WorldWideScience

Sample records for higher plant species

  1. Emission of NO from several higher plant species

    Science.gov (United States)

    Wildt, J.; Kley, D.; Rockel, A.; Rockel, P.; Segschneider, H. J.

    1997-03-01

    Emission of nitric oxide (NO) from a variety of plant species was observed in a continuously stirred tank reactor. During daytime and at NO concentrations below 1 ppb in the chamber air, NO emissions were observed for all studied nitrate-nourished plant species. A relation was found between the NO emission rates during daytime and the uptake rates of CO2. The ratio of the NO emission rate to the CO2 uptake was similar for all plants. Changes of the net rate of photosynthesis induced by variations of light intensity or changes of CO2 concentrations changed the NO emission rates correspondingly. The link between NO emissions and CO2 uptake during daytime allowed estimation of the potential of the vegetation to evolve NO on a global scale as 0.23 Tg N yr-1. Strong NO emissions during nights were observed when the nitrate concentration in the nutrient solution was enhanced. Then NO emissions were observed with flux densities comparable to the highest emission rates found from soils.

  2. Plant species richness sustains higher trophic levels of soil nematode communities after consecutive environmental perturbations.

    Science.gov (United States)

    Cesarz, Simone; Ciobanu, Marcel; Wright, Alexandra J; Ebeling, Anne; Vogel, Anja; Weisser, Wolfgang W; Eisenhauer, Nico

    2017-07-01

    The magnitude and frequency of extreme weather events are predicted to increase in the future due to ongoing climate change. In particular, floods and droughts resulting from climate change are thought to alter the ecosystem functions and stability. However, knowledge of the effects of these weather events on soil fauna is scarce, although they are key towards functioning of terrestrial ecosystems. Plant species richness has been shown to affect the stability of ecosystem functions and food webs. Here, we used the occurrence of a natural flood in a biodiversity grassland experiment that was followed by a simulated summer drought experiment, to investigate the interactive effects of plant species richness, a natural flood, and a subsequent summer drought on nematode communities. Three and five months after the natural flooding, effects of flooding severity were still detectable in the belowground system. We found that flooding severity decreased soil nematode food-web structure (loss of K-strategists) and the abundance of plant feeding nematodes. However, high plant species richness maintained higher diversity and abundance of higher trophic levels compared to monocultures throughout the flood. The subsequent summer drought seemed to be of lower importance but reversed negative flooding effects in some cases. This probably occurred because the studied grassland system is well adapted to drought, or because drought conditions alleviated the negative impact of long-term soil waterlogging. Using soil nematodes as indicator taxa, this study suggests that high plant species richness can maintain soil food web complexity after consecutive environmental perturbations.

  3. The evolutionary reality of species and higher taxa in plants: a survey of post-modern opinion and evidence.

    Science.gov (United States)

    Barraclough, Timothy G; Humphreys, Aelys M

    2015-07-01

    Species are normally considered to be the fundamental unit for understanding the evolution of biodiversity. Yet, in a survey of botanists in 1940, twice as many felt that plant genera were more natural units than plant species. Revisiting the survey, we found more people now regarded species as a more evolutionarily real unit, but a sizeable number still felt that genera were more evolutionarily real than species. Definitions of 'evolutionarily real' split into those based on shared evolutionary history and those based on shared evolutionary fate via ongoing evolutionary processes. We discuss recent work testing for shared evolutionary fate at the species and higher levels and present preliminary evidence for evolutionarily significant higher taxa in plants. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  4. Proteomics of terpenoid biosynthesis and secretion in trichomes of higher plant species.

    Science.gov (United States)

    Champagne, Antoine; Boutry, Marc

    2016-08-01

    Among the specialized (secondary) plant metabolites, terpenoids represent the most diverse family and are often involved in the defense against pathogens and herbivores. Terpenoids can be produced both constitutively and in response to the environment. At the front line of this defense strategy are the glandular trichomes, which are organs dedicated primarily to the production of specialized metabolites. Mass spectrometry-based proteomics is a powerful tool, which is very useful to investigate enzymes involved in metabolic pathways, such as the synthesis and secretion of terpenoids in glandular trichomes. Here we review the strategies used to investigate the specific roles of these particular organs from non-model plant species, mainly belonging to the Lamiaceae, Solanaceae, and Cannabaceae families. We discuss how proteomics helps to accurately pinpoint candidate proteins to be functionally characterized, and how technological progresses create opportunities for studying low-abundance proteins, such as the ones related to the synthesis and transport of specialized metabolites. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. UV Screening in Native and Non-native Plant Species in the Tropical Alpine: Implications for Climate Change-Driven Migration of Species to Higher Elevations.

    Science.gov (United States)

    Barnes, Paul W; Ryel, Ronald J; Flint, Stephan D

    2017-01-01

    Ongoing changes in Earth's climate are shifting the elevation ranges of many plant species with non-native species often experiencing greater expansion into higher elevations than native species. These climate change-induced shifts in distributions inevitably expose plants to novel biotic and abiotic environments, including altered solar ultraviolet (UV)-B (280-315 nm) radiation regimes. Do the greater migration potentials of non-native species into higher elevations imply that they have more effective UV-protective mechanisms than native species? In this study, we surveyed leaf epidermal UV-A transmittance (TUV A) in a diversity of plant species representing different growth forms to test whether native and non-native species growing above 2800 m elevation on Mauna Kea, Hawaii differed in their UV screening capabilities. We further compared the degree to which TUV A varied along an elevation gradient in the native shrub Vaccinium reticulatum and the introduced forb Verbascum thapsus to evaluate whether these species differed in their abilities to adjust their levels of UV screening in response to elevation changes in UV-B. For plants growing in the Mauna Kea alpine/upper subalpine, we found that adaxial TUV A, measured with a UVA-PAM fluorometer, varied significantly among species but did not differ between native (mean = 6.0%; n = 8) and non-native (mean = 5.8%; n = 11) species. When data were pooled across native and non-native taxa, we also found no significant effect of growth form on TUV A, though woody plants (shrubs and trees) were represented solely by native species whereas herbaceous growth forms (grasses and forbs) were dominated by non-native species. Along an elevation gradient spanning 2600-3800 m, TUV A was variable (mean range = 6.0-11.2%) and strongly correlated with elevation and relative biologically effective UV-B in the exotic V. thapsus; however, TUV A was consistently low (3%) and did not vary with elevation in the native V. reticulatum

  6. Higher plant and vertebrate species richness in Spanish and some mediterranean mountains

    Directory of Open Access Journals (Sweden)

    Martínez-Rica, J. P.

    1998-12-01

    Full Text Available This paper reviews the biodiversity of the Spanish and some other Mediterranean mountains. These have some of the richest areas for vascular plants recorded apart from some areas in the tropics. The number of endemic species is substantial. Six areas in Spain and four other Mediterranean areas are described in detail. A special plea is made for a comprehensive detailed vegetation map for European mountains to include the Spanish and Mediterranean mountains.

    [fr] Ce travail porte sur la biodiversité de quelques montagnes méditerranéennes, notamment celle de l'Espagne. Ces dernières montrent une flore vasculaire des plus riches au monde, si l'on excepte les pays tropicaux. Aussi le nombre d'espèces endémiques est très important. Six systèmes montagneux d'Espagne et quatre autres sur le pourtour méditerranéen sont étudiés en détail. Dans une section spéciale on étudie la carte de végétation synthétique des montagnes européennes, de façon à inclure les montagnes de l'Espagne et de la Méditerranée. [es] Se estudia la biodiversidad de las montañas españolas y de otras mediterráneas. Si se exceptúan algunas áreas tropicales, se trata de una de las áreas más ricas en plantas vasculares. El número de especies endémicas resulta sustancial. Se estudian con mayor detalle seis áreas montañosas de España y cuatro áreas más del Mediterráneo. De un modo particular se estudia un mapa sintético de vegetación de las montañas de Europa en relación con las montañas de España y del Mediterráneo.

  7. Classical mutagenesis in higher plants

    NARCIS (Netherlands)

    Koornneef, M.

    2002-01-01

    For a long time, mutagenesis research in plants focused on crop improvement and, especially for crop plants, opimised protocols were developed with barley being one of the favourite species. However, the interest in mutagenesis has shifted to basic plant research in the last 20 years, when the power

  8. Chromosomal replicons of higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Van' t Hof, J.

    1987-03-16

    This brief discussion of replicons of higher plants offers a glimpse into the properties of chromosomal DNA replication. It gives evidence that the S phase of unrelated plant species is comprised of temporally ordered replicon families that increase in number with genome size. This orderly process, which assures a normal inheritance of genetic material to recipient daughter cells, is maintained at the level of replicon clusters by two mutually exclusive mechanisms, one involving the rate at which single replicons replicate their allotment of DNA, and another by means of the tempo-pause. The same two mechanisms are used by cells to alter the pattern of chromosomal DNA replication just prior to and during normal development. Both mechanisms are genetically determined and produce genetic effects when disturbed of disrupted by additional non-conforming DNAs. Further insight into how these two mechanisms operate requires more molecular information about the nature of replicons and the factors that govern when a replicon family replicates. Plant material is a rich and ideal source for this information just awaiting exploitation. 63 refs.

  9. Classical mutagenesis in higher plants

    OpenAIRE

    Koornneef, M.

    2002-01-01

    For a long time, mutagenesis research in plants focused on crop improvement and, especially for crop plants, opimised protocols were developed with barley being one of the favourite species. However, the interest in mutagenesis has shifted to basic plant research in the last 20 years, when the power of mutant approaches in combination with molecular techniques to investigate the molecular nature of the genes became fully appreciated

  10. Cellulose biosynthesis in higher plants

    Directory of Open Access Journals (Sweden)

    Krystyna Kudlicka

    2014-01-01

    Full Text Available Knowledge of the control and regulation of cellulose synthesis is fundamental to an understanding of plant development since cellulose is the primary structural component of plant cell walls. In vivo, the polymerization step requires a coordinated transport of substrates across membranes and relies on delicate orientations of the membrane-associated synthase complexes. Little is known about the properties of the enzyme complexes, and many questions about the biosynthesis of cell wall components at the cell surface still remain unanswered. Attempts to purify cellulose synthase from higher plants have not been successful because of the liability of enzymes upon isolation and lack of reliable in vitro assays. Membrane preparations from higher plant cells incorporate UDP-glucose into a glucan polymer, but this invariably turns out to be predominantly β -1,3-linked rather than β -1,4-linked glucans. Various hypotheses have been advanced to explain this phenomenon. One idea is that callose and cellulose-synthase systems are the same, but cell disruption activates callose synthesis preferentially. A second concept suggests that a regulatory protein as a part of the cellulose-synthase complex is rapidly degraded upon cell disruption. With new methods of enzyme isolation and analysis of the in vitro product, recent advances have been made in the isolation of an active synthase from the plasma membrane whereby cellulose synthase was separated from callose synthase.

  11. Silicon transporters in higher plants.

    Science.gov (United States)

    Ma, Jian Feng

    2010-01-01

    Silicon (Si) is the second most abundant element in the Earth's crust and exerts beneficial effects on plant growth and production by alleviating both biotic and abiotic stresses including diseases, pests, lodging, drought and nutrient imbalance. Silicon is taken up by the roots in the form ofsilicic acid, a noncharged molecule. Recently both influx (Lsil) and efflux (Lsi2) transporters for silicic acid have been identified in gramineous plants including rice, barley and maize. Lsil and its homologs are influx Si transporters, which belong to a Nod26-like major intrinsic protein (NIP) subfamily in the aquaporin protein family. They are responsible for the transport of Si from the external solution to the root cells. On the other hand, Lsi2 and its homologs are efflux Si transporters, belonging to putative anion transporters and are responsible for the transport of Si out of the cells toward the xylem. All influx transporters show polar localization at the distal side. Among efflux transporters, Lsi2 in rice shows polar localization at the proximal side, but that in barley and maize does not show polar localization. The cell-specificity of localization of Si transporters and expression patterns are different between species. Rice Si transporters are also permeable to arsenite.

  12. Large-scale changes in the abundance of common higher plant species across Britain between 1978, 1990 and 1998 as a consequence of human activity: Tests of hypothesised changes in trait representation

    NARCIS (Netherlands)

    Smart, S.M.; Bunce, R.G.H.; Marrs, R.; LeDuc, M.; Firbank, L.G.; Maskell, L.C.; Scott, W.A.; Thompson, K.; Walker, K.J.

    2005-01-01

    Presence of higher plant species was recorded in 1455 permanently marked quadrats located across Britain in 1978, 1990 and 1998 in a stratified, random sample of 259 1 km squares. Significant increases and decreases in frequency of each species were summarised as changes in the representation of

  13. Jumping Genes Cross Plant Species Boundaries

    OpenAIRE

    Xianmin Diao; Michael Freeling; Damon Lisch

    2005-01-01

    The majority of well-documented cases of horizontal transfer between higher eukaryotes involve the movement of transposable elements between animals. Surprisingly, although plant genomes often contain vast numbers of these mobile genetic elements, no evidence of horizontal transfer of a nuclear-encoded transposon between plant species has been detected to date. The most mutagenic known plant transposable element system is the Mutator system in maize. Mu-like elements (MULEs) are widespread am...

  14. Radiation hormesis in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Sung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-03-01

    The most remarkable aspect in the hormesis law is that low dose of harmful agents can produce effect that are diametrically opposite to the effect found with high doses of the same agent. Minute quantities of a harmful agent bring about very small change in the organism and control mechanisms appear to subjugate normal processes to place the organism in a state of alert and repair. The stimulated organism is more responsive to changes in environmental factors than it did before being alerted. Routine functions, including repair and defense, have priority for available energy and material. The alerted organism utilizes nutrients more efficiently, grows faster, shows improved defense reactions, matures faster, reproduces more effectively, has less disease, and lives longer. Accelerated germination, sprouting, growth, development, blooming and ripening, and increased crop yield and resistance to disease are found in plants. Another concept supported by the data is that low doses of ionizing radiation provide increased resistance to subsequent high doses of radiation. The hormesis varies with subject plant, variety, state of seed, environmental and cultural conditions, physiologic function measured, dose rate and total exposure. The results of hormesis are less consistently found, probably due to the great number of uncontrolled variables in the experiments. The general dosage for radiation hormesis in about 100 times ambient or 100 times less than a definitely harmful dose, but these must be modified to the occasion. Although little is known about most mechanisms of hormesis reaction, overcompensation of repair mechanism is offered as on mechanism. Radiation hormesis can provide more efficient use of resources, maximum production of foods, and increased health by the use of ionizing radiation as a useful tool in our technologic society. Efficient utilization of nature`s resources demands support to explore the practical application of radiation hormesis.

  15. Sucrose transporters of higher plants.

    Science.gov (United States)

    Kühn, Christina; Grof, Christopher P L

    2010-06-01

    Recent advances have provided new insights into how sucrose is moved from sites of synthesis to sites of utilisation or storage in sink organs. Sucrose transporters play a central role, as they orchestrate sucrose allocation both intracellularly and at the whole plant level. Sucrose produced in mesophyll cells of leaves may be effluxed into the apoplasm of mesophyll or phloem parenchyma cells by a mechanism that remains elusive, but experimentally consistent with facilitated transport or energy-dependent sucrose/H(+) antiport. From the apoplasm, sucrose/H(+) symporters transport sucrose across the plasma membrane of cells making up the sieve element/companion cell (SE/CC) complex, the long distance conduits of the phloem. Phloem unloading of sucrose in key sinks such as developing seeds involves two sequential transport steps, sucrose efflux followed by sucrose influx. Besides plasma membrane specific sucrose transporters, sucrose transporters on the tonoplast contribute to the capacity for elevated sucrose accumulation in storage organs such as sugar beet roots or sugarcane culms. Except for several sucrose facilitators from seed coats of some leguminous plants all sucrose transporters cloned to date, including recently identified vacuolar sucrose transporters, have been characterised as sucrose/H(+) symporters. Transporters functioning to efflux sucrose into source or sink apoplasms as well as those supporting sucrose/H(+) antiport on tonoplasts, remain to be identified. Sucrose transporter expression and activity is tightly regulated at the transcriptional, post-transcriptional as well as post-translational levels. Light quality and phytohormones play essential regulatory roles and the sucrose molecule itself functions as a signal. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Predicting molybdenum toxicity to higher plants: Influence of soil properties

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, S.P., E-mail: steve.mcgrath@bbsrc.ac.u [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Mico, C. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Curdy, R. [Laboratory for Environmental Biotechnology (LBE), Swiss Federal Institute of Technology Lausanne (EPFL) Station 6 CH, 1015 Lausanne (Switzerland); Zhao, F.J. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom)

    2010-10-15

    The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED{sub 50}) of Mo in different soils, explaining > 65% of the variance in ED{sub 50} for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. - Amorphous iron oxides or organic carbon were found to be the best predictors of the toxicity threshold values of Mo to higher plants on different soils.

  17. Acentrosomal microtubule nucleation in higher plants.

    Science.gov (United States)

    Schmit, Anne-Catherine

    2002-01-01

    Higher plants have developed a unique pathway to control their cytoskeleton assembly and dynamics. In most other eukaryotes, microtubules are nucleated in vivo at the nucleation and organizing centers and are involved in the establishment of polarity. Although the major cytoskeletal components are common to plant and animal cells, which suggests conserved regulation mechanisms, plants do not possess centrosome-like organelles. Nevertheless, they are able to build spindles and have developed their own specific cytoskeletal arrays: the cortical arrays, the preprophase band, and the phragmoplast, which all participate in basic developmental processes, as shown by defective mutants. New approaches provide essential clues to understanding the fundamental mechanisms of microtubule nucleation. Gamma-tubulin, which is considered to be the universal nucleator, is the essential component of microtubule-nucleating complexes identified as gamma-tubulin ring complexes (gamma-TuRC) in centriolar cells. A gamma-tubulin small complex (gamma-TuSC) forms a minimal nucleating unit recruited at specific sites of activity. These components--gamma-tubulin, Spc98p, and Spc97p--are present in higher plants. They play a crucial role in microtubule nucleation at the nuclear surface, which is known as the main functional plant microtubule-organizing center, and also probably at the cell cortex and at the phragmoplast, where secondary nucleation sites may exist. Surprisingly, plant gamma-tubulin is distributed along the microtubule length. As it is not associated with Spc98p, it may not be involved in microtubule nucleation, but may preferably control microtubule dynamics. Understanding the mechanisms of microtubule nucleation is the major challenge of the current research.

  18. Fractionation of metal stable isotopes by higher plants

    Science.gov (United States)

    Von Blanckenburg, F.; Von Wiren, N.; Guelke, M.; Weiss, D.J.; Bullen, T.D.

    2009-01-01

    Higher plants induce chemical reactions in the rhizosphere, facilitating metal uptake by roots. Fractionation of the isotopes in nutrients such as calcium, iron, magnesium, and zinc produces a stable isotope composition in the plants that generally differs from that of the growth medium. Isotope fractionation also occurs during transport of the metals within most plants, but its extent depends on plant species and on the metal, in particular, on the metal's redox state and what ligand it is bound to. The metal stable isotope variations observed in plants create an isotope signature of life at the Earth's surface, contributing substantially to our understanding of metal cycling processes in the environment and in individual organisms.

  19. Invasive plant species in hardwood tree plantations

    Science.gov (United States)

    Rochelle R. Beasley; Paula M. Pijut

    2010-01-01

    Invasive plants are species that can grow and spread aggressively, mature quickly, and invade an ecosystem causing economic and environmental damage. Invasive plants usually invade disturbed areas, but can also colonize small areas quickly, and may spread and dominate large areas in a few short years. Invasive plant species displace native or desirable forest...

  20. Higher plant transformation: principles and molecular tools.

    Science.gov (United States)

    Anami, Sylvester; Njuguna, Elizabeth; Coussens, Griet; Aesaert, Stijn; Van Lijsebettens, Mieke

    2013-01-01

    In higher plants, genetic transformation, which is part of the toolbox for the study of living organisms, had been reported only 30 years ago, boosting basic plant biology research, generating superior crops, and leading to the new discipline of plant biotechnology. Here, we review its principles and the corresponding molecular tools. In vitro regeneration, through somatic embryogenesis or organogenesis, is discussed because they are prerequisites for the subsequent Agrobacterium tumefaciens-mediated transferred (T)-DNA or direct DNA transfer methods to produce transgenic plants. Important molecular components of the T-DNA are examined, such as selectable marker genes that allow the selection of transformed cells in tissue cultures and are used to follow the gene of interest in the next generations, and reporter genes that have been developed to visualize promoter activities, protein localizations, and protein-protein interactions. Genes of interest are assembled with promoters and termination signals in Escherichia coli by means of GATEWAY-derived binary vectors that represent the current versatile cloning tools. Finally, future promising developments in transgene technology are considered.

  1. Do invasive plant species alter soil health?

    Science.gov (United States)

    Invasive species may alter soil characteristics or interact with the soil microbial community to yield a competitive advantage. Our objectives were to determine: if invasive plant species alter soil properties important to soil health; and the long-term effects of invasive plant species on soil pro...

  2. Why Some Plant Species Are Rare

    NARCIS (Netherlands)

    Weiger Wamelink, G.W.; Goedhart, P.W.; Frissel, J.Y.

    2014-01-01

    Biodiversity, including plant species diversity, is threatened worldwide as a result of anthropogenic pressures such as an increase of pollutants and climate change. Rare species in particular are on the verge of becoming extinct. It is still unclear as to why some plant species are rare and others

  3. Plant invasion is associated with higher plant-soil nutrient concentrations in nutrient-poor environments.

    Science.gov (United States)

    Sardans, Jordi; Bartrons, Mireia; Margalef, Olga; Gargallo-Garriga, Albert; Janssens, Ivan A; Ciais, Phillipe; Obersteiner, Michael; Sigurdsson, Bjarni D; Chen, Han Y H; Peñuelas, Josep

    2017-03-01

    Plant invasion is an emerging driver of global change worldwide. We aimed to disentangle its impacts on plant-soil nutrient concentrations. We conducted a meta-analysis of 215 peer-reviewed articles and 1233 observations. Invasive plant species had globally higher N and P concentrations in photosynthetic tissues but not in foliar litter, in comparison with their native competitors. Invasive plants were also associated with higher soil C and N stocks and N, P, and K availabilities. The differences in N and P concentrations in photosynthetic tissues and in soil total C and N, soil N, P, and K availabilities between invasive and native species decreased when the environment was richer in nutrient resources. The results thus suggested higher nutrient resorption efficiencies in invasive than in native species in nutrient-poor environments. There were differences in soil total N concentrations but not in total P concentrations, indicating that the differences associated to invasive plants were related with biological processes, not with geochemical processes. The results suggest that invasiveness is not only a driver of changes in ecosystem species composition but that it is also associated with significant changes in plant-soil elemental composition and stoichiometry. © 2016 John Wiley & Sons Ltd.

  4. Passive CO2 concentration in higher plants.

    Science.gov (United States)

    Sage, Rowan F; Khoshravesh, Roxana

    2016-06-01

    Photorespiratory limitations on C3 photosynthesis are substantial in warm, low CO2 conditions. To compensate, certain plants evolved mechanisms to actively concentrate CO2 around Rubisco using ATP-supported CO2 pumps such as C4 photosynthesis. Plants can also passively accumulate CO2 without additional ATP expenditure by localizing the release of photorespired and respired CO2 around Rubisco that is diffusively isolated from peripheral air spaces. Passive accumulation of photorespired CO2 occurs when glycine decarboxylase is localized to vascular sheath cells in what is termed C2 photosynthesis, and through forming sheaths of chloroplasts around the periphery of mesophyll cells. The peripheral sheaths require photorespired CO2 to re-enter chloroplasts where it can be refixed. Passive accumulation of respiratory CO2 is common in organs such as stems, fruits and flowers, due to abundant heterotrophic tissues and high diffusive resistance along the organ periphery. Chloroplasts within these organs are able to exploit this high CO2 to reduce photorespiration. CO2 concentration can also be enhanced passively by channeling respired CO2 from roots and rhizomes into photosynthetic cells of stems and leaves via lacunae, aerenchyma and the xylem stream. Through passive CO2 concentration, C3 species likely improved their carbon economy and maintained fitness during episodes of low atmospheric CO2. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Cytoplasniic differentiation during microsporogenesis in higher plants

    Directory of Open Access Journals (Sweden)

    H. Dichinnson

    2014-01-01

    Full Text Available Conspicuous cytoplasmic dedifferentiation in the pollen mother cells takes place early in the meiotic prophase of many plants. This event involves the removal of much of the cytoplasmic RNA. and the differentiation of both plastids and mitochondria to approaching the sole expression of their genomes. Much of the RNA removed from the cytoplasm passes to the nucleoplasm where it is utilised in the construction of a new `generation' of ribusomes. These new ribosomes are incorporated into cytoplasmic `nuclewhich disintegrate in the post-meiotic cytoplasm, restoring its ribosomes to pre-prophase levels. These changes are interpreted as evidence of a process by which the cytoplasm is cleansed of sporophytic control elements, both for the expression of the new gametophytic genome, and in the female cells of higher plants, for transmission to the new generation. The absence of control elements (presumably long-term messenger RNA from the cytoplasm would result in the dedifferentiation observed in the organelles, and the low levels of reserves in these cells presumably results in characteristically lengthy and unusual redifferentiation of both plastids and mitochondria, once information-carrying molecules again enter the cytosol.

  6. The Invasive Plant Species Education Guide

    Science.gov (United States)

    Mason, Kevin; James, Krista; Carlson, Kitrina; D'Angelo, Jean

    2010-01-01

    To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS) Education Guide. The IPS Education Guide includes nine lessons that give students an…

  7. Mechanisms of male sterility in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Yasuo (Tsukuba Univ., Sakura, Ibaraki (Japan))

    1982-03-01

    The mechanisms causing male sterility in higher plants were classified into two major categories: genetic and non-genetic. The former was further divided into six classes: 1) Anomality in spindle mechanism during meiosis, 2) chromosomal anomality such as haploidy, polyploidy, aneuploidy, chromosome some deficiency, inversion and reciprocal translocation, 3) presence of male sterile genes, 4) cytoplasmic abnormality, 5) the combination of some specific cytoplasm with particular genes, and 6) infections of microorganisms or viruses. Each mechanism was briefly explained, and the methods for the maintenance of parent lines for heterosis breeding and hybrid seed production were described. The non-genetic male sterility was classified into four types, which are caused by 1) low or high temperature, 2) water deficiency, 3) application of chemicals, and 4) radiation, with a brief explanation given for each of them.

  8. Effect of free fall on higher plants.

    Science.gov (United States)

    Gordon, S. A.

    1973-01-01

    The influence of exposure to the free-fall state on the orientation, morphogenesis, physiology, and radiation response of higher plants is briefly summarized. It is proposed that the duration of the space-flight experiments has been to brief to permit meaningful effects of free fall on general biochemistry, growth, and development to appear. However, two types of significant effect did occur. The first is on differential growth - i.e., tropism and epinasty - resulting from the absence of a normal geostimulus. For these phenomena it is suggested that ground-based experiments with the clinostat would suffice to mimic the effect of the free-fall state. The second is an apparent interaction between the radiation response and some flight condition, yielding an enhanced microspore abortion, a disturbed spindle function, and a stunting of stamen hairs. It is suggested that this apparent interaction may be derived from a shift in the rhythm of the cell cycle, induced by the free fall.

  9. Why some plant species are rare.

    Directory of Open Access Journals (Sweden)

    G W Wieger Wamelink

    Full Text Available Biodiversity, including plant species diversity, is threatened worldwide as a result of anthropogenic pressures such as an increase of pollutants and climate change. Rare species in particular are on the verge of becoming extinct. It is still unclear as to why some plant species are rare and others are not. Are they rare due to: intrinsic reasons, dispersal capacity, the effects of management or abiotic circumstances? Habitat preference of rare plant species may play an important role in determining why some species are rare. Based on an extensive data set of soil parameters we investigated if rarity is due to a narrow habitat preference for abiotic soil parameters. For 23 different abiotic soil parameters, of which the most influential were groundwater-table, soil-pH and nutrient-contents, we estimated species responses for common and rare species. Based on the responses per species we calculated the range of occurrence, the range between the 5 and 95 percentile of the response curve giving the habitat preference. Subsequently, we calculated the average response range for common and rare species. In addition, we designed a new graphic in order to provide a better means for presentation of the results. The habitat preferences of rare species for abiotic soil conditions are significantly narrower than for common species. Twenty of the twenty-three abiotic parameters showed on average significantly narrower habitat preferences for rare species than for common species; none of the abiotic parameters showed on average a narrower habitat preference for common species. The results have major implications for the conservation of rare plant species; accordingly management and nature development should be focussed on the maintenance and creation of a broad range of environmental conditions, so that the requirements of rare species are met. The conservation of (abiotic gradients within ecosystems is particularly important for preserving rare species.

  10. New mite species associated with certain plant species from Guam

    Directory of Open Access Journals (Sweden)

    Gadi V.P. Reddy

    2011-04-01

    Full Text Available Several new mite species have been reported from certain plants from Guam. Most remarkably, the spider mite, Tetranychus marianae (Prostigmata: Tetranychidae and the predatory mite Phytoseius horridus (Mesostigmata: Phytoseiidae (Solanum melongena have been found on eggplant. The noneconomically important species of Brevipalpus californicus(Banks Prostigmata: Tenuipalpidae,Eupodes sp. (Acarina: Eupodidae and predator Cunaxa sp. (Prostigmata: Cunaxidae have been reported on guava (Psidium guajava L.. Also, the non-economically important species Brevipalpus californicus Prostigmata: Tenuipalpidae, Lepidoglyphus destructor (Astigmata: Glycyphagidae and a predator Amblyseius obtusus, species group Amblyseius near lentiginosus (Mesostigmata: Phytoseiidae, have been recorded on cycad (Cycas micronesica.

  11. Human impacts, plant invasion, and imperiled plant species in California.

    Science.gov (United States)

    Seabloom, Eric W; Williams, John W; Slayback, Daniel; Stoms, David M; Viers, Joshua H; Dobson, Andy P

    2006-08-01

    Invasive species are one of the fastest growing conservation problems. These species homogenize the world's flora and fauna, threaten rare and endemic species, and impose large economic costs. Here, we examine the distribution of 834 of the more than 1000 exotic plant taxa that have become established in California, USA. Total species richness increases with net primary productivity; however, the exotic flora is richest in low-lying coastal sites that harbor large numbers of imperiled species, while native diversity is highest in areas with high mean elevation. Weedy and invasive exotics are more tightly linked to the distribution of imperiled species than the overall pool of exotic species. Structural equation modeling suggests that while human activities, such as urbanization and agriculture, facilitate the initial invasion by exotic plants, exotics spread ahead of the front of human development into areas with high numbers of threatened native plants. The range sizes of exotic taxa are an order of magnitude smaller than for comparable native taxa. The current small range size of exotic species implies that California has a significant "invasion debt" that will be paid as exotic plants expand their range and spread throughout the state.

  12. The cytoskeleton and gravitropism in higher plants

    Science.gov (United States)

    Blancaflor, Elison B.

    2002-01-01

    The cellular and molecular mechanisms underlying the gravitropic response of plants have continued to elude plant biologists despite more than a century of research. Lately there has been increased attention on the role of the cytoskeleton in plant gravitropism, but several controversies and major gaps in our understanding of cytoskeletal involvement in gravitropism remain. A major question in the study of plant gravitropism is how the cytoskeleton mediates early sensing and signal transduction events in plants. Much has been made of the actin cytoskeleton as the cellular structure that sedimenting amyloplasts impinge upon to trigger the downstream signaling events leading to the bending response. There is also strong molecular and biochemical evidence that the transport of auxin, an important player in gravitropism, is regulated by actin. Organizational changes in microtubules during the growth response phase of gravitropism have also been well documented, but the significance of such reorientations in controlling differential cellular growth is unclear. Studies employing pharmacological approaches to dissect cytoskeletal involvement in gravitropism have led to conflicting results and therefore need to be interpreted with caution. Despite the current controversies, the revolutionary advances in molecular, biochemical, and cell biological techniques have opened up several possibilities for further research into this difficult area. The myriad proteins associated with the plant cytoskeleton that are being rapidly characterized provide a rich assortment of candidate regulators that could be targets of the gravity signal transduction chain. Cytoskeletal and ion imaging in real time combined with mutant analysis promises to provide a fresh start into this controversial area of research.

  13. Allelopathic Effects of Invasive Woody Plant Species in Hungary

    Directory of Open Access Journals (Sweden)

    CSISZÁR, Ágnes

    2009-01-01

    Full Text Available Allelopathy may play an important role in the invasion success of adventive plant species.The aim of this study was to determine the allelopathic potential of invasive woody plant species occurringin Hungary. Juglone index of fourteen invasive woody plant species in Hungary was determined by themethod of Szabó (1997, comparing the effects of juglone and substance extracted of plant species withunknown allelopathic potential on the germination rate, shoot length and rooth length of white mustard(Sinapis alba L. used as receiver species. Results have proven a more or less expressed allelopathicpotential in case of all species. The juglone index at higher concentration extracts (5 g dry plant materialextracted with 100 ml distilled water of almost every studied species approaches to 1 or is above 1, thismeans the effect of the extracts is similar to juglone or surpasses it. In terms of juglone index, theallelopathic potential of false indigo (Amorpha fruticosa L., tree-of-heaven (Ailanthus altissima (Mill.Swingle and hackberry (Celtis occidentalis L. were the highest. Besides these species the treatment withthe extracts of black walnut (Juglans nigra L., black cherry (Prunus serotina Ehrh. and green ash(Fraxinus pennsylvanica MARSH. var. subintegerrima (Vahl Fern. reduced extremely significantly thegermination rate, shoot and root length, compared to the control.

  14. Competition with wind-pollinated plant species alters floral traits of insect-pollinated plant species.

    Science.gov (United States)

    Flacher, Floriane; Raynaud, Xavier; Hansart, Amandine; Motard, Eric; Dajoz, Isabelle

    2015-09-03

    Plant traits related to attractiveness to pollinators (e.g. flowers and nectar) can be sensitive to abiotic or biotic conditions. Soil nutrient availability, as well as interactions among insect-pollinated plants species, can induce changes in flower and nectar production. However, further investigations are needed to determine the impact of interactions between insect-pollinated species and abiotically pollinated species on such floral traits, especially floral rewards. We carried out a pot experiment in which three insect-pollinated plant species were grown in binary mixtures with four wind-pollinated plant species, differing in their competitive ability. Along the flowering period, we measured floral traits of the insect-pollinated species involved in attractiveness to pollinators (i.e. floral display size, flower size, daily and total 1) flower production, 2) nectar volume, 3) amount of sucrose allocated to nectar). Final plant biomass was measured to quantify competitive interactions. For two out of three insect-pollinated species, we found that the presence of a wind-pollinated species can negatively impact floral traits involved in attractiveness to pollinators. This effect was stronger with wind-pollinated species that induced stronger competitive interactions. These results stress the importance of studying the whole plant community (and not just the insect-pollinated plant community) when working on plant-pollinator interactions.

  15. The proteome of higher plant mitochondria.

    Science.gov (United States)

    Rao, R S P; Salvato, F; Thal, B; Eubel, H; Thelen, J J; Møller, I M

    2017-03-01

    Plant mitochondria perform a wide range of functions in the plant cell ranging from providing energy and metabolic intermediates, via coenzyme biosynthesis and their own biogenesis to retrograde signaling and programmed cell death. To perform these functions, they contain a proteome of >2000 different proteins expressed in some cells under some conditions. The vast majority of these proteins are imported, in many cases by a dedicated protein import machinery. Recent proteomic studies have identified about 1000 different proteins in both Arabidopsis and potato mitochondria, but even for energy-related proteins, the most well-studied functional protein group in mitochondria, <75% of the proteins are recognized as mitochondrial by even one of six of the most widely used prediction algorithms. The mitochondrial proteomes contain proteins representing a wide range of different functions. Some protein groups, like energy-related proteins, membrane transporters, and de novo fatty acid synthesis, appear to be well covered by the proteome, while others like RNA metabolism appear to be poorly covered possibly because of low abundance. The proteomic studies have improved our understanding of basic mitochondrial functions, have led to the discovery of new mitochondrial metabolic pathways and are helping us towards appreciating the dynamic role of the mitochondria in the responses of the plant cell to biotic and abiotic stress. Copyright © 2016 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

  16. Does plant species co-occurrence influence soil mite diversity?

    Science.gov (United States)

    St John, Mark G; Wall, Diana H; Behan-Pelletier, Valerie M

    2006-03-01

    Few studies have considered whether plant taxa can be used as predictors of belowground faunal diversity in natural ecosystems. We examined soil mite (Acari) diversity beneath six grass species at the Konza Prairie Biological Station, Kansas, USA. We tested the hypotheses that soil mite species richness, abundance, and taxonomic diversity are greater (1) beneath grasses in dicultures (different species) compared to monocultures (same species), (2) beneath grasses of higher resource quality (lower C:N) compared to lower resource quality, and (3) beneath heterogeneous mixes of grasses (C3 and C4 grasses growing together) compared to homogeneous mixes (C3 or C4 grasses) using natural occurrences of plant species as treatments. This study is the first to examine the interaction between above- and belowground diversity in a natural setting with species-level resolution of a hyper-diverse taxon. Our results indicate that grasses in diculture supported a more species and phylogenetically rich soil mite fauna than was observed for monocultures and that this relationship was significant at depth but not in the upper soil horizon. We noted that mite species richness was not linearly related to grass species richness, which suggests that simple extrapolations of soil faunal diversity based on plant species inventories may underestimate the richness of associated soil mite communities. The distribution of mite size classes in dicultures was considerably different than those for monocultures. There was no difference in soil mite richness between grass combinations of differing resource quality, or resource heterogeneity.

  17. Nutritional and cultural aspects of plant species selection for a controlled ecological life support system

    Science.gov (United States)

    Hoff, J. E.; Howe, J. M.; Mitchell, C. A.

    1982-01-01

    The feasibility of using higher plants in a controlled ecological life support system is discussed. Aspects of this system considered important in the use of higher plants include: limited energy, space, and mass, and problems relating to cultivation and management of plants, food processing, the psychological impact of vegetarian diets, and plant propagation. A total of 115 higher plant species are compared based on 21 selection criteria.

  18. Egyptian plant species as new ozone indicators

    Energy Technology Data Exchange (ETDEWEB)

    Madkour, S.A.; Laurence, J.A

    2002-12-01

    Of more than 30 species of plants from Egypt screened for sensitivity to ozone, four were found to be suitable for use as bioindicators. - The aim of this study was to test and select one or more highly sensitive, specific and environmentally successful Egyptian bioindicator plants for ozone (O{sub 3}). For that purpose more than 30 Egyptian species and cultivars were subjected to extensive screening studies under controlled environmental and pollutant exposure conditions to mimic the Egyptian environmental conditions and O{sub 3} levels in urban and rural sites. Four plant species were found to be more sensitive to O{sub 3} than the universally used O{sub 3}-bioindicator, tobacco Bel W3, under the Egyptian environmental conditions used. These plant species, jute (Corchorus olitorius c.v. local), clover (Trifolium alexandrinum L. c.v. Masry), garden rocket (Eruca sativa c.v. local) and alfalfa (Medicago sativa L. c.v. local), ranked in order of decreasing sensitivity, exhibited typical O{sub 3} injury symptoms faster and at lower O{sub 3} concentrations than Bel W3. Three variables were tested in search of a reliable tool for the diagnosis and prediction of O{sub 3} response prior to the appearance of visible foliar symptoms: pigment degradation, stomatal conductance (g{sub s}) and net photosynthetic CO{sub 2} assimilation (P{sub net}). Pigment degradation was found to be unreliable in predicting species sensitivity to O{sub 3}. Evidence supporting stomatal conductance involvement in O{sub 3} tolerance was found only in tolerant species. A good correlation was found between g{sub s}, restriction of O{sub 3} and CO{sub 2} influx into the mesophyll tissues, and P{sub net}. Changes in P{sub net} seemed to depend largely on fluctuations in g{sub s}.

  19. Molecular farming: production of drugs and vaccines in higher plants.

    Science.gov (United States)

    Shinmyo, Atsuhiko; Kato, Ko

    2010-08-01

    On the basis of developments in plant biotechnology, drug and vaccine production by higher plants can be added to microbial and animal cell culture processes. When genes encoding drug or vaccine formation under a suitable promoter are introduced into plants, these useful compounds can be economically produced from CO(2) and inorganic chemicals using sunlight. The merits and demerits of the plant process are discussed in this paper.

  20. Management regimes and farming pratices enhancing plant species richness on ditch banks.

    NARCIS (Netherlands)

    Manhoudt, A.G.E.; Visser, A.J.; Snoo, de G.R.

    2007-01-01

    Plant species richness of ditch banks under different farming practices and management regimes was compared. To this end, species richness was inventoried on ditch banks on Dutch conventional and organic farms and on a number of experimental farms. Plant species richness was significantly higher on

  1. Food Plants of 19 butterflies species (Lepidoptera from Loreto, Peru

    Directory of Open Access Journals (Sweden)

    Joel Vásquez Bardales

    2017-04-01

    Full Text Available This work reports the food plants utilized by 19 species of butterflies from Allpahuayo-Mishana Research Center and the Community of San Rafael, Loreto, Peru. We report 23 plant species and one hybrid of angiosperms used by the butterflies. Larval host plants were 21 species and five were adult nectar sources. Two species were both host plant and nectar source: Passiflora coccinea Aubl. and Passiflora edulis Sims. The most frequently used plant families were Solanaceae, Passifloraceae, Fabaceae and Aristolochiaceae.

  2. INVENTORY OF THE INVASIVE ALIE N PLANT SPECIES IN INDONESIA

    Directory of Open Access Journals (Sweden)

    SRI S UDARMIYATI T JITROSOEDIRDJO

    2005-01-01

    Full Text Available An inventory of the alien plant species in Indone sia based on the existing references and herbarium specimens concluded that 1936 alien plant species ar e found in Indonesia which belong to 187 families. Field studies should be done to get the complete figur es of alien plant species in Indonesia. Based on the existing figures of the plant species, the invasive alien plant species can be iden tified, followed by studies on the assessment of losses, biology, management and their possible utilizations. Alien plant species are imported to Indonesia for cultivation, collection of the botanical garden, as experimental plants or other curiosities. Aside from plants purposely imported, there are also introduced plant propagules conta-minating imported agricultural products. These alien plant species can be beneficial or have a potential of being invasive. The alien cultivated species consisted of 67% of the total number. More than half of the cultivated plants are ornamental plants. Some of th e species are naturalized or escaped from cultivation and become wild and invasive. Some other natura lized species, adapted well without any problems of invasion. There are 339 species or 17% of the species r ecorded as weeds. The highest record of weeds is found in the family of Poaceae (57 species, follo wed by Asteraceae (53 species and Cyperaceae (35 species. There are 6 families having more than 10 species of weeds: Amaranthaceae, Asteraceae, Cyperaceae, Euphorbiaceae, Poaceae, and Rubiaceae. Three families have more than 100 species: Asteraceae 162 species, Poaceae 120 species, and Papillionaceae 103 species. Five species of aquatic and 20 species of terrestrial plants considered as important alien plant species in Indonesia were identified and some of their distributions noted

  3. The carbon fertilization effect over a century of anthropogenic CO2 emissions: higher intracellular CO2 and more drought resistance among invasive and native grass species contrasts with increased water use efficiency for woody plants in the US Southwest.

    Science.gov (United States)

    Drake, Brandon L; Hanson, David T; Lowrey, Timothy K; Sharp, Zachary D

    2017-02-01

    From 1890 to 2015, anthropogenic carbon dioxide emissions have increased atmospheric CO2 concentrations from 270 to 400 mol mol(-1) . The effect of increased carbon emissions on plant growth and reproduction has been the subject of study of free-air CO2 enrichment (FACE) experiments. These experiments have found (i) an increase in internal CO2 partial pressure (ci ) alongside acclimation of photosynthetic capacity, (ii) variable decreases in stomatal conductance, and (iii) that increases in yield do not increase commensurate with CO2 concentrations. Our data set, which includes a 115-year-long selection of grasses collected in New Mexico since 1892, is consistent with an increased ci as a response to historical CO2 increase in the atmosphere, with invasive species showing the largest increase. Comparison with Palmer Drought Sensitivity Index (PDSI) for New Mexico indicates a moderate correlation with Δ(13) C (r(2)  = 0.32, P CO2 in the event of reduced stomatal conductance in response to short-term water shortage. Comparison with C3 trees from arid environments (Pinus longaeva and Pinus edulis in the US Southwest) as well as from wetter environments (Bromus and Poa grasses in New Mexico) suggests differing responses based on environment; arid environments in New Mexico see increased intrinsic water use efficiency (WUE) in response to historic elevated CO2 while wetter environments see increased ci . This study suggests that (i) the observed increases in ci in FACE experiments are consistent with historical CO2 increases and (ii) the CO2 increase influences plant sensitivity to water shortage, through either increased WUE or ci in arid and wet environments, respectively. © 2016 John Wiley & Sons Ltd.

  4. Initial Survey Instructions for Invasive Plant Species Mapping and Monitoring

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Initial survey instructions for Invasive Plant Species Mapping, 1.01a, and Invasive Plant Species Monitoring, 1.01b, at Fish Springs National Wildlife Refuge. These...

  5. an assessment of seed propagation of oilferous plant species with

    African Journals Online (AJOL)

    nb

    This study assessed the propagation of non- edible oil plant species with potential for biodiesel production on 4 potting media forest, sandy, ... selected plant species Telfairia pedata, Jatropha curcas, Excoecaria bussei, Croton macrostachyus, Croton ...... of Key Non-edible Vascular Plant species of Economic Importance for.

  6. Taxonomic perspective of plant species yielding vegetable oils used ...

    African Journals Online (AJOL)

    A search conducted to determine the plants yielding vegetable oils resulted in 78 plant species with potential use in cosmetics and skin care products. The taxonomic position of these plant species is described with a description of vegetable oils from these plants and their use in cosmetic and skin care products.

  7. Plants on the move: plant-soil interactions in poleward shifting plant species

    NARCIS (Netherlands)

    Grunsven, van R.H.A.

    2008-01-01

    As a result of recent global climate change, areas that have previously been climatically unsuitable for species have now become suitable new habitats. Many plant-species are expanding their range polewards, colonizing these newly available areas. If these species are able to expand their range

  8. Species richness and patterns of invasion in plants, birds, and fishes in the United States

    Science.gov (United States)

    Thomas J. Stohlgren; David T. Barnett; Curtis H. Flather; Pam L. Fuller; Bruce G. Peterjohn; John T. Kartesz; Lawrence L. Master

    2006-01-01

    We quantified broad-scale patterns of species richness and species density (mean # species/km2) for native and non-indigenous plants, birds, and fishes in the continental USA and Hawaii. We hypothesized that the species density of native and non-indigenous taxa would generally decrease in northern latitudes and higher elevations following...

  9. Ecological Risk Assessment of Genetically Modified Higher Plants (GMHP)

    DEFF Research Database (Denmark)

    Kjær, C.; Damgaard, C.; Kjellsson, G.

    altered management of the fields, e.g. possible changes in for example leaching of pesticides or nitrogen, etc. Furthermore, we have abstained from suggesting number of species to test for specific issues because different risk assessment procedures have been developed which add a safety factor accounting...... for uncertainties in the extrapolation from limited laboratory studies to the species rich field environment. The relationship between the size of the safety factor and the number of species is therefore an issue of the risk assessment. Some of the issues raised in this report overlap with data needs...... of the project Biotechnology: elements in environmental risk assessment of genetically modified plants. December 1999 Christian Kjær Introduction In ecological risk assessment of transgenic plants, information on a wide range of subjects is needed for an effective and reliable assessment procedure...

  10. Consequences of plant invasions on compartmentalization and species' roles in plant-pollinator networks.

    Science.gov (United States)

    Albrecht, Matthias; Padrón, Benigno; Bartomeus, Ignasi; Traveset, Anna

    2014-08-07

    Compartmentalization-the organization of ecological interaction networks into subsets of species that do not interact with other subsets (true compartments) or interact more frequently among themselves than with other species (modules)-has been identified as a key property for the functioning, stability and evolution of ecological communities. Invasions by entomophilous invasive plants may profoundly alter the way interaction networks are compartmentalized. We analysed a comprehensive dataset of 40 paired plant-pollinator networks (invaded versus uninvaded) to test this hypothesis. We show that invasive plants have higher generalization levels with respect to their pollinators than natives. The consequences for network topology are that-rather than displacing native species from the network-plant invaders attracting pollinators into invaded modules tend to play new important topological roles (i.e. network hubs, module hubs and connectors) and cause role shifts in native species, creating larger modules that are more connected among each other. While the number of true compartments was lower in invaded compared with uninvaded networks, the effect of invasion on modularity was contingent on the study system. Interestingly, the generalization level of the invasive plants partially explains this pattern, with more generalized invaders contributing to a lower modularity. Our findings indicate that the altered interaction structure of invaded networks makes them more robust against simulated random secondary species extinctions, but more vulnerable when the typically highly connected invasive plants go extinct first. The consequences and pathways by which biological invasions alter the interaction structure of plant-pollinator communities highlighted in this study may have important dynamical and functional implications, for example, by influencing multi-species reciprocal selection regimes and coevolutionary processes. © 2014 The Author(s) Published by the Royal

  11. Computational identification of candidate nucleotide cyclases in higher plants

    KAUST Repository

    Wong, Aloysius Tze

    2013-09-03

    In higher plants guanylyl cyclases (GCs) and adenylyl cyclases (ACs) cannot be identified using BLAST homology searches based on annotated cyclic nucleotide cyclases (CNCs) of prokaryotes, lower eukaryotes, or animals. The reason is that CNCs are often part of complex multifunctional proteins with different domain organizations and biological functions that are not conserved in higher plants. For this reason, we have developed CNC search strategies based on functionally conserved amino acids in the catalytic center of annotated and/or experimentally confirmed CNCs. Here we detail this method which has led to the identification of >25 novel candidate CNCs in Arabidopsis thaliana, several of which have been experimentally confirmed in vitro and in vivo. We foresee that the application of this method can be used to identify many more members of the growing family of CNCs in higher plants. © Springer Science+Business Media New York 2013.

  12. Species richness of yeast communities in floral nectar of southern Spanish plants.

    Science.gov (United States)

    Pozo, María I; Herrera, Carlos M; Bazaga, Pilar

    2011-01-01

    Floral nectar of insect-pollinated plants often contains dense yeast populations, yet little quantitative information exists on patterns and magnitude of species richness of nectar-dwelling yeasts in natural plant communities. This study evaluates yeast species richness at both the plant community and plant species levels in a montane forest area in southern Spain, and also explores possible correlations between the incidence of different yeast species in nectar and their reported tolerance to high sugar concentrations, and between yeast diversity and pollinator composition. Yeast species occurring in a total of 128 field-collected nectar samples from 24 plant species were identified by sequencing the D1/D2 domain of the large subunit rDNA, and rarefaction-based analyses were used to estimate yeast species richness at the plant community and plant species levels, using nectar drops as elemental sampling units. Individual nectar samples were generally characterized by very low species richness (1.2 yeast species/sample, on average), with the ascomycetous Metschnikowia reukaufii and Metschnikowia gruessii accounting altogether for 84.7% of the 216 isolates identified. Other yeasts recorded included species in the genera Aureobasidium, Rhodotorula, Cryptococcus, Sporobolomyces, and Lecythophora. The shapes and slopes of observed richness accumulation curves were quite similar for the nectar drop and plant species approaches, but the two approaches yielded different expected richness estimates. Expected richness was higher for plant species-based than for nectar drop-based analyses, showing that the coverage of nectar yeast species occurring in the region would be improved by sampling additional host plant species. A significant correlation was found between incidence of yeast species in nectar and their reported ability to grow in a medium containing 50% glucose. Neither diversity nor incidence of yeasts was correlated with pollinator composition across plant species.

  13. Allelopathy of plant species of pharmaceutical importance to cultivated species

    Directory of Open Access Journals (Sweden)

    Álisson Sobrinho Maranho

    2012-11-01

    Full Text Available This study aimed to identify possible allelopathic effects of leaf aqueous extracts of Baccharis dracunculifolia DC., Pilocarpus pennatifolius Lem., Cyperus rotundus L., Morus rubra L., Casearia sylvestris Sw., and Plectranthus barbatus Andr. on the germination and initial growth of Lactuca sativa L., Brassica oleracea L. cv. capitata, B. oleracea L. cv. italica, B. pekinenses L., B. campestris L., Lycopersicum esculentum Miller, and Eruca sativa L. To obtain the aqueous extracts, leaves previously dried at a 1g.10mL-1 concentration were used, diluted in six solutions (10, 30, 50, 70, 90, and 100% and compared to control, distilled water, with five replications of 10 seeds for all vegetable species. The aqueous extracts of all species showed allelopathic potential for germination of seeds, the germination speed index, and the initial growth of shoots and roots of vegetable crops. The aqueous extracts of C. rotundus and P. barbatus promoted lower and higher allelopathic effects, respectively, and the vegetal structure mostly affected by the extracts was the primary root. The results indicate the existence of allelopathic potential in the species tested, so there’s a need for adopting care procedures when cultivating vegetables with them.

  14. Reciprocal effects of litter from exotic and congeneric native plant species via soil nutrients.

    Directory of Open Access Journals (Sweden)

    Annelein Meisner

    Full Text Available Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to congeneric native plant species. Here, we test how the legacy of litter from three exotic plant species affects their own performance in comparison to their congeneric natives that co-occur in the invaded habitat. We also analyzed litter effects on soil processes. In all three comparisons, soil with litter from exotic plant species had the highest respiration rates. In two out of the three exotic-native species comparisons, soil with litter from exotic plant species had higher inorganic nitrogen concentrations than their native congener, which was likely due to higher initial litter quality of the exotics. When litter from an exotic plant species had a positive effect on itself, it also had a positive effect on its native congener. We conclude that exotic plant species develop a legacy effect in soil from the invaded range through their litter inputs. This litter legacy effect results in altered soil processes that can promote both the exotic plant species and their native congener.

  15. Aquatic food production modules in bioregenerative life support systems based on higher plants

    Science.gov (United States)

    Bluem, V.; Paris, F.

    Most bioregenerative life support systems (BLSS) are based on gravitropic higher plants which exhibit growth and seed generation disturbances in microgravity. Even when used for a lunar or martian base the reduced gravity may induce a decreased productivity in comparison to Earth. Therefore, the implementation of aquatic biomass production modules in higher plant and/or hybrid BLSS may compensate for this and offer, in addition, the possibility to produce animal protein for human nutrition. It was shown on the SLS-89 and SLS-90 space shuttle missions with the C.E.B.A.S.-MINI MODULE that the edible non gravitropic rootless higher aquatic plant Ceratophyllum demeresum exhibits an undisturbed high biomass production rate in space and that the teleost fish species, Xiphophorus helleri, adapts rapidly to space conditions without loss of its normal reproductive functions. Based on these findings a series of ground-based aquatic food production systems were developed which are disposed for utilization in space. These are plant production bioreactors for the species mentioned above and another suitable candidate, the lemnacean (duckweed) species, Wolffia arrhiza. Moreover, combined intensive aquaculture systems with a closed food loop between herbivorous fishes and aquatic and land plants are being developed which may be suitable for integration into a BLSS of higher complexity.

  16. Mechanisms of silicon-mediated alleviation of abiotic stresses in higher plants: a review.

    Science.gov (United States)

    Liang, Yongchao; Sun, Wanchun; Zhu, Yong-Guan; Christie, Peter

    2007-05-01

    Although silicon (Si) is the second most abundant element both on the surface of the Earth's crust and in soils, it has not yet been listed among the essential elements for higher plants. However, the beneficial role of Si in stimulating the growth and development of many plant species has been generally recognized. Silicon is known to effectively mitigate various abiotic stresses such as manganese, aluminum and heavy metal toxicities, and salinity, drought, chilling and freezing stresses. However, mechanisms of Si-mediated alleviation of abiotic stresses remain poorly understood. The key mechanisms of Si-mediated alleviation of abiotic stresses in higher plants include: (1) stimulation of antioxidant systems in plants, (2) complexation or co-precipitation of toxic metal ions with Si, (3) immobilization of toxic metal ions in growth media, (4) uptake processes, and (5) compartmentation of metal ions within plants. Future research needs for Si-mediated alleviation of abiotic stresses are also discussed.

  17. Higher plant vegetation changes during Pliocene sapropel formation

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Menzel, D.; Schouten, S.; Bergen, P.F. van

    2004-01-01

    The 13C values of higher plant wax C27 33 n-alkanes were determined in three, time-equivalent Pliocene (2.943 Ma) sapropels and homogeneous calcareous ooze from three different sites forming an east-west transect in the eastern Mediterranean Basin in order to study the composition of the vegetation

  18. Functional architecture of higher plant photosystem II supercomplexes

    NARCIS (Netherlands)

    Caffarri, Stefano; Kouril, Roman; Kereiche, Sami; Boekema, Egbert J.; Croce, Roberta; Kereïche, Sami

    2009-01-01

    Photosystem II ( PSII) is a large multiprotein complex, which catalyses water splitting and plastoquinone reduction necessary to transform sunlight into chemical energy. Detailed functional and structural studies of the complex from higher plants have been hampered by the impossibility to purify it

  19. Matgrass sward plant species benefit from soil organisms

    NARCIS (Netherlands)

    Brinkman, E.P.; Raaijmakers, C.E.; Bakx-Schotman, J.M.T.; Hannula, S.E.; Kemmers, R.H.; Boer, de W.; Putten, van der W.H.

    2012-01-01

    Soil organisms are important in the structuring of plant communities. However, little is known about how to apply this knowledge to vegetation management. Here, we examined if soil organisms may promote plant species of characteristic habitats, and suppress plant species of disturbed habitats. We

  20. Diurnal adjustment in ultraviolet sunscreen protection is widespread among higher plants.

    Science.gov (United States)

    Barnes, Paul W; Flint, Stephan D; Tobler, Mark A; Ryel, Ronald J

    2016-05-01

    The accumulation of ultraviolet (UV)-absorbing compounds (flavonoids and related phenylpropanoids) in the epidermis of higher plants reduces the penetration of solar UV radiation to underlying tissues and is a primary mechanism of acclimation to changing UV conditions resulting from ozone depletion and climate change. Previously we reported that several herbaceous plant species were capable of rapid, diurnal adjustments in epidermal UV transmittance (T UV), but how widespread this phenomenon is among plants has been unknown. In the present study, we tested the generality of this response by screening 37 species of various cultivated and wild plants growing in four locations spanning a gradient of ambient solar UV and climate (Hawaii, Utah, Idaho and Louisiana). Non-destructive measurements of adaxial T UV indicated that statistically significant midday decreases in T UV occurred in 49 % of the species tested, including both herbaceous and woody growth forms, and there was substantial interspecific variation in the magnitude of these changes. In general, plants in Louisiana exhibited larger diurnal changes in T UV than those in the other locations. Moreover, across all taxa, the magnitude of these changes was positively correlated with minimum daily air temperatures but not daily UV irradiances. Results indicate that diurnal changes in UV shielding are widespread among higher plants, vary both within and among species and tend to be greatest in herbaceous plants growing in warm environments. These findings suggest that plant species differ in their UV protection "strategies" though the functional and ecological significance of this variation in UV sunscreen protection remains unclear at present.

  1. VT Biodiversity Project - Plant and Animal Species Atlas

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This database contains town-level totals of documented species records for several plant and animal taxa including vascular plants, trees,...

  2. Plant-soil feedbacks of exotic plant species across life forms: a meta-analysis

    NARCIS (Netherlands)

    Meisner, A.; Hol, W.H.G.; De Boer, W.; Krumins, J.A.; Wardle, D.A.; Van der Putten, W.H.

