WorldWideScience

Sample records for ground cover plants

  1. Epiphyte-cover on seagrass (Zostera marina L. leaves impedes plant performance and radial O2 loss from the below-ground tissue

    Directory of Open Access Journals (Sweden)

    Kasper Elgetti Brodersen

    2015-08-01

    Full Text Available The O2 budget of seagrasses is a complex interaction between several sources and sinks, which is strongly regulated by light availability and mass transfer over the diffusive boundary layer (DBL surrounding the plant. Epiphyte growth on leaves may thus strongly affect the O2 availability of the seagrass plant and its capability to aerate its rhizosphere as a defence against plant toxins.We used electrochemical and fiber-optic microsensors to quantify the O2 flux, DBL and light microclimate around leaves with and without filamentous algal epiphytes. We also quantified the below-ground radial O2 loss from roots (~1 mm from the root-apex to elucidate how this below-ground oxic microzone was affected by the presence of epiphytes.Epiphyte-cover on seagrass leaves (~21% areal cover resulted in reduced light quality and quantity for photosynthesis, thus leading to reduced plant fitness. A ~4 times thicker diffusive boundary layer around leaves with epiphyte-cover impeded gas (and nutrient exchange with the surrounding water-column and thus the amount of O2 passively diffusing into the leaves in darkness. During light exposure of the leaves, radial oxygen loss from the below-ground tissue was ~2 times higher from plants without epiphyte-cover. In contrast, no O2 was detectable at the surface of the root-cap tissue of plants with epiphyte-cover during darkness, leaving the plants more susceptible to sulphide intrusion.Epiphyte growth on seagrass leaves thus negatively affects the light climate and O2 uptake in darkness, hampering the plants performance and thereby reducing the oxidation capability of its below-ground tissue.

  2. Phytoseiidae (Acari: Mesostigmata) within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants.

    Science.gov (United States)

    Childers, Carl C; Denmark, Harold A

    2011-08-01

    Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the family Phytoseiidae (Acari: Mesostigmata) in central and south central Florida. Inner and outer canopy leaves, open flowers, fruit, twigs, and trunk scrapings were sampled monthly between September 1994 and January 1996. Vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards. The two remaining orchards were on full herbicide programs and ground cover plants were absent. Thirty-three species of phytoseiid mites were identified from 35,405 specimens collected within citrus tree canopies within the seven citrus orchards, and 8,779 specimens from vines and ground cover plants within five of the seven orchards. The six most abundant phytoseiid species found within citrus tree canopies were: Euseius mesembrinus (Dean) (20,948), Typhlodromalus peregrinus (Muma) (8,628), Iphiseiodes quadripilis (Banks) (2,632), Typhlodromips dentilis (De Leon) (592), Typhlodromina subtropica Muma and Denmark (519), and Galendromus helveolus (Chant) (315). The six most abundant species found on vines or ground cover plants were: T. peregrinus (6,608), E. mesembrinus (788), T. dentilis (451), I. quadripilis (203), T. subtropica (90), and Proprioseiopsis asetus (Chant) (48). The remaining phytoseiids included: Amblyseius aerialis (Muma), A. herbicolus (Chant), A. largoensis (Chant), A. multidentatus (Chant), A. sp. near multidentatus, A. obtusus (Koch), Chelaseius vicinus (Muma), Euseius hibisci Chant, Galendromus gratus (Chant), Metaseiulus mcgregori (Chant), Neoseiulus mumai (Denmark), N. vagus (Denmark), Phytoscutus sexpilis (Muma), Phytoseiulus macropilis (Banks), Proprioseiopsis detritus (Muma), P. dorsatus (Muma), P. macrosetae (Banks), P. rotundus (Muma), P. solens (De Leon), Typhlodromips deleoni (Muma), T. dillus (De Leon), T. dimidiatus (De Leon), T. mastus Denmark and Muma, T. simplicissimus (De Leon), and T. sp

  3. Intensity of Ground Cover Crop Arachis pintoi, Rhizobium Inoculation and Phosphorus Application and Their Effects on Field Growth and Nutrient Status of Cocoa Plants

    Directory of Open Access Journals (Sweden)

    John Bako Baon

    2006-08-01

    Full Text Available Arachis pintoiis potentially as a cover crop for cocoa (Theobroma cacaoL. farm, however information regarding its effect on the growth of cocoa plants in the field is very limited. The objective of this experiment is to investigate the combined influence of ground cover crop A. pintoi, rhizobial bacterial inoculation and phosphorus (P fertilizer on the growth of cocoa in the field and nutrient status. This experiment laid out in split-split plot design consisted of three levels of cover crop (without, A. pintoiand Calopogonium caeruleum, two levels of rhizobium inoculation (not inoculated and inoculated and two levels of phosphorus application (no P added and P added. The results showed that in field condition the presence of A. pintoias cover crop did not affect the growth of cocoa. On the other hand, C. caeruleumas cover crop tended to restrict cocoa growth compared to A. pintoi. Application of P increased leaf number of cocoa plant. Biomass production of A. pintoiwas 40% higher than C. caeruleum. Soil organic carbon and nitrogen contents were not affected by ground cover crops, though higher value (0.235% N and 1.63% organic C was obtained from combined treatments of inoculation and P addition or neither inoculation nor P addition. In the case of no rhizobium inoculation, soil N content in cocoa farm with A. pintoicover crop was lower than that of without cover crop or with C. caeruleum. Cover crop increased plant N content when there was no inoculation, on the other hand rhizobium inoculation decreased N content of cocoa tissue. Tissue P content of cocoa plant was not influenced by A. Pintoicover crop or by rhizobium inoculation, except that the P tissue content of cocoa was 28% higher when the cover crop was C. caeruleumand inoculated. Key words : Arachis pintoi, Theobroma cacao, Calopogonium caeruleum, rhizobium, nitrogen, phosphorus.

  4. Study of growth and development features of ten ground cover plants in Kish Island green space in warm season

    Directory of Open Access Journals (Sweden)

    S. Shooshtarian

    2016-05-01

    Full Text Available Having special ecological condition, Kish Island has a restricted range of native species of ornamental plants. Expansion of urban green space in this Island is great of importance due to its outstanding touristy position in the South of Iran. The purpose of this study was to investigate the growth and development of groundcover plants planted in four different regions of Kish Island and to recommend the most suitable and adaptable species for each region. Ten groundcover species included Festuca ovina L., Glaucium flavum Crantz., Frankenia thymifolia Desf., Sedum spurium Bieb., Sedum acre L., .Potentilla verna L., Carpobrotus acinaciformis (L. L. Bolus., Achillea millefolium L., Alternanthera dentata Moench. and Lampranthus spectabilis Haw. Evaluation of growth and development had been made by measurement of morphological characteristics such as height, covering area, leaf number and area, dry and fresh total weights and visual scoring. Physiological traits included proline and chlorophyll contents evaluated. This study was designed in factorial layout based on completely randomized blocks design with six replicates. Results showed that in terms of indices such as covering area, visual quality, height, total weight, and chlorophyll content, Pavioon and Sadaf plants had the most and the worst performances, respectively in comparison to other regions’ plants. Based on evaluated characteristics, C. acinaciformis, L. spectabilis and F. thymifolia had the most expansion and growth in all quadruplet regions and are recommend for planting in Kish Island and similar climates.

  5. Eupalopsellidae and Stigmaeidae (Acari: Prostigmata) within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines, and ground cover plants.

    Science.gov (United States)

    Childers, Carl C; Ueckermann, Eduard A

    2014-10-01

    Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the families Eupalopsellidae and Stigmaeidae (Acari: Prostigmata) in central and south central Florida. Inner and outer canopy leaves, fruit, twigs, and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. Two species of eupalopsellid mites (Exothorhis caudata Summers and Saniosulus harteni (van-Dis and Ueckermann)) were identified from 252 specimens collected within citrus tree canopies within the seven citrus orchards of which 249 were E. caudata. Only two E. caudata were collected from ground cover plants within five of the seven orchards. Eight species of Stigmaeidae were identified from 5,637 specimens: Agistemus floridanus Gonzalez, A. terminalis Gonzalez, Eustigmaeus arcuata (Chandhri), E. sp. near arcuata, E. segnis (Koch), Mediostigmaeus citri (Rakha and McCoy), Stigmaeus seminudus Wood, and Zetzellia languida Gonzalez were collected from within citrus tree canopies from seven orchard sites. Agistemus floridanus was the only species in either family that was abundant with 5,483 collected from within citrus tree canopies compared with only 39 from vine or ground cover plants. A total of 431 samples from one or more of 82 vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards and one or more eupalopsellids or stigmaeids were collected from 19 of these plants. Richardia brasiliensis (Meg.) Gomez had nine A. floridanus from 5 of 25 samples collected from this plant. Solanum sp. had five A. floridanus from three samples taken. Both eupalopsellid and stigmaeid species numbers represented orchards were on full herbicide programs and ground cover plants were absent. Agistemus floridanus was more abundant in the citrus orchards with on-going or recent herbicide programs compared with orchards having well-developed ground

  6. Database for estimating tree responses of walnut and other hardwoods to ground cover management practices

    Science.gov (United States)

    J.W. Van Sambeek

    2010-01-01

    The ground cover in plantings of walnut and other hardwoods can substantially affect tree growth and seed production. The number of alternative ground covers that have been suggested for establishment in tree plantings far exceeds the number that have already been tested with walnut and other temperate hardwoods. Knowing how other hardwood species respond to ground...

  7. Non-phytoseiid Mesostigmata within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants and additional collection records of mites in citrus orchards.

    Science.gov (United States)

    Childers, Carl C; Ueckermann, Eduard A

    2015-03-01

    Seven citrus orchards on reduced- to no-pesticide spray programs in central and south central Florida were sampled for non-phytoseiid mesostigmatid mites. Inner and outer canopy leaves, fruits, twigs and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. A total of 431 samples from one or more of 82 vine or ground cover plants were sampled monthly in five of the seven orchards. Two of the seven orchards (Mixon I and II) were on full herbicide programs and vines and ground cover plants were absent. A total of 2,655 mites (26 species) within the families: Ascidae, Blattisociidae, Laelapidae, Macrochelidae, Melicharidae, Pachylaelapidae and Parasitidae were identified. A total of 685 mites in the genus Asca (nine species: family Ascidae) were collected from within tree samples, 79 from vine or ground cover plants. Six species of Blattisociidae were collected: Aceodromus convolvuli, Blattisocius dentriticus, B. keegani, Cheiroseius sp. near jamaicensis, Lasioseius athiashenriotae and L. dentatus. A total of 485 Blattisociidae were collected from within tree samples compared with 167 from vine or ground cover plants. Low numbers of Laelapidae and Macrochelidae were collected from within tree samples. One Zygoseius furciger (Pachylaelapidae) was collected from Eleusine indica. Four species of Melicharidae were identified from 34 mites collected from within tree samples and 1,190 from vine or ground cover plants: Proctolaelaps lobatus was the most abundant species with 1,177 specimens collected from seven ground cover plants. One Phorytocarpais fimetorum (Parasitidae) was collected from inner leaves and four from twigs. Species of Ascidae, Blattisociidae, Melicharidae, Laelapidae and Pachylaelapidae were collected from 31 of the 82 vine or ground cover plants sampled, representing only a small fraction of the total number of Phytoseiidae collected from the same plants. Including the

  8. The Investigation of Species and Application of Ground Cover Plants in Jiaozuo%焦作市地被植物种类及应用调查

    Institute of Scientific and Technical Information of China (English)

    韩红军; 张桂芝; 马君丽; 孔德政

    2012-01-01

    根据对焦作市建成区地被植物进行实地调查,统计得出焦作市作为地被植物应用的灌木,藤本,一、二年生花卉,宿根、球根花卉、草类共有192种65科151属.灌木应用较多,宿根、球根花卉,一、二年生花卉应用较少;提出了应用频率最高的地被植物有:马棘、月季、剑麻、铺地柏、迎春等;焦作地被植物应用形式主要有以下几种;模纹花坛和绿篱,旷地造景,路缘造景等.最后提出优化灌草比例,引进新优品种的建议.%Based on the investigation of ground cover plants, which be divided into Bush, Fujimoto, one or two annual flower, Perennial and bulbs flowers and grasses, which we proposes 192 species in the Building area in the city of Jiaozuo belong to 65 families and 151 genera. Bush is widely used, on the contrary, one or two annual flowers and Perennial and bulbs flowers used very seldom. And we discover these plants as indigofera and rose and jasmine and sisal and winter juniper etc are used the most frequently. There are these kinds of application forms as follows: mode pattern flower and hedgerow, open areas landscaping, road edge landscaping. At the last, we proposed that Optimization the Proportion of bush and grass and introduction new and excellent variety.

  9. Physiological functions of plant cell coverings.

    Science.gov (United States)

    Hoson, Takayuki

    2002-08-01

    The cell coverings of plants have two important functions in plant life. Plant cell coverings are deeply involved in the regulation of the life cycle of plants: each stage of the life cycle, such as germination, vegetative growth, reproductive growth, and senescence, is strongly influenced by the nature of the cell coverings. Also, the apoplast, which consists of the cell coverings, is the field where plant cells first encounter the outer environment, and so becomes the major site of plant responses to the environment. In the regulation of each stage of the life cycle and the response to each environmental signal, some specific constituents of the cell coverings, such as xyloglucans in dicotyledons and 1,3,1,4-beta-glucans in Gramineae, act as the key component. The physiological functions of plant cell coverings are sustained by the metabolic turnover of these components. The components of the cell coverings are supplied from the symplast, but then they are modified or degraded in the apoplast. Thus, the metabolism of the cell coverings is regulated through the cross-talk between the symplast and the apoplast. The understanding of physiological functions of plant cell coverings will be greatly advanced by the use of genomic approaches. At the same time, we need to introduce nanobiological techniques for clarifying the minute changes in the cell coverings that occur in a small part within each cell.

  10. Absence of snow cover reduces understory plant cover and alters plant community composition in boreal forests.

    Science.gov (United States)

    Kreyling, Juergen; Haei, Mahsa; Laudon, Hjalmar

    2012-02-01

    Snow regimes affect biogeochemistry of boreal ecosystems and are altered by climate change. The effects on plant communities, however, are largely unexplored despite their influence on relevant processes. Here, the impact of snow cover on understory community composition and below-ground production in a boreal Picea abies forest was investigated using a long-term (8-year) snow cover manipulation experiment consisting of the treatments: snow removal, increased insulation (styrofoam pellets), and control. The snow removal treatment caused longer (118 vs. 57 days) and deeper soil frost (mean minimum temperature -5.5 vs. -2.2°C) at 10 cm soil depth in comparison to control. Understory species composition was strongly altered by the snow cover manipulations; vegetation cover declined by more than 50% in the snow removal treatment. In particular, the dominant dwarf shrub Vaccinium myrtillus (-82%) and the most abundant mosses Pleurozium schreberi (-74%) and Dicranum scoparium (-60%) declined strongly. The C:N ratio in V. myrtillus leaves and plant available N in the soil indicated no altered nitrogen nutrition. Fine-root biomass in summer, however, was negatively affected by the reduced snow cover (-50%). Observed effects are attributed to direct frost damage of roots and/ or shoots. Besides the obvious relevance of winter processes on plant ecology and distribution, we propose that shifts in the vegetation caused by frost damage may be an important driver of the reported alterations in biogeochemistry in response to altered snow cover. Understory plant performance clearly needs to be considered in the biogeochemistry of boreal systems in the face of climate change.

  11. 9种多年生地被植物在华北高寒区的抗寒性%Study on Cold -resistance of Several Ground Cover Plants in the Cold Plateau of North China

    Institute of Scientific and Technical Information of China (English)

    张晓磊; 马建平; 宋国亮; 李欣儒; 张立峰

    2012-01-01

    The study with introduced ground cover plants as meterials. Through observations on their natural growth conditions and growth morphology and demonstration tests of artificial low-temperature stress root cold physiological changes and physical growth of strain recovery validation studies, the results showed that 0 - -18℃ low temperature processing, the relative conductivity, soluble sugar and praline contents of nine perennial ground cover plants were all on the rise, while in the - 18- - 36℃ processing, soluble sugar and free proline content of Platycodon grandiforus. Hemerocallis stella remained rise after fall. The Hosta plantaginea, Aster novibelgii, Lilium brownii var. viridulum showed continuous downward trend. Combination of winter cold stress, sexual and physical strain to restore growth status showed that nine perennial ground cover plants could be successful overwintering in north China. Basis of resistance to the cold, the orders were Platycodon grandiforus 〉 HemerocaUis stella 〉 Hemerocallis middenclorffii 〉 Paeonia lactiflora 〉 P. lactiflora 〉 Sedum spectabile 〉 Hosta plantaginea 〉 Lilium brownii var. viridulum.%以引种的9种多年生地被植物为材料,通过对其在华北高寒区自然生长条件下的越冬性与生长形态观测,以及人工低温胁迫下根系抗寒生理指标变化与株体生长恢复的实证研究表明,0-18℃处理温段,9种地被植物的相对电导率、可溶性糖和游离脯氨酸含量均呈上升趋势;在-18--6℃处理温段,桔梗、金娃娃萱草可溶性搪和游离脯氨酸含量仍保持上升而后再下降,而玉椿、荷兰菊、百合则呈持续下降趋势。结合越冬性与低温胁迫下株体恢复生长状况认为,9种地被植物在华北高寒区常年环境下均可越冬,其抗寒能力依次为:桔梗〉金娃娃萱草〉大花萱草〉单瓣芍药〉重瓣芍药〉八宝景天〉玉簪〉荷兰菊〉百合。

  12. Law school design blends functionalism, energy conservation. [Earth-covered with ground-cover growing on roof

    Energy Technology Data Exchange (ETDEWEB)

    1976-08-01

    Construction is under way on a new University of Minnesota Law School Building, whose distinctive features include a stepped design on its southern elevation and an earth-covered roof to promote energy conservation. The design is described with emphasis on the library facilities. Energy conservation was a major design factor. The portion of the earth-covered roof will be 15 inches thick planted with low ground-cover vegetation. Overall ..mu.. value of the building envelope will be 0.11. (MCW)

  13. Estimating mean plant cover from different types of cover data: a coherent statistical framework

    National Research Council Canada - National Science Library

    Damgaard, C

    2014-01-01

    Plant cover is measured by different methods and it is important to be able to estimate mean cover and to compare estimates of plant cover across different sampling methods in a coherent statistical framework...

  14. Study on Water Adaptability of Seven Common Species of Ground Cover Plants in South China%华南地区7种常见园林地被植物水分适应性研究

    Institute of Scientific and Technical Information of China (English)

    钱瑭璜; 雷江丽; 庄雪影

    2012-01-01

    Water adaptability of seven common ground cover plants in South China were studied by pot experiment. The effect of biomass increment, root-crown ratio, florescence, diurnal variations of net photosynthetic rate and diurnal variations of net transpiration rate were determined in different soil water content. The experimental results showed that 7 ground cover plants could grow strongly in the soil w ith the water holding rate above 70% to 75%. Schefflera arboricola, Rhoeo discolor (L'He'rit.) Hance and Syngonium podophyllum Schott 'White Butterfly' could grow well and possess good ornamental value in the soil with minimum water holding rates of 30% to 35%; lxora coccinea L., Excoecaria cochinchinensis, Hymenocallis littoralis and Nephrolepis auriculata could grow well in the soil with minimum water holding rates of 50% to 55%.%以华南地区7种常见园林地被植物为研究对象,通过盆栽控水试验研究,综合比较了不同水分条件下植株的生长量、根冠比、花期、花量、净光合速率日变化、净蒸腾速率日变化等生长及光合指标的变化趋势.结果表明:1)在水分条件下限为土壤持水率的70%~75%时,7种参试植物均有较旺盛的生长势;2)在满足各参试植物园林观赏性的前提下,鹅掌藤(Schefflera arboricola)、蚌花[Rhoeo discolor (L’Hérit.)Hance]和[白蝶合果芋(Syngonium podophyllum Schott ‘White Butterfly’)在水分条件下限为土壤持水率的30%~35%时可以正常生长;而红花龙船化(Ixora coceinea L.)、红背桂(Excoecaria cochinchinensis)、水鬼蕉(Hymenocallis littoralis)和肾蕨(Nephrolepis auriculata)在水分条件下限为土壤持水率的50%~55%时可以正常生长.

  15. Propagation of food and cover plants for waterfowl

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the propagation of food and cover plants for waterfowl. The report covers the general conditions of development of aquatic plants. Please note...

  16. Development of Ground-Based Plant Sentinels

    Science.gov (United States)

    2007-11-02

    plants in response to different strains of Pseudomonas syringae. Planta . 217:767-775. De Moraes CM, Schultz JC, Mescher MC, Tumlinson JH. (2004...09-30-2004 Final Technical _ April 2001 - April 2003 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Developing Plants as Ground-based Sentinels 5b. GRANT...SUPPLEMENTARY NOTES 14. ABSTRACT 9 "Z Plants emit volatile mixes characteristic of exposure to both plant and animal (insect) pathogens (bacteria and fungi). The

  17. 地被植物在郑州都市区园林绿化中的组成结构及管理对策研究%The investigation and analysis about common ground cover plants of metropolitan area parks in Zhengzhou City

    Institute of Scientific and Technical Information of China (English)

    汪进; 杨旭; 高闪闪; 何瑞珍

    2014-01-01

    The ground cover plants in the major urban parks and plazas of Zhengzhou City were investigated by using on‐the‐spot statistical investigation in this paper ,and the vegeta‐tion characteristics , selection criteria , and maintenance management , etc . w ere discussed and analysed .The results showed that the species of ground cover plants are simplex ,with smaller size plantation and often separatly planted with many bare grounds and extensive management at late stage . T herefore , some effective measurs are proposed by reasonable planting according to the viewing characteristis of different species in different growth seasonsand enhancing their management in time ,which can greatly improve their ornamental value ,and hence increase the level of ground cover plants landscaping .%采用实地调查统计的方法对郑州市各大公园及路边广场的地被植物及其特点、选择标准、养护管理等进行了研究分析。结果表明:当前地被植物品种单一,种植面积较小,且多单独种植,混合应用较少,较多地段没有地被植物覆盖,后期管理粗放。建议充分利用每种地被植物不同时期的观赏特点,种植时合理搭配,及时管理,以大大提高观赏价值,从而提高地被植物的造景水平。

  18. Estimating ground water recharge from topography, hydrogeology, and land cover.

    Science.gov (United States)

    Cherkauer, Douglas S; Ansari, Sajjad A

    2005-01-01

    Proper management of ground water resources requires knowledge of the rates and spatial distribution of recharge to aquifers. This information is needed at scales ranging from that of individual communities to regional. This paper presents a methodology to calculate recharge from readily available ground surface information without long-term monitoring. The method is viewed as providing a reasonable, but conservative, first approximation of recharge, which can then be fine-tuned with other methods as time permits. Stream baseflow was measured as a surrogate for recharge in small watersheds in southeastern Wisconsin. It is equated to recharge (R) and then normalized to observed annual precipitation (P). Regression analysis was constrained by requiring that the independent and dependent variables be dimensionally consistent. It shows that R/P is controlled by three dimensionless ratios: (1) infiltrating to overland water flux, (2) vertical to lateral distance water must travel, and (3) percentage of land cover in the natural state. The individual watershed properties that comprise these ratios are now commonly available in GIS data bases. The empirical relationship for predicting R/P developed for the study watersheds is shown to be statistically viable and is then tested outside the study area and against other methods of calculating recharge. The method produces values that agree with baseflow separation from streamflow hydrographs (to within 15% to 20%), ground water budget analysis (4%), well hydrograph analysis (12%), and a distributed-parameter watershed model calibrated to total streamflow (18%). It has also reproduced the temporal variation over 5 yr observed at a well site with an average error < 12%.

  19. Study on Introduction and Cultivation Techniques of Four Color--leafed Plants of Ground Cover%四种地被类彩叶植物引种栽培技术研究

    Institute of Scientific and Technical Information of China (English)

    王太平

    2011-01-01

    对引进的4个地被类植物优良品种进行了引种试验,结果表明:红叶石楠和金森女贞在高度生长和冠幅增长方面优势明显,其次为红花檀木、洒金珊瑚;栽培试验表明:4个地被类植物经过几个生长期的栽培试验,形成了一套较完整的栽培技术措施,为4个优良品种的推广应用提供了技术保障。%In this paper, four species of ground cover were studied through introduction experiment and cul- tivation experiment. The results of introduction experiment show that Photinia serru alta and Ligustrum japonicum 'Howardii" have clear advantages on high-growth and crown-growth, followed by Lorpetalum Chinese Oliv. var. rubrum Yieh and Var. variegata D'ombr. The results of cultivation experiment show that after the experiment of several growth periods, a complete cultivation technique of these four species has been formed,which provides technical support for applying these four fine varieties.

  20. Decoupling factors affecting plant diversity and cover on extensive green roofs.

    Science.gov (United States)

    MacIvor, J Scott; Margolis, Liat; Puncher, Curtis L; Carver Matthews, Benjamin J

    2013-11-30

    Supplemental irrigation systems are often specified on green roofs to ensure plant cover and growth, both important components of green roof performance and aesthetics. Properties of the growing media environment too can alter the assemblage of plant species able to thrive. In this study we determine how plant cover, above ground biomass and species diversity are influenced by irrigation and growing media. Grass and forb vegetative cover and biomass were significantly greater in organic based growing media but there was no effect of supplemental irrigation, with two warm season grasses dominating in those treatments receiving no supplemental irrigation. On the other hand, plant diversity declined without irrigation in organic media, and having no irrigation in inorganic growing media resulted in almost a complete loss of cover. Sedum biomass was less in inorganic growing media treatments and species dominance shifted when growing media organic content increased. Our results demonstrate that supplemental irrigation is required to maintain plant diversity on an extensive green roof, but not necessarily plant cover or biomass. These results provide evidence that planting extensive green roofs with a mix of plant species can ensure the survival of some species; maintaining cover and biomass when supplemental irrigation is turned off to conserve water, or during extreme drought.

  1. Interrelationships between soil cover and plant cover depending on land use

    Directory of Open Access Journals (Sweden)

    Tiina Köster

    2013-05-01

    Full Text Available Interrelationships between soil cover and plant cover of normally developed (or postlithogenic mineral soils are analysed on the basis of four sampling soil groups. The four-link pedo-ecological sequence of analysed soils, rendzinas → brown soils → pseudopodzolic soils → gley-podzols, forms a representative cross section in relation to the normal mineral soils of Estonia. All groups differ substantially from each other in terms of soil properties (calcareousness, acidity, nutrition conditions, profile fabric and humus cover. The primary tasks of the research were (1 to elucidate the main pedo-ecological characteristics of the four soil groups and their suitability for plant cover, (2 to evaluate comparatively soils in terms of productivity, sustainability, biodiversity and environmental protection ability and (3 to analyse possibilities for ecologically sound matching of soil cover with suitable plant cover. On the basis of the same material, the influence of land-use change on humus cover (epipedon fabric, properties of the entire soil cover and soil–plant interrelationship were also analysed. An ecosystem approach enables us to observe particularities caused by specific properties of a soil type (species, variety in biological turnover and in the formation of biodiversity.

  2. [Diversity and stability of arthropod community in peach orchard under effects of ground cover vegetation].

    Science.gov (United States)

    Jiang, Jie-xian; Wan, Nian-feng; Ji, Xiang-yun; Dan, Jia-gui

    2011-09-01

    A comparative study was conducted on the arthropod community in peach orchards with and without ground cover vegetation. In the orchard with ground cover vegetation, the individuals of beneficial, neutral, and phytophagous arthropods were 1.48, 1.84 and 0.64 times of those in the orchard without ground cover vegetation, respectively, but the total number of arthropods had no significant difference with that in the orchard without ground cover vegetation. The species richness, Shannon's diversity, and Pielou's evenness index of the arthropods in the orchard with ground cover vegetation were 83.733 +/- 4.932, 4.966 +/- 0.110, and 0.795 +/- 0.014, respectively, being significantly higher than those in the orchard without ground cover vegetation, whereas the Berger-Parker's dominance index was 0.135 +/- 0.012, being significantly lower than that (0.184 +/- 0.018) in the orchard without ground cover vegetation. There were no significant differences in the stability indices S/N and Sd/Sp between the two orchards, but the Nn/Np, Nd/Np, and Sn/Sp in the orchard with ground cover vegetation were 0.883 +/- 0.123. 1714 +/- 0.683, and 0.781 +/- 0.040, respectively, being significantly higher than those in the orchard without ground cover vegetation. Pearson's correlation analysis indicated that in the orchard with ground cover vegetation, the Shannon's diversity index was significantly negatively correlated with Nd/Np, Sd/Sp, and S/N but had no significant correlations with Nn/Np and Sn/Sp, whereas in the orchard without ground cover vegetation, the diversity index was significantly positively correlated with Nn/Np and Nd/Np and had no significant correlations with Sd/Sp, Sn/Sp, and S/N.

  3. Legume ground covers alter defoliation response of black walnut saplings to drought and anthracnose

    Science.gov (United States)

    J. W. Van Sambeek

    2003-01-01

    Growth and premature defoliation of black walnut saplings underplanted 5 or 6 years earlier with six different ground covers were quantified in response to a summer drought or anthracnose. Walnut saplings growing with ground covers of hairy vetch, crownvetch, and to a lesser extent sericea lespedeza continued to have more rapid height and diameter growth than saplings...

  4. Interannual changes in snow cover and its impact on ground surface temperatures in Livingston Island (Antarctica)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2015-04-01

    In permafrost areas the seasonal snow cover is an important factor on the ground thermal regime. Snow depth and timing are important in ground insulation from the atmosphere, creating different snow patterns and resulting in spatially variable ground temperatures. The aim of this work is to characterize the interactions between ground thermal regimes and snow cover and the influence on permafrost spatial distribution. The study area is the ice-free terrains of northwestern Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". Air and ground temperatures and snow thickness data where analysed from 4 sites along an altitudinal transect in Hurd Peninsula from 2007 to 2012: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). The data covers 6 cold seasons showing different conditions: i) very cold with thin snow cover; ii) cold with a gradual increase of snow cover; iii) warm with thick snow cover. The data shows three types of periods regarding the ground surface thermal regime and the thickness of snow cover: a) thin snow cover and short-term fluctuation of ground temperatures; b) thick snow cover and stable ground temperatures; c) very thick snow cover and ground temperatures nearly constant at 0°C. a) Thin snow cover periods: Collado Ramos and Ohridski sites show frequent temperature variations, alternating between short-term fluctuations and stable ground temperatures. Nuevo Incinerador displays during most of the winter stable ground temperatures; b) Cold winters with a gradual increase of the snow cover: Nuevo Incinerador, Collado Ramos and Ohridski sites show similar behavior, with a long period of stable ground temperatures; c) Thick snow cover periods: Collado Ramos and Ohridski show long periods of stable ground, while Nuevo Incinerador shows temperatures close to 0°C since the beginning of the winter, due to early snow cover

  5. BRS Centauro – oat cultivar for ground cover and grazing

    Directory of Open Access Journals (Sweden)

    Alfredo do Nascimento Junior

    2015-04-01

    Full Text Available Plants and seeds of oat cultivar BRS Centauro, of the species Avena brevis Roth., are highly uniform. The crop cycle is long, the suitability as fodder excellent, and leaf production particularly high, resulting in better quality forage than that of the black oat forage controls.

  6. The effects of plant cover on population of pear psylla (Cacopsylla pyricola and its predators

    Directory of Open Access Journals (Sweden)

    Mohammad Saeed Emami

    2017-01-01

    Full Text Available Cacopsylla pyricola (Förster, 1848 (Hemiptera: Psyllidae is a serious pest of pear in all pear growing areas. In the scope of an integrated pest management, a two consecutive years study was carried out to determine the effects of plant cover on pear psyllid population and its predators. Two treatments including plant cover and bare ground were applied in a randomized complete block design with three replicates. The sampling of the pest and its predators were done weekly by beating technique and leaf sampling. The data were subjected to analysis of variance (ANOVA. The results showed that plant cover had significant effect on the increase of predators on the trees (P < 0.001. The psyllid specialist predator, Anthocoris nemoralis (Fabricius, 1794, had the highest population among the pear psyllid predators (0.29 per sample. Plant cover had no significant effect on reducing the population of eggs, nymphs and adults of the pear psyllid. Despite the increase in the population of predators led by plant cover, lack of their effectiveness to reduce the pear psyllid population is discussed.

  7. Diseases of Ornamental and Shade Trees, Shrubs, Vines, and Ground Covers.

    Science.gov (United States)

    Nichols, Lester P.

    This agriculture extension service publication from Pennsylvania State University covers the identification and control of common ornamental trees, shrubs, and ground cover diseases. The publication is divided into sections. The first section discusses the diseases of ornamental and shade trees, including general diseases and diseases of specific…

  8. Ground cover rice production system facilitates soil carbon and nitrogen stocks at regional scale

    Directory of Open Access Journals (Sweden)

    M. Liu

    2015-02-01

    Full Text Available Rice production is increasingly challenged by irrigation water scarcity, however covering paddy rice soils with films (ground cover rice production system: GCRPS can significantly reduce water demand as well as overcome temperature limitations at the beginning of the vegetation period resulting in increased grain yields in colder regions of rice production with seasonal water shortages. It has been speculated that the increased soil aeration and temperature under GCRPS may result in losses of soil organic carbon and nitrogen stocks. Here we report on a regional scale experiment, conducted by sampling paired adjacent Paddy and GCRPS fields at 49 representative sites in the Shiyan region, which is typical for many mountainous areas across China. Parameters evaluated included soil C and N stocks, soil physical and chemical properties, potential carbon mineralization rates, fractions of soil organic carbon and stable carbon isotopic composition of plant leaves. Furthermore, root biomass was quantified at maximum tillering stage at one of our paired sites. Against expectations the study showed that: (1 GCRPS significantly increased soil organic C and N stocks 5–20 years following conversion of production systems, (2 there were no differences between GCRPS and Paddy in soil physical and chemical properties for the various soil depths with the exception of soil bulk density, (3 GCRPS had lower mineralization potential for soil organic C compared with Paddy over the incubation period, (4 GCRPS showed lower δ15N in the soils and plant leafs indicating less NH3 volatilization in GCRPS than in Paddy; and (5 GCRPS increased yields and root biomass in all soil layers down to 40 cm depth. Our results suggest that GCRPS is an innovative rice production technique that not only increases yields using less irrigation water, but that it also is environmentally beneficial due to increased soil C and N stocks at regional scale.

  9. Effects of ground cover from branches of arboreal species on weed growth and maize yield

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    Full Text Available ABSTRACTCultivating maize under systems of alley cropping results in improvements to the soil, a reduction in weeds and an increase in yield. Studies using ground cover from tree shoots produce similar results. The aim of this study was to evaluate the effects on weed growth and maize yield of ground cover made up of 30 t ha-1 (fresh matter of branches from the tree species: neem (Azadirachta indica A. Juss, gliricidia [Gliricidia sepium(Jacq. Kunth ex Walp.], leucaena [Leucaena leucocephala (Lam. de Wit.] and sabiá (Mimosa caesalpiniifolia Benth.. Two treatment groups (cultivars and weed control were evaluated. The cultivars AG 1041 and AL Bandeirantes were subjected to the following treatments: no hoeing, double hoeing, and ground a cover of branches of the above species when sowing the maize. A randomised block design was used with split lots (cultivars in the lots and ten replications. The cultivars did not differ for green ear or grain yield. Double hoeing was more effective than ground cover at reducing the growth of weeds. However, both weeding and ground cover resulted in similar yields for green ears and grain, which were greater than those obtained with the unweeded maize.

  10. Mycotoxicogenic fungal inhibition by innovative cheese cover with aromatic plants.

    Science.gov (United States)

    Moro, Armando; Librán, Celia M; Berruga, M Isabel; Zalacain, Amaya; Carmona, Manuel

    2013-03-30

    The use of aromatic plants and their extracts with antimicrobial properties may be compromised in the case of cheese, as some type of fungal starter is needed during its production. Penicillium verrucosum is considered a common cheese spoiler. The aim of this study was to evaluate the innovative use of certain aromatic plants as natural cheese covers in order to prevent mycotoxicogenic fungal growth (P. verrucosum). A collection of 12 essential oils (EOs) was obtained from various aromatic plants by solvent-free microwave extraction technology, and volatile characterisation of the EOs was carried out by gas chromatography/mass spectrometry. The most effective EOs against P. verrucosum were obtained from Anethum graveolens, Hyssopus officinalis and Chamaemelum nobile, yielding 50% inhibition of fungal growth at concentration values lower than 0.02 µL mL⁻¹. All EOs showed high volatile heterogeneity, with α-phellandrene, pinocamphone, isopinocamphone, α-pinene, camphene, 1,8-cineole, carvacrol and trans-anethole being found to be statistically significant in the antifungal model. The use of these aromatic plants as natural covers on cheese can satisfactorily inhibit the growth of some mycotoxicogenic fungal spoilers. Among the volatile compounds present, α- and β-phellandrene were confirmed as the most relevant in the inhibition. © 2012 Society of Chemical Industry.

  11. Richness and cover of nontimber economic plants along altitude in temperate Himalayan forest-use types.

    Science.gov (United States)

    Tariq, Akash; Adnan, Muhammad; AbdElsalam, Naser M; Fouad, Hassan; Hussain, Kamran; Ullah, Riaz; Ullah, Ahsan

    2014-01-01

    Pakistani Himalaya stretches over a wide range of altitudinal gradients and supports high diversity of medicinal plants that are an important source for rural livelihood. Altitudinal effects on ground vegetation have already been indicated but ground vegetation is also under severe threat of grazing and over collection. The present study investigated the effect of altitude on medicinal plants abundance in both old-growth and derived woodland forests. Each of the five line transects was selected in old-growth and derived woodland forests. Each line transect consisted of four plots distributed at four altitudinal levels (2200, 2300, 2400, and 2500 m asl). Species richness under derived woodland had shown strong negative correlation (r = -0.95) with altitude while it was found to be nonsignificant under old-growth. Cover of most of the species such as Veronica laxa (r = -0.95, P ≤ 0.05) had shown significant negative correlation with altitude under derived woodland. Cover abundance of some species like Valeriana jatamansi and Viola canescens has also shown significant negative correlation under old-growth forest. Derived woodland can decrease the cover abundance of valuable medicinal plants towards extension at higher altitudes. Thus, protection of the derived woodland could serve as a tool for the improvement of rural livelihood and ecological restoration.

  12. Bacterial diseases of tomato plants in terms of open and covered growing of Ukraine

    Directory of Open Access Journals (Sweden)

    J.V. Kolomiets

    2017-06-01

    Full Text Available It was established that the main causes of mass diseases of tomato in covered ground in Ukraine are agents of bacterial black spotting, bacterial speck and in open ground are agent of bacterial cancer of tomato plants. Typical symptoms of diseases are wilting and die-off of young plants, blackening of fiber vascular bundles, black spotting of leaves and fruits, and fruit stem rot. It was studied morphological and cultural, as well as physiological and biochemical properties of the selected strains of the agents of tomato bacterial diseases. We recommended biological preparations Phytocide and Phytohelp based on the bacteria Bacillus subtilis, to restrict the development of the agents of bacterial black spotting Xanthomonas vesicatoria and bacterial cancer Clavibacter michiganensis subsp. michiganensis.

  13. Studies on deposition, adhesion and resuspension of radioactive substances on the ground surface and ground cover

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, Susumu; Kurihara, Kazuo [Meteorological Research Inst., Tsukuba, Ibaraki (Japan)

    1999-03-01

    After the Chernobyl` nuclear power plant accident, resuspension of radioactive nuclei into the atmosphere is recognized as the one of the important processes that must be considered in the estimation of inhalation doses to humans. In this study, resuspensions of particles from soil and grass have been studied. The resuspension of particles from bare soil was modelized by using Shao`s method. The resuspension of particles from grass was studied by a wind tunnel and a field experiment. Dependencies of the resuspension rate on time and on friction velocity were obtained clearly. And it was also found that the other meteorological parameters, such as temperature, relative humidity, solar radiation and condensation, affected the resuspension rate in the field. (author)

  14. Estimation of snow cover distribution in Beas basin, Indian Himalaya using satellite data and ground measurements

    Indian Academy of Sciences (India)

    H S Negi; A V Kulkarni; B S Semwal

    2009-10-01

    In the present paper,a methodology has been developed for the mapping of snow cover in Beas basin,Indian Himalaya using AWiFS (IRS-P6)satellite data.The complexities in the mapping of snow cover in the study area are snow under vegetation,contaminated snow and patchy snow. To overcome these problems,field measurements using spectroradiometer were carried out and reflectance/snow indices trend were studied.By evaluation and validation of different topographic correction models,it was observed that,the normalized difference snow index (NDSI)values remain constant with the variations in slope and aspect and thus NDSI can take care of topography effects.Different snow cover mapping methods using snow indices are compared to find the suitable mapping technique.The proposed methodology for snow cover mapping uses the NDSI (estimated using planetary re flectance),NIR band reflectance and forest/vegetation cover information.The satellite estimated snow or non-snow pixel information using proposed methodology was validated with the snow cover information collected at three observatory locations and it was found that the algorithm classify all the sample points correctly,once that pixel is cloud free.The snow cover distribution was estimated using one year (2004 –05)cloud free satellite data and good correlation was observed between increase/decrease areal extent of seasonal snow cover and ground observed fresh snowfall and standing snow data.

  15. Fractional Vegetation Cover of East African Wetlands Observed on Ground and from Space

    Science.gov (United States)

    Schmidt, M.; Amler, E.; Guerschmann, J. P.; Scarth, P.; Behn, K.; Thonfeld, F.

    2016-08-01

    Wetlands are important ecosystems providing numerous ecosystem services. They are of particular importance to communities in East Africa where agriculture is the most important economic sector and where food availability to households critical. During an intensive field campaign in the dry season of 2013 were Fractional Vegetation Cover (FVC) measurements, botanical vegetation cover and vegetation structure estimates acquired in three wetland test sites within the East African region. FVC cover data were collated in three strata: ground layer, midstorey and overstorey (woody vegetation greater than 2 m). Fractional cover estimates for the green and no-green vegetative fraction were calculated for Landsat MODIS imagery. These FVC data products were evaluated a) with FVC field data and b) relative to each other for their usability in the East African region. First results show some promise for further studies.

  16. Ground cover influence on evaporation and stable water isotopes in soil water

    Science.gov (United States)

    Magdalena Warter, Maria; Jiménez-Rodríguez, Cesar D.; Coenders-Gerrits, Miriam; Teuling, Adriaan J. Ryan

    2017-04-01

    Forest ecosystems are characterized by complex structures which influence hydrological processes such as evaporation. The vertical stratification of the forest modifies the effect of the evaporation process due to the composition and local distribution of species within the forest. The evaluation of it will improve the understanding of evaporation in forest ecosystems. To determine the influence of forest understory on the fractionation front, four ground cover types were selected from the Speulderbos forest in the Netherlands. The native species of Thamariskmoss (Thuidium thamariscinum), Rough Stalked Feathermoss (Brachythecium rutabulum), and Haircapmoss (Polytrichum commune) as well as one type of litter made up of Douglas-Fir needles (Pseudotsuga menziesii) were used to analyse the rate of evaporation and changes on the isotopic concentration of the soil water on an in-situ basis in a controlled environment. Over a period of 4 weeks soil water content and atmospheric conditions were continuously measured, while the rainfall simulations were performed with different amounts and timings. The reference water added to the boxes keeps a stable composition along the trial period with a δ ^2H value of -42.59±1.15 \\permil} and δ 18O of -6.01±0.21 \\permil}. The evaporation front in the four ground covers is located between 5 and 10 cm depth and deuterium excess values are bigger than 5 \\permil. The litter layer of Douglas-Fir needles is the cover with higher fractionation in respect to the added water at 10 cm depth (δ ^2H: -29.79 \\permil), while the Haircapmoss keeps the lower fractionation rate at 5 cm and 10 cm (δ ^2H: -33.62 and δ ^2H: -35.34 \\permil). The differences showed by the soil water beneath the different ground covers depict the influence of ground cover on fractionation rates of the soil water, underlining the importance of the spatial heterogeneity of the evaporation front in the first 15 cm of soil.

  17. Use of various remote sensing land cover products for plant functional type mapping over Siberia

    Science.gov (United States)

    Ottlé, C.; Lescure, J.; Maignan, F.; Poulter, B.; Wang, T.; Delbart, N.

    2013-11-01

    High-latitude ecosystems play an important role in the global carbon cycle and in regulating the climate system and are presently undergoing rapid environmental change. Accurate land cover data sets are required to both document these changes as well as to provide land-surface information for benchmarking and initializing Earth system models. Earth system models also require specific land cover classification systems based on plant functional types (PFTs), rather than species or ecosystems, and so post-processing of existing land cover data is often required. This study compares over Siberia, multiple land cover data sets against one another and with auxiliary data to identify key uncertainties that contribute to variability in PFT classifications that would introduce errors in Earth system modeling. Land cover classification systems from GLC 2000, GlobCover 2005 and 2009, and MODIS collections 5 and 5.1 are first aggregated to a common legend, and then compared to high-resolution land cover classification systems, vegetation continuous fields (MODIS VCFs) and satellite-derived tree heights (to discriminate against sparse, shrub, and forest vegetation). The GlobCover data set, with a lower threshold for tree cover and taller tree heights and a better spatial resolution, tends to have better distributions of tree cover compared to high-resolution data. It has therefore been chosen to build new PFT maps for the ORCHIDEE land surface model at 1 km scale. Compared to the original PFT data set, the new PFT maps based on GlobCover 2005 and an updated cross-walking approach mainly differ in the characterization of forests and degree of tree cover. The partition of grasslands and bare soils now appears more realistic compared with ground truth data. This new vegetation map provides a framework for further development of new PFTs in the ORCHIDEE model like shrubs, lichens and mosses, to represent the water and carbon cycles in northern latitudes better. Updated land cover

  18. PERFORMANCE OF ‘NANICÃO JANGADA’ BANANA PLANTS INTERCROPPED WITH WINTER COVER CROPS

    Directory of Open Access Journals (Sweden)

    RICARDO SFEIR DE AGUIAR

    Full Text Available ABSTRACT The use of cover crops species may be an important strategy in the pursuit of sustainability of agroecosystems, considering benefits to soil, such as improvements of physical and chemical characteristics, and weed control. The objective of this study was to evaluate the effect of winter cover crops and other soil managements on chemical soil properties, on the cycle, on the production of the first cycle and on the fruit quality of banana cv. Nanicão Jangada in Andirá – PR, Brazil. The experiment was carried out in a commercial. Planting of banana suckers from the grower area occurred in the first half of March 2011, with a spacing of 2.40 m between rows and 1.90 m between plants. The experiment was designed in randomized blocks with four replications and six plants per plot. The six treatments were: black oat (Avenastrigosa Schreb, forage turnip (Raphanus sativus L. var. oleiferus, consortium of black oat and forage turnip, chicken litter, residues of banana plants, and bare ground. The evaluations were vegetative development and life cycle of banana plants, yield and quality of fruits, soil chemical characterstics, and fresh and dry mass of green manures. The results were submitted to ANOVA (F Test, and Tukey test at 5 % probability. Black oat and black oat with forage turnip consortium were superior in biomass production. Systems of soil management had no effect on the variables, except in the periods between planting and flowering and between planting and harvest, which were shorter in the treatment of soil management with crop residues, longer in the treatment with forage turnip, and intermediate in the other treatments.

  19. Water consumption and water-saving characteristics of a ground cover rice production system

    Science.gov (United States)

    Jin, Xinxin; Zuo, Qiang; Ma, Wenwen; Li, Sen; Shi, Jianchu; Tao, Yueyue; Zhang, Yanan; Liu, Yang; Liu, Xiaofei; Lin, Shan; Ben-Gal, Alon

    2016-09-01

    The ground cover rice production system (GCRPS) offers a potentially water-saving alternative to the traditional paddy rice production system (TPRPS) by furrow irrigating mulched soil beds and maintaining soils under predominately unsaturated conditions. The guiding hypothesis of this study was that a GCRPS would decrease both physiological and non-physiological water consumption of rice compared to a TPRPS while either maintaining or enhancing production. This was tested in a two-year field experiment with three treatments (TPRPS, GCRPSsat keeping root zone average soil water content near saturated, and GCRPS80% keeping root zone average soil water content as 80-100% of field water capacity) and a greenhouse experiment with four treatments (TPRPS, GCRPSsat, GCRPSfwc keeping root zone average soil water content close to field water capacity, and GCRPS80%). The water-saving characteristics of GCRPS were analyzed as a function of the measured soil water conditions, plant parameters regarding growth and production, and water input and consumption. In the field experiment, significant reduction in both physiological and non-physiological water consumption under GCRPS lead to savings in irrigation water of ∼61-84% and reduction in total input water of ∼35-47%. Compared to TPRPS, deep drainage was reduced ∼72-88%, evaporation was lessened ∼83-89% and transpiration was limited ∼6-10% under GCRPS. In addition to saving water, plant growth and grain yield were enhanced under GCRPS due to increased soil temperature in the root zone. Therefore, water use efficiencies (WUEs), based on transpiration, irrigation and total input water, were respectively improved as much as 27%, 609% and 110% under GCRPS. Increased yield attributed to up to ∼19%, decreased deep drainage accounted for ∼75%, decreased evaporation accounted for ∼14% and reduced transpiration for ∼5% of the enhancement in WUE of input water under GCRPS, while increased runoff and water storage had

  20. Assessing post-fire ground cover in Mediterranean shrublands with field spectrometry and digital photography

    Science.gov (United States)

    Montorio Llovería, Raquel; Pérez-Cabello, Fernando; García-Martín, Alberto

    2016-09-01

    Fire severity can be assessed by identifying and quantifying the fractional abundance of post-fire ground cover types, an approach with great capacity to predict ecosystem response. Focused on shrubland formations of Mediterranean-type ecosystems, three burned areas (Ibieca and Zuera wildfires and Peñaflor experimental fire) were sampled in the summers of 2006 and 2007. Two different ground measurements were made for each of the 356 plots: (i) 3-band high spatial resolution photography (HSRP) and (ii) the hemispherical-conical reflectance factor (HCRF) in the visible to near-infrared spectral range (VNIR, 400-900 nm). Stepwise multiple lineal regression (SMLR) models were fitted to spectral variables (HCRF, first derivative spectra or FDS, and four absorption indices) to estimate the fractional cover of seven post-fire ground cover types (vegetation and soil - unburned and charred components - and ash - char and ash, individually and as a combined category). Models were developed and validated at the Peñaflor site (training, n = 217; validation, n = 88) and applied to the samples from the Ibieca and Zuera sites (n = 51). The best results were observed for the abundance estimations of green vegetation (Radj.20.70-0.90), unburned soil (Radj.20.40-0.75), and the combination of ashes (Radj.20.65-0.80). In comparison of spectral data, FDS outperforms reflectance or absorption data because of its higher accuracy levels and, importantly, its greater capacity to yield generalizable models. Future efforts should be made to improve the estimation of intermediate severity levels and upscaling the developed models. In the context of fire severity assessment, our study demonstrates the potential of hyperspectral data to estimate in a quick and objective manner post-fire ground cover fractions and thus provide valuable information to guide management responses.

  1. Land cover for Ukraine: the harmonization of remote sensing and ground-based data

    Science.gov (United States)

    Lesiv, M.; Shchepashchenko, D.; Shvidenko, A.; See, L. M.; Bun, R.

    2012-12-01

    This study focuses on the development of a land cover map of the Ukraine through harmonization of remote sensing and ground-based data. At present there is no land cover map of the Ukraine available that is of sufficient accuracy for use in environmental modeling. The existing remote sensing data are not enough accurate. In this study we compare the territory of the Ukraine from three global remote sensing products (GlobCover 2009, MODIS Land Cover and GLC-2000) using a fuzzy logic methodology in order to capture the uncertainty in the classification of land cover. The results for the Ukraine show that GlobCover 2009, MODIS Land Cover and GLC-2000 have a fuzzy agreement of 65%. We developed a weighted algorithm for the creation of a land cover map based on an integration of a number of global land cover and remote sensing products including the GLC-2000, GlobCover 2009, MODIS Land Cover, the Vegetation Continuous Fields product, digital map of administrative units and forest account data at the local level. This weighted algorithm is based on the results of comparing these products and an analysis of a dataset of validation points for different land cover types in the Ukraine. We applied this algorithm to generate a forest land cover type map. This raster map contains a forest expectation index that was calculated for each pixel. Forest land was then allocated based on forest statistics at the local level. Areas with a higher forest expectation index were allocated with forest first until the results matched the forest statistics. The result is the first digital map of forest (with a spatial resolution of 300m) for the Ukraine, which consistent with forest and land accounts, remote sensing datasets and GIS products. The forest land was well defined in forest rich areas (i.e. in the northern part of the Ukraine, the Carpathians and the Crimea); well less accurate areas were identified in the steppe due to heterogeneous land cover. Acknowledgements. This research was

  2. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    Directory of Open Access Journals (Sweden)

    Daniel Paredes

    Full Text Available Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history, the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard, or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae in 2,528 olive groves in Andalusia (Spain from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  3. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    Science.gov (United States)

    Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M; Campos, Mercedes

    2015-01-01

    Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history), the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard), or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae) in 2,528 olive groves in Andalusia (Spain) from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  4. Covering of heating load of object by using ground heat as a renewable energy source

    Directory of Open Access Journals (Sweden)

    Čenejac Aleksandra R.

    2012-01-01

    Full Text Available Rational use of energy, improving energy performance of buildings and use of renewable energy sources are the most important measures for reducing consumption of non-renewable primary energy (solid, liquid, and gaseous fuels, environmental protection and for the future sustainable development of mankind. In the total primary energy consumption great part is related to building industry, for heating spaces in which people stay and live. Renewable energy sources (RES present natural resources and they are one of the alternatives that allow obtaining heat for heating buildings, and by that they provide a significant contribution to the energy balance of a country. This paper analyzes the participation of ground source as RES, when the vertical (the probe in the ground and horizontal (registry in the ground heat exchangers are used for covering heating load of the building.

  5. Differences in plant cover and species composition of semiarid grassland communities of Central Mexico and its effects on net ecosystem exchange

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    J. Delgado-Balbuena

    2012-12-01

    Full Text Available Changes in land use across the semiarid grasslands of Northern Mexico have driven a decline of plant cover and alteration of plant species composition. A number of different plant communities have resulted from these changes, however, their implications on the carbon cycle and regional carbon balance are still poorly understood. Here, we examined the effects of plant cover loss and changes in species composition on net ecosystem CO2 exchange (NEE and their biotic and abiotic controls. Five typical plant community types were examined in the semiarid grassland by encasing the entire above-ground ecosystem using the geodesic dome method. Sites included an oat crop (crop, a moderately grazed grassland (moderate grazing, a 28 yr-old grazing exclosure (exclosure, an overgrazed site with low perennial grass cover (overgrazed, and an overgrazed site presenting shrub encroachment (shrub encroachment. For natural vegetation, rates of daytime NEE for sites with a high plant cover (exclosure and moderate grazing were similar (P>0.05 as compared to sites with low plant cover (overgrazed and shrub encroachment. However, night time NEE (carbon loss was more than double (P<0.05 for sites with high plant cover compared to sites with low cover, resulting into slight C sinks for the low plant cover sites and neutral or sources for the high plant cover sites on an annual basis. Differences in plant cover and its associated biomass defined the sensitivity to environmental controls. Thus, daytime NEE in low plant cover sites reached light compensation points at lower PPFD values than those from high plant cover sites. Differences in species composition did not influence NEE rates even though there were transient or permanent changes in C3 vs. C4 functional groups.

  6. Impact of the variability of the seasonal snow cover on the ground surface regimes in Hurd Peninsula (Livingston Island, Antarctic)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2014-05-01

    Seasonally snow cover has a great impact on the thermal regime of the active layer and permafrost. Ground temperatures over a year are strongly affected by the timing, duration, thickness, structure and physical and thermal properties of snow cover. The purpose of this communication is to characterize the shallow ground thermal regimes, with special reference to the understanding of the influence snow cover in permafrost spatial distribution, in the ice-free areas of the north western part of Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". We have analyzed and ground temperatures as well as snow thickness data in four sites distributed along an altitudinal transect in Hurd Peninsula from 2007 to 2013: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). At each study site, data loggers were installed for the monitoring of air temperatures (at 1.5 m high), ground temperatures (5, 20 and 40 cm depth) and for snow depth (2, 5, 10, 20, 40, 80 and 160 cm) at 4-hour intervals. The winter data suggests the existence of three types of seasonal stages regarding the ground surface thermal regime and the thickness of snow cover: (a) shallow snow cover with intense ground temperatures oscillations; (b) thick snow cover and low variations of soil temperatures; and (c) stability of ground temperatures. Ground thermal conditions are also conditioned by a strong variability. Winter data indicates that Nuevo Incinerador site experiences more often thicker snow cover with higher ground temperatures and absence of ground temperatures oscillations. Collado Ramos and Ohridski show frequent variations of snow cover thickness, alternating between shallow snow cover with high ground temperature fluctuation and thick snow cover and low ground temperature fluctuation. Reina Sofia in all the years has thick snow cover with little variations in soil

  7. Mechanizing Weakly Ground Termination Proving of Term Rewriting Systems by Structural and Cover-Set Inductions

    Institute of Scientific and Technical Information of China (English)

    Su Feng

    2005-01-01

    The paper presents three formal proving methods for generalized weakly ground terminating property, i.e.,weakly terminating property in a restricted domain of a term rewriting system, one with structural induction, one with cover-set induction, and the third without induction, and describes their mechanization based on a meta-computation model for term rewriting systems-dynamic term rewriting calculus. The methods can be applied to non-terminating, nonconfluent and/or non-left-linear term rewriting systems. They can do "forward proving" by applying propositions in the proof, as well as "backward proving" by discovering lemmas during the proof.

  8. Evidence of wintertime CO2 emission from snow-covered grounds in high latitudes

    Institute of Scientific and Technical Information of China (English)

    方精云; 唐艳鸿KOIZUMI; Hiroshi(Division; of; Plant; Ecology; National; Institute; of; Agro-Environmental; Sciences; Tsukuba; 305; Japan)BEKKU; Yukiko(National; Polar; Institute; Tokyo; 192; Japan)

    1999-01-01

    In order to measure CO2 flux in wintertime arctic ecosystems, CO2 gas was sampled from various snow-covered grounds by using a closed chamber method during the First China Arctic Scientific Expedition from March to May in 1995. The CO2 gas samples were measured by using an infra-red analyzer (IRGA). The results showed that (ⅰ) CO2 emission was detected from all kinds of the snow-covered grounds, which provides direct evidence that the arctic tundra is functioning as a source of atmospheric CO2; (ⅱ) CO2 release was also detected from the permanent ice profile and icecap, and (ⅲ) CO2 evolution from terrestrial ecosystems in higher latitudes increased with an increase of surface temperature in accordance with the exponential function. This indicates a close coincidence with that under normal temperature conditions, and provides a useful method for predicting change in CO2 flux in the arctic ecosystems with the global climate change.

  9. Cover plants with potential use for crop-livestock integrated systems in the Cerrado region

    Directory of Open Access Journals (Sweden)

    Arminda Moreira de Carvalho

    2011-10-01

    Full Text Available The objective of this work was to evaluate the effects of lignin, hemicellulose, and cellulose concentrations in the decomposition process of cover plant residues with potential use in no-tillage with corn, for crop-livestock integrated system, in the Cerrado region. The experiment was carried out at Embrapa Cerrados, in Planaltina, DF, Brazil in a split plot experimental design. The plots were represented by the plant species and the subplots by harvesting times, with three replicates. The cover plants Urochloa ruziziensis, Canavalia brasiliensis, Cajanus cajan, Pennisetum glaucum, Mucuna aterrima, Raphanus sativus, Sorghum bicolor were evaluated together with spontaneous plants in the fallow. Cover plants with lower lignin concentrations and, consequently, higher residue decomposition such as C. brasiliensis and U. ruziziensis promoted higher corn yield. High concentrations of lignin inhibit plant residue decomposition and this is favorable for the soil cover. Lower concentrations of lignin result in accelerated plant decomposition, more efficient nutrient cycling, and higher corn yield.

  10. 40 CFR 63.2132 - What parts of my plant does this subpart cover?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What parts of my plant does this... This Subpart Covers § 63.2132 What parts of my plant does this subpart cover? (a) This subpart applies..., but is not limited to, fermentation vessels (fermenters). The collection of equipment used in...

  11. Experimental evaluation of ALS point cloud ground extraction over different land cover in the Malopolska Province

    Science.gov (United States)

    Korzeniowska, Karolina; Mandlburger, Gottfried; Klimczyk, Agata

    2013-04-01

    The paper presents an evaluation of different terrain point extraction algorithms for Airborne Laser Scanning (ALS) point clouds. The research area covers eight test sites in the Małopolska Province (Poland) with varying point density between 3-15points/m² and surface as well as land cover characteristics. In this paper the existing implementations of algorithms were considered. Approaches based on mathematical morphology, progressive densification, robust surface interpolation and segmentation were compared. From the group of morphological filters, the Progressive Morphological Filter (PMF) proposed by Zhang K. et al. (2003) in LIS software was evaluated. From the progressive densification filter methods developed by Axelsson P. (2000) the Martin Isenburg's implementation in LAStools software (LAStools, 2012) was chosen. The third group of methods are surface-based filters. In this study, we used the hierarchic robust interpolation approach by Kraus K., Pfeifer N. (1998) as implemented in SCOP++ (Trimble, 2012). The fourth group of methods works on segmentation. From this filtering concept the segmentation algorithm available in LIS was tested (Wichmann V., 2012). The main aim in executing the automatic classification for ground extraction was operating in default mode or with default parameters which were selected by the developers of the algorithms. It was assumed that the default settings were equivalent to the parameters on which the best results can be achieved. In case it was not possible to apply an algorithm in default mode, a combination of the available and most crucial parameters for ground extraction were selected. As a result of these analyses, several output LAS files with different ground classification were achieved. The results were described on the basis of qualitative and quantitative analyses, both being in a formal description. The classification differences were verified on point cloud data. Qualitative verification of ground extraction was

  12. AN ASSESSMENT OF CITIZEN CONTRIBUTED GROUND REFERENCE DATA FOR LAND COVER MAP ACCURACY ASSESSMENT

    Directory of Open Access Journals (Sweden)

    G. M. Foody

    2015-08-01

    Full Text Available It is now widely accepted that an accuracy assessment should be part of a thematic mapping programme. Authoritative good or best practices for accuracy assessment have been defined but are often impractical to implement. Key reasons for this situation are linked to the ground reference data used in the accuracy assessment. Typically, it is a challenge to acquire a large sample of high quality reference cases in accordance to desired sampling designs specified as conforming to good practice and the data collected are normally to some degree imperfect limiting their value to an accuracy assessment which implicitly assumes the use of a gold standard reference. Citizen sensors have great potential to aid aspects of accuracy assessment. In particular, they may be able to act as a source of ground reference data that may, for example, reduce sample size problems but concerns with data quality remain. The relative strengths and limitations of citizen contributed data for accuracy assessment are reviewed in the context of the authoritative good practices defined for studies of land cover by remote sensing. The article will highlight some of the ways that citizen contributed data have been used in accuracy assessment as well as some of the problems that require further attention, and indicate some of the potential ways forward in the future.

  13. Changes in plant cover and functional traits induced by grazing in the arid Patagonian Monte

    Science.gov (United States)

    Bär Lamas, M. I.; Larreguy, C.; Carrera, A. L.; Bertiller, M. B.

    2013-08-01

    Grazing disturbance may affect the structure and functioning of arid rangelands. We analyzed the changes in plant cover and plant functional traits (plant height, SLA, N in green leaves) at the community, morphotype and species level in relation to grazing disturbance in arid ecosystems with more than 100 years of sheep grazing history. We identified two grazing areas and within each area we selected two representative and homogeneous sites located far (low grazing disturbance) and near (high grazing disturbance) from the single permanent watering point. We evaluated the plant cover at community, morphotype (evergreen tall shrubs, deciduous shrubs, dwarf shrubs, perennial herbs and perennial grasses) and species level at each site and randomly selected three individuals of modal size of each species to evaluate at them the selected plants traits. Plant cover was reduced by grazing disturbance at the community level. The cover of perennial grasses and evergreen tall shrubs decreased and that of dwarf shrubs increased with increasing grazing disturbance. Increasing cover of dwarf shrubs did not compensate the cover reduction of the other morphotypes. In contrast, plant height, SLA and N in green leaves were not affected by high grazing disturbance at community level as a consequence of positive and negative changes in these traits at morphotype and species levels induced by high grazing disturbance. We concluded that cover was the trait most affected by high grazing disturbance and positive and negative changes in other traits at plant morphotype or species level did not affect community attributes related to resistance against herbivory.

  14. Ground penetrating radar detection of subsnow liquid overflow on ice-covered lakes in interior Alaska

    Directory of Open Access Journals (Sweden)

    A. Gusmeroli

    2012-07-01

    Full Text Available Lakes are abundant throughout the pan-Arctic region. For many of these lakes ice cover lasts for up to two thirds of the year. This frozen cover allows human access to these lakes, which are therefore used for many subsistence and recreational activities, including water harvesting, fishing, and skiing. Safe access to these lakes may be compromised, however, when, after significant snowfall, the weight of the snow acts on the ice and causes liquid water to spill through weak spots and overflow at the snow-ice interface. Since visual detection of subsnow liquid overflow (SLO is almost impossible our understanding on SLO processes is still very limited and geophysical methods that allow SLO detection are desirable. In this study we demonstrate that a commercially available, lightweight 1GHz, ground penetrating radar system can detect and map extent and intensity of SLO. Radar returns from wet snow-ice interfaces are at least twice as much in strength than returns from dry snow-ice interface. The presence of SLO also affects the quality of radar returns from the base of the lake ice. During dry conditions we were able to profile ice thickness of up to 1 m, conversely, we did not retrieve any ice-water returns in areas affected by SLO.

  15. Fungal growth and biomass development is boosted by plants in snow-covered soil.

    Science.gov (United States)

    Kuhnert, Regina; Oberkofler, Irmgard; Peintner, Ursula

    2012-07-01

    Soil microbial communities follow distinct seasonal cycles which result in drastic changes in processes involving soil nutrient availability. The biomass of fungi has been reported to be highest during winter, but is fungal growth really occurring in frozen soil? And what is the effect of plant cover on biomass formation and on the composition of fungal communities? To answer these questions, we monitored microbial biomass N, ergosterol, and the amount of fungal hyphae during summer and winter in vegetated and unvegetated soils of an alpine primary successional habitat. The winter fungal communities were identified by rDNA ITS clone libraries. Winter soil temperatures ranged between -0.6°C and -0.1°C in snow-covered soil. We found distinct seasonal patterns for all biomass parameters, with highest biomass concentrations during winter in snow-covered soil. The presence of plant cover had a significant positive effect on the amount of biomass in the soil, but the type of plant cover (plant species) was not a significant factor. A mean hyphal ingrowth of 5.6 m g(-1) soil was detected in snow-covered soil during winter, thus clearly proving fungal growth during winter in snow-covered soil. Winter fungal communities had a typical species composition: saprobial fungi were dominating, among them many basidiomycete yeasts. Plant cover had no influence on the composition of winter fungal communities.

  16. Crop Ground Cover Fraction and Canopy Chlorophyll Content Mapping using RapidEye imagery

    Science.gov (United States)

    Zillmann, E.; Schonert, M.; Lilienthal, H.; Siegmann, B.; Jarmer, T.; Rosso, P.; Weichelt, T.

    2015-04-01

    Remote sensing is a suitable tool for estimating the spatial variability of crop canopy characteristics, such as canopy chlorophyll content (CCC) and green ground cover (GGC%), which are often used for crop productivity analysis and site-specific crop management. Empirical relationships exist between different vegetation indices (VI) and CCC and GGC% that allow spatial estimation of canopy characteristics from remote sensing imagery. However, the use of VIs is not suitable for an operational production of CCC and GGC% maps due to the limited transferability of derived empirical relationships to other regions. Thus, the operational value of crop status maps derived from remotely sensed data would be much higher if there was no need for reparametrization of the approach for different situations. This paper reports on the suitability of high-resolution RapidEye data for estimating crop development status of winter wheat over the growing season, and demonstrates two different approaches for mapping CCC and GGC%, which do not rely on empirical relationships. The final CCC map represents relative differences in CCC, which can be quickly calibrated to field specific conditions using SPAD chlorophyll meter readings at a few points. The prediction model is capable of predicting SPAD readings with an average accuracy of 77%. The GGC% map provides absolute values at any point in the field. A high R2 value of 80% was obtained for the relationship between estimated and observed GGC%. The mean absolute error for each of the two acquisition dates was 5.3% and 8.7%, respectively.

