江西省典型山地风电场水土流失特征和防治措施研究

风电场通常位于高海拔山地区，水土流失风险高、危害大，其水土流失防治措施体系建设十分重要。以江西省吉安市华润峡江玉峡风电场工程为例，从扰动面积、水土流失、挖填方量等方面分析山地风电场水土流失动态特征，探讨山地风电场水土流失防治措施体系建设和防治重点。结果显示：风电场风电机组区和道路工程区是新增扰动面积和水土流失量的主要区域，也是风电场水土流失防治的重点区域；水土保持措施应在施工期第1年布设完毕，这样才能起到有效防止水土流失的作用；单台风机挖填方量、造成的水土流失均小于同地区其他风电项目，表明其水土流失防治措施体系取得了显著成效；挡土埂和挂网喷播植草是两种有效的边坡防护措施，可为同地区其他风电项目水土保持设计提供参考。     

从水土保持角度优化和控制水电工程设计

水电工程建设将不可避免的扰动地表和破坏植被,加剧工程区水土流失。多数水电建设项目水土保持方案,主要在主体工程设计的基础上采取相应的水土保持措施,未能从全过程预防和治理工程建设造成的水土流失。四川省巴郎口水电站从水土保持角度优化和控制水电工程设计,实现全过程预防和治理工程建设造成的水土流失。在选址选线上应避开敏感区域,如水土保持实验示范区、水土流失治理成果区、生态脆弱区、泥石流易发区、大型滑坡体分布区、植被良好区等;以减少土石方量和工程占地为目标,对工程各项目进行优化设计;采取经济实用措施治理扰动面和弃渣堆放场,控制工程建设造成的水土流失。     

风电场项目交通道路防治区水土保持措施探讨

风电项目交通道路防治区是项目新增水土流失量最大的单元,是水土流失监测和防治的重点区域。依据开挖回填情况将风电项目交通道路防治区分为平缓路段(平地、山脊处路段)、全挖方路段、全填方路段和半挖半填路段四种类型区,并结合各种类型区的特点选择性地实施表土剥离及返还、排水沟、边坡防护、植物措施等水土保持措施,最大程度地防治因项目建设而造成的水土流失。     

山东省潍坊市公路建设项目水土保持损益分析

[目的]通过山东省潍坊市公路建设项目的水土保持损益分析,评价当地公路建设项目的水土保持影响程度。[方法]以潍坊地区S220,S221,S321和S327这4个公路建设项目为例,应用水土流失影响指数评价模型定量计算其水土流失影响指数(SWII)。[结果]S220,S221,S321和S327的水土流失影响指数(SWII)分别为0.194 2,0.158 8,0.175 8,0.167 1,全部低于全国公路项目SWII的平均值,表明潍坊地区公路项目建设造成的水土流失影响程度要低于全国平均水平。其主要原因是:平均项目占地面积(4.82hm~2/km)和影响范围(0.91hm~2/km)较小,土石方挖填量(5.06×104 m~3/km)和弃渣量(400m~3/km)较少,影响时间(21个月)短,水土流失总量(437t/km)不大。[结论]针对不同的公路建设项目,可通过减少项目的占地面积和影响范围,减少工程的土石方挖填量,特别是增加水土流失治理面积,来进一步减弱工程建设带来的水土流失影响。     

河北省坝上风电场建设区水土流失特点与植被恢复途径

以河北省坝上风电场建设区为研究对象,探讨风电场建设区水土流失特点、分区、防治重点及植被恢复措施。结果如下：风电场建设区水土流失特点为风电场工程的特殊性与坝上水土流失特征的相互耦合的表现;风电场建设区水土流失特点表现为点状与线状侵蚀并存,风蚀与水蚀共存,植被破坏点多面广、植被恢复难度大,土石方量较小、弃渣相对较少,水土流失重点在施工建设期等;风电场建设区的水土流失主要来自升压站、风机区、施工生产生活区、道路区、集电线路区和弃渣场等6个区域,不同区域的水土流失特点和防治重点各有侧重;坝上风电场建设区的植被恢复可采取封育恢复自然植被,清理表土集中覆盖、利用土壤种子库恢复植被及人工植被建设3类途径。     