    2014-01-01

    Invasive exotic plant species effects on soil biota and processes in their new range can promote or counteract invasions via changed plant–soil feedback interactions to themselves or to native plant species. Recent meta-analyses reveale that soil influenced by native and exotic plant species is

  3. Reactive oxygen species signaling in plants under abiotic stress.

    Science.gov (United States)

    Choudhury, Shuvasish; Panda, Piyalee; Sahoo, Lingaraj; Panda, Sanjib Kumar

    2013-04-01

    Abiotic stresses like heavy metals, drought, salt, low temperature, etc. are the major factors that limit crop productivity and yield. These stresses are associated with production of certain deleterious chemical entities called reactive oxygen species (ROS), which include hydrogen peroxide (H₂O₂), superoxide radical (O₂(-)), hydroxyl radical (OH(-)), etc. ROS are capable of inducing cellular damage by degradation of proteins, inactivation of enzymes, alterations in the gene and interfere in various pathways of metabolic importance. Our understanding on ROS in response to abiotic stress is revolutionized with the advancements in plant molecular biology, where the basic understanding on chemical behavior of ROS is better understood. Understanding the molecular mechanisms involved in ROS generation and its potential role during abiotic stress is important to identify means by which plant growth and metabolism can be regulated under acute stress conditions. ROS mediated oxidative stress, which is the key to understand stress related toxicity have been widely studied in many plants and the results in those studies clearly revealed that oxidative stress is the main symptom of toxicity. Plants have their own antioxidant defense mechanisms to encounter ROS that is of enzymic and non-enzymic nature . Coordinated activities of these antioxidants regulate ROS detoxification and reduces oxidative load in plants. Though ROS are always regarded to impart negative impact on plants, some reports consider them to be important in regulating key cellular functions; however, such reports in plant are limited. Molecular approaches to understand ROS metabolism and signaling have opened new avenues to comprehend its critical role in abiotic stress. ROS also acts as secondary messenger that signals key cellular functions like cell proliferation, apoptosis and necrosis. In higher eukaryotes, ROS signaling is not fully understood. In this review we summarize our understanding on ROS

  4. Phytophthora species, new threats to the plant health in Korea.

    Science.gov (United States)

    Hyun, Ik-Hwa; Choi, Woobong

    2014-12-01

    Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries into Korea from 1900 to 2010. The genus Phytophthora, classified in oomycetes, includes more than 120 species that are mostly recognized worldwide as highly invasive plant pathogens. After 2000, over 50 new species of Phytophthora were identified internationally as plant pathogens occurring in crops and forest trees. In Korea, Phytophthora is also one of the most serious plant pathogens. To date, 22 species (about one-fifth of known species) of the genus have been identified and reported as plant pathogens in the country. The likelihood of new exotic Phytophthora species being introduced into Korea continues to increase, thus necessitating intensive plant quarantine inspections. As new potential threats to plant health in Korea, six Phytophthora species, namely, P. alni, P. inundata, P. kernoviae, P. pinifolia, P. quercina, and P. ramorum, are discussed in this review with focus on history, disease, biology, management, and plant quarantine issues.

  5. Positive Effects of Plant Genotypic and Species Diversity on Anti-Herbivore Defenses in a Tropical Tree Species

    Science.gov (United States)

    Moreira, Xoaquín; Abdala-Roberts, Luis; Parra-Tabla, Víctor; Mooney, Kailen A.

    2014-01-01

    Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at high diversity may lead to reduced investment in defenses via growth-defense trade-offs. Alternatively, positive effects of plant diversity on plant growth may lead to increased herbivore abundance which in turn leads to a greater investment in plant defenses. The magnitude of trait variation underlying diversity effects is usually greater among species than among genotypes within a given species, so plant species diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects. Here we compared the relative importance of plant genotypic and species diversity on anti-herbivore defenses and whether such effects are mediated indirectly via diversity effects on plant growth and/or herbivore damage. To this end, we performed a large-scale field experiment where we manipulated genotypic diversity of big-leaf mahogany (Swietenia macrophylla) and tree species diversity, and measured effects on mahogany growth, damage by the stem-boring specialist caterpillar Hypsipyla grandella, and defensive traits (polyphenolics and condensed tannins in stem and leaves). We found that both forms of plant diversity had positive effects on stem (but not leaf) defenses. However, neither source of diversity influenced mahogany growth, and diversity effects on defenses were not mediated by either growth-defense trade-offs or changes in stem-borer damage. Although the mechanism(s) of diversity effects on plant defenses are yet to be determined, our study is one of the few to test for and show producer diversity effects on

  6. Positive effects of plant genotypic and species diversity on anti-herbivore defenses in a tropical tree species.

    Directory of Open Access Journals (Sweden)

    Xoaquín Moreira

    Full Text Available Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at high diversity may lead to reduced investment in defenses via growth-defense trade-offs. Alternatively, positive effects of plant diversity on plant growth may lead to increased herbivore abundance which in turn leads to a greater investment in plant defenses. The magnitude of trait variation underlying diversity effects is usually greater among species than among genotypes within a given species, so plant species diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects. Here we compared the relative importance of plant genotypic and species diversity on anti-herbivore defenses and whether such effects are mediated indirectly via diversity effects on plant growth and/or herbivore damage. To this end, we performed a large-scale field experiment where we manipulated genotypic diversity of big-leaf mahogany (Swietenia macrophylla and tree species diversity, and measured effects on mahogany growth, damage by the stem-boring specialist caterpillar Hypsipyla grandella, and defensive traits (polyphenolics and condensed tannins in stem and leaves. We found that both forms of plant diversity had positive effects on stem (but not leaf defenses. However, neither source of diversity influenced mahogany growth, and diversity effects on defenses were not mediated by either growth-defense trade-offs or changes in stem-borer damage. Although the mechanism(s of diversity effects on plant defenses are yet to be determined, our study is one of the few to test for and show producer

  7. Chlorine-containing natural compounds in higher plants

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1986-01-01

    More than 130 chlorine-containing compounds have been isolated from higher plants and ferns; about half are polyacetylenes, thiophenes and sesquiterpene lactones from the Asteraceae. A chlorinated chlorophyll may be an important part of photosystem 1. High biological activity is found in 4-chloro......-chloroindoleacetic acid from pea and in the cancerostatic maytansinoids. Many compounds are chlorohydrins isolated along with the related epoxides. Some compounds, like gibberellin A6 hydrochloride from bean, are perhaps artefacts....

  8. The effect of altitude on the presence of plant species in stands for Juniperus L. plant species on Kopaonik

    Directory of Open Access Journals (Sweden)

    Vasić Predrag

    2016-01-01

    Full Text Available In this paper we present an assessment of the altitude effect on the plant species presence in different plant communities - the species of Juniperus genus (Juniperus communis L., Juniperus oxycedrus L. and Juniperus sibirica Burgsdorf on Kopaonik Mountain. Two juniper species (Juniperus communis and Juniperus oxycedrus were recorded at altitudes ranging from 420 m to 1420 m, while the third species Juniperus sibirica was found at an altitude of 2100 m. It was determined that the plant communities with the presence of species of the Juniperus genus differ in botanical terms at different altitudes. It was found that there are plant species in certain communities that are present only at some altitudes, while others were present at almost all altitudes. The species of Hypericum perforatum L. is recorded in all of plant communities surveyed that proves its best adaptation to the conditions at different altitudes.

  9. Evaluating complementary networks of restoration plantings for landscape-scale occurrence of temporally dynamic species.

    Science.gov (United States)

    Ikin, Karen; Tulloch, Ayesha; Gibbons, Philip; Ansell, Dean; Seddon, Julian; Lindenmayer, David

    2016-10-01

    Multibillion dollar investments in land restoration make it critical that conservation goals are achieved cost-effectively. Approaches developed for systematic conservation planning offer opportunities to evaluate landscape-scale, temporally dynamic biodiversity outcomes from restoration and improve on traditional approaches that focus on the most species-rich plantings. We investigated whether it is possible to apply a complementarity-based approach to evaluate the extent to which an existing network of restoration plantings meets representation targets. Using a case study of woodland birds of conservation concern in southeastern Australia, we compared complementarity-based selections of plantings based on temporally dynamic species occurrences with selections based on static species occurrences and selections based on ranking plantings by species richness. The dynamic complementarity approach, which incorporated species occurrences over 5 years, resulted in higher species occurrences and proportion of targets met compared with the static complementarity approach, in which species occurrences were taken at a single point in time. For equivalent cost, the dynamic complementarity approach also always resulted in higher average minimum percent occurrence of species maintained through time and a higher proportion of the bird community meeting representation targets compared with the species-richness approach. Plantings selected under the complementarity approaches represented the full range of planting attributes, whereas those selected under the species-richness approach were larger in size. Our results suggest that future restoration policy should not attempt to achieve all conservation goals within individual plantings, but should instead capitalize on restoration opportunities as they arise to achieve collective value of multiple plantings across the landscape. Networks of restoration plantings with complementary attributes of age, size, vegetation structure, and

  10. Exotic plant species attack revegetation plants in post-coal mining areas

    Science.gov (United States)

    Yusuf, Muhammad; Arisoesilaningsih, Endang

    2017-11-01

    This study aimed to explore some invasive exotic plant species that have the potential to disrupt the growth of revegetation plants in post-coal mining areas. This research was conducted in a revegetation area of PT, Amanah Anugerah Adi Mulia (A3M) Kintap site, South Borneo. Direct observation was carried out on some revegetation areas by observing the growth of revegetation plants disturbed by exotic plant species and the spread of exotic plant species. Based on observation, several invasive exotic plant species were identified including Mikania cordata, Centrosema pubescence, Calopogonium mucunoides, Mimosa pudica, Ageratum conyzoides, and Chromolaena odorata. These five plant species grew wild in the revegetation area and showed ability to disrupt the growth of other plants. In some tree species, such as Acacia mangium, Paraserianthes falcataria, M. cordata could inhibit the growth and even kill the trees through covering the tree canopy. So, the trees could not receive optimum sun light for photosynthesis processes. M. cordata was also observed to have the most widespread distribution. Several exotic plant species such as C. mucunoides, M. pudica, and A. conyzoides were observed to have deep root systems compared with plant species used for revegetation. This growth characteristic allowed exotic plant species to win the competition for nutrient absorption with other plant species.

  11. Herbivory and dominance shifts among exotic and congeneric native plant species during plant community establishment

    DEFF Research Database (Denmark)

    Engelkes, Tim; Meisner, Annelein; Morriën, Elly

    2016-01-01

    this early stage of plant community development. Effects of herbivores on plant biomass depended on plant species or genus but not on plant status (i.e., exotic vs native). Thus, aboveground herbivory did not promote the dominance of exotic plant species during early establishment of the phylogenetically......Invasive exotic plant species often have fewer natural enemies and suffer less damage from herbivores in their new range than genetically or functionally related species that are native to that area. Although we might expect that having fewer enemies would promote the invasiveness of the introduced...... exotic plant species due to reduced enemy exposure, few studies have actually analyzed the ecological consequences of this situation in the field. Here, we examined how exposure to aboveground herbivores influences shifts in dominance among exotic and phylogenetically related native plant species...

  12. [Application of ISSR molecular marker in invasive plant species study].

    Science.gov (United States)

    Gui, Fu-Rong; Guo, Jian-Ying; Wan, Fang-Hao

    2007-04-01

    Alien species invasion is one of the most important drivers of worldwide environmental change, which may result in environmental degradation, biodiversity loss, and food and water shortage. It may also increase the possibility and severity of natural disasters, and damage international trade and benefits. In last two decades, DNA-based molecular markers were widely used to detect the genetic diversity of invaded alien species. Inter-simple sequence repeat (ISSR) is a microsatellite-based technique, with the superiorities of simple, quick, reliable, and generating higher levels of DNA polymorphism, and being used as a new molecular marker for genetic study. This paper introduced the principles, characteristics and procedures of ISSR, and summarized its applications in studying the genetic structure, genetic diversity, origin, distribution mode, phylogenesis, and breeding features of invasive plants.

  13. Consideration of higher seismic loads at existing plants

    Energy Technology Data Exchange (ETDEWEB)

    Liebig, J.; Pellissetti, M.

    2015-07-01

    Because of advancement of methods in probabilistic seismic hazard analysis, plenty of existing plants face higher seismic loads as an obligation from the national authorities. In case of such obligations safety related structures and equipment have to be reevaluated or requalified for the increased seismic loads. The paper provides solutions for different kinds of structures and equipment inside the plant, avoiding cost intensive hardware exchange. Due to higher seismic loads different kinds of structures and equipment inside a plant have to be reevaluated. For civil structures, primary components, mechanical components, distribution lines and electrical and I&C equipment different innovative concepts will be applied to keep structures and equipment qualified for the higher seismic loads. Detailed analysis, including the modeling of non-linear phenomena, or minor structural upgrades are cost competitive, compared to cost intensive hardware exchanges. Several case studies regarding the re-evaluation and requalification of structures and equipment due to higher seismic loads are presented. It is shown how the creation of coupled finite element models and the consistent propagation of acceleration time histories through the soil, building and primary circuit lead to a significant load reduction Electrical and I&C equipment is reinforced by smart upgrades which increase the natural equipment frequencies. Therefore for all devices inside the cabinets the local acceleration will not increase and the seismic qualification will be maintained. The case studies cover both classical deterministic and probabilistic re-evaluations (fragility analysis). Furthermore, the substantial benefits of non-linear limit load evaluation, such as push-over analysis of buildings and limit load analysis of fuel assemblies, are demonstrated. (Author)

  14. Regulation of cell division in higher plants. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Thomas W.

    2000-02-29

    Research in the latter part of the grant period was divided into two parts: (1) expansion of the macromolecular tool kit for studying plant cell division; (2) experiments in which the roles played by plant cell cycle regulators were to be cast in the light of the emerging yeast and animal cell paradigm for molecular control of the mitotic cycle. The first objectives were accomplished to a very satisfactory degree. With regard to the second part of the project, we were driven to change our objectives for two reasons. First, the families of cell cycle control genes that we cloned encoded such closely related members that the prospects for success at raising distinguishing antisera against each were sufficiently dubious as to be impractical. Epitope tagging is not feasible in Pisum sativum, our experimental system, as this species is not realistically transformable. Therefore, differentiating the roles of diverse cyclins and cyclin-dependent kinases was problematic. Secondly, our procedure for generating mitotically synchronized pea root meristems for biochemical studies was far too labor intensive for the proposed experiments. We therefore shifted our objectives to identifying connections between the conserved proteins of the cell cycle engine and factors that interface it with plant physiology and development. In this, we have obtained some very exciting results.

  15. Effect of plant species on nitrogen recovery in aquaponics.

    Science.gov (United States)

    Hu, Zhen; Lee, Jae Woo; Chandran, Kartik; Kim, Sungpyo; Brotto, Ariane Coelho; Khanal, Samir Kumar

    2015-01-01

    Nitrogen transformations in aquaponics with different edible plant species, i.e., tomato (Lycopersicon esculentum) and pak choi (Brassica campestris L. subsp. chinensis) were systematically examined and compared. Results showed that nitrogen utilization efficiencies (NUE) of tomato- and pak choi-based aquaponic systems were 41.3% and 34.4%, respectively. The abundance of nitrifying bacteria in tomato-based aquaponics was 4.2-folds higher than that in pak choi-based aquaponics, primarily due to its higher root surface area. In addition, tomato-based aquaponics had better water quality than that of pak choi-based aquaponics. About 1.5-1.9% of nitrogen input were emitted to atmosphere as nitrous oxide (N2O) in tomato- and pak choi-based aquaponic systems, respectively, suggesting that aquaponics is a potential anthropogenic source of N2O emission. Overall, this is the first intensive study that examined the role plant species played in aquaponics, which could provide new strategy in designing and operating an aquaponic system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Lead stress effects on physiobiochemical activities of higher plants.

    Science.gov (United States)

    Sengar, Rakesh Singh; Gautam, Madhu; Sengar, Rajesh Singh; Garg, Sanjay Kumar; Sengar, Kalpana; Chaudhary, Reshu

    2008-01-01

    Lead is a metallic pollutant emanating from various environmental sources including industrial wastes, combustion of fossil fuels, and use of agrochemicals. Lead may exist in the atmosphere as dusts, fumes, mists, and vapors, and in soil as a mineral. Soils along roadsides are rich in lead because vehicles burn leaded gasoline, which contributes to environmental lead pollution. Other important sources of lead pollution are geological weathering, industrial processing of ores and minerals, leaching of lead from solid wastes, and animal and human excreta. Lead is nondegradable, readily enters the food chain, and can subsequently endanger human and animal health. Lead is one of the most important environment pollutants and deserves the increasing attention it has received in recent decades. The present effort was undertaken to review lead stress effects on the physiobiochemical activity of higher plants. Lead has gained considerable attention as a potent heavy metal pollutant because of growing anthropogenic pressure on the environment. Lead-contaminated soils show a sharp decline in crop productivity. Lead is absorbed by plants mainly through the root system and in minor amounts through the leaves. Within the plants, lead accumulates primarily in roots, but some is translocated to aerial plant parts. Soil pH, soil particle size, cation-exchange capacity, as well as root surface area, root exudation, and mycorrhizal transpiration rate affect the availability and uptake of lead by plants. Only a limited amount of lead is translocated from roots to other organs because there are natural plant barriers in the root endodermis. At lethal concentrations, this barrier is broken and lead may enter vascular tissues. Lead in plants may form deposits of various sizes, present mainly in intercellular spaces, cell walls, and vacuoles. Small deposits of this metal are also seen in the endoplasmic reticulum, dictyosome, and dictyosome-derived vesicles. After entering the cells, lead

  17. Evaluation of allelopathic potential of selected plant species on ...

    African Journals Online (AJOL)

    The phytotoxicity of shoot leachates of selected plant species was assessed on germination, and on shootcut and seedling bioassays of Parthenium hysterophorus. Shoot leachates of selected plant species were effective in inhibiting germination of Parthenium seeds, with Azardirachta indica the most effective.

  18. Planting trials of 10 Mexican pine species in Hawaii

    Science.gov (United States)

    Craig D. Whitesell

    1974-01-01

    Ten species of Mexican pines were planted on adverse sites at 6450 feet (1970 m) elevation on Maui, and five species on similar sites at 3200 feet (975 m) elevation on Molokai, Hawaii. Initial survival was poor because of the low quality of the planting stock and harsh site conditions, but subsequent mortality was low. Growth and vigor has been satisfactory. Average...

  19. Cloning higher plants from aseptically cultured tissues and cells

    Science.gov (United States)

    Krikorian, A. D.

    1982-01-01

    A review of aseptic culture methods for higher plants is presented, which focuses on the existing problems that limit or prevent the full realization of cloning plants from free cells. It is shown that substantial progress in clonal multiplication has been made with explanted stem tips or lateral buds which can be stimulated to produce numerous precocious axillary branches. These branches can then be separated or subdivided and induced to root in order to yield populations of genetically and phenotypically uniorm plantlets. Similarly, undifferentiated calluses can sometimes be induced to form shoots and/or roots adventitiously. Although the cell culture techniques required to produce somatic embryos are presently rudimentary, steady advances are being made in learning how to stimulate formation of somatic or adventive embryos from totipotent cells grown in suspension cultures. It is concluded that many problems exist in the producing and growing of totipotent or morphogenetically competent cell suspensions, but the potential benefits are great.

  20. Fuel breaks affect nonnative species abundance in Californian plant communities

    Science.gov (United States)

    Kyle E Merriam; Jon E. Keeley; Jan L. Beyers

    2006-01-01

    We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment...

  1. Investigation of the plant species diversity, density, abundance and ...

    African Journals Online (AJOL)

    The plant species play very important role as they are not just planted to make the streets look beautiful but are a vital part of the ecosystem. They are a major source of the oxygen, help control, stabilise the climate and feed animals. The choice of planting alien trees instead of indigenous trees on the street was a big ...

  2. Plant Species Recovery on a Compacted Skid Road

    OpenAIRE

    Demir, Murat; Makineci, Ender; Gungor, Beyza Sat

    2008-01-01

    This study was executed to determine the plant species of herbaceous cover in a skid road subjected to soil compaction due to timber skidding in a beech (Fagus orientalis Lipsky.) stand. Our previous studies have shown that ground based timber skidding destroys the soils extremely, and degradations on ecosystem because of the timber skidding limit recovery and growth of plant cover on skid roads. However, some plant species show healthy habitat, recovery and they can survive after the extreme...

  3. A comparative study of AMF diversity in annual and perennial plant species from semiarid gypsum soils.

    Science.gov (United States)

    Alguacil, M. M.; Torrecillas, E.; Roldán, A.; Díaz, G.; Torres, P.

    2012-04-01

    The arbuscular mycorrhizal fungi (AMF) communities composition regulate plant interactions and determine the structure of plant communities. In this study we analysed the diversity of AMF in the roots of two perennial gypsophyte plant species, Herniaria fruticosa and Senecio auricula, and an annual herbaceous species, Bromus rubens, growing in a gypsum soil from a semiarid area. The objective was to determine whether perennial and annual host plants support different AMF communities in their roots and whether there are AMF species that might be indicators of specific functional plant roles in these ecosystems. The roots were analysed by nested PCR, cloning, sequencing of the ribosomal DNA small subunit region and phylogenetic analysis. Twenty AMF sequence types, belonging to the Glomus group A, Glomus group B, Diversisporaceae, Acaulosporaceae, Archaeosporaceae and Paraglomeraceae, were identified. Both gypsophyte perennial species had differing compositions of the AMF community and higher diversity when compared with the annual species, showing preferential selection by specific AMF sequences types. B. rubens did not show host specificity, sharing the full composition of its AMF community with both perennial plant species. Seasonal variations in the competitiveness of AM fungi could explain the observed differences in AMF community composition, but this is still a working hypothesis that requires the analysis of further data obtained from a higher number of both annual and perennial plant species in order to be fully tested.

  4. Metabolic engineering of higher plants and algae for isoprenoid production.

    Science.gov (United States)

    Kempinski, Chase; Jiang, Zuodong; Bell, Stephen; Chappell, Joe

    2015-01-01

    Isoprenoids are a class of compounds derived from the five carbon precursors, dimethylallyl diphosphate, and isopentenyl diphosphate. These molecules present incredible natural chemical diversity, which can be valuable for humans in many aspects such as cosmetics, agriculture, and medicine. However, many terpenoids are only produced in small quantities by their natural hosts and can be difficult to generate synthetically. Therefore, much interest and effort has been directed toward capturing the genetic blueprint for their biochemistry and engineering it into alternative hosts such as plants and algae. These autotrophic organisms are attractive when compared to traditional microbial platforms because of their ability to utilize atmospheric CO2 as a carbon substrate instead of supplied carbon sources like glucose. This chapter will summarize important techniques and strategies for engineering the accumulation of isoprenoid metabolites into higher plants and algae by choosing the correct host, avoiding endogenous regulatory mechanisms, and optimizing potential flux into the target compound. Future endeavors will build on these efforts by fine-tuning product accumulation levels via the vast amount of available "-omic" data and devising metabolic engineering schemes that integrate this into a whole-organism approach. With the development of high-throughput transformation protocols and synthetic biology molecular tools, we have only begun to harness the power and utility of plant and algae metabolic engineering.

  5. Challenging urban species diversity: contrasting phylogenetic patterns across plant functional groups in Germany.

    Science.gov (United States)

    Knapp, Sonja; Kühn, Ingolf; Schweiger, Oliver; Klotz, Stefan

    2008-10-01

    Cities are hotspots of plant species richness, harboring more species than their rural surroundings, at least over large enough scales. However, species richness does not necessarily cover all aspects of biodiversity such as phylogenetic relationships. Ignoring these relationships, our understanding of how species assemblages develop and change in a changing environment remains incomplete. Given the high vascular plant species richness of urbanized areas in Germany, we asked whether these also have a higher phylogenetic diversity than rural areas, and whether phylogenetic diversity patterns differ systematically between species groups characterized by specific functional traits. Calculating the average phylogenetic distinctness of the total German flora and accounting for spatial autocorrelation, we show that phylogenetic diversity of urban areas does not reflect their high species richness. Hence, high urban species richness is mainly due to more closely related species that are functionally similar and able to deal with urbanization. This diminished phylogenetic information might decrease the flora's capacity to respond to environmental changes.

  6. Soil microbial community structure of range-expanding plant species differs from co-occurring natives

    NARCIS (Netherlands)

    Morriën, W.E.; Putten, van der W.H.

    2013-01-01

    1. Due to global warming and other changes in the environment, many native and exotic plant species show range expansion from lower to higher latitudes. In the new range, the (in)ability of range-expanding plants to establish associations with local soil microbes can have important consequences for

  7. REVIEW: The Early Application of Electrophoresis of Protein in Higher Plant Taxonomy

    Directory of Open Access Journals (Sweden)

    SURANTO

    2002-07-01

    Full Text Available The aims of this research are firstly, to study the advantages of electrophoretic techniques. Secondly, to look at the usefulness of a few mediums support of electrophoretic proteins especially the acrylamide gel. Thirdly, to examine the number of plant organs which could be used as the sources of plant proteins, and how these plants protein should be applied in the medium support that has been selected. Besides, the staining and detection procedures would be described, while the application of electrophoretic approach in higher plant taxonomy will also be evaluated. In this study we recorded that a number of taxonomic problems usually caused by morphological complexity within species can be solved using this experimental approach of electrophoresis. This method has been considered very useful in helping taxonomists making decisions.

  8. Distribution patterns of rare earth elements in various plant species

    Energy Technology Data Exchange (ETDEWEB)

    Wyttenbach, A.; Tobler, L.; Furrer, V. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    The elements La, Ce, Nd, Sm, Eu, Gd, Tb, Yb and Lu have been determined in 6 different plant species by neutron activation analysis. When the concentrations of each species were normalized to Norway spruce, smooth curves were obtained which revealed systematic inter-species differences. (author) 3 figs., 4 refs.

  9. Site and plant species are important determinants of the Methylobacterium community composition in the plant phyllosphere.

    Science.gov (United States)

    Knief, Claudia; Ramette, Alban; Frances, Lisa; Alonso-Blanco, Carlos; Vorholt, Julia A

    2010-06-01

    The plant phyllosphere constitutes a habitat for numerous microorganisms; among them are members of the genus Methylobacterium. Owing to the ubiquitous occurrence of methylobacteria on plant leaves, they represent a suitable target for studying plant colonization patterns. The influence of the factor site, host plant species, time and the presence of other phyllosphere bacteria on Methylobacterium community composition and population size were evaluated in this study. Leaf samples were collected from Arabidopsis thaliana or Medicago truncatula plants and from the surrounding plant species at several sites. The abundance of cultivable Methylobacterium clearly correlated with the abundance of other phyllosphere bacteria, suggesting that methylobacteria constitute a considerable and rather stable fraction of the phyllosphere microbiota under varying environmental conditions. Automated ribosomal intergenic spacer analysis (ARISA) was applied to characterize the Methylobacterium community composition and showed the presence of similar communities on A. thaliana plants at most sites in 2 consecutive years of sampling. A substantial part of the observed variation in the community composition was explained by site and plant species, especially in the case of the plants collected at the Arabidopsis sites (50%). The dominating ARISA peaks that were detected on A. thaliana plants were found on other plant species grown at the same site, whereas some different peaks were detected on A. thaliana plants from other sites. This indicates that site-specific factors had a stronger impact on the Methylobacterium community composition than did plant-specific factors and that the Methylobacterium-plant association is not highly host plant species specific.

  10. Plant species loss affects life-history traits of aphids and their parasitoids.

    Directory of Open Access Journals (Sweden)

    Jana S Petermann

    Full Text Available The consequences of plant species loss are rarely assessed in a multi-trophic context and especially effects on life-history traits of organisms at higher trophic levels have remained largely unstudied. We used a grassland biodiversity experiment and measured the effects of two components of plant diversity, plant species richness and the presence of nitrogen-fixing legumes, on several life-history traits of naturally colonizing aphids and their primary and secondary parasitoids in the field. We found that, irrespective of aphid species identity, the proportion of winged aphid morphs decreased with increasing plant species richness, which was correlated with decreasing host plant biomass. Similarly, emergence proportions of parasitoids decreased with increasing plant species richness. Both, emergence proportions and proportions of female parasitoids were lower in plots with legumes, where host plants had increased nitrogen concentrations. This effect of legume presence could indicate that aphids were better defended against parasitoids in high-nitrogen environments. Body mass of emerged individuals of the two most abundant primary parasitoid species was, however, higher in plots with legumes, suggesting that once parasitoids could overcome aphid defenses, they could profit from larger or more nutritious hosts. Our study demonstrates that cascading effects of plant species loss on higher trophic levels such as aphids, parasitoids and secondary parasitoids begin with changed life-history traits of these insects. Thus, life-history traits of organisms at higher trophic levels may be useful indicators of bottom-up effects of plant diversity on the biodiversity of consumers.

  11. Soil vs. canopy seed storage and plant species coexistence in species-rich Australian shrublands.

    Science.gov (United States)

    Enright, N J; Mosner, E; Miller, B P; Johnson, N; Lamont, Byron B

    2007-09-01

    The fire-prone shrublands of southwestern Australia are renowned for their high plant species diversity and prominence of canopy seed storage (serotiny). We compared species richness, abundance, and life history attributes for soil and canopy seed banks in relation to extant vegetation among four sites with different substrate conditions and high species turnover (50-80%) to identify whether this unusual community-level organization of seed storage might contribute to maintenance of high species richness. Soil seed bank (SSB) densities were low to moderate (233-1435 seeds/m2) compared with densities for other Mediterranean-type vegetation and were lowest for sites with highest canopy seed bank (CSB) species richness and lowest nutrient availability, but not richness or abundance of resprouters. Annuals were infrequent in the lowest nutrient sites, but there was no evidence that small SSB size was due to low seed inputs or a trade-off between seed production/storage and seed size in response to low nutrient availability. Sorensen's similarity between SSB and extant vegetation was 26-43% but increased to 54-57% when the CSB was included, representing levels higher than reported for most other ecosystems. Resprouting species were well represented in both the SSB and CSB, and there was no evidence for lower seed production in resprouters than in non-sprouters overall. The SSB and CSB held no species in common and were characterized by markedly different seed dispersal attributes, with winged or small seeds in the CSB and seeds dispersed by ants, birds, and wind (though none with wings) in the SSB. There was no evidence of spatial differentiation in the distribution of seeds of SSB species between vegetated and open microsites that might facilitate species coexistence, but most woody non-sprouters showed aggregation at scales of 1-2 m, implying limited seed dispersal. High similarity between overall seed bank (SSB + CSB) and extant species composition, high number of

  12. Biochemical hydrogen isotope fractionation during biosynthesis in higher plants reflects carbon metabolism of the plant

    Science.gov (United States)

    Cormier, Marc-André; Kahmen, Ansgar

    2015-04-01

    Compound-specific isotope analyses of plant material are frequently applied to understand the response of plants to the environmental changes. As it is generally assume that the main factors controlling δ2H values in plants are the plant's source water and evaporative deuterium enrichment of leaf water, hydrogen isotope analyses of plant material are mainly applied regarding hydrological conditions at different time scales. However, only few studies have directly addressed the variability of the biochemical hydrogen isotope fractionation occurring during biosynthesis of organic compounds (ɛbio), accounting also for a large part in the δ2H values of plants but generally assumed to be constant. Here we present the results from a climate-controlled growth chambers experiment where tested the sensitivity of ɛbio to different light treatments. The different light treatments were applied to induce different metabolic status (autotrophic vs. heterotrophic) in 9 different plant species that we grew from large storage organs (e.g. tubers or roots). The results show a systematic ɛbio shift (up to 80 ) between the different light treatments for different compounds (i.e. long chain n-alkanes and cellulose). We suggest that this shift is due to the different NADPH pools used by the plants to build up the compounds from stored carbohydrates in heterotrophic or autotrophic conditions. Our results have important implications for the calibration and interpretation of sedimentary and tree rings records in geological studies. In addition, as the δ2H values reflect also strongly the carbon metabolism of the plant, our findings support the idea of δ2H values as an interesting proxy for plant physiological studies.

  13. Leaf miner and plant galler species richness on Acacia: relative importance of plant traits and climate.

    Science.gov (United States)

    Bairstow, Katy A; Clarke, Kerri L; McGeoch, Melodie A; Andrew, Nigel R

    2010-06-01

    Diversity patterns of herbivores have been related to climate, host plant traits, host plant distribution and evolutionary relationships individually. However, few studies have assessed the relative contributions of a range of variables to explain these diversity patterns across large geographical and host plant species gradients. Here we assess the relative influence that climate and host plant traits have on endophagous species (leaf miners and plant gallers) diversity across a suite of host species from a genus that is widely distributed and morphologically variable. Forty-six species of Acacia were sampled to encapsulate the diversity of species across four taxonomic sections and a range of habitats along a 950 km climatic gradient: from subtropical forest habitats to semi-arid habitats. Plant traits, climatic variables, leaf miner and plant galler diversity were all quantified on each plant species. In total, 97 leaf mining species and 84 plant galling species were recorded from all host plants. Factors that best explained leaf miner richness across the climatic gradient (using AIC model selection) included specific leaf area (SLA), foliage thickness and mean annual rainfall. The factor that best explained plant galler richness across the climatic gradient was C:N ratio. In terms of the influence of plant and climatic traits on species composition, leaf miner assemblages were best explained by SLA, foliage thickness, mean minimum temperature and mean annual rainfall, whilst plant gall assemblages were explained by C:N ratio, %P, foliage thickness, mean minimum temperature and mean annual rainfall. This work is the first to assess diversity and structure across a broad environmental gradient and a wide range of potential key climatic and plant trait determinants simultaneously. Such methods provide key insights into endophage diversity and provide a solid basis for assessing their responses to a changing climate.

  14. Functional architecture of higher plant photosystem II supercomplexes.

    Science.gov (United States)

    Caffarri, Stefano; Kouril, Roman; Kereïche, Sami; Boekema, Egbert J; Croce, Roberta

    2009-10-07

    Photosystem II (PSII) is a large multiprotein complex, which catalyses water splitting and plastoquinone reduction necessary to transform sunlight into chemical energy. Detailed functional and structural studies of the complex from higher plants have been hampered by the impossibility to purify it to homogeneity. In this work, homogeneous preparations ranging from a newly identified particle composed by a monomeric core and antenna proteins to the largest C(2)S(2)M(2) supercomplex were isolated. Characterization by biochemical methods and single particle electron microscopy allowed to relate for the first time the supramolecular organization to the protein content. A projection map of C(2)S(2)M(2) at 12 A resolution was obtained, which allowed determining the location and the orientation of the antenna proteins. Comparison of the supercomplexes obtained from WT and Lhcb-deficient plants reveals the importance of the individual subunits for the supramolecular organization. The functional implications of these findings are discussed and allow redefining previous suggestions on PSII energy transfer, assembly, photoinhibition, state transition and non-photochemical quenching.

  15. Formation of higher plant component microbial community in closed ecological system

    Science.gov (United States)

    Tirranen, L. S.

    2001-07-01

    Closed ecological systems (CES) place at the disposal of a researcher unique possibilities to study the role of microbial communities in individual components and of the entire system. The microbial community of the higher plant component has been found to form depending on specific conditions of the closed ecosystem: length of time the solution is reused, introduction of intrasystem waste water into the nutrient medium, effect of other component of the system, and system closure in terms of gas exchange. The higher plant component formed its own microbial complex different from that formed prior to closure. The microbial complex of vegetable polyculture is more diverse and stable than the monoculture of wheat. The composition of the components' microflora changed, species diversity decreased, individual species of bacteria and fungi whose numbers were not so great before the closure prevailed. Special attention should be paid to phytopathogenic and conditionally pathogenic species of microorganisms potentially hazardous to man or plants and the least controlled in CES. This situation can endanger creation of CES and make conjectural existence of preplanned components, man, specifically, and consequently, of CES as it is.

  16. Species composition, Plant Community structure and Natural ...

    African Journals Online (AJOL)

    Belete forest is one of the very few remnant moist evergreen montane forests in Ethiopia. The objective of this work was to study the vegetation structure, composition and Natural regeneration status of Belete moist evergreen montane forest. To investigate the plant community structure, composition and regeneration status ...

  17. Water-Wisteria as an ideal plant to study heterophylly in higher aquatic plants.

    Science.gov (United States)

    Li, Gaojie; Hu, Shiqi; Yang, Jingjing; Schultz, Elizabeth A; Clarke, Kurtis; Hou, Hongwei

    2017-08-01

    The semi-aquatic plant Water-Wisteria is suggested as a new model to study heterophylly due to its many advantages and typical leaf phenotypic plasticity in response to environmental factors and phytohormones. Water-Wisteria, Hygrophila difformis (Acanthaceae), is a fast growing semi-aquatic plant that exhibits a variety of leaf shapes, from simple leaves to highly branched compound leaves, depending on the environment. The phenomenon by which leaves change their morphology in response to environmental conditions is called heterophylly. In order to investigate the characteristics of heterophylly, we assessed the morphology and anatomy of Hygrophila difformis in different conditions. Subsequently, we verified that phytohormones and environmental factors can induce heterophylly and found that Hygrophila difformis is easily propagated vegetatively through either leaf cuttings or callus induction, and the callus can be easily transformed by Agrobacterium tumefaciens. These results suggested that Hygrophila difformis is a good model plant to study heterophylly in higher aquatic plants.

  18. Nitric oxide and reactive oxygen species in plant biotic interactions.

    Science.gov (United States)

    Scheler, Claudia; Durner, Jörg; Astier, Jeremy

    2013-08-01

    Nitric oxide (NO) and reactive oxygen species (ROS) are important signaling molecules in plants. Recent progress has been made in defining their role during plant biotic interactions. Over the last decade, their function in disease resistance has been highlighted and focused a lot of investigations. Moreover, NO and ROS have recently emerged as important players of defense responses after herbivore attacks. Besides their role in plant adaptive response development, NO and ROS have been demonstrated to be involved in symbiotic interactions between plants and microorganisms. Here we review recent data concerning these three sides of NO and ROS functions in plant biotic interactions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Thermal Hyperspectral Remote Sensing for Plant Species and Stress Detection

    Science.gov (United States)

    Schlerf, M.; Rock, G.; Ullah, S.; Gerhards, M.; Udelhoven, T.; Skidmore, A. K.

    2014-12-01

    Thermal infrared (TIR) spectroscopy offers a novel opportunity for measuring emissivity spectra of natural surfaces. Emissivity spectra are not directly measured, they first have to be retrieved from the raw measurements. Once retrieved, the spectra can be used, for example, to discriminate plant species or to detect plant stress. Knowledge of plant species distribution is essential for the sustainable management of ecosystems. Remote sensing of plant species has so far mostly been limited to data in the visible and near-infrared where, however, different species often reveal similar reflectance curves. Da Luz and Crowley showed in a recent paper that in the TIR plants indeed have distinct spectral features. Also with a certain species, subtle changes of emissivity in certain wavebands may occur, when biochemical compounds change due to osmotic adjustment induced by water stress. Here we show, that i) emissive imaging spectroscopy allows for reliable and accurate retrieval of plant emissivity spectra, ii) emissivity spectra are well suited to discriminate plant species, iii) a reduction in stomatal conductance (caused by stress) changes the thermal infrared signal. For 13 plant species in the laboratory and for 8 plant species in a field setup emissivity spectra were retrieved. A comparison shows, that for most species the shapes of the emissivity curves agree quite well, but that clear offsets between the two types of spectra exist. Discrimination analysis revealed that based on the lab spectra, 13 species could be distinguished with an average overall classification accuracy of 92% using the 6 best spectral bands. For the field spectra (8 species), a similar high OAA of 89% was achieved. Species discrimination is likely to be possible due to variations in the composition of the superficial epidermal layer of plant leaves and in internal chemical concentrations producing unique emissivity features. However, to date, which spectral feature is responsible for which

  20. Widespread plant species: Natives versus aliens in our changing world

    Science.gov (United States)

    Stohlgren, T.J.; Pysek, P.; Kartesz, J.; Nishino, M.; Pauchard, A.; Winter, M.; Pino, J.; Richardson, D.M.; Wilson, J.R.U.; Murray, B.R.; Phillips, M.L.; Ming-yang, L.; Celesti-Grapow, L.; Font, X.

    2011-01-01

    Estimates of the level of invasion for a region are traditionally based on relative numbers of native and alien species. However, alien species differ dramatically in the size of their invasive ranges. Here we present the first study to quantify the level of invasion for several regions of the world in terms of the most widely distributed plant species (natives vs. aliens). Aliens accounted for 51.3% of the 120 most widely distributed plant species in North America, 43.3% in New South Wales (Australia), 34.2% in Chile, 29.7% in Argentina, and 22.5% in the Republic of South Africa. However, Europe had only 1% of alien species among the most widespread species of the flora. Across regions, alien species relative to native species were either as well-distributed (10 comparisons) or more widely distributed (5 comparisons). These striking patterns highlight the profound contribution that widespread invasive alien plants make to floristic dominance patterns across different regions. Many of the most widespread species are alien plants, and, in particular, Europe and Asia appear as major contributors to the homogenization of the floras in the Americas. We recommend that spatial extent of invasion should be explicitly incorporated in assessments of invasibility, globalization, and risk assessments. ?? 2011 Springer Science+Business Media B.V.

  1. Widespread plant species: natives vs. aliens in our changing world

    Science.gov (United States)

    Stohlgren, Thomas J.; Pyšek, Petr; Kartesz, John; Nishino, Misako; Pauchard, Aníbal; Winter, Marten; Pino, Joan; Richardson, David M.; Wilson, John R.U.; Murray, Brad R.; Phillips, Megan L.; Ming-yang, Li; Celesti-Grapow, Laura; Font, Xavier

    2011-01-01

    Estimates of the level of invasion for a region are traditionally based on relative numbers of native and alien species. However, alien species differ dramatically in the size of their invasive ranges. Here we present the first study to quantify the level of invasion for several regions of the world in terms of the most widely distributed plant species (natives vs. aliens). Aliens accounted for 51.3% of the 120 most widely distributed plant species in North America, 43.3% in New South Wales (Australia), 34.2% in Chile, 29.7% in Argentina, and 22.5% in the Republic of South Africa. However, Europe had only 1% of alien species among the most widespread species of the flora. Across regions, alien species relative to native species were either as well-distributed (10 comparisons) or more widely distributed (5 comparisons). These striking patterns highlight the profound contribution that widespread invasive alien plants make to floristic dominance patterns across different regions. Many of the most widespread species are alien plants, and, in particular, Europe and Asia appear as major contributors to the homogenization of the floras in the Americas. We recommend that spatial extent of invasion should be explicitly incorporated in assessments of invasibility, globalization, and risk assessments.

  2. Human population, grasshopper and plant species richness in European countries

    Science.gov (United States)

    Steck, Claude E.; Pautasso, Marco

    2008-11-01

    Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species-people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population-biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.

  3. Effect of plant extracts on book deteriorated fungal species.

    Science.gov (United States)

    Kalbende, Swapna P; Dalal, Lalchand P

    2016-05-06

    The aim of the study was to evaluate the effect of leaf extracts of four plants against some isolated fungal species from deteriorated books. Aqueous, methanol and chloroform extracts of selected plant species were screened in vitro for their antifungal activity against some book deteriorating fungal species. Fifteen species belonging to 09 genera were isolated and identified from infested books in library. Aqueous and solvent extracts of leaves of Azadiracta indica, Callistemon citrinus, Eucalyptus lanceolatus and Pongamia pinnata were tested against some dominant fungal species viz. Chaetomium spiralis, Alternaria alternata, Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus and Rhizopus stolonifer. Solvent extracts exhibited potent inhibitory activity than aqueous extracts. However, these plant extracts exhibited moderate activity against A. flavus, C. spiralis, R. stolonifer and A. alternata.

  4. Plant Species Recovery on a Compacted Skid Road

    Directory of Open Access Journals (Sweden)

    Beyza Sat Gungor

    2008-05-01

    Full Text Available This study was executed to determine the plant species of herbaceous cover in a skid road subjected to soil compaction due to timber skidding in a beech (Fagus orientalis Lipsky. stand. Our previous studies have shown that ground based timber skidding destroys the soils extremely, and degradations on ecosystem because of the timber skidding limit recovery and growth of plant cover on skid roads. However, some plant species show healthy habitat, recovery and they can survive after the extreme degradation in study area. We evaluated composition of these plant species and their cover-abundance scales in 100 m x 3 m transect. 15 plant species were determined belongs to 12 plant families and Liliaceae was the highest representative plant family. Smilax aspera L., Epimedium pubigerum (DC. Moren et Decaisne, Carex distachya Desf. var. distachya Desf., Pteridium aquilinum (L. Kuhn., Trachystemon orientalis (L. G. Don, Hedera helix L. have the highest coverabundance scale overall of determined species on compacted skid road.

  5. Light intensity-dependent retrograde signalling in higher plants.

    Science.gov (United States)

    Szechyńska-Hebda, Magdalena; Karpiński, Stanisław

    2013-11-15

    Plants are able to acclimate to highly fluctuating light environment and evolved a short- and long-term light acclimatory responses, that are dependent on chloroplasts retrograde signalling. In this review we summarise recent evidences suggesting that the chloroplasts act as key sensors of light intensity changes in a wide range (low, high and excess light conditions) as well as sensors of darkness. They also participate in transduction and synchronisation of systemic retrograde signalling in response to differential light exposure of distinct leaves. Regulation of intra- and inter-cellular chloroplast retrograde signalling is dependent on the developmental and functional stage of the plastids. Therefore, it is discussed in following subsections: firstly, chloroplast biogenic control of nuclear genes, for example, signals related to photosystems and pigment biogenesis during early plastid development; secondly, signals in the mature chloroplast induced by changes in photosynthetic electron transport, reactive oxygen species, hormones and metabolite biosynthesis; thirdly, chloroplast signalling during leaf senescence. Moreover, with a help of meta-analysis of multiple microarray experiments, we showed that the expression of the same set of genes is regulated specifically in particular types of signals and types of light conditions. Furthermore, we also highlight the alternative scenarios of the chloroplast retrograde signals transduction and coordination linked to the role of photo-electrochemical signalling. Copyright © 2013 Elsevier GmbH. All rights reserved.

  6. Assessing The Ecological Status Of Woody Plant Species At Eroded ...

    African Journals Online (AJOL)

    Woody plant species up to 0.10 m and above in height growing in and within 0.5 m from the edges of ten gully erosion areas of Abia and Imo states of Nigeria were enumerated in January and July 2000 through July 2003. Questionnaires were served to find the causal factors of each gully. The plants were enumerated and ...

  7. Plant species richness regulates soil respiration through changes in productivity.

    NARCIS (Netherlands)

    Tavares Correa Dias, A.; van Ruijven, J.; Berendse, F.

    2010-01-01

    Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of

  8. Plant species richness regulates soil respiration through changes in productivity

    NARCIS (Netherlands)

    Dias, A.A.; Ruijven, van J.; Berendse, F.

    2010-01-01

    Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of

  9. Antimicrobial activity of some endemic plant species from Turkey ...

    African Journals Online (AJOL)

    Six plant extracts obtained from different parts such as the leaves, flowers and seeds of four species of the endemic plants in Turkey were tested on a total of 14 microorganisms, 10 of which were bacterial strains and 4 yeast strains. Verbascum eriocarpum (flower) extract was found to be effective against Staphylococcus ...

  10. Leafy spurge effects on patterns of plant species richness

    Science.gov (United States)

    Jack L. Butler; Daniel R. Cogan

    2004-01-01

    The objective of this study was to simultaneously evaluate the impact of leafy spurge (Euphorbia esula L.) on plant species richness within and among a wide variety of vegetation types typical of the region. The study was conducted in Theodore Roosevelt National Park in southwestern North Dakota where 11 plant associations were identified as being...

  11. Plant species responses to oil degradation and toxicity reduction in ...

    African Journals Online (AJOL)

    A field project located at the Botanical garden of the University of Port Harcourt was designed to evaluate changes in contaminants concentration and toxicity during phytoremediation. Vegetated plots were established by planting different plant species – legumes and vegetable (Abelmoschus, esculentus, Telfaria ...

  12. Plant species responses to oil degradation and toxicity reduction in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-05

    Jan 5, 2009 ... A field project located at the Botanical garden of the University of Port Harcourt was designed to evaluate changes in contaminants concentration and toxicity during phytoremediation. Vegetated plots were established by planting different plant species – legumes and vegetable (Abelmoschus, esculentus ...

  13. Exotic and indigenous problem plants species used, by the Bapedi ...

    African Journals Online (AJOL)

    EB

    Background: The ethnic usage of exotics and indigenous problem plants is a highly debated topic, as legislative requirements over-shadow their potential medicinal ... plant species are declared via Conservation of Agricultural Resource Act no. ... researchers from both home gardens and wild during organized tours while ...

  14. Species distribution modelling for plant communities: Stacked single species or multivariate modelling approaches?

    Science.gov (United States)

    Emilie B. Henderson; Janet L. Ohmann; Matthew J. Gregory; Heather M. Roberts; Harold S.J. Zald

    2014-01-01

    Landscape management and conservation planning require maps of vegetation composition and structure over large regions. Species distribution models (SDMs) are often used for individual species, but projects mapping multiple species are rarer. We compare maps of plant community composition assembled by stacking results from many SDMs with multivariate maps constructed...

  15. Intraspecific genetic variation and species coexistence in plant communities.

    Science.gov (United States)

    Ehlers, Bodil K; Damgaard, Christian F; Laroche, Fabien

    2016-01-01

    Many studies report that intraspecific genetic variation in plants can affect community composition and coexistence. However, less is known about which traits are responsible and the mechanisms by which variation in these traits affect the associated community. Focusing on plant-plant interactions, we review empirical studies exemplifying how intraspecific genetic variation in functional traits impacts plant coexistence. Intraspecific variation in chemical and architectural traits promotes species coexistence, by both increasing habitat heterogeneity and altering competitive hierarchies. Decomposing species interactions into interactions between genotypes shows that genotype × genotype interactions are often intransitive. The outcome of plant-plant interactions varies with local adaptation to the environment and with dominant neighbour genotypes, and some plants can recognize the genetic identity of neighbour plants if they have a common history of coexistence. Taken together, this reveals a very dynamic nature of coexistence. We outline how more traits mediating plant-plant interactions may be identified, and how future studies could use population genetic surveys of genotype distribution in nature and methods from trait-based ecology to better quantify the impact of intraspecific genetic variation on plant coexistence. © 2016 The Author(s).

  16. Tree-Dwelling Ants: Contrasting Two Brazilian Cerrado Plant Species without Extrafloral Nectaries

    Directory of Open Access Journals (Sweden)

    Jonas Maravalhas

    2012-01-01

    Full Text Available Ants dominate vegetation stratum, exploiting resources like extrafloral nectaries (EFNs and insect honeydew. These interactions are frequent in Brazilian cerrado and are well known, but few studies compare ant fauna and explored resources between plant species. We surveyed two cerrado plants without EFNs, Roupala montana (found on preserved environments of our study area and Solanum lycocarpum (disturbed ones. Ants were collected and identified, and resources on each plant noted. Ant frequency and richness were higher on R. montana (67%; 35 spp than S. lycocarpum (52%; 26, the occurrence of the common ant species varied between them, and similarity was low. Resources were explored mainly by Camponotus crassus and consisted of scale insects, aphids, and floral nectaries on R. montana and two treehopper species on S. lycocarpum. Ants have a high diversity on cerrado plants, exploring liquid and prey-based resources that vary in time and space and affect their presence on plants.

  17. Factors determining plant species richness in Alaskan artic tundra

    NARCIS (Netherlands)

    Welle, van der M.E.W.; Vermeulen, P.J.; Shaver, G.R.; Berendse, F.

    2003-01-01

    We studied the relationship between plant N:P ratio, soil characteristics and species richness in wet sedge and tussock tundra in northern Alaska at seven sites. We also collected data on soil characteristics, above-ground biomass, species richness and composition. The N:P ratio of the vegetation

  18. Location of plant species in Norway gathered as a part of a survey vegetation mapping programme

    Science.gov (United States)

    Bryn, Anders; Kristoffersen, Hans-Petter; Angeloff, Michael; Nystuen, Ingvild; Aune-Lundberg, Linda; Endresen, Dag; Svindseth, Christian; Rekdal, Yngve

    2015-01-01

    Georeferenced species data have a wide range of applications and are increasingly used for e.g. distribution modelling and climate change studies. As an integrated part of an on-going survey programme for vegetation mapping, plant species have been recorded. The data described in this paper contains 18.521 registrations of plants from 1190 different circular plots throughout Norway. All species localities are georeferenced, the spatial uncertainty is provided, and additional ecological information is reported. The published data has been gathered from 1991 until 2015. The entries contain all higher vascular plants and pteridophytes, and some cryptogams. Other ecological information is also provided for the species locations, such as the vegetation type, the cover of the species and slope. The entire material is stored and available for download through the GBIF server. PMID:26958614

  19. Location of plant species in Norway gathered as a part of a survey vegetation mapping programme

    Directory of Open Access Journals (Sweden)

    Anders Bryn

    2015-12-01

    Full Text Available Georeferenced species data have a wide range of applications and are increasingly used for e.g. distribution modelling and climate change studies. As an integrated part of an on-going survey programme for vegetation mapping, plant species have been recorded. The data described in this paper contains 18.521 registrations of plants from 1190 different circular plots throughout Norway. All species localities are georeferenced, the spatial uncertainty is provided, and additional ecological information is reported. The published data has been gathered from 1991 until 2015. The entries contain all higher vascular plants and pteridophytes, and some cryptogams. Other ecological information is also provided for the species locations, such as the vegetation type, the cover of the species and slope. The entire material is stored and available for download through the GBIF server.

  20. Plant responses to species removal and experimental warming in Alaskan tussock tundra

    Energy Technology Data Exchange (ETDEWEB)

    Hobbie, S.E.; Chapin, F.S. III [Univ. of California, Dept. of Integrative Biology, Berkeley, CA (United States); Shevtsova, A. [Univ. of Turku, Dept. of Biology, Section of Ecology, Turku (Finland)

    1999-07-01

    We manipulated air temperature and the presence of the seven dominant plant species in Alaskan tussock tundra and measured shoot growth, branching, aboveground biomass, and reproduction of the remaining plant species. Warming stimulated shoot growth of the dominant sedges and shrubs after one and two years of manipulation and total leaf biomass of the dominant shrubs after three years. Warming decreased aboveground biomass of Eriophorum vaginatum, Cassiope tetragona and most non-vascular species. Warming also reduced total reproductive output of two of three species measured. Removal of single species had no effect on shoot growth of the remaining species. However, total aboveground biomass and reproduction of Ledum palustre increased with removal of other shrub species, suggesting that competition limits biomass accumulation in L. palustre. Sphagnum removal increased the aboveground biomass of Betula nana. The higher frequency of significant warming versus species removal effects on plant growth and biomass suggests that direct limitation by environmental conditions is more important than limitation by species interactions in tussock tundra. Furthermore, we found no significant interactions between warming and species removal, suggesting that increased temperature per se will not alter the intensity of species interactions. When combined with knowledge of dispersal abilities and controls over establishment, extrapolation of species responses to environmental manipulation may thus allow us to predict effects of climate change on community composition. (au)

  1. Evolutionary history and stress regulation of the lectin superfamily in higher plants

    Directory of Open Access Journals (Sweden)

    Ramachandran Srinivasan

    2010-03-01

    Full Text Available Abstract Background Lectins are a class of carbohydrate-binding proteins. They play roles in various biological processes. However, little is known about their evolutionary history and their functions in plant stress regulation. The availability of full genome sequences from various plant species makes it possible to perform a whole-genome exploration for further understanding their biological functions. Results Higher plant genomes encode large numbers of lectin proteins. Based on their domain structures and phylogenetic analyses, a new classification system has been proposed. In this system, 12 different families have been classified and four of them consist of recently identified plant lectin members. Further analyses show that some of lectin families exhibit species-specific expansion and rapid birth-and-death evolution. Tandem and segmental duplications have been regarded as the major mechanisms to drive lectin expansion although retrogenes also significantly contributed to the birth of new lectin genes in soybean and rice. Evidence shows that lectin genes have been involved in biotic/abiotic stress regulations and tandem/segmental duplications may be regarded as drivers for plants to adapt various environmental stresses through duplication followed by expression divergence. Each member of this gene superfamily may play specialized roles in a specific stress condition and function as a regulator of various environmental factors such as cold, drought and high salinity as well as biotic stresses. Conclusions Our studies provide a new outline of the plant lectin gene superfamily and advance the understanding of plant lectin genes in lineage-specific expansion and their functions in biotic/abiotic stress-related developmental processes.

  2. Psychoactive plant species – actual list of plants prohibited in Poland

    OpenAIRE

    Simonienko, Katarzyna; Waszkiewicz, Napoleon; Szulc, Agata

    2013-01-01

    According to the Act on Counteracting Drug Addiction (20-th of March, 2009, Dz. U. Nr 63 poz. 520.) the list of federally prohibited plants in Poland was expanded to include 16 new species. Until that time the only illegal plant materials were cannabis, papaver, coca and most of their products. The actual list of herbal narcotics includes species which significantly influence on the central nervous system work but which are rarely described in the national literature. The plants usually come ...

  3. Mycorrhizal status helps explain invasion success of alien plant species.

    Science.gov (United States)

    Menzel, Andreas; Hempel, Stefan; Klotz, Stefan; Moora, Mari; Pyšek, Petr; Rillig, Matthias C; Zobel, Martin; Kühn, Ingolf

    2017-01-01

    It is still debated whether alien plants benefit from being mycorrhizal, or if engaging in the symbiosis constrains their establishment and spread in new regions. We analyzed the association between mycorrhizal status of alien plant species in Germany and their invasion success. We compared whether the representation of species with different mycorrhizal status (obligate, facultative, or non-mycorrhizal) differed at several stages of the invasion process. We used generalized linear models to explain the occupied geographical range of alien plants, incorporating interactions of mycorrhizal status with plant traits related to morphology, reproduction, and life-history. Non-naturalized aliens did not differ from naturalized aliens in the relative frequency of different mycorrhizal status categories. Mycorrhizal status significantly explained the occupied range of alien plants; with facultative mycorrhizal species inhabiting a larger range than non-mycorrhizal aliens and obligate mycorrhizal plant species taking an intermediate position. Aliens with storage organs, shoot metamorphoses, or specialized structures promoting vegetative dispersal occupied a larger range when being facultative mycorrhizal. We conclude that being mycorrhizal is important for the persistence of aliens in Germany and constitutes an advantage compared to being non-mycorrhizal. Being facultative mycorrhizal seems to be especially advantageous for successful spread, as the flexibility of this mycorrhizal status may enable plants to use a broader set of ecological strategies. © 2016 by the Ecological Society of America.

  4. IDENTIFICATION OF MICRORNAS IN 12 PLANT SPECIES OF FABACEAE

    Directory of Open Access Journals (Sweden)

    Abdul Ghani

    2013-09-01

    Full Text Available MicroRNAs (miRNAs are tiny, non-coding and regulatory RNAs approximately 21 nucleotides in length.They are reported in various plants but still needs discovery in important plant species. The 12 plant species ofFabaceae were subjected this time to identify their miRNAs. The comparative genomics approaches withcombination of various bioinformatics’ tools were applied to find the novel miRNAs. This research leads to thefinding of 29 miRNAs belonging to 13 miRNA families. From the 29 miRNAs, nine belongs to Arachis duranensis,four to Lotus japonicas, three to each Pisum sativum and Arachis hypogaea, two to each Arachis ipaensis andPhaseolus vulgaris and one to each Cicer arietinum, Phaseolus acutifolius, Lupinus luteus, Glycyrrhiza uralensis,Robinia pseudoacacia and Lathyrus odoratus. These findings will be useful in the future to design and developdesirable traits in the 12 plant species of Fabaceae.

