhanced the Cd toxicity . The mechanisms of Cd-Pb interaction are deserved to be further studied.
    Effects of long-term fertilization on vegetable field soil microbial characteristics.
    ZHANG En-ping;GAO Wei;ZHANG Shu-hong;LI Tian-lai
    2009, 28(07):  1288-1291 . 
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    Soil samples were collected from a long-term fertilized vegetable field to study the effects of different fertilization treatments on the ecological characteristics of soil microbes. Comparing with applying inorganic fertilizers alone, a combined application of organic manure and inorganic fertilizers increased the amounts of soil bacteria and actinomycetes significantly, and enhanced the fungal diversity. The amount of soil bacteria and the diversity and evenness of soil fungi were significantly higher in treatment organic manure plus low level nitrogen than in other treatments. Applying high level nitrogen alone decreased the amount of bacteria significantly, and the diversity and evenness of soil fungi were obviously lower than the control.
    Effects of elevated O3 and CO2 on Pinus tabulaeformis antioxidant system.
    LU Tao1,2;HE Xing-yuan1;CHEN Wei1
    2009, 28(07):  1316-1323 . 
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    Pinus tabulaeformis seedlings were planted in opened top chambers (OTCs) and exposed to 80 nmol·mol-1 of O3, 700 μmol·mol-1 of CO2, and 80 nmol·mol-1 of O3 plus 700 μmol·mol-1 of CO2 for four months to study the effects of elevated O3 or/and CO2 on their antioxidant system. Elevated O3 increased the H2O2 content in P. tabulaeforims needles significantly, which in turn depressed the activities of antioxidant enzymes such as SOD and APX, and exhausted the important antioxidant ASA, leading to a serious lipid peroxidation in the late exposure period. Elevated CO2 lowered the antioxidant enzyme activities and enhanced the ASA content in P. tabulaeformis needles, possibly due to its promotion effect on the synthesis of ASA or its reduction effect on ASA consumption, and thus, alleviated the oxidative stress, which was validated by the significantly lower H2O2 content and lipid peroxidation product (MDA) in the needles in the late exposure period. Comparing with those exposed to elevated O3, the P. tabulaeformis needles exposed to elevated O3 plus elevated CO2 had higher antioxidant enzyme activities and ASA content, illustrating that elevated CO2 abated the depression of antioxidant enzyme activities and the exhaustion of ASA content in P. tabulaeformis needles caused by elevated O3, and subsequently, alleviated the O3-induced oxidative damage in P. tabulaeformis.
    Colonization of arbuscular mycorrhizae in Magnolia cylindrica roots.
    YANG An-na1,2;ZHENG Yan1,2;CAO De-hua1;CHENG Cheng1
    2009, 28(07):  1292-1297 . 
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    The colonization of arbuscular mycorrhizal fungi (AMF) in the roots and rhizosphere soils of rare species Magnolia cylindrica sampled from its native and cultivation habitats was examined by the methods of alkaline lysising and acid fuchsin staining. All the M. cylindrica root samples were found be colonized by AMF and formed typical Paris-type AM. The AMF colonization in the root samples from native habitat was higher than that from cultivation habitat. Five genera and 22 species of AMF were isolated and identified from the rhizosphere soils by wet-sieving, and the similarity coefficient of AMF community between the two sampling sites was 096. The spore density of AMF was higher in the native habitat than in the cultivation habitat, but the reverse result was showed on Shannon-Wiener diversity index. It was suggested that the planting of M. cylindrica might not induce a great change in the community composition of AMF in rhizosphere soil.
    Responses of soil nitrogen mineralization to temperature change along an elevation gradient in Wuyi Mountains, China.
    XU Xian-gen1;ZHOU Yan1;RUAN Hong-hua1;HAN Yong1;YU Hua1;CAO Hui-min1;WANG Jia-she2;XU Zi-kun2
    2009, 28(07):  1298-1302 . 
