How do bryophytes govern generative recruitment of vascular plants?

NARCIS (Netherlands)

Soudzilovskaia, N.A.; Graae, B.J.; Douma, J.C.; Grau, O.; Milbau, A.; Shevtsova, A.; Wolters, L.; Cornelissen, J.H.C.

2011-01-01

Interactions between vascular plants and bryophytes determine plant community composition in many ecosystems. Yet, little is known about the importance of interspecific differences between bryophytes with respect to their effects on vascular plants. We compared the extent to which species-specific

Temporal deconvolution of vascular plant signatures delivered to coastal sediments

Science.gov (United States)

Vonk, J.; Drenzek, N. J.; Hughen, K. A.; Stanley, R.; Montluçon, D. B.; McIntyre, C.; Southon, J. R.; Santos, G.; Andersson, A.; Sköld, M.; Eglinton, T. I.

2017-12-01

Presently, relatively little is known about the amount of time that lapses between the photosynthetic fixation of carbon by vascular land plants and its incorporation into the marine sedimentary record. It is clear that there are multiple potential intermediate storage pools and transport trajectories that vascular plant carbon may experience, and the age of vascular plant carbon accumulating in marine sediments will reflect these different pre-depositional histories. Here we use molecular-level radiocarbon (14C) analysis to develop down-core 14C profiles for higher plant leaf wax-derived fatty acids isolated from sediments from three sites across a 60-degrees latitudinal gradient (Cariaco Basin, Saanich Inlet, and Mackenzie Delta). The sediment profiles were used as a direct measure of the storage and transport times experienced by these biomolecular tracer compounds. Residence times are evaluated by comparing these records to the 14C history of atmospheric CO2. Using a modeling framework, we conclude that there is, in addition to a variable "young" pool, a millennial pool of compounds that consists of 49-78 % of the fractional contribution of organic carbon (OC) that exhibits variable ages for the different depositional settings. For the Mackenzie Delta sediments, we find a mean age of the millennial pool of 28 ky, suggesting pre-aging in permafrost soils, whereas the millennial pool in Saanich Inlet and Cariaco Basin sediments is younger with 7.9 and 2.4-3.2 ky, respectively, suggesting limited storage in terrestrial reservoirs. The "young" pool, conditionally defined as vascular plant C in deltaic and marine settings undergoes pre-aging in terrestrial reservoirs. The age distribution, reflecting storage and transport times, depends on landscape-specific factors such as local topography, hydrographic characteristics, and degree of soil build-up and preservation.

Methane dynamics in Northern Wetlands: Significance of vascular plants

Energy Technology Data Exchange (ETDEWEB)

Joabsson, Anna

2001-09-01

The studies presented illustrate several different aspects of the impact of vascular plants on methane emissions from northern natural wetlands. The subject has been approached on different scales, ranging from the study of microbial substrates in the vicinity of a single plant root, to an attempt to extrapolate some of the results to the entire northern hemisphere north of 50 meridian. The main overall conclusions from the papers are that vascular plants affect net methane emissions 1) by offering an efficient route of transport to the atmosphere so that methane oxidation in oxic surface soils is avoided, and 2) by being sources of methanogenic substrate. The degree to which vascular wetland plants affect methane emissions seems to be dependent on species-specific differences in both the capacity to act as gas conduits and the exudation of labile carbon compounds to the soil. An intimate coupling between vascular plant production and methane emission was found in an Arctic tundra wetland, although other environmental variables (water table, temperature) also contributed significantly to the explained variation in methane exchange. Studies of vascular plant extidation of organic acids suggest that the available pool of methanogenic substrates is both qualitatively and quantitatively correlated to vascular plant production (photosynthetic rate). On global scales, vascular plant production as a single factor does not seem to be sufficient to explain the majority of variation in methane flux patterns. Based on comparable experiments at five different sites in the northwestern Eurasian and Greenlandic North, we suggest that mean seasonal soil temperature is the best predictor of methane exchange on broad spatial and temporal scales.

Early vascular plants in the Czech Republic

OpenAIRE

Uhlířová, Monika

2017-01-01

Vascular plants are characterized as a group of plants, which are already fully adapted to live on the land. Their evolution is a result of a set of adaptations that have required the necessary changes at anatomical and morphological level. Some evidences about the rise of vascular plants appear in the fossil record from the Middle Ordovician in the form of spores and later also from the Early Silurian in the form of megafossils. The aim of the thesis is to briefly describe and discuss the mo...

Origin and radiation of the earliest vascular land plants.

Science.gov (United States)

Steemans, Philippe; Hérissé, Alain Le; Melvin, John; Miller, Merrell A; Paris, Florentin; Verniers, Jacques; Wellman, Charles H

2009-04-17

Colonization of the land by plants most likely occurred in a stepwise fashion starting in the Mid-Ordovician. The earliest flora of bryophyte-like plants appears to have been cosmopolitan and dominated the planet, relatively unchanged, for some 30 million years. It is represented by fossilized dispersed cryptospores and fragmentary plant remains. In the Early Silurian, cryptospore abundance and diversity diminished abruptly as trilete spores appeared, became abundant, and underwent rapid diversification. This change coincides approximately with the appearance of vascular plant megafossils and probably represents the origin and adaptive radiation of vascular plants. We have obtained a diverse trilete spore occurrence from the Late Ordovician that suggests that vascular plants originated and diversified earlier than previously hypothesized, in Gondwana, before migrating elsewhere and secondarily diversifying.

Diversification of Root Hair Development Genes in Vascular Plants.

Science.gov (United States)

Huang, Ling; Shi, Xinhui; Wang, Wenjia; Ryu, Kook Hui; Schiefelbein, John

2017-07-01

The molecular genetic program for root hair development has been studied intensively in Arabidopsis ( Arabidopsis thaliana ). To understand the extent to which this program might operate in other plants, we conducted a large-scale comparative analysis of root hair development genes from diverse vascular plants, including eudicots, monocots, and a lycophyte. Combining phylogenetics and transcriptomics, we discovered conservation of a core set of root hair genes across all vascular plants, which may derive from an ancient program for unidirectional cell growth coopted for root hair development during vascular plant evolution. Interestingly, we also discovered preferential diversification in the structure and expression of root hair development genes, relative to other root hair- and root-expressed genes, among these species. These differences enabled the definition of sets of genes and gene functions that were acquired or lost in specific lineages during vascular plant evolution. In particular, we found substantial divergence in the structure and expression of genes used for root hair patterning, suggesting that the Arabidopsis transcriptional regulatory mechanism is not shared by other species. To our knowledge, this study provides the first comprehensive view of gene expression in a single plant cell type across multiple species. © 2017 American Society of Plant Biologists. All Rights Reserved.

Distributions of vascular plants in the Czech Republic. Part 4

Czech Academy of Sciences Publication Activity Database

Kaplan, Zdeněk; Danihelka, Jiří; Koutecký, P.; Šumberová, Kateřina; Ekrt, L.; Grulich, V.; Řepka, R.; Hroudová, Zdenka; Štěpánková, Jitka; Dvořák, V.; Dančák, M.; Dřevojan, P.; Wild, Jan

2017-01-01

Roč. 89, č. 2 (2017), s. 115-201 ISSN 0032-7786 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : distribution * maps * phytogeography Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 3.000, year: 2016

Distributions of vascular plants in the Czech Republic. Part 5

Czech Academy of Sciences Publication Activity Database

Kaplan, Zdeněk; Danihelka, Jiří; Šumberová, Kateřina; Chrtek, Jindřich; Rotreklová, O.; Ekrt, L.; Štěpánková, Jitka; Taraška, V.; Trávníček, B.; Prančl, Jan; Ducháček, M.; Hroneš, M.; Kobrlová, L.; Horák, D.; Wild, Jan

2017-01-01

Roč. 89, č. 4 (2017), s. 333-439 ISSN 0032-7786 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : distribution * maps * phytogeography Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 3.000, year: 2016

The phylogenetic distribution of extrafloral nectaries in plants.

Science.gov (United States)

Weber, Marjorie G; Keeler, Kathleen H

2013-06-01

Understanding the evolutionary patterns of ecologically relevant traits is a central goal in plant biology. However, for most important traits, we lack the comprehensive understanding of their taxonomic distribution needed to evaluate their evolutionary mode and tempo across the tree of life. Here we evaluate the broad phylogenetic patterns of a common plant-defence trait found across vascular plants: extrafloral nectaries (EFNs), plant glands that secrete nectar and are located outside the flower. EFNs typically defend plants indirectly by attracting invertebrate predators who reduce herbivory. Records of EFNs published over the last 135 years were compiled. After accounting for changes in taxonomy, phylogenetic comparative methods were used to evaluate patterns of EFN evolution, using a phylogeny of over 55 000 species of vascular plants. Using comparisons of parametric and non-parametric models, the true number of species with EFNs likely to exist beyond the current list was estimated. To date, EFNs have been reported in 3941 species representing 745 genera in 108 families, about 1-2 % of vascular plant species and approx. 21 % of families. They are found in 33 of 65 angiosperm orders. Foliar nectaries are known in four of 36 fern families. Extrafloral nectaries are unknown in early angiosperms, magnoliids and gymnosperms. They occur throughout monocotyledons, yet most EFNs are found within eudicots, with the bulk of species with EFNs being rosids. Phylogenetic analyses strongly support the repeated gain and loss of EFNs across plant clades, especially in more derived dicot families, and suggest that EFNs are found in a minimum of 457 independent lineages. However, model selection methods estimate that the number of unreported cases of EFNs may be as high as the number of species already reported. EFNs are widespread and evolutionarily labile traits that have repeatedly evolved a remarkable number of times in vascular plants. Our current understanding of the

New records of alien vascular plants from Marion and Prince Edward Islands, sub-Antarctic

NARCIS (Netherlands)

Gremmen, N.J.M.; Smith, V.

1999-01-01

A survey was made of the distribution of introduced vascular plants on Marion and Prince Edward Islands. The results of this survey were compared to results of previous surveys (1965/66, 1975, 1981, 1989). Four new introductions to Marion Island have taken place, three of which involved species that

Origins of native vascular plants of Antarctica: comments from a historical phytogeography viewpoint.

Science.gov (United States)

Mosyakin, S L; Bezusko, L G; Mosyakin, A S

2007-01-01

The article provides an overview of the problem of origin of the only native vascular plants of Antarctica, Deschampsia antartica (Poaceae) and Colobanthus quitensis (Caryophyllaceae), from the viewpoint of modern historical phytogeography and related fields of science. Some authors suggested the Tertiary relict status of these plants in Antarctica, while others favour their recent Holocene immigration. Direct data (fossil or molecular genetic ones) for solving this controversy is still lacking. However, there is no convincing evidence supporting the Tertiary relict status of these plants in Antarctica. Most probably D. antarctica and C. quitensis migrated to Antarctica in the Holocene or Late Pleistocene (last interglacial?) through bird-aided long-distance dispersal. It should be critically tested by (1) appropriate methods of molecular phylogeography, (2) molecular clock methods, if feasible, (3) direct paleobotanical studies, (4) paleoclimatic reconstructions, and (5) comparison with cases of taxa with similar distribution/dispersal patterns. The problem of the origin of Antarctic vascular plants is a perfect model for integration of modern methods of molecular phylogeography and phylogenetics, population biology, paleobiology and paleogeography for solving a long-standing enigma of historical plant geography and evolution.

Florabank1: a grid-based database on vascular plant distribution in the northern part of Belgium (Flanders and the Brussels Capital region

Directory of Open Access Journals (Sweden)

Wouter Van Landuyt

2012-05-01

Full Text Available Florabank1 is a database that contains distributional data on the wild flora (indigenous species, archeophytes and naturalised aliens of Flanders and the Brussels Capital Region. It holds about 3 million records of vascular plants, dating from 1800 till present. Furthermore, it includes ecological data on vascular plant species, redlist category information, Ellenberg values, legal status, global distribution, seed bank etc. The database is an initiative of “Flo.Wer” (www.plantenwerkgroep.be, the Research Institute for Nature and Forest (INBO: www.inbo.be and the National Botanic Garden of Belgium (www.br.fgov.be. Florabank aims at centralizing botanical distribution data gathered by both professional and amateur botanists and to make these data available to the benefit of nature conservation, policy and scientific research.The occurrence data contained in Florabank1 are extracted from checklists, literature and herbarium specimen information. Of survey lists, the locality name (verbatimLocality, species name, observation date and IFBL square code, the grid system used for plant mapping in Belgium (Van Rompaey 1943, is recorded. For records dating from the period 1972–2004 all pertinent botanical journals dealing with Belgian flora were systematically screened. Analysis of herbarium specimens in the collection of the National Botanic Garden of Belgium, the University of Ghent and the University of Liège provided interesting distribution knowledge concerning rare species, this information is also included in Florabank1. The data recorded before 1972 is available through the Belgian GBIF node (http://data.gbif.org/datasets/resource/10969/, not through FLORABANK1, to avoid duplication of information. A dedicated portal providing access to all published Belgian IFBL records at this moment is available at: http://projects.biodiversity.be/ifblAll data in Florabank1 is georeferenced. Every record holds the decimal centroid coordinates of the

Radiocontamination patterns of vascular plants in a forest ecosystem

International Nuclear Information System (INIS)

Nimis, P.L.; Bolognini, G.; Giovani, C.

1994-01-01

This study is based on measurements of radiocesium and potassium-40 in leaves, stems and roots of 48 vascular plants in a natural beech forest in the Carnic Alps (NE Italy). The data have been submitted to numerical classification, and the main results are: (a) radiocontamination patterns and ecology of the species are well related, (b) three main groups of species with different radiocontamination can be distinguished: plants in clearings, forest plants rooting in the organic soil layer, forest plants rooting in the mineral layer; (c) radiocesium tends to be retained in the roots, especially in plants in the clearings; (d) Pteridophytes, contrary to all other plants, are able to discriminate between cesium and potassium at leaf level; (e) for all other species, cesium and potassium, once taken up by the plant, exhibit a similar behaviour; (f) total contamination by radiocesium is related to the depth of the root systems, and to the unequal distribution of radiocesium in the soil profile. Species-specific mechanisms of differential absorption are not evident in the investigated forest; the radiocontamination of plants can be easily explained in ecological terms. Radiocontamination on a water basis (Bq/l) is suggested as being much more appropriate for solving certain radioecological problems

Physicochemical hydrodynamics of porous structures in vascular plants

Science.gov (United States)

Ryu, Jeongeun; Ahn, Sungsook; Kim, Seung-Gon; Kim, Taejoo; Lee, Sang Joon

2013-11-01

Transport of sap flow through xylem conduits of vascular plants has been considered as a passive process, because the xylem conduits are regarded as inert, dead wood. However, plants can actively regulate water transport using ion-mediated response for adapting to environmental changes. In order to understand the active regulation mechanism of physicochemical hydrodynamics of porous structures in vascular plants, the effects of specific ion types and their ionic ratios on the water transport were experimentally investigated under in vivocondition. Based on the experimental results, the principle of ionic effects will be explained through in-vitro comparative experiments and theoretical considerations. This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government (MSIP) (No. 2008-0061991).

Modelling the development and arrangement of the primary vascular structure in plants.

Science.gov (United States)

Cartenì, Fabrizio; Giannino, Francesco; Schweingruber, Fritz Hans; Mazzoleni, Stefano

2014-09-01

The process of vascular development in plants results in the formation of a specific array of bundles that run throughout the plant in a characteristic spatial arrangement. Although much is known about the genes involved in the specification of procambium, phloem and xylem, the dynamic processes and interactions that define the development of the radial arrangement of such tissues remain elusive. This study presents a spatially explicit reaction-diffusion model defining a set of logical and functional rules to simulate the differentiation of procambium, phloem and xylem and their spatial patterns, starting from a homogeneous group of undifferentiated cells. Simulation results showed that the model is capable of reproducing most vascular patterns observed in plants, from primitive and simple structures made up of a single strand of vascular bundles (protostele), to more complex and evolved structures, with separated vascular bundles arranged in an ordered pattern within the plant section (e.g. eustele). The results presented demonstrate, as a proof of concept, that a common genetic-molecular machinery can be the basis of different spatial patterns of plant vascular development. Moreover, the model has the potential to become a useful tool to test different hypotheses of genetic and molecular interactions involved in the specification of vascular tissues.

Vascular Gene Expression: A Hypothesis

Directory of Open Access Journals (Sweden)

Angélica Concepción eMartínez-Navarro

2013-07-01

Full Text Available The phloem is the conduit through which photoassimilates are distributed from autotrophic to heterotrophic tissues and is involved in the distribution of signaling molecules that coordinate plant growth and responses to the environment. Phloem function depends on the coordinate expression of a large array of genes. We have previously identified conserved motifs in upstream regions of the Arabidopsis genes, encoding the homologs of pumpkin phloem sap mRNAs, displaying expression in vascular tissues. This tissue-specific expression in Arabidopsis is predicted by the overrepresentation of GA/CT-rich motifs in gene promoters. In this work we have searched for common motifs in upstream regions of the homologous genes from plants considered to possess a primitive vascular tissue (a lycophyte, as well as from others that lack a true vascular tissue (a bryophyte, and finally from chlorophytes. Both lycophyte and bryophyte display motifs similar to those found in Arabidopsis with a significantly low E-value, while the chlorophytes showed either a different conserved motif or no conserved motif at all. These results suggest that these same genes are expressed coordinately in non- vascular plants; this coordinate expression may have been one of the prerequisites for the development of conducting tissues in plants. We have also analyzed the phylogeny of conserved proteins that may be involved in phloem function and development. The presence of CmPP16, APL, FT and YDA in chlorophytes suggests the recruitment of ancient regulatory networks for the development of the vascular tissue during evolution while OPS is a novel protein specific to vascular plants.

Non-native vascular plants from Canary Islands (Spain): nomenclatural and taxonomical adjustments

OpenAIRE

Verloove, F.

2013-01-01

Se propone correcciones taxonómicas y nomenclaturales respecto a 88 taxones no nativos de la lista de plantas vasculares de las Islas Canarias (España). Non-native vascular plants from Canary Islands (Spain): nomenclatural and taxonomical adjustments. Corrections and other adjustments are proposed for 88 non-native taxa from the checklist of vascular plants from the Canary Islands (Spain).

Moss and vascular plant indices in Ohio wetlands have similar environmental predictors

Science.gov (United States)

Stapanian, Martin A.; Schumacher, William; Gara, Brian; Adams, Jean V.; Viau, Nick

2016-01-01

Mosses and vascular plants have been shown to be reliable indicators of wetland habitat delineation and environmental quality. Knowledge of the best ecological predictors of the quality of wetland moss and vascular plant communities may determine if similar management practices would simultaneously enhance both populations. We used Akaike's Information Criterion to identify models predicting a moss quality assessment index (MQAI) and a vascular plant index of biological integrity based on floristic quality (VIBI-FQ) from 27 emergent and 13 forested wetlands in Ohio, USA. The set of predictors included the six metrics from a wetlands disturbance index (ORAM) and two landscape development intensity indices (LDIs). The best single predictor of MQAI and one of the predictors of VIBI-FQ was an ORAM metric that assesses habitat alteration and disturbance within the wetland, such as mowing, grazing, and agricultural practices. However, the best single predictor of VIBI-FQ was an ORAM metric that assessed wetland vascular plant communities, interspersion, and microtopography. LDIs better predicted MQAI than VIBI-FQ, suggesting that mosses may either respond more rapidly to, or recover more slowly from, anthropogenic disturbance in the surrounding landscape than vascular plants. These results supported previous predictive studies on amphibian indices and metrics and a separate vegetation index, indicating that similar wetland management practices may result in qualitatively the same ecological response for three vastly different wetland biological communities (amphibians, vascular plants, and mosses).

Use of gold nanoparticles to detect water uptake in vascular plants.

Science.gov (United States)

Hwang, Bae Geun; Ahn, Sungsook; Lee, Sang Joon

2014-01-01

Direct visualization of water-conducting pathways and sap flows in xylem vessels is important for understanding the physiology of vascular plants and their sap ascent. Gold nanoparticles (AuNPs) combined with synchrotron X-ray imaging technique is a new promising tool for investigating plant hydraulics in opaque xylem vessels of vascular plants. However, in practical applications of AuNPs for real-time quantitative visualization of sap flows, their interaction with a vascular network needs to be verified in advance. In this study, the effect of AuNPs on the water-refilling function of xylem vessels is experimentally investigated with three monocot species. Discrepancy in the water uptakes starts to appear at about 20 min to 40 min after the supply of AuNP solution to the test plant by the possible gradual accumulation of AuNPs on the internal structures of vasculature. However conclusively, it is observed that the water-refilling speeds in individual xylem vessels are virtually unaffected by hydrophilically surface-modified AuNPs (diameter ∼20 nm). Therefore, the AuNPs can be effectively used as flow tracers in the xylem vessels in the first 20∼30 min without any physiological barrier. As a result, AuNPs are found to be useful for visualizing various fluid dynamic phenomena occurring in vascular plants.

Toxicity, Uptake, and Translocation of Engineered Nanomaterials in Vascular plants.

Science.gov (United States)

Miralles, Pola; Church, Tamara L; Harris, Andrew T

2012-09-04

To exploit the promised benefits of engineered nanomaterials, it is necessary to improve our knowledge of their bioavailability and toxicity. The interactions between engineered nanomaterials and vascular plants are of particular concern, as plants closely interact with soil, water, and the atmosphere, and constitute one of the main routes of exposure for higher species, i.e. accumulation through the food chain. A review of the current literature shows contradictory evidence on the phytotoxicity of engineered nanomaterials. The mechanisms by which engineered nanomaterials penetrate plants are not well understood, and further research on their interactions with vascular plants is required to enable the field of phytotoxicology to keep pace with that of nanotechnology, the rapid evolution of which constantly produces new materials and applications that accelerate the environmental release of nanomaterials.

Diversity of vascular plants of Piestany and surroundings

International Nuclear Information System (INIS)

Penzesova, A.; Galusova, T.

2013-01-01

In the present work is a summary of the results of floristic research aimed at determining diversity of vascular plants of Piestany and its surroundings. Plant taxa we determined using the designation keys. We have compiled a list of plant species occurring in the monitored area, we evaluated the selected botanical-phytogeographical characteristics of flora, we've put together a list of local protected, endangered and rare species and a list of local invasive and expansive species according to sources. (Authors)

The mitochondrial genome of the lycophyte Huperzia squarrosa: the most archaic form in vascular plants.

Science.gov (United States)

Liu, Yang; Wang, Bin; Cui, Peng; Li, Libo; Xue, Jia-Yu; Yu, Jun; Qiu, Yin-Long

2012-01-01

Mitochondrial genomes have maintained some bacterial features despite their residence within eukaryotic cells for approximately two billion years. One of these features is the frequent presence of polycistronic operons. In land plants, however, it has been shown that all sequenced vascular plant chondromes lack large polycistronic operons while bryophyte chondromes have many of them. In this study, we provide the completely sequenced mitochondrial genome of a lycophyte, from Huperzia squarrosa, which is a member of the sister group to all other vascular plants. The genome, at a size of 413,530 base pairs, contains 66 genes and 32 group II introns. In addition, it has 69 pseudogene fragments for 24 of the 40 protein- and rRNA-coding genes. It represents the most archaic form of mitochondrial genomes of all vascular plants. In particular, it has one large conserved gene cluster containing up to 10 ribosomal protein genes, which likely represents a polycistronic operon but has been disrupted and greatly reduced in the chondromes of other vascular plants. It also has the least rearranged gene order in comparison to the chondromes of other vascular plants. The genome is ancestral in vascular plants in several other aspects: the gene content resembling those of charophytes and most bryophytes, all introns being cis-spliced, a low level of RNA editing, and lack of foreign DNA of chloroplast or nuclear origin.

The plant vascular system: Evolution, development and functions

Science.gov (United States)

William J. Lucas; Andrew Groover; Raffael Lichtenberger; Kaori Furuta; Shri-Ram Yadav; Yka Helariutta; Xin-Qiang He; Hiroo Fukuda; Julie Kang; Siobhan M. Brady; John W. Patrick; John Sperry; Akiko Yoshida; Ana-Flor Lopez-Millan; Michael A. Grusak; Pradeep Kachroo

2013-01-01

The emergence of the tracheophyte-based vascular system of land plants had major impacts on the evolution of terrestrial biology, in general, through its role in facilitating the development of plants with increased stature, photosynthetic output, and ability to colonize a greatly expanded range of environmental habitats. Recently, considerable progress has been made...

Aboveground persistence of vascular plants in relationship to the levels of airborne nutrient deposition

NARCIS (Netherlands)

Hendriks, R.J.J.; Ozinga, W.A.; Berg, van den L.J.L.; Noordwijk, E.; Schaminee, J.H.J.; Groenendael, van J.M.

2014-01-01

This paper examines whether high atmospheric nitrogen deposition affects aboveground persistence of vascular plants. We combined information on local aboveground persistence of vascular plants in 245 permanent plots in the Netherlands with estimated level of nitrogen deposition at the time of

Metabolic patterns of 14C incorporation by selected vascular plants following field incubations with acetate-2-14C in two plant successional stages in Glacier Bay, Alaska

International Nuclear Information System (INIS)

Wu, Pei-Hsing Lin

1975-01-01

Metabolic patterns of some vascular plants (Dryas sp., Vaccinium sp., Salix sp., Alnus sp., Epilobium sp.), occurring in successional habitats, following acetate-2- 14 C incubations in the field were demonstrated for the first time. Relative radioactivity within the alcoholic soluble fraction of each species reflects its distribution in successional communities. A high level of 14 C-sugars was present in the plants of the pioneer community; on the other hand a high level of 14 C-organic acids was present in the plants of the forest community. Three patterns, based on the relative activities of the sugar- and organic acid-pools were noted which correspond to the range and the frequency of occurrence of each species in the successional stages. Only two types of 14 C-amino acid levels were noted corresponding to the range of distribution. Plants having less than 10% relative radioactivity in amino acid-pools had a limited range of distribution and reside in only one habitat; plants having more than 10% radioactivity showed wider ranges of distribution occurring in at least two habitats. (auth.)

Double-filter identification of vascular-expressed genes using Arabidopsis plants with vascular hypertrophy and hypotrophy.

Science.gov (United States)

Ckurshumova, Wenzislava; Scarpella, Enrico; Goldstein, Rochelle S; Berleth, Thomas

2011-08-01

Genes expressed in vascular tissues have been identified by several strategies, usually with a focus on mature vascular cells. In this study, we explored the possibility of using two opposite types of altered tissue compositions in combination with a double-filter selection to identify genes with a high probability of vascular expression in early organ primordia. Specifically, we generated full-transcriptome microarray profiles of plants with (a) genetically strongly reduced and (b) pharmacologically vastly increased vascular tissues and identified a reproducible cohort of 158 transcripts that fulfilled the dual requirement of being underrepresented in (a) and overrepresented in (b). In order to assess the predictive value of our identification scheme for vascular gene expression, we determined the expression patterns of genes in two unbiased subsamples. First, we assessed the expression patterns of all twenty annotated transcription factor genes from the cohort of 158 genes and found that seventeen of the twenty genes were preferentially expressed in leaf vascular cells. Remarkably, fifteen of these seventeen vascular genes were clearly expressed already very early in leaf vein development. Twelve genes with published leaf expression patterns served as a second subsample to monitor the representation of vascular genes in our cohort. Of those twelve genes, eleven were preferentially expressed in leaf vascular tissues. Based on these results we propose that our compendium of 158 genes represents a sample that is highly enriched for genes expressed in vascular tissues and that our approach is particularly suited to detect genes expressed in vascular cell lineages at early stages of their inception. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Why are most aquatic plants widely distributed? Dispersal, clonal growth and small-scale heterogeneity in a stressful environment

NARCIS (Netherlands)

Santamaria, L.

2002-01-01

Non-marine aquatic vascular plants generally show broad distributional ranges. Climatic factors seem to have limited effects on their distributions, besides the determination of major disjunctions (tropical-temperate-subarctic). Dispersal should have been frequent enough to assure the quick

Sample sequencing of vascular plants demonstrates widespread conservation and divergence of microRNAs.

Science.gov (United States)

Chávez Montes, Ricardo A; de Fátima Rosas-Cárdenas, Flor; De Paoli, Emanuele; Accerbi, Monica; Rymarquis, Linda A; Mahalingam, Gayathri; Marsch-Martínez, Nayelli; Meyers, Blake C; Green, Pamela J; de Folter, Stefan

2014-04-23

Small RNAs are pivotal regulators of gene expression that guide transcriptional and post-transcriptional silencing mechanisms in eukaryotes, including plants. Here we report a comprehensive atlas of sRNA and miRNA from 3 species of algae and 31 representative species across vascular plants, including non-model plants. We sequence and quantify sRNAs from 99 different tissues or treatments across species, resulting in a data set of over 132 million distinct sequences. Using miRBase mature sequences as a reference, we identify the miRNA sequences present in these libraries. We apply diverse profiling methods to examine critical sRNA and miRNA features, such as size distribution, tissue-specific regulation and sequence conservation between species, as well as to predict putative new miRNA sequences. We also develop database resources, computational analysis tools and a dedicated website, http://smallrna.udel.edu/. This study provides new insights on plant sRNAs and miRNAs, and a foundation for future studies.

Vascular plants of Mt. Dosolsan in the Demilitarized Zone Civilian Control Line

Directory of Open Access Journals (Sweden)

Jong Bin An

2018-06-01

Full Text Available This study is aimed at identifying the distribution of vascular plants growing at Mt. Dosolsan in Yanggu-gun, Gangwon-do. Field surveys were conducted for each season from March 2014 to November 2016. The flora of study area is found to consist of 516 taxa, 91 families, 296 genus, 455 species, four subspecies, 50 varieties, and seven forma. Rare plants were found to be of 31 taxa. Among them, rare plant species consisted of critically endangered species (CR degree: 2 (Lilium dauricum Ker Gawl., Cypripedium macranthos Sw., endangered species (EN degree: 5 (Loranthus tanakae Franch. & Sav. etc., vulnerable species (VU degree: 7 (Dryopteris laeta (Kom. C.Chr. etc., and least concerned (LC degree: 17 (Botrychium virginianum (L. Sw. etc.. In all the surveyed areas, a total of 20 taxa (Pseudostellaria setulosa Ohwi etc. were found to be endemic to Korea. The floristic special plants found in the surveyed areas were two taxa of grade V, 24 taxa of grade IV, and 31 taxa of grade III. The naturalized plants were identified as 15 taxa and included Chenopodium album L., Lotus corniculatus L., Robinia pseudoacacia L. etc.

Diversity of vascular plants of Piestany and surroundings (presentation)

International Nuclear Information System (INIS)

Penzesova, A.; Galusova, T.

2013-01-01

In this presentation is a summary of the results of floristic research aimed at determining diversity of vascular plants of Piestany and its surroundings. Plant taxa we determined using the designation keys. We have compiled a list of plant species occurring in the monitored area, we evaluated the selected botanical-phytogeographical characteristics of flora, we've put together a list of local protected, endangered and rare species and a list of local invasive and expansive species according to sources. (Authors)

Bilaterally symmetric axes with rhizoids composed the rooting structure of the common ancestor of vascular plants.

Science.gov (United States)

Hetherington, Alexander J; Dolan, Liam

2018-02-05

There are two general types of rooting systems in extant land plants: gametophyte rhizoids and sporophyte root axes. These structures carry out the rooting function in the free-living stage of almost all land plant gametophytes and sporophytes, respectively. Extant vascular plants develop a dominant, free-living sporophyte on which roots form, with the exception of a small number of taxa that have secondarily lost roots. However, fossil evidence indicates that early vascular plants did not develop sporophyte roots. We propose that the common ancestor of vascular plants developed a unique rooting system-rhizoidal sporophyte axes. Here we present a synthesis and reinterpretation of the rootless sporophytes of Horneophyton lignieri , Aglaophyton majus , Rhynia gwynne-vaughanii and Nothia aphylla preserved in the Rhynie chert. We show that the sporophyte rooting structures of all four plants comprised regions of plagiotropic (horizontal) axes that developed unicellular rhizoids on their underside. These regions of axes with rhizoids developed bilateral symmetry making them distinct from the other regions which were radially symmetrical. We hypothesize that rhizoidal sporophyte axes constituted the rooting structures in the common ancestor of vascular plants because the phylogenetic positions of these plants span the origin of the vascular lineage.This article is part of a discussion meeting issue 'The Rhynie cherts: our earliest terrestrial ecosystem revisited'. © 2017 The Authors.

The compact Selaginella genome identifies changes in gene content associated with the evolution of vascular plants

Energy Technology Data Exchange (ETDEWEB)

Grigoriev, Igor V.; Banks, Jo Ann; Nishiyama, Tomoaki; Hasebe, Mitsuyasu; Bowman, John L.; Gribskov, Michael; dePamphilis, Claude; Albert, Victor A.; Aono, Naoki; Aoyama, Tsuyoshi; Ambrose, Barbara A.; Ashton, Neil W.; Axtell, Michael J.; Barker, Elizabeth; Barker, Michael S.; Bennetzen, Jeffrey L.; Bonawitz, Nicholas D.; Chapple, Clint; Cheng, Chaoyang; Correa, Luiz Gustavo Guedes; Dacre, Michael; DeBarry, Jeremy; Dreyer, Ingo; Elias, Marek; Engstrom, Eric M.; Estelle, Mark; Feng, Liang; Finet, Cedric; Floyd, Sandra K.; Frommer, Wolf B.; Fujita, Tomomichi; Gramzow, Lydia; Gutensohn, Michael; Harholt, Jesper; Hattori, Mitsuru; Heyl, Alexander; Hirai, Tadayoshi; Hiwatashi, Yuji; Ishikawa, Masaki; Iwata, Mineko; Karol, Kenneth G.; Koehler, Barbara; Kolukisaoglu, Uener; Kubo, Minoru; Kurata, Tetsuya; Lalonde, Sylvie; Li, Kejie; Li, Ying; Litt, Amy; Lyons, Eric; Manning, Gerard; Maruyama, Takeshi; Michael, Todd P.; Mikami, Koji; Miyazaki, Saori; Morinaga, Shin-ichi; Murata, Takashi; Mueller-Roeber, Bernd; Nelson, David R.; Obara, Mari; Oguri, Yasuko; Olmstead, Richard G.; Onodera, Naoko; Petersen, Bent Larsen; Pils, Birgit; Prigge, Michael; Rensing, Stefan A.; Riano-Pachon, Diego Mauricio; Roberts, Alison W.; Sato, Yoshikatsu; Scheller, Henrik Vibe; Schulz, Burkhard; Schulz, Christian; Shakirov, Eugene V.; Shibagaki, Nakako; Shinohara, Naoki; Shippen, Dorothy E.; Sorensen, Iben; Sotooka, Ryo; Sugimoto, Nagisa; Sugita, Mamoru; Sumikawa, Naomi; Tanurdzic, Milos; Theilsen, Gunter; Ulvskov, Peter; Wakazuki, Sachiko; Weng, Jing-Ke; Willats, William W.G.T.; Wipf, Daniel; Wolf, Paul G.; Yang, Lixing; Zimmer, Andreas D.; Zhu, Qihui; Mitros, Therese; Hellsten, Uffe; Loque, Dominique; Otillar, Robert; Salamov, Asaf; Schmutz, Jeremy; Shapiro, Harris; Lindquist, Erika; Lucas, Susan; Rokhsar, Daniel

2011-04-28

We report the genome sequence of the nonseed vascular plant, Selaginella moellendorffii, and by comparative genomics identify genes that likely played important roles in the early evolution of vascular plants and their subsequent evolution

Floristic inventory of vascular plant in Nam Ha National Biodiversity Conservation Area, Lao People's Democratic Republic

Directory of Open Access Journals (Sweden)

Jeong Ho Park

2018-06-01

Full Text Available The floristic inventory of vascular plants in Nam Ha National Biodiversity Conservation Area was conducted to understand the plant diversity in the northern area of Lao People's Democratic Republic. From the joint field surveys between Korean and Laos experts conducted during 2015–2017, it was found that there are 64 families, 145 genera, and 189 species distributed in the Nam Ba National Biodiversity Conservation Area, and a total of 56 families, 117 genera, and 148 species which comprise more than 78% of the total species were identified as endemic plants to the Lao People's Democratic Republic. Considering the usage of the plants, there are 91 species of medicinal plants, 33 species of ornamental plants, eight species of edible plants, and 16 species of economic plants. In addition, it was found out that Dalbergia balansae and Cinnamomum macrocarpum are categorized as vulnerable in the International Union for Conservation of Nature (IUCN Red list, and 13 more species are categorized as the least concern.

Vascular plant-mediated controls on atmospheric carbon assimilation and peat carbon decomposition under climate change.

Science.gov (United States)

Gavazov, Konstantin; Albrecht, Remy; Buttler, Alexandre; Dorrepaal, Ellen; Garnett, Mark H; Gogo, Sebastien; Hagedorn, Frank; Mills, Robert T E; Robroek, Bjorn J M; Bragazza, Luca

2018-03-23

Climate change can alter peatland plant community composition by promoting the growth of vascular plants. How such vegetation change affects peatland carbon dynamics remains, however, unclear. In order to assess the effect of vegetation change on carbon uptake and release, we performed a vascular plant-removal experiment in two Sphagnum-dominated peatlands that represent contrasting stages of natural vegetation succession along a climatic gradient. Periodic measurements of net ecosystem CO 2 exchange revealed that vascular plants play a crucial role in assuring the potential for net carbon uptake, particularly with a warmer climate. The presence of vascular plants, however, also increased ecosystem respiration, and by using the seasonal variation of respired CO 2 radiocarbon (bomb- 14 C) signature we demonstrate an enhanced heterotrophic decomposition of peat carbon due to rhizosphere priming. The observed rhizosphere priming of peat carbon decomposition was matched by more advanced humification of dissolved organic matter, which remained apparent beyond the plant growing season. Our results underline the relevance of rhizosphere priming in peatlands, especially when assessing the future carbon sink function of peatlands undergoing a shift in vegetation community composition in association with climate change. © 2018 John Wiley & Sons Ltd.

Vascular Plants of the Hanford Site

International Nuclear Information System (INIS)

Sackschewsky, Michael R.; Downs, Janelle L.

2001-01-01

This report provides an updated listing of the vascular plants present on and near the U.S. Department of Energy Hanford Site. This document is an update of a listing of plants prepared by Sackschewdky et al. in 1992. Since that time there has been a significant increase in the botanical knowledge of the Hanford Site. The present listing is based on an examination of herbarium collections held at PNNL, at WSU-Tri Cities, WSU-Pullman, Brigham Young University, and The University of Washington, and on examination of ecological literature derived from the Hanford and Benton county areas over the last 100 years. Based on the most recent analysis, there are approximately 725 different plant species that have been documented on or around the Hanford Site. This represents an approximate 20% increase in the number of species reported within Sackschewsky et al. (1992). This listing directly supports DOE and contractor efforts to assess the potential impacts of Hanford Site operations

Mapping and Quantification of Vascular Branching in Plants, Animals and Humans by VESGEN Software

Science.gov (United States)

Parsons-Wingerter, P. A.; Vickerman, M. B.; Keith, P. A.

2010-01-01

Humans face daunting challenges in the successful exploration and colonization of space, including adverse alterations in gravity and radiation. The Earth-determined biology of plants, animals and humans is significantly modified in such extraterrestrial environments. One physiological requirement shared by larger plants and animals with humans is a complex, highly branching vascular system that is dynamically responsive to cellular metabolism, immunological protection and specialized cellular/tissue function. VESsel GENeration (VESGEN) Analysis has been developed as a mature beta version, pre-release research software for mapping and quantification of the fractal-based complexity of vascular branching. Alterations in vascular branching pattern can provide informative read-outs of altered vascular regulation. Originally developed for biomedical applications in angiogenesis, VESGEN 2D has provided novel insights into the cytokine, transgenic and therapeutic regulation of angiogenesis, lymphangiogenesis and other microvascular remodeling phenomena. Vascular trees, networks and tree-network composites are mapped and quantified. Applications include disease progression from clinical ophthalmic images of the human retina; experimental regulation of vascular remodeling in the mouse retina; avian and mouse coronary vasculature, and other experimental models in vivo. We envision that altered branching in the leaves of plants studied on ISS such as Arabidopsis thaliana cans also be analyzed.

Soft X-ray induced chemical modification of polysaccharides in vascular plant cell walls

International Nuclear Information System (INIS)

Cody, George D.; Brandes, Jay; Jacobsen, Chris; Wirick, Susan

2009-01-01

Scanning transmission X-ray microscopy and micro carbon X-ray Absorption Near Edge Spectroscopy (C-XANES) can provide quantitative information regarding the distribution of the biopolymers cellulose, hemicellulose, and lignin in vascular plant cell walls. In the case of angiosperms, flowering plants, C-XANES may also be able to distinguish variations in lignin monomer distributions throughout the cell wall. Polysaccharides are susceptible to soft X-ray irradiation induced chemical transformations that may complicate spectral analysis. The stability of a model polysaccharide, cellulose acetate, to variable doses of soft X-rays under conditions optimized for high quality C-XANES spectroscopy was investigated. The primary chemical effect of soft X-ray irradiation on cellulose acetate involves mass loss coincident with de-acetylation. A lesser amount of vinyl ketone formation also occurs. Reduction in irradiation dose via defocusing does enable high quality pristine spectra to be obtained. Radiation induced chemical modification studies of oak cell wall reveals that cellulose and hemicellulose are less labile to chemical modification than cellulose acetate. Strategies for obtaining pristine C-XANES spectra of polysaccharides are presented.

Rare vascular plant species at risk : recovery by seeding?

NARCIS (Netherlands)

Pegtel, Dick M.

. Rare vascular plant species are endangered worldwide. Population losses are most commonly caused by human-related factors. Conservation management seeks to halt this adverse trend and if possible, to enhance long-lasting self-sustainable populations. In general, rare species are poorly recruited

VASCULAR PLANTS AS ENGINEERS OF OXYGEN IN AQUATIC SYSTEMS

Science.gov (United States)

The impact of organisms on oxygen is one of the most dramatic examples of ecosystem engineering on Earth. In aquatic systems, which have much lower oxygen concentrations than the atmosphere, vascular aquatic plants can affect oxygen concentrations significantly not only on long t...

Bacterial diversity in rhizosphere soil from Antarctic vascular plants of Admiralty Bay, maritime Antarctica.

Science.gov (United States)

Teixeira, Lia C R S; Peixoto, Raquel S; Cury, Juliano C; Sul, Woo Jun; Pellizari, Vivian H; Tiedje, James; Rosado, Alexandre S

2010-08-01

The Antarctic is a pristine environment that contributes to the maintenance of the global climate equilibrium. The harsh conditions of this habitat are fundamental to selecting those organisms able to survive in such an extreme habitat and able to support the relatively simple ecosystems. The DNA of the microbial community associated with the rhizospheres of Deschampsia antarctica Desv (Poaceae) and Colobanthus quitensis (Kunth) BartI (Caryophyllaceae), the only two native vascular plants that are found in Antarctic ecosystems, was evaluated using a 16S rRNA multiplex 454 pyrosequencing approach. This analysis revealed similar patterns of bacterial diversity between the two plant species from different locations, arguing against the hypothesis that there would be differences between the rhizosphere communities of different plants. Furthermore, the phylum distribution presented a peculiar pattern, with a bacterial community structure different from those reported of many other soils. Firmicutes was the most abundant phylum in almost all the analyzed samples, and there were high levels of anaerobic representatives. Also, some phyla that are dominant in most temperate and tropical soils, such as Acidobacteria, were rarely found in the analyzed samples. Analyzing all the sample libraries together, the predominant genera found were Bifidobacterium (phylum Actinobacteria), Arcobacter (phylum Proteobacteria) and Faecalibacterium (phylum Firmicutes). To the best of our knowledge, this is the first major bacterial sequencing effort of this kind of soil, and it revealed more than expected diversity within these rhizospheres of both maritime Antarctica vascular plants in Admiralty Bay, King George Island, which is part of the South Shetlands archipelago.

Species richness of vascular plants, bryophytes, and lichens along an altitudinal gradient in western Norway

Science.gov (United States)

Grytnes, John Arvid; Heegaard, Einar; Ihlen, Per G.

2006-05-01

Species richness patterns of ground-dwelling vascular plants, bryophytes, and lichens were compared along an altitudinal gradient (310-1135 m a.s.l.), in western Norway. Total species richness peaked at intermediate altitudes, vascular plant species richness peaked immediately above the forest limit (at 600-700 m a.s.l.), bryophyte species richness had no statistically significant trend, whereas lichen richness increased from the lowest point and up to the forest limit, with no trend above. It is proposed that the pattern in vascular plant species richness is enhanced by an ecotone effect. Bryophyte species richness responds to local scale factors whereas the lichen species richness may be responding to the shading from the forest trees.

Flora of vascular plants in the Chilgapsan Provincial Park, Korea

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Ro-Young Lee

2014-09-01

Full Text Available The flora of Chilgapsan Provincial Park in Cheongyang-gun (Chungcheongnam-do, Korea was surveyed from 2000 to 2014. In 19 field surveys, vascular plants were revealed 490 taxa belonging to 97 families, 309 genera, 433 species, four subspecies, 48 varieties, and five forms. Plants of various categories were discovered in this study. For the Korean endemic plants 15 taxa were recorded, and 11 taxa designated by the Korean Forest Service as rare plants were investigated in this region. The plants above the third degree among the floristic regional indicator plants designated by the Korean Ministry of Environment were 10 taxa. In addition, 33 taxa of naturalized and 73 taxa of cultivated plants were recorded.

New insights on the evolution of Leafy cotyledon1 (LEC1) type genes in vascular plants.

Science.gov (United States)

Cagliari, Alexandro; Turchetto-Zolet, Andreia Carina; Korbes, Ana Paula; Maraschin, Felipe Dos Santos; Margis, Rogerio; Margis-Pinheiro, Marcia

2014-01-01

NF-Y is a conserved oligomeric transcription factor found in all eukaryotes. In plants, this regulator evolved with a broad diversification of the genes coding for its three subunits (NF-YA, NF-YB and NF-YC). The NF-YB members can be divided into Leafy Cotyledon1 (LEC1) and non-LEC1 types. Here we presented a comparative genomic study using phylogenetic analyses to validate an evolutionary model for the origin of LEC-type genes in plants and their emergence from non-LEC1-type genes. We identified LEC1-type members in all vascular plant genomes, but not in amoebozoa, algae, fungi, metazoa and non-vascular plant representatives, which present exclusively non-LEC1-type genes as constituents of their NF-YB subunits. The non-synonymous to synonymous nucleotide substitution rates (Ka/Ks) between LEC1 and non-LEC1-type genes indicate the presence of positive selection acting on LEC1-type members to the fixation of LEC1-specific amino acid residues. The phylogenetic analyses demonstrated that plant LEC1-type genes are evolutionary divergent from the non-LEC1-type genes of plants, fungi, amoebozoa, algae and animals. Our results point to a scenario in which LEC1-type genes have originated in vascular plants after gene expansion in plants. We suggest that processes of neofunctionalization and/or subfunctionalization were responsible for the emergence of a versatile role for LEC1-type genes in vascular plants, especially in seed plants. LEC1-type genes besides being phylogenetic divergent also present different expression profile when compared with non-LEC1-type genes. Altogether, our data provide new insights about the LEC1 and non-LEC1 evolutionary relationship during the vascular plant evolution. Copyright © 2014 Elsevier Inc. All rights reserved.

Stomatal Blue Light Response Is Present in Early Vascular Plants.

Science.gov (United States)

Doi, Michio; Kitagawa, Yuki; Shimazaki, Ken-ichiro

2015-10-01

Light is a major environmental factor required for stomatal opening. Blue light (BL) induces stomatal opening in higher plants as a signal under the photosynthetic active radiation. The stomatal BL response is not present in the fern species of Polypodiopsida. The acquisition of a stomatal BL response might provide competitive advantages in both the uptake of CO2 and prevention of water loss with the ability to rapidly open and close stomata. We surveyed the stomatal opening in response to strong red light (RL) and weak BL under the RL with gas exchange technique in a diverse selection of plant species from euphyllophytes, including spermatophytes and monilophytes, to lycophytes. We showed the presence of RL-induced stomatal opening in most of these species and found that the BL responses operated in all euphyllophytes except Polypodiopsida. We also confirmed that the stomatal opening in lycophytes, the early vascular plants, is driven by plasma membrane proton-translocating adenosine triphosphatase and K(+) accumulation in guard cells, which is the same mechanism operating in stomata of angiosperms. These results suggest that the early vascular plants respond to both RL and BL and actively regulate stomatal aperture. We also found three plant species that absolutely require BL for both stomatal opening and photosynthetic CO2 fixation, including a gymnosperm, C. revoluta, and the ferns Equisetum hyemale and Psilotum nudum. © 2015 American Society of Plant Biologists. All Rights Reserved.

Taxonomic and phylogenetic diversity of vascular plants at Ma'anling volcano urban park in tropical Haikou, China: Reponses to soil properties.

Science.gov (United States)

Cheng, Xia-Lan; Yuan, Lang-Xing; Nizamani, Mir Mohammad; Zhu, Zhi-Xin; Friedman, Cynthia Ross; Wang, Hua-Feng

2018-01-01

Anthropogenic processes and socio-economic factors play important roles in shaping plant diversity in urban parks. To investigate how plant diversity of Ma' anling urban volcano park in Hainan Province, China respond to these factors, we carried out a field investigation on the taxonomic and phylogenetic diversity of vascular plants and soil properties in this area. We found 284 species of vascular plants belonging to 88 families and 241 genera, which included 194 native species, 23 invasive species, 31 naturalized species, 40 cultivars, and 4 rare / endangered plant species. Tree composition and richness significantly varied between different vegetation formations (plantation, secondary forest, and abandoned land). Plant species richness and community composition were significantly affected by elevation (El), soil water content (WC), total soil nitrogen (TN) and soil organic matter (SOM). There were significant diversity differences between plantations and abandoned lands, but not between the plantations and secondary forests. The flora in the study site was tropical in nature, characterized by pantropic distributions. Compared to adjacent areas, floristic composition in the study site was most similar to that of Guangdong, followed by that of Vietnam. Our study revealed the diversity patterns of volcanic plants and provided the basis for future planning of plant conservation, such as preserving plant species, maintaining plant habitats, and coordinating plant management in this region.

The Root-Associated Microbial Community of the World’s Highest Growing Vascular Plants

Czech Academy of Sciences Publication Activity Database

Angel, R.; Conrad, R.; Dvorský, Miroslav; Kopecký, Martin; Kotilínek, M.; Hiiesalu, Inga; Schweingruber, F. H.; Doležal, Jiří

2016-01-01

Roč. 72, č. 2 (2016), s. 394-406 ISSN 0095-3628 Institutional support: RVO:67985939 Keywords : vascular plants * upward migration * subnival soil * plant-associated bacteria Subject RIV: EF - Botanics Impact factor: 3.630, year: 2016

Sphagnum modifies climate-change impacts on subarctic vascular bog plants.

NARCIS (Netherlands)

Dorrepaal, E.; Aerts, R.; Cornelissen, J.H.C.; van Logtestijn, R.S.P; Callaghan, T.V.

2006-01-01

1. Vascular plant growth forms in northern peatlands differ in their strategies to cope with the harsh climate, low nutrient availability and progressively increasing height of the Sphagnum carpet in which they grow. Climate change may therefore affect growth forms differentially, both directly and

Distribution of vascular plants and macroalgae along salinity and elevation gradients in Oregon tidal marshes

Science.gov (United States)

Sea level rise due to global climate change may affect the spatial distribution of plants and macroalgae within tidal estuaries. We present preliminary results from on-going research in Oregon to determine how these potential abiotic drives correlate with the presence or absence...

The Heavy Links between Geological Events and Vascular Plants Evolution: A Brief Outline.

Science.gov (United States)

Piombino, Aldo

2016-01-01

Since the rise of photosynthesis, life has influenced terrestrial atmosphere, particularly the O2 and the CO2 content (the latter being originally more than 95%), changing the chemistry of waters, atmosphere, and soils. Billions of years after, a far offspring of these first unicellular forms conquered emerging lands, not only completely changing landscape, but also modifying geological cycles of deposition and erosion, many chemical and physical characteristics of soils and fresh waters, and, more, the cycle of various elements. So, there are no doubts that vascular plants modified geology; but it is true that also geology has affected (and, more, has driven) plant evolution. New software, PyRate, has determined vascular plant origin and diversification through a Bayesian analysis of fossil record from Silurian to today, particularly observing their origination and extinction rate. A comparison between PyRate data and geological history suggests that geological events massively influenced plant evolution and that also the rise of nonflowering seed plants and the fast diffusion of flowering plants can be explained, almost partly, with the environmental condition changes induced by geological phenomena.

Vascular Plants of the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Sackschewsky, Michael R.; Downs, Janelle L.

2001-09-28

This report provides an updated listing of the vascular plants present on and near the U.S. Department of Energy Hanford Site. This document is an update of a listing of plants prepared by Sackschewdky et al. in 1992. Since that time there has been a significant increase in the botanical knowledge of the Hanford Site. The present listing is based on an examination of herbarium collections held at PNNL, at WSU-Tri Cities, WSU-Pullman, Bringham Young University, and The University of Washington, and on examination of ecological literature derived from the Hanford and Benton county areas over the last 100 years. Based on the most recent analysis, there are approximately 725 different plant species that have been documented on or around the Hanford Site. This represents an approximate 20% increase in the number of species reported within Sackschewsky et al. (1992). This listing directly supports DOE and contractor efforts to assess the potential impacts of Hanford Site operations on the biological environment, including impacts to rare habitats and to species listed as endangered or\\ threatened. This document includes a listing of plants currently listed as endangered, threatened, or otherwise of concern to the Washington Natural Heritage Program or the U.S. Fish and Wildlife Service, as well as those that are currently listed as noxious weeds by the State of Washington. Also provided is an overview of how plants on the Hanford Site can be used by people. This information may be useful in developing risk assessment models, and as supporting information for clean-up level and remediation decisions.

Vascular Plant and Vertebrate Inventory of Casa Grande Ruins National Monument

Science.gov (United States)

Powell, Brian F.; Albrecht, Eric W.; Schmidt, Cecilia A.; Halvorson, William L.; Anning, Pamela; Docherty, Kathleen

2006-01-01

Executive Summary This report summarizes results of the first comprehensive biological inventory of Casa Grande Ruins National Monument (NM) in southern Arizona. Surveys at the monument were part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in Arizona and New Mexico. In 2001 and 2002 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at Casa Grande Ruins NM to document the presence, and in some cases relative abundance, of species. By using repeatable study designs and standardized field techniques, which included quantified survey effort, we produced inventories that can serve as the basis for a biological monitoring program. Of the National Park Service units in the region, no other has experienced as much recent ecological change as Casa Grande Ruins NM. Once situated in a large and biologically diverse mesquite bosque near the perennially flowing Gila River, the monument is now a patch of sparse desert vegetation surrounded by urban and commercial development that is rapidly replacing agriculture as the dominant land use in the area. Roads, highways, and canals surround the monument. Development, and its associated impacts, has important implications for the plants and animals that live in the monument. The plant species list is small and the distribution and number of non-native plants appears to be increasing. Terrestrial vertebrates are also being impacted by the changing landscape, which is increasing the isolation of these populations from nearby natural areas and thereby reducing the number of species at the monument. These observations are alarming and are based on our review of previous studies, our research in the monument, and our knowledge of the biogeography and ecology of the Sonoran Desert. Together, these data suggest that the monument has lost a significant portion of its historic complement of species and these changes will likely intensify as

Global transcriptome analysis reveals extensive gene remodeling, alternative splicing and differential transcription profiles in non-seed vascular plant Selaginella moellendorffii.