  17. Major forest changes and land cover transitions based on plant functional types derived from the ESA CCI Land Cover product

    Science.gov (United States)

    Li, Wei; Ciais, Philippe; MacBean, Natasha; Peng, Shushi; Defourny, Pierre; Bontemps, Sophie

    2016-05-01

    Land use and land cover change are of prime concern due to their impacts on CO2 emissions, climate change and ecological services. New global land cover products at 300 m resolution from the European Space Agency (ESA) Climate Change Initiative Land Cover (CCI LC) project for epochs centered around 2000, 2005 and 2010 were analyzed to investigate forest area change and land cover transitions. Plant functional types (PFTs) fractions were derived from these land cover products according to a conversion table. The gross global forest loss between 2000 and 2010 is 172,171 km2, accounting for 0.6% of the global forest area in year 2000. The forest changes are mainly distributed in tropical areas such as Brazil and Indonesia. Forest gains were only observed between 2005 and 2010 with a global area of 9844 km2, mostly from crops in Southeast Asia and South America. The predominant PFT transition is deforestation from forest to crop, accounting for four-fifths of the total increase of cropland area between 2000 and 2010. The transitions from forest to bare soil, shrub, and grass also contributed strongly to the total areal change in PFTs. Different PFT transition matrices and composition patterns were found in different regions. The highest fractions of forest to bare soil transitions were found in the United States and Canada, reflecting forest management practices. Most of the degradation from grassland and shrubland to bare soil occurred in boreal regions. The areal percentage of forest loss and land cover transitions generally decreased from 2000-2005 to 2005-2010. Different data sources and uncertainty in the conversion factors (converting from original LC classes to PFTs) contribute to the discrepancy in the values of change in absolute forest area.

  18. Testing the enemies hypothesis in peach orchards in two different geographic areas in eastern China: the role of ground cover vegetation.

    Directory of Open Access Journals (Sweden)

    Nian-Feng Wan

    Full Text Available Many studies have supported the enemies hypothesis, which suggests that natural enemies are more efficient at controlling arthropod pests in polyculture than in monoculture agro-ecosystems. However, we do not yet have evidence as to whether this hypothesis holds true in peach orchards over several geographic locations. In the two different geographic areas in eastern China (Xinchang a town in the Shanghai municipality, and Hudai, a town in Jiangsu Province during a continuous three-year (2010-2012 investigation, we sampled arthropod pests and predators in Trifolium repens L. and in tree canopies of peach orchards with and without the ground cover plant T. repens. No significant differences were found in the abundances of the main groups of arthropod pests and predators in T. repens between Hudai and Xinchang. The abundance, richness, Simpson's index, Shannon-Wiener index, and Pielou evenness index of canopy predators in ground cover areas increased by 85.5, 27.5, 3.5, 16.7, and 7.9% in Xinchang, and by 87.0, 27.6, 3.5, 17.0 and 8.0% in Hudai compared to those in the controls, respectively. The average abundance of Lepidoptera, Coleoptera, Homoptera, true bugs and Acarina canopy pests in ground cover areas decreased by 9.2, 10.2, 17.2, 19.5 and 14.1% in Xinchang, and decreased by 9.5, 8.2, 16.8, 20.1 and 16.6% in Hudai compared to that in control areas, respectively. Our study also found a higher density of arthropod species resources in T. repens, as some omnivorous pests and predators residing in T. repens could move between the ground cover and the orchard canopy. In conclusion, ground cover in peach orchards supported the enemies hypothesis, as indicated by the fact that ground cover T. repens promoted the abundance and diversity of predators and reduced the number of arthropod pests in tree canopies in both geographical areas.

  19. Testing the enemies hypothesis in peach orchards in two different geographic areas in eastern China: the role of ground cover vegetation.

    Science.gov (United States)

    Wan, Nian-Feng; Ji, Xiang-Yun; Jiang, Jie-Xian

    2014-01-01

    Many studies have supported the enemies hypothesis, which suggests that natural enemies are more efficient at controlling arthropod pests in polyculture than in monoculture agro-ecosystems. However, we do not yet have evidence as to whether this hypothesis holds true in peach orchards over several geographic locations. In the two different geographic areas in eastern China (Xinchang a town in the Shanghai municipality, and Hudai, a town in Jiangsu Province) during a continuous three-year (2010-2012) investigation, we sampled arthropod pests and predators in Trifolium repens L. and in tree canopies of peach orchards with and without the ground cover plant T. repens. No significant differences were found in the abundances of the main groups of arthropod pests and predators in T. repens between Hudai and Xinchang. The abundance, richness, Simpson's index, Shannon-Wiener index, and Pielou evenness index of canopy predators in ground cover areas increased by 85.5, 27.5, 3.5, 16.7, and 7.9% in Xinchang, and by 87.0, 27.6, 3.5, 17.0 and 8.0% in Hudai compared to those in the controls, respectively. The average abundance of Lepidoptera, Coleoptera, Homoptera, true bugs and Acarina canopy pests in ground cover areas decreased by 9.2, 10.2, 17.2, 19.5 and 14.1% in Xinchang, and decreased by 9.5, 8.2, 16.8, 20.1 and 16.6% in Hudai compared to that in control areas, respectively. Our study also found a higher density of arthropod species resources in T. repens, as some omnivorous pests and predators residing in T. repens could move between the ground cover and the orchard canopy. In conclusion, ground cover in peach orchards supported the enemies hypothesis, as indicated by the fact that ground cover T. repens promoted the abundance and diversity of predators and reduced the number of arthropod pests in tree canopies in both geographical areas.

  20. Forage radish winter cover crop suppresses winter annual weeds in fall and before corn planting

    Science.gov (United States)

    Forage radish (Raphanus sativus L. var. longipinnatus) is a new winter cover crop in the Mid-Atlantic region. The objective of this project was to characterize the repeatability, amount, and duration of weed suppression during and after a fall-planted forage radish cover crop and to quantify the sub...

  1. Citizen science land cover classification based on ground and satellite imagery: Case study Day River in Vietnam

    Science.gov (United States)

    Nguyen, Son Tung; Minkman, Ellen; Rutten, Martine

    2016-04-01

    Citizen science is being increasingly used in the context of environmental research, thus there are needs to evaluate cognitive ability of humans in classifying environmental features. With the focus on land cover, this study explores the extent to which citizen science can be applied in sensing and measuring the environment that contribute to the creation and validation of land cover data. The Day Basin in Vietnam was selected to be the study area. Different methods to examine humans' ability to classify land cover were implemented using different information sources: ground based photos - satellite images - field observation and investigation. Most of the participants were solicited from local people and/or volunteers. Results show that across methods and sources of information, there are similar patterns of agreement and disagreement on land cover classes among participants. Understanding these patterns is critical to create a solid basis for implementing human sensors in earth observation. Keywords: Land cover, classification, citizen science, Landsat 8

  2. Estimating Cotton Nitrogen Nutrition Status Using Leaf Greenness and Ground Cover Information

    Directory of Open Access Journals (Sweden)

    Farrah Melissa Muharam

    2015-05-01

    Full Text Available Assessing nitrogen (N status is important from economic and environmental standpoints. To date, many spectral indices to estimate cotton chlorophyll or N content have been purely developed using statistical analysis approach where they are often subject to site-specific problems. This study describes and tests a novel method of utilizing physical characteristics of N-fertilized cotton and combining field spectral measurements made at different spatial scales as an approach to estimate in-season chlorophyll or leaf N content of field-grown cotton. In this study, leaf greenness estimated from spectral measurements made at the individual leaf, canopy and scene levels was combined with percent ground cover to produce three different indices, named TCCLeaf, TCCCanopy, and TCCScene. These indices worked best for estimating leaf N at early flowering, but not for chlorophyll content. Of the three indices, TCCLeaf showed the best ability to estimate leaf N (R2 = 0.89. These results suggest that the use of green and red-edge wavelengths derived at the leaf scale is best for estimating leaf greenness. TCCCanopy had a slightly lower R2 value than TCCLeaf (0.76, suggesting that the utilization of yellow and red-edge wavelengths obtained at the canopy level could be used as an alternative to estimate leaf N in the absence of leaf spectral information. The relationship between TCCScene and leaf N was the lowest (R2 = 0.50, indicating that the estimation of canopy greenness from scene measurements needs improvement. Results from this study confirmed the potential of these indices as efficient methods for estimating in-season leaf N status of cotton.

  3. Effect of Polythene-covering on Above-ground tuberization and storage roots yield in Cassava (Manihot esculenta Crantz

    Directory of Open Access Journals (Sweden)

    Abdullahi N

    2014-02-01

    Full Text Available Present study aimed to investigate the effectiveness of polythene-covering on activation of dormant auxiliary buds on the stem for lateral tuber formation and the resultant effect on total storage roots yield. Three time intervals i.e. 1 day after planting, 30 days after planting and 60 days after planting used as treatment, and uncovered stem used as control. Treatments were tested in randomized complete block design with three replications. Regardless of the variety, stem polythene-covering at day 1 after planting showed the highest effect with respect to storage roots production and yield components tested. However, the effect of stem polythene-covering at day 1 after planting in terms of dry mass partitioning to storage roots was the lowest across all the treatments (25.50 to 27.37% of the biomass compared to that of stem covering at day 60 after planting (33.10 to 37.20%. This study opens new perspectives in cassava yield improvement which hitherto has not been exploited.

  4. Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance under Organic Management.

    Science.gov (United States)

    Lawson, Andrew; Cogger, Craig; Bary, Andy; Fortuna, Ann-Marie

    2015-01-01

    Cover crop benefits include nitrogen accumulation and retention, weed suppression, organic matter maintenance, and reduced erosion. Organic farmers need region-specific information on winter cover crop performance to effectively integrate cover crops into their crop rotations. Our research objective was to compare cover crop seeding mixtures, planting dates, and termination dates on performance of rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) monocultures and mixtures in the maritime Pacific Northwest USA. The study included four seed mixtures (100% hairy vetch, 25% rye-75% hairy vetch, 50% rye-50% hairy vetch, and 100% rye by seed weight), two planting dates, and two termination dates, using a split-split plot design with four replications over six years. Measurements included winter ground cover; stand composition; cover crop biomass, N concentration, and N uptake; and June soil NO3(-)-N. Rye planted in mid-September and terminated in late April averaged 5.1 Mg ha(-1) biomass, whereas mixtures averaged 4.1 Mg ha(-1) and hairy vetch 2.3 Mg ha(-1). Delaying planting by 2.5 weeks reduced average winter ground cover by 65%, biomass by 50%, and cover crop N accumulation by 40%. Similar reductions in biomass and N accumulation occurred for late March termination, compared with late April termination. Mixtures had less annual biomass variability than rye. Mixtures accumulated 103 kg ha(-1) N and had mean C:N ratio Cover crop mixtures provided a balance between biomass accumulation and N concentration, more consistent biomass over the six-year study, and were more effective at reducing winter weeds compared with monocultures.

  5. The role of snow cover in ground thermal conditions in three sites with contrasted topography in Sierra Nevada (Spain)

    Science.gov (United States)

    Oliva, Marc; Salvador, Ferran; Gómez Ortiz, Antonio; Salvà, Montserrat

    2014-05-01

    Snow cover has a high capacity to insulate the soil from the external thermal influences. In regions of high snowfall, such as the summit areas of the highest Iberian mountain ranges, the presence of a thick snow cover may condition the existence or inexistence of permafrost conditions. In order to analyze the impact of the thickness, duration and interannual variability of snow cover on the ground thermal regime in the massif of Sierra Nevada, we have analyzed soil temperatures at a depth of 2 cm for the period 2006-2012 in three sites of contrasting topography as well as air temperatures for the same period: (a) Corral del Veleta (3100 m) in a rock glacier located in the northern Veleta cirque, with high and persistent snow cover. (b) Collado de los Machos (3300 m), in a summit area with relict stone circles, with little snow accumulation due to wind effect. (c) Río Seco (3000 m), in a solifluction lobe located in this southern glacial cirque with moderate snowfall. Considering the air and 2 cm depth soil temperature records, the freezing degree-days were calculated for each year from November to May in order to characterize the role of snow as a thermal insulator of the ground during the cold season (Frauenfeld et al., 2007). In all cases, the highest values of freezing degree-days correspond to years with little snowfall (2006-2007, 2007-2008, 2011-2012), while in years with a thicker snow cover (2008-2009, 2009-2010, 2010-2011) the total freezing degree-days were significantly lower. The accumulation of freezing degree-days is maximum at the wind-exposed site of Collado de los Machos, where the wind redistributes snow and favours the penetration of cold into the ground. The opposite pattern occurs in the Veleta cirque, where most persistent snow cover conditions determine lower accumulated freezing degree-days than in Collado de los Machos and Rio Seco.

  6. Carbon balance of Arctic tundra under increased snow cover mediated by a plant pathogen

    Science.gov (United States)

    Olofsson, Johan; Ericson, Lars; Torp, Mikaela; Stark, Sari; Baxter, Robert

    2011-07-01

    Climate change is affecting plant community composition and ecosystem structure, with consequences for ecosystem processes such as carbon storage. Climate can affect plants directly by altering growth rates, and indirectly by affecting predators and herbivores, which in turn influence plants. Diseases are also known to be important for the structure and function of food webs. However, the role of plant diseases in modulating ecosystem responses to a changing climate is poorly understood. This is partly because disease outbreaks are relatively rare and spatially variable, such that that their effects can only be captured in long-term experiments. Here we show that, although plant growth was favoured by the insulating effects of increased snow cover in experimental plots in Sweden, plant biomass decreased over the seven-year study. The decline in biomass was caused by an outbreak of a host-specific parasitic fungus, Arwidssonia empetri, which killed the majority of the shoots of the dominant plant species, Empetrum hermaphroditum, after six years of increased snow cover. After the outbreak of the disease, instantaneous measurements of gross photosynthesis and net ecosystem carbon exchange were significantly reduced at midday during the growing season. Our results show that plant diseases can alter and even reverse the effects of a changing climate on tundra carbon balance by altering plant composition.

  7. Assessing alternative measures of tree canopy cover: Photo-interpreted NAIP and ground-based estimates

    Science.gov (United States)

    Chris Toney; Greg Liknes; Andy Lister; Dacia Meneguzzo

    2012-01-01

    In preparation for the development of the National Land Cover Database (NLCD) 2011 tree canopy cover layer, a pilot project for research and method development was completed in 2010 by the USDA Forest Service Forest Inventory and Analysis (FIA) program and Remote Sensing Applications Center (RSAC).This paper explores one of several topics investigated during the NLCD...

  8. Performance of quantitative vegetation sampling methods across gradients of cover in Great Basin plant communities

    Science.gov (United States)

    Pilliod, David S.; Arkle, Robert S.

    2013-01-01

    Resource managers and scientists need efficient, reliable methods for quantifying vegetation to conduct basic research, evaluate land management actions, and monitor trends in habitat conditions. We examined three methods for quantifying vegetation in 1-ha plots among different plant communities in the northern Great Basin: photography-based grid-point intercept (GPI), line-point intercept (LPI), and point-quarter (PQ). We also evaluated each method for within-plot subsampling adequacy and effort requirements relative to information gain. We found that, for most functional groups, percent cover measurements collected with the use of LPI, GPI, and PQ methods were strongly correlated. These correlations were even stronger when we used data from the upper canopy only (i.e., top “hit” of pin flags) in LPI to estimate cover. PQ was best at quantifying cover of sparse plants such as shrubs in early successional habitats. As cover of a given functional group decreased within plots, the variance of the cover estimate increased substantially, which required more subsamples per plot (i.e., transect lines, quadrats) to achieve reliable precision. For GPI, we found that that six–nine quadrats per hectare were sufficient to characterize the vegetation in most of the plant communities sampled. All three methods reasonably characterized the vegetation in our plots, and each has advantages depending on characteristics of the vegetation, such as cover or heterogeneity, study goals, precision of measurements required, and efficiency needed.

  9. Using LIDAR and Quickbird Data to Model Plant Production and Quantify Uncertainties Associated with Wetland Detection and Land Cover Generalizations

    Science.gov (United States)

    Cook, Bruce D.; Bolstad, Paul V.; Naesset, Erik; Anderson, Ryan S.; Garrigues, Sebastian; Morisette, Jeffrey T.; Nickeson, Jaime; Davis, Kenneth J.

    2009-01-01

    Spatiotemporal data from satellite remote sensing and surface meteorology networks have made it possible to continuously monitor global plant production, and to identify global trends associated with land cover/use and climate change. Gross primary production (GPP) and net primary production (NPP) are routinely derived from the MOderate Resolution Imaging Spectroradiometer (MODIS) onboard satellites Terra and Aqua, and estimates generally agree with independent measurements at validation sites across the globe. However, the accuracy of GPP and NPP estimates in some regions may be limited by the quality of model input variables and heterogeneity at fine spatial scales. We developed new methods for deriving model inputs (i.e., land cover, leaf area, and photosynthetically active radiation absorbed by plant canopies) from airborne laser altimetry (LiDAR) and Quickbird multispectral data at resolutions ranging from about 30 m to 1 km. In addition, LiDAR-derived biomass was used as a means for computing carbon-use efficiency. Spatial variables were used with temporal data from ground-based monitoring stations to compute a six-year GPP and NPP time series for a 3600 ha study site in the Great Lakes region of North America. Model results compared favorably with independent observations from a 400 m flux tower and a process-based ecosystem model (BIOME-BGC), but only after removing vapor pressure deficit as a constraint on photosynthesis from the MODIS global algorithm. Fine resolution inputs captured more of the spatial variability, but estimates were similar to coarse-resolution data when integrated across the entire vegetation structure, composition, and conversion efficiencies were similar to upland plant communities. Plant productivity estimates were noticeably improved using LiDAR-derived variables, while uncertainties associated with land cover generalizations and wetlands in this largely forested landscape were considered less important.

  10. Using LIDAR and Quickbird Data to Model Plant Production and Quantify Uncertainties Associated with Wetland Detection and Land Cover Generalizations

    Science.gov (United States)

    Cook, Bruce D.; Bolstad, Paul V.; Naesset, Erik; Anderson, Ryan S.; Garrigues, Sebastian; Morisette, Jeffrey T.; Nickeson, Jaime; Davis, Kenneth J.

    2009-01-01

    Spatiotemporal data from satellite remote sensing and surface meteorology networks have made it possible to continuously monitor global plant production, and to identify global trends associated with land cover/use and climate change. Gross primary production (GPP) and net primary production (NPP) are routinely derived from the MOderate Resolution Imaging Spectroradiometer (MODIS) onboard satellites Terra and Aqua, and estimates generally agree with independent measurements at validation sites across the globe. However, the accuracy of GPP and NPP estimates in some regions may be limited by the quality of model input variables and heterogeneity at fine spatial scales. We developed new methods for deriving model inputs (i.e., land cover, leaf area, and photosynthetically active radiation absorbed by plant canopies) from airborne laser altimetry (LiDAR) and Quickbird multispectral data at resolutions ranging from about 30 m to 1 km. In addition, LiDAR-derived biomass was used as a means for computing carbon-use efficiency. Spatial variables were used with temporal data from ground-based monitoring stations to compute a six-year GPP and NPP time series for a 3600 ha study site in the Great Lakes region of North America. Model results compared favorably with independent observations from a 400 m flux tower and a process-based ecosystem model (BIOME-BGC), but only after removing vapor pressure deficit as a constraint on photosynthesis from the MODIS global algorithm. Fine resolution inputs captured more of the spatial variability, but estimates were similar to coarse-resolution data when integrated across the entire vegetation structure, composition, and conversion efficiencies were similar to upland plant communities. Plant productivity estimates were noticeably improved using LiDAR-derived variables, while uncertainties associated with land cover generalizations and wetlands in this largely forested landscape were considered less important.

  11. User Charge Revenues for Wastewater Treatment Plants--Insufficient to Cover Operation and Maintenance.

    Science.gov (United States)

    1981-12-02

    AD-All 588 SEMERAL ACCOUNTINq OFFICE WASHINGTON DC COMUNITY AN--ETC F/S 13/2 USER CHARGE REVENUES FOR WASTEWATER TREATMENT PLANTS--INSUFFICI--ETC(U...COMPTROLLER GENERAL 0 Report To The Congress OF THE UNITED STATES User Charge Revenues For Wastewater = Treatment Piants-Insutficient To Cover Operation And...Maintenance Half of the 36 municipal wastewater treatment plants GAO reviewed in 10 States were not raising sufficient funds from their user charge iP

  12. Soil macrofauna communities under plant cover in a no-till system in Thailand

    Directory of Open Access Journals (Sweden)

    Phakphoom Tantachasatid

    2017-02-01

    Full Text Available The impact of no-till cropping systems with plant cover on soil macrofauna communities was assessed according to their abundance and biomass. The study was carried out in northeastern Thailand under a conventional cropping system (plow-based tillage, no-till cropping systems with plant cover (Brachiaria ruziziensis, Stylosanthes guianensis, S. guianensis associated with B. ruziziensis, rice straw and under a natural dipterocarp forest. Soil macrofauna populations were sampled in 2007 (June and October during the rainy season and at a beginning of the dry season, respectively. The results revealed that in the short term, the biological compartment responded quickly to the presence of plant cover, as shown by a significant increase in soil macrofauna abundance and total biomass. The highest mean total abundance (MTA of 4224 individuals/m2 at the end of planting period (October 2007 was observed under S. guianensis cover and also the highest mean total soil macrofauna biomass (MTB of 14.63 g/m2 was observed in the forest system in the same period. However, in the system of cultivation, the highest MTB of 11.33 g/m2 was observed under S. guianensis cover. Moreover, the change rate of soil macrofauna MTA was the highest under S. guianensis cover (+751.61% and the change rate of soil macrofauna MTB revealed that this change rate was highest in forest (+430.07%. However, in the other systems of cultivation, the highest change rate of MTB was under S. guianensis cover (+12.96%.

  13. A conceptual framework for dryland aeolian sediment transport along the grassland-forest continuum: Effects of woody plant canopy cover and disturbance

    Science.gov (United States)

    Breshears, David D.; Whicker, Jeffrey J.; Zou, Chris B.; Field, Jason P.; Allen, Craig D.

    2009-04-01

    Aeolian processes are of particular importance in dryland ecosystems where ground cover is inherently sparse because of limited precipitation. Dryland ecosystems include grassland, shrubland, savanna, woodland, and forest, and can be viewed collectively as a continuum of woody plant cover spanning from grasslands with no woody plant cover up to forests with nearly complete woody plant cover. Along this continuum, the spacing and shape of woody plants determine the spatial density of roughness elements, which directly affects aeolian sediment transport. Despite the extensiveness of dryland ecosystems, studies of aeolian sediment transport have generally focused on agricultural fields, deserts, or highly disturbed sites where rates of transport are likely to be greatest. Until recently, few measurements have been made of aeolian sediment transport over multiple wind events and across a variety of types of dryland ecosystems. To evaluate potential trends in aeolian sediment transport as a function of woody plant cover, estimates of aeolian sediment transport from recently published studies, in concert with rates from four additional locations (two grassland and two woodland sites), are reported here. The synthesis of these reports leads to the development of a new conceptual framework for aeolian sediment transport in dryland ecosystems along the grassland-forest continuum. The findings suggest that: (1) for relatively undisturbed ecosystems, shrublands have inherently greater aeolian sediment transport because of wake interference flow associated with intermediate levels of density and spacing of woody plants; and (2) for disturbed ecosystems, the upper bound for aeolian sediment transport decreases as a function of increasing amounts of woody plant cover because of the effects of the height and density of the canopy on airflow patterns and ground cover associated with woody plant cover. Consequently, aeolian sediment transport following disturbance spans the largest

  14. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta Forests.

    Directory of Open Access Journals (Sweden)

    Anne C S McIntosh

    Full Text Available Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs and multiple carbon-source substrate-induced respiration (MSIR of the forest floor microbial community environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis showed that two above-ground (mean tree diameter, litter cover and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs properties were associated with variation in understory plant community composition. These results provide

  15. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests.

    Science.gov (United States)

    McIntosh, Anne C S; Macdonald, S Ellen; Quideau, Sylvie A

    2016-01-01

    Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

  16. Fluvial adjustments to soil erosion and plant cover changes in the Central Spanish Pyrenees

    NARCIS (Netherlands)

    Beguería, S.; López-Moreno, J.I.; Gómez-Villar, A.; Rubio, V.; Lana-Renault, N.; García-Ruiz, J.M.

    2007-01-01

    Until the middle of the 20th Century, Pyrenean rivers were characterized by braided channels, unstable sedimentary structures and an almost complete lack of plant cover in the alluvial plain, due to the high sediment yield in hillslopes and the occurrence of frequent and intense flooding. This was p

  17. Soil erosion control, plant diversity, and arthropod communities under heterogeneous cover crops in an olive orchard.

    Science.gov (United States)

    Gómez, José Alfonso; Campos, Mercedes; Guzmán, Gema; Castillo-Llanque, Franco; Vanwalleghem, Tom; Lora, Ángel; Giráldez, Juan V

    2017-01-30

    A 3-year experiment compared in an olive orchard the effect of different cover crops' composition on runoff, water erosion, diversity of annual plants, and arthropod communities which could provide an alternative to conventional management based on tillage (CT). The cover crops evaluated were a seeded homogeneous grass (GC), a seeded mix of ten different species (MCseeded), and a non-seeded cover by vegetation naturally present at the farm after 20 years of mowing (MCnatural). The results suggest that heterogeneous cover crops can provide a viable alternative to homogeneous ones in olives, providing similar benefits in reducing runoff and soil losses compared to management based on bare soil. The reduction in soil loss was particularly large: 46.7 in CT to 6.5 and 7.9 t ha(-1) year(-1) in GC and MCseeded, respectively. The heterogeneous cover crops resulted in greater diversity of plant species and a modification of the arthropod communities with an increased number of predators for pests. The reduction of the cost of implanting heterogeneous cover crops, improvement of the seeding techniques, and selection of species included in the mixes require additional research to promote the use of this practice which can deliver enhanced environmental benefits.

  18. Quantifying the impact of cloud cover on ground radiation flux measurements using hemispherical images

    NARCIS (Netherlands)

    Roupioz, L.; Colin, J.; Jia, L.; Nerry, F.; Menenti, M.

    2015-01-01

    Linking observed or estimated ground incoming solar radiation with cloud coverage is difficult since the latter is usually poorly described in standard meteorological observation protocols. To investigate the benefits of detailed observation and characterization of cloud coverage and distribution

  19. 21 CFR 111.15 - What sanitation requirements apply to your physical plant and grounds?

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false What sanitation requirements apply to your... Plant and Grounds § 111.15 What sanitation requirements apply to your physical plant and grounds? (a...) Sanitation supervisors. You must assign one or more employees to supervise overall sanitation. Each of...

  20. The In-Transit Vigilant Covering Tour Problem of Routing Unmanned Ground Vehicles

    Science.gov (United States)

    2012-08-01

    15 Figure 2. A classic VRP ...17 Figure 3. Solution for a VRP ........................................................................................18 Figure 4. Solution...of NP-hard problems, such as the Traveling Salesman Problem (TSP), Vehicle Routing Problem ( VRP ), and Covering Salesman Problem (CSP) etc. We will

  1. Trait-based characterisation of soil exploitation strategies of banana, weeds and cover plant species

    Science.gov (United States)

    Tardy, Florence; Damour, Gaëlle; Dorel, Marc; Moreau, Delphine

    2017-01-01

    Cover plants can be introduced in cropping systems to provide agroecosystem services, including weed control via competition for resources. There is currently no consensus on how to identify the best cover plant species, while trait-based approaches are promising for screening plant species due to their agroecosystem service provision potential. This study was carried out to characterize soil exploitation strategies of cover plant species in banana agroecosystems using a trait-based approach, and in turn identify cover plant species with a high weed control potential via competition for soil resources in banana cropping systems. A field experiment was conducted on 17 cover plant species, two weed species and two banana cultivars grown individually. Four functional traits were measured. Two of them (i.e., the size of the zone explored by roots and the root impact density) were used to characterize root system soil exploration patterns. Two other traits (i.e., specific root length and root diameter) were used to characterize resource acquisition within the soil zone explored by the roots. All studied traits exhibited marked variations among species. The findings suggested a trade-off between the abilities of species to develop a limited number of large diameter roots exploring a large soil zone versus many thin roots exploring a smaller soil zone. Three soil-resource exploitation strategies were identified among species: (i) with large diameter roots that explore a large soil zone; (ii) with small diameter roots and a high specific length that explore a smaller soil zone; and (iii) with a high total root-impact density and an intermediate specific root length that explore the uppermost soil layers. Interestingly, in our panel of species, no correlations with regard to belowground and aboveground strategies were noted: species with an acquisitive belowground strategy could display an acquisitive or a conservative aboveground strategy. The findings of this study

  2. Trait-based characterisation of soil exploitation strategies of banana, weeds and cover plant species.

    Science.gov (United States)

    Tardy, Florence; Damour, Gaëlle; Dorel, Marc; Moreau, Delphine

    2017-01-01

    Cover plants can be introduced in cropping systems to provide agroecosystem services, including weed control via competition for resources. There is currently no consensus on how to identify the best cover plant species, while trait-based approaches are promising for screening plant species due to their agroecosystem service provision potential. This study was carried out to characterize soil exploitation strategies of cover plant species in banana agroecosystems using a trait-based approach, and in turn identify cover plant species with a high weed control potential via competition for soil resources in banana cropping systems. A field experiment was conducted on 17 cover plant species, two weed species and two banana cultivars grown individually. Four functional traits were measured. Two of them (i.e., the size of the zone explored by roots and the root impact density) were used to characterize root system soil exploration patterns. Two other traits (i.e., specific root length and root diameter) were used to characterize resource acquisition within the soil zone explored by the roots. All studied traits exhibited marked variations among species. The findings suggested a trade-off between the abilities of species to develop a limited number of large diameter roots exploring a large soil zone versus many thin roots exploring a smaller soil zone. Three soil-resource exploitation strategies were identified among species: (i) with large diameter roots that explore a large soil zone; (ii) with small diameter roots and a high specific length that explore a smaller soil zone; and (iii) with a high total root-impact density and an intermediate specific root length that explore the uppermost soil layers. Interestingly, in our panel of species, no correlations with regard to belowground and aboveground strategies were noted: species with an acquisitive belowground strategy could display an acquisitive or a conservative aboveground strategy. The findings of this study

  3. Mapping wind erosion hazard in Australia using MODIS-derived ground cover, soil moisture and climate data

    Science.gov (United States)

    Yang, X.; Leys, J.

    2014-03-01

    This paper describes spatial modeling methods to identify wind erosion hazard (WEH) areas across Australia using the recently available time-series products of satellite-derived ground cover, soil moisture and wind speed. We implemented the approach and data sets in a geographic information system to produce WEH maps for Australia at 500 m ground resolution on a monthly basis for the recent thirteen year period (2000-2012). These maps reveal the significant wind erosion hazard areas and their dynamic tendencies at paddock and regional scales. Dust measurements from the DustWatch network were used to validate the model and interpret the dust source areas. The modeled hazard areas and changes were compared with results from a rule-set approach and the Computational Environmental Management System (CEMSYS) model. The study demonstrates that the time series products of ground cover, soil moisture and wind speed can be jointly used to identify landscape erodibility and to map seasonal changes of wind erosion hazard across Australia. The time series wind erosion hazard maps provide detailed and useful information to assist in better targeting areas for investments and continuous monitoring, evaluation and reporting that will lead to reduced wind erosion and improved soil condition.

  4. Woody Plant Cover Dynamics in Sahelian Drylands from Earth Observation Based Seasonal Metrics

    Science.gov (United States)

    Brandt, M.; Hiernaux, P.; Fensholt, R.; Tagesson, T.; Rasmussen, K.; Mbow, C.

    2015-12-01

    Woody plants play an important role in drylands primary productivity and peoples' livelihood, however, due to their scattered appearance, quantifying and monitoring their abundance over a large area is challenging. From in situ measured woody cover we develop a phenology driven model to estimate the canopy cover of woody species in the Sahelian drylands. Annual maps are applied to monitor dynamics of woody populations in relation to climate and anthropogenic interference. The model estimates the total canopy cover of all woody phanerophytes and the concept is based on the significant difference in phenophases of dryland trees, shrubs and bushes as compared to that of the herbaceous plants. Whereas annual herbaceous are only green during the rainy season and senescence occurs shortly after flowering towards the last rains, most woody plants remain photosynthetically active over large parts of the year. We use Moderate Resolution Imaging Spectroradiometer (MODIS) and SPOT VEGETATION (VGT) seasonal metrics representing the dry season to reproduce in situ woody cover at 77 field sites (178 observations in 3x3 km plots between 2000 and 2014) in Niger, Mali and Senegal. The extrapolation to Sahel scale shows agreement between VGT and MODIS at an almost nine times higher woody cover than in the global tree cover product MOD44B which only captures trees of a certain minimum size. Trends over 15 years show that the pattern is closely related to population density and land cover/use. A negative woody cover change can be observed in densely populated areas, but a positive change is seen in sparsely populated regions. Whereas woody cover in cropland is generally stable, it is strongly positive in savannas and woodland. Discrepancies between the countries are huge and also deforestation can be observed at a more local scale. The method is applicable and derived woody cover maps of the Sahel are freely available. They represent an improvement of existing products and a

  5. CHEMISTRY OF PLANTS AND RECLAIMED GROUNDS ON SODA WASTE SITE AT JANIKOWO

    Directory of Open Access Journals (Sweden)

    Jan Siuta

    2014-10-01

    Full Text Available The paper presents the state of soda waste dumping site prior to reclamation, including the initial vegetation and properties of local grounds, the chemistry of plants colonizing the alkaline grounds in 2013 as well as the comparison of mineral element contents in leaves of trees spontaneously growing on the soda waste site in the years 2000 and 2013. The paper consists an integral part of a wider work concerning the effectiveness of sewage sludge application for bioremediation of highly saline and alkaline waste at the Janikowo Soda Plant. The spontaneous vegetation on soda waste in 2000 was scarce and patchy, its development conditioned by local microrelief where depressions provided water for plant establishment. The main species entering the site included grasses (Lolium perenne, Calamagrostis epigeios and herbs (Reseda lutea, Tussilago farfara and Picris hieracioides. The physico-chemical properties of waste grounds varied widely both horizontally and spatially. In 2013, the reclaimed dumping site was covered by a well-established meadow-likevegetation and the soil top layer (0–5 cm contained 9.2–13.9% Ca and 15–161 mg Cl/kg, at pH 7.6–7.8. The underlying 10–20 cm layer contained 21.1–63.3% Ca and 204–3110 mg Cl/kg, at pH 7.93–9.04. In the deeper 40-60 cm layer there was found 30.0-37.5% Ca and 9 920-16 320 mg Cl/kg, at pH 11.5–12.1. The vegetation growing in the vicinity of soil profiles contained: 1.65–3.36% N; 0.25–0.43% P; 1.38–2.95% K; 0.33–1.10 % Ca and 0.13–0.54% Mg. The contents of heavy metals in plants approximated the average amounts found in meadow clippings in Poland. The contents of main nutrients in leaves of trees spontaneously growing on the waste site were significantly higher in 2013 (2.70–3.21% N; 0.25–0.34% P and 0.98–1.75% K than in the year 2000 (1.70–2.04% N; 0.11–0.21% P and 0.54–0.80% K. The application of sewage sludge and subsequent fertilization of vegetation on waste

  6. Rapid plant-cover establishment on gold mine tailings in southern New Zealand: glasshouse screening trials.

    Science.gov (United States)

    Schroeder, K; Rufaut, C G; Smith, C; Mains, D; Craw, D

    2005-01-01

    The use of a short-term vegetation cover to temporarily control the negative environmental effects of inactive tailings ponds is notfrequently practiced during operational mining, but could have some merit This article reports on a glasshouse trial designed to examine some of the issues associated with short-term vegetation: fast germination of a high proportion of seed, the ability of seedlings to survive in unamended substrates, and potentially toxic substrate. Five nonindigenous plant species were tested--barley (Hordeum vulgare), rye corn (Secale cereale), Italian ryegrass (Lolium multifiorum), red clover (Trifolium pratense), and lucerne (Medicago sativa)--in five different types of substrate: unamended tailings, tailings and fertilizer, tailings and greenwaste, biosolid-blend compost, and local topsoil. The nutrient and heavy metal status (As, Cu, Cd, Ni, Pb) of each substrate type was determined Plant species performance was monitored over 14 wk Substrate metal concentrations were low except for As, which was elevated in all substrate types. Plants in unamended tailings grew less vigorously than plants in tailings and compost or in topsoil. Plant performance in tailings and fertiliser was greatly suppressed following a high fertilization rate. Metal uptake in plants was highest for As (0.4-77 mg kg(-1) DW) and Cu (5.3-50.3 mg kg(-1) DW). Future field trials are necessary to authenticate findings, but barley and rye corn are promising species for a short-term tailings cover.

  7. Mapping woody plant cover in desert grasslands using canopy reflectance modeling and MISR data

    Science.gov (United States)

    Chopping, Mark J.; Su, Lihong; Laliberte, Andrea; Rango, Albert; Peters, Debra P. C.; Martonchik, John V.

    2006-09-01

    A simplified geometric-optical model (SGM) was inverted using red band reflectance data acquired at 275 m in nine viewing angles from the Multiangle Imaging SpectroRadiometer (MISR) flown on NASA's Terra satellite, to provide estimates of fractional woody plant cover for large areas (over 3519 km2) in parts of the Chihuahuan Desert in New Mexico, USA. The use of the model in these semi-arid environments was enabled by the derivation of a priori estimates of the soil/understory background reflectance response. This was made possible by determining relationships between the kernel weights from a LiSparse-RossThin model adjusted against the same MISR data - together with spectral reflectance data derived from MISR's nadir-viewing camera - and the parameters of the Walthall model used to represent the background. Spatial distributions of retrieved fractional woody plant cover match those of % tree cover in the global MODIS Vegetation Continuous Fields product but also include shrubs. Good relationships were obtained with fractional shrub cover measured in pastures in the USDA, ARS Jornada Experimental Range but tree cover in higher elevation and riparian zones was dramatically over-estimated as a result of the fixing of crown height and shape parameters.

  8. Plant cover effect on Bolson tortoise (Gopherus flavomarginatus Legler 1959, Testudinidae burrow use

    Directory of Open Access Journals (Sweden)

    Jorge Luis Becerra-López

    2017-03-01

    Full Text Available The Bolson tortoise, Gopherus flavomarginatus, occurs within a restricted geographical area in the Mexican Chihuahuan Desert. We analyzed the variation in surface microhabitat with relation to the burrow occupancy for this tortoise at the Mapimí Biosphere Reserve, Mexico. In summer 2010, we monitored burrow activity (active, inactive, or abandoned and measured environmental factors that might influence the burrow’s occupancy by tortoises (air temperature, relative humidity and substrate temperature, both inside and outside the burrow, and the plant cover around it. Discriminant analysis was used to identify the importance of these variables influencing burrow occupancy. Correlation and linear regression analyses were performed to quantify the relation between environmental factors in the sampled burrows. Results. Sixty-one burrows were identified at the Tortugas locality. The first function’s auto-value analysis indicates that this function explains 97.9% of the variation in burrow activity status; high occupancy scores were associated with low substrate temperature inside the burrow. Plant cover was inversely proportional to substrate temperature inside the burrow. These results suggest the importance the density of plants surrounding the tortoise’s burrow as a key factor influencing the burrow microclimate and occupancy by the tortoises. Conclusions. Gopherus flavomarginatus inhabits burrows, in part, based on microhabitat structure, with plant cover being a main factor influencing burrow occupancy. Our findings indicate that human land use and vegetation management are important for conserving Bolson tortoises, and for understanding habitat conditions necessary for the successful establishment of populations elsewhere.

  9. Integrity and life estimation of turbine runner cover in a hydro power plant

    Directory of Open Access Journals (Sweden)

    A. Sedmak

    2016-03-01

    Full Text Available This paper presents integrity and life estimation of turbine runner cover in a vertical pipe turbines, Kaplan 200 MW nominal output power, produced in Russia, and built in six hydro-generation units of hydroelectric power plant „Đerdap 1” in Serbia. Fatigue and corrosion-fatigue interaction have been taken into account using experimentally obtained material properties, as well as analytical and numerical calculations of stress state, to estimate appropriate safety factors. Fatigue crack growth rate, da/dN, was also calculated, indicated that internal defects of circular or elliptical shape, found out by ultrasonic testing, do not affect reliable operation of runner cover.

  10. Permafrost, Seasonally Frozen Ground, Snow Cover and Vegetation in the USSR

    Science.gov (United States)

    1984-12-01

    Late Quaternary History and the Formation of Sedi- ments in the Marginal and Inland Seas (Pozdnechetvertichnaia Istorlia i Sedimentogenez...rasprostraneniia snezhnogo pokrova na poverkhnosti sushi zemnogo shara). In Geography of Snow Cover (Geo- grafiya Snezhnogo Prokrova). Moscow: Izdat...Papers, 18(3): 198-202. (36-1668) Vigdorchik, M.E. (1980) Arctic Pleistocene History and the Development of Submarine Permafrost. Boulder

  11. [Effects of ground cover and water-retaining agent on winter wheat growth and precipitation utilization].

    Science.gov (United States)

    Wu, Ji-Cheng; Guan, Xiu-Juan; Yang, Yong-Hui

    2011-01-01

    An investigation was made at a hilly upland in western Henan Province to understand the effects of water-retaining agent (0, 45, and 60 kg x hm(-2)), straw mulching (3000 and 6000 kg x hm(-2)), and plastic mulching (thickness straw- or plastic mulching was combined with the use of water-retaining agent. Comparing with the control, all the measures increased the soil moisture content at different growth stages by 0.1%-6.5%. Plastic film mulching had the best water-retention effect before jointing stage, whereas water-retaining agent showed its best effect after jointing stage. Soil moisture content was the lowest at flowering and grain-filling stages. Land cover increased the grain yield by 2.6%-20.1%. The yield increment was the greatest (14.2%-20.1%) by the combined use of straw mulching and water-retaining agent, followed by plastic mulching combined with water-retaining agent (11.9% on average). Land cover also improved the precipitation use efficiency (0.4-3.2 kg x mm(-1) x hm(-2)) in a similar trend as the grain yield. This study showed that land cover and water-retaining agent improved soil moisture and nutrition conditions and precipitation utilization, which in turn, promoted the tillering of winter wheat, and increased the grain number per ear and the 1000-grain mass.

  12. The Impact of Time Difference between Satellite Overpass and Ground Observation on Cloud Cover Performance Statistics

    Directory of Open Access Journals (Sweden)

    Jędrzej S. Bojanowski

    2014-12-01

    Full Text Available Cloud property data sets derived from passive sensors onboard the polar orbiting satellites (such as the NOAA’s Advanced Very High Resolution Radiometer have global coverage and now span a climatological time period. Synoptic surface observations (SYNOP are often used to characterize the accuracy of satellite-based cloud cover. Infrequent overpasses of polar orbiting satellites combined with the 3- or 6-h SYNOP frequency lead to collocation time differences of up to 3 h. The associated collocation error degrades the cloud cover performance statistics such as the Hanssen-Kuiper’s discriminant (HK by up to 45%. Limiting the time difference to 10 min, on the other hand, introduces a sampling error due to a lower number of corresponding satellite and SYNOP observations. This error depends on both the length of the validated time series and the SYNOP frequency. The trade-off between collocation and sampling error call for an optimum collocation time difference. It however depends on cloud cover characteristics and SYNOP frequency, and cannot be generalized. Instead, a method is presented to reconstruct the unbiased (true HK from HK affected by the collocation differences, which significantly (t-test p < 0.01 improves the validation results.

  13. Effect of heavy metals on seed germination and seedling growth of common ragweed and roadside ground cover legumes.

    Science.gov (United States)

    Bae, Jichul; Benoit, Diane L; Watson, Alan K

    2016-06-01

    In southern Québec, supplement roadside ground covers (i.e. Trifolium spp.) struggle to establish near edges of major roads and thus fail to assist turf recruitment. It creates empty niches vulnerable to weed establishment such as common ragweed (Ambrosia artemisiifolia). We hypothesized that heavy metal stresses may drive such species shifts along roadside edges. A growth chamber experiment was conducted to assess effects of metals (Zn, Pb, Ni, Cu, and Cd) on germination and seedling behaviors of roadside weed (A. artemisiifolia) and ground cover legumes (Coronilla varia, Lotus corniculatus, and Trifolium arvense). All metals inhibited T. arvense germination, but the effect was least on A. artemisiifolia. Low levels of Pb and Ni promoted germination initiation of A. artemisiifolia. Germination of L. corniculatus was not affected by Zn, Pb, and Ni, but inhibited by Cu and Cd. Germination of C. varia was decreased by Ni, Cu, and Cd and delayed by Zn and Pb. Metal additions hindered seedling growth of all test species, and the inhibitory effect on the belowground growth was greater than on the aboveground growth. Seedling mortality was lowest in A. artemisiifolia but highest in T. arvense when exposed to the metal treatments. L. corniculatus and C. varia seedlings survived when subjected to high levels of Zn, Pb, and Cd. In conclusion, the successful establishment of A. artemisiifolia along roadside edges can be associated with its greater tolerance of heavy metals. The findings also revealed that L. corniculatus is a potential candidate for supplement ground cover in metal-contaminated roadside edges in southern Québec, especially sites contaminated with Zn and Pb.

  14. Chapter 6: Tree-compatible ground covers for reforestation and erosion control

    Science.gov (United States)

    J. Burger; V. Davis; C. Zipper; J. Skousen; C. Barton; P. Angel

    2017-01-01

    Productive native forests create economic value for landowners, produce raw materials for wood-based products, and provide benefits such as watershed control, water quality protection, carbon storage, wildlife habitat, and native plant diversity. Owners of lands mined for coal in the Appalachian region are increasingly interested in assuring that productive forests are...

  15. Soybean growth and yield after single tillage and species mixture of cover plants

    Directory of Open Access Journals (Sweden)

    Gislaine Piccolo de Lima

    2012-10-01

    Full Text Available The use of cover crops is important for the agricultural crop and soil management in order to improve the system and, consequently, to increase yield. Therefore, the present study analyzed the effect of crop residues of black oat (Avena strigosa Schreb. (BO and a cocktail (CO of BO, forage turnip (Raphanus sativus L. (FT and common vetch (Vicia sativa L. (V on the emergence speed index (ESI, seedling emergence speed (SES plant height and soybean yield in different intervals between cover crop desiccation with glyphosate 480 (3 L ha-1 and BRS 232 cultivar sowing. Plots of 5 x 2.5 m with 1 m of border received four treatments with BO cover crops and four with CO as well as a control for each cover crop, at random, with five replications. The plots were desiccated in intervals of 1, 10, 20 and 30 days before soybean seeding. The harvest was manual while yield was adjusted to 13% of moisture content. The experimental design was completely randomized with splitplots and means compared by the Scott and Knott test at 5% of significance. The results showed that CO of cover crops can be recommended for soybean to obtain a more vigorous seedling emergence, from 10 days after cover crop desiccation.

  16. Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance under Organic Management.

    Directory of Open Access Journals (Sweden)

    Andrew Lawson

    Full Text Available Cover crop benefits include nitrogen accumulation and retention, weed suppression, organic matter maintenance, and reduced erosion. Organic farmers need region-specific information on winter cover crop performance to effectively integrate cover crops into their crop rotations. Our research objective was to compare cover crop seeding mixtures, planting dates, and termination dates on performance of rye (Secale cereale L. and hairy vetch (Vicia villosa Roth monocultures and mixtures in the maritime Pacific Northwest USA. The study included four seed mixtures (100% hairy vetch, 25% rye-75% hairy vetch, 50% rye-50% hairy vetch, and 100% rye by seed weight, two planting dates, and two termination dates, using a split-split plot design with four replications over six years. Measurements included winter ground cover; stand composition; cover crop biomass, N concentration, and N uptake; and June soil NO3(--N. Rye planted in mid-September and terminated in late April averaged 5.1 Mg ha(-1 biomass, whereas mixtures averaged 4.1 Mg ha(-1 and hairy vetch 2.3 Mg ha(-1. Delaying planting by 2.5 weeks reduced average winter ground cover by 65%, biomass by 50%, and cover crop N accumulation by 40%. Similar reductions in biomass and N accumulation occurred for late March termination, compared with late April termination. Mixtures had less annual biomass variability than rye. Mixtures accumulated 103 kg ha(-1 N and had mean C:N ratio <17:1 when planted in mid-September and terminated in late April. June soil NO3(--N (0 to 30 cm depth averaged 62 kg ha(-1 for rye, 97 kg ha(-1 for the mixtures, and 119 kg ha(-1 for hairy vetch. Weeds comprised less of the mixtures biomass (20% weeds by weight at termination compared with the monocultures (29%. Cover crop mixtures provided a balance between biomass accumulation and N concentration, more consistent biomass over the six-year study, and were more effective at reducing winter weeds compared with monocultures.

  17. Comparing distinct ground-based lightning location networks covering the Netherlands

    Science.gov (United States)

    de Vos, Lotte; Leijnse, Hidde; Schmeits, Maurice; Beekhuis, Hans; Poelman, Dieter; Evers, Läslo; Smets, Pieter

    2015-04-01

    Lightning can be detected using a ground-based sensor network. The Royal Netherlands Meteorological Institute (KNMI) monitors lightning activity in the Netherlands with the so-called FLITS-system; a network combining SAFIR-type sensors. This makes use of Very High Frequency (VHF) as well as Low Frequency (LF) sensors. KNMI has recently decided to replace FLITS by data from a sub-continental network operated by Météorage which makes use of LF sensors only (KNMI Lightning Detection Network, or KLDN). KLDN is compared to the FLITS system, as well as Met Office's long-range Arrival Time Difference (ATDnet), which measures Very Low Frequency (VLF). Special focus lies on the ability to detect Cloud to Ground (CG) and Cloud to Cloud (CC) lightning in the Netherlands. Relative detection efficiency of individual flashes and lightning activity in a more general sense are calculated over a period of almost 5 years. Additionally, the detection efficiency of each system is compared to a ground-truth that is constructed from flashes that are detected by both of the other datasets. Finally, infrasound data is used as a fourth lightning data source for several case studies. Relative performance is found to vary strongly with location and time. As expected, it is found that FLITS detects significantly more CC lightning (because of the strong aptitude of VHF antennas to detect CC), though KLDN and ATDnet detect more CG lightning. We analyze statistics computed over the entire 5-year period, where we look at CG as well as total lightning (CC and CG combined). Statistics that are considered are the Probability of Detection (POD) and the so-called Lightning Activity Detection (LAD). POD is defined as the percentage of reference flashes the system detects compared to the total detections in the reference. LAD is defined as the fraction of system recordings of one or more flashes in predefined area boxes over a certain time period given the fact that the reference detects at least one

  18. Effect of tillage and planting date on seasonal abundance and diversity of predacious ground beetles in cotton.

    Science.gov (United States)

    Shrestha, R B; Parajulee, M N

    2010-01-01

    A 2-year field study was conducted in the southern High Plains region of Texas to evaluate the effect of tillage system and cotton planting date window on seasonal abundance and activity patterns of predacious ground beetles. The experiment was deployed in a split-plot randomized block design with tillage as the main-plot factor and planting date as the subplot factor. There were two levels for each factor. The two tillage systems were conservation tillage (30% or more of the soil surface is covered with crop residue) and conventional tillage. The two cotton planting date window treatments were early May (normal planting) and early June (late planting). Five prevailing predacious ground beetles, Cicindela sexguttata F., Calosoma scrutator Drees, Pasimachus spp., Pterostichus spp., and Megacephala Carolina L. (Coleoptera: Carabidae), were monitored using pitfall traps at 2-week intervals from June 2002 to October 2003. The highest total number of ground beetles (6/trap) was observed on 9 July 2003. Cicindela sexguttata was the dominant ground dwelling predacious beetle among the five species. A significant difference between the two tillage systems was observed in the abundances of Pterostichus spp. and C. sexguttata. In 2002. significantly more Pterostichus spp. were recorded from conventional plots (0.27/trap) than were recorded from conservation tillage plots (0.05/trap). Significantly more C. sexguttata were recorded in 2003 from conservation plots (3.77/trap) than were recorded from conventional tillage plots (1.04/trap). There was a significant interaction between year and tillage treatments. However, there was no significant difference in the abundances of M. Carolina and Pasimachus spp. between the two tillage practices in either of the two years. M. Carolina numbers were significantly higher in late-planted cotton compared with those observed in normal-planted cotton. However, planting date window had no significant influence on the activity patterns of the

  19. After the fire: benefits of reduced ground cover for vervet monkeys (Cercopithecus aethiops).

    Science.gov (United States)

    Jaffe, Karin Enstam; Isbell, Lynne A

    2009-03-01

    Here we describe changes in ranging behavior and other activities of vervet monkeys (Cercopithecus aethiops) after a wildfire eliminated grass cover in a large area near the study group's home range. Soon after the fire, the vervets ranged farther away from tall trees that provide refuge from mammalian predators, and moved into the burned area where they had never been observed to go before the fire occurred. Visibility at vervet eye-level was 10 times farther in the burned area than in unburned areas. They traveled faster, and adult females spent more time feeding and less time scanning bipedally in the burned area than in the unburned area. The burned area's greater visibility may have lowered the animals' perceived risk of predation there, and may have provided them with an unusual opportunity to eat acacia ants.

  20. Rock climbing alters plant species composition, cover, and richness in Mediterranean limestone cliffs.

    Science.gov (United States)

    Lorite, Juan; Serrano, Fabio; Lorenzo, Adrián; Cañadas, Eva M; Ballesteros, Miguel; Peñas, Julio

    2017-01-01

    Rock climbing is among the outdoor activities that have undergone the highest growth since the second half of the 20th century. As a result, cliff habitats, historically one of the least disturbed by human colonization worldwide, are facing more intense human pressure than ever before. However, there is little data on the impact of this activity in plant-communities, and such information is indispensable for adequate manager decision-making. The goal of this study was to determine the impact of rock climbing on plant communities in terms of cover, richness, and composition in relation to climbing intensity on typical Mediterranean limestone cliffs. Three rock-climbing sites were selected in the Baetic range (SE Spain), corresponding to qualitative categories of climbing frequentation: i)"low" (low frequentation with intermittent climbing), ii)"medium" (high frequentation without overcrowding), and iii) "high" (high frequentation with overcrowding). Within each site, we selected climbing routes and adjacent areas free of climbing, then we carried out a photoplot-based sampling by rappelling. We analysed the images to calculate: richness, species cover, and total cover. This study shows that rock climbing negatively affected the cliff plant community at all three study sites. A significant decrease in plant cover, species richness and a shift in the community composition were recorded for climbed areas, the cover being the variable most sensitive to rock climbing. Impact observed proved to be related to the frequentation level. Low-frequentation sites, with usually more specialized climbers, underwent relatively mild damages, whereas at high frequentation sites the impact was severe and the conservation of the species, especially rare ones, became jeopardized. Our study is the first one available to investigate climbing impact on plant communities in Mediterranean areas, but more research on the impact of rock climbing is needed to assess the regulation of this

  1. An assessment of plant biointrusion at the Uranium Mill Tailings Remedial Action Project rock-covered disposal cells

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

    This study is one of a number of special studies that have been conducted regarding various aspects of the Uranium Mill Tailings Remedial Action (UMTRA) Project. This special study was proposed following routine surveillance and maintenance surveys and observations reported in a special study of vegetative covers (DOE, 1988), in which plants were observed growing up through the rock erosion layer at recently completed disposal cells. Some of the plants observed were deep-rooted woody species, and questions concerning root intrusion into disposal cells and the need to control plant growth were raised. The special study discussed in this report was designed to address some of the ramifications of plant growth on disposal cells that have rock covers. The NRC has chosen rock covers over vegetative covers in the arid western United States because licenses cannot substantiate that the vegetative covers will be significantly greater than 30 percent and preferably 70 percent,'' which is the amount of vegetation required to reduce flow to a point of stability.'' The potential impacts of vegetation growing in rock covers are not addressed by the NRC (1990). The objectives, then, of this study were to determine the species of plants growing on two rock-covered disposal cells, study the rooting pattern of plants on these cells, and identify possible impacts of plant root penetration on these and other UMTRA Project rock-covered cells.

  2. Land cover change and plants diversity in the Sahel: A case study from northern Burkina Faso

    Directory of Open Access Journals (Sweden)

    Abel Kadeba

    2015-04-01

    Full Text Available Understanding land cover degradation patterns and the effects of geomorphological units on phytodiversity is important for guiding management decisions and restoration strategies in the Sahelian vulnerables zones. This paper describes land cover degradation by combining Landsat TM image analysis and field data measurements in the Gourouol catchment of the Sahelian zone of Burkina Faso. Erdas Imagine 9.2 and Arc-GIS.10 were applied. The change patterns were obtained by superposing land cover maps for 1992 and 2010. The field data were collected by the mean of inventories according to the Braun-Blanquet phytosociological relevés methods. Plot sizes were 50 m x 20 m for woody species and 10 m x 10 m for herbaceous species. Six land cover types were identified and mapped: cultivated lands, bared lands, lowlands, which all spatially increased; and shrub-steppes, grasslands and water bodies, which all spatially decreased. The dynamic patterns based on the geomorphological units were non-degraded lowlands, stable sand dunes and degraded glacis. High plant diversity was found in lowlands, whereas low diversity occurred in glacis. A significant dissimilarity was observed between communities. The Shannon diversity indices in plant communities were approximately close to ln(species richness. The Pielou indices were close to 1, indicating a species fairly good distribution. Our results showed a variation of land cover over time and the effects of geomorphological units on phytodiversity. Furthermore, this variation helps oppose land degradation in the Sahel.

  3. Selective withdrawal to reduce regulation effects on ice cover downstream outlet of Alta power plant

    Energy Technology Data Exchange (ETDEWEB)

    Asvall, R.P. [Norwegian Water Resources and Energy Directorate, Oslo (Norway)

    2007-07-01

    Norway's controversial Alta hydroelectric power plant was constructed on one of the richest salmon rivers in Norway. There were serious concerns regarding how the power plant would influence ice conditions and fish habitat in the river. It was commissioned in 1987 following extensive environmental impact studies. Studies on water temperature, ice conditions and fish population have continued after commissioning in order to document changes caused by the power plant. The power station has two intakes in the dam. The storage capacity is 6 per cent of yearly inflow to the reservoir. The outlet of the power plant is located 2 km downstream the dam. The power plant discharge has been limited to 30 m{sup 3}/s in winter and as close as possible to natural flow during the fishing season. The reservoir is filled over a 2 to 3 week period during spring flood. Initially, only one intake to the power station was planned, but an upper intake was subsequently built to minimize the impact on fish, although the effect has been marginal. Before flow regulation, the river was ice covered except for limited leads. Flow regulation has reduced the ice cover considerably, and the water temperature has been slightly lower in summer and higher in fall and winter. After flow regulation, the amount of fish near the power station outlet decreased considerably, due in part to less shelter resulting from reduced ice cover. In order to improve conditions for the fish, the licence for the power plant is being modified to use the upper intake in winter to reduce water temperatures and make it possible for ice to form between the outlet of the power plant and Savko Lake. There are strong limitations on reductions in discharge in spring to protect the fish habitat. A new scheme of regulation based on use of the upper intake in winter will be implemented. The discharge must be increased in such a way that the ice release will be as close to thermal as possible. 3 refs., 7 figs.

  4. Temporal monitoring of the soil freeze-thaw cycles over snow-cover land by using off-ground GPR

    KAUST Repository

    Jadoon, Khan

    2013-07-01

    We performed off-ground ground-penetrating radar (GPR) measurements over a bare agricultural field to monitor the freeze-thaw cycles over snow-cover. The GPR system consisted of a vector network analyzer combined with an off-ground monostatic horn antenna, thereby setting up an ultra-wideband stepped-frequency continuous-wave radar. Measurements were performed during nine days and the surface of the bare soil was exposed to snow fall, evaporation and precipitation as the GPR antenna was mounted 110 cm above the ground. Soil surface dielectric permittivity was retrieved using an inversion of time-domain GPR data focused on the surface reflection. The GPR forward model used combines a full-waveform solution of Maxwell\\'s equations for three-dimensional wave propagation in planar layered media together with global reflection and transmission functions to account for the antenna and its interactions with the medium. Temperature and permittivity sensors were installed at six depths to monitor the soil dynamics in the top 8 cm depth. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and permittivity data and in particular freeze and thaw events were clearly visible. A good agreement of the trend was observed between the temperature, permittivity and GPR time-lapse data with respect to five freeze-thaw cycles. The GPR-derived permittivity was in good agreement with sensor observations. The proposed method appears to be promising for the real-time mapping and monitoring of the frozen layer at the field scale. © 2013 IEEE.

  5. Alelopatia de cultivos de cobertura vegetal sobre plantas infestantes = Allelopathy of cover crop on weed plants

    Directory of Open Access Journals (Sweden)

    Luciene Kazue Tokura

    2006-07-01

    Full Text Available O presente trabalho avaliou o potencial alelopático de cultivos de cobertura vegetal de trigo, aveia preta, milheto, nabo forrageiro e colza sobre o desenvolvimento de plantas infestantes e verificou qual das coberturas vegetais exerce maior controle sobre as mesmas. Os cultivos de cobertura vegetal foram implantados sob preparo convencional (uma aração e uma gradagem no Núcleo Experimental de Engenharia Agrícola (NEEA, da Universidade Estadual do Oeste do Paraná (Unioeste, Cascavel, Estado do Paraná. Mensalmente, realizou-se o acompanhamento e identificação das plantas infestantes emersas nas áreas de cobertura vegetal no período de agosto de 2000 a agosto de 2001. Os resultados obtidos permitiram concluir que das espécies encontradas, o capim marmelada foi o que apresentou maior potencial alelopático e a erva-de-santa-maria o menor. As coberturasvegetais que apresentaram melhor controle do total de plantas infestantes presentes na área experimental, incluindo àquelas com reconhecido potencial alelopático, foram aveia preta, colza, nabo forrageiro e milheto.This work evaluated the cover crop allelopathic potential of wheat, black oat, pearl millet, turnip and rape on the development of weed plants. It also verified which cover crop has larger control on the weed plants. The cover crop was implanted under conventional tillage (one disk plowing plus one disk harrowing in the Experimental Nucleus of Agricultural Engineering (NEEA, of the State University of the West of Paraná (Unioeste, Cascavel, Paraná State. Monthly (from August 2000 to August 2001, weed plants identification in the cover crop area was made. Results showed that from the found species, the alexander grass was the one that presented larger allelopathic potential, and, the mexican-tea was the one that presented smaller control. The vegetable coverings that presented larger control of the total of weed plants in the experimental area, including those with

  6. Urban heat island impacts on plant phenology: intra-urban variability and response to land cover

    Science.gov (United States)

    Zipper, Samuel C.; Schatz, Jason; Singh, Aditya; Kucharik, Christopher J.; Townsend, Philip A.; Loheide, Steven P., II

    2016-05-01

    Despite documented intra-urban heterogeneity in the urban heat island (UHI) effect, little is known about spatial or temporal variability in plant response to the UHI. Using an automated temperature sensor network in conjunction with Landsat-derived remotely sensed estimates of start/end of the growing season, we investigate the impacts of the UHI on plant phenology in the city of Madison WI (USA) for the 2012-2014 growing seasons. Median urban growing season length (GSL) estimated from temperature sensors is ˜5 d longer than surrounding rural areas, and UHI impacts on GSL are relatively consistent from year-to-year. Parks within urban areas experience a subdued expression of GSL lengthening resulting from interactions between the UHI and a park cool island effect. Across all growing seasons, impervious cover in the area surrounding each temperature sensor explains >50% of observed variability in phenology. Comparisons between long-term estimates of annual mean phenological timing, derived from remote sensing, and temperature-based estimates of individual growing seasons show no relationship at the individual sensor level. The magnitude of disagreement between temperature-based and remotely sensed phenology is a function of impervious and grass cover surrounding the sensor, suggesting that realized GSL is controlled by both local land cover and micrometeorological conditions.

  7. On the Importance of High-Resolution Time Series of Optical Imagery for Quantifying the Effects of Snow Cover Duration on Alpine Plant Habitat

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Dedieu

    2016-06-01

    Full Text Available We investigated snow cover dynamics using time series of moderate (MODIS to high (SPOT-4/5, Landsat-8 spatial resolution satellite imagery in a 3700 km2 region of the southwestern French Alps. Our study was carried out in the context of the SPOT (Take 5 Experiment initiated by the Centre National d’Etudes Spatiales (CNES, with the aim of exploring the utility of high spatial and temporal resolution multispectral satellite imagery for snow cover mapping and applications in alpine ecology. Our three objectives were: (i to validate remote sensing observations of first snow free day derived from the Normalized Difference Snow Index (NDSI relative to ground-based measurements; (ii to generate regional-scale maps of first snow free day and peak standing biomass derived from the Normalized Difference Vegetation Index (NDVI; and (iii to examine the usefulness of these maps for habitat mapping of herbaceous vegetation communities above the tree line. Imagery showed strong agreement with ground-based measurements of snow melt-out date, although R2 was higher for SPOT and Landsat time series (0.92 than for MODIS (0.79. Uncertainty surrounding estimates of first snow free day was lower in the case of MODIS, however (±3 days as compared to ±9 days for SPOT and Landsat, emphasizing the importance of high temporal as well as high spatial resolution for capturing local differences in snow cover duration. The main floristic differences between plant communities were clearly visible in a two-dimensional habitat template defined by the first snow free day and NDVI at peak standing biomass, and these differences were accentuated when axes were derived from high spatial resolution imagery. Our work demonstrates the enhanced potential of high spatial and temporal resolution multispectral imagery for quantifying snow cover duration and plant phenology in temperate mountain regions, and opens new avenues to examine to what extent plant community diversity and

  8. Expression profile analysis of genes involved in horizontal gravitropism bending growth in the creeping shoots of ground-cover chrysanthemum by suppression subtractive hybridization.

    Science.gov (United States)

    Xia, Shengjun; Chen, Yu; Jiang, Jiafu; Chen, Sumei; Guan, Zhiyong; Fang, Weimin; Chen, Fadi

    2013-01-01

    The molecular mechanisms underlying gravitropic bending of shoots are poorly understood and how genes related with this growing progress is still unclear. To identify genes related to asymmetric growth in the creeping shoots of chrysanthemum, suppression subtractive hybridization was used to visualize differential gene expression in the upper and lower halves of creeping shoots of ground-cover chrysanthemum under gravistimulation. Sequencing of 43 selected clones produced 41 unigenes (40 singletons and 1 unigenes), which were classifiable into 9 functional categories. A notable frequency of genes involve in cell wall biosynthesis up-regulated during gravistimulation in the upper side or lower side were found, such as beta tubulin (TUB), subtilisin-like protease (SBT), Glutathione S-transferase (GST), and expensing-like protein (EXP), lipid transfer proteins (LTPs), glycine-rich protein (GRP) and membrane proteins. Our findings also highlighted the function of some metal transporter during asymmetric growth, including the boron transporter (BT) and ZIP transporter (ZT), which were thought primarily for maintaining the integrity of cell walls and played important roles in cellulose biosynthesis. CmTUB (beta tubulin) was cloned, and the expression profile and phylogeny was examined, because the cytoskeleton of plant cells involved in the plant gravitropic bending growth is well known.