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    Aimed to examine the sensitivity of soil N mineralization to temperature change, soil samples were collected along an elevation gradient with four plant communities (evergreen broadleaf forest, coniferous forest, subalpine dwarf forest, and alpine meadow) in Wuyi Mountains Fujian of China. The soils were put in PVC tube, adjusted to 60% of field water-holding capacity, and incubated at 5 ℃, 15 ℃, 25 ℃, and 35 ℃ for 30 days, with their net N mineralization amount and N mineralization rate determined. For the soils from same altitudes, their net N mineralization amount and N mineralization rate increased significantly with increasing temperature; while for the soils from different altitudes, the two indices were in the order of subalpine dwarf forest> evergreen broadleaf forest>alpine meadow>coniferous forest. The Q10 value of soil N mineralization fluctuated between 103 and 154. The Q10 from 15 ℃ to 25 ℃ was higher than that from 5 ℃ to 15 ℃ and from 25 ℃ to 35 ℃, indicating that soil N mineralization was more sensitive to the temperature from 15 ℃ to 25 ℃.
    Effects of exogenous humic acids on soil phosphorus adsorption and desorption.
    YANG Kai1,3;GUAN Lian-zhu2;YAN Li2;ZHU Jiao-jun1;HE Jing4
    2009, 28(07):  1303-1307 . 
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    With red soil, brown soil, and drab soil as test soils, a laboratory incubation test was conducted to study the effects of exogenous humic acids on soil phosphorus (P) adsorption and desorption. Comparing with the control, applying humic acids decreased the adsorbed amount of P in soils, with the sequence of drab soil > red soil > brown soil. Humic acid application increased the desorbed amount and desorption rate of P in red soil and brown soil, the increment varied with the kinds of exogenous humic acid, but had less promotion effect on the P desorption in drab soil. The effects of exogenous humic acids on soil P adsorption and desorption were most obvious in red soil, followed by in brown soil, and in drab soil. Applying humic acids could enhance the P utilization rate in red soil and brown soil.
    Chemical properties of litter layers in coniferous forests of western Qinling Mountains.
    CHANG Ya-jun1;CAO Jing1;LI Jian-jian2;PAN Chun-lin3;CHEN Qi1;MA Li-de1
    2009, 28(07):  1308-1315 . 
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    Litterfall is the link between plant and soil, and the key in nutrient and energy cycling of forest ecosystem. The return of nutrients to forest floor and soil is controlled by the litterfall production and its elements concentration. By the methods of field investigation and laboratory analysis, the characteristics of the litter layers in coniferous forests of western Qinling Mountains, including the amount of litterfall and the content and storage of mineral elements in litter layer, were studied. In the test forests, the existing amount of litterfall varied from 846 to 2981 t·hm-2, and the annual litterfall ranged from 296 to 423 t·hm-2·a-1, indicating that the decomposition rate of the litterfall was relatively low, and the turnover of the nutrients was slow. The nutrient contents in litter layer varied significantly with tree species, but the nutrient storage in the litter layers of different tree species showed the same tendency of un-decomposed layer (U layer) < half-decomposed layer (S layer) < decomposed layer (D layer). The average storage of nutrients in the litter layers under different tree species was 35771 kg·hm-2 of Ca, 17572 kg·hm-2 of N, 10250 kg·hm-2 of Fe, 5421 kg·hm-2 of Mg, 3196 kg·hm-2 of K, and 1678 kg·hm-2 of P. The decomposition of litterfall resulted in the accumulation of mineral nutrients in decomposed layer (D layer), and different tree species and different management practices had greater effects on the properties of litterfall and its decomposition rate. The decomposition rate of litterfall was in the order of spruce forest<pine forest<larch forest.
    Effects of straw return pattern on the degradation of Bt protein released from Bt corns in field.
    WANG Jian-wu;FAN Hui-zhi;FENG Yuan-jiao
    2009, 28(07):  1324-1329 . 