Science.gov (United States)

Zhu, Yan; Chen, Longxian; Zhang, Chengjun; Hao, Pei; Jing, Xinyun; Li, Xuan

2017-01-25

Selaginella moellendorffii, a lycophyte, is a model plant to study the early evolution and development of vascular plants. As the first and only sequenced lycophyte to date, the genome of S. moellendorffii revealed many conserved genes and pathways, as well as specialized genes different from flowering plants. Despite the progress made, little is known about long noncoding RNAs (lncRNA) and the alternative splicing (AS) of coding genes in S. moellendorffii. Its coding gene models have not been fully validated with transcriptome data. Furthermore, it remains important to understand whether the regulatory mechanisms similar to flowering plants are used, and how they operate in a non-seed primitive vascular plant. RNA-sequencing (RNA-seq) was performed for three S. moellendorffii tissues, root, stem, and leaf, by constructing strand-specific RNA-seq libraries from RNA purified using RiboMinus isolation protocol. A total of 176 million reads (44 Gbp) were obtained from three tissue types, and were mapped to S. moellendorffii genome. By comparing with 22,285 existing gene models of S. moellendorffii, we identified 7930 high-confidence novel coding genes (a 35.6% increase), and for the first time reported 4422 lncRNAs in a lycophyte. Further, we refined 2461 (11.0%) of existing gene models, and identified 11,030 AS events (for 5957 coding genes) revealed for the first time for lycophytes. Tissue-specific gene expression with functional implication was analyzed, and 1031, 554, and 269 coding genes, and 174, 39, and 17 lncRNAs were identified in root, stem, and leaf tissues, respectively. The expression of critical genes for vascular development stages, i.e. formation of provascular cells, xylem specification and differentiation, and phloem specification and differentiation, was compared in S. moellendorffii tissues, indicating a less complex regulatory mechanism in lycophytes than in flowering plants. The results were further strengthened by the evolutionary trend of

Composition and distribution patterns of bryophytes at a reclaimed surface mine in Grundy County, Illinois, with a list of vascular plants

Energy Technology Data Exchange (ETDEWEB)

Rastorfer, J.R.

1981-12-01

Bryological surveys and collections were made in order to assess the natural colonization of mosses (and liverworts) on acid minesoils of a reclamation demonstration site located adjacent to Goose Lake Prairie State Park in northeastern Illinois. Four types of fine-textured mineral soils were recognized within the site; these were designated as abandoned (cultivated) field soil, oil minesoil (spoil), reclaimed minesoil 1972 to 1973, and reclaimed minesoil 1975 to 1976. The two reclaimed minesoils were distinguished by reclamation efforts begun in 1972 and 1975. Thirty moss taxa and one liverwort species were found on the site, and two additional moss species were found in areas adjacent to the site. Of the 33 bryophyte taxa recognized, 14 species of mosses were new reports for Grundy County. Comparative distribution patterns indicate that the major pioneer species of mosses on reclaimed minesoil were Barbula unguiculata, Ceratodon purpureus, Ditrichum pallidum, and Funaria hygrometrica. On the other hand, Bryum caespiticium and Weissia controversa were considered later seral species rather than primary invaders. Distribution patterns also indicate that mosses were generally unable to colonize unshaded bare reclaimed minesoil. However, moss colonization was successful in those areas where the harsh microhabitat conditions were ameliorated by vascular vegetation. Shoots of both living and dead higher plants most likely affect the proliferation of mosses by shading the soil surface, which results in increased moisture and decreased temperature at the soil surface in contrast to conditions of fully exposed soil.

Contrasting species-environment relationships in communities of testate amoebae, bryophytes and vascular plants along the fen-bog gradient.

Science.gov (United States)

Lamentowicz, Mariusz; Lamentowicz, Lukasz; van der Knaap, Willem O; Gabka, Maciej; Mitchell, Edward A D

2010-04-01

We studied the vegetation, testate amoebae and abiotic variables (depth of the water table, pH, electrical conductivity, Ca and Mg concentrations of water extracted from mosses) along the bog to extremely rich fen gradient in sub-alpine peatlands of the Upper Engadine (Swiss Alps). Testate amoeba diversity was correlated to that of mosses but not of vascular plants. Diversity peaked in rich fen for testate amoebae and in extremely rich fen for mosses, while for testate amoebae and mosses it was lowest in bog but for vascular plants in extremely rich fen. Multiple factor and redundancy analyses (RDA) revealed a stronger correlation of testate amoebae than of vegetation to water table and hydrochemical variables and relatively strong correlation between testate amoeba and moss community data. In RDA, hydrochemical variables explained a higher proportion of the testate amoeba and moss data than water table depth. Abiotic variables explained a higher percentage of the species data for testate amoebae (30.3% or 19.5% for binary data) than for mosses (13.4%) and vascular plants (10%). These results show that (1) vascular plant, moss and testate amoeba communities respond differently to ecological gradients in peatlands and (2) testate amoebae are more strongly related than vascular plants to the abiotic factors at the mire surface. These differences are related to vertical trophic gradients and associated niche differentiation.

Structural evolution of the 4/1 genes and proteins in non-vascular and lower vascular plants.

Science.gov (United States)

Morozov, Sergey Y; Milyutina, Irina A; Bobrova, Vera K; Ryazantsev, Dmitry Y; Erokhina, Tatiana N; Zavriev, Sergey K; Agranovsky, Alexey A; Solovyev, Andrey G; Troitsky, Alexey V

2015-12-01

The 4/1 protein of unknown function is encoded by a single-copy gene in most higher plants. The 4/1 protein of Nicotiana tabacum (Nt-4/1 protein) has been shown to be alpha-helical and predominantly expressed in conductive tissues. Here, we report the analysis of 4/1 genes and the encoded proteins of lower land plants. Sequences of a number of 4/1 genes from liverworts, lycophytes, ferns and gymnosperms were determined and analyzed together with sequences available in databases. Most of the vascular plants were found to encode Magnoliophyta-like 4/1 proteins exhibiting previously described gene structure and protein properties. Identification of the 4/1-like proteins in hornworts, liverworts and charophyte algae (sister lineage to all land plants) but not in mosses suggests that 4/1 proteins are likely important for plant development but not required for a primary metabolic function of plant cell. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Vascular Plant and Vertebrate Inventory of Chiricahua National Monument

Science.gov (United States)

Powell, Brian F.; Schmidt, Cecilia A.; Halvorson, William L.; Anning, Pamela

2009-01-01

This report summarizes the results of the first comprehensive inventory of vascular plants and vertebrates at Chiricahua National Monument (NM) in Arizona. This project was part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in the Sonoran Desert Network of parks in Arizona and New Mexico. In 2002, 2003, and 2004 we surveyed for plants and vertebrates (amphibians, reptiles, birds, and mammals) at Chiricahua NM to document the presence of species within the boundaries of the monument. Because we used repeatable study designs and standardized field methods, these inventories can serve as the first step in a biological monitoring program for the monument. This report is also the first summary of previous research from the monument and therefore it provides an important overview of survey efforts to date. We used data from our inventory and previous research to compile complete species lists for the monument and to assess inventory completeness. We recorded a total of 424 species, including 37 not previously found at the monument (Table 1). We found 10 species of non-native plants and one non-native mammal. Most non-native plants were found along the western boundary of the monument. Based on a review of our inventory and past research at the monument, there have been a total of 1,137 species of plants and vertebrates found at the monument. We believe the inventories of vascular plants and vertebrates are nearly complete and that the monument has one of the most complete inventories of any unit in the Sonoran Desert Network. The mammal community at the monument had the highest species richness (69 species) and the amphibian and reptile community was among the lowest species richness (33 species) of any park in the Sonoran Desert Network. Species richness of the plant and bird communities was intermediate. Among the important determinants of species richness for all groups is the geographic location of the monument

Interactions between soil phototrophs and vascular plants in Himalayan cold deserts

Czech Academy of Sciences Publication Activity Database

Řeháková, Klára; Čapková, Kateřina; Dvorský, Miroslav; Kopecký, Martin; Altman, Jan; Šmilauer, P.; Doležal, Jiří

2017-01-01

Roč. 115, dec 2017 (2017), s. 568-578 ISSN 0038-0717 R&D Projects: GA ČR GA13-13368S Institutional support: RVO:67985939 Keywords : microbial communities * vascular plants * interactions Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 4.857, year: 2016

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.

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

Role of endophytic fungi in the migration of the radionuclides in the vascular plants of the Ukrainian Polesye sphagniopratum

International Nuclear Information System (INIS)

Zhdanova, N.N.; Sokolova, E.V.; Kurchenko, I.N.; Orlov, A.A.

2002-01-01

It is known that the specific activity of 137 Cs in vegetative phytomass of cranberry and sphagnum in oligotrophic conditions of Ukrainian Polessye forest sphagniopratum amounts 5000 - 10000 Bq/kg of air-dry weight. Roots of cranberry in natural conditions never run up to peat and mainly are located in top layer of the sphagnum top which is sodden by a water, but specific activity of the radionuclide in swamp water is low (2 - 10 Bq/l). It was supposed that mycorrhizal and endophytic micromycetes take an essential part in transferring the mineral substances and 137 Cs from sphagnum mosses to ericoid plants under oligotrophic swamp conditions. Endophytic fungi from vascular plants were not investigated in Ukraine. The article is devoted to the estimation of distribution of endophytic fungi in plants which are dominants of the plant cover of sphagniopratum. 47 species of micromycetes which belong to 27 genera were identified. For moss and ericoid plants five mutual species of endophytic fungi was detected

THE DISTRIBUTION AND SPREAD OF ALIEN VASCULAR PLANTS ...

African Journals Online (AJOL)

Surveys of alien plants at subantarctic Prince Edward Island in 2001 show that the ranges of all three introduced species have increased since the last survey in 1998. Poa annua, the longest-established species, increased its range substantially after 1987, prior to which it was confined to a single site for more than 20 years ...

Microbial community dynamics and transformation of vascular plant detritus in two wetland ecosystems

International Nuclear Information System (INIS)

Moran, M.A.

1987-01-01

The microbial ecology of two wetland ecosystems in southeastern Georgia, USA, was studied with respect to microbial community dynamics and microbially-mediated transformations of vascular plant detritus. In the Okefenokee Swamp, biomass of microorganisms in the water column and sediments was generally lower in winter months and higher during spring and summer. Biomass and activity (measured as 14 C-lignocellulose mineralization) differed significantly among five habitats within the Okefenokee, and also among locations within each habitat. Significant heterogeneity in the structure of Okefenokee microbial communities was found at scales from 30 cm to 150 m. In field and laboratory studies of vascular plant decomposition in the Okefenokee and a salt marsh on Sapelo Island, the mathematical model which best describes decomposition kinetics is the decaying coefficient model

Vascular Plant and Vertebrate Inventory of Tuzigoot National Monument

Science.gov (United States)

Powell, Brian F.; Albrecht, E.W.; Halvorson, William Lee; Schmidt, Cecilia A.; Anning, P.; Docherty, K.

2005-01-01

Executive Summary From 2002 to 2004, we surveyed for plants and vertebrates (amphibians, reptiles, birds, and mammals) at Tuzigoot National Monument (NM) and adjacent areas in Arizona. This was the first effort of its kind in the area and was part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in Arizona and New Mexico. In addition to our own surveys, we also compiled a complete list of species that have been found by previous studies. We found 330 species, including 142 that had not previously been recorded at the monument (Table 1). We found 39 species of non-native plants, 11 non-native fishes, three non-native birds, and one non-native species each of amphibian and mammal. Based on our work and that of others, there have been 597 species of plants and vertebrates found at the monument. The bird community at the monument had the highest species richness of any national park unit in central and southern Arizona. We found all other taxa to have intermediate species richness compared to other park units in the region. This extraordinary species richness observed for birds, as well as for some other taxa, is due primarily to Tavasci Marsh and the Verde River, two critical sources of perennial water, which provide habitat for many regionally rare or uncommon species. The location of the monument at the northern edge of the Sonoran Desert and at the southern edge of the Mogollon Rim also plays an important role in determining the distribution and community composition of the plant and vertebrate communities. Based on our findings, we believe the high number of non-native species, especially fish and plants, should be of particular management concern. We detail other management challenges, most notably the rapid increase in housing and associated commercial development near the monument, which will continue to impact the plant and vertebrate communities. Based on our data and a review of past studies, we believe the

Raman imaging to investigate ultrastructure and composition of plant cell walls : distribution of lignin and cellulose in black spruce wood (Picea mariana)

Science.gov (United States)

Umesh P. Agarwal

2006-01-01

A detailed understanding of the structural organization of the cell wall of vascular plants is important from both the perspectives of plant biology and chemistry and of commercial utilization. A state-of-the-art 633-nm laser-based confocal Raman microscope was used to determine the distribution of cell wall components in the cross section of black spruce wood in situ...

Approaches in the determination of plant nutrient uptake and distribution in space flight conditions

Science.gov (United States)

Heyenga, A. G.; Forsman, A.; Stodieck, L. S.; Hoehn, A.; Kliss, M.

2000-01-01

The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the radionuclides calcium-45 and iron-59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

New Chorological Data for Rare Vascular Plants from Romania

Directory of Open Access Journals (Sweden)

Anastasiu Paulina

2015-11-01

Full Text Available New chorological data about seven rare vascular plant taxa are reported in the present paper: Conringia austriaca, Jurinea multiflora, Linaria arvensis, Nonea pallens, Ophrys apifera, Ophrys scolopax subsp. cornuta, Saponaria officinalis. For Linaria arvensis, previously considered doubtful in the absence of the herbarium material, we confirm its presence in Romania. The report of Nonea pallens is the first for Dobrogea, while the report of Jurinea multiflora is the first for Muntenia region of Romania.

Interferences between Sphagnum and vascular plants: effects on plant community structure and peat formation

OpenAIRE

Malmer, Nils; Albinsson, C; Svensson, B M; Wallén, Bo

2003-01-01

The interference between vascular plants and peat mosses with respect to nitrogen and phosphorus was studied in a fertilization experiment and with respect to competition for light in a removal experiment in poor fens with either soligenous or topogenous hydrology using Narthecium ossifragum (L.) Huds. and three species of Sphagnum sect. Sphagnum as targets. Adding fertilizer either on the moss surface or below it confirmed the hypotheses of an asymmetric competition for nutrients, viz. that ...

Comparative Genomics Yields Insights into Niche Adaptation of Plant Vascular Wilt Pathogens

NARCIS (Netherlands)

Klosterman, S.J.; Subbarao, K.V.; Kang, S.; Veronese, P.; Gold, S.E.; Thomma, B.P.H.J.; Chen, Z.J.; Henrissat, B.; Lee, Y.H.; Park, J.; Garcia-Pedrajas, M.D.; Barbara, D.J.; Anchieta, A.; Jonge, de R.; Santhanam, P.; Maruthachalam, K.; Atallah, Z.; Amyotte, S.G.; Paz, Z.; Inderbitzin, P.; Hayes, R.J.; Heiman, D.I.; Young, S.; Zeng, Q.; Engels, R.; Galagan, J.; Cuomo, C.; Dobinson, K.F.; Ma, L.J.

2011-01-01

The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species, causing billions of dollars in annual crop losses. The characteristic wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels, which undergo fluctuations in

Vascular flora and geoecology of Mont de la Table, Gaspesie, Quebec

Science.gov (United States)

Scott W. Bailey; Joann Hoy; Charles V. Cogbill

2015-01-01

The influence of substrate lithology on the distribution of many vascular and nonvascular plants has long been recognized, especially in alpine, subalpine, and other rocky habitats. In particular, plants have been classified as dependent on high-calcium substrates (i.e., calcicoles) based on common restriction to habitats developed in calcareous rocks, such as...

Dataset of herbarium specimens of threatened vascular plants in Catalonia.

Science.gov (United States)

Nualart, Neus; Ibáñez, Neus; Luque, Pere; Pedrol, Joan; Vilar, Lluís; Guàrdia, Roser

2017-01-01

This data paper describes a specimens' dataset of the Catalonian threatened vascular plants conserved in five public Catalonian herbaria (BC, BCN, HGI, HBIL and MTTE). Catalonia is an administrative region of Spain that includes large autochthon plants diversity and 199 taxa with IUCN threatened categories (EX, EW, RE, CR, EN and VU). This dataset includes 1,618 records collected from 17 th century to nowadays. For each specimen, the species name, locality indication, collection date, collector, ecology and revision label are recorded. More than 94% of the taxa are represented in the herbaria, which evidence the paper of the botanical collections as an essential source of occurrence data.

Disjunct populations of European vascular plant species keep the same climatic niches

DEFF Research Database (Denmark)

Wasof, Safaa; Lenoir, Jonathan; Aarrestad, Per Arild

2015-01-01

separated for thousands of years. Location: European Alps and Fennoscandia. Methods: Of the studied pool of 888 terrestrial vascular plant species occurring in both the Alps and Fennoscandia, we used two complementary approaches to test and quantify climatic-niche shifts for 31 species having strictly......Aim: Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly invasive, and has not, to date, been very conclusive. Here we assess the degree of niche conservatism between distant populations of native alpine plant species that have been...... to be largely valid for arctic-alpine plants....

Method for treating wastewater using microorganisms and vascular aquatic plants

Science.gov (United States)

Wolverton, B. C. (Inventor)

1983-01-01

A method for treating wastewater compresses subjecting the wastewater to an anaerobic setting step for at least 6 hours and passing the liquid effluent from the anaerobic settling step through a filter cell in an upflow manner. There the effluent is subjected first to the action of anaerobic and facultative microorganisms, and then to the action of aerobic microorganisms and the roots of at least one vascular aquatic plant.

Antioxidant and signal modulation properties of plant polyphenols in controlling vascular inflammation.

Science.gov (United States)

Kostyuk, Vladimir A; Potapovich, Alla I; Suhan, Tatyana O; de Luca, Chiara; Korkina, Liudmila G

2011-05-11

Oxidized low-density lipoproteins (oxLDL) play a critical role in the initiation of atherosclerosis through activation of inflammatory signaling. In the present work we investigated the role of antioxidant and signal modulation properties of plant polyphenols in controlling vascular inflammation. Significant decrease in intracellular NO level and superoxide overproduction was found in human umbilical vein endothelial cells (HUVEC) treated with oxLDL, but not with LDL. The redox imbalance was prevented by the addition of quercetin or resveratrol. Expression analysis of 14 genes associated with oxidative stress and inflammation revealed oxLDL-mediated up-regulation of genes specifically involved in leukocyte recruitment and adhesion. This up-regulation could be partially avoided by the addition of verbascoside or resveratrol, while treatment with quercetin resulted in a further increase in the expression of these genes. Lipopolysaccharide (LPS)-treated HUVEC were also used for the evaluation of anti-inflammatory potency of plant polyphenols. Significant differences between HUVEC treaded with oxLDL and LPS were found in both the expression pattern of inflammation-related genes and the effects of plant polyphenols on cellular responses. The present data indicate that plant polyphenols may affect vascular inflammation not only as antioxidants but also as modulators of inflammatory redox signaling pathways. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Constraining Biomarkers of Dissolved Organic Matter Sourcing Using Microbial Incubations of Vascular Plant Leachates of the California landscape

Science.gov (United States)

Harfmann, J.; Hernes, P.; Chuang, C. Y.; Kaiser, K.; Spencer, R. G.; Guillemette, F.

2017-12-01

Source origin of dissolved organic matter (DOM) is crucial in determining reactivity, driving chemical and biological processing of carbon. DOM source biomarkers such as lignin (a vascular plant marker) and D-amino acids (bacterial markers) are well-established tools in tracing DOM origin and fate. The development of high-resolution mass spectrometry and optical studies has expanded our toolkit; yet despite these advances, our understanding of DOM sources and fate remains largely qualitative. Quantitative data on DOM pools and fluxes become increasingly necessary as we refine our comprehension of its composition. In this study, we aim to calibrate and quantify DOM source endmembers by performing microbial incubations of multiple vascular plant leachates, where total DOM is constrained by initial vascular plant input and microbial production. Derived endmembers may be applied to endmember mixing models to quantify DOM source contributions in aquatic systems.

Macroecological and macroevolutionary patterns of leaf herbivory across vascular plants.

Science.gov (United States)

Turcotte, Martin M; Davies, T Jonathan; Thomsen, Christina J M; Johnson, Marc T J

2014-07-22

The consumption of plants by animals underlies important evolutionary and ecological processes in nature. Arthropod herbivory evolved approximately 415 Ma and the ensuing coevolution between plants and herbivores is credited with generating much of the macroscopic diversity on the Earth. In contemporary ecosystems, herbivory provides the major conduit of energy from primary producers to consumers. Here, we show that when averaged across all major lineages of vascular plants, herbivores consume 5.3% of the leaf tissue produced annually by plants, whereas previous estimates are up to 3.8× higher. This result suggests that for many plant species, leaf herbivory may play a smaller role in energy and nutrient flow than currently thought. Comparative analyses of a diverse global sample of 1058 species across 2085 populations reveal that models of stabilizing selection best describe rates of leaf consumption, and that rates vary substantially within and among major plant lineages. A key determinant of this variation is plant growth form, where woody plant species experience 64% higher leaf herbivory than non-woody plants. Higher leaf herbivory in woody species supports a key prediction of the plant apparency theory. Our study provides insight into how a long history of coevolution has shaped the ecological and evolutionary relationships between plants and herbivores. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Vasorelaxation induced by common edible tropical plant extracts in isolated rat aorta and mesenteric vascular bed.

Science.gov (United States)

Runnie, I; Salleh, M N; Mohamed, S; Head, R J; Abeywardena, M Y

2004-06-01

In this study, the vasodilatory actions of nine edible tropical plant extracts were investigated. Ipomoea batatas (sweet potato leaf), Piper betle (betel leaf), Anacardium occidentale (cashew leaf), Gynandropsis gynandra (maman leaf), Carica papaya (papaya leaf), and Mentha arvensis (mint leaf) extracts exhibited more than 50% relaxing effect on aortic ring preparations, while Piper betle and Cymbopogon citratus (lemongrass stalk) showed comparable vasorelaxation on isolated perfused mesenteric artery preparation. The vascular effect on the aortic ring preparations were mainly endothelium-dependent, and mediated by nitric oxide (NO) as supported by the inhibition of action in the presence of N(omega)-nitro-L-arginine (NOLA), an nitric oxide synthase (NOS) inhibitor, or by the removal of endothelium. In contrast, vasodilatory actions in resistance vessels (perfused mesenteric vascular beds) appear to involve several biochemical mediators, including NO, prostanoids, and endothelium-dependent hyperpolarizing factors (EDHFs). Total phenolic contents and antioxidant capacities varied among different extracts and found to be independent of vascular relaxation effects. This study demonstrates that many edible plants common in Asian diets to possess potential health benefits, affording protection at the vascular endothelium level.

Anti-atherosclerotic plants which modulate the phenotype of vascular smooth muscle cells.

Science.gov (United States)

Saleh Al-Shehabi, Tuqa; Iratni, Rabah; Eid, Ali H

2016-10-15

Cardiovascular disease (CVD) remains the leading cause of global death, with atherosclerosis being a major contributor to this mortality. Several mechanisms are implicated in the pathogenesis of this disease. A key element in the development and progression of atherosclerotic lesions is the phenotype of vascular smooth muscle cells. Under pathophysiologic conditions such as injury, these cells switch from a contractile to a synthetic phenotype that often possesses high proliferative and migratory capacities. Despite major advances made in the management and treatment of atherosclerosis, mortality associated with this disease remains high. This mandates that other approaches be sought. Herbal medicine, especially for the treatment of CVD, has been gaining more attention in recent years. This is in no small part due to the evidence-based values associated with the consumption of many plants as well as the relatively cheaper prices, easier access and conventional folk medicine "inherited" over generations. Sections: In this review, we provide a brief introduction about the pathogenesis of atherosclerosis then we highlight the role of vascular smooth muscle cells in this disease, especially when a phenotypic switch of these cells arises. We then thoroughly discuss the various plants that show potentially beneficial effects as anti-atherosclerotic, with prime attention given to herbs and plants that inhibit the phenotypic switch of vascular smooth muscle cells. Accumulating evidence provides the justification for the use of botanicals in the treatment or prevention of atherosclerosis. However, further studies, especially clinical ones, are warranted to better define several pharmacological parameters of these herbs, such as toxicity, tolerability, and efficacy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reconstructing relative genome size of vascular plants through geological time.

Science.gov (United States)

Lomax, Barry H; Hilton, Jason; Bateman, Richard M; Upchurch, Garland R; Lake, Janice A; Leitch, Ilia J; Cromwell, Avery; Knight, Charles A

2014-01-01

The strong positive relationship evident between cell and genome size in both animals and plants forms the basis of using the size of stomatal guard cells as a proxy to track changes in plant genome size through geological time. We report for the first time a taxonomic fine-scale investigation into changes in stomatal guard-cell length and use these data to infer changes in genome size through the evolutionary history of land plants. Our data suggest that many of the earliest land plants had exceptionally large genome sizes and that a predicted overall trend of increasing genome size within individual lineages through geological time is not supported. However, maximum genome size steadily increases from the Mississippian (c. 360 million yr ago (Ma)) to the present. We hypothesise that the functional relationship between stomatal size, genome size and atmospheric CO2 may contribute to the dichotomy reported between preferential extinction of neopolyploids and the prevalence of palaeopolyploidy observed in DNA sequence data of extant vascular plants. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Germination, survival and growth of three vascular plants on biological soil crusts from a Mexican tropical desert.

Science.gov (United States)

Godínez-Alvarez, H; Morín, C; Rivera-Aguilar, V

2012-01-01

Information about the effects of biological soil crusts (BSC) on germination, seedling survival and growth of vascular plants is controversial because they can have positive, neutral or negative effects. This controversy may be because most studies conducted until now have just analysed one or two recruitment stages independently. To understand the BSC effects on vascular plants, it is necessary to consider each stage of the recruitment process and synthesise all this information. The goal of this study was twofold. First, we analyse germination, seedling survival and growth of three vascular plants (Agave marmorata, Prosopis laevigata and Neobuxbaumia tetetzo) on BSC (cyanobacteria and mixed crust) from a tropical desert region of south-central México. Second, we synthesise the information to determine the total effect of BSC on plant species performance. We conducted experiments under controlled conditions to evaluate the proportion of germinated seeds, proportion of surviving seedlings and seedling dry weight in BSC and bare soil. Results showed that BSC have different effects on germination, seedling survival and growth of plant species. Plant species performance was qualitatively higher on BSC than bare soil. The highest performance of A. marmorata and P. laevigata was observed on cyanobacteria and mixed crusts, respectively. The highest performance of N. tetetzo was on both crust types. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

Distribution of Estimated 10-Year Risk of Recurrent Vascular Events and Residual Risk in a Secondary Prevention Population

NARCIS (Netherlands)

Kaasenbrood, Lotte; Boekholdt, S. Matthijs; van der Graaf, Yolanda; Ray, Kausik K.; Peters, Ron J. G.; Kastelein, John J. P.; Amarenco, Pierre; LaRosa, John C.; Cramer, Maarten J. M.; Westerink, Jan; Kappelle, L. Jaap; de Borst, Gert J.; Visseren, Frank L. J.

2016-01-01

Among patients with clinically manifest vascular disease, the risk of recurrent vascular events is likely to vary. We assessed the distribution of estimated 10-year risk of recurrent vascular events in a secondary prevention population. We also estimated the potential risk reduction and residual

Distribution of Estimated 10-Year Risk of Recurrent Vascular Events and Residual Risk in a Secondary Prevention Population

NARCIS (Netherlands)

Kaasenbrood, Lotte; Boekholdt, S. Matthijs; Van Der Graaf, Yolanda; Ray, Kausik K.; Peters, Ron J G; Kastelein, John J P; Amarenco, Pierre; Larosa, John C.; Cramer, Maarten J M; Westerink, Jan; Kappelle, L. Jaap; De Borst, Gert J.; Visseren, Frank L J

2016-01-01

Background: Among patients with clinically manifest vascular disease, the risk of recurrent vascular events is likely to vary. We assessed the distribution of estimated 10-year risk of recurrent vascular events in a secondary prevention population. We also estimated the potential risk reduction and

Challenges in tracing the fate and effects of atmospheric polycyclic aromatic hydrocarbon deposition in vascular plants.

Science.gov (United States)

Desalme, Dorine; Binet, Philippe; Chiapusio, Geneviève

2013-05-07

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic pollutants that raise environmental concerns because of their toxicity. Their accumulation in vascular plants conditions harmful consequences to human health because of their position in the food chain. Consequently, understanding how atmospheric PAHs are taken up in plant tissues is crucial for risk assessment. In this review we synthesize current knowledge about PAH atmospheric deposition, accumulation in both gymnosperms and angiosperms, mechanisms of transfer, and ecological and physiological effects. PAHs emitted in the atmosphere partition between gas and particulate phases and undergo atmospheric deposition on shoots and soil. Most PAH concentration data from vascular plant leaves suggest that contamination occurs by both direct (air-leaf) and indirect (air-soil-root) pathways. Experimental studies demonstrate that PAHs affect plant growth, interfering with plant carbon allocation and root symbioses. Photosynthesis remains the most studied physiological process affected by PAHs. Among scientific challenges, identifying specific physiological transfer mechanisms and improving the understanding of plant-symbiont interactions in relation to PAH pollution remain pivotal for both fundamental and applied environmental sciences.

Moss and liverwort xyloglucans contain galacturonic acid and are structurally distinct from the xyloglucans synthesized by hornworts and vascular plants.

Science.gov (United States)

Peña, Maria J; Darvill, Alan G; Eberhard, Stefan; York, William S; O'Neill, Malcolm A

2008-11-01

Xyloglucan is a well-characterized hemicellulosic polysaccharide that is present in the cell walls of all seed-bearing plants. The cell walls of avascular and seedless vascular plants are also believed to contain xyloglucan. However, these xyloglucans have not been structurally characterized. This lack of information is an impediment to understanding changes in xyloglucan structure that occurred during land plant evolution. In this study, xyloglucans were isolated from the walls of avascular (liverworts, mosses, and hornworts) and seedless vascular plants (club and spike mosses and ferns and fern allies). Each xyloglucan was fragmented with a xyloglucan-specific endo-glucanase and the resulting oligosaccharides then structurally characterized using NMR spectroscopy, MALDI-TOF and electrospray mass spectrometry, and glycosyl-linkage and glycosyl residue composition analyses. Our data show that xyloglucan is present in the cell walls of all major divisions of land plants and that these xyloglucans have several common structural motifs. However, these polysaccharides are not identical because specific plant groups synthesize xyloglucans with unique structural motifs. For example, the moss Physcomitrella patens and the liverwort Marchantia polymorpha synthesize XXGGG- and XXGG-type xyloglucans, respectively, with sidechains that contain a beta-D-galactosyluronic acid and a branched xylosyl residue. By contrast, hornworts synthesize XXXG-type xyloglucans that are structurally homologous to the xyloglucans synthesized by many seed-bearing and seedless vascular plants. Our results increase our understanding of the evolution, diversity, and function of structural motifs in land-plant xyloglucans and provide support to the proposal that hornworts are sisters to the vascular plants.

Response of photosynthetic carbon gain to ecosystem retrogression of vascular plants and mosses in the boreal forest.

Science.gov (United States)

Bansal, Sheel; Nilsson, Marie-Charlotte; Wardle, David A

2012-07-01

In the long-term absence of rejuvenating disturbances, forest succession frequently proceeds from a maximal biomass phase to a retrogressive phase characterized by reduced nutrient availability [notably nitrogen (N) and phosphorus (P)] and net primary productivity. Few studies have considered how retrogression induces changes in ecophysiological responses associated with photosynthetic carbon (C) gain, and only for trees. We tested the hypothesis that retrogression would negatively impact photosynthetic C gain of four contrasting species, and that this impact would be greater for vascular plants (i.e., trees and shrubs) than for non-vascular plants (i.e., mosses). We used a 5,000-year-old chronosequence of forested islands in Sweden, where retrogression occurs in the long-term absence of lightning-ignited wildfires. Despite fundamental differences in plant form and ecological niche among species, vascular plants and mosses showed similar ecophysiological responses to retrogression. The most common effects of retrogression were reductions in photosynthesis and respiration per unit foliar N, increases in foliar N, δ(13)C and δ(15)N, and decreases in specific leaf areas. In contrast, photosynthesis per unit mass or area generally did not change along the chronosequence, but did vary many-fold between vascular plants and mosses. The consistent increases in foliar N without corresponding increases in mass- or area-based photosynthesis suggest that other factor(s), such as P co-limitation, light conditions or water availability, may co-regulate C gain in retrogressive boreal forests. Against our predictions, traits of mosses associated with C and N were generally highly responsive to retrogression, which has implications for how mosses influence ecosystem processes in boreal forests.

Use of micro-PIXE to determine spatial distributions of copper in Brassica carinata plants exposed to CuSO4 or CuEDDS

International Nuclear Information System (INIS)

Cestone, Benedetta; Vogel-Mikuš, Katarina; Quartacci, Mike Frank; Rascio, Nicoletta; Pongrac, Paula; Pelicon, Primož; Vavpetič, Primož; Grlj, Nataša; Jeromel, Luka; Kump, Peter; Nečemer, Marijan; Regvar, Marjana; Navari-Izzo, Flavia

2012-01-01

A better understanding of the mechanisms that govern copper (Cu) uptake, distribution and tolerance in Brassica carinata plants in the presence of chelators is needed before significant progress in chelate-assisted Cu phytoextraction can be made. The aims of this study were therefore to characterise (S,S)-N,N′-ethylenediamine disuccinic acid (EDDS)-assisted Cu uptake, and to compare the spatial distribution patterns of Cu in the roots and leaves of B. carinata plants. The plants were treated with 30 μM or 150 μM CuSO 4 or CuEDDS in hydroponic solution. Quantitative Cu distribution maps and concentration profiles across root and leaf cross-sections of the desorbed plants were obtained by micro-proton induced X-ray emission. In roots, the 30 μM treatments with both CuSO 4 and CuEDDS resulted in higher Cu concentrations in epidermal/cortical regions. At 150 μM CuSO 4 , Cu was mainly accumulated in root vascular bundles, whereas with 150 μM CuEDDS, Cu was detected in endodermis and the adjacent inner cortical cell layer. Under all treatments, except with a H + -ATP-ase inhibitor, the Cu in leaves was localised mainly in vascular tissues. The incubation of plants with 150 μM CuEDDS enhanced metal translocation to shoots, in comparison to the corresponding CuSO 4 treatment. Inhibition of H + -ATPase activity resulted in reduced Cu accumulation in 30 μM CuEDDS-treated roots and 150 μM CuEDDS-treated leaves, and induced changes in Cu distribution in the leaves. This indicates that active mechanisms are involved in retaining Cu in the leaf vascular tissues, which prevent its transport to photosynthetically active tissues. The physiological significance of EDDS-assisted Cu uptake is discussed. - Highlights: ► We localised Cu in Brassica carinata treated with CuSO 4 or CuEDDS by micro-PIXE. ► EDDS-assisted Cu uptake and transport resulted in preserved root endodermis. ► EDDS enhanced Cu transport from roots to shoots. ► Cu sequestration within leaf veins

Shifts in bryophyte carbon isotope ratio across an elevation × soil age matrix on Mauna Loa, Hawaii: do bryophytes behave like vascular plants?

Science.gov (United States)

Waite, Mashuri; Sack, Lawren

2011-05-01

The carbon isotope ratio (δ(13)C) of vascular plant leaf tissue is determined by isotope discrimination, primarily mediated by stomatal and mesophyll diffusion resistances and by photosynthetic rate. These effects lead to predictable trends in leaf δ(13)C across natural gradients of elevation, irradiance and nutrient supply. Less is known about shifts in δ(13)C for bryophytes at landscape scale, as bryophytes lack stomata in the dominant gametophyte phase, and thus lack active control over CO(2) diffusion. Twelve bryophyte species were sampled across a matrix of elevation and soil ages on Mauna Loa, Hawaii Island. We tested hypotheses based on previous findings for vascular plants, which tend to have less negative δ(13)C at higher elevations or irradiances, and for leaves with higher leaf mass per area (LMA). Across the matrix, bryophytes spanned the range of δ(13)C values typical of C(3) vascular plants. Bryophytes were remarkably similar to vascular plants in exhibiting less negative δ(13)C with increasing elevation, and with lower overstory cover; additionally δ(13)C was related to bryophyte canopy projected mass per area, a trait analogous to LMA in vascular plants, also correlated negatively with overstory cover. The similarity of responses of δ(13)C in bryophytes and vascular plants to environmental factors, despite differing morphologies and diffusion pathways, points to a strong direct role of photosynthetic rate in determining δ(13)C variation at the landscape scale.

Vascular plant and vertebrate species richness in national parks of the eastern United States

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Hatfield, Jeffrey S.; Myrick, Kaci E.; Huston, Michael A.; Weckerly, Floyd W.; Green, M. Clay

2013-01-01

Given the estimates that species diversity is diminishing at 50-100 times the normal rate, it is critical that we be able to evaluate changes in species richness in order to make informed decisions for conserving species diversity. In this study, we examined the potential of vascular plant species richness to be used as a surrogate for vertebrate species richness in the classes of amphibians, reptiles, birds, and mammals. Vascular plants, as primary producers, represent the biotic starting point for ecological community structure and are the logical place to start for understanding vertebrate species associations. We used data collected by the United States (US) National Park Service (NPS) on species presence within parks in the eastern US to estimate simple linear regressions between plant species richness and vertebrate richness. Because environmental factors may also influence species diversity, we performed simple linear regressions of species richness versus natural logarithm of park area, park latitude, mean annual precipitation, mean annual temperature, and human population density surrounding the parks. We then combined plant species richness and environmental variables in multiple regressions to determine the variables that remained as significant predictors of vertebrate species richness. As expected, we detected significant relationships between plant species richness and amphibian, bird, and mammal species richness. In some cases, plant species richness was predicted by park area alone. Species richness of mammals was only related to plant species richness. Reptile species richness, on the other hand, was related to plant species richness, park latitude and annual precipitation, while amphibian species richness was related to park latitude, park area, and plant species richness. Thus, plant species richness predicted species richness of different vertebrate groups to varying degrees and should not be used exclusively as a surrogate for vertebrate

Vascular flora of Kenya, based on the Flora of Tropical East Africa

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Yadong Zhou

2017-11-01

Full Text Available Kenya, an African country with major higher plant diversity, has a corresponding diversity of plant associations, because of the wide geographic distribution, diverse climatic conditions and soil types. In this article, all vascular plants of Kenya were counted based on the completed "Flora of Tropical East Africa (FTEA", and all families and genera were revised using recent molecular systematics research, forming a "Synoptic List of Families and Genera of Kenyan Vascular Plants (SLFGKVP". In total, there are 225 families, 1538 genera and 6293 indigenous species and and 62 families, 302 genera and 588 exotic species in Kenya. The Fabaceae with 98 genera and 576 Species is the largest family. Two of the seven plant distribution regions of Kenya, K4 and K7 are the most species-richest areas with regard to both total and endemic species, with 3375 and 3191 total species and 174 and 185 endemic species in K4 and K7 respectively. While, K3 and K5 have the highest density of both total and endemic species. K1 has the lowest density of total species, and K2 has the lowest density of endemic species.

Vascular plant biodiversity of the lower Coppermine River valley and vicinity (Nunavut, Canada: an annotated checklist of an Arctic flora

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Jeffery M. Saarela

2017-01-01

Full Text Available The Coppermine River in western Nunavut is one of Canada’s great Arctic rivers, yet its vascular plant flora is poorly known. Here, we report the results of a floristic inventory of the lower Coppermine River valley and vicinity, including Kugluk (Bloody Falls Territorial Park and the hamlet of Kugluktuk. The study area is approximately 1,200 km2, extending from the forest-tundra south of the treeline to the Arctic coast. Vascular plant floristic data are based on a review of all previous collections from the area and more than 1,200 new collections made in 2014. Results are presented in an annotated checklist, including citation of all specimens examined, comments on taxonomy and distribution, and photographs for a subset of taxa. The vascular plant flora comprises 300 species (311 taxa, a 36.6% increase from the 190 species documented by previous collections made in the area over the last century, and is considerably more diverse than other local floras on mainland Nunavut. We document 207 taxa for Kugluk (Bloody Falls Territorial Park, an important protected area for plants on mainland Nunavut. A total of 190 taxa are newly recorded for the study area. Of these, 14 taxa (13 species and one additional variety are newly recorded for Nunavut (Allium schoenoprasum, Carex capitata, Draba lonchocarpa, Eremogone capillaris subsp. capillaris, Sabulina elegans, Eleocharis quinqueflora, Epilobium cf. anagallidifolium, Botrychium neolunaria, Botrychium tunux, Festuca altaica, Polygonum aviculare, Salix ovalifolia var. arctolitoralis, Salix ovalifolia var. ovalifolia and Stuckenia pectinata, seven species are newly recorded for mainland Nunavut (Carex gynocrates, Carex livida, Cryptogramma stelleri, Draba simmonsii, Festuca viviparoidea subsp. viviparoidea, Juncus alpinoarticulatus subsp. americanus and Salix pseudomyrsinites and 56 range extensions are reported. The psbA-trnH and rbcL DNA sequence data were used to help identify the three Botrychium

Ecologic and geographic distributions of the vascular plants of southern Nye County, and adjacent parts of Clark, Lincoln, and Esmeralda Counties, Nevada. [Based on collections made in 1970

Energy Technology Data Exchange (ETDEWEB)

Beatley, J. C.

1971-01-01

A catalog is compiled of the vascular plants indiginous to Nye, Clark, Lincoln, and Esmeralda Counties of Nevada based on collections made in 1970. This compilation is an update of previous collections in these areas and is a supplement to report, UCLA--12-705. (ERB)

Species diversity of vascular plants in Si Phang-nga National Park, Phangnga Province

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Leeratiwong, C.

2005-07-01

Full Text Available A survey of the vascular plants in Si Phang-nga National Park, Phangnga Province, was conducted from September 2002 to August 2003. Five hundred and forty three species of 287 genera and 111 families were collected. The most diverse family was Rubiaceae, 53 species. Four species of these collected plants are endemic to Thailand, Argostemma lobulatum, Aristolochia helix, Crinum thaianum and Mallotus hymenophyllus and three species, Hedyotis hedyotidea, Lipocarpha microcephala and Pterolobium intergum are newly recorded for southern Thailand.

Evolutionary aspects of non-cell-autonomous regulation in vascular plants: structural background and models to study

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Anastasiia I. Evkaikina

2014-02-01

Full Text Available Plasmodesmata (PD serve for the exchange of information in form of miRNA, proteins and mRNA between adjacent cells in the course of plant development. This fundamental role of PD is well established in angiosperms but has not yet been traced back to the evolutionary ancient plant taxa where functional studies lag behind studies of PD structure and ontogenetic origin. There is convincing evidence that the ability to form secondary (post-cytokinesis PD, which can connect any adjacent cells, contrary to primary PD which form during cytokinesis and link only cells of the same lineage, appeared in the evolution of higher plants at least twice: in seed plants and in some representatives of the Lycopodiophyta. The (inability to form secondary PD is manifested in the symplastic organization of the shoot apical meristem (SAM which in most taxa of seedless vascular plants differs dramatically from that in seed plants. Lycopodiophyta appear to be suitable models to analyze the transport of developmental regulators via PD in SAMs with symplastic organization both different from, as well as analogous to, that in angiosperms, and to understand the evolutionary aspects of the role of this transport in the morphogenesis of vascular plant taxa.

Flora-On: Occurrence data of the vascular flora of mainland Portugal.

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Pereira, Ana Júlia; Francisco, Ana; Porto, Miguel

2016-01-01

The Flora-On dataset currently includes 253,310 occurrence records for the class Embryopsidae (vascular plants), comprising data collated via the platform http://flora-on.pt/ relating to observation records of vascular plants across mainland Portugal. Observations are uploaded directly to the database primarily by experienced botanists and naturalists, typically on a weekly basis, and consist of geo-referenced data points for species (or infraspecific taxa) along with their date of observation and phenological state. The Flora-On project aims to compile and make publicly accessible chorological, ecological, morphological and photographic information for the entire vascular flora of Portugal. The project's website offers powerful query and visualization capabilities, of which we highlight the probabilistic bioclimatic and phenological queries which operate based on the empirical density distributions of species in those variables. Flora-On was created and continues to be maintained by volunteers who are Associate members of Sociedade Portuguesa de Botânica (Botanical Society of Portugal). Given its focus on research-grade and current data, the Flora-On project represents a significant contribution to the knowledge of the present distribution and status of the Portuguese flora.

Disentangling environmental correlates of vascular plant biodiversity in a Mediterranean hotspot.

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Molina-Venegas, Rafael; Aparicio, Abelardo; Pina, Francisco José; Valdés, Benito; Arroyo, Juan

2013-10-01

We determined the environmental correlates of vascular plant biodiversity in the Baetic-Rifan region, a plant biodiversity hotspot in the western Mediterranean. A catalog of the whole flora of Andalusia and northern Morocco, the region that includes most of the Baetic-Rifan complex, was compiled using recent comprehensive floristic catalogs. Hierarchical cluster analysis (HCA) and detrended correspondence analysis (DCA) of the different ecoregions of Andalusia and northern Morocco were conducted to determine their floristic affinities. Diversity patterns were studied further by focusing on regional endemic taxa. Endemic and nonendemic alpha diversities were regressed to several environmental variables. Finally, semi-partial regressions on distance matrices were conducted to extract the respective contributions of climatic, altitudinal, lithological, and geographical distance matrices to beta diversity in endemic and nonendemic taxa. We found that West Rifan plant assemblages had more similarities with Andalusian ecoregions than with other nearby northern Morocco ecoregions. The endemic alpha diversity was explained relatively well by the environmental variables related to summer drought and extreme temperature values. Of all the variables, geographical distance contributed by far the most to spatial turnover in species diversity in the Baetic-Rifan hotspot. In the Baetic range, elevation was the most significant driver of nonendemic species beta diversity, while lithology and elevation were the main drivers of endemic beta diversity. Despite the fact that Andalusia and northern Morocco are presently separated by the Atlantic Ocean and the Mediterranean Sea, the Baetic and Rifan mountain ranges have many floristic similarities - especially in their western ranges - due to past migration of species across the Strait of Gibraltar. Climatic variables could be shaping the spatial distribution of endemic species richness throughout the Baetic-Rifan hotspot. Determinants

A bHLH-Based Feedback Loop Restricts Vascular Cell Proliferation in Plants.

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Vera-Sirera, Francisco; De Rybel, Bert; Úrbez, Cristina; Kouklas, Evangelos; Pesquera, Marta; Álvarez-Mahecha, Juan Camilo; Minguet, Eugenio G; Tuominen, Hannele; Carbonell, Juan; Borst, Jan Willem; Weijers, Dolf; Blázquez, Miguel A

2015-11-23

Control of tissue dimensions in multicellular organisms requires the precise quantitative regulation of mitotic activity. In plants, where cells are immobile, tissue size is achieved through control of both cell division orientation and mitotic rate. The bHLH transcription factor heterodimer formed by target of monopteros5 (TMO5) and lonesome highway (LHW) is a central regulator of vascular width-increasing divisions. An important unanswered question is how its activity is limited to specify vascular tissue dimensions. Here we identify a regulatory network that restricts TMO5/LHW activity. We show that thermospermine synthase ACAULIS5 antagonizes TMO5/LHW activity by promoting the accumulation of SAC51-LIKE (SACL) bHLH transcription factors. SACL proteins heterodimerize with LHW-therefore likely competing with TMO5/LHW interactions-prevent activation of TMO5/LHW target genes, and suppress the over-proliferation caused by excess TMO5/LHW activity. These findings connect two thus-far disparate pathways and provide a mechanistic understanding of the quantitative control of vascular tissue growth. Copyright © 2015 Elsevier Inc. All rights reserved.

Plant water relations I: uptake and transport

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Plants, like all living things, are mostly water. Water is the matrix of life, and its availability determines the distribution and productivity of plants on earth. Vascular plants evolved structures that enable them to transport water long distances with little input of energy, but the hollow trach...

Vascular Plant and Vertebrate Inventory of Tumacacori National Historical Park

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Powell, Brian F.; Albrecht, Eric W.; Halvorson, William L.; Schmidt, Cecilia A.; Anning, Pamela; Docherty, Kathleen

2005-01-01

Executive Summary This report summarizes the results of the first comprehensive biological inventory of Tumacacori National Historical Park (NHP) in southern Arizona. These surveys were part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in Arizona and New Mexico. From 2000 to 2003 we surveyed for vascular plants and vertebrates (fish, amphibians, reptiles, birds, and mammals) at Tumacacori NHP to document presence of species within the administrative boundaries of the park's three units. Because we used repeatable study designs and standardized field techniques, these inventories can serve as the first step in a long-term monitoring program. We recorded 591 species at Tumacacori NHP, significantly increasing the number of known species for the park (Table 1). Species of note in each taxonomic group include: * Plants: second record in Arizona of muster John Henry, a non-native species that is ranked a 'Class A noxious weed' in California; * Amphibian: Great Plains narrow-mouthed toad; * Reptiles: eastern fence lizard and Sonoran mud turtle; * Birds: yellow-billed cuckoo, green kingfisher, and one observation of the endangered southwestern willow flycatcher; * Fishes: four native species including an important population of the endangered Gila topminnow in the Tumacacori Channel; * Mammals: black bear and all four species of skunk known to occur in Arizona. We recorded 79 non-native species (Table E.S.1), many of which are of management concern, including: Bermudagrass, tamarisk, western mosquitofish, largemouth bass, bluegill, sunfish, American bullfrog, feral cats and dogs, and cattle. We also noted an abundance of crayfish (a non-native invertebrate). We review some of the important non-native species and make recommendations to remove them or to minimize their impacts on the native biota of the park. Based on the observed species richness, Tumacacori NHP possesses high biological diversity of plants, fish

Gardening in the zone of death: an experimental assessment of the absolute elevation limit of vascular plants.

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Dvorský, Miroslav; Chlumská, Zuzana; Altman, Jan; Čapková, Kateřina; Řeháková, Klára; Macek, Martin; Kopecký, Martin; Liancourt, Pierre; Doležal, Jiří

2016-04-13

Vascular plants in the western Tibetan Plateau reach 6000 m--the highest elevation on Earth. Due to the significant warming of the region, plant ranges are expected to shift upwards. However, factors governing maximum elevational limits of plant are unclear. To experimentally assess these factors, we transplanted 12 species from 5750 m to 5900 m (upper edge of vegetation) and 6100 m (beyond range) and monitored their survival for six years. In the first three years (2009-2012), there were plants surviving beyond the regional upper limit of vegetation. This supports the hypothesis of dispersal and/or recruitment limitation. Substantial warming, recorded in-situ during this period, very likely facilitated the survival. The survival was ecologically a non-random process, species better adapted to repeated soil freezing and thawing survived significantly better. No species have survived at 6100 m since 2013, probably due to the extreme snowfall in 2013. In conclusion, apart from the minimum heat requirements, our results show that episodic climatic events are decisive determinants of upper elevational limits of vascular plants.

Patterns in species richness and distribution of vascular epiphytes in Chiapas, Mexico

NARCIS (Netherlands)

Wolf, J.H.D.; Flamenco-S., A.

2003-01-01

Aim We aim to assess regional patterns in the distribution and species richness of vascular epiphytes with an emphasis on forests that differ in altitude and the amount of rainfall. Location Tropical America, in particularly the 75000 km2 large state of Chiapas in southern Mexico at 14.5-18.0º N.

Physiological, vascular and nanomechanical assessment of hybrid poplar leaf traits in micropropagated plants and plants propagated from root cuttings: A contribution to breeding programs.

Science.gov (United States)

Ďurkovič, Jaroslav; Husárová, Hana; Javoříková, Lucia; Čaňová, Ingrid; Šuleková, Miriama; Kardošová, Monika; Lukáčik, Ivan; Mamoňová, Miroslava; Lagaňa, Rastislav

2017-09-01

Micropropagated plants experience significant stress from rapid water loss when they are transferred from an in vitro culture to either greenhouse or field conditions. This is caused both by inefficient stomatal control of transpiration and the change to a higher light intensity and lower humidity. Understanding the physiological, vascular and biomechanical processes that allow micropropagated plants to modify their phenotype in response to environmental conditions can help to improve both field performance and plant survival. To identify changes between the hybrid poplar [Populus tremula × (Populus × canescens)] plants propagated from in vitro tissue culture and those from root cuttings, we assessed leaf performance for any differences in leaf growth, photosynthetic and vascular traits, and also nanomechanical properties of the tracheary element cell walls. The micropropagated plants showed significantly higher values for leaf area, leaf length, leaf width and leaf dry mass. The greater leaf area and leaf size dimensions resulted from the higher transpiration rate recorded for this stock type. Also, the micropropagated plants reached higher values for chlorophyll a fluorescence parameters and for the nanomechanical dissipation energy of tracheary element cell walls which may indicate a higher damping capacity within the primary xylem tissue under abiotic stress conditions. The performance of the plants propagated from root cuttings was superior for instantaneous water-use efficiency which signifies a higher acclimation capacity to stressful conditions during a severe drought particularly for this stock type. Similarities were found among the majority of the examined leaf traits for both vegetative plant origins including leaf mass per area, stomatal conductance, net photosynthetic rate, hydraulic axial conductivity, indicators of leaf midrib vascular architecture, as well as for the majority of cell wall nanomechanical traits. This research revealed that

The French Muséum national d'histoire naturelle vascular plant herbarium collection dataset

Science.gov (United States)

Le Bras, Gwenaël; Pignal, Marc; Jeanson, Marc L.; Muller, Serge; Aupic, Cécile; Carré, Benoît; Flament, Grégoire; Gaudeul, Myriam; Gonçalves, Claudia; Invernón, Vanessa R.; Jabbour, Florian; Lerat, Elodie; Lowry, Porter P.; Offroy, Bérangère; Pimparé, Eva Pérez; Poncy, Odile; Rouhan, Germinal; Haevermans, Thomas

2017-02-01

We provide a quantitative description of the French national herbarium vascular plants collection dataset. Held at the Muséum national d'histoire naturelle, Paris, it currently comprises records for 5,400,000 specimens, representing 90% of the estimated total of specimens. Ninety nine percent of the specimen entries are linked to one or more images and 16% have field-collecting information available. This major botanical collection represents the results of over three centuries of exploration and study. The sources of the collection are global, with a strong representation for France, including overseas territories, and former French colonies. The compilation of this dataset was made possible through numerous national and international projects, the most important of which was linked to the renovation of the herbarium building. The vascular plant collection is actively expanding today, hence the continuous growth exhibited by the dataset, which can be fully accessed through the GBIF portal or the MNHN database portal (available at: https://science.mnhn.fr/institution/mnhn/collection/p/item/search/form). This dataset is a major source of data for systematics, global plants macroecological studies or conservation assessments.

The French Muséum national d’histoire naturelle vascular plant herbarium collection dataset

Science.gov (United States)

Le Bras, Gwenaël; Pignal, Marc; Jeanson, Marc L.; Muller, Serge; Aupic, Cécile; Carré, Benoît; Flament, Grégoire; Gaudeul, Myriam; Gonçalves, Claudia; Invernón, Vanessa R.; Jabbour, Florian; Lerat, Elodie; Lowry, Porter P.; Offroy, Bérangère; Pimparé, Eva Pérez; Poncy, Odile; Rouhan, Germinal; Haevermans, Thomas

2017-01-01

We provide a quantitative description of the French national herbarium vascular plants collection dataset. Held at the Muséum national d’histoire naturelle, Paris, it currently comprises records for 5,400,000 specimens, representing 90% of the estimated total of specimens. Ninety nine percent of the specimen entries are linked to one or more images and 16% have field-collecting information available. This major botanical collection represents the results of over three centuries of exploration and study. The sources of the collection are global, with a strong representation for France, including overseas territories, and former French colonies. The compilation of this dataset was made possible through numerous national and international projects, the most important of which was linked to the renovation of the herbarium building. The vascular plant collection is actively expanding today, hence the continuous growth exhibited by the dataset, which can be fully accessed through the GBIF portal or the MNHN database portal (available at: https://science.mnhn.fr/institution/mnhn/collection/p/item/search/form). This dataset is a major source of data for systematics, global plants macroecological studies or conservation assessments. PMID:28195585

Fungal root symbionts of high-altitude vascular plants in the Himalayas.