  5. Effects of herbivory by Diaprepes abbreviatus (Coleoptera: Curculionidae) larvae on four woody ornamental plant species.

    Science.gov (United States)

    Martin, Cliff G; Mannion, Catharine; Schaffer, Bruce

    2009-06-01

    The hypothesis that herbivory by Diaprepes root weevil larvae reduces leaf gas exchange and biomass was tested on buttonwood (Conocarpus erectus L.), Surinam cherry (Eugenia uniflora L.), mahogany (Swietenia mahagoni Jacq.), and pond apple (Annona glabra L). For Surinam cherry, net CO2 assimilation, transpiration, and stomatal conductance, but not internal CO2 concentration (collectively referred to as leaf gas exchange values), were 7-32% higher in noninfested than infested plants. For buttonwood, all four gas exchange values were 10-54% higher for noninfested than infested plants 3 h after infestation with large, seventh-instar larvae. However, by 4 wk after this infestation, net CO2 assimilation, transpiration, and stomatal conductance, but not internal CO2 concentration, were 11-37% higher for infested than for noninfested plants. For mahogany and pond apple, there were few or no significant differences in leaf gas exchange values between infested and noninfested plants. For all species, mean shoot and root fresh and dry weights were higher for noninfested than infested plants, with the differences most significant for buttonwood (37-85% higher), followed by Surinam cherry (37-143% higher), mahogany (49-84% higher), and pond apple (24-46% higher), which had no significant differences. There were significant differences among plant species in mean head capsule widths, thus larval instars, of larvae recovered from soil with the largest larvae from Surinam cherry (2.59 +/- 0.19 mm) and the smallest from mahogany (2.29 +/- 0.06 mm). Based on differences in leaf gas exchange and plant biomass between infested and noninfested plants of the four species tested, buttonwood and Surinam cherry are the most vulnerable to feeding by Diaprepes larvae followed by mahogany then pond apple.

  6. Mercury uptake and accumulation by four species of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Kathleen [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)]. E-mail: skinnk@sage.edu; Wright, Nicole [NEIWPCC-NYSDEC, 625 Broadway, 4th Floor, Albany, NY 12233-3502 (United States)]. E-mail: ndwright@gw.dec.state.ny.us; Porter-Goff, Emily [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)

    2007-01-15

    The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox[reg] (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox[reg] results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. - Four species of aquatic plants reduced mercury in water.

  7. Influences of Plant Species, Season and Location on Leaf Endophytic Bacterial Communities of Non-Cultivated Plants.

    Directory of Open Access Journals (Sweden)

    Tao Ding

    Full Text Available Bacteria are known to be associated endophytically with plants. Research on endophytic bacteria has identified their importance in food safety, agricultural production and phytoremediation. However, the diversity of endophytic bacterial communities and the forces that shape their compositions in non-cultivated plants are largely uncharacterized. In this study, we explored the diversity, community structure, and dynamics of endophytic bacteria in different plant species in the Tallgrass Prairie Preserve of northern Oklahoma, USA. High throughput sequencing of amplified segments of bacterial rDNA from 81 samples collected at four sampling times from five plant species at four locations identified 335 distinct OTUs at 97% sequence similarity, representing 16 phyla. Proteobacteria was the dominant phylum in the communities, followed by the phyla Bacteriodetes and Actinobacteria. Bacteria from four classes of Proteobacteria were detected with Alphaproteobacteria as the dominant class. Analysis of molecular variance revealed that host plant species and collecting date had significant influences on the compositions of the leaf endophytic bacterial communities. The proportion of Alphaproteobacteria was much higher in the communities from Asclepias viridis than from other plant species and differed from month to month. The most dominant bacterial groups identified in LDA Effect Size analysis showed host-specific patterns, indicating mutual selection between host plants and endophytic bacteria and that leaf endophytic bacterial compositions were dynamic, varying with the host plant's growing season in three distinct patterns. In summary, next generation sequencing has revealed variations in the taxonomic compositions of leaf endophytic bacterial communities dependent primarily on the nature of the plant host species.

  8. Higher Plants in life support systems: design of a model and plant experimental compartment

    Science.gov (United States)

    Hezard, Pauline; Farges, Berangere; Sasidharan L, Swathy; Dussap, Claude-Gilles

    The development of closed ecological life support systems (CELSS) requires full control and efficient engineering for fulfilling the common objectives of water and oxygen regeneration, CO2 elimination and food production. Most of the proposed CELSS contain higher plants, for which a growth chamber and a control system are needed. Inside the compartment the development of higher plants must be understood and modeled in order to be able to design and control the compartment as a function of operating variables. The plant behavior must be analyzed at different sub-process scales : (i) architecture and morphology describe the plant shape and lead to calculate the morphological parameters (leaf area, stem length, number of meristems. . . ) characteristic of life cycle stages; (ii) physiology and metabolism of the different organs permit to assess the plant composition depending on the plant input and output rates (oxygen, carbon dioxide, water and nutrients); (iii) finally, the physical processes are light interception, gas exchange, sap conduction and root uptake: they control the available energy from photosynthesis and the input and output rates. These three different sub-processes are modeled as a system of equations using environmental and plant parameters such as light intensity, temperature, pressure, humidity, CO2 and oxygen partial pressures, nutrient solution composition, total leaf surface and leaf area index, chlorophyll content, stomatal conductance, water potential, organ biomass distribution and composition, etc. The most challenging issue is to develop a comprehensive and operative mathematical model that assembles these different sub-processes in a unique framework. In order to assess the parameters for testing a model, a polyvalent growth chamber is necessary. It should permit a controlled environment in order to test and understand the physiological response and determine the control strategy. The final aim of this model is to have an envi

  9. Phosphatidylinositol species of suspension cultured plant cells

    Energy Technology Data Exchange (ETDEWEB)

    Heim, S.; Wagner, K.G.

    Suspension cultured Nicotiana tabacum and Catharanthus roseus cells were labeled with (/sup 3/H)inositol, the phospholipid fraction extracted and separated by thin layer chromatography. Three different solvent systems and reference compounds were used to assign the different /sup 3/H-labeled species by autoradiography. The ratio of (/sup 3/H)inositol incorporation into PI, PIP and PIP/sub 2/ was found to be 95:4:1; with some preparations a lyso-PI band was obtained which incorporated about a tenth of the label of the PIP band. With Catharanthus roseus cells a very faint band between PI and lyso-PI was detected which could not be assigned to a reference compound.

  10. Are the metabolomic responses to folivory of closely related plant species linked to macroevolutionary and plant-folivore coevolutionary processes?

    Energy Technology Data Exchange (ETDEWEB)

    Rivas-Ubach, Albert [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington 99354 USA; CREAF, Cerdanyola del Vallès 08913 Catalonia Spain; Hódar, José A. [Grupo de Ecología Terrestre, Departamento de Biología Animal y Ecología, Facultad de Ciencias, Universidad de Granada, 18071 Granada Spain; Sardans, Jordi [CREAF, Cerdanyola del Vallès 08913 Catalonia Spain; CSIC, Global Ecology Unit CREAF-CEAB-CSIC-UAB, Cerdanyola del Vallès 08913 Catalonia Spain; Kyle, Jennifer E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland Washington 99354 USA; Kim, Young-Mo [Biological Sciences Division, Pacific Northwest National Laboratory, Richland Washington 99354 USA; Oravec, Michal [Global Change Research Centre, Academy of Sciences of the Czech Republic, Bĕlidla 4a CZ-603 00 Brno Czech Republic; Urban, Otmar [Global Change Research Centre, Academy of Sciences of the Czech Republic, Bĕlidla 4a CZ-603 00 Brno Czech Republic; Guenther, Alex [Department of Earth System Science, University of California, Irvine California 92697 USA; Peñuelas, Josep [CREAF, Cerdanyola del Vallès 08913 Catalonia Spain; CSIC, Global Ecology Unit CREAF-CEAB-CSIC-UAB, Cerdanyola del Vallès 08913 Catalonia Spain

    2016-06-02

    The debate whether the coevolution of plants and insects or macroevolutionary processes (phylogeny) is the main driver determining the arsenal of molecular defensive compounds of plants remains unresolved. Attacks by herbivorous insects affect not only the composition of defensive compounds in plants but the entire metabolome (the set of molecular metabolites), including defensive compounds. Metabolomes are the final products of genotypes and are directly affected by macroevolutionary processes, so closely related species should have similar metabolomic compositions and may respond in similar ways to attacks by folivores. We analyzed the elemental compositions and metabolomes of needles from Pinus pinaster, P. nigra and P. sylvestris to determine if these closely related Pinus species with different coevolutionary histories with the caterpillars of the processionary moth respond similarly to attacks by this lepidopteran. All pines had different metabolomes and metabolic responses to herbivorous attack. The metabolomic variation among the pine species and the responses to folivory reflected their macroevolutionary relationships, with P. pinaster having the most divergent metabolome. The concentrations of phenolic metabolites were generally not higher in the attacked trees, which had lower concentrations of terpenes, suggesting that herbivores avoid individuals with high concentrations of terpenes. Our results suggest that macroevolutionary history plays important roles in the metabolomic responses of these pine species to folivory, but plant-insect coevolution probably constrains those responses. Combinations of different evolutionary factors and trade-offs are likely responsible for the different responses of each species to folivory, which is not necessarily exclusively linked to plant-insect coevolution.

  11. Generalist Bee Species on Brazilian Bee-Plant Interaction Networks

    Directory of Open Access Journals (Sweden)

    Astrid de Matos Peixoto Kleinert

    2012-01-01

    Full Text Available Determining bee and plant interactions has an important role on understanding general biology of bee species as well as the potential pollinating relationship between them. Bee surveys have been conducted in Brazil since the end of the 1960s. Most of them applied standardized methods and had identified the plant species where the bees were collected. To analyze the most generalist bees on Brazilian surveys, we built a matrix of bee-plant interactions. We estimated the most generalist bees determining the three bee species of each surveyed locality that presented the highest number of interactions. We found 47 localities and 39 species of bees. Most of them belong to Apidae (31 species and Halictidae (6 families and to Meliponini (14 and Xylocopini (6 tribes. However, most of the surveys presented Apis mellifera and/or Trigona spinipes as the most generalist species. Apis mellifera is an exotic bee species and Trigona spinipes, a native species, is also widespread and presents broad diet breath and high number of individuals per colony.

  12. Metalaxyl toxicity, uptake, and distribution in several ornamental plant species.

    Science.gov (United States)

    Wilson, P C; Whitwell, T; Klaine, S J

    2001-01-01

    Phytoremediation depends on the ability of plants to tolerate and assimilate contaminants. This research characterized the interaction between several ornamental plant species and the fungicidal active ingredient, metalaxyl [N-(2,6-dimethylphenyl)-N-(methoxyacetyl)alanine methyl ester]. Species evaluated included sweetflag (Acorus gramineus Sol. ex Aiton), canna (Canna hybrida L. 'Yellow King Humbert'), parrotfeather [Myriophyllum aquaticum (Vell.) Verdc.], and pickerelweed (Pontederia cordata L.). Metalaxyl tolerance levels for each species were determined by exposing plants for 7 d to solutions containing 0, 5, 10, 25, 50, 75, or 100 mg metalaxyl L-1 aqueous nutrient media. Response endpoints included fresh mass production after 7 d exposure and 7 d post-exposure and quantum efficiency using dark-adapted (Fv/Fm) and light-adapted (fluorescence yields) plants. Metalaxyl uptake and distribution within the plant was determined by growing plants in aqueous nutrient media containing 1.18 x 10(6) Bq L-1 [14C]metalaxyl (0.909 mg L-1) for 1, 3, 5, or 7 d. Plant tissues were combusted and analyzed by liquid scintillation counting. Metalaxyl had no effects on the endpoints measured, except for fresh mass production of sweetflag at the 75 and 100 mg L-1 treatment levels. However, leaf necrosis was apparent in most species after 5 d exposure to concentrations greater than 25 mg L-1. Metalaxyl removal from the spiked nutrient media ranged from 15 to 60% during the 7-d exposure period. The majority of metalaxyl removed from the solution was detected within individual plants. In nearly all cases, activity from the radiolabeled pesticide accumulated in the leaves. Uptake of metalaxyl was correlated with water uptake throughout the 7 d. These results suggest that all species examined may be good candidates for incorporation into a phytoremediation scheme for metalaxyl.

  13. Species boundaries in plant pathogenic fungi: a Colletotrichum case study.

    Science.gov (United States)

    Liu, Fang; Wang, Mei; Damm, Ulrike; Crous, Pedro W; Cai, Lei

    2016-04-14

    Accurate delimitation of plant pathogenic fungi is critical for the establishment of quarantine regulations, screening for genetic resistance to plant pathogens, and the study of ecosystem function. Concatenation analysis of multi-locus DNA sequence data represents a powerful and commonly used approach to recognizing evolutionary independent lineages in fungi. It is however possible to mask the discordance between individual gene trees, thus the speciation events might be erroneously estimated if one simply recognizes well supported clades as distinct species without implementing a careful examination of species boundary. To investigate this phenomenon, we studied Colletotrichum siamense s. lat., which is a cosmopolitan pathogen causing serious diseases on many economically important plant hosts. Presently there are significant disagreements among mycologists as to what constitutes a species in C. siamense s. lat., with the number of accepted species ranging from one to seven. In this study, multiple approaches were used to test the null hypothesis "C. siamense is a species complex", using a global strain collection. Results of molecular analyses based on the Genealogical Concordance Phylogenetic Species Recognition (GCPSR) and coalescent methods (e.g. Generalized Mixed Yule-coalescent and Poisson Tree Processes) do not support the recognition of any independent evolutionary lineages within C. siamense s. lat. as distinct species, thus rejecting the null hypothesis. This conclusion is reinforced by the recognition of genetic recombination, cross fertility, and the comparison of ecological and morphological characters. Our results indicate that reproductive isolation, geographic and host plant barriers to gene flow are absent in C. siamense s. lat. This discovery emphasized the importance of a polyphasic approach when describing novel species in morphologically conserved genera of plant pathogenic fungi.

  14. A greater foraging scale, not a higher foraging precision, may facilitate invasion by exotic plants in nutrient-heterogeneous conditions.

    Science.gov (United States)

    Chen, Bao-Ming; Su, Jin-Quan; Liao, Hui-Xuan; Peng, Shao-Lin

    2017-12-22

    Soil nutrient heterogeneity has been proposed to influence competitive outcomes among different plant species. Thus, it is crucial to understand the effects of environmental heterogeneity on competition between exotic invasive and native species. However, the effects of soil nutrient heterogeneity on the competition between invasive and native plants have rarely been linked to root foraging behaviour. In this study, a competition experiment was performed with two invasive-native species pairs (BP-VC, Bidens pilosa vs. Vernonia cinerea; MM-PS, Mikania micrantha vs. Paederia scandens) grown under homogeneous and heterogeneous conditions in a common greenhouse environment. Root activity was assessed by determining the amount of strontium (Sr) taken up by the shoot of each species. The invasive species exhibited a greater foraging scale, whereas the native species exhibited a higher foraging precision. A trade-off between foraging scale and precision was observed within each pair of invasive-native species. Compared with soil homogeneity, soil heterogeneity significantly increased the biomass of the two invasive species, B. pilosa and M. micrantha, under competitive conditions. Within each pair, the invasive species exhibited greater relative competitive ability with respect to shoot mass, and considerably more Sr taken up by the invasive species compared with the native species. The Sr acquisition results indicate that nutrient-poor conditions may facilitate the competitive ability of the native species V. cinerea, whereas M. micrantha may possess a stronger competitive ability regardless of soil nutrient conditions. Soil nutrient heterogeneity has the potential to promote the invasion of these two exotic species due to their larger foraging scale, stronger competitive ability and greater root activity relative to their counterpart native species. The present work highlights the importance of soil heterogeneity in plant invasion, particularly with regards to root

  15. The new flora of northeastern USA: quantifying introduced plant species occupancy in forest ecosystems.

    Science.gov (United States)

    Schulz, Bethany K; Gray, Andrew N

    2013-05-01

    Introduced plant species have significant negative impacts in many ecosystems and are found in many forests around the world. Some factors linked to the distribution of introduced species include fragmentation and disturbance, native species richness, and climatic and physical conditions of the landscape. However, there are few data sources that enable the assessment of introduced species occupancy in native plant communities over broad regions. Vegetation data from 1,302 forest inventory plots across 24 states in northeastern and mid-western USA were used to examine and compare the distribution of introduced species in relation to forest fragmentation across ecological provinces and forest types, and to examine correlations between native and introduced species richness. There were 305 introduced species recorded, and 66 % of all forested plots had at least one introduced species. Forest edge plots had higher constancy and occupancy of introduced species than intact forest plots, but the differences varied significantly among ecological provinces and, to a lesser degree, forest types. Weak but significant positive correlations between native and introduced species richness were observed most often in intact forests. Rosa multiflora was the most common introduced species recorded across the region, but Hieracium aurantiacum and Epipactus helleborine were dominant in some ecological provinces. Identifying regions and forest types with high and low constancies and occupation by introduced species can help target forest stands where management actions will be the most effective. Identifying seemingly benign introduced species that are more prevalent than realized will help focus attention on newly emerging invasives.

  16. Belowground competition drives invasive plant impact on native species regardless of nitrogen availability.

    Science.gov (United States)

    Broadbent, Arthur; Stevens, Carly J; Peltzer, Duane A; Ostle, Nicholas J; Orwin, Kate H

    2017-12-07

    Plant invasions and eutrophication are pervasive drivers of global change that cause biodiversity loss. Yet, how invasive plant impacts on native species, and the mechanisms underpinning these impacts, vary in relation to increasing nitrogen (N) availability remains unclear. Competition is often invoked as a likely mechanism, but the relative importance of the above and belowground components of this is poorly understood, particularly under differing levels of N availability. To help resolve these issues, we quantified the impact of a globally invasive grass species, Agrostis capillaris, on two co-occurring native New Zealand grasses, and vice versa. We explicitly separated above- and belowground interactions amongst these species experimentally and incorporated an N addition treatment. We found that competition with the invader had large negative impacts on native species growth (biomass decreased by half), resource capture (total N content decreased by up to 75%) and even nutrient stoichiometry (native species tissue C:N ratios increased). Surprisingly, these impacts were driven directly and indirectly by belowground competition, regardless of N availability. Higher root biomass likely enhanced the invasive grass's competitive superiority belowground, indicating that root traits may be useful tools for understanding invasive plant impacts. Our study shows that belowground competition can be more important in driving invasive plant impacts than aboveground competition in both low and high fertility ecosystems, including those experiencing N enrichment due to global change. This can help to improve predictions of how two key drivers of global change, plant species invasions and eutrophication, impact native species diversity.

  17. Reconciling functions and evolution of isoprene emission in higher plants.

    Science.gov (United States)

    Loreto, Francesco; Fineschi, Silvia

    2015-04-01

    Compilation and analysis of existing inventories reveal that isoprene is emitted by c. 20% of the perennial vegetation of tropical and temperate regions of the world. Isoprene emitters are found across different plant families without any clear phylogenetic thread. However, by critically appraising information in inventories, several ecological patterns of isoprene emission can be highlighted, including absence of emission from C4 and annual plants, and widespread emission from perennial and deciduous plants of temperate environments. Based on this analysis, and on available information on biochemistry, ecology and functional roles of isoprene, it is suggested that isoprene may not have evolved to help plants face heavy or prolonged stresses, but rather assists C3 plants to run efficient photosynthesis and to overcome transient and mild stresses, especially during periods of active plant growth in warm seasons. When the stress status persists, or when evergreen leaves cope with multiple and repeated stresses, isoprene biosynthesis is replaced by the synthesis of less volatile secondary compounds, in part produced by the same biochemical pathway, thus indicating causal determinism in the evolution of isoprene-emitting plants in response to the environment. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  18. Moss cushions facilitate water and nutrient supply for plant species on bare limestone pavements

    DEFF Research Database (Denmark)

    Jensen, Kaj Sand; Hammer, Kathrine

    2012-01-01

    Dense moss cushions of different size are distributed across the bare limestone pavements on Øland, SE Sweden. Increasing cushion size is predicted to physically protect and improve performance and colonization by vascular plants. Therefore, we tested water balance, phosphorus supply, and species...... richness, and evaluated duration of plant activity during desiccation as a function of ground area, for a large collection of moss cushions. We found that lower evaporation and higher water storage contributed equally to extending the desiccation period with increasing cushion size. Evaporation rates...... under stagnant conditions. One moss species was added to the species pool for every nine-fold increase in cushion area. Vascular plants were absent from the smallest cushions, whereas one or two species, on average, appeared in 375- and 8,500-cm(2) cushions with water available for 6 and 10 days during...

  19. Recovery of plant species richness during long-term fertilization of a species-rich grassland

    NARCIS (Netherlands)

    Pierik, M.; Van Ruijven, J.; Bezemer, T.M.; Geerts, R.H.E.M.; Berendse, F.

    2011-01-01

    Nutrient enrichment of habitats (eutrophication) is considered to be one of the main causes of plant diversity decline worldwide. Several experiments have shown a rapid loss of species in the first years after fertilization started. However, little is known about changes in species richness in the

  20. Plant functional traits of dominant native and invasive species in mediterranean-climate ecosystems.

    Science.gov (United States)

    Funk, Jennifer L; Standish, Rachel J; Stock, William D; Valladares, Fernando

    2016-01-01

    The idea that dominant invasive plant species outperform neighboring native species through higher rates of carbon assimilation and growth is supported by several analyses of global data sets. However, theory suggests that native and invasive species occurring in low-resource environments will be functionally similar, as environmental factors restrict the range of observed physiological and morphological trait values. We measured resource-use traits in native and invasive plant species across eight diverse vegetation communities distributed throughout the five mediterranean-climate regions, which are drought prone and increasingly threatened by human activities, including the introduction of exotic species. Traits differed strongly across the five regions. In regions with functional differences between native and invasive species groups, invasive species displayed traits consistent with high resource acquisition; however, these patterns were largely attributable to differences in life form. We found that species invading mediterranean-climate regions were more likely to be annual than perennial: three of the five regions were dominated by native woody species and invasive annuals. These results suggest that trait differences between native and invasive species are context dependent and will vary across vegetation communities. Native and invasive species within annual and perennial groups had similar patterns of carbon assimilation and resource use, which contradicts the widespread idea that invasive species optimize resource acquisition rather than resource conservation. .

  1. Biochemical Hydrogen Isotope Fractionation during Lipid Biosynthesis in Higher Plants

    Science.gov (United States)

    Kahmen, A.; Gamarra, B.; Cormier, M. A.

    2014-12-01

    Although hydrogen isotopes (δ2H) of leaf wax lipids are increasingly being applied as (paleo-) hydrological proxies, we still do not understand some of the basic processes that shape the δ2H values of these compounds. In general, it is believed that three variables shape the δ2H values of leaf wax lipids: source water δ2H values, evaporative deuterium (2H) enrichment of leaf water and the biosynthetic fractionation (ɛbio) during the synthesis of organic compounds. While the influences of source water δ2H values and leaf water evaporative 2H enrichment have been well documented, very little is known how ɛbio shapes the δ2H values of plant-derived lipids. I will present the results from recent experiments, where we show that the magnitude of ɛbio, and thus the δ2H value of plant-derived lipids, strongly depends on the carbon (C) metabolism of a plant. Specifically, I will show that plants that rely for their tissue formation on recently assimilated C have δ2H values in their n-alkanes that are up to 60‰ more negative than plants that depend for their tissue formation on stored carbohydrates. Our findings can be explained by the fact that NADPH is the primary source of hydrogen in plant lipids and that the δ2H value of NADPH differs whether NADPH was generated directly in the light reaction of photosynthesis or whether it was generated by processing stored carbohydrates. As such, the δ2H values of plant-derived lipids will directly depend on whether the tissue containing these lipids was synthesized using recent assimilates, e.g. in a C autonomous state or, if it was synthesized from stored or otherwise aquired C sources, e.g. in a not C autonomous state. Given the magnidude of this effect, our results have important implications for interpretation of plant-derived lipid δ2H values when used as (paleo-) hydrological proxies. In addition, our results suggest, that δ2H values of plant-derived lipids could be employed as a new tools to assess the C

  2. Reactive oxygen species and plant resistance to fungal pathogens.

    Science.gov (United States)

    Lehmann, Silke; Serrano, Mario; L'Haridon, Floriane; Tjamos, Sotirios E; Metraux, Jean-Pierre

    2015-04-01

    Reactive oxygen species (ROS) have been studied for their role in plant development as well as in plant immunity. ROS were consistently observed to accumulate in the plant after the perception of pathogens and microbes and over the years, ROS were postulated to be an integral part of the defence response of the plant. In this article we will focus on recent findings about ROS involved in the interaction of plants with pathogenic fungi. We will describe the ways to detect ROS, their modes of action and their importance in relation to resistance to fungal pathogens. In addition we include some results from works focussing on the fungal interactor and from studies investigating roots during pathogen attack. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Population dynamics of Scirtothrips dorsalis (Thysanoptera: Thripidae) and other thrips species on two ornamental host plant species in Southern Florida.

    Science.gov (United States)

    Mannion, Catharine M; Derksen, Andrew I; Seal, Dakshina R; Osborne, Lance S; Martin, Cliff G

    2014-08-01

    Since its 2005 introduction into the United States, chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), has become a problematic pest of agronomic, vegetable, fruit, and ornamental plants. Knowledge of its population dynamics may help managers better monitor and control S. dorsalis. Population estimates were recorded for S. dorsalis and other thrips species on Knock-Out rose (Rosa 'Radrazz') and green buttonwood (Conocarpus erectus L.) from July 2007 to September 2008 in two field plots (one per plant species) in Homestead, FL. Yellow sticky card traps and samples of terminals, flowers, buds, and leaves were collected. S. dorsalis accounted for 95% of all thrips individuals collected from plants and 84% from traps with the remainder including at least 18 other thrips species. More thrips were caught on or flying near rose plants (47,438) than on or near buttonwoods (5,898), and on-plant densities of S. dorsalis appeared higher for rose than for buttonwood. Compared with rose leaves, rose buds, terminals, and flowers each had higher numbers of S. dorsalis, and buds and terminals had higher densities. On each host plant species, S. dorsalis density fluctuated over time with peaks in the late spring, summer, and fall, but populations were consistently low in the late winter and early spring. On roses, increased plant damage ratings correlated with reduced numbers of flowers and buds, reduced mean flower areas, and increased on-plant number and density of S. dorsalis. There were positive correlations over time between S. dorsalis density and plant damage rating for rose flowers (R = 0.78; P = 0.0003) and for buttonwood terminals (R = 0.90; P = 0.0001). Yellow sticky card traps were effective for monitoring S. dorsalis and may be especially useful and economically justified for the most susceptible hosts, but they also work well for less susceptible hosts. A good S. dorsalis scouting program should hence consider trap catches and symptoms such as leaf

  4. Penetration and Toxicity of Nanomaterials in Higher Plants

    Directory of Open Access Journals (Sweden)

    Giuseppe Chichiriccò

    2015-05-01

    Full Text Available Nanomaterials (NMs comprise either inorganic particles consisting of metals, oxides, and salts that exist in nature and may be also produced in the laboratory, or organic particles originating only from the laboratory, having at least one dimension between 1 and 100 nm in size. According to shape, size, surface area, and charge, NMs have different mechanical, chemical, electrical, and optical properties that make them suitable for technological and biomedical applications and thus they are being increasingly produced and modified. Despite their beneficial potential, their use may be hazardous to health owing to the capacity to enter the animal and plant body and interact with cells. Studies on NMs involve technologists, biologists, physicists, chemists, and ecologists, so there are numerous reports that are significantly raising the level of knowledge, especially in the field of nanotechnology; however, many aspects concerning nanobiology remain undiscovered, including the interactions with plant biomolecules. In this review we examine current knowledge on the ways in which NMs penetrate plant organs and interact with cells, with the aim of shedding light on the reactivity of NMs and toxicity to plants. These points are discussed critically to adjust the balance with regard to the risk to the health of the plants as well as providing some suggestions for new studies on this topic.

  5. Intra-specific downsizing of frugivores affects seed germination of fleshy-fruited plant species

    Science.gov (United States)

    Pérez-Méndez, Néstor; Rodríguez, Airam; Nogales, Manuel

    2018-01-01

    The loss of largest-bodied individuals within species of frugivorous animals is one of the major consequences of defaunation. The gradual disappearance of large-bodied frugivores is expected to entail a parallel deterioration in seed dispersal functionality if the remaining smaller-sized individuals are not so effective as seed dispersers. While the multiple impacts of the extinction of large bodied species have been relatively well studied, the impact of intraspecific downsizing (i.e. the extinction of large individuals within species) on seed dispersal has rarely been evaluated. Here we experimentally assessed the impact of body-size reduction in the frugivorous lizard Gallotia galloti (Lacertidae), an endemic species of the Canary Islands, on the seed germination patterns of two fleshy-fruited plant species (Rubia fruticosa and Withania aristata). Seed germination curves and the proportions of germinated seeds were compared for both plant species after being defecated by large-sized individuals and small-sized individuals. The data show that seeds of W. aristata defecated by larger-sized lizards germinated faster and in a higher percentage than those defecated by small-sized lizards, while no differences were found for R. fruticosa seeds. Our results suggest that disappearance of the largest individuals of frugivorous species may impair recruitment of some plant species by worsening seed germination. They also warn us of a potential cryptic loss of seed dispersal functionality on defaunated ecosystems, even when frugivorous species remain abundant.

  6. Plant-soil feedback of native and range expanding plant species is insensitive to temperature

    NARCIS (Netherlands)

    Grunsven, van R.H.A.; Veenendaal, E.M.; Bezemer, T.M.; Putten, van der W.H.

    2010-01-01

    Temperature change affects many aboveground and belowground ecosystem processes. Here we investigate the effect of a 5°C temperature increase on plant–soil feedback. We compare plant species from a temperate climate region with immigrant plants that originate from warmer regions and have recently

  7. Plant species classification using deep convolutional neural network

    DEFF Research Database (Denmark)

    Dyrmann, Mads; Karstoft, Henrik; Midtiby, Henrik Skov

    2016-01-01

    Information on which weed species are present within agricultural fields is important for site specific weed management. This paper presents a method that is capable of recognising plant species in colour images by using a convolutional neural network. The network is built from scratch trained...... stabilisation and illumination, and images shot with hand-held mobile phones in fields with changing lighting conditions and different soil types. For these 22 species, the network is able to achieve a classification accuracy of 86.2%....

  8. Comprehensive review on phytotechnology: Heavy metals removal by diverse aquatic plants species from wastewater.

    Science.gov (United States)

    Rezania, Shahabaldin; Taib, Shazwin Mat; Md Din, Mohd Fadhil; Dahalan, Farrah Aini; Kamyab, Hesam

    2016-11-15

    Environmental pollution specifically water pollution is alarming both in the developed and developing countries. Heavy metal contamination of water resources is a critical issue which adversely affects humans, plants and animals. Phytoremediation is a cost-effective remediation technology which able to treat heavy metal polluted sites. This environmental friendly method has been successfully implemented in constructed wetland (CWs) which is able to restore the aquatic biosystem naturally. Nowadays, many aquatic plant species are being investigated to determine their potential and effectiveness for phytoremediation application, especially high growth rate plants i.e. macrophytes. Based on the findings, phytofiltration (rhizofiltration) is the sole method which defined as heavy metals removal from water by aquatic plants. Due to specific morphology and higher growth rate, free-floating plants were more efficient to uptake heavy metals in comparison with submerged and emergent plants. In this review, the potential of wide range of aquatic plant species with main focus on four well known species (hyper-accumulators): Pistia stratiotes, Eicchornia spp., Lemna spp. and Salvinia spp. was investigated. Moreover, we discussed about the history, methods and future prospects in phytoremediation of heavy metals by aquatic plants comprehensively. Copyright © 2016. Published by Elsevier B.V.

  9. Plant roots and spectroscopic methods - analyzing species, biomass and vitality.

    Science.gov (United States)

    Rewald, Boris; Meinen, Catharina

    2013-01-01

    In order to understand plant functioning, plant community composition, and terrestrial biogeochemistry, it is decisive to study standing root biomass, (fine) root dynamics, and interactions belowground. While most plant taxa can be identified by visual criteria aboveground, roots show less distinctive features. Furthermore, root systems of neighboring plants are rarely spatially segregated; thus, most soil horizons and samples hold roots of more than one species necessitating root sorting according to taxa. In the last decades, various approaches, ranging from anatomical and morphological analyses to differences in chemical composition and DNA sequencing were applied to discern species' identity and biomass belowground. Among those methods, a variety of spectroscopic methods was used to detect differences in the chemical composition of roots. In this review, spectroscopic methods used to study root systems of herbaceous and woody species in excised samples or in situ will be discussed. In detail, techniques will be reviewed according to their usability to discern root taxa, to determine root vitality, and to quantify root biomass non-destructively or in soil cores holding mixtures of plant roots. In addition, spectroscopic methods which may be able to play an increasing role in future studies on root biomass and related traits are highlighted.

  10. Mistletoe infection of woody plant species at Bahir Dar University ...

    African Journals Online (AJOL)

    Study of woody plants composition and invasion by mistletoes was conducted in Bahir Dar University main campus vegetation. A total of 28009 individual trees were checked for mistletoes infection and 764 trees were found parasitized. Three species of mistletoes were identified. Erianthemum dregi was more frequent and ...

  11. Extraction and antioxidant activities of two species Origanum plant ...

    African Journals Online (AJOL)

    The antioxidant of ethanolic extract of two species of Origanum and essential oil of plant Origanum vulgare were investigated and also the total phenolic and flavonoid content measured. The radical scavenging activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolic and flavonoid ...

  12. Plant species diversity in a changing agricultural landscape: the ...

    African Journals Online (AJOL)

    by loss of biodiversity, there is a need to define the conditions under which such impainnents woul.d occur and determine the management interventions needed to mitigate the situation. On this basis, the management of Kaweri. Coffee Plantation felt that there was a need to develop a database of plant species diversity that ...

  13. In vitro propagation of the elite species plant Pluchea lanceolata ...

    African Journals Online (AJOL)

    SAM

    2014-06-18

    Jun 18, 2014 ... In vitro propagation of the elite species plant Pluchea lanceolata: Assessment of genetic stability by random amplified polymorphic DNA (RAPD) analysis. Jain Nidhi* and H. N. Verma. School of Life Sciences, Jaipur National University, Jaipur (Raj.), 303012, India. Received 23 April, 2014; Accepted 2 June, ...

  14. The assessment of invasive alien plant species removal programs ...

    African Journals Online (AJOL)

    The occupation of natural environments by invasive alien plant species (IAPs) are a growing threat to ecosystems. This has resulted in the creation of government-based initiatives to mitigate invasion, however, there has been little progress towards assessing these initiatives. Remote sensing is a commonly used tool in the ...

  15. Stimulated rhizodegradation of atrazaine by selected plant species

    Science.gov (United States)

    The efficacy of vegetative buffer strips (VBS) in removing herbicides deposited from surface runoff is related to the ability of plant species to promote rapid herbicide degradation. A growth chamber study was conducted to investigate the rhizodegradation of 14C-atrazine and the relationship of degr...

  16. Eco-taxonomic distribution of plant species around motor mechanic ...

    African Journals Online (AJOL)

    Administrator

    2006-10-02

    Oct 2, 2006 ... motor mechanic workshops in Asaba and Benin City,. Nigeria: Identification of oil tolerant plant species. Anoliefo, G. O.1*, Ikhajiagbe, B. 2, Okonofhua, B. O.3 and Diafe, F. V. 1. 1Department of Botany, University of Benin, Benin City, Nigeria. 2Raw Materials Research and Development Council, Abuja, ...

  17. Rare and Endangered Geophyte Plant Species in Serpentine of Kosovo

    Directory of Open Access Journals (Sweden)

    Naim Berisha

    2014-12-01

    Full Text Available Our study documents information on rarity, geographical distribution, taxonomy and conservation status of 11 geophyte species in serpentine soils of Kosovo, already included in the Red Book of Vascular Flora of Kosovo. Kosovo’s serpentine vegetation represents a diversity that yet has not been sufficiently explored. Large serpentine complexes are found in the northern Kosovo but also southern part of the country is rich in serpentines, therefore in endemics. Serpentine rocks and soils are characterized by low level of principal plant nutrients (N, P, K, Ca and exceptionally high levels of Mg and Fe. Serpentines play particular importance for flora of the country due to their richness in endemic plant species. The following 11 plant species have been studied: Aristolochia merxmuelleri, Colchicum hungaricum, Crocus flavus, Crocus kosaninii, Epimedium alpinum, Gentiana punctata, Gladiolus illyricus, Lilium albanicum, Paeonia peregrina, Tulipa gesneriana and Tulipa kosovarica. Five out of eleven studied geophytes fall within Critically Endangered IUCN based threat category and five out of eleven are local endemics. Aristolochia merxmuelleri and Tulipa kosovarica are steno-endemic plant species that are found exclusively in serpentine soils. Information in our database should prove to be valuable to efforts in ecology, floristics, biosystematics, conservation and land management.

  18. Research Note Herbaceous plant species richness and composition ...

    African Journals Online (AJOL)

    Grazing veld condition was established using the spike-point sampling technique and the benchmark method for data analysis. The relationship between the herbaceous plant species richness and the veld condition scores was determined using the linear and curvilinear correlation analysis. Veld condition scores for the 12 ...

  19. Prescribed burning and its effect on plant biomass and species ...

    African Journals Online (AJOL)

    Three burning regime (fire protected, early burning, late burning) and their effects on plant biomass and species diversity in Dabagi forest Reserve of Sokoto State were investigated. Prescribed burning was carried out on randomly selected plots (10 m x 10 m) in November (early burn) and March (late burn) 2004.

  20. Accumulation of K+ and Cs+ in Tropical Plant Species

    Science.gov (United States)

    Velasco, H.; Anjos, R. M.; Zamboni, C. B.; Macario, K. D.; Rizzotto, M.; Cid, A. S.; Medeiros, I. M. A.; Fernández, J.; Rubio, L.; Audicio, P.; Lacerda, T.

    2010-08-01

    Concentrations of K+ and 137Cs+ in tissues of the Citrus aurantifolia were measured both by gamma spectrometry and neutron activation analysis, aiming to understand the behavior of monovalent inorganic cations in plants as well as its capability to store these elements. In contrast to K+, Cs+ ions are not essential elements to plants, what might explain the difference in bioavailability. However, our results have shown that 137Cs+ is positively correlated to 40K+ concentration within tropical plant species, suggesting that these elements might be assimilated in a similar way, and that they pass through the biological cycle together. A simple mathematical model was also proposed to describe the temporal evolution of 40K activity concentration in such tropical woody fruit species. This model exhibited close agreement with the 40K experimental results in the fruit ripening processes of lemon trees.

  1. Ecological Performances of Plant Species of Halophilous Hydromorphic Ecosystems

    Directory of Open Access Journals (Sweden)

    Maria Speranza

    2015-12-01

    Full Text Available Coastal wetlands are very special environments, characterized by soils permanently or seasonally saturated by salt or brackish water. They host microorganisms and plants able to adapt to anoxic conditions. This paper proposes a review of recent scientific papers dealing with the study of coastal wetlands from different points of view. Some studies examine the species composition and the pattern of the spatial distribution of plant communities, depending on the depth of the salt water table, as well as on other related factors. A significant number of studies analyse instead the coastal wetlands in their ability for the phytoremediation (phytostabilisation and/or phytoextraction and highlight the importance of interactions between the rhizosphere of the halophytes and the physical environment. Finally, more recent studies consider the plant species of the coastal wetlands as a source of useful products (food, feed, oils and expose the results of promising researches on their cultivation.

  2. A role for shoot protein in shoot-root dry matter allocation in higher plants.

    Science.gov (United States)

    Andrews, M; Raven, J A; Lea, P J; Sprent, J I

    2006-01-01

    It is stated in many recent publications that nitrate (NO3-) acts as a signal to regulate dry matter partitioning between the shoot and root of higher plants. Here we challenge this hypothesis and present evidence for the viewpoint that NO3- and other environmental effects on the shoot:root dry weight ratio (S:R) of higher plants are often related mechanistically to changes in shoot protein concentration. The literature on environmental effects on S:R is reviewed, focusing on relationships between S:R, growth and leaf NO3- and protein concentrations. A series of experiments carried out to test the proposal that S:R is dependent on shoot protein concentration is highlighted and new data are presented for tobacco (Nicotiana tabacum). KEY RESULTS/EVIDENCE: Results from the literature and new data for tobacco show that S:R and leaf NO3- concentration are not significantly correlated over a range of environmental conditions. A mechanism involving the relative availability of C and N substrates for growth in shoots can explain how shoot protein concentration can influence shoot growth and hence root growth and S:R. Generally, results in the literature are compatible with the hypothesis that macronutrients, water, irradiance and CO2 affect S:R through changes in shoot protein concentration. In detailed studies on several species, including tobacco, a linear regression model incorporating leaf soluble protein concentration and plant dry weight could explain the greater proportion of the variation in S:R within and between treatments over a wide range of conditions. It is concluded that if NO3- can influence the S:R of higher plants, it does so only over a narrow range of conditions. Evidence is strong that environmental effects on S:R are often related mechanistically to their effects on shoot protein concentration.

  3. Reduced plant-soil feedback of plant species expanding their range as compared to natives

    NARCIS (Netherlands)

    Grunsven, van R.H.A.; Putten, van der W.H.; Bezemer, T.M.; Tamis, W.L.M.; Berendse, F.; Veenendaal, E.M.

    2007-01-01

    1. As a result of global warming, species may spread into previously cool regions. Species that disperse faster than their natural enemies may become released from top-down control. We investigated whether plants originating from southern Europe and recently established in north-western Europe

  4. Plant species richness and ecosystem multifunctionality in global drylands

    Science.gov (United States)

    Maestre, Fernando T.; Quero, José L.; Gotelli, Nicholas J.; Escudero, Adriá; Ochoa, Victoria; Delgado-Baquerizo, Manuel; García-Gómez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; García-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceição, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitán, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gómez-González, Susana; Gutiérrez, Julio R.; Hernández, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Aníbal; Pucheta, Eduardo; Ramírez-Collantes, David A.; Romão, Roberto; Tighe, Matthew; Torres-Díaz, Cristian; Val, James; Veiga, José P.; Wang, Deli; Zaady, Eli

    2013-01-01

    Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report on the first global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth’s land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality, and always included species richness as a predictor variable. Our results suggest that preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands. PMID:22246775

  5. Plant species richness and ecosystem multifunctionality in global drylands

    Science.gov (United States)

    Maestre, Fernando T.; Quero, Jose L.; Gotelli, Nicholas J.; Escudero, Adrian; Ochoa, Victoria; Delgado-Baquerizo, Manuel; Garcia-Gomez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; Garcia-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceicao, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitan, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gomez-Gonzalez, Susana; Gutie, Julio R.; Hernandez, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Anibal; Pucheta, Eduardo; Ramirez-Collantes, David A.; Romao, Roberto; Tighe, Matthew; Torres-Diaz, Cristian; Val, James; Veiga, Jose P.; Wang, Deli; Zaady, Eli

    2012-01-01

    Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.

  6. [Species composition and spatial structure of plants in urban parks of Beijing].

    Science.gov (United States)

    Zhao, Juan-Juan; Ouyang, Zhi-Yun; Zheng, Hua; Xu, Wei-Hua; Wang, Xiao-Ke

    2009-02-01

    By the method of stratified random sampling, the species composition and spatial structure of the plants in 53 parks in Beijing urban area were investigated, aimed to provide basic information for the protection of plant diversity in the parks and the management of the parks. A total of 492 plant species belong to 96 families and 283 genera were recorded. Based on the data of 21 investigation items about the trees, shrubs, and grasses in the study area and related statistical analyses, the plant structural patterns commonly seen in the green space of the parks of Beijing urban area were introduced. Among the plants in the parks, native species occupied 53.86% of the total. The chorological composition of the genera embraced broad kinds of geographical elements in China, and the predominance of dominant plants was remarkable. In most green patches of the parks, herbaceous species were more abundant and had higher coverage, shrubs had relatively low coverage and were less beneath tree canopy, and trees and shrubs had lower species richness and density. The canopy breadth and the diameter of breast height of trees as well as the breadth of shrubs and the heights of trees and shrubs were basically at the second grade, but the canopy structure of the trees were better, with good conditions of sunlight and growth. The crown missing of the shrubs was relatively low. It was suggested from correlation analyses and document survey of Beijing parks construction history that park landscape design, alien species introduction; and cultivation management were the main factors affecting the species composition and spatial structure of the plants in Beijing urban parks.

  7. Phytotoxicity and uptake of nanoscale zero-valent iron (nZVI) by two plant species

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xingmao, E-mail: ma@engr.siu.edu [Civil and Environmental Engineering, Southern Illinois University Carbondale, IL 62901 (United States); Gurung, Arun [Civil and Environmental Engineering, Southern Illinois University Carbondale, IL 62901 (United States); Deng, Yang [Earth and Environmental Studies, Montclair State University, NJ 07403 (United States)

    2013-01-15

    Use of nano-scale zero valent iron (nZVI) for the treatment of various environmental pollutants has been proven successful. However, large scale introduction of engineered nanomaterials such as nZVI into the environment has recently attracted serious concerns. There is an urgent need to investigate the environmental fate and impact of nZVI due to the scope of its application. The goal of this study was to evaluate the toxicity and accumulation of bare nZVI by two commonly encountered plant species: cattail (Typha latifolia) and hybrid poplars (Populous deltoids × Populous nigra). Plant seedlings were grown hydroponically in a greenhouse and dosed with different concentrations of nZVI (0–1000 mg/L) for four weeks. The nZVI exhibited strong toxic effect on Typha at higher concentrations (> 200 mg/L) but enhanced plant growth at lower concentrations. nZVI also significantly reduced the transpiration and growth of hybrid poplars at higher concentrations. Microscopic images indicated that large amount of nZVI coated on plant root surface as irregular aggregates and some nZVI penetrated into several layers of epidermal cells. Transmission electron microscope (TEM) and scanning transmission electron microscope (STEM) confirmed the internalization of nZVI by poplar root cells but similar internalization was not observed for Typha root cells. The upward transport to shoots was minimal for both plant species. - Highlights: ► nZVI may exert phytotoxic effects on plants at concentrations (> 200 mg/L) often encountered in site remediation practices. ► nZVI deposits on plant root surface as aggregates and some could internalize in plant root cells. ► Plant uptake and accumulation of nZVI are plant species-dependent. ► Upward transport from roots to shoots was not observed.

  8. Molecular biology of gibberellins signaling in higher plants.

    Science.gov (United States)

    Itoh, Hironori; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto

    2008-01-01

    Gibberellins (GAs), a large family of tetracyclic, diterpenoid plant hormones, play an important role in regulating diverse processes throughout plant development. In recent years, significant advances have been made in the isolation of GA signaling components and GA-responsive genes. All available data have indicated that DELLA proteins are an essential negative regulator in the GA signaling pathway and GA derepresses DELLA-mediated growth suppression by inducing degradation of DELLA proteins through the ubiquitin-26S proteasome proteolytic pathway. Identification of GID1, a gene encoding an unknown protein with similarity to hormone-sensitive lipases, has revealed that GID1 acts as a functional GA receptor with a reasonable binding affinity to biologically active GAs. Furthermore, the GID1 receptor interacts with DELLA proteins in a GA-dependent manner. These results suggest that formation of a GID1-GA-DELLA protein complex targets DELLA protein into the ubiquitin-26S proteasome pathway for degradation.

  9. Antimicrobial potentials of some plant species of the Bignoniaceae family.

    Science.gov (United States)

    Binutu, O A; Lajubutu, B A

    1994-09-01

    The methanol extracts of the leaves and stem bark of four Bignoniaceae plants Jacaranda mimosifolia D. Dol., Tecoma stans Linn., Tabebuia rosea (Bertol) D.C., and Crescentia cujete Linn. were studied for their antimicrobial activity using a wide range of Gram-positive and Gram-negative bacteria and fungi. Extracts of both the leaves and stem bark of majority of plant species studied showed variable but remarkable broad spectrum antimicrobial activity. However, methanol extracts of Tecoma stans leaves was found to be effective against only Candida albicans at the concentrations employed. It was observed that the extracts of stem bark generally showed better antimicrobial activity than those of the leaves and some organisms were selectively more sensitive to the extracts than others. Preliminary phytochemical screening of these plants revealed the presence of tannins, flavonoids, alkaloids, quinones and traces of saponins. The antimicrobial activity observed are discussed in relation to the chemical constituents reportedly isolated from these plants and their traditional uses.

  10. Final Report for Regulation of Embryonic Development in Higher Plants

    Energy Technology Data Exchange (ETDEWEB)

    Harada, John J. [University of California, Davis

    2013-10-22

    The overall goal of the project was to define the cellular processes that underlie embryo development in plants at a mechanistic level. Our studies focused on a critical transcriptional regulator, Arabidopsis LEAFY COTYLEDON (LEC1), that is necessary and sufficient to induce processes required for embryo development. Because LEC1 regulates lipid accumulation during the maturation phase of embryo development, information about LEC1 may be useful in designing approaches to enhance biofuel production in plants. During the tenure of this project, we determined the molecular mechanisms by which LEC1 acts as a transcription factor in embryos. We also identified genes directly regulated by LEC1 and showed that many of these genes are involved in maturation processes. This information has been useful in dissecting the gene regulatory networks controlling embryo development. Finally, LEC1 is a novel isoform of a transcription factor that is conserved among eukaryotes, and LEC1 is active primarily in seeds. Therefore, we determined that the LEC1-type transcription factors first appeared in lycophytes during land plant evolution. Together, this study provides basic information that has implications for biofuel production.

  11. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding.

    Science.gov (United States)

    Ghahramanzadeh, R; Esselink, G; Kodde, L P; Duistermaat, H; van Valkenburg, J L C H; Marashi, S H; Smulders, M J M; van de Wiel, C C M

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non-invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnH-psbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH-psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics. © 2012 Blackwell Publishing Ltd.

  12. Plastid genomics in horticultural species: Importance and applications for plant diversity, evolution and biotechnology

    Directory of Open Access Journals (Sweden)

    Marcelo eRogalski

    2015-07-01

    Full Text Available During the evolution of the eukaryotic cell, plastids and mitochondria arose from an endosymbiotic process, which determined the presence of three genetic compartments into the incipient plant cell. After that, these three genetic materials from host and symbiont suffered several rearrangements, bringing on a complex interaction between nuclear and organellar gene products. Nowadays, plastids harbor a small genome with ~130 genes in a 100-220 kb sequence in higher plants. Plastid genes are mostly highly conserved between plant species, being useful for phylogenetic analysis in higher taxa. However, intergenic spacers have a relatively higher mutation rate and are important markers to study genetic diversity and divergence within natural plant populations. The predominant uniparental inheritance of plastids is like a highly desirable feature for phylogeny studies. Moreover, the gene content and genome rearrangements are efficient tools to capture and understand evolutionary events between different plant species. Currently, genetic engineering of the plastid genome (plastome offers a number of attractive advantages as high-level of foreign protein expression, marker-gene excision, gene expression in operon and transgene containment because of maternal inheritance of plastid genome in most crops. Therefore, plastid genome can be used for adding new characteristics related to synthesis of metabolic compounds, biopharmaceutical and tolerance to biotic and abiotic stresses. Here, we describe the importance and applications of plastid genome as tools for genetic and evolutionary studies, and plastid transformation focusing on increasing the performance of horticultural species in the field.

  13. Growth responses of maritime sand dune plant species to arbuscular mycorrhizal fungi

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    Mariusz Tadych

    2014-08-01

    Full Text Available In a pot experiment conducted in a greenhouse, the response of 6 plant species dominating in the succession of vegetation of a deflation hollow of the Łeba Bar to inoculation with arbuscular mycorrhizal fungi (AMF was investigated. The inoculum was a mixture of soil, roots and spores of 5 species of AMF with the dominant species Glomus aggregatum. Except for Corynephorus canescens and Festuca rubra subsp. arenaria, both the growth and the dry matter of above-ground parts of plants of Agrostis stolonifera, Ammophila arenaria, Corynephorus canescens, Juncus articulatus and J. balticus inoculated with AMF were higher than those growing in soils lacking infection propagules of these fungi. Inoculation with AMF decreased the dry matter of root: shoot ratios in 5 plant species. This property was not determined in Festuca rubra subsp. arenaria due to the death of all control plants. The level of mycorrhizal infection was low and did not correlate with the growth responses found. The high growth reaction of Juncus spp. to AMF found in this study suggests that the opinion of non-mycotrophy or low dependence of plants of Juncaceae on AMF was based on results of investigations of plants growing in wet sites known to inhibit the formation of mycorrhizae.

  14. The main goals of experiments with the higher plants in the project MARS - 500.

    Science.gov (United States)

    Sychev, Vladimir; Levinskikh, Margarita; Podolsky, Igor; Gushin, Vadim; Bingham, Gail; Bates, Scott

    At the present step of development of manned flight to Mars there is a current opinion that including a greenhouse in the composition of Life Support Systems (LSS) of Martian expedition would essentially improve a spacecraft habitat conditions and also would have impact to preventing of a number of possible consequences of continuous presence of human in artificial environment. Development of design objectives of future space greenhouses applicable for conditions of Martian expedition should be based, in our opinion, not only on the results of real space experiments, conducted onboard of orbital stations, but also on the results of ground-based experiments. In connection with above considerations there is a number of technological, biological and psychological experiments is planned to be conducted in the frame of MARS-500 project to resolve questions related to incorporation of higher plants in LSS of inter-planetary flights. The questions include: testing of developed elements of the greenhouse construction and methods for cultivation of vegetables under conditions of imitation of the flight of Martian expedition; selection of breeds and species of vegetables, characterized by high speed of biomass accumulation, attractive taste and appearance; investigation of growth, development and metabolism of plants under long-term continuous cultivation in manned pressurized object; comparison of the productivity of the plants as a function of utilization of different light source; determination of maximum amount of planted biomass of the plants and number of possible vegetation under conditions of long-term utilization of vegetation chamber of the greenhouse without substrate replacement; investigation of crops dietetic preferences of crew members; estimation of quality of plant biomass using seeding of the plants by microorganisms and nitrates and vitamins content as markers; development and approbation of methodical approaches to estimation of psychological factors of

  15. Plant DNA barcodes can accurately estimate species richness in poorly known floras.

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    Craig Costion

    Full Text Available BACKGROUND: Widespread uptake of DNA barcoding technology for vascular plants has been slow due to the relatively poor resolution of species discrimination (∼70% and low sequencing and amplification success of one of the two official barcoding loci, matK. Studies to date have mostly focused on finding a solution to these intrinsic limitations of the markers, rather than posing questions that can maximize the utility of DNA barcodes for plants with the current technology. METHODOLOGY/PRINCIPAL FINDINGS: Here we test the ability of plant DNA barcodes using the two official barcoding loci, rbcLa and matK, plus an alternative barcoding locus, trnH-psbA, to estimate the species diversity of trees in a tropical rainforest plot. Species discrimination accuracy was similar to findings from previous studies but species richness estimation accuracy proved higher, up to 89%. All combinations which included the trnH-psbA locus performed better at both species discrimination and richness estimation than matK, which showed little enhanced species discriminatory power when concatenated with rbcLa. The utility of the trnH-psbA locus is limited however, by the occurrence of intraspecific variation observed in some angiosperm families to occur as an inversion that obscures the monophyly of species. CONCLUSIONS/SIGNIFICANCE: We demonstrate for the first time, using a case study, the potential of plant DNA barcodes for the rapid estimation of species richness in taxonomically poorly known areas or cryptic populations revealing a powerful new tool for rapid biodiversity assessment. The combination of the rbcLa and trnH-psbA loci performed better for this purpose than any two-locus combination that included matK. We show that although DNA barcodes fail to discriminate all species of plants, new perspectives and methods on biodiversity value and quantification may overshadow some of these shortcomings by applying barcode data in new ways.

  16. Influence of different plant species on methane emissions from soil in a restored Swiss wetland.

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    Gurbir S Bhullar

    Full Text Available Plants are a major factor influencing methane emissions from wetlands, along with environmental parameters such as water table, temperature, pH, nutrients and soil carbon substrate. We conducted a field experiment to study how different plant species influence methane emissions from a wetland in Switzerland. The top 0.5 m of soil at this site had been removed five years earlier, leaving a substrate with very low methanogenic activity. We found a sixfold difference among plant species in their effect on methane emission rates: Molinia caerulea and Lysimachia vulgaris caused low emission rates, whereas Senecio paludosus, Carex flava, Juncus effusus and Typha latifolia caused relatively high rates. Centaurea jacea, Iris sibirica, and Carex davalliana caused intermediate rates. However, we found no effect of either plant biomass or plant functional groups--based on life form or productivity of the habitat--upon methane emission. Emissions were much lower than those usually reported in temperate wetlands, which we attribute to reduced concentrations of labile carbon following topsoil removal. Thus, unlike most wetland sites, methane production in this site was probably fuelled chiefly by root exudation from living plants and from root decay. We conclude that in most wetlands, where concentrations of labile carbon are much higher, these sources account for only a small proportion of the methane emitted. Our study confirms that plant species composition does influence methane emission from wetlands, and should be considered when developing measures to mitigate the greenhouse gas emissions.

  17. Influence of Different Plant Species on Methane Emissions from Soil in a Restored Swiss Wetland

    Science.gov (United States)

    Bhullar, Gurbir S.; Edwards, Peter J.; Olde Venterink, Harry

    2014-01-01

    Plants are a major factor influencing methane emissions from wetlands, along with environmental parameters such as water table, temperature, pH, nutrients and soil carbon substrate. We conducted a field experiment to study how different plant species influence methane emissions from a wetland in Switzerland. The top 0.5 m of soil at this site had been removed five years earlier, leaving a substrate with very low methanogenic activity. We found a sixfold difference among plant species in their effect on methane emission rates: Molinia caerulea and Lysimachia vulgaris caused low emission rates, whereas Senecio paludosus, Carex flava, Juncus effusus and Typha latifolia caused relatively high rates. Centaurea jacea, Iris sibirica, and Carex davalliana caused intermediate rates. However, we found no effect of either plant biomass or plant functional groups – based on life form or productivity of the habitat – upon methane emission. Emissions were much lower than those usually reported in temperate wetlands, which we attribute to reduced concentrations of labile carbon following topsoil removal. Thus, unlike most wetland sites, methane production in this site was probably fuelled chiefly by root exudation from living plants and from root decay. We conclude that in most wetlands, where concentrations of labile carbon are much higher, these sources account for only a small proportion of the methane emitted. Our study confirms that plant species composition does influence methane emission from wetlands, and should be considered when developing measures to mitigate the greenhouse gas emissions. PMID:24586894

  18. Light dependency of VOC emissions from selected Mediterranean plant species

    Science.gov (United States)

    Owen, S. M.; Harley, P.; Guenther, A.; Hewitt, C. N.

    The light, temperature and stomatal conductance dependencies of volatile organic compound (VOC) emissions from ten plant species commonly found in the Mediterranean region were studied using a fully controlled leaf cuvette in the laboratory. At standard conditions of temperature and light (30°C and 1000 μmol m -2 s -1 PAR), low emitting species ( Arbutus unedo, Pinus halepensis, Cistus incanus, Cistus salvifolius, Rosmarinus officinalis and Thymus vulgaris) emitted between 0.1 and 5.0 μg (C) (total VOCs) g -1 dw h -1, a medium emitter ( Pinus pinea) emitted between 5 and 10 μg (C) g -1 dw h -1 and high emitters ( Cistus monspeliensis, Lavendula stoechas and Quercus sp.) emitted more than 10 μg (C) g -1 dw h -1. VOC emissions from all of the plant species investigated showed some degree of light dependency, which was distinguishable from temperature dependency. Emissions of all compounds from Quercus sp. were light dependent. Ocimene was one of several monoterpene compounds emitted by P. pinea and was strongly correlated to light. Only a fraction of monoterpene emissions from C. incanus exhibited apparent weak light dependency but emissions from this plant species were strongly correlated to temperature. Data presented here are consistent with past studies, which show that emissions are independent of stomatal conductance. These results may allow more accurate predictions of monoterpene emission fluxes from the Mediterranean region to be made.

