Spatial heterogeneity of available zinc, copper, and manganese in Xiangcheng tobacco planting fields, Henan province, China

Geostatistical methods were used in combination with geographical information system (GIS ) technology to analyze the spatial distribution characteristics of available zinc, copper, and manganese in the Xiangcheng tobacco planting fields, Henan province, China. Analysis of the isotropic variogram indicated that the Zn semivariogram was well described with the Gaussian model, with the distance of spatial dependence being 900.7 m; while the Mn semivariogram was well described with spherical models, with the distance of spatial dependence being 14 060 m; and, the Cu semivariogram was well described with exponential models, with the distance of spatial dependence being 27 860.7 m. Mn and Zn were strongly spatially dependent, with the C₀/sill being 0.014 and 0.147 in this given region; while Cu was moderately spatially dependent, with the C₀/sill being 0.3528. With the kriging analysis, the spatial distribution maps of contents of these three trace elements in the Xiangcheng tobacco planting regions was drawn with the Arcview software. It was found that the soils with higher content of Mn were mainly distributed in the high mountains of the southern part of the given regions, while the soils with higher content of Cu were mainly distributed in the south, decreasing from the south to the north. The soil with contents of Zn in the range of 0.76–1.33 mg/kg existed in the high mountains of the west and middle parts of the investigated regions, accounting for 76.11% of the whole area.     

Spatial variability of soil fertility factors in the Xiangcheng tobacco planting region, China

It is essential to understand the spatial variability of soil properties in tobacco planting regions, so that the right decision can be made as to how many fertilizer rates are likely to be appropriated for the highquality tobacco production. A total of 159 soil samples were taken from the surface soil (0-20 cm) in the Xiangcheng tobacco planting fields, Henan Province, in April 2002 to examine the concentration of soil organic matter, pH, available N, available P, and available K. The spatial variability was evaluated using geostatistics and geographic information system (GIS) analyses. The results show that among those five soil fertility factors, the variation coefficient of soil pH was the smallest, while that of available P was the greatest, which resulted from different cultivation methods and uneven fertilization. Analysis of the isotropic variogram indicated that the soil pH, organic matter, and available P semivariogram were well described with spherical models, with the distance of spatial dependence being 21020, 19150, and 8460 m, respectively, whereas the available N and available K semivariogram were well described with an exponential model, with the distance of spatial dependence being ranged from 7484 to 25320 m. Soil pH value was strongly spatially dependent with C0/sill being 0.1935, while the other four soil fertility factors were moderately spatially dependent with C0/sill ranging between 0.3528 to 0.5260. Through the Kriging analysis, the spatial distribution maps of soil properties were drawn using the arcview software. This study provides a scientific basis for field management, which targets soil quality improvement in the Xiangcheng tobacco planting region.     

Spatial variability of soil fertility factors in the Xiangcheng tobacco planting region, China

It is essential to understand the spatial variability of soil properties in tobacco planting regions, so that the right decision can be made as to how many fertilizer rates are likely to be appropriated for the high-quality tobacco production. A total of 159 soil samples were taken from the surface soil (0-20cm) in the Xiangcheng tobacco planting fields, Henan Province, in April 2002 to examine the concentration of soil organic matter, pH, available N, available P, and available K. The spatial variability was evaluated using geostatistics and geographic information system (GIS) analyses. The results show that among those five soil fertility factors, the variation coefficient of soil pH was the smallest, while that of available P was the greatest, which resulted from different cultivation methods and uneven fertilization. Analysis of the isotropic variogram indicated that the soil pH, organic matter, and available P semivariogram were well described with spherical models, with the distance of spatial dependence being 21020, 19150, and 8460m, respectively, whereas the available N and available K semivariogram were well described with an exponential model, with the distance of spatial dependence being ranged from 7484 to 25320 m. Soil pH value was strongly spatially dependent with C0/sill being 0.1935, while the other four soil fertility factors were moderately spatially dependent with C0/sill ranging between 0.3528 to 0.5260. Through the Kriging analysis, the spatial distribution maps of soil properties were drawn using the arcview software. This study provides a scientific basis for field management, which targets soil quality improvement in the Xiangcheng tobacco planting region.     