Science.gov (United States)

Kotilínek, Milan; Hiiesalu, Inga; Košnar, Jiří; Šmilauerová, Marie; Šmilauer, Petr; Altman, Jan; Dvorský, Miroslav; Kopecký, Martin; Doležal, Jiří

2017-07-26

Arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) form symbiotic relationships with plants influencing their productivity, diversity and ecosystem functions. Only a few studies on these fungi, however, have been conducted in extreme elevations and none over 5500 m a.s.l., although vascular plants occur up to 6150 m a.s.l. in the Himalayas. We quantified AMF and DSE in roots of 62 plant species from contrasting habitats along an elevational gradient (3400-6150 m) in the Himalayas using a combination of optical microscopy and next generation sequencing. We linked AMF and DSE communities with host plant evolutionary history, ecological preferences (elevation and habitat type) and functional traits. We detected AMF in elevations up to 5800 m, indicating it is more constrained by extreme conditions than the host plants, which ascend up to 6150 m. In contrast, DSE were found across the entire gradient up to 6150 m. AMF diversity was unimodally related to elevation and positively related to the intensity of AMF colonization. Mid-elevation steppe and alpine plants hosted more diverse AMF communities than plants from deserts and the subnival zone. Our results bring novel insights to the abiotic and biotic filters structuring AMF and DSE communities in the Himalayas.

Effects of reindeer density on vascular plant diversity on North Scandinavian mountains

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Johan Olofsson

2005-04-01

Full Text Available We studied the effects of reindeer grazing on species richness and diversity of vascular plants on dolomite influenced low alpine sites in the species rich northern part of the Scandes using 8 sites with different reindeer densities. Two sites were situated inside Malla Strict Nature Reserve, where reindeer grazing have been totally prohibited since 1981, and strongly restricted since 1950s. The six other sites were located in other species rich hotspot sites standardized to be as similar to the dolomite-influenced sites in Malla Strict Reserve as possible but varying in reindeer densities commonly found in the Fennoscandian mountain chain. Each site with a habitat complex especially rich in rare vascular plants (the Dryas heath – low herb meadow complex was systematically sampled in four plots of 2 m x 10 m. The plots were divided to 20 squares of 1 m x 1 m, and complete species lists of vascular plants were compiled for each of the squares. The first DCA (detrended correspondence analysis axis was strongly related to an index of reindeer grazing, indicating that grazing has a strong impact on the composition of the vegetation. None of the characteristics indices of biodiversity (species richness, evenness or Shannon-Wiener H’ was correlated with reindeer density. The local abundances of categories consisting of relatively rare plants (Ca favored plants and red listed plants of Finland showed significant, positive correlation with the intensity of reindeer grazing. We conclude that even though the density of reindeer has no influence on the total species richness or diversity of vascular plants, reindeer may still be important for regional biodiversity as it seems to favour rare and threatened plants. Moreover, our results imply that standard diversity indices may have limited value in the context of conservation biology, as these indices are equally influenced by rarities and by trivial species.Abstract in Swedish / Sammandrag: Vi

Investigating water transport through the xylem network in vascular plants.

Science.gov (United States)

Kim, Hae Koo; Park, Joonghyuk; Hwang, Ildoo

2014-04-01

Our understanding of physical and physiological mechanisms depends on the development of advanced technologies and tools to prove or re-evaluate established theories, and test new hypotheses. Water flow in land plants is a fascinating phenomenon, a vital component of the water cycle, and essential for life on Earth. The cohesion-tension theory (CTT), formulated more than a century ago and based on the physical properties of water, laid the foundation for our understanding of water transport in vascular plants. Numerous experimental tools have since been developed to evaluate various aspects of the CTT, such as the existence of negative hydrostatic pressure. This review focuses on the evolution of the experimental methods used to study water transport in plants, and summarizes the different ways to investigate the diversity of the xylem network structure and sap flow dynamics in various species. As water transport is documented at different scales, from the level of single conduits to entire plants, it is critical that new results be subjected to systematic cross-validation and that findings based on different organs be integrated at the whole-plant level. We also discuss the functional trade-offs between optimizing hydraulic efficiency and maintaining the safety of the entire transport system. Furthermore, we evaluate future directions in sap flow research and highlight the importance of integrating the combined effects of various levels of hydraulic regulation.

Testing the Efficacy of DNA Barcodes for Identifying the Vascular Plants of Canada.

Science.gov (United States)

Braukmann, Thomas W A; Kuzmina, Maria L; Sills, Jesse; Zakharov, Evgeny V; Hebert, Paul D N

2017-01-01

Their relatively slow rates of molecular evolution, as well as frequent exposure to hybridization and introgression, often make it difficult to discriminate species of vascular plants with the standard barcode markers (rbcL, matK, ITS2). Previous studies have examined these constraints in narrow geographic or taxonomic contexts, but the present investigation expands analysis to consider the performance of these gene regions in discriminating the species in local floras at sites across Canada. To test identification success, we employed a DNA barcode reference library with sequence records for 96% of the 5108 vascular plant species known from Canada, but coverage varied from 94% for rbcL to 60% for ITS2 and 39% for matK. Using plant lists from 27 national parks and one scientific reserve, we tested the efficacy of DNA barcodes in identifying the plants in simulated species assemblages from six biogeographic regions of Canada using BLAST and mothur. Mean pairwise distance (MPD) and mean nearest taxon distance (MNTD) were strong predictors of barcode performance for different plant families and genera, and both metrics supported ITS2 as possessing the highest genetic diversity. All three genes performed strongly in assigning the taxa present in local floras to the correct genus with values ranging from 91% for rbcL to 97% for ITS2 and 98% for matK. However, matK delivered the highest species discrimination (~81%) followed by ITS2 (~72%) and rbcL (~44%). Despite the low number of plant taxa in the Canadian Arctic, DNA barcodes had the least success in discriminating species from this biogeographic region with resolution ranging from 36% with rbcL to 69% with matK. Species resolution was higher in the other settings, peaking in the Woodland region at 52% for rbcL and 87% for matK. Our results indicate that DNA barcoding is very effective in identifying Canadian plants to a genus, and that it performs well in discriminating species in regions where floristic diversity is

The distribution of 137Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

International Nuclear Information System (INIS)

Vinichuk, M.; Johanson, K.J.; Rydin, H.; Rosen, K.

2010-01-01

We record the distribution of 137 Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as 137 Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris 137 Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher 137 Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of 137 Cs within the plants. The patterns of 137 Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The 137 Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between 137 Cs and Rb (r = 0.89), and between 137 Cs and stable Cs (r = 0.84). This suggests similarities between 137 Cs and Rb in uptake and relocation within the Sphagnum, but that 137 Cs differs from K.

The distribution of (137)Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden.

Science.gov (United States)

Vinichuk, M; Johanson, K J; Rydin, H; Rosén, K

2010-02-01

We record the distribution of (137)Cs, K, Rb and Cs within individual Sphagnum plants (down to 20cm depth) as well as (137)Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris(137)Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher (137)Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of (137)Cs within the plants. The patterns of (137)Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The (137)Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10cm) of the plant (r=0.50). The strongest correlations were revealed between (137)Cs and Rb (r=0.89), and between (137)Cs and stable Cs (r=0.84). This suggests similarities between (137)Cs and Rb in uptake and relocation within the Sphagnum, but that (137)Cs differs from K. Copyright 2009 Elsevier Ltd. All rights reserved.

A comprehensive checklist of vascular epiphytes of the Atlantic Forest reveals outstanding endemic rates.

Science.gov (United States)

Freitas, Leandro; Salino, Alexandre; Neto, Luiz Menini; Elias Almeida, Thaís; Mortara, Sara Ribeiro; Stehmann, João Renato; Amorim, André Marcio; Guimarães, Elsie Franklin; Coelho, Marcus Nadruz; Zanin, Ana; Forzza, Rafaela Campostrini

2016-01-01

Knowledge of the geographic distribution of plants is essential to underpin the understanding of global biodiversity patterns. Vascular epiphytes are important components of diversity and functionality of Neotropical forests but, unlike their terrestrial counterparts, they are under-represented in large-scale diversity and biogeographic analyses. This is the case for the Atlantic Forest - one of the most diverse and threatened biomes worldwide. We provide the first comprehensive species list of Atlantic Forest vascular epiphytes; their endemism patterns and threatened species occurrence have also been analyzed. A list with 2,256 species of (hemi-)epiphytes - distributed in 240 genera and 33 families - is presented based on the updated Brazilian Flora Checklist. This represents more than 15% of the total vascular plant richness in the Atlantic Forest. Moreover, 256 species are included on the Brazilian Red List. More than 93% of the overall richness is concentrated in ten families, with 73% represented by Orchidaceae and Bromeliaceae species alone. A total of 78% of epiphytic species are endemic to the Atlantic Forest, in contrast to overall vascular plant endemism in this biome estimated at 57%. Among the non-endemics, 13% of epiphytic species also occur either in the Amazon or in the Cerrado - the other two largest biomes of Brazil - and only 8% are found in two or more Brazilian biomes. This pattern of endemism, in addition to available dated phylogenies of some genera, indicate the dominance of recent radiations of epiphytic groups in the Atlantic Forest, showing that the majority of divergences dating from the Pliocene onwards are similar to those that were recently reported for other Neotropical plants.

Use of micro-PIXE to determine spatial distributions of copper in Brassica carinata plants exposed to CuSO{sub 4} or CuEDDS

Energy Technology Data Exchange (ETDEWEB)

Cestone, Benedetta, E-mail: benedettacestone@yahoo.it [Department of Biology of Crop Plants, University of Pisa, Via del Borghetto 80, 56121 Pisa (Italy); Vogel-Mikus, Katarina [Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, S1-1000 Ljubljana (Slovenia); Quartacci, Mike Frank [Department of Biology of Crop Plants, University of Pisa, Via del Borghetto 80, 56121 Pisa (Italy); Rascio, Nicoletta [Department of Biology, University of Padova, Via Ugo Bassi 58/B, 35121 Padova (Italy); Pongrac, Paula [Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, S1-1000 Ljubljana (Slovenia); Pelicon, Primoz; Vavpetic, Primoz; Grlj, Natasa; Jeromel, Luka; Kump, Peter; Necemer, Marijan [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Regvar, Marjana [Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, S1-1000 Ljubljana (Slovenia); Navari-Izzo, Flavia [Department of Biology of Crop Plants, University of Pisa, Via del Borghetto 80, 56121 Pisa (Italy)

2012-06-15

A better understanding of the mechanisms that govern copper (Cu) uptake, distribution and tolerance in Brassica carinata plants in the presence of chelators is needed before significant progress in chelate-assisted Cu phytoextraction can be made. The aims of this study were therefore to characterise (S,S)-N,N Prime -ethylenediamine disuccinic acid (EDDS)-assisted Cu uptake, and to compare the spatial distribution patterns of Cu in the roots and leaves of B. carinata plants. The plants were treated with 30 {mu}M or 150 {mu}M CuSO{sub 4} or CuEDDS in hydroponic solution. Quantitative Cu distribution maps and concentration profiles across root and leaf cross-sections of the desorbed plants were obtained by micro-proton induced X-ray emission. In roots, the 30 {mu}M treatments with both CuSO{sub 4} and CuEDDS resulted in higher Cu concentrations in epidermal/cortical regions. At 150 {mu}M CuSO{sub 4}, Cu was mainly accumulated in root vascular bundles, whereas with 150 {mu}M CuEDDS, Cu was detected in endodermis and the adjacent inner cortical cell layer. Under all treatments, except with a H{sup +}-ATP-ase inhibitor, the Cu in leaves was localised mainly in vascular tissues. The incubation of plants with 150 {mu}M CuEDDS enhanced metal translocation to shoots, in comparison to the corresponding CuSO{sub 4} treatment. Inhibition of H{sup +}-ATPase activity resulted in reduced Cu accumulation in 30 {mu}M CuEDDS-treated roots and 150 {mu}M CuEDDS-treated leaves, and induced changes in Cu distribution in the leaves. This indicates that active mechanisms are involved in retaining Cu in the leaf vascular tissues, which prevent its transport to photosynthetically active tissues. The physiological significance of EDDS-assisted Cu uptake is discussed. - Highlights: Black-Right-Pointing-Pointer We localised Cu in Brassica carinata treated with CuSO{sub 4} or CuEDDS by micro-PIXE. Black-Right-Pointing-Pointer EDDS-assisted Cu uptake and transport resulted in preserved root

Lake sediment multi-taxon DNA from North Greenland records early post-glacial appearance of vascular plants and accurately tracks environmental changes

DEFF Research Database (Denmark)

Epp, L. S.; Gussarova, C.; Boessenkool, S.

2015-01-01

temperatures. Lake sediments contain DNA paleorecords of the surrounding ecosystems and can be used to retrieve a variety of organismal groups from a single sample. In this study, we analyzed vascular plant, bryophyte, algal (in particular diatom) and copepod DNA retrieved from a sediment core spanning...... phases, and distinct temporal changes in plant presence were recovered. The plant DNA was mostly in agreement with expected vegetation history, but very early occurrences of vascular plants, including the woody Empetrum nigrum, document terrestrial vegetation very shortly after glacial retreat. Our study...... core. Our DNA record was stratigraphically coherent, with no indication of leaching between layers, and our cross-taxon comparisons were in accordance with previously inferred local ecosystem changes. Authentic ancient plant DNA was retrieved from nearly all layers, both from the marine and the limnic...

The ALDH21 gene found in lower plants and some vascular plants codes for a NADP+ -dependent succinic semialdehyde dehydrogenase.

Science.gov (United States)

Kopečná, Martina; Vigouroux, Armelle; Vilím, Jan; Končitíková, Radka; Briozzo, Pierre; Hájková, Eva; Jašková, Lenka; von Schwartzenberg, Klaus; Šebela, Marek; Moréra, Solange; Kopečný, David

2017-10-01

Lower plant species including some green algae, non-vascular plants (bryophytes) as well as the oldest vascular plants (lycopods) and ferns (monilophytes) possess a unique aldehyde dehydrogenase (ALDH) gene named ALDH21, which is upregulated during dehydration. However, the gene is absent in flowering plants. Here, we show that ALDH21 from the moss Physcomitrella patens codes for a tetrameric NADP + -dependent succinic semialdehyde dehydrogenase (SSALDH), which converts succinic semialdehyde, an intermediate of the γ-aminobutyric acid (GABA) shunt pathway, into succinate in the cytosol. NAD + is a very poor coenzyme for ALDH21 unlike for mitochondrial SSALDHs (ALDH5), which are the closest related ALDH members. Structural comparison between the apoform and the coenzyme complex reveal that NADP + binding induces a conformational change of the loop carrying Arg-228, which seals the NADP + in the coenzyme cavity via its 2'-phosphate and α-phosphate groups. The crystal structure with the bound product succinate shows that its carboxylate group establishes salt bridges with both Arg-121 and Arg-457, and a hydrogen bond with Tyr-296. While both arginine residues are pre-formed for substrate/product binding, Tyr-296 moves by more than 1 Å. Both R121A and R457A variants are almost inactive, demonstrating a key role of each arginine in catalysis. Our study implies that bryophytes but presumably also some green algae, lycopods and ferns, which carry both ALDH21 and ALDH5 genes, can oxidize SSAL to succinate in both cytosol and mitochondria, indicating a more diverse GABA shunt pathway compared with higher plants carrying only the mitochondrial ALDH5. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Silicon in vascular plants: uptake, transport and its influence on mineral stress under acidic conditions.

Science.gov (United States)

Pontigo, Sofía; Ribera, Alejandra; Gianfreda, Liliana; de la Luz Mora, María; Nikolic, Miroslav; Cartes, Paula

2015-07-01

So far, considerable advances have been achieved in understanding the mechanisms of Si uptake and transport in vascular plants. This review presents a comprehensive update about this issue, but also provides the new insights into the role of Si against mineral stresses that occur in acid soils. Such information could be helpful to understand both the differential Si uptake ability as well as the benefits of this mineral element on plants grown under acidic conditions. Silicon (Si) has been widely recognized as a beneficial element for many plant species, especially under stress conditions. In the last few years, great efforts have been made to elucidate the mechanisms involved in uptake and transport of Si by vascular plants and recently, different Si transporters have been identified. Several researches indicate that Si can alleviate various mineral stresses in plants growing under acidic conditions, including aluminium (Al) and manganese (Mn) toxicities as well as phosphorus (P) deficiency all of which are highly detrimental to crop production. This review presents recent findings concerning the influence of uptake and transport of Si on mineral stress under acidic conditions because a knowledge of this interaction provides the basis for understanding the role of Si in mitigating mineral stress in acid soils. Currently, only four Si transporters have been identified and there is little information concerning the response of Si transporters under stress conditions. More investigations are therefore needed to establish whether there is a relationship between Si transporters and the benefits of Si to plants subjected to mineral stress. Evidence presented suggests that Si supply and its subsequent accumulation in plant tissues could be exploited as a strategy to improve crop productivity on acid soils.

The drivers of plant diversity

DEFF Research Database (Denmark)

Jensen, Kristine Engemann

dataset consisting of 72,533 vascular plant species in 432 families covering the New World. Eight plant growth forms were defined based on woodiness, structure, and root traits, and species names were standardized to the latest accepted scientific name. The data is used in Paper II and IV In Paper II we....... The study emphasise that using big, collected datasets is not without limitations, and we recommend using rarefaction for species richness estimation from such datasets. Paper IV investigates a well-known macroecological pattern, the latitudinal diversity gradient, for nine vascular plant functional groups......In this thesis we use a “big data” approach to describe and explain large-scale patterns of plant diversity. The botanical data used for the six papers come from three different databases covering the New World, North America, and Europe respectively. The data on plant distributions were combined...

Vascular Plant and Vertebrate Inventory of Organ Pipe Cactus National Monument

Science.gov (United States)

Schmidt, Cecilia A.; Powell, Brian F.; Halvorson, William L.

2007-01-01

Executive Summary We summarized inventory and monitoring efforts for plants and vertebrates at Organ Pipe Cactus National Monument (NM) in Arizona. We used data from previous research to compile complete species lists for the monument and to assess inventory completeness. There have been 1,031 species of plants and vertebrates observed at the monument. Most of the species on the list are documented by voucher specimens. There are 59 non-native species established in the monument: one mammal, three birds, and 55 non-native plants. Most non-native plant species were first recorded along roads. In each taxon-specific chapter, we highlight areas that contribute disproportionately to species richness or that have unique species for the monument. Of particular importance are Quitobaquito Springs and Pond, which are responsible for the monument having one of the highest number of bird species in the Sonoran Desert Network of parks. Quitobaquito also contains the only fish in the monument, the endangered Quitobaquito pupfish (Cyprinodon eremus). Other important resources for the plants and vertebrates include the xeroriparian washes (e.g., Alamo Canyon) and the Ajo Mountains. Based on the review of past studies, we believe the inventories of vascular plants and vertebrates are nearly complete and that the monument has one of the most complete inventories of any unit in the Sonoran Desert Network.

Gravity sensing and signal transduction in vascular plant primary roots.

Science.gov (United States)

Baldwin, Katherine L; Strohm, Allison K; Masson, Patrick H

2013-01-01

During gravitropism, the potential energy of gravity is converted into a biochemical signal. How this transfer occurs remains one of the most exciting mysteries in plant cell biology. New experiments are filling in pieces of the puzzle. In this review, we introduce gravitropism and give an overview of what we know about gravity sensing in roots of vascular plants, with special highlight on recent papers. When plant roots are reoriented sideways, amyloplast resedimentation in the columella cells is a key initial step in gravity sensing. This process somehow leads to cytoplasmic alkalinization of these cells followed by relocalization of auxin efflux carriers (PINs). This changes auxin flow throughout the root, generating a lateral gradient of auxin across the cap that upon transmission to the elongation zone leads to differential cell elongation and gravibending. We will present the evidence for and against the following players having a role in transferring the signal from the amyloplast sedimentation into the auxin signaling cascade: mechanosensitive ion channels, actin, calcium ions, inositol trisphosphate, receptors/ligands, ARG1/ARL2, spermine, and the TOC complex. We also outline auxin transport and signaling during gravitropism.

Survey of protected vascular plants on the Oak Ridge Reservation, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

Awl, D.J.; Pounds, L.R.; Rosensteel, B.A.; King, A.L.; Hamlett, P.A.

1996-06-01

Vascular plant surveys were initiated during fiscal year 1992 by the environmentally sensitive areas program to determine the baseline condition of threatened and endangered (T&E) vascular plant species on the Oak Ridge Reservation (ORR). T&E species receive protection under federal and state regulations. In addition, the National Environmental Policy Act (NEPA) requires that federally-funded projects avoid or mitigate impacts to listed species. T&E plant species found on or near the U.S. Department of Energy`s (DOE) Oak Ridge Reservation (ORR) are identified. Twenty-eight species identified on the ORR are listed by the Tennessee Department of Environment and Conservation as either endangered, threatened, or of special concern. Four of these have been under review by the U.S. Fish and Wildlife Service for possible listing (listed in the formerly-used C2 candidate category). Additional species listed by the state occur near and may be present on the ORR. A range of habitats support the rare taxa on the ORR: river bluffs, sinkholes, calcareous barrens, wetlands, utility corridors, and forests. The list of T&E plant species and their locations on the ORR should be considered provisional because the entire ORR has not been surveyed, and state and federal status of all species continues to be updated. The purpose of this document is to present information on the listed T&E plant species currently known to occur on the ORR as well as listed species potentially occurring on the ORR based on geographic range and habitat availability. For the purpose of this report, {open_quotes}T&E species{close_quotes} include all federal- and state-listed species, including candidates for listing, and species of special concern. Consideration of T&E plant habitats is an important component of resource management and land-use planning; protection of rare species in their natural habitat is the best method of ensuring their long-term survival.

Survey of protected vascular plants on the Oak Ridge Reservation, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Awl, D.J.; Pounds, L.R.; Rosensteel, B.A.; King, A.L.; Hamlett, P.A.

1996-06-01

Vascular plant surveys were initiated during fiscal year 1992 by the environmentally sensitive areas program to determine the baseline condition of threatened and endangered (T ampersand E) vascular plant species on the Oak Ridge Reservation (ORR). T ampersand E species receive protection under federal and state regulations. In addition, the National Environmental Policy Act (NEPA) requires that federally-funded projects avoid or mitigate impacts to listed species. T ampersand E plant species found on or near the U.S. Department of Energy's (DOE) Oak Ridge Reservation (ORR) are identified. Twenty-eight species identified on the ORR are listed by the Tennessee Department of Environment and Conservation as either endangered, threatened, or of special concern. Four of these have been under review by the U.S. Fish and Wildlife Service for possible listing (listed in the formerly-used C2 candidate category). Additional species listed by the state occur near and may be present on the ORR. A range of habitats support the rare taxa on the ORR: river bluffs, sinkholes, calcareous barrens, wetlands, utility corridors, and forests. The list of T ampersand E plant species and their locations on the ORR should be considered provisional because the entire ORR has not been surveyed, and state and federal status of all species continues to be updated. The purpose of this document is to present information on the listed T ampersand E plant species currently known to occur on the ORR as well as listed species potentially occurring on the ORR based on geographic range and habitat availability. For the purpose of this report, open-quotes T ampersand E speciesclose quotes include all federal- and state-listed species, including candidates for listing, and species of special concern. Consideration of T ampersand E plant habitats is an important component of resource management and land-use planning; protection of rare species in their natural habitat is the best method of ensuring their

Evolutionary genomics revealed interkingdom distribution of Tcn1-like chromodomain-containing Gypsy LTR retrotransposons among fungi and plants

Directory of Open Access Journals (Sweden)

Blinov Alexander

2010-04-01

Full Text Available Abstract Background Chromodomain-containing Gypsy LTR retrotransposons or chromoviruses are widely distributed among eukaryotes and have been found in plants, fungi and vertebrates. The previous comprehensive survey of chromoviruses from mosses (Bryophyta suggested that genomes of non-seed plants contain the clade which is closely related to the retrotransposons from fungi. The origin, distribution and evolutionary history of this clade remained unclear mainly due to the absence of information concerning the diversity and distribution of LTR retrotransposons in other groups of non-seed plants as well as in fungal genomes. Results In present study we preformed in silico analysis of chromodomain-containing LTR retrotransposons in 25 diverse fungi and a number of plant species including spikemoss Selaginella moellendorffii (Lycopodiophyta coupled with an experimental survey of chromodomain-containing Gypsy LTR retrotransposons from diverse non-seed vascular plants (lycophytes, ferns, and horsetails. Our mining of Gypsy LTR retrotransposons in genomic sequences allowed identification of numerous families which have not been described previously in fungi. Two new well-supported clades, Galahad and Mordred, as well as several other previously unknown lineages of chromodomain-containing Gypsy LTR retrotransposons were described based on the results of PCR-mediated survey of LTR retrotransposon fragments from ferns, horsetails and lycophytes. It appeared that one of the clades, namely Tcn1 clade, was present in basidiomycetes and non-seed plants including mosses (Bryophyta and lycophytes (genus Selaginella. Conclusions The interkingdom distribution is not typical for chromodomain-containing LTR retrotransposons clades which are usually very specific for a particular taxonomic group. Tcn1-like LTR retrotransposons from fungi and non-seed plants demonstrated high similarity to each other which can be explained by strong selective constraints and the

Plant ecdysteroids: plant sterols with intriguing distributions, biological effects and relations to plant hormones.

Science.gov (United States)

Tarkowská, Danuše; Strnad, Miroslav

2016-09-01

The present review summarises current knowledge of phytoecdysteroids' biosynthesis, distribution within plants, biological importance and relations to plant hormones. Plant ecdysteroids (phytoecdysteroids) are natural polyhydroxylated compounds that have a four-ringed skeleton, usually composed of either 27 carbon atoms or 28-29 carbon atoms (biosynthetically derived from cholesterol or other plant sterols, respectively). Their physiological roles in plants have not yet been confirmed and their occurrence is not universal. Nevertheless, they are present at high concentrations in various plant species, including commonly consumed vegetables, and have a broad spectrum of pharmacological and medicinal properties in mammals, including hepatoprotective and hypoglycaemic effects, and anabolic effects on skeletal muscle, without androgenic side-effects. Furthermore, phytoecdysteroids can enhance stress resistance by promoting vitality and enhancing physical performance; thus, they are considered adaptogens. This review summarises current knowledge of phytoecdysteroids' biosynthesis, distribution within plants, biological importance and relations to plant hormones.

The distribution of {sup 137}Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

Energy Technology Data Exchange (ETDEWEB)

Vinichuk, M., E-mail: mykhailo.vinichuk@mark.slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Chernyakhovsky Street, 10005 Zhytomyr (Ukraine); Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Rydin, H. [Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18D, SE-752 36 Uppsala (Sweden); Rosen, K. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden)

2010-02-15

We record the distribution of {sup 137}Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as {sup 137}Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris{sup 137}Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher {sup 137}Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of {sup 137}Cs within the plants. The patterns of {sup 137}Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The {sup 137}Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between {sup 137}Cs and Rb (r = 0.89), and between {sup 137}Cs and stable Cs (r = 0.84). This suggests similarities between {sup 137}Cs and Rb in uptake and relocation within the Sphagnum, but that {sup 137}Cs differs from K.

Plant physiology in theory and practice: an analysis of the WBE model for vascular plants.

Science.gov (United States)

Petit, Giai; Anfodillo, Tommaso

2009-07-07

The theoretical model of West, Brown and Enquist (hereafter WBE) proposed the fractal geometry of the transport system as the origin of the allometric scaling laws observed in nature. The WBE model has either been criticized for some restrictive and biologically unrealistic constraints or its reliability debated on the evidence of empirical tests. In this work, we revised the structure of the WBE model for vascular plants, highlighting some critical assumptions and simplifications and discuss them with regard to empirical evidence from plant anatomy and physiology. We conclude that the WBE model had the distinct merit of shedding light on some important features such as conduit tapering. Nonetheless, it is over-simplistic and a revised model would be desirable with an ontogenetic perspective that takes some important phenomena into account, such as the transformation of the inner sapwood into heartwood and the effect of hydraulic constraints in limiting the growth in height.

Working toward integrated models of alpine plant distribution.

Science.gov (United States)

Carlson, Bradley Z; Randin, Christophe F; Boulangeat, Isabelle; Lavergne, Sébastien; Thuiller, Wilfried; Choler, Philippe

2013-10-01

Species distribution models (SDMs) have been frequently employed to forecast the response of alpine plants to global changes. Efforts to model alpine plant distribution have thus far been primarily based on a correlative approach, in which ecological processes are implicitly addressed through a statistical relationship between observed species occurrences and environmental predictors. Recent evidence, however, highlights the shortcomings of correlative SDMs, especially in alpine landscapes where plant species tend to be decoupled from atmospheric conditions in micro-topographic habitats and are particularly exposed to geomorphic disturbances. While alpine plants respond to the same limiting factors as plants found at lower elevations, alpine environments impose a particular set of scale-dependent and hierarchical drivers that shape the realized niche of species and that require explicit consideration in a modelling context. Several recent studies in the European Alps have successfully integrated both correlative and process-based elements into distribution models of alpine plants, but for the time being a single integrative modelling framework that includes all key drivers remains elusive. As a first step in working toward a comprehensive integrated model applicable to alpine plant communities, we propose a conceptual framework that structures the primary mechanisms affecting alpine plant distributions. We group processes into four categories, including multi-scalar abiotic drivers, gradient dependent species interactions, dispersal and spatial-temporal plant responses to disturbance. Finally, we propose a methodological framework aimed at developing an integrated model to better predict alpine plant distribution.

Leaf wax n-alkane distributions in and across modern plants: Implications for paleoecology and chemotaxonomy

Science.gov (United States)

Bush, Rosemary T.; McInerney, Francesca A.

2013-09-01

, Sphagnum mosses are marked by their predominance of C23 and C25, chain lengths which are largely absent in terrestrial vascular plants. The results here support the use of C23 as a robust proxy for Sphagnum mosses in paleoecological studies, but not the use of C27, C29, and C31 to separate graminoids and woody plants from one another, as both groups produce highly variable but significant amounts of all three chain lengths. In Africa, C33 and C35 chain lengths appear to distinguish graminoids from some woody plants, but this may be a reflection of the differences in rainforest and savanna environments. Indeed, variation in the abundances of long n-alkane chain lengths may be responding in part to local environmental conditions, and this calls for a more directed examination of the effects of temperature and aridity on plant n-alkane distributions in natural environments.

Dynamic analysis on cavitation and embolization in vascular plants under tension

Science.gov (United States)

Ryu, Jeongeun; Hwang, Bae Geun; Kim, Yangmin; Lee, Sang Joon

2014-11-01

Plants can transport sap water from the soil to the tip of their leaves using the tensile forces created by leaf transpiration without any mechanical pumps. However, the high tension adversely induces a thermodynamically metastable state in sap water with negative pressure and gas bubbles are prone to be formed in xylem vessels. Cavitation easily breaks down continuous water columns and grows into embolization, which limits water transport through xylem vessels. Meanwhile, the repair process of embolization is closely related to water management and regulation of sap flow in plants. In this study, the cavitation and embolization phenomena of liquid water in vascular plants and a physical model system are experimentally and theoretically investigated in detail under in vivo and in vitro conditions. This study will not only shed light on the understanding of these multiphase flows under tension but also provide a clue to solve cavitation problems in micro-scale conduits and microfluidic network systems. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2008-0061991).

Investigation of gold nanoparticles uptake and their tissue level distribution in rice plants by laser ablation-inductively coupled-mass spectrometry

International Nuclear Information System (INIS)

Koelmel, Jeremy; Leland, Thomas; Wang, Huanhua; Amarasiriwardena, Dulasiri; Xing, Baoshan

2013-01-01

The tissue level uptake and spatial distribution of gold nanoparticles (AuNPs) in rice (Oryza sativa L.) roots and shoots under hydroponic conditions was investigated using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Rice plants were hydroponically exposed to positively, neutrally, and negatively charged AuNPs [AuNP1(+), AuNP2(0), AuNP3(−)] with a core diameter of 2 nm. Plants were exposed to AuNPs having 1.6 mg Au/L for 5 days or 0.14 mg Au/L for 3 months to elucidate how the surface charges of the nanoparticles affects their uptake into living plant tissues. The results demonstrate that terminal functional groups greatly affected the AuNP uptake into plant tissues. Au concentration determined by LA-ICP-MS in 5 day treated rice roots followed this order: AuNP1(+) > AuNP2(0) > AuNP3(−) but this order was reversed for rice shoots, indicating preferential translocation of AuNP3(−). Bioimages revealed distributions of mesophyll and vascular AuNP dependent on organ or AuNP concentration. Highlights: ► LA-ICP-MS technique was effectively used to quantify engineered AuNP in rice plant. ► Uptake and translocation of AuNPs are evident in rice roots and shoots. ► Organ level distribution of AuNPs is affected by their surface charges. ► Bioimaging of AuNP distribution in rice tissues by LA-ICP-MS was demonstrated. -- The tissue level uptake and spatial distribution of engineered gold nanoparticles (AuNP) by rice plants was demonstrated by LA-ICP-MS bioimaging

The conservation value of karst dolines for vascular plants in woodland habitats of Hungary: refugia and climate change

Directory of Open Access Journals (Sweden)

Zoltán Bátori

2014-01-01

Full Text Available Limestone (karst surfaces in Hungary are rich in dolines, in which many endangered vascular plant species occur. To date, the majority of studies dealing with doline vegetation have focused on the local rather than the landscape level, without using comparative data from other areas. However, in this study we aimed to compare the vegetation pattern and species composition of dolines under different climate regimes of Hungary with regard to regional species pools. The fieldwork was carried out between 2005 and 2012. Twenty dolines were selected in the Mecsek Mountains (southern Hungary and nine dolines in the Aggtelek Karst area (northern Hungary. More than 900 vascular plants and more than 2000 plots were included in the study. The moving split window (MSW technique, nestedness analysis and principal coordinates analysis (PCoA were used to reveal the vegetation patterns in dolines. Although we found remarkable differences between the species composition of the two regions, dolines of both regions play a similar role in the preservation of different groups of species. Many plants, in particular mountain species, are restricted to the bottom of dolines where appropriate environmental conditions exist. In addition, depending on the doline geometry, many species of drier and warmer forests have colonized the upper slopes and rims. Thus, we can conclude that karst dolines of Hungary can be considered as reservoirs for many vascular plant species, therefore they are particularly important from a conservation point of view. Moreover, these dolines will likely become increasingly indispensable refugia for biodiversity under future global warming.

Convergent evolution of vascular optimization in kelp (Laminariales).

Science.gov (United States)

Drobnitch, Sarah Tepler; Jensen, Kaare H; Prentice, Paige; Pittermann, Jarmila

2015-10-07

Terrestrial plants and mammals, although separated by a great evolutionary distance, have each arrived at a highly conserved body plan in which universal allometric scaling relationships govern the anatomy of vascular networks and key functional metabolic traits. The universality of allometric scaling suggests that these phyla have each evolved an 'optimal' transport strategy that has been overwhelmingly adopted by extant species. To truly evaluate the dominance and universality of vascular optimization, however, it is critical to examine other, lesser-known, vascularized phyla. The brown algae (Phaeophyceae) are one such group--as distantly related to plants as mammals, they have convergently evolved a plant-like body plan and a specialized phloem-like transport network. To evaluate possible scaling and optimization in the kelp vascular system, we developed a model of optimized transport anatomy and tested it with measurements of the giant kelp, Macrocystis pyrifera, which is among the largest and most successful of macroalgae. We also evaluated three classical allometric relationships pertaining to plant vascular tissues with a diverse sampling of kelp species. Macrocystis pyrifera displays strong scaling relationships between all tested vascular parameters and agrees with our model; other species within the Laminariales display weak or inconsistent vascular allometries. The lack of universal scaling in the kelps and the presence of optimized transport anatomy in M. pyrifera raises important questions about the evolution of optimization and the possible competitive advantage conferred by optimized vascular systems to multicellular phyla. © 2015 The Author(s).

Vascular Plant and Vertebrate Inventory of Coronado National Memorial

Science.gov (United States)

Schmidt, Cecilia A.; Powell, Brian F.; Swann, Don E.; Halvorson, William L.

2007-01-01

We conducted inventories for amphibians and reptiles, birds, and mammals; and summarized past inventories for vascular plants at Coronado National Memorial (NM) in Arizona. We used our data as well as data from previous research to compile species lists for the memorial, assess inventory completeness, and make suggestions on future monitoring efforts. There have been 940 species of plants and vertebrates recorded at Coronado NM (Table 1), of which 46 (5%) are non-native. The species richness of the memorial is one of the highest in the Sonoran Desert Network of park units, third only to park units that are two and one-half (Chiricahua National Monument), 19 (Saguaro National Park) and 70 (Organ Pipe Cactus National Monument) times larger in area. The high species diversities are due to the large elevational gradient, overlap of bigeographical regions, wide range of geology and soils, and diverse vegetation communities present at the memorial. Changes in species composition have occurred at the memorial over the last 20 years in all major taxonomic groups. These changes are likely due to increases in grassy plant species (both native and non-native) at the lower elevations of the memorial. We suspect that grassy plant cover has increased because of changes in grazing intensity, introduction of some non-native species, and a recent fire. All recent vertebrate inventories have yielded grassland obligate species not previously recorded at the memorial. Based on the review of past studies, we believe the inventory for most taxa, except bats, is nearly complete, though some rare or elusive species will likely be added with additional survey effort.

In vivo polymerization and manufacturing of wires and supercapacitors in plants

Science.gov (United States)

Stavrinidou, Eleni; Nilsson, K. Peter R.; Singh, Sandeep Kumar; Franco-Gonzalez, Juan Felipe; Volkov, Anton V.; Jonsson, Magnus P.; Grimoldi, Andrea; Elgland, Mathias; Zozoulenko, Igor V.; Berggren, Magnus

2017-01-01

Electronic plants, e-Plants, are an organic bioelectronic platform that allows electronic interfacing with plants. Recently we have demonstrated plants with augmented electronic functionality. Using the vascular system and organs of a plant, we manufactured organic electronic devices and circuits in vivo, leveraging the internal structure and physiology of the plant as the template, and an integral part of the devices. However, this electronic functionality was only achieved in localized regions, whereas new electronic materials that could be distributed to every part of the plant would provide versatility in device and circuit fabrication and create possibilities for new device concepts. Here we report the synthesis of such a conjugated oligomer that can be distributed and form longer oligomers and polymer in every part of the xylem vascular tissue of a Rosa floribunda cutting, forming long-range conducting wires. The plant’s structure acts as a physical template, whereas the plant’s biochemical response mechanism acts as the catalyst for polymerization. In addition, the oligomer can cross through the veins and enter the apoplastic space in the leaves. Finally, using the plant’s natural architecture we manufacture supercapacitors along the stem. Our results are preludes to autonomous energy systems integrated within plants and distribute interconnected sensor–actuator systems for plant control and optimization. PMID:28242683

Distributions of vascular plants in the Czech Republic. Part 1

Czech Academy of Sciences Publication Activity Database

Kaplan, Zdeněk; Danihelka, Jiří; Štěpánková, Jitka; Bureš, P.; Zázvorka, Jiří; Hroudová, Zdenka; Ducháček, M.; Grulich, V.; Řepka, R.; Dančák, M.; Prančl, Jan; Šumberová, Kateřina; Wild, Jan; Trávníček, B.

2015-01-01

Roč. 87, č. 4 (2015), s. 417-500 ISSN 0032-7786 R&D Projects: GA ČR GB14-36079G; GA MŠk(CZ) LD14045 Institutional support: RVO:67985939 Keywords : distribution * maps * phytogeography Subject RIV: EF - Botanics Impact factor: 2.711, year: 2015

Distributions of vascular plants in the Czech Republic. Part 2

Czech Academy of Sciences Publication Activity Database

Kaplan, Zdeněk; Danihelka, Jiří; Štěpánková, Jitka; Ekrt, L.; Chrtek, Jindřich; Zázvorka, Jiří; Grulich, V.; Řepka, R.; Prančl, Jan; Ducháček, M.; Kúr, P.; Šumberová, Kateřina; Brůna, Josef

2016-01-01

Roč. 88, č. 2 (2016), s. 229-322 ISSN 0032-7786 R&D Projects: GA ČR GB14-36079G; GA MŠk(CZ) LD14045 Institutional support: RVO:67985939 Keywords : distribution * maps * phytogeography Subject RIV: EF - Botanics Impact factor: 3.000, year: 2016

Vascular plant flora in the Cytadela cemeteries in Poznań (Poland

Directory of Open Access Journals (Sweden)

Aneta Czarna

2016-12-01

Full Text Available The paper presents the spontaneous vascular flora and the flora originating from old or contemporary plantations found in all six currently existing cemeteries located in immediate vicinity on the slopes of the Cytadela Park in Poznań. These studies were carried out in the years 2011–2014. Over this period, 255 species of vascular plants were found. The most interesting species include: Chionodoxa luciliae, Rumex rugosus, Aegopodium podagraria ‘Variegatum’, Ficaria verna f. plenifolia, Galanthus nivalis f. pleniflora, Ornithogalum boucheanum, Ranunculus repens ‘Plena’, and hybrids: Dactylis ×intercedens, Gagea ×pomeranica, Ornithogalum boucheanum × O. nutans, Viola cyanea × V. odorata. A great number of spring geophytes, namely 31 species, was also found. Among species occurring spontaneously outside the graves, some were new for Poland, e.g., Chionodoxa luciliae, Ornithogalum boucheanum × O. nutans, Viola cyanea × V. odorata, while others were new for the Wielkopolska region: Rumex rugosus, Dactylis ×intercedens, Gagea ×pomeranica, as well as new for Poznań: Erigeron ramosus, Lilium bulbiferum, Muscari armeniacus, M. neglectum, Pimpinella nigra, Poa subcaerulea, and Veronica hederifolia s. s.

Changes in the geographical distribution of plant species and climatic variables on the West Cornwall peninsula (South West UK).

Science.gov (United States)

Kosanic, Aleksandra; Anderson, Karen; Harrison, Stephan; Turkington, Thea; Bennie, Jonathan

2018-01-01

Recent climate change has had a major impact on biodiversity and has altered the geographical distribution of vascular plant species. This trend is visible globally; however, more local and regional scale research is needed to improve understanding of the patterns of change and to develop appropriate conservation strategies that can minimise cultural, health, and economic losses at finer scales. Here we describe a method to manually geo-reference botanical records from a historical herbarium to track changes in the geographical distributions of plant species in West Cornwall (South West England) using both historical (pre-1900) and contemporary (post-1900) distribution records. We also assess the use of Ellenberg and climate indicator values as markers of responses to climate and environmental change. Using these techniques we detect a loss in 19 plant species, with 6 species losing more than 50% of their previous range. Statistical analysis showed that Ellenberg (light, moisture, nitrogen) and climate indicator values (mean January temperature, mean July temperature and mean precipitation) could be used as environmental change indicators. Significantly higher percentages of area lost were detected in species with lower January temperatures, July temperatures, light, and nitrogen values, as well as higher annual precipitation and moisture values. This study highlights the importance of historical records in examining the changes in plant species' geographical distributions. We present a method for manual geo-referencing of such records, and demonstrate how using Ellenberg and climate indicator values as environmental and climate change indicators can contribute towards directing appropriate conservation strategies.

Changes in the geographical distribution of plant species and climatic variables on the West Cornwall peninsula (South West UK)

Science.gov (United States)

Kosanic, Aleksandra; Anderson, Karen; Harrison, Stephan; Turkington, Thea; Bennie, Jonathan

2018-01-01

Recent climate change has had a major impact on biodiversity and has altered the geographical distribution of vascular plant species. This trend is visible globally; however, more local and regional scale research is needed to improve understanding of the patterns of change and to develop appropriate conservation strategies that can minimise cultural, health, and economic losses at finer scales. Here we describe a method to manually geo-reference botanical records from a historical herbarium to track changes in the geographical distributions of plant species in West Cornwall (South West England) using both historical (pre-1900) and contemporary (post-1900) distribution records. We also assess the use of Ellenberg and climate indicator values as markers of responses to climate and environmental change. Using these techniques we detect a loss in 19 plant species, with 6 species losing more than 50% of their previous range. Statistical analysis showed that Ellenberg (light, moisture, nitrogen) and climate indicator values (mean January temperature, mean July temperature and mean precipitation) could be used as environmental change indicators. Significantly higher percentages of area lost were detected in species with lower January temperatures, July temperatures, light, and nitrogen values, as well as higher annual precipitation and moisture values. This study highlights the importance of historical records in examining the changes in plant species’ geographical distributions. We present a method for manual geo-referencing of such records, and demonstrate how using Ellenberg and climate indicator values as environmental and climate change indicators can contribute towards directing appropriate conservation strategies. PMID:29401494

The evolution of development of vascular cambia and secondary growth

Science.gov (United States)

Andrew Groover; Rachel Spicer

2010-01-01

Secondary growth from vascular cambia results in radial, woody growth of stems. The innovation of secondary vascular development during plant evolution allowed the production of novel plant forms ranging from massive forest trees to flexible, woody lianas. We present examples of the extensive phylogenetic variation in secondary vascular growth and discuss current...

Distribution of some vascular plants and anthropopressure zones in Warsaw

Directory of Open Access Journals (Sweden)

Barbara Sudnik-Wójcikowska

2014-01-01

Full Text Available The cartogramms of the species distribution within Warsaw were compared to the anthropopressure zones distinguished conventionally. Floras of individual zones differboth quantitatively and qualitatively. Some species are more confined to specific zones some have even an indicator value. The most interesting taxa are those found in sites where anthropopressure is the greatest.

Cavitation Resistance in Seedless Vascular Plants: The Structure and Function of Interconduit Pit Membranes1[W][OPEN

Science.gov (United States)

Brodersen, Craig; Jansen, Steven; Choat, Brendan; Rico, Christopher; Pittermann, Jarmila

2014-01-01

Plant water transport occurs through interconnected xylem conduits that are separated by partially digested regions in the cell wall known as pit membranes. These structures have a dual function. Their porous construction facilitates water movement between conduits while limiting the spread of air that may enter the conduits and render them dysfunctional during a drought. Pit membranes have been well studied in woody plants, but very little is known about their function in more ancient lineages such as seedless vascular plants. Here, we examine the relationships between conduit air seeding, pit hydraulic resistance, and pit anatomy in 10 species of ferns (pteridophytes) and two lycophytes. Air seeding pressures ranged from 0.8 ± 0.15 MPa (mean ± sd) in the hydric fern Athyrium filix-femina to 4.9 ± 0.94 MPa in Psilotum nudum, an epiphytic species. Notably, a positive correlation was found between conduit pit area and vulnerability to air seeding, suggesting that the rare-pit hypothesis explains air seeding in early-diverging lineages much as it does in many angiosperms. Pit area resistance was variable but averaged 54.6 MPa s m−1 across all surveyed pteridophytes. End walls contributed 52% to the overall transport resistance, similar to the 56% in angiosperm vessels and 64% in conifer tracheids. Taken together, our data imply that, irrespective of phylogenetic placement, selection acted on transport efficiency in seedless vascular plants and woody plants in equal measure by compensating for shorter conduits in tracheid-bearing plants with more permeable pit membranes. PMID:24777347

The Root-Associated Microbial Community of the World's Highest Growing Vascular Plants.

Science.gov (United States)

Angel, Roey; Conrad, Ralf; Dvorsky, Miroslav; Kopecky, Martin; Kotilínek, Milan; Hiiesalu, Inga; Schweingruber, Fritz; Doležal, Jiří

2016-08-01

Upward migration of plants to barren subnival areas is occurring worldwide due to raising ambient temperatures and glacial recession. In summer 2012, the presence of six vascular plants, growing in a single patch, was recorded at an unprecedented elevation of 6150 m.a.s.l. close to the summit of Mount Shukule II in the Western Himalayas (Ladakh, India). Whilst showing multiple signs of stress, all plants have managed to establish stable growth and persist for several years. To learn about the role of microbes in the process of plant upward migration, we analysed the root-associated microbial community of the plants (three individuals from each) using microscopy and tagged amplicon sequencing. No mycorrhizae were found on the roots, implying they are of little importance to the establishment and early growth of the plants. However, all roots were associated with a complex bacterial community, with richness and diversity estimates similar or even higher than the surrounding bare soil. Both soil and root-associated communities were dominated by members of the orders Sphingomonadales and Sphingobacteriales, which are typical for hot desert soils, but were different from communities of temperate subnival soils and typical rhizosphere communities. Despite taxonomic similarity on the order level, the plants harboured a unique set of highly dominant operational taxonomic units which were not found in the bare soil. These bacteria have been likely transported with the dispersing seeds and became part of the root-associated community following germination. The results indicate that developing soils act not only as a source of inoculation to plant roots but also possibly as a sink for plant-associated bacteria.

Distribution of Tomato spotted wilt virus in dahlia plants.

Science.gov (United States)

Asano, S; Hirayama, Y; Matsushita, Y

2017-04-01

Tomato spotted wilt virus (TSWV) causes significant losses in the production of the ornamental plant Dahlia variabilis in Japan. The purpose of this study was to examine the distribution of TSWV in dahlia plants and identify plant parts that can be used in the selection of TSWV-free plants. The distribution of TSWV was investigated using reverse transcriptional polymerase chain reaction (RT-PCR) and tissue blot immunoassay. The detection rate of TSWV in latent infected compound leaves was the highest in the petiole, and it decreased from the veins and rachis to the lamina. The tissue blot immunoassays of the leaflets showed an uneven distribution of TSWV, especially along the edge of the leaf blade. In stems, the detection rate of TSWV was high partway up the stem compared to that in the upper and the lower parts of the stem during the vegetative growth stage. A highly uneven distribution was observed in the bulb. Our results indicated that middle parts of the stem as well as the petioles, rachis, and veins of compound leaves are suitable for detection of TSWV in dahlias. This study is the first to report uneven distribution of TSWV in dahlia plants. In this study, the distribution of Tomato spotted wilt virus (TSWV) in various parts of dahlia plants was investigated for the first time. The distribution of TSWV was uneven in compound leaves, leaflets, stems, and bulbs. The middle parts of the stem or the petiole and leaf veins should be sampled to detect TSWV when selecting healthy plants. © 2017 The Society for Applied Microbiology.

Relationship between the shoot characteristics and plant resistance to vascular-streak dieback on cocoa

Directory of Open Access Journals (Sweden)

Agung Wahyu Soesilo

2014-12-01

Full Text Available Vascular-streak dieback (Oncobasidium theobromae is a serious disease on cocoa damaging the vegetative tissue especially on the branches and leaves. This research was aimed to identify the relationship between characteristics of sprouting ability and VSD resistance to confirm the response of cocoa to pruning treatment on VSD control and developing criteria for selection. Trial was carried out at Kaliwining Experimental Station of ICCRI, a VSD-endemic area by using 668 plants of hybrid populayion which were derivated from intercrossing among seven clones performing different response to VSD. The resistance was evaluated by scoring the plant damage with the scale of 0-6 on drought season in the year of 2009 and 2011. The characteristics of sprouting ability was assessed by recording the pruned trees for the variables of the number of re-growth shoot, shoot height, number of new shoot per pruned branches, shoot diameter and number of leaves per shoot. It was analyzed that the variables of the number of shoot per pruned branches, shoot diameter, shoot height and number of leaves per shoot were not significantly correlated to the score of VSD damage. Grouping of the resistance also performed similar results whereas mean of the sprouting variables were not different among group but the percentage of sprouted branches tend to be higher with the higher of the resistance (lower score. This result confirmed any mechanism of tolerance on VSD resistance by accelerating shoot rejuvenation on resistant plant. Key words : vascular-streak diaback, cocoa, resistance, characteristics of sprouting

Application of vascular aquatic plants for pollution removal, energy and food production in a biological system

Science.gov (United States)

Wolverton, B. C.; Barlow, R. M.; Mcdonald, R. C.

1975-01-01

Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications.

Do oxygen stable isotopes track precipitation moisture source in vascular plant dominated peatlands?

Science.gov (United States)

Charman, D.; Amesbury, M. J.; Newnham, R.; Loader, N.; Goodrich, J. P.; Gallego-Sala, A. V.; Royles, J.; Keller, E. D.; Baisden, W. T.

2014-12-01

Variations in the isotopic composition of precipitation are determined by fractionation processes which occur during temperature and humidity dependent phase changes associated with evaporation and condensation. Oxygen stable isotope ratios have therefore been frequently used as a source of palaeoclimate data from a variety of proxy archives. Exploitation of this record from ombrotrophic peatlands, where the source water used in cellulose synthesis is derived solely from precipitation, has been mostly limited to Northern Hemisphere Sphagnum-dominated bogs, with limited application in the Southern Hemisphere (SH) or in peatlands dominated by vascular plants. Throughout New Zealand (NZ), the preserved root matrix of the restionaceous wire rush (Empodisma spp.) forms deep peat deposits. NZ provides an ideal location to undertake empirical research into oxygen isotope fractionation in vascular peatlands because sites are ideally suited to single taxon analysis, preserve potentially high resolution full Holocene palaeoclimate records and are situated in the climatically sensitive SH mid-latitudes. Crucially, large gradients exist in the mean isotopic composition of precipitation across NZ, caused primarily by the relative influence of different climate modes. We test the capacity for δ18O analysis of Empodisma alpha cellulose from ombrotrophic restiad peatlands in NZ to provide a methodology for developing palaeoclimate records. We took surface plant, water and precipitation samples over spatial (six sites spanning >10° latitude) and temporal (monthly measurements over one year) gradients. We found a strong link between the isotopic compositions of surface root water, the most likely source water for plant growth, and precipitation in both datasets. Back-trajectory modelling of precipitation moisture source for rain days prior to sampling showed clear seasonality in the temporal data that was reflected in surface root water. The link between source water and plant

[Distribution of HCB discharged from a chemical plant in plants].

Science.gov (United States)

Chen, Jing; Wang, Lin-Ling; Lu, Xiao-Hua; Yuan, Song-Hu; Liu, Xi-Xiang; Wang, Yue; Zhao, Qian; Mei, Ling-Fang

2009-04-15

The distribution characteristics of hexachlorobenzene (HCB) in plant and rhizosphere soil in contamination conduit, a nearby river and a cropland were studied and the impact factors were also discussed. The results are summarized as follows: the range of the HCB concentration in plant and rhizosphere soil in investigation area were respectively from 4.45 microg x kg(-1) to 1,189.89 microg x kg(-1) (dw) and from 27.93 microg x kg(-1) to 3,480.71 microg x kg(-1) (dw). Higher enrichment of HCB in woodplant than herbs due to higher fat concentration in woodplant in the contamination conduit and the rich concentrtion factor of woodplant and herbs were 0.41-2.55 and 0.01-1.34. The range of HCB concentrations in plants in nearby croplands was significantly wide (4.45-333.1 microg x kg(-1)) while HCB concentrations in different parts of plant were various, e.g. HCB concentrations in fruit, root and shoot of taro were 318.77 microg x kg(-1), 281.02 microg x kg(-1) and 10.94 microg x kg(-1). There was a remarkable positive relation between the concentrations of HCB in plant and fat concentration of plant while no relativity between the concentrations of HCB in plant and those in ground soils in the contamination conduit and cropland. The concentration levels of HCB in plant and rhizosphere soil in river were dramatically decreased with increasing distance from contaminated conduit. There was a remarkable positive relation between the concentrations of HCB in plant and those in ground soils but no relation between concentrations of HCB in plant and fat concentration of plant in river. The distribution characteristics of HCB in plants were influenced by contaminated levels, fat concentration and Partition-transfer model.