  9. Plant growth on debris covered glacier surfaces - ecology, vegetation patterns and implications for debris mantled glaciers serving as cold and warm stage plant refugia in the past

    Science.gov (United States)

    Fickert, Thomas; Friend, Donald; Grüninger, Friederike; Molnia, Bruce; Richter, Michael

    2017-04-01

    As stated at the International Conference on Debris-Covered Glaciers in 2000, "debris-covered glaciers comprise a significant fraction of the global population of glaciers...." Given a minimum of debris thickness and sufficient stability, these surfaces host surprisingly diverse plant assemblages, both floristically and structurally. Observations of plant growth on glacier surfaces are reported from around the world - including mature forests with trees more than 50cm in diameter. Debris covered glacier surfaces are mobile habitats for plants, which migrate downhill with glacier movement, but are able to spread upward with strong anabatic valley winds. Plant growth is possible even on a very shallow debris cover. Depending on site conditions, floristic composition and structure of vegetation on debris covered glaciers represent a mosaic of environments, including subnival pioneer communities, glacier foreland early- to late-successional stages, and morainal locations. The taxa involved display a wide spectrum of adaptations to habitat conditions with particular migration and dispersal strategies. With a shallow debris cover, alpine/subnival taxa can grow considerably below their usual altitudinal niche due to the cooler subsurface soil temperatures. In contrast, a greater thickness of debris cover allows even thermophilous plants of lower elevations to grow on glacier surfaces. Employing the principle of actualism, debris covered glaciers provided important and previously undocumented refugia for plants during the Pleistocene cold stages from which alpine and arctic plant species were able to re-establish and spread in post-glacial time. This assumption is complementary to the two competing ideas to explain the fate of alpine and/or arctic taxa during the Pleistocene, the nunatak hypothesis (i.e. in-situ survival of plants on unglaciated summits) and tabula rasa theory (i.e. displacement of plants and subsequent remigration). Vice versa debris covered glaciers

  10. Estonian soil classification as a tool for recording information on soil cover and its matching with local site types, plant covers and humus forms classifications

    Science.gov (United States)

    Kõlli, Raimo; Tõnutare, Tõnu; Rannik, Kaire; Krebstein, Kadri

    2015-04-01

    Estonian soil classification (ESC) has been used successfully during more than half of century in soil survey, teaching of soil science, generalization of soil databases, arrangement of soils sustainable management and others. The Estonian normally developed (postlithogenic) mineral soils (form 72.4% from total area) are characterized by mean of genetic-functional schema, where the pedo-ecological position of soils (ie. location among other soils) is given by means of three scalars: (i) 8 stage lithic-genetic scalar (from rendzina to podzols) separates soils each from other by parent material, lithic properties, calcareousness, character of soil processes and others, (ii) 6 stage moisture and aeration conditions scalar (from aridic or well aerated to permanently wet or reductic conditions), and (iii) 2-3 stage soil development scalar, which characterizes the intensity of soil forming processes (accumulation of humus, podzolization). The organic soils pedo-ecological schema, which links with histic postlithogenic soils, is elaborated for characterizing of peatlands superficial mantle (form 23.7% from whole soil cover). The position each peat soil species among others on this organic (peat) soil matrix schema is determined by mean of 3 scalars: (i) peat thickness, (ii) type of paludification or peat forming peculiarities, and (iii) stage of peat decomposition or peat type. On the matrix of abnormally developed (synlithogenic) soils (all together 3.9%) the soil species are positioned (i) by proceeding in actual time geological processes as erosion, fluvial processes (at vicinity of rivers, lakes or sea) or transforming by anthropogenic and technological processes, and (ii) by 7 stage moisture conditions (from aridic to subaqual) of soils. The most important functions of soil cover are: (i) being a suitable environment for plant productivity; (ii) forming adequate conditions for decomposition, transformation and conversion of falling litter (characterized by humus

  11. Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillsid

    Institute of Scientific and Technical Information of China (English)

    陈欣; 杨一松; 唐建军

    2004-01-01

    Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m2 and separated by 2m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positive ecological effects on citrus orchard ecosystem stability.

  12. Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillside

    Institute of Scientific and Technical Information of China (English)

    陈欣; 杨一松; 唐建军

    2004-01-01

    Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang)orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m2 and separated by 2 m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positiveecological effects on citrus orchard ecosystem stability.

  13. Regularities of restoration of plant cover on the dumps of the Kuznetsk Basin

    Directory of Open Access Journals (Sweden)

    A. N. Kupriyanov

    2016-04-01

    Full Text Available The article considers the issues of the restoration vegetation on the dumps of the coal enterprises of the Kuznetsk Basin. Studies have shown that the dumps have a wide range of environmental conditions and are potentially suitable for establishment of plants. To negative environmental factors at the mine dumps include the lack of productive moisture, failed penetration, contrasting temperature regime on the different elements of the relief, and low potential fertility of the embryonic soils. Positive – high humidity in the depressions, the high content of fine-grained deposits in the lower part of the elephant dumps, excessive accumulation of snow in the winter on separate dumping sites. On disturbed lands identified eight technogenic ecotopes, characterized by various microrelief, moisture level, amount of fine fractions of technogenic eluvium determining favorable, moderately favorable and unfavorable conditions for vegetation of disturbed land. Selected three stages of syngenesis: pioneer stage, simple plant communities and complex plant communities. The stage of zonal phytocenosis on the dumps was not detected. The basis of diagnostic signs consists of the projective cover, the nature of the host plants, the number of species part of the zonal species. The selected criteria are universal and can be applicable to most dumps. Speed of syngenetic succession does not depend on calendar age of the dumps, and environmental conditions, which are formed on separate sites.

  14. Investigating Hydrogeologic Controls on Sandhill Wetlands in Covered Karst with 2D Resistivity and Ground Penetrating Radar

    Science.gov (United States)

    Downs, C. M.; Nowicki, R. S.; Rains, M. C.; Kruse, S.

    2015-12-01

    In west-central Florida, wetland and lake distribution is strongly controlled by karst landforms. Sandhill wetlands and lakes are sand-filled upland basins whose water levels are groundwater driven. Lake dimensions only reach wetland edges during extreme precipitation events. Current wetland classification schemes are inappropriate for identifying sandhill wetlands due to their unique hydrologic regime and ecologic expression. As a result, it is difficult to determine whether or not a wetland is impacted by groundwater pumping, development, and climate change. A better understanding of subsurface structures and how they control the hydrologic regime is necessary for development of an identification and monitoring protocol. Long-term studies record vegetation diversity and distribution, shallow ground water levels and surface water levels. The overall goals are to determine the hydrologic controls (groundwater, seepage, surface water inputs). Most recently a series of geophysical surveys was conducted at select sites in Hernando and Pasco County, Florida. Electrical resistivity and ground penetrating radar were employed to image sand-filled basins and the top of the limestone bedrock and stratigraphy of wetland slopes, respectively. The deepest extent of these sand-filled basins is generally reflected in topography as shallow depressions. Resistivity along inundated wetlands suggests the pools are surface expressions of the surficial aquifer. However, possible breaches in confining clay layers beneath topographic highs between depressions are seen in resistivity profiles as conductive anomalies and in GPR as interruptions in otherwise continuous horizons. These data occur at sites where unconfined and confined water levels are in agreement, suggesting communication between shallow and deep groundwater. Wetland plants are observed outside the historic wetland boundary at many sites, GPR profiles show near-surface layers dipping towards the wetlands at a shallower

  15. Plant uptake of radiocaesium from artificially contaminated soil monoliths covering major European soil types

    Energy Technology Data Exchange (ETDEWEB)

    Waegeneers, Nadia [Laboratory for Soil and Water Management, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium)], E-mail: nadia.waegeneers@agr.kuleuven.ac.be; Sauras-Yera, Teresa [Departament de Biologia Vegetal, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona (Spain); Thiry, Yves [SCK.CEN, Radioecology Laboratory, Boeretang 200, B-2400 Mol (Belgium); Vallejo, V. Ramon [Departament de Biologia Vegetal, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona (Spain); CEAM, Parque Tecnologico, Charles Darwin 14, 46980 Parterna (Spain); Smolders, Erik [Laboratory for Soil and Water Management, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium); Madoz-Escande, Chantal; Brechignac, Francois [SERLAB, ISPN, Department for Environmental Protection, CE-Cadarache Batiment 159, Saint-Paul-lez-Durance Cedex 13108 (France)

    2009-06-15

    Uptake of {sup 137}Cs was measured in different agricultural plant species (beans, lettuce, barley and ryegrass) grown in 5 undisturbed soil monoliths covering major European soil types. The first cultivation was made three years after soil contamination and plants were grown during 3 successive years. The plant-soil {sup 137}Cs transfer factors varied maximally 12-fold among soils and 35-fold among species when grown on the same soil. Single correlations between transfer factors and soil properties were found, but they varied widely with plant type and can hardly be used as a predictive tool because of the few soils used. The variation of {sup 137}Cs concentrations in plants among soils was related to differences in soil solution {sup 137}Cs and K concentrations, consistent with previous observations in hydroponics and pot trials. Absolute values of transfer factors could not be predicted based on a model validated for pot trials. The {sup 137}Cs activity concentration in soil solution decreased significantly (11- to 250-fold) for most soils in the 1997-1999 period and is partly explained by decreasing K in soil solution. Transfer factors of lettuce showed both increasing and decreasing trends between 2 consecutive years depending on soil type. The trends could be explained by the variation in {sup 137}Cs and K concentrations in soil solution. It is concluded that differences in {sup 137}Cs transfer factors among soils and trends in transfer factors as a function of time can be explained from soil solution composition, as shown previously for pot trials, although absolute values of transfer factors could not be predicted.

  16. Plant uptake of radiocaesium from artificially contaminated soil monoliths covering major European soil types.

    Science.gov (United States)

    Waegeneers, Nadia; Sauras-Yera, Teresa; Thiry, Yves; Vallejo, V Ramón; Smolders, Erik; Madoz-Escande, Chantal; Bréchignac, François

    2009-06-01

    Uptake of (137)Cs was measured in different agricultural plant species (beans, lettuce, barley and ryegrass) grown in 5 undisturbed soil monoliths covering major European soil types. The first cultivation was made three years after soil contamination and plants were grown during 3 successive years. The plant-soil (137)Cs transfer factors varied maximally 12-fold among soils and 35-fold among species when grown on the same soil. Single correlations between transfer factors and soil properties were found, but they varied widely with plant type and can hardly be used as a predictive tool because of the few soils used. The variation of (137)Cs concentrations in plants among soils was related to differences in soil solution (137)Cs and K concentrations, consistent with previous observations in hydroponics and pot trials. Absolute values of transfer factors could not be predicted based on a model validated for pot trials. The (137)Cs activity concentration in soil solution decreased significantly (11- to 250-fold) for most soils in the 1997-1999 period and is partly explained by decreasing K in soil solution. Transfer factors of lettuce showed both increasing and decreasing trends between 2 consecutive years depending on soil type. The trends could be explained by the variation in (137)Cs and K concentrations in soil solution. It is concluded that differences in (137)Cs transfer factors among soils and trends in transfer factors as a function of time can be explained from soil solution composition, as shown previously for pot trials, although absolute values of transfer factors could not be predicted.

  17. The importance of plant water use on evapotranspiration covers in semi-arid Australia

    Directory of Open Access Journals (Sweden)

    A. Schneider

    2012-10-01

    Full Text Available We estimated the evapotranspiration (ET for an area vegetated with characteristic semi-arid native Australian plant species on ET mine waste cover systems. These systems aim to minimise drainage into underlying hazardous wastes by maximising evaporation (E from the soil surface and transpiration from vegetation. An open top chamber was used to measure diurnal and daily ET of two plant species – Senna artemisioides (silver cassia and Sclerolaena birchii (galvanised burr – after a simulated rainfall event, as well as E from bare soil. Both ET and E decreased with increasing time after initial watering. Different temporal patterns were observed for daily ET from the two plant species and E from bare soil, revealing Senna artemisioides as intensive and Sclerolaena birchii as extensive water exploiters. A strong positive linear relationship was identified between ET (and E, and the atmospheric water demand represented by the vapour pressure deficit. The relationship always was more pronounced in the morning than in the afternoon, indicating a diminishing water supply from the soil associated with a declining unsaturated hydraulic conductivity of the soil in the afternoon. The slopes of the regression lines were steepest for Senna artemisioides, reflecting its intensive water-exploiting characteristics. We used the derived estimates of ET and E to predict the effect of species composition on plot ET in relation to total vegetation coverage. Although both species proved suitable for an operational ET cover system, vegetation coverage should exceed at least 50% in order to markedly influence plot ET, a value which is likely to be unsustainable in semi-arid climates.

  18. The importance of plant water use on evapotranspiration covers in semi-arid Australia

    Science.gov (United States)

    Schneider, A.; Arnold, S.; Doley, D.; Mulligan, D. R.; Baumgartl, T.

    2012-10-01

    We estimated the evapotranspiration (ET) for an area vegetated with characteristic semi-arid native Australian plant species on ET mine waste cover systems. These systems aim to minimise drainage into underlying hazardous wastes by maximising evaporation (E) from the soil surface and transpiration from vegetation. An open top chamber was used to measure diurnal and daily ET of two plant species - Senna artemisioides (silver cassia) and Sclerolaena birchii (galvanised burr) - after a simulated rainfall event, as well as E from bare soil. Both ET and E decreased with increasing time after initial watering. Different temporal patterns were observed for daily ET from the two plant species and E from bare soil, revealing Senna artemisioides as intensive and Sclerolaena birchii as extensive water exploiters. A strong positive linear relationship was identified between ET (and E), and the atmospheric water demand represented by the vapour pressure deficit. The relationship always was more pronounced in the morning than in the afternoon, indicating a diminishing water supply from the soil associated with a declining unsaturated hydraulic conductivity of the soil in the afternoon. The slopes of the regression lines were steepest for Senna artemisioides, reflecting its intensive water-exploiting characteristics. We used the derived estimates of ET and E to predict the effect of species composition on plot ET in relation to total vegetation coverage. Although both species proved suitable for an operational ET cover system, vegetation coverage should exceed at least 50% in order to markedly influence plot ET, a value which is likely to be unsustainable in semi-arid climates.

  19. Evaluation of the uncertainty due to land cover observation and conversion into plant functional types

    Science.gov (United States)

    Georgievski, Goran; Hartley, Andrew; MacBean, Natasha; Hagemann, Stefan

    2016-04-01

    Land surface processes represented in the latest generation of climate models (IPCC AR5) use the concept of Plant Functional Types (PFTs) to group different vegetation types and species according to similar physiological, biochemical and structural characteristics. The 5th IPCC Assessment Report recognizes the role of the Land Surface Models (LSMs) as one of the key contributors to uncertainty in climate change impacts projections. In the frame of the European Space Agency (ESA) Climate Change Initiative (CCI), a new global land cover (LC) data set was derived. We aim to investigate two sources of uncertainties in LSMs and their ranges: (i) uncertainty of ESA-CCI state of the art satellite observation of LC classes, and (ii) uncertainty due to LC conversion ("cross-walking (CW) procedure") into PFTs. Therefore, we have derived 5 perturbations of PFTs maps: (i) reference map (REF), (ii) map that minimizes biomass in LC observation and CW procedure (MinLC MinCW), (iii) map that minimizes biomass in LC observation with reference CW procedure (MinLC RefCW), (iv) map that maximizes biomass in LC observation with reference CW procedure (MaxLC RefCW), and (v) map that maximizes biomass in LC observation and CW procedure (MaxLC MaxCW). Our analysis demonstrates that there is still considerable uncertainty in the methods used to convert LC classes into the PFTs used by LSMs. Furthermore, uncertainty in the labelling of LC classes has an equal magnitude compared to the cross-walking uncertainty. In the next phase, we aim to quantify the sensitivity of the carbon, hydrological and energy cycles to LC and CW uncertainty with 3 LSMs (JSBACH, JULES, and ORHCIDEE). This work will enable us to both advice the land cover mapping community about the accuracy requirements for land cover maps, and to provide insights to the earth system modelling community on the implications of decisions taken when converting from land cover classes to PFTs.

  20. Local above-ground persistence of vascular plants : Life-history trade-offs and environmental constraints

    NARCIS (Netherlands)

    Ozinga, Wim A.; Hennekens, Stephan M.; Schaminee, Joop H. J.; Smits, Nina A. C.; Bekker, Renee M.; Roemermann, Christine; Klimes, Leos; Bakker, Jan P.; van Groenendael, Jan M.

    2007-01-01

    Questions: 1. Which plant traits and habitat characteristics best explain local above-ground persistence of vascular plant species and 2. Is there a trade-off between local above-ground persistence and the ability for seed dispersal and below-ground persistence in the soil seed bank? Locations: 845

  1. Local above-ground persistence of vascular plants: life-history trade-offs and environmental constraints

    NARCIS (Netherlands)

    Ozinga, W.A.; Hennekens, S.M.; Schaminée, J.H.J.; Smits, N.A.C.; Bekker, R.M.; Römermann, C.; Bakker, J.P.; Groenendael, van J.M.

    2007-01-01

    Questions: 1. Which plant traits and habitat characteristics best explain local above-ground persistence of vascular plant species and 2. Is there a trade-off between local above-ground persistence and the ability for seed dispersal and below-ground persistence in the soil seed bank? Locations: 845

  2. Linkages between land Cover, enzymes, and soil organic matter chemistry following encroachment of leguminous woody plant into grasslands

    Science.gov (United States)

    Filley, T. R.; Stott, D. E.; Boutton, T. W.; Creamer, C. A.; Olk, D.

    2009-12-01

    only weak trends with age when normalized to carbon content. Although, PPO was nearly invariant across the chronosequence, lignin content rose dramatically, normalized both to soil mass and to organic carbon content, indicating oxidase activity was not matched to input and lignin was selectively accruing in the below ground carbon pools. We propose that the dramatic increase in available N in the leguminous system suppressed microbial oxidase production allowing lignin to selectively accrue while microbial activity for the other plant biopolymers has nearly kept pace with input-consistent with recent findings in other temperate deciduous systems. These results have important implications for the modeling of woodland-grassland conversion and the dynamics of biogeochemical cycles in this globally significant land cover change.

  3. Predicting plant diversity patterns in Madagascar: understanding the effects of climate and land cover change in a biodiversity hotspot.

    Science.gov (United States)

    Brown, Kerry A; Parks, Katherine E; Bethell, Colin A; Johnson, Steig E; Mulligan, Mark

    2015-01-01

    Climate and land cover change are driving a major reorganization of terrestrial biotic communities in tropical ecosystems. In an effort to understand how biodiversity patterns in the tropics will respond to individual and combined effects of these two drivers of environmental change, we use species distribution models (SDMs) calibrated for recent climate and land cover variables and projected to future scenarios to predict changes in diversity patterns in Madagascar. We collected occurrence records for 828 plant genera and 2186 plant species. We developed three scenarios, (i.e., climate only, land cover only and combined climate-land cover) based on recent and future climate and land cover variables. We used this modelling framework to investigate how the impacts of changes to climate and land cover influenced biodiversity across ecoregions and elevation bands. There were large-scale climate- and land cover-driven changes in plant biodiversity across Madagascar, including both losses and gains in diversity. The sharpest declines in biodiversity were projected for the eastern escarpment and high elevation ecosystems. Sharp declines in diversity were driven by the combined climate-land cover scenarios; however, there were subtle, region-specific differences in model outputs for each scenario, where certain regions experienced relatively higher species loss under climate or land cover only models. We strongly caution that predicted future gains in plant diversity will depend on the development and maintenance of dispersal pathways that connect current and future suitable habitats. The forecast for Madagascar's plant diversity in the face of future environmental change is worrying: regional diversity will continue to decrease in response to the combined effects of climate and land cover change, with habitats such as ericoid thickets and eastern lowland and sub-humid forests particularly vulnerable into the future.

  4. Predicting plant diversity patterns in Madagascar: understanding the effects of climate and land cover change in a biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Kerry A Brown

    Full Text Available Climate and land cover change are driving a major reorganization of terrestrial biotic communities in tropical ecosystems. In an effort to understand how biodiversity patterns in the tropics will respond to individual and combined effects of these two drivers of environmental change, we use species distribution models (SDMs calibrated for recent climate and land cover variables and projected to future scenarios to predict changes in diversity patterns in Madagascar. We collected occurrence records for 828 plant genera and 2186 plant species. We developed three scenarios, (i.e., climate only, land cover only and combined climate-land cover based on recent and future climate and land cover variables. We used this modelling framework to investigate how the impacts of changes to climate and land cover influenced biodiversity across ecoregions and elevation bands. There were large-scale climate- and land cover-driven changes in plant biodiversity across Madagascar, including both losses and gains in diversity. The sharpest declines in biodiversity were projected for the eastern escarpment and high elevation ecosystems. Sharp declines in diversity were driven by the combined climate-land cover scenarios; however, there were subtle, region-specific differences in model outputs for each scenario, where certain regions experienced relatively higher species loss under climate or land cover only models. We strongly caution that predicted future gains in plant diversity will depend on the development and maintenance of dispersal pathways that connect current and future suitable habitats. The forecast for Madagascar's plant diversity in the face of future environmental change is worrying: regional diversity will continue to decrease in response to the combined effects of climate and land cover change, with habitats such as ericoid thickets and eastern lowland and sub-humid forests particularly vulnerable into the future.

  5. Pollen-based quantitative reconstructions of Holocene regional vegetation cover (plant-functional types and land-cover types) in Europe suitable for climate modelling.

    Science.gov (United States)

    Trondman, A-K; Gaillard, M-J; Mazier, F; Sugita, S; Fyfe, R; Nielsen, A B; Twiddle, C; Barratt, P; Birks, H J B; Bjune, A E; Björkman, L; Broström, A; Caseldine, C; David, R; Dodson, J; Dörfler, W; Fischer, E; van Geel, B; Giesecke, T; Hultberg, T; Kalnina, L; Kangur, M; van der Knaap, P; Koff, T; Kuneš, P; Lagerås, P; Latałowa, M; Lechterbeck, J; Leroyer, C; Leydet, M; Lindbladh, M; Marquer, L; Mitchell, F J G; Odgaard, B V; Peglar, S M; Persson, T; Poska, A; Rösch, M; Seppä, H; Veski, S; Wick, L

    2015-02-01

    We present quantitative reconstructions of regional vegetation cover in north-western Europe, western Europe north of the Alps, and eastern Europe for five time windows in the Holocene [around 6k, 3k, 0.5k, 0.2k, and 0.05k calendar years before present (bp)] at a 1° × 1° spatial scale with the objective of producing vegetation descriptions suitable for climate modelling. The REVEALS model was applied on 636 pollen records from lakes and bogs to reconstruct the past cover of 25 plant taxa grouped into 10 plant-functional types and three land-cover types [evergreen trees, summer-green (deciduous) trees, and open land]. The model corrects for some of the biases in pollen percentages by using pollen productivity estimates and fall speeds of pollen, and by applying simple but robust models of pollen dispersal and deposition. The emerging patterns of tree migration and deforestation between 6k bp and modern time in the REVEALS estimates agree with our general understanding of the vegetation history of Europe based on pollen percentages. However, the degree of anthropogenic deforestation (i.e. cover of cultivated and grazing land) at 3k, 0.5k, and 0.2k bp is significantly higher than deduced from pollen percentages. This is also the case at 6k in some parts of Europe, in particular Britain and Ireland. Furthermore, the relationship between summer-green and evergreen trees, and between individual tree taxa, differs significantly when expressed as pollen percentages or as REVEALS estimates of tree cover. For instance, when Pinus is dominant over Picea as pollen percentages, Picea is dominant over Pinus as REVEALS estimates. These differences play a major role in the reconstruction of European landscapes and for the study of land cover-climate interactions, biodiversity and human resources. © 2014 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

  6. Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains, northeastern China

    Institute of Scientific and Technical Information of China (English)

    XiaoLi Chang; HuiJun Jin; YanLin Zhang; HaiBin Sun

    2015-01-01

    Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of the soils in permafrost regions in the mid-latitudes and boreal regions, such as that on the western flank of the Da Xing'anling (Hinggan) Mountains, northeastern China. This paper gives a detailed analysis on meteorological data series from 2001 to 2010 provided by the Gen'he Weather Station, which is located in a talik of discontinuous permafrost zone and with sparse meadow on the observation field. It is inferred that snow cover is important for the ground thermal regime in the middle Da Xing'anling Mountains. Snow cover of 10-cm in thickness and five to six months in duration (generally November to next March) can reduce the heat loss from the ground to the atmosphere by 28%, and by 71% if the snow depth increases to 36 cm. Moreover, the occurrence of snow cover resulted in mean annual ground surface temperatures 4.7–8.2°C higher than the mean annual air temperatures recorded at the Gen'he Weather Station. The beginning date for stable snow cover establishment (SE date) and the initial snow depth (SDi) also had a great influences on the ground freezing process. Heavy snowfall before ground surface freeze-up could postpone and retard the freezing process in Gen'he. As a result, the duration of ground freezing was shortened by at least 20 days and the maximum depth of frost penetration was as much as 90 cm shallower.

  7. Diversity of bacteria nesting the plant cover of north Sinai deserts, Egypt

    Directory of Open Access Journals (Sweden)

    Amira L. Hanna

    2013-01-01

    Full Text Available North Sinai deserts were surveyed for the predominant plant cover and for the culturable bacteria nesting their roots and shoots. Among 43 plant species reported, 13 are perennial (e.g. Fagonia spp., Pancratium spp. and 30 annuals (e.g. Bromus spp., Erodium spp.. Eleven species possessed rhizo-sheath, e.g. Cyperus capitatus, Panicum turgidum and Trisetaria koelerioides. Microbiological analyses demonstrated: the great diversity and richness of associated culturable bacteria, in particular nitrogen-fixing bacteria (diazotrophs; the majority of bacterial residents were of true and/or putative diazotrophic nature; the bacterial populations followed an increasing density gradient towards the root surfaces; sizeable populations were able to reside inside the root (endorhizosphere and shoot (endophyllosphere tissues. Three hundred bacterial isolates were secured from studied spheres. The majority of nitrogen-fixing bacilli isolates belonged to Bacillus megaterium, Bacillus pumilus, Bacillus polymexa, Bacillus macerans, Bacillus circulans and Bacillus licheniformis. The family Enterobacteriaceae represented by Enterobacter agglomerans, Enterobacter sackazakii, Enterobacter cloacae, Serratia adorifera, Serratia liquefaciens and Klebsiella oxytoca. The non-Enterobacteriaceae population was rich in Pantoae spp., Agrobacterium rdiobacter, Pseudomonas vesicularis, Pseudomonas putida, Stenotrophomonas maltophilia, Ochrobactrum anthropi, Sphingomonas paucimobilis and Chrysemonas luteola. Gluconacetobacter diazotrophicus were reported inside root and shoot tissues of a number of tested plants. The dense bacterial populations reported speak well to the very possible significant role played by the endophytic bacterial populations in the survival, in respect of nutrition and health, of existing plants. Such groups of diazotrophs are good candidates, as bio-preparates, to support the growth of future field crops grown in deserts of north Sinai and irrigated by the

  8. Diversity of bacteria nesting the plant cover of north Sinai deserts, Egypt.

    Science.gov (United States)

    Hanna, Amira L; Youssef, Hanan H; Amer, Wafaa M; Monib, Mohammed; Fayez, Mohammed; Hegazi, Nabil A

    2013-01-01

    North Sinai deserts were surveyed for the predominant plant cover and for the culturable bacteria nesting their roots and shoots. Among 43 plant species reported, 13 are perennial (e.g. Fagonia spp., Pancratium spp.) and 30 annuals (e.g. Bromus spp., Erodium spp.). Eleven species possessed rhizo-sheath, e.g. Cyperus capitatus, Panicum turgidum and Trisetaria koelerioides. Microbiological analyses demonstrated: the great diversity and richness of associated culturable bacteria, in particular nitrogen-fixing bacteria (diazotrophs); the majority of bacterial residents were of true and/or putative diazotrophic nature; the bacterial populations followed an increasing density gradient towards the root surfaces; sizeable populations were able to reside inside the root (endorhizosphere) and shoot (endophyllosphere) tissues. Three hundred bacterial isolates were secured from studied spheres. The majority of nitrogen-fixing bacilli isolates belonged to Bacillus megaterium, Bacillus pumilus, Bacillus polymexa, Bacillus macerans, Bacillus circulans and Bacillus licheniformis. The family Enterobacteriaceae represented by Enterobacter agglomerans, Enterobacter sackazakii, Enterobacter cloacae, Serratia adorifera, Serratia liquefaciens and Klebsiella oxytoca. The non-Enterobacteriaceae population was rich in Pantoae spp., Agrobacterium rdiobacter, Pseudomonas vesicularis, Pseudomonas putida, Stenotrophomonas maltophilia, Ochrobactrum anthropi, Sphingomonas paucimobilis and Chrysemonas luteola. Gluconacetobacter diazotrophicus were reported inside root and shoot tissues of a number of tested plants. The dense bacterial populations reported speak well to the very possible significant role played by the endophytic bacterial populations in the survival, in respect of nutrition and health, of existing plants. Such groups of diazotrophs are good candidates, as bio-preparates, to support the growth of future field crops grown in deserts of north Sinai and irrigated by the water of El

  9. Planting date impacts on soil water management, plant growth, and weeds in cover-crop-based no-till corn production

    Science.gov (United States)

    Low input and organic farmers are increasingly utilizing cover crop mulches in maize production. Many farmers are delaying planting corn into these high residue environments to allow greater growth of the cover crop to maximize nitrogen fixation and improve mechanical termination with roller crimpe...

  10. Unmasking the soil cover's disruption by use of a dynamic model of measurement aerospace parameters of ground vegetation

    Directory of Open Access Journals (Sweden)

    E. V. Vysotskaya

    2016-03-01

    Full Text Available The "Introduction" describes topicality and importance of revealing the soil cover's disruption for a wide range of fields. It was shown that spectral brightness and colorimetric parameters of ground vegetation can be used for this task. However, a traditional scheme of data processing for remote sensing requires a long-term observations and can not always be applied, if quick decision-making is necessary or there is lack of information. Such cases require the use of special methods, one of which is a dynamic model developed with authors' participation based on the following basic relationships: (+,- (-, - (+, 0, (-, 0 (0,0. The section "Brief description of a dynamic model" describes the basic principles of dynamic systems used to solve the problem. Using above-mentioned relationships, the dynamics of a system consisting of several components is constructed and its main properties are listed. The main feature of this model is that the identification of structure and parameters of the dynamic system does not required sequential order of observations (as for models based on time series. This feature of the model enables for identifying the system's parameters of dynamics of the natural system to use information from a single picture taken from the spacecraft rather than long-term observations. The section "Materials and Methods" describes specific colorimetric parameters used to analyze the vegetation cover. The section "Obtained results" contains an example of the model's application to a satellite image for detecting the differences in two sites of a field with vegetation. One site is a recultivated area near the liquidated gas-oil well, another site is non-recultivated area at a considerable distance from the well (500-1000 m. The simulation results are described by eight signed graphs (4 graphs for each sites, whose structure allows to identify the system differences between the two cases. The section "Conclusions" summarizes the results of

  11. A comparison of ground and satellite observations of cloud cover to saturation pressure differences during a cold air outbreak

    Energy Technology Data Exchange (ETDEWEB)

    Alliss, R.J.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

    1996-04-01

    The role of clouds in the atmospheric general circulation and the global climate is twofold. First, clouds owe their origin to large-scale dynamical forcing, radiative cooling in the atmosphere, and turbulent transfer at the surface. In addition, they provide one of the most important mechanisms for the vertical redistribution of momentum and sensible and latent heat for the large scale, and they influence the coupling between the atmosphere and the surface as well as the radiative and dynamical-hydrological balance. In existing diagnostic cloudiness parameterization schemes, relative humidity is the most frequently used variable for estimating total cloud amount or stratiform cloud amount. However, the prediction of relative humidity in general circulation models (GCMs) is usually poor. Even for the most comprehensive GCMs, the predicted relative humidity may deviate greatly from that observed, as far as the frequency distribution of relative humidity is concerned. Recently, there has been an increased effort to improve the representation of clouds and cloud-radiation feedback in GCMs, but the verification of cloudiness parameterization schemes remains a severe problem because of the lack of observational data sets. In this study, saturation pressure differences (as opposed to relative humidity) and satellite-derived cloud heights and amounts are compared with ground determinations of cloud cover over the Gulf Stream Locale (GSL) during a cold air outbreak.

  12. Impact of no-till cover cropping of Italian ryegrass on above and below ground faunal communities inhabiting a soybean field with special emphasis on soybean cyst nematodes

    Science.gov (United States)

    Two field trials were conducted in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop in a no-till soybean (Glycine max) planting to 1) reduce populations of plant-parasitic nematodes (i.e., the soybean cyst nematode, Heterodera glycines and lesion nematodes...

  13. Geochemistry of ground water at the Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Marine, I.W.

    1976-09-01

    Subsurface hydrogeologic systems underlying the Savannah River Plant (SRP) were studied to determine the origin and age of the contained fluids. Three distinct systems exist beneath SRP: the Coastal Plain sediments, crystalline metamorphic basement rock, and a Triassic rock basin surrounded by the crystalline rock. The water in the Coastal Plain sediments is low in dissolved solids (approximately 30 mg/l), acidic (pH approximately 5.5), and comparatively recent. Water in the crystalline rock is high in dissolved solids (approximately 6000 mg/l), alkaline (pH approximately 8), and approximately 840,000 years old as determined by helium dating techniques. Water in the Triassic rock is highest in dissolved solids (approximately 18,000 mg/l) and is probably older than the water in the surrounding crystalline rock; a quantitative age was not determined. The origin of the water in the crystalline and Triassic rock could not be determined with certainty; however, it is not relic sea water. A detailed geologic-hydrologic history of the SRP region is presented.

  14. Effects of post-fire salvage logging and a skid trail treatment on ground cover, soils, and sediment production in the interior western United States

    Science.gov (United States)

    Joseph W. Wagenbrenner; Lee H. MacDonald; Robert N. Coats; Peter R. Robichaud; Robert E. Brown

    2015-01-01

    Post-fire salvage logging adds another set of environmental effects to recently burned areas, and previous studies have reported varying impacts on vegetation, soil disturbance, and sediment production with limited data on the underlying processes. Our objectives were to determine how: (1) ground-based post-fire logging affects surface cover, soil water repellency,...

  15. Effects of Post-Fire Plant Cover in the Performance of Two Cordilleran Cypress ( Austrocedrus chilensis) Seedling Stocktypes Planted in Burned Forests of Northeastern Patagonia, Argentina

    Science.gov (United States)

    Urretavizcaya, María F.; Gonda, Héctor E.; Defossé, Guillermo E.

    2017-03-01

    Cordilleran cypress ( Austrocedrus chilensis [D.Don] Pic. Serm. et Bizarri) forests occupy 140,000 ha along a sharp environmental gradient of central Andean-Patagonia in Argentina. Every summer, about 3200 ha of these forests are affected by wildfires, taking thereafter long time to recover. To accelerate forest recovery, we determined in xeric and mesic cypress stands burned 5 and 2 year before whether survival and growth of two planted cypress seedling stocktypes are affected by plant cover and contrasting precipitation conditions. Two experiments were conducted on each site, involving 100 replicates of two seedling stocktypes, having each significantly different morphological attributes. The experiments comprised a dry and humid growing season on each site. Both stocktypes performed similarly within stands, but differently between stands. In the xeric stand, plant cover had neutral effects on seedling survival, favored seedling height growth in the dry season, and was negative on collar diameter and stem growth. In the mesic site, high plant cover favored survival and height growth, but was inconsequential for collar diameter and stem growth. In this short-term post-fire period, and independent of precipitation received during both seasons (dry or humid), plant cover appears as playing a facilitative role, having neutral or even positive effects on survival and growth of planted seedlings. During the early post-fire successional stages, and besides seedling stocktype, there was a synergistic balance between light and soil moisture that seems to benefit planted seedling performance in burned cypress forests, and especially in mesic sites.

  16. Plant species potentially suitable for cover on low-level solid nuclear waste disposal sites: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Brenkert, A.L.; Parr, P.D.; Taylor, F.G.

    1984-09-01

    This report reviews available literature on soil conditions, hydrology, and climatological data and suggests plant species suitable for covering the low-level nuclear waste disposal areas in the White Oak Creek Watershed within the Oak Ridge Reservation. Literature on naturally invading species and secondary succession, on plant species used for reclamation of coal spoils and roadsides, and on horticultural species is reviewed. The potential of plant species to take up, or mine, the waste through deep rooting is assessed. The effects of vegetation cover on the water balance in a watershed are reviewed. Several conclusions are presented concerning the management of vegetation cover on low-level solid waste disposal areas. 163 references, 2 figures, 9 tables.

  17. Analysis of the Current Situation about Colored Gound Cover Plants in Gardens of Suqian City%彩叶地被植物在宿迁园林中的应用现状分析

    Institute of Scientific and Technical Information of China (English)

    许晶晶; 金青; 苏苑苑; 袁笑; 周燕; 李素华

    2011-01-01

    This paper focused on the evaluation and analysis of the application type, season change and the application form of the colored ground cover plants in the city of Suqian. The result shows that there are 23 types of colored ground cover plants using in the gardens in Suqian. These 23 types belong to 16 families and 22 geneses, in which red color and complex color have more tapes, For the application form, there are flower bed, flower platform, presbyopic glasses, road greening and basic plants. Nowadays, the configuration of the colored ground cover plants is still lack of scientific nature. And the diversification also needs improvement.%对宿迁市彩叶地被植物的应用种类、季相变化及应用形式进行评价分析,结果表明:宿迁园林中共应用彩叶地被植物23种,隶属16个科22个属,红色系和复色系种类较多,应用形式有花坛、花台、花境、道路绿化、林下和基础栽植;目前彩叶地被在配置上还缺乏科学性,景观设计风格多样性有待加强。

  18. Study on Site Specific Design Earthquake Ground Motion of Nuclear Power Plants in China1

    Institute of Scientific and Technical Information of China (English)

    Zhou Bochang; Li Xiaojun; Li Yaqi

    2008-01-01

    The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and design activities of nuclear power plants in China.Based on the research results from site seismic safety evaluation of domestic nuclear power plant projects in the last years,characteristics and differences of site specific design spectra are analyzed in comparison with standard response spectra,and the suitability of standard response spectra for domestic nuclear power plant projects is discussed.

  19. Using LiDAR and quickbird data to model plant production and quantify uncertainties associated with wetland detection and land cover generalizations

    Science.gov (United States)

    Cook, B.D.; Bolstad, P.V.; Naesset, E.; Anderson, R. Scott; Garrigues, S.; Morisette, J.T.; Nickeson, J.; Davis, K.J.

    2009-01-01

    Spatiotemporal data from satellite remote sensing and surface meteorology networks have made it possible to continuously monitor global plant production, and to identify global trends associated with land cover/use and climate change. Gross primary production (GPP) and net primary production (NPP) are routinely derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard satellites Terra and Aqua, and estimates generally agree with independent measurements at validation sites across the globe. However, the accuracy of GPP and NPP estimates in some regions may be limited by the quality of model input variables and heterogeneity at fine spatial scales. We developed new methods for deriving model inputs (i.e., land cover, leaf area, and photosynthetically active radiation absorbed by plant canopies) from airborne laser altimetry (LiDAR) and Quickbird multispectral data at resolutions ranging from about 30??m to 1??km. In addition, LiDAR-derived biomass was used as a means for computing carbon-use efficiency. Spatial variables were used with temporal data from ground-based monitoring stations to compute a six-year GPP and NPP time series for a 3600??ha study site in the Great Lakes region of North America. Model results compared favorably with independent observations from a 400??m flux tower and a process-based ecosystem model (BIOME-BGC), but only after removing vapor pressure deficit as a constraint on photosynthesis from the MODIS global algorithm. Fine-resolution inputs captured more of the spatial variability, but estimates were similar to coarse-resolution data when integrated across the entire landscape. Failure to account for wetlands had little impact on landscape-scale estimates, because vegetation structure, composition, and conversion efficiencies were similar to upland plant communities. Plant productivity estimates were noticeably improved using LiDAR-derived variables, while uncertainties associated with land cover generalizations and

  20. Detecting plant metabolic responses induced by ground shock using hyperspectral remote sensing and physiological contact measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pickles, W.L.; Cater, G.A.

    1996-12-03

    A series of field experiments were done to determine if ground shock could have induced physiological responses in plants and if the level of the response could be observed. The observation techniques were remote sensing techniques and direct contact physiological measurements developed by Carter for detecting pre-visual plant stress. The remote sensing technique was similar to that used by Pickles to detect what appeared to be ground shock induced plant stress above the 1993 Non Proliferation Experiment`s underground chemical explosion. The experiment was designed to provide direct plant physiological measurements and remote sensing ratio images and from the same plants at the same time. The simultaneous direct and remote sensing measurements were done to establish a ground truth dataset to compare to the results of the hyperspectral remote sensing measurements. In addition, the experiment was designed to include data on what was thought to be the most probable interfering effect, dehydration. The experimental design included investigating the relative magnitude of the shock induced stress effects compared to dehydration effects.

  1. AgRISTARS: Early warning and crop condition assessment. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions

    Science.gov (United States)

    Wiegand, C. L. (Principal Investigator); Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J.

    1981-01-01

    Emissive (10.5 to 12.5 microns) and reflective (0.55 to 1.1 microns) data for ten day scenes and infrared data for six night scenes of southern Texas were analyzed for plant cover, soil temperature, freeze, water stress, and evapotranspiration. Heat capacity mapping mission radiometric temperatures were: within 2 C of dewpoint temperatures, significantly correlated with variables important in evapotranspiration, and related to freeze severity and planting depth soil temperatures.

  2. Plant functional type classification for earth system models: results from the European Space Agency's Land Cover Climate Change Initiative

    Science.gov (United States)

    Poulter, B.; MacBean, N.; Hartley, A.; Khlystova, I.; Arino, O.; Betts, R.; Bontemps, S.; Boettcher, M.; Brockmann, C.; Defourny, P.; Hagemann, S.; Herold, M.; Kirches, G.; Lamarche, C.; Lederer, D.; Ottlé, C.; Peters, M.; Peylin, P.

    2015-07-01

    Global land cover is a key variable in the earth system with feedbacks on climate, biodiversity and natural resources. However, global land cover data sets presently fall short of user needs in providing detailed spatial and thematic information that is consistently mapped over time and easily transferable to the requirements of earth system models. In 2009, the European Space Agency launched the Climate Change Initiative (CCI), with land cover (LC_CCI) as 1 of 13 essential climate variables targeted for research development. The LC_CCI was implemented in three phases: first responding to a survey of user needs; developing a global, moderate-resolution land cover data set for three time periods, or epochs (2000, 2005, and 2010); and the last phase resulting in a user tool for converting land cover to plant functional type equivalents. Here we present the results of the LC_CCI project with a focus on the mapping approach used to convert the United Nations Land Cover Classification System to plant functional types (PFTs). The translation was performed as part of consultative process among map producers and users, and resulted in an open-source conversion tool. A comparison with existing PFT maps used by three earth system modeling teams shows significant differences between the LC_CCI PFT data set and those currently used in earth system models with likely consequences for modeling terrestrial biogeochemistry and land-atmosphere interactions. The main difference between the new LC_CCI product and PFT data sets used currently by three different dynamic global vegetation modeling teams is a reduction in high-latitude grassland cover, a reduction in tropical tree cover and an expansion in temperate forest cover in Europe. The LC_CCI tool is flexible for users to modify land cover to PFT conversions and will evolve as phase 2 of the European Space Agency CCI program continues.

  3. The effects of different soil cover management practices on plant biodiversity and soil properties in Mediterranean ancient olive orchards

    Science.gov (United States)

    Madzaric, Suzana; Aly, Adel; Ladisa, Gaetano; Calabrese, Generosa

    2014-05-01

    The effects of different soil cover management practices on plant biodiversity and soil properties in Mediterranean ancient olive orchards Madzaric S., Aly A., Ladisa G. and Calabrese G. The loss of natural plant cover due to the inappropriate soil cover management is often a decisive factor for soil degradation in Mediterranean area. This accompanied with typical climate, characterized by cool, wet winters and hot and dry summers leads to soil erosion and loss of productivity. Due to simplification of agricultural practice and to the attempt to decrease cost of production, keeping soil bare is a widespread agricultural practice in Mediterranean ancient olive orchards (AOOs). The consequences of this are degradation of soil quality and reduction of plant biodiversity. In last year's some alternative practices are proposed in order to protect soil and biodiversity. One of these practices is the "grassing" i.e. covering the soil by selected autochthonous plant species. Objectives of our study are: (1) to evaluate impact of different soil cover management practices on soil properties and plant biodiversity in AOOs and (2) to define a minimum indicators' set (Minimum Data Set - MDS) to evaluate the effectiveness of different agricultural practices in environmental performance of AOOs. A comparison was carried on considering two management systems (conventional vs. organic) and three agricultural practices: conventional with bare soil (CON), organic with soil covered by selected autochthonous species (MIX) and organic left to the native vegetation (NAT). In general a clear positive influence of organic management system was recognized. Some soil quality indicators (physical, chemical and biological) showed responsiveness in describing the effects of management system and agricultural practices on soil properties. The both approaches with vegetation cover on the soil surface (either sowing of mixture or soil left to the natural plant cover) performed better than

  4. Identification of Fungal Colonies on Ground Control and Flight Veggie Plant Pillows

    Science.gov (United States)

    Scotten, Jessica E.; Hummerick, Mary E.; Khodadad, Christina L.; Spencer, Lashelle E.; Massa, Gioia D.

    2017-01-01

    The Veggie system focuses on growing fresh produce that can be harvested and consumed by astronauts. The microbial colonies in each Veggie experiment are evaluated to determine the safety level of the produce and then differences between flight and ground samples. The identifications of the microbial species can detail risks or benefits to astronaut and plant health. Each Veggie ground or flight experiment includes six plants grown from seeds that are glued into wicks in Teflon pillows filled with clay arcillite and fertilizer. Fungal colonies were isolated from seed wicks, growth media, and lettuce (cv. 'Outredgeous') roots grown in VEG-01B pillows on ISS and in corresponding ground control pillows grown in controlled growth chambers. The colonies were sorted by morphology and identified using MicroSeq(TM) 500 16s rDNA Bacterial Identification System and BIOLOG GEN III MicroPlate(TM). Health risks for each fungal identification were then assessed using literature sources. The goal was to identify all the colonies isolated from flight and ground control VEG-01B plants, roots, and rooting medium and compare the resulting identifications.

  5. Yielding and nutritional value of Japanese bunching onion in relation to the date of planting and type of flat cover

    National Research Council Canada - National Science Library

    Eugeniusz Kołota; Katarzyna Adamczewska-Sowińska; Cecylia Uklańska-Pusz

    2013-01-01

    .... The seedlings, produced in multi-pots, were planted in the open field on 8-10 September, 9-10 October and 6-12 April, and covered with a perforated foil and agrotextile in mid-November or directly...

  6. Effect of plant cover on distribution of soil organic matter pools

    Science.gov (United States)

    Gunina, Anna; Kuzyakov, Yakov; Ryzhova, Irina

    2013-04-01

    Numerous studies reported that quality and quantity of primary production and also the rate of litter decomposition determine the carbon (C) content and its distribution in soils. Our objective was to examine how the type of plant cover affects C sequestration in the following pools: unprotected, spatial inaccessible, interacting with silt and clay, and biochemically protected SOM. The large lysimeters of Moscow State University allowed quantification of C stocks under broadleaf forest (Acer platanoides and Quercus robur), coniferous forest (Picea abies) and agricultural crops (9-field rotation), while other soil forming factors affecting SOC content were identical. In 1965 the lysimeters (S=9 m2, depth=1.5 m) were filled with carbonate free clay loam taken in Moscow region, originated from the Valday glaciation, and plant communities listed above were planted. We collected soil samples from the mineral horizons, from 0-5 cm depth, in spring 2012. The soils were physically separated by combination of the particle size and density fractionations (8 fractions in total), and C and N contents were analyzed. The total C and N contents in non-fractionated soil were higher under broadleaf forest (66 and 3.1 g kg-1), than under coniferous forest (34.5 and 1.23 g kg-1) and agricultural crops (13.7 and 0.9 g kg-1). Under forests 45-50% of Ctotal and 30% of Ntotal were in the unprotected pool, in agricultural soil these percentages were in 3 times less. The greatest portions of protected C were in spatial inaccessible pool: 28, 32 and 40% of the Ctotal for broadleaf forest, coniferous forest and agricultural crops, respectively. However, the total C amount in this pool under agricultural crops was in 3 times less, than under forests. This is indicative for the loss of C-rich macroaggregates and an increase of C-depleted microaggregates in agricultural soils due to the plowing. The amounts of C, stabilized by interactions with silt and clay, were nearly the same (3-6 g kg-1

  7. Impact of plant cover on fitness and behavioural traits of captive red-eyed tree frogs (Agalychnis callidryas.

    Directory of Open Access Journals (Sweden)

    Christopher J Michaels

    Full Text Available Despite the importance of ex situ conservation programmes as highlighted in the Amphibian Conservation Action Plan, there are few empirical studies that examine the influence of captive conditions on the fitness of amphibians, even for basic components of enclosure design such as cover provision. Maintaining the fitness of captive amphibian populations is essential to the success of ex situ conservation projects. Here we examined the impact of plant cover on measures of fitness and behaviour in captive red-eyed tree frogs (Agalychnis callidryas. We found significant effects of plant provision on body size, growth rates and cutaneous bacterial communities that together demonstrate a compelling fitness benefit from cover provision. We also demonstrate a strong behavioural preference for planted rather than non-planted areas. We also assessed the impact of plant provision on the abiotic environment in the enclosure as a potential driver of these behavioural and fitness effects. Together this data provides valuable information regarding enclosure design for a non-model amphibian species and has implications for amphibian populations maintained in captivity for conservation breeding programmes and research.

  8. Post-fire salvage logging alters species composition and reduces cover, richness, and diversity in Mediterranean plant communities.

    Science.gov (United States)

    Leverkus, Alexandro B; Lorite, Juan; Navarro, Francisco B; Sánchez-Cañete, Enrique P; Castro, Jorge

    2014-01-15

    An intense debate exists on the effects of post-fire salvage logging on plant community regeneration, but scant data are available derived from experimental studies. We analyzed the effects of salvage logging on plant community regeneration in terms of species richness, diversity, cover, and composition by experimentally managing a burnt forest on a Mediterranean mountain (Sierra Nevada, S Spain). In each of three plots located at different elevations, three replicates of three treatments were implemented seven months after the fire, differing in the degree of intervention: "Non-Intervention" (all trees left standing), "Partial Cut plus Lopping" (felling 90% of the trees, cutting the main branches, and leaving all the biomass in situ), and "Salvage Logging" (felling and piling the logs, and masticating the woody debris). Plant composition in each treatment was monitored two years after the fire in linear point transects. Post-fire salvage logging was associated with reduced species richness, Shannon diversity, and total plant cover. Moreover, salvaged sites hosted different species assemblages and 25% lower cover of seeder species (but equal cover of resprouters) compared to the other treatments. Cover of trees and shrubs was also lowest in Salvage Logging, which could suggest a potential slow-down of forest regeneration. Most of these results were consistent among the three plots despite plots hosting different plant communities. Concluding, our study suggests that salvage logging may reduce species richness and diversity, as well as the recruitment of woody species, which could delay the natural regeneration of the ecosystem. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. 1997 annual ground control operating plan for the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    This plan presents background information and a working guide to assist Mine Operations and Engineering in developing strategies for addressing ground control issues at the Waste Isolation Pilot Plant (WIPP). With the anticipated receipt of waste in late 1997, this document provides additional detail to Panel 1 activities and options. The plan also serves as a foundation document for development and revision of the annual long-term ground control plan. Section 2.0 documents the current status of all underground excavations with respect to location, geology, geometry, age, ground support, operational use, projected life, and physical conditions. Section 3.0 presents the methods used to evaluate ground conditions, including visual observations of the roof, ribs, and floor, inspection of observation holes, and review of instrumentation data. Section 4.0 lists several ground support options and specific applications of each. Section 5.0 discusses remedial ground control measures that have been implemented to date. Section 6.0 presents projections and recommendations for ground control actions based on the information in Sections 2.0 through 5.0 of this plan and on a rating of the critical nature of each specific area. Section 7.0 presents a summary statement, and Section 8.0 includes references. Appendix A provides an overview and critique of ground control systems that have been, or may be, used at the site. Because of the dynamic nature of the underground openings and associated geotechnical activities, this plan will be revised as additional data are incorporated.

  10. Contrasting land uses in Mediterranean agro-silvo-pastoral systems generated patchy diversity patterns of vascular plants and below-ground microorganisms.

    Science.gov (United States)

    Bagella, Simonetta; Filigheddu, Rossella; Caria, Maria Carmela; Girlanda, Mariangela; Roggero, Pier Paolo

    2014-12-01

    The aims of this paper were (i) to define how contrasting land uses affected plant biodiversity in Mediterranean agro-silvo-pastoral-systems across a gradient of disturbance regimes: cork oak forests, secondary grasslands, hay crops, grass covered vineyards, tilled vineyards; (ii) to determine whether these patterns mirrored those of below-ground microorganisms and whether the components of γ-diversity followed a similar model. The disturbance regimes affected plant assemblage composition. Species richness decreased with increasing land use intensity, the Shannon index showed the highest values in grasslands and hay crops. Plant assemblage composition patterns mirrored those of Basidiomycota and Ascomycota. Richness in Basidiomycota, denitrifying bacteria and microbial biomass showed the same trend as that observed for vascular plant richness. The Shannon index pattern of below-ground microorganisms was different from that of plants. The plant γ-diversity component model weakly mirrored those of Ascomycota. Patchy diversity patterns suggest that the maintenance of contrasting land uses associated with different productions typical of agro-silvo-pastoral-systems can guarantee the conservation of biodiversity.

  11. Cover plants and mineral nitrogen: effects on organic matter fractions in an oxisol under no-tillage in the cerrado

    Directory of Open Access Journals (Sweden)

    Isis Lima dos Santos

    2014-12-01

    Full Text Available Cover plants are essential for the sustainability of no-tillage systems in tropical regions. However, information on the effects of these plants and N fertilization on soil organic matter fractions is still scarce. This study evaluated the effect of cover crops with different chemical composition and of N topdressing on the labile and humified organic matter fractions of an Oxisol of the Cerrado (savanna-like vegetation. The study in a randomized complete block design was arranged in split-plots with three replications. Four cover species were tested in the plots and the presence or absence of N topdressing in the subplot. The following cover species were planted in succession to corn for eight years: Urochloa ruziziensis; Canavalia brasiliensis M. ex Benth; Cajanus cajan (L. Millsp; and Sorghum bicolor (L. Moench. In general, the cultivation of U. ruziziensis increased soil C levels, particularly of C in the humic acid and particulate organic C fractions, which are quality indicators of soil organic matter. The C in humic substances and mineral organic C accounted for the highest proportions of total organic C, demonstrating the strong interaction between organic matter, Fe and Al oxides and kaolinite, which are predominant in these weathered soils of the Cerrado.

  12. STRUCTURE AND CHARACTERISTICS OF TI-AL-NI SYSTEM COVERING, APPLIED ON THE STEEL GROUND USING ELECTRON-BEAM HEATING

    Directory of Open Access Journals (Sweden)

    I. V. Murashova

    2011-01-01

    Full Text Available The morphology of the system Ti-Al-Ni covering, received by means of self-distributing high-temperature synthesis, initiated by electron-beam heating, on the basis of steel St3 is investigated.

  13. Links between plant litter chemistry, species diversity, and below-ground ecosystem function.

    Science.gov (United States)

    Meier, Courtney L; Bowman, William D

    2008-12-16

    Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics of plant species diversity. We amended native soils with litter mixtures containing up to 4 alpine plant species, and we used 9 litter chemical traits to evaluate the chemical composition (i.e., the identity and quantity of compounds) and chemical diversity of the litter mixtures. The chemical composition of the litter mixtures was the strongest predictor of soil respiration, net N mineralization, and microbial biomass N. Soil respiration and net N mineralization rates were also significantly correlated with the chemical diversity of the litter mixtures. In contrast, soil C and N cycling rates were poorly correlated with plant species richness, and there was no relationship between species richness and the chemical diversity of the litter mixtures. These results indicate that the composition and diversity of chemical compounds in litter are potentially important functional traits affecting decomposition, and simple metrics like plant species richness may fail to capture variation in these traits. Litter chemical traits therefore provide a mechanistic link between organisms, species diversity, and key components of below-ground ecosystem function.

  14. Trends of six month nighttime ground-based cloud cover values over Manila Observatory (14.64N, 121.07E)

    Science.gov (United States)

    Gacal, G. F. B.; Lagrosas, N.

    2016-12-01

    The ground reflects thermal radiation during nighttime. Clouds reflect this radiation to the ground and cause increase in ambient temperature. In this study, trends of nighttime cloud cover are analyzed using a commercial camera (Canon Powershot A2300) that is operated continuously to capture images of clouds at 5 minute interval. The camera is situated inside a rain-proof box with a glass oculus and is placed on the rooftop of the Manila Observatory building. To detect pixels with clouds, the pictures are converted from its native JPEG format to grayscale format. The pixels are then screened for clouds by looking at the values of pixels with and without clouds. In grayscale format, pixels with clouds have greater pixel values than pixels without clouds. Based on the observations, a threshold pixel value of 17 is employed to discern pixels with clouds from pixels without clouds. When moon is present in the image, the grayscale image, which is in 8-bit unsigned integer format, is converted into double format. The moon signals are modelled using a two dimensional Gaussian function and is subtracted from the converted image (Gacal et al, 2016). This effectively removes the moon signals but preserves the cloud signals. This method is applied to the data collected from the months of January, February, March, October, November and December 2015. In Manila, dry months are from November to April. Wet months are from May to October. The trends of nighttime cloud cover values over Manila Observatory are shown in the figure below. Frequency distribution of cloud cover values of the first and last three months of the year show that dry and wet months have higher and lower frequency of low cloud cover values, respectively. The trend also exhibits a decrease of cloud cover from October to December but increases back from January until March. This is exhibited in the decrease in the frequency of cloud cover values in the 20%-100% range from October to December. This can be

  15. Plant-microbe and plant-insect interactions meet common grounds

    NARCIS (Netherlands)

    Schenk, P.; McGrath, K.C.; Lorito, M.; Pieterse, C.M.J.

    2008-01-01

    Plant–microbe and plant–insect interactions are of global importance for agriculture and of high interest to many plant scientists, microbiologists and entomologists. Traditionally, plant–microbe and plant–insect interactions have been looked at as two separate issues, but in recent years it has bec

  16. Plant-microbe and plant-insect interactions meet common grounds

    NARCIS (Netherlands)

    Schenk, P.; McGrath, K.C.; Lorito, M.; Pieterse, C.M.J.

    2008-01-01

    Plant–microbe and plant–insect interactions are of global importance for agriculture and of high interest to many plant scientists, microbiologists and entomologists. Traditionally, plant–microbe and plant–insect interactions have been looked at as two separate issues, but in recent years it has

  17. Planting Date and Seeding Rate Effects on Sunn Hemp Biomass and Nitrogen Production for a Winter Cover Crop

    Directory of Open Access Journals (Sweden)

    Kipling S. Balkcom

    2011-01-01

    Full Text Available Sunn hemp (Crotalaria juncea L. is a tropical legume that produces plant biomass and nitrogen (N quickly. Our objectives were to assess the growth of a new sunn hemp cultivar breed to produce seed in a temperate climate and determine the residual N effect on a rye (Secale cereale L. cover crop in east-central Alabama from 2007 to 2009. Plant populations, plant height, stem diameter, biomass production, and N content were determined for two sunn hemp planting dates, following corn (Zea mays L. and wheat (Triticum aestivum L. harvest, across different seeding rates (17, 34, 50, and 67 kg/ha. Rye biomass was measured the following spring. Sunn hemp biomass production was inconsistent across planting dates, but did relate to growing degree accumulation. Nitrogen concentrations were inversely related to biomass production, and subsequent N contents corresponded to biomass levels. Neither planting date nor seeding rate affected rye biomass production, but rye biomass averaged over both planting dates following wheat/sunn hemp averaged 43% and 33% greater than rye following fallow. Rye biomass following corn/sunn hemp was equivalent to fallow plots. Early planting dates are recommended for sunn hemp with seeding rates between 17 and 34 kg/ha to maximize biomass and N production.

  18. Plant functional type classification for Earth System Models: results from the European Space Agency's Land Cover Climate Change Initiative

    Directory of Open Access Journals (Sweden)

    B. Poulter

    2015-01-01

    Full Text Available Global land cover is a key variable in the earth system with feedbacks on climate, biodiversity and natural resources. However, global land-cover datasets presently fall short of user needs in providing detailed spatial and thematic information that is consistently mapped over time and easily transferable to the requirements of earth system models. In 2009, the European Space Agency launched the Climate Change Initiative (CCI, with land cover (LC_CCI as one of thirteen Essential Climate Variables targeted for research development. The LC_CCI was implemented in three phases, first responding to a survey of user needs, then developing a global, moderate resolution, land-cover dataset for three time periods, or epochs, 2000, 2005, and 2010, and the last phase resulting in a user-tool for converting land cover to plant functional type equivalents. Here we present the results of the LC_CCI project with a focus on the mapping approach used to convert the United Nations Land Cover Classification System to plant functional types (PFT. The translation was performed as part of consultative process among map producers and users and resulted in an open-source conversion tool. A comparison with existing PFT maps used by three-earth system modeling teams shows significant differences between the LC_CCI PFT dataset and those currently used in earth system models with likely consequences for modeling terrestrial biogeochemistry and land–atmosphere interactions. The LC_CCI tool is flexible for users to modify land cover to PFT conversions and will evolve as Phase 2 of the European Space Agency CCI program continues.

  19. The Effects of Disturbance History on Ground-Layer Plant Community Composition in British Columbia

    Directory of Open Access Journals (Sweden)

    Michael Ton

    2016-05-01

    Full Text Available Plant communities are sensitive to perturbations and may display alternative recovery pathways depending on disturbance history. In sub-boreal lodgepole pine forests of central interior British Columbia, Canada, fire and logging are two widespread landscape disturbances that overlap in many regions. We asked whether cumulative, short-interval disturbance from logging and fire resulted in different ground-layer plant communities than resulted from fire alone. Using field-collected data, we compared the taxonomic composition and functional traits of 3-year old plant communities that were either harvested 6-to-13 years prior, or not harvested prior to being burned in a large stand-replacing fire. The taxonomic composition diverged between the two treatments, driven primarily by differences in a few key indicator species such as Petasites frigidus and Vaccinium membranaceum. Analysis of individual species’ morphological traits indicated that only a few species vary in size in relation to disturbance history. Our data suggest that a history of forest harvest leaves a subtle footprint on post-fire ground-layer plant communities at early stages of succession.

  20. Comparative study of ground water treatment plants sludges to remove phosphorous from wastewater.

    Science.gov (United States)

    Bal Krishna, K C; Aryal, Ashok; Jansen, Troy

    2016-09-15

    Alum- and iron-based sludge obtained from water treatment plant produced during a unit treatment process (coagulation and flocculation) have been widely tested as a low-cost adsorbent to remove phosphorous (P) from wastewater. However, the effectiveness of iron-based sludge generated from the oxidation of iron which naturally occurs in the ground water has not been investigated. Moreover, influences of dominant metals ions comprised in the treatment plants sludges on P adsorption capacity and rate from wastewater are not yet known. This study, therefore, employed four different groundwater treatment plants sludges iron-based (from the oxidation of iron) and alum-based (from coagulation and flocculation process) to determine their P adsorption capacities and adsorption rates from the synthetic wastewater (SWW) and secondary effluent wastewater (SEWW). Although metals ions concentrations were the highest in the iron-based sludge amongst the sludge used in this study, it appeared to have the lowest P adsorption capacity and adsorption rate. A good correlation between aluminium to iron mass ratio and adsorption capacity for both types of waters were noted. However, a poor relation between aluminium to iron mass ratio and adsorption rates for the SEWW was observed. Further, the tested sludges were found to have a better P removal efficiency and adsorption capacity from the SEWW than from the SWW. Thus, this study demonstrates the ground water treatment plants sludges could be a low cost and effective adsorbent in removing P from wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Ground acceleration in a nuclear power plant; Aceleracion del suelo en una central nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Pena G, P.; Balcazar, M.; Vega R, E., E-mail: pablo.pena@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    A methodology that adopts the recommendations of international organizations for determining the ground acceleration at a nuclear power plant is outlined. Systematic presented here emphasizes the type of geological, geophysical and geotechnical studies in different areas of influence, culminating in assessments of Design Basis earthquake and the earthquake Operating Base. The methodology indicates that in regional areas where the site of the nuclear power plant is located, failures are identified in geological structures, and seismic histories of the region are documented. In the area of detail geophysical tools to generate effects to determine subsurface propagation velocities and spectra of the induced seismic waves are used. The mechanical analysis of drill cores allows estimating the efforts that generate and earthquake postulate. Studies show that the magnitude of the Fukushima earthquake, did not affect the integrity of nuclear power plants due to the rocky settlement found. (Author)

  2. Planting depth and rhizome size effects on below ground growth of licorice (Glycyrrhiza glabra L.

    Directory of Open Access Journals (Sweden)

    reza vali allah poor

    2009-06-01

    Full Text Available An experiment was carried out to evaluate the effects of planting depth and rhizome sizes on below ground growth of licorice (Glycyrrhiza glabra L. at research glasshouse of Mashhad Unversity in 2001. Factorial experiment containing 2 factors of planting depth (10, 20 and 40‌cm and rhizome sizes (1,2 and 3 buds or 4,7 and 10 gr with two replications in completely randomized block design was employed. Development of different variables during growing season including root and mother rhizome dry weight were measured.The highest and the lowest root dry weight (RDWhave been seen in depth of 20 and 40 cm‌, respectively. About 100 days after planting (DAP, RDW increaseed very slowly but thenafter increased faster‌. Rhizome of any sizes in‌ 20 cm, gave the highest RDW‌. Three-bud rhizomes produced the highest RDW and 1-bud rhizome produced the lowest. Mother rhizome dry weight (MRDW reduced untill 60 days after planting. After 75th day, MRDW has increased and all plants started to fill their mother rhizome and finally rhizome of depth 20 cm produced the highest dry weight. In 160 days after planting, mother rhizomes started to lose their weight‌. 1and 3 -bud mother rhizome produce the lowest and highest MRDW, respectively.

  3. Effect of multi-temporal forest cover change trajectories on forest plant diversity

    Science.gov (United States)

    One of the principal tenets of landscape ecology is that forest loss and fragmentation negatively affects biodiversity. However, historical fluctuations in forest cover resulting from repeated cycles of deforestation and reforestation are likely important in influencing patterns ...

  4. The Investigation on Application Status of Cover Plants and Ecological Adaptability for Introduced Cover Plant in Suqian%宿迁市地被植物应用现状及新引种地被的生态适应性调查研究

    Institute of Scientific and Technical Information of China (English)

    李素华; 许晶晶; 金青; 苏苑苑; 袁笑; 周燕

    2011-01-01

    对宿迁市地被植物的应用种类、季相变化及新引种的地被植物的覆盖度、越冬和越夏能力进行调查分析,结果表明:宿迁园林中共应用地被植物89种,以观叶灌木和宿根现叶类居多;夏季季相色彩最为丰富,但红色系花卉比例较大;在覆盖度、越冬和越夏能力评价中综合表现较好的为亮绿忍冬、地被石竹、大花六道木、水果兰、大滨菊,综合表现较差的为细茎针茅、紫露草.%The types of applications, seasonal color of ground cover plants,the coverage, winter and summer hardiness were investigated. Re-sulls showed that 89 kinds of cover plants were applied in gardens of Suqian, the foliage bush and the foliage perennial plants held great majority. The color of summer was richest, but the red series had higher proportion: according to the coverage and winter and summer cold resistance, Lonicera nilida' Maigrun' ,Dianthus plumarius, Abelia grandiflora, Teucrium fruticans, Chrysanthemum maximum were better, Stipa te-nuissima, Tradescantia albiftora were differential.

  5. Effect of Snow-cover Duration on Plant Species Diversity of Alpine Meadows on the Eastern Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Although snow cover plays an important role in structuring plant diversity in the alpine zone, there are few studies on the relationship between snow cover and species diversity of alpine meadows on the eastern Qinghai-Tibetan Plateau. To assess the effect of snow cover on plant species diversity of alpine meadows, we used ten parallel transects of 60 m × 1 m for this study and described the changes in species diversity and composition associated with snow depth. With the division of snow depth into six classes, the highest species richness (S) and species diversity (H') occurred with an intermediate snow depth, i.e., class Ⅲ and class Ⅳ, showing a unimodal curve with the increase in snow depth. The relationship between snow depth and plant diversity (both richness and Shannon index) could be depicted by quadratic equations. There was no evident relationship between diversity (both S and H') and soil water content, which implied that other more important factors influenced species diversity. The patterns of diversity found in our study were largely attributed to freeze-thaw alteration, length of growing season and disturbances of livestock grazing. Furthermore, snow depth affected species composition, as evaluated by the Sorensen's index of similarity. In addition, almost all species limited to one snow depth class were found only in class Ⅲ and class Ⅳ, indicating that intermediate snow depth was suitable for the survival and growth of many alpine species.