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    By using litterbag method, this paper studied the degradation of Bt protein released from Cry1Ab Bt corns 1246×1482 and H9235Bt/RR under two straw return patterns, i.e., buried in soil and covered on soil surface, and the DT50 and DT90 were fitted and estimated by shift-log model. Under the two straw return patterns, more than 90% of the Bt protein from the two Bt corns were degraded within one week, only 0004%〖KG-*2〗-〖KG-*7〗0069% of their initial Bt protein being detected after the Bt corn straws returned to field for 180 days. Less difference was observed in the degradation of Bt protein from Bt corn 1246×1482 under different straw return patterns, with the DT50 and DT90 being 090 d and 345 d when the straws were buried in soil, and 079 d and 503 d when covered on soil surface, respectively. However, the degradation of Bt protein from H9235Bt/RR was manifestly affected by the straw return pattern. At the early stage of straw return, the degradation rate of Bt protein from H9235Bt/RR was lower when the straws were buried in soil than covered on soil surface, with DT50 and DT90 being 680 d and 2176 d, and 054 d and 712 d, respectively. It was suggested that the Bt protein both from Bt corn 1246×1482 and from H9235Bt/RR could be degraded rapidly in field, and straw return pattern only affected the degradation of Bt protein from H9235Bt/RR, with a much higher degradation rate when the straws were covered on soil surface.
    Protein expression of two Spiraea species under effects of cold acclimation and de-acclimation.
    LIU Hui-min;YAN Yong-qing;CHE Yan-shuang;FENG Nan-nan;ZHANG Chao;FAN Chao;CHE Dai-di
    2009, 28(07):  1330-1334 . 
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    By the method of two-dimensional electrophoresis, this paper studied the effects of cold acclimation and de-acclimation on the protein expression of two Spiraea species with different cold resistance and photosynthesis capability. During cold acclimation and de-acclimation, S. bumalda ‘Goldmound’ produced cold acclimation-induced protein, while S. fritschiana did not. Two-dimensional electrophoresis indicated that after cold acclimation, S. fritschiana and S. bumalda ‘Goldmound’ had different protein expression. Through MS identification, there were three kinds of protein conspicuously expressed, two of which were unknown new proteins, their partial amino acid sequences being VSHLAGFSSNNPK and LKADKPTLLSEAK, and DPNDHPNPFTVK, DGNGFFLYLLDPDSSK, and NGDGMFLYLLDGLESK, respectively, and the other was ascorbate peroxidase, an enzyme closely related to photosynthesis. Cold acclimation made the ascorbate peroxidase in the two Spiraea species changed significantly.
    Toxicity of dibutyl phthalate to cladoceran Moina macrocopa.
    WANG Jin-xia;XI Yi-long;LIU Xiao-bo;CHEN Yan;HE Zhong-wen
    2009, 28(07):  1335-1339 . 
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    Acute toxicity and life-table experiments were conducted to study the acute toxicity of dibutyl phthalate (DBP) and its effects on the life table demographic parameters of freshwater cladoceran Monia macrocopa. The 48 h LC50 of M. macrocopa for DBP was 968 mg·L-1. DBP at 005〖KG-*2〗-〖KG-*7〗5000 μg·L-1 did not significantly affect the life expectancy at birth and the gross and net reproductive rates, but significantly affected the generation time and intrinsic rate of population increase of M. macrocopa (P<005). Comparing with the control, DBP at 5000 μg·L-1 significantly decreased the generation time, but increased the intrinsic rate of population increase.
    Community characteristics and seasonal changes of macrozoobenthos in intertidal zones of Hengsha and Changxing islands at Yangtze River estuary.
    TAO Shi-ru;JIANG Li-fen;WU Ji-hua;ZHAO Bin;LI Bo
    2009, 28(07):  1345-1350 . 
