红壤中铝的形态

以改进的连续分级提取方法,用１ｍｏｌ／Ｌ,ＫＣｌ,０．２ｍｏｌ／Ｌ,ＨＣｌ,０．１ｍｏｌ／Ｌ Ｎａ４Ｐ２Ｏ７（ｐＨ８．５）,ＤＣＢ溶液,０．３３ｍｏｌ／Ｌ,柠檬酸钠和０．５ｍｏｌ／Ｌ ＮａＯＨ为提取剂,把红壤中可提取的非晶态铝区分为交换态铝,肿附态无机羟基铝,有机配合态铝,氧化铁结合态铝,层间铝和非晶态铝硅酸盐。     

土壤中植物有效锰的形态分级

用４种方法测定土壤有效态锰含量,并加以比较和评价,从而确定出最优的土壤有效锰测定方法。研究结果表明,采用一种顺序浸提的方法能比较准确地反映土壤的供锰状况,锰组分及其相应浸提剂为：易溶态锰（０．０５ｍｌ／ＬＣａ（ＮＯ３）２）提取、弱吸附态锰（ｐＨ８．５,ＣａＤＴＰＡ－Ｂ４Ｏ７）、碳酸盐束缚态锰（石灰性土壤,用１．６ｍｏｌ／ＬＨＮＯ３快速浸提）或专性吸附态锰（非石灰性土壤,用１．６ｍｏｌ／ＬＨＮＯ３快速浸提）或专性吸附态锰（非石灰性土壤,ｐＨ４．４,０．０５ｍｏｌ／ＬＣａ（ＮＯ３）２＋０．０５ｍｏｌ／ＬＣｕ（ＮＯ３）２提取）和氧化锰（ｐＨ２．０,０．１ｍｏｌ／ＬＮＨ２ＯＨ．ＨＣｌ）。由盆栽试验辣椒吸收的锰与土壤锰相关分析结果显示,易溶态锰是植物最易吸收的锰,其回归方程为：Ｙ＝－１４．４０９＋２１．６５８Ｘ,ｒ＝０．     

镍对水稻生长发育影响和残留规律的研究

本文对吉林省砂壤水稻土进行镍（ＮｉＳＯ４·６Ｈ２Ｏ）的不同浓度对水稻生长发育影响和残留规律的盆栽试验研究。结果表明，镍对水稻的毒害作用主要表现在抑制水稻分蘖，使产量下降。土壤投加镍６０－２４０ｍｇ／ｋｇ条件下，可使水稻减产５％￣２５％。水稻各器官镍累积量随土壤投加镍量的增加而增加，其分布规律为：根〉〉茎叶〉糙米，表现出明显的规律性。用０．００５ｍｏｌ／Ｌ ＤＴＰＡ提取土壤中有效态镍能很好地体现水稻     

不同氮肥对铅锌矿必需放污染土壤中重金属的溶出及水稻苗吸收的影响

研究比较了５种氮肥对铅锌矿尾矿污染区土壤中Ｐｂ、Ｚｎ、Ｃｄ和Ｃｕ溶出的影响，讨论了它们对重金属溶出的机制，结合盆栽试验中水稻幼苗吸收重金属的相关性分析表明：５种氮肥对土壤中重金属的溶出有不同影响，且与氮肥的浓度有关。其中ＮＨ４ＨＣＯ３，（ＮＨ４）２ＨＰＯ４对Ｚｎ和Ｃｕ的溶出，ＮＨ４Ｃｌ和（ＮＨ４）２ＨＰＯ４对Ｃｄ的溶出均有较大的促进作用，而１０＾－２ｍｏｌ／Ｌ的（ＮＨ４）２ＨＰＯ４，ＮＨ４ＨＣＯ３     

HGMS技术与NaOH溶液浓缩土壤铁锰氧化物的效果比较

以我国中南地区几种土壤和土壤锰结核为材料，比较了高梯度磁分选仪与５ｍｏｌ．ｌ＾－１ＮａＯＨ溶液对土壤铁锰氧化物的浓缩效果。结果表明：（１）以１：１型高岭石为主的土样，经５ｍｏｌ．Ｌ＾－１ＮａＯＨ溶液处理后，其氧化铁浓缩倍数高于ＨＧＭＳ处理后的样品，以２：１型层状酸盐矿物为主的土壤浓缩倍数则相反。（２）ＨＧＭＳ处理浓缩土样锰结核中的锰氧化物，其浓缩倍数比５ｍｏｌ．Ｌ＾－１ＮａＯＨ溶液处理的低；但前者     

一次注射3H-Leu测定肉仔鸡内源氨基酸排泄量的方法学研究

给强饲无氮饲粮（ＮＦＤ），ＮＦＤ＋３．２０％酶解酪蛋白（ＥＨＣ），以豆粕为唯一氮源粗蛋白（ＣＰ）为５％及２０％半合成饲粮的肉仔鸡，静脉注射３０μＣｉ／ｋｇ体重＾３Ｈ－Ｌｅｕ注射后５ｍｉｎ，４ｈ，２４ｈ，３６ｈ及４８ｈ测定血浆游离Ｌｅｕ比放射性强度（ＳＲｐ）及４８ｈ内排泄物比放射性强度（ＳＲ）。结果表明，不同饲粮排泄物内源Ｌｅｕ比放射性强度（ＳＲｅ）与ＳＲｐ定积分值与之比恒等，证明我们提出的一次注射     