  19. A systematic search for positive selection in higher plants (Embryophytes

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    Roth Christian

    2006-06-01

    Full Text Available Abstract Background Previously, a database characterizing examples of Embryophyte gene family lineages showing evidence of positive selection was reported. Of the gene family trees, 138 Embryophyte branches showed Ka/Ks>>1 and are candidates for functional adaptation. The database and these examples have now been studied in further detail to better understand the molecular basis for plant genome evolution. Results Neutral modeling showed an excess of positive and/or negative selection in the database over a neutral expectation centered on the mean Ka/Ks ratio. Out of 673 families with assigned structures, 490 have at least one branch with Ka/Ks >>1 in a region of the protein, enabling a picture of selective pressures delineated by protein structure. Most gene families allowed reconstruction back to the last common ancestor of flowering plants (Magnoliophytes without saturation of 4- fold degenerate codon position. Positive selection occurred in a wide variety of gene families with different functions, including in the self incompatibility locus, in defense against pathogens, in embryogenesis, in cold acclimation, and in electrontransport. Structurally, selective pressures were similar between alpha-helices and beta- sheets, but were less negative and more variant on the surface and away from the hydrophobic core. Conclusion Positive selection was detected statistically significantly in a small and nonrandom minority of gene families in a systematic analysis of embryophyte gene families. More sensitive methods increased the level of positive selection that was detected and presented a structural basis for the role of positive selection in plant genomes.

  20. Progress Towards an Interdisciplinary Science of Plant Phenology: Building Predictions Across Space, Time and Species Diversity

    Science.gov (United States)

    Wolkovich, Elizabeth M.; Cook, Benjamin I.; Davies, T. Jonathan

    2013-01-01

    Climate change has brought renewed interest in the study of plant phenology - the timing of life history events. Data on shifting phenologies with warming have accumulated rapidly, yet research has been comparatively slow to explain the diversity of phenological responses observed across latitudes, growing seasons and species. Here, we outline recent efforts to synthesize perspectives on plant phenology across the fields of ecology, climate science and evolution. We highlight three major axes that vary among these disciplines: relative focus on abiotic versus biotic drivers of phenology, on plastic versus genetic drivers of intraspecific variation, and on cross-species versus autecological approaches. Recent interdisciplinary efforts, building on data covering diverse species and climate space, have found a greater role of temperature in controlling phenology at higher latitudes and for early-flowering species in temperate systems. These efforts have also made progress in understanding the tremendous diversity of responses across species by incorporating evolutionary relatedness, and linking phenological flexibility to invasions and plant performance. Future research with a focus on data collection in areas outside the temperate mid-latitudes and across species' ranges, alongside better integration of how risk and investment shape plant phenology, offers promise for further progress.

  1. Plant species dispersed by Galapagos tortoises surf the wave of habitat suitability under anthropogenic climate change.

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    Diego Ellis-Soto

    Full Text Available Native biodiversity on the Galapagos Archipelago is severely threatened by invasive alien species. On Santa Cruz Island, the abundance of introduced plant species is low in the arid lowlands of the Galapagos National Park, but increases with elevation into unprotected humid highlands. Two common alien plant species, guava (Psidium guajava and passion fruit (Passiflora edulis occur at higher elevations yet their seeds are dispersed into the lowlands by migrating Galapagos tortoises (Chelonoidis spp.. Tortoises transport large quantities of seeds over long distances into environments in which they have little or no chance of germination and survival under current climate conditions. However, climate change is projected to modify environmental conditions on Galapagos with unknown consequences for the distribution of native and introduced biodiversity. We quantified seed dispersal of guava and passion fruit in tortoise dung piles and the distribution of adult plants along two elevation gradients on Santa Cruz to assess current levels of 'wasted' seed dispersal. We computed species distribution models for both taxa under current and predicted future climate conditions. Assuming that tortoise migratory behaviour continues, current levels of "wasted" seed dispersal in lowlands were projected to decline dramatically in the future for guava but not for passion fruit. Tortoises will facilitate rapid range expansion for guava into lowland areas within the Galapagos National Park where this species is currently absent. Coupled with putative reduction in arid habitat for native species caused by climate change, tortoise driven guava invasion will pose a serious threat to local plant communities.

  2. Plant species dispersed by Galapagos tortoises surf the wave of habitat suitability under anthropogenic climate change.

    Science.gov (United States)

    Ellis-Soto, Diego; Blake, Stephen; Soultan, Alaaeldin; Guézou, Anne; Cabrera, Fredy; Lötters, Stefan

    2017-01-01

    Native biodiversity on the Galapagos Archipelago is severely threatened by invasive alien species. On Santa Cruz Island, the abundance of introduced plant species is low in the arid lowlands of the Galapagos National Park, but increases with elevation into unprotected humid highlands. Two common alien plant species, guava (Psidium guajava) and passion fruit (Passiflora edulis) occur at higher elevations yet their seeds are dispersed into the lowlands by migrating Galapagos tortoises (Chelonoidis spp.). Tortoises transport large quantities of seeds over long distances into environments in which they have little or no chance of germination and survival under current climate conditions. However, climate change is projected to modify environmental conditions on Galapagos with unknown consequences for the distribution of native and introduced biodiversity. We quantified seed dispersal of guava and passion fruit in tortoise dung piles and the distribution of adult plants along two elevation gradients on Santa Cruz to assess current levels of 'wasted' seed dispersal. We computed species distribution models for both taxa under current and predicted future climate conditions. Assuming that tortoise migratory behaviour continues, current levels of "wasted" seed dispersal in lowlands were projected to decline dramatically in the future for guava but not for passion fruit. Tortoises will facilitate rapid range expansion for guava into lowland areas within the Galapagos National Park where this species is currently absent. Coupled with putative reduction in arid habitat for native species caused by climate change, tortoise driven guava invasion will pose a serious threat to local plant communities.

  3. Conserved upstream open reading frames in higher plants

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    Schultz Carolyn J

    2008-07-01

    Full Text Available Abstract Background Upstream open reading frames (uORFs can down-regulate the translation of the main open reading frame (mORF through two broad mechanisms: ribosomal stalling and reducing reinitiation efficiency. In distantly related plants, such as rice and Arabidopsis, it has been found that conserved uORFs are rare in these transcriptomes with approximately 100 loci. It is unclear how prevalent conserved uORFs are in closely related plants. Results We used a homology-based approach to identify conserved uORFs in five cereals (monocots that could potentially regulate translation. Our approach used a modified reciprocal best hit method to identify putative orthologous sequences that were then analysed by a comparative R-nomics program called uORFSCAN to find conserved uORFs. Conclusion This research identified new genes that may be controlled at the level of translation by conserved uORFs. We report that conserved uORFs are rare (

  4. CBL-CIPK network for calcium signaling in higher plants

    Science.gov (United States)

    Luan, Sheng

    Plants sense their environment by signaling mechanisms involving calcium. Calcium signals are encoded by a complex set of parameters and decoded by a large number of proteins including the more recently discovered CBL-CIPK network. The calcium-binding CBL proteins specifi-cally interact with a family of protein kinases CIPKs and regulate the activity and subcellular localization of these kinases, leading to the modification of kinase substrates. This represents a paradigm shift as compared to a calcium signaling mechanism from yeast and animals. One example of CBL-CIPK signaling pathways is the low-potassium response of Arabidopsis roots. When grown in low-K medium, plants develop stronger K-uptake capacity adapting to the low-K condition. Recent studies show that the increased K-uptake is caused by activation of a specific K-channel by the CBL-CIPK network. A working model for this regulatory pathway will be discussed in the context of calcium coding and decoding processes.

  5. Variation in grazing tolerance among three tallgrass prairie plant species.

    Science.gov (United States)

    Damhoureyeh, Said A; Hartnett, David C

    2002-10-01

    Three tallgrass prairie plant species, two common perennial forbs (Artemisia ludoviciana and Aster ericoides [Asteraceae]) and a dominant C(4) perennial grass (Sorghastrum nutans) were studied under field and greenhouse conditions to evaluate interspecific variation in grazing tolerance (compensatory growth capacity). Adaptation to ungulate grazing was also assessed by comparing defoliation responses of plants from populations with a 25-yr history of no grazing or moderate ungulate grazing. Under field conditions, all three species showed significant reductions in shoot relative growth rates (RGR), biomass, and reproduction with defoliation. In the two forbs, clipping resulted in negative shoot RGR and reductions in both number and length of shoot branches per ramet. Sorghastrum nutans maintained positive RGR under defoliation due to a compensatory increase in leaf production. Defoliation reduced rhizome production in A. ericoides and S. nutans, but not in A. ludoviciana. Clipping significantly reduced sexual reproductive allocation in all three species, although S. nutans showed a smaller reduction than the forbs. All three species showed similar responses to defoliation in burned and unburned sites. Under greenhouse conditions, a similar clipping regimen resulted in smaller reductions in growth and reproduction than those observed in the field. For all three species, the grazing tolerance indices calculated under natural field conditions were significantly lower than those estimated from greenhouse-grown plants, and the interspecific patterns of grazing tolerance were different. Aster ericoides exhibited the highest overall defoliation tolerance under greenhouse conditions, followed by S. nutans. Artemisia ludoviciana, the only study species that is typically not grazed by ungulates in the field, showed the lowest grazing tolerance. In the field experiment S. nutans showed the highest grazing tolerance and the two forbs had similar low tolerance indices. These

  6. Arbuscular mycorrhizae of dominant plant species in Yungas forests, Argentina.

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    Becerra, Alejandra G; Cabello, Marta; Zak, Marcelo R; Bartoloni, Norberto

    2009-01-01

    In Argentina the Yungas forests are among the ecosystems most affected by human activity, with loss of biodiversity. To assess the arbuscular mycorrhizal (AM) colonization and the arbuscular mycorrhizal fungi (AMF) spore numbers in these ecosystems, the roots of the most dominant native plants (one tree, Alnus acuminata; three herbaceous, Duchesnea indica, Oxalis conorrhiza, Trifolium aff. repens; and one shrub, Sambucus peruviana) were studied throughout the year from two sites of Yungas forests. Assessments of mycorrhizal colonization (percent root length, intraradical structures) were made by washing and staining the roots. Soil samples of each plant species were pooled and subsamples were obtained to determine AM spore numbers. The herbaceous species formed both Arum- and Paris-type morphologies, whereas the tree and the shrub species formed respectively single structural types of Arum- and Paris-type. AM colonization, intraradical fungi structures and AMF spore numbers displayed variation in species, seasons and sites. D. indica showed the highest AM colonization, whereas the highest spore numbers was observed in the rhizosphere of A. acuminata. No correlation was observed between spore numbers and root length percentage colonized by AM fungi. Results of this study showed that Alnus acuminata is facultatively AM. The AM colonization, intraradical fungi structures and AMF spore numbers varied in species depending on phenological, climatic and edaphic conditions.

  7. Transgenic tobacco plants having a higher level of methionine are more sensitive to oxidative stress.

    Science.gov (United States)

    Hacham, Yael; Matityahu, Ifat; Amir, Rachel

    2017-07-01

    Methionine is an essential amino acid the low level of which limits the nutritional quality of plants. We formerly produced transgenic tobacco (Nicotiana tabacum) plants overexpressing CYSTATHIONE γ-SYNTHASE (CGS) (FA plants), methionine's main regulatory enzyme. These plants accumulate significantly higher levels of methionine compared with wild-type (WT) plants. The aim of this study was to gain more knowledge about the effect of higher methionine content on the metabolic profile of vegetative tissue and on the morphological and physiological phenotypes. FA plants exhibit slightly reduced growth, and metabolic profiling analysis shows that they have higher contents of stress-related metabolites. Despite this, FA plants were more sensitive to short- and long-term oxidative stresses. In addition, compared with WT plants and transgenic plants expressing an empty vector, the primary metabolic profile of FA was altered less during oxidative stress. Based on morphological and metabolic phenotypes, we strongly proposed that FA plants having higher levels of methionine suffer from stress under non-stress conditions. This might be one of the reasons for their lesser ability to cope with oxidative stress when it appeared. The observation that their metabolic profiling is much less responsive to stress compared with control plants indicates that the delta changes in metabolite contents between non-stress and stress conditions is important for enabling the plants to cope with stress conditions. © 2017 Scandinavian Plant Physiology Society.

  8. Phylogenetic placement of plant pathogenic Sclerotium species among teleomorph genera.

    Science.gov (United States)

    Xu, Zhihan; Harrington, Thomas C; Gleason, Mark L; Batzer, Jean C

    2010-01-01

    Phylogenetic analyses and morphological characteristics were used to assess the taxonomic placement of eight plant-pathogenic Sclerotium species. Members of this genus produce only sclerotia and no fruiting bodies or spores, so Sclerotium species have been difficult to place taxonomically. Sequences of rDNA large subunit (LSU) and internal transcribed spacer (ITS) regions were determined for isolates of Sclerotium cepivorum, S. coffeicola, S. denigrans, S. hydrophilum, Ceratorhiza oryzae-sativae, S. perniciosum, S. rhizodes, S. rolfsii and S. rolfsii var. delphinii. Parsimony analysis grouped two species previously thought to be in the Basidiomycota, S. denigrans and S. perniciosum, within the Ascomycota; these species were found to have affinities with the teleomorph genera Sclerotinia and Stromatinia and the asexual Sclerotium cepivorum, which was known earlier to be related to Sclerotinia species. The other Sclerotium species were placed in one of two basidiomycetous groups, genera Athelia or Ceratobasidium. Based on rDNA analysis and morphology the basidiomycetous Sclerotium hydrophilum and S. rhizodes were transferred to genus Ceratorhiza, the anamorph of Ceratobasidium species. Sclerotium coffeicola was found to be close to S. rolfsii var. delphinii and S. rolfsii var. rolfsii, which was shown earlier to have an Athelia teleomorph.

  9. Sesquiterpene lactones and monoterpene glucosides from plant species Picris echoides

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    MILUTIN STEFANOVIC

    2000-11-01

    Full Text Available Investigation of the constituents of the aerial parts of domestic plant species Picris echoides afforded the sesquiterpene lactones, i.e., guaianolides jacquilenin (1, 11-epi-jacquilenin (2, achillin (3 and eudesmanolide telekin (4. The chemical indentification of the two monoterpene glucosides (–-cis-chrysanthenol-b-D-glucopyranoside (5 and its 6’-acetate 6 is also repoted. The guaianolide achillin (3 and the two monoterpene glucosides 5 and 6 were isolated for the first time from this plant species. Isolation was achieved by column chromatography and the structures were established mainly by the interpretation of their physical and spectral data, which were in agreement with those in the literature.

  10. Higher-taxon richness as a surrogate for species richness in chemosynthetic communities

    Science.gov (United States)

    Doerries, M. B.; Van Dover, C. L.

    2003-06-01

    Estimations of biodiversity and species richness in deep-sea marine ecosystems are impeded by time-consuming methods of species identification. In conservation biology, in environmental monitoring, and in paleontology, a higher-taxon approach (e.g., identification to genera or families) can be used as a surrogate for species richness. We applied a higher-taxon approach to well-documented chemosynthetic communities associated with seep and vent mussel beds to test its applicability in these systems. Significant positive correlations between cumulative number of species and cumulative number of higher taxa were found at the generic, family, and order levels. The number of these higher taxa can be used to predict species richness in vent and seep mussel beds.

  11. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding

    NARCIS (Netherlands)

    Ghahramanzadeh, R.; Esselink, G.; Kodde, L.P.; Duistermaat, H.; Valkenburg, van J.L.C.H.; Marashi, S.H.; Smulders, M.J.M.; Wiel, van de C.C.M.

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to

  12. Plant phenology and absence of sex-biased gall attack on three species of Baccharis.

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    Mário M Espírito-Santo

    Full Text Available Dioecy represents a source of variation in plant quality to herbivores due to sexual differences in intensity and timing of resource allocation to growth, defense and reproduction. Male plants have higher growth rates and should be more susceptible to herbivores than females, due to a lower investment in defense and reproduction.We compared resource investment to growth and reproduction and its consequences to herbivore attack on three Baccharis species along one year (B. dracunculifolia, B. ramosissima, and B. concinna. Phenological patterns presented by the three species of Baccharis were quite different over time, but the number of fourth-level shoots and plant growth rate did not differ between sexes in any studied species. Intersexual difference in reproductive investment was only observed for B. concinna, with female individuals supporting higher inflorescence density than male individuals throughout the year. Gall abundance on the three Baccharis species was not influenced by plant sex. However, all plant traits evaluated here positively influenced the gall abundance on B. concinna, whereas only the number of fourth-level shoots positively influenced gall abundance on B. ramosissima and B. dracunculifolia.The absence of differential reproductive allocation may have contributed to similar growth and shoot production between the sexes, with bottom-up effects resulting in gender similarities in gall abundance patterns. The number of fourth-level shoots, an indicator of meristem availability to herbivores, was the most important driver of the abundance of the galling insects regardless of host plant gender or species. Albeit the absence of intersexual variation in insect gall abundance is uncommon in the literature, the detailed study of the exceptions may bring more light to understand the mechanisms and processes behind such trend.

  13. [Reactive oxygen species and stress signaling in plants].

    Science.gov (United States)

    Kolupaev, Iu E; Karpets, Iu V

    2014-01-01

    Data on the basic processes and the compartments, involved in formation of reactive oxygen species (ROS) in plant cells, are generalised. The features of structure and regulation of NADPH-oxidase as the one of main enzymatic producers of ROS are characterized. The two-component histidine kinases, ROS-sensitive transcript-factors, ROS-sensitive protein kinase and redox-regulated ionic channels are discussed as the possible sensors of redox-signals in plant cells. The interaction between ROS and other signal mediators, in particular nitric oxide and calcium ions, is discussed. The ROS role as the signal mediators in the development of plant resistance to hyperthermia, osmotic shock and other abiotic stressors is analyzed.

  14. Molecular insights into Zeaxanthin-dependent quenching in higher plants.

    Science.gov (United States)

    Xu, Pengqi; Tian, Lijin; Kloz, Miroslav; Croce, Roberta

    2015-09-01

    Photosynthetic organisms protect themselves from high-light stress by dissipating excess absorbed energy as heat in a process called non-photochemical quenching (NPQ). Zeaxanthin is essential for the full development of NPQ, but its role remains debated. The main discussion revolves around two points: where does zeaxanthin bind and does it quench? To answer these questions we have followed the zeaxanthin-dependent quenching from leaves to individual complexes, including supercomplexes. We show that small amounts of zeaxanthin are associated with the complexes, but in contrast to what is generally believed, zeaxanthin binding per se does not cause conformational changes in the complexes and does not induce quenching, not even at low pH. We show that in NPQ conditions zeaxanthin does not exchange for violaxanthin in the internal binding sites of the antennas but is located at the periphery of the complexes. These results together with the observation that the zeaxanthin-dependent quenching is active in isolated membranes, but not in functional supercomplexes, suggests that zeaxanthin is acting in between the complexes, helping to create/participating in a variety of quenching sites. This can explain why none of the antennas appears to be essential for NPQ and the multiple quenching mechanisms that have been observed in plants.

  15. The alpine cushion plant Silene acaulis as foundation species: a bug's-eye view to facilitation and microclimate.

    Directory of Open Access Journals (Sweden)

    Olivia Molenda

    Full Text Available Alpine ecosystems are important globally with high levels of endemic and rare species. Given that they will be highly impacted by climate change, understanding biotic factors that maintain diversity is critical. Silene acaulis is a common alpine nurse plant shown to positively influence the diversity and abundance of organisms--predominantly other plant species. The hypothesis that cushion or nurse plants in general are important to multiple trophic levels has been proposed but rarely tested. Alpine arthropod diversity is also largely understudied worldwide, and the plant-arthropod interactions reported are mostly negative, that is,. herbivory. Plant and arthropod diversity and abundance were sampled on S. acaulis and at paired adjacent microsites with other non-cushion forming vegetation present on Whistler Mountain, B.C., Canada to examine the relative trophic effects of cushion plants. Plant species richness and abundance but not Simpson's diversity index was higher on cushion microsites relative to other vegetation. Arthropod richness, abundance, and diversity were all higher on cushion microsites relative to other vegetated sites. On a microclimatic scale, S. acaulis ameliorated stressful conditions for plants and invertebrates living inside it, but the highest levels of arthropod diversity were observed on cushions with tall plant growth. Hence, alpine cushion plants can be foundation species not only for other plant species but other trophic levels, and these impacts are expressed through both direct and indirect effects associated with altered environmental conditions and localized productivity. Whilst this case study tests a limited subset of the membership of alpine animal communities, it clearly demonstrates that cushion-forming plant species are an important consideration in understanding resilience to global changes for many organisms in addition to other plants.

  16. Carotenoids in certain higher plants from various ecological niches of Egypt

    Directory of Open Access Journals (Sweden)

    B. Czeczuga

    2015-01-01

    Full Text Available The carotenoids content in Posidonia oceanica, Nelumbium nuciferum, Opuntia ficus-indica and Zygophyllum album from different ecological niches in Egypt was studied. Considerable differences, both qualitative and quantitative among four investigated plant species were found.

  17. [Psychoactive plant species--actual list of plants prohibited in Poland].

    Science.gov (United States)

    Simonienko, Katarzyna; Waszkiewicz, Napoleon; Szulc, Agata

    2013-01-01

    According to the Act on Counteracting Drug Addiction (20-th of March, 2009, Dz. U. Nr 63 poz. 520.) the list of federally prohibited plants in Poland was expanded to include 16 new species. Until that time the only illegal plant materials were cannabis, papaver, coca and most of their products. The actual list of herbal narcotics includes species which significantly influence on the central nervous system work but which are rarely described in the national literature. The plants usually come from distant places, where--among primeval cultures--are used for ritual purposes. In our civilization the plants are usually used experimentally, recreationally or to gain particular narcotic effects. The results of the consumption vary: they can be specific or less typical, imitate other substances intake, mental disorders or different pathological states. The plant active substances can interact with other medicaments, be toxic to internal organs, cause serious threat to health or even death. This article describes the sixteen plant species, which are now prohibited in Poland, their biochemical ingredients and their influence on the human organism.

  18. Activity of crude extracts from Brazilian cerrado plants against clinically relevant Candida species.

    Science.gov (United States)

    Correia, Amabel Fernandes; Silveira, Dâmaris; Fonseca-Bazzo, Yris Maria; Magalhães, Pérola Oliveira; Fagg, Christopher William; da Silva, Elton Clementino; Gomes, Suelí Maria; Gandolfi, Lenora; Pratesi, Riccardo; de Medeiros Nóbrega, Yanna Karla

    2016-07-11

    Medicinal plants have traditionally been used in many parts of the world as alternative medicine. Many extracts and essential oils isolated from plants have disclosed biological activity, justifying the investigation of their potential antimicrobial activity. In this study, the in vitro antifungal activity of six Brazilian Cerrado medicinal plant species were evaluated against clinically relevant Candida species. The crude extract plants were evaluated against American Type Culture Collection (ATCC) standard strains of Candida spp. using disk diffusion method and determining the minimum inhibitory concentration (MIC). The chemical study results were confirmed by HPLC method. All six plant species showed antifungal activity. Among the species studied, Eugenia dysenterica and Pouteria ramiflora showed significant inhibitory activity against C. tropicalis at lowest MIC value of 125 and 500 μg/disc, respectively. The Eugenia dysenterica also disclosed MIC value of 125 μg/disc against C. famata, 250 μg/disc against C. krusei and 500 μg/disc against C. guilliermondii and C. parapsilosis. Pouteria torta, Bauhinia rufa, Erythroxylum daphnites and Erythroxylum subrotundum showed activity against the yeast strains with MIC value of 1000 μg/disc. The chemical study of the most bioactive extracts of Eugenia dysenterica and Pouteria ramiflora revealed catechin derivatives and flavonoids as main components. All six evaluated plant species showed good antifungal potential against several Candida strains. However, E .dysenterica and P. ramiflora showed the higher inhibitory effect against the non-albicans Candida species. Our results may contribute to the continuing search of new natural occurring products with antifungal activity.

  19. Changes in plant species composition of coastal dune habitats over a 20-year period.

    Science.gov (United States)

    Del Vecchio, Silvia; Prisco, Irene; Acosta, Alicia T R; Stanisci, Angela

    2015-03-05

    Coastal sandy ecosystems are increasingly being threatened by human pressure, causing loss of biodiversity, habitat degradation and landscape modifications. However, there are still very few detailed studies focussing on compositional changes in coastal dune plant communities over time. In this work, we investigated how coastal dune European Union (EU) habitats (from pioneer annual beach communities to Mediterranean scrubs on the landward fixed dunes) have changed during the last 20 years. Using phytosociological relevés conducted in 1989-90 and in 2010-12, we investigated changes in floristic composition over time. We then compared plant cover and the proportion of ruderal, alien and habitat diagnostic species ('focal species') in the two periods. Finally, we used Ellenberg indicator values to define the 'preferences' of the plant species for temperature and moisture. We found that only fore dune habitats showed significant differences in species cover between the two time periods, with higher plant cover in the more recent relevés and a significant increase in thermophilic species. Although previous studies have demonstrated consistent habitat loss in this area, we observed that all coastal dune plant communities remain well represented, after a 20-year period. However, fore dunes have been experiencing significant compositional changes. Although we cannot confirm whether the observed changes are strictly related to climatic changes, to human pressure or to both, we hypothesize that a moderate increment in average yearly temperature may have promoted the increase in plant cover and the spread of thermophilic species. Thus, even though human activities are major driving forces of change in coastal dune vegetation, at the community scale climatic factors may also play important roles. Our study draws on re-visitation studies which appear to constitute a powerful tool for the assessment of the conservation status of EU habitats. Published by Oxford University

  20. ANTIFUNGAL POTENTIAL OF PLANT SPECIES FROM BRAZILIAN CAATINGA AGAINST DERMATOPHYTES.

    Science.gov (United States)

    Biasi-Garbin, Renata Perugini; Demitto, Fernanda de Oliveira; Amaral, Renata Claro Ribeiro do; Ferreira, Magda Rhayanny Assunção; Soares, Luiz Alberto Lira; Svidzinski, Terezinha Inez Estivalet; Baeza, Lilian Cristiane; Yamada-Ogatta, Sueli Fumie

    2016-01-01

    Trichophyton rubrum and Trichophyton mentagrophytes complex, or Trichophyton spp. are the main etiologic agents of dermatophytosis, whose treatment is limited by the high cost of antifungal treatments, their various side effects, and the emergence of resistance amongst these species. This study evaluated the in vitro antidermatophytic activity of 23 crude extracts from nine plant species of semiarid vegetation (caatinga) found in Brazil. The extracts were tested at concentrations ranging from 1.95 to 1,000.0 mg/mL by broth microdilution assay against the reference strains T. rubrum ATCC 28189 and T. mentagrophytes ATCC 11481, and 33 clinical isolates of dermatophytes. All plants showed a fungicidal effect against both fungal species, with MIC/MFC values of the active extracts ranging from 15.6 to 250.0 µg/mL. Selected extracts of Eugenia uniflora (AcE), Libidibia ferrea (AE), and Persea americana (AcE) also exhibited a fungicidal effect against all clinical isolates of T. rubrum and T. mentagrophytes complex. This is the first report of the antifungal activity of Schinus terebinthifolius, Piptadenia colubrina, Parapiptadenia rigida, Mimosa ophthalmocentra, and Persea americana against both dermatophyte species.

  1. Soil-to-plant transfer of uranium and its distribution between plant parts in four boreal forest species

    Energy Technology Data Exchange (ETDEWEB)

    Roivanen, P.; Makkonen, S.; Holopainen, T.; Juutilainen, J. (Univ. of Eastern Finland, Kuopio (Finland), Dept. of Environmental Science)

    2011-07-01

    Uranium (U) can be released to the environment through the entire nuclear fuel cycle. U uptake by plants is an important process for possible adverse effects in ecosystems. The soil-to-plant transfer of natural U and its distribution across plant parts were investigated in May lily (Maianthemum bifolium), narrow buckler fern (Dryopteris carthusiana), rowan (Sorbus aucuparia) and Norway spruce (Picea abies). Concentration ratios (CR) between plant and soil were calculated. The CRs for roots were higher than those for the above-ground parts of the plants. Soil pH was the only soil parameter showing an effect on CRs. No significant differences were noticed between species. The CRs observed were consistent with those reported previously in other forest types. The pooled values of 0.06 for roots and 0.005 for stems/petioles and leaves/needles can be considered as good estimates of CR values to be used in modelling the U uptake in boreal forest species. (orig.)

  2. Sampling plant diversity and rarity at landscape scales: importance of sampling time in species detectability.

    Science.gov (United States)

    Zhang, Jian; Nielsen, Scott E; Grainger, Tess N; Kohler, Monica; Chipchar, Tim; Farr, Daniel R

    2014-01-01

    Documenting and estimating species richness at regional or landscape scales has been a major emphasis for conservation efforts, as well as for the development and testing of evolutionary and ecological theory. Rarely, however, are sampling efforts assessed on how they affect detection and estimates of species richness and rarity. In this study, vascular plant richness was sampled in 356 quarter hectare time-unlimited survey plots in the boreal region of northeast Alberta. These surveys consisted of 15,856 observations of 499 vascular plant species (97 considered to be regionally rare) collected by 12 observers over a 2 year period. Average survey time for each quarter-hectare plot was 82 minutes, ranging from 20 to 194 minutes, with a positive relationship between total survey time and total plant richness. When survey time was limited to a 20-minute search, as in other Alberta biodiversity methods, 61 species were missed. Extending the survey time to 60 minutes, reduced the number of missed species to 20, while a 90-minute cut-off time resulted in the loss of 8 species. When surveys were separated by habitat type, 60 minutes of search effort sampled nearly 90% of total observed richness for all habitats. Relative to rare species, time-unlimited surveys had ∼ 65% higher rare plant detections post-20 minutes than during the first 20 minutes of the survey. Although exhaustive sampling was attempted, observer bias was noted among observers when a subsample of plots was re-surveyed by different observers. Our findings suggest that sampling time, combined with sample size and observer effects, should be considered in landscape-scale plant biodiversity surveys.

  3. Determinants of host species range in plant viruses.

    Science.gov (United States)

    Moury, Benoît; Fabre, Frédéric; Hébrard, Eugénie; Froissart, Rémy

    2017-04-01

    Prediction of pathogen emergence is an important field of research, both in human health and in agronomy. Most studies of pathogen emergence have focused on the ecological or anthropic factors involved rather than on the role of intrinsic pathogen properties. The capacity of pathogens to infect a large set of host species, i.e. to possess a large host range breadth (HRB), is tightly linked to their emergence propensity. Using an extensive plant virus database, we found that four traits related to virus genome or transmission properties were strongly and robustly linked to virus HRB. Broader host ranges were observed for viruses with single-stranded genomes, those with three genome segments and nematode-transmitted viruses. Also, two contrasted groups of seed-transmitted viruses were evidenced. Those with a single-stranded genome had larger HRB than non-seed-transmitted viruses, whereas those with a double-stranded genome (almost exclusively RNA) had an extremely small HRB. From the plant side, the family taxonomic rank appeared as a critical threshold for virus host range, with a highly significant increase in barriers to infection between plant families. Accordingly, the plant-virus infectivity matrix shows a dual structure pattern: a modular pattern mainly due to viruses specialized to infect plants of a given family and a nested pattern due to generalist viruses. These results contribute to a better prediction of virus host jumps and emergence risks.

  4. Plant-associated bacterial populations on native and invasive plant species: comparisons between 2 freshwater environments.

    Science.gov (United States)

    Olapade, Ola A; Pung, Kayleigh

    2012-06-01

    Plant-microbial interactions have been well studied because of the ecological importance of such relationships in aquatic systems. However, general knowledge regarding the composition of these biofilm communities is still evolving, partly as a result of several confounding factors that are attributable to plant host properties and to hydrodynamic conditions in aquatic environments. In this study, the occurrences of various bacterial phylogenetic taxa on 2 native plants, i.e., mayapple (Podophyllum peltatum L.) and cow parsnip (Heracleum maximum Bartram), and on an invasive species, i.e., garlic mustard (Alliaria petiolata (M. Bieb.) Cavara & Grande), were quantitatively examined using nucleic acid staining and fluorescence in situ hybridization. The plants were incubated in triplicates for about a week within the Kalamazoo River and Pierce Cedar Creek as well as in microcosms. The bacterial groups targeted for enumeration are known to globally occur in relatively high abundance and are also ubiquitously distributed in freshwater environments. Fluorescence in situ hybridization analyses of the bacterioplankton assemblages revealed that the majority of bacterial cells that hybridized with the different probes were similar between the 2 sites. In contrast, the plant-associated populations while similar on the 3 plants incubated in Kalamazoo River, their representations were highest on the 2 native plants relative to the invasive species in Pierce Cedar Creek. Overall, our results further suggested that epiphytic bacterial assemblages are probably under the influences of and probably subsequently respond to multiple variables and conditions in aquatic milieus.

  5. Tree Species Richness and Stand Productivity in Low-Density Cluster Plantings with Oaks (Quercus robur L. and Q. petraea (Mattuschka Liebl.

    Directory of Open Access Journals (Sweden)

    Christian Kuehne

    2013-08-01

    Full Text Available Low density plantings complemented by natural regeneration is an increasingly common reforestation technique to ensure growth of a sufficient number of trees from desired species while maintaining natural processes such as succession. One such form of low density planting that aims at lowering establishment costs—oak clusters—has been developed as an alternative to row planting since the 1980s in central Europe. However, whether cluster planting provides higher species richness and productivity than high density row planting has not previously been analyzed. Here, we compare tree species richness and productivity (measured as stand basal area between oak cluster plantings and conventional row planting in young (10–26 years old forest stands at seven study sites in Germany. Tree species richness was significantly higher in cluster plantings than in row plantings, whereas total basal areas were comparable. Naturally regenerated trees contributed on average to 43% of total stand basal area in cluster plantings, which was significantly higher than in row plantings. Total stand basal area in cluster planting was significantly related to the density of naturally regenerated trees. In turn, tree species diversity, density and basal area of naturally regenerated trees were increased with the size of unplanted area between clusters. Our results demonstrate that the admixture of naturally regenerated, early and mid-successional tree species compensates for a possible loss in productivity from planting fewer oaks. Low density cluster plantings can offer significant environmental benefits, at least for the first few decades of stand development, without compromising productivity.

  6. Extractor capacity of different plant species cultivated in wetlands used to pig wastewater treatment

    Directory of Open Access Journals (Sweden)

    Antonio Teixeira de Matos

    2009-08-01

    Full Text Available The objective of this study was to evaluate the extracting capacity of different plant species when cultivated in constructed wetlands systems (CWS for the treatment of pig wastewaters (PW. For this, four CWS were constructed with 24.0 m x 1.1 m x 0.7 m, sealed with geomembrana of polyvinyl chloride (PVC and filled with 0.4 m of gravel “zero”. In CWS1, CWS2 and CWS3 were planted cattail (Typha latifolia L., Alternanthera philoxeroides (Mart. Griseb. and grass-Tifton 85 (Cynodon dactylon Pers., respectively. In CWS4 was planted Alternanthera on the 1st third, Typha in 2nd third and tifton-85 in the 3rd third of the bed. After passing through a organic filter filled with crushed sugar cane bagasse, the ARS was applied in SACS in a flow of 0.8 m3 d-1, which provided a detention time of 4.8 days. There was a trend to obtain higher extraction of pollutants by plants grown at the beginning of the CWS. The Alternanthera plant species that was presented greater capacity for nutrient extractor, extracting 9.5 and 23% of all total-N and K applied through ARS. Plants extracted small amounts of copper from the ARS. Because of the improved performance of plants, Alternanthera or Tifton-85 grass must be cultivated in CWS for the ARS treatment.

  7. Plant-species diversity correlates with genetic variation of an oligophagous seed predator.

    Directory of Open Access Journals (Sweden)

    Liisa Laukkanen

    Full Text Available Several characteristics of habitats of herbivores and their food-plant communities, such as plant-species composition and plant quality, influence population genetics of both herbivores and their host plants. We investigated how different ecological and geographic factors affect genetic variation in and differentiation of 23 populations of the oligophagous seed predator Lygaeus equestris (Heteroptera in southwestern Finland and in eastern Sweden. We tested whether genetic differentiation of the L. equestris populations was related to the similarity of vegetation, and whether there was more within-population genetic variation in habitats with a high number of plant species or in those with a large population of the primary food plant, Vincetoxicum hirundinaria. We also tested whether genetic differentiation of the populations was related to the geographic distance, and whether location of the populations on islands or on mainland, island size, or population size affected within-population genetic variation. Pairwise FST ranged from 0 to 0.1 indicating low to moderate genetic differentiation of populations. Differentiation increased with geographic distance between the populations, but was not related to the similarity of vegetation between the habitats. Genetic variation within the L. equestris populations did not increase with the population size of the primary food plant. However, the more diverse the plant community the higher was the level of genetic variation within the L. equestris population. Furthermore, the level of genetic variation did not vary significantly between island and mainland populations. The effect of the population size on within-population genetic variation was related to island size. Usually small populations are susceptible to loss of genetic variation, but small L. equestris populations on large islands seemed to maintain a relatively high level of within-population genetic variation. Our findings suggest that, in

  8. Evaluating Hypotheses of Plant Species Invasions on Mediterranean Islands: Inverse Patterns between Alien and Endemic Species

    Directory of Open Access Journals (Sweden)

    Alexander Bjarnason

    2017-08-01

    Full Text Available Invasive alien species cause major changes to ecosystem functioning and patterns of biodiversity, and the main factors involved in invasion success remain contested. Using the Mediterranean island of Crete, Greece as a case study, we suggest a framework for analyzing spatial data of alien species distributions, based on environmental predictors, aiming to gain an understanding of their spatial patterns and spread. Mediterranean islands are under strong ecological pressure from invading species due to their restricted size and increased human impact. Four hypotheses of invasibility, the “propagule pressure hypothesis” (H1, “biotic resistance hypothesis vs. acceptance hypothesis” (H2, “disturbance-mediated hypothesis” (H3, and “environmental heterogeneity hypothesis” (H4 were tested. Using data from alien, native, and endemic vascular plant species, the propagule pressure, biotic resistance vs. acceptance, disturbance-mediated, and environmental heterogeneity hypotheses were tested with Generalized Additive Modeling (GAM of 39 models. Based on model selection, the optimal model includes the positive covariates of native species richness, the negative covariates of endemic species richness, and land area. Variance partitioning between the four hypotheses indicated that the biotic resistance vs. acceptance hypothesis explained the vast majority of the total variance. These results show that areas of high species richness have greater invasibility and support the acceptance hypothesis and “rich-get-richer” distribution of alien species. The negative correlation between alien and endemic species appears to be predominantly driven by altitude, with fewer alien and more endemic species at greater altitudes, and habitat richness. The negative relationship between alien and endemic species richness provides potential for understanding patterns of endemic and alien species on islands, contributing to more effective conservation

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    Although many plant communities are invaded by multiple nonnative species, we have limited information on how a species' origin affects ecosystem function. We tested how differences in species richness and origin affect productivity and seedling establishment. We created phylogenetically paired......-interaction models to describe how species' interactions influenced diversity-productivity relationships. Communities with more species had higher total biomass than did monoculture communities, but native and nonnative communities diverged in root : shoot ratios and the mechanism responsible for increased...... productivity: positive selection effect in nonnative communities and positive complementarity effect in native communities. Seedling establishment was 46% lower in nonnative than in native communities and was correlated with the average selection effect. Interspecific interactions contributed to productivity...

  10. Biological Invasion Influences the Outcome of Plant-Soil Feedback in the Invasive Plant Species from the Brazilian Semi-arid.

    Science.gov (United States)

    de Souza, Tancredo Augusto Feitosa; de Andrade, Leonaldo Alves; Freitas, Helena; da Silva Sandim, Aline

    2017-05-30

    Plant-soil feedback is recognized as the mutual interaction between plants and soil microorganisms, but its role on the biological invasion of the Brazilian tropical seasonal dry forest by invasive plants still remains unclear. Here, we analyzed and compared the arbuscular mycorrhizal fungi (AMF) communities and soil characteristics from the root zone of invasive and native plants, and tested how these AMF communities affect the development of four invasive plant species (Cryptostegia madagascariensis, Parkinsonia aculeata, Prosopis juliflora, and Sesbania virgata). Our field sampling revealed that AMF diversity and frequency of the Order Diversisporales were positively correlated with the root zone of the native plants, whereas AMF dominance and frequency of the Order Glomerales were positively correlated with the root zone of invasive plants. We grew the invasive plants in soil inoculated with AMF species from the root zone of invasive (I changed) and native (I unaltered) plant species. We also performed a third treatment with sterilized soil inoculum (control). We examined the effects of these three AMF inoculums on plant dry biomass, root colonization, plant phosphorous concentration, and plant responsiveness to mycorrhizas. We found that I unaltered and I changed promoted the growth of all invasive plants and led to a higher plant dry biomass, mycorrhizal colonization, and P uptake than control, but I changed showed better results on these variables than I unaltered. For plant responsiveness to mycorrhizas and fungal inoculum effect on plant P concentration, we found positive feedback between changed-AMF community (I changed) and three of the studied invasive plants: C. madagascariensis, P. aculeata, and S. virgata.

  11. Production characteristics of the "higher plants-soil-like substrate" system as an element of the bioregenerative life support system

    Science.gov (United States)

    Velichko, V. V.; Tikhomirov, A. A.; Ushakova, S. A.; Tikhomirova, N. A.; Shihov, V. N.; Tirranen, L. S.; Gribovskaya, I. A.

    2013-01-01

    The study addresses the possibility of long-duration operation of a higher plant conveyor, using a soil-like substrate (SLS) as the root zone. Chufa (Cyperus esculentus L.), radish (Raphanus sativus L.), and lettuce (Lactuca sativa L.) were used as study material. A chufa community consisting of 4 age groups and radish and lettuce communities consisting of 2 age groups were irrigated with a nutrient solution, which contained mineral elements extracted from the SLS. After each harvest, inedible biomass of the harvested plants and inedible biomasses of wheat and saltwort were added to the SLS. The amounts of the inedible biomasses of wheat and saltwort to be added to the SLS were determined based on the nitrogen content of the edible mass of harvested plants. CO2 concentration in the growth chamber was maintained within the range of 1100-1700 ppm. The results of the study show that higher plants can be grown quite successfully using the proposed process of plant waste utilization in the SLS. The addition of chufa inedible biomass to the SLS resulted in species-specific inhibition of growth of both cultivated crops and microorganisms in the "higher plants - SLS" system. There were certain differences between the amounts of some mineral elements removed from the SLS with the harvested edible biomass and those added to it with the inedible biomasses of wheat and saltwort.

  12. Effect of different plant species in pilot constructed wetlands for wastewater reuse in agriculture

    Directory of Open Access Journals (Sweden)

    Salvatore Barbagallo

    2013-09-01

    Full Text Available In this paper the first results of an experiment carried out in Southern Italy (Sicily on the evapotranspiration (ET and removal in constructed wetlands with five plant species are presented. The pilot plant used for this study is made of twelve horizontal sub-surface flow constructed wetlands (each with a surface area of 4.5 m2 functioning in parallel, and it is used for tertiary treatment of part of the effluents from a conventional municipal wastewater treatment plant (trickling filter. Two beds are unplanted (control while ten beds are planted with five different macrophyte species: Cyperus papyrus, Vetiveria zizanoides, Miscanthus x giganteus, Arundo donax and Phragmites australis (i.e., every specie is planted in two beds to have a replication. The influent flow rate is measured in continuous by an electronic flow meter. The effluent is evaluated by an automatic system that measure the discharged volume for each bed. Physical, chemical and microbiological analyses were carried out on wastewater samples collected at the inlet of CW plant and at the outlet of the twelve beds. An automatic weather station is installed close to the experimental plant, measuring air temperature, wind speed and direction, rainfall, global radiation, relative humidity. This allows to calculate the reference Evapotranspiration (ET0 with the Penman-Monteith formula, while the ET of different plant species is measured through the water balance of the beds. The first results show no great differences in the mean removal performances of the different plant species for TSS, COD and E.coli, ranged from, respectively, 82% to 88%, 60% to 64% and 2.7 to 3.1 Ulog. The average removal efficiency of nutrient (64% for TN; 61 for NH4-N, 31% for PO4-P in the P.australis beds was higher than that other beds. From April to November 2012 ET measured for plant species were completely different from ET0 and ETcontrol, underlining the strong effect of vegetation. The cumulative

  13. Effects of the Extraterrestrial Environment on Plants: Recommendations for Future Space Experiments for the MELiSSA Higher Plant Compartment

    Directory of Open Access Journals (Sweden)

    Silje A. Wolff

    2014-05-01

    Full Text Available Due to logistical challenges, long-term human space exploration missions require a life support system capable of regenerating all the essentials for survival. Higher plants can be utilized to provide a continuous supply of fresh food, atmosphere revitalization, and clean water for humans. Plants can adapt to extreme environments on Earth, and model plants have been shown to grow and develop through a full life cycle in microgravity. However, more knowledge about the long term effects of the extraterrestrial environment on plant growth and development is necessary. The European Space Agency (ESA has developed the Micro-Ecological Life Support System Alternative (MELiSSA program to develop a closed regenerative life support system, based on micro-organisms and higher plant processes, with continuous recycling of resources. In this context, a literature review to analyze the impact of the space environments on higher plants, with focus on gravity levels, magnetic fields and radiation, has been performed. This communication presents a roadmap giving directions for future scientific activities within space plant cultivation. The roadmap aims to identify the research activities required before higher plants can be included in regenerative life support systems in space.

  14. Effects of the Extraterrestrial Environment on Plants: Recommendations for Future Space Experiments for the MELiSSA Higher Plant Compartment.

    Science.gov (United States)

    Wolff, Silje A; Coelho, Liz H; Karoliussen, Irene; Jost, Ann-Iren Kittang

    2014-05-05

    Due to logistical challenges, long-term human space exploration missions require a life support system capable of regenerating all the essentials for survival. Higher plants can be utilized to provide a continuous supply of fresh food, atmosphere revitalization, and clean water for humans. Plants can adapt to extreme environments on Earth, and model plants have been shown to grow and develop through a full life cycle in microgravity. However, more knowledge about the long term effects of the extraterrestrial environment on plant growth and development is necessary. The European Space Agency (ESA) has developed the Micro-Ecological Life Support System Alternative (MELiSSA) program to develop a closed regenerative life support system, based on micro-organisms and higher plant processes, with continuous recycling of resources. In this context, a literature review to analyze the impact of the space environments on higher plants, with focus on gravity levels, magnetic fields and radiation, has been performed. This communication presents a roadmap giving directions for future scientific activities within space plant cultivation. The roadmap aims to identify the research activities required before higher plants can be included in regenerative life support systems in space.

  15. Plant Size as Determinant of Species Richness of Herbivores, Natural Enemies and Pollinators across 21 Brassicaceae Species.

    Directory of Open Access Journals (Sweden)

    Hella Schlinkert

    Full Text Available Large plants are often more conspicuous and more attractive for associated animals than small plants, e.g. due to their wider range of resources. Therefore, plant size can positively affect species richness of associated animals, as shown for single groups of herbivores, but studies usually consider intraspecific size differences of plants in unstandardised environments. As comprehensive tests of interspecific plant size differences under standardised conditions are missing so far, we investigated effects of plant size on species richness of all associated arthropods using a common garden experiment with 21 Brassicaceae species covering a broad interspecific plant size gradient from 10 to 130 cm height. We recorded plant associated ecto- and endophagous herbivores, their natural enemies and pollinators on and in each aboveground plant organ, i.e. flowers, fruits, leaves and stems. Plant size (measured as height from the ground, the number of different plant organ entities and their biomass were assessed. Increasing plant size led to increased species richness of associated herbivores, natural enemies and pollinating insects. This pattern was found for ectophagous and endophagous herbivores, their natural enemies, as well as for herbivores associated with leaves and fruits and their natural enemies, independently of the additional positive effects of resource availability (i.e. organ biomass or number of entities and, regarding natural enemies, herbivore species richness. We found a lower R2 for pollinators compared to herbivores and natural enemies, probably caused by the high importance of flower characteristics for pollinator species richness besides plant size. Overall, the increase in plant height from 10 to 130 cm led to a 2.7-fold increase in predicted total arthropod species richness. In conclusion, plant size is a comprehensive driver of species richness of the plant associated arthropods, including pollinators, herbivores and their

  16. Short communication: occurrence of Arcobacter species in industrial dairy plants.

    Science.gov (United States)

    Serraino, A; Giacometti, F

    2014-01-01

    The present study investigated the presence of Arcobacter spp. in industrial dairy plants. Between February and September 2013, pasteurized milk used for cheesemaking, processing and cleaning water, cheese, and environmental samples from different plant sites, including surfaces in contact or not in contact with food, were sampled. A total of 126 samples were analyzed by the cultural method and isolates were identified by multiplex PCR. Arcobacter spp. were isolated from 22 of 75 environmental samples (29.3%): of them, 22.7% were surfaces in contact with food and 38.7% surfaces not in contact with food. A total of 135 Arcobacter spp. isolates were obtained; of these, 129 and 6 were identified as Arcobacter butzleri and Arcobacter cryaerophilus, respectively. All food processing water and pasteurized milk samples were negative for Arcobacter species. We were not able to determine the primary source of contamination, but the isolation of both A. butzleri and A. cryaerophilus in surfaces in contact with food before and during manufacturing suggests that Arcobacter spp. are not or are only partially affected by routine sanitizing procedures in the industrial dairy plants studied. The efficacy of sanitizing procedures should be evaluated and further studies are needed to determine whether certain Arcobacter strains persist for long periods of time in industrial dairy plants and whether they can survive in different types of cheese in cases of postprocessing contamination. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. Species Richness of Yeast Communities in Floral Nectar of Southern Spanish Plants

    OpenAIRE

    Pozo, María I.; Herrera, Carlos M.; Bazaga, Pilar

    2011-01-01

    Floral nectar of insect-pollinated plants often contains dense yeast populations, yet little quantitative information exists on patterns and magnitude of species richness of nectar-dwelling yeasts in natural plant commu- nities. This study evaluates yeast species richness at both the plant community and plant species levels in a montane forest area in southern Spain, and also explores possible correlations between the incidence of different yeast species in nectar and their reported tolerance...

  18. Effects of ion pairing with calcium and magnesium on selenate availability to higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Parker, D.R.; Tice, K.R.; Thomason, D.N. [Univ. of California, Riverside, CA (United States). Dept. of Soil and Environmental Sciences

    1997-03-01

    The effects of solution speciation on the bioavailability of trace metals are well documented, but the role of speciation in the bioavailability of oxyanionic trace elements that may form significant ion pairs with Ca and Mg in saline media has not been investigated. The authors assessed the effects of such ion pairing on the availability of selenate to representative monocotyledonous and dicotyledonous higher plants. Formation constants for the CaSO{sub 4}{sup 0} formation was confirmed, but the value of 10{sup 2.7} for CaSeO{sub 4}{sup 0} was found to be in error; a value of 10{sup 2.0} is proposed here as the correct formation constant. Five solution culture experiments were conducted using alfalfa (Medicago sativa L.) or tall wheatgrass (Elytrigia pontica [Podp.] Holub) with treatments consisting of NaSeO{sub 4} levels in combination with various levels of MgCl{sub 2} or CaCl{sub 2}. Both shoot Se concentrations and whole-plant Se contents were highly correlated with the free SeO{sub 4}{sup 2{minus}} activity but were poorly correlated with the sum of the free ion plus Ca and Mg ion pair species. Thus, the authors have shown, for the first time, that the free ion model of trace metal bioavailability is also valid for oxyanions that form complexes with Ca and Mg in saline media but that this conclusion hinges critically on the accuracy of the pertinent formation constants.

  19. Bioprospecting on invasive plant species to prevent seed dispersal.

    Science.gov (United States)

    Guzzetti, Lorenzo; Galimberti, Andrea; Bruni, Ilaria; Magoni, Chiara; Ferri, Maura; Tassoni, Annalisa; Sangiovanni, Enrico; Dell' Agli, Mario; Labra, Massimo

    2017-10-23

    The most anthropized regions of the world are characterized by an impressive abundance of invasive plants, which alter local biodiversity and ecosystem services. An alternative strategy to manage these species could be based on the exploitation of their fruits in a framework of bioprospecting to obtain high-added value compounds or phytocomplexes that are useful for humans. Here we tested this hypothesis on three invasive plants (Lonicera japonica Thunb., Phytolacca americana L., and Prunus serotina Ehrh.) in the Po plain (northern Italy) which bear fruits that are highly consumed by frugivorous birds and therefore dispersed over large distances. Our biochemical analyses revealed that unripe fruit shows high antioxidant properties due to the presence of several classes of polyphenols, which have a high benchmark value on the market. Fruit collection for phytochemical extraction could really prevent seed dispersal mediated by frugivorous animals and produce economic gains to support local management actions.

  20. 45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.

    Science.gov (United States)

    2010-10-01

    ... native mammals, birds, and plants. 670.25 Section 670.25 Public Welfare Regulations Relating to Public... Protected Species of Mammals, Birds, and Plants § 670.25 Designation of specially protected species of native mammals, birds, and plants. The following species has been designated as Specially Protected...

  1. Increased plant carbon translocation linked to overyielding in grassland species mixtures

    NARCIS (Netherlands)

    Deyn, de G.B.; Quirk, H.; Oakley, S.; Ostle, N.J.; Bardgett, R.D.

    2012-01-01

    Plant species richness and productivity often show a positive relationship, but the underlying mechanisms are not fully understood, especially at the plant species level. We examined how growing plants in species mixture influences intraspecific rates of short-term carbon (C-) translocation, and

  2. Plant–soil feedbacks of exotic plant species across life forms: a meta-analysis

    NARCIS (Netherlands)

    Meisner, A.; Hol, W.H.G.; Boer, de W.; Krumins, J.A.; Wardle, D.A.; Putten, van der W.H.

    2014-01-01

    Invasive exotic plant species effects on soil biota and processes in their new range can promote or counteract invasions via changed plant–soil feedback interactions to themselves or to native plant species. Recent meta-analyses reveale that soil influenced by native and exotic plant species is

  3. Herbicides: an unexpected ally for native plants in the war against invasive species

    Science.gov (United States)

    Andrea Watts; Tim Harrington; Dave Peter

    2015-01-01

    Herbicides are primarily used for protecting agricultural crops from weeds and controlling vegetation competition in newly planted forest stands. Yet for over 40 years, they have also proven useful in controlling invasive plant species in natural areas. Nonnative invasive plant species, if not controlled, can displace native species and disrupt an ecosystem by changing...

  4. Plant species diversity in a Neotropical wetland: patterns of similarity, effects of distance, and altitude

    Directory of Open Access Journals (Sweden)

    FRANCIELLI BAO

    2017-12-01

    Full Text Available ABSTRACT The Brazilian Pantanal is an extensive wetland with heterogeneous habitats, primarily due to the river-floodplain system and plants with differential adaptations and reproductive strategies. Factors such as altitude, distance among plant formations, and flood pulse must be considered to better understand its diversity. Aiming to assess the influence of biogeographic patterns in this system, we analyzed the floristic composition of six areas along the Paraguay River, including residual relieves, verifying the pattern of similarity, and effects of distance and altitude. We recorded 356 species in 87 families, mostly perennial (75%, and some annuals (15% and pluriannuals (5%. Herbaceous plants were the most represented (48%, followed by arboreal (23%, shrubby (15% and epiphytic (14% habits, only 12% being endemic to Brazil. The studied areas showed low floristic similarity, but higher resemblance of species between neighboring areas, and no relation with altitude. The upper Paraguay River is diverse, with high spatial variability of species, predominantly perennial. The river-floodplain connectivity may be a determinant factor in species richness and occurrence of endemic species.

  5. Effects of ‘Target’ Plant Species Body Size on Neighbourhood Species Richness and Composition in Old-Field Vegetation

    Science.gov (United States)

    Schamp, Brandon S.; Aarssen, Lonnie W.; Wight, Stephanie

    2013-01-01

    Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with the fact that large and small plant species generally coexist, and relatively smaller species are more common in virtually all plant communities. Here, we use replicates of ten relatively large old-field plant species to explore the competitive impact of target individual size on their surrounding neighbourhoods compared to nearby neighbourhoods of the same size that are not centred by a large target individual. While target individuals of the largest of our test species, Centaurea jacea L., had a strong impact on neighbouring species, in general, target species size was a weak predictor of the number of other resident species growing within its immediate neighbourhood, as well as the number of resident species that were reproductive. Thus, the presence of a large competitor did not restrict the ability of neighbouring species to reproduce. Lastly, target species size did not have any impact on the species size structure of neighbouring species; i.e. they did not restrict smaller, supposedly poorer competitors, from growing and reproducing close by. Taken together, these results provide no support for a size-advantage in competition restricting local species richness or the ability of small species to coexist and successfully reproduce in the immediate neighbourhood of a large species. PMID:24349177

  6. Effects of 'target' plant species body size on neighbourhood species richness and composition in old-field vegetation.

    Directory of Open Access Journals (Sweden)

    Brandon S Schamp

    Full Text Available Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with the fact that large and small plant species generally coexist, and relatively smaller species are more common in virtually all plant communities. Here, we use replicates of ten relatively large old-field plant species to explore the competitive impact of target individual size on their surrounding neighbourhoods compared to nearby neighbourhoods of the same size that are not centred by a large target individual. While target individuals of the largest of our test species, Centaurea jacea L., had a strong impact on neighbouring species, in general, target species size was a weak predictor of the number of other resident species growing within its immediate neighbourhood, as well as the number of resident species that were reproductive. Thus, the presence of a large competitor did not restrict the ability of neighbouring species to reproduce. Lastly, target species size did not have any impact on the species size structure of neighbouring species; i.e. they did not restrict smaller, supposedly poorer competitors, from growing and reproducing close by. Taken together, these results provide no support for a size-advantage in competition restricting local species richness or the ability of small species to coexist and successfully reproduce in the immediate neighbourhood of a large species.

  7. Plant mortality varies with arbuscular mycorrhizal fungal species identities in a self-thinning population

    Science.gov (United States)

    Zhang, Qian; Tang, Jianjun; Chen, Xin

    2011-01-01

    Because arbuscular mycorrhizal fungal (AMF) species differ in stimulating the growth of particular host plant species, AMF species may vary in their effects on plant intra-specific competition and the self-thinning process. We tested this hypothesis using a microcosm experiment with Medicago sativa L. as a model plant population and four AMF species. Our results showed that the AMF species Glomus diaphanum stimulated host plant growth more than the other three AMF species did when the plants were grown individually. Glomus diaphanum also induced the highest rate of mortality in the self-thinning plant populations. We also found a positive correlation between mortality and growth response to colonization. Our results demonstrate that AMF species can affect plant mortality and the self-thinning process by affecting plant growth differently. PMID:21147829

  8. Contribution of PsbS Function and Stomatal Conductance to Foliar Temperature in Higher Plants.

    Science.gov (United States)

    Kulasek, Milena; Bernacki, Maciej Jerzy; Ciszak, Kamil; Witoń, Damian; Karpiński, Stanisław

    2016-07-01

    Natural capacity has evolved in higher plants to absorb and harness excessive light energy. In basic models, the majority of absorbed photon energy is radiated back as fluorescence and heat. For years the proton sensor protein PsbS was considered to play a critical role in non-photochemical quenching (NPQ) of light absorbed by PSII antennae and in its dissipation as heat. However, the significance of PsbS in regulating heat emission from a whole leaf has never been verified before by direct measurement of foliar temperature under changing light intensity. To test its validity, we here investigated the foliar temperature changes on increasing and decreasing light intensity conditions (foliar temperature dynamics) using a high resolution thermal camera and a powerful adjustable light-emitting diode (LED) light source. First, we showed that light-dependent foliar temperature dynamics is correlated with Chl content in leaves of various plant species. Secondly, we compared the foliar temperature dynamics in Arabidopsis thaliana wild type, the PsbS null mutant npq4-1 and a PsbS-overexpressing transgenic line under different transpiration conditions with or without a photosynthesis inhibitor. We found no direct correlations between the NPQ level and the foliar temperature dynamics. Rather, differences in foliar temperature dynamics are primarily affected by stomatal aperture, and rapid foliar temperature increase during irradiation depends on the water status of the leaf. We conclude that PsbS is not directly involved in regulation of foliar temperature dynamics during excessive light energy episodes. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  9. Foliar pH as a new plant trait: can it explain variation in foliar chemistry and carbon cycling processes among subarctic plant species and types?