Attempts to Localize and Identify the Gravity-sensing Device of Plant Seedlings

Science.gov (United States)

Bandurski, R. S.; Schulze, A.; Momonoki, Y.; Desrosiers, M.; Fearn-Desrosiers, D.

1985-01-01

The growth hormone asymmetry develops within three minutes following the initiation of the gravitational asymmetry and radio-labeled compounds being transported from the seed to the shoot also show asymmetric distribution. It is found that the target of the gravity stimulus resides primarily in the permability of the vascular tissue that regulates the supply of hormone to the surrounding tissues. It is hypothesized that the gravitational stimulus induces an asymmetric change in the rate of secretion of the growth hormone, IAA, from the vascular tissue into the surrounding cortical cells. More hormone would be secreted from the vascular stele proximal to the lower side of a horizontally placed plant shoot than from the upper side. This results in more growth hormone in the lower cortical (plus epidermal) cells, and ultimately more growth, such that the plant grows asymmetrically and, ultimately attain its normal vertical orientation. A theory was developed of how plants respond to the gravitational stimulus. The theory is based upon the analytical results concerning the effects of gravity on the distribution of the plant growth hormone, IAA, in both its free and conjugated forms, and upon the effect of the growth stimulis on the distribution of externally applied radio-labeled compounds. Its advantage is that it is testable and that it is built upon solid knowledge of the effects of the gravitational stimulus upon the endogenous growth hormone, IAA, and upon the distribution of externally applied radio-labeled compounds.

Convergent evolution of vascular optimization in kelp (Laminariales)

DEFF Research Database (Denmark)

Drobnitch, Sarah Tepler; Jensen, Kaare Hartvig; Prentice, Paige

2015-01-01

Terrestrial plants and mammals, although separated by a great evolutionary distance, have each arrived at a highly conserved body plan in which universal allometric scaling relationships govern the anatomy of vascular networks and key functional metabolic traits. The universality of allometric...... (Phaeophyceae) are one such group—as distantly related to plants as mammals, they have convergently evolved a plant-like body plan and a specialized phloem-like transport network. To evaluate possible scaling and optimization in the kelp vascular system, we developed a model of optimized transport anatomy...... and tested it with measurements of the giant kelp, Macrocystis pyrifera, which is among the largest and most successful of macroalgae. We also evaluated three classical allometric relationships pertaining to plant vascular tissues with a diverse sampling of kelp species. Macrocystis pyrifera displays strong...

Mercury distribution characteristics in primary manganese smelting plants

International Nuclear Information System (INIS)

Back, Seung-Ki; Sung, Jin-Ho; Moon, Young-Hoon; Kim, Young-Hee; Seok, Kwang-Seol; Song, Geum-Ju; Seo, Yong-Chil

2017-01-01

The mercury (Hg) distribution characteristics were investigated in three primary manganese smelting plants in Korea for the assessment of anthropogenic Hg released. Input and output materials were sampled from each process, and Hg concentrations in the samples were analyzed. Among the input materials, the most mercury was found in the manganese ore (83.1–99.7%) and mercury was mainly released through fly ash or off gas, depending on the condition of off gas cleaning system. As off gas temperature decreases, proportion and concentration of emitted gaseous elemental mercury (Hg 0 ) in off gas decreases. Based on mass balance study from these three plants and national manganese production data, the total amount of mercury released from those Korean plants was estimated to 644 kg/yr. About half of it was emitted into the air while the rest was released to waste as fly ash. With the results of this investigation, national inventory for Hg emission and release could be updated for the response to Minamata Convention on Mercury. - Graphical abstract: 1. Lack of data on mercury (Hg) distribution in manganese smelters. 2. Mass distribution of Hg released from 3 plants (as normalized values) were made as follows by measurements. 3. Information of distribution of Hg in Manganese smelters would be used for emission in to air and releases to other streams for the nation and globe in UNEP mercury report. - Highlights: • The mass balance study by on-site measurement from primary manganese smelting plants was made at first time in the world. • Hg distribution and main input and release pathways of Hg from primary manganese smelting plants could be found as the first time. • Gas temperature in bag filter affects Hg behavior and speciation changes in APCDs. • National inventory of Hg emssion has been updated with new data. - Mercury distribution in manganese smelting plant was investigated as the first measurements at commercial plants in the world. National Hg release

Intelligent distributed control for nuclear power plants

International Nuclear Information System (INIS)

Klevans, E.H.

1992-01-01

This project was initiated in September 1989 as a three year project to develop and demonstrate Intelligent Distributed Control (IDC) for Nuclear Power Plants. The body of this Third Annual Technical Progress report summarizes the period from September 1991 to October 1992. There were two primary goals of this research project. The first goal was to combine diagnostics and control to achieve a highly automated power plant as described by M.A. Schultz. His philosophy, is to improve public perception of the safety of nuclear power plants by incorporating a high degree of automation where a greatly simplified operator control console minimizes the possibility of human error in power plant operations. To achieve this goal, a hierarchically distributed control system with automated responses to plant upset conditions was pursued in this research. The second goal was to apply this research to develop a prototype demonstration on an actual power plant system, the EBR-2 stem plant. Emphasized in this Third Annual Technical Progress Report is the continuing development of the in-plant intelligent control demonstration for the final project milestone and includes: simulation validation and the initial approach to experiment formulation

Insertional mutagenesis in the vascular wilt pathogen Verticillium dahliae

NARCIS (Netherlands)

Santhanam, P.

2014-01-01

Vascular wilt diseases caused by soil-borne pathogens are among the most

devastating plant diseases worldwide. The ascomycete fungus Verticillium dahliae

causes vascular wilt diseases in hundreds of dicotyledonous plant species, including

important crops such as eggplant,

Distributed voltage control coordination between renewable generation plants in MV distribution grids

DEFF Research Database (Denmark)

Petersen, Lennart; Iov, Florin

2017-01-01

This study focuses on distributed voltage control coordination between renewable generation plants in medium-voltage distribution grids (DGs). A distributed offline coordination concept has been defined in a previous publication, leading to satisfactory voltage regulation in the DG. However, here...

Vegetation dynamics at the upper elevational limit of vascular plants in Himalaya.

Science.gov (United States)

Dolezal, Jiri; Dvorsky, Miroslav; Kopecky, Martin; Liancourt, Pierre; Hiiesalu, Inga; Macek, Martin; Altman, Jan; Chlumska, Zuzana; Rehakova, Klara; Capkova, Katerina; Borovec, Jakub; Mudrak, Ondrej; Wild, Jan; Schweingruber, Fritz

2016-05-04

A rapid warming in Himalayas is predicted to increase plant upper distributional limits, vegetation cover and abundance of species adapted to warmer climate. We explored these predictions in NW Himalayas, by revisiting uppermost plant populations after ten years (2003-2013), detailed monitoring of vegetation changes in permanent plots (2009-2012), and age analysis of plants growing from 5500 to 6150 m. Plant traits and microclimate variables were recorded to explain observed vegetation changes. The elevation limits of several species shifted up to 6150 m, about 150 vertical meters above the limit of continuous plant distribution. The plant age analysis corroborated the hypothesis of warming-driven uphill migration. However, the impact of warming interacts with increasing precipitation and physical disturbance. The extreme summer snowfall event in 2010 is likely responsible for substantial decrease in plant cover in both alpine and subnival vegetation and compositional shift towards species preferring wetter habitats. Simultaneous increase in summer temperature and precipitation caused rapid snow melt and, coupled with frequent night frosts, generated multiple freeze-thaw cycles detrimental to subnival plants. Our results suggest that plant species responses to ongoing climate change will not be unidirectional upward range shifts but rather multi-dimensional, species-specific and spatially variable.

SPECIES COMPOSITION, DISTRIBUTION, LIFE FORMS AND FOLK NOMENCLATURE OF FOREST AND COMMON LAND PLANTS OF WESTERN CHITWAN, NEPAL

Science.gov (United States)

Dangol, D. R.

2012-01-01

This paper enumerates 349 plant species belonging to 77 families of vascular plants collected in the winter seasons of 1996 and 2000 by the flora teams of the Population and Ecology Research Laboratory, Nepal. Of the total species, 249 species belong to dicotyledons, 87 species to monocotyledons and 13 species to pteridophytes. Among the families, dicotyledons contributed the highest number of families (55 in number) followed by monocotyledons and pteridophytes. In the study areas, species composition varies with the type of habitats in the study plots. Some species are unique in distribution. The highest unique species are contributed by common lands (87 spp.), followed by the Chitwan National Park forest (36 spp.) and Tikauli forest (32 spp.). Ageratum houstonianum Mill., Cynodon dactylon (L.) Pers., Imperata cylindrica (L.) Beauv., Rungia parviflora (Retz.) Nees, Saccharum spontaneum L. and Thelypteris auriculata (J. Sm.) K. Iwats are the most common species across all the research blocks. Of the listed plants, many plants have local names either in Nepalese or other tribal languages. Plants are named in different ways on the basis of habit, habitat, smell, taste, and morphological characters of the plants, which are also the basis of nomenclature in plant taxonomy. PMID:22962539

Linear-motion tattoo machine and prefabricated needle sets for the delivery of plant viruses by vascular puncture inoculation

Science.gov (United States)

Vascular puncture inoculation (VPI) of plant viruses previously has been conducted either manually or by use of a commercial engraving tool and laboratory-fabricated needle arrays. In an effort to improve this technique, a linear-motion tattoo machine driving industry-standard needle arrays was tes...

Ethnobotany of food plants in the high river Ter valley (Pyrenees, Catalonia, Iberian Peninsula): non-crop food vascular plants and crop food plants with medicinal properties.

Science.gov (United States)

Rigat, Montse; Bonet, Maria Àngels; Garcia, Sònia; Garnatje, Teresa; Vallès, Joan

2009-01-01

The present study reports a part of the findings of an ethnobotanical research project conducted in the Catalan region of the high river Ter valley (Iberian Peninsula), concerning the use of wild vascular plants as food and the medicinal uses of both wild and cultivated food plants. We have detected 100 species which are or have been consumed in this region, 83 of which are treated here (the remaining are the cultivated food plants without additional medicinal uses). Some of them, such as Achillea ptarmica subsp. pyrenaica, Convolvulus arvensis, Leontodon hispidus, Molopospermum peloponnesiacum and Taraxacum dissectum, have not been previously reported, or have only very rarely been cited or indicated as plant foods in very restricted geographical areas. Several of these edible wild plants have a therapeutic use attributed to them by local people, making them a kind of functional food. They are usually eaten raw, dressed in salads or cooked; the elaboration of products from these species such as liquors or marmalades is a common practice in the region. The consumption of these resources is still fairly alive in popular practice, as is the existence of homegardens, where many of these plants are cultivated for private consumption.

Using herbarium-derived DNAs to assemble a large-scale DNA barcode library for the vascular plants of Canada.

Science.gov (United States)

Kuzmina, Maria L; Braukmann, Thomas W A; Fazekas, Aron J; Graham, Sean W; Dewaard, Stephanie L; Rodrigues, Anuar; Bennett, Bruce A; Dickinson, Timothy A; Saarela, Jeffery M; Catling, Paul M; Newmaster, Steven G; Percy, Diana M; Fenneman, Erin; Lauron-Moreau, Aurélien; Ford, Bruce; Gillespie, Lynn; Subramanyam, Ragupathy; Whitton, Jeannette; Jennings, Linda; Metsger, Deborah; Warne, Connor P; Brown, Allison; Sears, Elizabeth; Dewaard, Jeremy R; Zakharov, Evgeny V; Hebert, Paul D N

2017-12-01

Constructing complete, accurate plant DNA barcode reference libraries can be logistically challenging for large-scale floras. Here we demonstrate the promise and challenges of using herbarium collections for building a DNA barcode reference library for the vascular plant flora of Canada. Our study examined 20,816 specimens representing 5076 of 5190 vascular plant species in Canada (98%). For 98% of the specimens, at least one of the DNA barcode regions was recovered from the plastid loci rbcL and matK and from the nuclear ITS2 region. We used beta regression to quantify the effects of age, type of preservation, and taxonomic affiliation (family) on DNA sequence recovery. Specimen age and method of preservation had significant effects on sequence recovery for all markers, but influenced some families more (e.g., Boraginaceae) than others (e.g., Asteraceae). Our DNA barcode library represents an unparalleled resource for metagenomic and ecological genetic research working on temperate and arctic biomes. An observed decline in sequence recovery with specimen age may be associated with poor primer matches, intragenomic variation (for ITS2), or inhibitory secondary compounds in some taxa.

Tree size predicts vascular epiphytic richness of traditional cultivated tea plantations in Southwestern China

Directory of Open Access Journals (Sweden)

Qing Wang

2017-04-01

Full Text Available Species–area relationship has been widely addressed on many plant communities, but very few have conducted on epiphytic communities. Epiphytic plants are plentiful on ancient tea trees (Camelia sinensis var. assamica in the well-known Jingmai tea plantation area, Langcang region of Yunnan Province, SW China, and add to the plant community biodiversity. We investigated 343 tea trees with various ground diameter, canopy area, under branch height, and tree height. A total of 146 vascular epiphytic plants, belonging to 19 species in seven families were recorded from the trunk or branches of 93 (27.11% investigated trees. We examined in situ abundance, richness, and diversity (Shannon–Weiner index of the recorded vascular epiphytes, and their relationships to tree variables. Our results showed that the distribution (abundance, richness, and diversity of epiphytic plants are significantly related to the canopy area (p<0.05 and basal diameter (p<0.0001 of tea trees, supporting their use as key factors and good predictor for the epiphyte’s appearance in this type of agro-ecosystems. We also concluded that the species–area relationship is a useful epiphytic species community research tool.

Compiled data on the vascular aquatic plant program, 1975 - 1977. [for sewage lagoon

Science.gov (United States)

Wolverton, B. C.; Mcdonald, R.

1977-01-01

The performance of a single cell, facultative sewage lagoon was significantly improved with the introduction of vascular aquatic plants. Water hyacinth (Eichhornia crassipes) was the dominant plant from April to November; duckweed (Lemna spp.) and (Spirodela spp.) flourished from December to March. This 2 ha lagoon received approximately 475 cu m/day of untreated sewage and has a variable COD sub 5 loading rate of 22-30 kg/ha/day. During the first 14 months of operation with aquatic plants, the average influent BOD sub 5 was reduced by 95% from 110 mg/l to an average of 5 mg/l in the effluent. The average influent suspended solids were reduced by 90% from 97 mg/l to 10 mg/l in the effluent. Significant reductions in nitrogen and phosphorus were effected. The monthly kjeldahl nitrogen for influent and effluent averaged 12.0 and 3.4 mg/l, respectively, a reduction of 72%. The total phosphorus was reduced on an average of 56% from 3.7 mg/l influent to 1.6 mg/l effluent.

Plant species distribution along environmental gradient: do belowground interactions with fungi matter?

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Loïc ePellissier

2013-12-01

Full Text Available The distribution of plants along environmental gradients is constrained by abiotic and biotic factors. Cumulative evidence attests of the impact of abiotic factors on plant distributions, but only few studies discuss the role of belowground communities. Soil fungi, in particular, are thought to play an important role in how plant species assemble locally into communities. We first review existing evidence, and then test the effect of the number of soil fungal operational taxonomic units (OTUs on plant species distributions using a recently collected dataset of plant and metagenomic information on soil fungi in the Western Swiss Alps. Using species distribution models, we investigated whether the distribution of individual plant species is correlated to the number of OTUs of two important soil fungal classes known to interact with plants: the Glomeromycetes, that are obligatory symbionts of plants, and the Agaricomycetes, that may be facultative plant symbionts, pathogens, or wood decayers. We show that including the fungal richness information in the models of plant species distributions improves predictive accuracy. Number of fungal OTUs is especially correlated to the distribution of high elevation plant species. We suggest that high elevation soil show greater variation in fungal assemblages that may in turn impact plant turnover among communities. We finally discuss how to move beyond correlative analyses, through the design of field experiments manipulating plant and fungal communities along environmental gradients.

14CO2 labeling. A reliable technique for rapid measurement of total root exudation capacity and vascular sap flow in crop plants

International Nuclear Information System (INIS)

Bhupinder Singh; Sumedha Ahuja; Renu Pandey; Singhal, R.K.

2014-01-01

Root release of organic compounds and rate of the vascular sap flow are important for understanding the nutrient and the source-sink dynamics in plants, however, their determination is procedurally cumbersome and time consuming. We report here a simple method involving 14 C labeling for rapid and reliable measurement of root exudates and vascular sap flow rate in a variable groundnut population developed through seed gamma irradiation using a cobalt source ( 60 Co). An experimental hypothesis that a higher 14 C level in the vascular sap would indicate a higher root release of carbon by the roots into the rhizosphere was verified. (author)

Intelligent distributed control for nuclear power plants

International Nuclear Information System (INIS)

Klevans, E.H.; Edwards, R.M.; Ray, A.; Lee, K.Y.; Garcia, H.E.: Chavez, C.M.; Turso, J.A.; BenAbdennour, A.

1991-01-01

In September of 1989 work began on the DOE University Program grant DE-FG07-89ER12889. The grant provides support for a three year project to develop and demonstrate Intelligent Distributed Control (IDC) for Nuclear Power Plants. The body of this Second Annual Technical Progress report covers the period from September 1990 to September 1991. It summarizes the second year accomplishments while the appendices provide detailed information presented at conference meetings. These are two primary goals of this research. The first is to combine diagnostics and control to achieve a highly automated power plant as described by M.A. Schultz, a project consultant during the first year of the project. This philosophy, as presented in the first annual technical progress report, is to improve public perception of the safety of nuclear power plants by incorporating a high degree automation where greatly simplified operator control console minimizes the possibility of human error in power plant operations. A hierarchically distributed control system with automated responses to plant upset conditions is the focus of our research to achieve this goal. The second goal is to apply this research to develop a prototype demonstration on an actual power plant system, the EBR-II steam plant

Effects of microgravity on growth hormone concentration and distribution in plants

Science.gov (United States)

Schulze, Aga; Jensen, Philip; Desrosiers, Mark; Bandurski, Robert S.

1989-01-01

On earth, gravity affects the distribution of the plant growth hormone, indole-3-acetic acid (IAA), in a manner such that the plant grows into a normal vertical orientation (shoots up, roots down). How the plant controls the amount and distribution of IAA is only partially understood and is currently under investigation in this laboratory. The question to be answered in the flight experiment concerns the effect of gravity on the concentration, turn over, and distribution of the growth hormone. The answer to this question will aid in understanding the mechanism by which plants control the amount and distribution of growth hormone. Such knowledge of a plant's hormonal metabolism may aid in the growth of plants in space and will lead to agronomic advances.

The distribution and spread of alien vascular plants on Prince Edward Island

NARCIS (Netherlands)

Ryan, P.G.; Smith, V.; Gremmen, N.J.M.

2003-01-01

Surveys of alien plants at subantarctic Prince Edward Island in 2001 show that the ranges of all three introduced species have increased since the last survey in 1998. Poa annua, the longest-established species, increased its range substantially after 1987, prior to which it was confined to a single

Species richness of vascular plants along the climatic range of the Spanish dehesas at two spatial scales

Directory of Open Access Journals (Sweden)

Jose M. Garcia del Barrio

2014-04-01

Full Text Available Aims of study: The goals of this paper are to summarize and to compare plant species richness and floristic similarity at two spatial scales; mesohabitat (normal, eutrophic, and oligotrophic dehesas and dehesa habitat; and to establish guidelines for conserving species diversity in dehesas.Area of study: We considered four dehesa sites in the western Peninsular Spain, located along a climatic and biogeographic gradient from north to south. Main results: Average alpha richness for mesohabitats was 75.6 species, and average alpha richness for dehesa sites was 146.3. Gamma richness assessed for the overall dehesa habitat was 340.0 species. The species richness figures of normal dehesa mesohabitat were significantly lesser than of the eutrophic mesohabitat and lesser than the oligotrophic mesohabitat too. No significant differences were found for species richness among dehesa sites. We have found more dissimilarity at local scale (mesohabitat than at regional scale (habitat. Finally, the results of the similarity assessment between dehesa sites reflected both climatic and biogeographic gradients.Research highlights: An effective conservation of dehesas must take into account local and regional conditions all along their distribution range for ensuring the conservation of the main vascular plant species assemblages as well as the associated fauna.Keywords: Agroforestry systems; mesohabitat; non-parametric estimators; alpha richness; gamma richness; floristic similarity; climatic and biogeographic range.

The evolution of plant secretory structures and emergence of terpenoid chemical diversity.

Science.gov (United States)

Lange, Bernd Markus

2015-01-01

Secretory structures in terrestrial plants appear to have first emerged as intracellular oil bodies in liverworts. In vascular plants, internal secretory structures, such as resin ducts and laticifers, are usually found in conjunction with vascular bundles, whereas subepidermal secretory cavities and epidermal glandular trichomes generally have more complex tissue distribution patterns. The primary function of plant secretory structures is related to defense responses, both constitutive and induced, against herbivores and pathogens. The ability to sequester secondary (or specialized) metabolites and defense proteins in secretory structures was a critical adaptation that shaped plant-herbivore and plant-pathogen interactions. Although this review places particular emphasis on describing the evolution of pathways leading to terpenoids, it also assesses the emergence of other metabolite classes to outline the metabolic capabilities of different plant lineages.

Traditional ecological knowledge among Sami reindeer herders in northern Sweden about vascular plants grazed by reindeer

Directory of Open Access Journals (Sweden)

Berit Inga

2013-03-01

Full Text Available Traditional knowledge about how reindeer utilize forage resources was expected to be crucial to reindeer herders. Seventeen Sami reindeer herders in four reindeer herding communities in Sweden (“samebyar” in Swedish were interviewed about plants species considered to be important reindeer food plants in scientific literature. Among 40 plant species, which the informants were asked to identify and indicate whether and when they were grazed by reindeer, they identified a total of 21 plant taxa and five plant groups. They especially recognised species that were used as human food by the Sami themselves, but certain specific forage plants were also identified. Detailed knowledge of vascular plants at the species level was surprisingly general, which may indicate that knowledge of pasture resources in a detailed species level is not of vital importance. This fact is in sharp contradiction to the detailed knowledge that Sami people express for example about reindeer (as an animal or snow (as physical element. The plausible explanation is that observations of individual plant species are unnecessarily detailed information in large-scale reindeer pastoralism, because the animals graze freely under loose herding and border surveillance.

Electronic plants

Science.gov (United States)

Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

2015-01-01

The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

Tourism and recreation listed as a threat for a wide diversity of vascular plants: a continental scale review.

Science.gov (United States)

Rankin, Benjamin Luke; Ballantyne, Mark; Pickering, Catherine Marina

2015-05-01

Tourism and recreation are diverse and popular activities. They may also contribute to the risk of extinction for some plants because of the range and severity of their impacts, including in protected areas: but which species, where and how? To evaluate the extent to which tourism and recreation may be threatening process for plants, we conducted a continental level review of listed threats to endangered vascular plants using data from Australia. Of the 659 vascular plant species listed as critically endangered or endangered by the Australian Government, tourism and recreation were listed as a threat(s) for 42%. This is more than those listed as threatened by climate change (26%) and close to the proportion listed as threatened by altered fire regimes (47%). There are plant species with tourism and recreation listed threats in all States and Territories and from all but one bioregion in Australia. Although more than 45 plant families have species with tourism and recreation listed as threats, orchids were the most common species listed as at risk from these threats (90 species). The most common types of threats listed were visitors collecting plants in protected areas (113 species), trampling by hikers and others (84 species), damage from recreational vehicles (59 species) and road infrastructure (39 species). Despite the frequency with which tourism and recreation were listed as threats in Australia, research quantifying these threats and methods to ameliorate their impacts are still limited. Although this lack of information contributes to the challenge of managing tourism and recreation, impacts from visitors will often be easier to manage within natural areas than those from larger scale threats such as altered fire regimes and climate change. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Altitudinal patterns of species richness and species range size of vascular plants in Xiaolong- shan Reserve of Qinling Mountain: a test of Rapoport' s rule].

Science.gov (United States)

Zheng, Zhi; Gong, Da-Jie; Sun, Cheng-Xiang; Li, Xiao-Jun; Li, Wan-Jiang

2014-09-01

Altitudinal patterns of species richness and species range size and their underlying mechanisms have long been a key topic in biogeography and biodiversity research. Rapoport's rule stated that the species richness gradually declined with the increasing altitude, while the species ranges became larger. Using altitude-distribution database from Xiaolongshan Reverse, this study explored the altitudinal patterns of vascular plant species richness and species range in Qinling Xiaolongshan Reserve, and examined the relationships between species richness and their distributional middle points in altitudinal bands for different fauna, taxonomic units and growth forms and tested the Rapoport's rule by using Stevens' method, Pagel's method, mid-point method and cross-species method. The results showed that the species richness of vascular plants except small-range species showed a unimodal pattern along the altitude in Qinling Xiaolongshan Reserve and the highest proportion of small-range species was found at the lower altitudinal bands and at the higher altitudinal bands. Due to different assemblages and examining methods, the relationships between species distributing range sizes and the altitudes were different. Increasing taxonomic units was easier to support Rapoport's rule, which was related to niche differences that the different taxonomic units occupied. The mean species range size of angiosperms showed a unimodal pattern along the altitude, while those of the gymnosperms and pteridophytes were unclearly regular. The mean species range size of the climbers was wider with the increasing altitude, while that of the shrubs which could adapt to different environmental situations was not sensitive to the change of altitude. Pagel's method was easier to support the Rapoport's rule, and then was Steven's method. On the contrary, due to the mid-domain effect, the results of the test by using the mid-point method showed that the mean species range size varied in a unimodal

The "Martian" flora: new collections of vascular plants, lichens, fungi, algae, and cyanobacteria from the Mars Desert Research Station, Utah

Science.gov (United States)

Freebury, Colin E.; Hamilton, Paul B.; Saarela, Jeffery M.

2016-01-01

Abstract The Mars Desert Research Station is a Mars analog research site located in the desert outside of Hanksville, Utah, U.S.A. Here we present a preliminary checklist of the vascular plant and lichen flora for the station, based on collections made primarily during a two-week simulated Mars mission in November, 2014. Additionally, we present notes on the endolithic chlorophytes and cyanobacteria, and the identification of a fungal genus also based on these collections. Altogether, we recorded 38 vascular plant species from 14 families, 13 lichen species from seven families, six algae taxa including both chlorophytes and cyanobacteria, and one fungal genus from the station and surrounding area. We discuss this floristic diversity in the context of the ecology of the nearby San Rafael Swell and the desert areas of Wayne and Emery counties in southeastern Utah. PMID:27350765

Vascular development of the grapevine (Vitis vinifera L.) inflorescence rachis in response to flower number, plant growth regulators and defoliation.

Science.gov (United States)

Gourieroux, Aude M; Holzapfel, Bruno P; McCully, Margaret E; Scollary, Geoffrey R; Rogiers, Suzy Y

2017-09-01

The grapevine inflorescence is a determinate panicle and as buds emerge, shoot, flower and rachis development occur simultaneously. The growth and architecture of the rachis is determined by genetic and environmental factors but here we examined the role of flower and leaf number as well as hormones on its elongation and vascular development. The consequences of rachis morphology and vascular area on berry size and composition were also assessed. One week prior to anthesis, Merlot and Cabernet Sauvignon field vines were exposed to manual flower removal, exogenous plant growth regulators or pre-bloom leaf removal. Manual removal of half the flowers along the vertical axis of the inflorescence resulted in a shorter rachis in both cultivars. Conversely, inflorescences treated with gibberellic acid (GA 3 ) and the synthetic cytokinin, 6-benzylaminopurine (BAP) resulted in a longer rachis while pre-bloom removal of all leaves on the inflorescence-bearing shoot did not alter rachis length relative to untreated inflorescences. Across the treatments, the cross-sectional areas of the conducting xylem and phloem in the rachis were positively correlated to rachis girth, flower number at anthesis, bunch berry number, bunch berry fresh mass and bunch sugar content at harvest. Conversely, average berry size and sugar content were not linked to rachis vascular area. These data indicate that the morphological and vascular development of the rachis was more responsive to flower number and plant growth regulators than to leaf removal.

Regulation of plant vascular stem cells by endodermis-derived EPFL-family peptide hormones and phloem-expressed ERECTA-family receptor kinases.

Science.gov (United States)

Uchida, Naoyuki; Tasaka, Masao

2013-12-01

Plant vasculatures are complex tissues consisting of (pro)cambium, phloem, and xylem. The (pro)cambium serves as vascular stem cells that produce all vascular cells. The Arabidopsis ERECTA (ER) receptor kinase is known to regulate the architecture of inflorescence stems. It was recently reported that the er mutation enhances a vascular phenotype induced by a mutation of TDR/PXY, which plays a significant role in procambial proliferation, suggesting that ER participates in vascular development. However, detailed molecular mechanisms of the ER-dependent vascular regulation are largely unknown. Here, this work found that ER and its paralogue, ER-LIKE1, were redundantly involved in procambial development of inflorescence stems. Interestingly, their activity in the phloem was sufficient for vascular regulation. Furthermore, two endodermis-derived peptide hormones, EPFL4 and EPFL6, were redundantly involved in such regulation. It has been previously reported that EPFL4 and EPFL6 act as ligands of phloem-expressed ER for stem elongation. Therefore, these findings indicate that cell-cell communication between the endodermis and the phloem plays an important role in procambial development as well as stem elongation. Interestingly, similar EPFL-ER modules control two distinct developmental events by slightly changing their components: the EPFL4/6-ER module for stem elongation and the EPFL4/6-ER/ERL1 module for vascular development.

Using herbarium-derived DNAs to assemble a large-scale DNA barcode library for the vascular plants of Canada1

Science.gov (United States)

Kuzmina, Maria L.; Braukmann, Thomas W. A.; Fazekas, Aron J.; Graham, Sean W.; Dewaard, Stephanie L.; Rodrigues, Anuar; Bennett, Bruce A.; Dickinson, Timothy A.; Saarela, Jeffery M.; Catling, Paul M.; Newmaster, Steven G.; Percy, Diana M.; Fenneman, Erin; Lauron-Moreau, Aurélien; Ford, Bruce; Gillespie, Lynn; Subramanyam, Ragupathy; Whitton, Jeannette; Jennings, Linda; Metsger, Deborah; Warne, Connor P.; Brown, Allison; Sears, Elizabeth; Dewaard, Jeremy R.; Zakharov, Evgeny V.; Hebert, Paul D. N.

2017-01-01

Premise of the study: Constructing complete, accurate plant DNA barcode reference libraries can be logistically challenging for large-scale floras. Here we demonstrate the promise and challenges of using herbarium collections for building a DNA barcode reference library for the vascular plant flora of Canada. Methods: Our study examined 20,816 specimens representing 5076 of 5190 vascular plant species in Canada (98%). For 98% of the specimens, at least one of the DNA barcode regions was recovered from the plastid loci rbcL and matK and from the nuclear ITS2 region. We used beta regression to quantify the effects of age, type of preservation, and taxonomic affiliation (family) on DNA sequence recovery. Results: Specimen age and method of preservation had significant effects on sequence recovery for all markers, but influenced some families more (e.g., Boraginaceae) than others (e.g., Asteraceae). Discussion: Our DNA barcode library represents an unparalleled resource for metagenomic and ecological genetic research working on temperate and arctic biomes. An observed decline in sequence recovery with specimen age may be associated with poor primer matches, intragenomic variation (for ITS2), or inhibitory secondary compounds in some taxa. PMID:29299394

Fifty-five new records of vascular plants, and other discoveries for the flora of Santa Catarina, southern Brazil

DEFF Research Database (Denmark)

Funez, Luís A.; Hassemer, Gustavo; Ferreira, João Paulo R.

2017-01-01

The flora of Santa Catarina is the best known in Brazil, and yet considerable knowledge gaps remain. Aiming at filling these gaps, we present here 55 new records of vascular plants for this Brazilian state, and the re-collection of four species after more than 50 years. About 50% of new records...

Gravity-induced asymmetric distribution of a plant growth hormone

Science.gov (United States)

Bandurski, R. S.; Schulze, A.; Momonoki, Y.

1984-01-01

Dolk (1936) demonstrated that gravistimulation induced an asymmetric distribution of auxin in a horizontally-placed shoot. An attempt is made to determine where and how that asymmetry arises, and to demonstrate that the endogenous auxin, indole-3-acetic acid, becomes asymmetrically distributed in the cortical cells of the Zea mays mesocotyl during 3 min of geostimulation. Further, indole-3-acetic acid derived by hydrolysis of an applied transport form of the hormone, indole-3-acetyl-myo-inositol, becomes asymmetrically distributed within 15 min of geostimulus time. From these and prior data is developed a working theory that the gravitational stimulus induces a selective leakage, or secretion, of the hormone from the vascular tissue to the cortical cells of the mesocotyl.

The Vascular Pathogen Verticillium longisporum Does Not Affect Water Relations and Plant Responses to Drought Stress of Its Host, Brassica napus.

Science.gov (United States)

Lopisso, Daniel Teshome; Knüfer, Jessica; Koopmann, Birger; von Tiedemann, Andreas

2017-04-01

Verticillium longisporum is a host-specific vascular pathogen of oilseed rape (Brassica napus L.) that causes economic crop losses by impairing plant growth and inducing premature senescence. This study investigates whether plant damage through Verticillium stem striping is due to impaired plant water relations, whether V. longisporum affects responses of a susceptible B. napus variety to drought stress, and whether drought stress, in turn, affects plant responses to V. longisporum. Two-factorial experiments on a susceptible cultivar of B. napus infected or noninfected with V. longisporum and exposed to three watering levels (30, 60, and 100% field capacity) revealed that drought stress and V. longisporum impaired plant growth by entirely different mechanisms. Although both stresses similarly affected plant growth parameters (plant height, hypocotyl diameter, and shoot and root dry matter), infection of B. napus with V. longisporum did not affect any drought-related physiological or molecular genetic plant parameters, including transpiration rate, stomatal conductance, photosynthesis rate, water use efficiency, relative leaf water content, leaf proline content, or the expression of drought-responsive genes. Thus, this study provides comprehensive physiological and molecular genetic evidence explaining the lack of wilt symptoms in B. napus infected with V. longisporum. Likewise, drought tolerance of B. napus was unaffected by V. longisporum, as was the level of disease by drought conditions, thus excluding a concerted action of both stresses in the field. Although it is evident that drought and vascular infection with V. longisporum impair plant growth by different mechanisms, it remains to be determined by which other factors V. longisporum causes crop loss.

Control of renewable distributed power plants

OpenAIRE

Bullich Massagué, Eduard

2015-01-01

The main objective of this master thesis is to design a power plant controller for a photo- voltaic (PV) power plant. In a first stage, the current situation of the status of the electrical grid is analysed. The electrical network structure is moving from a conventional system (with centralized power generation, unidirectional power ows, easy control) to a smart grid system consisting on distributed generation, renewable energies, smart and complex control architecture and ...

Immunocytochemical analysis of the subcellular distribution of ferritin in Imperata cylindrica (L.) Raeuschel, an iron hyperaccumulator plant.

Science.gov (United States)

de la Fuente, Vicenta; Rodríguez, Nuria; Amils, Ricardo

2012-05-01

Ferritin is of interest at the structural and functional level not only as storage for iron, a critical element, but also as a means to prevent cell damage produced by oxidative stress. The main objective of this work was to confirm by immunocytochemistry the presence and the subcellular distribution of the ferritin detected by Mösbauer spectroscopy in Imperata cylindrica, a plant which accumulates large amounts of iron. The localization of ferritin was performed in epidermal, parenchymal and vascular tissues of shoots and leaves of I. cylindrica. The highest density of immunolabeling in shoots appeared in the intracellular space of cell tissues, near the cell walls and in the cytoplasm. In leaves, ferritin was detected in the proximity of the dense network of the middle lamella of cell walls, following a similar path to that observed in shoots. Immunolabeling was also localized in chloroplasts. The abundance of immunogold labelling in mitochondria for I. cylindrica was rather low, probably because the study dealt with tissues from old plants. These results further expand the localization of ferritin in cell components other than chloroplasts and mitochondria in plants. Copyright © 2011 Elsevier GmbH. All rights reserved.

Vascular plants promote ancient peatland carbon loss with climate warming.

Science.gov (United States)

Walker, Tom N; Garnett, Mark H; Ward, Susan E; Oakley, Simon; Bardgett, Richard D; Ostle, Nicholas J

2016-05-01

Northern peatlands have accumulated one third of the Earth's soil carbon stock since the last Ice Age. Rapid warming across northern biomes threatens to accelerate rates of peatland ecosystem respiration. Despite compensatory increases in net primary production, greater ecosystem respiration could signal the release of ancient, century- to millennia-old carbon from the peatland organic matter stock. Warming has already been shown to promote ancient peatland carbon release, but, despite the key role of vegetation in carbon dynamics, little is known about how plants influence the source of peatland ecosystem respiration. Here, we address this issue using in situ (14)C measurements of ecosystem respiration on an established peatland warming and vegetation manipulation experiment. Results show that warming of approximately 1 °C promotes respiration of ancient peatland carbon (up to 2100 years old) when dwarf-shrubs or graminoids are present, an effect not observed when only bryophytes are present. We demonstrate that warming likely promotes ancient peatland carbon release via its control over organic inputs from vascular plants. Our findings suggest that dwarf-shrubs and graminoids prime microbial decomposition of previously 'locked-up' organic matter from potentially deep in the peat profile, facilitating liberation of ancient carbon as CO2. Furthermore, such plant-induced peat respiration could contribute up to 40% of ecosystem CO2 emissions. If consistent across other subarctic and arctic ecosystems, this represents a considerable fraction of ecosystem respiration that is currently not acknowledged by global carbon cycle models. Ultimately, greater contribution of ancient carbon to ecosystem respiration may signal the loss of a previously stable peatland carbon pool, creating potential feedbacks to future climate change. © 2016 John Wiley & Sons Ltd.

Vascular Plant and Vertebrate Inventory of Tonto National Monument

Science.gov (United States)

Albrecht, Eric W.; Powell, Brian F.; Halvorson, William L.; Schmidt, Cecilia A.

2007-01-01

This report summarizes the results of the first biological inventory of plants and vertebrates at Tonto National Monument (NM). From 2001 to 2003, we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at Tonto NM to record species presence. We focused most of our efforts along the Cave Springs riparian area, but surveyed other areas as well. We recorded 149 species in the riparian area, and 369 species overall in the monument, including 65 plant species and four bird species that were previously unrecorded for the monument. We recorded 78 plant species in the riparian area that previous studies had not indicated were present there. Several species of each taxonomic group were found only in the riparian area, suggesting that because of their concentration in this small area these populations are vulnerable to disturbance and may be of management concern. Four of the bird species that we recorded (Bell's vireo, yellow warbler, summer tanager, and Abert's towhee) have been identified as riparian 'obligate' species by other sources. Bird species that are obligated to riparian areas are targets of conservation concern due to widespread degradation of riparian areas in the desert southwest over the last century. The flora and fauna of the riparian area would benefit from continued limited public access. The dependence of the riparian area on the spring and surface flow suggests monitoring of this resource per se would benefit management of the riparian area's flora and fauna as well. The monument would benefit from incorporating monitoring protocols developed by the Sonoran Desert Network Inventory and Monitoring program rather than initiating a separate program for the riparian area. Park managers can encourage the Inventory and Monitoring program to address the unique monitoring challenges presented by small spatial areas such as this riparian area, and can request specific monitoring recommendations. We suggest that repeat

Proceedings: Distributed digital systems, plant process computers, and networks

International Nuclear Information System (INIS)

1995-03-01

These are the proceedings of a workshop on Distributed Digital Systems, Plant Process Computers, and Networks held in Charlotte, North Carolina on August 16--18, 1994. The purpose of the workshop was to provide a forum for technology transfer, technical information exchange, and education. The workshop was attended by more than 100 representatives of electric utilities, equipment manufacturers, engineering service organizations, and government agencies. The workshop consisted of three days of presentations, exhibitions, a panel discussion and attendee interactions. Original plant process computers at the nuclear power plants are becoming obsolete resulting in increasing difficulties in their effectiveness to support plant operations and maintenance. Some utilities have already replaced their plant process computers by more powerful modern computers while many other utilities intend to replace their aging plant process computers in the future. Information on recent and planned implementations are presented. Choosing an appropriate communications and computing network architecture facilitates integrating new systems and provides functional modularity for both hardware and software. Control room improvements such as CRT-based distributed monitoring and control, as well as digital decision and diagnostic aids, can improve plant operations. Commercially available digital products connected to the plant communications system are now readily available to provide distributed processing where needed. Plant operations, maintenance activities, and engineering analyses can be supported in a cost-effective manner. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

Sap flow and sugar transport in plants

DEFF Research Database (Denmark)

Jensen, Kaare Hartvig; Berg-Sørensen, Kirstine; Bruus, Henrik

2016-01-01

Green plants are Earth’s primary solar energy collectors. They harvest the energy of the Sun by converting light energy into chemical energy stored in the bonds of sugar molecules. A multitude of carefully orchestrated transport processes are needed to move water and minerals from the soil to sites...... of photosynthesis and to distribute energy-rich sugars throughout the plant body to support metabolism and growth. The long-distance transport happens in the plants’ vascular system, where water and solutes are moved along the entire length of the plant. In this review, the current understanding of the mechanism...... and the quantitative description of these flows are discussed, connecting theory and experiments as far as possible. The article begins with an overview of low-Reynolds-number transport processes, followed by an introduction to the anatomy and physiology of vascular transport in the phloem and xylem. Next, sugar...

Vegetation dynamics at the upper elevational limit of vascular plants in Himalaya

Czech Academy of Sciences Publication Activity Database

Doležal, Jiří; Dvorský, Miroslav; Kopecký, Martin; Liancourt, Pierre; Hiiesalu, Inga; Macek, Martin; Altman, Jan; Chlumská, Z.; Řeháková, Klára; Čapková, Kateřina; Borovec, Jakub; Mudrák, Ondřej; Wild, Jan; Schweingruber, F. H.

2016-01-01

Roč. 6, May (2016), s. 1-13, č. článku 24881. ISSN 2045-2322 R&D Projects: GA ČR GA13-13368S EU Projects: European Commission(XE) 267243 Institutional support: RVO:67985939 ; RVO:60077344 Keywords : climate change * plant age * plant distribution Subject RIV: EH - Ecology, Behaviour Impact factor: 4.259, year: 2016

Herbarium of vascular plants collection of the university of extremadura (Spain).

Science.gov (United States)

Espinosa, Marta; López, Josefa

2013-01-01

The herbarium of University of Extremadura (UNEX Herbarium) is formed by 36451 specimens of vascular plants whose main origin is the autonomous region of Extremadura (Spain) and Portugal, although it also contains a smaller number of specimens from different places, including the rest of peninsular Spain, the Baleares Islands, the Macaronesian region (Canary Islands, Madeira and Azores), northwest of Africa (Morocco) and Brazil. 98% of the total records are georeferenced. It is an active collection in continuous growth. Its data can be accessed through the GBIF data portal at http://data.gbif.org/datasets/resource/255 and http://www.eweb.unex.es/eweb/botanica/herbario/. This paper describes the specimen associated data set of the UNEX Herbarium, with an objective to disseminate the data contained in a data set with potential users, and promote the multiple uses of the data.

Revisiting the origin and diversification of vascular plants through a comprehensive Bayesian analysis of the fossil record.

Science.gov (United States)

Silvestro, Daniele; Cascales-Miñana, Borja; Bacon, Christine D; Antonelli, Alexandre

2015-07-01

Plants have a long evolutionary history, during which mass extinction events dramatically affected Earth's ecosystems and its biodiversity. The fossil record can shed light on the diversification dynamics of plant life and reveal how changes in the origination-extinction balance have contributed to shaping the current flora. We use a novel Bayesian approach to estimate origination and extinction rates in plants throughout their history. We focus on the effect of the 'Big Five' mass extinctions and on estimating the timing of origin of vascular plants, seed plants and angiosperms. Our analyses show that plant diversification is characterized by several shifts in origination and extinction rates, often matching the most important geological boundaries. The estimated origin of major plant clades predates the oldest macrofossils when considering the uncertainties associated with the fossil record and the preservation process. Our findings show that the commonly recognized mass extinctions have affected each plant group differently and that phases of high extinction often coincided with major floral turnovers. For instance, after the Cretaceous-Paleogene boundary we infer negligible shifts in diversification of nonflowering seed plants, but find significantly decreased extinction in spore-bearing plants and increased origination rates in angiosperms, contributing to their current ecological and evolutionary dominance. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

The moss Funaria hygrometrica has cuticular wax similar to vascular plants, with distinct composition on leafy gametophyte, calyptra and sporophyte capsule surfaces.

Science.gov (United States)

Busta, Lucas; Budke, Jessica M; Jetter, Reinhard

2016-09-01

Aerial surfaces of land plants are covered with a waxy cuticle to protect against water loss. The amount and composition of cuticular waxes on moss surfaces had rarely been investigated. Accordingly, the degree of similarity between moss and vascular plant waxes, and between maternal and offspring moss structure waxes is unknown. To resolve these issues, this study aimed at providing a comprehensive analysis of the waxes on the leafy gametophyte, gametophyte calyptra and sporophyte capsule of the moss Funaria hygrometrica Waxes were extracted from the surfaces of leafy gametophytes, gametophyte calyptrae and sporophyte capsules, separated by gas chromatography, identified qualitatively with mass spectrometry, and quantified with flame ionization detection. Diagnostic mass spectral peaks were used to determine the isomer composition of wax esters. The surfaces of the leafy gametophyte, calyptra and sporophyte capsule of F. hygrometrica were covered with 0·94, 2·0 and 0·44 μg cm(-2) wax, respectively. While each wax mixture was composed of mainly fatty acid alkyl esters, the waxes from maternal and offspring structures had unique compositional markers. β-Hydroxy fatty acid alkyl esters were limited to the leafy gametophyte and calyptra, while alkanes, aldehydes and diol esters were restricted to the sporophyte capsule. Ubiquitous fatty acids, alcohols, fatty acid alkyl esters, aldehydes and alkanes were all found on at least one surface. This is the first study to determine wax coverage (μg cm(-2)) on a moss surface, enabling direct comparisons with vascular plants, which were shown to have an equal amount or more wax than F. hygrometrica Wax ester biosynthesis is of particular importance in this species, and the ester-forming enzyme(s) in different parts of the moss may have different substrate preferences. Furthermore, the alkane-forming wax biosynthesis pathway, found widely in vascular plants, is active in the sporophyte capsule, but not in the leafy

A clade in the QUASIMODO2 family evolved with vascular plants and supports a role for cell wall composition in adaptation to environmental changes.

Science.gov (United States)

Fuentes, Sara; Pires, Nuno; Østergaard, Lars

2010-08-01

The evolution of plant vascular tissue is tightly linked to the evolution of specialised cell walls. Mutations in the QUASIMODO2 (QUA2) gene from Arabidopsis thaliana were previously shown to result in cell adhesion defects due to reduced levels of the cell wall component homogalacturonic acid. In this study, we provide additional information about the role of QUA2 and its closest paralogues, QUASIMODO2 LIKE1 (QUL1) and QUL2. Within the extensive QUA2 family, our phylogenetic analysis shows that these three genes form a clade that evolved with vascular plants. Consistent with a possible role of this clade in vasculature development, QUA2 is highly expressed in the vascular tissue of embryos and inflorescence stems and overexpression of QUA2 resulted in temperature-sensitive xylem collapse. Moreover, in-depth characterisation of qua2 qul1 qul2 triple mutant and 35S::QUA2 overexpression plants revealed contrasting temperature-dependent stem development with dramatic effects on stem width. Taken together, our results suggest that the QUA2-specific clade contributed to the evolution of vasculature and illustrate the important role that modification of cell wall composition plays in the adaptation to changing environmental conditions, including changes in temperature.

Post-translational control of nitrate reductase activity responding to light and photosynthesis evolved already in the early vascular plants.

Science.gov (United States)

Nemie-Feyissa, Dugassa; Królicka, Adriana; Førland, Nina; Hansen, Margarita; Heidari, Behzad; Lillo, Cathrine

2013-05-01

Regulation of nitrate reductase (NR) by reversible phosphorylation at a conserved motif is well established in higher plants, and enables regulation of NR in response to rapid fluctuations in light intensity. This regulation is not conserved in algae NR, and we wished to test the evolutionary origin of the regulatory mechanism by physiological examination of ancient land plants. Especially a member of the lycophytes is of interest since their NR is candidate for regulation by reversible phosphorylation based on sequence analysis. We compared Selaginella kraussiana, a member of the lycophytes and earliest vascular plants, with the angiosperm Arabidopsis thaliana, and also tested the moss Physcomitrella patens. Interestingly, optimization of assay conditions revealed that S. kraussiana NR used NADH as an electron donor like A. thaliana, whereas P. patens NR activity depended on NADPH. Examination of light/darkness effects showed that S. kraussiana NR was rapidly regulated similar to A. thaliana NR when a differential (Mg(2+) contra EDTA) assay was used to reveal activity state of NR. This implies that already existing NR enzyme was post-translationally activated by light in both species. Light had a positive effect also on de novo synthesis of NR in S. kraussiana, which could be shown after the plants had been exposed to a prolonged dark period (7 days). Daily variations in NR activity were mainly caused by post-translational modifications. As for angiosperms, the post-translational light activation of NR in S. kraussiana was inhibited by 3-(3,4-dichlorophenyl)-1*1-dimethylurea (DCMU), an inhibitor of photosynthesis and stomata opening. Evolutionary, a post-translational control mechanism for NR have occurred before or in parallel with development of vascular tissue in land plants, and appears to be part of a complex mechanisms for coordination of CO2 and nitrogen metabolism in these plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

Plant growth and metal distribution in tissues of Prosopis juliflora-velutina grown on chromium contaminated soil in the presence of Glomus deserticola.

Science.gov (United States)

Arias, Jack A; Peralta-Videa, Jose R; Ellzey, Joanne T; Viveros, Marian N; Ren, Minghua; Mokgalaka-Matlala, Ntebogeng S; Castillo-Michel, Hiram; Gardea-Torresdey, Jorge L

2010-10-01

Arbuscular mycorrhizal fungi have been known to increase metal uptake in plants. In this study, mesquite (Prosopis juliflora-velutina) inoculated with Glomus deserticola or amended with EDTA were grown for 30 days in soil containing Cr(III) or Cr(VI) at 0, 40, 80, and 160 mg kg(-1). Total amylase activity (TAA) was monitored as a stress indicator. Element concentrations and distribution in tissue were determined using ICP-OES, electron scanning microprobe, and TEM. Inoculated Cr(VI) treated plants had 21% and 30% more Cr than uninoculated and EDTA treated roots, respectively, at 80 mg Cr kg(-1) treatment. In the case of Cr(III), EDTA produced the highest Cr accumulation in roots. TAA was higher in inoculated plants grown with Cr(III) at 80 and 160 mg kg(-1) and Cr(VI) at 40 and 160 mg kg(-1). The X-ray mapping showed higher metal concentrations in the vascular system of inoculated plants and the TEM micrographs demonstrated the presence of G. deserticola in roots.

Co-optimal distribution of leaf nitrogen and hydraulic conductance in plant canopies.

Science.gov (United States)

Peltoniemi, Mikko S; Duursma, Remko A; Medlyn, Belinda E

2012-05-01

Leaf properties vary significantly within plant canopies, due to the strong gradient in light availability through the canopy, and the need for plants to use resources efficiently. At high light, photosynthesis is maximized when leaves have a high nitrogen content and water supply, whereas at low light leaves have a lower requirement for both nitrogen and water. Studies of the distribution of leaf nitrogen (N) within canopies have shown that, if water supply is ignored, the optimal distribution is that where N is proportional to light, but that the gradient of N in real canopies is shallower than the optimal distribution. We extend this work by considering the optimal co-allocation of nitrogen and water supply within plant canopies. We developed a simple 'toy' two-leaf canopy model and optimized the distribution of N and hydraulic conductance (K) between the two leaves. We asked whether hydraulic constraints to water supply can explain shallow N gradients in canopies. We found that the optimal N distribution within plant canopies is proportional to the light distribution only if hydraulic conductance, K, is also optimally distributed. The optimal distribution of K is that where K and N are both proportional to incident light, such that optimal K is highest to the upper canopy. If the plant is constrained in its ability to construct higher K to sun-exposed leaves, the optimal N distribution does not follow the gradient in light within canopies, but instead follows a shallower gradient. We therefore hypothesize that measured deviations from the predicted optimal distribution of N could be explained by constraints on the distribution of K within canopies. Further empirical research is required on the extent to which plants can construct optimal K distributions, and whether shallow within-canopy N distributions can be explained by sub-optimal K distributions.

Mosses Are Better than Leaves of Vascular Plants in Monitoring Atmospheric Heavy Metal Pollution in Urban Areas.

Science.gov (United States)

Jiang, Yanbin; Fan, Miao; Hu, Ronggui; Zhao, Jinsong; Wu, Yupeng

2018-05-29

Mosses and leaves of vascular plants have been used as bioindicators of environmental contamination by heavy metals originating from various sources. This study aims to compare the metal accumulation capabilities of mosses and vascular species in urban areas and quantify the suitability of different taxa for monitoring airborne heavy metals. One pleurocarpous feather moss species, Haplocladium angustifolium , and two evergreen tree species, Cinnamomum bodinieri Osmanthus fragrans , and substrate soil were sampled in the urban area of different land use types in Wuhan City in China. The concentrations of Ag, As, Cd, Co, Cr, Cu, Mn, Mo, Ni, V, Pb, and Zn in these samples were analyzed by inductively coupled plasma mass spectrometry. The differences of heavy metals concentration in the three species showed that the moss species was considerably more capable of accumulating heavy metals than tree leaves (3 times to 51 times). The accumulated concentration of heavy metals in the moss species depended on the metal species and land use type. The enrichment factors of metals for plants and the correlations of metals in plants with corresponding metals in soil reflected that the accumulated metals in plants stemmed mostly from atmospheric deposition, rather than the substrate soil. Anthropogenic factors, such as traffic emissions from automobile transportation and manufacturing industries, were primarily responsible for the variations in metal pollutants in the atmosphere and subsequently influenced the metal accumulation in the mosses. This study elucidated that the moss species H. angustifolium is relatively more suitable than tree leaves of C. bodinieri and O. fragrans in monitoring heavy metal pollution in urban areas, and currently Wuhan is at a lower contamination level of atmospheric heavy metals than some other cities in China.

Uptake and distribution of mercury within higher plants

Energy Technology Data Exchange (ETDEWEB)

Beauford, W; Barber, J; Barringer, A R

1977-04-15

The uptake and distribution of inorganic mercury (HgCl/sub 2/) within higher plants (Pisum sativum and Mentha spicata) was examined using solution culture and radiotracer techniques. Plants were found to tolerate an external level of 1 mgHg/kg of solution but both physiological and biochemical processes were affected at 5 mgHg/kg and 10 mgHg/kg. The uptake of Hg into plants grown in hydroponic solution was a function of external concentration. Over the concentration range considered the accumulation of Hg in the roots was linear on a log-log basis although the uptake of the element into the shoots appeared to be two-phased. The distribution of Hg in plants was asymmetrical with much greater amounts of the element in the roots than the shoots. Although the level of Hg increased generally in plant tissues with increasing external levels, the proportion retained in the roots, relative to the shoots, was constant (approximately 95%). Two binding characteristics of the Hg within plant tissue were detected. A major proportion of Hg was tightly bound, being unaffected by treatment with ethanol and hydrochloric acid. The remaining Hg in the tissue was removed by either water or hydrochloric acid treatment. Cell fractionation indicated that the major binding component of Hg in plant tissues was the cell wall.