牛体外受精胚胎在不同温度下保存后的存活率

本研究探讨了保存温度和保存时间对牛体外受精胚胎存活率的影响。试验１测定第７，８ｄ的囊胚分别在４℃，２０℃和３９℃下保存（或培养）４～６ｈ，２４ｈ和４８ｈ后在体外培养的孵化率。在４℃下保存的胚胎的孵化率分别为７１．２％，５７．１％及２７．０％，显著低于对照组（８７．８％，Ｐ＜０．０１）。在２０℃和３９℃下保存（或培养）４～６ｈ不影响胚胎孵化率（分别为８４．９％，８５．９％），但保存２４ｈ和４８ｈ后，孵化率均显著降低（Ｐ＜０．０１）。试验２用ＰＲＩＤ阴道栓处理青年母牛，使其发情同期化，在发情开始后的第７ｄ，用非手术法给每头母牛移植２枚在２０℃下保存３～７ｈ或１８～２４ｈ的囊胚。移植保存３～７ｈ的胚胎获得的妊娠率、双胎率分别为７１．０％和５０．０％；移植保存１８～２４ｈ的胚胎的妊娠率显著降低（４１．５％），但双胎率（４１．２％）与保存３～７ｈ者无显著差异（Ｐ＞０．０５）。     

磁混肥肥效试验研究：I.梨树施用磁混肥的效果

试验结果表明：对梨树用磁混肥，处理３、４、５比混肥２、６和习惯用肥１处理增产，其中以处理４产量最高。糖／酸比值为６７．３；ＳＯＤ酶、Ｈ２Ｏ２酶前期活力强，有利于抗衰老，后期两种酶活性降低，有利于促进梨果成熟。春梢、花簇、果台附梢数处理４最多，有利于梨树来年增花结果。     

土壤有机矿质复合体研究 Ⅶ．土壤结合态腐殖质的形成特点及其结合特征

本文系统剖析了熊毅－傅积平改进区分的土壤结合态腐殖质的形成特点，胡，富组成及其结合特征。结果表明：（１）用０．１ｍｏｌ／ＬＮａＯＨ及０．１ｍｏｌ／ＬＮａＯＨ＋０．１ｍｏｌ／ＬＮａ４Ｐ２Ｏ７混合液连续浸提的松结态（Ｈ１）和稳结态（Ｈ２）腐殖质所占的比例随土壤ｐＨ升高分别呈减少和增加趋势。统计分析显示Ｈ１与游离态铁，铝呈极显著的正相关，与交换性钙呈极显著负相关，Ｈ２则与交换性钙呈极显著正相关，而与游离     

快速冷冻牛体外受精胚胎

本文研究不同类型的防冻剂及其浓度对快速冷冻牛胚胎的效果。试验Ⅰ：７日龄囊胚先分别放入含１０％（Ｖ／Ｖ）甘油或１０％（Ｖ／Ｖ）乙二醇改良的磷酸盐缓冲液（ＰＢＬ）中，室温下平衡１０ｍｉｎ。然后，分别移入１．５ｍｏｌ／Ｌ，２．０ｍｏｌ／Ｌ甘油或２．０ｍｏｌ／Ｌ，３．０ｍｏｌ／Ｌ乙二醇＋０．２５ｍｏｌ／Ｌ蔗糖ＰＢＬ液中，１０ｍｉｎ后将胚胎放进冰箱的结冰层（约─２３℃），３５ｍｉｎ后直接投入液氮。冻后孵化率最高的处理组为１．５ｍｏｌ／Ｌ甘油＋０．２５ｍｏｌ／Ｌ蔗糖（８２．４％），其极显著（Ｐ＜０．０１）地高于２．０ｍｏｌ／Ｌ甘油＋０．２５ｍｏｌ／Ｌ蔗糖（１５．４％），２．０ｍｏｌ／Ｌ乙二醇＋０．２５ｍｏｌ／Ｌ蔗糖（６３．９％），３．０ｍｏｌ／Ｌ乙二醇＋０．２５ｍｏｌ／Ｌ蔗糖（３８．７％）。试验Ⅱ：７日龄胚胎先在１０％（Ｖ／Ｖ）甘油中平衡１０ｍｉｎ，而后，分别移入１．５ｍｏｌ／Ｌ甘油＋０，０．２５，０．５ｍｏｌ／Ｌ蔗糖，停留１０ｍｉｎ后快速冷冻。解冻后，胚胎分别用０．５，０．２５，０ｍｏｌ／Ｌ蔗糖除甘油。结果表明：解冻液中的蔗糖浓度对胚胎的存活力无显著影响。当冷冻处理为１．５ｍｏｌ／Ｌ甘油＋０．２５ｍｏｌ／Ｌ蔗糖时，胚     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Changes in trace element speciation in kola north surface waters during snow melt

The powerful mass-flow of melt water during the brief period of spring thaw provides a surge of pollutants and causes extremely toxic short term conditions. Together with the increase in total metal concentrations during this period, a redistribution in metal speciation occurs that increases the proportion of more toxic forms. Concentrations of ion-exchangeable fractions of nickel (Ni), copper (Cu), aluminium (Al), and manganese (Mn) show strong negative correlations with pH. The sum of complex metal species shows a strong positive correlation with total organic carbon (TOC). A data analysis model based on relationships observed between key parameters and metal behaviour together with gidrological data allowed an assessmrnt of the metal impact on waterbodies from accumulated airborne pollution (Ni, Cu) as well as from accelerated leaching from watersheds (Al, Mn).     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.