    Science.gov (United States)

    Cornelissen, J H C; Quested, H M; van Logtestijn, R S P; Pérez-Harguindeguy, N; Gwynn-Jones, D; Díaz, S; Callaghan, T V; Press, M C; Aerts, R

    2006-03-01

    Plant traits have become popular as predictors of interspecific variation in important ecosystem properties and processes. Here we introduce foliar pH as a possible new plant trait, and tested whether (1) green leaf pH or leaf litter pH correlates with biochemical and structural foliar traits that are linked to biogeochemical cycling; (2) there is consistent variation in green leaf pH or leaf litter pH among plant types as defined by nutrient uptake mode and higher taxonomy; (3) green leaf pH can predict a significant proportion of variation in leaf digestibility among plant species and types; (4) leaf litter pH can predict a significant proportion of variation in leaf litter decomposability among plant species and types. We found some evidence in support of all four hypotheses for a wide range of species in a subarctic flora, although cryptogams (fern allies and a moss) tended to weaken the patterns by showing relatively poor leaf digestibility or litter decomposability at a given pH. Among seed plant species, green leaf pH itself explained only up to a third of the interspecific variation in leaf digestibility and leaf litter up to a quarter of the interspecific variation in leaf litter decomposability. However, foliar pH substantially improved the power of foliar lignin and/or cellulose concentrations as predictors of these processes when added to regression models as a second variable. When species were aggregated into plant types as defined by higher taxonomy and nutrient uptake mode, green-specific leaf area was a more powerful predictor of digestibility or decomposability than any of the biochemical traits including pH. The usefulness of foliar pH as a new predictive trait, whether or not in combination with other traits, remains to be tested across more plant species, types and biomes, and also in relation to other plant or ecosystem traits and processes.

  10. DNA barcoding in Atlantic Forest plants: what is the best marker for Sapotaceae species identification?

    Directory of Open Access Journals (Sweden)

    Caio Vinicius Vivas

    2014-12-01

    Full Text Available The Atlantic Forest is a phytogeographic domain with a high rate of endemism and large species diversity. The Sapotaceae is a botanical family for which species identification in the Atlantic Forest is difficult. An approach that facilitates species identification in the Sapotaceae is urgently needed because this family includes threatened species and valuable timber species. In this context, DNA barcoding could provide an important tool for identifying species in the Atlantic Forest. In this work, we evaluated four plant barcode markers (matK, rbcL, trnH-psbA and the nuclear ribosomal internal transcribed spacer region -ITS in 80 samples from 26 species of Sapotaceae that occur in the Atlantic Forest. ITS yielded the highest average interspecific distance (0.122, followed by trnH-psbA (0.019, matK (0.008 and rbcL (0.002. For species discrimination, ITS provided the best results, followed by matK, trnH-psbA and rbcL. Furthermore, the combined analysis of two, three or four markers did not result in higher rates of discrimination than obtained with ITS alone. These results indicate that the ITS region is the best option for molecular identification of Sapotaceae species from the Atlantic Forest.

  11. Stochastic species turnover and stable coexistence in a species-rich, fire-prone plant community.

    Directory of Open Access Journals (Sweden)

    Wilfried Thuiller

    Full Text Available Understanding the mechanisms that maintain diversity is important for managing ecosystems for species persistence. Here we used a long-term data set to understand mechanisms of coexistence at the local and regional scales in the Cape Floristic Region, a global hotspot of plant diversity. We used a dataset comprising 81 monitoring sites, sampled in 1966 and again in 1996, and containing 422 species for which growth form, regeneration mode, dispersal distance and abundances at both the local (site and meta-community scales are known. We found that species presence and abundance were stable at the meta-community scale over the 30 year period but highly unstable at the local scale, and were not influenced by species' biological attributes. Moreover, rare species were no more likely to go extinct at the local scale than common species, and that alpha diversity in local communities was strongly influenced by habitat. We conclude that stochastic environmental fluctuations associated with recurrent fire buffer populations from extinction, thereby ensuring stable coexistence at the meta-community scale by creating a "neutral-like" pattern maintained by niche-differentiation.

  12. Reactive oxygen species, essential molecules, during plant-pathogen interactions.

    Science.gov (United States)

    Camejo, Daymi; Guzmán-Cedeño, Ángel; Moreno, Alexander

    2016-06-01

    Reactive oxygen species (ROS) are continually generated as a consequence of the normal metabolism in aerobic organisms. Accumulation and release of ROS into cell take place in response to a wide variety of adverse environmental conditions including salt, temperature, cold stresses and pathogen attack, among others. In plants, peroxidases class III, NADPH oxidase (NOX) locates in cell wall and plasma membrane, respectively, may be mainly enzymatic systems involving ROS generation. It is well documented that ROS play a dual role into cells, acting as important signal transduction molecules and as toxic molecules with strong oxidant power, however some aspects related to its function during plant-pathogen interactions remain unclear. This review focuses on the principal enzymatic systems involving ROS generation addressing the role of ROS as signal molecules during plant-pathogen interactions. We described how the chloroplasts, mitochondria and peroxisomes perceive the external stimuli as pathogen invasion, and trigger resistance response using ROS as signal molecule. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Biological invasions: economic and environmental costs of alien plant, animal, and microbe species

    National Research Council Canada - National Science Library

    Pimentel, David

    2011-01-01

    ...: Economic and Environmental Costs of Alien Plant, Animal, and Microbe Species, this reference discusses how non-native species invade new ecosystems and the subsequent economic and environmental effects of these species...

  14. Tracking lags in historical plant species' shifts in relation to regional climate change.

    Science.gov (United States)

    Ash, Jeremy D; Givnish, Thomas J; Waller, Donald M

    2017-03-01

    Can species shift their distributions fast enough to track changes in climate? We used abundance data from the 1950s and the 2000s in Wisconsin to measure shifts in the distribution and abundance of 78 forest-understory plant species over the last half-century and compare these shifts to changes in climate. We estimated temporal shifts in the geographic distribution of each species using vectors to connect abundance-weighted centroids from the 1950s and 2000s. These shifts in distribution reflect colonization, extirpation, and changes in abundance within sites, separately quantified here. We then applied climate analog analyses to compute vectors representing the climate change that each species experienced. Species shifted mostly to the northwest (mean: 49 ± 29 km) primarily reflecting processes of colonization and changes in local abundance. Analog climates for these species shifted even further to the northwest, however, exceeding species' shifts by an average of 90 ± 40 km. Most species thus failed to match recent rates of climate change. These lags decline in species that have colonized more sites and those with broader site occupancy, larger seed mass, and higher habitat fidelity. Thus, species' traits appear to affect their responses to climate change, but relationships are weak. As climate change accelerates, these lags will likely increase, potentially threatening the persistence of species lacking the capacity to disperse to new sites or locally adapt. However, species with greater lags have not yet declined more in abundance. The extent of these threats will likely depend on how other drivers of ecological change and interactions among species affect their responses to climate change. © 2016 John Wiley & Sons Ltd.

  15. Predicting plant invasions under climate change: are species distribution models validated by field trials?

    Science.gov (United States)

    Sheppard, Christine S; Burns, Bruce R; Stanley, Margaret C

    2014-09-01

    Climate change may facilitate alien species invasion into new areas, particularly for species from warm native ranges introduced into areas currently marginal for temperature. Although conclusions from modelling approaches and experimental studies are generally similar, combining the two approaches has rarely occurred. The aim of this study was to validate species distribution models by conducting field trials in sites of differing suitability as predicted by the models, thus increasing confidence in their ability to assess invasion risk. Three recently naturalized alien plants in New Zealand were used as study species (Archontophoenix cunninghamiana, Psidium guajava and Schefflera actinophylla): they originate from warm native ranges, are woody bird-dispersed species and of concern as potential weeds. Seedlings were grown in six sites across the country, differing both in climate and suitability (as predicted by the species distribution models). Seedling growth and survival were recorded over two summers and one or two winter seasons, and temperature and precipitation were monitored hourly at each site. Additionally, alien seedling performances were compared to those of closely related native species (Rhopalostylis sapida, Lophomyrtus bullata and Schefflera digitata). Furthermore, half of the seedlings were sprayed with pesticide, to investigate whether enemy release may influence performance. The results showed large differences in growth and survival of the alien species among the six sites. In the more suitable sites, performance was frequently higher compared to the native species. Leaf damage from invertebrate herbivory was low for both alien and native seedlings, with little evidence that the alien species should have an advantage over the native species because of enemy release. Correlations between performance in the field and predicted suitability of species distribution models were generally high. The projected increase in minimum temperature and reduced

  16. Antifungal Effect of Plant Essential Oils on Controlling Phytophthora Species

    Directory of Open Access Journals (Sweden)

    Jahanshir Amini

    2016-02-01

    Full Text Available In this study, antifungal activity of essential oils of Cymbopogon citratus and Ocimum basilicum and two fungicides Mancozeb and Metalaxyl-Mancozeb in six different concentrations were investigated for controlling three species of Phytophthora, including P. capsici, P. drechsleri and P. melonis on pepper, cucumber and melon under in vitro and greenhouse conditions, respectively. Under the in vitro condition, the median effective concen- tration (EC₅₀ values (ppm of plant essential oils and fungicides were measured. In greenhouse, soil infested with Phytophthora species was treated by adding 50 ml of essential oils and fungicides (100 ppm. Disease severity was determined after 28 days. Among two tested plant essential oils, C. citratus had the lowest EC₅₀ values for inhibition of the mycelial growth of P. capsici (31.473, P. melonis (33.097 and P. drechsleri (69.112, respectively. The mean EC₅₀ values for Metalaxyl-Mancozeb on these pathogens were 20.87, 20.06 and 17.70, respectively. Chemical analysis of plant essential oils by GC-MS showed that, among 42 compounds identified from C. citratus, two compounds β-geranial (α-citral (39.16% and z-citral (30.95% were the most abundant. Under the greenhouse condition, Metalaxyl-Mancozeb caused the greatest reduction in disease severity, 84.2%, 86.8% and 92.1% on melon, cucumber, and pepper, respectively. The C. citratus essential oil reduced disease severity from 47.4% to 60.5% compared to the untreated control (p≤0.05. Essential oils of O. basilicum had the lowest effects on the pathogens under in vitro and greenhouse conditions. These results show that essential oils may contribute to the development of new antifungal agents to protect the crops from Phytophthora diseases.

  17. Antifungal Effect of Plant Essential Oils on Controlling Phytophthora Species

    Science.gov (United States)

    Amini, Jahanshir; Farhang, Vahid; Javadi, Taimoor; Nazemi, Javad

    2016-01-01

    In this study, antifungal activity of essential oils of Cymbopogon citratus and Ocimum basilicum and two fungicides Mancozeb and Metalaxyl-Mancozeb in six different concentrations were investigated for controlling three species of Phytophthora, including P. capsici, P. drechsleri and P. melonis on pepper, cucumber and melon under in vitro and greenhouse conditions, respectively. Under the in vitro condition, the median effective concen- tration (EC50) values (ppm) of plant essential oils and fungicides were measured. In greenhouse, soil infested with Phytophthora species was treated by adding 50 ml of essential oils and fungicides (100 ppm). Disease severity was determined after 28 days. Among two tested plant essential oils, C. citratus had the lowest EC50 values for inhibition of the mycelial growth of P. capsici (31.473), P. melonis (33.097) and P. drechsleri (69.112), respectively. The mean EC50 values for Metalaxyl-Mancozeb on these pathogens were 20.87, 20.06 and 17.70, respectively. Chemical analysis of plant essential oils by GC-MS showed that, among 42 compounds identified from C. citratus, two compounds β-geranial (α-citral) (39.16%) and z-citral (30.95%) were the most abundant. Under the greenhouse condition, Metalaxyl-Mancozeb caused the greatest reduction in disease severity, 84.2%, 86.8% and 92.1% on melon, cucumber, and pepper, respectively. The C. citratus essential oil reduced disease severity from 47.4% to 60.5% compared to the untreated control (p≤0.05). Essential oils of O. basilicum had the lowest effects on the pathogens under in vitro and greenhouse conditions. These results show that essential oils may contribute to the development of new antifungal agents to protect the crops from Phytophthora diseases. PMID:26889111

  18. Does resource availability, resource heterogeneity or species turnover mediate changes in plant species richness in grazed grasslands?

    NARCIS (Netherlands)

    Bakker, C; Blair, JM; Knapp, AK

    2003-01-01

    Grazing by large ungulates often increases plant species richness in grasslands of moderate to high productivity. In a mesic North American grassland with and without the presence of bison (Bos bison), a native ungulate grazer, three non-exclusive hypotheses for increased plant species richness in

  19. Small mammals as indicators of cryptic plant species diversity in the central Chilean plant endemicity hotspot

    Directory of Open Access Journals (Sweden)

    Meredith Root-Bernstein

    2014-12-01

    Full Text Available Indicator species could help to compensate for a shortfall of knowledge about the diversity and distributions of undersampled and cryptic species. This paper provides background knowledge about the ecological interactions that affect and are affected by herbaceous diversity in central Chile, as part of the indicator species selection process. We focus on the ecosystem engineering role of small mammals, primarily the degu Octodon degus. We also consider the interacting effects of shrubs, trees, avian activity, livestock, slope, and soil quality on herbaceous communities in central Chile. We sampled herbaceous diversity on a private landholding characterized by a mosaic of savanna, grassland and matorral, across a range of degu disturbance intensities. We find that the strongest factors affecting endemic herbaceous diversity are density of degu runways, shrub cover and avian activity. Our results show that the degu, a charismatic and easily identifiable and countable species, could be used as an indicator species to aid potential conservation actions such as private protected area uptake. We map areas in central Chile where degus may indicate endemic plant diversity. This area is larger than expected, and suggests that significant areas of endemic plant communities may still exist, and should be identified and protected.

  20. Understanding Aquaporin Transport System in Eelgrass (Zostera marina L., an Aquatic Plant Species

    Directory of Open Access Journals (Sweden)

    S. M. Shivaraj

    2017-08-01

    Full Text Available Aquaporins (AQPs are a class of integral membrane proteins involved in the transport of water and many other small solutes. The AQPs have been extensively studied in many land species obtaining water and nutrients from the soil, but their distribution and evolution have never been investigated in aquatic plant species, where solute assimilation is mostly through the leaves. In this regard, identification of AQPs in the genome of Zostera marina L. (eelgrass, an aquatic ecological model species could reveal important differences underlying solute uptake between land and aquatic species. In the present study, genome-wide analysis led to the identification of 25 AQPs belonging to four subfamilies, plasma membrane intrinsic proteins (PIPs, tonoplast intrinsic proteins (TIPs, nodulin 26-like intrinsic proteins (NIPs, small basic intrinsic proteins (SIPs in eelgrass. As in other monocots, the XIP subfamily was found to be absent from the eelgrass genome. Further classification of subfamilies revealed a unique distribution pattern, namely the loss of the NIP2 (NIP-III subgroup, which is known for silicon (Si transport activity and ubiquitously present in monocot species. This finding has great importance, since the eelgrass population stability in natural niche is reported to be associated with Si concentrations in water. In addition, analysis of available RNA-seq data showed evidence of expression in 24 out of the 25 AQPs across four different tissues such as root, vegetative tissue, male flower and female flower. In contrast to land plants, higher expression of PIPs was observed in shoot compared to root tissues. This is likely explained by the unique plant architecture of eelgrass where most of the nutrients and water are absorbed by shoot rather than root tissues. Similarly, higher expression of the TIP1 and TIP5 families was observed specifically in male flowers suggesting a role in pollen maturation. This genome-wide analysis of AQP distribution

  1. In vitro culture of higher plants as a tool in the propagation of horticultural crops.

    NARCIS (Netherlands)

    Pierik, R.L.M.

    1988-01-01

    In vitro culture of higher plants is the culture, under sterile conditions, of plants, seeds, embryos, organs, explants, tissues, cells and protoplasts on nutrient media. This type of culture has shown spectacular development since 1975, resulting in the production and regeneration of viable

  2. Duck productivity in restored species-rich native and species-poor non-native plantings.

    Directory of Open Access Journals (Sweden)

    Ryan D Haffele

    Full Text Available Conservation efforts to increase duck production have led the United States Fish and Wildlife Service to restore grasslands with multi-species (3-5 mixtures of introduced cool season vegetation often termed dense nesting cover (DNC. The effectiveness of DNC to increase duck production has been variable, and maintenance of the cover type is expensive. In an effort to decrease the financial and ecological costs (increased carbon emissions from plowing and reseeding of maintaining DNC and provide a long-term, resilient cover that will support a diversity of grassland fauna, restoration of multi-species (16-32 plantings of native plants has been explored. We investigated the vegetation characteristics, nesting density and nest survival between the 2 aforementioned cover types in the Prairie Pothole Region of North Dakota, USA from 2010-2011 to see if restored-native plantings provide similar benefits to nesting hens as DNC. We searched 14 fields (7 DNC, 271 ha; and 7 restored native, 230 ha locating 3384 nests (1215 in restored-native vegetation and 2169 in DNC in 2010-2011. Nest survival was similar between cover types in 2010, while DNC had greater survival than native plantings in 2011. Densities of nests adjusted for detection probability were not different between cover types in either year. We found no structural difference in vegetation between cover types in 2010; however, a difference was detected during the late sampling period in 2011 with DNC having deeper litter and taller vegetation. Our results indicate restored-native plantings are able to support similar nesting density as DNC; however, nest survival is more stable between years in DNC. It appears the annual variation in security between cover types goes undetected by hens as hens selected cover types at similar levels both years.

  3. Nutritive values of some food plants, fresh and processed fish species

    Directory of Open Access Journals (Sweden)

    Ali Aberoumand

    2015-12-01

    Full Text Available The chemical composition of four edible plant foods species, three fish species and one prawn were analyzed in Food Chemistry Laboratory of Behbahan Khatam Alanbia University of Technology, Behbahan, Iran in 2014. The analysis of fatty acid and sugars composition were performed by gas liquid chromatography and high performance liquid chromatography, respectively. Protein and lipid content were founded higher in baked and fried in fish S. commersonnianus (74.29%, (20.20%, fish Sphyraena helleri (88.12% and (17.77%, respectively. Ash content in fish S. commersonnianus varies from 9.80% to 15.34%, and in fish S. helleri from 5.83% to 7.68%. Based on the proximate analysis, it can be calculated that an edible portion of 100 g of studied edible plant foods provides, on average, around 303.9±1.04 kcal. The plant Portulaca neglecta is suitable for high temperature food processes. The macronutrient profile in general revealed that the wild plant foods were with rich sources of protein and carbohydrates, and had low amounts of fat. The highest protein, the lowest fat and energy contents were found in boiled in both fish species; therefore, boiling can be recommended as the best cooking method for healthy diet.

  4. Regional assessment of ozone sensitive tree species using bioindicator plants.

    Science.gov (United States)

    Coulston, John W; Smith, Gretchen C; Smith, William D

    2003-04-01

    Tropospheric ozone occurs at phytotoxic levels in the northeastern and mid-Atlantic regions of the United States. Quantifying possible regional-scale impacts of ambient ozone on forest tree species is difficult and is confounded by other factors, such as moisture and light, which influence the uptake of ozone by plants. Biomonitoring provides an approach to document direct foliar injury irrespective of direct measure of ozone uptake. We used bioindicator and field plot data from the USDA Forest Service to identify tree species likely to exhibit regional-scale ozone impacts. Approximately 24% of sampled sweetgum (Liquidambar styraciflua), 15% of sampled loblolly pine (Pinus taeda), and 12% of sampled black cherry (Prunus serotina) trees were in the highest risk category. Sweetgum and loblolly pine trees were at risk on the coastal plain of Maryland, Virginia and Delaware. Black cherry trees were at risk on the Allegheny Plateau (Pennsylvania), in the Allegheny Mountains (Pennsylvania, West Virginia, and Maryland) as well as coastal plain areas of Maryland and Virginia. Our findings indicate a need for more in-depth study of actual impacts on growth and reproduction of these three species.

  5. Congruence and Diversity of Butterfly-Host Plant Associations at Higher Taxonomic Levels

    Science.gov (United States)

    Ferrer-Paris, José R.; Sánchez-Mercado, Ada; Viloria, Ángel L.; Donaldson, John

    2013-01-01

    We aggregated data on butterfly-host plant associations from existing sources in order to address the following questions: (1) is there a general correlation between host diversity and butterfly species richness?, (2) has the evolution of host plant use followed consistent patterns across butterfly lineages?, (3) what is the common ancestral host plant for all butterfly lineages? The compilation included 44,148 records from 5,152 butterfly species (28.6% of worldwide species of Papilionoidea) and 1,193 genera (66.3%). The overwhelming majority of butterflies use angiosperms as host plants. Fabales is used by most species (1,007 spp.) from all seven butterfly families and most subfamilies, Poales is the second most frequently used order, but is mostly restricted to two species-rich subfamilies: Hesperiinae (56.5% of all Hesperiidae), and Satyrinae (42.6% of all Nymphalidae). We found a significant and strong correlation between host plant diversity and butterfly species richness. A global test for congruence (Parafit test) was sensitive to uncertainty in the butterfly cladogram, and suggests a mixed system with congruent associations between Papilionidae and magnoliids, Hesperiidae and monocots, and the remaining subfamilies with the eudicots (fabids and malvids), but also numerous random associations. The congruent associations are also recovered as the most probable ancestral states in each node using maximum likelihood methods. The shift from basal groups to eudicots appears to be more likely than the other way around, with the only exception being a Satyrine-clade within the Nymphalidae that feed on monocots. Our analysis contributes to the visualization of the complex pattern of interactions at superfamily level and provides a context to discuss the timing of changes in host plant utilization that might have promoted diversification in some butterfly lineages. PMID:23717448

  6. Congruence and diversity of butterfly-host plant associations at higher taxonomic levels.

    Directory of Open Access Journals (Sweden)

    José R Ferrer-Paris

    Full Text Available We aggregated data on butterfly-host plant associations from existing sources in order to address the following questions: (1 is there a general correlation between host diversity and butterfly species richness?, (2 has the evolution of host plant use followed consistent patterns across butterfly lineages?, (3 what is the common ancestral host plant for all butterfly lineages? The compilation included 44,148 records from 5,152 butterfly species (28.6% of worldwide species of Papilionoidea and 1,193 genera (66.3%. The overwhelming majority of butterflies use angiosperms as host plants. Fabales is used by most species (1,007 spp. from all seven butterfly families and most subfamilies, Poales is the second most frequently used order, but is mostly restricted to two species-rich subfamilies: Hesperiinae (56.5% of all Hesperiidae, and Satyrinae (42.6% of all Nymphalidae. We found a significant and strong correlation between host plant diversity and butterfly species richness. A global test for congruence (Parafit test was sensitive to uncertainty in the butterfly cladogram, and suggests a mixed system with congruent associations between Papilionidae and magnoliids, Hesperiidae and monocots, and the remaining subfamilies with the eudicots (fabids and malvids, but also numerous random associations. The congruent associations are also recovered as the most probable ancestral states in each node using maximum likelihood methods. The shift from basal groups to eudicots appears to be more likely than the other way around, with the only exception being a Satyrine-clade within the Nymphalidae that feed on monocots. Our analysis contributes to the visualization of the complex pattern of interactions at superfamily level and provides a context to discuss the timing of changes in host plant utilization that might have promoted diversification in some butterfly lineages.

  7. Imperfect replacement of native species by non-native species as pollinators of endemic Hawaiian plants.

    Science.gov (United States)

    Aslan, Clare E; Zavaleta, Erika S; Tershy, Bernie; Croll, Don; Robichaux, Robert H

    2014-04-01

    Native plant species that have lost their mutualist partners may require non-native pollinators or seed dispersers to maintain reproduction. When natives are highly specialized, however, it appears doubtful that introduced generalists will partner effectively with them. We used visitation observations and pollination treatments (experimental manipulations of pollen transfer) to examine relationships between the introduced, generalist Japanese White-eye (Zosterops japonicus) and 3 endemic Hawaiian plant species (Clermontia parviflora, C. montis-loa, and C. hawaiiensis). These plants are characterized by curved, tubular flowers, apparently adapted for pollination by curve-billed Hawaiian honeycreepers. Z. japonicus were responsible for over 80% of visits to flowers of the small-flowered C. parviflora and the midsize-flowered C. montis-loa. Z. japonicus-visited flowers set significantly more seed than did bagged flowers. Z. japonicus also demonstrated the potential to act as an occasional Clermontia seed disperser, although ground-based frugivory by non-native mammals likely dominates seed dispersal. The large-flowered C. hawaiiensis received no visitation by any birds during observations. Unmanipulated and bagged C. hawaiiensis flowers set similar numbers of seeds. Direct examination of Z. japonicus and Clermontia morphologies suggests a mismatch between Z. japonicus bill morphology and C. hawaiiensis flower morphology. In combination, our results suggest that Z. japonicus has established an effective pollination relationship with C. parviflora and C. montis-loa and that the large flowers of C. hawaiiensis preclude effective visitation by Z. japonicus. © 2013 Society for Conservation Biology.

  8. Mineral nutrition of campos rupestres plant species on contrasting nutrient-impoverished soil types.

    Science.gov (United States)

    Oliveira, Rafael S; Galvão, Hugo C; de Campos, Mariana C R; Eller, Cleiton B; Pearse, Stuart J; Lambers, Hans

    2015-02-01

    In Brazil, the campos rupestres occur over the Brazilian shield, and are characterized by acidic nutrient-impoverished soils, which are particularly low in phosphorus (P). Despite recognition of the campos rupestres as a global biodiversity hotspot, little is known about the diversity of P-acquisition strategies and other aspects of plant mineral nutrition in this region. To explore nutrient-acquisition strategies and assess aspects of plant P nutrition, we measured leaf P and nitrogen (N) concentrations, characterized root morphology and determined the percentage arbuscular mycorrhizal (AM) colonization of 50 dominant species in six communities, representing a gradient of soil P availability. Leaf manganese (Mn) concentration was measured as a proxy for carboxylate-releasing strategies. Communities on the most P-impoverished soils had the highest proportion of nonmycorrhizal (NM) species, the lowest percentage of mycorrhizal colonization, and the greatest diversity of root specializations. The large spectrum of leaf P concentration and variation in root morphologies show high functional diversity for nutritional strategies. Higher leaf Mn concentrations were observed in NM compared with AM species, indicating that carboxylate-releasing P-mobilizing strategies are likely to be present in NM species. The soils of the campos rupestres are similar to the most P-impoverished soils in the world. The prevalence of NM strategies indicates a strong global functional convergence in plant mineral nutrition strategies among severely P-impoverished ecosystems. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  9. Directional Selection from Host Plants Is a Major Force Driving Host Specificity in Magnaporthe Species.

    Science.gov (United States)

    Zhong, Zhenhui; Norvienyeku, Justice; Chen, Meilian; Bao, Jiandong; Lin, Lianyu; Chen, Liqiong; Lin, Yahong; Wu, Xiaoxian; Cai, Zena; Zhang, Qi; Lin, Xiaoye; Hong, Yonghe; Huang, Jun; Xu, Linghong; Zhang, Honghong; Chen, Long; Tang, Wei; Zheng, Huakun; Chen, Xiaofeng; Wang, Yanli; Lian, Bi; Zhang, Liangsheng; Tang, Haibao; Lu, Guodong; Ebbole, Daniel J; Wang, Baohua; Wang, Zonghua

    2016-05-06

    One major threat to global food security that requires immediate attention, is the increasing incidence of host shift and host expansion in growing number of pathogenic fungi and emergence of new pathogens. The threat is more alarming because, yield quality and quantity improvement efforts are encouraging the cultivation of uniform plants with low genetic diversity that are increasingly susceptible to emerging pathogens. However, the influence of host genome differentiation on pathogen genome differentiation and its contribution to emergence and adaptability is still obscure. Here, we compared genome sequence of 6 isolates of Magnaporthe species obtained from three different host plants. We demonstrated the evolutionary relationship between Magnaporthe species and the influence of host differentiation on pathogens. Phylogenetic analysis showed that evolution of pathogen directly corresponds with host divergence, suggesting that host-pathogen interaction has led to co-evolution. Furthermore, we identified an asymmetric selection pressure on Magnaporthe species. Oryza sativa-infecting isolates showed higher directional selection from host and subsequently tends to lower the genetic diversity in its genome. We concluded that, frequent gene loss or gain, new transposon acquisition and sequence divergence are host adaptability mechanisms for Magnaporthe species, and this coevolution processes is greatly driven by directional selection from host plants.

  10. On the present status of distribution and threats of high value medicinal plants in the higher altitude forests of the Indian eastern Himalaya

    Directory of Open Access Journals (Sweden)

    P. R. Gajurel

    2015-05-01

    Full Text Available The eastern Himalaya region is a rich repository of medicinal plants.  Excessive collection and unsustainable harvesting of medicinal plants from the wild are leading to a depletion of populations and threatening species in the region.  A study was conducted to explore the diversity, distribution and population status of selected medicinal plants species in the higher altitudes of Arunachal Pradesh, India through extensive field surveys and consultations with the local communities.  Out of about 75 medicinal plants recorded, 41 rare and commercially important medicinal plants were observed in the sub-temperate to alpine forest within an altitudinal range of 1500–4500 m.  Taxonomically these species fall under 25 families of higher plants, of which 31 are dicots, seven are monocots and three gymnosperms.  Many threatened species like Taxus wallichiana, Coptis teeta, Panax pseudoginseng, Panax sikkimensis were recorded in specific localities.  The western part of the state exhibits maximum species diversity.  Out of the various threats observed, improper harvesting, habitat loss and trade are found to be more destructive to the population.  Intensive efforts from both in situ and ex situ conservation practices are necessary for sustainable management and conservation of these species

  11. [Effects of islanding on plant species diversity in Thousand-island Lake region].

    Science.gov (United States)

    Lu, Jianbo; Dung, Lizhong; Xu, Gaofu

    2005-09-01

    In this paper, the typical area of fragmentation in Thousand-island Lake region was selected to study the effects of islanding on plant species diversity after reservoir built. 26 quadrates were installed on 18 small, medium and large islands to investigate the species and number of trees and shrubs, with inland as the control One-way variance analysis (ANOVA) showed that the species richness of trees was significantly different (F = 13.055, P = 0.000) among all kinds of islands, which was significantly higher on large islands than on small and medium ones, but not significantly different from that on inland. The species richness of shrubs was not significantly different among all kinds of islands and inland. Spearman correlation analysis showed that the species richness of trees was significantly positively correlated with island area, while the correlation between specie richness of shrubs and island area was not significant. Shannon-Wiener Index (H) analysis suggested that the diversity of both trees and shrubs on large islands was the highest, followed by on inland, but the diversity of shrubs was larger on small than on medium islands. The analysis of Simpson index and Pielou index showed that the species evenness of trees was the highest, but the dominance was the lowest on medium and large islands, while the species evenness of shrubs was the highest on medium and small islands, but the dominance was the lowest on small islands.

  12. Effects of long-term radiation exposure on the higher aquatic plants in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Shevtsova, N.; Gudkov, D. [Institute of Hydrobiology (Russian Federation)

    2014-07-01

    germinated seeds) and pinnacle deviations was registered in plants from the most radioactive contaminated water bodies. Also the decreasing of parasitic stability of one of aquatic plant communities' dominant species - the common reed is observed. The data of the mite Steneotarsonemus phragmitidis and the parasitic fungus Claviceps purpurea hitting of the common reed, correlated with radiation dose rate. It was determined the positive correlation between absorbed dose rate and chromosome aberration rate in roots of the twelve aquatic plants' species from sampling water bodies. The highest rate of chromosome aberrations (up to 17 %) were registered in plants with high level of morphological deviations in seeds germs, but not panicles. The data obtained from the complex analysis of natural aquatic plant communities from the radioactive contaminated water bodies testify about rather high level of genetic efficiency of low doses of long-term exposure. For higher aquatic plants from ChEZ there is observed a realization of radiobiological reactions on morphological and reproductive levels on the background of genetic instability induced by low doses. Document available in abstract form only. (authors)

  13. The comet assay in higher terrestrial plant model: Review and evolutionary trends.

    Science.gov (United States)

    Lanier, Caroline; Manier, Nicolas; Cuny, Damien; Deram, Annabelle

    2015-12-01

    The comet assay is a sensitive technique for the measurement of DNA damage in individual cells. Although it has been primarily applied to animal cells, its adaptation to higher plant tissues significantly extends the utility of plants for environmental genotoxicity research. The present review focuses on 101 key publications and discusses protocols and evolutionary trends specific to higher plants. General consensus validates the use of the percentage of DNA found in the tail, the alkaline version of the test and root study. The comet protocol has proved its effectiveness and its adaptability for cultivated plant models. Its transposition in wild plants thus appears as a logical evolution. However, certain aspects of the protocol can be improved, namely through the systematic use of positive controls and increasing the number of nuclei read. These optimizations will permit the increase in the performance of this test, namely when interpreting mechanistic and physiological phenomena. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Aluminum, a Friend or Foe of Higher Plants in Acid Soils

    Science.gov (United States)

    Bojórquez-Quintal, Emanuel; Escalante-Magaña, Camilo; Echevarría-Machado, Ileana; Martínez-Estévez, Manuel

    2017-01-01

    Aluminum (Al) is the most abundant metal in the earth’s crust, but its availability depends on soil pH. Despite this abundance, Al is not considered an essential element and so far no experimental evidence has been put forward for a biological role. In plants and other organisms, Al can have a beneficial or toxic effect, depending on factors such as, metal concentration, the chemical form of Al, growth conditions and plant species. Here we review recent advances in the study of Al in plants at physiological, biochemical and molecular levels, focusing mainly on the beneficial effect of Al in plants (stimulation of root growth, increased nutrient uptake, the increase in enzyme activity, and others). In addition, we discuss the possible mechanisms involved in improving the growth of plants cultivated in soils with acid pH, as well as mechanisms of tolerance to the toxic effect of Al. PMID:29075280

  15. Ecophysiological studies of Mediterranean plant species at the Castelporziano estate

    Science.gov (United States)

    Manes, Fausto; Seufert, Günther; Vitale, Marcello

    The aim of this work was to characterize the eco-physiological performance of the main plant species of the Castelporziano site by single leaf investigations. We measured the leaf gas exchange of Quercus ilex L., Pinus pinea L., Pistacia lentiscus L. and Asphodelus microcarpus L. for several days. Additionally, the xylem water potential of Quercus ilex, Pinus pinea and Pistacia lentiscus was recorded in order to obtain more physiological background information for the discussion of the trace gas emissions. This study indicates significantly different physiological responses to the different environmental conditions. In particular, summer conditions (high values of light, air temperature and low xylem water potentials) caused the depression of photosynthesis in Quercus ilex and Pinus pinea but did not affect photosynthesis of Pistacia lentiscus and Asphodelus microcarpus. This should be taken into account when discussing VOC emission rates and fluxes.

  16. Productivity is a poor predictor of plant species richness

    Science.gov (United States)

    Adler, Peter B.; Seabloom, Eric W.; Borer, Elizabeth T.; Hillebrand, Helmut; Hautier, Yann; Hector, Andy; Harpole, W. Stanley; O'Halloran, Lydia R.; Grace, James B.; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Brown, Cynthia S.; Buckley, Yvonne M.; Calabrese, Laura B.; Chu, Cheng-Jin; Cleland, Elsa E.; Collins, Scott L.; Cottingham, Kathryn L.; Crawley, Michael J.; Damschen, Ellen Ingman; Davies, Kendi F.; DeCrappeo, Nicole M.; Fay, Philip A.; Firn, Jennifer; Frater, Paul; Gasarch, Eve I.; Gruner, Daneil S.; Hagenah, Nicole; Lambers, Janneke Hille Ris; Humphries, Hope; Jin, Virginia L.; Kay, Adam D.; Kirkman, Kevin P.; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Lambrinos, John G.; Li, Wei; MacDougall, Andrew S.; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John W.; Mortensen, Brent; Orrock, John L.; Prober, Suzanne M.; Pyke, David A.; Risch, Anita C.; Schuetz, Martin; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren L.; Wang, Gang; Wragg, Peter D.; Wright, Justin P.; Yang, Louie H.

    2011-01-01

    For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters-2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity an

  17. Functional diversity supports the physiological tolerance hypothesis for plant species richness along climatic gradients

    Science.gov (United States)

    Spasojevic, Marko J.; Grace, James B.; Harrison, Susan; Damschen, Ellen Ingman

    2013-01-01

    1. The physiological tolerance hypothesis proposes that plant species richness is highest in warm and/or wet climates because a wider range of functional strategies can persist under such conditions. Functional diversity metrics, combined with statistical modeling, offer new ways to test whether diversity-environment relationships are consistent with this hypothesis. 2. In a classic study by R. H. Whittaker (1960), herb species richness declined from mesic (cool, moist, northerly) slopes to xeric (hot, dry, southerly) slopes. Building on this dataset, we measured four plant functional traits (plant height, specific leaf area, leaf water content and foliar C:N) and used them to calculate three functional diversity metrics (functional richness, evenness, and dispersion). We then used a structural equation model to ask if ‘functional diversity’ (modeled as the joint responses of richness, evenness, and dispersion) could explain the observed relationship of topographic climate gradients to species richness. We then repeated our model examining the functional diversity of each of the four traits individually. 3. Consistent with the physiological tolerance hypothesis, we found that functional diversity was higher in more favorable climatic conditions (mesic slopes), and that multivariate functional diversity mediated the relationship of the topographic climate gradient to plant species richness. We found similar patterns for models focusing on individual trait functional diversity of leaf water content and foliar C:N. 4. Synthesis. Our results provide trait-based support for the physiological tolerance hypothesis, suggesting that benign climates support more species because they allow for a wider range of functional strategies.

  18. Expression and occurrence of uracil-DNA glycosylase in higher plants.

    Science.gov (United States)

    Bones, Atle M

    1993-08-01

    Uracil-DNA glycosylase (UDG) is the first enzyme in the base excision repair pathway for removal of uracil in DNA. DNA repair capacity is likely to be a critical factor in mutagenesis and thereby in the capacity to prevent genetic damage and unwanted variation. We have studied expression of UDG in 9 higher plant species. The highest expression of UDG was measured in Solanum tuberosum. A comparison of 6 Solanum tuberosum cultivars showed that the specific activity ranged from 30 pmol mg1 protein min-1 in the cultivar Laila to 80 pmol mg-1 protein min-1 in the cultivar Ostara. Measurement of UDG in Begonia X cheimantha gave no indications of enzyme activity. The possible effects of no or low UDG activity is discussed. In vitro cultures of Solanum tuberosum and Thymus vulgaris were used to examine the effect of auxin and cytokinin on the UDG activity. Axillary shoots of Solanum tuberosum were cultured on medium including 20 variations in hormone concentration. Auxin (1-naphtaleneacetic acid) increased the expression of UDG. Plants cultured on medium supplemented with 3 mg 1-1 1-naphtaleneacetic acid showed a specific UDG activity which was approximately 3-fold higher than the activity in controls. The cytokinin benzyladenine reduced the specific UDG activity at concentrations in the range 0.25-10 mg 1-1 . In vitro cultured Saintpaulia ionantha was used to examine UDG activity during initiation, conditioning and multiplication cycles. In general, highest expression of UDG was measured in the conditioning cycle on hormone free medium. Measurement of UDG expression during single subculture periods, clearly showed that UDG expression may vary over one culture period. Expression of UDG was in general highest three weeks after transfer to fresh medium. Of different seedling organs from 0- to 15-day-old Brassica napus L., roots and hypocotyls showed the highest UDG activities. In cotyledons a very low and nearly constant specific activity was observed. In 12-day

  19. Seasonal variations in plant species effects on soil N and P dynamics.

    Science.gov (United States)

    Eviner, Valerie T; Chapin, F Stuart; Vaughn, Charles E

    2006-04-01

    It is well established that plant species influence ecosystem processes, but we have little ability to predict which vegetation changes will alter ecosystems, or how the effects of a given species might vary seasonally. We established monocultures of eight plant species in a California grassland in order to determine the plant traits that account for species impacts on nitrogen and phosphorus cycling. Plant species differed in their effects on net N mineralization and nitrification rates, and the patterns of species differences varied seasonally. Soil PO4- and microbial P were more strongly affected by slope position than by species. Although most studies focus on litter chemistry as the main determinant of plant species effects on nutrient cycling, this study showed that plant species affected biogeochemical cycling through many traits, including direct traits (litter chemistry and biomass, live-tissue chemistry and biomass) and indirect traits (plant modification of soil bioavailable C and soil microclimate). In fact, species significantly altered N and P cycling even without litter inputs. It became particularly critical to consider the effects of these multiple traits in order to account for seasonal changes in plant species effects on ecosystems. For example, species effects on potential rates of net N mineralization were most strongly influenced by soil bioavailable C in the fall and by litter chemistry in the winter and spring. Under field conditions, species effects on soil microclimate influenced rates of mineralization and nitrification, with species effects on soil temperature being critical in the fall and species effects on soil moisture being important in the dry spring. Overall, this study clearly demonstrated that in order to gain a mechanistic, predictive understanding of plant species effects on ecosystems, it is critical to look beyond plant litter chemistry and to incorporate the effects of multiple plant traits on ecosystems.

  20. Biomass of tree species as a response to planting density and interspecific competition

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    2014-04-01

    Full Text Available Planting trees is an important way to promote the recovery of degraded areas in the Caatinga region. Experiments (E1, E2, and E3 were conducted in a randomized blocks design, with three, three, and five replicates, respectively. The objectives were to evaluate biomass of the shoots of: a gliricidia (G and sabiá (S, as a response to planting density; b G, S, and neem (N in competition; c G, and S in agroforestry. E1 was conducted in split-plots, and planting densities (400, 600, 800, 1000, and 1200 plants ha-1 as subplots. E2 consisted of a factorial comprising the following plots: GGG, NGN, SGS, NNN, GNG, SNS, SSS, GSG, NSN (each letter represents a row of plants. E3 was conducted with G and S in agroforestry experiment. The trees were harvested after 54, 42, and 27 months old, in E1, E2 and E3, respectively. In E1, G presented higher green biomass of the stems and leaf at smaller densities than S, but lower green biomass of branches at most densities. The species did not differ for mean stem dry biomass and leaf dry biomass, but G showed higher branch dry biomass at most densities. Higher planting densities increased green and dry biomass of stems, branches, and leaves in S, but decreased those characteristics in G, with the exception of leaf dry mass, which was not influenced by density. In E2, the behavior of each species was identical in plots containing the same or different species. Griricidia showed the highest green biomass of stems and branches, and the highest values for geren biomass of the leaf were observed for gliricidia and neem. The highest stem, branch, and leaf dry biomass values were obtained for G, S, and N, respectively. In E3, G was superior for stem and leaf green biomass, and for stem and branch dry biomass. There were no differences between species for the other biomass values.

  1. Wild Plant Species with Extremely Small Populations Require Conservation and Reintroduction in China

    Science.gov (United States)

    Hai Ren; Qianmei Zhang; Hongfang Lu; Hongxiao Liu; Qinfeng Guo; Jun Wang; Shuguang Jian; Hai’ou Bao

    2012-01-01

    China is exceptionally rich in biodiversity, with more than 30000 vascular plant species that include many endemic genera, species of ancient origin, and cultivated plants (Yang et al. 2005). Because of rapid economic development, population growth, pollution, and continuing resource exploitation, China’s plant diversity faces severe threats. According to the Chinese...

  2. Two-Photon or Higher-Order Absorbing Optical Materials for Generation of Reactive Species

    Science.gov (United States)

    Cumpston, Brian (Inventor); Lipson, Matthew (Inventor); Marder, Seth R. (Inventor); Perry, Joseph W. (Inventor)

    2013-01-01

    Disclosed are highly efficient multiphoton absorbing compounds and methods of their use. The compounds generally include a bridge of pi-conjugated bonds connecting electron donating groups or electron accepting groups. The bridge may be substituted with a variety of substituents as well. Solubility, lipophilicity, absorption maxima and other characteristics of the compounds may be tailored by changing the electron donating groups or electron accepting groups, the substituents attached to or the length of the pi-conjugated bridge. Numerous photophysical and photochemical methods are enabled by converting these compounds to electronically excited states upon simultaneous absorption of at least two photons of radiation. The compounds have large two-photon or higher-order absorptivities such that upon absorption, one or more Lewis acidic species, Lewis basic species, radical species or ionic species are formed.

  3. Chemical composition and digestibility of some browse plant species collected from Algerian arid rangelands

    Energy Technology Data Exchange (ETDEWEB)

    Boufennara, S.; Lopez, S.; Boussebouna, H.; Bodas, R.; Bouazza, L.

    2012-11-01

    Many wild browse and bush species are undervalued mainly because of insufficient knowledge about their potential feeding value. The objective was to evaluate some nutritional attributes of various Algerian browse and shub species (Atriplex halimus, Artemisia campestris, Artemisia herba-alba, Astragalus gombiformis, Calobota saharae, Retama raetam, Stipagrostis pungens, Lygeum spartum and Stipa tenacissima). Chemical composition, phenols and tannins concentration, in vitro digestibility, in vitro gas production kinetics and in vitro bio-assay for assessment of tannins using buffered rumen fluid, and in situ disappearence of the edible parts of the plants (leaves, thin twigs and flowers) were determined. In general, protein content in dicotyledon species was always greater than in monocotyledon grasses, these showing higher neutral and acid detergent fibre and lower lignin contents than dicots. The tannin concentrations varied considerably between species, but in general the plants investigated in this study had low tannin contents (except for Artemisia spp. and S. tenacissima). Monocots showed lower in vitro and in situ digestibilities, fermentation rate, cumulative gas production and extent of degradation than dicot species. The plants were clustered by principal components analysis in two groups: poor-quality grasses and the most digestible dicot species. Chemical composition (neutral detergent fibre and protein) and digestibility were the main influential variables determining the ranking. In conclusion, A. halimus, A. campestris, A. herba-alba and A. gombiformis can be considered of greater nutritional value than the highly fibrous and low digestible grasses (S. pungens, L. spartum and S. tenacissima) that should be considered emergency roughages. (Author) 46 refs.

  4. Comparative analysis of miRNAs and their targets across four plant species

    Directory of Open Access Journals (Sweden)

    Lenz Dorina

    2011-11-01

    Full Text Available Abstract Background MicroRNA (miRNA mediated regulation of gene expression has been recognized as a major posttranscriptional regulatory mechanism also in plants. We performed a comparative analysis of miRNAs and their respective gene targets across four plant species: Arabidopsis thaliana (Ath, Medicago truncatula(Mtr, Brassica napus (Bna, and Chlamydomonas reinhardtii (Cre. Results miRNAs were obtained from mirBase with 218 miRNAs for Ath, 375 for Mtr, 46 for Bna, and 73 for Cre, annotated for each species respectively. miRNA targets were obtained from available database annotations, bioinformatic predictions using RNAhybrid as well as predicted from an analysis of mRNA degradation products (degradome sequencing aimed at identifying miRNA cleavage products. On average, and considering both experimental and bioinformatic predictions together, every miRNA was associated with about 46 unique gene transcripts with considerably variation across species. We observed a positive and linear correlation between the number miRNAs and the total number of transcripts across different plant species suggesting that the repertoire of miRNAs correlates with the size of the transcriptome of an organism. Conserved miRNA-target pairs were found to be associated with developmental processes and transcriptional regulation, while species-specific (in particular, Ath pairs are involved in signal transduction and response to stress processes. Conserved miRNAs have more targets and higher expression values than non-conserved miRNAs. We found evidence for a conservation of not only the sequence of miRNAs, but their expression levels as well. Conclusions Our results support the notion of a high birth and death rate of miRNAs and that miRNAs serve many species specific functions, while conserved miRNA are related mainly to developmental processes and transcriptional regulation with conservation operating at both the sequence and expression level.

  5. Species area relationships in mediterranean-climate plant communities

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    Keeley, Jon E.; Fotheringham, C.J.

    2003-01-01

    Aim To determine the best-fit model of species–area relationships for Mediterranean-type plant communities and evaluate how community structure affects these species–area models.Location Data were collected from California shrublands and woodlands and compared with literature reports for other Mediterranean-climate regions.Methods The number of species was recorded from 1, 100 and 1000 m2 nested plots. Best fit to the power model or exponential model was determined by comparing adjusted r2 values from the least squares regression, pattern of residuals, homoscedasticity across scales, and semi-log slopes at 1–100 m2 and 100–1000 m2. Dominance–diversity curves were tested for fit to the lognormal model, MacArthur's broken stick model, and the geometric and harmonic series.Results Early successional Western Australia and California shrublands represented the extremes and provide an interesting contrast as the exponential model was the best fit for the former, and the power model for the latter, despite similar total species richness. We hypothesize that structural differences in these communities account for the different species–area curves and are tied to patterns of dominance, equitability and life form distribution. Dominance–diversity relationships for Western Australian heathlands exhibited a close fit to MacArthur's broken stick model, indicating more equitable distribution of species. In contrast, Californian shrublands, both postfire and mature stands, were best fit by the geometric model indicating strong dominance and many minor subordinate species. These regions differ in life form distribution, with annuals being a major component of diversity in early successional Californian shrublands although they are largely lacking in mature stands. Both young and old Australian heathlands are dominated by perennials, and annuals are largely absent. Inherent in all of these ecosystems is cyclical disequilibrium caused by periodic fires. The

  6. Non-conjugated small molecule FRET for differentiating monomers from higher molecular weight amyloid beta species.

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    Chongzhao Ran

    2011-04-01

    Full Text Available Systematic differentiation of amyloid (Aβ species could be important for diagnosis of Alzheimer's disease (AD. In spite of significant progress, controversies remain regarding which species are the primary contributors to the AD pathology, and which species could be used as the best biomarkers for its diagnosis. These controversies are partially caused by the lack of reliable methods to differentiate the complicated subtypes of Aβ species. Particularly, differentiation of Aβ monomers from toxic higher molecular weight species (HrMW would be beneficial for drug screening, diagnosis, and molecular mechanism studies. However, fast and cheap methods for these specific aims are still lacking.We demonstrated the feasibility of a non-conjugated FRET (Förster resonance energy transfer technique that utilized amyloid beta (Aβ species as intrinsic platforms for the FRET pair assembly. Mixing two structurally similar curcumin derivatives that served as the small molecule FRET pair with Aβ40 aggregates resulted in a FRET signal, while no signal was detected when using Aβ40 monomer solution. Lastly, this FRET technique enabled us to quantify the concentrations of Aβ monomers and high molecular weight species in solution.We believe that this FRET technique could potentially be used as a tool for screening for inhibitors of Aβ aggregation. We also suggest that this concept could be generalized to other misfolded proteins/peptides implicated in various pathologies including amyloid in diabetes, prion in bovine spongiform encephalopathy, tau protein in AD, and α-synuclein in Parkinson disease.

  7. Differential responses of soil bacteria, fungi, archaea and protists to plant species richness and plant functional group identity

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    Dassen, Sigrid; Cortois, Roeland; Martens, Henk; Hollander, de Mattias; Kowalchuk, George A.; Putten, van der Wim H.; Deyn, De Gerlinde B.

    2017-01-01

    Plants are known to influence belowground microbial community structure along their roots, but the impacts of plant species richness and plant functional group (FG) identity on microbial communities in the bulk soil are still not well understood. Here, we used 454-pyrosequencing to analyse the soil

  8. Divergent composition but similar function of soil food webs of individual plants: plant species and community effects.

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    Bezemer, T M; Fountain, M T; Barea, J M; Christensen, S; Dekker, S C; Duyts, H; van Hal, R; Harvey, J A; Hedlund, K; Maraun, M; Mikola, J; Mladenov, A G; Robin, C; de Ruiter, P C; Scheu, S; Setälä, H; Smilauer, P; van der Putten, W H

    2010-10-01

    Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and providers of resources to the soil food web, are of vital importance for the composition, structure, and functioning of soil communities. However, whether natural soil food webs that are completely open to immigration and emigration differ underneath individual plants remains unknown. In a biodiversity restoration experiment we first compared the soil nematode communities of 228 individual plants belonging to eight herbaceous species. We included grass, leguminous, and non-leguminous species. Each individual plant grew intermingled with other species, but all plant species had a different nematode community. Moreover, nematode communities were more similar when plant individuals were growing in the same as compared to different plant communities, and these effects were most apparent for the groups of bacterivorous, carnivorous, and omnivorous nematodes. Subsequently, we analyzed the composition, structure, and functioning of the complete soil food webs of 58 individual plants, belonging to two of the plant species, Lotus corniculatus (Fabaceae) and Plantago lanceolata (Plantaginaceae). We isolated and identified more than 150 taxa/groups of soil organisms. The soil community composition and structure of the entire food webs were influenced both by the species identity of the plant individual and the surrounding plant community. Unexpectedly, plant identity had the strongest effects on decomposing soil organisms, widely believed to be generalist feeders. In contrast, quantitative food web modeling showed that the composition of the plant community influenced nitrogen mineralization under individual plants, but that plant species identity did not affect nitrogen or carbon

  9. Higher β-diversity observed for herbs over woody plants is driven by stronger habitat filtering in a tropical understory.

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    Murphy, Stephen J; Salpeter, Kara; Comita, Liza S

    2016-08-01

    Herbaceous plants are a key component of tropical forests. Previous work indicates that herbs contribute substantially to the species richness of tropical plant communities. However, the processes structuring tropical herb diversity, and how they contrast with woody communities, have been underexplored. Within the understory of a 50-ha forest dynamics plot in central Panama, we compared the diversity, distribution, and abundance of vascular herbaceous plants with woody seedlings (i.e., tree and lianas woody seedlings, indicating higher spatial variation in this stratum. We observed no correlation between local richness or compositional uniqueness of herbs and woody seedlings across sites, indicating that different processes control the spatial patterns of woody and herbaceous diversity and composition. Habitat associations were strongest for herbs, as indicated by greater compositional dissimilarity among habitat types. Likewise, environmental variables explained a larger proportion of the variation in species richness and composition for herbs than for woody seedlings (richness = 25%, 14%, 12%; composition = 25%, 9%, 6%, for herbs, trees, and lianas, respectively). These differences between strata did not appear to be due to differences in lifespan alone, based on data from adult trees. Our results point to contrasting assembly mechanisms for herbaceous and woody communities, with herbs showing stronger niche-derived structure. Future research on tropical herbaceous communities is likely to yield new insights into the many processes structuring diverse plant communities. © 2016 by the Ecological Society of America.

  10. Ecological studies of plants for the control of environmental pollution. IV. Growth of various plant species as influenced by soil applied cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Cha, J.W.; Kim, B.W.

    1975-03-01

    The relations of the growth response of plants, i.e. 4 species of crops, 12 species of roadside trees and 5 species of horticultural plants to cadmium (Cd) were studied in pot cultures. Growth in dry weight of corn, soybeans, barley, and wheat plants was decreased with an increase in Cd concentration. Damage to corn plants caused by Cd treatment was more or less recovered when it was grown in soil with calcium, but the other three crops did not recover. Although crop plants used here absorbed a small amount of Cd through the roots, the Cd content in the shoots was directly proportionate to the concentration of Cd added to the soil. Additions of calcium and sulfur to soil were sufficient to change the soil pH. The chlorosis on leaves caused by Cd treatment was observed in 2 species such as Euonymus japonica and Rhododendron yedoense out of 5 species of the horticultural plants, especially at 50 ppm of Cd. Euonymus japonica had symptoms of chlorosis and defoliation, and at higher concentrations the symptoms were more severe. At 200 ppm of Cd little damage was observed in Pinus koraiensis and Ginkgo biloba, but severe chlorosis was observed in Robinia pseudoacacia and Sabina chinensis, Buxus koreana, Abies holophylla and Platanus orientalis. Nevertheless, those plants that had serious damage at 200 ppm of Cd showed weakened symptoms by adding calcium to the soil. There were many Cd tolerant species out of the plants used in this experiment, such as Crassula falcata, Chrysanthemum morifolium, Hibiscus syriacus, Ligustrum ovalifolium, Liriodendron tulipeferia, and Lespedeza crytobotrys.

  11. Geographic distribution and host plants of Raoiella indica and associated mite species in northern Venezuela.

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    Vásquez, Carlos; de Moraes, Gilberto J

    2013-05-01

    The red palm mite (RPM), Raoiella indica Hirst (Acari: Tenuipalpidae), is an invasive pest in the New World, where it is currently considered a serious threat to coconut and banana crops. It was first reported from northern Venezuela in 2007. To determine its current distribution in this country, surveys were carried out from October 2008 to April 2010 on coconut (Cocos nucifera L.), banana (Musa spp.), ornamental plants and weeds in northern Venezuela. Higher population levels of RPM were registered on commercial coconut farms in Falcón and Sucre states but also on other plant species naturally growing along the coastal line in Anzoategui, Aragua, Carabobo, Monagas and Nueva Esparta states. Out of 34 botanical species evaluated, all RPM stages were observed only on eight arecaceous, one musaceous and one streliziaceous species, indicating that the pest developed and reproduced only on these plants. Mite specimens found on weeds were considered spurious events, as immature stages of the pest were never found on these. Amblyseius largoensis (Muma) (Acari: Phytoseiidae) was the most frequent predatory mite associated with RPM in all sampling sites. The results indicate that RPM has spread to extensive areas of northern Venezuela since its initial detection in Güiria, Sucre state. Considering the report of this pest mite in northern Brazil in the late 2009, additional samplings in southern Venezuela should be carried out, to evaluate the possible presence of RPM also in that region.

  12. Host plant use among closely related Anaea butterfly species (Lepidoptera, Nymphalidae, Charaxinae

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    QUEIROZ J. M.

    2002-01-01

    Full Text Available There is a great number of Charaxinae (Lepidoptera: Nymphalidae species in the tropics whose larvae feed on several plant families. However the genus Anaea is almost always associated with Croton species (Euphorbiaceae. This work describes patterns of host plant use by immature and adult abundance on different vertical strata of sympatric Anaea species in a forest of Southeastern Brazil. Quantitative samples of leaves were taken in April/1999 and May/2000 to collect eggs and larvae of four Anaea species on C.alchorneicarpus, C. floribundus and C. salutaris in a semideciduous forest. Sampled leaves were divided into three classes of plant phenological stage: saplings, shrubs and trees. The results showed that the butterfly species are segregating in host plant use on two scales: host plant species and plant phenological stages. C. alchorneicarpus was used by only one Anaea species, whereas C. floribundus was used by three species and C. salutaris by four Anaea species. There was one Anaea species concentrated on sapling, another on sapling/shrub and two others on shrub/tree leaves. Adults of Anaea were more frequent at canopy traps but there were no differences among species caught in traps at different vertical positions. This work supplements early studies on host plant use among Charaxinae species and it describes how a guild of closely related butterfly species may be organized in a complex tropical habitat.

