广西合山煤田岩溶发育规律及机制研究

通过对合山煤田区119个钻孔揭露的溶洞数量、线溶洞率与高程之间的关系,地表岩溶出露的形态、位置、地下强径流带的分布状况的研究,总结了区内岩溶在垂向上和平面上岩溶的发育规律,并从区内岩石的物质基础、构造条件、水化学特征、水的循环交替作用等四个方面阐述了区内岩溶的发育机制。结果表明：煤田区岩溶发育具有平面上的不均一性和垂向上的成层分布特征。前者体现了岩溶在平面上发育受地层岩性、地质构造及水文地质条件等因素的影响;后者反映了间歇性上升的新构造运动及侵蚀、溶蚀基准面和可溶岩出露厚度的变化对岩溶发育的控制。     

川南古叙地区岩溶发育特征及影响因素探讨

四川盆地南缘古蔺—叙永一带岩溶发育具有鲜明的规律特征,多级水平溶洞说明研究区经历了几个不同的地质时期,代表了主要的水平溶蚀作用,相邻两层不同高程的溶洞之间则被垂向的溶洞、溶隙所串联,又反映了以垂向溶蚀作用为主的另一个时期,水平和垂向溶蚀的交替出现是本区岩溶的一个重要形式,同时以岩溶为介质的阶梯状管道流特征十分明显。文中统计了研究区内各岩溶类型的基本发育特征,总结了岩溶发育的高程分带以及岩溶管道流循环特征,探讨了该类岩溶模式除受到挽近构造运动作间歇性上升的影响外,河谷下蚀变迁以及地下水循环演化也是形成区内多级岩溶的因素之一,从而为人类工程活动提供一定的指导意义。     

重庆走马岭隧道岩溶及岩溶水发育特征

走马岭隧道通过方斗山背斜可溶岩地区。岩溶发育强烈。在分析隧址区地质环境的基础上，详细论述隧址区岩溶发育分布规律和特征，岩溶水补、径、排条件及化学特征，为隧道安全施工提供科学依据并提出建议。     

四川某隧道岩溶水文地质条件及涌水量初步研究

拟建隧道位于黄龙景区,通过段主要为强溶蚀岩溶-裂隙含水岩层,区内构造活跃、地形切割强烈,隧道遭遇岩溶涌突水的危险性较大.通过分析该隧道岩溶水文地质环境.论述了隧址区岩溶发育分布规律、岩溶水补径排条件及化学特征,并采用地下水径流模数法和大气降水入渗法2种方法对比计算对隧道涌水量做出初步预测评价,为施工提供依据.     

贵州省岩溶区水土流失、石漠化受岩溶环境制约

贵州省处于珠江流域、长江流域分水岭地带,其水土流失、石漠化受岩溶环境制约。珠江流域石灰岩类岩石连片分布,出露面积占碳酸盐岩出露总面积的60.75%,白云岩类岩石占4.15%,岩溶地貌以峰丛洼地、谷地和岩溶峡谷为特征,其轻度水土流失面积占水土流失总面积的61.35%,重度石漠化面积占总石漠化面积的22.01%;长江流域白云岩、石灰岩及碎屑岩呈北东向互层分布,其中白云岩类岩石组合出露面积占31.17%,石灰岩类岩石组合出露面积占40.66%,岩溶地貌以岩溶槽谷、岩溶高原为特征,轻度水土流失面积占水土流失总面积的44.17%,重度石漠化面积占总石漠化面积的11.78%。水土流失、石漠化演变的统计结果显示,水土流失与石漠化是同一生态退化过程中的不同阶段,石漠化是土壤侵蚀长期作用的结果,土壤侵蚀是石漠化过程中某一阶段作用强度的体现,二者在成因上存在因果关系。     

典型岩溶石漠化区根系生境及其类型研究

在贵州岩溶石漠化区,根据碳酸盐岩分布、地貌类型及岩石类型分布情况,共计调查152个根系生境剖面,利用岩性、产状、根系分布范围内的岩石斑块数、土层深度、裂缝宽度、垂直剖面土壤分布范围、植物根系分布的长宽幅度等指标,采用RDA排序方法,分析根系生长空间类型及其特征;采用定性和定量分析相结合的方法进行快速聚类,划分植物根系生境类型,并进行生境类型命名及类型特征描述.结果表明:1)石漠化区植物根系生长空间分为表层空间、单层空间、多层空间3种类型,植物根系对多层空间类型利用最多;2)贵州岩溶石漠化区根系生境分为18个类型,各类型特征不同.研究成果加深了对岩溶石漠化区植物根系生境的认识,对植物生态修复与石漠化治理均具有重要的意义.     

滑坡体上黄土洞穴的发育特征及其成因机制

采用野外调查和室内分析相结合的方法,以定西常家河滑坡区为研究区,在分析黄土滑坡和黄土洞穴区域分布特征的基础上,研究了黄土滑坡和黄土洞穴的地形地貌分布特征以及滑坡体上黄土洞穴的发育特征。研究结果表明,黄土滑坡和黄土洞穴在分布特征上具有一定的相关性,滑坡体上黄土洞穴发育密度明显增大、发育程度增高。研究了滑坡体上黄土洞穴的成因机制,认为黄土滑坡对黄土洞穴发育的影响主要是通过影响黄土土性、节理裂隙、水力条件以及微地形地貌来实现的。研究成果不仅有助于对黄土洞穴成因、发育特征的认识,而且对黄土滑坡的防治具有重要意义。     

福建省建瓯市地质灾害发育特征及形成机制

[目的]分析建瓯市地质灾害发育特征及成因,以便进一步做好建瓯市地质灾害防灾减灾工作。[方法]在区域地质灾害详细调查的基础上,分析建瓯市地质灾害的发育类型、规模、分布以及危害性等特征,总结区内地质灾害的发育规律。针对地质灾害的地形条件、地层岩性以及典型致灾土体的土工试验研究,结合对典型灾害点的讨论分析,确定建瓯市地质灾害的形成机制及土体抗剪强度特征。[结果](1)建瓯市地质灾害以小规模滑坡为主,数量众多,普遍表现为表层堆积土顺基岩面滑塌的发育特点;(2)区内地质灾害多发的原因是由于多期次构造运动导致岩体破碎,易构成不稳定结构面组合,加之表层风化土体抗剪强度较低,在人为切坡及强降雨条件诱发下,导致了斜坡的变形破坏。[结论]建瓯市地质环境条件较差,不合理的切坡易诱发滑坡。     

五指山隧道岩溶发育及涌水的特征研究

五指山隧址区有10种岩溶形态,在隧址区地质调查基础上,分析了五指山地区岩溶发育的演化历史.采用径流模数法、年降雨有效渗入时间系数法及地下水动力系数法对各区段隧道涌水进行了计算,并对隧道贯通前后涌水动态变化进行了分析.五指山隧道主要涌水位置有5处,其中进口段的“8.6”断层突水和出口段的膏溶角砾岩突水,突水量大,给隧道施工和隧址区环境带来严重影响.     

西南地区石漠化防治对策初探

石漠化是特指湿润的喀斯特(岩溶)地区的一种土地退化现象和过程.我国石漠化主要分布在西南岩溶山区,以贵州为中心的桂、滇、川、渝、鄂、湘等省(市、区)最为集中,面积达54万km2,是全球三大岩溶集中连片区中面积最大、岩溶发育最强烈的典型生态脆弱区.本文分析了石漠化的成因,提出了控制人口增长、改革耕作方式、健全政策法规、发展生态农业等防治对策.     

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,     

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.     

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.     

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,     

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.