  6. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    KAUST Repository

    Jadoon, Khan

    2015-09-18

    We tested an off-ground ground-penetrating radar (GPR) system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  7. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Khan Zaib Jadoon

    2015-09-01

    Full Text Available We tested an off-ground ground-penetrating radar (GPR system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  8. Forms of phosphorus in an oxisol under different soil tillage systems and cover plants in rotation with maize

    Directory of Open Access Journals (Sweden)

    Arminda Moreira de Carvalho

    2014-06-01

    Full Text Available Phosphorus fractions play a key role in sustaining the productivity of acid-savanna Oxisols and are influenced by tillage practices. The aim of this study was to quantify different P forms in an Oxisol (Latossolo Vermelho-Amarelo from the central savanna region of Brazil under management systems with cover crops in maize rotation. Three cover crops (Canavalia brasiliensis, Cajanus cajan (L., and Raphanus sativus L. were investigated in maize rotation systems. These cover crops were compared to spontaneous vegetation. The inorganic forms NaHCO3-iP and NaOH-iP represented more than half of the total P in the samples collected at the depth of 5-10 cm during the rainy season when the maize was grown. The concentration of inorganic P of greater availability (NaHCO3-iP and NaOH-iP was higher in the soil under no-tillage at the depth of 5-10 cm during the rainy season. Concentrations of organic P were higher during the dry season, when the cover crops were grown. At the dry season, organic P constituted 70 % of the labile P in the soil planted to C. cajan under no-tillage. The cover crops were able to maintain larger fractions of P available to the maize, resulting in reduced P losses to the unavailable pools, mainly in no-tillage systems.

  9. Effects of plant cover on properties of rhizosphere and inter-plant soil in a semiarid valley, SW China

    NARCIS (Netherlands)

    Qu, Laiye; Huang, Yuanyuan; Ma, Keming; Zhang, Yuxin; Biere, A.

    2016-01-01

    Plant establishment is widely recognized as an effective way to prevent soil erosion in arid and semiarid ecosystems. Artemisia gmelinii, a pioneering species in many degraded ecosystems in China, is effective in improving soil properties and controlling runoff and soil loss, but mechanisms underlyi

  10. Effects of plant cover on properties of rhizosphere and inter-plant soil in a semiarid valley, SW China

    NARCIS (Netherlands)

    Qu, Laiye; Huang, Yuanyuan; Ma, Keming; Zhang, Yuxin; Biere, A.

    2016-01-01

    Plant establishment is widely recognized as an effective way to prevent soil erosion in arid and semiarid ecosystems. Artemisia gmelinii, a pioneering species in many degraded ecosystems in China, is effective in improving soil properties and controlling runoff and soil loss, but mechanisms

  11. Soil bulk electrical resistivity and forage ground cover: nonlinear models in an alfalfa (Medicago sativa L. case study

    Directory of Open Access Journals (Sweden)

    Roberta Rossi

    2015-12-01

    Full Text Available Alfalfa is a highly productive and fertility-building forage crop; its performance, can be highly variable as influenced by within-field soil spatial variability. Characterising the relations between soil and forage- variation is important for optimal management. The aim of this work was to model the relationship between soil electrical resistivity (ER and plant productivity in an alfalfa (Medicago sativa L. field in Southern Italy. ER mapping was accomplished by a multi-depth automatic resistivity profiler. Plant productivity was assessed through normalised difference vegetation index (NDVI at 2 dates. A non-linear relationship between NDVI and deep soil ER was modelled within the framework of generalised additive models. The best model explained 70% of the total variability. Soil profiles at six locations selected along a gradient of ER showed differences related to texture (ranging from clay to sandy-clay loam, gravel content (0 to 55% and to the presence of a petrocalcic horizon. Our results prove that multi-depth ER can be used to localise permanent soil features that drive plant productivity.

  12. Cover Image Identification of Plant Species for Crop Pollinator Habitat Enhancement in the Northern Prairies

    Directory of Open Access Journals (Sweden)

    Diana Bizecki Robson

    2014-09-01

    Full Text Available Wild pollinators have a positive impact on the productivity of insect-pollinated crops. Consequently, landowners are being encouraged to maintain and grow wildflower patches to provide habitat for important pollinators. Research on plant-pollinator interaction matrices indicates that a small number of “core” plants provide a disproportionately high amount of pollen and nectar to insects. This matrix data can be used to help design wildflower plantings that provide optimal resources for desirable pollinators. Existing interaction matrices from three tall grass prairie preserves in the northern prairies were used to identify core plant species that are visited by wild pollinators of a common insect-pollinated crop, namely canola (Brassica napus L.. The wildflower preferences of each insect taxon were determined using quantitative insect visitation and floral abundance data. Phenology data were used to calculate the degree of floral synchrony between the wildflowers and canola. Using this information I ranked the 41 wildflowers that share insect visitors with canola according to how useful they are for providing pollinators with forage before and after canola flowers. The top five species were smooth blue aster (Symphyotrichum laeve (L. A. & D. Löve, stiff goldenrod (Solidago rigida L., wild bergamot (Monarda fistulosa L., purple prairie-clover (Dalea purpurea Vent. and Lindley’s aster (Symphyotrichum ciliolatum (Lindl. A. & D. Löve. By identifying the most important wild insects for crop pollination, and determining when there will be “pollen and nectar gaps”, appropriate plant species can be selected for companion plantings to increase pollinator populations and crop production.

  13. Multi-group biodiversity in shallow lakes along gradients of phosphorus and water plant cover

    NARCIS (Netherlands)

    Declerck, S.A.J.; Vandekerkhove, J.; Johansson, L.; Muylaert, K.; Conde-Porcuna, J-M.; van der Gucht, K.; Pérez-Martínez, C.; Lauridsen, T.; Schwenk, K.; Zwart, G.; Rommens, W.; López-Ramos, J.; Jeppesen, E.; Vyverman, W.; Brendonck, L.; De Meester, L.

    2005-01-01

    This study aimed at unraveling the structure underlying the taxon-richness matrix of shallow lakes. We assessed taxon richness of a large variety of food-web components at different trophic levels (bacteria, ciliates, phytoplankton, zooplankton, fish, macro-invertebrates, and water plants) in 98

  14. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions. [Rio Grande Valley, Texas

    Science.gov (United States)

    Wiegand, C. L.; Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J. (Principal Investigator)

    1979-01-01

    The author has identified the following significant results. Procedures to edit cloud-contaminated pixels from those pixels representing Earth surface features were investigated. Because clouds are more reflective than Earth features and are colder than Earth surface features most of the year at 26 N latitude, either a raw digital count ratio or a ratio of reflectance percentage for the VIS band to the temperature works well. For this procedure, the two bands of data need to be registered to the ground scene.

  15. Ground layer plant species turnover and beta diversity in southern-European old-growth forests.

    Science.gov (United States)

    Sabatini, Francesco Maria; Burrascano, Sabina; Tuomisto, Hanna; Blasi, Carlo

    2014-01-01

    Different assembly processes may simultaneously affect local-scale variation of species composition in temperate old-growth forests. Ground layer species diversity reflects chance colonization and persistence of low-dispersal species, as well as fine-scale environmental heterogeneity. The latter depends on both purely abiotic factors, such as soil properties and topography, and factors primarily determined by overstorey structure, such as light availability. Understanding the degree to which plant diversity in old-growth forests is associated with structural heterogeneity and/or to dispersal limitation will help assessing the effectiveness of silvicultural practices that recreate old-growth patterns and structures for the conservation or restoration of plant diversity. We used a nested sampling design to assess fine-scale species turnover, i.e. the proportion of species composition that changes among sampling units, across 11 beech-dominated old-growth forests in Southern Europe. For each stand, we also measured a wide range of environmental and structural variables that might explain ground layer species turnover. Our aim was to quantify the relative importance of dispersal limitation in comparison to that of stand structural heterogeneity while controlling for other sources of environmental heterogeneity. For this purpose, we used multiple regression on distance matrices at the within-stand extent, and mixed effect models at the extent of the whole dataset. Species turnover was best predicted by structural and environmental heterogeneity, especially by differences in light availability and in topsoil nutrient concentration and texture. Spatial distances were significant only in four out of eleven stands with a relatively low explanatory power. This suggests that structural heterogeneity is a more important driver of local-scale ground layer species turnover than dispersal limitation in southern European old-growth beech forests.

  16. Ground layer plant species turnover and beta diversity in southern-European old-growth forests.

    Directory of Open Access Journals (Sweden)

    Francesco Maria Sabatini

    Full Text Available Different assembly processes may simultaneously affect local-scale variation of species composition in temperate old-growth forests. Ground layer species diversity reflects chance colonization and persistence of low-dispersal species, as well as fine-scale environmental heterogeneity. The latter depends on both purely abiotic factors, such as soil properties and topography, and factors primarily determined by overstorey structure, such as light availability. Understanding the degree to which plant diversity in old-growth forests is associated with structural heterogeneity and/or to dispersal limitation will help assessing the effectiveness of silvicultural practices that recreate old-growth patterns and structures for the conservation or restoration of plant diversity. We used a nested sampling design to assess fine-scale species turnover, i.e. the proportion of species composition that changes among sampling units, across 11 beech-dominated old-growth forests in Southern Europe. For each stand, we also measured a wide range of environmental and structural variables that might explain ground layer species turnover. Our aim was to quantify the relative importance of dispersal limitation in comparison to that of stand structural heterogeneity while controlling for other sources of environmental heterogeneity. For this purpose, we used multiple regression on distance matrices at the within-stand extent, and mixed effect models at the extent of the whole dataset. Species turnover was best predicted by structural and environmental heterogeneity, especially by differences in light availability and in topsoil nutrient concentration and texture. Spatial distances were significant only in four out of eleven stands with a relatively low explanatory power. This suggests that structural heterogeneity is a more important driver of local-scale ground layer species turnover than dispersal limitation in southern European old-growth beech forests.

  17. Land Use and Land Cover, Existing land use derived from orthoimagery. Ground-truthing from discussion with local plan commission members., Published in 2000, 1:12000 (1in=1000ft) scale, Portage County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Land Use and Land Cover dataset current as of 2000. Existing land use derived from orthoimagery. Ground-truthing from discussion with local plan commission members..

  18. Crop cover the principal influence on non-crop ground beetle (Coleoptera, Carabidae) activity and assemblages at the farm scale in a long-term assessment.

    Science.gov (United States)

    Eyre, M D; Sanderson, R A; McMillan, S D; Critchley, C N R

    2016-04-01

    Ground beetle data were generated using pitfall traps in the 17-year period from 1993 to 2009 and used to investigate the effects of changes in surrounding crop cover on beetle activity and assemblages, together with the effects of weather variability. Beetles were recorded from non-crop field margins (overgrown hedges). Crop cover changes explained far more variation in the beetle assemblages recorded than did temperature and rainfall variation. A reduction in management intensity and disturbance in the crops surrounding the traps, especially the introduction and development of willow coppice, was concomitant with changes in individual species activity and assemblage composition of beetles trapped in non-crop habitat. There were no consistent patterns in either overall beetle activity or in the number of species recorded over the 17-year period, but there was a clear change from assemblages dominated by smaller species with higher dispersal capability to ones with larger beetles with less dispersal potential and a preference for less disturbed agroecosystems. The influence of surrounding crops on ground beetle activity in non-crop habitat has implications for ecosystem service provision by ground beetles as pest predators. These results are contrary to conventional assumptions and interpretations, which suggest activity of pest predators in crops is influenced primarily by adjacent non-crop habitat. The long-term nature of the assessment was important in elucidation of patterns and trends, and indicated that policies such as agri-environment schemes should take cropping patterns into account when promoting management options that are intended to enhance natural pest control.

  19. [Pediatric cases in preclinical emergency medicine: critical aspects in the range of missions covered by ground ambulance and air rescue services].

    Science.gov (United States)

    Schlechtriemen, T; Masson, R; Burghofer, K; Lackner, C K; Altemeyer, K H

    2006-03-01

    The aim of this study was to demonstrate differences in structure and severity of pediatric emergencies treated by aeromedical (air rescue) or ground ambulances services. Conclusions for the training of emergency physicians are discussed. In a 3-year study period, a total of 9,274 pediatric emergencies covered by the ADAC air rescue service are compared to 4,344 pediatric patients of ground ambulance services in Saarland. In aeromedical services pediatric emergencies are more frequent (12.9% vs. 6.4%), trauma predominates (59.9% vs. 35.6%) and severe injuries or diseases occur more frequently (30.5% vs. 15.0%). In both groups pediatric emergency cases are concentrated into very few diagnostic groups: more than one third of the cases involving pre-school children is due to convulsions. Respiratory diseases and intoxication are the next most frequent causes and are more common in ground ambulance patients. Head trauma is the most common diagnosis in cases of pediatric trauma, followed by musculoskeletal and thoracoabdominal trauma. All types of severe trauma are more frequent in pediatric patients of the aeromedical services. Training of emergency physicians should include pediatric life support and specific information about frequent pediatric emergency situations. For emergency physicians in aeromedical services, an intensive training in pediatric trauma life support is also necessary.

  20. On-Orbit and Ground Performance of the PGBA Plant Growth Facility

    Science.gov (United States)

    Hoehn, A.; Chamberlain, D. J.; Forsyth, S. W.; Hanna, D. S.; Scovazzo, P.; Stodieck, L. S.; Heyenga, G.; Kliss, Mark

    1997-01-01

    PGBA, a plant growth facility developed for commercial space biotechnology research, successfully grew a total of 30 plants (6 species) for 10 days on board the Space Shuttle Endeavour (STS-77) and is scheduled for reflight on board MSL-1 (STS-83) for a 16 day flight. The PGBA life support systems provide atmospheric, thermal, and humidity control as well as lighting and nutrient supply in a 23.6 liter chamber. Atmosphere treatment includes ethylene and other hydrocarbon removal, CO2 replenishment, and O2 control. The normally closed system uses controlled CO2 replenishment from the crew cabin as required by the plants. Temperature is controlled (1 C) at user-specified setpoints between 20-32 C, using water-filled coolant loops, solid state Peltier thermoelectric devices, and liquid heat exchangers. The thermoelectric cooling systems were optimized for low power consumption and high cooling efficiencies. Relative humidity is maintained between 60-100% using a cooled porous metal plate to remove water vapor from the air stream without cooling the bulk air below the dew point. The lighting system utilizes three compact fluorescent bi-axial lights with variable lighting control and light intensity (PAR) between 220 and 330 micromol/sq m/s at a distance of 20 cm in spaceflight configuration (on orbit power limited to 230 Watt for entire payload). A ground, up to 550 micromol/sq m/s light intensity can be achieved with 330 Watt payload power consumption. Plant water and nutrient support is sustained via the 'Nutrient Pack' system including the passive or active 'Water Replenishable Nutrient Pack.' The root matrix material (soil or Agar) and nutrient formulation of each pack is prepared according to plant species and experimental requirements. These systems were designed by NASA Ames personnel. Data acquisition and control systems provide 32 channels of environmental data as well as digitized or analog video signals for downlink.

  1. Vegetation Cover and Habitat Heterogeneity derived from QuickBird data as proxies of Local Plant Species Richness in recently burned areas

    Science.gov (United States)

    Viedma, Olga; Torres, Ivan; Moreno, Jose Manuel

    2010-05-01

    In fire-prone ecosystems, it is very common that, following fire, plant species richness increases very markedly, mainly due to an explosion of annuals, following a rapid change during the first few years after the blaze. Herbs play a major role in the system, among other, by fixing nutrients that might be lost, or by changing competitive interactions with shrubs or tree seedlings. But assessing species richness, particularly, herbaceous one, in space and at large scale is very costly. Furthermore, the scale of measurement is also important. In this work we attempted to asses plant species richness during the first year after fire in an abandoned dehesa (open parkland) at three scales (1 m2, 25 m2 and 100 m2) using QuickBird images. The study area was located in Central Spain (Anchuras, Ciudad Real), and was affected by a large summer fire (ca. 2000 ha). Before the fire the system was composed of a shrubland intermixed with trees and open spaces. Two 90x180 m plots were selected and field species richness measures were made at the three scales, using a nested design. Field-based data were related to remotely sensed data using Regression Trees (RT) and Boosted Regression Trees (BRT) modelling. Explanatory spectral and textural remotely sensed data were ecologically interpreted based on vegetation cover ground-based data. We found that areas with low spectral contrast and high reflectivity were dominated by herbaceous species, and had greater species richness than those characterized by low contrast and medium-low reflectivity, which were dominated by shrubs and trees. The highest species richness was found in the areas characterized by high contrast and medium-high reflectivity, which had a mix of herbs and woody layers. Variance explained varied depending on the modelling approach and the scale, from 21% and 50% for 1 m2 using RT and BRT, respectively; to 65% and 79% for 100 m2. The contribution of different life forms in model fitting was scale-dependent. At

  2. Did debris-covered glaciers serve as pleistocene refugia for plants? A new hypothesis derived from observations of recent plant growth on glacier surfaces

    Science.gov (United States)

    Fickert, T.; Friend, D.; Gruninger, F.; Molnia, B.; Richter, M.

    2007-01-01

    This study proposes a new hypothesis: Debris-covered glaciers served as Pleistocene biological refugia. This is based on detailed studies of vascular plant growth on six debris-mantled glaciers, literally around the world, as well as many casual observations also across the globe. We find that such glaciers are quite common and are distributed globally. Using Carbon Glacier, Mount Rainier, U.S.A., as a type locality and case study, we show aspects of the floristic and structural diversity as well as spatial patterns of plant growth on the glacier surface. Migration strategies, root characteristics, and origin and dispersal strategies for vascular plant species are documented. Also reported are special microclimatic conditions in these areas allowing for this remarkable plant ecology. We find that alpine taxa can grow considerably below their usual altitudinal niche due to the cooler subsurface soil temperatures found on glacial debris with ice underneath, and that may have significantly altered the spatial distribution of such flora during full glacial conditions. This in turn creates previously undocumented areas from which alpine, and perhaps arctic, plant species reestablished in post-glacial time. This hypothesis is complementary to both the nunatak hypothesis and tabula rasa theory and possibly helps solve the ongoing controversy between them. ?? 2007 Regents of the University of Colorado.

  3. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions. [south Texas

    Science.gov (United States)

    Wiegand, C. L.; Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J. (Principal Investigator)

    1981-01-01

    Emissive and reflective data for 10 days, and IR data for 6 nights in south Texas scenes were analyzed after procedures were developed for removing cloud-affected data. HCMM radiometric temperatures were: within 2 C of dewpoint temperatures on nights when air temperature approached dewpoint temperatures; significantly correlated with variables important in evapotranspiration; and, related to freeze severity and planting depth soil temperatures. Vegetation greenness indexes calculated from visible and reflective IR bands of NOAA-6 to -9 meteorological satellites will be useful in the AgRISTARS program for seasonal crop development, crop condition, and drought applications.

  4. Evaluation of decommissioning alternatives for the Pilot Plant Complex, Aberdeen Proving Ground

    Energy Technology Data Exchange (ETDEWEB)

    Rueda, J.; Zimmerman, R.E.

    1995-09-01

    This report presents an evaluation of four decommissioning alternatives for the Pilot Plant Complex (PPC), an inactive chemical weapons research, development, and production facility consisting of nine buildings located in the Edgewood Area of the Aberdeen Proving Ground in Maryland. Decommissioning the PPC involves six steps: (1) assessing existing conditions; (2) dismantling the aboveground portions of the buildings (including the floor slabs, paved roads, and sidewalks within the PPC); (3) reducing the size of the demolition debris and sealing the debris in containers for later testing and evaluation; (4) testing and evaluating the debris; (5) conducting site operation and maintenance activities; and (6) recycling or disposing of the debris with or without prior treatment, as appropriate.

  5. Effects of Different Concentrations of Gibberellin on the Flowering of Ground-cover Chrysanthemum 'Zichonglou'%不同浓度赤霉素对地被菊‘紫重楼’开花特性的影响

    Institute of Scientific and Technical Information of China (English)

    王媛; 崔雁汇; 孔一昌; 张强; 吕晋慧

    2012-01-01

    The effects of different concentrations of gibberellin on plant height, crown breadth, flowering characteristic (flowering season, flower number, petals number, flower diameter) and the pollen germination viability of ground-cover Chrysanthemum ' Zichonglou' were studied, which could provided substantial base for the hybrid breeding and regulating flower season of ground-cover Chrysanthemum. The results showed that 100-500 mg/L of gibberellin might cause the dewing color season 6-10 days ahead of time, the starting flower season 7-12 days ahead of time, and the abundant flowering season 2-7 days ahead of time. With the increase of gibberellin concentration ranging from 0 to 500 mg/L, internode and plant height were increased, but the flower number, petals number, crown breadth, and flower diameter were inhibited. The longest internode and plant height occurred with 500 mg/L gibberellin treatment. The pollen germination viability were improved by 100-300 mg/L of gibberellin, and impressed by 500 mg/L gibberellin.%笔者探讨不同浓度赤霉素(GA3)对地被菊‘紫重楼’株高、冠幅、开花特性(花期、开花量、花朵重瓣性、花径)和花粉生活力的影响,旨在为地被菊杂交育种、花期调控提供参考依据.试验结果表明,喷施100~500 mg/L GA3后,‘紫重楼’露色期、始花期及盛花期分别提前6~10天、7~12天和2~7天;GA3有利于节间伸长和株高增加,但植株开花量和花瓣重瓣性降低,冠幅、花径减小.其中,500 mg/L GA3处理下的地被菊节间长度与株高显著高于其他水平;100~300 mg/L GA3处理可促进花粉生活力,500 mg/L对花粉生活力有抑制作用.

  6. Ground-based RGB imaging to determine the leaf water potential of potato plants

    Science.gov (United States)

    Zakaluk, Robert F.

    The determination of plant water status from leaf water potential (Psi L) data obtained by conventional methods is impractical for meeting real time irrigation monitoring requirements. This research, undertaken first, in a greenhouse and then in the field, examined the use of artificial neural network (ANN) modeling of RGB (red green blue) images, captured by a ground-based, five mega pixel digital camera, to predict the leaf water potential of potato (Solanum tuberosum L). The greenhouse study examined cv. Russet Burbank, while the field study examined cv. Sangre. The protocol was similar in both studies: (1) images were acquired over different soil nitrate (N) and volumetric water content levels, (2) images were radiometrically calibrated, (3) green foliage was classified and extracted from the images, and (4) image transformations, and vegetation indices were calculated and transformed using principal components analysis (PCA). The findings from both studies were similar: (1) the R and G bands were more important than the B image band in the classification of green leaf pigment, (2) soil N showed an inverse linear relationship against leaf reflectance in the G image band, (3) the ANN model input neuron weights with more separation between soil N and PsiL were more important than other input neurons in predicting PsiL, and (4) the measured and predicted PsiL validation datasets were normally distributed with equal variances and means that were not significantly different. Based on these research findings, the ground-based digital camera proved to be an adequate sensor for image acquisition and a practical tool for acquiring data for predicting the PsiL of potato plants. Keywords: nitrogen, IHS transformation, chromaticity transformation, principal components, vegetation indices, remote sensing, artificial neural network, digital camera.

  7. Technogenic contaminations of the soil-plant cover in the Primorsky Krai, Russia

    Science.gov (United States)

    Molchanova, Inna; Pozolotina, Vera; Mikhailovskaya, Ludmila; Antonova, Elena; Zhuravlev, Yury; Timofeeva, Yana; Burdukovsky, Maxim

    2013-04-01

    All economical development of the countries carries out monitoring as with the aim to estimate impact of the industrial enterprises and nuclear-energetic complexes as consequences of the nuclear accidents. The investigation the region of the Far East due to proximity to epicentre of accident on Fukushima-1 NPP is of a great interest. The aim of this work are radioecological investigations and estimate technogenic load on the ecosystems of tightly populated plots of the shore zone of the Vladivostok region. Eight plots were located on the investigated territory. The tree fall, forest litters and soils were sampling from the profile cuts of layer by layer, up to 20 cm. The artificial radionuclides (Sr-90 and Cs-134,137), as heavy metals and microelements (Co, Cu, Zn, Pb and Mn) content in the prepared samples was determined. The stock of Sr-90 fluctuates from 0.3 to 1.3 kBq/m2 and Cs-137 was from 0.4 to 3.0 kBq/m2 in the examined soils. On the whole, the level of the radionuclides content in the soil cover is within the limits of the background that was formed in the belt between 50° and 60° of northern latitude. The presence in investigated samples of Cs-134 indicates to contribution of accidental fallout of Fukushima-1 into contamination of the components of the natural ecosystems. In a year's time after the accident the stock of this isotope in the soils was 0.01-0.20 kBq/m^2. It is by factor of 10-100 lower than the stock of Cs-137. Taking into account that the ratio Cs-134/Cs-137 on the moment of accident was equal to unity (1:1). It can be estimated the quantity of Cs-137 entering into environment during post - accident period. This quantity was an average 0.03-0.30 kBq/m2 (with correction on radionuclides decay). The observation for the state of the soil cover includes the estimate of the level and peculiarities of distribution in the soils of heavy metals and microelements. Their content in the soils is formed from Clarke number and additional industrial

  8. Phenology and cover of plant growth forms predict herbivore habitat selection in a high latitude ecosystem.

    Science.gov (United States)

    Iversen, Marianne; Fauchald, Per; Langeland, Knut; Ims, Rolf A; Yoccoz, Nigel G; Bråthen, Kari Anne

    2014-01-01

    The spatial and temporal distribution of forage quality is among the most central factors affecting herbivore habitat selection. Yet, for high latitude areas, forage quantity has been found to be more important than quality. Studies on large ungulate foraging patterns are faced with methodological challenges in both assessing animal movements at the scale of forage distribution, and in assessing forage quality with relevant metrics. Here we use first-passage time analyses to assess how reindeer movements relate to forage quality and quantity measured as the phenology and cover of growth forms along reindeer tracks. The study was conducted in a high latitude ecosystem dominated by low-palatable growth forms. We found that the scale of reindeer movement was season dependent, with more extensive area use as the summer season advanced. Small-scale movement in the early season was related to selection for younger stages of phenology and for higher abundances of generally phenologically advanced palatable growth forms (grasses and deciduous shrubs). Also there was a clear selection for later phenological stages of the most dominant, yet generally phenologically slow and low-palatable growth form (evergreen shrubs). As the summer season advanced only quantity was important, with selection for higher quantities of one palatable growth form and avoidance of a low palatable growth form. We conclude that both forage quality and quantity are significant predictors to habitat selection by a large herbivore at high latitude. The early season selectivity reflected that among dominating low palatability growth forms there were palatable phenological stages and palatable growth forms available, causing herbivores to be selective in their habitat use. The diminishing selectivity and the increasing scale of movement as the season developed suggest a response by reindeer to homogenized forage availability of low quality.

  9. Effects of spatially variable snow cover on thermal regime and hydrology of an Arctic ice wedge polygon landscape identified using ground penetrating radar and LIDAR datasets

    Science.gov (United States)

    Gusmeroli, A.; Liljedahl, A. K.; Peterson, J. E.; Hubbard, S. S.; Hinzman, L. D.

    2012-12-01

    Ice wedge polygons are common in Arctic terrains underlain by permafrost. Permafrost degradation could transform low- into high centered polygons, causing profound changes in the hydrologic regime of Arctic lands, which in turn, could affect the energy balance and subsurface biodegradation of organic carbon responsible for greenhouse gas production. Understanding the linkages between microtopography, snow cover, thermal properties, and thaw depth is critical for developing a predictive understanding of terrestrial ecosystems and their feedbacks to climate. In this study, we use high frequency (500-1000 MHz) ground penetrating radar (GPR) data acquired in spring 2012 within the Next Generation Ecosystem Experiment (NGEE) study site in Barrow, AK to characterize the spatial variability of snow distribution. We compare it's distribution to microtopography, estimated using LIDAR data, and thaw depth, also estimated using ground penetrating radar collected at different times during the year and simulated over time using mechanistic thermal-hydrologic modeling. The high spatial resolution offered by LIDAR and ground penetrating radar permit detailed investigations of the control of microtopography on snow and thaw layer depth. Results suggest that microtopographical variations are responsible for substantial differences in snow accumulation. In low centered polygons, snow depth can be up to four times greater in the troughs than on the rims. Both modeling and observations suggest that the microtopography-governed snow thickness affects the thermal properties of the subsurface and thus the thaw layer thickness; regions with thicker snowpack generally correspond to regions of greater thaw depth. We conclude that a transition from low- to high centered polygons will not only impact watershed runoff but, since snow accumulation is sensitive to the microtopography, it will also impact snow distribution. In turn, snow distribution affects thaw depth thickness, and the

  10. Reductions of plant cover induced by sheep grazing change the above-belowground partition and chemistry of organic C stocks in arid rangelands of Patagonian Monte, Argentina.

    Science.gov (United States)

    Larreguy, C; Carrera, A L; Bertiller, M B

    2017-09-01

    The objective of this study was to estimate the size and chemical quality of the total organic C stock and its partition between above-belowground plant parts and soil at sites with different plant cover induced by sheep grazing in the arid Patagonian Monte. This study was conducted at six representative sites with increasing signs of canopy disturbance attributed to grazing pressure. We used faeces density as a proxy of grazing pressure at each site. We assessed the total plant cover, shrub and perennial grass cover, total standing aboveground biomass (AGB), litter mass and belowground biomass (BGB) at each site. We further estimated the content of organic C, lignin and soluble phenols in plant compartments and the content of organic C, organic C in humic substances (recalcitrant C) and water soluble C (labile C) in soil at each site. Total plant cover was significantly related to grazing pressure. Standing AGB and litter mass decreased with increasing canopy disturbance while BGB did not vary across sites. Total organic C stock and the organic C stock in standing AGB increased with increasing total plant, shrub, and perennial grass cover. The organic C stock in litter mass increased with increasing total plant and shrub cover, while the organic C stock in BGB did not vary across sites. Lignin content in plant compartments increased with increasing total and shrub cover, while soluble phenols content did not change across sites. The organic C stock and the water soluble C content in soil were positively associated with perennial grass cover. Changes in total plant cover induced by grazing pressure negatively affected the size of the total organic C stock, having minor impact on the size of belowground than aboveground components. The reduction of perennial grass cover was reflected in decreasing chemical quality of the organic C stock in soil. Accordingly, plant managerial strategies should not only be focused on the amount of organic C sequestered but also on the

  11. Migration and Enrichment of Arsenic in the Rock-Soil-Crop Plant System in Areas Covered with Black Shale, Korea

    Directory of Open Access Journals (Sweden)

    Ji-Min Yi

    2003-01-01

    Full Text Available The Okchon black shale, which is part of the Guryongsan Formation or the Changri Formation of Cambro-Ordovician age in Korea provides a typical example of natural geological materials enriched with potentially toxic elements such as U, V, Mo, As, Se, Cd, and Zn. In this study, the Dukpyung and the Chubu areas were selected to investigate the migration and enrichment of As and other toxic elements in soils and crop plants in areas covered with black shale. Rock and soil samples digested in 4-acid solution (HCl+HNO3+HF+HClO4 were analyzed for As and other heavy metals by ICP-AES and ICP-MS, and plant samples by INAA. Mean concentration of As in Okchon black shale is higher than those of both world average values of shale and black shale. Especially high concentration of 23.2 mg As kg-1 is found in black shale from the Dukpyung area. Mean concentration of As is highly elevated in agricultural soils from the Dukpyung (28.2 mg kg-1 and the Chubu areas (32.6 mg kg-1. As is highly elevated in rice leaves from the Dukpyung (1.14 mg kg-1 and the Chubu areas (1.35 mg kg-1. The biological absorption coefficient (BAC of As in plant species decreases in the order of rice leaves > corn leaves > red pepper = soybean leaves = sesame leaves > corn stalks > corn grains. This indicates that leafy plants tend to accumulate As from soil to a greater degree than cereal products such as grains.

  12. Ground measurements of the hemispherical-directional reflectance of Arctic snow covered tundra for the validation of satellite remote sensing products

    Science.gov (United States)

    Ball, C. P.; Marks, A. A.; Green, P.; Mac Arthur, A.; Fox, N.; King, M. D.

    2013-12-01

    Surface albedo is the hemispherical and wavelength integrated reflectance over the visible, near infrared and shortwave infrared regions of the solar spectrum. The albedo of Arctic snow can be in excess of 0.8 and it is a critical component in the global radiation budget because it determines the proportion of solar radiation absorbed, and reflected, over a large part of the Earth's surface. We present here our first results of the angularly resolved surface reflectance of Arctic snow at high solar zenith angles (~80°) suitable for the validation of satellite remote sensing products. The hemispherical directional reflectance factor (HDRF) of Arctic snow covered tundra was measured using the GonioRAdiometric Spectrometer System (GRASS) during a three-week field campaign in Ny-Ålesund, Svalbard, in March/April 2013. The measurements provide one of few existing HDRF datasets at high solar zenith angles for wind-blown Arctic snow covered tundra (conditions typical of the Arctic region), and the first ground-based measure of HDRF at Ny-Ålesund. The HDRF was recorded under clear sky conditions with 10° intervals in view zenith, and 30° intervals in view azimuth, for several typical sites over a wavelength range of 400-1500 nm at 1 nm resolution. Satellite sensors such as MODIS, AVHRR and VIIRS offer a method to monitor the surface albedo with high spatial and temporal resolution. However, snow reflectance is anisotropic and is dependent on view and illumination angle and the wavelength of the incident light. Spaceborne sensors subtend a discrete angle to the target surface and measure radiance over a limited number of narrow spectral bands. Therefore, the derivation of the surface albedo requires accurate knowledge of the surfaces bidirectional reflectance as a function of wavelength. The ultimate accuracy to which satellite sensors are able to measure snow surface properties such as albedo is dependant on the accuracy of the BRDF model, which can only be assessed

  13. Improvement of sweet potato yield using mixtures of ground fish bone and plant residues

    Directory of Open Access Journals (Sweden)

    A C Novianantya

    2017-01-01

    Full Text Available The Indonesian government begins to promote food diversification program. The government expects the Indonesian people can consume food crops other than rice, such as wheat, potatoes and sweet potatoes. While, the level of production of sweet potato production decreased in the period of 2012-2015 with total production of only 2,218,992 t/ha. In an effort to increase the production of sweet potato, improvements are needed through application of organic fertilizers like composts. The purpose of this study was to explore the effect of composted manure with ground fish bone, legume residues, and Tithonia on soil chemical properties and sweet potato production includes tuber weight and levels of starch sweet potato crops.The results showedthat application of 5 t compost/ha and 35 kg Trichoderma biofertilizer/ha increased pH, water content, organic carbon, total N, available P, total Kl, CEC,exchangeable Ca, plant height, tuber weight and levels of sweet potato starc

  14. Drought and root herbivory interact to alter the response of above-ground parasitoids to aphid infested plants and associated plant volatile signals.

    Directory of Open Access Journals (Sweden)

    Muhammad Tariq

    Full Text Available Multitrophic interactions are likely to be altered by climate change but there is little empirical evidence relating the responses of herbivores and parasitoids to abiotic factors. Here we investigated the effects of drought on an above/below-ground system comprising a generalist and a specialist aphid species (foliar herbivores, their parasitoids, and a dipteran species (root herbivore.We tested the hypotheses that: (1 high levels of drought stress and below-ground herbivory interact to reduce the performance of parasitoids developing in aphids; (2 drought stress and root herbivory change the profile of volatile organic chemicals (VOCs emitted by the host plant; (3 parasitoids avoid ovipositing in aphids feeding on plants under drought stress and root herbivory. We examined the effect of drought, with and without root herbivory, on the olfactory response of parasitoids (preference, plant volatile emissions, parasitism success (performance, and the effect of drought on root herbivory. Under drought, percentage parasitism of aphids was reduced by about 40-55% compared with well watered plants. There was a significant interaction between drought and root herbivory on the efficacy of the two parasitoid species, drought stress partially reversing the negative effect of root herbivory on percent parasitism. In the absence of drought, root herbivory significantly reduced the performance (e.g. fecundity of both parasitoid species developing in foliar herbivores. Plant emissions of VOCs were reduced by drought and root herbivores, and in olfactometer experiments parasitoids preferred the odour from well-watered plants compared with other treatments. The present work demonstrates that drought stress can change the outcome of interactions between herbivores feeding above- and below-ground and their parasitoids, mediated by changes in the chemical signals from plants to parasitoids. This provides a new insight into how the structure of terrestrial

  15. Comparison and Intercalibration of Vegetation Indices from Different Sensors for Monitoring Above-Ground Plant Nitrogen Uptake in Winter Wheat

    Directory of Open Access Journals (Sweden)

    Yan Zhu

    2013-03-01

    Full Text Available Various sensors have been used to obtain the canopy spectral reflectance for monitoring above-ground plant nitrogen (N uptake in winter wheat. Comparison and intercalibration of spectral reflectance and vegetation indices derived from different sensors are important for multi-sensor data fusion and utilization. In this study, the spectral reflectance and its derived vegetation indices from three ground-based sensors (ASD Field Spec Pro spectrometer, CropScan MSR 16 and GreenSeeker RT 100 in six winter wheat field experiments were compared. Then, the best sensor (ASD and its normalized difference vegetation index (NDVI (807, 736 for estimating above-ground plant N uptake were determined (R2 of 0.885 and RMSE of 1.440 g·N·m−2 for model calibration. In order to better utilize the spectral reflectance from the three sensors, intercalibration models for vegetation indices based on different sensors were developed. The results indicated that the vegetation indices from different sensors could be intercalibrated, which should promote application of data fusion and make monitoring of above-ground plant N uptake more precise and accurate.

  16. Downstairs drivers--root herbivores shape communities of above-ground herbivores and natural enemies via changes in plant nutrients.

    Science.gov (United States)

    Johnson, Scott N; Mitchell, Carolyn; McNicol, James W; Thompson, Jacqueline; Karley, Alison J

    2013-09-01

    1. Terrestrial food webs are woven from complex interactions, often underpinned by plant-mediated interactions between herbivores and higher trophic groups. Below- and above-ground herbivores can influence one another via induced changes to a shared host plant, potentially shaping the wider community. However, empirical evidence linking laboratory observations to natural field populations has so far been elusive. 2. This study investigated how root-feeding weevils (Otiorhynchus sulcatus) influence different feeding guilds of herbivore (phloem-feeding aphids, Cryptomyzus galeopsidis, and leaf-chewing sawflies, Nematus olfaciens) in both controlled and field conditions. 3. We hypothesized that root herbivore-induced changes in plant nutrients (C, N, P and amino acids) and defensive compounds (phenolics) would underpin the interactions between root and foliar herbivores, and ultimately populations of natural enemies of the foliar herbivores in the field. 4. Weevils increased field populations of aphids by ca. 700%, which was followed by an increase in the abundance of aphid natural enemies. Weevils increased the proportion of foliar essential amino acids, and this change was positively correlated with aphid abundance, which increased by 90% on plants with weevils in controlled experiments. 5. In contrast, sawfly populations were 77% smaller during mid-June and adult emergence delayed by >14 days on plants with weevils. In controlled experiments, weevils impaired sawfly growth by 18%, which correlated with 35% reductions in leaf phosphorus caused by root herbivory, a previously unreported mechanism for above-ground-below-ground herbivore interactions. 6. This represents a clear demonstration of root herbivores affecting foliar herbivore community composition and natural enemy abundance in the field via two distinct plant-mediated nutritional mechanisms. Aphid populations, in particular, were initially driven by bottom-up effects (i.e. plant-mediated effects of root

  17. The Effect of Plastic-Covered Ridge and Furrow Planting on the Grain Filling and Hormonal Changes of Winter Wheat

    Institute of Scientific and Technical Information of China (English)

    LIU Yang; HAN Juan; WEN Xiao-xia; WU Wei; GUO Qiang; ZENG Ai; LIAO Yun-cheng

    2013-01-01

    Although plastic-covered ridge and furrow planting (RF) has been reported to produce substantial increases in the grain weight of winter wheat, the underlying mechanism is not yet understood. The present study used two cultivars, Xinong 538 and Zhoumai 18, and RF and traditional lfatten planting (TF, control) with the objective of investigating the effect of RF on wheat grain iflling and the possible relationship of hormonal changes in the wheat grains under RF to grain iflling. The results indicated that RF signiifcantly increased the grain weight, although the effects on grain iflling were different: RF signiifcantly increased the grain-iflling rate and grain weight of inferior grains, whereas RF had no signiifcant effect on grain-iflling rate and grain weight of superior grains. The ifnal grain weight of inferior grains under RF was 39.1 and 50.7 mg for Xinong 538 and Zhoumai 18, respectively, 3.6 and 3.4 mg higher than the values under TF. However, the ifnal grain weight of superior grains under RF was only 0.6 and 0.8 mg higher than under TF for Xinong 538 and Zhoumai 18, respectively. RF signiifcantly decreased the ethylene and gibberellic acid content in the inferior grains and increased the indole-3-acetic acid, abscisic acid and zeatin+zeatin riboside content in the inferior grains; however, no signiifcant difference between RF and TF was observed for the hormonal content in the superior grains. Based on these results, we concluded that RF signiifcantly modulated hormonal changes in the inferior grains and, thus, affected the grain iflling and grain weight of the inferior grains;in contrast, RF had no signiifcant effect on grain iflling, grain weight and hormonal changes in the superior wheat grains.

  18. Environmental geophysics of the Pilot Plant on the west branch of Canal Creek, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    McGinnis, L.D.; Miller, S.F.; Daudt, C.R.; Thompson, M.D.; Borden, H.; Benson, M. [Argonne National Lab., IL (United States). Reclamation Engineering and Geosciences Section; Wrobel, J. [Directorate of Safety, Health, and Environment, Aberdeen Proving Ground, MD (United States)

    1994-05-01

    Plans to demolish and remediate the Pilot Plant complex in the Edgewood Area of Aberdeen Proving Ground have served to initiate a series of nonintrusive, environmental-geophysical studies. The studies are assisting in the location and identification of pipes, tanks, trenches, and liquid waste in the subsurface. Multiple databases have been integrated to provide support for detection of underground utilities and to determine the stratigraphy and lithology of the subsurface. The studies were conducted within the double security fence and exterior to the double fence, down gradient toward the west branch of Canal Creek. To determine if contaminants found in the creek were associated with the Pilot Plant, both the east and west banks were included in the study area. Magnetic, conductivity, inductive emf, and ground-penetrating-radar anomalies outline buried pipes, trenches, and various pieces of hardware associated with building activities. Ground-penetrating-radar imagery also defines a paleovalley cut 30 ft into Potomac Group sediments of Cretaceous age. The paleovalley crosses the site between Building E5654 and the Pilot Plant fence. The valley is environmentally significant because it may control the pathways of contaminants. The Pilot Plant complex was used to manufacture CC2 Impregnite and incapacitating agents; it also served as a production facility for nerve agents.

  19. Unattended instruments for ground-based hyperspectral measurements: development and application for plant photosynthesis monitoring

    Science.gov (United States)

    Cogliati, S.; Rossini, M.; Meroni, M.; Barducci, A.; Julitta, T.; Colombo, R.

    2011-12-01

    and long-term hyperspectral data in different measurement conditions. As a demonstration of the potential of these instruments for monitoring plant photosynthesis, the collected time series (NDVI, PRI and F@760) were successfully used as inputs of Light Use Efficiency (LUE). However, HSI and MRI would be also useful to routinely collect at ground observations of other environmental compartments, for example for calibration/validation of RS data and products.

  20. Diversity and stability of arthropod community in peach orchard under effects of ground cover vegetation%桃园生草对桃树节肢动物群落多样性与稳定性的影响

    Institute of Scientific and Technical Information of China (English)

    蒋杰贤; 万年峰; 季香云; 淡家贵

    2011-01-01

    A comparative study was conducted on the arthropod community in peach orchards with and without ground cover vegetation. In the orchard with ground cover vegetation, the individuals of beneficial, neutral, and phytophagous arthropods were 1. 48, 1. 84 and 0. 64 times of those in the orchard without ground cover vegetation, respectively, but the total number of arthropods had no significant difference with that in the orchard without ground cover vegetation. The species richness, Shannon' s diversity, and Pielou' s evenness index of the arthropods in the orchard with ground cov-er vegetation were 83. 733±4. 932, 4. 966±0. 110, and 0. 795±0. 014, respectively, being signifi-cantly higher than those in the orchard without ground cover vegetation, whereas the Berger-Parker' s dominance index was 0. 135±0. 012, being significantly lower than that (0. 184±0. 018) in the orchard without ground cover vegetation. There were no significant differences in the stability indices S/N and Sd/Sp between the two orchards, but the Nn/Np, Nd/Np, and Sn/Sp in the orchard with ground cover vegetation were 0. 883±0. 123. 1714±0. 683, and 0. 781 ±0. 040, respectively, being significantly higher than those in the orchard without ground cover vegetation. Pearson' s cor-relation analysis indicated that in the orchard with ground cover vegetation, the Shannon' s diversity index was significantly negatively correlated with Nd/Np, Sd/Sp, and S/N but had no significant correlations with Nn/Np and Sn/Sp, whereas in the orchard without ground cover vegetation, the di-versity index was significantly positively correlated with Nn/Np and Nd/Np and had no significant correlations with Sd/Sp ,Sn/Sp, and S/N.%对种植白三叶草的桃园(生草桃园)和非生草桃园的桃树节肢动物群落进行分析比较.结果表明:生草桃园桃树天敌、中性类群和植食类群数量分别是非生草桃园的1.48、1.84和0.64倍,而节肢动物群落个体总数无显著差异;与非

  1. Effects of ground cover on the niches of main insect pests and their natural enemies in peach orchard%桃园生草对桃树上主要害虫及天敌生态位的影响

    Institute of Scientific and Technical Information of China (English)

    万年峰; 季香云; 蒋杰贤; 淡家贵

    2011-01-01

    horizontal niche (0. 996) , widest vertical niche (0. 983 ) , and widest time niche ( 0. 932) , while the corre sponding values in the peach orchard without T. repens were 0. 900, 0. 800, and 0. 818, respec tively. The three-dimensional niche of the mam msect pests in peach orchard with ground covei T. repens was Halyomorpha halys > Cicadellidae > Fulgoridae > Aphididae > Lyonetia clerkella > Dichocrocis punctiferalis > Aromia bungii > Grapholitha molesta > Pseudaulacaspis pentagona, while that in the peach orchard without T. repens was Aphididae > Cicadellidae > Halyomorpha halys > Aromia bungii > Grapholitha molesta > Fulgoridae > Pseudaulacaspis pentagona > Lyone tia clerkella > Dichocrocis punctiferalis. The three-dimensional niche of the main natural enemies in peach orchard with ground cover T. repens was spider > Orius spp. > Chrysopa > parasitic wasp > Coccinellidae > Syrphidae, while that in the peach orchard without T. repens was spider > Chrysopa > Coccinellidae > Parasitic wasp > OriuS spp. > Syrphidae. The OriuS spp. , Coc cinellidae, Syrphidae, and parasitic wasp in the peach orchard without T. repens all showed an evidence of delayed activity. The three-dimensional niches of natural enemy Orius spp. and main insect-pests overlapped greater in the orchard with T. repens than in that without T. repens, and the temporal synchrony and spatial similarity of natural enemies and insect-pests were overall su perior in the orchard with T. repens. Our results showed the positive effect of planting clover as ground cover on the biological control of insect pests in peach orchard.

  2. Depth-distribution patterns and control of soil organic carbon in coastal salt marshes with different plant covers

    Science.gov (United States)

    Bai, Junhong; Zhang, Guangliang; Zhao, Qingqing; Lu, Qiongqiong; Jia, Jia; Cui, Baoshan; Liu, Xinhui

    2016-01-01

    This study was carried out in three kinds of salt marshes according to the vegetation covers, including Phragmites australis salt marsh (PSM), Suaeda salus salt marsh (SSM) and Tamarix chinensis-Suaeda salus salt marsh (TSSM). We applied allometric function, exponential function and logistic function to model the depth distribution of the SOCv and SOCc for each salt marsh, respectively. The results showed that the exponential function fits the depth distribution of the SOCv more well than other two functions. The SOCc can be fitted very well by all three functions for three salt marsh (Adj. R2 > 0.99), of which the allometric function was the best one. The mean topsoil concentration factors (TCFs) of three salt marshes were beyond 0.1, which means the SOC enrichment in surface soils due to plant cycling, but TCFs in PSM were significantly higher than those in SSM (P soils. The results of general linear model (GLM) suggested that four soil properties (soil water content, pH, soil salt content and silt+clay) and their interactive effects explained about 80% of the total variation of SOC stock in the top 20 cm soils and the 20–100 cm soil layers. PMID:27708421

  3. Depth-distribution patterns and control of soil organic carbon in coastal salt marshes with different plant covers

    Science.gov (United States)

    Bai, Junhong; Zhang, Guangliang; Zhao, Qingqing; Lu, Qiongqiong; Jia, Jia; Cui, Baoshan; Liu, Xinhui

    2016-10-01

    This study was carried out in three kinds of salt marshes according to the vegetation covers, including Phragmites australis salt marsh (PSM), Suaeda salus salt marsh (SSM) and Tamarix chinensis-Suaeda salus salt marsh (TSSM). We applied allometric function, exponential function and logistic function to model the depth distribution of the SOCv and SOCc for each salt marsh, respectively. The results showed that the exponential function fits the depth distribution of the SOCv more well than other two functions. The SOCc can be fitted very well by all three functions for three salt marsh (Adj. R2 > 0.99), of which the allometric function was the best one. The mean topsoil concentration factors (TCFs) of three salt marshes were beyond 0.1, which means the SOC enrichment in surface soils due to plant cycling, but TCFs in PSM were significantly higher than those in SSM (P < 0.05). Nearly 30% of SOC was concentrated in the top 20 cm soils. The results of general linear model (GLM) suggested that four soil properties (soil water content, pH, soil salt content and silt+clay) and their interactive effects explained about 80% of the total variation of SOC stock in the top 20 cm soils and the 20–100 cm soil layers.

  4. A synthesis of terrestrial mercury in the western United States: Spatial distribution defined by land cover and plant productivity

    Science.gov (United States)

    Obrist, Daniel; Pearson, Christopher; Webster, Jackson; Kane, Tyler J.; Lin, Che-Jen; Aiken, George R.; Alpers, Charles N.

    2016-01-01

    A synthesis of published vegetation mercury (Hg) data across 11 contiguous states in the western United States showed that aboveground biomass concentrations followed the order: leaves (26 μg kg− 1) ~ branches (26 μg kg− 1) > bark (16 μg kg− 1) > bole wood (1 μg kg− 1). No spatial trends of Hg in aboveground biomass distribution were detected, which likely is due to very sparse data coverage and different sampling protocols. Vegetation data are largely lacking for important functional vegetation types such as shrubs, herbaceous species, and grasses.Soil concentrations collected from the published literature were high in the western United States, with 12% of observations exceeding 100 μg kg− 1, reflecting a bias toward investigations in Hg-enriched sites. In contrast, soil Hg concentrations from a randomly distributed data set (1911 sampling points; Smith et al., 2013a) averaged 24 μg kg− 1 (A-horizon) and 22 μg kg− 1 (C-horizon), and only 2.6% of data exceeded 100 μg kg− 1. Soil Hg concentrations significantly differed among land covers, following the order: forested upland > planted/cultivated > herbaceous upland/shrubland > barren soils. Concentrations in forests were on average 2.5 times higher than in barren locations. Principal component analyses showed that soil Hg concentrations were not or weakly related to modeled dry and wet Hg deposition and proximity to mining, geothermal areas, and coal-fired power plants. Soil Hg distribution also was not closely related to other trace metals, but strongly associated with organic carbon, precipitation, canopy greenness, and foliar Hg pools of overlying vegetation. These patterns indicate that soil Hg concentrations are related to atmospheric deposition and reflect an overwhelming influence of plant productivity — driven by water availability — with productive landscapes showing high soil Hg accumulation and unproductive barren soils and shrublands

  5. A synthesis of terrestrial mercury in the western United States: Spatial distribution defined by land cover and plant productivity.

    Science.gov (United States)

    Obrist, Daniel; Pearson, Christopher; Webster, Jackson; Kane, Tyler; Lin, Che-Jen; Aiken, George R; Alpers, Charles N

    2016-10-15

    A synthesis of published vegetation mercury (Hg) data across 11 contiguous states in the western United States showed that aboveground biomass concentrations followed the order: leaves (26μgkg(-1))~branches (26μgkg(-1))>bark (16μgkg(-1))>bole wood (1μgkg(-1)). No spatial trends of Hg in aboveground biomass distribution were detected, which likely is due to very sparse data coverage and different sampling protocols. Vegetation data are largely lacking for important functional vegetation types such as shrubs, herbaceous species, and grasses. Soil concentrations collected from the published literature were high in the western United States, with 12% of observations exceeding 100μgkg(-1), reflecting a bias toward investigations in Hg-enriched sites. In contrast, soil Hg concentrations from a randomly distributed data set (1911 sampling points; Smith et al., 2013a) averaged 24μgkg(-1) (A-horizon) and 22μgkg(-1) (C-horizon), and only 2.6% of data exceeded 100μgkg(-1). Soil Hg concentrations significantly differed among land covers, following the order: forested upland>planted/cultivated>herbaceous upland/shrubland>barren soils. Concentrations in forests were on average 2.5 times higher than in barren locations. Principal component analyses showed that soil Hg concentrations were not or weakly related to modeled dry and wet Hg deposition and proximity to mining, geothermal areas, and coal-fired power plants. Soil Hg distribution also was not closely related to other trace metals, but strongly associated with organic carbon, precipitation, canopy greenness, and foliar Hg pools of overlying vegetation. These patterns indicate that soil Hg concentrations are related to atmospheric deposition and reflect an overwhelming influence of plant productivity - driven by water availability - with productive landscapes showing high soil Hg accumulation and unproductive barren soils and shrublands showing low soil Hg values. Large expanses of low-productivity, arid ecosystems

  6. Ground and surface water for drinking: a laboratory study on genotoxicity using plant tests

    Directory of Open Access Journals (Sweden)

    Donatella Feretti

    2012-02-01

    Full Text Available Surface waters are increasingly utilized for drinking water because groundwater sources are often polluted. Several monitoring studies have detected the presence of mutagenicity in drinking water, especially from surface sources due to the reaction of natural organic matter with disinfectant. The study aimed to investigate the genotoxic potential of the products of reaction between humic substances, which are naturally present in surface water, and three disinfectants: chlorine dioxide, sodium hypochlorite and peracetic acid. Commercial humic acids dissolved in distilled water at different total organic carbon (TOC concentrations were studied in order to simulate natural conditions of both ground water (TOC=2.5 mg/L and surface water (TOC=7.5 mg/L. These solutions were treated with the biocides at a 1:1 molar ratio of C:disinfectant and tested for genotoxicity using the anaphase chromosomal aberration and micronucleus tests in Allium cepa, and the Vicia faba and Tradescantia micronucleus tests. The tests were carried out after different times and with different modes of exposure, and at 1:1 and 1:10 dilutions of disinfected and undisinfected humic acid solutions. A genotoxic effect was found for sodium hypochlorite in all plant tests, at both TOCs considered, while chlorine dioxide gave positive results only with the A.cepa tests. Some positive effects were also detected for PAA (A.cepa and Tradescantia. No relevant differences were found in samples with different TOC values. The significant increase in all genotoxicity end-points induced by all tested disinfectants indicates that a genotoxic potential is exerted even in the presence of organic substances at similar concentrations to those frequently present in drinking water.

  7. Ground and surface water for drinking: a laboratory study on genotoxicity using plant tests.

    Science.gov (United States)

    Feretti, Donatella; Ceretti, Elisabetta; Gustavino, Bianca; Zerbini, Llaria; Zani, Claudia; Monarca, Silvano; Rizzoni, Marco

    2012-02-17

    Surface waters are increasingly utilized for drinking water because groundwater sources are often polluted. Several monitoring studies have detected the presence of mutagenicity in drinking water, especially from surface sources due to the reaction of natural organic matter with disinfectant. The study aimed to investigate the genotoxic potential of the products of reaction between humic substances, which are naturally present in surface water, and three disinfectants: chlorine dioxide, sodium hypochlorite and peracetic acid. Commercial humic acids dissolved in distilled water at different total organic carbon (TOC) concentrations were studied in order to simulate natural conditions of both ground water (TOC=2.5 mg/L) and surface water (TOC=7.5 mg/L). These solutions were treated with the biocides at a 1:1 molar ratio of C:disinfectant and tested for genotoxicity using the anaphase chromosomal aberration and micronucleus tests in Allium cepa, and the Vicia faba and Tradescantia micronucleus tests. The tests were carried out after different times and with different modes of exposure, and at 1:1 and 1:10 dilutions of disinfected and undisinfected humic acid solutions. A genotoxic effect was found for sodium hypochlorite in all plant tests, at both TOCs considered, while chlorine dioxide gave positive results only with the A.cepa tests. Some positive effects were also detected for PAA (A.cepa and Tradescantia). No relevant differences were found in samples with different TOC values. The significant increase in all genotoxicity end-points induced by all tested disinfectants indicates that a genotoxic potential is exerted even in the presence of organic substances at similar concentrations to those frequently present in drinking water.

  8. Monitoring of a debris-covered and avalanche-fed glacier in the Eastern Italian Alps using ground-based SfM-MVS

    Science.gov (United States)

    Piermattei, Livia; Carturan, Luca; Cazorzi, Federico; Colucci, Renato R.; Dalla Fontana, Giancarlo; Forte, Emanuele

    2015-04-01

    The Montasio Occidentale glacier is a 0.07 km2 wide, avalanche-fed glacier located at very low-altitude (1860-2050 m a.s.l.) in the Eastern Italian Alps. The glacier is still active and shows a detectable mass transfer from the accumulation area to the lower ablation area, which is covered by a thick debris mantle. Geometric changes and mass balance have been monitored starting in 2010, combining glaciological methods and high-resolution geodetic surveying with a terrestrial laser scanner (TLS). The TLS technique has proved to be very effective in determining the volume change of this glacier, but presents several limitations as high costs, high level of specialized training and low portability. On the other hand, the recent improvements in close-range photogrammetric techniques like the Structure from Motion (SfM), combined with dense image matching algorithms as Multi View Stereo (MVS), make them competitive for high quality 3D models production. The purpose of this work was to apply ground-based photogrammetric surveys for the monitoring of the annual mass balance and surface processes of Montasio Occidentale glacier. A consumer-grade SLR camera and the SfM-MVS software PhotoScan were used to detect the changes in the surface topography of the glacier from 2012 to 2014. Different data acquisition settings were tested, in order to optimize the quality and the spatial coverage of the 3D glacier model. The accuracy of the image-based 3D models was estimated in stable areas outside the glacier, using the TLS 3D model as reference. A ground penetrating radar (GPR) survey was carried out in 2014, simultaneously to the photogrammetric survey, that was used to compare the snow height estimations obtained by photogrammetry with those obtained by geophysics. The achieved results indicate that the resolution and accuracy of the 3D models generated by the SfM-MVS technique are comparable with those obtained from TLS surveys. Consequently, almost identical volumetric changes

  9. Dried, ground banana plant leaves (Musa spp.) for the control of Haemonchus contortus and Trichostrongylus colubriformis infections in sheep.

    Science.gov (United States)

    Gregory, L; Yoshihara, E; Ribeiro, B L M; Silva, L K F; Marques, E C; Meira, E B S; Rossi, R S; Sampaio, P H; Louvandini, H; Hasegawa, M Y

    2015-12-01

    To evaluate the anthelmintic effect of Musa spp. leaves, 12 animals were artificially infected with Haemonchus contortus, and another 12 animals were infected with Trichostrongylus colubriformis. Then, both treatment groups were offered 400 g of dried ground banana plant leaves, and the control animals were offered only 1000 g of coast cross hay. During the trials, the animals received weekly physical examinations. The methods used to evaluate the efficiency of this treatment were packed cell volume, total plasma protein and faecal egg counts, and egg hatchability tests were performed on days -2, +3, +6, +9, +13 and +15. Coproculture tests were performed on day -2 to confirm monospecific infections. In the FEC and EHT, a statistically significant difference (0.04, 0.005; p  0.05) for Haemochus contortus group in all tests. Our results confirmed previous findings suggesting that dried ground banana plant leaves possess anthelmintic activity.

  10. Optimizing placements of ground-based snow sensors for areal snow cover estimation using a machine-learning algorithm and melt-season snow-LiDAR data

    Science.gov (United States)

    Oroza, C.; Zheng, Z.; Glaser, S. D.; Bales, R. C.; Conklin, M. H.

    2016-12-01

    We present a structured, analytical approach to optimize ground-sensor placements based on time-series remotely sensed (LiDAR) data and machine-learning algorithms. We focused on catchments within the Merced and Tuolumne river basins, covered by the JPL Airborne Snow Observatory LiDAR program. First, we used a Gaussian mixture model to identify representative sensor locations in the space of independent variables for each catchment. Multiple independent variables that govern the distribution of snow depth were used, including elevation, slope, and aspect. Second, we used a Gaussian process to estimate the areal distribution of snow depth from the initial set of measurements. This is a covariance-based model that also estimates the areal distribution of model uncertainty based on the independent variable weights and autocorrelation. The uncertainty raster was used to strategically add sensors to minimize model uncertainty. We assessed the temporal accuracy of the method using LiDAR-derived snow-depth rasters collected in water-year 2014. In each area, optimal sensor placements were determined using the first available snow raster for the year. The accuracy in the remaining LiDAR surveys was compared to 100 configurations of sensors selected at random. We found the accuracy of the model from the proposed placements to be higher and more consistent in each remaining survey than the average random configuration. We found that a relatively small number of sensors can be used to accurately reproduce the spatial patterns of snow depth across the basins, when placed using spatial snow data. Our approach also simplifies sensor placement. At present, field surveys are required to identify representative locations for such networks, a process that is labor intensive and provides limited guarantees on the networks' representation of catchment independent variables.

  11. Hydrogeology and simulation of ground-water flow at the Gettysburg Elevator Plant Superfund Site, Adams County, Pennsylvania

    Science.gov (United States)

    Low, Dennis J.; Goode, Daniel J.; Risser, Dennis W.

    2000-01-01

    Ground water in Triassic-age sedimentary fractured-rock aquifers in the area of Gettysburg, Pa., is used as drinking water and for industrial and commercial supply. In 1983, ground water at the Gettysburg Elevator Plant was found by the Pennsylvania Department of Environmental Resources to be contaminated with trichloroethene, 1,1,1-trichloroethane, and other synthetic organic compounds. As part of the U.S. Environmental Protection Agency?s Comprehensive Environmental Response, Compensation, and Liability Act, 1980 process, a Remedial Investigation was completed in July 1991, a method of site remediation was issued in the Record of Decision dated June 1992, and a Final Design Report was completed in May 1997. In cooperation with the U.S. Environmental Protection Agency in the hydrogeologic assessment of the site remediation, the U.S. Geological Survey began a study in 1997 to determine the effects of the onsite and offsite extraction wells on ground-water flow and contaminant migration from the Gettysburg Elevator Plant. This determination is based on hydrologic and geophysical data collected from 1991 to 1998 and on results of numerical model simulations of the local ground-water flow-system. The Gettysburg Elevator Site is underlain by red, green, gray, and black shales of the Heidlersburg Member of the Gettysburg Formation. Correlation of natural-gamma logs indicates the sedimentary rock strike about N. 23 degrees E. and dip about 23 degrees NW. Depth to bedrock onsite commonly is about 6 feet but offsite may be as deep as 40 feet. The ground-water system consists of two zones?a thin, shallow zone composed of soil, clay, and highly weathered bedrock and a thicker, nonweathered or fractured bedrock zone. The shallow zone overlies the bedrock zone and truncates the dipping beds parallel to land surface. Diabase dikes are barriers to ground-water flow in the bedrock zone. The ground-water system is generally confined or semi-confined, even at shallow depths. Depth

  12. ARADISH - Development of a Standardized Plant Growth Chamber for Experiments in Gravitational Biology Using Ground Based Facilities

    Science.gov (United States)

    Schüler, Oliver; Krause, Lars; Görög, Mark; Hauslage, Jens; Kesseler, Leona; Böhmer, Maik; Hemmersbach, Ruth

    2016-06-01

    Plant development strongly relies on environmental conditions. Growth of plants in Biological Life Support Systems (BLSS), which are a necessity to allow human survival during long-term space exploration missions, poses a particular problem for plant growth, as in addition to the traditional environmental factors, microgravity (or reduced gravity such as on Moon or Mars) and limited gas exchange hamper plant growth. Studying the effects of reduced gravity on plants requires real or simulated microgravity experiments under highly standardized conditions, in order to avoid the influence of other environmental factors. Analysis of a large number of biological replicates, which is necessary for the detection of subtle phenotypical differences, can so far only be achieved in Ground Based Facilities (GBF). Besides different experimental conditions, the usage of a variety of different plant growth chambers was a major factor that led to a lack of reproducibility and comparability in previous studies. We have developed a flexible and customizable plant growth chamber, called ARAbidopsis DISH (ARADISH), which allows plant growth from seed to seedling, being realized in a hydroponic system or on Agar. By developing a special holder, the ARADISH can be used for experiments with Arabidopsis thaliana or a plant with a similar habitus on common GBF hardware, including 2D clinostats and Random Positioning Machines (RPM). The ARADISH growth chamber has a controlled illumination system of red and blue light emitting diodes (LED), which allows the user to apply defined light conditions. As a proof of concept we tested a prototype in a proteomic experiment in which plants were exposed to simulated microgravity or a 90° stimulus. We optimized the design and performed viability tests after several days of growth in the hardware that underline the utility of ARADISH in microgravity research.

  13. Assessing quality and quantity of groundwater DOC in relation to plant export from different over-winter green-cover treatments in tillage farming systems

    Science.gov (United States)

    Premrov, Alina; Coxon, Catherine; Hackett, Richard; Richards, Karl

    2010-05-01

    The biogeochemistry of nitrogen is often connected to carbon and C/N dynamics. The dissolved organic carbon (DOC) electron donor availability can be related to groundwater denitrification (Buss, et al. 2005). Therefore groundwater nitrate attenuation processes are also frequently linked to carbon availability. In recent years the role of over-winter green cover in tillage farming has been studied extensively. Nevertheless further research on the biogeochemical effect of green cover on soil/sediment and groundwater quality is still needed. In particular plant roots are known to exude different types of organic compounds, but their role in groundwater quality has not been investigated in depth. According to Cannavo et al. (2004a,b), in addition to quantity, the quality of water-extractable soil organic matter (e.g. molecular size/weight) has also an important role for microbial activity. In this study we investigate the effect of over-winter green-cover on potential DOC export to shallow groundwater (2 - 5 m below ground level), located on tillage land in Oak Park, Carlow, Ireland. The experiment includes three over-winter green-cover treatments: natural green-cover, mustard and no-cover (sprayed with herbicide following harvest); and is underlain by a sand and gravel aquifer. The site is equipped with 4 shallow piezometers per treatment (total no. of piezometers is 20, including treatments and surrounding piezometers). In addition to monitoring the quantity of DOC concentrations in shallow groundwater under different green cover treatments over time, an attempt was made to evaluate the quality of dissolved organic matter in shallow groundwater using Excitation Emission Fluorescence Matrix (EEFM) profiles obtained from analyses performed on a Varian Fluorescence Spectrophotometer of a single batch of samples (from all 20 installed piezometers in September 2009). To evaluate the quality of dissolved organic matter in shallow groundwater, computation of the

  14. Testing the generality of above-ground biomass allometry across plant functional types at the continent scale.

    Science.gov (United States)

    Paul, Keryn I; Roxburgh, Stephen H; Chave, Jerome; England, Jacqueline R; Zerihun, Ayalsew; Specht, Alison; Lewis, Tom; Bennett, Lauren T; Baker, Thomas G; Adams, Mark A; Huxtable, Dan; Montagu, Kelvin D; Falster, Daniel S; Feller, Mike; Sochacki, Stan; Ritson, Peter; Bastin, Gary; Bartle, John; Wildy, Dan; Hobbs, Trevor; Larmour, John; Waterworth, Rob; Stewart, Hugh T L; Jonson, Justin; Forrester, David I; Applegate, Grahame; Mendham, Daniel; Bradford, Matt; O'Grady, Anthony; Green, Daryl; Sudmeyer, Rob; Rance, Stan J; Turner, John; Barton, Craig; Wenk, Elizabeth H; Grove, Tim; Attiwill, Peter M; Pinkard, Elizabeth; Butler, Don; Brooksbank, Kim; Spencer, Beren; Snowdon, Peter; O'Brien, Nick; Battaglia, Michael; Cameron, David M; Hamilton, Steve; McAuthur, Geoff; Sinclair, Jenny

    2016-06-01

    Accurate ground-based estimation of the carbon stored in terrestrial ecosystems is critical to quantifying the global carbon budget. Allometric models provide cost-effective methods for biomass prediction. But do such models vary with ecoregion or plant functional type? We compiled 15 054 measurements of individual tree or shrub biomass from across Australia to examine the generality of allometric models for above-ground biomass prediction. This provided a robust case study because Australia includes ecoregions ranging from arid shrublands to tropical rainforests, and has a rich history of biomass research, particularly in planted forests. Regardless of ecoregion, for five broad categories of plant functional type (shrubs; multistemmed trees; trees of the genus Eucalyptus and closely related genera; other trees of high wood density; and other trees of low wood density), relationships between biomass and stem diameter were generic. Simple power-law models explained 84-95% of the variation in biomass, with little improvement in model performance when other plant variables (height, bole wood density), or site characteristics (climate, age, management) were included. Predictions of stand-based biomass from allometric models of varying levels of generalization (species-specific, plant functional type) were validated using whole-plot harvest data from 17 contrasting stands (range: 9-356 Mg ha(-1) ). Losses in efficiency of prediction were biomass prediction in 92% of the 53 species tested. Further, overall efficiency of stand-level biomass prediction was 99%, with a mean absolute prediction error of only 13%. Hence, for cost-effective prediction of biomass across a wide range of stands, we recommend use of generic allometric models based on plant functional types. Development of new species-specific models is only warranted when gains in accuracy of stand-based predictions are relatively high (e.g. high-value monocultures).