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    Macrobenthic faunas were sampled at nine sites in the intertidal zones of Hengsha and Changxing islands in October (autumn) 2006 and April (spring) 2007 to study the community characteristics and spatiotemporal patterns of macrozoobenthos in the study area. A total of 13 macrozoobenthos species were identified, belonging to Crustacea (2 species), Mollusca (3 species), Polychaeta (3 species), and others (5 species). The density and biomass of the macrozoobenthos had less difference between spring and autumn, but had significant differences between Hengsha Island and Changxing Island (P<005), being higher at the sites of Hengsha Island. In autumn 2006, the density of macrozoobenthos was significantly higher in mid-intertidal zone than in high- and low-intertidal zones (P<005); while in spring 2007, this density was lower in low-intertidal zone than in the other two zones (P<005). However, the biomass of macrozoobenthos had no significant differences among the three intertidal zones both in autumn 2006 and in spring 2007. There were no significant differences in the biomass between seasons except for low-intertidal zone (P<0.05). The diversity and evenness indices of the macrozoobenthos had no significant differences between seasons and among sampling sites. Bray-Cutis and MDS analysis also showed that there were no significant differences in the macrozoobenthic communities among the sampling sites.
    Impact of tea gardens managed with different cultivation methods on stream benthic macroinvertebrate communities.
    CHEN Ai-qing1,2;XIONG Xing-ping2;WANG Bei-xin1;JIANG Li-hong1;LAN Ce-jie1
    2009, 28(07):  1340-1344 . 
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    The impact of tea garden on stream water quality and benthic macroinvertebrate communities is of growing concern. In April 2007, an investigation was made on the water quality and benthic macroinvertebrates at 17 sites in the first and second order streams in Zhejiang Province of China, among which, 12 sites were disturbed by the tea gardens managed with common cultivation method or green and organic cultivation methods in the hills and plains in Songyang and Fuyang counties and in the mountains in Jiande and Wuyi counties, and 5 reference sites were not disturbed by the tea gardens in the hills and mountains in Fuyang and Jiande counties. The ammonium nitrogen, total nitrogen, total phosphorus, chemical oxygen demand, and conductivity in the streams disturbed by tea gardens were higher than those in reference streams. The total nitrogen (5506 mg·L-1) and total phosphorus (0053 mg·L-1) in the streams disturbed by hilly tea gardens were about two times higher than those in the streams disturbed by mountain tea gardens, and the richness of benthic macroinvertebrate in the streams disturbed by hilly tea gardens was significantly lower than that in reference streams (P<001). No significant difference (P<005) was observed in the richness of benthic macroinvertebrate between the streams disturbed by mountain tea gardens and the reference streams. Non-metric multidimensional scaling (nMDS) analysis of Bray-Curtis species similarities showed that the benthic macroinvertebrate communities in the streams disturbed by mountain tea gardens and in the reference streams had the highest species similarity (stress value=009), followed by those in the streams disturbed by plain tea gardens and croplands.
    Key issues of ecological migration in northern deserted areas of China.
    ZHANG Li-xiao1;LIU Jie2
    2009, 28(07):  1394-1398 . 
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    In this paper, the concept of ecological migration was redefined, both in connotation and in extension. It was considered that ecological migration was the involuntary migration implemented by government, aimed to protect, restore and recover the seriously degraded local ecosystem. The underlying relationship between land desertification and ecological migration in northern China was analyzed from the aspects of self-examination of anti-desertification strategies and of population threshold for serious land degradation, which suggested that effective coordinating mechanism of human-land relationship could be worked via ecological migration activities. The groundwork, characteristics, and problems associated with the pilot projects of ecological migration in northern China were summarized after investigating two pilot ecological migration villages of Malaqin and Luanjingtan. The most urgent task at present was to push the assessment and monitoring work associated with ecological migration to reduce the economic, ecological, and societal risks.
    Bug diversity in habitats with Kerria yunannensis cultivation.
    CHEN Yan-lin1;CHEN You-qing2;LI Qiao1;SHU Zhe-jun1;YANG Xi1
    2009, 28(07):  1351-1355 . 