  13. Recovery of woody plant species richness in secondary forests in China: a meta-analysis.

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    Liu, Xiaofei; Liu, Xuehua; Skidmore, Andrew; Garcia, Claude

    2017-09-06

    There is considerable uncertainty concerning changes in plant diversity of Chinese secondary forests, particularly with respect to diversity recovery following anthropogenic disturbance. Here we present a meta-analysis of the recovery of woody plant species richness in secondary forests in China, with nearby primary forests as a reference. A total of 125 pairs of secondary-primary forest data reported in 55 publications were identified across China. We analyzed the data by region and logging history to examine their influences on secondary forest recovery. Our results indicated that the woody plant richness of secondary forests in China was close to fully recovered when compared to the primary forest, with the recovery ratio being 85-103%. Higher recovery ratios were observed in central, northeast and southwest China, with lower recovery ratios seen in east, south and northwest China, and the recovery in central China significantly reached the primary forests (reference) level. Concerning logging histories, the recovery ratios showed two peak values, with one at 21-40 years after clear cutting and the other at 61-80 years. We reveal the fundamental recovery patterns of woody plant species richness in secondary forests in China. These patterns provide information for the sustainable management of secondary forest resources.

  14. Plant trait-species abundance relationships vary with environmental properties in subtropical forests in eastern china.

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    En-Rong Yan

    Full Text Available Understanding how plant trait-species abundance relationships change with a range of single and multivariate environmental properties is crucial for explaining species abundance and rarity. In this study, the abundance of 94 woody plant species was examined and related to 15 plant leaf and wood traits at both local and landscape scales involving 31 plots in subtropical forests in eastern China. Further, plant trait-species abundance relationships were related to a range of single and multivariate (PCA axes environmental properties such as air humidity, soil moisture content, soil temperature, soil pH, and soil organic matter, nitrogen (N and phosphorus (P contents. At the landscape scale, plant maximum height, and twig and stem wood densities were positively correlated, whereas mean leaf area (MLA, leaf N concentration (LN, and total leaf area per twig size (TLA were negatively correlated with species abundance. At the plot scale, plant maximum height, leaf and twig dry matter contents, twig and stem wood densities were positively correlated, but MLA, specific leaf area, LN, leaf P concentration and TLA were negatively correlated with species abundance. Plant trait-species abundance relationships shifted over the range of seven single environmental properties and along multivariate environmental axes in a similar way. In conclusion, strong relationships between plant traits and species abundance existed among and within communities. Significant shifts in plant trait-species abundance relationships in a range of environmental properties suggest strong environmental filtering processes that influence species abundance and rarity in the studied subtropical forests.

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

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    Mmoto L. Masubelele

    2009-01-01

    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.

  16. Phytotoxic Activity of Ocimum tenuiflorum Extracts on Germination and Seedling Growth of Different Plant Species

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    A. K. M. Mominul Islam

    2014-01-01

    Full Text Available Phytotoxic activity of Ocimum tenuiflorum (Lamiaceae plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum, lettuce (Lactuca sativa, alfalfa (Medicago sativa, Italian ryegrass (Lolium multiflorum, barnyard grass (Echinochloa crus-galli, and timothy (Phleum pratense at four different concentrations. The plant extracts at concentrations greater than 30 mg dry weight equivalent extract mL−1 reduced significantly the total germination percent (GP, germination index (GI, germination energy (GE, speed of emergence (SE, seedling vigour index (SVI, and coefficient of the rate of germination (CRG of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T50 and mean germination time (MGT were increased at the same or higher than this concentration. The increasing trend of T50 and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species by O. tenuiflorum plant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10 mg dry weight equivalent extract mL−1. The I50 values for shoot and root growth were ranged from 26 to 104 mg dry weight equivalent extract mL−1. Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest that O. tenuiflorum plant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds.

  17. 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.

  18. Plant species richness leaves a legacy of enhanced root litter-induced decomposition in soil

    NARCIS (Netherlands)

    Cong, Wen-Feng; van Ruijven, Jasper; van der Werf, Wopke; De Deyn, Gerlinde B.; Mommer, Liesje; Berendse, Frank; Hoffland, Ellis

    2015-01-01

    Increasing plant species richness generally enhances plant biomass production, which may enhance accumulation of carbon (C) in soil. However, the net change in soil C also depends on the effect of plant diversity on C loss through decomposition of organic matter. Plant diversity can affect organic

  19. Bird species richness is associated with phylogenetic relatedness, plant species richness, and altitudinal range in Inner Mongolia.

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    Liang, Chenxia; Feng, Gang; Si, Xingfeng; Mao, Lingfeng; Yang, Guisheng; Svenning, Jens-Christian; Yang, Jie

    2018-01-01

    Bird species richness is mediated by local, regional, and historical factors, for example, competition, environmental heterogeneity, contemporary, and historical climate. Here, we related bird species richness with phylogenetic relatedness of bird assemblages, plant species richness, topography, contemporary climate, and glacial-interglacial climate change to investigate the relative importance of these factors. This study was conducted in Inner Mongolia, an arid and semiarid region with diverse vegetation types and strong species richness gradients. The following associated variables were included as follows: phylogenetic relatedness of bird assemblages (Net Relatedness Index, NRI), plant species richness, altitudinal range, contemporary climate (mean annual temperature and precipitation, MAT and MAP), and contemporary-Last Glacial Maximum (LGM) change in climate (change in MAT and change in MAP). Ordinary least squares linear, simultaneous autoregressive linear, and Random Forest models were used to assess the associations between these variables and bird species richness across this region. We found that bird species richness was correlated negatively with NRI and positively with plant species richness and altitudinal range, with no significant correlations with contemporary climate and glacial-interglacial climate change. The six best combinations of variables ranked by Random Forest models consistently included NRI, plant species richness, and contemporary-LGM change in MAT. Our results suggest important roles of local ecological factors in shaping the distribution of bird species richness across this semiarid region. Our findings highlight the potential importance of these local ecological factors, for example, environmental heterogeneity, habitat filtering, and biotic interactions, in biodiversity maintenance.

  20. Microbial abundance in rhizosphere of medicinal and aromatic plant species in conventional and organic growing systems

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    Adamović Dušan

    2015-01-01

    Full Text Available This study was aimed at comparing the abundance of microorganisms in the rhizosphere of four different medicinal and aromatic plant species (basil, mint, dill and marigold grown under both conventional and organic management on the chernozem soil at the experimental field of Bački Petrovac (Institute of Field and Vegetable Crops, Novi Sad, Serbia. Two sampling terms (June 1 and July 18, 2012 were performed to collect samples for microbiological analyses. The microbial abundance was higher in organic than in conventional system while at the same time significant differences were obtained only with dill rhizosphere. The differences in number of microorganisms belonging to different groups relied upon both plant species and sampling term. Thus, in mint, the recorded number of azotobacters and fungi was significantly higher whereas the number of ammonifiers was significantly lower. The present results indicate that organic growing system affected the abundance of microorganisms in rhizosphere of species investigated, especially in the second term of sampling.

  1. Biochemical and Physiological Characteristics of Photosynthesis in Plants of Two Calathea Species.

    Science.gov (United States)

    Nguyen, Hoang Chinh; Lin, Kuan-Hung; Hsiung, Tung-Chuan; Huang, Meng-Yuan; Yang, Chi-Ming; Weng, Jen-Hsien; Hsu, Ming-Huang; Chen, Po-Yen; Chang, Kai-Chieh

    2018-03-01

    Plants of the genus Calathea possess many leaf colors, and they are economically important because they are widely used as ornamentals for interior landscaping. Physiological performances and photosynthetic capacities of C. insignis and C. makoyana were investigated. The photosynthetic efficiencies of C. insignis and C. makoyana were significantly increased when the photosynthetic photon flux density (PPFD) increased from 0 to 600 μmol photons·m -2 ·s -1 and became saturated with a further increase in the PPFD. The two Calathea species had lower values of both the light saturation point and maximal photosynthetic rate, which indicated that they are shade plants. No significant differences in predawn Fv/Fm values (close to 0.8) were observed between dark-green (DG) and light-green (LG) leaf sectors in all tested leaves. However, the effective quantum yield of photosystem II largely decreased as the PPFD increased. An increase in the apparent photosynthetic electron transport rate was observed in both species to a maximum at 600 μmol·m -2 ·s -1 PPFD, following by a decrease to 1500 μmol·m -2 ·s -1 PPFD. Compared to LG leaf extracts, DG leaf extracts contained higher levels of chlorophyll (Chl) a , Chl b , Chls a + b , carotenoids (Cars), anthocyanins (Ants), flavonoids (Flas), and polyphenols (PPs) in all plants, except for the Ant, Fla and PP contents of C. insignis plants. Calathea insignis also contained significantly higher levels of total protein than did C. makoyana . The adjusted normalized difference vegetation index (NDVI), photochemical reflectance index (PRI), red-green, and flavonol index (FlavI) were significantly correlated to leaf Chls a + b , Cars, Ants, and Flas in C. makoyana , respectively, and can be used as indicators to characterize the physiology of these plants.

  2. A strategy for characterization of persistent heteroduplex DNA in higher plants.

    Science.gov (United States)

    Dong, Chun-Bo; Mao, Jian-Feng; Suo, Yu-Jing; Shi, Le; Wang, Jun; Zhang, Ping-Dong; Kang, Xiang-Yang

    2014-10-01

    Heteroduplex DNA (hDNA) generated during homologous recombination (HR) is an important component that shapes genetic diversity in sexually reproducing organisms. However, studies of this process in higher plants are limited. This is because hDNAs are difficult to capture in higher plants as their reproductive developmental model only produces normal gametes and does not preserve the mitotic products of the post-meiotic segregation (PMS) process which is crucial for studying hDNAs. In this study, using the model system for tree and woody perennial plant biology (Populus), we propose a strategy for characterizing hDNAs in higher plants. We captured hDNAs by constructing triploid hybrids originating from a cross between unreduced 2n eggs (containing hDNA information as a result of inhibition chromosome segregation at the PMS stage) with normal male gametes. These triploid hybrids allowed us to detect the frequency and location of persistent hDNAs resulting from HR at the molecular level. We found that the frequency of persistent hDNAs, which ranged from 5.3 to 76.6%, was related to locations of the simple sequence repeat markers at the chromosomes, such as the locus-centromere distance, the surrounding DNA sequence and epigenetic information, and the richness of protein-coding transcripts at these loci. In summary, this study provides a method for characterizing persistent hDNAs in higher plants. When high-throughput sequencing techniques can be incorporated, genome-wide persistent hDNA assays for higher plants can be easily carried out using the strategy presented in this study. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  3. Impact of Cropping Systems, Soil Inoculum, and Plant Species Identity on Soil Bacterial Community Structure.

    Science.gov (United States)

    Ishaq, Suzanne L; Johnson, Stephen P; Miller, Zach J; Lehnhoff, Erik A; Olivo, Sarah; Yeoman, Carl J; Menalled, Fabian D

    2017-02-01

    Farming practices affect the soil microbial community, which in turn impacts crop growth and crop-weed interactions. This study assessed the modification of soil bacterial community structure by organic or conventional cropping systems, weed species identity [Amaranthus retroflexus L. (redroot pigweed) or Avena fatua L. (wild oat)], and living or sterilized inoculum. Soil from eight paired USDA-certified organic and conventional farms in north-central Montana was used as living or autoclave-sterilized inoculant into steam-pasteurized potting soil, planted with Am. retroflexus or Av. fatua and grown for two consecutive 8-week periods to condition soil nutrients and biota. Subsequently, the V3-V4 regions of the microbial 16S rRNA gene were sequenced by Illumina MiSeq. Treatments clustered significantly, with living or sterilized inoculum being the strongest delineating factor, followed by organic or conventional cropping system, then individual farm. Living inoculum-treated soil had greater species richness and was more diverse than sterile inoculum-treated soil (observed OTUs, Chao, inverse Simpson, Shannon, P Organically farmed inoculum-treated soil had greater species richness, more diversity (observed OTUs, Chao, Shannon, P conventionally farmed inoculum-treated soil. Cyanobacteria were higher in pots growing Am. retroflexus, regardless of inoculum type, for three of the four organic farms. Results highlight the potential of cropping systems and species identity to modify soil bacterial communities, subsequently modifying plant growth and crop-weed competition.

  4. Seed Dispersal and Germination Traits of 70 Plant Species Inhabiting the Gurbantunggut Desert in Northwest China

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    Huiliang Liu

    2014-01-01

    Full Text Available Seed dispersal and germination were examined for 70 species from the cold Gurbantunggut Desert in northwest China. Mean and range (3 orders of magnitude of seed mass were smaller and narrower than those in other floras (5–8 orders of magnitude, which implies that selection favors relatively smaller seeds in this desert. We identified five dispersal syndromes (anemochory, zoochory, autochory, barochory, and ombrohydrochory, and anemochorous species were most abundant. Seed mass (F=3.50, P=0.01, seed size (F=8.31, P<0.01, and seed shape (F=2.62, P=0.04 differed significantly among the five dispersal syndromes and barochorous species were significantly smaller and rounder than the others. There were no significant correlations between seed mass (seed weight (P=0.15, seed size (P=0.38, or seed shape (variance (P=0.95 and germination percentage. However, germination percentages differed significantly among the dispersal syndromes (F=3.64, P=0.01 and seeds of ombrohydrochorous species had higher germination percentages than those of the other species. In the Gurbantunggut Desert, the percentage of species with seed dormancy was about 80%. In general, our studies suggest that adaptive strategies in seed dispersal and germination of plants in this area are closely related to the environment in which they live and that they are influenced by natural selection forces.

  5. Increased plant carbon translocation linked to overyielding in grassland species mixtures.

    Directory of Open Access Journals (Sweden)

    Gerlinde B De Deyn

    Full Text Available Plant species richness and productivity often show a positive relationship, but the underlying mechanisms are not fully understood, especially at the plant species level. We examined how growing plants in species mixture influences intraspecific rates of short-term carbon (C- translocation, and determined whether such short-term responses are reflected in biomass yields. We grew monocultures and mixtures of six common C3 grassland plant species in outdoor mesocosms, applied a (13C-CO(2 pulse in situ to trace assimilated C through plants, into the soil, and back to the atmosphere, and quantified species-specific biomass. Pulse derived (13C enrichment was highest in the legumes Lotus corniculatus and Trifolium repens, and relocation (i.e. transport from the leaves to other plant parts of the recently assimilated (13C was most rapid in T. repens grown in 6-species mixtures. The grass Anthoxanthum odoratum also showed high levels of (13C enrichment in 6-species mixtures, while (13C enrichment was low in Lolium perenne, Plantago lanceolata and Achillea millefolium. Rates of C loss through respiration were highest in monocultures of T. repens and relatively low in species mixtures, while the proportion of (13C in the respired CO(2 was similar in monocultures and mixtures. The grass A. odoratum and legume T. repens were most promoted in 6-species mixtures, and together with L. corniculatus, caused the net biomass increase in 6-species mixtures. These plant species also had highest rates of (13C-label translocation, and for A. odoratum and T. repens this effect was greatest in plant individuals grown in species mixtures. Our study reveals that short-term plant C translocation can be accelerated in plant individuals of legume and C3 grass species when grown in mixtures, and that this is strongly positively related to overyielding. These results demonstrate a mechanistic coupling between changes in intraspecific plant carbon physiology and increased

  6. Identification and Management of Multiple Threats to Rare and Endangered Plant Species

    Science.gov (United States)

    2013-07-30

    Benefits: Biodiversity conservation projects should critically consider effects of multiple stressors; however, our results emphasize the...increased invasion of nonnative plant species, and shifts in soil invertebrate and microbial communities (Bohlen et. al., 2004b; Hale et. al., 2005a...native plant invasions Invasion of non-native plants is considered a major threat to native biodiversity ; non-native plants can displace native species

  7. Diverse belowground resource strategies underlie plant species coexistence and spatial distribution in three grasslands along a precipitation gradient.

    Science.gov (United States)

    Li, Hongbo; Liu, Bitao; McCormack, M Luke; Ma, Zeqing; Guo, Dali

    2017-12-01

    Functional traits and their variation mediate plant species coexistence and spatial distribution. Yet, how patterns of variation in belowground traits influence resource acquisition across species and plant communities remains obscure. To characterize diverse belowground strategies in relation to species coexistence and abundance, we assessed four key belowground traits - root diameter, root branching intensity, first-order root length and mycorrhizal colonization - in 27 coexisting species from three grassland communities along a precipitation gradient. Species with thinner roots had higher root branching intensity, but shorter first-order root length and consistently low mycorrhizal colonization, whereas species with thicker roots enhanced their capacity for resource acquisition by producing longer first-order roots and maintaining high mycorrhizal colonization. Plant species observed across multiple sites consistently decreased root branching and/or mycorrhizal colonization, but increased lateral root length with decreasing precipitation. Additionally, the degree of intraspecific trait variation was positively correlated with species abundance across the gradient, indicating that high intraspecific trait variation belowground may facilitate greater fitness and chances of survival across multiple habitats. These results suggest that a small set of critical belowground traits can effectively define diverse resource acquisition strategies in different environments and may forecast species survival and range shifts under climate change. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  8. Loss of selenium in drying and storage of agronomic plant species

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel

    1970-01-01

    In two experiments with Se75, loss of selenium from agricultural species was noted during both drying and storage. The loss of selenium during drying was to some extent overshadowed by the influence of self-absorption caused by the water in the fresh material. The results showed that even plant...... material of non-indicator plantslose volatile selenium at drying temperatures of 60°C or higher, and in some cases even at temperatures below 60°C. The results also showed that storage as briquettes gives the lowest storage loss of selenium....

  9. Effects of antimony and arsenic on antioxidant enzyme activities of two steppic plant species in an old antimony mining area.

    Science.gov (United States)

    Benhamdi, Asma; Bentellis, Alima; Rached, Oualida; Du Laing, Gijs; Mechakra, Aicha

    2014-04-01

    The present work was undertaken to determine strategies and antioxidant enzyme activities involved in the adaptation of two wild steppic plants (Hedysarum pallidum Desf. and Lygeum spartum L.) to the toxic environment of the abandoned antimony mining area of Djebel Hamimat (Algeria). For this purpose, soils and plants were collected in different zones coinciding with a Sb and As concentrations gradient in the soil. Antimony (Sb) and arsenic (As) were analyzed by ICP-OES in the soils and the aboveground parts and roots of the plants. Malondialdehyde (MDA) and antioxidant enzyme activities were measured by spectrometry. Results show levels of Sb and As exceptionally high in most soil and plant samples. The two species accumulate differently Sb and As in their above and belowground parts. MDA levels, in the two parts of both species, increase significantly with increasing soil Sb and As concentrations, but they are significantly higher in H. pallidum than in L. spartum. The activities of antioxidant enzymes differ significantly according to the soil metalloid concentrations, the plant species considered and the plant part. Apart from superoxide dismutase (SOD) whose activity is, overall, higher in H. pallidum than in L. spartum, the activities of all the other enzymes studied (glutathione S-transferase (GST), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX)) are generally higher in L. spartum than in H. pallidum. For both species, APX and GST are overall more active in the upper parts than in the roots, while it is the reverse for SOD and CAT. POD is more active in the upper parts than in the roots of L. spartum and the reverse applies to H. pallidum. It appears that the two studied plant species use different tolerance strategies to protect themselves against elevated As and Sb concentrations.

  10. 78 FR 40669 - Endangered and Threatened Wildlife and Plants; Endangered Species Status for Cape Sable...

    Science.gov (United States)

    2013-07-08

    ... and Plants; Endangered Species Status for Cape Sable Thoroughwort, Florida Semaphore Cactus, and... thoroughwort), Consolea corallicola (Florida semaphore cactus), and Harrisia aboriginum (aboriginal prickly...

  11. Effect of surface charge on the uptake and distribution of gold nanoparticles in four plant species.

    Science.gov (United States)

    Zhu, Zheng-Jiang; Wang, Huanhua; Yan, Bo; Zheng, Hao; Jiang, Ying; Miranda, Oscar R; Rotello, Vincent M; Xing, Baoshan; Vachet, Richard W

    2012-11-20

    Small (6-10 nm) functionalized gold nanoparticles (AuNPs) featuring different, well-defined surface charges were used to probe the uptake and distribution of nanomaterials in terrestrial plants, including rice, radish, pumpkin, and perennial ryegrass. Exposure of the AuNPs to plant seedlings under hydroponic conditions for a 5-day period was investigated. Results from these studies indicate that AuNP uptake and distribution depend on both nanoparticle surface charge and plant species. The experiments show that positively charged AuNPs are most readily taken up by plant roots, while negatively charged AuNPs are most efficiently translocated into plant shoots (including stems and leaves) from the roots. Radish and ryegrass roots generally accumulated higher amounts of the AuNPs (14-900 ng/mg) than rice and pumpkin roots (7-59 ng/mg). Each of the AuNPs used in this study were found to accumulate to statistically significant extents in rice shoots (1.1-2.9 ng/mg), while none of the AuNPs accumulated in the shoots of radishes and pumpkins.

  12. Higher photosynthesis, nutrient- and energy-use efficiencies contribute to invasiveness of exotic plants in a nutrient poor habitat in northeast China.

    Science.gov (United States)

    Liu, Ming-Chao; Kong, De-Liang; Lu, Xiu-Rong; Huang, Kai; Wang, Shuo; Wang, Wei-Bin; Qu, Bo; Feng, Yu-Long

    2017-08-01

    The roles of photosynthesis-related traits in invasiveness of introduced plant species are still not well elucidated, especially in nutrient-poor habitats. In addition, little effort has been made to determine the physiological causes and consequences of the difference in these traits between invasive and native plants. To address these problems, we compared the differences in 16 leaf functional traits related to light-saturated photosynthetic rate (P max ) between 22 invasive and native plants in a nutrient-poor habitat in northeast China. The invasive plants had significantly higher P max , photosynthetic nitrogen- (PNUE), phosphorus- (PPUE), potassium- (PKUE) and energy-use efficiencies (PEUE) than the co-occurring natives, while leaf nutrient concentrations, construction cost (CC) and specific leaf area were not significantly different between the invasive and native plants. The higher PNUE contributed to higher P max for the invasive plants, which in turn contributed to higher PPUE, PKUE and PEUE. CC changed independently with other traits such as P max , PNUE, PPUE, PKUE and PEUE, showing two trait dimensions, which may facilitate acclimation to multifarious niche dimensions. Our results indicate that the invasive plants have a superior resource-use strategy, i.e. higher photosynthesis under similar resource investments, contributing to invasion success in the barren habitat. © 2017 Scandinavian Plant Physiology Society.

  13. Reactive Oxygen Species Generation-Scavenging and Signaling during Plant-Arbuscular Mycorrhizal and Piriformospora indica Interaction under Stress Condition.

    Science.gov (United States)

    Nath, Manoj; Bhatt, Deepesh; Prasad, Ram; Gill, Sarvajeet S; Anjum, Naser A; Tuteja, Narendra

    2016-01-01

    A defined balance between the generation and scavenging of reactive oxygen species (ROS) is essential to utilize ROS as an adaptive defense response of plants under biotic and abiotic stress conditions. Moreover, ROS are not only a major determinant of stress response but also act as signaling molecule that regulates various cellular processes including plant-microbe interaction. In particular, rhizosphere constitutes the biologically dynamic zone for plant-microbe interactions which forms a mutual link leading to reciprocal signaling in both the partners. Among plant-microbe interactions, symbiotic associations of arbuscular mycorrhizal fungi (AMF) and arbuscular mycorrhizal-like fungus especially Piriformospora indica with plants are well known to improve plant growth by alleviating the stress-impacts and consequently enhance the plant fitness. AMF and P. indica colonization mainly enhances ROS-metabolism, maintains ROS-homeostasis, and thereby averts higher ROS-level accrued inhibition in plant cellular processes and plant growth and survival under stressful environments. This article summarizes the major outcomes of the recent reports on the ROS-generation, scavenging and signaling in biotic-abiotic stressed plants with AMF and P. indica colonization. Overall, a detailed exploration of ROS-signature kinetics during plant-AMF/P. indica interaction can help in designing innovative strategies for improving plant health and productivity under stress conditions.

  14. 75 FR 18959 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for 48 Species...

    Science.gov (United States)

    2010-04-13

    ... species under consideration within the same ecosystem. For example, the threat of avian malaria is unique..., p. 45) or pasture. Intentional and inadvertent introduction of alien plant and animal species has...

  15. Detecting fragmentation extinction thresholds for forest understory plant species in peninsular Spain.

    Directory of Open Access Journals (Sweden)

    Marta Rueda

    Full Text Available Ecological theory predicts that fragmentation aggravates the effects of habitat loss, yet empirical results show mixed evidences, which fail to support the theory instead reinforcing the primary importance of habitat loss. Fragmentation hypotheses have received much attention due to their potential implications for biodiversity conservation, however, animal studies have traditionally been their main focus. Here we assess variation in species sensitivity to forest amount and fragmentation and evaluate if fragmentation is related to extinction thresholds in forest understory herbs and ferns. Our expectation was that forest herbs would be more sensitive to fragmentation than ferns due to their lower dispersal capabilities. Using forest cover percentage and the proportion of this percentage occurring in the largest patch within UTM cells of 10-km resolution covering Peninsular Spain, we partitioned the effects of forest amount versus fragmentation and applied logistic regression to model occurrences of 16 species. For nine models showing robustness according to a set of quality criteria we subsequently defined two empirical fragmentation scenarios, minimum and maximum, and quantified species' sensitivity to forest contraction with no fragmentation, and to fragmentation under constant forest cover. We finally assessed how the extinction threshold of each species (the habitat amount below which it cannot persist varies under no and maximum fragmentation. Consistent with their preference for forest habitats probability occurrences of all species decreased as forest cover contracted. On average, herbs did not show significant sensitivity to fragmentation whereas ferns were favored. In line with theory, fragmentation yielded higher extinction thresholds for two species. For the remaining species, fragmentation had either positive or non-significant effects. We interpret these differences as reflecting species-specific traits and conclude that although

  16. Detecting fragmentation extinction thresholds for forest understory plant species in peninsular Spain.

    Science.gov (United States)

    Rueda, Marta; Moreno Saiz, Juan Carlos; Morales-Castilla, Ignacio; Albuquerque, Fabio S; Ferrero, Mila; Rodríguez, Miguel Á

    2015-01-01

    Ecological theory predicts that fragmentation aggravates the effects of habitat loss, yet empirical results show mixed evidences, which fail to support the theory instead reinforcing the primary importance of habitat loss. Fragmentation hypotheses have received much attention due to their potential implications for biodiversity conservation, however, animal studies have traditionally been their main focus. Here we assess variation in species sensitivity to forest amount and fragmentation and evaluate if fragmentation is related to extinction thresholds in forest understory herbs and ferns. Our expectation was that forest herbs would be more sensitive to fragmentation than ferns due to their lower dispersal capabilities. Using forest cover percentage and the proportion of this percentage occurring in the largest patch within UTM cells of 10-km resolution covering Peninsular Spain, we partitioned the effects of forest amount versus fragmentation and applied logistic regression to model occurrences of 16 species. For nine models showing robustness according to a set of quality criteria we subsequently defined two empirical fragmentation scenarios, minimum and maximum, and quantified species' sensitivity to forest contraction with no fragmentation, and to fragmentation under constant forest cover. We finally assessed how the extinction threshold of each species (the habitat amount below which it cannot persist) varies under no and maximum fragmentation. Consistent with their preference for forest habitats probability occurrences of all species decreased as forest cover contracted. On average, herbs did not show significant sensitivity to fragmentation whereas ferns were favored. In line with theory, fragmentation yielded higher extinction thresholds for two species. For the remaining species, fragmentation had either positive or non-significant effects. We interpret these differences as reflecting species-specific traits and conclude that although forest amount is of

  17. Reactive oxygen species mediate growth and death in submerged plants

    Directory of Open Access Journals (Sweden)

    Bianka eSteffens

    2013-06-01

    Full Text Available Aquatic and semi-aquatic plants are well adapted to survive partial or complete submergence which is commonly accompanied by oxygen deprivation. The gaseous hormone ethylene controls a number of adaptive responses to submergence including adventitious root growth and aerenchyma formation. Reactive oxygen species (ROS act as signaling intermediates in ethylene-controlled submergence adaptation and possibly also independent of ethylene. ROS levels are controlled by synthesis, enzymatic metabolism and nonenzymatic scavenging. While the actors are by and large known, we still have to learn about altered ROS at the subcellular level and how they are brought about, and the signaling cascades that trigger a specific response. This review briefly summarizes our knowledge on the contribution of ROS to submergence adaptation and describes spectrophotometrical, histochemical and live cell imaging detection methods that have been used to study changes in ROS abundance. Electron paramagnetic resonance (EPR spectroscopy is introduced as a method that allows identification and quantification of specific ROS in cell compartments. The use of advanced technologies such as EPR spectroscopy will be necessary to untangle the intricate and partially interwoven signaling networks of ethylene and ROS.

  18. Climate change may threaten habitat suitability of threatened plant species within Chinese nature reserves

    Science.gov (United States)

    Wan, Jizhong

    2016-01-01

    Climate change has the potential to alter the distributions of threatened plant species, and may therefore diminish the capacity of nature reserves to protect threatened plant species. Chinese nature reserves contain a rich diversity of plant species that are at risk of becoming more threatened by climate change. Hence, it is urgent to identify the extent to which future climate change may compromise the suitability of threatened plant species habitats within Chinese nature reserves. Here, we modelled the climate suitability of 82 threatened plant species within 168 nature reserves across climate change scenarios. We used Maxent modelling based on species occurrence localities and evaluated climate change impacts using the magnitude of change in climate suitability and the degree of overlap between current and future climatically suitable habitats. There was a significant relationship between overlap with current and future climate suitability of all threatened plant species habitats and the magnitude of changes in climate suitability. Our projections estimate that the climate suitability of more than 60 threatened plant species will decrease and that climate change threatens the habitat suitability of plant species in more than 130 nature reserves under the low, medium, and high greenhouse gas concentration scenarios by both 2050s and 2080s. Furthermore, future climate change may substantially threaten tree plant species through changes in annual mean temperature. These results indicate that climate change may threaten plant species that occur within Chinese nature reserves. Therefore, we suggest that climate change projections should be integrated into the conservation and management of threatened plant species within nature reserves. PMID:27326373

  19. Higher-order neural processing tunes motion neurons to visual ecology in three species of hawkmoths.

    Science.gov (United States)

    Stöckl, A L; O'Carroll, D; Warrant, E J

    2017-06-28

    To sample information optimally, sensory systems must adapt to the ecological demands of each animal species. These adaptations can occur peripherally, in the anatomical structures of sensory organs and their receptors; and centrally, as higher-order neural processing in the brain. While a rich body of investigations has focused on peripheral adaptations, our understanding is sparse when it comes to central mechanisms. We quantified how peripheral adaptations in the eyes, and central adaptations in the wide-field motion vision system, set the trade-off between resolution and sensitivity in three species of hawkmoths active at very different light levels: nocturnal Deilephila elpenor, crepuscular Manduca sexta, and diurnal Macroglossum stellatarum. Using optical measurements and physiological recordings from the photoreceptors and wide-field motion neurons in the lobula complex, we demonstrate that all three species use spatial and temporal summation to improve visual performance in dim light. The diurnal Macroglossum relies least on summation, but can only see at brighter intensities. Manduca, with large sensitive eyes, relies less on neural summation than the smaller eyed Deilephila, but both species attain similar visual performance at nocturnal light levels. Our results reveal how the visual systems of these three hawkmoth species are intimately matched to their visual ecologies. © 2017 The Author(s).

  20. Iodine uptake by spinach (Spinacia oleracea L.) plants grown in solution culture: effects of iodine species and solution concentrations.

    Science.gov (United States)

    Zhu, Y-G; Huang, Y-Z; Hu, Y; Liu, Y-X

    2003-04-01

    A hydroponic experiment was carried out to investigate the effects of iodine species and solution concentrations on iodine uptake by spinach (Spinacia oleracea L.). Five iodine concentrations (0, 1, 10, 50 and 100 microM) for iodate (IO(3)(-)) and iodide (I(-)) were used. Results show that higher concentrations of I(-) (> or =10 microM) had some detrimental effect on plant growth, while IO(3)(-) had little effect on the biomass production of spinach plants. Increases in iodine concentration in the growth solution significantly enhanced I concentrations in plant tissues. The detrimental effect of I(-) on plant growth was probably due to the excessively high accumulation of I in plant tissues. The solution-to-spinach leaf transfer factors (TF(leaf), fresh weight basis) for plants treated with iodide were between 14.2 and 20.7 at different solution concentrations of iodide; TF(leaf) for plants treated with iodate decreased gradually from 23.7 to 2.2 with increasing solution concentrations of iodate. The distribution coefficients (DCs) of I between leaves and roots were constantly higher for plants treated with iodate than those treated with iodide. DCs for plants treated with iodide increased with increasing solution concentrations of iodide, while DCs for plants treated with iodate (around 5.5) were similar across the range of solution concentrations of iodate used in this experiment. The implications of iodine accumulation in leafy vegetables in human iodine nutrition are also discussed. Copyright 2002 Elsevier Science Ltd.

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

    OpenAIRE

    Wasof, Safaa; Lenoir, Jonathan; Aarrestad, Per Arild; Alsos, Inger Greve; Armbruster, W. Scott; Austrheim, Gunnar; Bakkestuen, Vegar; Birks, H. John B.; Bråthen, Kari Anne; Broennimann, Olivier; Brunet, Jörg; Bruun, Hans Henrik; Dahlberg, Carl Johan; Diekmann, Martin; Dullinger, Stefan

    2015-01-01

    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 separated for thousands of years.LocationEuropean Alps and Fennoscandia. Methods Of the studied pool of 888 terrestrial vascular plant species occurring in both the Alps and Fennoscandia, we used tw...

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

    Science.gov (United States)

    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

  3. Whole-plant allocation to storage and defense in juveniles of related evergreen and deciduous shrub species.

    Science.gov (United States)

    Wyka, T P; Karolewski, P; Żytkowiak, R; Chmielarz, P; Oleksyn, J

    2016-05-01

    In evergreen plants, old leaves may contribute photosynthate to initiation of shoot growth in the spring. They might also function as storage sites for carbohydrates and nitrogen (N). We hence hypothesized that whole-plant allocation of carbohydrates and N to storage in stems and roots may be lower in evergreen than in deciduous species. We selected three species pairs consisting of an evergreen and a related deciduous species: Mahonia aquifolium (Pursh) Nutt. and Berberis vulgaris L. (Berberidaceae), Prunus laurocerasus L. and Prunus serotina Ehrh. (Rosaceae), and Viburnum rhytidophyllum Hemsl. and Viburnum lantana L. (Adoxaceae). Seedlings were grown outdoors in pots and harvested on two dates during the growing season for the determination of biomass, carbohydrate and N allocation ratios. Plant size-adjusted pools of nonstructural carbohydrates in stems and roots were lower in the evergreen species of Berberidaceae and Adoxaceae, and the slope of the carbohydrate pool vs plant biomass relationship was lower in the evergreen species of Rosaceae compared with the respective deciduous species, consistent with the leading hypothesis. Pools of N in stems and roots, however, did not vary with leaf habit. In all species, foliage contained more than half of the plant's nonstructural carbohydrate pool and, in late summer, also more than half of the plant's N pool, suggesting that in juvenile individuals of evergreen species, leaves may be a major storage site. Additionally, we hypothesized that concentration of defensive phenolic compounds in leaves should be higher in evergreen than in deciduous species, because the lower carbohydrate pool in stems and roots of the former restricts their capacity for regrowth following herbivory and also because of the need to protect their longer-living foliage. Our results did not support this hypothesis, suggesting that evergreen plants may rely predominantly on structural defenses. In summary, our study indicates that leaf habit has

  4. Molecular Properties and Functional Divergence of the Dehydroascorbate Reductase Gene Family in Lower and Higher Plants.

    Directory of Open Access Journals (Sweden)

    Yuan-Jie Zhang

    Full Text Available Dehydroascorbate reductase (DHAR, which reduces oxidized ascorbate, is important for maintaining an appropriate ascorbate redox state in plant cells. To date, genome-wide molecular characterization of DHARs has only been conducted in bryophytes (Physcomitrella patens and eudicots (e.g. Arabidopsis thaliana. In this study, to gain a general understanding of the molecular properties and functional divergence of the DHARs in land plants, we further conducted a comprehensive analysis of DHARs from the lycophyte Selaginella moellendorffii, gymnosperm Picea abies and monocot Zea mays. DHARs were present as a small gene family in all of the land plants we examined, with gene numbers ranging from two to four. All the plants contained cytosolic and chloroplastic DHARs, indicating dehydroascorbate (DHA can be directly reduced in the cytoplasm and chloroplast by DHARs in all the plants. A novel vacuolar DHAR was found in Z. mays, indicating DHA may also be reduced in the vacuole by DHARs in Z. mays. The DHARs within each species showed extensive functional divergence in their gene structures, subcellular localizations, and enzymatic characteristics. This study provides new insights into the molecular characteristics and functional divergence of DHARs in land plants.

  5. Frost sensitivity of various deciduous plant species during leaf development in spring

    Science.gov (United States)

    Estrella, Nicole; Heinzmann, Verena; Menzel, Annette

    2017-04-01

    Frost damage in deciduous woody plants is a major climate component affecting fitness and distribution of species. It is a trade-off between early bud burst enlarging the potential growing season and frost risk for deciduous plants in many regions. In a warming world observed earlier budburst may lead to an increased risk of spring frost damage caused by higher variability in temperatures (IPCC 2007). Lenz et al. (2013) showed that leaves are in general more sensitive to frost in later leaf development stages. But still there is little knowledge on stages of leaf development and their susceptibility to frost damage in many deciduous species. Additionally there might be variation with plant traits or different strategies within specific groups of species. Frost risk minimization can also be achieved by variability in bud burst within a specimen. Therefore, in this study we observed more than 174 individual plant specimen of 96 deciduous woody plant species growing in a comparable microclimate outside on the campus of the Technical University of Munich in Freising, southern Germany. Their phenology was intensively studied from 12th of March to 4th of May, including variation within a specimen. Several times twigs for the frost experiment were cut in different stages of leaf development and exposed to freezing temperatures of -4 and -6°C in two lab freezers. Since the leaf development in spring 2015 started comparably late, too many species emerged simultaneously leading to some capacity problems in the freezers. Nevertheless, our results still reveal novel aspects concerning leaf development and frost sensitivity. The phenological development proceeded in general from outside to inside of the crown (59%), in 33% of the cases all over the plant simultaneously. Sporadic, inside to outside or vertical development characteristics occurred in rare cases (8%). Mixed model analysis indicated impacts on phenology by plant family, natural origin, pollination mode, and

  6. Exotic and indigenous problem plants species used, by the Bapedi ...

    African Journals Online (AJOL)

    EB

    play a significant role in the primary health care needs of socio-economic vulnerable people. Keywords: Bapedi, exotics, indigenous problem plants, sexually transmitted infections. African Health ..... plants for the treatment of oral diseases in.

  7. Effects of invasive plant species on pollinator service and reproduction in native plants at Acadia National Park

    Science.gov (United States)

    Stubbs, C.J.; Drummond, F.; Ginsberg, H.

    2007-01-01

    Invasive plant species can have profound negative effects on natural communities by competively excluding native species. Berberis thunbergii (Japanese barberry), Frangula alnus (glossy or alder buckthorn) and Lythrum salicaria (purple loosestrife) are invasive species known to reduce native plant diversity and are thus of great concern to Acadia National Park. Pollinators visit them for nectar and pollen. The effects of invasive plant species on pollinator behavior were investigated by comparing pollinator visitation to co-flowering native and invasive species with visitation to native species growing alone. The effect of invasives on pollination of native plants was studied by comparing fruit set in patches of the native species growing near invasives with patches far from invasive species in Acadia National Park. The coflowering pairs were as follows: in the spring native Vaccinium angustifolium (lowbush blueberry) was paired with B. thunbergii; in early summer native Viburnum nudum (wild raisin) was paired with F. alnus ; in late summer native Spiraea alba (meadowsweet) was paired with L. salicaria. We investigated whether these invasives competed with native plants for pollinators in Acadia and thus negatively affected native plant reproduction. Our objectives were to determine: 1) the influence, if any, of each invasive on pollinator visitation to a co-flowering native species, 2) factors that might affect visitation, 3) invasive pollen transfer to native plants, and 4) whether invasives influence native plant reproduction (fruit set). Our findings indicate that at times the number of flower visitors to natives was lower or the species composition of visitors different when invasives were present, that invasives sometimes attracted more pollinators, that generally the invasives were more rewarding as far as nectar and pollen availability for pollinators, and that generally native plant fruit set and seed set was not significantly lowered in the presence of

  8. Comparison of carbon balance in Mediterranean pilot constructed wetlands vegetated with different C4 plant species.

    Science.gov (United States)

    Barbera, Antonio C; Borin, Maurizio; Cirelli, Giuseppe L; Toscano, Attilio; Maucieri, Carmelo

    2015-02-01

    This study investigates carbon dioxide (CO2) and methane (CH4) emissions and carbon (C) budgets in a horizontal subsurface flow pilot-plant constructed wetland (CW) with beds vegetated with Cyperus papyrus L., Chrysopogon zizanioides (L.) Roberty, and Mischantus × giganteus Greef et Deu in the Mediterranean basin (Sicily) during the 1st year of plant growing season. At the end of the vegetative season, M. giganteus showed the higher biomass accumulation (7.4 kg m(-2)) followed by C. zizanioides (5.3 kg m(-2)) and C. papyrus (1.8 kg m(-2)). Significantly higher emissions of CO2 were detected in the summer, while CH4 emissions were maximum during spring. Cumulative CO2 emissions by C. papyrus and C. zizanioides during the monitoring period showed similar trends with final values of about 775 and 1,074 g m(-2), respectively, whereas M. giganteus emitted 3,395 g m(-2). Cumulative CH4 bed emission showed different trends for the three C4 plant species in which total gas release during the study period was for C. papyrus 12.0 g m(-2) and ten times higher for M. giganteus, while C. zizanioides bed showed the greatest CH4 cumulative emission with 240.3 g m(-2). The wastewater organic carbon abatement determined different C flux in the atmosphere. Gas fluxes were influenced both by plant species and monitored months with an average C-emitted-to-C-removed ratio for C. zizanioides, C. papyrus, and M. giganteus of 0.3, 0.5, and 0.9, respectively. The growing season C balances were positive for all vegetated beds with the highest C sequestered in the bed with M. giganteus (4.26 kg m(-2)) followed by C. zizanioides (3.78 kg m(-2)) and C. papyrus (1.89 kg m(-2)). To our knowledge, this is the first paper that presents preliminary results on CO2 and CH4 emissions from CWs vegetated with C4 plant species in Mediterranean basin during vegetative growth.

  9. Ascomycota has a faster evolutionary rate and higher species diversity than Basidiomycota.

    Science.gov (United States)

    Wang, Haiying; Guo, Shouyu; Huang, Manrong; Thorsten, Lumbsch H; Wei, Jiangchun

    2010-10-01

    Differences in rates of nucleotide or amino acid substitutions among major groups of organisms are repeatedly found and well documented. A growing body of evidence suggests a link between the rate of neutral molecular change within populations and the evolution of species diversity. More than 98% of terrestrial fungi belong to the phyla Ascomycota or Basidiomycota. The former is considerably richer in number of species than the latter. We obtained DNA sequences of 21 protein-coding genes from the lichenized fungus Rhizoplaca chrysoleuca and used them together with sequences from GenBank for subsequent analyses. Three datasets were used to test rate discrepancies between Ascomycota and Basidiomycota and that within Ascomycota: (i) 13 taxa including 105 protein-coding genes, (ii) nine taxa including 21 protein-coding genes, and (iii) nuclear LSU rDNA of 299 fungal species. Based on analyses of the 105 protein-coding genes and nuclear LSU rDNA datasets, we found that the evolutionary rate was higher in Ascomycota than in Basidiomycota. The differences in substitution rates between Ascomycota and Basidiomycota were significant. Within Ascomycota, the species-rich Sordariomycetes has the fastest evolutionary rate, while Leotiomycetes has the slowest. Our results indicate that the main contribution to the higher substitution rates in Ascomycota does not come from mutualism, ecological conditions, sterility, metabolic rate or shorter generation time, but is possibly caused by the founder effect. This is another example of the correlation between species number and evolutionary rates, which is consistent with the hypothesis that the founder effect is responsible for accelerated substitution rates in diverse clades.

  10. Relationships between Plant Biomass and Species Richness under ...

    African Journals Online (AJOL)

    Significantly, the highest species richness (4.9 species m-2) was recorded in the enclosure grazing management site whereas the lowest (3.4 species m-2) was recorded in the benchmark grazing site when all grazing sites and farming systems were combined. The relationship between species richness and biomass was ...

  11. Gene expression and regulation of higher plants under soil water stress.

    Science.gov (United States)

    Ni, Fu-Tai; Chu, Li-Ye; Shao, Hong-Bo; Liu, Zeng-Hui

    2009-06-01

    Higher plants not only provide human beings renewable food, building materials and energy, but also play the most important role in keeping a stable environment on earth. Plants differ from animals in many aspects, but the important is that plants are more easily influenced by environment than animals. Plants have a series of fine mechanisms for responding to environmental changes, which has been established during their long-period evolution and artificial domestication. The machinery related to molecular biology is the most important basis. The elucidation of it will extremely and purposefully promote the sustainable utilization of plant resources and make the best use of its current potential under different scales. This molecular mechanism at least includes drought signal recognition (input), signal transduction (many cascade biochemical reactions are involved in this process), signal output, signal responses and phenotype realization, which is a multi-dimension network system and contains many levels of gene expression and regulation. We will focus on the physiological and molecular adaptive machinery of plants under soil water stress and draw a possible blueprint for it. Meanwhile, the issues and perspectives are also discussed. We conclude that biological measures is the basic solution to solving various types of issues in relation to sustainable development and the plant measures is the eventual way.

  12. Climate and soil factors influencing seedling recruitment of plant species used for dryland restoration

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Erickson, Todd E.; Martini, Dylan C.; Dixon, Kingsley W.; Merritt, David J.

    2016-06-01

    Land degradation affects 10-20 % of drylands globally. Intensive land use and management, large-scale disturbances such as extractive operations, and global climate change, have contributed to degradation of these systems worldwide. Restoring these damaged environments is critical to improving ecosystem services and functions, conserve biodiversity, and contribute to climate resilience, food security, and landscape sustainability. Here, we present a case study on plant species of the mining intensive semi-arid Pilbara region in Western Australia that examines the effects of climate and soil factors on the restoration of drylands. We analysed the effects of a range of rainfall and temperature scenarios and the use of alternative soil materials on seedling recruitment of key native plant species from this area. Experimental studies were conducted in controlled environment facilities where conditions simulated those found in the Pilbara. Soil from topsoil (T) stockpiles and waste materials (W) from an active mine site were mixed at different proportions (100 % T, 100 % W, and two mixes of topsoil and waste at 50 : 50 and 25 : 75 ratios) and used as growth media. Our results showed that seedling recruitment was highly dependent on soil moisture and emergence was generally higher in the topsoil, which had the highest available water content. In general, responses to the climate scenarios differed significantly among the native species which suggest that future climate scenarios of increasing drought might affect not only seedling recruitment but also diversity and structure of native plant communities. The use of waste materials from mining operations as growth media could be an alternative to the limited topsoil. However, in the early stages of plant establishment successful seedling recruitment can be challenging in the absence of water. These limitations could be overcome by using soil amendments but the cost associated to these solutions at large landscape scales

  13. Design and optimization of an experimental bioregenerative life support system with higher plants and silkworms

    Science.gov (United States)

    Hu, Enzhu; Bartsev, Sergey I.; Zhao, Ming; Liu, Professor Hong

    The conceptual scheme of an experimental bioregenerative life support system (BLSS) for planetary exploration was designed, which consisted of four elements - human metabolism, higher plants, silkworms and waste treatment. 15 kinds of higher plants, such as wheat, rice, soybean, lettuce, mulberry, et al., were selected as regenerative component of BLSS providing the crew with air, water, and vegetable food. Silkworms, which producing animal nutrition for crews, were fed by mulberry-leaves during the first three instars, and lettuce leaves last two instars. The inedible biomass of higher plants, human wastes and silkworm feces were composted into soil like substrate, which can be reused by higher plants cultivation. Salt, sugar and some household material such as soap, shampoo would be provided from outside. To support the steady state of BLSS the same amount and elementary composition of dehydrated wastes were removed periodically. The balance of matter flows between BLSS components was described by the system of algebraic equations. The mass flows between the components were optimized by EXCEL spreadsheets and using Solver. The numerical method used in this study was Newton's method.

  14. Physiological aspects of the production and conversion of DMSP in marine algae and higher plants

    NARCIS (Netherlands)

    Stefels, J

    Dimethylsulphoniopropionate (DMSP) is a compound produced in several classes of algae and higher plants that live in the marine environment. Considering its generally high intracellular concentrations, DMSP has a function in the osmotic protection of algal cells. Due to the relatively slow

  15. Fruit Plants Species along Corridor in Kopendukuh Village as a Resource for Rural Tourism Development

    Directory of Open Access Journals (Sweden)

    Widya Kristiyanti Putri

    2015-02-01

    Full Text Available This research aims to identify fruit plants species which is potential for tourism attraction, spatially describes fruit plants distribution and identify local people’s response for fruit plants as tourims attraction in Kopendukuh village, Banyuwangi. Survey was done along the villages corridors. The fruit plant species along corridors was identified and mapped using GPS. Furthermore, semi-structural interview was used to gain informations of local people response about fruit plants as tourism attraction. There were about 18 species and 162 individuals were found along corridor of Kopendukuh village. Fruit plants always found in local home gardens along rural corridor. Local peoples argue that fruit planst s important for numerous purposes. Local people support tourism development in rural area which based on the fruit plants richness (i.e. agrotourism. Keywords: fruit plants, mapping, corridor, rural tourism.

  16. The role of growth form and correlated traits in competitive ranking of six perennial ruderal plant species grown in unbalanced mixtures

    Science.gov (United States)

    Dietz, Hansjörg; Steinlein, Thomas; Ullmann, Isolde

    1998-02-01

    The competitive abilities of six perennial ruderal plants of three different growth forms were compared via yield measures using an additive diallel experimental design with unbalanced mixtures (9:3 or 3:9 plants per pot, respectively). Thus, in a given mixture species A was grown in two configurations: three individuals in centre position of the pot together with nine plants of species B in border position and vice versa. Effect competitive abilities as well as response competitive abilities of the species were significantly related to canopy height and plant biomass. The species with lower rosette growth form and smaller biomasses were weaker competitors than the species possessing elevated canopies along with higher biomasses, whereas total leaf area was not significantly correlated with competitive ability between species. Species differences in competitive ability were stronger between the plants grown in the central position than between those grown in the border position. Furthermore, interactions between species-specific traits and configuration could be observed, indicating the importance of species proportions and arrangement patterns for evaluation of competitive outcome in the field. The degree of complete transitivity of the competitive network of the six ruderal species, which was significantly higher than expected under the null model in our experimental design, also seemed to depend on species proportions in mixture. Shifts in root:shoot ratio of the centre plants when faced with competition by the border plants were in the direction of higher shoot allocation for the weak competitors with rosette growth form irrespective of the neighbour species, except for Bunias orientalis, which showed a more plastic response. The stronger competitors showed higher root allocation ( Urtica dioica) or were hardly affected at all. Consistent with the results of our experiment, the weaker competitors occur at rather frequently disturbed and therefore transient

  17. Investigating Effects of Invasive Species on Plant Community Structure

    Science.gov (United States)

    Franklin, Wilfred

    2008-01-01

    In this article, the author presents a field study project that explores factors influencing forest community structure and lifts the veil off of "plant blindness." This ecological study consists of three laboratories: (1) preliminary field trip to the study site; (2) plant survey; and (3) analyzing plant community structure with descriptive…

  18. Plant species richness and abundance in residential yards across a tropical watershed: implications for urban sustainability

    Directory of Open Access Journals (Sweden)

    Cristina P. Vila-Ruiz

    2014-09-01

    Full Text Available Green spaces within residential areas provide important contributions to the sustainability of urban systems. Therefore, studying the characteristics of these areas has become a research priority in cities worldwide. This project evaluated various aspects of the plant biodiversity of residential yards (i.e., front yards and back yards within the Río Piedras watershed in the San Juan metropolitan area of Puerto Rico. Our work included gathering information on vegetation composition and abundance of woody species (i.e., trees, shrubs, palms, ferns and large herbs (>2 m height, species origin (native vs. introduced, and species uses (ornamental, food, and medicinal plants. A total of 424 yards were surveyed within an area of 187,191 m². We found 383 woody species, with shrubs being the most abundant plant habitat. As expected, residential yards hosted a disproportionate amount of introduced species (69.5%. The most common shrub species were all non-native ornamentals, whereas the most common tree species included food trees as well as ornamental plants and two native species. Front yards hosted more ornamental species per unit area than backyards, while the latter had more food plants. The high amount of introduced species may present a challenge in terms of implementation of plant conservation initiatives if there is no clear definition of urban conservation goals. On the other hand, the high frequency of yards containing food plants may facilitate the development of residential initiatives that could provide future adaptive capacity to food shortages.

  19. Predicting molybdenum toxicity to higher plants: Estimation of toxicity threshold values

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, S.P., E-mail: steve.mcgrath@bbsrc.ac.u [Soil Science Department, Centre for Soils and Ecosystems Function, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Mico, C.; Zhao, F.J.; Stroud, J.L. [Soil Science Department, Centre for Soils and Ecosystems Function, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Zhang, H.; Fozard, S. [Division of Environmental Science, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2010-10-15

    Four plant species (oilseed rape, Brassica napus L.; red clover, Trifolium pratense L.; ryegrass, Lolium perenne L.; and tomato, Lycopersicon esculentum L.) were tested on ten soils varying widely in soil properties to assess molybdenum (Mo) toxicity. A larger range (66-fold-609-fold) of added Mo concentrations resulting in 50% inhibition of yield (ED{sub 50}) was found among soils than among plant species (2-fold-38-fold), which illustrated that the soils differed widely in the expression of Mo toxicity. Toxicity thresholds based on soil solution Mo narrowed the variation among soils compared to thresholds based on added Mo concentrations. We conclude that plant bioavailability of Mo in soil depends on Mo solubility, but this alone did not decrease the variability in observed toxicity enough to be used in risk assessment and that other soil properties influencing Mo toxicity to plants need to be considered. - Mo toxicity thresholds varied widely in different soils and therefore soil properties need to be taken into account in order to assess the risk of Mo exposure.

  20. Phototolerance of lichens, mosses and higher plants in an alpine environment: analysis of photoreactions.

    Science.gov (United States)

    Heber, U; Bilger, W; Bligny, R; Lange, O L

    2000-11-01

    Adaptation to excessive light is one of the requirements of survival in an alpine environment particularly for poikilohydric organisms which in contrast to the leaves of higher plants tolerate full dehydration. Changes in modulated chlorophyll fluorescence and 820-nm absorption were investigated in the lichens Xanthoria elegans (Link) Th. Fr. and Rhizocarpon geographicum (L.) DC, in the moss Grimmia alpestris Limpr. and the higher plants Geum montanum L., Gentiana lutea L. and Pisum sativum L., all collected at altitudes higher than 2000 m above sea level. In the dehydrated state, chlorophyll fluorescence was very low in the lichens and the moss, but high in the higher plants. It increased on rehydration in the lichens and the moss, but decreased in the higher plants. Light-induced charge separation in photosystem II was indicated by pulse-induced fluorescence increases only in dried leaves, not in the dry moss and dry lichens. Strong illumination caused photodamage in the dried leaves, but not in the dry moss and dry lichens. Light-dependent increases in 820-nm absorption revealed formation of potential quenchers of chlorophyll fluorescence in all dehydrated plants, but energy transfer to quenchers decreased chlorophyll fluorescence only in the moss and the lichens, not in the higher plants. In hydrated systems, coupled cyclic electron transport is suggested to occur concurrently with linear electron transport under strong actinic illumination particularly in the lichens because far more electrons became available after actinic illumination for the reduction of photo-oxidized P700 than were available in the pool of electron carriers between photosystems II and I. In the moss Grimmia, but not in the lichens or in leaves, light-dependent quenching of chlorophyll fluorescence was extensive even under nitrogen, indicating anaerobic thylakoid acidification by persistent cyclic electron transport. In the absence of actinic illumination, acidification by ca. 8% CO2 in

  1. Rhizosphere effect of colonizer plant species on the development of soil microbial community during primary succession on postmining sites

    Energy Technology Data Exchange (ETDEWEB)

    Elhottova, D.; Kristufek, V.; Maly, S.; Frouz, J. [Academy of Sciences of the Czech Republic, Ceske Budejovice (Czech Republic). Inst. for Soil Biology

    2009-07-01

    The impact of pioneer plant species Tussilago farfara on structural, functional, and growth characterization of microbial community colonizing the spoil colliery substrate was studied in a laboratory microcosm experiment. Microcosms consisting of spoil substrate (0.7 dm{sup 3} of tertiary alkaline clay sediment from Sokolov brown-coal mine area) from a pioneer site (without vegetation, 5 years after heaping) were cultivated in a greenhouse with one plant of this species. Plant roots substantially increased microbial diversity and biomass after one season (7 months) of cultivation. Roots influenced the microbial community and had nearly twice the size, higher growth, and metabolic potential in comparison to the control. The development of microbial specialists improves the plant nutrient status. Bacterial nitrogen (N{sub 2}) fixators (Bradyrhizobium japonicum, Rhizobium radiobacter) and arbuscular mycorrhizal fungi were confirmed in the rhizosphere of Tussilago farfara.

  2. Traits related to species persistence and dispersal explain changes in plant communities subjected to habitat loss

    DEFF Research Database (Denmark)

    Marini, Lorenzo; Bruun, Hans Henrik; Heikkinen, Risto

    2012-01-01

    Aim Habitat fragmentation is a major driver of biodiversity loss but it is insufficiently known how much its effects vary among species with different life-history traits; especially in plant communities, the understanding of the role of traits related to species persistence and dispersal...... of habitat loss on plant species richness was pervasive across different regions, whereas the effect of habitat isolation on species richness was not evident. This area effect was, however, not equal for all the species, and life-history traits related to both species persistence and dispersal modified plant...... sensitivity to habitat loss, indicating that both landscape and local processes determined large-scale dynamics of plant communities. High competitive ability for light, annual life cycle and animal dispersal emerged as traits enabling species to cope with habitat loss. Main conclusions In highly fragmented...

  3. Bird species richness is associated with phylogenetic relatedness, plant species richness, and altitudinal range in Inner Mongolia

    OpenAIRE

    Liang, Chenxia; Feng, Gang; Si, Xingfeng; Mao, Lingfeng; Yang, Guisheng; Svenning, Jens Christian; Yang, Jie

    2018-01-01

    Abstract Bird species richness is mediated by local, regional, and historical factors, for example, competition, environmental heterogeneity, contemporary, and historical climate. Here, we related bird species richness with phylogenetic relatedness of bird assemblages, plant species richness, topography, contemporary climate, and glacial‐interglacial climate change to investigate the relative importance of these factors. This study was conducted in Inner Mongolia, an arid and semiarid region ...