南四湖区农田土壤有机质和微量元素空间分布特征及影响因素

基于地统计学和GIS技术相结合的方法,研究了南四湖区农田土壤有机质和微量元素的空间分布特征及其影响因素。结果表明,土壤有机质和微量元素均属中等变异程度,除硼符合正态分布外,其余土壤属性均符合对数正态分布。结构分析表明,除硼为纯块金效应外,土壤有机质和其它微量元素空间自相关性较强,其中结构性因素起主导作用。克里格插值结果表明,土壤有机质分布总体趋势为由北向南逐渐降低,锰、铜、锌分布总体趋势为中部高,南北两端低。影响因素分析表明,土壤类型、耕层质地、坡度、土地利用类型和地貌类型对土壤有机质均有显著影响。土壤类型主要是由于成土母质的差异影响土壤有机质的高低与分布,随质地由砂变粘、坡度由低变高,土壤有机质含量逐步升高,田间管理水平的差异是造成不同土地利用类型下土壤有机质含量差异的主要原因。微量元素中,除硼不受影响外,铁、锰、铜和锌与土壤类型、耕层质地、坡度、土地利用类型和地貌类型密切相关。     

枣园中枣瘿蚊和草间小黑蛛的空间分布格局及空间依赖性

利用地统计学原理和方法,对枣园中枣瘿蚊及其天敌草间小黑蛛种群的空间结构和空间相关性进行了研究.结果表明,6月8日、8月27日、10月19日枣树主要生育期阶段,枣瘿蚊种群的半变异函数模型为球形.在林间基本上呈聚集分布,其样点空间依赖性距离分别为26.3、7.8和22.0 m,其空间依赖性程度分别为88.05%、85.77%和87.58%.草间小黑蛛种群的半变异函数也为球形,呈聚集分布,空间依赖距离分别为28.3、22.5和22.2 m,且在该取样尺度下,总变异中分别有90.09%、87.96%和85.72%是由空间依赖性产生的.两者空间依赖关系说明草间小黑蛛对枣瘿蚊有较强的追随作用.     

沈阳市苏家屯区耕层土壤养分空间变异性研究

利用地统计学和地理信息系统相结合的方法。研究了沈阳市苏家屯区耕地土壤(0～20cm)有机质、速效氮、速效磷、速效钾含量的空间变异性特征。结果表明,各变量符合正态分布或经对数转换后符合正态分布,最佳的变异函数理论模型均为球状模型,有机质具有较强的空间相关性(C0与C0+C比值为24．11％),速效氮、速效磷、速效钾具有中度的空间相关性(C0与C0+C比值分别为29．53％、60．77％、58．82％),各变量的空间自相关距离分别为26．051、28．293、15．132和23．813km。有机质和速效氮的空间变异主要受结构性因子(如成土因子)的影响,速效磷和速效钾主要受随机性因子(如施肥)的影响,Kriging插值绘制出的养分含量空间分布图显示了养分的空间分布格局,它将有助于进一步监测养分动态,为农业和环境管理提供数字地图支持。     

Spatial heterogeneity of DTPA-extractable zinc in cultivated soils induced by city pollution and land use

The spatial heterogeneity of DTPA-extractable zinc in the cultivated soils of Shenyang suburbs in Liaoning Province of China was investigated, and its map was drawn by the methods of geostatistics combined with geographic information system. The data of soil DTPA-extractable zinc fitted normal distribution after logarithm transformation, and its semivariogram fitted a spherical model. The semivariogram indicated that the spatial dependence of soil DTPA-extractable zinc content was moderate, with the spatial dependence range of 1.69 km and the fractal dimension of 1.96. Stochastic factors contributed to 49.9% of the spatial variability, while structural factors contributed to 50.1% of it. The spatial heterogeneity of soil DTPA-extractable zinc shown by a kriged interpolation map was deeply influenced by stochastic factors such as city pollution, land use pattern and crop distributions. For example, the average content of Zn in vegetable garden soils was 2.5-4 times as much as in their originated soils, an     

Spatial heterogeneity of DTPA-extractable zinc in cultivated soils induced by city pollution and land use