山地型风电场工程水土保持方案编制中应注意的问题

风电是一种清洁能源,大量风电场的建成并投入使用,可以调整区域能源结构,带动当地的经济发展,但如果不注重工程建设中的水土流失防治问题,不仅影响工程的正常施工和运行,而且会给周边的生态环境带来一定的负面影响。风电场工程建设造成的水土流失具有多种侵蚀形式并存、扰动地表面积大、影响范围广、土壤侵蚀集中在施工期等特点。分析总结了山地型风电场工程水土保持方案编制中应注意的问题:要结合同类工程现场调查,综合确定风机区、道路区等直接影响区的范围;有关风速的介绍不能照搬当地气象站收集的资料,要查阅主体设计报告中工程区的近地面风速;项目土石方平衡要结合工程实际分区进行计算;在水土保持监测设计中要考虑对风力侵蚀的监测等。     

地铁项目水土流失特点及水土保持临时措施探讨

地铁指在地下运行为主的城市轨道交通系统,具有扰动地表面积大、土石方开挖量大、建设周期长、弃渣处理难度大等特点。该类项目的主要水土流失区域有车站、区间、附属设施区、施工生产生活区、改移工程区等,而施工期是产生水土流失的主要时段。随着城市轨道交通项目的增多,做好该类项目建设期的水土保持临时措施防治显得极为重要。     

西易党新煤矿水土保持监测成果分析

据对监测资料分析,西易党新煤矿建设项目,建设期的水土保持防治责任范围为22.84 hm2,比水土保持方案确定的面积减少4.46 hm2;建设期实际产生的土石方总量为5.22万m3,其中挖方2.61万m3,填方2.61万m3,挖填平衡,无弃方;原地貌的土壤侵蚀量为1 170 t,建设期的土壤侵蚀量为2 324 t,防治措施实施后的土壤侵蚀量为275.2 t,由于工程建设扰动新增土壤侵蚀量1 154 t,各项水土保持措施实施后土壤侵蚀量降低42.9%;扰动土地整治率98.97%,水土流失总治理度98.05%,拦渣率98%,土壤流失控制比0.83,林草植被恢复率97.43%,林草覆盖率38.98%,达到了一级防治标准要求。     

六安至武汉公路安徽段水土流失及其防治措施初步研究

拟建公路所经地段多为山岭重丘区，挖填量大，开挖面广，直接破坏地表植被，改变原地貌形态，堆放大量弃土、弃渣，极易产生新的水土流失。采取类比法来预测工程建设中的新增水土流失量，从而得出工程建设中的填挖方边坡、临时设施占地和弃渣场为水土流失防治重点，并提出了相应的工程加植物的综合防治措施。     

大型线性工程水土保持方案编制要点研究

大型线性工程具有工程线路长、扰动范围广、跨越不同地形地貌区、土石方挖填量多、取土场和弃渣场数量多等特点，为水土保持方案编制带来一定难题。基于河道治理工程、水库灌溉工程、燃气管道工程、引调水工程等项目的水土保持方案编制经验，从水土流失防治区划分、工程占地分析与评价、土石方平衡分析与综合利用、穿(跨)越工程水土流失防治、弃渣场选址等方面提出大型线性工程水土保持方案编制要点，以期为同类工程水土保持方案编制提供借鉴。     

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。     

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.     

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.     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

Potassium Fixation and Release Characteristics in Rhizosphere and Nonrhizosphere Soils for a Rapeseed–Rice Cropping Sequence

Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L^?1 nitric acid (HNO₃) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L^?1 ammonium acetate (NH₄OAc) and 1.0 mol L^?1 HNO₃ extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.     

Electron donor and pH relationships for biologically enhanced dissolution of chlorinated solvent DNAPL in groundwater

Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.     

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.     

Increase in auxiliary photoprotective photosynthetic pigments in wheat seedlings induced by Azospirillum brasilense

Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene. This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots. Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production or the positive response of the plants towards A. brasilense Cd inoculation.     

Responses of native legume desert trees used for reforestation in the Sonoran Desert to plant growth-promoting microorganisms in screen house

Three slow-growing legume trees used for desert reforestation and urban gardening in the Sonoran Desert of Northwestern Mexico and the Southwestern USA were evaluated whether their growth can be promoted by inoculation with plant growth-promoting bacteria (Azospirillum brasilense and Bacillus pumilus), unidentified arbuscular mycorrhizal (AM) fungi (mainly Glomus sp.), and supplementation with common compost under regular screenhouse cultivation common to these trees in nurseries. Mesquite amargo (Prosopis articulata) and yellow palo verde (Parkinsonia microphylla) had different positive responses to several of the parameters tested while blue palo verde (Parkinsonia florida) did not respond. Survival of all tree species was over 80% and survival of mesquite was almost 100% after 10 months of cultivation. Inoculation with growth-promoting microorganisms induced significant effects on the leaf gas exchange of these trees, measured as transpiration and diffusive resistance, when these trees were cultivated without water restrictions.