  15. Water-saving ground cover rice production system reduces net greenhouse gas fluxes in an annual rice-based cropping system

    Directory of Open Access Journals (Sweden)

    Z. Yao

    2014-06-01

    Full Text Available To safeguard food security and preserve precious water resources, the technology of water-saving ground cover rice production system (GCRPS is being increasingly adopted for the rice cultivation. However, changes in soil water status and temperature under GCRPS may affect soil biogeochemical processes that control the biosphere–atmosphere exchanges of methane (CH4, nitrous oxide (N2O and carbon dioxide (CO2. The overall goal of this study is to better understand how net ecosystem greenhouse gas exchanges (NEGE and grain yields are affected by GCRPS in an annual rice-based cropping system. Our evaluation was based on measurements of the CH4 and N2O fluxes and soil heterotrophic respiration (CO2 emission over a complete year, as well as the estimated soil carbon sequestration intensity for six different fertilizer treatments for conventional paddy and GCRPS. The fertilizer treatments included urea application and no N fertilization for both conventional paddy (CUN and CNN and GCRPS (GUN and GNN, solely chicken manure (GCM and combined urea and chicken manure applications (GUM for GCRPS. Averaging across all the fertilizer treatments, GCRPS increased annual N2O emission and grain yield by 40% and 9%, respectively, and decreased annual CH4 emission by 69%, while GCRPS did not affect soil CO2 emissions relative to the conventional paddy. The annual direct emission factors of N2O were 4.01, 0.087 and 0.50% for GUN, GCM and GUM, respectively, and 1.52% for the conventional paddy (CUN. The annual soil carbon sequestration intensity under GCRPS was estimated to be an average of −1.33 Mg C ha−1 yr−1, which is approximately 44% higher than the conventional paddy. The annual NEGE were 10.80–11.02 Mg CO2-eq ha−1 yr−1 for the conventional paddy and 3.05–9.37 Mg CO2-eq ha−1 yr−1 for the GCRPS, suggesting the potential feasibility of GCRPS in reducing net greenhouse effect from rice cultivation. Using organic fertilizers for GCRPS

  16. Plant functional type classification for earth system models: results from the European Space Agency's Land Cover Climate Change Initiative

    NARCIS (Netherlands)

    Poulter, B.; MacBean, N.; Hartley, A.; Khlystova, I.; Arino, O.; Betts, R.; Bontemps, S.; Boettcher, M.; Brockmann, C.; Defourny, P.; Hagemann, S.; Herold, M.; Kirches, C.; Lamarche, C.; Lederer, D.; Ottlé, C.; Peters, M.; Peylin, P.

    2015-01-01

    Global land cover is a key variable in the earth system with feedbacks on climate, biodiversity and natural resources. However, global land cover data sets presently fall short of user needs in providing detailed spatial and thematic information that is consistently mapped over time and easily trans

  17. Cover Plastic Planting Technology of Spring Virus-free Potato%春季脱毒马铃薯地膜覆盖栽培技术

    Institute of Scientific and Technical Information of China (English)

    张金龙

    2012-01-01

    The paper introduced cover plastic planting technology of spring virus-free potato,such as plowing soil deeply,cutting into parts and sprouting,cover plastic cultivation,fertilizing basic fertilizer,field management,pest control and so on,in order to provide a reference.%介绍春季脱毒马铃薯地膜覆盖栽培技术,包括土壤深翻、切块催芽、覆膜栽培、施基肥、田间管理、病虫害防治等方面内容,以供参考。

  18. Responses of fungal root colonization, plant cover and leaf nutrients to long-term exposure to elevated atmospheric CO2 and warming in a subarctic birch forest understory

    DEFF Research Database (Denmark)

    Olsrud, Maria; Carlsson, Bengt Å.; Svensson, Brita M.

    2010-01-01

    Responses of the mycorrhizal fungal community in terrestrial ecosystems to global change factors are not well understood. However, virtually all land plants form symbiotic associations with mycorrhizal fungi, with approximately 20% of the plants' net primary production transported down....... To place the belowground results into an ecosystem context we also investigated how plant cover and nutrient concentrations in leaves responded to elevated atmospheric CO2 concentrations and warming. The ErM colonization in ericaceous dwarf shrubs increased under elevated atmospheric CO2 concentrations......, but did not respond to warming following 6 years of treatment. This suggests that the higher ErM colonization under elevated CO2 might be due to increased transport of carbon belowground to acquire limiting resources such as N, which was diluted in leaves of ericaceous plants under enhanced CO2...

  19. Effect of Fly Ash Disposal on Ground Water Quality Near Parichha Thermal Power Plant, Jhansi – A Case Study

    Directory of Open Access Journals (Sweden)

    Shubham Kanchan

    2015-08-01

    Full Text Available Thermal power plant generates a huge amount of fly ash on combustion of coal which is becoming a major environmental issue. Thermal power plants are greatly facing a fly ash management problem. Open dumping of fly ash can deteriorate the groundwater quality by runoff. In the present investigation, the ground water samples were collected from nearby areas of Parichha Thermal Power Plant at six locations during the period of Jan 2014 to May 2014. The samples were taken to the laboratory and analyzed for physico-chemical properties and heavy metal content. The physico-chemical analysis was done for the parameters like pH, Turbidity, Temperature, Electrical Conductivity, Alkalinity, Total Dissolved Solids, Total Hardness, Calcium Hardness and Magnesium Hardness. The concentration of Turbidity, EC and Alkalinity was exceeding the standard at all locations and shows that the groundwater of the area is not fit for drinking. The ground water samples were also analyzed for the presence of lead and cadmium and it was found that lead was exceeding the limit although cadmium was found within the limit.

  20. Plants as green as phones: Novel insights into plant-mediated communication between below- and above-ground insects

    NARCIS (Netherlands)

    Soler Gamborena, R.; Harvey, J.A.; Bezemer, T.M.; Stuefer, J.F.

    2008-01-01

    can act as vertical communication channels or ‘green phones’ linking soil-dwelling insects and insects in the aboveground ecosystem. When root-feeding insects attack a plant, the direct defense system of the shoot is activated, leading to an accumulation of phytotoxins in the leaves. The protection

  1. Ground-water quality of the Upper Floridan Aquifer near an abandoned manufactured gas plant in Albany, Georgia

    Science.gov (United States)

    Chapman, M.J.

    1993-01-01

    Manufactured gas plants produced gas for heating and lighting in the United States from as early as 1816 into the 1960's. By-products including, but not limited to, oil residues and tar, were generated during the gas-manufacturing process. Organic compounds (hydrocarbons) were detected in water in the upper water-bearing zone of the Upper Floridan aquifer near an abandoned manufactured gas plant (MGP) in Albany, Georgia, during an earlier investigation in 1990. Chemical analyses of ground-water samples collected from five existing monitoring wells in 1991 verify the presence of hydrocarbons and metals in the upper water-beating zone of the Upper Floridan aquifer. One well was drilled into the lower water-beating zone of the Upper Floridan aquifer in 1991 for water-quality sampling and water-level monitoring. Analyses of ground water sampled from this well did not show evidence of benzene, toluene, xylene, napthalene, acenaphthlene, or other related compounds detected in the upper water-bearing zone in the study area. Low concentrations of tetrachloroethane, trichloromethane, and l,2-cisdichloroethene were detected in a water sample from the deeper well; however, these compounds were not detected in the upper water-bearing zone in the study area. Inorganic constituent concentrations also were substantially lower in the deeper well. Overall, ground water sampled from the lower water-bearing zone had lower specific conductance and alkalinity; and lower concentrations of dissolved solids, iron, and manganese compared to ground water sampled from the upper water-bearing zone. Water levels for the upper and lower water-bearing zones were similar throughout the study period.

  2. Soil-to-plant transfer of native selenium for wild vegetation cover at selected locations of the Czech Republic.

    Science.gov (United States)

    Száková, Jiřina; Tremlová, Jana; Pegová, Kristýna; Najmanová, Jana; Tlustoš, Pavel

    2015-06-01

    Total selenium (Se) contents were determined in aboveground biomass of wild plant species growing in two uncultivated meadows at two different locations. The soils in these locations had pseudototal (Aqua Regia soluble) Se in concentration ranges of between 0.2 and 0.3 mg kg(-1) at the first location, and between 0.7 and 1.4 mg kg(-1) at the second location. The plant species represented 29 plant families where the most numerous ones were Poaceae, Rosaceae, Fabaceae , and Asteraceae. The selenium contents in the plants varied between undetectable levels (Aegopodium podagraria, Achillea millefolium, Lotus corniculatus) and 0.158 mg kg(-1) (Veronica arvensis, Veronicaceae). The Se levels were roughly one order of magnitude lower compared to other elements with similar soil content, such as cadmium and molybdenum. The transfer factors of Se, quantifying the element transfer from soil to plants, varied between <0.001 and 0.146 with no significant differences between the locations, confirming the limited soil-plant selenium transfer regardless of location, soil Se level, and plant species. Among the plant families, no unambiguous trend to potential elevated Se uptake was observed. Low Se content in the soil and its plant availability was comparable to other Se-deficient areas within Europe.

  3. Experimental studies of the characteristics of solar-power-plant heliostats on a proving ground - The fixed-heliostat method

    Science.gov (United States)

    Tepliakov, D. I.; Aparisi, R. R.

    The specific features of a new method for investigating the energy characteristics of heliostats for a tower-type solar plant are examined. The method consists in fixing a heliostat in a certain position in the case of which the spot formed by reflected solar radiation due to the apparent motion of the sun is displaced on the surface of an instrumented screen. Midday experiments on a meridional proving ground are discussed, and the practical implementation of the fixed-heliostat method is described.

  4. PLANT MULCH TO TREAT TCE IN GROUND WATER IN A PRB (ABSTRACT ONLY)

    Science.gov (United States)

    In the past ten years, passive reactive barriers (PRBs) have found widespread application to treat chlorinated solvent contamination in ground water. The traditional PRB commonly uses granular zero-valent iron and/or iron alloys as filling materials for treatment of chlorinated ...

  5. The short term influence of aboveground biomass cover crops on C sequestration and β–glucosidase in a vineyard ground under semiarid conditions

    Directory of Open Access Journals (Sweden)

    Fernando Peregrina

    2014-10-01

    Full Text Available Tillage and semiarid Mediterranean climatic conditions accelerate soil organic matter losses in Spanish vineyards. Previous studies showed that cover crops can increase soil organic carbon (SOC in Mediterranean vineyards. The objectives of this study were to evaluate the influence of two different cover crops in the short term on soil C sequestration in a semiarid vineyard and to study the potential use of both β–glucosidase enzimatic activity (GLU and the GLU/SOC ratio in order to assess the SOC increase. The experiment was carried out in a cv. Tempranillo (Vitis vinifera L. vineyard on a Oxyaquic Xerorthent soil in Rioja winegrowing region (NE, Spain. The experimental design was established in 2009 with three treatments: conventional tillage; sown barley cover crop (Hordeum vulgare, L.; sown Persian clover cover crop (Trifolium resupinatum L.. Carbon in the aboveground biomass with each cover crop was monitored. Soil was sampled in June 2011 and June 2012, and SOC, GLU and the GLU/SOC ratio were determined. After 3 years both cover crops increased SOC at soil surface with C sequestration rates of 0.47 and 1.19 t C ha-1 yr-1 for BV and CV respectively. GLU and GLU/SOC ratio increased in both cover crops at 0-5 cm soil depth. The C sequestration rates and GLU were related to the cover crops aboveground biomass. In consequence, in semiarid vineyards under cover crops GLU could be an appropriate indicator to asses the increase of SOC and the soil quality improvement in the short-term (2-3 years.

  6. Above- and below-ground effects of plant diversity depend on species origin

    DEFF Research Database (Denmark)

    Kuebbing, Sara E.; Classen, Aimee Taylor; Sanders, Nate

    2015-01-01

    Although many plant communities are invaded by multiple nonnative species, we have limited information on how a species' origin affects ecosystem function. We tested how differences in species richness and origin affect productivity and seedling establishment. We created phylogenetically paired...... native and nonnative plant communities in a glasshouse experiment to test diversity-productivity relationships and responsible mechanisms (i.e. selection or complementarity effects). Additionally, we tested how productivity and associated mechanisms influenced seedling establishment. We used diversity...

  7. The effect of compost treatments and a plant cover with Agrostis tenuis on the immobilization/mobilization of trace elements in a mine-contaminated soil.

    Science.gov (United States)

    Alvarenga, P; de Varennes, A; Cunha-Queda, A C

    2014-01-01

    A semi-field experiment was conducted to evaluate the use of mixed municipal solid waste compost (MMSWC) and green waste-derived compost (GWC) as immobilizing agents in aided-phytostabilization of a highly acidic soil contaminated with trace elements, with and without a plant cover of Agrostis tenuis. The compost application ratio was 50 Mg ha(-1), and GWC amended soil was additionally limed and supplemented with mineral fertilizers. Both treatments had an equivalent capacity to raise soil organic matter and pH, without a significant increase in soil salinity and in pseudo-total As, Cu, Pb, and Zn concentrations, allowing the establishment of a plant cover. Effective bioavailable Cu and Zn decreased as a consequence of both compost treatments, while effective bioavailable As increased by more than twice but remained as a small fraction of its pseudo-total content. Amended soil had higher soil enzymatic activities, especially in the presence of plants. Accumulation factors for As, Cu, Pb, and Zn by A. tenuis were low, and their concentrations in the plant were lower than the maximum tolerable levels for cattle. As a consequence, the use of A. tenuis can be recommended for assisted phytostabilization of this type of mine soil, in combination with one of the compost treatments evaluated.

  8. Basis for the development of a scenario for ground water risk assessment of plant protection products to banana crop in the frame work of regulation 1107/2009

    Science.gov (United States)

    Alonso-Prados, Elena; Fernández-Getino, Ana Patricia; Alonso-Prados, Jose Luis

    2014-05-01

    The risk assessment to ground water of pesticides and their main metabolites is a data requirement under regulation 1107/2009, concerning the placing of plant protection products on the market. Predicted environmental concentrations (PEC) are calculated according to the recommendations of Forum for the Co-ordination of pesticide fate models and Their Use (FOCUS). The FOCUS groundwater working group developed scenarios for the main crops in European Union. However there are several crops which grow under specific agro-environmental conditions not covered by these scenarios and it is frequent to use the defined scenarios as surrogates. This practice adds an uncertainty factor in the risk assessment. One example is represented by banana crop which in Europe is limited to sub-tropical environmental conditions and with specific agronomic practices. The Canary Islands concentrates the higher production of banana in the European Union characterized by volcanic soils. Banana is located at low altitudes where soils have been eroded or degraded, and it is a common practice to transport soil materials from the high-mid altitudes to the low lands for cultivation. These cultivation plots are locally named "sorribas". These volcanic soils, classified as Andosols according to the FAO classification, have special physico-chemical properties due to noncrystalline materials and layer silicates. The good stability of these soils and their high permeability to water make them relatively resistant to water erosion. Physical properties of volcanic clayey soils are strongly affected by allophone and Fe and Al oxyhidroxides. The rapid weathering of porous volcanic material results in accumulation of stable organo-mineral complexes and short-range-order mineral such as allophane, imogolite and ferrihydrite. These components induce strong aggregation that partly favors properties such as: reduced swelling, increased aggregate stability of clay minerals, high soil water retention capacity

  9. Land cover changes based on plant successions:Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed

    Institute of Scientific and Technical Information of China (English)

    YAN; Jianzhong; ZHANG; Yili; BAI; Wanqi; LIU; Yanhua; BAO

    2005-01-01

    To link regional land use/cover changes with environmental effects, land cover changes are required to reflect vegetation successions, whereas the land cover classification systems commonly used nowadays cannot serve this purpose. In this paper, a new land cover classification system is established in which land covers are classified by the vegetation successions, taking Zamtang County, Barkam County and Jinchuan County in the upper Dadu River watershed as a study area. Using multi-temporal remote sensing images, the land cover data of 1967, 1986 and 2000 are obtained by means of integration of unsupervised classification and visual interpretation methods. The database facilitates the study of land use/cover changes, environmental effects and ecological construction. Land cover changes reflect the main ecological processes in the upper Dadu River watershed. The landscape composed mainly of grasslands, wildwoods and alpine scrubs in 1967 was changed to that of grasslands, secondary forests, alpine scrubs, fragmentary wildwoods, artificial forests, secondary scrubs in 2000, meanwhile, the landscape got more fragmentized. The total area of the forests decreased by 9.43%.Study results have shown the process of restoration of logged areas in forest centers. From 1967 to 2000, only 6.86 percents of logged areas were converted to shrubs, meadows or croplands, and the rest were converted into artificial forests or secondary forests. So the ecological shelter functions will be restored, stage by stage. Firewood collection, charcoal production and overgrazing are the three major triggers for the extensive degradation of alpine oak forests, Sabina tibetica forests and meadows. The arid valley grasslands expanded too. The degradation of vegetation in the southern slopes impairs ecological shelter functions and affects livelihood of local residents, so it is essential to find effective measures for ecological restoration and reconstruction. Field investigations have found that

  10. Impacts of Combination of Cover Plants on Pests and Natural Enemies in Apple Orchards%苹果园地面植被优化组合对害虫和天敌群落的影响

    Institute of Scientific and Technical Information of China (English)

    卢增斌; 于毅; 门兴元; 李丽莉; 庄乾营; 张思聪; 严毓骅

    2016-01-01

    increased populations of natural enemies could ef-fectively suppress the pest abundance on cover plants.The responses of arthropods in apple tree canopy to dif-ferent cover plant combinations were also different.The abundance of natural enemies in 100% M.sativa, 25% L.supine and 35% L.supine regions were 1.08,1.29 and 2.48 times of that in clean -cultivated or-chards,respectively,and the density of pests were 71.95%,62.68% and 74.41% of that in clean -culti-vated orchards,respectively;further more,these combinations of cover plants promoted the establishment and enlargement of natural enemy populations in early spring,and the species richness and diversity of natural ene-mies also increased significantly.These results clearly indicated that different comopositions of ground cover plants could regulate the structure of arthropod community and natural enemy populations in apple tree cano-py,create advantageous conditions for natural enemies but not for pests.Therefore,cover plants play impor-tant roles in promoting the eatablishment and enlargement of natural enemy population in early spring and en-hancing biocontrol of pests.

  11. Evaluation of Plant Growth Regulators for Use in Grounds Maintenance at Military Installations

    Science.gov (United States)

    1992-07-01

    and Eldridge, B. J. 1989. Plant growth regulators suppress established orchard sod and dandelion ( Taraxacum officinale ) population. Weed Technology 3...Solanium carolinense L. Dandelion - Taraxicum officinale Field Pansy - Viola rafinesquii Greene Fivefingers Cinquefoil - Potentilla canadensis L. Hop Clover...Erigeron annuus Dandelion - Taraxacum aticinale Field Bindweed - Convolvulus arvensis L. Field Pussytoes - Antennaria neglecta Foxglove Beardtongues

  12. Survival of plant pathogens in static piles of ground green waste.

    Science.gov (United States)

    Downer, A J; Crohn, D; Faber, B; Daugovish, O; Becker, J O; Menge, J A; Mochizuki, M J

    2008-05-01

    Ground green waste is used as mulch in ornamental landscapes and for tree crops such as avocados. Survival of Armillaria mellea, Phytophthora cinnamomi, Sclerotinia sclerotiorum, and Tylenchulus semipenetrans was assessed for 8 weeks within unturned piles of either recently ground or partially composted green waste. S. sclerotiorum survived at the pile surface and at 10, 30, and 100 cm within the pile for the entire 8 weeks in both fresh green waste (FGW) and aged green waste (AGW). A. mellea and T. semipenetrans did not survive more than 2 days in FGW, while P. cinnamomi persisted for over 21 days in FGW. AGW was less effective in reducing pathogen viability than FGW, most likely because temperatures in AGW peaked at 45 degrees C compared with 70 degrees C in FGW. Survival modeling curves based on pile temperatures indicate the time to inactivate 10 propagules of pathogens was 11, 30, 363, and 50 days for A. mellea, P. cinnamomi, S. sclerotiorum, and T. semipenetrans, respectively. Sclerotia-forming pathogens pose the greatest risk for escape; to ensure eradication of persistent fungi, green waste stockpiles should be turned intermittently to mix pile contents and move pathogen propagules to a location within the pile where they are more likely to be killed by heat, microbial attack, or chemical degradation.

  13. Hydro-peaking at Tonstad power plant in Norway Modelled effects on currents, temperatures and ice cover

    Energy Technology Data Exchange (ETDEWEB)

    Tjomsland, Torulv; Bakken, Tor Haakon.

    2012-07-01

    Hydro-peaking ing was done by pumping water from Sirdalsvatn to Homstoelvatn by night and using it for production the following day. The effect of the hydro-peaking was simulated by mathematical modelling. Hydro-peaking led to considerably changes in water level in Homstoelvatn, 3.5 m up and down each day. For Sirdalsvatn the difference was around 3/4 m. Hydro-peaking increased the current speed and current pattern especially near the openings of the tunnels in Sirdalsvatn and Homstoelvatn. The vertical mixing was increased throughout the lake. In Sirdalsvatn the hydro-peaking led to reduced temperatures near surface and increased temperatures at greater depths due to increased vertical mixing, especially during the autumn and the first part of winter. The circulation period was delayed and prolonged by a week or two. In Sirdalsvatn hydro-peaking resulted in a shorter period with ice cover. In both Sirdalsvatn and Homstoelvatn reduced ice cover formation may be connected to areas near the tunnel due to increased current velocities. Rapid water level changes may break up continuous ice cover along the shores.(Author)

  14. Effects of environmental chemicals on useful insects and pests. Studies on the aluminium tolerance of some forest ground cover species. Nutz- und Schadinsekten in Abhaengigkeit von Umweltchemikalien. Aluminiumtoleranz von Waldbodenpflanzen

    Energy Technology Data Exchange (ETDEWEB)

    Albert, A.; Bogenschuetz, H.; Buecking, W.; Hradetzky, J.; Koenig, E.; Kublin, E.

    1986-01-01

    In the present issue one of four contributions deals with the aluminium tolerance of some forest ground cover species. Growth results are indicated for the forest ground cover species Poa nemoralis, Luzula luzuloides, Deschampsia flexuosa, Nardus stricta, Milium effusum and Melica uniflora as potted cultures on sand receiving nitrogen in different ratios of form and in different concentrations, the aluminium concentration being variable in the culture broths with a pH-value of 4.0. Low aluminium concentrations (10.8 mg/l Al) in the culture broths enhanced the growth of all species, some species were adversely affected and showed impaired growth (Poa nemoralis, Milium effusum, Melica uniflora) from high aluminium-ion concentrations (108 mg/l Al), but others had their best growth results - varying according to the form of nitrogen offered - only if aluminium concentrations in the culture broth were high. The species examined accumulate aluminium in their above-ground biomass to varying extents. With 21 figs., 12 tabs.

  15. Mechanosensitivity below Ground: Touch-Sensitive Smell-Producing Roots in the Shy Plant Mimosa pudica.

    Science.gov (United States)

    Musah, Rabi A; Lesiak, Ashton D; Maron, Max J; Cody, Robert B; Edwards, David; Fowble, Kristen L; Dane, A John; Long, Michael C

    2016-02-01

    The roots of the shy plant Mimosa pudica emit a cocktail of small organic and inorganic sulfur compounds and reactive intermediates into the environment, including SO2, methanesulfinic acid, pyruvic acid, lactic acid, ethanesulfinic acid, propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, phenothiazine, and thioformaldehyde, an elusive and highly unstable compound that, to our knowledge, has never before been reported to be emitted by a plant. When soil around the roots is dislodged or when seedling roots are touched, an odor is detected. The perceived odor corresponds to the emission of higher amounts of propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, and phenothiazine. The mechanosensitivity response is selective. Whereas touching the roots with soil or human skin resulted in odor detection, agitating the roots with other materials such as glass did not induce a similar response. Light and electron microscopy studies of the roots revealed the presence of microscopic sac-like root protuberances. Elemental analysis of these projections by energy-dispersive x-ray spectroscopy revealed them to contain higher levels of K(+) and Cl(-) compared with the surrounding tissue. Exposing the protuberances to stimuli that caused odor emission resulted in reductions in the levels of K(+) and Cl(-) in the touched area. The mechanistic implications of the variety of sulfur compounds observed vis-à-vis the pathways for their formation are discussed. © 2016 American Society of Plant Biologists. All Rights Reserved.

  16. Planting date and seeding rate effects on sunn hemp biomass and nitrogen production for a winter cover crop

    Science.gov (United States)

    Sunn hemp (Crotalaria juncea L.) is a tropical legume that produces plant biomass and nitrogen (N) quickly. Our objectives were to assess the growth of a new sunn hemp cultivar breed to produce seed in a temperate climate and determine the residual N effect on a subsequent rye (Secale cereale L.) wi...

  17. Groundwater monitoring in the Savannah River Plant Low Level Waste Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.

    1983-12-31

    This document describes chemical mechanisms that may affect trace-level radionuclide migration through acidic sandy clay soils in a humid environment, and summarizes the extensive chemical and radiochemical analyses of the groundwater directly below the SRP Low-Level Waste (LLW) Burial Ground (643-G). Anomalies were identified in the chemistry of individual wells which appear to be related to small amounts of fission product activity that have reached the water table. The chemical properties which were statistically related to trace level transport of Cs-137 and Sr-90 were iron, potassium, sodium and calcium. Concentrations on the order of 100 ppM appear sufficient to affect nuclide migration. Several complexation mechanisms for plutonium migration were investigated.

  18. Reconnaissance of Soil, Ground Water, and Plant Contamination at an Abandoned Oilfield-Service Site near Shawnee, Oklahoma, 2005-2006

    Science.gov (United States)

    Mashburn, Shana L.; Smith, S. Jerrod

    2007-01-01

    The U.S. Geological Survey, in cooperation with the Absentee Shawnee Tribe of Oklahoma, began a reconnaissance study of a site in Pottawatomie County, Oklahoma, in 2005 by testing soil, shallow ground water, and plant material for the presence of trace elements and semivolatile organic compounds. Chemical analysis of plant material at the site was investigated as a preliminary tool to determine the extent of contamination at the site. Thirty soil samples were collected from 15 soil cores during October 2005 and analyzed for trace elements and semivolatile organic compounds. Five small-diameter, polyvinyl-chloride-cased wells were installed and ground-water samples were collected during December 2005 and May 2006 and analyzed for trace elements and semivolatile organic compounds. Thirty Johnsongrass samples and 16 Coralberry samples were collected during September 2005 and analyzed for 53 constituents, including trace elements. Results of the soil, ground-water, and plant data indicate that the areas of trace element and semivolatile organic compound contamination are located in the shallow (A-horizon) soils near the threading barn. Most of the trace-element concentrations in the soils on the study site were either similar to or less than trace-element concentrations in background soils. Several trace elements and semivolatile organic compounds exceeded the U.S. Environmental Protection Agency, Region 6, Human Health Medium-Specific Screening Levels 2007 for Tap Water, Residential Soils, Industrial Indoor Soils, and Industrial Outdoor Soils. There was little or no correlation between the plant and soil sample concentrations and the plant and ground-water concentrations based on the current sample size and study design. The lack of correlation between trace-element concentrations in plants and soils, and plants and ground water indicate that plant sampling was not useful as a preliminary tool to assess contamination at the study site.

  19. Simulated Sea-Level Rise Effects on the Above and Below-Ground Growth of Two Tidal Marsh Plant Species

    Science.gov (United States)

    Schile, L. M.; Callaway, J. C.; Kelly, M.

    2011-12-01

    Sea-level is expected to rise between 55 and 140 cm in the next century and is likely to have significant effects on the distribution and maintenance of tidal wetlands; however, little is known about the effects of increased sea level on Pacific coast tidal marsh vegetation. We initiated a field experiment in March 2011 to examine how increased depth and duration of inundation affect above and below-ground growth of two tidal wetland plant species: Schoenoplectus acutus and S. americanus. PVC planters, referred to as marsh organs, were installed at fixed elevations in channels at two ancient marshes in the San Francisco Bay Estuary: Browns Island and Rush Ranch. Each marsh organ structure is comprised of five rows of three six-inch PVC pipes, with each row 15cm lower than the row above, and was filled with surrounding mudflat sediment. Elevations span 60 cm and were chosen to be lower than the average current elevations of both species at each marsh to reflect projected increases in sea level. Rhizomes were collected from Browns Island, the less-saline site, and were cut to uniform sizes before planting. In every row, each species was grown individually and together. On a monthly basis, plant heights were recorded and pore-water sulfide concentration, salinity, and soil oxidation-reduction potential were measured. Schoenoplectus americanus growth and density significantly decreased with increased inundation at both sites. Schoenoplectus acutus growth was impacted more significantly at lower elevations at Rush Ranch but had little variation in density and growth across elevations at Browns Island. Salinity and sulfide concentrations varied little across elevations within a site but differed between sites. Above and belowground biomass will be collected in September 2011 to measure total annual productivity. The experiment provides basic yet crucial information on the impacts of increased inundation on tidal wetland vegetation and insight into potential changes in

  20. Aerial Survey Results for 131I Deposition on the Ground after the Fukushima Daiichi Nuclear Power Plant Accident

    Energy Technology Data Exchange (ETDEWEB)

    Torii, Tatsuo [JAEA; Sugita, Takeshi [JAEA; Okada, Colin E. [NSTec; Reed, Michael S. [NSTec; Blumenthal, Daniel J. [NNSA

    2013-08-01

    In March 2011 the second largest accidental release of radioactivity in history occurred at the Fukushima Daiichi nuclear power plant following a magnitude 9.0 earthquake and subsequent tsunami. Teams from the U.S. Department of Energy, National Nuclear Security Administration Office of Emergency Response performed aerial surveys to provide initial maps of the dispersal of radioactive material in Japan. The initial results from the surveys did not report the concentration of 131I. This work reports on analyses performed on the initial survey data by a joint Japan-US collaboration to determine 131I ground concentration. This information is potentially useful in reconstruction of the inhalation and external exposure doses from this short-lived radionuclide. The deposited concentration of 134Cs is also reported.

  1. Estimating spatial distribution of daily snow depth with kriging methods: combination of MODIS snow cover area data and ground-based observations

    Directory of Open Access Journals (Sweden)

    C. L. Huang

    2015-09-01

    Full Text Available Accurately measuring the spatial distribution of the snow depth is difficult because stations are sparse, particularly in western China. In this study, we develop a novel scheme that produces a reasonable spatial distribution of the daily snow depth using kriging interpolation methods. These methods combine the effects of elevation with information from Moderate Resolution Imaging Spectroradiometer (MODIS snow cover area (SCA products. The scheme uses snow-free pixels in MODIS SCA images with clouds removed to identify virtual stations, or areas with zero snow depth, to compensate for the scarcity and uneven distribution of stations. Four types of kriging methods are tested: ordinary kriging (OK, universal kriging (UK, ordinary co-kriging (OCK, and universal co-kriging (UCK. These methods are applied to daily snow depth observations at 50 meteorological stations in northern Xinjiang Province, China. The results show that the spatial distribution of snow depth can be accurately reconstructed using these kriging methods. The added virtual stations improve the distribution of the snow depth and reduce the smoothing effects of the kriging process. The best performance is achieved by the OK method in cases with shallow snow cover and by the UCK method when snow cover is widespread.

  2. A review of the developments of self-etching primers and adhesives -Effects of acidic adhesive monomers and polymerization initiators on bonding to ground, smear layer-covered teeth.

    Science.gov (United States)

    Ikemura, Kunio; Kadoma, Yoshinori; Endo, Takeshi

    2011-01-01

    This paper reviews the developments of self-etching primers and adhesives, with a special focus on the effect of acidic adhesive monomers and polymerization initiators on bonding to ground, smear layer-covered teeth. Ionized acidic adhesive monomers chemically interact with tooth substrates and facilitate good bonding to ground dentin. Polymerization initiators in self-etching primers further promote effective bonding to ground dentin. To promote bonding to both dentin and enamel, phosphonic acid monomers such as 6-methacryloyloxyhexyl phosphonoacetate (6-MHPA) were developed. These novel adhesive monomers also have a water-soluble nature and are hence endowed with sufficient demineralization capability. A new single-bottle, self-etching, 2-hydroxyethyl methacrylate (HEMA)-free adhesive comprising 6-MHPA and 4-acryloyloxyethoxycarbonylphthalic acid (4-AET) was developed. This novel adhesive enabled strong adhesion to both ground enamel and dentin, but its formulation stability was influenced by pH value of the adhesive. To develop hydrolytically stable, single-bottle, self-etching adhesives, hydrolytically stable, radical-polymerizable acidic monomers with amide or ether linkages have been developed.

  3. The effects of initial planting density on above- and below-ground biomass in a 25-year-old Fagus orientalis Lipsky plantation in Hopa, Turkey

    OpenAIRE

    Güner, Sinan; Yağcı, Volkan; Tilki, Fahrettin; Çelik, Nejat

    2010-01-01

    The aim of this study was to determine the influence of initial planting density on above- and below- ground biomass in 25 years old oriental beech stands located in Hopa, Artvin, Turkey. The initial spacings used in this study were 0.7 x 2.0 m ( high planting density) and 2.0 x 2.0 m (low planting density). To analyse the planting density response of trees of different sizes (diameter), the sample trees within each stand density class were classified into four dbh classes (dbh1, dbh2, dbh3, ...

  4. Characterization of iron and manganese precipitates from an in situ ground water treatment plant.

    Science.gov (United States)

    Mettler, S; Abdelmoula, M; Hoehn, E; Schoenenberger, R; Weidler, P; von Gunten, U

    2001-01-01

    Aquifer samples from the precipitation zone of an in situ iron and manganese removal plant that was operated for 10 years were analyzed for iron and manganese minerals. Measurements were performed by various chemical extraction techniques (5 M HCI, 0.008 M Ti(III)-EDTA, 0.114 M ascorbic acid), X-ray diffraction and Mössbauer spectroscopy. Chemical extractions showed that iron was precipitated as ferric oxides, whereas manganese was not oxidized but deposited as Mn(II) probably within carbonates. The ferric oxides in particular accumulate preferentially in the smaller grain- size fractions. This tendency was observed to a lesser extent for manganese. X-ray diffraction and Mössbauer spectroscopy showed that the ferric oxides were mainly crystalline (goethite, 50% to 100% of the iron). Ferrihydrite was found as well, but only as a minor fraction (< or = 12%). Pure manganese minerals were not found by X-ray diffraction. The precipitated amounts of iron (5 to 27 micromol/g Fe as ferric oxide) and manganese (1 to 4 micromol/g Mn) during 10 years operation of the treatment plant agree with values that were estimated from operational parameters (9 to 31 micromol/g Fe and 3 to 6 micromol/g Mn). Considering the small amounts of precipitated iron and manganese, no long-term risks of clogging of the aquifer are expected.

  5. Algorithm for Detection of Ground and Canopy Cover in Micropulse Photon-Counting Lidar Altimeter Data in Preparation for the ICESat-2 Mission

    Science.gov (United States)

    Herzfeld, Ute Christina; McDonald, Brian W.; Neumann, Thomas Allen; Wallin, Bruce F.; Neumann, Thomas A.; Markus, Thorsten; Brenner, Anita; Field, Christopher

    2014-01-01

    NASA's Ice, Cloud and Land Elevation Satellite-II (ICESat-2) mission is a decadal survey mission (2016 launch). The mission objectives are to measure land ice elevation, sea ice freeboard, and changes in these variables, as well as to collect measurements over vegetation to facilitate canopy height determination. Two innovative components will characterize the ICESat-2 lidar: 1) collection of elevation data by a multibeam system and 2) application of micropulse lidar (photon-counting) technology. A photon-counting altimeter yields clouds of discrete points, resulting from returns of individual photons, and hence new data analysis techniques are required for elevation determination and association of the returned points to reflectors of interest. The objective of this paper is to derive an algorithm that allows detection of ground under dense canopy and identification of ground and canopy levels in simulated ICESat-2 data, based on airborne observations with a Sigma Space micropulse lidar. The mathematical algorithm uses spatial statistical and discrete mathematical concepts, including radial basis functions, density measures, geometrical anisotropy, eigenvectors, and geostatistical classification parameters and hyperparameters. Validation shows that ground and canopy elevation, and hence canopy height, can be expected to be observable with high accuracy by ICESat-2 for all expected beam energies considered for instrument design (93.01%-99.57% correctly selected points for a beam with expected return of 0.93 mean signals per shot (msp), and 72.85%-98.68% for 0.48 msp). The algorithm derived here is generally applicable for elevation determination from photoncounting lidar altimeter data collected over forested areas, land ice, sea ice, and land surfaces, as well as for cloud detection.

  6. Development of a ground hydrology model suitable for global climate modeling using soil morphology and vegetation cover, and an evaluation of remotely sensed information

    Science.gov (United States)

    Zobler, L.; Lewis, R.

    1988-01-01

    The long-term purpose was to contribute to scientific understanding of the role of the planet's land surfaces in modulating the flows of energy and matter which influence the climate, and to quantify and monitor human-induced changes to the land environment that may affect global climate. Highlights of the effort include the following: production of geo-coded, digitized World Soil Data file for use with the Goddard Institute for Space Studies (GISS) climate model; contribution to the development of a numerical physically-based model of ground hydrology; and assessment of the utility of remote sensing for providing data on hydrologically significant land surface variables.

  7. An Algorithm for Detection of Ground and Canopy Cover in Micropulse Photon-Counting Lidar Altimeter Data in Preparation of the ICESat-2 Mission

    Science.gov (United States)

    Herzfeld, Ute C.; McDonald, Brian W.; Wallins, Bruce F.; Markus, Thorsten; Neumann, Thomas A.; Brenner, Anita

    2012-01-01

    The Ice, Cloud and Land Elevation Satellite-II (ICESat-2) mission has been selected by NASA as a Decadal Survey mission, to be launched in 2016. Mission objectives are to measure land ice elevation, sea ice freeboard/ thickness and changes in these variables and to collect measurements over vegetation that will facilitate determination of canopy height, with an accuracy that will allow prediction of future environmental changes and estimation of sea-level rise. The importance of the ICESat-2 project in estimation of biomass and carbon levels has increased substantially, following the recent cancellation of all other planned NASA missions with vegetation-surveying lidars. Two innovative components will characterize the ICESat-2 lidar: (1) Collection of elevation data by a multi-beam system and (2) application of micropulse lidar (photon counting) technology. A micropulse photon-counting altimeter yields clouds of discrete points, which result from returns of individual photons, and hence new data analysis techniques are required for elevation determination and association of returned points to reflectors of interest including canopy and ground in forested areas. The objective of this paper is to derive and validate an algorithm that allows detection of ground under dense canopy and identification of ground and canopy levels in simulated ICESat-2-type data. Data are based on airborne observations with a Sigma Space micropulse lidar and vary with respect to signal strength, noise levels, photon sampling options and other properties. A mathematical algorithm is developed, using spatial statistical and discrete mathematical concepts, including radial basis functions, density measures, geometrical anisotropy, eigenvectors and geostatistical classification parameters and hyperparameters. Validation shows that the algorithm works very well and that ground and canopy elevation, and hence canopy height, can be expected to be observable with a high accuracy during the ICESat

  8. MELiSSA Pilot Plant: A facility for ground demonstration of a closed life support system

    Science.gov (United States)

    Godia, Francesc; Fossen, Arnaud; Peiro, Enrique; Gerbi, Olivier; Dussap, Gilles; Leys, Natalie; Arnau, Carolina; Milian, Ernest

    MELiSSA (Micro Ecological Life Support System Alternative) is an international collaborative effort focused on the development of a Life Support System for long-term Space missions. The goals of the MELiSSA loop are the recovery of food, water and oxygen from wastes, i.e. CO2 and organic wastes, using light as a source of energy. It is conceived as a series of compartments, each one performing a specific function within this cycle, inspired in the terrestrial ecological systems. Each one of the compartments is colonized with specific bacteria or higher plants depending on its dedicated function. Therefore, its design and operational conditions should guarantee that only a given specific biological activity takes place in each compartment. Moreover, this has to be done in a controlled manner, both at the subsystems level (i.e., compartments) and at the overall system level (i.e., complete loop). In order to achieve the complete operation of such a Closed Ecological System, in a first step each compartment has to be developed at individual level, and its operation demonstrated under its associated control law. In a second step, the complete loop needs to be integrated by the connection of the different compartments in the gas, loop and solid phases. An extensive demonstration of MELiSSA loop under terrestrial conditions is a mandatory step in the process of its adaptation to space. This is the main goal of the MPP. The demonstration scenario for the MPP is the respiration equivalent of a human being, and production of 20 percent of the diet of one person. To serve this goal, the different compartments of the MELiSSA loop have been designed and sized at the pilot scale level, and further characterized. Nowadays, the focus of the MELiSSA Pilot Plant is on the integration of its compartments. To this end, the integration challenge is concentrated in three compartments devoted to the following functions: nitrification (Compartment 3, an axenic co-culture of Nitrosomonas

  9. Controllable Alternating Magnetic Technology Research for Inducing Plants Breeding on Ground

    Directory of Open Access Journals (Sweden)

    Guo-wen HU

    2013-04-01

    Full Text Available Controllable alternating induction magnetic field generation technology which induces plant seeds to breed on floor space has been developed. The incentive ferrite induction coil is used in the device to produce induced magnetic field. The common AC-DC-AC topology was adopted for the variable frequency power supply, realizing the VF. AC-DC-AC AC power inverter circuit adopts SPWM inverter frequency modulation and voltage regulation mode, realizing the effect of sinusoidal variable. In order to improve the conversion efficiency of the system electrical energy to magnetic energy, the RLC series resonant circuit is chosen in the circuit of output magnetic field. The induction magnetic field in the air gap is the work area for seeds experiment. Its adjustable frequency range: 20~200Hz, adjustable field range: 0~500Gs. The experimental study of rice seeds shows that different magnetic environment has a significant impact on the biological characteristics of rice seeds.

  10. EXOTIC AND INVASIVE AQUATIC PLANTS IN GREAT LAKES COASTAL WETLANDS: DISTRIBUTION AND RELATION TO WATERSHED LAND USE AND PLANT RICHNESS AND COVER

    Science.gov (United States)

    This manuscript provides previously unavailable information to researchers and managers concerning exotic plants in the Great Lakes...This work arises out of our broader efforts to describe biota - habitat relationships in coastal wetlands, and as such falls under Aquatic Stresso...

  11. Exergy and Exergoeconomic Model of a Ground-Based CAES Plant for Peak-Load Energy Production

    Directory of Open Access Journals (Sweden)

    Giampaolo Manfrida

    2013-02-01

    Full Text Available Compressed Air Energy Storage is recognized as a promising technology for applying energy storage to grids which are more and more challenged by the increasing contribution of renewable such as solar or wind energy. The paper proposes a medium-size ground-based CAES system, based on pressurized vessels and on a multiple-stage arrangement of compression and expansion machinery; the system includes recovery of heat from the intercoolers, and its storage as sensible heat in two separate (hot/cold water reservoirs, and regenerative reheat of the expansions. The CAES plant parameters were adapted to the requirements of existing equipment (compressors, expanders and heat exchangers. A complete exergy analysis of the plant was performed. Most component cost data were procured from the market, asking specific quotations to the industrial providers. It is thus possible to calculate the final cost of the electricity unit (kWh produced under peak-load mode, and to identify the relative contribution between the two relevant groups of capital and component inefficiencies costs.

  12. Ground-based remote sensing profiling and numerical weather prediction model to manage nuclear power plants meteorological surveillance in Switzerland

    Directory of Open Access Journals (Sweden)

    B. Calpini

    2011-08-01

    Full Text Available The meteorological surveillance of the four nuclear power plants in Switzerland is of first importance in a densely populated area such as the Swiss Plateau. The project "Centrales Nucléaires et Météorologie" CN-MET aimed at providing a new security tool based on one hand on the development of a high resolution numerical weather prediction (NWP model. The latter is providing essential nowcasting information in case of a radioactive release from a nuclear power plant in Switzerland. On the other hand, the model input over the Swiss Plateau is generated by a dedicated network of surface and upper air observations including remote sensing instruments (wind profilers and temperature/humidity passive microwave radiometers. This network is built upon three main sites ideally located for measuring the inflow/outflow and central conditions of the main wind field in the planetary boundary layer over the Swiss Plateau, as well as a number of surface automatic weather stations (AWS. The network data are assimilated in real-time into the fine grid NWP model using a rapid update cycle of eight runs per day (one forecast every three hours. This high resolution NWP model has replaced the former security tool based on in situ observations (in particular one meteorological mast at each of the power plants and a local dispersion model. It is used to forecast the dynamics of the atmosphere in the planetary boundary layer (typically the first 4 km above ground layer and over a time scale of 24 h. This tool provides at any time (e.g. starting at the initial time of a nuclear power plant release the best picture of the 24-h evolution of the air mass over the Swiss Plateau and furthermore generates the input data (in the form of simulated values substituting in situ observations required for the local dispersion model used at each of the nuclear power plants locations. This paper is presenting the concept and two validation studies as well as the results of an

  13. Plant Cover and Soil Biochemical Properties in a Mine Tailing Pond Five Years After Application of Marble Wastes and Organic Amendments

    Institute of Scientific and Technical Information of China (English)

    R. ZORNOZA; A. FAZ; D. M. CARMONA; S. KABAS; S. MART(I)NEZ-MART(I)NEZ; J. A. ACOSTA

    2012-01-01

    Tailing ponds pose environmental hazards,such as toxic metals which can contaminate the surroundings through wind and water erosions and leaching.Various chemical and biochemical properties,together with extractable and soluble metals were measured five years after reclamation of a polluted soil affected by former mining activities.This abandoned mine site contains large amounts of Fe-oxyhydroxides,sulphates,and heavy metals.As a consequence,soils remain bare and the soil organic matter content is low (< 3 g kg-1).Marble waste,pig manure and sewage sludge were applied in 2004.Plant cover and richness,and soil chemical,biochemical and biological parameters were analysed five years later.Results showed that all soil biochemical properties as well as vegetation cover and richness were higher in treated soils than in the untreated contaminated plots (control),although organic matter,pH values and extractable metals concentrations were similar among treatments.Soluble cadmium and zinc were lower in the amended plots than in control.As a general pattern,soil amended with pig manure showed higher values of most biochemical properties compared to sewage sludge application,while the doses did not have a great effect,being only significant for β-glucosidase,phosphodiesterase and arylsulfatase.Significant correlations were found between vegetation cover,richness and soil biochemical properties,suggesting a high interdependence between plant colonization and reactivation of biogeochemical cycles during five years.This study confirms the high effectiveness of an initial application of the amendments tested to initialize the recovery of ecosystems in bare mine soils under Mediterranean semiarid conditions. This research also shows the high sensitivity of certain biochemical properties in order to evaluate soil quality and reactivation of nutrients cycles in reclaimed mine soils.

  14. The impact of biofuel poplar cultivation on ground-level ozone and premature human mortality depends on cultivar selection and planting location

    OpenAIRE

    Ashworth, Kirsti; Wild, Oliver; Eller, A. S. D.; Hewitt, C.N.

    2015-01-01

    Isoprene and other volatile organic compounds emitted from vegetation play a key role in governing the formation of ground-level ozone. Emission rates of such compounds depend critically on the plant species. Future land use change, driven by the cultivation of biofuel feedstocks, will change the distribution of plant species and hence the magnitude and distribution of emissions. Here we use relationships between biomass yield and isoprene emissions derived from experimental data for 29 comme...

  15. Testing the growth rate hypothesis in vascular plants with above- and below-ground biomass.

    Science.gov (United States)

    Yu, Qiang; Wu, Honghui; He, Nianpeng; Lü, Xiaotao; Wang, Zhiping; Elser, James J; Wu, Jianguo; Han, Xingguo

    2012-01-01

    The growth rate hypothesis (GRH) proposes that higher growth rate (the rate of change in biomass per unit biomass, μ) is associated with higher P concentration and lower C:P and N:P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N:C under N limitation and positively correlated with P:C under P limitation. However, the N:P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C:N:P stoichiometry. Furthermore, μ and C:N:P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations.

  16. Testing the growth rate hypothesis in vascular plants with above- and below-ground biomass.

    Directory of Open Access Journals (Sweden)

    Qiang Yu

    Full Text Available The growth rate hypothesis (GRH proposes that higher growth rate (the rate of change in biomass per unit biomass, μ is associated with higher P concentration and lower C:P and N:P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N:C under N limitation and positively correlated with P:C under P limitation. However, the N:P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C:N:P stoichiometry. Furthermore, μ and C:N:P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations.

  17. Quantification of tillage, plant cover, and cumulative rainfall effects on soil surface microrelief by statistical, geostatistical and fractal indices

    Directory of Open Access Journals (Sweden)

    J. Paz-Ferreiro

    2008-07-01

    Full Text Available Changes in soil surface microrelief with cumulative rainfall under different tillage systems and crop cover conditions were investigated in southern Brazil. Surface cover was none (fallow or the crop succession maize followed by oats. Tillage treatments were: 1 conventional tillage on bare soil (BS, 2 conventional tillage (CT, 3 minimum tillage (MT and 4 no tillage (NT under maize and oats. Measurements were taken with a manual relief meter on small rectangular grids of 0.234 and 0.156 m2, throughout growing season of maize and oats, respectively. Each data set consisted of 200 point height readings, the size of the smallest cells being 3×5 cm during maize and 2×5 cm during oats growth periods. Random Roughness (RR, Limiting Difference (LD, Limiting Slope (LS and two fractal parameters, fractal dimension (D and crossover length (l were estimated from the measured microtopographic data sets. Indices describing the vertical component of soil roughness such as RR, LD and l generally decreased with cumulative rain in the BS treatment, left fallow, and in the CT and MT treatments under maize and oats canopy. However, these indices were not substantially affected by cumulative rain in the NT treatment, whose surface was protected with previous crop residues. Roughness decay from initial values was larger in the BS treatment than in CT and MT treatments. Moreover, roughness decay generally tended to be faster under maize than under oats. The RR and LD indices decreased quadratically, while the l index decreased exponentially in the tilled, BS, CT and MT treatments. Crossover length was sensitive to differences in soil roughness conditions allowing a description of microrelief decay due to rainfall in the tilled treatments, although better correlations between

  18. Effects of fire and three fire-fighting chemicals on main soil properties, plant nutrient content and vegetation growth and cover after 10 years

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Fernández, M., E-mail: mariafernandez@iiag.csic.es; Gómez-Rey, M.X., E-mail: mxgomez@iiag.csic.es; González-Prieto, S.J., E-mail: serafin@iiag.csic.es

    2015-05-15

    The study addresses a knowledge-gap in the long-term ecological consequences of fire and fire-fighting chemicals. Ten years after a prescribed fire and the application of three fire-fighting chemicals, their effects on the soil–plant system were evaluated. Five treatments were established: unburnt soils (US) and burnt soils treated with water alone (BS), foaming agent (BS + Fo), Firesorb (BS + Fi) and ammonium polyphosphate (BS + Ap). Soils (0–2 cm depth) and foliar material of shrubs (Erica umbellata, Pterospartum tridentatum and Ulex micranthus) and trees (Pinus pinaster) were analysed for total N, δ{sup 15}N, and soil-available and plant total macronutrients and trace elements. Soil pH, NH{sub 4}{sup +}–N and NO{sub 3}{sup −}–N; pine basal diameter and height; and shrub cover and height were also measured. Compared with US plots, burnt soils had less nitrates and more Mo. Although differences were not always significant, BS + Ap had the highest levels of soil available P, Na and Al. Plants from BS + Ap plots had higher values of δ{sup 15}N (P. pinaster and E. umbellata), P (all species), Na (P. tridentatum and U. micranthus) and Mg (E. umbellata and P. tridentatum) than other treatments; while K in plants from BS + Ap plots was the highest among treatments for P. pinaster and the lowest for the shrubs. Pines in US plots were higher and wider than in burnt treatments, except for BS + Ap, where the tallest and widest trees were found, although half of them were either dead (the second highest mortality after BS + Fi) or had a distorted trunk. BS + Ap was the treatment with strongest effects on plants, showing E. umbellata the lowest coverage and height, P. tridentatum the highest coverage, U. micranthus one of the lowest coverages and being the only treatment where Genista triacanthos was absent. Consequently, it is concluded that both fire and ammonium polyphosphate application had significant effects on the soil–plant system after 10 years

  19. Long-term simulated nitrogen deposition alters the plant cover dynamics of a Mediterranean rosemary shrubland in Central Spain through defoliation.

    Science.gov (United States)

    Cabal, Ciro; Ochoa-Hueso, Raúl; Pérez-Corona, María Esther; Manrique, Esteban

    2017-04-07

    Nitrogen (N) deposition due to anthropogenic pollution is a major driver of the global biodiversity loss. We studied the effect of experimental N and phosphorus (P) fertilization (0, 10, 20, and 50 kg N ha(-1) year(-1) and 14 kg P ha(-1) year(-1) over the background deposition levels) on plant cover dynamics of a rosemary (Rosmarinus officinalis L.) shrubland after 8 years of nutrient addition in a semiarid Mediterranean ecosystem from Central Spain. We specifically aimed at testing whether N deposition has the potential to influence the observed expanding trend of woody vegetation into areas dominated by grassland, biological soil crusts, and bare soil. Our results show that N addition loads above 10 kg N ha(-1) year(-1) reverted the cover dynamics of shrubs. Under N addition conditions, N was no longer a limiting nutrient and other elements, especially P and calcium, determined the seasonal growth of young twigs. Interestingly, N fertilization did not inhibit the growth of young shoots; our estimates point to a reduced rosemary leaf lifespan that is driving individuals to death. This may be triggered by long-term accumulation of N compounds in leaves, suggesting the need to consider the old organs and tissues in long-lived perennial plants, where N toxicity effects could be more mediated by accumulation processes. Shrublands are a widely distributed ecosystem type in biodiverse Mediterranean landscapes, where shrubs play a key role as nurse plants. Therefore, the disappearance of shrublands may accelerate the biodiversity loss associated with other global change drivers, hamper the recruitment of seedlings of woody species, and, as a consequence, accelerate desertification.

  20. Land Cover

    Data.gov (United States)

    Kansas Data Access and Support Center — The Land Cover database depicts 10 general land cover classes for the State of Kansas. The database was compiled from a digital classification of Landsat Thematic...

  1. Modeling increasing effect of soil temperature through plastic film mulch in ground cover rice production system using CERES-Rice%基于CERES-Rice模型的覆膜旱作稻田增温效应模拟

    Institute of Scientific and Technical Information of China (English)

    马雯雯; 金欣欣; 石建初; 宁松瑞; 李森; 陶玥玥; 张亚男; 左强

    2015-01-01

    水稻覆膜旱作技术具有显著的节水、增温、防污和减排效应,是节水稻作技术体系的重要措施之一,将CERES-Rice模型用于覆膜旱作条件时,必须首先解决覆膜增温效应的准确模拟问题。该文拟应用热量传输理论及目前旱地作物生产系统中采用的覆膜增温效应模拟方法,来模拟水稻覆膜旱作生产体系中的增温效应,从而为完善 CERES-Rice 模型并使其能用于覆膜旱作水稻的生长模拟奠定基础。参数调校与模型检验验证通过2013、2014年在湖北房县开展的2 a水稻覆膜旱作田间试验来进行,共涉及淹水(对照)、覆膜湿润栽培和覆膜旱作共3个水分处理,分别对2个生长季、2个覆膜处理地表5 cm及地下10、20 cm处温度的变化过程进行了模拟,结果表明:经过参数调校后,所建立的覆膜增温模型可较好地模拟覆膜稻田地表和剖面上土壤温度的变化规律,地表5 cm处土壤温度模拟值与实测值的均方根差、相对均方根差分别低于1.8℃和10%,相关系数在0.89以上(P<0.01);尽管地下10、20 cm处的模拟误差稍大,也基本可满足要求,相应的均方根误差<3.2℃,相对均方根差<15%,相关系数>0.65(P<0.01)。%As one of the most promising water-saving rice production technologies, the ground cover rice production system (GCRPS) has been found to save water application, increase soil temperature, and reduce nitrogen pollution and methane emission. However, the feasibility of CERES-Rice, a software package widely and successfully applied in the traditional paddy rice production system (TPRPS), for simulating the rice growth in the GCRPS still remains unknown and needs further research. Undoubtedly, it should be based on accurately quantifying the effect of soil temperature enhancement caused by the ground cover material (chosen as the plastic film in this study). Therefore, the objective of

  2. A richer, greener and smaller alpine world: review and projection of warming-induced plant cover change in the Swedish Scandes.

    Science.gov (United States)

    Kullman, Leif

    2010-03-01

    Alpine plant life is proliferating, biodiversity is on the rise and the mountain world appears more productive and inviting than ever. Upper range margin rise of trees and low-altitude (boreal) plant species, expansion of alpine grasslands and dwarf-shrub heaths are the modal biotic adjustments during the past few decades, after a century of substantial climate warming in the Swedish Scandes. This course of biotic landscape evolution has reached historical dimensions and broken a multi-millennial trend of plant cover retrogression, alpine tundra expansion, floristic and faunal impoverishment, all imposed by progressive and deterministic neoglacial climate cooling. Continued modest warming over the present century will likely be beneficial to alpine biodiversity, geoecological stability, resilience, sustainable reindeer husbandry and aesthetic landscape qualities. These aspects are highlighted by an integrative review of results from long-term monitoring of subalpine/alpine vegetation in the Swedish Scandes. This forms the basis for some tentative projections of landscape transformations in a potentially warmer future. Notably, these results and projections are not necessarily valid in other regions and differ in some respects from model predictions. Continued monitoring is mandatory as a basis for generation of more realistic vegetation and ecosystem models.

  3. Quantification of greenhouse gas (GHG) emissions from wastewater treatment plants using a ground-based remote sensing approach

    Science.gov (United States)

    Delre, Antonio; Mønster, Jacob; Scheutz, Charlotte

    2016-04-01

    The direct release of nitrous oxide (N2O) and methane (CH4) from wastewater treatment plants (WWTP) is important because it contributes to the global greenhouse gases (GHGs) release and strongly effects the WWTP carbon footprint. Biological nitrogen removal technologies could increase the direct emission of N2O (IPCC, 2006), while CH4 losses are of environmental, economic and safety concern. Currently, reporting of N2O and CH4 emissions from WWTPs are performed mainly using methods suggested by IPCC which are not site specific (IPCC, 2006). The dynamic tracer dispersion method (TDM), a ground based remote sensing approach implemented at DTU Environment, was demonstrated to be a novel and successful tool for full-scale CH4 and N2O quantification from WWTPs. The method combines a controlled release of tracer gas from the facility with concentration measurements downwind of the plant (Mønster et al., 2014; Yoshida et al., 2014). TDM in general is based on the assumption that a tracer gas released at an emission source, in this case a WWTP, disperses into the atmosphere in the same way as the GHG emitted from process units. Since the ratio of their concentrations remains constant along their atmospheric dispersion, the GHG emission rate can be calculated using the following expression when the tracer gas release rate is known: EGHG=Qtr*(CGHG/Ctr)*(MWGHG/MWtr) EGHG is the GHG emission in mass per time, Qtr is the tracer release in mass per time, CGHG and Ctr are the concentrations measured downwind in parts per billion subtracted of their background values and integrated over the whole plume, and MWGHG and MWtr are the molar weights of GHG and tracer gas respectively (Mønster et al. 2014). In this study, acetylene (C2H2) was used as tracer. Downwind plume concentrations were measured driving along transects with two cavity ring down spectrometers (Yoshida et al., 2014). TDM was successfully applied in different seasons at several Scandinavian WWTPs characterized by

  4. Reflection on plant cover of climate change: Decline Anatolian black pines on district between Afsin-Goksun (Kahramanmaras, Turkey

    Directory of Open Access Journals (Sweden)

    Celalettin Duran

    2013-01-01

    Full Text Available The purpose of this study was to examine decline Anatolian black pines [Pinus nigra Arn. subsp. pallasiana (Lamb. Holmboe] on Tuluce hill district between Afsin-Goksun region in Kahramanmaras province. As a result of the Ecological (climate, soil, air pollution and Biological (insect, fungus, parasite plant etc. researches; other factors the exception of drought have no priority affection on black pine deaths. As on Turkey, drought conditions have dominated on the region after the year 1994. These changes have been occurred by constantly deaths in community of black pines on the south-facing slope (between the years 2000-2009. Increasing temperature and evaporation, decreasing relative humidity and rainfall-runoff is clearly for the region. In addition, there were not air pollution and infected primer insect-fungus damage. This also strengthens the impact of drought. Identified areas of tree deaths in recent years are generally near the inner regions (the steppe areas. Climate change and drought must be an indication of pushing towards more humid areas of black pine forests which is able to approaching much more onto the steppes of inner Anatolian.

  5. Enhanced analysis methods to derive the spatial distribution of 131I deposition on the ground by airborne surveys at an early stage after the Fukushima Daiichi nuclear power plant accident.

    Science.gov (United States)

    Torii, Tatsuo; Sugita, Takeshi; Okada, Colin E; Reed, Michael S; Blumenthal, Daniel J

    2013-08-01

    This paper applies both new and well tested analysis methods to aerial radiological surveys to extract the I ground concentrations present after the March 2011 Fukushima Daiichi nuclear power plant (NPP) accident. The analysis provides a complete map of I deposition, an important quantity incalculable at the time of the accident due to the short half-life of I and the complexity of the analysis. A map of I deposition is the first step in conducting internal exposure assessments, population dose reconstruction, and follow-up epidemiological studies. The short half-life of I necessitates the use of aerial radiological surveys to cover the large area quickly, thoroughly, and safely. Teams from the U.S. Department of Energy National Nuclear Security Administration (DOE/NNSA) performed aerial radiological surveys to provide initial maps of the dispersal of radioactive material in Japan. This work reports on analyses performed on a subset of the initial survey data by a joint Japan-U.S. collaboration to determine I ground concentrations. The analytical results show a high concentration of I northwest of the NPP, consistent with the previously reported radioactive cesium deposition, but also shows a significant I concentration south of the plant, which was not observed in the original cesium analysis. The difference in the radioactive iodine and cesium patterns is possibly the result of differences in the ways these materials settle out of the air.

  6. The role of above-ground competition and nitrogen vs. phosphorus enrichment in seedling survival of common European plant species of semi-natural grasslands

    Science.gov (United States)

    Ceulemans, Tobias; Hulsmans, Eva; Berwaers, Sigi; Van Acker, Kasper; Honnay, Olivier

    2017-01-01

    Anthropogenic activities have severely altered fluxes of nitrogen and phosphorus in ecosystems worldwide. In grasslands, subsequent negative effects are commonly attributed to competitive exclusion of plant species following increased above-ground biomass production. However, some studies have shown that this does not fully account for nutrient enrichment effects, questioning whether lowering competition by reducing grassland productivity through mowing or herbivory can mitigate the environmental impact of nutrient pollution. Furthermore, few studies so far discriminate between nitrogen and phosphorus pollution. We performed a full factorial experiment in greenhouse mesocosms combining nitrogen and phosphorus addition with two clipping regimes designed to relax above-ground competition. Next, we studied the survival and growth of seedlings of eight common European grassland species and found that five out of eight species showed higher survival under the clipping regime with the lowest above-ground competition. Phosphorus addition negatively affected seven plant species and nitrogen addition negatively affected four plant species. Importantly, the negative effects of nutrient addition and higher above-ground competition were independent of each other for all but one species. Our results suggest that at any given level of soil nutrients, relaxation of above-ground competition allows for higher seedling survival in grasslands. At the same time, even at low levels of above-ground competition, nutrient enrichment negatively affects survival as compared to nutrient-poor conditions. Therefore, although maintaining low above-ground competition appears essential for species’ recruitment, for instance through mowing or herbivory, these management efforts are likely to be insufficient and we conclude that environmental policies aimed to reduce both excess nitrogen and particularly phosphorus inputs are also necessary. PMID:28333985

  7. Effects of fire and three fire-fighting chemicals on main soil properties, plant nutrient content and vegetation growth and cover after 10 years.

    Science.gov (United States)

    Fernández-Fernández, M; Gómez-Rey, M X; González-Prieto, S J

    2015-05-15

    The study addresses a knowledge-gap in the long-term ecological consequences of fire and fire-fighting chemicals. Ten years after a prescribed fire and the application of three fire-fighting chemicals, their effects on the soil-plant system were evaluated. Five treatments were established: unburnt soils (US) and burnt soils treated with water alone (BS), foaming agent (BS+Fo), Firesorb (BS+Fi) and ammonium polyphosphate (BS+Ap). Soils (0-2 cm depth) and foliar material of shrubs (Erica umbellata, Pterospartum tridentatum and Ulex micranthus) and trees (Pinus pinaster) were analysed for total N, δ(15)N, and soil-available and plant total macronutrients and trace elements. Soil pH, NH₄(+)-N and NO₃(-)-N; pine basal diameter and height; and shrub cover and height were also measured. Compared with US plots, burnt soils had less nitrates and more Mo. Although differences were not always significant, BS+Ap had the highest levels of soil available P, Na and Al. Plants from BS+Ap plots had higher values of δ(15)N (P. pinaster and E. umbellata), P (all species), Na (P. tridentatum and U. micranthus) and Mg (E. umbellata and P. tridentatum) than other treatments; while K in plants from BS+Ap plots was the highest among treatments for P. pinaster and the lowest for the shrubs. Pines in US plots were higher and wider than in burnt treatments, except for BS+Ap, where the tallest and widest trees were found, although half of them were either dead (the second highest mortality after BS+Fi) or had a distorted trunk. BS+Ap was the treatment with strongest effects on plants, showing E. umbellata the lowest coverage and height, P. tridentatum the highest coverage, U. micranthus one of the lowest coverages and being the only treatment where Genista triacanthos was absent. Consequently, it is concluded that both fire and ammonium polyphosphate application had significant effects on the soil-plant system after 10 years.

  8. [Effects of ground surface mulching in tea garden on soil water and nutrient dynamics and tea plant growth].

    Science.gov (United States)

    Sun, Li-tao; Wang, Yu; Ding, Zhao-tang

    2011-09-01

    Taking a 2-year-old tea garden in Qingdao of Shandong Province as test object, this paper studied the effects of different mulching modes on the soil water and nutrient dynamics and tea plant growth. Four treatments were installed, i.e., no mulching (CK), straw mulching (T1), plastic film mulching (T2), and straw plus plastic film mulching (T3). Comparing with CK, mulching could keep the soil water content at a higher level, and enhance the water use efficiency. In treatments T1 and T3, the tea growth water use efficiency and yield water use efficiency increased by 43%-48% and 7%-13%, respectively, compared with CK. Also in treatments T1 and T3, the contents of soil organic matter, available-N, nitrate-N, and ammonium-N increased significantly, with the soil fertility improved, and the leaf nitrate-N content and nitrate reductase activity increased, which promoted the tea growth and yield (12%-13% higher than CK) and made the peak period of bud growth appeared earlier. Considering the tea growth and yield, water and nutrient use efficiency, environment safety and economic benefit, straw mulching could be an effective ground surface mulching mode for young tea garden.