The spatial heterogeneity of DTPA-extractable zinc in the cultivated soils of Shenyang suburbs in Liaoning Province of China was investigated, and its map was drawn by the methods of geostatistics combined with geographic information system. The data of soil DTPA-extractable zinc fitted normal distribution after logarithm transformation, and its semivariogram fitted a spherical model. The semivariogram indicated that the spatial dependence of soil DTPA-extractable zinc content was moderate, with the spatial dependence range of 1.69 km and the fractal dimension of 1.96. Stochastic factors contributed to 49.9% of the spatial variability, while structural factors contributed to 50.1% of it. The spatial heterogeneity of soil DTPA-extractable zinc shown by a kriged interpolation map was deeply influenced by stochastic factors such as city pollution, land use pattern and crop distributions. For example, the average content of Zn in vegetable garden soils was 2.5–4 times as much as in their originated soils, and was lower in paddy soils than in their originated soils. The areas with a higher content of soil DTPA-extractable zinc appeared in the near suburbs and the riverside along Hunhe River and the wastewater drainage of Xihe River, and the extremely high values in the near suburb of the city’s residential area were a striking feature, indicating the key role of city pollution in the spatial heterogeneity of soil DTPA-extractable zinc. When recorded in the form of a soil pollution map, the results of such a survey make it possible to identify the unusually polluted areas, and to provide more information for precise agriculture and environmental control.     

海河低平原区农田重金属含量的空间变异性——以河北省肥乡县为例

随着工业和农业的快速发展,农田受到重金属污染的压力越来越大,其土壤环境质量的及时监测和掌握重金属在其空间的变异规律对农业生产具有十分重要的意义。利用地统计学和GIS技术对海河低平原区（肥乡县）农田土壤耕层（0—20Cm）8种重金属含量空间变异性进行了研究。结果表明：去除异常值后,8种重金属含量都符合正态分布,且其含量算术平均值未超过国家土壤环境质量二级标准。通过变异函数分析,Ph和Cr具有纯块金效应,Cu和Zn符合指数模型,Ni和Cd符合球状模型,地和As符合带基台值的线性模型。在该地区以2．0km为取样间距较大,以后调查时应该缩小间隔。Zn和Cd的空间变异性受人为因素影响较小,而Cu、Ni、Hg和As的空间变异性受人为因素影响较大,Ph和Cr在整个研究尺度上具有恒定的变异。Cu、Zn、Ni、Hg、As和Cd的变程差异较大,在2．5—13．7km之间。通过普通kriging法局部插值,Cu、Zn、Ni和As含量由西南部向东北部含量逐步升高,但是Hg却表现出相反的分布趋势。这将为当地正在开展的优势农产品区域布局规划提供理论依据。     

纵向岭谷区公路沿线土壤表层重金属空间分异特征

以纵向岭谷区内云南省境内的丽江～景洪公路沿线作为案例研究区,根据路段所处的地理位置、公路等级、修建的时段,将其分为北段、中段和南段。通过公路沿线94个样点的土壤表层重金属全量分析,研究了土壤重金属沿公路的纵向、横向和垂向分异特征性。在纵向上,Cu,Zn,Pb,Cr,Cd,As,Mg和Mn等8种重金属全量存在北段高于中段和南段的特征;相关性分析结果表明公路建设对铅、镉、锌的纵向差异存在一定影响。横向空间分异性显示,虽然在不同的土壤种类和利用方式下,土壤重金属含量值差异很大,但公路沿线重金属与公路距离之间存在显著相关关系,表明公路对横向的空间分异性存在决定性影响,影响带宽度约为50m垂向分析结果表明,自然土壤中重金属的垂向分异性不如横向分异明显,仅显示在近公路处有重金属富集现象;而在公路施工区,受人工护坡等工程的局部影响,垂向分异性不显著。     