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    The bug communities in a secondary forest having cultivated Kerria yunannensis for five years (plot Ⅰ), and in the plantations having cultivated K. yunannensis for three years (plot Ⅱ), one year (plot Ⅲ), and zero year (plot Ⅳ) in Lüchun County of Yunnan Province were investigated by sweep netting method. A total of 423 specimens were collected, representing 47 species in 7 families of Heteroptera. The species composition and diversity of the bug communities differed with the plots. In plot I, the species richness was higher, while the diversity was moderate because of the more Cletomorpha insignis individuals. Among the plantations, plot Ⅳ was richest in species, lowest in dominance, and highest in evenness and diversity, followed by plot Ⅲ, and plot Ⅱ. With the increasing year of K. yunannensis cultivation, the species richness and diversity of bug communities tended to decrease because of their competition with lac insects.
    Mechanisms of enzyme-catalyzed dissimilatory Fe(Ⅲ) reduction and its molecular regulation: A review.
    HUANG Can1,2;WU Hong-dong2;HE Qing-ming2;PENG Xu-ya1,2
    2009, 28(07):  1381-1387 . 
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    Dissimilatory Fe(Ⅲ)-reducing bacteria are spread throughout the domain of bacteria and archaea. They are phylogenetically diverse and have been isolated under various environment conditions. Unlike other electron acceptors, Fe(Ⅲ) has a very low solubility and exists primarily as insoluble Fe oxide under neutral pH. At present, the mechanisms of gathering and reducing Fe(Ⅲ) are still poorly understood. Taking Shewanella and Geobacter as examples, this paper reviewed three kinds of possible mechanisms of microbial enzyme-catalyzed dissimilatory Fe(Ⅲ) reduction and its molecular regulation, i.e., direct contact between microbial cell and Fe(Ⅲ) oxides, siderrophores, and electron shuttling compounds. Many membrane-bound cytochrome proteins are involved in the dissimilatory Fe(Ⅲ) reduction, forming a complicated regulation network. This paper also proposed future research directions on the mechanisms of enzyme-catalyzed dissimilatory Fe(Ⅲ) reduction so as to better understand this important biochemical process.
    Effects of climate and its change on the occurrence of oriental migratory locust around Bohai Bay.
    YAO Shu-ran1;HUO Zhi-guo2;GUAN Fu-lai3;LI Chun-qiang1
    2009, 28(07):  1356-1360 . 
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    Based on the investigation data of oriental migratory locust occurrence and corresponding meteorological records, a comprehensive analysis was made on the relationships between the occurrence of the locusts and the climate factors in coastal and low-lying locust areas around Bohai Bay. The difference in the locust occurrence between these two areas was mainly due to the effects of climate factors, and air temperature was the main one. The air temperature in March and April was 02 ℃〖KG-*2〗-〖KG-*7〗04 ℃ lower in coastal than in low-lying locust area, resulting in 2〖KG-*2〗-〖KG-*7〗3 days delay of the occurrence of summer locust nymphs before third phase in coastal locust area. In other months, the air temperature in coastal locust area was higher, and due to the accumulative effect of air temperature, the occurrence of summer locust nymphs after third phase took place earlier. The occurrence of autumn locusts had a smaller variation than that of summer locusts, which was corresponded to the small change of air temperature in summer. The different change pattern of air temperature in the coastal and low-lying locust areas around Bohai Bay since the 1990s was the main cause for the variations of locust phase, and the summer locust occurrence happened sooner or later was closely related with the air temperature in March and April.
    Characteristics of avian communities in winter in Shahu of Hubei Province, China.
    LUO Zu-kui1,2;YUE Feng1;WU Fa-qing2;LOU Li-gao3;SHU Shi2;WANG Tian-hou1
    2009, 28(07):  1361-1367 . 