  4. Plant population differentiation and climate change: responses of grassland species along an elevational gradient.

    Science.gov (United States)

    Frei, Esther R; Ghazoul, Jaboury; Matter, Philippe; Heggli, Martin; Pluess, Andrea R

    2014-02-01

    Mountain ecosystems are particularly susceptible to climate change. Characterizing intraspecific variation of alpine plants along elevational gradients is crucial for estimating their vulnerability to predicted changes. Environmental conditions vary with elevation, which might influence plastic responses and affect selection pressures that lead to local adaptation. Thus, local adaptation and phenotypic plasticity among low and high elevation plant populations in response to climate, soil and other factors associated with elevational gradients might underlie different responses of these populations to climate warming. Using a transplant experiment along an elevational gradient, we investigated reproductive phenology, growth and reproduction of the nutrient-poor grassland species Ranunculus bulbosus, Trifolium montanum and Briza media. Seeds were collected from low and high elevation source populations across the Swiss Alps and grown in nine common gardens at three different elevations with two different soil depths. Despite genetic differentiation in some traits, the results revealed no indication of local adaptation to the elevation of population origin. Reproductive phenology was advanced at lower elevation in low and high elevation populations of all three species. Growth and reproduction of T. montanum and B. media were hardly affected by garden elevation and soil depth. In R. bulbosus, however, growth decreased and reproductive investment increased at higher elevation. Furthermore, soil depth influenced growth and reproduction of low elevation R. bulbosus populations. We found no evidence for local adaptation to elevation of origin and hardly any differences in the responses of low and high elevation populations. However, the consistent advanced reproductive phenology observed in all three species shows that they have the potential to plastically respond to environmental variation. We conclude that populations might not be forced to migrate to higher elevations

  5. Rapeseed (Brassica napus L. as a protein plant species

    Directory of Open Access Journals (Sweden)

    Marinković Radovan

    2010-01-01

    Full Text Available Proteins of plant origin have a profound impact on human and animal lives. It is impossible to solve worldwide nutrition problem without taking into concern needs for proteins. Inadequate nutrition can only be improved by providing adequate proteins. Humans need c. 120g proteins daily, a third of which should come from meat and milk. Certain population categories, such as the sick, children, pregnant women and sportspeople are more sensitive to lack of protein. Oil crops synthesise oil, which is the basic reserve material in seed, but they also synthesise high levels of protein and can serve as protein source for human and animal nutrition. Generally speaking, protein content in seed of rapeseed at site R. Šančevi was from 19.60% (NS-L-74 to 25.93% JR-NS-36, and at site Sombor from 19.26% (NS-L-74 to 24.06% and 24.09% (NS-L-46 and cultivar Mira. Genotype NS-L-74 had the lowest protein content at both testing sites. Higher protein content was evident with spring genotypes than with winter gentypes. .

  6. The relationship between the spectral diversity of satellite imagery, habitat heterogeneity, and plant species richness

    Science.gov (United States)

    Steven D. Warren; Martin Alt; Keith D. Olson; Severin D. H. Irl; Manuel J. Steinbauer; Anke Jentsch

    2014-01-01

    Assessment of habitat heterogeneity and plant species richness at the landscape scale is often based on intensive and extensive fieldwork at great cost of time and money. We evaluated the use of satellite imagery as a quantitativemeasure of the relationship between the spectral diversity of satellite imagery, habitat heterogeneity, and plant species richness. A 16 km2...

  7. Determining a charge for the clearing of invasive alien plant species ...

    African Journals Online (AJOL)

    South Africa is running out of water supply options. One option, however, is to control invasive alien plant species (IAPs) within water catchment areas and in riparian zones. The National Water Act and subsequent documentation provide a guide for the use of economic instruments to manage invasive alien plant species at ...

  8. Fire frequency and tree canopy structure influence plant species diversity in a forest-grassland ecotone

    Science.gov (United States)

    David W. Peterson; Peter B. Reich

    2008-01-01

    Disturbances and environmental heterogeneity are two factors thought to influence plant species diversity, but their effects are still poorly understood in many ecosystems. We surveyed understory vegetation and measured tree canopy cover on permanent plots spanning an experimental fire frequency gradient to test fire frequency and tree canopy effects on plant species...

  9. Influence of plant species on population dynamics, genotypic diversity and antibiotic production by indigenous Pseudomonas spp

    NARCIS (Netherlands)

    Bergsma-Vlami, M.; Prins, M.E.; Raaijmakers, J.M.

    2005-01-01

    The population dynamics, genotypic diversity and activity of naturally-occurring 2,4-diacetylphloroglucinol (DAPG)-producing Pseudomonas spp. was investigated for four plant species (wheat, sugar beet, potato, lily) grown in two different soils. All four plant species tested, except lily and in some

  10. Number of endemic and native plant species in the Galapagos Archipelago in relation to geographical parameters

    DEFF Research Database (Denmark)

    Willerslev, Eske; Hansen, Anders J.; Nielsen, Kirstine Klitgaard

    2002-01-01

    By simple and multiple regression analyses we investigate updated species numbers of endemic and native vascular plants and seed plants in the Galapagos Archipelago in relation to geographical parameters. We find that the best models to describe species numbers are regression models with log...

  11. Pollinator networks, alien species and the conservation of rare plants: Trinia glauca as a case study

    NARCIS (Netherlands)

    Carvalheiro, L.G.; Barbosa, E.R.; Memmott, J.

    2008-01-01

    1. Despite the essential role of pollination in the maintenance of many rare plant species, conservation management plans rarely consider the service of pollination. 2. This study identifies the main pollinators of a rare English plant species, Trinia glauca (Apiaceae), and provides recommendations

  12. Impacts of invading alien plant species on water flows at stand and catchment scales

    CSIR Research Space (South Africa)

    Le Maitre, David C

    2015-05-01

    Full Text Available in vegetation structure and the physiology of the dominant plant species result in changes in surface runoff and groundwater discharge, whether they involve native or alien plant species. Where there is little change in vegetation structure [e.g. leaf area...

  13. Impact of mine dumps on transport the invasive plant species to Upper Silesia

    Science.gov (United States)

    Sotkova, N.; Lokajickova, B.; Mec, J.; Svehlakova, H.; Stalmachova, B.

    2017-10-01

    Human activities significantly change the species composition in the area. The main factor of change was the mining industry, which changed the natural conditions on Upper Silesia. The anthropogenic relief of mine dumps are the main centre of alien plant in an industrial landscape. The poster deals with the state of the invasive plant species by the phyto-sociological surveys on Upper Silesia.

  14. The effects of fire-breaks on plant diversity and species composition ...

    African Journals Online (AJOL)

    There is a dearth of knowledge on the effects of annual burning of fire-breaks on species composition, plant diversity and soil properties. Whittaker's plant diversity technique was used to gather data on species composition and diversity in four grassland communities on the Loskop Dam Nature Reserve (LDNR). The study ...

  15. Are non-native plants perceived to be more risky? Factors influencing horticulturists' risk perceptions of ornamental plant species.

    Directory of Open Access Journals (Sweden)

    Franziska Humair

    Full Text Available Horticultural trade is recognized as an important vector in promoting the introduction and dispersal of harmful non-native plant species. Understanding horticulturists' perceptions of biotic invasions is therefore important for effective species risk management. We conducted a large-scale survey among horticulturists in Switzerland (N = 625 to reveal horticulturists' risk and benefit perceptions from ornamental plant species, their attitudes towards the regulation of non-native species, as well as the factors decisive for environmental risk perceptions and horticulturists' willingness to engage in risk mitigation behavior. Our results suggest that perceived familiarity with a plant species had a mitigating effect on risk perceptions, while perceptions of risk increased if a species was perceived to be non-native. However, perceptions of the non-native origin of ornamental plant species were often not congruent with scientific classifications. Horticulturists displayed positive attitudes towards mandatory trade regulations, particularly towards those targeted against known invasive species. Participants also expressed their willingness to engage in risk mitigation behavior. Yet, positive effects of risk perceptions on the willingness to engage in risk mitigation behavior were counteracted by perceptions of benefits from selling non-native ornamental species. Our results indicate that the prevalent practice in risk communication to emphasize the non-native origin of invasive species can be ineffective, especially in the case of species of high importance to local industries and people. This is because familiarity with these plants can reduce risk perceptions and be in conflict with scientific concepts of non-nativeness. In these cases, it might be more effective to focus communication on well-documented environmental impacts of harmful species.

  16. Mapping National Plant Biodiversity Patterns in South Korea with the MARS Species Distribution Model.

    Directory of Open Access Journals (Sweden)

    Hyeyeong Choe

    Full Text Available Accurate information on the distribution of existing species is crucial to assess regional biodiversity. However, data inventories are insufficient in many areas. We examine the ability of Multivariate Adaptive Regression Splines (MARS multi-response species distribution model to overcome species' data limitations and portray plant species distribution patterns for 199 South Korean plant species. The study models species with two or more observations, examines their contribution to national patterns of species richness, provides a sensitivity analysis of different range threshold cutoff approaches for modeling species' ranges, and presents considerations for species modeling at fine spatial resolution. We ran MARS models for each species and tested four threshold methods to transform occurrence probabilities into presence or absence range maps. Modeled occurrence probabilities were extracted at each species' presence points, and the mean, median, and one standard deviation (SD calculated to define data-driven thresholds. A maximum sum of sensitivity and specificity threshold was also calculated, and the range maps from the four cutoffs were tested using independent plant survey data. The single SD values were the best threshold tested for minimizing omission errors and limiting species ranges to areas where the associated occurrence data were correctly classed. Eight individual species range maps for rare plant species were identified that are potentially affected by resampling predictor variables to fine spatial scales. We portray spatial patterns of high species richness by assessing the combined range maps from three classes of species: all species, endangered and endemic species, and range-size rarity of all species, which could be used in conservation planning for South Korea. The MARS model is promising for addressing the common problem of few species occurrence records. However, projected species ranges are highly dependent on the

  17. Pioneer plant species contributing to phytoestabilization of contaminated soils in mine areas

    Science.gov (United States)

    João Batista, Maria; Gonzalez-Fernandez, Oscar; Abreu, Maria Manuela; Carvalho, Luisa; Queralt, Ignasi

    2013-04-01

    Young and mature leaves from several plant species of the genus Cistus L. (C. crispus, C. ladanifer, C. monspeliensis, C. salviifolius), Erica australis L., and Lavandula sampaioana (Rozeira) Rivas Mart., T.E. Díaz& Fern. Gonz., as well as soils where plants grew, were sampled in various areas of São Domingos abandoned mine. The São Domingos mine, dating from pre-Roman times, is 60 km SE of Beja, Southeast Portugal. This mine belongs to the world class metallogenetic province of the Iberian Pyrite Belt. Sampling occurred throughout spring and winter to better understand plant behaviour and natural attenuation of contaminated soils. Multiple Correspondence Analysis (MCA) was used to synthesize the information and group characteristics that could justify different chemical concentrations. Soils are extremely acid (pH between 3.4 and 5.2) and present a wide range of Corganic concentrations (10.2-109 g/kg). Total nitrogen and extractable phosphorus concentrations are low to very low, but extractable potassium show medium to high concentrations. Chemical elements concentrations, analysed for total fraction, were great in soils, especially arsenic and lead that can attain 7.6 g/kg and 17.2 g/kg, respectively. However, only a small percentage (in general < 1%) of the total concentration of the chemical elements were water soluble (extracted by DIN 38414-S4 method) or extracted with the DTPA or ammonium acetate aqueous solutions. Cistus plants showed different behaviour on the trace-elements uptake and translocation. Winter and spring variations in most chemical elements concentrations in the plants leaves are not significantly different, except for arsenic, probably because plants were not exposed to important dry conditions during the sampling seasons. Nevertheless, MCA of the individuals makes a clear distinction between winter and spring leaves. Generally, mature leaves have higher concentrations of arsenic, copper, iron, lead, manganese and zinc than younger ones

  18. Inherent and environmental patterns in biomass allocation and allometry among higher plants

    Science.gov (United States)

    Poorter, Hendrik

    2017-04-01

    It is well-known that plants may adjust the distribution of biomass over leaves, stems and roots depending on environmental conditions. It is also clear that size is an important factor as well. However, good quantitative insights are lacking. In this talk I analyse biomass allocation patterns to leaves, stems and roots of herbs and woody species. A database was compiled with 11.000 records of leaf, stem and root biomass for 1200 species. First, I'll derive general dose-response curves that describe the relationship between biomass allocation and the 12 most important a-biotic environmental factors and compare them with the changes in leaf, stem and root morphology. Second, I'll focus on allometric relationships between the various organs and test to what extent they comply with models like that for Metabolic Scaling Theory, where the slope of the log-log relationship between leaf and root biomass is expected to have a value of ¾. Third, I analyse how leaf, stem and root mass fractions change as a function of total plant size. This offers a great opportunity to test to what extent there are systematic differences in allocation patterns related to phylogeny (e.g. Gymnosperms vs. Angiosperms, grasses vs. herbaceous dicots) and functional group (e.g. deciduous vs. evergreens). Poorter et al. (2012) Biomass allocation to leaves, stems and roots: meta-analyses of interspecific variation and environmental control. New Phytol. 193: 30-50. Poorter & Sack (2012) Pitfalls and possibilities in the analysis of biomass allocation patterns in plants. Front. Plant Sci. 3: 259. Poorter et al. (2015) How does biomass distribution change with size and differ among species? New Phytol. 208: 736-749

  19. Impacts of sea level rise and climate change on coastal plant species in the central California coast

    Directory of Open Access Journals (Sweden)

    Kendra L. Garner

    2015-05-01

    Full Text Available Local increases in sea level caused by global climate change pose a significant threat to the persistence of many coastal plant species through exacerbating inundation, flooding, and erosion. In addition to sea level rise (SLR, climate changes in the form of air temperature and precipitation regimes will also alter habitats of coastal plant species. Although numerous studies have analyzed the effect of climate change on future habitats through species distribution models (SDMs, none have incorporated the threat of exposure to SLR. We developed a model that quantified the effect of both SLR and climate change on habitat for 88 rare coastal plant species in San Luis Obispo, Santa Barbara, and Ventura Counties, California, USA (an area of 23,948 km2. Our SLR model projects that by the year 2100, 60 of the 88 species will be threatened by SLR. We found that the probability of being threatened by SLR strongly correlates with a species’ area, elevation, and distance from the coast, and that 10 species could lose their entire current habitat in the study region. We modeled the habitat suitability of these 10 species under future climate using a species distribution model (SDM. Our SDM projects that 4 of the 10 species will lose all suitable current habitats in the region as a result of climate change. While SLR accounts for up to 9.2 km2 loss in habitat, climate change accounts for habitat suitability changes ranging from a loss of 1,439 km2 for one species to a gain of 9,795 km2 for another species. For three species, SLR is projected to reduce future suitable area by as much as 28% of total area. This suggests that while SLR poses a higher risk, climate changes in precipitation and air temperature represents a lesser known but potentially larger risk and a small cumulative effect from both.

  20. Plants, birds and butterflies: short-term responses of species communities to climate warming vary by taxon and with altitude.

    Science.gov (United States)

    Roth, Tobias; Plattner, Matthias; Amrhein, Valentin

    2014-01-01

    As a consequence of climate warming, species usually shift their distribution towards higher latitudes or altitudes. Yet, it is unclear how different taxonomic groups may respond to climate warming over larger altitudinal ranges. Here, we used data from the national biodiversity monitoring program of Switzerland, collected over an altitudinal range of 2500 m. Within the short period of eight years (2003-2010), we found significant shifts in communities of vascular plants, butterflies and birds. At low altitudes, communities of all species groups changed towards warm-dwelling species, corresponding to an average uphill shift of 8 m, 38 m and 42 m in plant, butterfly and bird communities, respectively. However, rates of community changes decreased with altitude in plants and butterflies, while bird communities changed towards warm-dwelling species at all altitudes. We found no decrease in community variation with respect to temperature niches of species, suggesting that climate warming has not led to more homogenous communities. The different community changes depending on altitude could not be explained by different changes of air temperatures, since during the 16 years between 1995 and 2010, summer temperatures in Switzerland rose by about 0.07°C per year at all altitudes. We discuss that land-use changes or increased disturbances may have prevented alpine plant and butterfly communities from changing towards warm-dwelling species. However, the findings are also consistent with the hypothesis that unlike birds, many alpine plant species in a warming climate could find suitable habitats within just a few metres, due to the highly varied surface of alpine landscapes. Our results may thus support the idea that for plants and butterflies and on a short temporal scale, alpine landscapes are safer places than lowlands in a warming world.

  1. Number of endemic and native plant species in the Galapagos Archipelago in relation to geographical parameters

    DEFF Research Database (Denmark)

    Willerslev, E.; Hansen, Anders J.; Nielsen, K. K.

    2002-01-01

    By simple and multiple regression analyses we investigate updated species numbers of endemic and native vascular plants and seed plants in the Galapagos Archipelago in relation to geographical parameters. We find that the best models to describe species numbers are regression models with log-tran...... explained variation is in general small. The results show that the species area relationships are different for native and endemic species. This is discussed in relation to classical island biogeographical models, and the concepts of radiative speciation. Udgivelsesdato: 2002......By simple and multiple regression analyses we investigate updated species numbers of endemic and native vascular plants and seed plants in the Galapagos Archipelago in relation to geographical parameters. We find that the best models to describe species numbers are regression models with log......-transformed species numbers as dependent and log-transformed modified area (i.e. area not covered with barren lava) as an independent variable. This holds both for total species number, for native species number, for endemic species number and for total number of seed plants as well as number of endemic seed plants...

  2. Herbs versus Trees: Influences on Teenagers' Knowledge of Plant Species

    Science.gov (United States)

    Lückmann, Katrin; Menzel, Susanne

    2014-01-01

    The study reports on species knowledge among German adolescents (n = 507) as: (1) self-assessed evaluation of one's species knowledge; and (2) factual knowledge about popular local herbs and trees. Besides assessing species knowledge, we were interested in whether selected demographic factors, environmental attitude (as measured through the New…

  3. Use of plant woody species electrical potential for irrigation scheduling.

    Science.gov (United States)

    Ríos-Rojas, Liliana; Morales-Moraga, David; Alcalde, José A; Gurovich, Luis A

    2015-01-01

    The electrical response of plants to environmental stimuli can be measured and quantitatively related to the intensity of several stimulating sources, like temperature, solar radiation, soil water content, evapotranspiration rates, sap flow and dendrometric cycles. These relations can be used to assess the influence of different environmental situations on soil water availability to plants, defined as a steady state condition between leaf transpirative flow and soil water flow to plant roots. A restricted soil water flow due to soil dryness can trigger water stress in plants, if the atmospheric evaporative demand is high, causing partial stomata closure as a physiological response to avoid plant dehydration; water stressed and unstressed plants manifest a differential electrical response. Real time plant electrical response measurements can anticipate actions that prevent the plant reaching actual stress conditions, optimizing stomata gas exchange and photosynthetic rates. An electrophysiological sensor developed in this work, allows remote real-time recording information on plant electrical potential (EP) in the field, which is highly related to EP measurements obtained with a laboratory Keithley voltmeter sensor used in an highly controlled experimental setup. Our electrophysiological sensor is a wireless, autonomous devise, which transmits EP information via Internet to a data server. Using both types of sensors (EP electrodes with a Keithley voltmeter and the electrophysiological sensor), we measured in real time the electrical responses of Persea americana and Prunus domestica plants, to induced water deficits. The differential response for 2 scenarios: irrigation and water restriction is identified by a progressive change in slope on the daily maximal and minimal electric signal values in stressed plants, and a zero-slope for similar signals for well-watered plants. Results show a correspondence between measured signals obtained by our electrophysiological

  4. Subordinate plant species moderate drought effects on earthworms communities in grasslands

    OpenAIRE

    Mariotte Pierre; Le Bayon Renee-Claire; Eisenhauer Nico; Guenat Claire; Buttler Alexandre

    2016-01-01

    Loss of plant diversity resulting from forecasted drought events is likely to alter soil functioning and affect earthworm communities. Plant soil interactions are expected to play an important role in mediating climate change effects on soil decomposers. In this study we test above belowground linkages after drought by focusing on the effects of subordinate plant species on earthworm communities. Using a combination of subordinate species removal and experimental drought we show that subordin...

  5. Interactions between root-feeding nematodes depend on plant species identity

    OpenAIRE

    Brinkman, E.P.; Duyts, H.; van der Putten, W.H.

    2008-01-01

    Root-feeding nematodes play an important role in structuring the composition of natural plant communities. Little is known about the role of intra- and interspecific interactions in determining the abundance of root-feeding nematodes in natural ecosystems. We examined interactions between two ectoparasitic root-feeding nematodes on two plant species: a good host plant for both nematode species and a good host for only one of the nematodes. We tested the hypothesis that root herbivore competit...

  6. INVASIVE ALIEN PLANT SPECIES USED FOR THE TREATMENT OF VARIOUS DISEASES IN LIMPOPO PROVINCE, SOUTH AFRICA

    OpenAIRE

    Maema, Lesibana Peter; Potgieter, Martin; Mahlo, Salome Mamokone

    2016-01-01

    Background: Invasive alien plant species (IAPs) are plants that have migrated from one geographical region to non-native region either intentional or unintentional. The general view of IAPs in environment is regarded as destructive to the ecosystem and they pose threat to native vegetation and species. However, some of these IAPS are utilized by local inhabitants as a substitute for scarce indigenous plants. The aim of the study is to conduct ethnobotanical survey on medicinal usage of invasi...

  7. Exudate Chemical Profiles Derived from Lespedeza and Other Tallgrass Prairie Plant Species

    Science.gov (United States)

    2017-05-01

    Tallgrass Prairie Plant Species by David B. Ringelberg, Alyssa M. Beck, Ryan R. Busby, Imee G. Smith, and Anthony C. Yannarell ABSTRACT: Lespedeza...vironment, this work examines the interrelationships that exist between (a) plant -associated mi- crobiota from closely related native and (b) introduced...congeneric plant species. The hypothesis being tested is that if Lespedeza cuneata successfully alters the native soil microenvironment through the

  8. KEY TO THE POWDERY MILDEW SPECIES ON THE BASIS OF THE HOST PLANT FAMILIES AND GENERA

    Directory of Open Access Journals (Sweden)

    E. V. Rakhimova

    2015-05-01

    Full Text Available Key on the basis of the host plant taxonomy, symptoms of the infected plants and microscopic features of fungi was composed for identification of powdery mildews of the Kazakhstan. Features, which were used for identification of fungus, were the number of asci in cleistothecium, the number of ascospores in ascus and the type of appendages of cleistothecium. Key was composed for 81 species and 25 variations of Erysiphales fungi, infecting 739 species of host plants, which belong to 305 genera.

  9. Reactive oxygen species generation-scavenging and signaling during plant-arbuscular mycorrhizal and Piriformospora indica interaction under stress condition

    Directory of Open Access Journals (Sweden)

    Manoj Nath

    2016-10-01

    Full Text Available A defined balance between the generation and scavenging of reactive oxygen species (ROS is essential to utilize ROS as an adaptive defense response of plants under biotic and abiotic stress conditions. Moreover, ROS are not only a major determinant of stress response but also acts as signaling molecule that regulates various cellular processes including plant-microbe interaction. In particular, rhizosphere constitutes the biologically dynamic zone for plant–microbe interactions which forms a mutual link leading to reciprocal signaling in both the partners. Among plant–microbe interactions, symbiotic associations of arbuscular mycorrhizal fungi (AMF and arbuscular mycorrhizal-like fungus especially Piriformospora indica with plants are well known to improve plant growth by alleviating the stress-impacts and consequently enhance the plant fitness. AMF and P. indica colonization mainly enhances ROS-metabolism, maintains ROS-homeostasis, and thereby averts higher ROS-level accrued inhibition in plant cellular processes and plant growth and survival under stressful environments. This article summarizes the major outcomes of the recent reports on the ROS-generation and scavenging and signaling in biotic-abiotic stressed plants with AMF and P. indica colonization. Overall, a detailed exploration of ROS-signature kinetics during plant-AMF/P. indica interaction can help in designing innovative strategies for improving plant health and productivity under stress conditions.

  10. Alien Roadside Species More Easily Invade Alpine than Lowland Plant Communities in a Subarctic Mountain Ecosystem

    Science.gov (United States)

    Lembrechts, Jonas J.; Milbau, Ann; Nijs, Ivan

    2014-01-01

    Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment. PMID:24586947

  11. Image spectroscopy and stable isotopes elucidate functional dissimilarity between native and nonnative plant species in the aquatic environment.

    Science.gov (United States)

    Santos, Maria J; Hestir, Erin L; Khanna, Shruti; Ustin, Susan L

    2012-02-01

    • Nonnative species may change ecosystem functionality at the expense of native species. Here, we examine the similarity of functional traits of native and nonnative submersed aquatic plants (SAP) in an aquatic ecosystem. • We used field and airborne imaging spectroscopy and isotope ratios of SAP species in the Sacramento-San Joaquin Delta, California (USA) to assess species identification, chlorophyll (Chl) concentration, and differences in photosynthetic efficiency. • Spectral separability between species occurs primarily in the visible and near-infrared spectral regions, which is associated with morphological and physiological differences. Nonnatives had significantly higher Chl, carotene, and anthocyanin concentrations than natives and had significantly higher photochemical reflectance index (PRI) and δ(13) C values. • Results show nonnative SAPs are functionally dissimilar to native SAPs, having wider leaf blades and greater leaf area, dense and evenly distributed vertical canopies, and higher pigment concentrations. Results suggest that nonnatives also use a facultative C(4) -like photosynthetic pathway, allowing efficient photosynthesis in high-light and low-light environments. Differences in plant functionality indicate that nonnative SAPs have a competitive advantage over native SAPs as a result of growth form and greater light-use efficiency that promotes growth under different light conditions, traits affecting system-wide species distributions and community composition. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  12. Variation in habitat suitability does not always relate to variation in species' plant functional traits

    OpenAIRE

    Thuiller, Wilfried; Albert, Cécile H.; Dubuis, Anne; Randin, Christophe; Guisan, Antoine

    2009-01-01

    Habitat suitability models, which relate species occurrences to environmental variables, are assumed to predict suitable conditions for a given species. If these models are reliable, they should relate to change in plant growth and function. In this paper, we ask the question whether habitat suitability models are able to predict variation in plant functional traits, often assumed to be a good surrogate for a species' overall health and vigour. Using a thorough sampling design, we show a tigh...

  13. IMPACT OF WOODY PLANTS SPECIES ON SOIL PHYSIO-CHEMICAL PROPERTIES ALONG GRAZING GRADIENTS IN RANGELANDS OF EASTERN ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Mohammed Mussa Abdulahi

    2016-12-01

    Full Text Available In the lowlands of arid and semiarid rangelands woody plants plays an important role in soil fertility maintenance, providing food, medicine, cosmetics, fodder, fuel wood and pesticides. A better understanding of the interaction of woody plants on their immediate environment is needed to guide optimum management of native vegetation in the production landscapes. However, the impact of woody plant species on soil properties remains poorly understood. This study evaluates the impact of two dominant woody plant species (A. senegal and B. aegyptica on soil physico-chemical properties along grazing gradients in rangelands of eastern Ethiopia. Six trees of each species were selected from light, moderate and heavy grazing sites.  Soil sample data at two depths (0-15 and 16-30 cm were collected from under and open areas of A. senegal and B. aegyptica from each grazing sites, and analysed for nutrient contents. The nutrient status of soil under both woody species was significantly higher especially with regard to soil organic matter (4.37%, total nitrogen (0.313%, and available phosphorus (11.62 than the open grassland with soil organic matter (3.82%, total nitrogen (0.246%, and available phosphorus (10.94 mg/Kg soil for A. Senegal. The soil organic matter (3.93%, total nitrogen (0.285%, available phosphorus (11.66 mg/Kg soil were significantly higher than open grassland with soil organic matter (3.52%, total nitrogen (0.218%, available phosphorus (10.73 mg/Kg soil for B. aegyptica. This was more pronounced in the top 15 cm of soil under A. senegal woody plant species and on the light and moderate grazing site. Therefore, this tree has a significant effect on soil fertility improvement in resource poor rangelands and as a result, it is important to retain scattered A. senegal and B. aegyptica plants in the lowlands of eastern Ethiopia.

  14. Above- and belowground insect herbivores differentially affect soil nematode communities in species-rich plant communities

    NARCIS (Netherlands)

    Deyn, de G.B.; Ruijven, van J.; Raaijmakers, C.E.; Ruiter, de P.C.; Putten, van der W.H.

    2007-01-01

    Interactions between above- and belowground invertebrate herbivores alter plant diversity, however, little is known on how these effects may influence higher trophic level organisms belowground. Here we explore whether above- and belowground invertebrate herbivores which alter plant community

  15. Rejoinder to Harrison (2008): The myth of plant species saturation

    Science.gov (United States)

    Thomas J. Stohlgren; Curtis Flather; Catherine S. Jarnevich; David T. Barnett; John Kartesz

    2008-01-01

    We find ourselves in general agreement with many of Harrison's remarks especially since we both find our data present a ' strong case that at county to state scales, exotic plant invasions have led to few native plant extinctions' (emphasis added, Harrison 2007: 000). Where we differ appears related to the breadth of scales to which our conclusions may...

  16. Hemicryptophytes plant species as indicator of grassland state in ...

    African Journals Online (AJOL)

    Plots of 10 m X 10 m were installed along a land use gradient (from communal lands to the protected area via the buffer zone) in three vegetation types for plant biomass harvesting and hemicryptophytes traits measurement. The hemicryptophyte density, biovolume, tussock size, contact frequency, contribution to total plant ...

  17. Susceptibility of Australian plant species to Phytophthora ramorum

    Science.gov (United States)

    Kylie Ireland; Daniel H& uuml; berli; Bernard Dell; Ian Smith; David Rizzo; Giles. Hardy

    2010-01-01

    Phytophthora ramorum is an invasive plant pathogen causing considerable and widespread damage in nurseries, gardens, and natural woodland ecosystems of the United States and Europe, and is classified as a Category 1 pest in Australia. It is of particular interest to Australian plant biosecurity as, like P. cinnamomi; it has...

  18. Above- and below-ground vertebrate herbivory may each favour a different subordinate species in an aquatic plant community.

    Science.gov (United States)

    Hidding, Bert; Nolet, Bart A; de Boer, Thijs; de Vries, Peter P; Klaassen, Marcel

    2010-01-01

    At least two distinct trade-offs are thought to facilitate higher diversity in productive plant communities under herbivory. Higher investment in defence and enhanced colonization potential may both correlate with decreased competitive ability in plants. Herbivory may thus promote coexistence of plant species exhibiting divergent life history strategies. How different seasonally tied herbivore assemblages simultaneously affect plant community composition and diversity is, however, largely unknown. Two contrasting types of herbivory can be distinguished in the aquatic vegetation of the shallow lake Lauwersmeer. In summer, predominantly above-ground tissues are eaten, whereas in winter, waterfowl forage on below-ground plant propagules. In a 4-year exclosure study we experimentally separated above-ground herbivory by waterfowl and large fish in summer from below-ground herbivory by Bewick's swans in winter. We measured the individual and combined effects of both herbivory periods on the composition of the three-species aquatic plant community. Herbivory effect sizes varied considerably from year to year. In 2 years herbivore exclusion in summer reinforced dominance of Potamogeton pectinatus with a concomitant decrease in Potamogeton pusillus, whereas no strong, unequivocal effect was observed in the other 2 years. Winter exclusion, on the other hand, had a negative effect on Zannichellia palustris, but the effect size differed considerably between years. We suggest that the colonization ability of Z. palustris may have enabled this species to be more abundant after reduction of P. pectinatus tuber densities by swans. Evenness decreased due to herbivore exclusion in summer. We conclude that seasonally tied above- and below-ground herbivory may each stimulate different components of a macrophyte community as they each favoured a different subordinate plant species.

  19. Higher plant modelling for life support applications: first results of a simple mechanistic model

    Science.gov (United States)

    Hezard, Pauline; Dussap, Claude-Gilles; Sasidharan L, Swathy

    2012-07-01

    In the case of closed ecological life support systems, the air and water regeneration and food production are performed using microorganisms and higher plants. Wheat, rice, soybean, lettuce, tomato or other types of eatable annual plants produce fresh food while recycling CO2 into breathable oxygen. Additionally, they evaporate a large quantity of water, which can be condensed and used as potable water. This shows that recycling functions of air revitalization and food production are completely linked. Consequently, the control of a growth chamber for higher plant production has to be performed with efficient mechanistic models, in order to ensure a realistic prediction of plant behaviour, water and gas recycling whatever the environmental conditions. Purely mechanistic models of plant production in controlled environments are not available yet. This is the reason why new models must be developed and validated. This work concerns the design and test of a simplified version of a mathematical model coupling plant architecture and mass balance purposes in order to compare its results with available data of lettuce grown in closed and controlled chambers. The carbon exchange rate, water absorption and evaporation rate, biomass fresh weight as well as leaf surface are modelled and compared with available data. The model consists of four modules. The first one evaluates plant architecture, like total leaf surface, leaf area index and stem length data. The second one calculates the rate of matter and energy exchange depending on architectural and environmental data: light absorption in the canopy, CO2 uptake or release, water uptake and evapotranspiration. The third module evaluates which of the previous rates is limiting overall biomass growth; and the last one calculates biomass growth rate depending on matter exchange rates, using a global stoichiometric equation. All these rates are a set of differential equations, which are integrated with time in order to provide

  20. Restricted variation in plant barcoding markers limits identification in closely related bryophyte species.

    Science.gov (United States)

    Hassel, Kristian; Segreto, Rossana; Ekrem, Torbjørn

    2013-11-01

    Species-level identification and delimitation of bryophytes using the proposed general barcode markers for land plants has been challenging. Bryophyta (mosses) is the second most species-rich group of land plants after angiosperms, and it is thus of great importance to find useful barcoding regions also for this group of plants. We investigated how the plastid regions atpF-atpH, rbcL and trnH-psbA and the nuclear ITS2 region performed as barcode markers on closely related bryophyte taxa of selected moss (Bartramia, Distichium, Fissidens, Meesia and Syntrichia) and liverwort (Blepharostoma) genera from boreal and arctic regions. We also evaluated how sequencing success of herbarium specimens is related to length of the sequenced fragment, specimen age and taxonomic group. Sequencing success was higher for shorter fragments and younger herbarium specimens, but was lower than expected in the genera Distichium and Fissidens, indicating imperfect universality of the primers used. None of the studied DNA barcode regions showed a consistent barcode gap across the studied genera. As a single locus, the region atpF-atpH performed slightly better than rbcL and ITS2 and much better than trnH-psbA in terms of grouping conspecific sequences in monophyletic groups. This marker also gave a higher percentage of correct hits when conducting blast searches on a local database of identified sequences. Concatenated data sets of two and three markers grouped more conspecific sequences in monophyletic groups, but the improvement was not great compared with atpF-atpH alone. A discussion of recent studies testing barcode regions for bryophytes is given. We conclude that atpF-atpH, rbcL and ITS2 are to be the most promising barcode markers for mosses. © 2013 John Wiley & Sons Ltd.

  1. Uptake and translocation of plutonium in two plant species using hydroponics.

    Science.gov (United States)

    Lee, J H; Hossner, L R; Attrep, M; Kung, K S

    2002-01-01

    This study presents determinations of the uptake and translocation of Pu in Indian mustard (Brassica juncea) and sunflower (Helianthus annuus) from Pu contaminated solution media. The initial activity levels of Pu were 18.50 and 37.00 Bq ml(-1), for Pu-nitrate [239Pu(NO3)4] and for Pu-citrate [239Pu(C6H5O7)+] in nutrient solution. Plutonium-diethylenetriaminepentaacetic acid (DTPA: [239Pu-C14H23O10N3] solution was prepared by adding 0, 5, 10, and 50 microg of DTPA ml(-1) with 239Pu(NO3)4 in nutrient solution. Concentration ratios (CR, Pu concentration in dry plant material/Pu concentration in nutrient solution) and transport indices (Tl, Pu content in the shoot/Pu content in the whole plant) were calculated to evaluate Pu uptake and translocation. All experiments were conducted in hydroponic solution in an environmental growth chamber. Plutonium concentration in the plant tissue was increased with increased Pu contamination. Plant tissue Pu concentration for Pu-nitrate and Pu-citrate application was not correlated and may be dependent on plant species. For plants receiving Pu-DTPA, the Pu concentration was increased in the shoots but decreased in the roots resulting in a negative correlation between the Pu concentrations in the plant shoots and roots. The Pu concentration in shoots of Indian mustard was increased for application rates up to 10 microg DTPA ml(-1) and up to 5 microg DTPA ml(-1) for sunflower. Similar trends were observed for the CR of plants compared to the Pu concentration in the shoots and roots, whereas the Tl was increased with increasing DTPA concentration. Plutonium in shoots of Indian mustard was up to 10 times higher than that in shoots of sunflower. The Pu concentration in the apparent free space (AFS) of plant root tissue of sunflower was more affected by concentration of DTPA than that of Indian mustard.

  2. THRIPS SPECIES (INSECTA: THYSANOPTERA OF ORNAMENTAL PLANTS FROM THE PARKS AND GREENHOUSES OF ADP PITESTI

    Directory of Open Access Journals (Sweden)

    Daniela Bărbuceanu

    2012-04-01

    Full Text Available The observations carried-out in 2008/2010 to ornamental plants from parks and greenhouses of ADP Pitesti relieve 12 species of thrips. One species of them, Frankliniella occidentalis was identified in greenhouses on Rosa sp., Dianthus sp. and Zantedeschia sp. In parks, the thrips species belong to 12 species, dominated by Frankliniella intonsa. All of them are polypfagous and divided in two throphic levels: primary and secondary consumers. The thrips species are mentioned for the first time in Romania on this host plant. In greenhouses are necessary intensive chemical treatments and methods of cultural hygiene to limit the F. occidentalis populations.

  3. Comparative analysis of microsatellites in chloroplast genomes of lower and higher plants.

    Science.gov (United States)

    George, Biju; Bhatt, Bhavin S; Awasthi, Mayur; George, Binu; Singh, Achuit K

    2015-11-01

    Microsatellites, or simple sequence repeats (SSRs), contain repetitive DNA sequence where tandem repeats of one to six base pairs are present number of times. Chloroplast genome sequences have been  shown to possess extensive variations in the length, number and distribution of SSRs. However, a comparative analysis of chloroplast microsatellites is not available. Considering their potential importance in generating genomic diversity, we have systematically analysed the abundance and distribution of simple and compound microsatellites in 164 sequenced chloroplast genomes from wide range of plants. The key findings of these studies are (1) a large number of mononucleotide repeats as compared to SSR(2-6)(di-, tri-, tetra-, penta-, hexanucleotide repeats) are present in all chloroplast genomes investigated, (2) lower plants such as algae show wide variation in relative abundance, density and distribution of microsatellite repeats as compared to flowering plants, (3) longer SSRs are excluded from coding regions of most chloroplast genomes, (4) GC content has a weak influence on number, relative abundance and relative density of mononucleotide as well as SSR(2-6). However, GC content strongly showed negative correlation with relative density (R (2) = 0.5, P plants possesses relatively more genomic diversity compared to higher plants.

  4. Biohydrogenation of Fatty Acids Is Dependent on Plant Species and Feeding Regimen of Dairy Cows

    DEFF Research Database (Denmark)

    Petersen, Majbritt Bonefeld; Jensen, Søren Krogh

    2014-01-01

    and LA between single plant species and feeding regimens. Rumen fluid was collected from cows fed either total mixed ration (TMR), species-rich silage (HERB), or grass silage (GRASS). Five single species (alfalfa, birdsfoot trefoil, chicory, English plantain, and salad burnet) and a grass–clover mixture...

  5. 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

    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 be...

  6. Palyonological studies of the semi-desert plant species from Pakistan

    African Journals Online (AJOL)

    The detailed palynological description of 40 angiospermic plant species, belonging to 22 families and 38 genera were made. Out of the 22 families, 3 families were monocotyledonous and 19 dicotyledonous. The Brassicaceae and Papilionaceae were the largest families regarding number of species having four species ...

  7. Phytochemicals of selected plant species of the Apocynaceae and Asclepiadaceae from Western Ghats, Tamil Nadu, India

    Science.gov (United States)

    A concern about the declining supply of petroleum products has led to a renewed interest in evaluating plant species as potential alternate sources of energy. Five species of the Apocynaceae and three species of the Asclepiadaceae from the Western Ghats were evaluated as alternative sources of energ...

  8. Race to Displace: A Game to Model the Effects of Invasive Species on Plant Communities

    Science.gov (United States)

    Hopwood, Jennifer L.; Flowers, Susan K.; Seidler, Katie J.; Hopwood, Erica L.

    2013-01-01

    Invasive species are a substantial threat to biodiversity. Educating students about invasive species introduces fundamental concepts in biology, ecology, and environmental science. In the Race to Displace game, students assume the characteristics of select native or introduced plants and experience first hand the influences of species interactions…

  9. 7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.

    Science.gov (United States)

    2010-01-01

    ..., to be critical.” The Act also: (i) Defines endangered species as any species in danger of extinction... animals. 650.22 Section 650.22 Agriculture Regulations of the Department of Agriculture (Continued... Related Environmental Concerns § 650.22 Rare, threatened, and endangered species of plants and animals. (a...

  10. The role of cattle in maintaining plant species diversity in wet dune valleys

    NARCIS (Netherlands)

    Aptroot, A.; van Dobben, H. F.; Slim, P. A.; Olff, H.

    The succession of species-rich wetland vegetation in dune valleys into species-poor dwarf shrub vegetation was followed by means of permanent vegetation plots, in which the cover of vascular plant, moss and lichen species were recorded over a period of up to 33 years. Low density cattle grazing is

  11. Plant-Species Diversity Correlates with Genetic Variation of an Oligophagous Seed Predator

    OpenAIRE

    Liisa Laukkanen; Pia Mutikainen; Anne Muola; Roosa Leimu

    2014-01-01

    Several characteristics of habitats of herbivores and their food-plant communities, such as plant-species composition and plant quality, influence population genetics of both herbivores and their host plants. We investigated how different ecological and geographic factors affect genetic variation in and differentiation of 23 populations of the oligophagous seed predator Lygaeus equestris (Heteroptera) in southwestern Finland and in eastern Sweden. We tested whether genetic differentiation of ...

  12. Plant roots and spectroscopic methods – analyzing species, biomass and vitality

    OpenAIRE

    Rewald, Boris; Meinen, Catharina

    2013-01-01

    In order to understand plant functioning, plant community composition, and terrestrial biogeochemistry, it is decisive to study standing root biomass, (fine) root dynamics, and interactions belowground. While most plant taxa can be identified by visual criteria aboveground, roots show less distinctive features. Furthermore, root systems of neighboring plants are rarely spatially segregated; thus, most soil horizons and samples hold roots of more than one species necessitating root sorting acc...

  13. Plant roots and spectroscopic methods–analysing species, biomass and vitality

    OpenAIRE

    Boris eRewald; Catharina eMeinen

    2013-01-01

    In order to understand plant functioning, plant community composition and terrestrial biogeochemistry it is decisive to study standing root biomass, (fine) root dynamics and interactions below ground. While most plant taxa can be identified by visual criteria above ground, roots show less distinctive features. Furthermore, root systems of neighbouring plants are rarely spatially segregated; thus, most soil horizons and samples hold roots of more than one species necessitating root sorting acc...

  14. PRESENCE OF ARTHROPOD PESTS ON EIGHT SPECIES OF BANKER PLANTS IN A GREENHOUSE

    OpenAIRE

    Parolin, Pia; INRA, UR 880, F-06903 Sophia Antipolis, France.; Bresch, Cécile; INRA, UR 880, F-06903 Sophia Antipolis, France.; Ruiz, Gauthier; INRA, UR 880, F-06903 Sophia Antipolis, France.; Poncet, Christine; INRA, UR 880, F-06903 Sophia Antipolis, France

    2013-01-01

    Despite precautions, the spontaneous invasion of undesired arthropod pests in greenhouses seems to be unavoidable. Secondary plants can be employed in biological control to enhance the proliferation of desired natural enemies of arthropod pests. However, these additional plants may also attract pests which in turn attack the crop plants. The present study is part of a long-term experiment to test eight species of banker plants (BPs) and their efficiency for biological protection against the s...

  15. The CW domain, a structural module shared amongst vertebrates, vertebrate-infecting parasites and higher plants.

    Science.gov (United States)

    Perry, Jason; Zhao, Yunde

    2003-11-01

    A previously undetected domain, named CW for its conserved cysteine and tryptophan residues, appears to be a four-cysteine zinc-finger motif found exclusively in vertebrates, vertebrate-infecting parasites and higher plants. Of the twelve distinct nuclear protein families that comprise the CW domain-containing superfamily, only the microrchida (MORC) family has begun to be characterized. However, several families contain other domains suggesting a relationship between the CW domain and either chromatin methylation status or early embryonic development.

  16. Body lift, drag and power are relatively higher in large-eared than in small-eared bat species

    DEFF Research Database (Denmark)

    Håkansson, Jonas; Jakobsen, Lasse; Hedenström, Anders

    2017-01-01

    than previously assumed and that the large-eared species has a higher body drag coefficient, but also produces relatively more ear/body lift than the small-eared species, in line with prior studies on model bats. The measured aerodynamic power of P. auritus was higher than predicted from...... mitigate the cost by producing aerodynamic lift. Here we compare quantitative aerodynamic measures of flight efficiency of two bat species, one large-eared (Plecotus auritus) and one small-eared (Glossophaga soricina), flying freely in a wind tunnel. We find that the body drag of both species is higher...

  17. Chemostratigraphic evidence of higher-plant evolution in the Taranaki Basin, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Killops, S.D.; Raine, J.I.; Woolhouse, A.D.; Weston, R.J. [Institute of Geology and Nuclear Science, Lower Hutt (New Zealand)

    1995-05-01

    Correlation between palynological and biomarker records of higher-plant development during the Cretaceous and Paleogene in Taranaki Basin, New Zealand is good. Gymnosperms, particularly podocarps, were the chief members of coastal plain swamp flora during the Late Cretaceous, and contributed significant quantities of diterpanes, often dominated by isopimarane, to organic-rich sediments. Angiosperms increased in relative abundance through the Paleocene and became the dominant higher plants in the Eocene; their contributions to coaly sediments are characterized by various triterpanes, particularly 18 alpha(H)-oleanane and its C-24 A-ring degraded counterpart. This change in dominance of higher-land groups can be followed by the use of an angiosperm/gymnosperm index (AGI) based on the relative concentrations of selected triterpanes and diterpanes in m/z 191 and m/z 123 mass chromatograms. Plant biomarker distributions do not provide as precise age indications as do pollen assemblages, but they may be more representative of the vegetation growing in a particular area of a peat swamp.

  18. Impact of invertebrate herbivory in grasslands depends on plant species diversity.

    Science.gov (United States)

    Stein, Claudia; Unsicker, Sybille B; Kahmen, Ansgar; Wagner, Markus; Audorff, Volker; Auge, Harald; Prati, Daniel; Weisser, Wolfgang W

    2010-06-01

    Invertebrate herbivores are ubiquitous in most terrestrial ecosystems, and theory predicts that their impact on plant community biomass should depend on diversity and productivity of the associated plant communities. To elucidate general patterns in the relationship between invertebrate herbivory, plant diversity, and productivity, we carried out a long-term herbivore exclusion experiment at multiple grassland sites in a mountainous landscape of central Germany. Over a period of five years, we used above- and belowground insecticides as well as a molluscicide to manipulate invertebrate herbivory at 14 grassland sites, covering a wide range of plant species diversity (13-38 species/m2) and aboveground plant productivity (272-1125 g x m(-2) x yr(-1)), where plant species richness and productivity of the sites were not significantly correlated. Herbivore exclusion had significant effects on the plant communities: it decreased plant species richness and evenness, and it altered plant community composition. In particular, exclusion of belowground herbivores promoted grasses at the expense of herbs. In contrast to our expectation, herbivore effects on plant community biomass were not influenced by productivity. However, effect size of invertebrate herbivores was negatively correlated with plant diversity of the grasslands: the effect of herbivory on biomass tended to be negative at sites of high diversity and positive at sites of low diversity. In general, the effects of aboveground herbivores were relatively small as compared to belowground herbivores, which were important drivers of plant community composition. Our study is the first to show that variation in the effects of invertebrate herbivory on plant communities across a landscape is significantly influenced by plant species richness.

  19. Exotic species and the structure of a plant-galling network

    Directory of Open Access Journals (Sweden)

    Walter Santos de Araujo

    2017-06-01

    Full Text Available Gall-inducing insects are highly specialized herbivores and is expected that networks composed by gall-inducing insects and their host plants are also very specialized. However, presence of exotic species might reduce the interaction number for native species, which would lead to changes in the specialization of plant-galling networks. In this study, we use network metrics to describe, for the first time, the structure of a network of gall-inducing insects associated to ornamental host plants. We found that the plant-galling network has a low-connected structure and is more modular than expected by chance. Native insect herbivores were significantly more frequent on native host plant species, while exotic herbivores occurred mostly on exotic host plant species. On the other hand, the number of interactions between insect herbivores and native or exotic plant species did not vary. Our findings show that plant-galling networks are very specialized and structured independently of exotic species presence.

  20. The abundance of pink-pigmented facultative methylotrophs in the root zone of plant species in invaded coastal sage scrub habitat.

    Directory of Open Access Journals (Sweden)

    Irina C Irvine

    Full Text Available Pink-pigmented facultative methylotrophic bacteria (PPFMs are associated with the roots, leaves and seeds of most terrestrial plants and utilize volatile C(1 compounds such as methanol generated by growing plants during cell division. PPFMs have been well studied in agricultural systems due to their importance in crop seed germination, yield, pathogen resistance and drought stress tolerance. In contrast, little is known about the PPFM abundance and diversity in natural ecosystems, let alone their interactions with non-crop species. Here we surveyed PPFM abundance in the root zone soil of 5 native and 5 invasive plant species along ten invasion gradients in Southern California coastal sage scrub habitat. PPFMs were present in every soil sample and ranged in abundance from 10(2 to 10(5 CFU/g dry soil. This abundance varied significantly among plant species. PPFM abundance was 50% higher in the root zones of annual or biennial species (many invasives than perennial species (all natives. Further, PPFM abundance appears to be influenced by the plant community beyond the root zone; pure stands of either native or invasive species had 50% more PPFMs than mixed species stands. In sum, PPFM abundance in the root zone of coastal sage scrub plants is influenced by both the immediate and surrounding plant communities. The results also suggest that PPFMs are a good target for future work on plant-microorganism feedbacks in natural ecosystems.

  1. [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

  2. [Investigation on Wild Original Plant Species of Chinese Medicinal Herbs in Quanzhou City, Fujian Province].

    Science.gov (United States)

    Huang, Xiu-zhen; Zou, Xiu-hong

    2014-12-01

    To explore the original plants of wild medicinal herbs in Quanzhou City, Fujian Province and find out the species of these plants. Based on the field investigation, specimen collection and literature reference, inductive analysis of the wild original plants of Chinese medicinal herbs in Quanzhou City had been carried out. After investigation, it was discovered that there were 84 families 155 genera 184 species of original plants of Chinese medicinal herbs in Quanzhou City, of which 6 families 7 genera 9 species belonged to pteridophytes; 2 families 2 genera 2 species belonged to gymnosperms; and the rest were angio-sperms. Among the angiosperms, dicotyledons accounted for 62 families 117 genera 139 species; monocotyledons took up 14 families 29 genera 34 species. The plants mentioned above were the original plants of the 186 Chinese medicinal herbs and decoction pieces in the Chinese Pharmacopoeia (2010 edition). This paper has explored the wild original plant species of Chinese medicinal herbs in Quanzhou City, Fujian Province to provide not only the basis for the local government's development and utilization of wild Chinese medicinal herbs but also the data for the fourth national survey of Chinese medicinal herb resources.

  3. Does plant species richness guarantee the resilience of local medical systems? A perspective from utilitarian redundancy.

    Directory of Open Access Journals (Sweden)

    Flávia Rosa Santoro

    Full Text Available Resilience is related to the ability of a system to adjust to disturbances. The Utilitarian Redundancy Model has emerged as a tool for investigating the resilience of local medical systems. The model determines the use of species richness for the same therapeutic function as a facilitator of the maintenance of these systems. However, predictions generated from this model have not yet been tested, and a lack of variables exists for deeper analyses of resilience. This study aims to address gaps in the Utilitarian Redundancy Model and to investigate the resilience of two medical systems in the Brazilian semi-arid zone. As a local illness is not always perceived in the same way that biomedicine recognizes, the term "therapeutic targets" is used for perceived illnesses. Semi-structured interviews with local experts were conducted using the free-listing technique to collect data on known medicinal plants, usage preferences, use of redundant species, characteristics of therapeutic targets, and the perceived severity for each target. Additionally, participatory workshops were conducted to determine the frequency of targets. The medical systems showed high species richness but low levels of species redundancy. However, if redundancy was present, it was the primary factor responsible for the maintenance of system functions. Species richness was positively associated with therapeutic target frequencies and negatively related to target severity. Moreover, information about redundant species seems to be largely idiosyncratic; this finding raises questions about the importance of redundancy for resilience. We stress the Utilitarian Redundancy Model as an interesting tool to be used in studies of resilience, but we emphasize that it must consider the distribution of redundancy in terms of the treatment of important illnesses and the sharing of information. This study has identified aspects of the higher and lower vulnerabilities of medical systems, adding

  4. The exploration of plant species in nature reserve of Mount Mutis East Nusa Tenggara Province

    Directory of Open Access Journals (Sweden)

    Solikin Solikin

    2016-04-01

    Full Text Available This research was aimed to explore and inventory the plant diversity, especially medicinal plants in Nature Reserve of Mount Mutis. Data were collected in Fatumnasi Village, Fatumnasi District of South Central Timor Regency in Octo-ber 2011 through plant exploration and interview the local people. Plants inventory was conducted along the tracks during exploration. Herbs vegetation analysis was conducted among the tree stands of Eucalyptus urophylla. In addi-tion, orchid vegetation analysis was only conducted to orchids that have been found attaching to Eucalyptus urophylla trees. Results showed that there were about 52 family, 78 genera and 84 species of plants in the observed area. Tree species was dominated by 'ampupu' (Eucalyptus urophylla, while orchid species was dominated by Eria retusa. Herbaceous plant communities were dominated by Centella asiatica, Cyperus sp. and Cynodon dactylon. There were about eight plant species of medicinal plants and one food plant species found in the forestthat have been known by local people. Keywords: exploration, inventory, Mount Mutis, nature reserve

  5. Cultural significance of medicinal plant families and species among Quechua farmers in Apillapampa, Bolivia.

    Science.gov (United States)

    Thomas, Evert; Vandebroek, Ina; Sanca, Sabino; Van Damme, Patrick

    2009-02-25

    Medicinal plant use was investigated in Apillapampa, a community of subsistence farmers located in the semi-arid Bolivian Andes. The main objectives were to identify the culturally most significant medicinal plant families and species in Apillapampa. A total of 341 medicinal plant species was inventoried during guided fieldtrips and transect sampling. Data on medicinal uses were obtained from fifteen local Quechua participants, eight of them being traditional healers. Contingency table and binomial analyses of medicinal plants used versus the total number of inventoried species per family showed that Solanaceae is significantly overused in traditional medicine, whereas Poaceae is underused. Also plants with a shrubby habitat are significantly overrepresented in the medicinal plant inventory, which most likely relates to their year-round availability to people as compared to most annual plants that disappear in the dry season. Our ranking of medicinal species according to cultural importance is based upon the Quality Use Agreement Value (QUAV) index we developed. This index takes into account (1) the average number of medicinal uses reported for each plant species by participants; (2) the perceived quality of those medicinal uses; and (3) participant consensus. According to the results, the QUAV index provides an easily derived and valid appraisal of a medicinal plant's cultural significance.

  6. Root uptake of uranium by a higher plant model (Phaseolus vulgaris) bioavailability from soil solution

    Energy Technology Data Exchange (ETDEWEB)

    Laroche, L.; Henner, P.; Camilleri, V.; Garnier-Laplace, J. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Uranium behaviour in soils is controlled by actions and interactions between physicochemical and biological processes that also determine its bioavailability. In soil solution, uranium(+VI) aqueous speciation undergoes tremendous changes mainly depending on pH, carbonates, phosphates and organic matter. In a first approach to identify bioavailable species of U to plants, cultures were performed using hydroponics, to allow an easy control of the composition of the exposure media. The latter, here an artificial soil solution, was designed to control the uranium species in solution. The geochemical speciation code JCHESS using a database compiled from the OECD/NEA thermochemical database project and verified was used to perform the solution speciation calculations. On this theoretical basis, three domains were defined for short-duration well-defined laboratory experiments in simplified conditions: pH 4.9, 5.8 and 7 where predicted dominant species are uranyl ions, hydroxyl complexes and carbonates respectively. For these domains, biokinetics and characterization of transmembrane transport according to a classical Michaelis Menten approach were investigated. The Free Ion Model (or its derived Biotic Ligand Model) was tested to determine if U uptake is governed by the free uranyl species or if other metal complexes can be assimilated. The effect of different variables on root assimilation efficiency and phyto-toxicity was explored: presence of ligands such as phosphates or carbonates and competitive ions such as Ca{sup 2+} at the 3 pH. According to previous experiments, uranium was principally located in roots whatever the pH and no difference in uranium uptake was evidenced between the main growth stages of the plant. Within the 3 studied chemical domains, results from short-term kinetics evidenced a linear correlation between total uranium concentration in bean roots and that in exposure media, suggesting that total uranium in soil solution could be a good predictor

  7. Larvicidal properties of two asclepiadaceous plant species against the mosquito Anopheles arabiensis Patton (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Amal Elsayed Edriss

    2013-01-01

    Full Text Available Certain mosquito species are important vectors of fatal human diseases, among which Anopheles arabiensis is known to be associated with malaria transmission in different tropical and subtropical areas. Since chemical control of mosquitoes was linked with numerous drawbacks, like resistance development, the search for effective environmentally sound alternatives is urgently needed. Therefore, it was aimed by this study to evaluate some extracts prepared from two asclepiadaceous plants, viz., Solenostemma argel “Hargel” (seeds and leaves and Calotropis procera “Usher” (leaves and flowers, as natural larvicides against An. arabiensis. The main parameters included bioassays of treatments for knockdown and residual effects, besides phytochemical analysis of the tested extracts. The results revealed variable groups of secondary metabolites in the two plants, with S. argel seemed to be the richest one. Hence, S. argel extracts caused higher larval mortalities than those of C. procera. This could be ascribed to some potent secondary metabolites in the former plant, which needs further studies. Almost all the high concentrations of S. argel extracts exerted the highest knockdown effect (90% mortality after 24 h, which were comparable with those obtained by two standard insecticides. The highest doses of petroleum ether and water extracts of this plant also manifested significantly higher residual effects than the other extracts after three days following treatments, but were surpassed by the chemical insecticides thereafter. However, S. argel seed petroleum ether extract at 0.5% was the most effective of all botanicals up to three weeks of exposure. This extract needs to be evaluated under field conditions for proper exploitation as mosquito larvicide.

  8. An Ethnobotanical Survey on Fuel Wood and Timber plant Species ...

    African Journals Online (AJOL)

    A survey was conducted to explore the fuel wood species and timber producing species of Kaghan valleys, Pakistan. Consumption pattern and impact on the forest resources were also taken into consideration. A questionnaire was used as a survey instrument to obtain desired data. For this study, 10 villages were randomly ...

  9. Seed longevity of dominant plant species from degraded savanna in ...

    African Journals Online (AJOL)

    The intermittent and extended germination of seeds of the same species from the same batch shown by some species may be regarded as an ecological adaptation to prevent synchronous germination in unpredictable harsh environments, whereas prompt germination of some Acacia seeds may be viewed as a strategy to ...

  10. Ethical perception of cross-species gene transfer in plant

    African Journals Online (AJOL)

    Jane

    2011-09-30

    Sep 30, 2011 ... the ethical acceptance of cross-species gene transfers in developing country. Key words: Ethical perception, genetically modified (GM) rice, cross-species gene transfer, Malaysia. INTRODUCTION. Rice is a staple food in much of Asia countries including. Malaysia, and by 2025 about 60% more rice must ...