Copper,Lead, Cadmium,and Zinc Sorption By Waterlogged and Air-Dry Soil

Competitive sorption of copper (Cu), lead (Pb), cadmium (Cd), and zinc (Zn) was studied in three soils of contrasting chemical and physical properties under air-dry and waterlogged conditions. Competitive sorption was determined using the standard batch technique using six solutions, each with Cu, Pb, Cd, and Zn concentrations of approximately 0, 2.5, 5, 10, 20, and 50?mg L^?1Waterlogged soils tended to sorb higher amounts of added Cu, Pb, Zn and Cd relative to soils in the air-dry condition; however, this increase in sorption was generally not statistically (p<0.05) significant. The magnitude of sorption under both waterlogged and air-dry conditions was affected by the type and amount of soil materials involved in metal sorption processes, and competition between other metals for the sorption sites. Metal sorption was closely correlated with soil properties such as cation exchange capacity, organic carbon, and Fe and Mn hydrous oxides. Exchangeable Al may have markedly reduced metal sorption due to its strong affinity for the sorption sites, while increases in exchangeable Mn may have enhanced Zn and Cd sorption. Heavy metal sorption was best described as a combination of both specific and nonspecific interactions. The extractability of Cu, Pb, Cd, and Zn under waterlogged and air-dry conditions was also studied. Three solutions containing these metals were mixed with each soil to achieve a final concentration of 0, 50, and 500?mg kg^?1. Each soil was extracted every 7 days using 1?M MgCl₂ (pH 7) to determine metal extractability. Metal extractability initially decreased then increased due to waterlogging. The increased extractability of added metals was closely related to increased solubility of Fe and Mn suggesting that dissolution of Fe and Mn, oxides under reducing conditions caused a release of previously sorbed Cu, Pb, Cd, and Zn.     

Spatial heterogeneity of DTPA-extractable zinc in cultivated soils induced by city pollution and land use

The spatial heterogeneity of DTPA-extractable zinc in the cultivated soils of Shenyang suburbs in Liaoning Province of China was investigated, and its map was drawn by the methods of geostatistics combined with geographic information system. The data of soil DTPA-extractable zinc fitted normal distribution after logarithm transformation, and its semivariogram fitted a spherical model. The semivariogram indicated that the spatial dependence of soil DTPA-extractable zinc content was moderate, with the spatial dependence range of 1.69 km and the fractal dimension of 1.96. Stochastic factors contributed to 49.9% of the spatial variability, while structural factors contributed to 50.1% of it. The spatial heterogeneity of soil DTPA-extractable zinc shown by a kriged interpolation map was deeply influenced by stochastic factors such as city pollution, land use pattern and crop distributions. For example, the average content of Zn in vegetable garden soils was 2.5-4 times as much as in their originated soils, and was lower in paddy soils than in their originated soils. The areas with a higher content of soil DTPA-extractable zinc appeared in the near suburbs and the riverside along Hunhe River and the wastewater drainage of Xihe River, and the extremely high values in the near suburb of the city's residential area were a striking feature, indicating the key role of city pollution in the spatial heterogeneity of soil DTPA-extractable zinc. When recorded in the form of a soil pollution map,the results of such a survey make it possible to identify the unusually polluted areas, and to provide more information for precise agriculture and environmental control.     

根瘤菌对土壤铜、锌和镉形态分配的影响

以湖南郴州红壤和河北巩义褐土为供试土壤。制备Cu、Zn、Cd污染土壤。接种大豆根瘤菌(Rhi-zobium fredii)HN01,用连续提取法浸提土壤中不同形态的重金属．结果表明。褐土接种根瘤菌后固相结合态Zn总量降低10％。专性吸附态、氧化锰结合态和有机结合态Zn减少达9％～26％．红壤中结合态Zn的总量变化不显著,但专性吸附态和氧化锰结合态Zn含量显著减少。交换态Zn含量显著增加．褐土中接种根瘤菌抑制了Cu向土壤溶液的释放,固相结合态Cu总量增加18％,可交换态、专性吸附态、氧化锰结合态和有机结合态的Cu增加20％～54％．接种根瘤菌对土壤中Cd的溶解没有明显的抑制或促进作用,但改变了红壤中各形态Cd的含量高低顺序．Cd污染红壤中可交换态和有机结合态Cd含量分别增加22％和11％,专性吸附态和氧化锰结合态Cd分别减少14％和29％．根瘤菌对不同类型重金属及不同土壤中重金属形态影响的差异主要与土壤pH降低有关．     

浙江油茶产地土壤和果实金属元素含量特征

为探讨油茶(Camellia oleifera)产地土壤和油茶果实中金属元素分布和富集特征,在油茶果实成熟期,对浙江5个油茶产地土壤及油茶果实中金属元素进行污染分析和富集能力评价.结果表明,浙江油茶产地土壤中Pb、Cr、Cd、As、Hg、Ni、Cu和Zn含量低于农用地土壤污染风险筛选值,综合污染等级为安全.个别产区常山...     