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    By the method of line transect, a bird survey was conducted in the Shahu Nature Reserve of Hubei Province from December 2006 to January 2007. According to the habitat characteristics, the avian communities were classified into four catalogues, i.e., reed community, grassland community, farmland community, and water area community. A total of 76 bird species was recorded, which belonged to 28 families and 12 orders, accounting for 1667% of 456 bird species in the Province. Among the bird species recorded, 1 species was in the Grade Ⅰand 10 species was in the Grade Ⅱ national key protected birds, 1 species belonged to endangered species, 2 species belonged to vulnerable species, and 1 species belonged to rare species. The overall α diversity index (H′), evenness (J), and predominant index (C) of the avian communities were 237, 055, and 017, and the H′, J, and C were 167〖KG-*2〗-〖KG-*7〗244, 050〖KG-*2〗-〖KG-*7〗086, and 011〖KG-*2〗-〖KG-*7〗026, respectively. The similarity index (Si) of farmland-grassland avian communities was the highest (074) while that of farmland-water area avian communities was the lowest (040), and the Bray-Curtis (CN) index of reed-grassland avian communities was the highest (000640) while that of farmland-water area avian communities was the lowest (000022). Inter-habitat’s heterogeneity and human activities were the main factors affecting the characteristics of the avian community in Shahu in winter.
    Spatial patterns of habitation areas in conurbations of central Liaoning Province.
    ZHANG Jian-zhong1;TANG Ling2,3;LI Xiao-yu2;CHEN Wei2;GAO Yan-ni2,3;ZHANG Guo-you2,3;WANG Hou-jun4
    2009, 28(07):  1368-1372 . 
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    Based on the Landsat TM image in 2006 and by using Erdas and ArcGIS software, in combining with the theories of regionalization and settlement geography, the spatial patterns of the habitation areas in the conurbations of central Liaoning Province were studied. In the test habitation areas, small patches occupied a large proportion, with the patches smaller than 1 km2 accounted for 96.38% of all patches. Shenyang and some other conurbations took up the main position in the habitation areas. The habitation areas could be regionalized into east region, Shenyang region, and west region. Shenyang region had the largest average patch area and the highest urbanization; west region had the highest patch density and the densest habitation area; while east region had the smallest average patch area and the lowest patch density, with the development of habitation area being slower than the other two regions. The habitation areas in the three regions were in stochastic distribution, but the reference index (the nearest index) differed obviously among the regions. Centric cities had great effects on the distribution of habitation areas, with the radiation range in the sequence of Shenyang > Anshan > Tieling > Yingkou > Liaoyang > Benxi > Fushun.
    Eco-physiological effect of calcium imbalance caused by environmental acidification: A review.
    WU Fei-hua1,2;PEI Zhen-ming2;ZHENG Hai-lei1,2,3
    2009, 28(07):  1373-1380 . 
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    Environmental acidification is one of the major problems caused by global climate change. Due to the long-term effects of acid rain, the pH of terrestrial and lake ecosystems presents a declining trend, and in the meanwhile, acidification of marine ecosystem also occurs because of the dramatic increase of atmospheric CO2 concentration. Calcium homeostasis in organisms or/and ecosystems can be disturbed by environmental acidification. In marine ecosystem, calcium-rich species will have difficulties in maintaining their external calcium carbonate skeletons, resulting in the declining of coral calcification and the corroding of pteropod shell. With the decrease of ocean pH and carbonate ion concentration, the reproduction of marine organisms may be declined. In terrestrial ecosystem, organisms cannot absorb enough essential calcium because large quantity of bio-available calcium has been depleted from the ecosystem by the long-term acid rain. Therefore, anthropogenic acidification has caused the decline in calcium-rich species populations such as snail and Daphnia in soil and fresh waters, and birds also have low reproductive success as a result of calcium deficiency under long-term acid rain stress. In plants, acid rain disturbs calcium signal transduction cascades, and further, negatively affects physiological processes such as photosynthesis, stress-resistance, and reproduction, with the ecological consequences such as primary productivity and biodiversity decrease and forest decline. It may be a universal ecological pattern that calcium-rich species will be much more difficult in survival under the scenario of calcium homeostasis in ecosystems being disturbed by environmental acidification.