Transmission and distribution of information in power plants

International Nuclear Information System (INIS)

Pinkernell, H.

1978-01-01

Operation of modern large-site power plants is no longer imaginable without facilities for automatic control. Brown-Boveri Company has developed a promising control system for power plants called Procontrol k. An essential piece of the system is DATRAS k, a digital bus-oriented data transport system for transmitting and distributing signals in power plants. DATRAS will save a large amount of cables and reduce the constructional effect. It offers opportunities for diagnosis and service and by means of continuous monitoring of all system components it will essentially improve plant availability. (orig.) [de

Phylogenetic distribution of plant snoRNA families

DEFF Research Database (Denmark)

Patra Bhattacharya, Deblina; Canzler, Sebastian; Kehr, Stephanie

2016-01-01

RNAs and box H/ACA snoRNAs, which are clearly distinguished by conserved sequence motifs and the type of chemical modification that they govern. Similarly to microRNAs, snoRNAs appear in distinct families of homologs that affect homologous targets. In animals, snoRNAs and their evolution have been studied...... in much detail. In plants, however, their evolution has attracted comparably little attention. RESULTS: In order to chart the phylogenetic distribution of individual snoRNA families in plants, we applied a sophisticated approach for identifying homologs of known plant snoRNAs across the plant kingdom....... In response to the relatively fast evolution of snoRNAs, information on conserved sequence boxes, target sequences, and secondary structure is combined to identify additional snoRNAs. We identified 296 families of snoRNAs in 24 species and traced their evolution throughout the plant kingdom. Many of the plant...

Can oxygen stable isotopes be used to track precipitation moisture source in vascular plant-dominated peatlands?

Science.gov (United States)

Amesbury, Matthew J.; Charman, Dan J.; Newnham, Rewi M.; Loader, Neil J.; Goodrich, Jordan; Royles, Jessica; Campbell, David I.; Keller, Elizabeth D.; Baisden, W. Troy; Roland, Thomas P.; Gallego-Sala, Angela V.

2015-11-01

Variations in the isotopic composition of precipitation are determined by fractionation processes which occur during temperature- and humidity-dependent phase changes associated with evaporation and condensation. Oxygen stable isotope ratios have therefore been frequently used as a source of palaeoclimate data from a variety of proxy archives, which integrate this signal over time. Applications from ombrotrophic peatlands, where the source water used in cellulose synthesis is derived solely from precipitation, have been mostly limited to Northern Hemisphere Sphagnum-dominated bogs, with few in the Southern Hemisphere or in peatlands dominated by vascular plants. New Zealand (NZ) provides an ideal location to undertake empirical research into oxygen isotope fractionation in vascular peatlands because single taxon analysis can be easily carried out, in particular using the preserved root matrix of the restionaceous wire rush (Empodisma spp.) that forms deep Holocene peat deposits throughout the country. Furthermore, large gradients are observed in the mean isotopic composition of precipitation across NZ, caused primarily by the relative influence of different climate modes. Here, we test whether δ18O of Empodisma α-cellulose from ombrotrophic restiad peatlands in NZ can provide a methodology for developing palaeoclimate records of past precipitation δ18O. Surface plant, water and precipitation samples were taken over spatial (six sites spanning >10° latitude) and temporal (monthly measurements over one year) gradients. A link between the isotopic composition of root-associated water, the most likely source water for plant growth, and precipitation in both datasets was found. Back-trajectory modelling of precipitation moisture source for rain days prior to sampling showed clear seasonality in the temporal data that was reflected in root-associated water. The link between source water and plant cellulose was less clear, although mechanistic modelling predicted mean

Influence of natural and anthropogenic factors on the distribution of xerothermic plants in the lower San river valley (SE Poland

Directory of Open Access Journals (Sweden)

Rafał Krawczyk

2012-12-01

Full Text Available The aim of the present study was to describe the distribution of xerothermic species of vascular plants in the lower San River valley and the relationship between their density and the intensity of selected environmental (natural and anthropogenic factors. Xerothermic species occurred more frequently in the present valley floor compared to the glacial terrace. Within the present valley, the highest density was observed in the floodplain. The examined species also occurred more often on steep slopes of the valley, at the margins of the present valley terraces, and in the area of occurrence of aeolian sands. Moreover, a positive correlation has been found between the number of xerothermic species and the area of polyhemeroby ecosystems. The distribution of xero- and thermophilous species is determined by natural edaphic and geomorphological factors as well as anthropogenic ones (land use, lowering of the groundwater level as a result of river regulation.

Cross-scale modelling of alien and native vascular plant species richness in Great Britain: where is geodiversity information most relevant?

Science.gov (United States)

Bailey, Joseph; Field, Richard; Boyd, Doreen

2016-04-01

We assess the scale-dependency of the relationship between biodiversity and novel geodiversity information by studying spatial patterns of native and alien (archaeophytes and neophytes) vascular plant species richness at varying spatial scales across Great Britain. Instead of using a compound geodiversity metric, we study individual geodiversity components (GDCs) to advance our understanding of which aspects of 'geodiversity' are most important and at what scale. Terrestrial native (n = 1,490) and alien (n = 1,331) vascular plant species richness was modelled across the island of Great Britain at two grain sizes and several extent radii. Various GDCs (landforms, hydrology, geology) were compiled from existing national datasets and automatically extracted landform coverage information (e.g. hollows, valleys, peaks), the latter using a digital elevation model (DEM) and geomorphometric techniques. More traditional predictors of species richness (climate, widely-used topography metrics, land cover diversity, and human population) were also incorporated. Boosted Regression Tree (BRT) models were produced at all grain sizes and extents for each species group and the dominant predictors were assessed. Models with and without geodiversity data were compared. Overarching patterns indicated a clear dominance of geodiversity information at the smallest study extent (12.5km radius) and finest grain size (1x1km), which substantially decreased for each increase in extent as the contribution of climatic variables increased. The contribution of GDCs to biodiversity models was chiefly driven by landform information from geomorphometry, but hydrology (rivers and lakes), and to a lesser extent materials (soil, superficial deposits, and geology), were important, also. GDCs added significantly to vascular plant biodiversity models in Great Britain, independently of widely-used topographic metrics, particularly for native species. The wider consideration of geodiversity alongside

Decentralised electrical distribution network in power plants

International Nuclear Information System (INIS)

Mannila, P.; Lehtonen, M.

2000-02-01

A centralised network is a dominating network solution in today's power plants. In this study a centralised and a decentralised network were designed in order to compare them economically and technically. The emphasis of this study was on economical aspects, but also the most important technical aspects were included. The decentralised network requires less space and less cabling since there is no switchgear building and distribution transformers are placed close to the consumption in the field of a power plant. MV-motors and distribution transformers build up a ring. Less cabling and an absent switchgear building cause considerable savings. Component costs of both of the networks were estimated by using data from fulfilled power plant projects and turned out to be smaller for the decentralised network. Simulations for the decentralised network were done in order to find a way to carry out earth fault protection and location. It was found out that in high resistance earthed system the fault distance can be estimated by a relatively simple method. The decentralised network uses a field bus, which offers many new features to the automation system of a power plant. Diversified information can be collected from the protection devices in order to schedule only the needed maintenance duties at the right time. Through the field bus it is also possible to control remotely a power plant. The decentralised network is built up from ready-to-install modules. These modules are tested by the module manufacturer decreasing the need for field testing dramatically. The work contribution needed in the electrification and the management of a power plant project reduces also due the modules. During the lifetime of a power plant, maintenance is easier and more economical. (orig.)

Contrasts between bryophyte and vascular plant synecological responses in an SO/sub 2/-stressed white spruce association in Central Alberta

Energy Technology Data Exchange (ETDEWEB)

Winner, W.E.; Bewley, J.D.

1978-01-01

Canopy coverage analysis was used to examine the synecological changes exhibited by vascular plants and terrestrial mosses in a white spruce association exposed to SO/sub 2/ fumigation. Both these understory components were found to decline in coverage as SO/sub 2/ stress increased, but mosses were more sensitive to SO/sub 2/ in the more heavily stressed areas. This was observed along both an angle-dependent and a distance-dependent gradient of pollution stress. Diversity steadily declined with increasing SO/sub 2/ stress along the angle-dependent gradient but some localized increases in diversity occurred with increasing stress along the distance-dependent gradient. This was due to invasion of openings resulting from attrition of SO/sub 2/-sensitive species by weedy angiosperms and by vegetative growth of moss species more tolerant of pollution stress. Conclusions have been drawn about the productive strategy of vascular plants and mosses subjected to increasing concentrations of SO/sub 2/. We have elucidated the ecological consequences for community structure of the systematic removal of pollution-sensitive understory species from an otherwise stable vegetation unit.

Does cross-taxon analysis show similarity in diversity patterns between vascular plants and bryophytes? Some answers from a literature review.

Science.gov (United States)

Bagella, Simonetta

2014-04-01

The objective of this study was to clarify the taxon surrogacy hypothesis relative to vascular plants and bryophytes. A literature review was conducted to obtain papers that met the following criteria: (i) they examined species richness values; or (ii) they evaluated the species richness within the same study sites, or under the same spatial variation conditions. Twenty-seven papers were accessed. The richness of the two taxa, compared in 32 cases, positively co-varied in about half of the comparisons. The response to the spatial variation in environmental or human-induced factors of the two taxa in terms of species richness was rather variable. Based on current knowledge, the main documented findings regard forest habitats and nival gradients. In forest habitats, co-variation in species richness is likely when similar environments are analysed and seems to be strengthened for boreal forests. Along the nival gradient, a different response in terms of richness of the two taxa suggests that vascular plants cannot be considered good surrogates for bryophytes. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Intelligent distributed control for nuclear power plants

International Nuclear Information System (INIS)

Klevans, E.H.

1993-01-01

This project was initiated in September 1989 as a three year project to develop and demonstrate Intelligent Distributed Control (IDC) for Nuclear Power Plants. There were two primary goals of this research project. The first goal was to combine diagnostics and control to achieve a highly automated power plant as described by M.A. Schultz. The second goal was to apply this research to develop a prototype demonstration on an actual power plant system, the EBR-2 steam plant. Described in this Final (Third Annual) Technical Progress Report is the accomplishment of the project's final milestone, an in-plant intelligent control experiment conducted on April 1, 1993. The development of the experiment included: simulation validation, experiment formulation and final programming, procedure development and approval, and experimental results. Other third year developments summarized in this report are: (1) a theoretical foundation for Reconfigurable Hybrid Supervisory Control, (2) a steam plant diagnostic system, (3) control console design tools and (4) other advanced and intelligent control

Root distribution pattern of Colocasia- 32P plant injection technique

International Nuclear Information System (INIS)

Eapen, Suja; Salam, M.A.; Wahid, P.A.

1995-01-01

A 32 P plant injection technique was employed to study the variation in the root production and distribution patterns of colocasia var. Cheruchempu grown in the coconut garden and in the open. Root production of colocasia was more with the plants grown in the open compared to the plants grown in the coconut garden. The root distribution pattern of colocasia differed with light environments under which the plants are grown. Colocasia grown in the coconut garden developed a compact root system while that grown in the open condition developed a spreading root system. The root zone comprising 20 cm laterally around the plant and 40 cm vertically from the surface (L 0-20 D 0-40 ) can be considered as the active root zone of colocasia. (author). 9 refs., 4 figs., 1 tab

Unpreferred plants affect patch choice and spatial distribution of European brown hares

Science.gov (United States)

Kuijper, D. P. J.; Bakker, J. P.

2008-11-01

Many herbivore species prefer to forage on patches of intermediate biomass. Plant quality and forage efficiency are predicted to decrease with increasing plant standing crop which explains the lower preference of the herbivore. However, often is ignored that on the long-term, plant species composition is predicted to change with increasing plant standing crop. The amount of low-quality, unpreferred food plants increases with increasing plant standing crop. In the present study the effects of unpreferred plants on patch choice and distribution of European brown hare in a salt-marsh system were studied. In one experiment, unpreferred plants were removed from plots. In the second experiment, plots were planted with different densities of an unpreferred artificial plant. Removal of unpreferred plants increased hare-grazing pressure more than fivefold compared to unmanipulated plots. Planting of unpreferred plants reduced hare-grazing pressure, with a significant reduction of grazing already occurring at low unpreferred plant density. Spatial distribution of hares within this salt-marsh system was related to spatial arrangement of unpreferred plants. Hare-grazing intensity decreased strongly with increasing abundance of unpreferred plants despite a high abundance of principal food plants. The results of this study indicate that plant species replacement is an important factor determining patch choice and spatial distribution of hares next to changing plant quality. Increasing abundance of unpreferred plant species can strengthen the decreasing patch quality with increasing standing crop and can decrease grazing intensity when preferred food plants are still abundantly present.

Arabidopsis thaliana plants lacking the ARP2/3 complex show defects in cell wall assembly and auxin distribution.

Science.gov (United States)

Pratap Sahi, Vaidurya; Cifrová, Petra; García-González, Judith; Kotannal Baby, Innu; Mouillé, Gregory; Gineau, Emilie; Müller, Karel; Baluška, František; Soukup, Aleš; Petrášek, Jan; Schwarzerová, Katerina

2017-12-25

The cytoskeleton plays an important role in the synthesis of plant cell walls. Both microtubules and actin cytoskeleton are known to be involved in the morphogenesis of plant cells through their role in cell wall building. The role of ARP2/3-nucleated actin cytoskeleton in the morphogenesis of cotyledon pavement cells has been described before. Seedlings of Arabidopsis mutants lacking a functional ARP2/3 complex display specific cell wall-associated defects. In three independent Arabidopsis mutant lines lacking subunits of the ARP2/3 complex, phenotypes associated with the loss of the complex were analysed throughout plant development. Organ size and anatomy, cell wall composition, and auxin distribution were investigated. ARP2/3-related phenotype is associated with changes in cell wall composition, and the phenotype is manifested especially in mature tissues. Cell walls of mature plants contain less cellulose and a higher amount of homogalacturonan, and display changes in cell wall lignification. Vascular bundles of mutant inflorescence stems show a changed pattern of AUX1-YFP expression. Plants lacking a functional ARP2/3 complex have decreased basipetal auxin transport. The results suggest that the ARP2/3 complex has a morphogenetic function related to cell wall synthesis and auxin transport. © The Author(s) 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Projected range contractions of European protected oceanic montane plant communities: focus on climate change impacts is essential for their future conservation.

Science.gov (United States)

Hodd, Rory L; Bourke, David; Skeffington, Micheline Sheehy

2014-01-01

Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the north-west hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1) oceanic montane bryophytes and vascular plants; 2) species belonging to different montane plant communities; 3) species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need significantly

Projected range contractions of European protected oceanic montane plant communities: focus on climate change impacts is essential for their future conservation.

Directory of Open Access Journals (Sweden)

Rory L Hodd

Full Text Available Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the north-west hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1 oceanic montane bryophytes and vascular plants; 2 species belonging to different montane plant communities; 3 species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need

Mechanisms of Vascular Damage by Hemorrhagic Snake Venom Metalloproteinases: Tissue Distribution and In Situ Hydrolysis

Science.gov (United States)

Baldo, Cristiani; Jamora, Colin; Yamanouye, Norma; Zorn, Telma M.; Moura-da-Silva, Ana M.

2010-01-01

Background Envenoming by viper snakes constitutes an important public health problem in Brazil and other developing countries. Local hemorrhage is an important symptom of these accidents and is correlated with the action of snake venom metalloproteinases (SVMPs). The degradation of vascular basement membrane has been proposed as a key event for the capillary vessel disruption. However, SVMPs that present similar catalytic activity towards extracellular matrix proteins differ in their hemorrhagic activity, suggesting that other mechanisms might be contributing to the accumulation of SVMPs at the snakebite area allowing capillary disruption. Methodology/Principal Findings In this work, we compared the tissue distribution and degradation of extracellular matrix proteins induced by jararhagin (highly hemorrhagic SVMP) and BnP1 (weakly hemorrhagic SVMP) using the mouse skin as experimental model. Jararhagin induced strong hemorrhage accompanied by hydrolysis of collagen fibers in the hypodermis and a marked degradation of type IV collagen at the vascular basement membrane. In contrast, BnP1 induced only a mild hemorrhage and did not disrupt collagen fibers or type IV collagen. Injection of Alexa488-labeled jararhagin revealed fluorescent staining around capillary vessels and co-localization with basement membrane type IV collagen. The same distribution pattern was detected with jararhagin-C (disintegrin-like/cysteine-rich domains of jararhagin). In opposition, BnP1 did not accumulate in the tissues. Conclusions/Significance These results show a particular tissue distribution of hemorrhagic toxins accumulating at the basement membrane. This probably occurs through binding to collagens, which are drastically hydrolyzed at the sites of hemorrhagic lesions. Toxin accumulation near blood vessels explains enhanced catalysis of basement membrane components, resulting in the strong hemorrhagic activity of SVMPs. This is a novel mechanism that underlies the difference between

Floristic composition and spatial distribution of vascular epiphytes in the restingas of Maracanã, Brazil

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Adriano Costa Quaresma

2014-03-01

Full Text Available Vascular epiphytes constitute a life form that is important to maintaining the biological diversity of forest ecosystems, because they provide food resources and specialized microenvironments for fauna in the forest canopy. This study aimed to describe the floristic composition and ecological aspects of vascular epiphytes occurring in the restingas (coastal woodlands within the Algodoal-Maiandeua Environmentally Protected Area, located in the municipality of Maracanã, in the state of Pará, Brazil. We sampled five 50 × 50 m plots (three in dry restinga forest and two in floodplain restinga forest, the sampled area therefore totaling 1.25 ha. In the plots sampled, vascular epiphytes were identified and described according to their frequency, abundance, importance value (IV, functional group and vertical distribution (trunk, lower crown or upper crown of the host. For both forest types, we identified 477 individuals belonging to five families, nine genera and 11 species. The most species-rich families were Araceae and Orchidaceae. The species with the highest density, frequency and IV were the secondary hemiepiphytes Philodendron acutatum, Anthurium pentaphyllum and Philodendron muricatum, collectively accounting for 92.1% of all sampled individuals. The true epiphytes predominated. Epiphytic species richness and abundance was greater on the host trunk than in the lower or upper crown. The seasonal climate and structure of the forest favored greater abundance of secondary hemiepiphytes and a higher frequency of epiphytes on the trunks of their hosts.

Future changes in South American biomass distributions, biome distributions and plant trait spectra is dependent on applied atmospheric forcings.

Science.gov (United States)

Langan, Liam; Scheiter, Simon; Higgins, Steven

2017-04-01

It remains poorly understood why the position of the forest-savanna biome boundary, in a domain defined by precipitation and temperature, differs in South America, Africa and Australia. Process based Dynamic Global Vegetation Models (DGVMs) are a valuable tool to investigate the determinants of vegetation distributions, however, many DGVMs fail to predict the spatial distribution or indeed presence of the South American savanna biome. Evidence suggests fire plays a significant role in mediating forest-savanna biome boundaries, however, fire alone appear to be insufficient to predict these boundaries in South America. We hypothesize that interactions between precipitation, constraints on tree rooting depth and fire, affect the probability of savanna occurrence and the position of the savanna-forest boundary. We tested our hypotheses at tropical forest and savanna sites in Brazil and Venezuela using a novel DGVM, aDGVM2, which allows plant trait spectra, constrained by trade-offs between traits, to evolve in response to abiotic and biotic conditions. Plant hydraulics is represented by the cohesion-tension theory, this allowed us to explore how soil and plant hydraulics control biome distributions and plant traits. The resulting community trait distributions are emergent properties of model dynamics. We showed that across much of South America the biome state is not determined by climate alone. Interactions between tree rooting depth, fire and precipitation affected the probability of observing a given biome state and the emergent traits of plant communities. Simulations where plant rooting depth varied in space provided the best match to satellite derived biomass estimates and generated biome distributions that reproduced contemporary biome maps well. Future projections showed that biomass distributions, biome distributions and plant trait spectra will change, however, the magnitude of these changes are highly dependent on the applied atmospheric forcings.

Determination of microelement distribution in different components of soil-plant system

International Nuclear Information System (INIS)

Luu Viet Hung; Maslov, O.D.; Gustova, M.V.; Trinh Thi Thu My; Phung Khac Nam Ho

2011-01-01

Leaves, stem, and roots of two shrub types: tea (Camellia sinensis), sweet leaf (Sauropus androgynus) and two herb types: vetiver grass (Vetiveria zizanioides L.Nash), maize (Zea mays L) and Thucuc soil where the plants grow, were collected to be studied. Contents of 22 elements in the samples were determined by three methods: XRFA (X-Ray Fluorescence Analysis), GAA (Gamma Activation Analysis), and tracking method to study distribution of these elements in plants and soil-plant relationship. The study was carried out at the Flerov Laboratory of Nuclear Reactions, JINR, Dubna. Distribution of the elements in the soil-plant system was studied

Estrogen, vascular estrogen receptor and hormone therapy in postmenopausal vascular disease.

Science.gov (United States)

Khalil, Raouf A

2013-12-15

Cardiovascular disease (CVD) is less common in premenopausal women than men of the same age or postmenopausal women, suggesting vascular benefits of estrogen. Estrogen activates estrogen receptors ERα, ERβ and GPR30 in endothelium and vascular smooth muscle (VSM), which trigger downstream signaling pathways and lead to genomic and non-genomic vascular effects such as vasodilation, decreased VSM contraction and growth and reduced vascular remodeling. However, randomized clinical trials (RCTs), such as the Women's Health Initiative (WHI) and Heart and Estrogen/progestin Replacement Study (HERS), have shown little vascular benefits and even adverse events with menopausal hormone therapy (MHT), likely due to factors related to the MHT used, ER profile, and RCT design. Some MHT forms, dose, combinations or route of administration may have inadequate vascular effects. Age-related changes in ER amount, distribution, integrity and post-ER signaling could alter the vascular response to MHT. The subject's age, preexisting CVD, and hormone environment could also reduce the effects of MHT. Further evaluation of natural and synthetic estrogens, phytoestrogens, and selective estrogen-receptor modulators (SERMs), and the design of appropriate MHT combinations, dose, route and 'timing' could improve the effectiveness of conventional MHT and provide alternative therapies in the peri-menopausal period. Targeting ER using specific ER agonists, localized MHT delivery, and activation of specific post-ER signaling pathways could counter age-related changes in ER. Examination of the hormone environment and conditions associated with hormone imbalance such as polycystic ovary syndrome may reveal the causes of abnormal hormone-receptor interactions. Consideration of these factors in new RCTs such as the Kronos Early Estrogen Prevention Study (KEEPS) could enhance the vascular benefits of estrogen in postmenopausal CVD. Copyright © 2013 Elsevier Inc. All rights reserved.

Unravelling aspects of spatial and temporal distribution of Verticillium dahliae in olive, maple and ash trees and improvement of detection methods

NARCIS (Netherlands)

Keykhasaber, Mojtaba

2017-01-01

Vascular wilts caused by xylem-colonizing pathogens are among the most devastating plant diseases that affect a wide range of plant species worldwide. Information on the distribution of V. dahliae in infected trees helps to design an appropriate and efficient sampling method for reliable

Vascular Plant and Vertebrate Inventory of Montezuma Castle National Monument

Science.gov (United States)

Schmidt, Cecilia A.; Drost, Charles A.; Halvorson, William Lee

2006-01-01

Executive Summary We summarize past inventory efforts for vascular plants and vertebrates at Montezuma Castle National Monument (NM) in Arizona. We used data from previous research to compile complete species lists for the monument and to assess inventory completeness. There have been 784 species recorded at Montezuma Castle NM, of which 85 (11%) are non-native. In each taxon-specific chapter we highlight areas of resources that contributed to species richness or unique species for the monument. Of particular importance are Montezuma Well and Beaver and Wet Beaver creeks and the surrounding riparian vegetation, which are responsible for the monument having one of the highest numbers of bird species in the Sonoran Desert Network of park units. Beaver Creek is also home to populations of federally-listed fish species of concern. Other important resources include the cliffs along the creeks and around Montezuma Well (for cliff and cave roosting bats). Based on the review of past studies, we believe the inventory for most taxa is nearly complete, though some rare or elusive species will be added with additional survey effort. We recommend additional inventory, monitoring and research studies.

Mapping local and global variability in plant trait distributions

Energy Technology Data Exchange (ETDEWEB)

Butler, Ethan E.; Datta, Abhirup; Flores-Moreno, Habacuc; Chen, Ming; Wythers, Kirk R.; Fazayeli, Farideh; Banerjee, Arindam; Atkin, Owen K.; Kattge, Jens; Amiaud, Bernard; Blonder, Benjamin; Boenisch, Gerhard; Bond-Lamberty, Ben; Brown, Kerry A.; Byun, Chaeho; Campetella, Giandiego; Cerabolini, Bruno E. L.; Cornelissen, Johannes H. C.; Craine, Joseph M.; Craven, Dylan; de Vries, Franciska T.; Díaz, Sandra; Domingues, Tomas F.; Forey, Estelle; González-Melo, Andrés; Gross, Nicolas; Han, Wenxuan; Hattingh, Wesley N.; Hickler, Thomas; Jansen, Steven; Kramer, Koen; Kraft, Nathan J. B.; Kurokawa, Hiroko; Laughlin, Daniel C.; Meir, Patrick; Minden, Vanessa; Niinemets, Ülo; Onoda, Yusuke; Peñuelas, Josep; Read, Quentin; Sack, Lawren; Schamp, Brandon; Soudzilovskaia, Nadejda A.; Spasojevic, Marko J.; Sosinski, Enio; Thornton, Peter E.; Valladares, Fernando; van Bodegom, Peter M.; Williams, Mathew; Wirth, Christian; Reich, Peter B.

2017-12-01

Accurate trait-environment relationships and global maps of plant trait distributions represent a needed stepping stone in global biogeography and are critical constraints of key parameters for land models. Here, we use a global data set of plant traits to map trait distributions closely coupled to photosynthesis and foliar respiration: specific leaf area (SLA), and dry mass-based concentrations of leaf nitrogen (Nm) and phosphorus (Pm); We propose two models to extrapolate geographically sparse point data to continuous spatial surfaces. The first is a categorical model using species mean trait values, categorized into plant functional types (PFTs) and extrapolating to PFT occurrence ranges identified by remote sensing. The second is a Bayesian spatial model that incorporates information about PFT, location and environmental covariates to estimate trait distributions. Both models are further stratified by varying the number of PFTs; The performance of the models was evaluated based on their explanatory and predictive ability. The Bayesian spatial model leveraging the largest number of PFTs produced the best maps; The interpolation of full trait distributions enables a wider diversity of vegetation to be represented across the land surface. These maps may be used as input to Earth System Models and to evaluate other estimates of functional diversity.

Costs of Residential Solar PV Plants in Distribution Grid Networks

DEFF Research Database (Denmark)

Kjær, Søren Bækhøj; Yang, Guangya; Ipsen, Hans Henrik

2015-01-01

In this article we investigate the impact of residential solar PV plants on energy losses in distribution networks and their impact on distribution transformers lifetime. Current guidelines in Denmark states that distribution transformers should not be loaded with more than 67% solar PV power...

DNA Barcoding the Canadian Arctic Flora: Core Plastid Barcodes (rbcL + matK) for 490 Vascular Plant Species

Science.gov (United States)

Saarela, Jeffery M.; Sokoloff, Paul C.; Gillespie, Lynn J.; Consaul, Laurie L.; Bull, Roger D.

2013-01-01

Accurate identification of Arctic plant species is critical for understanding potential climate-induced changes in their diversity and distributions. To facilitate rapid identification we generated DNA barcodes for the core plastid barcode loci (rbcL and matK) for 490 vascular plant species, representing nearly half of the Canadian Arctic flora and 93% of the flora of the Canadian Arctic Archipelago. Sequence recovery was higher for rbcL than matK (93% and 81%), and rbcL was easier to recover than matK from herbarium specimens (92% and 77%). Distance-based and sequence-similarity analyses of combined rbcL + matK data discriminate 97% of genera, 56% of species, and 7% of infraspecific taxa. There is a significant negative correlation between the number of species sampled per genus and the percent species resolution per genus. We characterize barcode variation in detail in the ten largest genera sampled (Carex, Draba, Festuca, Pedicularis, Poa, Potentilla, Puccinellia, Ranunculus, Salix, and Saxifraga) in the context of their phylogenetic relationships and taxonomy. Discrimination with the core barcode loci in these genera ranges from 0% in Salix to 85% in Carex. Haplotype variation in multiple genera does not correspond to species boundaries, including Taraxacum, in which the distribution of plastid haplotypes among Arctic species is consistent with plastid variation documented in non-Arctic species. Introgression of Poa glauca plastid DNA into multiple individuals of P. hartzii is problematic for identification of these species with DNA barcodes. Of three supplementary barcode loci (psbA–trnH, psbK–psbI, atpF–atpH) collected for a subset of Poa and Puccinellia species, only atpF–atpH improved discrimination in Puccinellia, compared with rbcL and matK. Variation in matK in Vaccinium uliginosum and rbcL in Saxifraga oppositifolia corresponds to variation in other loci used to characterize the phylogeographic histories of these Arctic-alpine species. PMID

Diversity and above-ground biomass patterns of vascular flora induced by flooding in the drawdown area of China's Three Gorges Reservoir.

Directory of Open Access Journals (Sweden)

Qiang Wang

Full Text Available Hydrological alternation can dramatically influence riparian environments and shape riparian vegetation zonation. However, it was difficult to predict the status in the drawdown area of the Three Gorges Reservoir (TGR, because the hydrological regime created by the dam involves both short periods of summer flooding and long-term winter impoundment for half a year. In order to examine the effects of hydrological alternation on plant diversity and biomass in the drawdown area of TGR, twelve sites distributed along the length of the drawdown area of TGR were chosen to explore the lateral pattern of plant diversity and above-ground biomass at the ends of growing seasons in 2009 and 2010. We recorded 175 vascular plant species in 2009 and 127 in 2010, indicating that a significant loss of vascular flora in the drawdown area of TGR resulted from the new hydrological regimes. Cynodon dactylon and Cyperus rotundus had high tolerance to short periods of summer flooding and long-term winter flooding. Almost half of the remnant species were annuals. Species richness, Shannon-Wiener Index and above-ground biomass of vegetation exhibited an increasing pattern along the elevation gradient, being greater at higher elevations subjected to lower submergence stress. Plant diversity, above-ground biomass and species distribution were significantly influenced by the duration of submergence relative to elevation in both summer and previous winter. Several million tonnes of vegetation would be accumulated on the drawdown area of TGR in every summer and some adverse environmental problems may be introduced when it was submerged in winter. We conclude that vascular flora biodiversity in the drawdown area of TGR has dramatically declined after the impoundment to full capacity. The new hydrological condition, characterized by long-term winter flooding and short periods of summer flooding, determined vegetation biodiversity and above-ground biomass patterns along the

Non-native species in the vascular flora of highlands and mountains of Iceland

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Pawel Wasowicz

2016-01-01

Full Text Available The highlands and mountains of Iceland are one of the largest remaining wilderness areas in Europe. This study aimed to provide comprehensive and up-to-date data on non-native plant species in these areas and to answer the following questions: (1 How many non-native vascular plant species inhabit highland and mountainous environments in Iceland? (2 Do temporal trends in the immigration of alien species to Iceland differ between highland and lowland areas? (3 Does the incidence of alien species in the disturbed and undisturbed areas within Icelandic highlands differ? (4 Does the spread of non-native species in Iceland proceed from lowlands to highlands? and (5 Can we detect hot-spots in the distribution of non-native taxa within the highlands? Overall, 16 non-native vascular plant species were detected, including 11 casuals and 5 naturalized taxa (1 invasive. Results showed that temporal trends in alien species immigration to highland and lowland areas are similar, but it is clear that the process of colonization of highland areas is still in its initial phase. Non-native plants tended to occur close to man-made infrastructure and buildings including huts, shelters, roads etc. Analysis of spatio-temporal patterns showed that the spread within highland areas is a second step in non-native plant colonization in Iceland. Several statically significant hot spots of alien plant occurrences were identified using the Getis-Ord Gi* statistic and these were linked to human disturbance. This research suggests that human-mediated dispersal is the main driving force increasing the risk of invasion in Iceland’s highlands and mountain areas.

Application of the Red List Index for conservation assessment of Spanish vascular plants.

Science.gov (United States)

Saiz, Juan Carlos Moreno; Lozano, Felipe Domínguez; Gómez, Manuel Marrero; Baudet, Ángel Bañares

2015-06-01

The International Union for Conservation of Nature (IUCN) Red List Index (RLI) is used to measure trends in extinction risk of species over time. The development of 2 red lists for Spanish vascular flora during the past decade allowed us to apply the IUCN RLI to vascular plants in an area belonging to a global biodiversity hotspot. We used the Spanish Red Lists from 2000 and 2010 to assess changes in level of threat at a national scale and at the subnational scales of Canary Islands, Balearic Islands, and peninsular Spain. We assigned retrospective IUCN categories of threat to 98 species included in the Spanish Red List of 2010 but absent in the Spanish Red List of 2000. In addition, we tested the effect of different random and taxonomic and spatial Spanish samples on the overall RLI value. From 2000 to 2010, the IUCN categories of 768 species changed (10% of Spanish flora), mainly due to improved knowledge (63%), modifications in IUCN criteria (14%), and changes in threat status (12%). All measured national and subnational RLI values decreased during this period, indicating a general decline in the conservation status of the Spanish vascular flora. The Canarian RLI value (0.84) was the lowest, although the fastest deterioration in conservation status occurred on peninsular Spain (from 0.93 in 2000 to 0.92 in 2010). The RLI values based on subsamples of the Spanish Red List were not representative of RLI values for the entire country, which would discourage the use of small areas or small taxonomic samples to assess general trends in the endangerment of national biotas. The role of the RLI in monitoring of changes in biodiversity at the global and regional scales needs further reassessment because additional areas and taxa are necessary to determine whether the index is sufficiently sensitive for use in assessing temporal changes in species' risk of extinction. © 2015 Society for Conservation Biology.

Intelligent distributed control for nuclear power plants

International Nuclear Information System (INIS)

Klevans, E.H.

1991-01-01

In September of 1989 work began on the DOE University Program grant DE-FG07-89ER12889. The grant provides support for a three year project to develop and demonstrate Intelligent Distributed Control (IDC) for Nuclear Power Plants. The body of this First Annual Technical Progress report summarizes the first year tasks while the appendices provide detailed information presented at conference meetings. One major addendum report, authored by M.A. Schultz, describes the ultimate goals and projected structure of an automatic distributed control system for EBR-2. The remaining tasks of the project develop specific implementations of various components required to demonstrate the intelligent distributed control concept

SIFlore, a dataset of geographical distribution of vascular plants covering five centuries of knowledge in France: Results of a collaborative project coordinated by the Federation of the National Botanical Conservatories.

Science.gov (United States)

Just, Anaïs; Gourvil, Johan; Millet, Jérôme; Boullet, Vincent; Milon, Thomas; Mandon, Isabelle; Dutrève, Bruno

2015-01-01

More than 20 years ago, the French Muséum National d'Histoire Naturelle (MNHN, Secretariat of the Fauna and Flora) published the first part of an atlas of the flora of France at a 20km spatial resolution, accounting for 645 taxa (Dupont 1990). Since then, at the national level, there has not been any work on this scale relating to flora distribution, despite the obvious need for a better understanding. In 2011, in response to this need, the Federation des Conservatoires Botaniques Nationaux (FCBN, http://www.fcbn.fr) launched an ambitious collaborative project involving eleven national botanical conservatories of France. The project aims to establish a formal procedure and standardized system for data hosting, aggregation and publication for four areas: flora, fungi, vegetation and habitats. In 2014, the first phase of the project led to the development of the national flora dataset: SIFlore. As it includes about 21 million records of flora occurrences, this is currently the most comprehensive dataset on the distribution of vascular plants (Tracheophyta) in the French territory. SIFlore contains information for about 15'454 plant taxa occurrences (indigenous and alien taxa) in metropolitan France and Reunion Island, from 1545 until 2014. The data records were originally collated from inventories, checklists, literature and herbarium records. SIFlore was developed by assembling flora datasets from the regional to the national level. At the regional level, source records are managed by the national botanical conservatories that are responsible for flora data collection and validation. In order to present our results, a geoportal was developed by the Fédération des conservatoires botaniques nationaux that allows the SIFlore dataset to be publically viewed. This portal is available at: http://siflore.fcbn.fr. As the FCBN belongs to the Information System for Nature and Landscapes' (SINP), a governmental program, the dataset is also accessible through the websites of

ERTS-1 imagery and native plant distributions

Science.gov (United States)

Musick, H. B.; Mcginnies, W.; Haase, E.; Lepley, L. K.

1974-01-01

A method is developed for using ERTS spectral signature data to determine plant community distribution and phenology without resolving individual plants. An Exotech ERTS radiometer was used near ground level to obtain spectral signatures for a desert plant community, including two shrub species, ground covered with live annuals in April and dead ones in June, and bare ground. It is shown that comparisons of scene types can be made when spectral signatures are expressed as a ratio of red reflectivity to IR reflectivity or when they are plotted as red reflectivity vs. IR reflectivity, in which case the signature clusters of each component are more distinct. A method for correcting and converting the ERTS radiance values to reflectivity values for comparison with ground truth data is appended.

A role of TDIF peptide signaling in vascular cell differentiation is conserved among euphyllophytes

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Yuki eHirakawa

2015-11-01

Full Text Available Peptide signals mediate a variety of cell-to-cell communication crucial for plant growth and development. During Arabidopsis thaliana vascular development, a CLE (CLAVATA3/EMBRYO SURROUNDING REGION-related family peptide hormone, TDIF (tracheary element differentiation inhibitory factor, regulates procambial cell fate by its inhibitory activity on xylem differentiation. To address if this activity is conserved among vascular plants, we performed comparative analyses of TDIF signaling in non-flowering vascular plants (gymnosperms, monilophytes and lycophytes. We identified orthologs of TDIF/CLE as well as its receptor TDR/PXY (TDIF RECEPTOR/PHLOEM INTERCALATED WITH XYLEM in Ginkgo biloba, Adiantum aethiopicum and Selaginella kraussiana by RACE-PCR. The predicted TDIF peptide sequences in seed plants and monilophytes were identical to that of A. thaliana TDIF. We examined the effects of exogenous CLE peptide-motif sequences of TDIF in these species. We found that liquid culturing of dissected leaves or shoots was useful for examining TDIF activity during vascular development. TDIF treatment suppressed xylem/tracheary element differentiation of procambial cells in G. bioloba and A. aethiopicum leaves. In contrast, neither TDIF nor putative endogenous TDIF inhibited xylem differentiation in developing shoots and rhizophores of S. kraussiana. These data suggest that activity of TDIF in vascular development is conserved among extant euphyllophytes. In addition to the conserved function, via liquid culturing of its bulbils, we found a novel inhibitory activity on root growth in the monilophyte Asplenium x lucrosum suggesting lineage-specific co-option of peptide signaling occurred during the evolution of vascular plant organs.

Mapping multi-scale vascular plant richness in a forest landscape with integrated LiDAR and hyperspectral remote-sensing.

Science.gov (United States)

Hakkenberg, C R; Zhu, K; Peet, R K; Song, C

2018-02-01

The central role of floristic diversity in maintaining habitat integrity and ecosystem function has propelled efforts to map and monitor its distribution across forest landscapes. While biodiversity studies have traditionally relied largely on ground-based observations, the immensity of the task of generating accurate, repeatable, and spatially-continuous data on biodiversity patterns at large scales has stimulated the development of remote-sensing methods for scaling up from field plot measurements. One such approach is through integrated LiDAR and hyperspectral remote-sensing. However, despite their efficiencies in cost and effort, LiDAR-hyperspectral sensors are still highly constrained in structurally- and taxonomically-heterogeneous forests - especially when species' cover is smaller than the image resolution, intertwined with neighboring taxa, or otherwise obscured by overlapping canopy strata. In light of these challenges, this study goes beyond the remote characterization of upper canopy diversity to instead model total vascular plant species richness in a continuous-cover North Carolina Piedmont forest landscape. We focus on two related, but parallel, tasks. First, we demonstrate an application of predictive biodiversity mapping, using nonparametric models trained with spatially-nested field plots and aerial LiDAR-hyperspectral data, to predict spatially-explicit landscape patterns in floristic diversity across seven spatial scales between 0.01-900 m 2 . Second, we employ bivariate parametric models to test the significance of individual, remotely-sensed predictors of plant richness to determine how parameter estimates vary with scale. Cross-validated results indicate that predictive models were able to account for 15-70% of variance in plant richness, with LiDAR-derived estimates of topography and forest structural complexity, as well as spectral variance in hyperspectral imagery explaining the largest portion of variance in diversity levels. Importantly

Color Doppler Ultrasonographic Findings of Vascular Leiomyoma: Pathologic Correlation

Energy Technology Data Exchange (ETDEWEB)

Ko, Ji Young; Koh, Sung Hye; Min, Soo Kee; Choi, A Lam; Jang, Kyung Mi; Lee, Yul; Lee, Kwan Seop; Lee, Hyun; Sohn, Jeong Hee [Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Kim, Sam Soo [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

2009-12-15

To evaluate the distribution of color flow signals on color Doppler ultrasonography of vascular leiomyomas and to correlate them with pathologic findings. We retrospectively analyzed color Doppler ultrasonographic images and pathologic slides of six vascular leiomyomas. We classified the patterns of distribution of color flow signals into localized compact cluster types and non-cluster types, and the pathologic findings into three subtypes: solid, venous and cavernous. All cases showed well-defined homogenous hypoechoic subcutaneous masses on gray-scale ultrasonography. Three cases showed localized compact cluster types on color Doppler ultrasonography, one in each subtype (solid, venous and cavernous). For the three non-cluster types, again there was on in each subtype. In addition, on pathologic analysis the zone of the localized compact cluster of color flow signals coincided with a cluster of larger, vascular caliber masses. Localized compact clusters of color flow signals on color Doppler ultrasonography were seen in 50% of our cases and correlated with a cluster of larger vascular caliber in the mass. But the pattern of distribution of color flows didn't show a correlation with pathologic type

Color Doppler Ultrasonographic Findings of Vascular Leiomyoma: Pathologic Correlation

International Nuclear Information System (INIS)

Ko, Ji Young; Koh, Sung Hye; Min, Soo Kee; Choi, A Lam; Jang, Kyung Mi; Lee, Yul; Lee, Kwan Seop; Lee, Hyun; Sohn, Jeong Hee; Kim, Sam Soo

2009-01-01

To evaluate the distribution of color flow signals on color Doppler ultrasonography of vascular leiomyomas and to correlate them with pathologic findings. We retrospectively analyzed color Doppler ultrasonographic images and pathologic slides of six vascular leiomyomas. We classified the patterns of distribution of color flow signals into localized compact cluster types and non-cluster types, and the pathologic findings into three subtypes: solid, venous and cavernous. All cases showed well-defined homogenous hypoechoic subcutaneous masses on gray-scale ultrasonography. Three cases showed localized compact cluster types on color Doppler ultrasonography, one in each subtype (solid, venous and cavernous). For the three non-cluster types, again there was on in each subtype. In addition, on pathologic analysis the zone of the localized compact cluster of color flow signals coincided with a cluster of larger, vascular caliber masses. Localized compact clusters of color flow signals on color Doppler ultrasonography were seen in 50% of our cases and correlated with a cluster of larger vascular caliber in the mass. But the pattern of distribution of color flows didn't show a correlation with pathologic type

Distribution of uranium series radionuclides in upland vegetation of northern Saskatchewan

International Nuclear Information System (INIS)

Sheard, J.W.

1986-01-01

Multivariate methods are used to explore patterns of accumulation of radionuclides and stable elements among 10 plant species at four localities in northern Saskatchewan. Principal components analysis and canonical correlation analysis of the radionuclides and stable elements showed that lead-210 and polonium-210 are correlated with crustal elements distributed in the atmoshpere and therefore are accumulated more abundantly by lichen and moss species than by vascular plants. Uranium showed a similar trend. Neither these radionuclides nor radium-226 showed strong correlations with other stable elements. The highest accumulation of uranium was in the Wollaston Lake region, especially for the nonvascular plants, where the soil levels are lowest. This tends to substantiate previous suggestions that uranium available for uptake by vascular plants is associated with groundwater rather than soil particles. Canonical variates analysis on radionuclide levels in vegetation by species group shows that trees, shrubs, lichens, and moss all have significantly different patterns of accumulation. The vascular and nonvascular groups are separated primarily by lead-210 and polonium- 210 accumulation. The trees and shrubs are separated by radium-226 levels. A similar analysis by locality showed significant differences in radionuclide accumulation by vegetation in all possible pairs of localities, except between the two Wollaston Lake localities. The largest distances were between regions and were based primarily on uranium accumulation in the nonvascular plants. Differences in radium-226 levels among the shrub species are responsible for the significant difference between the two localities in the Churchill River region

Potential Responses of Vascular Plants from the Pristine "Lost World" of the Neotropical Guayana Highlands to Global Warming: Review and New Perspectives.

Science.gov (United States)

Rull, Valentí; Vegas-Vilarrúbia, Teresa

2017-01-01

The neotropical Guayana Highlands (GH) are one of the few remaining pristine environments on Earth, and they host amazing biodiversity with a high degree endemism, especially among vascular plants. Despite the lack of direct human disturbance, GH plants and their communities are threatened with extinction from habitat loss due to global warming (GW). Geographic information systems simulations involving the entire known vascular GH flora (>2430 species) predict potential GW-driven extinctions on the order of 80% by the end of this century, including nearly half of the endemic species. These estimates and the assessment of an environmental impact value for each species led to the hierarchization of plants by their risk of habitat loss and the definition of priority conservation categories. However, the predictions assume that all species will respond to GW by migrating upward and at equal rates, which is unlikely, so current estimates should be considered preliminary and incomplete (although they represent the best that can be done with the existing information). Other potential environmental forcings (i.e., precipitation shifts, an increase in the atmospheric CO 2 concentration) and idiosyncratic plant responses (i.e., resistance, phenotypic acclimation, rapid evolution) should also be considered, so detailed eco-physiological studies of the more threatened species are urgently needed. The main obstacles to developing such studies are the remoteness and inaccessibility of the GH and, especially, the difficulty in obtaining official permits for fieldwork.

Integration of distributed plant process computer systems to nuclear power generation facilities

International Nuclear Information System (INIS)

Bogard, T.; Finlay, K.

1996-01-01

Many operating nuclear power generation facilities are replacing their plant process computer. Such replacement projects are driven by equipment obsolescence issues and associated objectives to improve plant operability, increase plant information access, improve man machine interface characteristics, and reduce operation and maintenance costs. This paper describes a few recently completed and on-going replacement projects with emphasis upon the application integrated distributed plant process computer systems. By presenting a few recent projects, the variations of distributed systems design show how various configurations can address needs for flexibility, open architecture, and integration of technological advancements in instrumentation and control technology. Architectural considerations for optimal integration of the plant process computer and plant process instrumentation ampersand control are evident from variations of design features

The fate of arsenic, cadmium and lead in Typha latifolia: A case study on the applicability of micro-PIXE in plant ionomics

International Nuclear Information System (INIS)

Lyubenova, Lyudmila; Pongrac, Paula; Vogel-Mikuš, Katarina; Mezek, Gašper Kukec; Vavpetič, Primož; Grlj, Nataša; Regvar, Marjana; Pelicon, Primož; Schröder, Peter

2013-01-01

Highlights: ► Uptake, accumulation and distribution of multi-elemental pollution. ► Quantitative analysis of the spatal distribution of nutrients in roots and rhizomes. ► Typha latifolia – plant species important for phytoremediation of hazardous xenobiotics. ► Low amounts of Cd and Pb in the inner tissues of roots and rhizomes. ► Predominantly As was found within the vascular tissue – high mobility of the element. -- Abstract: Understanding the uptake, accumulation and distribution of toxic elements in plants is crucial to the design of effective phytoremediation strategies, especially in the case of complex multi-element pollution. Using micro-proton induced X-ray emission, the spatial distribution of Na, Mg, Al, Si, P, S, Cl, K, Ca, Mn, Fe, Zn, As, Br, Rb, Sr, Cd and Pb have been quantitatively resolved in roots and rhizomes of an obligate wetland plant species, Typha latifolia, treated with a mixture of 100 μM each of As, Cd and Pb, together. The highest concentrations of As, Cd and Pb were found in the roots of the T. latifolia, with tissue-specific distributions. The As was detected in the root rhizodermis, and in the rhizome the majority of the As was within the vascular tissues, which indicates the high mobility of As within T. latifolia. The Cd was detected in the root exodermis, and in the vascular bundle and epidermis of the rhizome. The highest Pb concentrations were detected in the root rhizodermis and exodermis, and in the epidermis of the rhizome. These data represent an essential step in the resolution of fundamental questions in plant ionomics

The fate of arsenic, cadmium and lead in Typha latifolia: A case study on the applicability of micro-PIXE in plant ionomics

Energy Technology Data Exchange (ETDEWEB)

Lyubenova, Lyudmila [Helmholtz Zentrum München, German Research Centre for Environmental Health, Department of Environmental Sciences, Research Unit Microbe–Plant Interactions, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Pongrac, Paula; Vogel-Mikuš, Katarina [University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, SI-1000 Ljubljana (Slovenia); Mezek, Gašper Kukec; Vavpetič, Primož; Grlj, Nataša [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Regvar, Marjana [University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, SI-1000 Ljubljana (Slovenia); Pelicon, Primož [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Schröder, Peter, E-mail: peter.schroeder@helmholtz-muenchen.de [Helmholtz Zentrum München, German Research Centre for Environmental Health, Department of Environmental Sciences, Research Unit Microbe–Plant Interactions, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany)

2013-03-15

Highlights: ► Uptake, accumulation and distribution of multi-elemental pollution. ► Quantitative analysis of the spatal distribution of nutrients in roots and rhizomes. ► Typha latifolia – plant species important for phytoremediation of hazardous xenobiotics. ► Low amounts of Cd and Pb in the inner tissues of roots and rhizomes. ► Predominantly As was found within the vascular tissue – high mobility of the element. -- Abstract: Understanding the uptake, accumulation and distribution of toxic elements in plants is crucial to the design of effective phytoremediation strategies, especially in the case of complex multi-element pollution. Using micro-proton induced X-ray emission, the spatial distribution of Na, Mg, Al, Si, P, S, Cl, K, Ca, Mn, Fe, Zn, As, Br, Rb, Sr, Cd and Pb have been quantitatively resolved in roots and rhizomes of an obligate wetland plant species, Typha latifolia, treated with a mixture of 100 μM each of As, Cd and Pb, together. The highest concentrations of As, Cd and Pb were found in the roots of the T. latifolia, with tissue-specific distributions. The As was detected in the root rhizodermis, and in the rhizome the majority of the As was within the vascular tissues, which indicates the high mobility of As within T. latifolia. The Cd was detected in the root exodermis, and in the vascular bundle and epidermis of the rhizome. The highest Pb concentrations were detected in the root rhizodermis and exodermis, and in the epidermis of the rhizome. These data represent an essential step in the resolution of fundamental questions in plant ionomics.

Distributed continuous energy scheduling for dynamic virtual power plants

International Nuclear Information System (INIS)

Niesse, Astrid

2015-01-01

This thesis presents DynaSCOPE as distributed control method for continuous energy scheduling for dynamic virtual power plants (DVPP). DVPPs aggregate the flexibility of distributed energy units to address current energy markets. As an extension of the Virtual Power Plant concept they show high dynamics in aggregation and operation of energy units. Whereas operation schedules are set up for all energy units in a day-ahead planning procedure, incidents may render these schedules infeasible during execution, like deviation from prognoses or outages. Thus, a continuous scheduling process is needed to ensure product fulfillment. With DynaSCOPE, software agents representing single energy units solve this problem in a completely distributed heuristic approach. Using a stepped concept, several damping mechanisms are applied to allow minimum disturbance while continuously trying to fulfill the product as contracted at the market.

Distribution of Cenozoic plant relicts in China explained by drought in dry season.

Science.gov (United States)

Huang, Yongjiang; Jacques, Frédéric M B; Su, Tao; Ferguson, David K; Tang, Hui; Chen, Wenyun; Zhou, Zhekun

2015-09-15

Cenozoic plant relicts are those groups that were once widespread in the Northern Hemisphere but are now restricted to some small isolated areas as a result of drastic climatic changes. They are good proxies to study how plants respond to climatic changes since their modern climatic requirements are known. Herein we look at the modern distribution of 65 palaeoendemic genera in China and compare it with the Chinese climatic pattern, in order to find a link between the plant distribution and climate. Central China and Taiwan Island are shown to be diversity centres of Cenozoic relict genera, consistent with the fact that these two regions have a shorter dry season with comparatively humid autumn and spring in China. Species distribution models indicate that the precipitation parameters are the most important variables to explain the distribution of relict genera. The Cenozoic wide-scale distribution of relict plants in the Northern Hemisphere is therefore considered to be linked to the widespread humid climate at that time, and the subsequent contraction of their distributional ranges was probably caused by the drying trend along with global cooling.

Vascular Plant and Vertebrate Inventory of Saguaro National Park, Tucson Mountain District

Science.gov (United States)

Powell, Brian F.; Halvorson, William L.; Schmidt, Cecilia A.

2007-01-01

This report summarizes the results of the first comprehensive inventory of plants and vertebrates at the Tucson Mountain District (TMD) of Saguaro National Park, Arizona. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at the district to document the presence of species within its boundaries. Park staff also carried out extensive infrared-triggered camera work for medium and large mammals from 2002-2005 and results from that effort are reported here. Our spatial sampling design for all taxa employed a combination of random and nonrandom survey sites. Survey effort was greatest for medium and large mammals and herpetofauna. Because we used repeatable study designs and standardized field methods, these inventories can serve as the first step in a biological monitoring program for the district. We also provide an overview of previous survey efforts in the district. We use data from our inventory and other surveys to compile species lists and to assess inventory completeness. The survey effort for herpetofauna, birds, and medium and large mammals was the most comprehensive ever undertaken in the district. We recorded a total of 320 plant and vertebrate species, including 21 species not previously found in the district (Table 1). Based on a review of our inventory and past research at the district, there have been a total of 723 species of plants and vertebrates found there. We believe inventories for most taxonomic groups are nearly complete. Based on our surveys, we believe the native plant and vertebrate community compositions of the district are relatively intact, though some species loss has occurred and threats are increasing, particularly to herpetofauna and larger mammals. Of particular note is the relatively small number of non-native species and their low abundance in the district, which is in contrast to many nearby natural areas. Rapidly expanding development on the west, north, and east sides of

Photosynthate partitioning and distribution in soybean plant

International Nuclear Information System (INIS)

Latche, J.; Cavalie, G.

1983-01-01

Plants were grown in a controlled environment chamber and fed with a modified Hoagland solution containing nitrate as nitrogen source (N+ medium). Soybeans, 33 days old (flowering stage), 45 and 56 days old (pods formation and filling stages) were used for experimentation. In each experiment, the eight trifoliated leaf (F 8 ) was exposed to 14 CO 2 (10 μCi; 400 vpm), in the light (80 W x m -2 ) for 30 min. After a 6 h chase period (22 - 25 0 C; 80 W x m -2 ), the radiocarbon distribution among plant parts was determined and labelled compounds were identified. (orig.)