东北地区中部主要农业土壤中若干金属元素的背景值

农业土壤是自然土壤开垦种植后,在自然因素和人为活动双重影响下长期形成的。所以农业土壤中各种元素的含量既与自然土壤有关联,而又与自然土壤有一些差异。采集东北地区中部近70个土壤剖面200个样品,用原子吸收法、阳极溶出伏安法和萤光光度法等分别测定了镉、铜、铁、汞、锰、镍、铅、锯、锌、硒等元素的含量。通动表土与心土对比法,4 d法和(?)+2s法剔除异常值,采取直方图法、概率纸法、Vistelius置信带法、Kolmogorov,Smirnov法和偏度、峰度法进行检验,综合判定元素概率分布类型。分别以表层土壤的(?)±S和M/D-M·D表示耕种暗棕壤、耕种黑土,耕种暗色草甸土和水稻土的元素背景值。 随着农业土壤腐殖质层的变薄和耕作层有机质含量的下降,许多元素的含量随之降低,尤以汞、锰、硒、锶为明显。     

深圳市不同功能区土壤表层重金属污染及其综合生态风险评价

在综合考虑深圳市城市功能区分异特征的基础上,进行全市表层土壤系统采样,全面监测土壤表层8种重金属元素污染状况,分析不同重金属元素含量的统计学特征,探讨不同城市功能区对土壤表层重金属污染的影响,采用内梅罗指数和潜在生态危害指数评估不同重金属元素和不同城市功能区的生态风险水平,分别进行基于两种方法的全市重金属污染生态风险分区。结果表明: 1)深圳市土壤表层的Mn、Ni、Cr和Pb 4种元素受人为活动的影响程度较低,Cd、Zn、Cu和As 4类元素受人为活动影响较大。地表环境约束因素背景下的高强度城市化和工业化过程,是各种重金属污染区域分异和功能区分异的决定性因素。2)深圳市土壤重金属污染风险较高的重金属元素为Cd、Zn、Cu和Pb,特别是Pb污染问题尤为突出,必须加强管控工作。深圳市总体土壤表层重金属污染风险水平高于国内相关城市,需要引起足够重视。3)内梅罗指数法和潜在生态危害指数法的侧重点不同,在单一重金属元素风险判断、不同城市功能区生态风险的总体评价,以及市域土壤重金属污染生态风险分级评价方面结果差异较大,组合使用效果更好。     

小菜蛾幼虫空间格局的地统计学分析

应用地统计学方法分析了小菜蛾Plutellaxylostella (L .)幼虫空间格局 ,建立了东西和南北 2个方向上多个半变异函数曲线模型。结果表明 ,在菜花 (Brassicaolenaceavar.botrylis)和早甘蓝 (Brassisaoleracea)地中小菜蛾幼虫种群的半变异函数曲线皆为球形 ,其空间格局为聚集型 ;小菜蛾幼虫在菜花上和在早甘蓝上的空间变程分别为 0 62～ 1 5 9m和 2 47～ 5 98m ,空间不连续性强度分别为 0 8779～0 9999和 0 862 1～ 0 91 2 4。     

The impact of spatial structure on the accuracy of contour maps of small data sets

Spatial analysis of insect counts provides important information about how insect species respond to the heterogeneity of a given sampling space. Contour mapping is widely used to visualize spatial pest distribution patterns in anthropogenic environments, and in this study we outlined recommendations regarding semivariogram analysis of small data sets (N < 50). Second, we examined how contour maps based upon linear kriging were affected by the spatial structure of the given data set, as error estimation of contour maps appears to have received little attention in the entomological domain. We used weekly trap catches of the warehouse beetle, Trogoderma variabile, and the accuracy assessment was based upon data sets that had either a random spatial structure or were characterized by asymptotic spatial dependence. Asymptotic spatial dependence (typically described with a semivariogram analysis) means that trap catches at locations close to each other are more similar than trap catches at locations further apart. Trap catches were poorly predicted for data sets with a random spatial structure, while there was a significant correlation between observed and predicted trap catches for the spatially rearranged data sets. Therefore, for data sets with a random spatial structure we recommend visualization of the insect counts as scale-sized dots rather than as contour maps.     