    Application of natural enemies in biological control of Lantana camara.
    GUI Fu-rong1,2;LI Zheng-yue1;WAN Fang-hao2
    2009, 28(07):  1388-1393 . 
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    Alien species invasion is one of factors seriously threatened the biodiversity worldwide, giving significant impacts on economy, ecology, and social security. Lantana camara is a perennial woody shrub native to the tropical and sub-tropical zones of the Americas, and now, is a major invasive weed in many regions of the world, invading both natural and agricultural ecosystems. The present paper summarized the application of natural enemies of L. camara, including predatory insects and pathogens, and assessed the biological control efficiency of these natural enemies. Further studies on L. camara, such as its molecular ecology, were also suggested.
    Problems and countermeasures of agricultural environment in China.
    REN Jing-ming1,2;YU Yuan-xiu1,2; WANG Ru-song1
    2009, 28(07):  1399-1405 . 
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    The problems of agricultural environment in China were summarized systematically from the aspects of agricultural natural resources, eco-environment destruction, and environmental pollution. Their causes were analyzed, and the countermeasures were put forward. As a whole, our agricultural natural resources were in shortage and polluted heavily, agro-ecological environment destruction was quite serious, agricultural non-point pollution from fertilizers, pesticides, and plastic film became more and more serious, and the improper disposal of straw, contamination of livestock and birds breeding, rural living pollution, contamination by township enterprises, and the pollution transferred from cities deteriorated agricultural environment. These problems were correlated with some agricultural policies to a large extent. In addition, the imperfect legislation in agro-environmental protection, the lack of effective law execution, the weak awareness in environmental protection, and the imperfect environmental management system were all the main reasons of agro-environmental problems. Based on these causations, several countermeasures were put forward to solve the problems of agro-environment, i.e., to develop strategic environmental assessment of agricultural policy, pay attention to ecological construction, promote the resources to be used in high efficiency, develop eco-agriculture, control the inputs of agro-chemicals reasonably, implement cleaner production in planting industry, enhance the inspection and management of the contamination of livestock and birds breeding, constitute prompting mechanism, reduce agricultural non-point source pollution, establish regulatory mechanism of rural environment, and strengthen publicity and education to improve the environmental awareness of farmers.
    Application and development of vetiver system in China: Twenty years retrospection.
    XU Li-yu
    2009, 28(07):  1406-1414 . 
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    Vetiver system is a low cost and effective system which has been used for soil and water conservation, infrastructure protection, pollution control and treatment, and natural disaster prevention. It is already 20 years past since it was introduced to China in 1988. This paper reviewed the research and application of vetiver system in our agriculture, slope stabilization, and environmental protection, introduced the development and roles of China Vetiver Network, and proposed the potential of vetiver system in barren land afforestation, mine tail re-vegetation, bio-fuel, and green house effect relief.
    Effects of shading on biomass allocation and morphological characteristics of Dichondra repens.
    ZHU Xiao-feng;ZHOU Shou-biao;ZHENG He-quan;YANG Ji-hui;LIU Shou-feng
    2009, 28(07):  1419-1422 . 
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    A pot experiment was conducted to study the biomass allocation and morphological characteristics of Dichondra repens under different levels of shading (100%, 66%, 205%, and 9% transparency). With the increase of shading, the biomass per plant decreased after an initial increase, being the maximum under 66% transparency. The biomass allocation per plant also varied with increasing shading. Leaf mass ratio and petiole mass ratio increased while root mass ratio decreased, and stem mass ratio increased first and decreased then. The branching angle decreased with increasing shading, and the stem length, branching intensity, leaf area, and petiole length decreased after an initial increase. D. repens had definite adaptability to varied light environment. Moderate shading benefited the growth and development of D. repens, i.e., increased the modular numbers and biomass accumulation, while high light intensity or high shading did harms to D. repens growth.
    Technical difficulties and solutions of subsurface infiltration system in domestic wastewater treatment.