Mosses in Ohio wetlands respond to indices of disturbance and vascular plant integrity

Science.gov (United States)

Stapanian, Martin A.; Schumacher, William; Gara, Brian; Viau, Nick

2016-01-01

We examined the relationships between an index of wetland habitat quality and disturbance (ORAM score) and an index of vascular plant integrity (VIBI-FQ score) with moss species richness and a moss quality assessment index (MQAI) in 45 wetlands in three vegetation types in Ohio, USA. Species richness of mosses and MQAI were positively associated with ORAM and VIBI-FQ scores. VIBI-FQ score was a better predictor of both moss species richness and MQAI than was either ORAM score or vegetation type. This result was consistent with the strict microhabitat requirements for many moss species, which may be better assessed by VIBI-FQ than ORAM. Probability curves as a function of VIBI-FQ score were then generated for presence of groups of moss species having the same degree of fidelity to substrate and plant communities relative to other species in the moss flora (coefficients of conservatism, CCs). Species having an intermediate- or high degree of fidelity to substrate and plant communities (i.e., species with CC ≥ 5) had a 50% probability of presence (P50) and 90% probability of presence (P90) in wetlands with intermediate- and high VIBI-FQ scores, respectively. Although moss species richness, probability of presence of species based on CC, and MQAI may reflect wetland habitat quality, the 95% confidence intervals around P50 and P90 values may be too wide for regulatory use. Moss species richness, MQAI, and presence of groups of mosses may be more useful for evaluating moss habitat quality in wetlands than a set of “indicator species.”

Relay Protection Coordination for Photovoltaic Power Plant Connected on Distribution Network

OpenAIRE

Nikolovski, Srete; Papuga, Vanja; Knežević, Goran

2014-01-01

This paper presents a procedure and computation of relay protection coordination for a PV power plant connected to the distribution network. In recent years, the growing concern for environment preservation has caused expansion of photovoltaic PV power plants in distribution networks. Numerical computer simulation is an indispensable tool for studying photovoltaic (PV) systems protection coordination. In this paper, EasyPower computer program is used with the module Power Protector. Time-curr...

Northward invading non-native vascular plant species in and adjacent to Wood Buffalo National Park

Energy Technology Data Exchange (ETDEWEB)

Wein, R.W.; Wein, G.; Bahret, S.; Cody, W.J. (Alberta University, Edmonton, AB (Canada). Canadian Circumpolar Institute)

A survey of the non-native vascular plant species in Wood Buffalo National Park, Canada's largest forested National Park, documented their presence and abundance in key locations. Most of the fifty-four species (nine new records) were found in disturbed sites including roadsides, settlements, farms, areas of altered hydrological regimes, recent bums, and intensive bison grazing. Species that have increased most in geographic area and abundance in recent years include [ital Agropyron repens], [ital Bromus inermis], [ital Chenopodium album], [ital Melilotus spp.], [ital Trifolium spp.], [ital Plantago major], [ital Achillea millefolium], [ital Crepis tectorum] and [ital Sonchus arvensis]. An additional 20 species, now common in the Peace River and Fort Vermilion areas, have the potential to invade the Park if plant communities are subjected to additional stress as northern climates are modified by the greenhouse effect and as other human-caused activities disturb the vegetation. It is recommended that permanent plots be located in key locations and monitored for species invasion and changing abundances as input to management plans.

Plant Distribution Data Show Broader Climatic Limits than Expert-Based Climatic Tolerance Estimates.

Directory of Open Access Journals (Sweden)

Caroline A Curtis

Full Text Available Although increasingly sophisticated environmental measures are being applied to species distributions models, the focus remains on using climatic data to provide estimates of habitat suitability. Climatic tolerance estimates based on expert knowledge are available for a wide range of plants via the USDA PLANTS database. We aim to test how climatic tolerance inferred from plant distribution records relates to tolerance estimated by experts. Further, we use this information to identify circumstances when species distributions are more likely to approximate climatic tolerance.We compiled expert knowledge estimates of minimum and maximum precipitation and minimum temperature tolerance for over 1800 conservation plant species from the 'plant characteristics' information in the USDA PLANTS database. We derived climatic tolerance from distribution data downloaded from the Global Biodiversity and Information Facility (GBIF and corresponding climate from WorldClim. We compared expert-derived climatic tolerance to empirical estimates to find the difference between their inferred climate niches (ΔCN, and tested whether ΔCN was influenced by growth form or range size.Climate niches calculated from distribution data were significantly broader than expert-based tolerance estimates (Mann-Whitney p values << 0.001. The average plant could tolerate 24 mm lower minimum precipitation, 14 mm higher maximum precipitation, and 7° C lower minimum temperatures based on distribution data relative to expert-based tolerance estimates. Species with larger ranges had greater ΔCN for minimum precipitation and minimum temperature. For maximum precipitation and minimum temperature, forbs and grasses tended to have larger ΔCN while grasses and trees had larger ΔCN for minimum precipitation.Our results show that distribution data are consistently broader than USDA PLANTS experts' knowledge and likely provide more robust estimates of climatic tolerance, especially for

Origin and Evolution of The Early- Silurian Land Vascular Plants: Evidence From Biomarkers

Science.gov (United States)

Jin, R.

2016-12-01

Origin and early evolution of land vascular plants, is one of the most intriguing hotspots in the life science research. During the 1970s and 1980s,Pinnatiramosus qianensis was found in early-Silurian strata in guizhou of south China.43 years have passed. But so far, the biological characteristics and belonging of the age of this unique plant have been debated again and again, up in the air.Biomarkers have a good stability in the process of organic evolution, no more or less changed, so they have a special `function of mark'. While biomarkers can provide information about organic matter of hydrocarbon source rock (the source), the period of deposition and burial (diagenesis) environmental conditions, and many other aspects of information.This paper obtained the sedimentary environment, source of organic matter input and other relevant information, through extracting and analyzing biomarkers of the 26 samples in the late Ordovician to early Silurian strata in NorthGuizhou areas. According to the results, Pr/Ph of late Ordovician Meitan Fm-early Silurian Hanjiadian Fm is high.It manifests more pristane, characterized by reductive environment. At the bottom of the Hanjiadian Fm, Pr/Ph has a volatility.Some huge environmental changes may have taken place in the corresponding period. N-alkanes do not have parity advantage or has even carbon advantage slightly.The peak carbon is mainly in low carbon number.(C21 + C22)/(C28 + C29) is high.Aquatic organisms is a major source of organic matter during this period,C21-/C22+ is low.This may be caused by the relatively serious loss of light hydrocarbon during the separation of components. In the Hanjiadian Fm,information of C29/C27 sterane ratios and oleanane index showed a trend of rising at the same time, indicating that during this period, there was a gradual increase input in the number of higher plants.The stable carbon isotope of saturated hydrocarbon and aromatic hydrocarbon in the Hanjiadian Fm also gradually become

Endangered plant species of the Nevada Test Site, Ash Meadows, and Central-Southern Nevada

International Nuclear Information System (INIS)

Beatley, J.C.

1977-02-01

A total of 15 vascular plant taxa, currently appearing on the Endangered Species list, occur in southern Nye County, Nevada, and/or adjacent Inyo County, California. It is the purpose of this report to record in detail the locations of the plant collections upon which the distributions are based, and other information relevant to their status as Endangered Species, and to recommend the areas to be designated critical habitats

Endangered plant species of the Nevada Test Site, Ash Meadows, and Central-Southern Nevada

Energy Technology Data Exchange (ETDEWEB)

Beatley, J.C.

1977-02-01

A total of 15 vascular plant taxa, currently appearing on the Endangered Species list, occur in southern Nye County, Nevada, and/or adjacent Inyo County, California. It is the purpose of this report to record in detail the locations of the plant collections upon which the distributions are based, and other information relevant to their status as Endangered Species, and to recommend the areas to be designated critical habitats.

Photosynthetic limitations in two Antarctic vascular plants: importance of leaf anatomical traits and Rubisco kinetic parameters.

Science.gov (United States)

Sáez, Patricia L; Bravo, León A; Cavieres, Lohengrin A; Vallejos, Valentina; Sanhueza, Carolina; Font-Carrascosa, Marcel; Gil-Pelegrín, Eustaquio; Javier Peguero-Pina, José; Galmés, Jeroni

2017-05-17

Particular physiological traits allow the vascular plants Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl. to inhabit Antarctica. The photosynthetic performance of these species was evaluated in situ, focusing on diffusive and biochemical constraints to CO2 assimilation. Leaf gas exchange, Chl a fluorescence, leaf ultrastructure, and Rubisco catalytic properties were examined in plants growing on King George and Lagotellerie islands. In spite of the species- and population-specific effects of the measurement temperature on the main photosynthetic parameters, CO2 assimilation was highly limited by CO2 diffusion. In particular, the mesophyll conductance (gm)-estimated from both gas exchange and leaf chlorophyll fluorescence and modeled from leaf anatomy-was remarkably low, restricting CO2 diffusion and imposing the strongest constraint to CO2 acquisition. Rubisco presented a high specificity for CO2 as determined in vitro, suggesting a tight co-ordination between CO2 diffusion and leaf biochemistry that may be critical ultimately to optimize carbon balance in these species. Interestingly, both anatomical and biochemical traits resembled those described in plants from arid environments, providing a new insight into plant functional acclimation to extreme conditions. Understanding what actually limits photosynthesis in these species is important to anticipate their responses to the ongoing and predicted rapid warming in the Antarctic Peninsula. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Northern peatland carbon biogeochemistry. The influence of vascular plants and edaphic factors on carbon dioxide and methane exchange

International Nuclear Information System (INIS)

Oequist, M.

2001-01-01

The findings reported in this thesis and in the accompanying papers are based on both laboratory and field investigations of carbon transformation dynamics on the process scale and at the resolution of individual peatland plant communities. The data from one of the studies also is extrapolated in an attempt to identify environmental controls on regional scales in order to predict the response of northern peatlands to climate warming. The laboratory experiments focus on how climate variations, inducing fluctuations in groundwater level and also soil freeze-thaw cycles, influences organic matter mineralisation to carbon dioxide and methane. The field studies investigate year-to-year variations and interdecadal differences in carbon gas exchange at a subarctic peatland, and also how the physiological activities of vascular plants control methane emission rates. The main conclusions presented include: Soil freeze-thaw events may be very important for the annual carbon balance in northern peatlands, because they have the potential to increase mineralisation rates and alter biogeochemical degradation pathways. Vascular plants exert a strong influence on methane flux dynamics during the growing season, both by mediating methane transport and through substrate-based interactions with the soil microbial community. However, there are important species-related factors that govern the nature and extent of this influence. Caution has to be taken when extrapolating field data to estimate regional carbon exchange because the relevance of the specific environmental parameters that control this exchange varies depending on resolution. On broad spatial and temporal scales the best predictor of peatland methane emissions is mean soil temperature, but also microbial substrate availability (expressed as the organic acid concentration in peat water) is of importance. This temperature sensitivity represents a strong potential feedback mechanism on climate change

[Relation between species distribution of plant community and soil factors under grazing in alpine meadow].

Science.gov (United States)

Niu, Yu Jie; Yang, Si Wei; Wang, Gui Zhen; Liu, Li; Du, Guo Zhen; Hua, Li Min

2017-12-01

The research selected the alpine meadow located in the northeastern margin of the Qinghai-Tibet Plateau to study the changes of vegetation community and soil properties under different grazing intensities, as well as the quantitative relation between the distribution patterns of plant species and the physical and chemical properties of soil. The results showed that the grazing caused the differentiation of the initial vegetation community with the dominant plants, Elymus nutans and Stipa grandis. In the plots with high and low grazing intensities, the dominant plants had changed to Kobresia humilis and Melissitus ruthenica, and E. nutans and Poa crymophila, respectively. With the increase of grazing intensity, the plant richness, importance value and biomass were significantly decreased. The sequence of plant species importance value in each plot against grazing intensity could be fitted by a logarithmic model. The number of required plant species was reduced while the importance value of the remaining plant species accounted for 50% of the importance value in the whole vegetation community. The available P, available K, soil compaction, soil water content, stable infiltration rate and large aggregate index were significantly changed with grazing intensity, however, the changes were different. The CCA ordination showed that the soil compaction was the key factor affecting the distribution pattern of the plant species under grazing. The variance decomposition indicated that the soil factors together explained 30.5% of the distribution of the plant species, in particular the soil physical properties alone explained 22.8% of the distribution of the plant species, which had the highest rate of contribution to the plant species distribution. The soil physical properties affected the distribution pattern of plant species on grazed alpine meadow.

Wild edible plant knowledge, distribution and transmission

DEFF Research Database (Denmark)

Turreira Garcia, Nerea; Theilade, Ida; Meilby, Henrik

2015-01-01

the distribution, transmission and loss of traditional ecological knowledge (TEK) concerning WEPs used by a Mayan community of Guatemala and to enumerate such plants. Methods: The case study was carried out in a semi-isolated community where part of the population took refuge in the mountains in 1982...... key informants. Information about the theoretical dimension of knowledge was gathered through free listing and a questionnaire survey, while practical skills were assessed using a plant identification test with photographs. All villagers older than 7 years participated in the research (n = 62......% of the cases, which led to increased knowledge of plants and ability to recognise them. Conclusions: The WEP survey may serve as a reference point and as a useful compilation of knowledge for the community for their current and future generations. This study shows that the elder and the refugees living...

Control of Vascular Streak Dieback Disease of Cocoa with Flutriafol Fungicides

Directory of Open Access Journals (Sweden)

Febrilia Nur'aini

2014-12-01

Full Text Available Vascular streak dieback caused by the fungus Oncobasidium theobromae is one of the important diseases in cocoa crop in Indonesia. One approach to control the disease is by using fungicides. The aim of this research was to determine the effect of class triazole fungicides to the intensity of the vascular streak dieback disease on cocoa seedling phase, immature and mature cocoa. Experiments were conducted in Kotta Blater, PTPN XII and Kaliwining, Indonesian  Coffee and Cocoa Research Institute. Flutriafol 250 g/l with a concentration 0,05%, 0,1% and 0,15% foliar sprayed on cocoa seedlings, immature and mature cocoa. Active compound combination of Azoxystrobin and Difenoconazole with 0,1% concentration used as a comparation fungicides. The result showed that Flutriafol with 0,05%, 0,1% and 0,15% concentration and Azoxystrobin & Difenoconazol with 0,1% concentration could suppress the vascular streak dieback disease on seedlings. On immature plants, the application of Flutriafol was not effectively suppress the vascular streak dieback disease whereas the fungicide comparison could suppress with the efficacy level of 46.22%. On mature plants,both of fungicides could not suppress the vascular streak dieback disease. Key words: Fungicide, cocoa, vascular streak dieback, triazole, flutriafol, azoxystrobin+difenoconazol

Threatened Plants in China’s Sanjiang Plain: Hotspot Distributions and Gap Analysis

Directory of Open Access Journals (Sweden)

Baojia Du

2018-01-01

Full Text Available Global biodiversity is markedly decreasing in response to climate change and human disturbance. Sanjiang Plain is recognized as a biodiversity hotspot in China due to its high forest and wetland coverage, but species are being lost at an unprecedented rate, induced by anthropogenic activities. Identifying hotspot distributions and conservation gaps of threatened species is of particular significance for enhancing the conservation of biodiversity. Specifically, we integrated the principles and methods of spatial hotspot inspection, geographic information system (GIS technology and spatial autocorrelation analysis along with fieldwork to determine the spatial distribution patterns and unprotected hotspots of vulnerable and endangered plants in Sanjiang Plain. A gap analysis of the conservation status of vulnerable and endangered plants was conducted. Our results indicate that six nationally-protected plants were not observed in nature reserves or were without any protection, while the protection rates were <10% for 10 other nationally-protected plants. Protected areas (PAs cover <5% of the distribution areas for 31 threatened plant species, while only five species are covered by national nature reserves (NNRs within >50% of the distribution areas. We found 30 hotspots with vulnerable and endangered plants in the study area, but the area covered by NNRs is very limited. Most of the hotspots were located in areas with a high-high aggregation of plant species. Therefore, it is necessary to expand the area of existing nature reserves, establish miniature protection plots and create new PAs and ecological corridors to link the existing PAs. Our findings can contribute to the design of a PA network for botanical conservation.

Herbarium of the University of Malaga (Spain: Vascular Plants Collection

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Jose García Sánchez

2013-09-01

Full Text Available The herbarium of University of Málaga (MGC Herbarium is formed by four biological collections. The vascular plants collection (MGC-Cormof is the main collection of the herbarium. MGC-Cormof dataset aims to digitize and publish data associated with over 76.000 specimens deposited in the collection, of which 97.2% of the specimens are identified at species level. Since 2011, the University of Malaga’s Central Research Service (SCAI has been responsible for maintaining the herbariums and the dataset. The collection is growing continuously, with an annual intake of about 1.500 specimens. Nearly 96% of the collection is digitized, by Herbar v3.7.1 software (F. Pando et al. 1996–2011, making over 73.000 specimens accessible through the GBIF network (http://data.gbif.org/datasets/resource/8105/. At present, 247 families and 8.110 taxa, distributed in angiosperms (93.97%, ferns and fern allies (4.89% and gymnosperms (1.14%, constitute the MGC-Cormof collection. The families and genera best represented in the collection are Compositae, Leguminosae, Gramineae, Labiatae, Caryophyllaceae, Teucrium, Silene, Asplenium, Linaria and Quercus. Most of the specimens are from the Western Mediterranean Region, fundamentally Southern Spain (Andalusia: 82% of specimens and Northern Morocco (2.17%. Approximately, 63% of the specimens are georeferenced. The identification of the specimens in the collection has been carried out by the plant biology department at the University of Malaga and plus 40% of the specimens has been reviewed by experts. The MGC-Cormof dataset has been revised by DarwinTest v3.2 tool (Ortega-Maqueda and Pando 2008 before being published in GBIF. The data included in this database are important for conservation works, taxonomy, flora, cartography, phenology, palynology, among others.El Herbario de la Universidad de Málaga (Herbario MGC está constituido por cuatro colecciones biológicas. La colección de plantas vasculares (MGC Cormof es la

Predicting plant distribution in an heterogeneous Alpine landscape: does soil matter?

Science.gov (United States)

Buri, Aline; Cianfrani, Carmen; Pradervand, Jean-Nicolas; Guisan, Antoine

2016-04-01

Topographic and climatic factors are usually used to predict plant distribution because they are known to explain their presence or absence. Soil properties have been widely shown to influence plant growth and distributions. However, they are rarely taken into account as predictors of plant species distribution models (SDM) in an edaphically heterogeneous landscape. Or, when it happens, interpolation techniques are used to project soil factors in space. In heterogeneous landscape, such as in the Alps region, where soil properties change abruptly as a function of environmental conditions over short distances, interpolation techniques require a huge quantities of samples to be efficient. This is costly and time consuming, and bring more errors than predictive approach for an equivalent number of samples. In this study we aimed to assess whether soil proprieties may be generalized over entire mountainous geographic extents and can improve predictions of plant distributions over traditional topo-climatic predictors. First, we used a predictive approach to map two soil proprieties based on field measurements in the western Swiss Alps region; the soil pH and the ratio of stable isotopes 13C/12C (called δ13CSOM). We used ensemble forecasting techniques combining together several predictive algorithms to build models of the geographic variation in the values of both soil proprieties and projected them in the entire study area. As predictive factors, we employed very high resolution topo-climatic data. In a second step, output maps from the previous task were used as an input for vegetation regional models. We integrated the predicted soil proprieties to a set of basic topo-climatic predictors known to be important to model plants species. Then we modelled the distribution of 156 plant species inhabiting the study area. Finally, we compared the quality of the models having or not soil proprieties as predictors to evaluate their effect on the predictive power of our models

Potential Responses of Vascular Plants from the Pristine “Lost World” of the Neotropical Guayana Highlands to Global Warming: Review and New Perspectives

Science.gov (United States)

Rull, Valentí; Vegas-Vilarrúbia, Teresa

2017-01-01

The neotropical Guayana Highlands (GH) are one of the few remaining pristine environments on Earth, and they host amazing biodiversity with a high degree endemism, especially among vascular plants. Despite the lack of direct human disturbance, GH plants and their communities are threatened with extinction from habitat loss due to global warming (GW). Geographic information systems simulations involving the entire known vascular GH flora (>2430 species) predict potential GW-driven extinctions on the order of 80% by the end of this century, including nearly half of the endemic species. These estimates and the assessment of an environmental impact value for each species led to the hierarchization of plants by their risk of habitat loss and the definition of priority conservation categories. However, the predictions assume that all species will respond to GW by migrating upward and at equal rates, which is unlikely, so current estimates should be considered preliminary and incomplete (although they represent the best that can be done with the existing information). Other potential environmental forcings (i.e., precipitation shifts, an increase in the atmospheric CO2 concentration) and idiosyncratic plant responses (i.e., resistance, phenotypic acclimation, rapid evolution) should also be considered, so detailed eco-physiological studies of the more threatened species are urgently needed. The main obstacles to developing such studies are the remoteness and inaccessibility of the GH and, especially, the difficulty in obtaining official permits for fieldwork. PMID:28179913

Vascular Plant and Vertebrate Inventory of Saguaro National Park, Rincon Mountain District

Science.gov (United States)

Powell, Brian F.; Halvorson, William Lee; Schmidt, Cecilia A.

2006-01-01

Executive Summary This report summarizes the results of the first comprehensive inventory of plants and vertebrates at the Rincon Mountain District (RMD) of Saguaro National Park, Arizona. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at the district to document the presence of species within its boundaries. Park staff also surveyed for medium and large mammals using infrared-triggered cameras from 1999 to 2005. This report summarizes the methods and results of these two efforts. Our spatial sampling design was ambitious and was one of the first of its kind in the region to colocate study sites for vegetation and vertebrates using a stratified random design. We also chose the location of some study sites non-randomly in areas that we thought would have the highest species richness. Because we used repeatable study designs and standardized field methods, these inventories can serve as the first step in a biological monitoring program for the district. We also provide an important overview of most previous survey efforts in the district. We use data from our inventory and other surveys to compile species lists and to assess inventory completeness. With the exception of plants, our survey effort was the most comprehensive ever undertaken in the district. We recorded a total of 801 plant and vertebrate species, including 50 species not previously found in the district (Table 1) of which five (all plants) are non-native species. Based on a review of our inventory and past research at the district, there have been a total of 1,479 species of plants and vertebrates found there. We believe inventories for all taxonomic groups are nearly complete. In particular, the plant, amphibian and reptile, and mammal species lists are the most complete of any comparably large natural area of the 'sky island' region of southern Arizona and adjacent Mexico. For each taxon-specific chapter we discuss patterns of species

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. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Distributed Low-Complexity Controller for Wind Power Plant in Derated Operation

DEFF Research Database (Denmark)

Biegel, Benjamin; Madjidian, Daria; Spudic, Vedrana

2013-01-01

We consider a wind power plant of megawatt wind turbines operating in derated mode. When operating in this mode, the wind power plant controller is free to distribute power set-points to the individual turbines, as long as the total power demand is met. In this work, we design a controller...... that exploits this freedom to reduce the fatigue on the turbines in the wind power plant. We show that the controller can be designed in a decentralized manner, such that each wind turbine is equipped with a local low-complexity controller relying only on few measurements and little communication. As a basis...... for the controller design, a linear wind turbine model is constructed and verified in an operational wind power plant of megawatt turbines. Due to limitations of the wind power plant available for tests, it is not possible to implement the developed controller; instead the final distributed controller is evaluated...

Plant distribution-altitude and landform relationships in karstic sinkholes of Mediterranean region of Turkey.

Science.gov (United States)

Ozkan, Kürsad; Gulsoy, Serkan; Mert, Ahmet; Ozturk, Munir; Muys, Bart

2010-01-01

The purpose of this study was to investigate the relationships between the plant distribution and the altitude-shape-size characteristics of sinkholes, and the landform characteristics inside sinkholes in the Mediterranean region of Turkey. Block kriging, Factor analysis, Cluster Analysis and Detrended Correspondence Analysis were performed. The sinkhole type and altitudinal zone were found to be the significant factors affecting the plant distribution. However, the sinkhole type was more important than the altitudinal zone. Hence, the sinkholes were first subdivided into groups according to types and then the groups were divided into subgroups according to the altitudinal zones. Consequently, 4 groups were defined; A-type sinkholes [1400-1550 m (A1), 1550-1700 m (A2)] and B-type sinkholes [1400-1550 (B1), 1550-1700 m (B2)]. The B-type was wider vertically and shorter horizontally than A-type sinkholes. Significant differences were found between the plant distribution and slope position inside the sinkholes. Plant distribution in the lower slopes was different from that in the flats and ridges in the B1 sub-type of B-type. Plant distribution in B2 subtype was different among the slope positions (ridge, middle slope, lower slope, and flat). Although distribution of plants is different in different parts (ridges, upper slope, middle slope, lower slope and basal flats) of A sinkhole, the differences between the parts of intermediate slope position are not significant. A high plant variability along short distances in the sinkholes was observed in the study area. That is why the site of sinkholes have a big potential for the distribution of many species. Hence, the area must be separated as strictly protected zone.

The perception of strigolactones in vascular plants.

Science.gov (United States)

Lumba, Shelley; Holbrook-Smith, Duncan; McCourt, Peter

2017-05-17

Small-molecule hormones play central roles in plant development, ranging from cellular differentiation and organ formation to developmental response instruction in changing environments. A recently discovered collection of related small molecules collectively called strigolactones are of particular interest, as these hormones also function as ecological communicators between plants and fungi and between parasitic plants and their hosts. Advances from model plant systems have begun to unravel how, as a hormone, strigolactone is perceived and transduced. In this Review, we summarize this information and examine how understanding strigolactone hormone signaling is leading to insights into parasitic plant infections. We specifically focus on how the development of chemical probes can be used in combination with model plant systems to dissect strigolactone's perception in the parasitic plant Striga hermonthica. This information is particularly relevant since Striga is considered one of the largest impediments to food security in sub-Saharan Africa.

Scheduling the maintenance of gaseous diffusion and electric power distribution plants

International Nuclear Information System (INIS)

Chauvet, D.

1990-01-01

A computer aided scheduling applied to the maintenance of a uranium enrichment plant is presented. The plant exploits gaseous diffusion and electric power distribution plants, for which the operating conditions must be satisfied. The management and the execution of the maintenance actions are computer aided. Concerning the techniques, the cost, the safety and the scheduling actions were optimized [fr

Responsiveness of performance and morphological traits to experimental submergence predicts field distribution pattern of wetland plants

NARCIS (Netherlands)

Luo, Fang-Li; Huang, Lin; Lei, Ting; Xue, Wei; Li, Hong-Li; Yu, Fei-Hai; Cornelissen, J.H.C.

2016-01-01

Question: Plant trait mean values and trait responsiveness to different environmental regimes are both important determinants of plant field distribution, but the degree to which plant trait means vs trait responsiveness predict plant distribution has rarely been compared quantitatively. Because

Water and soil biotic relations in Mercury distribution

Science.gov (United States)

Siegel, S. M.; Siegel, B. Z.; Puerner, N.; Speitel, T.; Thorarinsson, F.

1975-01-01

The distribution of Hg is considered both in terms of its availability in soil fractions and the relationship between Hg in plant samples and Hg in ambient soils or other supportive media. The plants were grouped by habitat into epipedic-epiphytic (mosses, lichens) and endopedic-aquatic-marine (Basidiomycetes and algae) samples; nonvascular and vascular forms were also distinguished. Sources included Alaska, Hawaii, New England and Iceland. Brief consideration was also given to Hg distribution in a plant-animal-soil community. Data were expressed in terms of plant Hg content and plant substratum concentration ratio. Average Hg contents and concentration ratios, and modal ranges for the ratios were determined. The results showed similar average Hg contents in all groups (126 to 199 ppb) but a low value (84 ppb) in the lichens; terrestrial forms had ratios of 3.5 to 7.6 whereas the marine algae yielded a figure of 78.7. A secondary mode in the range 0 to 0.1 appeared only in the Alaska-New England Group, over 500 km distant from active thermal sites. Evidence for both exclusion and concentration behavior was obtained.

Vascular Plants of the Chimbote Wetlands, Peru

OpenAIRE

Arana, César; Salinas, Letty

2013-01-01

Los humedales de Chimbote (09°05’51"S; 78°32’52"O) presentan una flora vascular compuesta por 41 especies en 18 familias. El 61% magnoliópsidas y el 39% liliópsidas. Las familias con mayor número de especies fueron Poaceae, Cyperaceae y Asteraceae. Las formas de crecimiento dominantes fueron las hierbas (85%) seguidas de arbustos (10%). En comparación con los humedales costeros de Lima, en Chimbote se presenta mayor riqueza de especies que en Medio Mundo (16 especies) y El Paraíso (25), aunqu...

TAS3 miR390-dependent loci in non-vascular land plants: towards a comprehensive reconstruction of the gene evolutionary history

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Sergey Y. Morozov

2018-04-01

Full Text Available Trans-acting small interfering RNAs (ta-siRNAs are transcribed from protein non-coding genomic TAS loci and belong to a plant-specific class of endogenous small RNAs. These siRNAs have been found to regulate gene expression in most taxa including seed plants, gymnosperms, ferns and mosses. In this study, bioinformatic and experimental PCR-based approaches were used as tools to analyze TAS3 and TAS6 loci in transcriptomes and genomic DNAs from representatives of evolutionary distant non-vascular plant taxa such as Bryophyta, Marchantiophyta and Anthocerotophyta. We revealed previously undiscovered TAS3 loci in plant classes Sphagnopsida and Anthocerotopsida, as well as TAS6 loci in Bryophyta classes Tetraphidiopsida, Polytrichopsida, Andreaeopsida and Takakiopsida. These data further unveil the evolutionary pathway of the miR390-dependent TAS3 loci in land plants. We also identified charophyte alga sequences coding for SUPPRESSOR OF GENE SILENCING 3 (SGS3, which is required for generation of ta-siRNAs in plants, and hypothesized that the appearance of TAS3-related sequences could take place at a very early step in evolutionary transition from charophyte algae to an earliest common ancestor of land plants.

TAS3 miR390-dependent loci in non-vascular land plants: towards a comprehensive reconstruction of the gene evolutionary history.

Science.gov (United States)

Morozov, Sergey Y; Milyutina, Irina A; Erokhina, Tatiana N; Ozerova, Liudmila V; Troitsky, Alexey V; Solovyev, Andrey G

2018-01-01

Trans-acting small interfering RNAs (ta-siRNAs) are transcribed from protein non-coding genomic TAS loci and belong to a plant-specific class of endogenous small RNAs. These siRNAs have been found to regulate gene expression in most taxa including seed plants, gymnosperms, ferns and mosses. In this study, bioinformatic and experimental PCR-based approaches were used as tools to analyze TAS3 and TAS6 loci in transcriptomes and genomic DNAs from representatives of evolutionary distant non-vascular plant taxa such as Bryophyta, Marchantiophyta and Anthocerotophyta. We revealed previously undiscovered TAS3 loci in plant classes Sphagnopsida and Anthocerotopsida, as well as TAS6 loci in Bryophyta classes Tetraphidiopsida, Polytrichopsida, Andreaeopsida and Takakiopsida. These data further unveil the evolutionary pathway of the miR390-dependent TAS3 loci in land plants. We also identified charophyte alga sequences coding for SUPPRESSOR OF GENE SILENCING 3 (SGS3), which is required for generation of ta-siRNAs in plants, and hypothesized that the appearance of TAS3-related sequences could take place at a very early step in evolutionary transition from charophyte algae to an earliest common ancestor of land plants.

Community-Weighted Mean Plant Traits Predict Small Scale Distribution of Insect Root Herbivore Abundance.

Directory of Open Access Journals (Sweden)

Ilja Sonnemann

Full Text Available Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content along transects in grasslands of different management intensity in three regions in Germany. We calculated community-weighted mean plant traits to test whether the functional plant community composition determines the small scale distribution of insect root herbivores. To analyze spatial patterns in plant species and trait composition and insect root herbivore abundance we computed Mantel correlograms. Insect root herbivores mainly comprised click beetle (Coleoptera, Elateridae larvae (43% in the investigated grasslands. Total insect root herbivore numbers were positively related to community-weighted mean traits indicating high plant growth rates and biomass (specific leaf area, reproductive- and vegetative plant height, and negatively related to plant traits indicating poor tissue quality (leaf C/N ratio. Generalist Elaterid larvae, when analyzed independently, were also positively related to high plant growth rates and furthermore to root dry mass, but were not related to tissue quality. Insect root herbivore numbers were not related to plant cover, plant species richness and soil water content. Plant species composition and to a lesser extent plant trait composition displayed spatial autocorrelation, which was not influenced by land use intensity. Insect root herbivore abundance was not spatially autocorrelated. We conclude that in semi-natural grasslands with a high share of generalist insect root herbivores, insect root herbivores affiliate with large, fast growing plants, presumably because of availability of high quantities of food. Affiliation of

Distributing radiation management system of nuclear power plants

International Nuclear Information System (INIS)

Mihoya, Eiichi; Akashi, Michio

1999-01-01

The importance of radiation management for nuclear facilities including nuclear power plants has increased as the general public understanding has progressed, and necessary information for management must be processed exactly and quickly. In nuclear power plants, radiation management is performed by each individual operation, and collected information is managed by the system of each operation. The distributing radiation management system has been developed aiming to use a general-purpose LAN and make quick and efficient use of information managed by individual operations. This paper describes the system configuration and functions. (author)

Florisitic summary of 'Manual of Vascular Plants of Northeastern United States and Adjacent Canada', second edition

Science.gov (United States)

Bennett, J.P.

1996-01-01

The second edition of the Manual of Vascular Plants of Northeastern United States and Adjacent Canada by Gleason and Cronquist (1991) is the most recent and up-to-date taxonomic treatment of the flora of that region. Since no floristic summary of the Manual was included in the publication, a computer analysis of the taxonomic data of the Manual was performed in order to generate a floristic summary. Totals of 4285 species, 1091 genera, and 191 families were tabulated. The largest genus was Carex, with 230 species; the largest family was the Asteraceae, with 528 species. Comparisons made with earlier floras of the same region indicated small declines on the order of 10% for these taxonomic groups.

Plant architecture and prey distribution influence foraging behavior of the predatory mite Phytoseiulus persimilis (Acari: Phytoseiidae).

Science.gov (United States)

Gontijo, Lessando M; Nechols, James R; Margolies, David C; Cloyd, Raymond A

2012-01-01

The arrangement, number, and size of plant parts may influence predator foraging behavior, either directly, by altering the rate or pattern of predator movement, or, indirectly, by affecting the distribution and abundance of prey. We report on the effects of both plant architecture and prey distribution on foraging by the predatory mite, Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae), on cucumber (Cucumis sativus L.). Plants differed in leaf number (2- or 6-leafed), and there were associated differences in leaf size, plant height, and relative proportions of plant parts; but all had the same total surface area. The prey, the twospotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae), were distributed either on the basal leaf or on all leaves. The effect of plant architecture on predator foraging behavior varied depending on prey distribution. The dimensions of individual plant parts affected time allocated to moving and feeding, but they did not appear to influence the frequency with which predators moved among different plant parts. Overall, P. persimilis moved less, and fed upon prey longer, on 6-leafed plants with prey on all leaves than on plants representing other treatment combinations. Our findings suggest that both plant architecture and pattern of prey distribution should be considered, along with other factors such as herbivore-induced plant volatiles, in augmentative biological control programs.

Distributed control system for CANDU 9 nuclear power plant

International Nuclear Information System (INIS)

Harber, J.E.; Kattan, M.K.; Macbeth, M.J.

1996-01-01

Canadian designed CANDU pressurized heavy water nuclear reactors have been world leaders in electrical power generation. The CANDU 9 project is AECL's next reactor design. The CANDU 9 plant monitoring, annunciation, and control functions are implemented in two evolutionary systems; the distributed control system (DCS) and the plant display system (PDS). The CDS implements most of the plant control functions in a single hardware platform. The DCS communicates with the PDS to provide the main operator interface and annunciation capabilities of the previous control computer designs along with human interface enhancements required in a modern control system. (author)

Beyond a climate-centric view of plant distribution: edaphic variables add value to distribution models.

Science.gov (United States)

Beauregard, Frieda; de Blois, Sylvie

2014-01-01

Both climatic and edaphic conditions determine plant distribution, however many species distribution models do not include edaphic variables especially over large geographical extent. Using an exceptional database of vegetation plots (n = 4839) covering an extent of ∼55,000 km2, we tested whether the inclusion of fine scale edaphic variables would improve model predictions of plant distribution compared to models using only climate predictors. We also tested how well these edaphic variables could predict distribution on their own, to evaluate the assumption that at large extents, distribution is governed largely by climate. We also hypothesized that the relative contribution of edaphic and climatic data would vary among species depending on their growth forms and biogeographical attributes within the study area. We modelled 128 native plant species from diverse taxa using four statistical model types and three sets of abiotic predictors: climate, edaphic, and edaphic-climate. Model predictive accuracy and variable importance were compared among these models and for species' characteristics describing growth form, range boundaries within the study area, and prevalence. For many species both the climate-only and edaphic-only models performed well, however the edaphic-climate models generally performed best. The three sets of predictors differed in the spatial information provided about habitat suitability, with climate models able to distinguish range edges, but edaphic models able to better distinguish within-range variation. Model predictive accuracy was generally lower for species without a range boundary within the study area and for common species, but these effects were buffered by including both edaphic and climatic predictors. The relative importance of edaphic and climatic variables varied with growth forms, with trees being more related to climate whereas lower growth forms were more related to edaphic conditions. Our study identifies the potential

Phylogenetic distribution of plant snoRNA families.

Science.gov (United States)

Patra Bhattacharya, Deblina; Canzler, Sebastian; Kehr, Stephanie; Hertel, Jana; Grosse, Ivo; Stadler, Peter F

2016-11-24

Small nucleolar RNAs (snoRNAs) are one of the most ancient families amongst non-protein-coding RNAs. They are ubiquitous in Archaea and Eukarya but absent in bacteria. Their main function is to target chemical modifications of ribosomal RNAs. They fall into two classes, box C/D snoRNAs and box H/ACA snoRNAs, which are clearly distinguished by conserved sequence motifs and the type of chemical modification that they govern. Similarly to microRNAs, snoRNAs appear in distinct families of homologs that affect homologous targets. In animals, snoRNAs and their evolution have been studied in much detail. In plants, however, their evolution has attracted comparably little attention. In order to chart the phylogenetic distribution of individual snoRNA families in plants, we applied a sophisticated approach for identifying homologs of known plant snoRNAs across the plant kingdom. In response to the relatively fast evolution of snoRNAs, information on conserved sequence boxes, target sequences, and secondary structure is combined to identify additional snoRNAs. We identified 296 families of snoRNAs in 24 species and traced their evolution throughout the plant kingdom. Many of the plant snoRNA families comprise paralogs. We also found that targets are well-conserved for most snoRNA families. The sequence conservation of snoRNAs is sufficient to establish homologies between phyla. The degree of this conservation tapers off, however, between land plants and algae. Plant snoRNAs are frequently organized in highly conserved spatial clusters. As a resource for further investigations we provide carefully curated and annotated alignments for each snoRNA family under investigation.

Rare earth element abundances and distribution patterns in plant materials

International Nuclear Information System (INIS)

Aidid, S.B.

1994-01-01

Eight out of the fourteen rare earth elements were estimated from the leaves of Pelthophorum pterocarpum, the leaves and roots of Impatiens balsamina, and the soils from four sampling sites by instrumental neutron activation analysis. The chondrite normalized rare earth element abundances and distribution patterns in the plant materials were found to be significantly correlated to the abundances of the rare earth elements occurring in the soils. The extent of accumulation of the rare earth elements in some plant materials was also governed by the age of the plants and the plant organs. (author) 16 refs.; 4 figs.; 3 tabs

Identification of the vascular plants of Churchill, Manitoba, using a DNA barcode library

Directory of Open Access Journals (Sweden)

Kuzmina Maria L

2012-11-01

Full Text Available Abstract Background Because arctic plant communities are highly vulnerable to climate change, shifts in their composition require rapid, accurate identifications, often for specimens that lack diagnostic floral characters. The present study examines the role that DNA barcoding can play in aiding floristic evaluations in the arctic by testing the effectiveness of the core plant barcode regions (rbcL, matK and a supplemental ribosomal DNA (ITS2 marker for a well-studied flora near Churchill, Manitoba. Results This investigation examined 900 specimens representing 312 of the 354 species of vascular plants known from Churchill. Sequencing success was high for rbcL: 95% for fresh specimens and 85% for herbarium samples (mean age 20 years. ITS2 worked equally well for the fresh and herbarium material (89% and 88%. However, sequencing success was lower for matK, despite two rounds of PCR amplification, which reflected less effective primer binding and sensitivity to the DNA degradation (76% of fresh, 45% of herbaria samples. A species was considered as taxonomically resolved if its members showed at least one diagnostic difference from any other taxon in the study and formed a monophyletic clade. The highest species resolution (69% was obtained by combining information from all three genes. The joint sequence information for rbcL and matK distinguished 54% of 286 species, while rbcL and ITS2 distinguished 63% of 285 species. Discrimination of species within Salix, which constituted 8% of the flora, was particularly problematic. Despite incomplete resolution, the barcode results revealed 22 misidentified herbarium specimens, and enabled the identification of field specimens which were otherwise too immature to identify. Although seven cases of ITS2 paralogy were noted in the families Cyperaceae, Juncaceae and Juncaginaceae, this intergenic spacer played an important role in resolving congeneric plant species at Churchill. Conclusions Our results

Identification of the vascular plants of Churchill, Manitoba, using a DNA barcode library.

Science.gov (United States)

Kuzmina, Maria L; Johnson, Karen L; Barron, Hannah R; Hebert, Paul Dn

2012-11-28

Because arctic plant communities are highly vulnerable to climate change, shifts in their composition require rapid, accurate identifications, often for specimens that lack diagnostic floral characters. The present study examines the role that DNA barcoding can play in aiding floristic evaluations in the arctic by testing the effectiveness of the core plant barcode regions (rbcL, matK) and a supplemental ribosomal DNA (ITS2) marker for a well-studied flora near Churchill, Manitoba. This investigation examined 900 specimens representing 312 of the 354 species of vascular plants known from Churchill. Sequencing success was high for rbcL: 95% for fresh specimens and 85% for herbarium samples (mean age 20 years). ITS2 worked equally well for the fresh and herbarium material (89% and 88%). However, sequencing success was lower for matK, despite two rounds of PCR amplification, which reflected less effective primer binding and sensitivity to the DNA degradation (76% of fresh, 45% of herbaria samples). A species was considered as taxonomically resolved if its members showed at least one diagnostic difference from any other taxon in the study and formed a monophyletic clade. The highest species resolution (69%) was obtained by combining information from all three genes. The joint sequence information for rbcL and matK distinguished 54% of 286 species, while rbcL and ITS2 distinguished 63% of 285 species. Discrimination of species within Salix, which constituted 8% of the flora, was particularly problematic. Despite incomplete resolution, the barcode results revealed 22 misidentified herbarium specimens, and enabled the identification of field specimens which were otherwise too immature to identify. Although seven cases of ITS2 paralogy were noted in the families Cyperaceae, Juncaceae and Juncaginaceae, this intergenic spacer played an important role in resolving congeneric plant species at Churchill. Our results provided fast and cost-effective solution to create a

Diversity, expression and mRNA targeting abilities of Argonaute-targeting miRNAs among selected vascular plants.

Science.gov (United States)

Jagtap, Soham; Shivaprasad, Padubidri V

2014-12-02

Micro (mi)RNAs are important regulators of plant development. Across plant lineages, Dicer-like 1 (DCL1) proteins process long ds-like structures to produce micro (mi) RNA duplexes in a stepwise manner. These miRNAs are incorporated into Argonaute (AGO) proteins and influence expression of RNAs that have sequence complementarity with miRNAs. Expression levels of AGOs are greatly regulated by plants in order to minimize unwarranted perturbations using miRNAs to target mRNAs coding for AGOs. AGOs may also have high promoter specificity-sometimes expression of AGO can be limited to just a few cells in a plant. Viral pathogens utilize various means to counter antiviral roles of AGOs including hijacking the host encoded miRNAs to target AGOs. Two host encoded miRNAs namely miR168 and miR403 that target AGOs have been described in the model plant Arabidopsis and such a mechanism is thought to be well conserved across plants because AGO sequences are well conserved. We show that the interaction between AGO mRNAs and miRNAs is species-specific due to the diversity in sequences of two miRNAs that target AGOs, sequence diversity among corresponding target regions in AGO mRNAs and variable expression levels of these miRNAs among vascular plants. We used miRNA sequences from 68 plant species representing 31 plant families for this analysis. Sequences of miR168 and miR403 are not conserved among plant lineages, but surprisingly they differ drastically in their sequence diversity and expression levels even among closely related plants. Variation in miR168 expression among plants correlates well with secondary structures/length of loop sequences of their precursors. Our data indicates a complex AGO targeting interaction among plant lineages due to miRNA sequence diversity and sequences of miRNA targeting regions among AGO mRNAs, thus leading to the assumption that the perturbations by viruses that use host miRNAs to target antiviral AGOs can only be species-specific. We also show

Research and design of distributed intelligence fault diagnosis system in nuclear power plant

International Nuclear Information System (INIS)

Liu Yongkuo; Xie Chunli; Cheng Shouyu; Xia Hong

2011-01-01

In order to further reduce the misoperation after the faults occurring of nuclear power plant, according to the function distribution of nuclear power equipment and the distributed control features of digital instrument control system, a nuclear power plant distributed condition monitoring and fault diagnosis system was researched and designed. Based on decomposition-integrated diagnostic thinking, a fuzzy neural network and RBF neural network was presented to do the distributed local diagnosis and multi-source information fusion technology for the global integrated diagnosis. Simulation results show that the developed distributed status monitoring and fault diagnosis system can diagnose more typical accidents of PWR to provide effective diagnosis and operation information. (authors)

Genome Analysis of Conserved Dehydrin Motifs in Vascular Plants

Directory of Open Access Journals (Sweden)

Ahmad A. Malik

2017-05-01

Full Text Available Dehydrins, a large family of abiotic stress proteins, are defined by the presence of a mostly conserved motif known as the K-segment, and may also contain two other conserved motifs known as the Y-segment and S-segment. Using the dehydrin literature, we developed a sequence motif definition of the K-segment, which we used to create a large dataset of dehydrin sequences by searching the Pfam00257 dehydrin dataset and the Phytozome 10 sequences of vascular plants. A comprehensive analysis of these sequences reveals that lysine residues are highly conserved in the K-segment, while the amino acid type is often conserved at other positions. Despite the Y-segment name, the central tyrosine is somewhat conserved, but can be substituted with two other small aromatic amino acids (phenylalanine or histidine. The S-segment contains a series of serine residues, but in some proteins is also preceded by a conserved LHR sequence. In many dehydrins containing all three of these motifs the S-segment is linked to the K-segment by a GXGGRRKK motif (where X can be any amino acid, suggesting a functional linkage between these two motifs. An analysis of the sequences shows that the dehydrin architecture and several biochemical properties (isoelectric point, molecular mass, and hydrophobicity score are dependent on each other, and that some dehydrin architectures are overexpressed during certain abiotic stress, suggesting that they may be optimized for a specific abiotic stress while others are involved in all forms of dehydration stress (drought, cold, and salinity.

Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

NARCIS (Netherlands)

Rietkerk, M.G.; Ouedraogo, T.; Kumar, L.; Sanou, S.; Langevelde, F. van; Kiema, A.; Koppel, J. van de; Andel, J. van; Hearne, J.; Skidmore, A.K.; Ridder, N. de; Stroosnijder, L.; Prins, H.H.T.

2002-01-01

We studied fine-scale spatial plant distribution in relation to the spatial distribution of erodible soil particles, organic matter, nutrients and soil water on a sandy to sandy loam soil in the Sahel. We hypothesized that the distribution of annual plants would be highly spatially autocorrelated

Evaluation of the Environmental DNA Method for Estimating Distribution and Biomass of Submerged Aquatic Plants.

Science.gov (United States)

Matsuhashi, Saeko; Doi, Hideyuki; Fujiwara, Ayaka; Watanabe, Sonoko; Minamoto, Toshifumi

2016-01-01

The environmental DNA (eDNA) method has increasingly been recognized as a powerful tool for monitoring aquatic animal species; however, its application for monitoring aquatic plants is limited. To evaluate eDNA analysis for estimating the distribution of aquatic plants, we compared its estimated distributions with eDNA analysis, visual observation, and past distribution records for the submerged species Hydrilla verticillata. Moreover, we conducted aquarium experiments using H. verticillata and Egeria densa and analyzed the relationships between eDNA concentrations and plant biomass to investigate the potential for biomass estimation. The occurrences estimated by eDNA analysis closely corresponded to past distribution records, and eDNA detections were more frequent than visual observations, indicating that the method is potentially more sensitive. The results of the aquarium experiments showed a positive relationship between plant biomass and eDNA concentration; however, the relationship was not always significant. The eDNA concentration peaked within three days of the start of the experiment in most cases, suggesting that plants do not release constant amounts of DNA. These results showed that eDNA analysis can be used for distribution surveys, and has the potential to estimate the biomass of aquatic plants.

Estimation of initiating event distribution at nuclear power plants by Bayesian procedure

International Nuclear Information System (INIS)

Chen Guangming

1995-01-01

Initiating events at nuclear power plants such as human errors or components failures may lead to a nuclear accident. The study of the frequency of these events or the distribution of the failure rate is necessary in probabilistic risk assessment for nuclear power plants. This paper presents Bayesian modelling methods for the analysis of the distribution of the failure rate. The method can also be utilized in other related fields especially where the data is sparse. An application of the Bayesian modelling in the analysis of distribution of the time to recover Loss of Off-Site Power ( LOSP) is discussed in the paper

North Carolina Seagrass Submersed Rooted Vasculars 1990 Geoform

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

North Carolina Seagrass Submersed Rooted Vasculars 1990 Substrate

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

North Carolina Seagrass Submersed Rooted Vasculars 1990 Biotic

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

What are the most crucial soil factors for predicting the distribution of alpine plant species?

Science.gov (United States)

Buri, A.; Pinto-Figueroa, E.; Yashiro, E.; Guisan, A.

2017-12-01

Nowadays the use of species distribution models (SDM) is common to predict in space and time the distribution of organisms living in the critical zone. The realized environmental niche concept behind the development of SDM imply that many environmental factors must be accounted for simultaneously to predict species distributions. Climatic and topographic factors are often primary included, whereas soil factors are frequently neglected, mainly due to the paucity of soil information available spatially and temporally. Furthermore, among existing studies, most included soil pH only, or few other soil parameters. In this study we aimed at identifying what are the most crucial soil factors for explaining alpine plant distributions and, among those identified, which ones further improve the predictive power of plant SDMs. To test the relative importance of the soil factors, we performed plant SDMs using as predictors 52 measured soil properties of various types such as organic/inorganic compounds, chemical/physical properties, water related variables, mineral composition or grain size distribution. We added them separately to a standard set of topo-climatic predictors (temperature, slope, solar radiation and topographic position). We used ensemble forecasting techniques combining together several predictive algorithms to model the distribution of 116 plant species over 250 sites in the Swiss Alps. We recorded the variable importance for each model and compared the quality of the models including different soil proprieties (one at a time) as predictors to models having only topo-climatic variables as predictors. Results show that 46% of the soil proprieties tested become the second most important variable, after air temperature, to explain spatial distribution of alpine plants species. Moreover, we also assessed that addition of certain soil factors, such as bulk soil water density, could improve over 80% the quality of some plant species models. We confirm that soil p

Plant community composition and species richness in the High Arctic tundra: from the present to the future

DEFF Research Database (Denmark)

Nabe-Nielsen, Jacob; Normand, Signe; Hui, Francis K.C.

2017-01-01

of these conditions is limited due to the scarcity of studies, especially in the High Arctic. 2. We investigated variations in vascular plant community composition and species richness based on 288 plots distributed on three sites along a coast-inland gradient in Northeast Greenland using a stratified random design......1. Arctic plant communities are altered by climate changes. The magnitude of these alterations depends on whether species distributions are determined by macroclimatic conditions, by factors related to local topography, or by biotic interactions. Our current understanding of the relative importance....... We used an information theoretic approach to determine whether variations in species richness were best explained by macroclimate, by factors related to local topography (including soil water) or by plant-plant interactions. Latent variable models were used to explain patterns in plant community...

Safety and security analysis for distributed control system in nuclear power plants

International Nuclear Information System (INIS)

Lu Zhigang; Liu Baoxu

2011-01-01

The Digital Distributed Control System (DCS) is the core that manages all monitoring and operation tasks in a Nuclear Power Plant (NPP). So, Digital Distributed Control System in Nuclear Power Plant has strict requirements for control and automation device safety and security due to many factors. In this article, factors of safety are analyzed firstly, while placing top priority on reliability, quality of supply and stability have also been carefully considered. In particular, advanced digital and electronic technologies are adopted to maintain sufficient reliability and supervisory capabilities in nuclear power plants. Then, security of networking and information technology have been remarked, several design methodologies considering the security characteristics are suggested. Methods and technologies of this article are being used in testing and evaluation for a real implement of a nuclear power plant in China. (author)

Aquatic vascular plants as handicraft: a case study in southern Brazil

Directory of Open Access Journals (Sweden)

Mabel R. Báez-Lizarazo

2017-11-01

Full Text Available ABSTRACT This study aimed to evaluate knowledge about and the usage and importance of aquatic vascular plants (AVPs in the production of handicrafts by communities on the north coast of the state of Rio Grande do Sul in southern Brazil. The snowball technique was employed to locate people who use and have knowledge regarding the use of AVPs for handicrafts. Data were collected through semi-structured interviews and guided tours with 35 interviewees who were involved in artisanal activity at the time of the study. The data were analyzed using the importance value (IV index and the consensus value for the forms of use (CMU. The Spearman correlation test (rs was employed to determine the correlations of each social variable with the knowledge variables, and Mann-Whitney U tests to verify whether men and women exhibited differences in knowledge. The interviewees cited 16 AVPs that were employed in 17 types of handicrafts, among which the four main species were Schoenoplectus californicus, Typha domingensis, T. latifolia and Androtrichum giganteum. Interviewee age, residence time on site and time working with handicrafts were the main social parameters that described the level of knowledge and use of AVPs. These AVPs reflect cultural knowledge and complement family incomes.

Spatial root distribution of plants growing in vertical media for use in living walls

DEFF Research Database (Denmark)

Jørgensen, Lars; Dresbøll, Dorte Bodin; Thorup-Kristensen, Kristian

2014-01-01

Background and Aims: For plants growing in living walls, the growth potential is correlated to the roots ability to utilize resources in all parts of the growing medium and thereby to the spatial root distribution. The aim of the study was to test how spatial root distribution was affected...... root growth was limited for plants in the middle or lower parts of the medium and 15N measurements confirmed that only plants in the bottom of the box had active roots in the bottom of the medium. The species differed in root architecture and spatial root distribution. Conclusions: The choice...... by growing medium, planting position and competition from other plants. Methods: Five species (Campanula poscharskyana cv. 'Stella', Fragaria vesca cv. 'Småland', Geranium sanguineum cv. 'Max Frei', Sesleria heufleriana and Veronica officinalis cv. 'Allgrün') were grown in three growing media (coir and two...