  9. Numerical scheme for non-linear model of supercritical fluid extraction from polydisperse ground plant material: single transport system

    Science.gov (United States)

    Salamatin, A.

    2016-11-01

    Numerical algorithm is developed for modelling non-linear mass transfer process in supercritical fluid extraction (SFE). The ground raw material is considered as polydisperse, characterized by discrete number of effective particle fractions. Two continuous interacting counterparts separated by permeable membrane are distinguished in plant material build-up. The apoplast plays role of transport channels during extraction, and symplast contains extractable oil. The complete SFE model is non-linear as a result of non-linearity of oil dissolution kinetics. The computational scheme is based on the finite-volume approximation method and Thomas elimination procedure. The resulting system of algebraic equations is solved iteratively. Special attention is paid to polydisperse substrates, when particle scale characteristics of all fractions interact with each other through pore phase concentration on the vessel scale. Stability of the developed algorithm is demonstrated in numerical tests. Special iterative procedure guarantees a monotonic decrease of oil content in individual particles of substrate. It is also shown that in the limit of the so-called shrinking core approach the number of mesh nodes on a particle scale should be increased.

  10. 氯盐融雪剂对4种地被植物种子萌发的影响%Effect of chloride deicing salts on seed germination of four ground covers species

    Institute of Scientific and Technical Information of China (English)

    杨冬; 周广柱

    2015-01-01

    The effects of deicing salts on seed germination and growth of shoots and roots of four kinds of ground covers (Poa pratensts, Bromus inermis Layss,Coreopsis basalis,Cosmos bipinnatus Cav. ) were studied. The length of roots and shoots of ground covers were also determined in this paper. The results showed that the inhibition effect on seed germination and growth response in the four kinds of ground covers was increased with increasing concentration of deicing salts. Cosmos bipinnatus Cav.showed the highest tolerance to deicing salts, followed by Bromus inermis Layss, Coreopsis basalis and Poa pratensis. The critical value of tolerance to deicing salts were 14.69 g/L, 10.04 g/L, 7.38 g/L and 7.31 g/L forCosmos bipinnatus Cav, Bromus inermis Layss, Coreopsis basalis and Poa pratensis,respectively and the maximum value were 21.08 g/L, 16.51 g/L, 14.67 g/L and 13.50 g/L, respectively.%以草地早熟禾、无芒雀麦、金鸡菊、波斯菊4种地被植物种子为研究材料,探讨不同浓度氯盐类融雪剂对其发芽的影响。结果表明:随着融雪剂浓度的增加,4种地被植物种子萌发、幼芽、幼根生长受到的抑制作用增强。4种地被植物对融雪剂胁迫的耐受能力大小依次为波斯菊>无芒雀麦>金鸡菊>草地早熟禾,耐受临界值分别为14.69 g/L、10.04 g/L、7.38 g/L和7.31 g/L,极限值分别为21.08 g/L、16.51 g/L、14.67 g/L和13.50 g/L。

  11. The use of olive-mill waste compost to promote the plant vegetation cover in a trace-element-contaminated soil.

    Science.gov (United States)

    Pardo, Tania; Martínez-Fernández, Domingo; Clemente, Rafael; Walker, David J; Bernal, M Pilar

    2014-01-01

    The applicability of a mature compost as a soil amendment to promote the growth of native species for the phytorestoration of a mine-affected soil from a semi-arid area (SE Spain), contaminated with trace elements (As, Cd, Cu, Mn, Pb and Zn), was evaluated in a 2-year field experiment. The effects of an inorganic fertiliser were also determined for comparison. Bituminaria bituminosa was the selected native plant since it is a leguminous species adapted to the particular local pedoclimatic conditions. Compost addition increased total organic-C concentrations in soil with respect to the control and fertiliser treatments, maintained elevated available P concentrations throughout the duration of the experiment and stimulated soil microbial biomass, while trace elements extractability in the soil was rather low due to the calcareous nature of the soil and almost unaltered in the different treatments. Tissue concentrations of P and K in B. bituminosa increased after the addition of compost, associated with growth stimulation. Leaf Cu concentration was also increased by the amendments, although overall the trace elements concentrations can be considered non-toxic. In addition, the spontaneous colonisation of the plots by a total of 29 species of 15 different families at the end of the experiment produced a greater vegetation cover, especially in plots amended with compost. Therefore, the use of compost as a soil amendment appears to be useful for the promotion of a vegetation cover and the phytostabilisation of moderately contaminated soils under semi-arid conditions.

  12. Land Use and Land Cover, WI Agricultural Statistics Service (WASS) WI Cropland Data Layer. Agriculture and non-ag land cover categories based on survey data (ground truth), satellite imagery classification, FSA common land unit, and 2001 National Land Cover dataset., Published in 2008, 1:100000 (1in=8333ft) scale, Wisconsin Department of Agriculture, Trade & Consumer Protection.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Land Use and Land Cover dataset, published at 1:100000 (1in=8333ft) scale, was produced all or in part from Field Observation information as of 2008. It is...

  13. Benthic Cover

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic cover (habitat) maps are derived from aerial imagery, underwater photos, acoustic surveys, and data gathered from sediment samples. Shallow to moderate-depth...

  14. Wind farm and solar park effects on plant-soil carbon cycling: uncertain impacts of changes in ground-level microclimate.

    Science.gov (United States)

    Armstrong, Alona; Waldron, Susan; Whitaker, Jeanette; Ostle, Nicholas J

    2014-06-01

    Global energy demand is increasing as greenhouse gas driven climate change progresses, making renewable energy sources critical to future sustainable power provision. Land-based wind and solar electricity generation technologies are rapidly expanding, yet our understanding of their operational effects on biological carbon cycling in hosting ecosystems is limited. Wind turbines and photovoltaic panels can significantly change local ground-level climate by a magnitude that could affect the fundamental plant-soil processes that govern carbon dynamics. We believe that understanding the possible effects of changes in ground-level microclimates on these phenomena is crucial to reducing uncertainty of the true renewable energy carbon cost and to maximize beneficial effects. In this Opinions article, we examine the potential for the microclimatic effects of these land-based renewable energy sources to alter plant-soil carbon cycling, hypothesize likely effects and identify critical knowledge gaps for future carbon research.

  15. Natural radioactivity of ground waters and soil in the vicinity of the ash repository of the coal-fired power plant. Nikola Tesla A in Obrenovac, Yugoslavia

    Energy Technology Data Exchange (ETDEWEB)

    Vukovic, Z.; Madic, M.; Vukovic, D. [Institute of Nuclear Sciences Vinca, Belgrade (Yugoslavia)

    1996-11-01

    Radioactivity of U, Th and {sup 40}K has been investigated in the vicinity of the ash repository of coal-fired Nikola Tesla A power plant in Obrenovac (Yugoslavia). Using alpha and gamma spectrometry, luminescence spectrophotometry, it was found that the ash repository is a source of radionuclides of the uranium and thorium series; and these radionuclides were found in the ground water up to a distance of several hundred metres. The influence of the repository on the soil radioactivity was minimal.

  16. Using Satellite Remote Sensing to Map Changes in Aquatic Invasive Plant Cover in the Sacramento-San Joaquin River Delta of California

    Science.gov (United States)

    Potter, Christopher

    2017-01-01

    Waterways of the Sacramento San Joaquin Delta have recently become infested with invasive aquatic weeds such as floating water hyacinth (Eichhoria crassipes) and water primrose (Ludwigia peploides). These invasive plants cause many negative impacts, including, but not limited to: the blocking of waterways for commercial shipping and boating; clogging of irrigation screens, pumps and canals; and degradation of biological habitat through shading. Zhang et al. (1997, Ecological Applications, 7(3), 1039-1053) used NASA Landsat satellite imagery together with field calibration measurements to map physical and biological processes within marshlands of the San Francisco Bay. Live green biomass (LGB) and related variables were correlated with a simple vegetation index ratio of red and near infra-red bands from Landsat images. More recently, the percent (water area) cover of water hyacinth plotted against estimated LGB of emergent aquatic vegetation in the Delta from September 2014 Landsat imagery showed a 80% overall accuracy. For the past two years, we have partnered with the U. S. Department of Agriculture (USDA) and the Department of Plant Sciences, University of California at Davis to conduct new validation surveys of water hyacinth and water primrose coverage and LGB in Delta waterways. A plan is underway to transfer decision support tools developed at NASA's Ames Research Center based on Landsat satellite images to improve Delta-wide integrated management of floating aquatic weeds, while reducing chemical control costs. The main end-user for this application project will be the Division of Boating and Waterways (DBW) of the California Department of Parks and Recreation, who has the responsibility for chemical control of water hyacinth in the Delta.

  17. Acoustic Characterization of Grass-cover Ground

    Science.gov (United States)

    2014-11-20

    for noise and rever- beration control. Examples of porous media are cements, ceramics, rocks, building insulation , foams and soil. Characterizing the... air is consid- ered as lossless fluid and Eqs. 2.1 and 2.2 can be applied without approximations. However, when acoustic waves travel in narrow...3.1) In Eq. 3.1, P1 and P2 are the acoustic pressures measured at each respective microphone, Pi is the incident pressure, k0 is wave number in air , ω

  18. Radioactive contamination of the soil-plant cover at certain locations of Primorsky Krai, Sakhalin Island and Kamchatka Peninsula: Assessment of the Fukushima fallout.

    Science.gov (United States)

    Mikhailovskaya, L N; Molchanova, I V; Pozolotina, V N; Zhuravlev, Yu N; Timofeeva, Ya O; Burdukovsky, M L

    2017-06-01

    The contamination densities of soil-plant cover at certain locations within the Primorsky Krai, Sakhalin Island and Kamchatka Peninsula attributable to (90)Sr, (137)Cs and (239,240)Pu were 500-1390 Bq m(-2), 980-2300 Bq m(-2) and 37-74 Bq m(-2), respectively. These values do not exceed average global background levels, typical for mid-latitudes of the Northern Hemisphere. The spatial distribution of radionuclides depends on the climatic conditions of the region. A positive dependence of the (90)Sr and (137)Cs contamination densities, as well as additional (137)Cs from NPP "Fukushima" in the soil, was determined based on the sum of annual atmospheric precipitation within the study areas. No trends in the spatial distribution of Pu isotopes were observed. The (137)Cs contribution from the "Fukushima" NPP constitutes 11-300 Bq m(-2) in the Primorsky Krai, Sakhalin Island and at the Kamchatka peninsula, i.e., 1-22% of the total amount of radionuclides in the soil. The contribution of this radionuclide to the contamination of moss-lichen vegetation ranged from 7 to 42%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Effect of intercropping wheat with forage legumes on wheat production and ground cover Efeito do consórcio entre trigo e leguminosas forrageiras na produção de trigo e na cobertura de solo

    Directory of Open Access Journals (Sweden)

    Gilberto Omar Tomm

    2001-03-01

    Full Text Available The use of winter legumes in southern Brazil is hindered by the slow growth of these species during establishment exposing soil surface to erosion. Introduction of these species along with spring wheat (Triticum aestivum L. was studied as a means of increasing ground cover during their initial establishment period, without reducing wheat grain yield. Two experiments were conducted in nearby areas, one in each year. Birdsfoot trefoil (Lotus corniculatus L., red clover (Trifolium pratense L. cultivar Quiñequelli, white clover (T. repens L., and arrowleaf clover (T. vesiculosum Savi did not reduce cereal yield in either year. Wheat yield was reduced by intercropped red clover cultivar Kenland and by subclover (T. subterraneum L. in the first year. No grain yield differences due to intercropping with any legume were detected in the second year, when rainfall was below normal. Intercropping with wheat showed to be a practical alternative to enhance ground cover at establishing forage legumes.O uso de leguminosas forrageiras no sul do Brasil é dificultado pelo lento crescimento dessas espécies no ano de estabelecimento, o que expõe o solo à erosão. Estudou-se a introdução dessas leguminosas concomitantemente ao trigo (Triticum aestivum L. com o objetivo de aumentar a cobertura de solo durante o seu desenvolvimento inicial, sem reduzir o rendimento de grãos de trigo. Foram realizados dois experimentos em áreas próximas, um em cada ano. O cornichão (Lotus corniculatus L., o trevo-vermelho (Trifolium pratense L., cultivar Quiñequelli, o trevo-branco (T. repens L. e o trevo-vesiculoso (T. vesiculosum Savi não reduziram o rendimento de trigo em nenhum dos anos. O rendimento de grãos de trigo foi reduzido pelo trevo-vermelho, cultivar Kenland, e pelo trevo subterrâneo (T. subterraneum L., no primeiro ano. No segundo ano, em que, durante o período de desenvolvimento de trigo, a precipitação pluvial foi inferior à normal, não se

  20. Grau de cobertura do solo e dinâmica da vegetação em olivais de sequeiro com a introdução de herbicidas Ground cover and dynamic of weeds after the introduction of herbicides as soil management system in a rainfed olive orchard

    Directory of Open Access Journals (Sweden)

    Manuel Ângelo Rodrigues

    2009-12-01

    herbicides as soil management strategies in a rainfed olive orchard. The field experiment was carried out in Mirandela, NE Portugal. The soil management treatments included: conventional tillage; post-emergence herbicide (glyphosate; and post-emergence plus residual herbicide (diuron+glyphosate+terb utilazine. The ground cover percentage and the botanical composition of vegetation were monitored since 2002 to 2007 from the point-quadrat method. Both the herbicide formulations killed efficiently the vegetation in a single annual application. The ground cover percentages in conventional tillage, prior to the first tillage event, varied between 50 to 80 % beneath the trees and between 30 to 60 % in the open space. The ground cover percentages in April, in the treatment of glyphosate, were in the range of 60 to 90 % and 40 to 50 % beneath the trees and between rows, respectively. In the residual herbicide plot the ground cover percentages were always very low. The soil of the glyphosate plot was covered with vegetation over all the year. In au-tumn/spring the soil was covered with green weeds and in the summer with a mulching of the dead material. In the glyphosate plot the dynamic of species was high. One year after the first application of herbicide, Ornithopus compressus appeared as the most abundant species. Thereafter, acquired relevance species with short growing cycles which seeds mature before April (e.g. Mibora minima, Logfia gallica and other that produce a high number of seeds easily spread by wind (e.g. Hypochaeris radicata, Conyza canadensis and which seeds proceeded from surrounding untilled fields and rural-tracks or from individual plants that escaped to the herbicide control.

  1. The effect of plant growth promoting rhizobacteria (PGPR on quantitative and qualitative characteristics of Sesamum indicum L. with application of cover crops of Lathyrus sp. and Persian clover (Trifolium resopinatum L.

    Directory of Open Access Journals (Sweden)

    M. Jahan

    2016-05-01

    Full Text Available Cover crops cultivation and application of plant growth rhizobacteria are the key factors to enhance agroecosystem health. A field experiment was conducted at the Research Farm of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season of 2009-2010. A split plot arrangement based on a complete randomized block design with three replications was used. Cultivation and no cultivation of Lathyrus sp. and Persian clover (Trifolium resopinatum in autumn assigned to the main plots. The sub plot factor consisted of three different types of biofertilizers plus control, including 1-nitroxin (containing of Azotobacter sp. and Azospirillum sp., 2- phosphate solubilizing bacteria (PSB (containing of Bacillus sp. and Pseudomonas sp., 3- biosulfur (containing of Thiobacillus ssp. and 4- control (no fertilizer. The results showed the effect of cover crops on seed number and seed weight per plant, biological and seed yield was significant, as the seed yield increased of 9 %. In general, biofertilizers showed superiority due to the most studied traits compared to control. Nitroxin, PSB and biosulfur increased biological yield of 44, 28 and 26 % compared to control, respectively. Cover crops and biofertilizers interactions, showed significant effect on all studied traits, as the highest and the lowest harvest index resulted in cover crop combined with biofertilizers (22.1% and cultivation and no cultivation of cover crops combined with control (15.3%, respectively. The highest seed oil and protein content resulted from cover crops plus biofertilizers (42.4% and cover crops plus PSB (22.5%, respectively. In general, the results showed cover crops cultivation in combination with biofertilizers application could be an ecological alternative for chemical fertilizers, in addition of achieving advantages of cover crops. According to the results, it should be possible to design an ecological cropping system and produce appropriate and healthy

  2. Study on draught resistance of five herb ground cover plants%5种草本地被植物抗旱性研究

    Institute of Scientific and Technical Information of China (English)

    史燕山; 骆建霞; 王煦; 赵坤平; 刘玉冬; 黄俊轩

    2005-01-01

    对5种草本地被植物(银水苏Stachys‘Sliver Carpet’,百里香丁Thymus mongolicus Ronn,金叶过路黄Lysimachia christinae,佛甲草Sedum Lineare,常夏石竹Dianthus plumarius)干旱胁迫处理后的植株外部形态表现、水分临界饱和亏、叶片游离脯氨酸含量以及叶片细胞电导率等指标进行了观察测定.结果表明,干旱胁迫下,5种地被植物的生长势下降;叶片游离脯氨酸含量及电导率增加,且抗旱性相对较弱的植物增加幅度较大;复水后各种植物恢复程度不同;在用水分临界饱和亏反映植物的抗脱水能力及抗旱能力时,应与测定该值时离体叶片至永久萎蔫所用的时间结合起来考虑,否则可能与其实际表现不符.综合分析认为,5种草本地被植物抗旱性由强至弱顺序为:佛甲草>常夏石竹>银水苏>百里香>金叶过路黄.

  3. Impact of Biofuel Poplar Cultivation on Ground-Level Ozone and Premature Human Mortality Depends on Cultivar Selection and Planting Location.

    Science.gov (United States)

    Ashworth, Kirsti; Wild, Oliver; Eller, Allyson S D; Hewitt, C Nick

    2015-07-21

    Isoprene and other volatile organic compounds emitted from vegetation play a key role in governing the formation of ground-level ozone. Emission rates of such compounds depend critically on the plant species. The cultivation of biofuel feedstocks will contribute to future land use change, altering the distribution of plant species and hence the magnitude and distribution of emissions. Here we use relationships between biomass yield and isoprene emissions derived from experimental data for 29 commercially available poplar hybrids to assess the impact that the large-scale cultivation of poplar for use as a biofuel feedstock will have on air quality, specifically ground-level ozone concentrations, in Europe. We show that the increases in ground-level ozone across Europe will increase the number of premature deaths attributable to ozone pollution each year by up to 6%. Substantial crop losses (up to ∼9 Mt y(-1) of wheat and maize) are also projected. We further demonstrate that these impacts are strongly dependent on the location of the poplar plantations, due to the prevailing meteorology, the population density, and the dominant crop type of the region. Our findings indicate the need for a concerted and centralized decision-making process that considers all aspects of future land use change in Europe, and not just the effect on greenhouse gas emissions.

  4. Integrated plant phenotypic responses to contrasting above- and below-ground resources: key roles of specific leaf area and root mass fraction.

    Science.gov (United States)

    Freschet, Grégoire T; Swart, Elferra M; Cornelissen, Johannes H C

    2015-06-01

    Plants adapt phenotypically to different conditions of light and nutrient supply, supposedly in order to achieve colimitation of these resources. Their key variable of adjustment is the ratio of leaf area to root length, which relies on plant biomass allocation and organ morphology. We recorded phenotypic differences in leaf and root mass fractions (LMF, RMF), specific leaf area (SLA) and specific root length (SRL) of 12 herbaceous species grown in factorial combinations of high/low irradiance and fertilization treatments. Leaf area and root length ratios, and their components, were influenced by nonadditive effects between light and nutrient supply, and differences in the strength of plant responses were partly explained by Ellenberg's species values representing ecological optima. Changes in allocation were critical in plant responses to nutrient availability, as the RMF contribution to changes in root length was 2.5× that of the SRL. Contrastingly, morphological adjustments (SLA rather than LMF) made up the bulk of plant response to light availability. Our results suggest largely predictable differences in responses of species and groups of species to environmental change. Nevertheless, they stress the critical need to account for adjustments in below-ground mass allocation to understand the assembly and responses of communities in changing environments.

  5. The presence of a below-ground neighbour alters within-plant seed size distribution in Phaseolus vulgaris

    NARCIS (Netherlands)

    Chen, B.; During, H.J.; Vermeulen, P.J.; Anten, N.P.R.

    2014-01-01

    * Background and Aims Considerable variation in seed size commonly exists within plants, and is believed to be favoured under natural selection. This study aims to examine the extent to which seed size distribution depends on the presence of competing neighbour plants. * Methods Phaseolus vulgaris p

  6. Effect of the density of transplants in reforestation on the morphological quality of the above-ground part of European beech (Fagus sylvatica L. six years after planting

    Directory of Open Access Journals (Sweden)

    Kateřina Houšková

    2013-01-01

    Full Text Available Quality of the above-ground part of European beech planted at different densities and spacing patterns for the purpose of artificial forest regeneration was monitored 3, 4 and 6 years after planting. The initial numbers of beech transplants were 5,000 pcs.ha−1, 10,000 pcs.ha−1, 15,000 pcs.ha−1 and 20,000 pcs.ha−1. The spacing pattern of transplants was either square or rectangular nearly in all variants: 1.4 × 1.4 m, 2 × 1 m, 1 × 1 m, 0.8 × 0.8 m, 1 ×0.65 m, 0.7 × 0.7 m and 1 × 0.5 m. Conclusions following out from the research are as follows: 1. neither the chosen density of transplants nor their spacing pattern had an essential influence on the after-planting loss or damage of trees; 2. through the planting of larger-diameter transplants it is possible to achieve canopy closure more rapidly as well as faster growth of the plantation; these beech plants keep the edge in growth and quality even 6 years after planting; 3. the higher is the beech plantation density, the less individuals occur in such a plantation with inappropriate stem form; 4. beech plants of the worst quality were found on plots with the lowest initial density of transplants (5,000 and 10,000 pcs.ha−1, yet the number of promising trees was sufficient even there. Thus, none of the experimental numbers of transplants per hectare or spacing arrangements of the European beech transplants can be claimed as inappropriate; however, further monitoring of the plots is necessary.

  7. Closure certification report for the Bear Creek burial grounds B area and walk-in pits at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    On July 5, 1993, the revised RCRA Closure Plan for the Bear Creek Burial Grounds B Area and Walk-In Pits at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, DOE/OR/01-1100&D3 and Y/ER-53&D3, was approved by the Tennessee Department of Environment and Conservation (TDEC). The closure activities described in that closure plan have been performed. The purpose of this document is to summarize the closure activities for B Area and Walk-In Pits (WIPs), including placement of the Kerr Hollow Quarry debris at the WIPs.

  8. High plains cover crop research

    Science.gov (United States)

    Some recent statements have been made about the benefits of growing cover crops in mixtures as compared with single-species plantings of cover crops. Those stated benefits have included greatly reduced water use, enhanced soil microbiological activity, increased biomass productivity, and enhanced wa...

  9. Midwest Cover Crops Field Guide

    Science.gov (United States)

    Producers who want to prevent soil erosion, improve nutrient cycling, sustain their soils, and protect/maintain the environment have been returning to a very old practice: planting cover crops. Cover crops are effective tools for reducing soil erosion and increasing nutrient recycling on farmlands, ...

  10. Establishment of morphology simulation model for above-ground part of cotton plant%棉花地上部形态模拟模型的建立

    Institute of Scientific and Technical Information of China (English)

    陈超; 潘学标; 张立祯; 庞艳梅; 刘琰琰

    2012-01-01

    were made on the dimensions and biomass of above-ground plant organs for each phytomer throughout the seasons. Growth stage-specific target files (a description of plant part weight and dimension based on plant topological structure) were established from the measured data. The relationship between biomass and morphology of the above-ground cotton plant parts was analyzed and used to establish a cotton simulation model for above-ground parts. This algorithm improved the development and morphogenesis modules in COTGROW. A preliminary model calibration was carried out using the experimental data for 2008 and 2009, and the model was validated using independent experimental data for 2010. The results showed that the simulated values agreed well with the measured ones. Correlation coefficient (R) and root mean squared error (RMSE) between the measured and simulated values of morphological parameters were determined. The determined R for plant height, main stem node number, fruiting branch number, fruiting branch node number, internode length, internode diameter, leaf blade length, leaf blade width, petiole length, petiole diameter, boll length and boll diameter were 0.99, 0.99, 0.99, 0.92, 0.95, 0.93, 0.75, 0.71, 0.81, 0.62, 0.98 and 0.98, respectively. The corresponding determined RMSE for the above parameters were 3.85 cm, 0.64, 0.52, 0.66, 1.00 cm, 0.15 cm, 1.58 cm, 2.39 cm, 2.54 cm, 0.05 cm, 0.13 cm and 0.10 cm, respectively. The results indicated that the model achieved a good performance in simulating the growth processes of the above-ground parts of cotton plant. It was further possible to build a visual plant model from the above model.%为构建基于生理生态过程的棉花虚拟生长模型,本研究以棉花模型COTGROW为基础,利用棉花品种“美棉33B”的3年田间密度试验数据,分析了棉株器官生物量-形态的关系,改进了COTGROW模型中的发育和形态发生模块,建立了基于生理生态过程的棉花地上部分形态模

  11. Ground Vehicle Robotics

    Science.gov (United States)

    2013-08-20

    Ground Vehicle Robotics Jim Parker Associate Director, Ground Vehicle Robotics UNCLASSIFIED: Distribution Statement A. Approved for public...DATE 20 AUG 2013 2. REPORT TYPE Briefing Charts 3. DATES COVERED 09-05-2013 to 15-08-2013 4. TITLE AND SUBTITLE Ground Vehicle Robotics 5a...Willing to take Risk on technology -User Evaluated -Contested Environments -Operational Data Applied Robotics for Installation & Base Ops -Low Risk

  12. Improved ground-based remote-sensing systems help monitor plant response to climate and other changes

    Science.gov (United States)

    Dye, Dennis G.; Bogle, Rian C.

    2016-05-26

    Scientists at the U.S. Geological Survey are improving and developing new ground-based remote-sensing instruments and techniques to study how Earth’s vegetation responds to changing climates. Do seasonal grasslands and forests “green up” early (or late) and grow more (or less) during unusually warm years? How do changes in temperature and precipitation affect these patterns? Innovations in ground-based remote-sensing instrumentation can help us understand, assess, and mitigate the effects of climate change on vegetation and related land resources.

  13. Microbial assimilation of 14C of ground and unground plant materials decomposing in a loamy sand and a clay soil

    DEFF Research Database (Denmark)

    Sørensen, P.; Ladd, J.N.; Amato, M.

    1996-01-01

    . More C-14 and N were mineralized and less microbial biomass C-14 accumulated in soils amended with unground than with ground subclover leaves. Differences in the amounts of (CO2)-C-14 and biomass C-14 were established during the initial 7 days of decomposition. At this time, biomass C-14 in the two...... of particle sizes >50 mu m accounted fro 5-6% input C-14 in the loamy sand; the proportions were little affected by grinding of the clover leaf amendment. In contrast, the amounts of biomass C-14 in the fraction of particle sizes soils. Thus......, the increased amounts of biomass C-14 in soils amended with ground leaves were mainly associated with clay plus silt size particles and microaggregates. After 7 d of decomposition, non-biomass C-14 in the two soil fractions accounted for about 40% of input C-14, irrespective of soil type and particle size...

  14. Variable-density ground-water flow and paleohydrology in the Waste Isolation Pilot Plant (WIPP) region, southeastern New Mexico

    Science.gov (United States)

    Davies, P.B.

    1989-01-01

    Variable-density groundwater flow was studied near the Waste Isolation Pilot Plant in southeastern New Mexico. An analysis of the relative magnitude of pressure-related and density-related flow-driving forces indicates that density-related gravity effects are not significant at the plant and to the west but are significant in areas to the north, northeast, and south. A regional-scale model of variable-density groundwater flow in the Culebra Dolomite member of the Rustler Formation indicates that the flow velocities are relatively rapid (10 to the minus 7th power m/sec) west of the site and extremely slow (10 to the minus 11th power m/sec) east and northeast of the site. In the transition zone between those two extremes, which includes the plant, velocities are highly variable. Sensitivity simulations indicate that the central and western parts of the region, including the plant, are fairly well isolated from the eastern and northeastern boundaries. Vertical-flux simulations indicate that as much as 25% of total inflow to the Culebra could be entering as vertical flow, with most of this flow occurring west of the plant. A simple cross-sectional model was developed to examine the flow system as it drains through time following recharge during a past glacial pluvial. This model indicates that the system as a whole drains very slowly and that it apparently could have sustained flow from purely transient drainage following recharge of the system during the Pleistocene. (USGS)

  15. Climate change may alter breeding ground distributions of eastern migratory monarchs (Danaus plexippus via range expansion of Asclepias host plants.

    Directory of Open Access Journals (Sweden)

    Nathan P Lemoine

    Full Text Available Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp. host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in

  16. Climate change may alter breeding ground distributions of eastern migratory monarchs (Danaus plexippus) via range expansion of Asclepias host plants.

    Science.gov (United States)

    Lemoine, Nathan P

    2015-01-01

    Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months

  17. Plant life form based habitat monitoring in a European landscape framework for early warning of changes in land cover and biodiversity

    DEFF Research Database (Denmark)

    Brandt, Jesper; Olsen, Martin; Bloch-Petersen, Margit

    -based connection between the remote sensing-based monitoring of the environment and the site-specific indicators of biodiversity. The landscape-based framework permits a methodology for an operational monitoring that can serve as an early warning system, relating changes in biodiversity to changes in land cover...... of agricultural land use, general land cover and tree and shrub cover of small biotopes), it has not been difficult to integrate the BioHab framework in the SBMP-monitoring system, thus permitting the monitoring system to deliver an additional important European perspective with only very limited extra resources...... landscape monitoring systems. In the intensively used Danish agricultural landscape it has been natural to concentrate on the dynamics of small biotopes. An area covering landscape monitoring program with emphasis on small biotopes (SBMP) has developed since 1981, and a continuation of this monitoring...

  18. The Effects of Winter Cover Crops and Plant Growth Promoting Rhizobacteria on some Soil Fertility Aspects and Crop Yield in an Organic Production System of Ocimum basilicum L.

    OpenAIRE

    M. Jahan; M.B Amiri; J Shabahang; Ahmadi, F; F. Soleymani

    2014-01-01

    Sustainable agriculture systems emphasized on the on-farm inputs likes use of biofertilizers, crop rotation and cover crops. This experiment was conducted in a split plots arrangement with two factors based on randomized complete block design with three replications during years 2009-2010, at Research Farm of Ferdowsi University of Mashhad. The main factor consisted of cultivation and no cultivation of cover crops in autumn. The sub factor was biofertilizer application with four levels, inclu...

  19. feasibility of winter cover crop production under rainfed conditions in ...

    African Journals Online (AJOL)

    ACSS

    Low winter rainfall poses a challenge to production of high biomass from cover ... February planted cover crops had the lowest residues remaining at maize ..... Interaction effects of planting date and cover crop species on cover crop dry weight at termination in Eastern Cape ... to weed species density (per m2) at cover crop.

  20. Sganzerla Cover

    Directory of Open Access Journals (Sweden)

    Victor da Rosa

    2014-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-7917.2014v19n1p158 Neste artigo, realizo uma leitura do cinema de Rogério Sganzerla, desde o clássico O bandido da luz vermelha até os documentários filmados na década de oitenta, a partir de duas noções centrais: cover e over. Para isso, parto de uma controvérsia com o ensaio de Ismail Xavier, Alegorias do subdesenvolvimento, em que o crítico realiza uma leitura do cinema brasileiro da década de sessenta através do conceito de alegoria; depois releio uma série de textos críticos do próprio Sganzerla, publicados em Edifício Sganzerla, procurando repensar as ideias de “herói vazio” ou “cinema impuro” e sugerindo assim uma nova relação do seu cinema com o tempo e a representação; então busco articular tais ideias com certos procedimentos de vanguarda, como a falsificação, a cópia, o clichê e a colagem; e finalmente procuro mostrar que, no cinema de Sganzerla, a partir principalmente de suas reflexões sobre Orson Welles, a voz é usada de maneira a deformar a interpretação naturalista.

  1. Cover Picture.

    Science.gov (United States)

    Breuning; Ruben; Lehn; Renz; Garcia; Ksenofontov; Gütlich; Wegelius; Rissanen

    2000-07-17

    The cover picture shows how both, fine arts and science, avail themselves of a system of intertwined symbolic and iconic languages. They make use of a common set of abstracted signs to report on their results. Thus, already in 1925, Wassily Kandinsky painted a masterpiece (bottom), which now, 75 years later, might be regarded as a blueprint for a scientific project. In his painting, Kandinsky pictured a grid-shaped sign that resembles in effect an actual molecular switch. Apparently following an enigmatic protocol, the groups of Lehn and Gütlich (see p. 2504 ff. for more details) constructed a grid-type inorganic architecture that operates as a three-level magnetic switch (center) triggered by three external perturbations (p, T, hnu). The switching principle is based on the spin-crossover phenomenon of Fe(II) ions and can be monitored by Mössbauer spectroscopy (left) and magnetic measurements (rear). Maybe not by chance, the English translation of the title of the painting "signs" is a homonym of "science", since both presented works are a product of the insatiable curiosity of man and his untiring desire to recognize his existence.

  2. The Effects of Winter Cover Crops and Plant Growth Promoting Rhizobacteria on some Soil Fertility Aspects and Crop Yield in an Organic Production System of Ocimum basilicum L.

    Directory of Open Access Journals (Sweden)

    M Jahan

    2014-03-01

    Full Text Available Sustainable agriculture systems emphasized on the on-farm inputs likes use of biofertilizers, crop rotation and cover crops. This experiment was conducted in a split plots arrangement with two factors based on randomized complete block design with three replications during years 2009-2010, at Research Farm of Ferdowsi University of Mashhad. The main factor consisted of cultivation and no cultivation of cover crops in autumn. The sub factor was biofertilizer application with four levels, included 1-Nitroxin® (containing Azotobacter spp. and Azospirillum spp., 2-Biophosphorous® (Bacillus sp. and Pseudomonas sp., 3-Nitroxin® + Biophosphorous® and 4-Control. Results showed that most characteristics, e.g. seed yield and harvest index were increased with no cover crop cultivation. However in control treatment, the biological yield, seed yield and harvest index were more than biofertilizeres treatments, as Nitroxin® and Biophosphorous® ranked after the control. Amongst the biofertilizers, Biophosphorus® had the most positive effects. The maximum grain weight was obtained from Nitroxin®+ Biophosphorous® treatment. The interaction effects of biofertilizer and cover crops were significant among some characteristics. The results showed that the interaction between biofertilizers and no cover crop cultivation was significant, as use of the biofertilizers especially Nitroxin® and Biophosphorous® in no cover crop condition increased the amounts of biological yield and seed yield.

  3. 小湾水电站顶盖取水试验研究%Research on the Experiment of Getting Unit Cooling Water from Turbine Head Cover in Xiaowan Hydropower Plant

    Institute of Scientific and Technical Information of China (English)

    朱丽辉; 武赛波

    2013-01-01

      介绍澜沧江小湾水电站顶盖取水试验,并对试验情况进行一定研究分析,供相关人员参考。%A brief introduction to the experiment of getting unit cooling water from turbine head cover in Xiaowan hydropower plant was presented. Several important findings are achieved based on the analysis of the results of the experiment.

  4. Testing of ground fault relay response during the energisation of megawatt range electric boilers in thermal power plants

    DEFF Research Database (Denmark)

    Silva, Filipe Miguel Faria da; Bak, Claus Leth; Davidsen, Troels

    2015-01-01

    , during the energisation of a boiler. A special case for concern was the presence of an electric arc between the electrodes of the boiler and the water in the boiler during approximately 2s at the energisation, which can in theory be seen as a ground fault by the relay. The voltage and current transient......Large controllable loads may support power systems with an increased penetration of fluctuating renewable energy, by providing a rapid response to a change in the power production. Megawatt range electric boilers are an example of such controllable loads, capable of change rapidly...

  5. Performance and Carbon Emission Analysis on Glass-covering Greenhouse Heating with Ground Source Heat Pump Technology%玻璃温室地源热泵供暖性能与碳排放分析

    Institute of Scientific and Technical Information of China (English)

    柴立龙; 马承伟

    2012-01-01

    The heating test was conducted in a glass-covering multi-span greenhouse ( 756 m ) with groundwater-style GSHP technology. The heat quantity estimating models based on air enthalpy difference method ( AEDM) were developed according to the heating characteristics of GSHP. The economical performance and carbon footprint ( greenhouse gas emission level) of the GSHP was analyzed and compared with currently widely used coal fired heating system ( CFHs) and natural gas fired heating system (GFHs) based on investigated various energy sources price during heating tests. According to the compared results, the GSHPs heating cost is higher than CFHs, but lower than GFHs. Meanwhile, GSHPs CO2 emission during heating is higher than GFHs, but lower than CFHs.In view of the strong coupling between temperature and relative humidity in the greenhouse simulation system, an adaptive decoupling method based on dynamic matrix control was proposed. Taking the measure of feedforward compensation to eliminate interaction between channels of temperature and humidity, an adaptive decoupling algorithm by weighting was designed. The proposed method can adjust the decoupling parameters online under different operating modes, effectively overcome the effect of model severe mismatch to control accuracy. Compared with the traditional PID control, simulation and experimental results both indicated the proposed strategy greatly improved the control performance.%在北京地区一栋玻璃连栋温室(756 m2)中采用地下水式地源热泵(ground source heat pump,简称GSHP)技术进行了冬季供暖试验,并结合GSHP技术的供热特点构建了基于供热末端空气焓差法的供热量计算模型以及供热系统性能分析方法.根据供暖期北京地区能源价格水平,对比当前广泛使用的燃煤供暖系统和天然气供暖系统,系统地评价了GSHP技术的碳排放(温室气体排放水平)和供暖经济性.GSHP供暖成本低于同期燃气供暖,但

  6. Accuracy analysis of vegetation cover measurement using digital photography for regular planted woodland%规则林地覆盖度照相测量法的精度分析

    Institute of Scientific and Technical Information of China (English)

    赵继强; 谢东辉; 孟夏; 穆西晗; 阎广建

    2013-01-01

    为定量研究照相法测量规则林地覆盖度中采样策略、相机非垂直拍摄等因素对覆盖度计算结果的影响,该文对河北怀来的一片梨树林进行了实地测量,通过对测量数据的统计计算,利用植被结构生成软件 Onyx tree professional重建梨树林场景,采用基于物理的光线追踪算法模拟相机拍摄的照片,提出了规则林地覆盖度照相法测量的采样方案,并通过计算机模拟检验了采样方案。通过精确控制模拟相机的拍摄条件,进一步分析了非垂直拍摄对测量精度的影响。结果表明,相机的非竖直拍摄对覆盖度计算结果的精度有较大的影响,误差最大可达27.9%。该文提出的测量方案为规则林地的覆盖度实地测量提供了参考。%Digital photography is now the most widely used method to obtain the vegetation cover in field measurements. It uses a digital camera to shoot the research area straight downward, classify the digital images into plants and soil, and calculate the percentages of the pixel numbers of plants. When measuring the vegetation cover of regular planted woodland with digital photography, the accuracy of the calculated vegetation cover is affected by following factors such as the sampling strategy and non-vertical shooting of digital camera. However, it is difficult to analyze these factors mentioned above quantitatively in situ measurement because there are lots of uncertain errors involved. In this study, we used the computer simulation method to evaluate these factors because in a computer simulated scene, we can strictly control all these uncertainties. We measured a regular planted pyrus orchard to get the structural data in Huailai (40.373°N, 115.723°E), Heibei province. Through statistics of the measured structural data, a regular planted pyrus orchard scene was reconstructed with the plants structural generating software, onyx tree professional which is widely used in forest

  7. Selenium and its species distribution in above-ground plant parts of selenium enriched buckwheat (Fagopyrum esculentum Moench).

    Science.gov (United States)

    Vogrincic, Maja; Cuderman, Petra; Kreft, Ivan; Stibilj, Vekoslava

    2009-11-01

    Common buckwheat (Fagopyrum esculentum Moench) was foliarly sprayed with a water solution containing 10 mg Se(VI) L(-1) at the beginning of flowering. The total Se content in plant parts in the untreated group was low, whereas in the Se-sprayed group it was approximately 50- to 500-fold higher, depending on the plant part (708-4231 ng Se g(-1) DM(-1) (DM: dry matter)). We observed a similar distribution of Se in plant parts in both control and treated groups, with the highest difference in Se content being in ripe seeds. Water-soluble Se compounds were extracted by enzymatic hydrolysis with protease XIV, resulting in above 63% of soluble Se from seeds, approximately 14% from stems, leaves and inflorescences and less than 1% from husks. Se-species were determined in enzymatic extracts using HPLC-UV-HG-AFS (HPLC-hydride generation-atomic fluorescence spectrometry with UV treatment). The main Se species found in seeds was SeMet ( approximately 60% according to total Se content), while in stems, leaves and inflorescences the only form of soluble Se present was Se(VI) (up to 10% of total Se). In husks no Se-species were detected. We observed an instability of Se(IV) in seed extracts as a possible consequence of binding to the matrix components. Therefore, special care concerning sample extraction and the storage time of the extracts should be taken.

  8. Relationships between plant diversity and the abundance and α-diversity of predatory ground beetles (Coleoptera: Carabidae) in a mature Asian temperate forest ecosystem.

    Science.gov (United States)

    Zou, Yi; Sang, Weiguo; Bai, Fan; Axmacher, Jan Christoph

    2013-01-01

    A positive relationship between plant diversity and both abundance and diversity of predatory arthropods is postulated by the Enemies Hypothesis, a central ecological top-down control hypothesis. It has been supported by experimental studies and investigations of agricultural and grassland ecosystems, while evidence from more complex mature forest ecosystems is limited. Our study was conducted on Changbai Mountain in one of the last remaining large pristine temperate forest environments in China. We used predatory ground beetles (Coleoptera: Carabidae) as target taxon to establish the relationship between phytodiversity and their activity abundance and diversity. Results showed that elevation was the only variable included in both models predicting carabid activity abundance and α-diversity. Shrub diversity was negatively and herb diversity positively correlated with beetle abundance, while shrub diversity was positively correlated with beetle α-diversity. Within the different forest types, a negative relationship between plant diversity and carabid activity abundance was observed, which stands in direct contrast to the Enemies Hypothesis. Furthermore, plant species density did not predict carabid α-diversity. In addition, the density of herbs, which is commonly believed to influence carabid movement, had little impact on the beetle activity abundance recorded on Changbai Mountain. Our study indicates that in a relatively large and heterogeneous mature forest area, relationships between plant and carabid diversity are driven by variations in environmental factors linked with altitudinal change. In addition, traditional top-down control theories that are suitable in explaining diversity patterns in ecosystems of low diversity appear to play a much less pronounced role in highly complex forest ecosystems.

  9. Relationships between plant diversity and the abundance and α-diversity of predatory ground beetles (Coleoptera: Carabidae in a mature Asian temperate forest ecosystem.

    Directory of Open Access Journals (Sweden)

    Yi Zou

    Full Text Available A positive relationship between plant diversity and both abundance and diversity of predatory arthropods is postulated by the Enemies Hypothesis, a central ecological top-down control hypothesis. It has been supported by experimental studies and investigations of agricultural and grassland ecosystems, while evidence from more complex mature forest ecosystems is limited. Our study was conducted on Changbai Mountain in one of the last remaining large pristine temperate forest environments in China. We used predatory ground beetles (Coleoptera: Carabidae as target taxon to establish the relationship between phytodiversity and their activity abundance and diversity. Results showed that elevation was the only variable included in both models predicting carabid activity abundance and α-diversity. Shrub diversity was negatively and herb diversity positively correlated with beetle abundance, while shrub diversity was positively correlated with beetle α-diversity. Within the different forest types, a negative relationship between plant diversity and carabid activity abundance was observed, which stands in direct contrast to the Enemies Hypothesis. Furthermore, plant species density did not predict carabid α-diversity. In addition, the density of herbs, which is commonly believed to influence carabid movement, had little impact on the beetle activity abundance recorded on Changbai Mountain. Our study indicates that in a relatively large and heterogeneous mature forest area, relationships between plant and carabid diversity are driven by variations in environmental factors linked with altitudinal change. In addition, traditional top-down control theories that are suitable in explaining diversity patterns in ecosystems of low diversity appear to play a much less pronounced role in highly complex forest ecosystems.

  10. Limited Impact of a Fall-Seeded, Spring-Terminated Rye Cover Crop on Beneficial Arthropods.

    Science.gov (United States)

    Dunbar, Mike W; Gassmann, Aaron J; O'Neal, Matthew E

    2017-04-01

    Cover crops are beneficial to agroecosystems because they decrease soil erosion and nutrient loss while increasing within-field plant diversity. Greater plant diversity within cropping systems can positively affect beneficial arthropod communities. We hypothesized that increasing plant diversity within annually rotated corn and soybean with the addition of a rye cover crop would positively affect the beneficial ground and canopy-dwelling communities compared with rotated corn and soybean grown without a cover crop. From 2011 through 2013, arthropod communities were measured at two locations in Iowa four times throughout each growing season. Pitfall traps were used to sample ground-dwelling arthropods within the corn and soybean plots and sweep nets were used to measure the beneficial arthropods in soybean canopies. Beneficial arthropods captured were identified to either class, order, or family. In both corn and soybean, community composition and total community activity density and abundance did not differ between plots that included the rye cover crop and plots without the rye cover crop. Most taxa did not significantly respond to the presence of the rye cover crop when analyzed individually, with the exceptions of Carabidae and Gryllidae sampled from soybean pitfall traps. Activity density of Carabidae was significantly greater in soybean plots that included a rye cover crop, while activity density of Gryllidae was significantly reduced in plots with the rye cover crop. Although a rye cover crop may be agronomically beneficial, there may be only limited effects on beneficial arthropods when added within an annual rotation of corn and soybean. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Mechanosensitivity below Ground: Touch-Sensitive Smell-Producing Roots in the Shy Plant Mimosa pudica1[OPEN

    Science.gov (United States)

    Musah, Rabi A.; Lesiak, Ashton D.; Maron, Max J.; Edwards, David; Fowble, Kristen L.; Long, Michael C.

    2016-01-01

    The roots of the shy plant Mimosa pudica emit a cocktail of small organic and inorganic sulfur compounds and reactive intermediates into the environment, including SO2, methanesulfinic acid, pyruvic acid, lactic acid, ethanesulfinic acid, propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, phenothiazine, and thioformaldehyde, an elusive and highly unstable compound that, to our knowledge, has never before been reported to be emitted by a plant. When soil around the roots is dislodged or when seedling roots are touched, an odor is detected. The perceived odor corresponds to the emission of higher amounts of propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, and phenothiazine. The mechanosensitivity response is selective. Whereas touching the roots with soil or human skin resulted in odor detection, agitating the roots with other materials such as glass did not induce a similar response. Light and electron microscopy studies of the roots revealed the presence of microscopic sac-like root protuberances. Elemental analysis of these projections by energy-dispersive x-ray spectroscopy revealed them to contain higher levels of K+ and Cl− compared with the surrounding tissue. Exposing the protuberances to stimuli that caused odor emission resulted in reductions in the levels of K+ and Cl− in the touched area. The mechanistic implications of the variety of sulfur compounds observed vis-à-vis the pathways for their formation are discussed. PMID:26661932

  12. Analysis of Vegetative on Six Different Landfill Cover Profiles in an Arid Environment.

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, Stephen F.; McClellan, Yvonne; Reavis, Bruce A.; Dwyer, Brian P.; Newman, Gretchen; Wolters, Gale

    2005-05-01

    A large-scale field demonstration comparing final landfill cover designs was constructed and monitored at Sandia National Laboratories in Albuquerque, New Mexico. Two conventional designs (a RCRA Subtitle 'D' Soil Cover and a RCRA Subtitle 'C' Compacted Clay Cover) were constructed side-by-side with four alternative cover test plots designed for arid environments. The demonstration was intended to evaluate the various cover designs based on their respective water balance performance, ease and reliability of construction, and cost. A portion of this project involves the characterization of vegetation establishment and growth on the landfill covers. The various prototype landfill covers were expected to have varying flux rates (Dwyer et al 2000). The landfill covers were further expected to influence vegetation establishment and growth, which may impact site erosion potential and long-term site integrity. Objectives of this phase were to quantify the types of plants occupying each site, the percentage of ground covered by these plants, the density (number of plants per unit area) of plants, and the plant biomass production. The results of this vegetation analysis are presented in this report.3 DRAFT07/06/14AcknowledgementsWe would like to thank all technical and support staff from Sandia and the USDA Forest Service's Rocky Mountain Station not included in the authors' list of this document for their valuable contributions to this research. We would also like to acknowledge the Department of Energy's Subsurface Contaminants Focus Area for funding this work.4

  13. Solar radiation concentrators paired with multijunction photoelectric converters in ground-based solar power plants (part I)

    Science.gov (United States)

    Ionova, E. A.; Ulanov, M. V.; Davidyuk, N. Yu.; Sadchikov, N. A.

    2016-12-01

    We have developed a method for determining parameters of radiation concentrator in solar power plants. To estimate the efficiency of concentrators in the form of Fresnel lenses in setups with three-junction photoelectric converters, the concept of the efficiency of the concentrator-photoelectric converter pair has been introduced. We have proposed a method for calculating the refracting profile of concentrators taking into account the dispersion relation for the refractive index and its variations with temperature for the material of the refracting profile of the concentrator (Wacker RT604 silicone compound). The results of calculation make it possible to achieve the maximal efficiency of the concentrator-photoelectric converter pair in the presence of chromatic aberrations in the optical system of solar radiation concentration.

  14. 半地下全覆盖式MBR工艺再生水厂工程设计%Design of Semi-underground and Fully Covered Water Reclamation Plant Using MBR Process

    Institute of Scientific and Technical Information of China (English)

    胡龙

    2012-01-01

    以合肥市滨湖新区塘西河再生水厂为例,介绍了半地下全覆盖式MBR再生水厂的工程设计要点.重点讨论了工艺设计、平面与竖向设计、结构设计、通风采光照明设计、除臭设计、绿化设计,对半地下全覆盖式再生水厂设计中的特殊问题予以说明.%Taking Tangxihe Water Reclamation Plant in Binhu new district, Heifei as example, the engineering design key points of semi-underground and fully covered water reclamation plant using MBR process are introduced. Designs of process, horizontal and vertical arrangements, structure, ventilation and lighting, deodorization, and greening are discussed. Special issues on the design of semi-underground and fully covered water reclamation plant using MBR process are described.

  15. 应用Vc发酵弃渣防治保护地病害%Application of Vc fermentation waste residue on prevention and control of plant diseases in protective ground

    Institute of Scientific and Technical Information of China (English)

    朱可丽; 苏振成; 吕素霞; 张忠泽

    2003-01-01

    The prevention and control of tomato plant diseases were conducted in protective ground using Vc fermentation waste residue treated by enzymolysis and ultrasonic wave. The results showed that the seedlings planted for 3 weeks on the protective ground soil continuously cropped tomato plant for 9 years and fertilized 75, 150 and 300kg·hm-2 grew well. Their biomass were increased by 123%, 164% and 182%, and the disease incidence rates were decreased by 59%, 78% and 85%, respectively. Under application of 300 kg·hm-2 Vc fermentation waste residue, the products of tomato grown for 10 weeks on the soil continuously cropped tomato plant for 9, 6 and 2 years were increased by 60%, 43% and 14%, respectively, and the disease incidence rates were all de-creased by 50% .

  16. Forests and Forest Cover, Forest areas as captured by orthophotography. Contains some attribution of forest type depending on imagery and ground-truthing if available., Published in 2007, 1:2400 (1in=200ft) scale, Howard County Government.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Forests and Forest Cover dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Orthoimagery information as of 2007. It is described...

  17. Land Use and Land Cover, Existing land use derived from orthoimagery. Ground-truthing from discussion with local plan commission members., Published in 2000, 1:12000 (1in=1000ft) scale, Portage County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Land Use and Land Cover dataset, published at 1:12000 (1in=1000ft) scale, was produced all or in part from Orthoimagery information as of 2000. It is described...

  18. Managing cover crops: an economic perspective

    Science.gov (United States)

    Common reasons given by producers as to why they do not adopt cover crops are related to economics: time, labor, and cost required for planting and managing cover crops. While many of the agronomic benefits of cover crops directly relate to economics, there are costs associated with adopting the pra...

  19. Below-ground interspecific competition for water in a rubber agroforestry system may enhance water utilization in plants.

    Science.gov (United States)

    Wu, Junen; Liu, Wenjie; Chen, Chunfeng

    2016-01-19

    Rubber-based (Hevea brasiliensis) agroforestry systems are regarded as the best way to improve the sustainability of rubber monocultures, but few reports have examined water use in such systems. Accordingly, we tested whether interplanting facilitates water utilization of rubber trees using stable isotope (δD, δ(18)O, and δ(13)C) methods and by measuring soil water content (SWC), shoot potential, and leaf C and N concentrations in a Hevea-Flemingia agroforestry system in Xishuangbanna, southwestern China. We detected a big difference in the utilization of different soil layer water between both species in this agroforestry system, as evidenced by the opposite seasonal fluctuations in both δD and δ(18)O in stem water. However, similar predawn shoot potential of rubber trees at both sites demonstrating that the interplanted species did not affect the water requirements of rubber trees greatly. Rubber trees with higher δ(13)C and more stable physiological indexes in this agroforestry system showed higher water use efficiency (WUE) and tolerance ability, and the SWC results suggested this agroforestry is conductive to water conservation. Our results clearly indicated that intercropping legume plants with rubber trees can benefit rubber trees own higher N supply, increase their WUE and better utilize soil water of each soil layer.

  20. Ground Vehicle Robotics Presentation

    Science.gov (United States)

    2012-08-14

    Mr. Jim Parker Associate Director Ground Vehicle Robotics Distribution Statement A. Approved for public release Report Documentation Page...Briefing 3. DATES COVERED 01-07-2012 to 01-08-2012 4. TITLE AND SUBTITLE Ground Vehicle Robotics Presentation 5a. CONTRACT NUMBER 5b. GRANT...ABSTRACT Provide Transition-Ready, Cost-Effective, and Innovative Robotics and Control System Solutions for Manned, Optionally-Manned, and Unmanned

  1. A comparative study of satellite and ground-based phenology.

    Science.gov (United States)

    Studer, S; Stöckli, R; Appenzeller, C; Vidale, P L

    2007-05-01

    Long time series of ground-based plant phenology, as well as more than two decades of satellite-derived phenological metrics, are currently available to assess the impacts of climate variability and trends on terrestrial vegetation. Traditional plant phenology provides very accurate information on individual plant species, but with limited spatial coverage. Satellite phenology allows monitoring of terrestrial vegetation on a global scale and provides an integrative view at the landscape level. Linking the strengths of both methodologies has high potential value for climate impact studies. We compared a multispecies index from ground-observed spring phases with two types (maximum slope and threshold approach) of satellite-derived start-of-season (SOS) metrics. We focus on Switzerland from 1982 to 2001 and show that temporal and spatial variability of the multispecies index correspond well with the satellite-derived metrics. All phenological metrics correlate with temperature anomalies as expected. The slope approach proved to deviate strongly from the temporal development of the ground observations as well as from the threshold-defined SOS satellite measure. The slope spring indicator is considered to indicate a different stage in vegetation development and is therefore less suited as a SOS parameter for comparative studies in relation to ground-observed phenology. Satellite-derived metrics are, however, very susceptible to snow cover, and it is suggested that this snow cover should be better accounted for by the use of newer satellite sensors.

  2. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions. [Lower Rio Grande Valley Test Site: Weslaco, Texas; Falco Reservoir and the Gulf of Mexico

    Science.gov (United States)

    Wiegand, C. L.; Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J. (Principal Investigator)

    1980-01-01

    The author has identified the following significant results. HCMM day/night coverage 12 hours apart cannot be obtained at 26 deg N latitude; nor have any pairs 36 hours apart been obtained. A day-IR scene and a night scene for two different dates were analyzed. A profile across the test site for the same latitude shows that the two profiles are near mirror images of each other over land surfaces and that the temperature of two large water bodies, Falcon Reservoir and the Gulf of Mexico, are nearly identical on two dates. During the time interval between overpasses, the vegetative cover remained static due to winter dormancy. The data suggest that day/night temperature differences measured weeks apart may yield meaningful information about the contrast between daytime maximum and nighttime minimum temperatures for a given site.

  3. The impact of daily covers on sidewall leakage in landfills

    Energy Technology Data Exchange (ETDEWEB)

    Welker, A. L. [Villanova Univ., Dept. of Civil Engineering, PA (United States)

    2000-09-01

    Typically, sanitary landfills are covered by 15 cm of locally available soil on a daily basis. This practice is intended to limit short term negative effects of the waste material on the above-ground environment such as odor, fire, or vermin attraction. Daily placement of compacted soil creates low hydraulic conductivity stratifying layers within the landfill which, in due course, may result in side-slope seepage, decreased stability and decreased efficiency of methane gas venting. The expense of soil acquisitions and the the diminishing availability of landfill space increases the need for alternative materials to replace the daily cover. This paper examines the the threat of sidewall landfill leakage for a hypothetical landfill with traditional soil cover and an alternative daily cover, to demonstrate that the threat of sidewall leakage is real and can be decreased with the use of alternative material as the daily cover such as crushed glass, sludge from waste-water treatment plants, industrial waste, foams and various geosynthetics. At the same time, results of the modelling study showed that with proper drainage sidewall seepage will not occur even with a daily cover that has a hydraulic conductivity two orders of magnitude smaller than the waste, despite positive pressure building up on top of the daily cover. These results imply that the threat of sidewall leakage is minimal, and while alternative daily cover material would help to reduce it even further, their use is most likely to be the result of economic, not technical, considerations. 12 refs., 3 tabs., 4 figs.

  4. Land Cover - Minnesota Land Cover Classification System

    Data.gov (United States)

    Minnesota Department of Natural Resources — Land cover data set based on the Minnesota Land Cover Classification System (MLCCS) coding scheme. This data was produced using a combination of aerial photograph...

  5. Cobertura do solo e estoque de nutrientes de duas leguminosas perenes, considerando espaçamentos e densidades de plantio Soil cover and nutrient accumulation of two perennial legumes as functions of spacing and planting densities

    Directory of Open Access Journals (Sweden)

    A. Perin

    2004-02-01

    arrangement 2 x 2 x 4, with four replications. The treatments consisted of the plant species Galactia striata and Pueraria phaseoloides, planted in two spacings (25 and 50 cm apart and four sowing densities (5, 10, 15 and 20 plants m-1. The most adequate density for a fast soil cover was 10 plants m-1 for Pueraria phaseoloides and Galactia striata, in a 25 cm spacing between planting rows. The highest dry matter production and accumulation of N, P and K in the aerial part of the plant were found in the first cut, in a spacing of 25 cm and row density of 10 plants m-1. The 25 cm spacing with 10 plants m-1 was identified as the most adequate combination for the formation of a full soil cover with Pueraria phaseoloides and Galactia striata.

  6. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  7. Spatial distributions of radionuclides deposited onto ground soil around the Fukushima Dai-ichi Nuclear Power Plant and their temporal change until December 2012.

    Science.gov (United States)

    Mikami, Satoshi; Maeyama, Takeshi; Hoshide, Yoshifumi; Sakamoto, Ryuichi; Sato, Shoji; Okuda, Naotoshi; Demongeot, Stéphanie; Gurriaran, Rodolfo; Uwamino, Yoshitomo; Kato, Hiroaki; Fujiwara, Mamoru; Sato, Tetsuro; Takemiya, Hiroshi; Saito, Kimiaki

    2015-01-01

    Spatial distributions and temporal changes of radioactive fallout released by the Fukushima Dai-ichi Nuclear Power Plant accident have been investigated by two campaigns with three measurement schedules. The inventories (activities per unit area) of the radionuclides deposited onto ground soil were measured using portable gamma-ray spectrometers at nearly 1000 locations (at most) per measurement campaign. Distribution maps of the inventories of (134)Cs, (137)Cs, and (110m)Ag as of March, September, and December 2012 were constructed. No apparent temporal change of the radionuclide inventories was observed from March to December 2012. Weathering effects (e.g., horizontal mobility) were not noticeable during this period. Spatial dependence in the ratios of (134)Cs/(137)Cs and (110m)Ag/(137)Cs were observed in the Tohoku and Kanto regions. The detailed maps of (134)Cs and (137)Cs as of September 2012 and December 2012 were constructed using the relationship between the air dose rate and the inventory.

  8. Ground and excited state proton transfer of the bioactive plant flavonol robinetin in a protein environment: spectroscopic and molecular modeling studies.

    Science.gov (United States)

    Pahari, Biswa Pathik; Chaudhuri, Sudip; Chakraborty, Sandipan; Sengupta, Pradeep K

    2015-02-12

    We performed spectroscopic and molecular modeling studies to explore the interaction of the bioactive plant flavonol robinetin (3,7,3',4',5'-OH flavone), with the carrier protein human serum albumin (HSA). Multiparametric fluorescence sensing, exploiting the intrinsic "two color" fluorescence of robinetin (comprising excited state intramolecular proton transfer (ESIPT) and charge transfer (CT) emissions) reveals that binding to HSA significantly affects the emission and excitation profiles, with strongly blue-shifted (∼29 nm) normal fluorescence and remarkable increase in the ESIPT fluorescence anisotropy (r) and lifetime (τ). Flavonol-induced HSA (tryptophan) fluorescence quenching data yield the dynamic quenching constant (KD) as 5.42 × 10(3) M(-1) and the association constant (Ks) as 5.59 × 10(4) M(-1). Time-resolved fluorescence anisotropy decay studies show dramatic (∼170 times) increase in the rotational correlation time (τ(rot)), reflecting greatly enhanced restrictions in motion of robinetin in the protein matrix. Furthermore, prominent induced circular dichroism (ICD) bands appear, indicating that the chiral environment of HSA strongly perturbs the electronic transitions of the intrinsically achiral robinetin molecule. Molecular docking calculations suggest that robinetin binds in subdomain IIA of HSA, where specific interactions with basic residues promote ground state proton abstraction and stabilize an anionic species, which is consistent with spectroscopic observations.

  9. Site-Specific PSHA for Nuclear Power Plants in France: Variability of the Predicted Ground Motion Quantified with a Logic Tree and Monte Carlo Approach

    Science.gov (United States)

    Clément, C.; Baize, S.; Beauval, C.; Bonilla, L. F.; Scotti, O.

    2003-04-01

    The current French Nuclear Regulation for the evaluation of seismic hazard is deterministic. Nevertheless, in order to provide results to an ongoing Probabilistic Safety Assessment study that is being carried out at IRSN, we are developing a site-specific Probabilistic Seismic Hazard Assessment (PSHA) for nuclear power plants in France. The methodology proposed in this study combines a logic tree structure with a Monte Carlo exploration. This allows an exhaustive quantification of the impact on the hazard level due to both epistemic and random uncertainties. The region of interest for this study is the South East of France where the knowledge of the seismic potential of the known structures is sparse. We explore uncertainties inherent in seismicity catalogues, source models, attenuation laws and definitions of the seismic source geometries. In particular we focus on fault sources for which we propose numerous scenarios that consider rupture on single and multiple segments. The purpose of the methodology developed in the framework of this study is to 1) calculate seismic hazard with probabilities as low as 10-7 2) quantify the variability of the hazard level 3) identify the most probable scenarios and compute the associated ground motions at the site of interest.

  10. Carbonaceous and nitrogenous disinfection by-product formation in the surface and ground water treatment plants using Yellow River as water source

    Institute of Scientific and Technical Information of China (English)

    Yukun Hou; Wenhai Chu; Meng Ma

    2012-01-01

    This work investigated the formation of carbonaceous and nitrogenous disinfection by-preducts (C-DBPs,N-DBPs) upon chlorination of water samples collected from a surface water and a ground water treatment plant (SWTP and GWTP) where the conventional treatment processes,i.e.,coagulation,sedimentation,and filtration were employed.Twenty DBPs,including four trihalomethanes,nine haloacetic acids,seven N-DBPs (dichloroacetamide,trichloroacetamide,dichloroacetonitrile,trich loroacetonitrile,bromochloroacetonitrile,dibromoacetonitrile and trichloronitromethane),and eight volatile chlorinated compounds (dichlomethane (DCM),1,2-dichloroethane,tetrachloroethylene,chlorobenzene,1,2-dichlorobenzene,1,4-dichlorobenzene,1,2,3-trichlorobenzene and 1,2,4-trichlorobenzene) were detected in the two WTPs.The concentrations of these contaminants were all below their corresponding maximum contamination levels (MCLs) regulated by the Standards for Drinking Water Quality of China (GB5749-2006) except for DCM (17.1 μg/L detected vs.20 μg/L MCL).The SWTP had much higher concentrations of DBPs detected in the treated water as well as the DBP formation potentials tested in the filtered water than the GWTP,probably because more precursors (e.g.,dissolved organic carbon,dissolved organic nitrogen) were present in the water source of the SWTP.

  11. The Porcupine herd of barren ground caribou

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the porcupine herd of the barren ground caribou. The report covers the short history, the winter range, migration route, phenology, movements and...

  12. Biogeochemistry of REE elements and tetrad effect in the soil-plant system: a study on volcanic rock covers in southernmost Brazil

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Lima e Cunha

    2012-12-01

    Full Text Available This paper deals with the distribution of REE in rock, soil and plant in an area of monzonitic rocks from southernmost Brazil. The REE patterns in Schinus lensticifolius show a negative-Ce anomaly and a prominent tetrad effect, characterized as W-type that are not present in rock and soil samples. The REE patterns in the soils and rocks sampled are very similar and there is no fractionation of REE during the processes of soil formation. The W-type patterns are interpreted as indicating that REE were absorved by S. lentiscifolius as simple ions rather than as complex ions, or, alternatively, that the transport of REE in the plant metabolic processes was as free ions. The recognition of tetrads, either, M- or W-type patterns, is an additional tool for understanding the biogeochemistry of REE and can contribute to the study of monitoring processes of contaminated environment or to mineral prospecting.Este trabalho trata da distribuição dos ETR na rocha, solo e planta em área de ocorrência de rochas monzoníticas do extremo sul do Brasil. O padrão dos ETR em Schinus lentiscifolius apresenta anomalia negativa de Ce e significativo efeito tétrade, do tipo W, ausente no padrão da rocha e do solo. A configuração das curvas da rocha e do solo é similar e sem fracionamento das ETR durante a pedogênese. O padrão em W é interpretado como decorrente da absorção dos ETR pela planta na forma de íons livres e não complexados, ou, alternativamente, que o transporte das ETR nos processos metabólicos foi na forma de íons livres. O reconhecimento de tétrades, seja do tipo W ou M, é uma ferramenta adicional na compreensão da biogeoquímica dos ETR e pode contribuir para o estudo de processos de monitoramento de ambientes contaminados ou para pesquisas em prospecção mineral.

  13. Vegetation survey of Four Mile Creek wetlands. [Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C.

    1990-11-01

    A survey of forested wetlands along upper Four Mile Creek was conducted. The region from Road 3 to the creek headwaters was sampled to evaluate the composition of woody and herbaceons plant communities. All sites were found to fall into either the Nyssa sylvatica (Black Gum) -- Persea borbonia (Red Bay) or Nyssa sylvatica -- Acer rubrum (Red Maple) types. These community types are generally species-rich and diverse. Previous studies (Greenwood et al., 1990; Mackey, 1988) demonstrated contaminant stress in areas downslope from the F- and H-Area seepage basins. In the present study there were some indications of contaminant stress. In the wetland near H-Area, shrub basal area, ground cover stratum species richness, and diversity were low. In the area surrounding the F-Area tree kill zone, ground cover stratum cover and shrub basal area were low and ground cover stratum species richness was low. The moderately stressed site at F-Area also showed reduced overstory richness and diversity and reduced ground cover stratum richness. These results could, however, be due to the very high basal area of overstory trees in both stressed F-Area sites that would reduce light availability to understory plants. No threatened or endangered plant species were found in the areas sampled. 40 refs., 4 figs., 8 tabs.

  14. Sulphur and nitrogen supply - soil acidification and the absorption of nutrients in plants; Svovel og nitrogentilfoersel - jordforsuring og plantenes naeringstilgang

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamsen, G.