    LI Ying-hua1,2;SUN Tie-heng1,2,3;LI Hai-bo1;HU Xiao-min2
    2009, 28(07):  1415-1418 . 
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    Natural wastewater treatment system exampled by land treatment system is based on the principles of recycling and reusing wastewater, harmonious with the environment, unified optimization, and differencing with the positions. Land wastewater treatment technology cannot only remove most of the pollutants in domestic wastewater, but also made it with high reusing rates. In order to promote the technical innovation of this kind of wastewater eco-treatment system and its wide application in China, and to provide a scientific and technical basis for the system implementation, a discussion was made on the subsurface wastewater infiltration system. Its process, characteristics, and principles were introduced, and the technical challenges in its application and corresponding solutions, including substrate choosing methods and the ways to relieve soil collision and enhance nitrogen removal were presented. The authors suggested that strengthened pretreatment should be emphasized, and the ways for raising hydraulic load should be adopted.
    Effects of thermal acclimation and performance temperature on locomotive performance of Polyrhachis vicina.
    SU Li-na1; LI Xiao-chen2
    2009, 28(07):  1423-1426 . 
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    Beneficial acclimation hypothesis (BAH) predicts that the animals acclimated to a particular temperature can enhance their performance and fitness at that temperature, in comparison with those acclimated to other temperatures. Taking Polyrhachis vicina as test object, this paper studied its locomotive performance under effects of thermal acclimation and performance temperature. The P. vicina adults were divided into two groups and acclimated to 20 ℃ and 30 ℃ for four weeks, respectively, and after then, their pause frequency, sprint speed, and maximum continuous locomotion distance were measured at 20 ℃ and 30 ℃. It was indicated that the acclimation temperature, performance temperature, and their interaction had significant effects on the locomotive performance of P. vicina. The P. vicina adults acclimated to a particular temperature performed better at that temperature than those acclimated to a different temperature, which supported the BAH.
    Determination of soil meso- and microfauna biomass.
    WANG Run-run; LIU Xin-min
    2009, 28(07):  1427-1429 . 
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    Because of the smaller body size of soil meso- and microfauna, no meth ods are preferable for the direct determination of their biomass; while model es timation, as an indirect method, is not widely used due to its time-consuming. Therefore, there is a lack of the index soil meso- and microfauna biomass in mos t published literatures. In this paper, potassium dichromate volumetry and chlor oform fumigation extraction were adopted to determine the organic carbon content of soil meso- and microfauna, and the obtained data were compared with those of model estimation. The results showed that potassium dichromate volumetry had the advantages of rapid and easily handling, being available for the batch dete rminations of soil meso- and microfauna biomass.
    Proposed procedure in designing and planning stratified random selection investigation of urban vegetation.
    ZHAO Juan-juan1;OUYANG Zhi-yun1;ZHENG Hua1;XU Wei-hua1;WANG Xiao-ke1; NI Yong-ming2
    2009, 28(07):  1430-1436 . 
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    Systematic design and planning of investigation processes is the fundamental guarantee of successful vegetation survey and scientific data analysis. Urban plants are under intense disturbance by human activities, and the resulted urban style of vegetation structure and open space composition makes the detailed planning of vegetation investigation become undoubtedly necessary. However, for such an important issue, few studies have been reported. As a most commonly used method of urban vegetation investigation, stratified random selection investigation is the topic of this paper. Based on enormous publications and practical experiences, the authors proposed the systematic processes of investigation planning, with the details and points of attention for field work of urban vegetation survey introduced. The main body of urban vegetation investigation was divided into three parts, i.e., sampling design, plots design, and field work details. Sampling design was mainly concerned with the boundary and size of research area, stratification rules, and distribution principles for sampling efforts; plot design involved the determination of sampling unit and plot size; and field work details mainly involve a list of specific items to be investigated, processes to be conducted, apparatus to be prepared, staffs to be coordinated, and other details to ensure the accuracy and precision of the data and the smooth going of the investigation.