Increasing functional modularity with residence time in the co-distribution of native and introduced vascular plants

Czech Academy of Sciences Publication Activity Database

Hui, C.; Richardson, D. M.; Pyšek, Petr; Le Roux, J. J.; Kučera, T.; Jarošík, Vojtěch

Sep 2013, č. 4 (2013), , 1-8, no-2454 ISSN 2041-1723 Institutional support: RVO:67985939 Keywords : plant invasions * nature reserves * species pool Subject RIV: EF - Botanics Impact factor: 10.742, year: 2013

Alien plant species list and distribution for Camdeboo National Park, Eastern Cape Province, South Africa

Directory of Open Access Journals (Sweden)

Mmoto L. Masubelele

2009-09-01

Full Text Available Protected areas globally are threatened by the potential negative impacts that invasive alien plants pose, and Camdeboo National Park (CNP, South Africa, is no exception. Alien plants have been recorded in the CNP since 1981, before it was proclaimed a national park by South African National Parks in 2005. This is the first publication of a list of alien plants in and around the CNP. Distribution maps of some of the first recorded alien plant species are also presented and discussed. To date, 39 species of alien plants have been recorded, of which 13 are invasive and one is a transformer weed. The majority of alien plant species in the park are herbaceous (39% and succulent (24% species. The most widespread alien plant species in the CNP are Atriplex inflata (= A. lindleyi subsp. inflata, Salsola tragus (= S. australis and cacti species, especially Opuntia ficus-indica. Eradication and control measures that have been used for specific problematic alien plant species are described. Conservation implications: This article represents the first step in managing invasive alien plants and includes the collation of a species list and basic information on their distribution in and around the protected area. This is important for enabling effective monitoring of both new introductions and the distribution of species already present. We present the first species list and distribution information for Camdeboo National Park.

Changes In water translocation in the vascular tissue of grape during fruit development

International Nuclear Information System (INIS)

Zhaosen, X.; Forney, C.F.

2014-01-01

The relationship between vascular water translocation in grapes and berry growth was investigated. Berry growth, firmness and turgor were measured, and the structure and function of the vascular bundles for water translocation was observed. During phase I fruit development, the dorsal and central vascular bundles rapidly translocated introduced dye in the pedicle. The speed of dye translocation was highest in the dorsal vascular bundles of phase I fruit with a speed of 0.97cm/h. After phase II, both the distribution of dye and the speed of dye translocation in the fruit vascular tissue decreased, with speeds in the dorsal and central vascular bundles being 0.08 cm/h and 0.72 cm/h, respectively. During phase III, the distribution of dye was still lower than phase I. After phase II, the walls of some xylem vessels were indistinct and broken. After phase III, even though the water translocation efficiency of the xylem decreased, sugar accumulation in the berry as well as osmoregulation increased. (author)

Land degradation and halophytic plant diversity of milleyha wetland ecosystem (samandag-hatay), Turkey

International Nuclear Information System (INIS)

Altay, V.

2012-01-01

Investigations were undertaken during 2010-2011 to study effect of human induced land degradation on structure of some halophytic plant communities. Over all 183 taxa of vascular plant were recorded. Out of these 76 were of typical halophytes. The dominant plant taxa were; Phragmites australis, Halimione portulacoides and Bolboschoenus maritimus. The threatened categories of these taxa were identified from the Red Data Book of Turkey together with their distribution. The impact of degradation on the habitats due to land use for agriculture, organic and inorganic waste disposal and housing for tourisitc purposes were identified and conservation measures were outlined in this study. (author)

Reproductive organ and vascular specific promoter of the rice plasma membrane Ca2+ATPase mediates environmental stress responses in plants.

Science.gov (United States)

Huda, Kazi Md Kamrul; Banu, Mst Sufara Akhter; Pathi, Krishna Mohan; Tuteja, Narendra

2013-01-01

Plasma membrane Ca(2+)ATPase is a transport protein in the plasma membrane of cells and helps in removal of calcium (Ca(2+)) from the cell, hence regulating Ca(2+) level within cells. Though plant Ca(2+)ATPases have been shown to be involved in plant stress responses but their promoter regions have not been well studied. The 1478 bp promoter sequence of rice plasma membrane Ca(2+)ATPase contains cis-acting elements responsive to stresses and plant hormones. To identify the functional region, serial deletions of the promoter were fused with the GUS sequence and four constructs were obtained. These were differentially activated under NaCl, PEG cold, methyl viologen, abscisic acid and methyl jasmonate treatments. We demonstrated that the rice plasma membrane Ca(2+)ATPase promoter is responsible for vascular-specific and multiple stress-inducible gene expression. Only full-length promoter showed specific GUS expression under stress conditions in floral parts. High GUS activity was observed in roots with all the promoter constructs. The -1478 to -886 bp flanking region responded well upon treatment with salt and drought. Only the full-length promoter presented cold-induced GUS expression in leaves, while in shoots slight expression was observed for -1210 and -886 bp flanking region. The -1210 bp deletion significantly responded to exogenous methyl viologen and abscisic acid induction. The -1210 and -886 bp flanking region resulted in increased GUS activity in leaves under methyl jasmonate treatments, whereas in shoots the -886 bp and -519 bp deletion gave higher expression. Salicylic acid failed to induce GUS activities in leaves for all the constructs. The rice plasma membrane Ca(2+)ATPase promoter is a reproductive organ-specific as well as vascular-specific. This promoter contains drought, salt, cold, methyl viologen, abscisic acid and methyl jasmonate related cis-elements, which regulated gene expression. Overall, the tissue-specificity and inducible nature of this

Reproductive organ and vascular specific promoter of the rice plasma membrane Ca2+ATPase mediates environmental stress responses in plants.

Directory of Open Access Journals (Sweden)

Kazi Md Kamrul Huda

Full Text Available Plasma membrane Ca(2+ATPase is a transport protein in the plasma membrane of cells and helps in removal of calcium (Ca(2+ from the cell, hence regulating Ca(2+ level within cells. Though plant Ca(2+ATPases have been shown to be involved in plant stress responses but their promoter regions have not been well studied.The 1478 bp promoter sequence of rice plasma membrane Ca(2+ATPase contains cis-acting elements responsive to stresses and plant hormones. To identify the functional region, serial deletions of the promoter were fused with the GUS sequence and four constructs were obtained. These were differentially activated under NaCl, PEG cold, methyl viologen, abscisic acid and methyl jasmonate treatments. We demonstrated that the rice plasma membrane Ca(2+ATPase promoter is responsible for vascular-specific and multiple stress-inducible gene expression. Only full-length promoter showed specific GUS expression under stress conditions in floral parts. High GUS activity was observed in roots with all the promoter constructs. The -1478 to -886 bp flanking region responded well upon treatment with salt and drought. Only the full-length promoter presented cold-induced GUS expression in leaves, while in shoots slight expression was observed for -1210 and -886 bp flanking region. The -1210 bp deletion significantly responded to exogenous methyl viologen and abscisic acid induction. The -1210 and -886 bp flanking region resulted in increased GUS activity in leaves under methyl jasmonate treatments, whereas in shoots the -886 bp and -519 bp deletion gave higher expression. Salicylic acid failed to induce GUS activities in leaves for all the constructs.The rice plasma membrane Ca(2+ATPase promoter is a reproductive organ-specific as well as vascular-specific. This promoter contains drought, salt, cold, methyl viologen, abscisic acid and methyl jasmonate related cis-elements, which regulated gene expression. Overall, the tissue-specificity and inducible

Layered distributed architecture for plant automation

International Nuclear Information System (INIS)

Aravamuthan, G.; Verma, Yachika; Ranjan, Jyoti; Chachondia, Alka S.; Ganesh, G.

2005-01-01

The development of plant automation system and associated software remains one of the greatest challenges to the widespread implementation of highly adaptive re-configurable automation technology. This paper presents a layered distributed architecture for a plant automation system designed to support rapid reconfiguration and redeployment of automation components. The paper first presents evolution of automation architecture and their associated environment in the past few decades and then presents the concept of layered system architecture and the use of automation components to support the construction of a wide variety of automation system. It also highlights the role of standards and technology, which can be used in the development of automation components. We have attempted to adhere to open standards and technology for the development of automation component at a various layers. It also highlights the application of this concept in the development of an Operator Information System (OIS) for Advanced Heavy Water Reactor (AHWR). (author)

DISTRIBUTION OF ALLERGENIC PLANTS IN RUSSIA

Directory of Open Access Journals (Sweden)

Tatiana V. Dikareva

2015-01-01

Full Text Available We analyzed, for the first time ever, the geographical distribution of the main allergenic plants in Russia. All materials were organized as database and attached to the map in GIS Mapinfo. For each region of Russian Federation, two indices were calculated: the total number of allergenic plants in the region and the “allergenic index”. A series of maps wascompiled: the number of spring-flowering species, the number of summer-flowering species,the total number of species flowering during the whole year, the overall allergen danger during spring and summer seasons, respectively, and the overall allergen danger during the whole year. In terms of the number of allergenic species and by the “allergenic index,” the most dangerous regions appeared to be the Ryazan and Voronezh Oblasts, while the less dangerous – the Chukotka Autonomous Okrug, and the Magadan Oblast. The maps may serve as a reference source for allergologists and allergy sufferers.

Distributed Control Systems in New Nuclear Power Plants

International Nuclear Information System (INIS)

Doerfler, Joseph

2008-01-01

With the growing demand for energy many countries have expressed interest in constructing new plants over the next 15 to 20 years. These expectations have presented a challenge to the nuclear industry to provide a high volume of construction. A key strategy to meet this challenge is developing an advanced nuclear power plant design that allows for a modular construction, a high level of standardization, passive safety features, reduced number of components, and a short bid-to-build time. In addition, the implementation of the plant control system has evolved as new technologies emerge to support these goals. The purpose of this paper is to discuss the ways that the distributed control and information systems in the new generation of nuclear power plants will differ from those currently in service. The new designs provide opportunities to improve overall performance through the use of bus technology, a video display driven Human System Interface, enhanced diagnostics and improved maintenance features. However, the new technologies must fully address requirements for cyber security and high reliability. This paper will give an overview of new technology, improvements, as well as emerging issues in new plant design. (authors)

Distributed Control Systems in New Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Doerfler, Joseph [Westinghouse Electric Company, 4350 Northern Pike, Monroeville, PA 15146 (United States)

2008-07-01

With the growing demand for energy many countries have expressed interest in constructing new plants over the next 15 to 20 years. These expectations have presented a challenge to the nuclear industry to provide a high volume of construction. A key strategy to meet this challenge is developing an advanced nuclear power plant design that allows for a modular construction, a high level of standardization, passive safety features, reduced number of components, and a short bid-to-build time. In addition, the implementation of the plant control system has evolved as new technologies emerge to support these goals. The purpose of this paper is to discuss the ways that the distributed control and information systems in the new generation of nuclear power plants will differ from those currently in service. The new designs provide opportunities to improve overall performance through the use of bus technology, a video display driven Human System Interface, enhanced diagnostics and improved maintenance features. However, the new technologies must fully address requirements for cyber security and high reliability. This paper will give an overview of new technology, improvements, as well as emerging issues in new plant design. (authors)

Bioprinting for vascular and vascularized tissue biofabrication.

Science.gov (United States)

Datta, Pallab; Ayan, Bugra; Ozbolat, Ibrahim T

2017-03-15

Bioprinting is a promising technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision. Bioprinting enables the deposition of various biologics including growth factors, cells, genes, neo-tissues and extra-cellular matrix-like hydrogels. Benefits of bioprinting have started to make a mark in the fields of tissue engineering, regenerative medicine and pharmaceutics. Specifically, in the field of tissue engineering, the creation of vascularized tissue constructs has remained a principal challenge till date. However, given the myriad advantages over other biofabrication methods, it becomes organic to expect that bioprinting can provide a viable solution for the vascularization problem, and facilitate the clinical translation of tissue engineered constructs. This article provides a comprehensive account of bioprinting of vascular and vascularized tissue constructs. The review is structured as introducing the scope of bioprinting in tissue engineering applications, key vascular anatomical features and then a thorough coverage of 3D bioprinting using extrusion-, droplet- and laser-based bioprinting for fabrication of vascular tissue constructs. The review then provides the reader with the use of bioprinting for obtaining thick vascularized tissues using sacrificial bioink materials. Current challenges are discussed, a comparative evaluation of different bioprinting modalities is presented and future prospects are provided to the reader. Biofabrication of living tissues and organs at the clinically-relevant volumes vitally depends on the integration of vascular network. Despite the great progress in traditional biofabrication approaches, building perfusable hierarchical vascular network is a major challenge. Bioprinting is an emerging technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision

Herbarium of the university of malaga (Spain): vascular plants collection.

Science.gov (United States)

García-Sánchez, José; Cabezudo, Baltasar

2013-01-01

The herbarium of University of Málaga (MGC Herbarium) is formed by four biological collections. The vascular plants collection (MGC-Cormof) is the main collection of the herbarium. MGC-Cormof dataset aims to digitize and publish data associated with over 76.000 specimens deposited in the collection, of which 97.2% of the specimens are identified at species level. Since 2011, the University of Malaga's Central Research Service (SCAI) has been responsible for maintaining the herbariums and the dataset. The collection is growing continuously, with an annual intake of about 1.500 specimens. Nearly 96% of the collection is digitized, by Herbar v3.7.1 software (F. Pando et al. 1996-2011), making over 73.000 specimens accessible through the GBIF network (http://data.gbif.org/datasets/resource/8105/). At present, 247 families and 8.110 taxa, distributed in angiosperms (93.97%), ferns and fern allies (4.89%) and gymnosperms (1.14%), constitute the MGC-Cormof collection. The families and genera best represented in the collection are Compositae, Leguminosae, Gramineae, Labiatae, Caryophyllaceae, Teucrium, Silene, Asplenium, Linaria and Quercus. Most of the specimens are from the Western Mediterranean Region, fundamentally Southern Spain (Andalusia: 82% of specimens) and Northern Morocco (2.17%). Approximately, 63% of the specimens are georeferenced. The identification of the specimens in the collection has been carried out by the plant biology department at the University of Malaga and plus 40% of the specimens has been reviewed by experts. The MGC-Cormof dataset has been revised by DarwinTest v3.2 tool (Ortega-Maqueda and Pando 2008) before being published in GBIF. The data included in this database are important for conservation works, taxonomy, flora, cartography, phenology, palynology, among others. El Herbario de la Universidad de Málaga (Herbario MGC) está constituido por cuatro colecciones biológicas. La colección de plantas vasculares (MGC Cormof) es la colecci

Uptake and distribution of 137Cs, stable Cs and K in rice plants

International Nuclear Information System (INIS)

Tsukada, Hirofumi; Hasegawa, Hidenao

2003-01-01

The uptake and distributions of 137 Cs, stable Cs and K were determined for rice plant components, including polished rice, rice bran, hulls, leaves, stems, and roots. The distribution of 137 Cs in polished rice and rice bran was similar to that of stable Cs, while that of K was different. The concentration ratios of Cs/K in leaves increased in older leaf blade positions, which meant that the translocation rate of stable Cs, was slower than that of K. At harvest the dry weight of polished rice accounted for 34% of the entire rice plant, while the distributions of stable Cs in the polished rice and the non-edible parts were 7 and 93%, respectively. These findings suggest that the transfer and distribution of stable Cs in rice plants are different from those of K, and the behavior of stable Cs provides a useful analogue in predicting the fate of 137 Cs in an agricultural environment. (author)

Beyond a climate-centric view of plant distribution: edaphic variables add value to distribution models.

Directory of Open Access Journals (Sweden)

Frieda Beauregard

Full Text Available Both climatic and edaphic conditions determine plant distribution, however many species distribution models do not include edaphic variables especially over large geographical extent. Using an exceptional database of vegetation plots (n = 4839 covering an extent of ∼55,000 km2, we tested whether the inclusion of fine scale edaphic variables would improve model predictions of plant distribution compared to models using only climate predictors. We also tested how well these edaphic variables could predict distribution on their own, to evaluate the assumption that at large extents, distribution is governed largely by climate. We also hypothesized that the relative contribution of edaphic and climatic data would vary among species depending on their growth forms and biogeographical attributes within the study area. We modelled 128 native plant species from diverse taxa using four statistical model types and three sets of abiotic predictors: climate, edaphic, and edaphic-climate. Model predictive accuracy and variable importance were compared among these models and for species' characteristics describing growth form, range boundaries within the study area, and prevalence. For many species both the climate-only and edaphic-only models performed well, however the edaphic-climate models generally performed best. The three sets of predictors differed in the spatial information provided about habitat suitability, with climate models able to distinguish range edges, but edaphic models able to better distinguish within-range variation. Model predictive accuracy was generally lower for species without a range boundary within the study area and for common species, but these effects were buffered by including both edaphic and climatic predictors. The relative importance of edaphic and climatic variables varied with growth forms, with trees being more related to climate whereas lower growth forms were more related to edaphic conditions. Our study

Spatially-explicit estimation of geographical representation in large-scale species distribution datasets.

Science.gov (United States)

Kalwij, Jesse M; Robertson, Mark P; Ronk, Argo; Zobel, Martin; Pärtel, Meelis

2014-01-01

Much ecological research relies on existing multispecies distribution datasets. Such datasets, however, can vary considerably in quality, extent, resolution or taxonomic coverage. We provide a framework for a spatially-explicit evaluation of geographical representation within large-scale species distribution datasets, using the comparison of an occurrence atlas with a range atlas dataset as a working example. Specifically, we compared occurrence maps for 3773 taxa from the widely-used Atlas Florae Europaeae (AFE) with digitised range maps for 2049 taxa of the lesser-known Atlas of North European Vascular Plants. We calculated the level of agreement at a 50-km spatial resolution using average latitudinal and longitudinal species range, and area of occupancy. Agreement in species distribution was calculated and mapped using Jaccard similarity index and a reduced major axis (RMA) regression analysis of species richness between the entire atlases (5221 taxa in total) and between co-occurring species (601 taxa). We found no difference in distribution ranges or in the area of occupancy frequency distribution, indicating that atlases were sufficiently overlapping for a valid comparison. The similarity index map showed high levels of agreement for central, western, and northern Europe. The RMA regression confirmed that geographical representation of AFE was low in areas with a sparse data recording history (e.g., Russia, Belarus and the Ukraine). For co-occurring species in south-eastern Europe, however, the Atlas of North European Vascular Plants showed remarkably higher richness estimations. Geographical representation of atlas data can be much more heterogeneous than often assumed. Level of agreement between datasets can be used to evaluate geographical representation within datasets. Merging atlases into a single dataset is worthwhile in spite of methodological differences, and helps to fill gaps in our knowledge of species distribution ranges. Species distribution

Role of hormones in controlling vascular differentiation and the mechanism of lateral root initiation.

Science.gov (United States)

Aloni, Roni

2013-11-01

The vascular system in plants is induced and controlled by streams of inductive hormonal signals. Auxin produced in young leaves is the primary controlling signal in vascular differentiation. Its polar and non-polar transport pathways and major controlling mechanisms are clarified. Ethylene produced in differentiating protoxylem vessels is the signal that triggers lateral root initiation, while tumor-induced ethylene is a limiting and controlling factor of crown gall development and its vascular differentiation. Gibberellin produced in mature leaves moves non-polarly and promotes elongation, regulates cambium activity and induces long fibers. Cytokinin from the root cap moves upward to promote cambial activity and stimulate shoot growth and branching, while strigolactone from the root inhibits branching. Furthermore, the role of the hormonal signals in controlling the type of differentiating vascular elements and gradients of conduit size and density, and how they regulate plant adaptation and have shaped wood evolution are elucidated.

Weibull distribution in reliability data analysis in nuclear power plant

International Nuclear Information System (INIS)

Ma Yingfei; Zhang Zhijian; Zhang Min; Zheng Gangyang

2015-01-01

Reliability is an important issue affecting each stage of the life cycle ranging from birth to death of a product or a system. The reliability engineering includes the equipment failure data processing, quantitative assessment of system reliability and maintenance, etc. Reliability data refers to the variety of data that describe the reliability of system or component during its operation. These data may be in the form of numbers, graphics, symbols, texts and curves. Quantitative reliability assessment is the task of the reliability data analysis. It provides the information related to preventing, detect, and correct the defects of the reliability design. Reliability data analysis under proceed with the various stages of product life cycle and reliability activities. Reliability data of Systems Structures and Components (SSCs) in Nuclear Power Plants is the key factor of probabilistic safety assessment (PSA); reliability centered maintenance and life cycle management. The Weibull distribution is widely used in reliability engineering, failure analysis, industrial engineering to represent manufacturing and delivery times. It is commonly used to model time to fail, time to repair and material strength. In this paper, an improved Weibull distribution is introduced to analyze the reliability data of the SSCs in Nuclear Power Plants. An example is given in the paper to present the result of the new method. The Weibull distribution of mechanical equipment for reliability data fitting ability is very strong in nuclear power plant. It's a widely used mathematical model for reliability analysis. The current commonly used methods are two-parameter and three-parameter Weibull distribution. Through comparison and analysis, the three-parameter Weibull distribution fits the data better. It can reflect the reliability characteristics of the equipment and it is more realistic to the actual situation. (author)

Voltage Control Support and Coordination between Renewable Generation Plants in MV Distribution Systems

DEFF Research Database (Denmark)

Petersen, Lennart; Iov, Florin; Hansen, Anca Daniela

2016-01-01

This paper focusses on voltage control support and coordination between renewable generation plants in medium voltage distribution systems. An exemplary benchmark grid in Denmark, including a number of flexible ReGen plants providing voltage control functionality, is used as a base case. First......, voltage sensitivity analysis is performed to quantify node voltage variations due to injections of reactive power for given operational points of the network. The results are then used to develop an adaptive voltage droop control method, where various droop settings are allocated to each ReGen plant...... according to the sensitivity indices of corresponding node voltages and the location of respective ReGen plants in the distribution system. Case studies are performed in time-domain to analyze the impact of voltage fluctuations due to active power variations of ReGen plants in order to verify...

The distribution and degradation of chlormequat in wheat plants

NARCIS (Netherlands)

Dekhuijzen, H.M.; Vonk, C.R.

The distribution and degradation of chlormequat chloride (2-chloro 1,2-14C ethyltrimethylammonium chloride) was determined after uptake by the roots of summer wheat seedlings. This plant regulator was readily translocated from the roots to the above ground parts and converted into choline. Choline

Community-level plant-soil feedbacks explain landscape distribution of native and non-native plants.

Science.gov (United States)

Kulmatiski, Andrew

2018-02-01

Plant-soil feedbacks (PSFs) have gained attention for their potential role in explaining plant growth and invasion. While promising, most PSF research has measured plant monoculture growth on different soils in short-term, greenhouse experiments. Here, five soil types were conditioned by growing one native species, three non-native species, or a mixed plant community in different plots in a common-garden experiment. After 4 years, plants were removed and one native and one non-native plant community were planted into replicate plots of each soil type. After three additional years, the percentage cover of each of the three target species in each community was measured. These data were used to parameterize a plant community growth model. Model predictions were compared to native and non-native abundance on the landscape. Native community cover was lowest on soil conditioned by the dominant non-native, Centaurea diffusa , and non-native community cover was lowest on soil cultivated by the dominant native, Pseudoroegneria spicata . Consistent with plant growth on the landscape, the plant growth model predicted that the positive PSFs observed in the common-garden experiment would result in two distinct communities on the landscape: a native plant community on native soils and a non-native plant community on non-native soils. In contrast, when PSF effects were removed, the model predicted that non-native plants would dominate all soils, which was not consistent with plant growth on the landscape. Results provide an example where PSF effects were large enough to change the rank-order abundance of native and non-native plant communities and to explain plant distributions on the landscape. The positive PSFs that contributed to this effect reflected the ability of the two dominant plant species to suppress each other's growth. Results suggest that plant dominance, at least in this system, reflects the ability of a species to suppress the growth of dominant competitors

NASAs VESGEN: Systems Analysis of Vascular Phenotypes from Stress and Other Signaling Pathways Using GeneLab.

Science.gov (United States)

Parsons-Wingerter, Patricia A.; Weitzel, Alexander; Vyas, Ruchi J.; Murray, Matthew C.; Wyatt, Sarah E.

2016-01-01

One fundamental requirement shared by humans with all higher terrestrial life forms, including insect wings, higher land plants and other vertebrates, is a complex, fractally branching vascular system. NASA's VESsel GENeration Analysis (VESGEN) software maps and quantifies vascular trees, networks, and tree-network composites according to weighted physiological rules such as vessel connectivity, tapering and bifurcational branching. According to fluid dynamics, successful vascular transport requires a complex distributed system of highly regulated laminar flow. Microvascular branching rules within vertebrates, dicot leaves and the other organisms therefore display many similarities. One unifying perspective is that vascular patterning offers a useful readout that necessarily integrates complex molecular signaling pathways. VESGEN has elucidated changes in vascular pattern resulting from inflammatory, stress response, developmental and other signaling within numerous tissues and major model organisms studied for Space Biology. For a new VESGEN systems approach, we analyzed differential gene expression in leaves of Arabidopsis thaliana reported by GeneLab (GLDS-7) for spaceflight. Vascular-related changes in leaf gene expression were identified that can potentially be phenocopied by mutants in ground-based experiments. To link transcriptional, protein and other molecular change with phenotype, alterations in the Euclidean and dynamic dimensions (x,y,t) of vascular patterns for Arabidopsis leaves and other model species are being co-localized with signaling patterns of single molecular expression analyzed as information dimensions (i,j,k,...). Previously, Drosophila microarray data returned from space suggested significant changes in genes related to wing venation development that include EGF, Notch, Hedghog, Wingless and Dpp signaling. Phenotypes of increasingly abnormal ectopic wing venation in the (non-spaceflight) Drosophila wing generated by overexpression of a

Plant species distribution in relation to water-table depth and soil redox potential in montane riparian meadows

Science.gov (United States)

Kathleen A. Dwire; J. Boone Kauffman; John E. Baham

2006-01-01

The distribution of riparian plant species is largely driven by hydrologic and soil variables, and riparian plant communities frequently occur in relatively distinct zones along streamside elevational and soil textural gradients. In two montane meadows in northeast Oregon, USA, we examined plant species distribution in three riparian plant communities¡ªdefined as wet,...

Vascular training and endovascular practice in Europe

DEFF Research Database (Denmark)

Liapis, C.D.; Avgerinos, E.D.; Sillesen, H.

2009-01-01

specialties was distributed to a VS educator within 14 European countries. European Vascular and Endovascular Monitor (EVEM) data also were processed to correlate endovascular practice with training models. RESULTS: Fourteen questionnaires were gathered. Vascular training in Europe appears in 3 models: 1....... Mono-specialty (independence): 7 countries, 2. Subspecialty: 5 countries, 3. An existing specialty within general surgery: 2 countries. Independent compared to non-independent certification shortens overall training length (5.9 vs 7.9 years, p=0.006), while increasing overall training devoted......% respectively. Countries with independent vascular certification, despite their lower average endovascular index (procedures per 100,000 population), reported a higher growth rate of aortic endovascular procedures (VS independent 132% vs VS non-independent 87%), within a four-year period (2003-2007). Peripheral...

45Ca distribution and transport in saponin skinned vascular smooth muscle

International Nuclear Information System (INIS)

Stout, M.A.; Diecke, F.P.

1983-01-01

45 Ca distribution and transport were studied in chemically skinned strips of caudal artery from Kyoto Wistar rats. Sarcolemmal membranes were made hyperpermeable by exposure for 60 min to solutions containing 0.1 mg/ml of saponin. Skinned helical strips responded with graded contractions to changes in ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid buffered free Ca solutions (10(-7) to 10(-5) M) and were sensitive to the Mg-ATP concentration. Tissues loaded in the presence of 10(-7) M Ca contracted in response to 10 mM caffeine. These experiments indicate the strips are skinned and possess a functional regulatory and contractile system and an intact Ca sequestering system. 45 Ca distributes in three compartments in skinned caudal artery strips. The Ca contents of two components are linear functions of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration and desaturate at rapid rates. They correspond to the extracellular and cytoplasmic spaces. A significantly smaller component releases Ca at comparatively slower rates. 45 Ca uptake by the slow component consists of an ATP-dependent and an ATP-independent fraction. The 45 Ca content of the ATP-dependent fraction is a function of the free Ca concentration and is independent of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration. Its content was enhanced by oxalate and was abolished by Triton X-100 skinning solutions. The ATP-independent component was not affected by Triton X-100 skinning and may represent Ca binding to cytoplasmic molecules and structures. The sequestered Ca was released with caffeine or Ca but not by epinephrine. The observations indicate that the sarcoplasmic reticulum and mitochondria of vascular smooth muscle strips skinned with saponin retain their functional integrity after saponin skinning

Patterns and drivers of plant functional group dominance across the Western Hemisphere: a macroecological re-assessment based on a massive botanical dataset

DEFF Research Database (Denmark)

Jensen, Kristine Engemann; Sandel, Brody Steven; Enquist, Brian

2016-01-01

a standardized plant species occurrence dataset of unprecedented size covering the entire New World. Functional group distributions were estimated from 3 648 533 standardized occurrence records for a total of 83 854 vascular plant species, extracted from the Botanical Information and Ecology Network (BIEN......Plant functional group dominance has been linked to climate, topography and anthropogenic factors. Here, we assess existing theory linking functional group dominance patterns to their drivers by quantifying the spatial distribution of plant functional groups at a 100-km grid scale. We use......) database. Seven plant functional groups were considered, describing major differences in structure and function: epiphytes; climbers; ferns; herbs; shrubs; coniferous trees; and angiosperm trees. Two measures of dominance (relative number of occurrences and relative species richness) were analysed against...

Diversity of chasmophytes in the vascular flora of Greece: floristic analysis and phytogeographical patterns

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Panitsa Maria

2017-10-01

Full Text Available Cliffs are among the environments with the most adverse conditions for living organisms because of the limited availability of soil, moisture, and nutrients, and owing to the harsh conditions of exposure. They constitute shelters for rare, endemic, and range-restricted plant taxa. A main database has been prepared which includes vascular plant taxa that are obligate or facultative chasmophytes and also contains information about their life form, chorology, protection status, occurrence in more than 135 places such as cliffs, gorges, or open rocky habitats, and their geographical distribution in the 13 phytogeographical regions of Greece based on available floristic, vegetation, and phytosociological literature and on the authors' own collections and observations. The paper presents an analysis of the total diversity of cliff plant species, as well as the diversity of obligate chasmophytic plant species, endemics, and range-restricted taxa, in addition to the results of studying the distribution patterns of different subsets of plant taxa in the different phytogeographical regions of Greece. Hemicryptophytes and chamaephytes are the dominant life forms of the chasmophytic taxa. Among 935 species and subspecies registered, 476 are obligate chasmophytes, of which the majority are Greek endemics. Hierarchical cluster analysis of different subsets of plant taxa revealed affinities of the cliff flora of different phytogeographical regions. Additionally, 15 chasmophytic taxa mentioned in Annexes II, IV, and V of EEC Directive 92/43 belong to the cliff flora, of which 10 are obligate chasmophytes and nine have a priority for protection. Eighteen taxa are included in the IUCN Red List of Threatened Species, of which four are critically endangered (CR, seven are vulnerable (VU, and three are endangered (EN. The distinct correlation between endemism and chasmophytic ecology is emphasized, since a detailed understanding of the local distribution and

Virtual Geographic Simulation of Light Distribution within Three-Dimensional Plant Canopy Models

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Liyu Tang

2017-12-01

Full Text Available Virtual geographic environments (VGEs have been regarded as an important new means of simulating, analyzing, and understanding complex geological processes. Plants and light are major components of the geographic environment. Light is a critical factor that affects ecological systems. In this study, we focused on simulating light transmission and distribution within a three-dimensional plant canopy model. A progressive refinement radiosity algorithm was applied to simulate the transmission and distribution of solar light within a detailed, three-dimensional (3D loquat (Eriobotrya japonica Lindl. canopy model. The canopy was described in three dimensions, and each organ surface was represented by a set of triangular facets. The form factors in radiosity were calculated using a hemi-cube algorithm. We developed a module for simulating the instantaneous light distribution within a virtual canopy, which was integrated into ParaTree. We simulated the distribution of photosynthetically active radiation (PAR within a loquat canopy, and calculated the total PAR intercepted at the whole canopy scale, as well as the mean PAR interception per unit leaf area. The ParaTree-integrated radiosity model simulates the uncollided propagation of direct solar and diffuse sky light and the light-scattering effect of foliage. The PAR captured by the whole canopy based on the radiosity is approximately 9.4% greater than that obtained using ray tracing and TURTLE methods. The latter methods do not account for the scattering among leaves in the canopy in the study, and therefore, the difference might be due to the contribution of light scattering in the foliage. The simulation result is close to Myneni’s findings, in which the light scattering within a canopy is less than 10% of the incident PAR. Our method can be employed for visualizing and analyzing the spatial distribution of light within a canopy, and for estimating the PAR interception at the organ and canopy

Distribution of mercury in vegetation at Almaden, Spain

Energy Technology Data Exchange (ETDEWEB)

Huckabee, J.W.; Diaz, F.S.; Janzen, S.A.; Solomon, J.

1983-03-01

An ecological survey of the distribution of mercury in vegetation was initiated in 1975 in the vicinity of the mercury mine at Almaden, Spain. Samples were collected in autumn 1975, spring 1976, autumn 1976, and spring 1977, and chemical analyses for total mercury (..sigma.. Hg) were completed in 1979. Mean ..sigma.. Hg concentration in terrestrial plants ranged from > 100 ..mu..g g/sup -1/ within 0.5 km of the mine, to 0.20 ..mu..g g/sup -1/ 20 km distant from the mine. Different plant species had different concenrations of ..sigma.. Hg, but moss species usually had higher ..sigma.. Hg concentration than vascular plants. Woody plants were lower in ..sigma.. Hg concentration that forbs. Woody plants apparently accumulated ..sigma.. Hg primarily from atmospheric particulates. Traces of methylated mercury were detected in some plants. The ..sigma.. Hg concentrations in the 2483 vegetation samples reported here are much greater, even at distances of 25 km up-wind from the mine, than other reported ..sigma.. Hg values in comparable vegetation.

Correlates of monoicy and dioicy in hornworts, the apparent sister group to vascular plants.

Science.gov (United States)

Villarreal, Juan Carlos; Renner, Susanne S

2013-11-02

Whether male and female gametes are produced by single or separate individuals shapes plant mating and hence patterns of genetic diversity among and within populations. Haploid-dominant plants ("bryophytes": liverworts, mosses and hornworts) can have unisexual (dioicous) or bisexual (monoicous) gametophytes, and today, 68% of liverwort species, 57% of moss species, and 40% of hornwort species are dioicous. The transitions between the two sexual systems and possible correlations with other traits have been studied in liverworts and mosses, but not hornworts. Here we use a phylogeny for 98 of the 200 species of hornworts, the sister group to vascular plants, representing roughly equal proportions of all monoicous and all dioicous species, to test whether transitions in sexual systems are predominantly from monoicy to dioicy as might be expected based on studies of mosses. We further investigate possible correlations between sexual system and spore size, antheridium number, ploidy level, and diversification rate, with character selection partly based on findings in mosses and liverworts. Hornworts underwent numerous transitions between monoicy and dioicy. The transition rate from dioicy to monoicy was 2× higher than in the opposite direction, but monoicous groups have higher extinction rates; diversification rates do not correlate with sexual system. A correlation important in mosses, that between monoicy and polyploidy, apparently plays a small role: of 20 species with chromosome counts, only one is polyploid, the monoicous Anthoceros punctatus. A contingency test revealed that transitions to dioicy were more likely in species with small spores, supporting the hypothesis that small but numerous spores may be advantageous for dioicous species that depend on dense carpets of gametophytes for reproductive assurance. However, we found no evidence for increased antheridium-per-chamber numbers in dioicous species. Sexual systems in hornworts are labile, and the higher

Floristic composition and taxonomic distribution of plants in the ...

African Journals Online (AJOL)

Floristic composition and taxonomic distribution of plants in the dryland of Northwestern Nigeria. ... Analysis of abundance and rarity of species reveals that 10% and 90% of the encountered species were abundant and rare respectively in the study area. These finding poses serious ecological concerns in the study area, ...

Hydraulic efficiency and safety of vascular and non-vascular components in Pinus pinaster leaves.

Science.gov (United States)

Charra-Vaskou, Katline; Badel, Eric; Burlett, Régis; Cochard, Hervé; Delzon, Sylvain; Mayr, Stefan

2012-09-01

Leaves, the distal section of the soil-plant-atmosphere continuum, exhibit the lowest water potentials in a plant. In contrast to angiosperm leaves, knowledge of the hydraulic architecture of conifer needles is scant. We investigated the hydraulic efficiency and safety of Pinus pinaster needles, comparing different techniques. The xylem hydraulic conductivity (k(s)) and embolism vulnerability (P(50)) of both needle and stem were measured using the cavitron technique. The conductance and vulnerability of whole needles were measured via rehydration kinetics, and Cryo-SEM and 3D X-ray microtomographic observations were used as reference tools to validate physical measurements. The needle xylem of P. pinaster had lower hydraulic efficiency (k(s) = 2.0 × 10(-4) m(2) MPa(-1) s(-1)) and safety (P(50) = - 1.5 MPa) than stem xylem (k(s) = 7.7 × 10(-4) m(2) MPa(-1) s(-1); P(50) = - 3.6 to - 3.2 MPa). P(50) of whole needles (both extra-vascular and vascular pathways) was - 0.5 MPa, suggesting that non-vascular tissues were more vulnerable than the xylem. During dehydration to - 3.5 MPa, collapse and embolism in xylem tracheids, and gap formation in surrounding tissues were observed. However, a discrepancy in hydraulic and acoustic results appeared compared with visualizations, arguing for greater caution with these techniques when applied to needles. Our results indicate that the most distal parts of the water transport pathway are limiting for hydraulics of P. pinaster. Needle tissues exhibit a low hydraulic efficiency and low hydraulic safety, but may also act to buffer short-term water deficits, thus preventing xylem embolism.

Distribution of 15N-labeled urea injected into field-grown corn plants

International Nuclear Information System (INIS)

Zhou, X.; Madrmootoo, C.A.; Mackenzie, A.F.; Smith, D.L.

1998-01-01

Nitrogen (N) assimilate supply to developing corn (Zea mays L.) ears plays a critical role in grain dry weight accumulation. The use of stem-perfused/injected 15N labeled compounds to determine the effects of an artificial N source on the subsequent distribution of injected N and grain weight of field-grown corn plants has not been reported previously. Our objective was to assess the distribution of N added via an artificial source. Three soil N fertilizer levels (0, 180, and 270 kg N ha-1) and three N solutions (distilled water control and 15N enriched urea at 15 and 30 mM N) were arranged in a split-plot design. Three N concentrations were injected using a pressurized stem injection technique. The injection started fifteen days after silking and continued until immediately prior to plant physiological maturity. The average uptake volume was 256 mL over the 30-day injection period. The N supplied via injection represented 1.5 to 3% of the total plant N. Neither soil applied N fertilizer nor injected N altered dry matter distribution among plant tissues. As the concentration of N in the injected solutions increased, N concentrations increased in the grain and upper stalks, and % 15N atom excess in ear+1 leaves and leaves increased. The relative degree of 15N enrichment for each of the tissues measured was injected internode grain upper stalks leaves lower stalks cob husk ear + 1 leaf ear leaf. This study indicated that the exogenous N supplied via stem-injection, was incorporated into all the measured plant parts, although not uniformly. The distribution of the injected 15N was affected both by the proximity of sinks to the point of injection and the strength of the various sinks

The vascular plants: open system of growth.

Science.gov (United States)

Basile, Alice; Fambrini, Marco; Pugliesi, Claudio

2017-03-01

What is fascinating in plants (true also in sessile animals such as corals and hydroids) is definitely their open and indeterminate growth, as a result of meristematic activity. Plants as well as animals are characterized by a multicellular organization, with which they share a common set of genes inherited from a common eukaryotic ancestor; nevertheless, circa 1.5 billion years of evolutionary history made the two kingdoms very different in their own developmental biology. Flowering plants, also known as angiosperms, arose during the Cretaceous Period (145-65 million years ago), and up to date, they count around 235,000 species, representing the largest and most diverse group within the plant kingdom. One of the foundations of their success relies on the plant-pollinator relationship, essentially unique to angiosperms that pushed large speciation in both plants and insects and on the presence of the carpel, the structure devoted to seed enclosure. A seed represents the main organ preserving the genetic information of a plant; during embryogenesis, the primary axis of development is established by two groups of pluripotent cells: the shoot apical meristem (SAM), responsible for gene rating all aboveground organs, and the root apical meristem (RAM), responsible for producing all underground organs. During postembryonic shoot development, axillary meristem (AM) initiation and outgrowth are responsible for producing all secondary axes of growth including inflorescence branches or flowers. The production of AMs is tightly linked to the production of leaves and their separation from SAM. As leaf primordia are formed on the flanks of the SAM, a region between the apex and the developing organ is established and referred to as boundary zone. Interaction between hormones and the gene network in the boundary zone is fundamental for AM initiation. AMs only develop at the adaxial base of the leaf; thus, AM initiation is also strictly associated with leaf polarity. AMs

Graph analysis of cell clusters forming vascular networks

Science.gov (United States)

Alves, A. P.; Mesquita, O. N.; Gómez-Gardeñes, J.; Agero, U.

2018-03-01

This manuscript describes the experimental observation of vasculogenesis in chick embryos by means of network analysis. The formation of the vascular network was observed in the area opaca of embryos from 40 to 55 h of development. In the area opaca endothelial cell clusters self-organize as a primitive and approximately regular network of capillaries. The process was observed by bright-field microscopy in control embryos and in embryos treated with Bevacizumab (Avastin), an antibody that inhibits the signalling of the vascular endothelial growth factor (VEGF). The sequence of images of the vascular growth were thresholded, and used to quantify the forming network in control and Avastin-treated embryos. This characterization is made by measuring vessels density, number of cell clusters and the largest cluster density. From the original images, the topology of the vascular network was extracted and characterized by means of the usual network metrics such as: the degree distribution, average clustering coefficient, average short path length and assortativity, among others. This analysis allows to monitor how the largest connected cluster of the vascular network evolves in time and provides with quantitative evidence of the disruptive effects that Avastin has on the tree structure of vascular networks.

Rodent seed predation as a biotic filter influencing exotic plant abundance and distribution

Science.gov (United States)

D. E. Pearson; J. L. Hierro; M. Chiuffo; D. Villarreal

2014-01-01

Biotic resistance is commonly invoked to explain why many exotic plants fail to thrive in introduced ranges, but the role of seed predation as an invasion filter is understudied. Abiotic conditions may also influence plant populations and can interact with consumers to determine plant distributions, but how these factors jointly influence invasions is poorly understood...

Influence of seasons, different plant parts, and plant growth stages on saponin quantity and distribution in Bacopa monnieri

Directory of Open Access Journals (Sweden)

Watoo Phrompittayarat

2011-04-01

Full Text Available Brahmi or Bacopa monnieri (L. Wettst. is becoming popular as a food supplement due to its enhancing effect onmemory and intellect. Previous studies showed that a group of saponins are active compounds in this plant. However, untilnow little evidence has been obtained to indicate whether saponins are consistently present throughout the plant growthstages or the compounds are affected by the seasons. In order to answer those questions, we cultivated Brahmi under thenet house in three seasons. Influence of plant growth stages on saponin quantity and distribution was also investigated.In each season, treatments were plant ages with different plant parts having a factorial completely randomized design with 3replications. Five saponins, i.e. bacoside A3, bacopaside II, bacopaside X, bacopasaponin C and bacopaside I, were analyzedusing HPLC and reported as total saponins.The results showed that total saponin contents in Brahmi were the highest in rainy season while the weight yield ofBrahmi was the highest in summer. Ages of Brahmi (1-4 months slightly affected total saponin content. High level of totalsaponins (1.91±0.48% w/w was detected at the shoot of Brahmi. These findings indicate that the saponin quantity is affectedby seasons and the distribution of the saponins is different in each part of the plant. This information will be beneficial tothe production of Brahmi for both household and industry

The effect of environmental change on vascular plant and cryptogam communities from the Falkland Islands and the Maritime Antarctic

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Convey Peter

2007-12-01

Full Text Available Abstract Background Antarctic terrestrial vegetation is subject to one of the most extreme climates on Earth. Currently, parts of Antarctica are one of the fastest warming regions on the planet. During 3 growing seasons, we investigated the effect of experimental warming on the diversity and abundance of coastal plant communities in the Maritime Antarctic region (cryptogams only and the Falkland Islands (vascular plants only. We compared communities from the Falkland Islands (51°S, mean annual temperature 7.9°C, with those of Signy Island (60°S, -2.1°C and Anchorage Island (67°S, -2.6°C, and experimental temperature manipulations at each of the three islands using Open Top Chambers (OTCs. Results Despite the strong difference in plant growth form dominance between the Falkland Islands and the Maritime Antarctic, communities across the gradient did not differ in total diversity and species number. During the summer months, the experimental temperature increase at 5 cm height in the vegetation was similar between the locations (0.7°C across the study. In general, the response to this experimental warming was low. Total lichen cover showed a non-significant decreasing trend at Signy Island (p Conclusion These results suggest that small temperature increases may rapidly lead to decreased soil moisture, resulting in more stressful conditions for plants. The more open plant communities (grass and lichen appeared more negatively affected by such changes than dense communities (dwarf shrub and moss.

Voltage regulator placement in radial distribution system using plant ...

African Journals Online (AJOL)

user

location and number along with tap setting of the voltage regulators that ... can be fixed or switched type; they are considered integer multiple of a capacitor unit ..... By simulating the growth process of plant phototropism, a probability model ..... He is referee for IEE Proceedings - Generation Transmission and Distribution and ...

Microarray Data Analysis of Space Grown Arabidopsis Leaves for Genes Important in Vascular Patterning

Science.gov (United States)

Weitzeal, A. J.; Wyatt, S. E.; Parsons-Wingerter, P.

2016-01-01

Venation patterning in leaves is a major determinant of photosynthesis efficiency because of its dependency on vascular transport of photoassimilates, water, and minerals. Arabidopsis thaliana grown in microgravity show delayed growth and leaf maturation. Gene expression data from the roots, hypocotyl, and leaves of A. thaliana grown during spaceflight vs. ground control analyzed by Affymetrix microarray are available through NASAs GeneLab (GLDS-7). We analyzed the data for differential expression of genes in leaves resulting from the effects of spaceflight on vascular patterning. Two genes were found by preliminary analysis to be upregulated during spaceflight that may be related to vascular formation. The genes are responsible for coding an ARGOS like protein (potentially affecting cell elongation in the leaves), and an F-boxkelch-repeat protein (possibly contributing to protoxylem specification). Further analysis that will focus on raw data quality assessment and a moderated t-test may further confirm upregulation of the two genes and/or identify other gene candidates. Plants defective in these genes will then be assessed for phenotype by the mapping and quantification of leaf vascular patterning by NASAs VESsel GENeration (VESGEN) software to model specific vascular differences of plants grown in spaceflight.

General regularities of Sr 90 distribution in system soil-plant under natural conditions

International Nuclear Information System (INIS)

Gudeliene, I.; Marchiulioniene, D.; Petroshius, R.

2006-01-01

Sr 90 distribution in system 'soil - underground part of plant - aboveground part of plant' was investigated. It was determined that Sr 90 activity concentration in underground and aboveground part of plants and in mosses was not dependent on its activity concentration in soil. There was direct dependence of Sr 90 activity concentration in aboveground on underground parts of plants. Sr 90 transfer factor from soil to underground part of plants and mosses was directly dependent on this radionuclide activity concentration in them. (authors)

Improved Predictions of the Geographic Distribution of Invasive Plants Using Climatic Niche Models

Science.gov (United States)

Ramírez-Albores, Jorge E.; Bustamante, Ramiro O.

2016-01-01

Climatic niche models for invasive plants are usually constructed with occurrence records taken from literature and collections. Because these data neither discriminate among life-cycle stages of plants (adult or juvenile) nor the origin of individuals (naturally established or man-planted), the resulting models may mispredict the distribution ranges of these species. We propose that more accurate predictions could be obtained by modelling climatic niches with data of naturally established individuals, particularly with occurrence records of juvenile plants because this would restrict the predictions of models to those sites where climatic conditions allow the recruitment of the species. To test this proposal, we focused on the Peruvian peppertree (Schinus molle), a South American species that has largely invaded Mexico. Three climatic niche models were constructed for this species using high-resolution dataset gathered in the field. The first model included all occurrence records, irrespective of the life-cycle stage or origin of peppertrees (generalized niche model). The second model only included occurrence records of naturally established mature individuals (adult niche model), while the third model was constructed with occurrence records of naturally established juvenile plants (regeneration niche model). When models were compared, the generalized climatic niche model predicted the presence of peppertrees in sites located farther beyond the climatic thresholds that naturally established individuals can tolerate, suggesting that human activities influence the distribution of this invasive species. The adult and regeneration climatic niche models concurred in their predictions about the distribution of peppertrees, suggesting that naturally established adult trees only occur in sites where climatic conditions allow the recruitment of juvenile stages. These results support the proposal that climatic niches of invasive plants should be modelled with data of

A review of plant-based compounds and medicinal plants effective on atherosclerosis

Directory of Open Access Journals (Sweden)

Mehrnoosh Sedighi

2017-01-01

Full Text Available Atherosclerosis is one of the most important cardiovascular diseases that involve vessels through the development of fatty streaks and plaques. Plant-based compounds can help treat or prevent atherosclerosis through affecting the involved factors. The main purpose of this review article is to investigate and introduce medicinal plants and their potential activities regarding antioxidant properties, effective on lipids level and development of plaque, atherosclerosis, and progression of atherosclerosis as well as the development of cardiovascular disease and ischemia. To search for the relevant articles indexed in Information Sciences Institute, PubMed, Scientific Information Database, IranMedex, and Scopus between 1980 and 2013, with further emphasis on those indexed from 2004 to 2015, we used these search terms: atherosclerosis, antioxidant, cholesterol, inflammation, and the medicinal plants below. Then, the articles with inclusion criteria were used in the final analysis of the findings. Plant-based active compounds, including phenols, flavonoids, and antioxidants, can be effective on atherosclerosis predisposing factors and hence in preventing this disease and associated harmful complications, especially through reducing cholesterol, preventing increase in free radicals, and ultimately decreasing vascular plaque and vascular resistance. Hence, medicinal plants can contribute to treating atherosclerosis and preventing its progression through reducing cholesterolemia, free radicals, inflammation, vascular resistance, and certain enzymes. They, alone or in combination with hypocholesterolemic drugs, can therefore be useful for patients with hyperlipidemia and its complications.

Spatial Distribution and Sampling Plans for Grapevine Plant Canopy-Inhabiting Scaphoideus titanus (Hemiptera: Cicadellidae) Nymphs.

Science.gov (United States)

Rigamonti, Ivo E; Brambilla, Carla; Colleoni, Emanuele; Jermini, Mauro; Trivellone, Valeria; Baumgärtner, Johann

2016-04-01

The paper deals with the study of the spatial distribution and the design of sampling plans for estimating nymph densities of the grape leafhopper Scaphoideus titanus Ball in vine plant canopies. In a reference vineyard sampled for model parameterization, leaf samples were repeatedly taken according to a multistage, stratified, random sampling procedure, and data were subjected to an ANOVA. There were no significant differences in density neither among the strata within the vineyard nor between the two strata with basal and apical leaves. The significant differences between densities on trunk and productive shoots led to the adoption of two-stage (leaves and plants) and three-stage (leaves, shoots, and plants) sampling plans for trunk shoots- and productive shoots-inhabiting individuals, respectively. The mean crowding to mean relationship used to analyze the nymphs spatial distribution revealed aggregated distributions. In both the enumerative and the sequential enumerative sampling plans, the number of leaves of trunk shoots, and of leaves and shoots of productive shoots, was kept constant while the number of plants varied. In additional vineyards data were collected and used to test the applicability of the distribution model and the sampling plans. The tests confirmed the applicability 1) of the mean crowding to mean regression model on the plant and leaf stages for representing trunk shoot-inhabiting distributions, and on the plant, shoot, and leaf stages for productive shoot-inhabiting nymphs, 2) of the enumerative sampling plan, and 3) of the sequential enumerative sampling plan. In general, sequential enumerative sampling was more cost efficient than enumerative sampling.

Using geomorphological variables to predict the spatial distribution of plant species in agricultural drainage networks.

Science.gov (United States)

Rudi, Gabrielle; Bailly, Jean-Stéphane; Vinatier, Fabrice

2018-01-01

To optimize ecosystem services provided by agricultural drainage networks (ditches) in headwater catchments, we need to manage the spatial distribution of plant species living in these networks. Geomorphological variables have been shown to be important predictors of plant distribution in other ecosystems because they control the water regime, the sediment deposition rates and the sun exposure in the ditches. Whether such variables may be used to predict plant distribution in agricultural drainage networks is unknown. We collected presence and absence data for 10 herbaceous plant species in a subset of a network of drainage ditches (35 km long) within a Mediterranean agricultural catchment. We simulated their spatial distribution with GLM and Maxent model using geomorphological variables and distance to natural lands and roads. Models were validated using k-fold cross-validation. We then compared the mean Area Under the Curve (AUC) values obtained for each model and other metrics issued from the confusion matrices between observed and predicted variables. Based on the results of all metrics, the models were efficient at predicting the distribution of seven species out of ten, confirming the relevance of geomorphological variables and distance to natural lands and roads to explain the occurrence of plant species in this Mediterranean catchment. In particular, the importance of the landscape geomorphological variables, ie the importance of the geomorphological features encompassing a broad environment around the ditch, has been highlighted. This suggests that agro-ecological measures for managing ecosystem services provided by ditch plants should focus on the control of the hydrological and sedimentological connectivity at the catchment scale. For example, the density of the ditch network could be modified or the spatial distribution of vegetative filter strips used for sediment trapping could be optimized. In addition, the vegetative filter strips could constitute

Characterization of midrib vascular bundles of selected medicinal species in Rubiaceae

Science.gov (United States)

Nurul-Syahirah, M.; Noraini, T.; Latiff, A.

2016-11-01

An anatomical study was carried out on mature leaves of five selected medicinal species of Rubiaceae from Peninsular Malaysia. The chosen medicinal species were Aidia densiflora, Aidia racemosa, Chasallia chartacea, Hedyotis auricularia and Ixora grandifolia. The objective of this study is to determine the taxonomic value of midrib anatomical characteristics. Leaves samples were collected from Taman Paku Pakis, Universiti Kebangsaan Malaysia, Bangi, Selangor and Kledang Saiong Forest Reserve, Perak, Malaysia. Leaves samples then were fixed in spirit and acetic acid (3:1), the midrib parts then were sectioned using sliding microtome, cleared using Clorox, stained in Safranin and Alcian blue, mounted in Euparal and were observed under light microscope. Findings in this study have shown all species have collateral bundles. The midrib vascular bundles characteristics that can be used as tool to differentiate between species or genus are vascular bundles system (opened or closed), shape and arrangement of main vascular bundles, presence of both additional and medullary vascular bundles, position of additional vascular bundles, shape of medullary vascular bundles, presence of sclerenchyma cells ensheathed the vascular bundles. As a conclusion, midrib anatomical characteristics can be used to identify and discriminate medicinal plants species studied in the Rubiaceae.

Co-ordination of physiological and morphological responses of stomata to elevated [CO2] in vascular plants.

Science.gov (United States)

Haworth, Matthew; Elliott-Kingston, Caroline; McElwain, Jennifer C

2013-01-01

Plant stomata display a wide range of short-term behavioural and long-term morphological responses to atmospheric carbon dioxide concentration ([CO(2)]). The diversity of responses suggests that plants may have different strategies for controlling gas exchange, yet it is not known whether these strategies are co-ordinated in some way. Here, we test the hypothesis that there is co-ordination of physiological (via aperture change) and morphological (via stomatal density change) control of gas exchange by plants. We examined the response of stomatal conductance (G(s)) to instantaneous changes in external [CO(2)] (C(a)) in an evolutionary cross-section of vascular plants grown in atmospheres of elevated [CO(2)] (1,500 ppm) and sub-ambient [O(2)] (13.0 %) compared to control conditions (380 ppm CO(2), 20.9 % O(2)). We found that active control of stomatal aperture to [CO(2)] above current ambient levels was not restricted to angiosperms, occurring in the gymnosperms Lepidozamia peroffskyana and Nageia nagi. The angiosperm species analysed appeared to possess a greater respiratory demand for stomatal movement than gymnosperm species displaying active stomatal control. Those species with little or no control of stomatal aperture (termed passive) to C(a) were more likely to exhibit a reduction in stomatal density than species with active stomatal control when grown in atmospheres of elevated [CO(2)]. The relationship between the degree of stomatal aperture control to C(a) above ambient and the extent of any reduction in stomatal density may suggest the co-ordination of physiological and morphological responses of stomata to [CO(2)] in the optimisation of water use efficiency. This trade-off between stomatal control strategies may have developed due to selective pressures exerted by the costs associated with passive and active stomatal control.