Comparison of the metal-ion-promoted dephosphorylation of the 5'-triphosphates of adenosine, inosine, guanosine and cytidine by Mn2+, Ni2+ and Zn2+ in binary and ternary complexes.

The dependence of the rate of dephosphorylation of ATP, ITP, GTP and CTP (= NTP), expressed as first-order rate constants (50 degrees C; I = 0.1 M, NaClO4), on pH (2 to 10), in the absence and presence of Mn2+, Ni2+, and Zn2+, was investigated. The reaction is accelerated by Zn2+ and passes through a pH optimum at about 8 for the system Zn2+-ATP or 9 for Zn2+-ITP and Zn2+-GTP; this is analogous to observations made earlier with the corresponding Cu2+ systems. By computing the pH dependence of the distribution of the several species present in these systems it is shown that the highest rates are observed in the pH regions where the concentration of Zn(ATP)2-, Zn(ITP-H)3-, or Zn(GTP-H)3- dominates. By evaluating the pH dependence evidence is given that the attacking nucleophile is OH- or H2O for Zn (ATP)2- and H2O for Zn (ITP-H)3- or Zn(GTP-H)3-. For all these complexes metal-ion/nucleic-base interactions are known, leading to the formation of macrochelates. These metal-ion/nucleic-base interactions are crucial for the observation of a metal-ion-promoted dephosphorylation; in agreement with this, and the small tendency of the cytosine moiety to coordinate, the CTP systems are rather stable towards dephosphorylation. It should be noted that these experimental results do not necessarily mean that the macrochelates usually described are the reactive complexes, but only that the active complex must be closely related to them (e.g. isomers, etc). Although for the Ni2+ systems with ATP, ITP, and GTP, and for the Mn2+-ATP system a metal-ion/nucleic-base interaction is also known, these systems are not very sensitive to hydrolytic cleavage of the terminal P-O-P bond. The only known significant structural difference between the Ni2+-NTP or the Mn2+-ATP complexes and those of Cu2+ or Zn2+ is that Ni2+ Mn2+ coordinate to all three phsophate groups, whereas Cu2+ and Zn2+ involve only the beta and gamma ones. This structure-reactivity relationship is rationalized by the suggestion that in the active species the metal ion should be coordinated to the alpha,beta-phosphate groups leaving the gamma-group open to nucleophilic attack. Obviously, an initial beta,gamma-coordination is suitable for a shift of the metal ion along the phosphate back-bone into the reactive alpha-beta-position, while for an alpha,beta,gamma-coordination only the less favorable removal of the coordinated gamma-group remains. The metal-ion/nucleic-base interaction is considered as being important for achieving this reactive structure. The connection between trans-phosphorylation in vitro and in vivo is discussed. It is also shown that the formation of mixed-ligand or ternary complexes inhibits the dephosphorylation process. This is on the one hand of interest with regard to the transport of hydrolysis-sensitive phosphates in nature, while on the other it casts doubts on conclusions based on experiments carried out in the presence of buffers, because these contain weak bases and hence potential ligands.     

Some soil-plant and root-shoot relationships of copper,zinc and manganese in white clover and perennial ryegrass

Summary White clover and perennial ryegrass were grown separately, in pots maintained under controlled environment conditions, for a period of 7 months on ten soils. The proportion of the total soil content of each element taken up by the ryegrass, including that in roots, ranged from 0.88 to 2.18% for Cu, from 0.82 to 2.80% for Zn and from 0.25 to 3.15% for Mn. Uptake by the clover was within these ranges for Cu and Zn, but ranged from 0.10 to 1.71% for Mn.After adjustment for the effects of soil contamination, the ratio of root concentration: shoot concentration was always greater than 1 for both Cu and Zn, and for Cu, though not for Zn, it was considerably greater with ryegrass than with clover. For Mn, the ratio of root:shoot concentration was often greater than 1, and differences between clover and grass were not consistent.Concentrations of Cu and Zn in the shoots were always greater in the clover than in the grass, but concentrations of Mn were generally greater in the grass than the clover.