    1996-01-01

    Ecologically, soil is of the greatest interest as a growth medium for plants, and which affects the quality of ground water and surface water. In this connection, the paper looks upon how the increased deposition of sulphur, nitrogen and hydrogen ions affect the quality of soil as a growth medium for plants. Topics cover: Interaction between soil and plants, effects of acid rain in soil, and the effects of acid rain on plants. 11 refs., 1 tab.

  15. Understory plant biomass dynamics of prescribed burned Pinus palustris stands

    Science.gov (United States)

    C.A. Gonzalez-Benecke; L.J. Samuelson; T.A. Stokes; W.P. Cropper Jr; T.A. Martin; K.H. Johnsen

    2015-01-01

    Longleaf pine (Pinus palustris Mill.) forests are characterized by unusually high understory plant species diversity, but models describing understory ground cover biomass, and hence fuel load dynamics, are scarce for this fire-dependent ecosystem. Only coarse scale estimates, being restricted on accuracy and geographical extrapolation,...

  16. Native and exotic plant cover vary inversely along a climate gradient 11 years following stand-replacing wildfire in a dry coniferous forest, Oregon, USA.

    Science.gov (United States)

    Dodson, Erich K; Root, Heather T

    2015-02-01

    Community re-assembly following future disturbances will often occur under warmer and more moisture-limited conditions than when current communities assembled. Because the establishment stage is regularly the most sensitive to climate and competition, the trajectory of recovery from disturbance in a changing environment is uncertain, but has important consequences for future ecosystem functioning. To better understand how ongoing warming and rising moisture limitation may affect recovery, we studied native and exotic plant composition 11 years following complete stand-replacing wildfire in a dry coniferous forest spanning a large gradient in climatic moisture deficit (CMD) from warm and dry low elevation sites to relatively cool and moist higher elevations sites. We then projected future precipitation, temperature and CMD at our study locations for four scenarios selected to encompass a broad range of possible future conditions for the region. Native perennials dominated relatively cool and moist sites 11 years after wildfire, but were very sparse at the warmest and driest (high CMD) sites, particularly when combined with high topographic sun exposure. In contrast, exotic species (primarily annual grasses) were dominant or co-dominant at the warmest and driest sites, especially with high topographic sun exposure. All future scenarios projected increasing temperature and CMD in coming decades (e.g., from 4.5% to 29.5% higher CMD by the 2080's compared to the 1971-2000 average), even in scenarios where growing season (May-September) precipitation increased. These results suggest increasing temperatures and moisture limitation could facilitate longer term (over a decade) transitions toward exotic-dominated communities after severe wildfire when a suitable exotic seed source is present. © 2014 John Wiley & Sons Ltd.

  17. Does seeding after severe forest fires in western USA mitigate negative impacts on soils and plant communities?

    Science.gov (United States)

    D. Peppin; P. Fule; J. Beyers; C. Sieg; M. Hunter

    2011-01-01

    Broadcast seeding is one of the most widely used post-wildfire emergency response treatments intended to reduce soil erosion, increase vegetative ground cover, and minimize establishment and spread of non-native plant species. However, seeding treatments can also have negative effects such as competition with recovering native plant communities and inadvertent...

  18. Localizing Ground-Penetrating Radar

    Science.gov (United States)

    2014-11-01

    ing Ground-Penetrating Radar (LGPR) uses very high frequency (VHF) radar reflections of underground features to generate base- line maps and then...Innovative ground- penetrating radar that maps underground geological features provides autonomous vehicles with real-time localization. Localizing...NOV 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Localizing Ground-Penetrating Radar 5a. CONTRACT NUMBER

  19. ASSESSMENT OF VEGETATION COVER ON SODA WASTE DISPOSAL SITE AT JANIKOWO, FOLLOWING 13-YEAR-LONG RECLAMATION

    Directory of Open Access Journals (Sweden)

    Kazimierz Henryk Dyguś

    2014-10-01

    Full Text Available The results are presented of vegetation survey on the alkaline and saline soda waste disposal site at Janikowo Soda Plant near Toruń (central Poland. The site was subject to reclamation using diverse techniques including sewage sludge and ash, starting from the year 2000 onwards. The survey was made to evaluate the status of plant succession as well as stability and diversity of vegetation cover. The vegetation was inventoried using the cover-frequency method, on a 10 x 10 m quadrat samples randomly distributed over the reclaimed area. Communities were classified using the Central-European approach by Braun-Blanquet (1964. In 2013, the vegetation was well established and provided a dense cover of the substrate. 108 plant species were found compared to some 5–8 plants which arrived spontaneously until the year 2000. Species richness increased 15 fold since the year when reclamation started. Species of graminoid and Asteraceae families prevailed in most patches of local vegetation. The vegetation cover on sites treated with a mixt of power plant ash and sewage sludge was less stable and less diverse than that on sites where sewage sludge only was applied. Annuals and biennials dominated in the vegetation on ash grounds while more competitive perennials prevailed on sewage sludge substrates. On the latter substrates there develop plant communities classified as an association of smooth meadow grass and common yarrow Poa pratensis-Achillea millefolium, whose species combination closely resembles that of seminatural fresh meadows. On the ash grounds, a variety of associations of ruderal plants were found with dominating Loesel mustard and common mugwort Sisymbrium loeselii-Artemisia vulgaris. Phytoindicatory methods using Ellenberg values have shown that waste substrates contained increased salt concentrations, however, there was no indication of increased heavy metal contents, as no plants tolerating excessive amounts of heavy metals were

  20. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  1. What Medicare Covers

    Science.gov (United States)

    ... What Part A covers Medicare Part A hospital insurance covers inpatient hospital care, skilled nursing facility, hospice, lab tests, surgery, ... Medicare Covers Drug Coverage (Part D) Supplements & Other Insurance Claims & ... doctors, providers, hospitals & plans Where can I get covered medical items? ...

  2. Ground failure in direct current systems of the Itaipu Hydroelectric Power Plant, Parana, Brazil. Impact in the operation; Falla a tierra en sistemas de corriente continua en la Central Hidroelectrica Itaipu, PR, Brasil. Impacto en la operacion

    Energy Technology Data Exchange (ETDEWEB)

    Soto Santacruz, Heriberto [Itaipu Binacional, Foz do Iguacu, PR (Brazil)]. E-mail: soto@itaipu.gov.py

    1998-07-01

    The objective of this work is to share with other companies the operation experience obtained by researching the direct current systems ground failure, in the Itaipu Hydroelectric Power Plant. During the research process electrical and/or electronic components can be damaged, and also human failures can occurred during the circuit connection and disconnection manoeuvres, necessary for the identification of the components causing the failures.

  3. Managing cover crops on strawberry furrow bottoms

    Science.gov (United States)

    Bare furrows in strawberry fields with plastic mulch covered beds can lead to lots of soil erosion and runoff during winter rainy periods. This article describes how growers can plant and manage cover crops in these furrows to minimize runoff and soil erosion. This is based on on-going research at...

  4. Root characteristics of cover crops and their erosion-reducing potential during concentrated runoff

    Science.gov (United States)

    de Baets, S.; Poesen, J.

    2009-04-01

    In the loam region in central Belgium, a lot of research has been conducted on the effects of cover crops for preventing splash and interrill erosion and on their nutrient pumping effectiveness. As this is a very effective erosion and environment conservation technique, planting cover crops during the winter season is widely applied in the loess belt. Most of these cover crops freeze at the beginning of the winter period. Consequently, the above-ground biomass becomes less effective in protecting the soil from water erosion. Apart from the effects of the above-ground biomass in protecting the soil against raindrop impacts and reducing flow velocities by the retarding effects of their stems, plant roots also play an important role in improving soil strength. Previous research showed that roots contribute to a large extent to the resistance of topsoils against concentrated flow erosion. Unfortunately, information on root properties of common cover crops (e.g. Sinapis alba, Phacelia tanacetifoli, Lolium perenne, Avena sativa, Secale cereale, Raphanus sativus subsp. oleiferus) is very scarce. Therefore, root density distribution with depth and their erosion-reducing effects during concentrated flow erosion were assessed by conducting root auger measurements and concentrated flow experiments at the end of the growth period (December). The preliminary results indicate that the studied cover crops are not equally effective in preventing soil loss by concentrated flow erosion at the end of the growing season. Cover crops with thick roots, such as Sinapis alba and Raphanus sativus subsp. oleiferus are less effective than cover crops with fine-branched roots such as Phacelia tanacetifoli, Lolium perenne (Ryegrass), Avena sativa (Oats) and Secale cereale (Rye) in preventing soil losses by concentrated flow erosion. These results enable soil managers to select the most suitable crops and maximize soil protection.

  5. Symbiotic N2-fixation by the cover crop Pueraria phaseoloides as influenced by litter mineralization

    DEFF Research Database (Denmark)

    Vesterager, J.M.; Østerby, S.; Jensen, E.S.

    1995-01-01

    The perennial legume Pueraria phaseoloides is widely used as a cover crop in rubber and oil palm plantations. However, very little knowledge exists on the effect of litter mineralization from P. phaseoloides on its symbiotic N-2- fixation. The contribution from symbiotic N-2-fixation (Ndfa......) and litter N (Ndfl) to total plant N in P phaseoloides was determined in a pot experiment using a N-15 cross-labeling technique. For determination of N-2-fixation the non-fixing plant Axonopus compressus was used as a reference. The experiment was carried out in a growth chamber during 9 weeks with a sandy...... soil and 4 rates of ground litter (C/N=16, 2.8% N). P. phaseoloides plants supplied with the highest amount of litter produced 26% more dry matter and fixed 23% more N than plants grown in soil with no litter application, but the percentage of Ndfa decreased slightly, but significantly, from 87 to 84...

  6. Pooling of ground-mounted photovoltaic plants under Art. 19 Section 1a of the 2012 German Renewable Energy Law; Die Zusammenfassung von Photovoltaik-Freiflaechenanlagen nach paragraph 19 Abs. 1a EEG 2012

    Energy Technology Data Exchange (ETDEWEB)

    Assion, Anja; Goetze, Roman [GOeTZE Rechtsanwaelte, Leipzig (Germany)

    2013-11-01

    Under the 2012 PV amendment to the German Renewable Energy Law (EEG) compensation payments for electricity generated from solar radiation energy harvested on ground-mounted photovoltaic plants are now restricted to plants up to an installed capacity of 10 MW. For photovoltaic plants of greater capacity the right to compensation no longer applies to that in excess of 10 MW. The intent of the legislature in limiting the right to compensation according to a plant's capacity is to moderate the rate of newly installed capacity, promote local production close to the point of use, and to preserve landscapes and guard against land consumption. The new regulation is a novelty in as far it applies to ground-mounted plants. It combines a cap on the electricity generating capacity for which operators are entitled to compensation with a regulation on the pooling of plants (fictitious single plant) for purposes of compensation calculation. This regulation has given rise to many controversial issues in practice. This is due in part to the absence of case law and the failure, to date, to draw up special conventions, for example on the part of the EEG Clearing Office. At present there is virtually no aspect of the situation over which the grid operators are in agreement. The purpose of this article is to present the current state of the discussion, assess the positions brought forward so far and use this as a basis for developing a new view on the interpretation of Art. 19 Section 1a of the EEG.

  7. Cover crop biomass harvest for bioenergy: implications for crop productivity

    Science.gov (United States)

    Winter cover crops, such as rye (Secale cereale), are usually used in conservation agriculture systems in the Southeast. Typically, the cover crop is terminated two to three weeks before planting the summer crop, with the cover biomass left on the soil surface as a mulch. However, these cover crops ...

  8. Sky cover from MFRSR observations

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-07-01

    Full Text Available The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their modeled clear-sky counterparts are the main components of a new method for estimating the fractional sky cover of different cloud types, including cumuli. The performance of this method is illustrated using 1-min resolution data from a ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR. The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM Climate Research Facility (ACRF Southern Great Plains (SGP site during the summer of 2007 and represent 13 days with cumuli. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

  9. Impacts of cattle grazing on spatio-temporal variability of soil moisture and above-ground live plant biomass in mixed grasslands

    Science.gov (United States)

    Virk, Ravinder

    Areas with relatively high spatial heterogeneity generally have more biodiversity than spatially homogeneous areas due to increased potential habitat. Management practices such as controlled grazing also affect the biodiversity in grasslands, but the nature of this impact is not well understood. Therefore this thesis studies the impacts of variation in grazing on soil moisture and biomass heterogeneity. These are not only important in terms of management of protected grasslands, but also for designing an effective grazing system from a livestock management point of view. This research is a part of the cattle grazing experiment underway in Grasslands National Park (GNP) of Canada since 2006, as part of the adaptive management process for restoring ecological integrity of the northern mixed-grass prairie region. An experimental approach using field measurements and remote sensing (Landsat) was combined with modelling (CENTURY) to examine and predict the impacts of grazing intensity on the spatial heterogeneity and patterns of above-ground live plant biomass (ALB) in experimental pastures in a mixed grassland ecosystem. The field-based research quantified the temporal patterns and spatial variability in both soil moisture (SM) and ALB, and the influence of local intra-seasonal weather variability and slope location on the spatio-temporal variability of SM and ALB at field plot scales. Significant impacts of intra-seasonal weather variability, slope position and grazing pressure on SM and ALB across a range of scales (plot and local (within pasture)) were found. Grazing intensity significantly affected the ALB even after controlling for the effect of slope position. Satellite-based analysis extended the scale of interest to full pastures and the surrounding region to assess the effects of grazing intensity on the spatio-temporal pattern of ALB in mixed grasslands. Overall, low to moderate grazing intensity showed increase in ALB heterogeneity whereas no change in ALB

  10. Grounded cognition.

    Science.gov (United States)

    Barsalou, Lawrence W

    2008-01-01

    Grounded cognition rejects traditional views that cognition is computation on amodal symbols in a modular system, independent of the brain's modal systems for perception, action, and introspection. Instead, grounded cognition proposes that modal simulations, bodily states, and situated action underlie cognition. Accumulating behavioral and neural evidence supporting this view is reviewed from research on perception, memory, knowledge, language, thought, social cognition, and development. Theories of grounded cognition are also reviewed, as are origins of the area and common misperceptions of it. Theoretical, empirical, and methodological issues are raised whose future treatment is likely to affect the growth and impact of grounded cognition.

  11. Cover crops and their effects on the biomass yield of Serjania marginata plants Culturas de cobertura e seus efeitos na produção de biomassa de plantas de Serjania marginata

    Directory of Open Access Journals (Sweden)

    Luciane Almeri Tabaldi

    2012-04-01

    Full Text Available The use of cover crops can reduce or even eliminate the use of nitrogenous fertilizers, contributing to a more sustainable agriculture and ensuring the conservation of natural resources. Thus, the aim of this research was to evaluate the use of cover crops to improve the biomass yield of Serjania marginata plants. The experiment was carried out at the Federal University of Grande Dourados, in Dourados-MS, from December 2009 to February 2011. A split plot design was used in a randomized block design with four replications, being evaluated in plots three species of tropical legumes (Stizolobium aterrimum, Crotalaria spectabilis and Canavalia ensiformes, and one control plot (without cover crops, and in subplots the addition or not of nitrogen (N (at 150 days after transplant (DAT. Plants of S. marginata in each subplot were harvested at 240 and 350 DAT. S. aterrimum and C. ensiformes showed higher accumulation of fresh (average of 37.61t ha-1 and dry (average of 6.39t ha-1 biomass of shoot in flowering, compared with the C. spectabilis (21.92 and 4.63t ha-1, respectively. The contribution of cover crops as a likely source of N only was observed for S. aterrimum and C. ensiforme, which promoted an increase in chlorophyll index, leaf area, fresh and dry weight of leaves and stem of S. marginata plants, in absence of N. In leaves of S. marginata, only C. ensiformes contributed significantly to an increase in N levels, while an increase in K levels was observed with all cover crop treatments, when compared to control. Pre-cultivation with S. aterrimum and C. ensiformes provided an increase in P levels in leaves of S. marginata. Therefore, S. aterrimum and C. ensiformes were the most promising cover crops for growing of S. marginata, improving the biomass yield and probably the N economy.O uso de culturas de cobertura pode reduzir ou até mesmo eliminar o uso de fertilizantes nitrogenados, contribuindo para uma agricultura mais sustentável e

  12. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    1999-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...

  13. Branched polynomial covering maps

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    2002-01-01

    A Weierstrass polynomial with multiple roots in certain points leads to a branched covering map. With this as the guiding example, we formally define and study the notion of a branched polynomial covering map. We shall prove that many finite covering maps are polynomial outside a discrete branch...

  14. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... such as lowpermeability clay soils and geomembranes are required. The avoidance of water input to organic waste may impede the microbial stabilization processes including gas generation. Therefore watertight top covers may be in conflict with the purposes of reactor landfills (see Chapter 10.6). At some sites covers...... sometimes are made to include components for recirculation of landfill leachate (see Section 10.9.2 for more details). The top cover is an important factor in the water management of landfills. Details about water infiltration through top covers and its influence on the hydrology of the landfill is covered...

  15. 冬季覆盖作物对双季稻光合特性的影响%Effects of Different Winter Cover Plants on Photosynthetic Characteristics of Double-cropping Rice

    Institute of Scientific and Technical Information of China (English)

    唐海明; 肖小平; 汤文光; 杨光立; 汤海涛

    2011-01-01

    The effects of four different winter cover plants, ryegrass, Chinese milk vetch, rape and potato, on photosynthetic characteristics of double-cropping rice in southern China were studied in experimental field from 2008 to 2009. The results showed that compared with the CK (fallow in winter), the treatments of ryegrass, Chinese milk vetch and potato increased obviously the LAI, chlorophyll content and net photosynthetic rate in leaves of the double-cropping rice during the whole growth stages, raised the grain yield and increased total bio-energy and the solar energy utilization ratio of stem, leaf and grain of double-cropping rice.%以冬闲为对照,研究了黑麦草、紫云英、油菜和马铃薯4种冬季覆盖作物对双季稻的光合特性的影响.结果表明:黑麦草、紫云英和马铃薯3种冬季覆盖作物处理能明显提高双季稻各个生长发育时期叶片的叶面积指数、叶绿素含量和净光合速率,增加稻谷产量,提高生物能及植株茎叶光能利用率、籽粒光能利用率和总光能利用率.

  16. Analysis of the strong motion records obtained from the 2007 Niigataken Chuetsuoki earthquake and determination of the design basis ground motions at the Kashiwazaki Kariwa Nuclear Power Plant. Part 1. Outline of the strong motion records and estimation of factors in large amplification

    Energy Technology Data Exchange (ETDEWEB)

    Tokumitsu, Ryoichi; Kikuchi, Masatomo; Nishimura, Isao (Nuclear Asset Management Dept., Tokyo Electric Power Company, Tokyo (Japan)), e-mail: tokumitsu.r@tepco.co.jp; Shiba, Yoshiaki (Earthquake Engineering Sector, Central Research Inst. of Electric Power Industry, Chiba (Japan)), e-mail: cbar@criepi.denken.or.jp; Tanaka, Shinya (Architectural Dept., Tokyo Electric Power Services CO., LTD.,Tokyo (Japan)), e-mail: s.tanaka@tepsco.co.jp

    2009-07-01

    In order to investigate the primary factor of the large ground motion observed at the Kashiwazaki Kariwa Nuclear Power Plant in the Niigataken Chuetsu-Oki Earthquake, the source, propagation and site effect of the Niigataken Chuetsu-Oki Earthquake, with the analysis and ground motion simulation analysis of observation record was examined

  17. Efficiency of conventional anode beds versus vertical deep ground bed for cathodic protection of pipes in petrochemical plants - a practical experience; Eficiencia de leitos convencionais de anodos versus leitos em poco vertical profundo para protecao catodica de tubulacoes em plantas petroquimicas. Uma experiencia pratica

    Energy Technology Data Exchange (ETDEWEB)

    Baria, Alexandre; Silva, Luciano Pereira da; Mueller Filho, Francisco [Katodica Projetos Eletronicos e Servicos Ltda., XX (Brazil); Miocque, Andre [De Nora do Brasil Ltda., XX (Brazil). Dept. de Protecao Catodica

    1998-07-01

    Efficiency obtained with vertical deep ground bed cathodic protection systems compared to traditional shallow vertical ground bed systems for Petrochemical and Industrial Plants pipelines corrosion protection is discussed. The characteristics and differences of design and installation for both kind of cathodic protection systems is focalized. (author)

  18. The Comprehensive Research on the Industrial Plant Construction Technology of Large Area Concrete Ground Floor%工业厂房大面积混凝土地坪施工技术综合研究

    Institute of Scientific and Technical Information of China (English)

    李明

    2014-01-01

    With the continuous development of modern ind-ustry and the continuous optimization of production techno-logy, d large area concrete ground floors are widely used in industrial workshop floor of construction engineering. This ar-ticle combines with engineering example, carries on the comp-rehensive study to the industrial plant construction technology of large area concrete ground floors to provide reference for readers.%随着现代化工业的不断发展和生产工艺的不断优化,大面积混凝土地坪越来越广泛地被应用于工业厂房地坪施工工程中。本文结合工程实例,对工业厂房大面积混凝土地坪施工技术进行了综合研究,以供读者参考。

  19. Ethylenediurea (EDU): a research tool for assessment and verification of the effects of ground level ozone on plants under natural conditions.

    Science.gov (United States)

    Manning, William J; Paoletti, Elena; Sandermann, Heinrich; Ernst, Dieter

    2011-12-01

    Ethylenediurea (EDU) has been widely used to prevent ozone (O(3)) injury and crop losses in crop plants and growth reductions in forest trees. Successful use requires establishing a dose/response curve for EDU and the proposed plant in the absence of O(3) and in the presence of O(3) before initiating multiple applications to prevent O(3) injury. EDU can be used to verify foliar O(3) symptoms in the field, and to screen plants for sensitivity to O(3) under ambient conditions. Despite considerable research, the mode of action of EDU remains elusive. Additional research on the mode of action of EDU in suppressing O(3) injury in plants may also be helpful in understanding the mode of action of O(3) in causing injury in plants.

  20. Cover crops to improve soil health and pollinator habitat in nut orchards

    Science.gov (United States)

    Jerry. Van Sambeek

    2017-01-01

    Recently several national programs have been initiated calling for improving soil health and creating pollinator habitat using cover crops. Opportunities exist for nut growers to do both with the use of cover crops in our nut orchards. Because we can include perennial ground covers as cover crops, we have even more choices than landowners managing cover crops during...

  1. Ground Wars

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis

    Political campaigns today are won or lost in the so-called ground war--the strategic deployment of teams of staffers, volunteers, and paid part-timers who work the phones and canvass block by block, house by house, voter by voter. Ground Wars provides an in-depth ethnographic portrait of two...... infrastructures that utilize large databases with detailed individual-level information for targeting voters, and armies of dedicated volunteers and paid part-timers. Nielsen challenges the notion that political communication in America must be tightly scripted, controlled, and conducted by a select coterie...... of professionals. Yet he also quashes the romantic idea that canvassing is a purer form of grassroots politics. In today's political ground wars, Nielsen demonstrates, even the most ordinary-seeming volunteer knocking at your door is backed up by high-tech targeting technologies and party expertise. Ground Wars...

  2. Use of various remote sensing land cover products for PFT mapping over Siberia

    Directory of Open Access Journals (Sweden)

    C. Ottlé

    2013-06-01

    Full Text Available High-latitude ecosystems play an important role in the global carbon cycle and in regulating the climate system and are presently undergoing rapid environmental change. Accurate land cover datasets are required to both document these changes as well as to provide land-surface information for benchmarking and initializing earth system models. Earth system models also require specific land cover classification systems based on plant functional types, rather than species or ecosystems, and so post-processing of existing land cover data is often required. This study compares over Siberia, multiple land cover datasets against one another and with auxiliary data to identify key uncertainties that contribute to variability in Plant Functional Type (PFT classifications that would introduce errors in earth system modeling. Land cover classification systems from GLC 2000, GlobCover 2005 and 2009, and MODIS collections 5 and 5.1 are first aggregated to a common legend, and then compared to high-resolution land cover classification systems, continuous vegetation fields (MODIS-VCF and satellite-derived tree heights (to discriminate against sparse, shrub, and forest vegetation. The GlobCover dataset, with a lower threshold for tree cover and taller tree heights and a better spatial resolution, tends to have better distributions of tree cover compared to high-resolution data. It has therefore been chosen to build new PFTs maps for the ORCHIDEE land surface model at 1 km scale. Compared to the original PFT dataset, the new PFT maps based on GlobCover 2005 and an updated cross-walking approach mainly differ in the characterization of forests and degree of tree cover. The partition of grasslands and bare soils now appears more realistic compared with ground-truth data. This new vegetation map provides a framework for further development of new PFTs in the ORCHIDEE model like shrubs, lichens and mosses, to better represent the water and carbon cycles in northern

  3. Use of various remote sensing land cover products for PFT mapping over Siberia

    Science.gov (United States)

    Ottlé, C.; Lescure, J.; Maignan, F.; Poulter, B.; Wang, T.; Delbart, N.

    2013-06-01

    High-latitude ecosystems play an important role in the global carbon cycle and in regulating the climate system and are presently undergoing rapid environmental change. Accurate land cover datasets are required to both document these changes as well as to provide land-surface information for benchmarking and initializing earth system models. Earth system models also require specific land cover classification systems based on plant functional types, rather than species or ecosystems, and so post-processing of existing land cover data is often required. This study compares over Siberia, multiple land cover datasets against one another and with auxiliary data to identify key uncertainties that contribute to variability in Plant Functional Type (PFT) classifications that would introduce errors in earth system modeling. Land cover classification systems from GLC 2000, GlobCover 2005 and 2009, and MODIS collections 5 and 5.1 are first aggregated to a common legend, and then compared to high-resolution land cover classification systems, continuous vegetation fields (MODIS-VCF) and satellite-derived tree heights (to discriminate against sparse, shrub, and forest vegetation). The GlobCover dataset, with a lower threshold for tree cover and taller tree heights and a better spatial resolution, tends to have better distributions of tree cover compared to high-resolution data. It has therefore been chosen to build new PFTs maps for the ORCHIDEE land surface model at 1 km scale. Compared to the original PFT dataset, the new PFT maps based on GlobCover 2005 and an updated cross-walking approach mainly differ in the characterization of forests and degree of tree cover. The partition of grasslands and bare soils now appears more realistic compared with ground-truth data. This new vegetation map provides a framework for further development of new PFTs in the ORCHIDEE model like shrubs, lichens and mosses, to better represent the water and carbon cycles in northern latitudes. Updated

  4. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    is landscaped in order to fit into the surrounding area/environment or meet specific plans for the final use of the landfill. To fulfill the above listed requirements landfill covers are often multicomponent systems which are placed directly on top of the waste. The top cover may be placed immediately after...... the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... however, top covers may be the only environmental protection measure. In some landfill regulations (for instance the Subtitle D landfills receiving municipal solid waste in the USA) it is required to minimize infiltration into the waste layers. Therefore top covers containing liner components...

  5. Percent Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forests provide economic and ecological value. High percentages of forest cover (FORPCT) generally indicate healthier ecosystems and cleaner surface water. More...

  6. Saturated Domino Coverings

    CERN Document Server

    Buchanan, Andrew; Ryba, Alex

    2011-01-01

    A domino covering of a board is saturated if no domino is redundant. We introduce the concept of a fragment tiling and show that a minimal fragment tiling always corresponds to a maximal saturated domino covering. The size of a minimal fragment tiling is the domination number of the board. We define a class of regular boards and show that for these boards the domination number gives the size of a minimal X-pentomino covering. Natural sequences that count maximal saturated domino coverings of square and rectangular boards are obtained. These include the new sequences A193764, A193765, A193766, A193767, and A193768 of OEIS.

  7. Percent Forest Cover (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Forests provide economic and ecological value. High percentages of forest cover (FORPCTFuture) generally indicate healthier ecosystems and cleaner surface water....

  8. Plant volatiles.

    Science.gov (United States)

    Baldwin, Ian T

    2010-05-11

    Plant volatiles are the metabolites that plants release into the air. The quantities released are not trivial. Almost one-fifth of the atmospheric CO2 fixed by land plants is released back into the air each day as volatiles. Plants are champion synthetic chemists; they take advantage of their anabolic prowess to produce volatiles, which they use to protect themselves against biotic and abiotic stresses and to provide information - and potentially disinformation - to mutualists and competitors alike. As transferors of information, volatiles have provided plants with solutions to the challenges associated with being rooted in the ground and immobile.

  9. Antimicrobial activity of plant compounds against Salmonella Typhimurium DT104 in ground pork and the influence of heat and storage on the activity

    Science.gov (United States)

    The objectives of this study were to investigate the influence of heat (70oC for 5 min) and cold-storage (4oC up to 7 days) on the effectiveness of oregano and cinnamon essential oils and powdered olive and apple extracts against Salmonella Typhimurium DT104 in ground pork and to evaluate the activi...

  10. 塔式太阳能电站聚光镜场的土地利用率研究%Study on ground coverage of heliostats field in central receiver solar power plant

    Institute of Scientific and Technical Information of China (English)

    丁婷婷; 祝雪妹

    2012-01-01

    Most conventional heliostats field consist of rectangular heliostats, which have regular arrangement in central receiver solar power plant. The maximum ground coverage possible of such heliostats field without colliding neighboring reflectors is 58%. In this paper, a regular and radial arrangement of heliostats field is presented, a ground coverage model of different shape reflectors is carried out, and calculates different ground coverage in different situations. The simulation results show that a maximum ground coverage will obtain when width -height ratio of rectangular reflectors and hexagonal reflectors meet necessary condition. With die shape of hexagonal reflectors ground coverage is up to 100%.%塔式太阳能热发电站的聚光镜场大多是由按一定规律排列的矩形定日镜组成,在相邻定日镜间无机械碰撞的情况下,聚光镜场的最大土地利用率仅为58%.文章提出了选用规则交错排列的聚光镜场布置方案,建立不同形状定日镜的土地利用模型,并计算出不同情况下的最大土地利用率.通过仿真得出,矩形定日镜和六边形定日镜在一定长宽比时可获得最大土地利用率,其中六边形定日镜的土地利用率最高,约为100%.

  11. Ethylenediurea (EDU): A research tool for assessment and verification of the effects of ground level ozone on plants under natural conditions

    Energy Technology Data Exchange (ETDEWEB)

    Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9320 (United States); Paoletti, Elena, E-mail: e.paoletti@ipp.cnr.it [IPP CNR, Via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Sandermann, Heinrich [ecotox.freiburg, Schubertstr. 1, D-79104 Freiburg (Germany); Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Institute of Biochemical Plant Pathology, D-85764 Neuherberg (Germany); Ernst, Dieter [ecotox.freiburg, Schubertstr. 1, D-79104 Freiburg (Germany)

    2011-12-15

    Ethylenediurea (EDU) has been widely used to prevent ozone (O{sub 3}) injury and crop losses in crop plants and growth reductions in forest trees. Successful use requires establishing a dose/response curve for EDU and the proposed plant in the absence of O{sub 3} and in the presence of O{sub 3} before initiating multiple applications to prevent O{sub 3} injury. EDU can be used to verify foliar O{sub 3} symptoms in the field, and to screen plants for sensitivity to O{sub 3} under ambient conditions. Despite considerable research, the mode of action of EDU remains elusive. Additional research on the mode of action of EDU in suppressing O{sub 3} injury in plants may also be helpful in understanding the mode of action of O{sub 3} in causing injury in plants. - EDU is a verified and effective tool for the assessment of the effects of ozone on plants.

  12. 马铃薯大棚套黑膜覆盖栽培技术%Planting Potato Using Black Plastic Film Mulching in an Anti-fogging Agricultural Plastic Film Covered Tunnel

    Institute of Scientific and Technical Information of China (English)

    林长治

    2013-01-01

    Potato has become a main crop in winter cropping system in Changle, but due to differences in cultivation, management and variation in annual climate conditions, potato yield and quality vary to a large extent. Planting potato using black plastic film mulching combined with drip irrigation under the mulching for fertigation in an anti-fogging agricultural plastic film covered tunnel provides potato a stable entironments for growth, and thereby increasing yield and quality of potato. Also by using this technique, potato could be marketed more than a month earlier. Therefore, the profit could be increased for potato farmers.%马铃薯已成为长乐市冬季农业生产的主要作物,但由于栽培技术与管理水平差异,年际气候变化较大,产量和品质也大不相同。马铃薯大棚套黑膜覆盖栽培技术通过构建温室大棚覆盖塑料无滴膜,起垄播种后覆盖黑色地膜,膜下铺设灌溉和施肥用的滴灌带等方法,为马铃薯生长发育提供了一个相对稳定的生态环境,可有效地提高马铃薯的产量和品质,且比露地栽培提早一个多月上市,稳定增加农户种植效益。

  13. Land Cover Characterization Program

    Science.gov (United States)

    ,

    1997-01-01

    The U.S. Geological Survey (USGS) has a long heritage of leadership and innovation in land use and land cover mapping. The USGS Anderson system defined the principles for land use and land cover mapping that have been the model both nationally and internationally for more than 20 years. The Land Cover Characterization Program (LCCP) is founded on the premise that the Nation's needs for land cover and land use data are diverse and increasingly sophisticated. The range of projects, programs, and organizations that use land cover data to meet their planning, management, development, and assessment objectives has expanded significantly. The reasons for this are numerous, and include the improved capabilities provided by geographic information systems, better and more data-intensive analytic models, and increasing requirements for improved information for decision making. The overall goals of the LCCP are to:

  14. Land Cover Trends Project

    Science.gov (United States)

    Acevedo, William

    2006-01-01

    The Land Cover Trends Project is designed to document the types, rates, causes, and consequences of land cover change from 1973 to 2000 within each of the 84 U.S. Environmental Protection Agency (EPA) Level III ecoregions that span the conterminous United States. The project's objectives are to: * Develop a comprehensive methodology using probability sampling and change analysis techniques and Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), and Enhanced Thematic Mapper (ETM) data for estimating regional land cover change. * Characterize the spatial and temporal characteristics of conterminous U.S. land cover change for five periods from 1973 to 2000 (nominally 1973, 1980, 1986, 1992, and 2000). * Document the regional driving forces and consequences of change. * Prepare a national synthesis of land cover change.

  15. Flat covers of modules

    CERN Document Server

    Xu, Jinzhong

    1996-01-01

    Since the injective envelope and projective cover were defined by Eckmann and Bas in the 1960s, they have had great influence on the development of homological algebra, ring theory and module theory. In the 1980s, Enochs introduced the flat cover and conjectured that every module has such a cover over any ring. This book provides the uniform methods and systematic treatment to study general envelopes and covers with the emphasis on the existence of flat cover. It shows that Enochs' conjecture is true for a large variety of interesting rings, and then presents the applications of the results. Readers with reasonable knowledge in rings and modules will not have difficulty in reading this book. It is suitable as a reference book and textbook for researchers and graduate students who have an interest in this field.

  16. Manhole cover point locations across Guam's developed areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a point feature dataset with points across Guam's developed areas. The points represent manhole cover locations, ground elevation and manhole access depth.

  17. Land Cover Trends Geotagged Photography: 1999-2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The United States Geological Survey (USGS) Land Cover Trends field photography collection is a national-scale, ground-reference dataset which initially served as a...

  18. Propagation of Sound Through the Atmosphere: Effects of Ground Cover

    Science.gov (United States)

    1978-06-19

    surface. The impedance measurements were limited to the -f -quency range 220 Hz to 1000 Hz due to the experimental saometry. In this region, however...frequency limit of 100 Hz. In this range, the surface wave predicted by the theory used to analyze the data was not calculated to be a significant fraction...RETURN rND FUNCION EAST611101,D31*1 DIME~ýIOW 11M(4 LEAST52 =IS MAE IS BXZST QUALITY FRLI=40 C D)UNA4I𔃻 AS TEVFITF 1,FD)AN4fN C(~r PHECTLO T( US AI

  19. 石油化工生产装置低压系统接线及接地型式%Wiring and Grounding Types of Low Voltage System in Petrochemical Plants

    Institute of Scientific and Technical Information of China (English)

    任佩佳; 邵文平; 姜旭; 董柏屹

    2016-01-01

    简述低压系统接地的型式,介绍了石油化工生产装置低压系统的接线方式,根据用电负荷特点及工程实际绘制了石油化工生产装置低压系统接线图,探讨关于低压系统三极、四极断路器选择的问题,结合实际分别阐述电动机配电电缆芯数选择问题及变压器中性点工作接地线截面的确定。%Grounding types of low-voltage system were described, wiring of low-voltage system in petrochemical plants was introduced, wiring diagram of low-voltage system in petrochemical plants was drew based on electrical load characteristics and engineering practice, choice of level 3 and level 4 circuit breakers in the low voltage system was discussed. Combined with the actual conditons, selection of the motor power cables was also discussed, and the neutral point grounding wire section of transformer was determined.

  20. A Water Balance Study of Four Landfill Cover Designs at Material Disposal Area B in Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    David D. Breshears; Fairley J. Barnes; John W. Nyhan; Johnny A. Salazar

    1998-09-01

    The goal of disposing of low-level radioactive and hazardous waste in shallow landfills is to reduce risk to human health and the environment by isolating contaminants until they no longer pose an unacceptable hazard. In order to achieve this, the Department of Energy Environmental Restoration Program is comparing the performance of several different surface covers at Material Disposal Area (MDA) B in Los Alamos. Two conventional landfill were compared with an improved cover designed to minimize plant and animal intrusion and to minimize water infiltration into the underlying wastes. The conventional covers varied in depth and both conventional and improved designs had different combinations of vegetation (grass verses shrub) and gravel mulch (no mulch verses mulch). These treatments were applied to each of 12 plots and water balance parameters were measured from March1987 through June 1995. Adding a gravel mulch significantly influenced the plant covered field plots receiving no gravel mulch averaged 21.2% shrub cover, while plots with gravel had a 20% larger percent cover of shrubs. However, the influence of gravel mulch on the grass cover was even larger than the influence on shrub cover, average grass cover on the plots with no gravel was 16.3%, compared with a 42% increase in grass cover due to gravel mulch. These cover relationships are important to reduce runoff on the landfill cover, as shown by a regression model that predicts that as ground cover is increased from 30 to 90%,annual runoff is reduced from 8.8 to 0.98 cm-a nine-fold increase. We also found that decreasing the slope of the landfill cover from 6 to 2% reduced runoff from the landfill cover by 2.7-fold. To minimize the risk of hazardous waste from landfills to humans, runoff and seepage need to be minimized and evapotranspiration maximized on the landfill cover. This has to be accomplished for dry and wet years at MDA B. Seepage consisted of 1.9% and 6.2% of the precipitation in the average and

  1. The development of plant food processing in the Levant: insights from use-wear analysis of Early Epipalaeolithic ground stone tools.

    Science.gov (United States)

    Dubreuil, Laure; Nadel, Dani

    2015-11-19

    In recent years, the study of percussive, pounding and grinding tools has provided new insights into human evolution, more particularly regarding the development of technology enabling the processing and exploitation of plant resources. Some of these studies focus on early evidence for flour production, an activity frequently perceived as an important step in the evolution of plant exploitation. The present paper investigates plant food preparation in mobile hunter-gatherer societies from the Southern Levant. The analysis consists of a use-wear study of 18 tools recovered from Ohalo II, a 23 000-year-old site in Israel showing an exceptional level of preservation. Our sample includes a slab previously interpreted as a lower implement used for producing flour, based on the presence of cereal starch residues. The use-wear data we have obtained provide crucial information about the function of this and other percussive tools at Ohalo II, as well as on investment in tool manufacture, discard strategies and evidence for plant processing in the Late Pleistocene. The use-wear analysis indicates that the production of flour was a sporadic activity at Ohalo II, predating by thousands of years the onset of routine processing of plant foods.

  2. Differences in rates of decrease of environmental radiation dose rates by ground surface property in Fukushima City after the Fukushima Daiichi nuclear power plant accident.

    Science.gov (United States)

    Kakamu, Takeyasu; Kanda, Hideyuki; Tsuji, Masayoshi; Kobayashi, Daisuke; Miyake, Masao; Hayakawa, Takehito; Katsuda, Shin-ichiro; Mori, Yayoi; Okouchi, Toshiyasu; Hazama, Akihiro; Fukushima, Tetsuhito

    2013-01-01

    After the Great East Japan Earthquake on 11 March 2011, the environmental radiation dose in Fukushima City increased. On 11 April, 1 mo after the earthquake, the environmental radiation dose rate at various surfaces in the same area differed greatly by surface property. Environmental radiation measurements continue in order to determine the estimated time to 50% reduction in environmental radiation dose rates by surface property in order to make suggestions for decontamination in Fukushima. The measurements were carried out from 11 April to 11 November 2011. Forty-eight (48) measurement points were selected, including four kinds of ground surface properties: grass (13), soil (5), artificial turf (7), and asphalt (23). Environmental radiation dose rate was measured at heights of 100 cm above the ground surface. Time to 50% reduction of environmental radiation dose rates was estimated for each ground surface property. Radiation dose rates on 11 November had decreased significantly compared with those on 11 April for all surface properties. Artificial turf showed the longest time to 50% reduction (544.32 d, standard error: 96.86), and soil showed the shortest (213.20 d, standard error: 35.88). The authors found the environmental radiation dose rate on artificial materials to have a longer 50% reduction time than that on natural materials. These results contribute to determining an order of priority for decontamination after nuclear disasters.

  3. Estimating above-ground biomass by fusion of LiDAR and multispectral data in subtropical woody plant communities in topographically complex terrain in North-eastern Australia

    Institute of Scientific and Technical Information of China (English)

    Sisira Ediriweera; Sumith Pathirana; Tim Danaher; Doland Nichols

    2014-01-01

    We investigated a strategy to improve predicting capacity of plot-scale above-ground biomass (AGB) by fusion of LiDAR and Land-sat5 TM derived biophysical variables for subtropical rainforest and eucalypts dominated forest in topographically complex landscapes in North-eastern Australia. Investigation was carried out in two study areas separately and in combination. From each plot of both study areas, LiDAR derived structural parameters of vegetation and reflectance of all Landsat bands, vegetation indices were employed. The regression analysis was carried out separately for LiDAR and Landsat derived variables indi-vidually and in combination. Strong relationships were found with LiDAR alone for eucalypts dominated forest and combined sites compared to the accuracy of AGB estimates by Landsat data. Fusing LiDAR with Landsat5 TM derived variables increased overall performance for the eucalypt forest and combined sites data by describing extra variation (3% for eucalypt forest and 2% combined sites) of field estimated plot-scale above-ground biomass. In contrast, separate LiDAR and imagery data, and fusion of LiDAR and Landsat data performed poorly across structurally complex closed canopy subtropical rainforest. These findings reinforced that obtaining accurate estimates of above ground biomass using remotely sensed data is a function of the complexity of horizontal and vertical structural diversity of vegetation.

  4. 10 CFR 950.31 - Covered event dispute resolution.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Covered event dispute resolution. 950.31 Section 950.31 Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Dispute Resolution Process § 950.31 Covered event dispute resolution. (a) If a sponsor disagrees with the Covered...

  5. Application of bounding spectra to seismic design of piping based on the performance of above ground piping in power plants subjected to strong motion earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, J.D. [Stevenson and Associates, Cleveland, OH (United States)

    1995-02-01

    This report extends the potential application of Bounding Spectra evaluation procedures, developed as part of the A-46 Unresolved Safety Issue applicable to seismic verification of in-situ electrical and mechanical equipment, to in-situ safety related piping in nuclear power plants. The report presents a summary of earthquake experience data which define the behavior of typical U.S. power plant piping subject to strong motion earthquakes. The report defines those piping system caveats which would assure the seismic adequacy of the piping systems which meet those caveats and whose seismic demand are within the bounding spectra input. Based on the observed behavior of piping in strong motion earthquakes, the report describes the capabilities of the piping system to carry seismic loads as a function of the type of connection (i.e. threaded versus welded). This report also discusses in some detail the basic causes and mechanisms for earthquake damages and failures to power plant piping systems.

  6. Covering folded shapes

    Directory of Open Access Journals (Sweden)

    Oswin Aichholzer

    2014-05-01

    Full Text Available Can folding a piece of paper flat make it larger? We explore whether a shape S must be scaled to cover a flat-folded copy of itself. We consider both single folds and arbitrary folds (continuous piecewise isometries \\(S\\to\\mathbb{R}^2\\. The underlying problem is motivated by computational origami, and is related to other covering and fixturing problems, such as Lebesgue's universal cover problem and force closure grasps. In addition to considering special shapes (squares, equilateral triangles, polygons and disks, we give upper and lower bounds on scale factors for single folds of convex objects and arbitrary folds of simply connected objects.

  7. Adding structure to land cover - using fractional cover to study animal habitat use.

    Science.gov (United States)

    Bevanda, Mirjana; Horning, Ned; Reineking, Bjoern; Heurich, Marco; Wegmann, Martin; Mueller, Joerg

    2014-01-01

    Linking animal movements to landscape features is critical to identify factors that shape the spatial behaviour of animals. Habitat selection is led by behavioural decisions and is shaped by the environment, therefore the landscape is crucial for the analysis. Land cover classification based on ground survey and remote sensing data sets are an established approach to define landscapes for habitat selection analysis. We investigate an approach for analysing habitat use using continuous land cover information and spatial metrics. This approach uses a continuous representation of the landscape using percentage cover of a chosen land cover type instead of discrete classes. This approach, fractional cover, captures spatial heterogeneity within classes and is therefore capable to provide a more distinct representation of the landscape. The variation in home range sizes is analysed using fractional cover and spatial metrics in conjunction with mixed effect models on red deer position data in the Bohemian Forest, compared over multiple spatio-temporal scales. We analysed forest fractional cover and a texture metric within each home range showing that variance of fractional cover values and texture explain much of variation in home range sizes. The results show a hump-shaped relationship, leading to smaller home ranges when forest fractional cover is very homogeneous or highly heterogeneous, while intermediate stages lead to larger home ranges. The application of continuous land cover information in conjunction with spatial metrics proved to be valuable for the explanation of home-range sizes of red deer.

  8. Analysis of Causes of Karst Collapse and the Corresponding Countermeasures During the Running of Ground Source Heat Pump in the Covered Karst Areas%覆盖型岩溶区地下水地源热泵工程岩溶塌陷成因及对策研究

    Institute of Scientific and Technical Information of China (English)

    段启杉; 曹振东; 孟凡涛; 宋小庆

    2015-01-01

    地下水地源热泵工程是抽取地下水,以地下水为换热介质,提取能量之后全部回灌于含水层中。因此地下水地源热泵是改变地下水局部水位高程,整体上不影响地下水流场的变化。覆盖型岩溶区地质环境承载力较差,地下水的开发利用过程,可能加强诱发岩溶塌陷的因素,发生岩溶塌陷。在地下水地源热泵的建设和运行中,控制水位降深、尽量避免水位波动和瞬间水位变化过大等措施,达到预防岩溶塌陷的目的。而岩溶塌陷预防措施的研究给覆盖型岩溶区地下水地源热泵的建设和运行提供技术支撑。%Ground source heat pump engineering is pumping groundwater, groundwater as heat transfer medium, extract the energy after full recharge in the aquifer. So the groundwater source heat pump is to change the local groundwater level elevation, on the whole does not affect the change of the groundwater flow field. Covered karst area with poor bearing capacity of geological envi-ronment, the development and utilization of groundwater, karst collapse could strengthen induced factors, karst collapse occurred. In groundwater in the construction and operation of ground source heat pump, control the water level drawdown, avoid water level fluctuation and instantaneous water level change is too big, so as to achieve the purpose of prevention of karst collapse, and preven-tive measures of karst collapse research covered karst area groundwater source heat pump with pumping and technical support for the construction and operation.

  9. Differential productivity of Bristol Bay spawning grounds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Bristol Bay escapement surveys covering a period of several years show that, irrespective of fluctuations in total numbers on a system, certain grounds display a...

  10. Measurements of radar ground returns

    NARCIS (Netherlands)

    Loor, G.P. de

    1974-01-01

    The ground based measurement techniques for the determination of the radar back-scatter of vegetation and soils as used in The Netherlands will be described. Two techniques are employed: one covering a large sample area (> 1000 m2) but working at low grazing angels only and one (short range) coverin

  11. Percent Wetland Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be...

  12. Percent of Impervious Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — High amounts of impervious cover (parking lots, rooftops, roads, etc.) can increase water runoff, which may directly enter surface water. Runoff from roads often...

  13. Percent Wetland Cover (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be...

  14. GAP Land Cover - Image

    Data.gov (United States)

    Minnesota Department of Natural Resources — This raster dataset is a simple image of the original detailed (1-acre minimum), hierarchically organized vegetation cover map produced by computer classification of...

  15. GAP Land Cover - Vector

    Data.gov (United States)

    Minnesota Department of Natural Resources — This vector dataset is a detailed (1-acre minimum), hierarchically organized vegetation cover map produced by computer classification of combined two-season pairs of...

  16. Projected 2020 Land Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Projected 2020 land cover was developed to provide one scenario of development in the year 2020. It was used to generate several metrics to compare to 1992 metrics...

  17. Impact of the construction of a hydroelectric power plant on the land cover and use: study of the basin Lajeado Bonito - RS; Impacto da construcao de uma usina hidreletrica no uso e cobertura da terra: estudo da bacia Lajeado Bonito-RS

    Energy Technology Data Exchange (ETDEWEB)

    Tramontina, Juliana; Breunig, Fabio Marcelo [Universidade Federal de Santa Maria (UFSM), RS (Brazil)

    2015-07-01

    This work aims to analyze the impact of the construction of a hydroelectric power plant on land cover and use in Lajeado Bonito-RS watershed. The study evaluated the temporal evolution of land cover and use in the watershed for the period before and after to installation of hydroelectric plant Foz do Chapeco (2009 to 2010). For temporal analysis, two images were interpreted, one orbital image of High Resolution Camera (HRC) onboard of the CBERS-2B, acquired in December 29, 2009. And a high-resolution image obtained from Google Earth application, acquired at December 26, 2010. The land cover and use maps were generated by vector editing SPRING software. We found that the predominant land use related to agriculture and livestock, including bare soil. In 2009 this class accounted for 70.23% of the total area, while it come to represent 61.8% in 2010. At the same time, there was increase of areas with native forest cover, from 27.49% covered by forest in 2009, to 31% in 2010. The results showed that in both 2009 and 2010 years, approximately 49% of permanent preservation area were used inappropriately. (author)

  18. Linking above- and below-ground biodiversity: abundance and trophic complexity in soil as a response to experimental plant communities on abandoned arable land

    NARCIS (Netherlands)

    Korthals, G.W.; Smilauer, P.; Van Dijk, C.; Van der Putten, W.H.

    2001-01-01

    1. This study investigates the effects of experimental plant communities on different trophic levels in the soil food web of abandoned arable land. 2. In April 1996, a biodiversity experiment commenced using a continuation of agricultural crop rotation (CCR), spontaneous succession with naturally co

  19. Effect of above-ground plant species on soil microbial community structure and its impact on suppression of Rhizoctonia solani AG3

    NARCIS (Netherlands)

    Garbeva, P.; Postma, J.; Veen, van J.A.; Elsas, van J.D.

    2006-01-01

    The extent of soil microbial diversity is seen to be critical to the maintenance of soil health and quality. Different agricultural practices are able to affect soil microbial diversity and thus the level of suppressiveness of plant diseases. In a 4-year field experiment, we investigated the microbi

  20. a Study on Producing Highly Reliabile Reference Data Sets for Global Land Cover Validation

    Science.gov (United States)

    Soyama, N.; Muramatsu, K.; Daigo, M.; Ochiai, F.; Fujiwara, N.

    2016-06-01

    Validating the accuracy of land cover products using a reliable reference dataset is an important task. A reliable reference dataset is produced with information derived from ground truth data. Recently, the amount of ground truth data derived from information collected by volunteers has been increasing globally. The acquisition of volunteer-based reference data demonstrates great potential. However information given by volunteers is limited useful vegetation information to produce a complete reference dataset based on the plant functional type (PFT) with five specialized forest classes. In this study, we examined the availability and applicability of FLUXNET information to produce reference data with higher levels of reliability. FLUXNET information was useful especially for forest classes for interpretation in comparison with the reference dataset using information given by volunteers.

  1. Dinâmica do potássio nos resíduos vegetais de plantas de cobertura no Cerrado Potassium dynamics in crop residues of cover plants in Cerrado

    Directory of Open Access Journals (Sweden)

    José Luiz Rodrigues Torres

    2008-08-01

    Full Text Available A produção de biomassa, a manutenção dos resíduos vegetais sobre o solo e sua posterior decomposição são fatores de grande importância no estudo da ciclagem de nutrientes. Este estudo foi desenvolvido na área experimental do CEFET-Uberaba-MG, onde foram avaliados oito tipos de coberturas vegetais: milheto (Pennisetum americanum sin. tiphoydes, braquiária (Brachiaria brizantha, sorgo-forrageiro (Sorghum bicolor L. Moench, guandu (Cajanus cajan (L. Mill sp., crotalária (Crotalarea juncea, aveia-preta (Avena strigosa Schreb, pousio e área em preparo convencional de solo (testemunha em área de Cerrado, na região do Triângulo Mineiro. Avaliaram-se a fitomassa seca (FS, a decomposição dos resíduos em bolsas de decomposição, e a liberação de K. Utilizou-se um modelo matemático para descrever a decomposição dos resíduos e a liberação de K, e calcularam-se a constante de decomposição (k e o tempo de meia-vida (T½. O milheto, o sorgo e a crotalária foram as coberturas que apresentaram maiores produções de matéria seca. O maior acúmulo de K ocorreu em gramíneas e a maior liberação de K ocorreu no milheto, aveia, braquiária e crotalária nos primeiros 42 dias após manejo, nos dois períodos avaliados. A braquiária apresentou o menor T½ vida e a maior taxa de liberação de K.Crop residue production, plant residue maintenance and their decomposition are important factors in the understanding of nutrient recycling process. To evaluate K accumulation and release a study with eight cover crops types was developed: pearl millet (Pennisetum americanum sin. tiphoydes, brachiaria grass (Brachiaria brizantha, sorghum (Sorghum bicolor L. Moench, pigeonpea (Cajanus cajan (L. Millsp, sunn hemp (Crotalarea juncea and black oats (Avena strigosa Schreb, fallow land and conventional culture (control in the experimental area of CEFET-Uberaba-MG, in a Cerrado area. The dry mass production, crop residue decomposition in litter bags

  2. 盐胁迫对7种草本地被植物生长及光合特性的影响%Effects of salt stress on growth and physiological characteristic of seven herbaceous ground cover plants

    Institute of Scientific and Technical Information of China (English)

    骆建霞; 柴慈江; 史燕山; 徐雯; 俞佳佳

    2006-01-01

    采用盆栽试验法,研究了不同浓度NaCl盐胁迫对二色补血草(Limonium bicolor)、佛甲草(Sedum lineare Thunb.)、千叶蓍(Achillea millefolium)、丛生福禄考(Phlox subulata)、百里香(Thymus mongolicus Ronn)、地被石竹(Dianthus acicularis)和高羊茅(Festuca arundinacea Schreb)等7种地被植物生长及光合特性的影响.结果表明,盐胁迫使参试植物生长受到抑制,但受抑制程度有明显区别,相对生长量由大至小依次为高羊毛(86.52%)>二色补血草(78.78%)>千叶蓍(65.38%)>地被石竹(56.68%)>百里香(41.05%)>佛甲草(32.25%)>丛生福禄考(0.00%);盐胁迫下7种植物的光合速率(Pn)和气孔导度(Gs)均下降,但下降幅度在各种植物间差异较大,高羊茅和二色补血草的下降幅度较小,佛甲草和丛生福禄考的较大;7种植物胞间CO2浓度(Ci)的变化规律较复杂.综合分析7种草本地被植物的相对生长量和光合指标可知,其耐盐性由强至弱依次为:二色补血草>高羊茅>千叶蓍>地被石竹>百里香>佛甲草>丛生福禄考.

  3. Conversion of RAPD Marker Linked to Creep Plant Type in Ground-Cover Chrysanthemum to SCAR Marker%与地被菊株型匍匐性连锁RAPD标记的SCAR转化

    Institute of Scientific and Technical Information of China (English)

    赵静媛; 陈素梅; 陈发棣

    2009-01-01

    @@ 地被菊(Dendranthema grandiflorum)是20世纪80年代由陈俊愉院士首先提出的菊花新品种群(王彭伟等,1990;Chen et al.,1995),因株型低矮或匍匐、多分枝、抗性强、适应性广、成型快、覆盖能力强、着花繁密,同时具备绿化、美化、彩化和香化功能,园林应用前景广阔(于忠香,2004).

  4. Uso de malhas pigmentadas e mulching em túneis para cultivo de rúcula: efeito no ambiente e nas plantas modelo Use of pigmented mesh covers tunnels and mulchings for growing roquette: environmental effects on model plants

    Directory of Open Access Journals (Sweden)

    Rafael Ricardo Cantu

    2013-05-01

    Full Text Available O uso de malhas pigmentadas em cultivos de hortaliças folhosas permite a melhor adequação do ambiente às plantas, com destaque para a rúcula. Essa hortaliça vem conquistando maior espaço no mercado consumidor brasileiro desde o final da década de 90. Essa pesquisa teve por objetivo avaliar as condições ambientais proporcionadas pelo uso de telas pigmentadas na cobertura de túneis de cultivo, relacionando com as respostas agronômicas da rúcula, cultivada dentro desses túneis sobre diferentes coberturas de solo. As coberturas de túneis foram: a Chromatinet® azul, Chromatinet® vermelha, tela aluminizada prata, Sombrite® 50% e filme plástico transparente de polietileno de baixa densidade de 100µ. As coberturas de solo, também denominadas mulchings, dentro dos túneis foram: o filme plástico de polietileno de cor preta; de polietileno de dupla-face nas cores preta e branca, com a face branca voltada para cima; casca de arroz e a ausência de mulching. O delineamento utilizado foi o de blocos ao acaso com 24 tratamentos e três repetições. Nas condições do experimento, o emprego de algumas coberturas de túnel e de solo modificou o ambiente e melhorou as respostas agronômicas das plantas de rúcula.The use of pigmented screens for growing vegetable crops provides an opportunity for adjusting environmental conditions, especially for roquette. This vegetable crop is consumed mainly as raw, and has a large proportion in Brazilian vegetable market since 1990s. The present research was aimed to evaluate the effect the altered environmental conditions (by using pigmented screens tunnels on agronomic performance of roquette, grown inside tunnels having different color covers. Coverage screens colors were blue, red, silver, screen of shading 50% and transparent plastic. Beside this the effect of different mulching practices was also evaluated inside the tunnels. The experiment was laid out under randomized complete blocks design

  5. Potencial alelopático de plantas de cobertura no controle de picão-preto (Bidens pilosa L. Cover plants allelopathic potential in Bidens pilosa L. control

    Directory of Open Access Journals (Sweden)

    Cícero Monti Teixeira

    2004-06-01

    Full Text Available Extratos aquosos da parte aérea de mucuna-preta (Stilozobium aterrimum Piper & Tracy, mucuna rajada (Stilozobium sp., Crotalaria juncea L., Crotalaria spectabilis Roth, guandu e guandu anão (Cajanus cajan (L. Druce foram preparados com o objetivo de se determinar a potencialidade alelopática dessas espécies, largamente utilizadas como plantas de cobertura, sobre sementes de alface (planta-teste e aquênios de picão-preto (Bidens pilosa L.. Os experimentos foram conduzidos no Laboratório de Análise de Sementes da Universidade Federal de Lavras, durante o mês de abril de 2003. Foram avaliados o índice de velocidade de germinação (IVG e a germinação final. No experimento com alface, houve redução significativa da germinação apenas para o extrato aquoso de crotalária juncea. Para as outras espécies, houve uma tendência de redução na germinação, porém, não diferindo da testemunha com água destilada. O IVG apresentou redução significativa nos tratamentos com extratos aquosos de crotalária juncea, guandu comum, mucuna-rajada e mucuna-preta. As outras espécies tiveram uma tendência em reduzir o IVG, porém, não diferindo da testemunha. No experimento com picão-preto, a germinação apresentou comportamento semelhante ao experimento com alface, com redução significativa apenas para o tratamento com crotalária juncea, porém, para o IVG, houve redução significativa apenas para a mucuna-preta, com uma tendência de redução para os tratamentos com as outras espécies, mas não diferindo da testemunha.Aqueous extracts from aerial part of black mucuna (Stilozobium aterrimum Piper & Tracy, striped mucuna (Stilozobium sp, Crotalaria juncea L., Crotalaria spectabilis Roth., guandu (Cajanus cajan (L. Druce and dwarf guandu (Cajanus cajan were prepared with the objective of studying the allelopathic potential of these species, broadly used as cover plants, on lettuce seeds (test plant and aquenes of Bidens pilosa L.. The

  6. The kill date as a management tool for cover cropping success.

    Directory of Open Access Journals (Sweden)

    María Alonso-Ayuso

    Full Text Available Integrating cover crops (CC in rotations provides multiple ecological services, but it must be ensured that management does not increase pre-emptive competition with the subsequent crop. This experiment was conducted to study the effect of kill date on: (i CC growth and N content; (ii the chemical composition of residues; (iii soil inorganic N and potentially mineralizable N; and (iv soil water content. Treatments were fallow and a CC mixture of barley (Hordeum vulgare L. and vetch (Vicia sativa L. sown in October and killed on two different dates in spring. Above-ground biomass and chemical composition of CC were determined at harvest, and ground cover was monitored based on digital image analysis. Soil mineral N was determined before sowing and after killing the CC, and potentially mineralizable N was measured by aerobic incubation at the end of the experiment. Soil water content was monitored daily to a depth of 1.1 m using capacitance sensors. Under the present conditions of high N availability, delaying kill date increased barley above-ground biomass and N uptake from deep soil layers; little differences were observed in vetch. Postponing kill date increased the C/N ratio and the fiber content of plant residues. Ground cover reached >80% by the first kill date (∼1250°C days. Kill date was a means to control soil inorganic N by balancing the N retained in the residue and soil, and showed promise for mitigating N losses. The early kill date decreased the risk of water and N pre-emptive competition by reducing soil depletion, preserving rain harvested between kill dates and allowing more time for N release in spring. The soil potentially mineralizable N was enhanced by the CC and kill date delay. Therefore kill date is a crucial management variable for maximizing the CC benefits in agricultural systems.

  7. The kill date as a management tool for cover cropping success.

    Science.gov (United States)

    Alonso-Ayuso, María; Gabriel, José Luis; Quemada, Miguel

    2014-01-01

    Integrating cover crops (CC) in rotations provides multiple ecological services, but it must be ensured that management does not increase pre-emptive competition with the subsequent crop. This experiment was conducted to study the effect of kill date on: (i) CC growth and N content; (ii) the chemical composition of residues; (iii) soil inorganic N and potentially mineralizable N; and (iv) soil water content. Treatments were fallow and a CC mixture of barley (Hordeum vulgare L.) and vetch (Vicia sativa L.) sown in October and killed on two different dates in spring. Above-ground biomass and chemical composition of CC were determined at harvest, and ground cover was monitored based on digital image analysis. Soil mineral N was determined before sowing and after killing the CC, and potentially mineralizable N was measured by aerobic incubation at the end of the experiment. Soil water content was monitored daily to a depth of 1.1 m using capacitance sensors. Under the present conditions of high N availability, delaying kill date increased barley above-ground biomass and N uptake from deep soil layers; little differences were observed in vetch. Postponing kill date increased the C/N ratio and the fiber content of plant residues. Ground cover reached >80% by the first kill date (∼1250°C days). Kill date was a means to control soil inorganic N by balancing the N retained in the residue and soil, and showed promise for mitigating N losses. The early kill date decreased the risk of water and N pre-emptive competition by reducing soil depletion, preserving rain harvested between kill dates and allowing more time for N release in spring. The soil potentially mineralizable N was enhanced by the CC and kill date delay. Therefore kill date is a crucial management variable for maximizing the CC benefits in agricultural systems.

  8. SpinSat Mission Ground Truth Characterization

    Science.gov (United States)

    2014-09-01

    SpinSat Mission Ground Truth Characterization Andrew Nicholas, Ted Finne, Ivan Galysh, Anthony Mai, Jim Yen Naval Research Laboratory, Washington...mission overview, ground truth characterization and unique SSA observation opportunities of the mission. 1. MISSION CONCEPT The Naval Research...2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE SpinSat Mission Ground Truth Characterization 5a. CONTRACT

  9. Climate under cover

    CERN Document Server

    Takakura, Tadashi

    2002-01-01

    1.1. INTRODUCTION Plastic covering, either framed or floating, is now used worldwide to protect crops from unfavorable growing conditions, such as severe weather and insects and birds. Protected cultivation in the broad sense, including mulching, has been widely spread by the innovation of plastic films. Paper, straw, and glass were the main materials used before the era of plastics. Utilization of plastics in agriculture started in the developed countries and is now spreading to the developing countries. Early utilization of plastic was in cold regions, and plastic was mainly used for protection from the cold. Now plastic is used also for protection from wind, insects and diseases. The use of covering techniques started with a simple system such as mulching, then row covers and small tunnels were developed, and finally plastic houses. Floating mulch was an exception to this sequence: it was introduced rather recently, although it is a simple structure. New development of functional and inexpensive films trig...

  10. 中国核电工程场地设计地震动参数确定相关问题%The issues related to determination of site specific design ground motion for nuclear power plants in China

    Institute of Scientific and Technical Information of China (English)

    李小军; 贺秋梅; 侯春林

    2013-01-01

      基于中国核电工程选址和建设的实际工作,探讨了核电工程场地设计地震动参数确定几个环节中的关键问题,包括不同地震危险性分析方法的采用、地震动衰减关系的选取和设计地震动参数的综合取值等.分析了地震动衰减关系不确定性和弥散地震衰减关系等问题处理方式的变迁,比较分析了地震危险性分析确定性方法中构造地震、弥散地震的计算结果和概率方法计算结果的差异及对设计地震动参数确定的控制作用.研究表明:a.综合考虑地震危险性分析的确定性方法和概率方法的计算结果已成为中国核电工程场地地震安全性评价中确定设计地震动参数的基本思路,其中弥散地震是一个需要特殊考虑的问题;b.确定性方法和概率方法计算结果对场地设计地震动参数的控制作用受区域地震活动性强弱的影响;c.在地震活动性较弱的地区,确定性方法特别是弥散地震计算结果基本上控制着场地设计地震动参数的取值,而在地震活动性相对较强的地区,更倾向于由概率方法计算结果控制.%Based on the recent practical work of evaluation of seismic safety for the nuclear power plant site selection and construction in China,some key issues were discussed involved in the determination of site specific design ground motion for nuclear power plants,including the seismic hazard analysis methods,the ground motion attenuation relations,and the methods of determining design ground motion parameter. The coun-termeasure change was analyzed to consider the uncertainty of ground motion attenuation relation and the ground motion attenuation relation of diffuse earthquake;the differences were discussed between the computed results from the probabilistic method and the approaches of the diffuse earthquakes and tectonic earthquakes in the deter-ministic method,and their controlling effects were also discussed

  11. Self-reseeding annual legumes for cover cropping in rainfed managed olive orchards

    Energy Technology Data Exchange (ETDEWEB)

    Ângelo Rodrigues, M.; Ferreira, I. Q.; Freitas, S.L.; Pires, J.M.; Arrobas, M.P.

    2015-07-01

    Given the environmental impact of nitrogen (N)-fertilizer manufacture and use, the sustainable management of agro-systems should be sought by growing N-fixing legumes. In this work, eleven self-reseeding annual legumes were grown in pure stands as mulching cover crops in a rainfed olive orchard managed without grazing animals. Dry matter yield, N content in above-ground biomass, groundcover percentage and persistence of the sown species were assessed during four growing seasons. All covers provided enough soil protection over the year, with living plants during the autumn/winter period and a mulch of dead residues during the summer. The legumes overcame a false break observed in the third year recovering the dominance of the covers in the fourth growing season. This means that the seed bank established in previous seasons ensured the persistence of the sown legume even when a gap in seed production occurred. The early-maturing cultivars produced less biomass and fixed less N (approx. 50 kg N/ha/yr present in the above-ground biomass) than the late-maturing ones, but would compete less for water since the growing cycle finished earlier in the spring. They seem best suited to being grown in dry farmed olive orchards with low N demand in drought prone regions. (Author)

  12. Reusable pipe flange covers

    Energy Technology Data Exchange (ETDEWEB)

    Holden, James Elliott (Simpsonville, SC); Perez, Julieta (Houston, TX)

    2001-01-01

    A molded, flexible pipe flange cover for temporarily covering a pipe flange and a pipe opening includes a substantially round center portion having a peripheral skirt portion depending from the center portion, the center portion adapted to engage a front side of the pipe flange and to seal the pipe opening. The peripheral skirt portion is formed to include a plurality of circumferentially spaced tabs, wherein free ends of the flexible tabs are formed with respective through passages adapted to receive a drawstring for pulling the tabs together on a back side of the pipe flange.