Voltage Control Support and Coordination between Renewable Generation Plants in MV Distribution Systems

DEFF Research Database (Denmark)

Petersen, Lennart; Iov, Florin; Hansen, Anca Daniela

2016-01-01

This paper focusses on voltage control support and coordination between renewable generation plants in medium voltage distribution systems. An exemplary benchmark grid in Denmark, including a number of flexible ReGen plants providing voltage control functionality, is used as a base case. First...

Visualizing metabolite distribution and enzymatic conversion in plant tissues by desorption electrospray ionization mass spectrometry imaging

DEFF Research Database (Denmark)

Li, Bin; Baden, Camilla Knudsen; Hansen, Natascha Kristine Krahl

2013-01-01

In comparison to the technology platforms developed to localize transcripts and proteins, imaging tools for visualization of metabolite distributions in plant tissues are less well developed and lack versatility. This hampers our understanding of plant metabolism and dynamics. In this study we...... demonstrate that Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI) of tissue imprints on porous Teflon can be used to accurately image the distribution of even labile plant metabolites such as hydroxynitrile glucosides, which normally undergo enzymatic hydrolysis by specific ß......-glucosidases upon cell disruption. This fast and simple sample preparation resulted in no substantial differences in the distribution and ratios of all hydroxynitrile glucosides between leaves from wildtype Lotus japonicus and a ß-glucosidase mutant plant lacking the ability to hydrolyze certain hydroxynitrile...

Spectroscopic verification of zinc absorption and distribution in the desert plant Prosopis juliflora-velutina (velvet mesquite) treated with ZnO nanoparticles.

Science.gov (United States)

Hernandez-Viezcas, J A; Castillo-Michel, H; Servin, A D; Peralta-Videa, J R; Gardea-Torresdey, J L

2011-06-01

The impact of metal nanoparticles (NPs) on biological systems, especially plants, is still not well understood. The aim of this research was to determine the effects of zinc oxide (ZnO) NPs in velvet mesquite (Prosopis juliflora-velutina). Mesquite seedlings were grown for 15 days in hydroponics with ZnO NPs (10 nm) at concentrations varying from 500 to 4000 mg L(-1). Zinc concentrations in roots, stems and leaves were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES). Plant stress was examined by the specific activity of catalase (CAT) and ascorbate peroxidase (APOX); while the biotransformation of ZnO NPs and Zn distribution in tissues was determined by X-ray absorption spectroscopy (XAS) and micro X-ray fluorescence (μXRF), respectively. ICP-OES results showed that Zn concentrations in tissues (2102 ± 87, 1135 ± 56, and 628 ± 130 mg kg(-1) d wt in roots, stems, and leaves, respectively) were found at 2000 mg ZnO NPs L(-1). Stress tests showed that ZnO NPs increased CAT in roots, stems, and leaves, while APOX increased only in stems and leaves. XANES spectra demonstrated that ZnO NPs were not present in mesquite tissues, while Zn was found as Zn(II), resembling the spectra of Zn(NO(3))(2). The μXRF analysis confirmed the presence of Zn in the vascular system of roots and leaves in ZnO NP treated plants.

A meta-analysis of leaf nitrogen distribution within plant canopies

NARCIS (Netherlands)

Hikosaka, Kouki; Anten, Niels P.R.; Borjigidai, Almaz; Kamiyama, Chiho; Sakai, Hidemitsu; Hasegawa, Toshihiro; Oikawa, Shimpei; Iio, Atsuhiro; Watanabe, Makoto; Koike, Takayoshi; Nishina, Kazuya; Ito, Akihiko

2016-01-01

Background and aims Leaf nitrogen distribution in the plant canopy is an important determinant for canopy photosynthesis. Although the gradient of leaf nitrogen is formed along light gradients in the canopy, its quantitative variations among species and environmental responses remain unknown.

An evaluation of the predictive performance of distributional models for flora and fauna in north-east New South Wales.

Science.gov (United States)

Pearce, J; Ferrier, S; Scotts, D

2001-06-01

To use models of species distributions effectively in conservation planning, it is important to determine the predictive accuracy of such models. Extensive modelling of the distribution of vascular plant and vertebrate fauna species within north-east New South Wales has been undertaken by linking field survey data to environmental and geographical predictors using logistic regression. These models have been used in the development of a comprehensive and adequate reserve system within the region. We evaluate the predictive accuracy of models for 153 small reptile, arboreal marsupial, diurnal bird and vascular plant species for which independent evaluation data were available. The predictive performance of each model was evaluated using the relative operating characteristic curve to measure discrimination capacity. Good discrimination ability implies that a model's predictions provide an acceptable index of species occurrence. The discrimination capacity of 89% of the models was significantly better than random, with 70% of the models providing high levels of discrimination. Predictions generated by this type of modelling therefore provide a reasonably sound basis for regional conservation planning. The discrimination ability of models was highest for the less mobile biological groups, particularly the vascular plants and small reptiles. In the case of diurnal birds, poor performing models tended to be for species which occur mainly within specific habitats not well sampled by either the model development or evaluation data, highly mobile species, species that are locally nomadic or those that display very broad habitat requirements. Particular care needs to be exercised when employing models for these types of species in conservation planning.

Spatial distribution and environmental analysis of the alpine flora in the Pyrenees

Directory of Open Access Journals (Sweden)

D. Gómez

2017-09-01

Full Text Available On the basis of the digital edition of the “Atlas of the vascular flora of the Pyrenees” (www.florapyrenaea. org, the alpine flora of this mountain range is delimited in order to know its diversity and the different patterns of its spatial distribution, along with some other environmental characteristics. The Pyrenean alpine flora is made up of 645 taxa (630 species and 15 subspecies. All the administrative regions harbour more than 60% of the alpine plants, with Catalonia and Aragon reaching the highest values (around 90%. Along the altitudinal gradient, the highest plant diversity is found between 2300 and 2600 m. a. s. l., although 25% of the total alpine flora goes beyond 3000 m. On the other hand, a remarkable number of alpine plants live in the lowlands, and thus more than 300 alpine plants can be found below 1500 m. The average altitude range of the alpine plants is 1369 m, 300 m wider than that observed for the whole Pyrenean flora. Life-forms, habitat distribution and habitat naturalness of alpine plants are significantly different from those of the whole Pyrenean flora. Distribution of abundance categories also shows values of rarity significantly lower among alpine plants than for the whole flora. More than half the Pyrenean endemic plants are present in the alpine flora. High diversity and wide ecological amplitude of the alpine flora must be taken into account either when considering vulnerability of alpine plants facing “global change” or when addressing conservation policies for the whole Pyrenees from a common perspective.

Regional climate model downscaling may improve the prediction of alien plant species distributions

Science.gov (United States)

Liu, Shuyan; Liang, Xin-Zhong; Gao, Wei; Stohlgren, Thomas J.

2014-12-01

Distributions of invasive species are commonly predicted with species distribution models that build upon the statistical relationships between observed species presence data and climate data. We used field observations, climate station data, and Maximum Entropy species distribution models for 13 invasive plant species in the United States, and then compared the models with inputs from a General Circulation Model (hereafter GCM-based models) and a downscaled Regional Climate Model (hereafter, RCM-based models).We also compared species distributions based on either GCM-based or RCM-based models for the present (1990-1999) to the future (2046-2055). RCM-based species distribution models replicated observed distributions remarkably better than GCM-based models for all invasive species under the current climate. This was shown for the presence locations of the species, and by using four common statistical metrics to compare modeled distributions. For two widespread invasive taxa ( Bromus tectorum or cheatgrass, and Tamarix spp. or tamarisk), GCM-based models failed miserably to reproduce observed species distributions. In contrast, RCM-based species distribution models closely matched observations. Future species distributions may be significantly affected by using GCM-based inputs. Because invasive plants species often show high resilience and low rates of local extinction, RCM-based species distribution models may perform better than GCM-based species distribution models for planning containment programs for invasive species.

Process planning and accuracy distribution of marine power plant modularization

Directory of Open Access Journals (Sweden)

ZHANG Jinguo

2018-02-01

Full Text Available [Objectives] Modular shipbuilding can shorten the cycle of design and construction, lower production costs and improve the quality of products, but higher shipbuilding capabilities are required, especially for the installation of power plants. Because of such characteristics of modular shipbuilding as the high precision of docking links, long size equipment installation chain and quantitative docking interfaces, docking installation is very difficult due to high docking deviation and low accuracy of docking installation, leading to the abnormal vibration of equipment. In order to solve this problem, [Methods] on the basis of domestic shipbuilding capability, numerical calculation methods are used to analyze the accuracy distribution of modular installation. [Results] The results show that the accuracy distribution of different docking links is reasonable and feasible, and the setting of adjusting allowance matches the requirements of shipbuilding. [Conclusions] This method provides a reference for the modular construction of marine power plants.

Major Vascular Neurocognitive Disorder: A Reappraisal to Vascular Dementia

Directory of Open Access Journals (Sweden)

Emre Kumral

2017-03-01

Full Text Available Major vascular neurocognitive disorder (NCD is the second leading form of dementia after Alzheimer’s disease, accounting for 17-20% of all dementias. Vascular NCD is a progressive disease caused by reduced cerebral blood flow related to multiple large volume or lacunar infarcts that induce a sudden onset and stepwise decline in cognitive abilities. Despite its prevalence and clinical importance, there is still controversy in the terminology of vascular NCD. Only after the release of Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5 (2013 did the American Psychiatric Association define vascular dementia as “major vascular NCD”. This review includes an overview of risk factors, pathophysiology, types, diagnostic and clinical features of major vascular NCD, and current treatment options of vascular NCD regarding to DSM-5 criteria

Protein Kinase C Inhibitors as Modulators of Vascular Function and Their Application in Vascular Disease

Directory of Open Access Journals (Sweden)

Raouf A. Khalil

2013-03-01

Full Text Available Blood pressure (BP is regulated by multiple neuronal, hormonal, renal and vascular control mechanisms. Changes in signaling mechanisms in the endothelium, vascular smooth muscle (VSM and extracellular matrix cause alterations in vascular tone and blood vessel remodeling and may lead to persistent increases in vascular resistance and hypertension (HTN. In VSM, activation of surface receptors by vasoconstrictor stimuli causes an increase in intracellular free Ca2+ concentration ([Ca2+]i, which forms a complex with calmodulin, activates myosin light chain (MLC kinase and leads to MLC phosphorylation, actin-myosin interaction and VSM contraction. Vasoconstrictor agonists could also increase the production of diacylglycerol which activates protein kinase C (PKC. PKC is a family of Ca2+-dependent and Ca2+-independent isozymes that have different distributions in various blood vessels, and undergo translocation from the cytosol to the plasma membrane, cytoskeleton or the nucleus during cell activation. In VSM, PKC translocation to the cell surface may trigger a cascade of biochemical events leading to activation of mitogen-activated protein kinase (MAPK and MAPK kinase (MEK, a pathway that ultimately increases the myofilament force sensitivity to [Ca2+]i, and enhances actin-myosin interaction and VSM contraction. PKC translocation to the nucleus may induce transactivation of various genes and promote VSM growth and proliferation. PKC could also affect endothelium-derived relaxing and contracting factors as well as matrix metalloproteinases (MMPs in the extracellular matrix further affecting vascular reactivity and remodeling. In addition to vasoactive factors, reactive oxygen species, inflammatory cytokines and other metabolic factors could affect PKC activity. Increased PKC expression and activity have been observed in vascular disease and in certain forms of experimental and human HTN. Targeting of vascular PKC using PKC inhibitors may function in

Microarray Data Analysis of Space Grown Arabidopsis Leaves for Genes Important in Vascular Patterning. Analysis of Space Grown Arabidopsis with Microarray Data from GeneLab: Identification of Genes Important in Vascular Patterning

Science.gov (United States)

Weitzel, A. J.; Wyatt, S. E.; Parsons-Wingerter, P.

2016-01-01

Venation patterning in leaves is a major determinant of photosynthesis efficiency because of its dependency on vascular transport of photo-assimilates, water, and minerals. Arabidopsis thaliana grown in microgravity show delayed growth and leaf maturation. Gene expression data from the roots, hypocotyl, and leaves of A. thaliana grown during spaceflight vs. ground control analyzed by Affymetrix microarray are available through NASA's GeneLab (GLDS-7). We analyzed the data for differential expression of genes in leaves resulting from the effects of spaceflight on vascular patterning. Two genes were found by preliminary analysis to be up-regulated during spaceflight that may be related to vascular formation. The genes are responsible for coding an ARGOS (Auxin-Regulated Gene Involved in Organ Size)-like protein (potentially affecting cell elongation in the leaves), and an F-box/kelch-repeat protein (possibly contributing to protoxylem specification). Further analysis that will focus on raw data quality assessment and a moderated t-test may further confirm up-regulation of the two genes and/or identify other gene candidates. Plants defective in these genes will then be assessed for phenotype by the mapping and quantification of leaf vascular patterning by NASA's VESsel GENeration (VESGEN) software to model specific vascular differences of plants grown in spaceflight.

Mercury distribution characteristics in primary manganese smelting plants.

Science.gov (United States)

Back, Seung-Ki; Sung, Jin-Ho; Moon, Young-Hoon; Kim, Young-Hee; Seok, Kwang-Seol; Song, Geum-Ju; Seo, Yong-Chil

2017-08-01

The mercury (Hg) distribution characteristics were investigated in three primary manganese smelting plants in Korea for the assessment of anthropogenic Hg released. Input and output materials were sampled from each process, and Hg concentrations in the samples were analyzed. Among the input materials, the most mercury was found in the manganese ore (83.1-99.7%) and mercury was mainly released through fly ash or off gas, depending on the condition of off gas cleaning system. As off gas temperature decreases, proportion and concentration of emitted gaseous elemental mercury (Hg 0 ) in off gas decreases. Based on mass balance study from these three plants and national manganese production data, the total amount of mercury released from those Korean plants was estimated to 644 kg/yr. About half of it was emitted into the air while the rest was released to waste as fly ash. With the results of this investigation, national inventory for Hg emission and release could be updated for the response to Minamata Convention on Mercury. Copyright © 2017. Published by Elsevier Ltd.

Site selection and evaluation for nuclear power plants with respect to population distribution

International Nuclear Information System (INIS)

1980-01-01

This safety guide, relating population distribution to site selection and evaluation, for nuclear power plants, forms part of the IAEA's programme, referred to as the NUSS programme (Nuclear Safety Standards). The guide presents population distribution data, requirements, examples of site screening methods, and an overview of radiological impact assessment with respect to population distribution

The migration, accumulation and distribution of 59Fe in rice plants and soils

International Nuclear Information System (INIS)

Wang Yumin; Xu Shiming; Xu Guanren

1990-07-01

The 59 Fe is one of radionuclides in the waste water discharged from nuclear power plants. The accumulation and distribution of 59 Fe in rice plants at different growing stages and the accumulation and migration in soils of different textures were studied by using solution containing 59 FeCl 3 as a tracer. At the same contaminated activity, the distribution in the soils are discussed. According to the biological consequences caused by 59 Fe entering indirectly into agroecological environment, the possible methods for treatment and utilization of agricultural products are suggested

A study of quantitative radiography for moisture content distributions in plant

International Nuclear Information System (INIS)

Kawabata, Y.; Hino, M.; Horie, T.

2003-01-01

Vacuum pre-cooling in cut flower or perishable vegetables industry are used for protecting from the deterioration of the perishables during transportation. Some improvements of the pre-cooling way, however, are required for a bruise in plant on the way of handling. Neutron radiography is suitable to detect and observe the bruise in plant, especially, moisture content distributions in leaves, flowers and stalks. Neutron spectrum in irradiation neutron beams is required for obtaining quantitative moisture contents in plant. The neutron spectrum measurements for determination of effective cross-section of water are carried out at CN-3 experimental hole of Kyoto University Reactor (KUR) by time of flight method. Moisture content distributions in leaves of chrysanthemum, before and after the vacuum pre-cooling are measured by cold neutron radiography at the experimental hole. The local decreases of moisture contents caused by a bruise on the surface of the leaves are measured quantitatively by the cold neutron radiography. The quantitative changes of the moisture content in the leaves are able to read out from the cold neutron radiography image. (M. Suetake)

Predictive models of threatened plant species distribution in the Iberian arid south-east

OpenAIRE

Benito, Blas M.

2013-01-01

Poster on the distribution of three rare, endemic and endangered annual plants of arid zones in the south-eastern Iberian peninsula. Presented in the workshop "Predictive Modelling of Species Distribution: New Tools for the XXI Century (Baeza, Spain, november 2005).

Evaluation of blood flow distribution asymmetry and vascular geometry in patients with Fontan circulation using 4-D flow MRI

International Nuclear Information System (INIS)

Jarvis, Kelly; Markl, Michael; Schnell, Susanne; Barker, Alex J.; Garcia, Julio; Chowdhary, Varun; Carr, James; Lorenz, Ramona; Rose, Michael; Robinson, Joshua D.; Rigsby, Cynthia K.

2016-01-01

Asymmetrical caval to pulmonary blood flow is suspected to cause complications in patients with Fontan circulation. The aim of this study was to test the feasibility of 4-D flow MRI for characterizing the relationship between 3-D blood flow distribution and vascular geometry. We hypothesized that both flow distribution and geometry can be calculated with low interobserver variability and will detect a direct relationship between flow distribution and Fontan geometry. Four-dimensional flow MRI was acquired in 10 Fontan patients (age: 16 ± 4 years [mean ± standard deviation], range: 9-21 years). The Fontan connection was isolated by 3-D segmentation to evaluate flow distribution from the inferior vena cava (IVC) and superior vena cava (SVC) to the left and right pulmonary arteries (LPA, RPA) and to characterize geometry (cross-sectional area, caval offset, vessel angle). Flow distribution results indicated SVC flow tended toward the RPA while IVC flow was more evenly distributed (SVC to RPA: 78% ± 28 [9-100], IVC to LPA: 54% ± 28 [4-98]). There was a significant relationship between pulmonary artery cross-sectional area and flow distribution (IVC to RPA: R"2=0.50, P=0.02; SVC to LPA: R"2=0.81, P=0.0004). Good agreement was found between observers and for flow distribution when compared to net flow values. Four-dimensional flow MRI was able to detect relationships between flow distribution and vessel geometry. Future studies are warranted to investigate the potential of patient specific hemodynamic analysis to improve diagnostic capability. (orig.)

Evaluation of blood flow distribution asymmetry and vascular geometry in patients with Fontan circulation using 4-D flow MRI

Energy Technology Data Exchange (ETDEWEB)

Jarvis, Kelly; Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Chicago, IL (United States); Schnell, Susanne; Barker, Alex J.; Garcia, Julio; Chowdhary, Varun; Carr, James [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Lorenz, Ramona [University Medical Center Freiburg, Department of Radiology, Freiburg (Germany); Rose, Michael [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Robinson, Joshua D. [Northwestern University, Department of Pediatrics, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert H. Lurie Children' s Hospital of Chicago, Division of Cardiology, Chicago, IL (United States); Rigsby, Cynthia K. [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)

2016-10-15

Asymmetrical caval to pulmonary blood flow is suspected to cause complications in patients with Fontan circulation. The aim of this study was to test the feasibility of 4-D flow MRI for characterizing the relationship between 3-D blood flow distribution and vascular geometry. We hypothesized that both flow distribution and geometry can be calculated with low interobserver variability and will detect a direct relationship between flow distribution and Fontan geometry. Four-dimensional flow MRI was acquired in 10 Fontan patients (age: 16 ± 4 years [mean ± standard deviation], range: 9-21 years). The Fontan connection was isolated by 3-D segmentation to evaluate flow distribution from the inferior vena cava (IVC) and superior vena cava (SVC) to the left and right pulmonary arteries (LPA, RPA) and to characterize geometry (cross-sectional area, caval offset, vessel angle). Flow distribution results indicated SVC flow tended toward the RPA while IVC flow was more evenly distributed (SVC to RPA: 78% ± 28 [9-100], IVC to LPA: 54% ± 28 [4-98]). There was a significant relationship between pulmonary artery cross-sectional area and flow distribution (IVC to RPA: R{sup 2}=0.50, P=0.02; SVC to LPA: R{sup 2}=0.81, P=0.0004). Good agreement was found between observers and for flow distribution when compared to net flow values. Four-dimensional flow MRI was able to detect relationships between flow distribution and vessel geometry. Future studies are warranted to investigate the potential of patient specific hemodynamic analysis to improve diagnostic capability. (orig.)

An ancestral stomatal patterning module revealed in the non-vascular land plant Physcomitrella patens

Science.gov (United States)

Chater, Caspar C.; Kamisugi, Yasuko

2016-01-01

The patterning of stomata plays a vital role in plant development and has emerged as a paradigm for the role of peptide signals in the spatial control of cellular differentiation. Research in Arabidopsis has identified a series of epidermal patterning factors (EPFs), which interact with an array of membrane-localised receptors and associated proteins (encoded by ERECTA and TMM genes) to control stomatal density and distribution. However, although it is well-established that stomata arose very early in the evolution of land plants, until now it has been unclear whether the established angiosperm stomatal patterning system represented by the EPF/TMM/ERECTA module reflects a conserved, universal mechanism in the plant kingdom. Here, we use molecular genetics to show that the moss Physcomitrella patens has conserved homologues of angiosperm EPF, TMM and at least one ERECTA gene that function together to permit the correct patterning of stomata and that, moreover, elements of the module retain function when transferred to Arabidopsis. Our data characterise the stomatal patterning system in an evolutionarily distinct branch of plants and support the hypothesis that the EPF/TMM/ERECTA module represents an ancient patterning system. PMID:27407102

General Analysis of System Efficiency in Application of Combined Power Plants for Gas-Distribution Station

Directory of Open Access Journals (Sweden)

A. D. Kachan

2004-01-01

Full Text Available The paper proposes utilization of discharged heat of gas-piston engine (GPE or contact steam-gas plants (SGP with the purpose to heat up gas at gas-distribution stations (GDS of combined power plants with turbine and gas-expansion units. Calculations prove significant economic efficiency of the proposed variant in comparison with the application of ordinary gas- turbine units. Technical and economic calculation is used to determine gas-piston engine or contact steam-gas plant power for specific operational conditions of gas-distribution stations and utilization rate of discharged heat.

Additive Manufacturing of Vascular Grafts and Vascularized Tissue Constructs.

Science.gov (United States)

Elomaa, Laura; Yang, Yunzhi Peter

2017-10-01

There is a great need for engineered vascular grafts among patients with cardiovascular diseases who are in need of bypass therapy and lack autologous healthy blood vessels. In addition, because of the severe worldwide shortage of organ donors, there is an increasing need for engineered vascularized tissue constructs as an alternative to organ transplants. Additive manufacturing (AM) offers great advantages and flexibility of fabrication of cell-laden, multimaterial, and anatomically shaped vascular grafts and vascularized tissue constructs. Various inkjet-, extrusion-, and photocrosslinking-based AM techniques have been applied to the fabrication of both self-standing vascular grafts and porous, vascularized tissue constructs. This review discusses the state-of-the-art research on the use of AM for vascular applications and the key criteria for biomaterials in the AM of both acellular and cellular constructs. We envision that new smart printing materials that can adapt to their environment and encourage rapid endothelialization and remodeling will be the key factor in the future for the successful AM of personalized and dynamic vascular tissue applications.

[Study on species and distribution of flora of national rare and endangered medicinal plant in the Three Gorges area].

Science.gov (United States)

Chen, Shao-Cheng

2013-04-01

According to the China Plant Red Data Book and National Key Protected Wild Plants, the distribution of the rare and endangered plants and national conservative plants in the Three Gorges area were investigated and statistically analyzed. Its floristic composition and characteristics of geographical distribution were explored. As a result, a total of 97 species of medicinal flora belonging to rare and endangered national protection plants were found in the Three Gorges area. They come from 81 genera of 46 families. Their vertical distribution is obvious and horizontal distribution has discontinuous overlap. There are many ancient relict medicinal plants in the Three Gorges area. These medicinal plants have obvious temperate characteristics, and are easily found at warm and moist ravines and hillsides; The proportion of tree is much higher than that of herb, vine, shrub and fern. Most of them belong to specific and monotypic genera.

Within-plant distribution of Aulacorthum solani (Hemiptera: Aphididae), on various greenhouse plants with implications for control.

Science.gov (United States)

Jandricic, S E; Mattson, N S; Wraight, S P; Sanderson, J P

2014-04-01

Foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), has recently undergone a status change from an occasional pest to a serious pest in greenhouses of North America and the United Kingdom. Little nonanecdotal information exists on the ecology of this insect in greenhouse crops. To help improve integrated pest management decisions for A. solani, the within-plant distribution of this pest was explored on a variety of common greenhouse plants in both the vegetative and flowering stage. This aphid generally was found on lower leaves of vegetative plants, but was found higher in the canopy on reproductive plants (on flowers, flower buds, or upper leaves). Aphid numbers were not consistently positively correlated with total leaf surface areas within plant strata across plant species. Thus, the observed differences in preferred feeding sites on vegetative versus flowering plants are possibly a response to differences in nutritional quality of the various host-plant tissues. Despite being anecdotally described as a "stem-feeding aphid," A. solani was rarely found feeding on stems at the population densities established in our tests, with the exception of racemes of scarlet sage (Salvia splendans). Although some previous reports suggested that A. solani prefers to feed on new growth of plants, our results indicate that mature leaves are preferred over growing tips and young leaves. The implications of the within-plant feeding preferences of A. solani populations with respect to both biological and chemical control are discussed.

Large-scale proteome comparative analysis of developing rhizomes of the ancient vascular plant Equisetum hyemale.

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Tiago Santana Balbuena

2012-06-01

Full Text Available Equisetum hyemale is a widespread vascular plant species, whose reproduction is mainly dependent on the growth and development of the rhizomes. Due to its key evolutionary position, the identification of factors that could be involved in the existence of the rhizomatous trait may contribute to a better understanding of the role of this underground organ for the successful propagation of this and other plant species. In the present work, we characterized the proteome of E. hyemale rhizomes using a GeLC-MS spectral-counting proteomics strategy. A total of 1,911 and 1,860 non-redundant proteins were identified in the rhizomes apical tip and elongation zone, respectively. Rhizome- characteristic proteins were determined by comparisons of the developing rhizome tissues to developing roots. A total of 87 proteins were found to be up-regulated in both E. hyemale rhizome tissues in relation to developing roots. Hierarchical clustering indicated a vast dynamic range in the expression of the 87 characteristic proteins and revealed, based on the expression profile, the existence of 9 major protein groups. Gene ontology analyses suggested an over-representation of the terms involved in macromolecular and protein biosynthetic processes, gene expression and nucleotide and protein binding functions. Spatial differences analysis between the rhizome apical tip and the elongation zone revealed that only eight proteins were up-regulated in the apical tip including RNA-binding proteins and an acyl carrier protein, as well as a KH-domain protein and a T-complex subunit; while only seven proteins were up-regulated in the elongation zone including phosphomannomutase, galactomannan galactosyltransferase, endoglucanase 10 and 25 and mannose-1-phosphate guanyltransferase subunits alpha and beta. This is the first large scale characterization of the proteome of a plant rhizome. Implications of the findings were discussed in relation to other underground organs and related

Fluid distribution network and steam generators and method for nuclear power plant training simulator

International Nuclear Information System (INIS)

Alliston, W.H.; Johnson, S.J.; Mutafelija, B.A.

1975-01-01

A description is given of a training simulator for the real-time dynamic operation of a nuclear power plant which utilizes apparatus that includes control consoles having manual and automatic devices corresponding to simulated plant components and indicating devices for monitoring physical values in the simulated plant. A digital computer configuration is connected to the control consoles to calculate the dynamic real-time simulated operation of the plant in accordance with the simulated plant components to provide output data including data for operating the control console indicating devices. In the method and system for simulating a fluid distribution network of the power plant, such as that which includes, for example, a main steam system which distributes steam from steam generators to high pressure turbine steam reheaters, steam dump valves, and feedwater heaters, the simultaneous solution of linearized non-linear algebraic equations is used to calculate all the flows throughout the simulated system. A plurality of parallel connected steam generators that supply steam to the system are simulated individually, and include the simulation of shrink-swell characteristics

Plant-soil distribution of potentially toxic elements in response to elevated atmospheric CO2.

Science.gov (United States)

Duval, Benjamin D; Dijkstra, Paul; Natali, Susan M; Megonigal, J Patrick; Ketterer, Michael E; Drake, Bert G; Lerdau, Manuel T; Gordon, Gwyneth; Anbar, Ariel D; Hungate, Bruce A

2011-04-01

The distribution of contaminant elements within ecosystems is an environmental concern because of these elements' potential toxicity to animals and plants and their ability to hinder microbial ecosystem services. As with nutrients, contaminants are cycled within and through ecosystems. Elevated atmospheric CO2 generally increases plant productivity and alters nutrient element cycling, but whether CO2 causes similar effects on the cycling of contaminant elements is unknown. Here we show that 11 years of experimental CO2 enrichment in a sandy soil with low organic matter content causes plants to accumulate contaminants in plant biomass, with declines in the extractable contaminant element pools in surface soils. These results indicate that CO2 alters the distribution of contaminant elements in ecosystems, with plant element accumulation and declining soil availability both likely explained by the CO2 stimulation of plant biomass. Our results highlight the interdependence of element cycles and the importance of taking a broad view of the periodic table when the effects of global environmental change on ecosystem biogeochemistry are considered.

Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton

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Martin D. Oliveira

2014-03-01

Full Text Available Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton. The striped mealybug, Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae, is a widely distributed and polyphagous pest species, which naturally occurs on cotton plants in Brazil. This study evaluated the establishment and population growth as well as the within-plant distribution of F. virgata on four cotton cultivars: CNPA 7H (white fibers, BRS Verde, BRS Safira, and BRS Rubi (colored fibers. The experiment was conducted in a complete randomized design with four treatments (cultivars and 18 replications of each. Thus, cotton plants of each cultivar were infested with 100 newly hatched nymphs of F. virgata. The number of adult female mealybugs and the total number of mealybugs per plant were quantified, respectively, at 25 and 50 days after infestation. The developmental and pre-reproductive periods were also determined. Furthermore, we verified the distribution of F. virgata on the plant parts at 25 and 50 days after infestation. Ferrisia virgata showed similar growth of 412-fold in the four cotton cultivars studied. Also, the nymphs were spread on infested leaves; the secondgeneration nymphs were spread and established in all plant parts. Our results characterize F. virgata as having much potential as an important cotton pest in Brazil.

Patterns of genetic diversity in three plant lineages endemic to the Cape Verde Islands.

Science.gov (United States)

Romeiras, Maria M; Monteiro, Filipa; Duarte, M Cristina; Schaefer, Hanno; Carine, Mark

2015-05-15

Conservation of plant diversity on islands relies on a good knowledge of the taxonomy, distribution and genetic diversity of species. In recent decades, a combination of morphology- and DNA-based approaches has become the standard for investigating island plant lineages and this has led, in some cases, to the discovery of previously overlooked diversity, including 'cryptic species'. The flora of the Cape Verde archipelago in the North Atlantic is currently thought to comprise ∼740 vascular plant species, 92 of them endemics. Despite the fact that it is considered relatively well known, there has been a 12 % increase in the number of endemics in the last two decades. Relatively few of the Cape Verde plant lineages have been included in genetic studies so far and little is known about the patterns of diversification in the archipelago. Here we present an updated list for the endemic Cape Verde flora and analyse diversity patterns for three endemic plant lineages (Cynanchum, Globularia and Umbilicus) based on one nuclear (ITS) and four plastid DNA regions. In all three lineages, we find genetic variation. In Cynanchum, we find two distinct haplotypes with no clear geographical pattern, possibly reflecting different ploidy levels. In Globularia and Umbilicus, differentiation is evident between populations from northern and southern islands. Isolation and drift resulting from the small and fragmented distributions, coupled with the significant distances separating the northern and southern islands, could explain this pattern. Overall, our study suggests that the diversity in the endemic vascular flora of Cape Verde is higher than previously thought and further work is necessary to characterize the flora. Published by Oxford University Press on behalf of the Annals of Botany Company.

Predicting Vascular Plant Diversity in Anthropogenic Peatlands: Comparison of Modeling Methods with Free Satellite Data

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Ivan Castillo-Riffart

2017-07-01

Full Text Available Peatlands are ecosystems of great relevance, because they have an important number of ecological functions that provide many services to mankind. However, studies focusing on plant diversity, addressed from the remote sensing perspective, are still scarce in these environments. In the present study, predictions of vascular plant richness and diversity were performed in three anthropogenic peatlands on Chiloé Island, Chile, using free satellite data from the sensors OLI, ASTER, and MSI. Also, we compared the suitability of these sensors using two modeling methods: random forest (RF and the generalized linear model (GLM. As predictors for the empirical models, we used the spectral bands, vegetation indices and textural metrics. Variable importance was estimated using recursive feature elimination (RFE. Fourteen out of the 17 predictors chosen by RFE were textural metrics, demonstrating the importance of the spatial context to predict species richness and diversity. Non-significant differences were found between the algorithms; however, the GLM models often showed slightly better results than the RF. Predictions obtained by the different satellite sensors did not show significant differences; nevertheless, the best models were obtained with ASTER (richness: R2 = 0.62 and %RMSE = 17.2, diversity: R2 = 0.71 and %RMSE = 20.2, obtained with RF and GLM respectively, followed by OLI and MSI. Diversity obtained higher accuracies than richness; nonetheless, accurate predictions were achieved for both, demonstrating the potential of free satellite data for the prediction of relevant community characteristics in anthropogenic peatland ecosystems.

Determination and distribution of 210Po in tobacco plants from Poland

International Nuclear Information System (INIS)

Skwarzec, B.; Struminska, D.I.; Ulatowski, J.; Golebiowski, M.

2001-01-01

One of the most radiotoxic elements, 210 Po in different parts of tobacco plant from Poland was determined. Investigation revealed that polonium is non-uniformly distributed within tobacco plant. Tobacco leaves constituting about 50% of the wet mass, contain 87.1% of the total burden of 210 Po. Among the analyzed leaves about 66% of polonium is located in the oldest, over-ground part. It was indicated that 210 Po is generally taken up by tobacco from the dry or wet deposition of the radioactive fall-out onto the plant. Moreover, 210 Po concentration in tobacco leaves from Poland are higher than that in the other countries. (author)

Vascular Wall-Resident Multipotent Stem Cells of Mesenchymal Nature within the Process of Vascular Remodeling: Cellular Basis, Clinical Relevance, and Implications for Stem Cell Therapy.

Science.gov (United States)

Klein, Diana

2016-01-01

Until some years ago, the bone marrow and the endothelial cell compartment lining the vessel lumen (subendothelial space) were thought to be the only sources providing vascular progenitor cells. Now, the vessel wall, in particular, the vascular adventitia, has been established as a niche for different types of stem and progenitor cells with the capacity to differentiate into both vascular and nonvascular cells. Herein, vascular wall-resident multipotent stem cells of mesenchymal nature (VW-MPSCs) have gained importance because of their large range of differentiation in combination with their distribution throughout the postnatal organism which is related to their existence in the adventitial niche, respectively. In general, mesenchymal stem cells, also designated as mesenchymal stromal cells (MSCs), contribute to the maintenance of organ integrity by their ability to replace defunct cells or secrete cytokines locally and thus support repair and healing processes of the affected tissues. This review will focus on the central role of VW-MPSCs within vascular reconstructing processes (vascular remodeling) which are absolute prerequisite to preserve the sensitive relationship between resilience and stability of the vessel wall. Further, a particular advantage for the therapeutic application of VW-MPSCs for improving vascular function or preventing vascular damage will be discussed.

Holocene Paleohydrological Changes in Northern Michigan: Interpretations of Biomarker Distributions and Compound Specific Stable Isotope Analysis from Peatlands

Science.gov (United States)

Nichols, J. E.; Booth, R. K.; Jackson, S. T.; Pendall, E. G.; Huang, Y.

2006-12-01

Sediments of ombrotrophic peatlands are excellent archives for reconstructing past changes in precipitation/evaporation (P/E) balance. Multiproxy analysis of these sediments is critical for better understanding of climatic events experienced by these highly sensitive systems, as each proxy may respond to different climate parameters. In this study, we use distributions of n-alkanes and δD of Sphagnum biomarkers to interpret paleohydrology from sediments of Irwin Smith Bog, northern Michigan. We then integrate these data with pollen data and testate amoebae-inferred water table depth. Sphagnum moss is the dominant peat former in ombrotrophic bogs, but vascular plants become abundant when water tables are drawn down. Thus, the abundance of Sphagnum relative to vascular plants is indicative of peatland hydrology. The n-alkanes produced by Sphagnum differ from vascular plants in the relative abundance of the different homologues, with the former having excess amounts of shorter chain C23 n-alkane. We use several measures (compound ratios, PCA) to show changes in then-alkane distributions in the sediments, and thus changes in the peatland plant community. Our data provide high- resolution, quantitative paleohydrological records for the study region that are consistent with other records. We also show that the relative abundance of a newly identified Sphagnum biomarker, 2-heptacosanone, can be used to reconstruct changing plant communities. Because ombrotrophic systems lose water by evaporation, drier/warmer conditions cause hydrogen isotopic enrichment of bog water and Sphagnum biomarkers. We measured the δD of C23 n-alkane and 2-heptacosanone to provide additional paleoclimate information. Our multiproxy approach allows us to better understand the climate changes during key intervals of the Holocene. For example, a sharp decrease in the abundance of Tsuga canadensis (hemlock) pollen has been previously identified in records from many places throughout eastern North

Exclusion of brown lemmings reduces vascular plant cover and biomass in Arctic coastal tundra: resampling of a 50 + year herbivore exclosure experiment near Barrow, Alaska

International Nuclear Information System (INIS)

Johnson, D R; Lara, M J; Tweedie, C E; Shaver, G R; Batzli, G O; Shaw, J D

2011-01-01

To determine the role lemmings play in structuring plant communities and their contribution to the 'greening of the Arctic', we measured plant cover and biomass in 50 + year old lemming exclosures and control plots in the coastal tundra near Barrow, Alaska. The response of plant functional types to herbivore exclusion varied among land cover types. In general, the abundance of lichens and bryophytes increased with the exclusion of lemmings, whereas graminoids decreased, although the magnitude of these responses varied among land cover types. These results suggest that sustained lemming activity promotes a higher biomass of vascular plant functional types than would be expected without their presence and highlights the importance of considering herbivory when interpreting patterns of greening in the Arctic. In light of the rapid environmental change ongoing in the Arctic and the potential regional to global implications of this change, further exploration regarding the long-term influence of arvicoline rodents on ecosystem function (e.g. carbon and energy balance) should be considered a research priority.

Using NASA's GeneLab for VESGEN Systems Analysis of Vascular Phenotypes from Stress and Other Signaling Pathways

Science.gov (United States)

Parsons-Wingerter, P.; Weitzel, Alexander; Vyas, R. J.; Murray, M. C.; Vickerman, M. B.; Bhattacharya, S.; Wyatt, S. E.

2016-01-01

One fundamental requirement shared by humans with all higher terrestrial life forms, including other vertebrates, insects, and higher land plants, is a complex, fractally branching vascular system. NASA's VESsel GENeration Analysis (VESGEN) software maps and quantifies vascular trees, networks, and tree-network composites according to weighted physiological rules such as vessel connectivity, tapering and bifurcational branching. According to fluid dynamics, successful vascular transport requires a complex distributed system of highly regulated laminar flow. Microvascular branching rules within vertebrates, dicot leaves and the other organisms therefore display many similarities. A unifying perspective is that vascular patterning offers a useful readout of molecular signaling that necessarily integrates these complex pathways. VESGEN has elucidated changes in vascular pattern resulting from inflammatory, developmental and other signaling within numerous tissues and major model organisms studied for Space Biology. For a new VESGEN systems approach, we analyzed differential gene expression in leaves of Arabidopsis thaliana reported by GeneLab (GLDS-7) for spaceflight. Vascularrelated changes in leaf gene expression were identified that can potentially be phenocopied by mutants in ground-based experiments. To link transcriptional, protein and other molecular change with phenotype, alterations in the spatial and dynamic dimensions of vascular patterns for Arabidopsis leaves and other model species are being co-localized with signaling patterns of single molecular expression analyzed as information dimensions. Previously, Drosophila microarray data returned from space suggested significant changes in genes related to wing venation development that include EGF, Notch, Hedghog, Wingless and Dpp signaling. Phenotypes of increasingly abnormal ectopic wing venation in the (non-spaceflight) Drosophila wing generated by overexpression of a Notch antagonist were analyzed by

Vascular Plant and Vertebrate Inventory of Gila Cliff Dwellings National Monument

Science.gov (United States)

Powell, Brian F.; Albrecht, Eric W.; Halvorson, William L.; Schmidt, Cecilia A.; Docherty, Kathleen; Anning, Pamela

2006-01-01

Executive Summary This report summarizes the results of the first comprehensive biological inventory of Gila Cliff Dwellings National Monument (NM) in western New Mexico. This project was part of a larger effort to inventory plants and vertebrates in eight National Park Service units in Arizona and New Mexico. Our surveys address many of the objectives that were set forth in the monument's natural resource management plan almost 20 years ago, but until this effort, those goals were never accomplished. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at Gila Cliff Dwellings NM to document presence of species within the boundaries of the monument. For all taxonomic groups that we studied, we collected 'incidental' sightings on U.S. Forest Service lands adjacent to the monument, and in a few cases we did formal surveys on those lands. Because we used repeatable study designs and standardized field techniques, these inventories can serve as the first step in a biological monitoring program for Gila Cliff Dwellings NM and surrounding lands. We recorded 552 species at Gila Cliff Dwellings NM and the surrounding lands (Table 1). We found no non-native species of reptiles, birds, or mammals, one non-native amphibian (American bullfrog), and 33 non-native plants. Particularly on lands adjacent to the monument we found that the American bullfrog was very abundant, which is a cause for significant management concern. Species of non-native plants that are of management concern include red brome, bufflegrass, and cheatgrass. For a park unit of its size and geographic location, we found the plant and vertebrate communities to be fairly diverse; for each taxonomic group we found representative species from a wide range of taxonomic orders and/or families. The monument's geographic location, with influences from the Rocky Mountain, Chihuahuan Desert, and Madrean ecological provinces, plays an important role in determining

Vascular plant flora of the alpine zone in the southern Rocky Mountains, U.S.A

Science.gov (United States)

James F. Fowler; B. E. Nelson; Ronald L. Hartman

2014-01-01

Field detection of changes in occurrence, distribution, or abundance of alpine plant species is predicated on knowledge of which species are in specific locations. The alpine zone of the Southern Rocky Mountain Region has been systematically inventoried by the staff and floristics graduate students from the Rocky Mountain Herbarium over the last 27 years. It is...

Phytogeography of the vascular páramo flora of Podocarpus National Park, south Ecuador

NARCIS (Netherlands)

Lozano, P.; Cleef, A.M.; Bussmann, R.W.

2009-01-01

A plant ecological transect study of the páramos of the Podocarpus massif, southern Ecuador, was carried out between July 2001 and August 2004. Including herbarium records 187 vascular plant genera were found, which were used for the present phytogeographical analysis. Three geographic flora

Flora of vascular plants of selected Poznań cemeteries

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Aneta Czarna

2012-12-01

Full Text Available The presence of 395 species of vascular flora at four rarely used cemeteries within the Poznań city was confirmed in 2010. Apart from naturally occurring species, cultivated species were noted equally. Among species appearing spontaneously between the graves, species new for the flora of Poland: Chionodoxa forbesii, Ch. luciliae, Puschkinia scilloides, new for the flora of Wielkopolska: Bidens ferulifolius, Hyacinthoides hispanica and new for the flora of Poznań: Erigeron ramosus, Lilium bulbiferum, Pimpinella nigra, Poa subcaerulea, Veronica hederifolia s.s., were recorded. Names of taxa originating from cultivation are underlined.

Reliability study: steam generation and distribution system, Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Baker, F.E.; Davis, E.L.; Dent, J.T.; Walters, D.E.; West, R.M.

1982-10-01

A reliability study for determining the ability of the Steam Generation and Distribution System to provide reliable and adequate service through the year 2000 has been completed. This study includes an evaluation of the X-600 Steam Plant and the steam distribution system. The Steam Generation and Distribution System is in good overall condition, but to maintain this condition, the reliability study team made twelve recommendations. Eight of the recommendations are for repair or replacement of existing equipment and have a total estimated cost of $540,000. The other four recommendations are for additional testing, new procedure implementation, or continued investigations

[Distribution pattern of riparian invasive plants in Luanhe Basin, North China and its relationship with environment].

Science.gov (United States)

Ren, Ying; He, Ping; Xu, Jie; Jia, Jiao

2017-06-18

In this study, the invasive plant species from the riparian vegetation in 56 sampling sites of Luanhe Basin were identified, and the correlations between their composition, spatial distribution and environmental factors were explored. In the basin, a total of 26 invasive species were registered, which belonged to 19 genera and 12 families, and 73.1% of them were annual plants. Asteraceae and Amaranthaceae were the two dominant families with the most invasive species, attributing to 50% of the total invasive species. Amaranthus retroflexus, Bidens frondosa and Chenopodium serotinum appeared with the highest frequencies. The number of invasive species and the invasive intensity at each site were significantly negatively correlated with the altitude. The distribution of invasive plants was significantly influenced by the intensity of human activities. The invasive plants were mainly distributed in the plain area, shallow mountainous area with many reservoirs, and the mountainous area with developed tourism around Chengde City, meanwhile, only few species with broad ecological amplitude existed in the plateau area. In general, species with higher invasive grades were mainly distributed in low and medium altitude areas below 400 m. Except for A. retroflexus, no high-grade invasive plants were discovered in high altitude area so far.

Distributed control and instrumentation systems for future nuclear power plants

International Nuclear Information System (INIS)

Yan, G.; L'Archeveque, J.V.R.

1976-01-01

The centralized dual computer system philosophy has evolved as the key concept underlying the highly successful application of direct digital control in CANDU power reactors. After more than a decade, this basis philosophy bears re-examination in the light of advances in system concepts--notably distributed architectures. A number of related experimental programs, all aimed at exploring the prospects of applying distributed systems in Canadian nuclear power plants are discussed. It was realized from the outset that the successful application of distributed systems depends on the availability of a highly reliable, high capacity, low cost communications medium. Accordingly, an experimental facility has been established and experiments have been defined to address such problem areas as interprocess communications, distributed data base design and man/machine interfaces. The design of a first application to be installed at the NRU/NRX research reactors is progressing well

Selectivity by host plants affects the distribution of arbuscular mycorrhizal fungi: evidence from ITS rDNA sequence metadata

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Yang Haishui

2012-04-01

Full Text Available Abstract Background Arbuscular mycorrhizal fungi (AMF can form obligate symbioses with the vast majority of land plants, and AMF distribution patterns have received increasing attention from researchers. At the local scale, the distribution of AMF is well documented. Studies at large scales, however, are limited because intensive sampling is difficult. Here, we used ITS rDNA sequence metadata obtained from public databases to study the distribution of AMF at continental and global scales. We also used these sequence metadata to investigate whether host plant is the main factor that affects the distribution of AMF at large scales. Results We defined 305 ITS virtual taxa (ITS-VTs among all sequences of the Glomeromycota by using a comprehensive maximum likelihood phylogenetic analysis. Each host taxonomic order averaged about 53% specific ITS-VTs, and approximately 60% of the ITS-VTs were host specific. Those ITS-VTs with wide host range showed wide geographic distribution. Most ITS-VTs occurred in only one type of host functional group. The distributions of most ITS-VTs were limited across ecosystem, across continent, across biogeographical realm, and across climatic zone. Non-metric multidimensional scaling analysis (NMDS showed that AMF community composition differed among functional groups of hosts, and among ecosystem, continent, biogeographical realm, and climatic zone. The Mantel test showed that AMF community composition was significantly correlated with plant community composition among ecosystem, among continent, among biogeographical realm, and among climatic zone. The structural equation modeling (SEM showed that the effects of ecosystem, continent, biogeographical realm, and climatic zone were mainly indirect on AMF distribution, but plant had strongly direct effects on AMF. Conclusion The distribution of AMF as indicated by ITS rDNA sequences showed a pattern of high endemism at large scales. This pattern indicates high specificity

Selectivity by host plants affects the distribution of arbuscular mycorrhizal fungi: evidence from ITS rDNA sequence metadata.

Science.gov (United States)

Yang, Haishui; Zang, Yanyan; Yuan, Yongge; Tang, Jianjun; Chen, Xin

2012-04-12

Arbuscular mycorrhizal fungi (AMF) can form obligate symbioses with the vast majority of land plants, and AMF distribution patterns have received increasing attention from researchers. At the local scale, the distribution of AMF is well documented. Studies at large scales, however, are limited because intensive sampling is difficult. Here, we used ITS rDNA sequence metadata obtained from public databases to study the distribution of AMF at continental and global scales. We also used these sequence metadata to investigate whether host plant is the main factor that affects the distribution of AMF at large scales. We defined 305 ITS virtual taxa (ITS-VTs) among all sequences of the Glomeromycota by using a comprehensive maximum likelihood phylogenetic analysis. Each host taxonomic order averaged about 53% specific ITS-VTs, and approximately 60% of the ITS-VTs were host specific. Those ITS-VTs with wide host range showed wide geographic distribution. Most ITS-VTs occurred in only one type of host functional group. The distributions of most ITS-VTs were limited across ecosystem, across continent, across biogeographical realm, and across climatic zone. Non-metric multidimensional scaling analysis (NMDS) showed that AMF community composition differed among functional groups of hosts, and among ecosystem, continent, biogeographical realm, and climatic zone. The Mantel test showed that AMF community composition was significantly correlated with plant community composition among ecosystem, among continent, among biogeographical realm, and among climatic zone. The structural equation modeling (SEM) showed that the effects of ecosystem, continent, biogeographical realm, and climatic zone were mainly indirect on AMF distribution, but plant had strongly direct effects on AMF. The distribution of AMF as indicated by ITS rDNA sequences showed a pattern of high endemism at large scales. This pattern indicates high specificity of AMF for host at different scales (plant taxonomic

Variation in n-Alkane Distributions of Modern Plants: Questioning Applications of n-Alkanes in Chemotaxonomy and Paleoecology

Science.gov (United States)

Bush, R. T.; McInerney, F. A.

2010-12-01

Long chain n-alkanes (n-C21 to n-C37) are synthesized as part of the epicuticular leaf wax of terrestrial plants and are among the most recognizable and widely used plant biomarkers. n-Alkane distributions have been utilized in previous studies on modern plant chemotaxonomy, testing whether taxa can be identified based on characteristic n-alkane profiles. Dominant n-alkanes (e.g. n-C27 or n-C31) have also been ascribed to major plant groups (e.g. trees or grasses respectively) and have been used in paleoecology studies to reconstruct fluctuations in plant functional types. However, many of these studies have been based on relatively few modern plant data; with the wealth of modern n-alkane studies, a more comprehensive analysis of n-alkanes in modern plants is now possible and can inform the usefulness of n-alkane distributions as paleoecological indicators. The work presented here is a combination of measurements made using plant leaves collected from the Chicago Botanic Garden and a compilation of published literature data from six continents. We categorized plants by type: angiosperms, gymnosperms, woody plants, forbs, grasses, ferns and pteridophytes, and mosses. We then quantified n-alkane distribution parameters such as carbon preference index (CPI), average chain length (ACL), and dispersion (a measure of the spread of the profile over multiple chain lengths) and used these to compare plant groups. Among all plants, one of the emergent correlations is a decrease in dispersion with increasing CPI. Within and among plant groups, n-alkane distributions show a very large range of variation, and the results show little or no correspondence between broad plant groups and a single dominant n-alkane or a ratio of n-alkanes. These findings are true both when data from six continents are combined and when plants from a given region are compared (North America). We also compared the n-alkane distributions of woody angiosperms, woody gymnosperms, and grasses with one

Industrial Electricity. In-Plant Distribution. Vocational Trade and Industrial Education.

Science.gov (United States)

Teague, Cash; Pewewardy, Garner

This curriculum guide, part of a series of industrial electricity curriculum guides, consists of materials for use in teaching a course on the in-plant distribution of electricity. Discussed in the introductory lessons are the National Electrical Code, power equipment, and blueprint reading. The next section, a series of units on branch-circuit…

Non-invasive vascular imaging: assessing tumour vascularity

International Nuclear Information System (INIS)

Delorme, S.; Knopp, M.V.

1998-01-01

Non-invasive assessment of vascularity is a new diagnostic approach to characterise tumours. Vascular assessment is based on the pathophysiology of tumour angiogenesis and its diagnostic implications for tumour biology, prognosis and therapy response. Two current techniques investigating vascular features in addition to morphology are Doppler ultrasonography and contrast-enhanced MRI. Diagnostic differentiation has been shown to be possible with Doppler, and a high degree of observed vascularity could be linked to an aggressive course of the disease. Dynamic MRI using gadolinium chelates is already used clinically to detect and differentiate tumours. The histological correlation shows that capillary permeability is increased in malignant tumours and is the best criterion for differentiation from benign processes. Permeability and perfusion factors seem to be more diagnostic than overall vessel density. New clinical applications are currently being established for therapy monitoring. Further instrumental developments will bring harmonic imaging in Doppler, and faster imaging techniques, higher spatial resolution and novel pharmacokinetic concepts in MRI. Upcoming contrast agents for both Doppler and MRI will further improve estimation of intratumoural blood volume and vascular permeability. (orig.)

The flora phenotype ontology (FLOPO): tool for integrating morphological traits and phenotypes of vascular plants

KAUST Repository

Hoehndorf, Robert

2016-11-14

Background The systematic analysis of a large number of comparable plant trait data can support investigations into phylogenetics and ecological adaptation, with broad applications in evolutionary biology, agriculture, conservation, and the functioning of ecosystems. Floras, i.e., books collecting the information on all known plant species found within a region, are a potentially rich source of such plant trait data. Floras describe plant traits with a focus on morphology and other traits relevant for species identification in addition to other characteristics of plant species, such as ecological affinities, distribution, economic value, health applications, traditional uses, and so on. However, a key limitation in systematically analyzing information in Floras is the lack of a standardized vocabulary for the described traits as well as the difficulties in extracting structured information from free text. Results We have developed the Flora Phenotype Ontology (FLOPO), an ontology for describing traits of plant species found in Floras. We used the Plant Ontology (PO) and the Phenotype And Trait Ontology (PATO) to extract entity-quality relationships from digitized taxon descriptions in Floras, and used a formal ontological approach based on phenotype description patterns and automated reasoning to generate the FLOPO. The resulting ontology consists of 25,407 classes and is based on the PO and PATO. The classified ontology closely follows the structure of Plant Ontology in that the primary axis of classification is the observed plant anatomical structure, and more specific traits are then classified based on parthood and subclass relations between anatomical structures as well as subclass relations between phenotypic qualities. Conclusions The FLOPO is primarily intended as a framework based on which plant traits can be integrated computationally across all species and higher taxa of flowering plants. Importantly, it is not intended to replace established