  13. Primary succession seen through the shifted patterns of plant traits and soil macrofauna above/under-ground activity, a different ecological perspective towards post mining sites

    Science.gov (United States)

    Moradi, Jabbar; Mudrak, Ondrej; Frouz, Jan

    2016-04-01

    Using of trait distribution is becoming a promising field of ecology. Community weighted mean (CWM) values, in this regard, can summarize the shifts in the mean trait values within communities via environmental selection for a specific functional trait. Although traits have been widely used to describe relationships between plants and environmental variables, they are less used in study of interactions with other trophical levels. In 2013, we conducted a study to see the effect of plant community traits on soil and soil macrofauna epigeic/endogeic activity. We used sites of 10, 18, 28 and 55 years old in a succession sequence located at Sokolov post-mining site, Czech Republic. In each site we studied bare, grassy and woody patches. Vegetation traits, namely plant forms (i.e. grass, forb, legume, shrub and tree), canopy height, LDMC (leaf dry matter content), seed mass, and presence/absence of taproot during the whole life cycle were identified in 1-m×1-m quadrates. Soil fauna samples were collected from the same patches. Four patches were sampled in each plot and patch type. Fauna were extracted with a Tullgren apparatus, identified to family and counted. Their numbers were expressed per m2. CWM values of plan traits and faunal surface activity were calculated using the FD package in R. The computed values were transferred afterwards to CANOCO for further analyses. The effect of patches and age on dependent variables was determined with two-way ANOVAs. The higher LDMC in grassy and woody patches, particularly its correlation with 28 yrs site, can be related to higher reported P levels in 28 yrs site in specific, and generally higher nutrient return and C accumulation in vegetated sites. The absence of taproot in vegetated patches and 28 yrs site can be because of more competition with other species. It seems that the correlation between seed mass with oldest site and legume form is, roughly, a result of the change in community composition from forbs and grasses

  14. Índice de cobertura vegetal pela cultura do milho no período de chuvas intensas no sul de Minas Gerais Plant cover index in the period of intensive rainfall for corn crop at south of Minas Gerais state, Brazil

    Directory of Open Access Journals (Sweden)

    Fabiana Silva de Souza

    2010-04-01

    Full Text Available A cobertura vegetal é a defesa natural do solo contra a erosão hídrica. Nos modelos de estimativas de perdas de solo, o efeito da cobertura vegetal na interceptação da energia cinética da chuva é a variável chave na modelagem do processo erosivo. Assim sendo, objetivou-se avaliar a eficiência da cobertura vegetal, proporcionada pela cultura do milho, e suas relações com os atributos fitotécnicos desta cultura para alguns híbridos. O estudo foi realizado no campo demonstrativo de híbridos de milho da Universidade Federal de Lavras, localizada no município de Lavras, MG. Para determinação da cobertura vegetal utilizou-se um aparato que consiste em uma estrutura horizontal, contendo orifícios para visualização dos pontos com cobertura e sem cobertura vegetal, sendo as leituras feitas de forma aleatória e transversalmente às linhas da cultura. Os atributos fitotécnicos avaliados foram altura da planta, estande, matéria seca e produção de grãos. Diante dos resultados pode-se concluir que o maior índice de cobertura vegetal foi observado para os híbridos de milho P 30F33, P 30F90, P 3021, STRIKE, FORT, VALENT, UFLA 2001, UFLA 2004, CO 32, D 8480, D 8420 DKB 333B, DKB 440, evidenciando boa qualidade como planta protetora do solo. No período de maior ocorrência de chuvas, na região sul de Minas Gerais, a cultura do milho pode minimizar o efeito do processo erosivo. A produção de matéria seca relacionou-se bem com o índice de cobertura vegetal, podendo ser um indicativo quanto à proteção do solo.The plant cover is a natural protection of soil against water erosion. In estimative models of soil loss, the effect of plant cover in the interception of rainfall kinetic energy is the key variable in the modeling of the erosive process. Thus, the aim of this work is to evaluate the efficiency of the plant cover provided by the corn crop and their relations with the phytotechnical attributes of this crop for its respective

  15. 'Grounded' Politics

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2012-01-01

    play within one particular neighbourhood: Nørrebro in the Danish capital, Copenhagen. The article introduces the concept of grounded politics to analyse how groups of Muslim immigrants in Nørrebro use the space, relationships and history of the neighbourhood for identity political statements....... The article further describes how national political debates over the Muslim presence in Denmark affect identity political manifestations within Nørrebro. By using Duncan Bell’s concept of mythscape (Bell, 2003), the article shows how some political actors idealize Nørrebro’s past to contest the present...

  16. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jian-Ying; Ibragimov, Rashid

    2013-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting ...

  17. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jiong; Ibragimov, Rashid

    2015-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting ...

  18. Covering All Options

    Science.gov (United States)

    Kennedy, Mike

    2011-01-01

    The day a school opens its doors for the first time, the flooring will be new and untarnished. When the flooring is in such pristine condition, many flooring materials--carpeting, vinyl, terrazzo, wood or some other surface--will look good. But school and university planners who decide what kind of material covers the floors of their facilities…

  19. CORINE Land Cover 2006

    DEFF Research Database (Denmark)

    Stjernholm, Michael

    "CORINE land cover" er en fælleseuropæisk kortlægning af arealanvendelse/arealdække. Arealanvendelse/arealdække er i Danmark kortlagt efter CORINE metode og klasseopdeling med satellitbilleder fra 3 forskellige tidsperioder, fra begyndelsen af 1990'erne (CLC90), fra år 2000 (CLC2000) og fra år 2006...

  20. CORINE Land Cover 2006

    DEFF Research Database (Denmark)

    Stjernholm, Michael

    "CORINE land cover" er en fælleseuropæisk kortlægning af arealanvendelse/arealdække. Arealanvendelse/arealdække er i Danmark kortlagt efter CORINE metode og klasseopdeling med satellitbilleder fra 3 forskellige tidsperioder, fra begyndelsen af 1990'erne (CLC90), fra år 2000 (CLC2000) og fra år 2006...

  1. Do cover crop mixtures have the same ability to suppress weeds as competitive monoculture cover crops?

    Directory of Open Access Journals (Sweden)

    Brust, Jochen

    2014-02-01

    Full Text Available An increasing number of farmers use cover crop mixtures instead of monoculture cover crops to improve soil and crop quality. However, only little information is available about the weed suppression ability of cover crop mixtures. Therefore, two field experiments were conducted in Baden-Württemberg between 2010 and 2012, to compare growth and weed suppression of monoculture cover crops and cover crop mixtures. In the first experiment, heterogeneous results between yellow mustard and the cover crop mixture occurred. For further research, a field experiment was conducted in 2012 to compare monocultures of yellow mustard and hemp with three cover crop mixtures. The evaluated mixtures were: “MELO”: for soil melioration; “BETA”: includes only plant species with no close relation to main cash crops in Central Europe and “GPS”: for usage as energy substrate in spring. Yellow mustard, MELO, BETA and GPS covered 90% of the soil in less than 42 days and were able to reduce photosynthetically active radiation (PAR on soil surface by more than 96% after 52 days. Hemp covered 90% of the soil after 47 days and reduced PAR by 91% after 52 days. Eight weeks after planting, only BETA showed similar growth to yellow mustard which produced the highest dry matter. The GPS mixture had comparatively poor growth, while MELO produced similar dry matter to hemp. Yellow mustard, MELO and BETA reduced weed growth by 96% compared with a no cover crop control, while hemp and GPS reduced weeds by 85% and 79%. In spring, weed dry matter was reduced by more than 94% in plots with yellow mustard and all mixtures, while in hemp plots weeds were only reduced by 71%. The results suggest that the tested cover crop mixtures offer similar weed suppression ability until spring as the monoculture of the competitive yellow mustard.

  2. Dielectric Covered Planar Antennas

    Science.gov (United States)

    Llombart Juan, Nuria (Inventor); Lee, Choonsup (Inventor); Chattopadhyay, Goutam (Inventor); Gill, John J. (Inventor); Skalare, Anders J. (Inventor); Siegel, Peter H. (Inventor)

    2014-01-01

    An antenna element suitable for integrated arrays at terahertz frequencies is disclosed. The antenna element comprises an extended spherical (e.g. hemispherical) semiconductor lens, e.g. silicon, antenna fed by a leaky wave waveguide feed. The extended spherical lens comprises a substantially spherical lens adjacent a substantially planar lens extension. A couple of TE/TM leaky wave modes are excited in a resonant cavity formed between a ground plane and the substantially planar lens extension by a waveguide block coupled to the ground plane. Due to these modes, the primary feed radiates inside the lens with a directive pattern that illuminates a small sector of the lens. The antenna structure is compatible with known semiconductor fabrication technology and enables production of large format imaging arrays.

  3. Singular coverings of toposes

    CERN Document Server

    Bunge, Marta

    2006-01-01

    The self-contained theory of certain singular coverings of toposes called complete spreads, that is presented in this volume, is a field of interest to topologists working in knot theory, as well as to various categorists. It extends the complete spreads in topology due to R. H. Fox (1957) but, unlike the classical theory, it emphasizes an unexpected connection with topos distributions in the sense of F. W. Lawvere (1983). The constructions, though often motivated by classical theories, are sometimes quite different from them. Special classes of distributions and of complete spreads, inspired respectively by functional analysis and topology, are studied. Among the former are the probability distributions; the branched coverings are singled out amongst the latter. This volume may also be used as a textbook for an advanced one-year graduate course introducing topos theory with an emphasis on geometric applications. Throughout the authors emphasize open problems. Several routine proofs are left as exercises, but...

  4. On directed coverings

    DEFF Research Database (Denmark)

    Fajstrup, Lisbeth

    In [1], we study coverings in the setting of directed topology. Unfortunately, there is a condition missing in the definition of a directed covering. Some of the results in [1] require this extra condition and in fact it was claimed to follow from the original definition. It is the purpose...... of this note to give the right definition and point out how this affects the statements in that paper. Moreover, we give an example of a dicovering in the sense of [1], which does not satisfy the extra condition. Fortunately, with the extra condition, the subsequent results are now correct. [1] L. Fajstrup......, Dicovering spaces, Homology Homotopy Appl. 5 (2003), no. 2, 1-17....

  5. No consistent effect of plant species richness on resistance to simulated climate change for above- or below-ground processes in managed grasslands.

    Science.gov (United States)

    Dormann, Carsten F; von Riedmatten, Lars; Scherer-Lorenzen, Michael

    2017-06-17

    Species richness affects processes and functions in many ecosystems. Since management of temperate grasslands is directly affecting species composition and richness, it can indirectly govern how systems respond to fluctuations in environmental conditions. Our aim in this study was to investigate whether species richness in managed grasslands can buffer the effects of drought and warming manipulations and hence increase the resistance to climate change. We established 45 plots in three regions across Germany, each with three different management regimes (pasture, meadow and mown pasture). We manipulated spring warming using open-top chambers and summer drought using rain-out shelters for 4 weeks. Measurements of species richness, above- and below-ground biomass and soil carbon and nitrogen concentrations showed significant but inconsistent differences among regions, managements and manipulations. We detected a three-way interaction between species richness, management and region, indicating that our study design was sensitive enough to detect even intricate effects. We could not detect a pervasive effect of species richness on biomass differences between treatments and controls, indicating that a combination of spring warming and summer drought effects on grassland systems are not consistently moderated by species richness. We attribute this to the relatively high number of species even at low richness levels, which already provides the complementarity required for positive biodiversity-ecosystem functioning relationships. A review of the literature also indicates that climate manipulations largely fail to show richness-buffering, while natural experiments do, suggesting that such manipulations are milder than reality or incur treatment artefacts.

  6. Modeling and synthesis of strong ground motion

    Indian Academy of Sciences (India)

    S T G Raghu Kanth

    2008-11-01

    Success of earthquake resistant design practices critically depends on how accurately the future ground motion can be determined at a desired site. But very limited recorded data are available about ground motion in India for engineers to rely upon. To identify the needs of engineers, under such circumstances, in estimating ground motion time histories, this article presents a detailed review of literature on modeling and synthesis of strong ground motion data. In particular, modeling of seismic sources and earth medium, analytical and empirical Green’s functions approaches for ground motion simulation, stochastic models for strong motion and ground motion relations are covered. These models can be used to generate realistic near-field and far-field ground motion in regions lacking strong motion data. Numerical examples are shown for illustration by taking Kutch earthquake-2001 as a case study.

  7. Covering R-trees

    CERN Document Server

    Berestovskii, V N

    2007-01-01

    We show that every inner metric space X is the metric quotient of a complete R-tree via a free isometric action, which we call the covering R-tree of X. The quotient mapping is a weak submetry (hence, open) and light. In the case of compact 1-dimensional geodesic space X, the free isometric action is via a subgroup of the fundamental group of X. In particular, the Sierpin'ski gasket and carpet, and the Menger sponge all have the same covering R-tree, which is complete and has at each point valency equal to the continuum. This latter R-tree is of particular interest because it is "universal" in at least two senses: First, every R-tree of valency at most the continuum can be isometrically embedded in it. Second, every Peano continuum is the image of it via an open light mapping. We provide a sketch of our previous construction of the uniform universal cover in the special case of inner metric spaces, the properties of which are used in the proof.

  8. Water Holding Function of Above-ground Structure of Plant Community in Upper Reaches of Chishui River%赤水河上游植物群落地上结构持水功能评价

    Institute of Scientific and Technical Information of China (English)

    肖卫平; 喻阳华; 严令斌; 喻理飞

    2015-01-01

    The upstream plant community in Chishui River was chosen as research object to build the evaluation in-dex system of plant community water-holding function by using PCA and RDA sort-based analysis for screening water holding function index of above-ground structure of plant communities.Based on the assessment of water holding a-bility of 27 samples by the index weighted product , the results showed that differences in the structure of plant com-munity was the major cause for different water holding levels.In all analyzed plant communities, only croton, with combination of cypress presented higher water-holding ability, and then were the community of shrub, climax and timber forest, while the shrub-grass, brush stage, as well as bamboo standing in tree layer were the lowest.%以赤水河上游森林群落为研究对象,采用PCA和RDA排序分析,筛选植物群落地上部分组成及结构的持水功能指标,构建了植物群落持水功能评价指标体系,并采用指标加权乘积法评价赤水河上游27块森林群落样地的持水能力。结果表明,灌草、灌木、灌丛阶段群落及乔林阶段中竹林为低持水群落,次顶极群落和多数乔林群落为中持水群落,仅乔林阶段中巴豆+柏木群落中2块样地为高持水群落。导致群落持水功能差异的主因是持水结构组成不同。

  9. Introduction of Cover Picture

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Cypripedium guttatum Sw is a plant of Cypripedium L. (Orchidaceae), which has biological effects such as sedation, analgesia, sweating, and antipyretic. Modern research shows that this Chinese herbal medicine can be used for the treatment of neurasthenia, epilepsy, febrile convulsion, headache, and stomachache. It is widely distributed in Northeast China, and Shandong, Shanxi, Sichuan, and Yunnan

  10. Comparison of regional and global land cover products and the implications for biogenic emission modeling.

    Science.gov (United States)

    Huang, Ling; McDonald-Buller, Elena; McGaughey, Gary; Kimura, Yosuke; Allen, David T

    2015-10-01

    Accurate estimates of biogenic emissions are required for air quality models that support the development of air quality management plans and attainment demonstrations. Land cover characterization is an essential driving input for most biogenic emissions models. This work contrasted the global Moderate Resolution Imaging Spectroradiometer (MODIS) land cover product against a regional land cover product developed for the Texas Commissions on Environmental Quality (TCEQ) over four climate regions in eastern Texas, where biogenic emissions comprise a large fraction of the total inventory of volatile organic compounds (VOCs) and land cover is highly diverse. The Model of Emissions of Gases and Aerosols from Nature (MEGAN) was utilized to investigate the influences of land cover characterization on modeled isoprene and monoterpene emissions through changes in the standard emission potential and emission activity factor, both separately and simultaneously. In Central Texas, forest coverage was significantly lower in the MODIS land cover product relative to the TCEQ data, which resulted in substantially lower estimates of isoprene and monoterpene emissions by as much as 90%. Differences in predicted isoprene and monoterpene emissions associated with variability in land cover characterization were primarily caused by differences in the standard emission potential, which is dependent on plant functional type. Photochemical modeling was conducted to investigate the effects of differences in estimated biogenic emissions associated with land cover characterization on predicted ozone concentrations using the Comprehensive Air Quality Model with Extensions (CAMx). Mean differences in maximum daily average 8-hour (MDA8) ozone concentrations were 2 to 6 ppb with maximum differences exceeding 20 ppb. Continued focus should be on reducing uncertainties in the representation of land cover through field validation. Uncertainties in the estimation of biogenic emissions associated with

  11. Uptake of Uranium and Other Elements of Concern by Plants Growing on Uranium Mill Tailings Disposal Cells

    Science.gov (United States)

    Joseph, C. N.; Waugh, W.; Glenn, E.

    2015-12-01

    The U.S. Department of Energy (DOE) is responsible for long-term stewardship of disposal cells for uranium mill tailings throughout the United States. Rock-armored disposal cell covers create favorable habitat for deep-rooted plants by reducing soil evaporation, increasing soil water storage, and trapping windblown dust, thereby providing water and nutrients for plant germination and establishment. DOE is studying the tradeoffs of potential detrimental and beneficial effects of plants growing on disposal cell covers to develop a rational and consistent vegetation management policy. Plant roots often extend vertically through disposal cell covers into underlying tailings, therefore, uptake of tailings contaminants and dissemination through animals foraging on stems and leaves is a possible exposure pathway. The literature shows that plant uptake of contaminants in uranium mill tailings occurs, but levels can vary widely depending on plant species, tailings and soil chemistry, and cover soil hydrology. Our empirical field study measured concentrations of uranium, radium, thorium, molybdenum, selenium, manganese, lead, and arsenic in above ground tissues harvested from plants growing on disposal cells near Native American communities in western states that represent a range of climates, cover designs, cover soil types, and vegetation types. For risk screening, contaminant levels in above ground tissues harvested from plants on disposal cells were compared to Maximum Tolerance Levels (MTLs) set for livestock by the National Research Council, and to tissue levels in the same plant species growing in reference areas near disposal cells. Although tailings were covered with uncontaminated soils, for 14 of 46 comparisons, levels of uranium and other contaminants were higher in plants growing on disposal cells compared to reference area plants, indicating possible mobilization of these elements from the tailing into plant tissues. However, with one exception, all plant

  12. Radiochemical Analyses of the Filter Cake, Granular Activated Carbon, and Treated Ground Water from the DTSC Stringfellow Superfund Site Pretreatment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Esser, B K; McConachie, W; Fischer, R; Sutton, M; Szechenyi, S

    2005-09-16

    The Department of Toxic Substance Control (DTSC) requested that Lawrence Livermore National Laboratory (LLNL) evaluate the treatment process currently employed at the Department's Stringfellow Superfund Site Pretreatment Plant (PTP) site to determine if wastes originating from the site were properly managed with regards to their radioactivity. In order to evaluate the current management strategy, LLNL suggested that DTSC characterize the effluents from the waste treatment system for radionuclide content. A sampling plan was developed; samples were collected and analyzed for radioactive constituents. Following is brief summary of those results and what implications for waste characterization may be made. (1) The sampling and analysis provides strong evidence that the radionuclides present are Naturally Occurring Radioactive Material (NORM). (2) The greatest source of radioactivity in the samples was naturally occurring uranium. The sample results indicate that the uranium concentration in the filter cake is higher than the Granular Activated Carbon (GAC) samples. (11 -14 and 2-6 ppm respectively). (3) No radiologic background for geologic materials has been established for the Stringfellow site, and comprehensive testing of the process stream has not been conducted. Without site-specific testing of geologic materials and waste process streams, it is not possible to conclude if filter cake and spent GAC samples contain radioactivity concentrated above natural background levels, or if radionuclides are being concentrated by the waste treatment process. Recommendation: The regulation of Technologically Enhanced, Naturally Occurring Radioactive Materials (T-NORM) is complex. Since the results of this study do not conclusively demonstrate that natural radioactive materials have not been concentrated by the treatment process it is recommended that the DTSC consult with the Department of Health Services (DHS) Radiological Health Branch to determine if any further

  13. Resource Conservation and Recovery Act (RCRA) Part B permit application for container storage units at the Oak Ridge Y-12 Plant

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    This document contains Part B of the Permit Application for Container Storage Units at the Oak Ridge Y-12 Plant. Sections cover the following areas: Facility description; Waste characteristics; Process information; Ground water monitoring; Procedures to prevent hazards; Contingency plan; Personnel training; Closure plan, post closure plan, and financial requirements; Recordkeeping; Other federal laws; Organic air emissions; Solid waste management units; and Certification.

  14. Effects of selenium hyperaccumulation on plant-plant interactions: evidence for elemental allelopathy?

    Science.gov (United States)

    El Mehdawi, Ali F; Quinn, Colin F; Pilon-Smits, Elizabeth A H

    2011-07-01

    • Few studies have investigated plant-plant interactions involving hyperaccumulator plants. Here, we investigated the effect of selenium (Se) hyperaccumulation on neighboring plants. • Soil and litter Se concentrations were determined around the hyperaccumulators Astragalus bisulcatus and Stanleya pinnata and around the nonhyperaccumulators Medicago sativa and Helianthus pumilus. We also compared surrounding vegetative cover, species composition and Se concentration in two plant species (Artemisia ludoviciana and Symphyotrichum ericoides) growing either close to or far from Se hyperaccumulators. Then, Arabidopsis thaliana germination and growth were compared on soils collected next to the hyperaccumulators and the nonhyperaccumulators. • Soil collected around hyperaccumulators contained more Se (up to 266 mg Se kg(-1) ) than soil collected around nonhyperaccumulators. Vegetative ground cover was 10% lower around Se hyperaccumulators compared with nonhyperaccumulators. The Se concentration was higher in neighboring species A. ludoviciana and S. ericoides when growing close to, compared with far from, Se hyperaccumulators. A. thaliana showed reduced germination and growth, and higher Se accumulation, when grown on soil collected around Se hyperaccumulators compared with soil collected around nonaccumulators. • In conclusion, Se hyperaccumulators may increase the surrounding soil Se concentration (phytoenrichment). The enhanced soil Se contents around hyperaccumulators can impair the growth of Se-sensitive plant species, pointing to a possible role of Se hyperaccumulation in elemental allelopathy. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  15. Covered Clause Elimination

    CERN Document Server

    Heule, Marijn; Biere, Armin

    2010-01-01

    Generalizing the novel clause elimination procedures developed in [M. Heule, M. J\\"arvisalo, and A. Biere. Clause elimination procedures for CNF formulas. In Proc. LPAR-17, volume 6397 of LNCS, pages 357-371. Springer, 2010.], we introduce explicit (CCE), hidden (HCCE), and asymmetric (ACCE) variants of a procedure that eliminates covered clauses from CNF formulas. We show that these procedures are more effective in reducing CNF formulas than the respective variants of blocked clause elimination, and may hence be interesting as new preprocessing/simplification techniques for SAT solving.

  16. Preliminary results of simulation of hypo magnetic conditions and variations in energetic range of cosmic rays in ground-based experiments on plant objects

    Science.gov (United States)

    Belisheva, Natalia; Petrashova, Dina; Shchegolev, Boris

    The most dangerous for the astronauts and cosmonauts are the cosmic rays and drastic decrease of the tension of geomagnetic field (GMF) on the Earth orbit and in the open space. The tension in the interplanetary magnetic field is 10 nT, whereas the tension of GMF is 10 (4) nT on the Earth surface. We carried out the preliminary experiments for study the effects of hypo magnetic conditions and variations in energetic range of cosmic rays (CR) on the plant objects (Vigna radiata, Phaseolus vulgaris, Allium cepa and A. fistulosum, Cucumis sativis). GMF was weakened by using special shielding chamber made on the basis of the amorphous alloy magnetic material. The camera is able to weaken the GMF from 48 μT till 0.192 μT. Modulation of the energetic range of the neutron component of secondary CR was performed with using of the shielding by graphite and by paraffin. The influence of hypo magnetic field and the neutron intensity were studied on the germination of seeds, the growth, the length and the side branches of the roots in the experimental samples. We found that the sensitivity to the hypo magnetic field and to the variations in energetic range of neutrons can vary from object to object. For instance, exposure of the hypo magnetic field on black bean and mung bean stimulated the growth of the roots while do not affect on the white bean. Likewise sensitivity of Phaseolus vulgaris (black and white bean) and Vigna radiata (mung bean) to exposure of nucleon component of cosmic rays on the Earth's surface are differed. It was found that modification of energetic range of CR by using graphite shielding leads to a change in sign of correlation between the length of roots in all experimental samples and the nucleon component of CR compared with the control samples. This is evidence that physiology of biological objects significantly are modified in hypo magnetic environment, as well as under exposure of the CR in different energetic ranges during the space flights. Our

  17. 10 CFR 950.33 - Covered costs dispute resolution.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Covered costs dispute resolution. 950.33 Section 950.33 Energy DEPARTMENT OF ENERGY STANDBY SUPPORT FOR CERTAIN NUCLEAR PLANT DELAYS Dispute Resolution Process § 950.33 Covered costs dispute resolution. (a) If a sponsor disagrees with the Claim...

  18. Influência da cobertura vegetal do solo na qualidade dos frutos de videira 'Niagara Rosada' Influence of soil cover with grass and leguminous plants on fruit characteristics of table grape variety Niagara Rosada

    Directory of Open Access Journals (Sweden)

    Elaine Bahia Wutke

    2005-12-01

    Full Text Available Devido ao aumento no custo de produção com a utilização de cobertura morta com capim nas ruas da videira 'Niagara Rosada' e à dificuldade para sua aquisição, objetivou-se a possibilidade de substituí-la por plantas de cobertura intercalares. Em experimentos realizados em Indaiatuba e Jundiaí-SP, de 1999-2000 a 2003-2004, instalaram-se seis tratamentos nas entrelinhas, em blocos ao acaso e quatro repetições, constando de área no limpo; vegetação espontânea roçada; cobertura com capim seco de Brachiaria decumbens; cobertura verde de aveia preta (Avena strigosa; cobertura verde de chícharo (Lathyrus sativus; cobertura verde de tremoço (Lupinus albus, de março a outubro, seguidas de cobertura verde de mucuna anã (Mucuna deeringiana de outubro a março. Determinaram-se massa, comprimento e largura do cacho, engaço e bagas, número total de bagas por cacho e diâmetro do pedicelo de bagas, comparando-se os valores médios pelo teste de Duncan ao nível de 5%. Na média dos anos, os resultados com a cobertura verde foram similares ou mais favoráveis que os da cobertura com braquiária seca, podendo-se substituí-la por coberturas vegetais intercalares com gramínea e leguminosas, o ano todo, sem interferência negativa na qualidade comercial dos frutos.Grape vineyard in Southern Brazil utilize a large amount of mulch during autumn-winter season demanding extra efforts and costs, being its acquisition very difficult nowadays. In order to evaluate the possibility of replacing the tradicionally mulch by green cover species in the inter-row strip, two experiments were carried out in Indaiatuba and Jundiaí, SP, Brazil, from 1999/00 to 2003/04, with the table variety Niagara Rosada. The experimental design was a randomized block with four replications and six treatments: 1 no weeded area; 2 cut spontaneous local vegetation; 3 mulch of Brachiaria decumbens; 4 green cover of Avena strigosa from March to October followed by green cover of

  19. Soybean growth and yield under cover crops

    Directory of Open Access Journals (Sweden)

    Priscila de Oliveira

    2013-04-01

    Full Text Available The use of cover crops in no-tillage systems can provide better conditions for the development of soybean plants with positive effects on grain yield and growth analysis techniques allow researchers to characterize and understand the behavior of soybean plants under different straw covers. Thus, the aim of this study was to characterize, using growth analysis, yield components and agronomic performance of soybean under common bean, Brachiaria brizantha and pearl millet straws. The experiment was performed on a soil under cerrado in the municipality of Santo Antônio de Goiás, GO. The experiment was arranged in a randomized complete block design with three treatments (cover crops and five replications. Soybean grain yield was lower in the B. brizantha straw treatment (3,708 kg ha-1 than both in the pearl millet (4.772 kg ha-1 and common bean straw treatments (5,200 kg ha-1. The soybean growth analysis in B. brizantha, pearl millet and common bean allowed characterizing the variation in the production of dry matter of leaves, stems, pods and total and leaf area index that provided different grain yields. The cover crop directly affects the soybean grain yield.

  20. Cover Crop Biomass and Corn Yield Following 13 Rye, Wheat, and Triticale Cultivars Used as Winter Cover Crops

    Science.gov (United States)

    Winter cover crops have the potential to reduce nitrate leaching and erosion in corn-soybean rotations in the upper Midwest. The cover crop growing season between harvest and planting of corn and soybean, however, is short and cold. Additionally, previous studies in Iowa have indicated that winter r...

  1. Influence of snow cover distribution on soil temperature and nutrient dynamics in alpine pedoenvironments

    Directory of Open Access Journals (Sweden)

    Michele Freppaz

    2011-02-01

    Full Text Available In Alpine sites snow is present on the ground from six to eight months per year in relation to elevation and exposure. Water is therefore immobilized into the solid state for the greater part of the winter season and released to the ground in a short period during spring snowmelt. In these areas, snow distribution exercises a fundamental role in influencing soil temperature and nutrient dynamics, in particular of nitrogen, with great consequences on plant nutrition. The dormant vegetation period, the low temperatures and the persistent snow cover suggest that soil biological activity is only concentrated during summer. As a matter of fact, soils covered with a consistent snow cover are isolated from the air temperature and can not freeze during winter. A snowpack of sufficient thickness, accumulated early in winter, insulates the ground from the surrounding atmosphere maintaining soil temperature closed to 0 °C during the whole winter season. The elevation of the snow line and the shorter permanence of snow on the ground, as a result of global warming (IPCC, 1996, 2001, might reduce the insulation effect of the snowpack, exposing soils of the mountain belt to lower temperatures and to a greater frequency of freeze/thaw cycles, which might alter organic matter dynamics and soil nutrient availability. Such thermal stresses may determine the lysis of microbial cells and the consequent increase of nitrogen and carbon mineralization by the survived microorganisms. Moreover, the freeze/thaw cycles can determine the exposure of exchange surfaces not available before, with release of organic matter of non-microbial origin, which may become available to surviving microorganisms for respiration. The reduced or absent microbial immobilization may cause the accumulation of remarkable amounts of inorganic nitrogen in soil, potentially leachable during spring snowmelt, when plants have not still started the growing season. Changes of snow distribution in

  2. Influence of snow cover distribution on soil temperature and nutrient dynamics in alpine pedoenvironments

    Directory of Open Access Journals (Sweden)

    Ermanno Zanini

    Full Text Available In Alpine sites snow is present on the ground from six to eight months per year in relation to elevation and exposure. Water is therefore immobilized into the solid state for the greater part of the winter season and released to the ground in a short period during spring snowmelt. In these areas, snow distribution exercises a fundamental role in influencing soil temperature and nutrient dynamics, in particular of nitrogen, with great consequences on plant nutrition. The dormant vegetation period, the low temperatures and the persistent snow cover suggest that soil biological activity is only concentrated during summer. As a matter of fact, soils covered with a consistent snow cover are isolated from the air temperature and can not freeze during winter. A snowpack of sufficient thickness, accumulated early in winter, insulates the ground from the surrounding atmosphere maintaining soil temperature closed to 0 °C during the whole winter season. The elevation of the snow line and the shorter permanence of snow on the ground, as a result of global warming (IPCC, 1996, 2001, might reduce the insulation effect of the snowpack, exposing soils of the mountain belt to lower temperatures and to a greater frequency of freeze/thaw cycles, which might alter organic matter dynamics and soil nutrient availability. Such thermal stresses may determine the lysis of microbial cells and the consequent increase of nitrogen and carbon mineralization by the survived microorganisms. Moreover, the freeze/thaw cycles can determine the exposure of exchange surfaces not available before, with release of organic matter of non-microbial origin, which may become available to surviving microorganisms for respiration. The reduced or absent microbial immobilization may cause the accumulation of remarkable amounts of inorganic nitrogen in soil, potentially leachable during spring snowmelt, when plants have not still started the growing season. Changes of snow distribution in

  3. Covering walks in graphs

    CERN Document Server

    Fujie, Futaba

    2014-01-01

    Covering Walks  in Graphs is aimed at researchers and graduate students in the graph theory community and provides a comprehensive treatment on measures of two well studied graphical properties, namely Hamiltonicity and traversability in graphs. This text looks into the famous Kӧnigsberg Bridge Problem, the Chinese Postman Problem, the Icosian Game and the Traveling Salesman Problem as well as well-known mathematicians who were involved in these problems. The concepts of different spanning walks with examples and present classical results on Hamiltonian numbers and upper Hamiltonian numbers of graphs are described; in some cases, the authors provide proofs of these results to illustrate the beauty and complexity of this area of research. Two new concepts of traceable numbers of graphs and traceable numbers of vertices of a graph which were inspired by and closely related to Hamiltonian numbers are introduced. Results are illustrated on these two concepts and the relationship between traceable concepts and...

  4. Post-fire succession of ground vegetation of central Siberia in Scots pine forests

    Science.gov (United States)

    Kovaleva, N.; Ivanova, G. A.; Conard, S. G.

    2012-04-01

    Extensive wildfires have affected the Russian region in the last decade. Scots pine forests (Pinus sylvestris L.) are widespread in central Siberia and fire occurrence is high in these forests, whose dominant fire regime is one of frequent surface fires. We studied post- fire succession of ground vegetation has been studied on nine experimental fires of varying severity (from 620 to 5220 kW/m) in middle taiga Scots pine forests of central Siberia (Russia). It proved from our study that all species of the succession process are present from initial stages. We did not find any trend of ground vegetation diversity with the time during 8 years after the fire. Our investigation showed that post- fire recovery of the ground vegetation is determined by initial forest type, fire severity and litter burning depth. Fire severity had a clear effect in initial succession in study area and it clearly had an impact on percentage cover, biomass and structure of ground vegetation. In a lesser degree the small shrubs are damaged during ground fires. The dominating species (Vaccinium vitis-idaea and V. myrtillus) regained the cover values above or close to 6—8 years. The post- fire biomass of ground vegetation 93—100% consists of species (Vaccinium vitis-idaea and V. myrtillus) that survived after the fire and increased in the cover with the time. In pine forests mosses and lichens suffer to a greater degree after ground fires. Lichen layer was completely lost after the fires of any severity. Decrease of mosses species diversity takes place after ground fires. The post- fire cover and species diversity of the green mosses were progressively lower with increasing the fire severity during the observation period. Maximum changes are discovered in the post- fire structure of plant microgroups after the high- severity fire which resulted in intensive invasion by the post- fire mosses (Polytrichum strictum and P. commune). There is a positive trend of green moss microgroups recovery

  5. Identification and quantification of nitrogen cycling processes in cryptogamic covers

    Science.gov (United States)

    Weber, Bettina; Wu, Dianming; Lenhart, Katharina; Tamm, Alexandra; Ruckteschler, Nina; Rodríguez-Caballero, Emilio; Elbert, Wolfgang; Burrows, Susannah; Clough, Tim; Steinkamp, Jörg; Meusel, Hannah; Behrendt, Thomas; Büdel, Burkhard; Andreae, Meinrat O.; Sörgel, Matthias; Cheng, Yafang; Crutzen, Paul; Keppler, Frank; Su, Hang; Pöschl, Ulrich

    2016-04-01

    Cryptogamic covers (CC) comprise communities of photoautotrophic cyanobacteria, lichens, algae, and bryophytes together with heterotrophic bacteria, microfungi, and archaea in varying proportions. Depending on their habitat, cryptogamic rock covers, cryptogamic plant covers, and cryptogamic soil covers are distinguished. The latter comprise biological soil crusts (biocrusts), which globally occur under dryland conditions. In a first assessment of their global role, we quantified that CC fix ˜49 Tg of nitrogen (N) per year (Elbert et al., 2013), corresponding to ˜1/2 of the maximum terrestrial biological N fixation determined in the latest IPCC report. The fixed N is used for biomass formation and partially leached into the ground, where it can be taken up by plants or transformed into N oxides, being emitted into the atmosphere. We show that biocrusts release nitric oxide (NO) and nitrous acid (HONO), which are key species in the global cycling of nitrogen and in the production of ozone and hydroxyl radicals, regulating the oxidizing power and self-cleaning capacity of the atmosphere. Based on laboratory, field and satellite measurement data, we obtained a best estimate of 1.1 Tg a-1 of NO-N and 0.6 Tg a-1 of HONO-N being globally emitted by biocrusts, corresponding to ˜20% of the global nitrogen oxide emissions from soils under natural vegetation (Weber et al., 2015). During full wetting and drying cycles, emissions peaked at low water contents suggesting NO- and HONO-formation under aerobic conditions during nitrification. Other measurements revealed that cryptogamic organisms release nitrous oxide (N2O), a greenhouse gas of crucial importance for climate change. The emission rates varied with temperature, humidity, and N deposition, but divided by respiratory CO2 emission they formed an almost constant ratio, which allowed upscaling on the global scale. We estimated annual N2O emissions of 0.3 - 0.6 Tg by cryptogams, accounting for 4-9% of the global N2O

  6. Using malaise traps to sample ground beetles (Coleoptera: Carabidae).

    Energy Technology Data Exchange (ETDEWEB)

    Ulyshen, Michael D., James L. Hanula, and Scott Horn

    2005-01-01

    Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and trap-shy species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce different results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002). Further complications arise from seasonal patterns of movement among the beetles themselves (Maelfait and Desender 1990), as well as numerous climatic factors, differences in plant cover, and variable surface conditions (Adis 1979). Because of these limitations, pitfall trap data give an incomplete picture of the carabid community and should be interpreted carefully. Additional methods, such as use of Berlese funnels and litter washing (Spence and Niemela 1994), collection from lights (Usis and MacLean 1998), and deployment of flight intercept devices (Liebherr and Mahar 1979; Paarmann and Stork 1987), should be incorporated in surveys to better ascertain the species composition and relative numbers of ground beetles. Flight intercept devices, like pitfall traps, have the advantage of being easy to use and replicate, but their value to carabid surveys is largely unknown. Here we demonstrate the effectiveness of Malaise traps for sampling ground beetles in a bottomland hardwood forest.

  7. Using malaise traps to sample ground beetles (Coleoptera. Carabidae)

    Energy Technology Data Exchange (ETDEWEB)

    Ulyshen, Michael D. [USDA Forest Service, Savannah River, New Ellenton, SC (United States); Hanula, James L. [USDA Forest Service, Savannah River, New Ellenton, SC (United States); Horn, Scott [USDA Forest Service, Savannah River, New Ellenton, SC (United States)

    2012-04-02

    Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and trap-shy species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce different results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002). Further complications arise from seasonal patterns of movement among the beetles themselves (Maelfait and Desender 1990), as well as numerous climatic factors, differences in plant cover, and variable surface conditions (Adis 1979). Because of these limitations, pitfall trap data give an incomplete picture of the carabid community and should be interpreted carefully. Additional methods, such as use of Berlese funnels and litter washing (Spence and Niemela 1994), collection from lights (Usis and MacLean 1998), and deployment of flight intercept devices (Liebherr and Mahar 1979; Paarmann and Stork 1987), should be incorporated in surveys to better ascertain the species composition and relative numbers of ground beetles. Flight intercept devices, like pitfall traps, have the advantage of being easy to use and replicate, but their value to carabid surveys is largely unknown. Here we demonstrate the effectiveness of Malaise traps for sampling ground beetles in a bottomland hardwood forest.

  8. Land Use and Land Cover - Montana Land Cover Framework 2013

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This statewide land cover theme is a baseline digital map of Montana's natural and human land cover. The baseline map is adapted from the Northwest ReGAP project...

  9. Sky cover from MFRSR observations: cumulus clouds

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-01-01

    Full Text Available The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their model clear-sky counterparts are two main components of a new method for estimating the fractional sky cover of different cloud types, including cumulus clouds. The performance of this method is illustrated using 1-min resolution data from ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR. The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM Climate Research Facility (ACRF Southern Great Plains (SGP site during the summer of 2007 and represent 13 days with cumulus clouds. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

  10. Georadar Measurements for the Snow Cover Density

    Directory of Open Access Journals (Sweden)

    A. Godio

    2009-01-01

    Full Text Available Ground Probing Radar (GPR devices is adopted for the analysis of thickness and the mechanical properties (density of the snow cover in some test site in Alps, in Northern Italy. The performances of standard radar systems for the snow cover characterisation are analysed, the main aim is to assess the reliability of the method to estimate the snow density, the snowpack thickness and the depth resolution in terms of capability to detect thin layers. The main relationships between the electrical permittivity and the density of the dry-snow are applied to estimate the density vertical profiles inferred by the GPR investigation. The data were calibrated and compared with the results coming from direct measurements of the density and thickness.

  11. Cooling experiments using dummies covered by leaves.

    Science.gov (United States)

    Althaus, L; Stückradt, S; Henssge, C; Bajanowski, T

    2007-03-01

    One main method to estimate the time of death is the measurement of the body temperature. The cooling of a corpse depends on a number of conditions including the surroundings. In cases where the cooling conditions differ from the defined standard, a corrective factor is used to characterise the influence of clothing, air movement, the properties of the supporting base and the humidity. Nothing is known about the significance of other circumstances, for example of a tegument by leaves or wet leaves. Therefore, the cooling of dummies which were placed on a 2-cm-thick layer of wet/dry leaves and covered by a 10-cm-thick layer of leaves was investigated. Corrective factors of 1.0 for wet leaves on the ground and of 1.3 and 1.5 for drier leaves were found. If the dummies were additionally covered, corrective factors ranged between 1.8 and 2.7.

  12. Floating geomembrane cover improves biogas collection

    Energy Technology Data Exchange (ETDEWEB)

    McMahon, J.

    2009-07-15

    Canadian corn products refiner, Casco Inc., recently upgraded a wastewater anaerobic digester at its automated corn wet milling facility on the St. Lawrence River, in Cardinal Ontario. The upgrade includes an improved floating and insulated geomembrane cover, designed and installed by Geomembrane Technologies Inc. The cover effectively streamlines biogas collection, improves biogas odour control and optimizes bioreactor heat retention. Casco's bulk volume fermenter (BVF) was designed and built in 1988 by ADI Systems Inc. It is limited to receiving 641,000 gallons of wastewater per day from several areas of the plant. Wastewater sludge is usually treated by anaerobic digestion. At Casco, raw solids are added directly to the BVF bioreactor, where they are digested, minimizing waste sludge handling. In essence, anaerobic digestion is a renewable energy source which converts wastewater to a methane- and carbon dioxide-rich biogas suitable for energy production, replacing fossil fuels. The insulated geomembrane cover captures and reclaims all the biogas from the treatment process that is going on inside the tank. Without a cover, the biogas would be released to the atmosphere. The new geomembrane cover collects an average of 236,000 cubic feet of biogas per day, at a 65 per cent methane concentration, from the BVF bioreactor. 2 figs.

  13. Energy demand in the system sowing in different (Glycine max (L) Merril) systems planting and covering; Demanda energetica na semeadura de soja (Glycine max (L) Merril) em diferentes sistemas de manejo e cobertura do solo

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Elcio Hiroyoshi [Universidade Estadual Paulista (UNESP), Ilha Solteira, SP (Brazil)], E-mail: elcio@agr.feis.unesp.br; Benez, Sergio Hugo; Silva, Paulo Roberto Arbex; Seki, Andre Satoshi [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil); Mahl, Denise [Universidade Estadual de Maringa (UEM), Cidade Gaucha, PR (Brazil)

    2010-07-01

    The difficulty of producing quality forage associated to the high tax of decomposition of the covering killed of the soil and the low operational efficiency of agricultural machines did with that the present work was accomplished in the Experimental Farm Lageado, FCA/ UNESP of the Campus of Botucatu, on an Alsisol, with objective to analyze the energy demand requested in the soy sowing in different systems of handling of the soil (no-tillage, conventional tillage and reduced tillage), on cultural remains of black oats picked for hay, sorghum picked for humid silage of grains and spontaneous vegetation. The used experimental design was a split plot to the factorial type 3x3 with four repetitions and portions of 140 m{sup 2}, Meantime to the results, was ended that the coverings of the soil didn't influence in the values of traction force, potency, displacement speed and increase of the consumption of fuel happened and non accommodation of the turned of the tractor-seeder-fertilizer. Associate to the structural conditions of the soil as absence of traffic of machines and low index of rain fall. (author)

  14. Scientific Analysis Cover Sheet for Radionuclide Screening

    Energy Technology Data Exchange (ETDEWEB)

    G. Ragan

    2002-08-09

    pressurized water reactor (PWR) fuel, U.S. Department of Energy (DOE) spent nuclear fuel (DSNF), and high-level waste (HLW). Average and outlying (high burnup, high initial enrichment, low age, or otherwise exceptional) forms of each waste-form type are considered. This analysis has been prepared in accordance with a technical work plan (BSC 2002c). In a review of Revision 00 of this radionuclide screening analysis, the NRC found that ''processes that affect transport in the biosphere, such as uptake by plants and bioaccumulation are not accounted for'' and that ''the direct exposure pathway is not accounted for'' (Beckman 2001, Section 5.3.2.1). The NRC also found that the solubility and sorption classes were too broadly defined, noting, for example, that Se is in the same solubility and sorptivity groups as Np and U, yet is ''more soluble than Np and U by several orders of magnitude'' (Beckman 2001, Section 5.3.2.1). This revision seeks to build upon the strengths of the earlier screening method while responding to the specific concerns raised by the NRC and other reviewers. In place of simple inhalation and ingestion dose conversion factors, the revised radionuclide screening uses screening factors that also take into account soil accumulation, uptake by plants, exposure to contaminated ground, and other features of the biosphere that were neglected in the previous screening. Whereas the previous screening analysis allowed only two solubility classes (soluble and insoluble), the revised screening introduces an intermediate solubility class to better segregate the radionuclides into transport groups.

  15. Allegheny County Land Cover Areas

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Land Cover dataset demarcates 14 land cover types by area; such as Residential, Commercial, Industrial, Forest, Agriculture, etc. If viewing this description on...

  16. Allegheny County Land Cover Areas

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Land Cover dataset demarcates 14 land cover types by area; such as Residential, Commercial, Industrial, Forest, Agriculture, etc. If viewing this description...

  17. Allegheny County Land Cover Areas

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Land Cover dataset demarcates 14 land cover types by area; such as Residential, Commercial, Industrial, Forest, Agriculture, etc. If viewing this description on...

  18. Space Constrained Dynamic Covering

    CERN Document Server

    Antonellis, Ioannis; Dughmi, Shaddin

    2009-01-01

    In this paper, we identify a fundamental algorithmic problem that we term space-constrained dynamic covering (SCDC), arising in many modern-day web applications, including ad-serving and online recommendation systems in eBay and Netflix. Roughly speaking, SCDC applies two restrictions to the well-studied Max-Coverage problem: Given an integer k, X={1,2,...,n} and I={S_1, ..., S_m}, S_i a subset of X, find a subset J of I, such that |J| <= k and the union of S in J is as large as possible. The two restrictions applied by SCDC are: (1) Dynamic: At query-time, we are given a query Q, a subset of X, and our goal is to find J such that the intersection of Q with the union of S in J is as large as possible; (2) Space-constrained: We don't have enough space to store (and process) the entire input; specifically, we have o(mn), sometimes even as little as O((m+n)polylog(mn)) space. The goal of SCDC is to maintain a small data structure so as to answer most dynamic queries with high accuracy. We present algorithms a...

  19. Cover crops and N credits

    Science.gov (United States)

    Cover crops often provide many short- and long-term benefits to cropping systems. Legume cover crops can significantly reduce the N fertilizer requirement of non-legume cash crops that follow. The objectives of this presentation were to: I) educate stakeholders about the potential benefits of cover ...

  20. On L-injective Covers

    Institute of Scientific and Technical Information of China (English)

    周德旭

    2004-01-01

    We use the class of L-injective modules to define L-injective covers, and provide the characterizations of L-injective covers by the properties of kernels of homomorphisms. We prove that the right L-noetherian right L-hereditary ring is just such that every right R-module has an L-injective cover which is monic. We also use kernels of homomorphisms to investigate L-simple L-injective covers and give some constructions ofL-simple L-iniective covers.

  1. Holocene land-cover reconstructions for studies on land cover-climate feedbacks

    Directory of Open Access Journals (Sweden)

    M.-J. Gaillard

    2010-03-01

    Full Text Available The major objectives of this paper are: (1 to review the pros and cons of the scenarios of past anthropogenic land cover change (ALCC developed during the last ten years, (2 to discuss issues related to pollen-based reconstruction of the past land-cover and introduce a new method, REVEALS (Regional Estimates of VEgetation Abundance from Large Sites, to infer long-term records of past land-cover from pollen data, (3 to present a new project (LANDCLIM: LAND cover – CLIMate interactions in NW Europe during the Holocene currently underway, and show preliminary results of REVEALS reconstructions of the regional land-cover in the Czech Republic for five selected time windows of the Holocene, and (4 to discuss the implications and future directions in climate and vegetation/land-cover modeling, and in the assessment of the effects of human-induced changes in land-cover on the regional climate through altered feedbacks. The existing ALCC scenarios show large discrepancies between them, and few cover time periods older than AD 800. When these scenarios are used to assess the impact of human land-use on climate, contrasting results are obtained. It emphasizes the need of REVEALS model-based land-cover reconstructions. They might help to fine-tune descriptions of past land-cover and lead to a better understanding of how long-term changes in ALCC might have influenced climate. The REVEALS model is proved to provide better estimates of the regional vegetation/land-cover changes than the traditional use of pollen percentages. Thus, the application of REVEALS opens up the possibility of achieving a more robust assessment of land cover at regional- to continental-spatial scale throughout the Holocene. We present maps of REVEALS estimates for the percentage cover of 10 plant functional types (PFTs at 200 BP and 6000 BP, and of the two open-land PFTs "grassland" and "agricultural land" at five time-windows from 6000 BP to recent time. The LANDCLIM results are

  2. Effects of cryptogamic covers on the global carbon and nitrogen balance as investigated by different approaches

    Science.gov (United States)

    Weber, Bettina; Porada, Philipp; Elbert, Wolfgang; Burrows, Susannah; Caesar, Jennifer; Steinkamp, Jörg; Tamm, Alexandra; Andreae, Meinrat O.; Büdel, Burkhard; Kleidon, Axel; Pöschl, Ulrich

    2014-05-01

    Cryptogamic covers are composed of cyanobacteria, green algae, lichens, bryophytes, fungi and bacteria in varying proportions. As cryptogamic ground covers, comprising biological soil and rock crusts they occur on many terrestrial ground surfaces. Cryptogamic plant covers, containing epiphytic and epiphyllic crusts as well as foliose or fruticose lichens and bryophytes spread over large portions of terrestrial plant surfaces. Photoautotrophic organisms within these crusts sequester atmospheric CO2 and many of them include nitrogen-fixing cyanobacteria, utilizing atmospheric N2 to form ammonium which can be readily used by vascular plants. In a large-scale data analysis approach, we compiled all available data on the physiological properties of cryptogamic covers and developed a model to calculate their annual nitrogen fixation and net primary production. Here, we obtained a total value of 3.9 Pg a-1 for the global net uptake of carbon by cryptogamic covers, which corresponds to approximately 7% of the estimated global net primary production of terrestrial vegetation. Nitrogen assimilation of cryptogamic covers revealed a global estimate of ~49 Tg a-1, accounting for as much as about half the estimated total terrestrial biological nitrogen fixation. In a second approach, we calculated the global carbon uptake by lichens and bryophytes by means of a process-based model. In this model, we used gridded climate data combined with key habitat properties (as e.g. disturbance intervals) to predict the processes which control net carbon uptake, i.e. photosynthesis, respiration, water uptake and evaporation. The model relies on equations frequently used in dynamic vegetation models, which were combined with concepts specific to lichens and bryophytes. As this model only comprises lichens and bryophytes, the predicted terrestrial net uptake of 0.34 to 3.3 Gt a-1 is in accordance with our empirically-derived estimate. Based on this result, we quantified the amount of nitrogen

  3. 14 CFR 27.1193 - Cowling and engine compartment covering.

    Science.gov (United States)

    2010-01-01

    ... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Powerplant Fire Protection... part of the cowling or engine compartment in the normal ground and flight attitudes. (c) No drain may... covering must be provided to preclude hazardous damage to rotors or critical control components in the...

  4. Multi-temporal Assessment of Forest Cover, Stocking parameters ...

    African Journals Online (AJOL)

    user

    The study assessed forest cover, stocking parameters and above-ground tree biomass dynamics in the ..... closed woodland, open woodland, bushed grassland, Marshaland, ... structure. Three VIs were tested i.e. Atmospherically Resistance. Vegetation Index .... (2008) and Vihemäki (2009) have argued that a complex.

  5. Land Cover Classification Using ALOS Imagery For Penang, Malaysia

    Science.gov (United States)

    Sim, C. K.; Abdullah, K.; MatJafri, M. Z.; Lim, H. S.

    2014-02-01

    This paper presents the potential of integrating optical and radar remote sensing data to improve automatic land cover mapping. The analysis involved standard image processing, and consists of spectral signature extraction and application of a statistical decision rule to identify land cover categories. A maximum likelihood classifier is utilized to determine different land cover categories. Ground reference data from sites throughout the study area are collected for training and validation. The land cover information was extracted from the digital data using PCI Geomatica 10.3.2 software package. The variations in classification accuracy due to a number of radar imaging processing techniques are studied. The relationship between the processing window and the land classification is also investigated. The classification accuracies from the optical and radar feature combinations are studied. Our research finds that fusion of radar and optical significantly improved classification accuracies. This study indicates that the land cover/use can be mapped accurately by using this approach.

  6. UMTRA project disposal cell cover biointrusion sensitivity assessment, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    This study provides an analysis of potential changes that may take place in a Uranium Mill Tailings Remedial Action (UMTRA) Project disposal cell cover system as a result of plant biointrusion. Potential changes are evaluated by performing a sensitivity analysis of the relative impact of root penetrations on radon flux out of the cell cover and/or water infiltration into the cell cover. Data used in this analysis consist of existing information on vegetation growth on selected cell cover systems and information available from published studies and/or other available project research. Consistent with the scope of this paper, no new site-specific data were collected from UMTRA Project sites. Further, this paper does not focus on the issue of plant transport of radon gas or other contaminants out of the disposal cell cover though it is acknowledged that such transport has the potential to be a significant pathway for contaminants to reach the environment during portions of the design life of a disposal cell where plant growth occurs. Rather, this study was performed to evaluate the effects of physical penetration and soil drying caused by plant roots that have and are expected to continue to grow in UMTRA Project disposal cell covers. An understanding of the biological and related physical processes that take place within the cover systems of the UMTRA Project disposal cells helps the U.S. Department of Energy (DOE) determine if the presence of a plant community on these cells is detrimental, beneficial, or of mixed value in terms of the cover system`s designed function. Results of this investigation provide information relevant to the formulation of a vegetation control policy.

  7. Replacing fallow by cover crops: economic sustainability

    Science.gov (United States)

    Gabriel, José Luis; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Replacing fallow by cover crops in intensive fertilized systems has been demonstrated as an efficient tool for reducing nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of this new technology is still limited because they are either unwilling or unable, although adoption reluctance is frequently rooted in low economic profitability, low water se efficiency or poor knowledge. Economic analyses permit a comparison between the profit that farmers obtain from agricultural products and the cost of adopting specific agricultural techniques. The goal of this study was to evaluate the economic impact of replacing the usual winter fallow with cover crops (barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo)) in irrigated maize systems and variable Mediterranean weather conditions using stochastic Monte-Carlo simulations of key farms' financial performance indicators. The three scenarios studied for each cover crop were: i) just leaving the cover crop residue in the ground, ii) leaving the cover crop residue but reduce following maize fertilization according to the N available from the previous cover crop and iii) selling the cover crop residue for animal feeding. All the scenarios were compared with respect to a typical maize-fallow rotation. With observed data from six different years and in various field trials, looking for different weather conditions, probability distribution functions of maize yield, cover crop biomass production and N fertilizer saving was fitted. Based in statistical sources maize grain price, different forage prices and the cost of fertilizer were fitted to probability distribution functions too. As result, introducing a cover crop involved extra costs with respect to fallow as the initial investment, because new seed, herbicide or extra field operations. Additional

  8. Engineered soil covers for management of salt impacted sites

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, D.A. [SEACOR Environmental Inc., Vancouver, BC (Canada); Tratch, D.J. [Watermark Consulting Ltd., Regina, SK (Canada)

    2005-07-01

    The use of engineered soil cover systems to mitigate environmental impacts from tailings and waste rock piles is becoming an accepted practice. This paper presented design concepts for soil covers related to reclamation practices in the mining industry as an effective risk management practice at salt impacted sites. Research and field programs have demonstrated that a layered engineered soil cover can reduce or eliminate infiltration. Key components of the system included re-establishing surface vegetation to balance precipitation fluxes with evapotranspiration potential, and design of a capillary break below the rooting zone to minimize deeper seated infiltration. It was anticipated that the incorporation of a vegetation cover and a capillary break would minimize infiltration into the waste rock or tailing pile and reduce the generation of acid rock drainage (ARD). Design of a layered soil cover requires the incorporation of meteorological data, moisture retention characteristics of the impacted soils, and proposed engineered cover materials. Performance of the soil cover was predicted using a finite element model combined with meteorological data from the site area, unsaturated soil properties of the parent sub-surface soils and potential covered materials. The soil cover design consisted of re-vegetation and a loose clay cover overlying a compacted till layer. The design was conducted for an off site release of salt impacted pasture land adjacent to a former highway maintenance yard. The model predicted minimal infiltration during high precipitation events and no infiltration during low precipitation events. Results indicated that the proposed soil cover would enable re-establishment of a productive agricultural ground cover, as well as minimizing the potential for additional salt migration. It was concluded that further research and development is needed to ensure that the cover system is an acceptable method for long-term risk management. 17 refs., 5 figs.

  9. Estimating pinyon and juniper cover across Utah using NAIP imagery

    Directory of Open Access Journals (Sweden)

    Darrell B. Roundy

    2016-11-01

    Full Text Available Expansion of Pinus L. (pinyon and Juniperus L. (juniper (P-J trees into sagebrush (Artemisia L. steppe communities can lead to negative effects on hydrology, loss of wildlife habitat, and a decrease in desirable understory vegetation. Tree reduction treatments are often implemented to mitigate these negative effects. In order to prioritize and effectively plan these treatments, rapid, accurate, and inexpensive methods are needed to estimate tree canopy cover at the landscape scale. We used object based image analysis (OBIA software (Feature AnalystTM for ArcMap 10.1®, ENVI Feature Extraction®, and Trimble eCognition Developer 8.2® to extract tree canopy cover using NAIP (National Agricultural Imagery Program imagery. We then compared our extractions with ground measured tree canopy cover (crown diameter and line point intercept on 309 plots across 44 sites in Utah. Extraction methods did not consistently over- or under-estimate ground measured P-J canopy cover except where tree cover was >45%. Estimates of tree canopy cover using OBIA techniques were strongly correlated with estimates using the crown diameter method (r = 0.93 for ENVI, 0.91 for Feature AnalystTM, and 0.92 for eCognition. Tree cover estimates using OBIA techniques had lower correlations with tree cover measurements using the line-point intercept method (r = 0.85 for ENVI, 0.83 for Feature AnalystTM, and 0.83 for eCognition. All software packages accurately and inexpensively extracted P-J canopy cover from NAIP imagery when the imagery was not blurred, and when P-J cover was not mixed with Amelanchier alnifolia (Utah serviceberry and Quercus gambelii (Gambel’s oak, which had similar spectral values as P-J.

  10. Hanford site ground water protection management plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    Ground water protection at the Hanford Site consists of preventative and remedial measures that are implemented in compliance with a variety of environmental regulations at local, state, and federal levels. These measures seek to ensure that the resource can sustain a broad range of beneficial uses. To effectively coordinate and ensure compliance with applicable regulations, the U.S. Department of Energy has issued DOE Order 5400.1 (DOE 1988a). This order requires all U.S. Department of Energy facilities to prepare separate ground water protection program descriptions and plans. This document describes the Ground Water Protection Management Plan (GPMP) for the Hanford Site located in the state of Washington. DOE Order 5400.1 specifies that the GPMP covers the following general topical areas: (1) documentation of the ground water regime; (2) design and implementation of a ground water monitoring program to support resource management and comply with applicable laws and regulations; (3) a management program for ground water protection and remediation; (4) a summary and identification of areas that may be contaminated with hazardous waste; (5) strategies for controlling hazardous waste sources; (6) a remedial action program; and (7) decontamination, decommissioning, and related remedial action requirements. Many of the above elements are currently covered by existing programs at the Hanford Site; thus, one of the primary purposes of this document is to provide a framework for coordination of existing ground water protection activities. The GPMP provides the ground water protection policy and strategies for ground water protection/management at the Hanford Site, as well as an implementation plan to improve coordination of site ground water activities.

  11. Small-scale indirect effects determine the outcome of a tripartite plant-disperser-granivore interaction.

    Science.gov (United States)

    Boulay, Raphaël; Carro, Francisco; Soriguer, Ramón C; Cerdá, Xim

    2009-09-01

    The microhabitat in which plants grow affects the outcome of their interactions with animals, particularly non-specialist consumers. Nevertheless, as most research on this topic has dealt with either mutualists or antagonists, little is known about the indirect effects of plant microhabitats on the outcome of tripartite interactions involving plants and both mutualists (e.g. seed dispersers) and antagonists (e.g. granivores). During three consecutive years, we analysed small-scale variations in the interaction of a perennial myrmecochore, Helleborus foetidus, with its seed dispersers and consumers as a function of the intensity of plant cover. Most seeds were released during the day and were rapidly removed by ants. Nevertheless, the proportion of ant-removed seeds was higher for plants located in open microhabitats than for plants surrounded by dense vegetation and rocky cover. Ant sampling revealed that seed removers were equally abundant, irrespective of the level of cover. By contrast, a few tiny ant species that feed on the reward without transporting the seeds were more abundant in highly covered microhabitats, irrespective of hellebore diaspore availability. These "cheaters" decrease the chance of removal by removers and increase the probability of seeds remaining on the ground until night, when granivore mice Apodemus sylvaticus become active. Mice also preferred foraging in covered microhabitats, where they consumed a larger proportion of seeds. Therefore, the density of cover indirectly increased seed predation risk by attracting more seed predators and cheater ants that contribute to increase seed availability for seed predators. Our results emphasize the importance of considering the indirect effects of plant microhabitat on their dispersal success. They highlight the indirect effect of cheaters that are likely to interfere in mutualisms and may lead to their collapse unless external factors such as spatio-temporal heterogeneity in seed availability

  12. Influence of cover crop and intercrop systems on Bemisia argentifolli (Hemiptera: Aleyrodidae) infestation and associated squash silverleaf disorder in zucchini.

    Science.gov (United States)

    Manandhar, Roshan; Hooks, Cerruti R R; Wright, Mark G

    2009-04-01

    Field experiments were conducted to evaluate the effects of cover cropping and intercropping on population densities of silverleaf whitefly, Bemisia argentifolli Bellow and Perring, and the incidence of squash silverleaf disorder (SSL) in zucchini, Cucurbita pepo L., in Oahu, HI. Two cover crops, buckwheat (BW), Fagopyrum esculentum Moench, and white clover (WC), Trifolium repens L., or sunn hemp (SH), Crotolaria juncea L., and an intercropped vegetable, okra, Abelmonchus esculentus L., were evaluated during the 2003, 2005, and 2006 growing seasons, respectively. Population densities of whiteflies and SSL severity varied during the three field experiments. In 2003, the severity of SSL and percentage of leaves displaying symptoms were significantly lower on zucchini plants in WC than BW plots throughout the crops' growth cycle. Additionally, the percentage of leaves per plant displaying SSL symptoms was significantly greater in bare-ground (BG) compared with the pooled BW and WC treatments on each inspection date. In 2005, zucchini intercropped with okra had lower numbers of adult whiteflies and resulted in significantly lower severity of SSL than pooled BW and WC treatments. During 2006, zucchini grown with SH had significantly lower numbers of all whitefly stages (i.e., egg, immature, and adult) and less SSL severity symptoms than BW. Despite these differences in whitefly numbers and SSL severity, marketable yields were not significantly lower in BW compared with WC or SH treatment plots during the study. The mechanisms underlying these results and the feasibility of using cover crops and intercrops to manage B. argentifolli and SSL are discussed.

  13. Set Covering Problems with General Objective Functions

    CERN Document Server

    Cardinal, Jean

    2008-01-01

    We introduce a parameterized version of set cover that generalizes several previously studied problems. Given a ground set V and a collection of subsets S_i of V, a feasible solution is a partition of V such that each subset of the partition is included in one of the S_i. The problem involves maximizing the mean subset size of the partition, where the mean is the generalized mean of parameter p, taken over the elements. For p=-1, the problem is equivalent to the classical minimum set cover problem. For p=0, it is equivalent to the minimum entropy set cover problem, introduced by Halperin and Karp. For p=1, the problem includes the maximum-edge clique partition problem as a special case. We prove that the greedy algorithm simultaneously approximates the problem within a factor of (p+1)^1/p for any p in R^+, and that this is the best possible unless P=NP. These results both generalize and simplify previous results for special cases. We also consider the corresponding graph coloring problem, and prove several tr...

  14. Development and Validation of a SPME-GC-MS Method for In situ Passive Sampling of Root Volatiles from Glasshouse-Grown Broccoli Plants Undergoing Below-Ground Herbivory by Larvae of Cabbage Root Fly, Delia radicum L.

    Science.gov (United States)

    Deasy, William; Shepherd, Tom; Alexander, Colin J; Birch, A Nicholas E; Evans, K Andrew

    2016-11-01

    Research on plant root chemical ecology has benefited greatly from recent developments in analytical chemistry. Numerous reports document techniques for sampling root volatiles, although only a limited number describe in situ collection. To demonstrate a new method for non-invasive in situ passive sampling using solid phase micro extraction (SPME), from the immediate vicinity of growing roots. SPME fibres inserted into polyfluorotetrafluoroethylene (PTFE) sampling tubes located in situ which were either perforated, covered with stainless steel mesh or with microporous PTFE tubing, were used for non-invasive sub-surface sampling of root volatiles from glasshouse-grown broccoli. Sampling methods were compared with above surface headspace collection using Tenax TA. The roots were either mechanically damaged or infested with Delia radicum larvae. Principal component analysis (PCA) was used to investigate the effect of damage on the composition of volatiles released by broccoli roots. Analyses by gas chromatography-mass spectrometry (GC-MS) with SPME and automated thermal desorption (ATD) confirmed that sulphur compounds, showing characteristic temporal emission patterns, were the principal volatiles released by roots following insect larval damage. Use of SPME with in situ perforated PTFE sampling tubes was the most robust method for out-of-lab sampling. This study describes a new method for non-invasive passive sampling of volatiles in situ from intact and insect damaged roots using SPME. The method is highly suitable for remote sampling and has potential for wide application in chemical ecology/root/soil research. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Combinatorial aspects of covering arrays

    Directory of Open Access Journals (Sweden)

    Charles J. Colbourn

    2004-11-01

    Full Text Available Covering arrays generalize orthogonal arrays by requiring that t -tuples be covered, but not requiring that the appearance of t -tuples be balanced.Their uses in screening experiments has found application in software testing, hardware testing, and a variety of fields in which interactions among factors are to be identified. Here a combinatorial view of covering arrays is adopted, encompassing basic bounds, direct constructions, recursive constructions, algorithmic methods, and applications.

  16. Ground water and energy

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This national workshop on ground water and energy was conceived by the US Department of Energy's Office of Environmental Assessments. Generally, OEA needed to know what data are available on ground water, what information is still needed, and how DOE can best utilize what has already been learned. The workshop focussed on three areas: (1) ground water supply; (2) conflicts and barriers to ground water use; and (3) alternatives or solutions to the various issues relating to ground water. (ACR)