  11. Individual-based ant-plant networks: diurnal-nocturnal structure and species-area relationship.

    Science.gov (United States)

    Dáttilo, Wesley; Fagundes, Roberth; Gurka, Carlos A Q; Silva, Mara S A; Vieira, Marisa C L; Izzo, Thiago J; Díaz-Castelazo, Cecília; Del-Claro, Kleber; Rico-Gray, Victor

    2014-01-01

    Despite the importance and increasing knowledge of ecological networks, sampling effort and intrapopulation variation has been widely overlooked. Using continuous daily sampling of ants visiting three plant species in the Brazilian Neotropical savanna, we evaluated for the first time the topological structure over 24 h and species-area relationships (based on the number of extrafloral nectaries available) in individual-based ant-plant networks. We observed that diurnal and nocturnal ant-plant networks exhibited the same pattern of interactions: a nested and non-modular pattern and an average level of network specialization. Despite the high similarity in the ants' composition between the two collection periods, ant species found in the central core of highly interacting species totally changed between diurnal and nocturnal sampling for all plant species. In other words, this "night-turnover" suggests that the ecological dynamics of these ant-plant interactions can be temporally partitioned (day and night) at a small spatial scale. Thus, it is possible that in some cases processes shaping mutualistic networks formed by protective ants and plants may be underestimated by diurnal sampling alone. Moreover, we did not observe any effect of the number of extrafloral nectaries on ant richness and their foraging on such plants in any of the studied ant-plant networks. We hypothesize that competitively superior ants could monopolize individual plants and allow the coexistence of only a few other ant species, however, other alternative hypotheses are also discussed. Thus, sampling period and species-area relationship produces basic information that increases our confidence in how individual-based ant-plant networks are structured, and the need to consider nocturnal records in ant-plant network sampling design so as to decrease inappropriate inferences.

  12. The Effect of Designated Pollutants on Plant Species

    Science.gov (United States)

    1981-01-01

    fertilizer and 12 kg pre-emergence weed killer (Dacthal) per hectare during plowing. Two-week-old zinnia and marigold plants, started in peat pots in the...sterilized U.C. Soil Mix II (Lerman, 1976). Plants were watered regularly and fertilized weekly with a nutrient solution (Hoagland and Aaron, 1950...Tagetes patula L. Goldie 3 SENSITIVE [50-75% injury at 25 mg m7 3] Radish Raphanus sativus L. Comet 2 Sudan grass Sorgham vulgare (Piper) Hitchc. Sudanese 4

  13. The Impact of Root Temperature on Photosynthesis and Isoprene Emission in Three Different Plant Species

    Directory of Open Access Journals (Sweden)

    Mauro Medori

    2012-01-01

    Full Text Available Most of the perennial plant species, particularly trees, emit volatile organic compounds (BVOCs such as isoprene and monoterpenes, which in several cases have been demonstrated to protect against thermal shock and more generally against oxidative stress. In this paper, we show the response of three strong isoprene emitter species, namely, Phragmites australis, Populus x euramericana, and Salix phylicifolia exposed to artificial or natural warming of the root system in different conditions. This aspect has not been investigated so far while it is well known that warming the air around a plant stimulates considerably isoprene emission, as also shown in this paper. In the green house experiments where the warming corresponded with high stress conditions, as confirmed by higher activities of the main antioxidant enzymes, we found that isoprene uncoupled from photosynthesis at a certain stage of the warming treatment and that even when photosynthesis approached to zero isoprene emission was still ongoing. In the field experiment, in a typical cold-limited environment, warming did not affect isoprene emission whereas it increased significantly CO2 assimilation. Our findings suggest that the increase of isoprene could be a good marker of heat stress, whereas the decrease of isoprene a good marker of accelerated foliar senescence, two hypotheses that should be better investigated in the future.

  14. Estimation of soil-to-plant transfer factors of radiocesium in 99 wild plant species grown in arable lands 1 year after the Fukushima 1 Nuclear Power Plant accident.

    Science.gov (United States)

    Yamashita, Jun; Enomoto, Takashi; Yamada, Masao; Ono, Toshiro; Hanafusa, Tadashi; Nagamatsu, Tomohiro; Sonoda, Shoji; Yamamoto, Yoko

    2014-01-01

    One year after the deposition of radionuclides from the Fukushima 1 Nuclear Power Plant (A formal name is Fukushima Daiichi Nuclear Power Station) in March 2011, radiocesium (¹³⁴Cs, ¹³⁷Cs) concentrations ([Cs]) were comprehensively investigated in the wild plants of 99 species most of which were annual or summer green perennial herbs and started to grow from April 2012 at the heavily contaminated fields of paddy (three study sites) and upland (one study site) in Fukushima Prefecture. The survey was conducted three times (April, July and October) in the year. In each site, soils (soil cores of 5-cm depth) and plants (aerial shoots) were collected for determination of [Cs] on a dry weight basis, and then the transfer factor (TF) of radiocesium from soil to plant ([Cs]plant/[Cs]soil) was estimated in each species. The [Cs] values of both soils and plants largely varied. However, some species exhibited relatively high TF values (more than 0.4) (e.g., Athyrium yokoscense, Dryopteris tokyoensis, and Cyperus brevifolius), while others exhibited almost negligible values (less than 0.01) (e.g., Salix miyabeana, Humulus scandens, and Elymus tsukushiensis). In addition, judging from the 11 species grown in both paddy and upland fields, TF values were generally higher in the paddy fields. The estimation of phytoextraction efficiency of soil radiocesium by weed communities in the paddy fields suggests that the weed community is not a practical candidate for phytoremediation technique.

  15. Moving Uphill: Microbial Facilitation at the Leading Edge of Plant Species Distributional Shifts

    Science.gov (United States)

    Suding, K.; Farrer, E.; Spasojevic, M.; Porazinska, D.; Bueno de Mesquita, C.; Schmidt, S. K.

    2016-12-01

    Climate change is expected to influence species distributions and reshuffle patterns of biodiversity. A key challenge to our understanding of these effects is that biotic interactions - new species to compete with, new stressors that increase dependence on facilitation, new prey or predators - will likely affect the ability of species to track climate at the leading edges of their distributional range. While it is well established that soil biota strongly influence plant abundance and diversity, it has been difficult to quantify the key belowground dynamics. This presentation will investigate the influence of one key biotic interaction, between plants and soil microbiota, on the ability of plant species to track climate change and expand their range uphill in a high montane system in the Front Range of Colorado. High-resolution photography from 1972 and 2008 indicate colonization of tundra vegetation in formerly unvegetated areas. Observational work on the distributions patterns of both plants and soil microbiota (bacteria, fungi and nematodes) in a spatially-explicit grid at the upper edge of plant distributions indicate strong, mostly positive, associations between plant species and soil taxa. Abiotic factors, while important, consistently underpredicted the occurrence of plant species and, in nine of the 12 most common tundra plants, co-occurring microbial taxa were important predictors of plant occurrence. Comparison of plant and microbial distributional patterns in 2007 and 2015 indicate the influence of microbial community composition on assembly and beta-diversity of the plant community over time. Plant colonization patterns in this region previously devoid of vegetation will likely influence carbon, nitrogen and phosphorus dynamics, with downstream consequences on nutrient limitation and phytoplankton composition in alpine lakes.

  16. Patterns of plant species richness, rarity, endemism, and uniqueness in an arid landscape

    Science.gov (United States)

    Stohlgren, T.J.; Guenther, D.A.; Evangelista, P.H.; Alley, N.

    2005-01-01

    Most current conservation literature focuses on the preservation of hotspots of species diversity and endemism, as if the two were geographically synonymous. At landscape scales this may not be the case. We collected data from 367 1000-m2 plots in the Grand Staircase–Escalante National Monument, Utah, USA, to show that: (1) the vast majority of plant species are locally rare; (2) species-rich areas are generally in rare, mesic, or high-elevation habitats such as aspen stands or riparian zones high in soil N and P; (3) endemic species (to the Colorado Plateau and the Monument) were generally found in relatively species-rich, but low-elevation, xeric vegetation type areas low in soil P; (4) unique species assemblages were found in areas moderately high in endemism and species richness; and (5) nonnative plant species were widely distributed, but more prevalent in species-rich, mesic sites high in soil fertility or disturbed sites, and significantly less prevalent in plots with endemic species. We show that primary hotspots of species richness, high endemism, and unique species assemblages are not co-located on the landscape. Hence, conservation strategies may have to consider a much broader concept of “hotspots” to adequately preserve native plant species and the processes that foster persistence.

  17. Limiting similarity and Darwin's naturalization hypothesis: understanding the drivers of biotic resistance against invasive plant species.

    Science.gov (United States)

    Yannelli, F A; Koch, C; Jeschke, J M; Kollmann, J

    2017-03-01

    Several hypotheses have been proposed to explain biotic resistance of a recipient plant community based on reduced niche opportunities for invasive alien plant species. The limiting similarity hypothesis predicts that invasive species are less likely to establish in communities of species holding similar functional traits. Likewise, Darwin's naturalization hypothesis states that invasive species closely related to the native community would be less successful. We tested both using the invasive alien Ambrosia artemisiifolia L. and Solidago gigantea Aiton, and grassland species used for ecological restoration in central Europe. We classified all plant species into groups based on functional traits obtained from trait databases and calculated the phylogenetic distance among them. In a greenhouse experiment, we submitted the two invasive species at two propagule pressures to competition with communities of ten native species from the same functional group. In another experiment, they were submitted to pairwise competition with native species selected from each functional group. At the community level, highest suppression for both invasive species was observed at low propagule pressure and not explained by similarity in functional traits. Moreover, suppression decreased asymptotically with increasing phylogenetic distance to species of the native community. When submitted to pairwise competition, suppression for both invasive species was also better explained by phylogenetic distance. Overall, our results support Darwin's naturalization hypothesis but not the limiting similarity hypothesis based on the selected traits. Biotic resistance of native communities against invasive species at an early stage of establishment is enhanced by competitive traits and phylogenetic relatedness.

  18. From plants to birds: higher avian predation rates in trees responding to insect herbivory.

    Directory of Open Access Journals (Sweden)

    Elina Mäntylä

    Full Text Available BACKGROUND: An understanding of the evolution of potential signals from plants to the predators of their herbivores may provide exciting examples of co-evolution among multiple trophic levels. Understanding the mechanism behind the attraction of predators to plants is crucial to conclusions about co-evolution. For example, insectivorous birds are attracted to herbivore-damaged trees without seeing the herbivores or the defoliated parts, but it is not known whether birds use cues from herbivore-damaged plants with a specific adaptation of plants for this purpose. METHODOLOGY: We examined whether signals from damaged trees attract avian predators in the wild and whether birds could use volatile organic compound (VOC emissions or net photosynthesis of leaves as cues to detect herbivore-rich trees. We conducted a field experiment with mountain birches (Betula pubescens ssp. czerepanovii, their main herbivore (Epirrita autumnata and insectivorous birds. Half of the trees had herbivore larvae defoliating trees hidden inside branch bags and half had empty bags as controls. We measured predation rate of birds towards artificial larvae on tree branches, and VOC emissions and net photosynthesis of leaves. PRINCIPAL FINDINGS AND SIGNIFICANCE: The predation rate was higher in the herbivore trees than in the control trees. This confirms that birds use cues from trees to locate insect-rich trees in the wild. The herbivore trees had decreased photosynthesis and elevated emissions of many VOCs, which suggests that birds could use either one, or both, as cues. There was, however, large variation in how the VOC emission correlated with predation rate. Emissions of (E-DMNT [(E-4,8-dimethyl-1,3,7-nonatriene], beta-ocimene and linalool were positively correlated with predation rate, while those of highly inducible green leaf volatiles were not. These three VOCs are also involved in the attraction of insect parasitoids and predatory mites to herbivore-damaged plants

  19. Invasive clonal plant species have a greater root-foraging plasticity than non-invasive ones.

    Science.gov (United States)

    Keser, Lidewij H; Dawson, Wayne; Song, Yao-Bin; Yu, Fei-Hai; Fischer, Markus; Dong, Ming; van Kleunen, Mark

    2014-03-01

    Clonality is frequently positively correlated with plant invasiveness, but which aspects of clonality make some clonal species more invasive than others is not known. Due to their spreading growth form, clonal plants are likely to experience spatial heterogeneity in nutrient availability. Plasticity in allocation of biomass to clonal growth organs and roots may allow these plants to forage for high-nutrient patches. We investigated whether this foraging response is stronger in species that have become invasive than in species that have not. We used six confamilial pairs of native European clonal plant species differing in invasion success in the USA. We grew all species in large pots under homogeneous or heterogeneous nutrient conditions in a greenhouse, and compared their nutrient-foraging response and performance. Neither invasive nor non-invasive species showed significant foraging responses to heterogeneity in clonal growth organ biomass or in aboveground biomass of clonal offspring. Invasive species had, however, a greater positive foraging response in terms of root and belowground biomass than non-invasive species. Invasive species also produced more total biomass. Our results suggest that the ability for strong root foraging is among the characteristics promoting invasiveness in clonal plants.

  20. Development and reproduction of Panonychus citri (Prostigmata: Tetranychidae) on different species and varieties of citrus plants.

    Science.gov (United States)

    Zanardi, Odimar Zanuzo; Bordini, Gabriela Pavan; Franco, Aline Aparecida; de Morais, Matheus Rovere; Yamamoto, Pedro Takao

    2015-12-01

    The species and varieties of citrus plants that are currently grown can favor the population growth of the citrus red mite Panonychus citri (McGregor) (Prostigmata: Tetranychidae) and alter the pest management programs in citrus groves. In this study we evaluated, in the laboratory, the development and reproduction of P. citri and estimated its life table parameters when reared on four varieties of Citrus sinensis (L.) Osbeck (Valencia, Pera, Natal, and Hamlin), one variety of Citrus reticulata Blanco (Ponkan) and one variety of Citrus limon (L.) Burm. (Sicilian). The incubation period and egg viability were not affected by the host plant. However, the development and survival of the immature stage were significantly lower on Hamlin orange than on Valencia, Pera and Natal oranges, Ponkan mandarin and Sicilian lemon. The fecundity and oviposition period of females were lower on Hamlin orange than on the other hosts. Mites reared on Valencia orange and Sicilian lemon had a higher net reproductive rate (R 0 ), intrinsic growth rate (r) and finite rate of increase (λ), and a shorter interval between generations (T) than on Pera, Natal and Hamlin oranges and Ponkan mandarin. On the other hand, mites reared on Hamlin orange had the lowest R 0 , r and λ and the highest T among the hosts. Based on the results obtained we recommend that for Valencia orange and Sicilian lemon, the mite monitoring programs should be more intense to detect the initial infestation of pest, avoiding the damage in plants and the increase in production costs.

  1. Effect of arbuscular mycorrhizal fungi on the potential of three wild plant species for phytoextraction of mercury from small-scale gold mine tailings

    Directory of Open Access Journals (Sweden)

    A. Fiqri

    2016-04-01

    Full Text Available A study that was aimed to explore the effects of arbuscular mycorrhizal (AM fungi inoculation on the potential of wild plant species (Paspalum conjugatum, Cyperus kyllingia, and Lindernia crustacea for phytoextraction of mercury from small-scale gold mine tailings was conducted in a glasshouse. Each of the plant seedlings was planted in a plastic pot containing 10 kg of planting medium (mixture of tailings and compost; 50%: 50% by weight. Treatments tested were three plant species and doses of AM fungi inoculation, i.e. 0 and 30 spores/plant. At harvest of 63 days, plant shoot and root were analyzed for mercury concentration. The remaining planting media in the pots were used for growing maize for 84 days. The results showed that the most potential plant species for phytoextraction of mercury was Paspalum conjugatum, while the most mercury tolerant plant was Cyperus kyllingia. Without AM fungi inoculation, the highest accumulation of mercury (44.87 mg/kg was found in the root of Paspalum conjugatum. If AM fungi were inoculated, the highest accumulation of mercury (56.30 mg/kg was also found in the shoot of Paspalum conjugatum. Results of the second experiment proved that the growth and biomass production of maize after mycophytoextraction by the plant species were higher than those of maize grown on media without mycophytoextraction of mercury.

  2. Threatened plant species of the Nevada Test Site, Ash Meadows, central-southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Beatley, J.C.

    1977-04-01

    This report is a companion one to Endangered Plant Species of the Nevada Test Site, Ash Meadows, and Central-Southern Nevada (COO-2307-11) and deals with the threatened plant species of the same area. The species are those cited in the Federal Register, July 1, 1975, and include certain ones listed as occurring only in California or Arizona, but which occur also in central-southern Nevada. As with the earlier report, the purpose of this one is to record in detail the location of the past plant collections which constitute the sole or principal basis for defining the species' distributions and frequency of occurrence in southern Nye County, Nevada, and to recommend the area of the critical habitat where this is appropriate. Many of the species occur also in southern California, and for these the central-southern Nevada records are presented for consideration of the overall status of the species throughout its range.

  3. Native and Non-Native Supergeneralist Bee Species Have Different Effects on Plant-Bee Networks.

    Science.gov (United States)

    Giannini, Tereza C; Garibaldi, Lucas A; Acosta, Andre L; Silva, Juliana S; Maia, Kate P; Saraiva, Antonio M; Guimarães, Paulo R; Kleinert, Astrid M P

    2015-01-01

    Supergeneralists, defined as species that interact with multiple groups of species in ecological networks, can act as important connectors of otherwise disconnected species subsets. In Brazil, there are two supergeneralist bees: the honeybee Apis mellifera, a non-native species, and Trigona spinipes, a native stingless bee. We compared the role of both species and the effect of geographic and local factors on networks by addressing three questions: 1) Do both species have similar abundance and interaction patterns (degree and strength) in plant-bee networks? 2) Are both species equally influential to the network structure (nestedness, connectance, and plant and bee niche overlap)? 3) How are these species affected by geographic (altitude, temperature, precipitation) and local (natural vs. disturbed habitat) factors? We analyzed 21 plant-bee weighted interaction networks, encompassing most of the main biomes in Brazil. We found no significant difference between both species in abundance, in the number of plant species with which each bee species interacts (degree), and in the sum of their dependencies (strength). Structural equation models revealed the effect of A. mellifera and T. spinipes, respectively, on the interaction network pattern (nestedness) and in the similarity in bee's interactive partners (bee niche overlap). It is most likely that the recent invasion of A. mellifera resulted in its rapid settlement inside the core of species that retain the largest number of interactions, resulting in a strong influence on nestedness. However, the long-term interaction between native T. spinipes and other bees most likely has a more direct effect on their interactive behavior. Moreover, temperature negatively affected A. mellifera bees, whereas disturbed habitats positively affected T. spinipes. Conversely, precipitation showed no effect. Being positively (T. spinipes) or indifferently (A. mellifera) affected by disturbed habitats makes these species prone to

  4. Native and Non-Native Supergeneralist Bee Species Have Different Effects on Plant-Bee Networks.

    Directory of Open Access Journals (Sweden)

    Tereza C Giannini

    Full Text Available Supergeneralists, defined as species that interact with multiple groups of species in ecological networks, can act as important connectors of otherwise disconnected species subsets. In Brazil, there are two supergeneralist bees: the honeybee Apis mellifera, a non-native species, and Trigona spinipes, a native stingless bee. We compared the role of both species and the effect of geographic and local factors on networks by addressing three questions: 1 Do both species have similar abundance and interaction patterns (degree and strength in plant-bee networks? 2 Are both species equally influential to the network structure (nestedness, connectance, and plant and bee niche overlap? 3 How are these species affected by geographic (altitude, temperature, precipitation and local (natural vs. disturbed habitat factors? We analyzed 21 plant-bee weighted interaction networks, encompassing most of the main biomes in Brazil. We found no significant difference between both species in abundance, in the number of plant species with which each bee species interacts (degree, and in the sum of their dependencies (strength. Structural equation models revealed the effect of A. mellifera and T. spinipes, respectively, on the interaction network pattern (nestedness and in the similarity in bee's interactive partners (bee niche overlap. It is most likely that the recent invasion of A. mellifera resulted in its rapid settlement inside the core of species that retain the largest number of interactions, resulting in a strong influence on nestedness. However, the long-term interaction between native T. spinipes and other bees most likely has a more direct effect on their interactive behavior. Moreover, temperature negatively affected A. mellifera bees, whereas disturbed habitats positively affected T. spinipes. Conversely, precipitation showed no effect. Being positively (T. spinipes or indifferently (A. mellifera affected by disturbed habitats makes these species prone to

  5. Results of the first stage (2002-2009) of investigation of higher plants onboard RS ISS, as an element of future closed Life Support Systems

    Science.gov (United States)

    Sychev, Vladimir; Levinskikh, Margarita; Podolsky, Igor; Bingham, Gail; Novikova, Nataliya; Sugimoto, Manabu

    A key task for biomedical human support in long-term manned space expeditions is the develop-ment of the Life Support System (LSS). It is expected that in the first continuous interplanetary expeditions LSS of only a few biological elements of the LSS, such as higher plants will be in-cluded. Therefore, investigations of growth and development of higher plants for consideration in the LSS are of high importance. In a period from October, 2002 to December 2009, 15 ex-periments on cultivation of different plants, including two genetically marked species of dwarf peas, a leaf vegetable strain of Mizuna, radish, barley and wheat were conducted in space greenhouse "LADA" onboard Russian Segment (RS) of International Space Station (ISS). The experiments resulted in the conclusion that the properties of growth and development of plants grown in space greenhouse "LADA" were unaffected by spaceflight conditions. In experiments conducted in a period from 2003 to 2005, it was shown for the first time that pea plants pre-serve reproductive functions, forming viable seeds during at least four continuous full cycles of ontogenesis ("seed to seed") under spaceflight conditions. No changes were found in the genetic apparatus of the pea plants in the four "space" generations. Since 2005, there have been routine collections of microbiological samples from the surfaces of the plants grown on-board in "LADA" greenhouse. Analysis has shown that the properties of contamination of the plants grown aboard by microorganism contain no abnormal patterns. Since 2008, the plants cultivated in "LADA" greenhouse have been frozen onboard RS ISS in the MELFI refrigerator and transferred to the Earth for further investigations. Investigations of Mizuna plants grown and frozen onboard of ISS, showed no differences between "ground control" and "space" plants in chemical and biochemical properties. There also no stress-response was found in kashinriki strain barley planted and frozen onboard ISS.

  6. Identifying plant traits: a key aspect for suitable species selection in ecological restoration of semiarid slopes

    Science.gov (United States)

    Bochet, Esther; García-Fayos, Patricio

    2017-04-01

    In the context of ecological restoration, one of the greatest challenges for practitioners and scientists is to select suitable species for revegetation purposes. In semiarid environments where restoration projects often fail, little attention has been paid so far to the contribution of plant traits to species success. The objective of this study was to (1) identify plant traits associated with species success on four roadside situations along an erosion-productivity gradient, and (2) to provide an ecological framework for selecting suitable species on the basis of their morphological and functional traits, applied to semiarid environments. We analyzed the association of 10 different plant traits with species success of 296 species surveyed on the four roadside situations in a semiarid region (Valencia, Spain). Plant traits included general plant traits (longevity, woodiness) and more specific root-, seed- and leaf-related traits (root type, sprouting ability, seed mucilage, seed mass, seed susceptibility to removal, specific leaf area and leaf dry matter content). All of them were selected according to the prevailing limiting ecogeomorphological processes acting along the erosion-productivity gradient. We observed strong shifts along the erosion-productivity gradient in the traits associated to species success. At the harshest end of the gradient, the most intensely eroded and driest one, species success was mainly associated to seed resistance to removal by runoff and to resistance to drought. At the opposite end of the gradient, the most productive one, species success was associated to a competitive-ruderal plant strategy (herbaceous successful species with high specific leaf area and low leaf dry matter content). Our study provides an ecologically-based approach for selecting suitable native species on the basis or their morphological and functional traits and supports a differential trait-based selection of species as regards roadslope type and aspect. In

  7. Roles of Organic Acid Anion Secretion in Aluminium Tolerance of Higher Plants

    Science.gov (United States)

    Yang, Lin-Tong; Qi, Yi-Ping; Jiang, Huan-Xin; Chen, Li-Song

    2013-01-01

    Approximately 30% of the world's total land area and over 50% of the world's potential arable lands are acidic. Furthermore, the acidity of the soils is gradually increasing as a result of the environmental problems including some farming practices and acid rain. At mildly acidic or neutral soils, aluminium(Al) occurs primarily as insoluble deposits and is essentially biologically inactive. However, in many acidic soils throughout the tropics and subtropics, Al toxicity is a major factor limiting crop productivity. The Al-induced secretion of organic acid (OA) anions, mainly citrate, oxalate, and malate, from roots is the best documented mechanism of Al tolerance in higher plants. Increasing evidence shows that the Al-induced secretion of OA anions may be related to the following several factors, including (a) anion channels or transporters, (b) internal concentrations of OA anions in plant tissues, (d) temperature, (e) root plasma membrane (PM) H+-ATPase, (f) magnesium (Mg), and (e) phosphorus (P). Genetically modified plants and cells with higher Al tolerance by overexpressing genes for the secretion and the biosynthesis of OA anions have been obtained. In addition, some aspects needed to be further studied are also discussed. PMID:23509687

  8. Roles of Organic Acid Anion Secretion in Aluminium Tolerance of Higher Plants

    Directory of Open Access Journals (Sweden)

    Lin-Tong Yang

    2013-01-01

    Full Text Available Approximately 30% of the world’s total land area and over 50% of the world’s potential arable lands are acidic. Furthermore, the acidity of the soils is gradually increasing as a result of the environmental problems including some farming practices and acid rain. At mildly acidic or neutral soils, aluminium(Al occurs primarily as insoluble deposits and is essentially biologically inactive. However, in many acidic soils throughout the tropics and subtropics, Al toxicity is a major factor limiting crop productivity. The Al-induced secretion of organic acid (OA anions, mainly citrate, oxalate, and malate, from roots is the best documented mechanism of Al tolerance in higher plants. Increasing evidence shows that the Al-induced secretion of OA anions may be related to the following several factors, including (a anion channels or transporters, (b internal concentrations of OA anions in plant tissues, (d temperature, (e root plasma membrane (PM H+-ATPase, (f magnesium (Mg, and (e phosphorus (P. Genetically modified plants and cells with higher Al tolerance by overexpressing genes for the secretion and the biosynthesis of OA anions have been obtained. In addition, some aspects needed to be further studied are also discussed.

  9. Regulation of photosynthesis by ion channels in cyanobacteria and higher plants.

    Science.gov (United States)

    Checchetto, Vanessa; Teardo, Enrico; Carraretto, Luca; Formentin, Elide; Bergantino, Elisabetta; Giacometti, Giorgio Mario; Szabo, Ildiko

    2013-12-01

    Photosynthesis converts light energy into chemical energy, and supplies ATP and NADPH for CO2 fixation into carbohydrates and for the synthesis of several compounds which are essential for autotrophic growth. Oxygenic photosynthesis takes place in thylakoid membranes of chloroplasts and photosynthetic prokaryote cyanobacteria. An ancestral photoautotrophic prokaryote related to cyanobacteria has been proposed to give rise to chloroplasts of plants and algae through an endosymbiotic event. Indeed, photosynthetic complexes involved in the electron transport coupled to H(+) translocation and ATP synthesis are similar in higher plants and cyanobacteria. Furthermore, some of the protein and solute/ion conducting machineries also share common structure and function. Electrophysiological and biochemical evidence support the existence of ion channels in the thylakoid membrane in both types of organisms. By allowing specific ion fluxes across thylakoid membranes, ion channels have been hypothesized to either directly or indirectly regulate photosynthesis, by modulating the proton motive force. Recent molecular identification of some of the thylakoid-located channels allowed to obtain genetic proof in favor of such hypothesis. Furthermore, some ion channels of the envelope membrane in chloroplasts have also been shown to impact on this light-driven process. Here we give an overview of thylakoid/chloroplast located ion channels of higher plants and of cyanobacterium Synechocystis sp. PCC 6803. We focus on channels shown to be implicated in the regulation of photosynthesis and discuss the possible mechanisms of action. © 2013 Elsevier B.V. All rights reserved.

  10. Composition, architecture and dynamics of the photosynthetic apparatus in higher plants.

    Science.gov (United States)

    Nevo, Reinat; Charuvi, Dana; Tsabari, Onie; Reich, Ziv

    2012-04-01

    The process of oxygenic photosynthesis enabled and still sustains aerobic life on Earth. The most elaborate form of the apparatus that carries out the primary steps of this vital process is the one present in higher plants. Here, we review the overall composition and supramolecular organization of this apparatus, as well as the complex architecture of the lamellar system within which it is harbored. Along the way, we refer to the genetic, biochemical, spectroscopic and, in particular, microscopic studies that have been employed to elucidate the structure and working of this remarkable molecular energy conversion device. As an example of the highly dynamic nature of the apparatus, we discuss the molecular and structural events that enable it to maintain high photosynthetic yields under fluctuating light conditions. We conclude the review with a summary of the hypotheses made over the years about the driving forces that underlie the partition of the lamellar system of higher plants and certain green algae into appressed and non-appressed membrane domains and the segregation of the photosynthetic protein complexes within these domains. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

  11. UV-A radiation effects on higher plants: Exploring the known unknown.

    Science.gov (United States)

    Verdaguer, Dolors; Jansen, Marcel A K; Llorens, Laura; Morales, Luis O; Neugart, Susanne

    2017-02-01

    Ultraviolet-A radiation (UV-A: 315-400nm) is a component of solar radiation that exerts a wide range of physiological responses in plants. Currently, field attenuation experiments are the most reliable source of information on the effects of UV-A. Common plant responses to UV-A include both inhibitory and stimulatory effects on biomass accumulation and morphology. UV-A effects on biomass accumulation can differ from those on root: shoot ratio, and distinct responses are described for different leaf tissues. Inhibitory and enhancing effects of UV-A on photosynthesis are also analysed, as well as activation of photoprotective responses, including UV-absorbing pigments. UV-A-induced leaf flavonoids are highly compound-specific and species-dependent. Many of the effects on growth and development exerted by UV-A are distinct to those triggered by UV-B and vary considerably in terms of the direction the response takes. Such differences may reflect diverse UV-perception mechanisms with multiple photoreceptors operating in the UV-A range and/or variations in the experimental approaches used. This review highlights a role that various photoreceptors (UVR8, phototropins, phytochromes and cryptochromes) may play in plant responses to UV-A when dose, wavelength and other conditions are taken into account. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Plant species with extremely small populations (PSESP in China: A seed and spore biology perspective

    Directory of Open Access Journals (Sweden)

    Ellie Merrett Wade

    2016-10-01

    Full Text Available Approximately one fifth of the world's plants are at risk of extinction. Of these, a significant number exist as populations of few individuals, with limited distribution ranges and under enormous pressure due to habitat destruction. In China, these most-at-risk species are described as ‘plant species with extremely small populations’ (PSESP. Implementing conservation action for such listed species is urgent. Storing seeds is one of the main means of ex situ conservation for flowering plants. Spore storage could provide a simple and economical method for fern ex situ conservation. Seed and spore germination in nature is a critical step in species regeneration and thus in situ conservation. But what is known about the seed and spore biology (storage and germination of at-risk species? We have used China's PSESP (the first group listing as a case study to understand the gaps in knowledge on propagule biology of threatened plant species. We found that whilst germination information is available for 28 species (23% of PSESP, storage characteristics are only known for 8% of PSESP (10 species. Moreover, we estimate that 60% of the listed species may require cryopreservation for long-term storage. We conclude that comparative biology studies are urgently needed on the world's most threatened taxa so that conservation action can progress beyond species listing.

  13. Individual species-area relationship of woody plant communities in a heterogeneous subtropical monsoon rainforest.

    Directory of Open Access Journals (Sweden)

    Cheng-Han Tsai

    Full Text Available The spatial structure of species richness is often characterized by the species-area relationship (SAR. However, the SAR approach rarely considers the spatial variability of individual plants that arises from species interactions and species' habitat associations. Here, we explored how the interactions of individual plants of target species influence SAR patterns at a range of neighborhood distances. We analyzed the data of 113,988 woody plants of 110 species from the Fushan Forest Dynamics Plot (25 ha, northern Taiwan, which is a subtropical rainforest heavily influenced by typhoons. We classified 34 dominant species into 3 species types (i.e., accumulator, repeller, or no effect by testing how the individual species-area relationship (i.e., statistics describing how neighborhood species richness changes around individuals of target species departs (i.e., positively, negatively, or with no obvious trend from a null model that accounts for habitat association. Deviation from the null model suggests that the net effect of species' interactions increases (accumulate or decreases (repel neighborhood species richness. We found that (i accumulators were dominant at small interaction distances (30 m; (iii repellers were rarely detected; and (iv large-sized and abundant species tended to be accumulators. The findings suggest that positive species interactions have the potential to accumulate neighborhood species richness, particularly through size- and density-dependent mechanisms. We hypothesized that the frequently disturbed environment of this subtropical rainforest (e.g., typhoon-driven natural disturbances such as landslides, soil erosion, flooding, and windthrow might create the spatial heterogeneity of species richness and promote positive species interactions.

  14. The correlation between antimutagenic activity and total phenolic content of extracts of 31 plant species with high antioxidant activity.

    Science.gov (United States)

    Makhafola, Tshepiso Jan; Elgorashi, Esameldin Elzein; McGaw, Lyndy Joy; Verschaeve, Luc; Eloff, Jacobus Nicolaas

    2016-11-29

    activity. The selected 31 extracts contained well defined antioxidant compounds. These species had good DPPH free radical antioxidant activity with EC 50 values ranging from 1.20 to 19.06 μg/ml. Some of the plant extracts had higher antioxidant activity than L-ascorbic acid (vitamin C). The total phenolic contents ranged from 5.17 to 18.65 mg GAE (gallic acid equivalent)/g plant extract). The total phenolic content of the plant extracts correlated well with the respective antioxidant activity of the plant extracts. No plant extract with good antioxidant activity had mutagenic activity. Several extracts had antimutagenic activity. The percentage inhibition of 4-NQO ranged from 0.8 to 77% in Salmonella typhimurium TA98 and from 0.8 to 99% in strain TA100. There was a direct correlation between the presence of antioxidant activity and antimutagenic activity of the plant extracts. Although no plant extract had mutagenic activity on its own, some of the plant extracts enhanced the mutagenicity of 4-NQO, a phenomenon referred to as comutagenicity. Some of the plant extracts investigated in this study had potential antimutagenic activities. The antimutagenic activities may be associated with the presence of antioxidant polyphenols in the extracts. From the results plant extracts were identified that were not mutagenic, not cytotoxic and that may be antimutagenic in the Ames test. For most plant extracts, at the highest concentration used (5 mg/ml), the level of antimutagenicity was below the recommended 45% to conclude whether plants have good antimutagenic activity. However, in most screening studies for antimutagenesis, a 20% decrease in the number of revertants must be obtained in order to score the extract as active. Psoralea pinnata L. had the highest percentage antimutagenicity recorded in this study (76.67 and 99.83% in S. typhimurium TA98 and TA100 respectively) at assayed concentration of 5 mg/ml. The results indicate that investigating antioxidant activity and the

  15. Variation of gas exchange within native plant species of Switzerland and relationships with ozone injury: an open-top experiment.

    Science.gov (United States)

    Zhang, J; Ferdinand, J A; Vanderheyden, D J; Skelly, J M; Innes, J L

    2001-01-01

    Gas exchange and ozone-induced foliar injury were intensively measured during a 6-day period in mid-August 1998 on leaves of Acer pseudoplatanus, Betula pendula, Corylus avellana, Fagus sylvatica, Fraxinus excelsior, Morus nigra, Prunus avium, Prunus serotina, Rhamnus cathartica, and Viburnum lantana at a forest nursery site in Canton Ticino, Switzerland. Plants were grown in four open plots (AA), four open-top chambers receiving carbon-filtered (CF) air, and four receiving non-filtered (NF) air. Significant variation in gas exchange (F > 12.7, P photosynthesis and average stomatal conductance differing by a factor of two. Species also varied significantly in foliar injury for those leaves for which we measured gas exchange (F = 39.6, P Plants grown in CF chambers had significantly higher net photosynthesis (A) and stomatal conductance to water vapor (gwv), and lower foliar injury than plants grown in NF chambers and AA plots; interactions between species and ozone treatments were significant for all variables (F > or = 2.2, P 0.1). Although A and gwv decreased and foliar injury increased with leaf age, the magnitude of these changes was lower for plants grown in CF chambers than for plants grown in NF chambers and AA plots. Neither ozone uptake threshold (r = 0.26, P > 0.20) nor whole-plant injury (r = -0.15, P > 0.41) was significantly correlated with stomatal conductance across these species. It appears that the relationships between stomatal conductance and foliar injury are species-specific and interactions between physiology and environments and leaf biochemical processes must be considered in determining species sensitivity to ambient ozone exposures.

  16. INVASIVE ALIEN PLANT SPECIES USED FOR THE TREATMENT OF VARIOUS DISEASES IN LIMPOPO PROVINCE, SOUTH AFRICA

    Science.gov (United States)

    Maema, Lesibana Peter; Potgieter, Martin; Mahlo, Salome Mamokone

    2016-01-01

    Background: Invasive alien plant species (IAPs) are plants that have migrated from one geographical region to non-native region either intentional or unintentional. The general view of IAPs in environment is regarded as destructive to the ecosystem and they pose threat to native vegetation and species. However, some of these IAPS are utilized by local inhabitants as a substitute for scarce indigenous plants. The aim of the study is to conduct ethnobotanical survey on medicinal usage of invasive plant species in Waterberg District, Limpopo Province, South Africa. Materials and methods: An ethnobotanical survey on invasive plant species was conducted to distinguish species used for the treatment of various ailments in the Waterberg, District in the area dominated by Bapedi traditional healers. About thirty Bapedi traditional healers (30) were randomly selected via the snowball method. A guided field work by traditional healers and a semi-structured questionnaire was used to gather information from the traditional healers. The questionnaire was designed to gather information on the local name of plants, plant parts used and methods of preparation which is administered by the traditional healers. Results: The study revealed that Schinus molle L., Catharanthus roseus (L.), Datura stramonium L., Opuntia stricta (Haw.) Haw., Opuntia ficus- indica, Sambucus canadensis L., Ricinus communis L., Melia azedarch L., Argemone ochroleuca and Eriobotrya japónica are used for treatment of various diseases such as chest complaint, blood purification, asthma, hypertension and infertility. The most plant parts that were used are 57.6% leaves, followed by 33.3% roots, and whole plant, seeds and bark at 3% each. Noticeably, most of these plants are cultivated (38%), followed by 28% that are common to the study area, 20% abundant, 12% wild, and 3% occasionally. Schinus molle is the most frequently used plant species for the treatment of various ailments in the study area. National

  17. INVASIVE ALIEN PLANT SPECIES USED FOR THE TREATMENT OF VARIOUS DISEASES IN LIMPOPO PROVINCE, SOUTH AFRICA.

    Science.gov (United States)

    Maema, Lesibana Peter; Potgieter, Martin; Mahlo, Salome Mamokone

    2016-01-01

    Invasive alien plant species (IAPs) are plants that have migrated from one geographical region to non-native region either intentional or unintentional. The general view of IAPs in environment is regarded as destructive to the ecosystem and they pose threat to native vegetation and species. However, some of these IAPS are utilized by local inhabitants as a substitute for scarce indigenous plants. The aim of the study is to conduct ethnobotanical survey on medicinal usage of invasive plant species in Waterberg District, Limpopo Province, South Africa. An ethnobotanical survey on invasive plant species was conducted to distinguish species used for the treatment of various ailments in the Waterberg, District in the area dominated by Bapedi traditional healers. About thirty Bapedi traditional healers (30) were randomly selected via the snowball method. A guided field work by traditional healers and a semi-structured questionnaire was used to gather information from the traditional healers. The questionnaire was designed to gather information on the local name of plants, plant parts used and methods of preparation which is administered by the traditional healers. The study revealed that Schinus molle L., Catharanthus roseus (L.), Datura stramonium L., Opuntia stricta (Haw.) Haw., Opuntia ficus- indica, Sambucus canadensis L., Ricinus communis L., Melia azedarch L., Argemone ochroleuca and Eriobotrya japónica are used for treatment of various diseases such as chest complaint, blood purification, asthma, hypertension and infertility. The most plant parts that were used are 57.6% leaves, followed by 33.3% roots, and whole plant, seeds and bark at 3% each. Noticeably, most of these plants are cultivated (38%), followed by 28% that are common to the study area, 20% abundant, 12% wild, and 3% occasionally. Schinus molle is the most frequently used plant species for the treatment of various ailments in the study area. National Environmental Management Biodiversity Act (NEMBA

  18. Padus serotina (Rosaceae, a new host plant for some species of parasitic microfungi

    Directory of Open Access Journals (Sweden)

    Nałgorzata Ruszkiewicz-Michalska

    2014-08-01

    Full Text Available Four species of parasitic microfungi were collected recenUy on Padus serotina (Ehrh. Borkh. (Rosaceae in Poland. Three species, Phyllactina guttata (Wallr. ex Fr. Lév. (Erysiphales, Monilia linhartiana Sacc. (Hyphomycetes, and Microsphaeropsis olivacea (Bonord. Höhn. (Coelomycetes, have not been reported before on thc plant, and Padus serotina is a new host for them. Monnilia linhartiana Sacc. is a new species for Poland. The fourth species, Podosphaera tridactyla (Wallr. de Baly var. tridactyla (Erysiphales, is known only from three localities in Europe, and has been collected on the host plant in Poland for the first time.

  19. Habitat types on the Hanford Site: Wildlife and plant species of concern

    Energy Technology Data Exchange (ETDEWEB)

    Downs, J.L.; Rickard, W.H.; Brandt, C.A. [and others

    1993-12-01

    The objective of this report is to provide a comprehensive source of the best available information on Hanford Site sensitive and critical habitats and plants and animals of importance or special status. In this report, sensitive habitats include areas known to be used by threatened, endangered, or sensitive plant or animal species, wetlands, preserves and refuges, and other sensitive habitats outlined in the Hanford Site Baseline Risk Assessment Methodology. Potentially important species for risk assessment and species of special concern with regard to their status as threatened, endangered, or sensitive are described, and potential habitats for these species identified.

  20. Transcriptional Regulation of Aluminum-Tolerance Genes in Higher Plants: Clarifying the Underlying Molecular Mechanisms

    Directory of Open Access Journals (Sweden)

    Abhijit A. Daspute

    2017-08-01

    Full Text Available Aluminum (Al rhizotoxicity is one of the major environmental stresses that decrease global food production. Clarifying the molecular mechanisms underlying Al tolerance may contribute to the breeding of Al-tolerant crops. Recent studies identified various Al-tolerance genes. The expression of these genes is inducible by Al. Studies of the major Arabidopsis thaliana Al-tolerance gene, ARABIDOPSIS THALIANA ALUMINUM-ACTIVATED MALATE TRANSPORTER 1 (AtALMT1, which encodes an Al-activated malate transporter, revealed that the Al-inducible expression is regulated by a SENSITIVE TO PROTON RHIXOTOXICITY 1 (STOP1 zinc-finger transcription factor. This system, which involves STOP1 and organic acid transporters, is conserved in diverse plant species. The expression of AtALMT1 is also upregulated by several phytohormones and hydrogen peroxide, suggesting there is crosstalk among the signals involved in the transcriptional regulation of AtALMT1. Additionally, phytohormones and reactive oxygen species (ROS activate various transcriptional responses, including the expression of genes related to increased Al tolerance or the suppression of root growth under Al stress conditions. For example, Al suppressed root growth due to abnormal accumulation of auxin and cytokinin. It activates transcription of TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 and other phytohormone responsive genes in distal transition zone, which causes suppression of root elongation. On the other hand, overexpression of Al inducible genes for ROS-detoxifying enzymes such as GLUTATHIONE–S-TRANSFERASE, PEROXIDASE, SUPEROXIDE DISMUTASE enhances Al resistance in several plant species. We herein summarize the complex transcriptional regulation of an Al-inducible genes affected by STOP1, phytohormones, and ROS.

  1. Removal of the pharmaceuticals ibuprofen and iohexol by four wetland plant species in hydroponic culture: plant uptake and microbial degradation.

    Science.gov (United States)

    Zhang, Yang; Lv, Tao; Carvalho, Pedro N; Arias, Carlos A; Chen, Zhanghe; Brix, Hans

    2016-02-01

    We aimed at assessing the effects of four wetland plant species commonly used in constructed wetland systems: Typha, Phragmites, Iris and Juncus for removing ibuprofen (IBU) and iohexol (IOH) from spiked culture solution and exploring the mechanisms responsible for the removal. IBU was nearly completely removed by all plant species during the 24-day experiment, whereas the IOH removal varied between 13 and 80 %. Typha and Phragmites were the most efficient in removing IBU and IOH, respectively, with first-order removal rate constants of 0.38 and 0.06 day(-1), respectively. The pharmaceuticals were taken up by the roots and translocated to the aerial tissues. However, at the end of the experiment, plant accumulation constituted only up to 1.1 and 5.7 % of the amount of IBU and IOH spiked initially. The data suggest that the plants mainly function by facilitating pharmaceutical degradation in the rhizosphere through release of root exudates.

  2. Effect of different plant species on nutrient removal and rhizospheric microorganisms distribution in horizontal-flow constructed wetlands.

    Science.gov (United States)

    Meng, Panpan; Hu, Wenrong; Pei, Haiyan; Hou, Qingjie; Ji, Yan

    2014-01-01

    Three macrophyte species, Phragmites australis, Arundo donax L., and Typha latifolia L. have been separately grown in a horizontal-flow (HF) constructed wetland (CW) fed with domestic wastewater to investigate effects of plant species on nutrient removal and rhizospheric microorganisms. All the three mesocosms have been in operation for eight months under the loading rates of 1.14 g Nm(-2) d(-1) and 0.014gP m(-2) d(-1). Appropriately 34-43% phosphorus (P) was removed in HF CWs, and no distinct difference was found among the plants. In the growing season, A. donax L. removed 31.19 gm(-2) of nitrogen (N), followed by P. australis (29.96 g m(-2)), both of which were significantly higher than T. latifolia L. (7.21 g m(-2). Depending on the species, plants absorbed 1.73-7.15% of the overall N, and 0.06-0.56% of the P input. At least 10 common dominant microorganisms were found in the rhizosphere of all the three plants, and 6 of the 10 kinds of bacteria had close relationship with denitrifying bacteria, implying that denitrifiers were dominant microorganism distributed in rhizosphere of wetland plants.

  3. Regulation of chloroplast number and DNA synthesis in higher plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mullet, J.E.

    1995-11-10

    The long term objective of this research is to understand the process of chloroplast development and its coordination with leaf development in higher plants. This is important because the photosynthetic capacity of plants is directly related to leaf and chloroplast development. This research focuses on obtaining a detailed description of leaf development and the early steps in chloroplast development including activation of plastid DNA synthesis, changes in plastid DNA copy number, activation of chloroplast transcription and increases in plastid number per cell. The grant will also begin analysis of specific biochemical mechanisms by isolation of the plastid DNA polymerase, and identification of genetic mutants which are altered in their accumulation of plastid DNA and plastid number per cell.

  4. Regulation of chloroplast number and DNA synthesis in higher plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mullet, J.E.

    1995-11-10

    The long term objective of this research is to understand the process of chloroplast development and its coordination with leaf development in higher plants. This is important because the photosynthetic capacity of plants is directly related to leaf and chloroplast development. This research focuses on obtaining a detailing description of leaf development and the early steps in chloroplast development including activation of plastid DNA synthesis, changes in plastid DNA copy number, activation of chloroplast transcription and increases in plastid number per cell. The grant will also begin analysis of specific biochemical mechanisms by isolation of the plastid DNA polymerase, and identification of genetic mutants which are altered in their accumulation of plastid DNA and plastid number per cell.

  5. Screening of different Trichoderma species against agriculturally important foliar plant pathogens.

    Science.gov (United States)

    Prabhakaran, Narayanasamy; Prameeladevi, Thokala; Sathiyabama, Muthukrishnan; Kamil, Deeba

    2015-01-01

    Different isolates of Trichoderma were isolated from soil samples which were collected from different part of India. These isolates were grouped into four Trichoderma species viz., Trichoderma asperellum (Ta), T. harzianum (Th), T. pseudokoningii (Tp) and T. longibrachiatum (Tl) based on their morphological characters. Identification of the above isolates was also confirmed through ITS region analysis. These Trichoderma isolates were tested for in vitro biological control of Alternaria solani, Bipolaris oryzae, Pyricularia oryzae and Sclerotinia scierotiorum which cause serious diseases like early blight (target spot) of tomato and potato, brown leaf spot disease in rice, rice blast disease, and white mold disease in different plants. Under in vitro conditions, all the four species of Trichoderma (10 isolates) proved 100% potential inhibition against rice blast pathogen Pyracularia oryzae. T. harzianum (Th-01) and T. asperellum (Ta-10) were effective with 86.6% and 97.7%, growth inhibition of B. oryzae, respectively. Among others, T. pseudokoningii (Tp-08) and T. Iongibrachiatum (Tl-09) species were particularly efficient in inhibiting growth of S. sclerotiorum by 97.8% and 93.3%. T. Iongibrachiatum (TI-06 and TI-07) inhibited maximum mycelial growth of A. solani by 87.6% and 84.75. However, all the T. harzianum isolates showed significantly higher inhibition against S. sclerotiorum (CD value 9.430), causing white mold disease. This study led to the selection of potential Trichoderma isolates against rice blast, early blight, brown leaf spot in rice and white mold disease in different crops.

  6. Proposed classification of invasive alien plant species in South Africa: towards prioritizing species and areas for management action

    CSIR Research Space (South Africa)

    Nel, JL

    2004-01-01

    Full Text Available Many invasive alien plant species in South Africa are already well-established and cause substantial damage, while scores of others are at the early stages of invasion (only recently introduced and/or entering a phase of rapid population growth...

  7. Plant species' origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands.

    Science.gov (United States)

    Seabloom, Eric W; Borer, Elizabeth T; Buckley, Yvonne M; Cleland, Elsa E; Davies, Kendi F; Firn, Jennifer; Harpole, W Stanley; Hautier, Yann; Lind, Eric M; MacDougall, Andrew S; Orrock, John L; Prober, Suzanne M; Adler, Peter B; Anderson, T Michael; Bakker, Jonathan D; Biederman, Lori A; Blumenthal, Dana M; Brown, Cynthia S; Brudvig, Lars A; Cadotte, Marc; Chu, Chengjin; Cottingham, Kathryn L; Crawley, Michael J; Damschen, Ellen I; Dantonio, Carla M; DeCrappeo, Nicole M; Du, Guozhen; Fay, Philip A; Frater, Paul; Gruner, Daniel S; Hagenah, Nicole; Hector, Andy; Hillebrand, Helmut; Hofmockel, Kirsten S; Humphries, Hope C; Jin, Virginia L; Kay, Adam; Kirkman, Kevin P; Klein, Julia A; Knops, Johannes M H; La Pierre, Kimberly J; Ladwig, Laura; Lambrinos, John G; Li, Qi; Li, Wei; Marushia, Robin; McCulley, Rebecca L; Melbourne, Brett A; Mitchell, Charles E; Moore, Joslin L; Morgan, John; Mortensen, Brent; O'Halloran, Lydia R; Pyke, David A; Risch, Anita C; Sankaran, Mahesh; Schuetz, Martin; Simonsen, Anna; Smith, Melinda D; Stevens, Carly J; Sullivan, Lauren; Wolkovich, Elizabeth; Wragg, Peter D; Wright, Justin; Yang, Louie

    2015-07-15

    Exotic species dominate many communities; however the functional significance of species' biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native diversity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands.

  8. Plant species from coal mine overburden dumping site in Satui, South Kalimantan, Indonesia

    Directory of Open Access Journals (Sweden)

    Vivi Novianti

    2017-07-01

    Full Text Available Coal mine overburden (OB materials were nutrient-poor, loosely adhered particles of shale, stones, boulders, and cobbles, also contained elevated concentration of trace metals. This condition cause OB substrate did not support plants growth. However, there were certain species that able to grow on overburden dumping site. This investigation sought to identify plants species that presence on coal mine overburden. The research was conducted on opencast coal mine OB dumping site in Satui, South Kalimantan. Vegetation sampling was carried out on six different ages of coal mine OB dumps (7, 10, 11, 42, 59 and 64 month using line transect. Species identification used information from local people, AMDAL report of PT Arutmin Indonesia-Satui mine project, and website. There were 123 plant species, consisted of 79 herbs (Cyperaceae, Poaceae and Asteraceae, 10 lianes, bryophyte, 9 ferns, 10 shrubs, and 14 trees. A number of Poaceae, i.e., Paspalumconjugatum, Paspalumdilatatum, and Echinochloacolona generally present among the stones, boulders, and cobbles. While Cyperaceae such as Fimbristylis miliaceae, Cyperus javanicus, Rhyncospora corymbosa and Scleria sumatrensis most often foundinand around thebasin/pond with its smooth and humid substrate characteristics. Certain species of shrubs and trees present on the 7 month OB dumping site. They wereChromolaena odorata, Clibadium surinamense, Melastoma malabathricum, Trema micrantha, and Solanum torvum (Shrubs, Ochroma pyramidale and Homalanthus populifolius (trees. This plant species could be used for accelerating primary succession purpose on coal mine overburden dumping site. Nevertheless, species selection was needed to avoid planting invasive species.

  9. The influences of arbuscular mycorrhizal fungus on phytostabilization of lead/zinc tailings using four plant species.

    Science.gov (United States)

    Gu, Hai-Hong; Zhou, Zheng; Gao, Yu-Qian; Yuan, Xue-Tao; Ai, Yan-Jun; Zhang, Jun-Ying; Zuo, Wen-Zhe; Taylor, Alicia A; Nan, Shi-Qing; Li, Fu-Ping

    2017-08-03

    A greenhouse experiment was conducted to investigate the effects of the arbuscular mycorrhizal fungus Funneliformis mosseae on three parameters: Pb, Zn, Cu and Cd accumulation, translocation and plant growth in perennial ryegrass (Lolium perenne), tall fescue (Festuca arundinacea), showy stonecrop (Hylotelephium spectabile) and Purple Heart (Tradescantia pallida). The purpose of this work is to enhance site-specific phytostabilization of lead/zinc mine tailings using native plant species. The results showed that mycorrhizal fungi inoculation significantly increased plant biomass of F. arundinacea, H. spectabile and T. pallida. The Pb, Zn, Cu and Cd concentrations in roots were higher than those in shoots both with and without mycorrhizae, with the exception of the Zn concentration in H. spectabile. Mycorrhizae generally increased metal concentrations in roots and decreased metal concentrations in shoots of L. perenne and F. arundinacea. In addition, it was found that the majority of the bioconcentration and translocation factors were lower than 1 and mycorrhizal fungi inoculation further reduced these values. These results suggest that appropriate plant species inoculated with mycorrhiza might be a potential approach to revegetating mine tailing sites and that H. spectabile is an appropriate plant for phytostabilization of Pb/Zn tailings in northern China due to its higher biomass production and lower metal accumulation in shoots.

  10. Evaluation of four local plant species for insecticidal activity against ...

    African Journals Online (AJOL)

    Les propriétés insecticides de quatre plantes médicinales locales: Ricinus communis Linn. (haricot de ricin), Jatropha curcas Linn. (noix de purge/corail), Anacardium occidentale Linn. (noix de cajou), et Erythrophleum sauveolens (le mançone) étaient étudiées sous les conditions de laboratoire contre deux ravageurs de ...

  11. Biodiversity and ethnobotanical potentials of plant species of ...

    African Journals Online (AJOL)

    Plant biodiversity and ethnobotanical potentials of University of Agriculture Makurdi (UAM) Wildlife Park and Ikwe Games Reserve, Benue State, Nigeria, were investigated in this study. Floristic survey was conducted in the two reserves using stratified sampling technique based on the three identified microhabitats in each of ...

  12. Variation of interception loss with different plant species at the ...

    African Journals Online (AJOL)

    USER

    INTRODUCTION. Not all precipitation which falls to a watershed reaches the soil surface to become available for plant growth, stem flow, or ground water recharge. The result of this interaction is dependent upon vegetable and precipitation characteristic (Kenneth, 1996). Further more, several things can happen to precipi-.

  13. Specific plant induced biofilm formation in Methylobacterium species

    Directory of Open Access Journals (Sweden)

    Priscilla B Rossetto

    2011-09-01

    Full Text Available Two endophytic strains of Methylobacterium spp. were used to evaluate biofilm formation on sugarcane roots and on inert wooden sticks. Results show that biofilm formation is variable and that plant surface and possibly root exudates have a role in Methylobacterium spp. host recognition, biofilm formation and successful colonization as endophytes.

  14. In vitro propagation of the elite species plant Pluchea lanceolata ...

    African Journals Online (AJOL)

    Nodal segments were cultured in MS medium supplemented with auxin and cytokinin and their combinations. The objective was to produce genetically identical plants, via multiple shoot induction from nodal segment. The culture medium consisted of Murashige and Skoog medium supplemented with one of 3 cytokinins ...

  15. Conservation status of vascular plant species from the QMM / Rio ...

    African Journals Online (AJOL)

    A botanical inventory of the Mandena littoral forest, completed in 1991 as part of an environmental impact assessment study for a titanium oxide mining project being developed by QMM / Rio Tinto in the Tolagnaro (Fort Dauphin) region of southeastern Madagascar, identified 29 plant taxa as priorities for conservation, ...

  16. Specific plant induced biofilm formation in Methylobacterium species

    Science.gov (United States)

    Rossetto, Priscilla B.; Dourado, Manuella N.; Quecine, Maria C.; Andreote, Fernando D.; Araújo, Welington L.; Azevedo, João L.; Pizzirani-Kleiner, Aline A.

    2011-01-01

    Two endophytic strains of Methylobacterium spp. were used to evaluate biofilm formation on sugarcane roots and on inert wooden sticks. Results show that biofilm formation is variable and that plant surface and possibly root exudates have a role in Methylobacterium spp. host recognition, biofilm formation and successful colonization as endophytes. PMID:24031703

  17. Specific plant induced biofilm formation in Methylobacterium species.

    Science.gov (United States)

    Rossetto, Priscilla B; Dourado, Manuella N; Quecine, Maria C; Andreote, Fernando D; Araújo, Welington L; Azevedo, João L; Pizzirani-Kleiner, Aline A

    2011-07-01

    Two endophytic strains of Methylobacterium spp. were used to evaluate biofilm formation on sugarcane roots and on inert wooden sticks. Results show that biofilm formation is variable and that plant surface and possibly root exudates have a role in Methylobacterium spp. host recognition, biofilm formation and successful colonization as endophytes.

  18. A new herbarium-based method for reconstructing the phenology of plant species across large areas

    National Research Council Canada - National Science Library

    Lavoie, Claude; Lachance, Daniel

    2006-01-01

    ... associated with sampling locations. In this study, we propose a new herbarium-based method for reconstructing the flowering dates of plant species that have been collected across large areas. Coltsfoot...

  19. Plant species diversity affects infiltration capacity in an experimental grassland through changes in soil properties

    NARCIS (Netherlands)

    Fischer, C.; Tischer, J.; Roscher, C.; Eisenhauer, N.; Ravenek, J.; Gleixner, G.; Attinger, S.; Jensen, B.; Kroon, de H.; Mommer, L.; Scheu, S.; Hildebrandt, A.

    2015-01-01

    Background and aims Soil hydraulic properties drive water distribution and availability in soil. There exists limited knowledge of how plant species diversity might influence soil hydraulic properties. Methods We quantified the change in infiltration capacity affected by soil structural variables

  20. Vascular Plant Species Occurrences - Okefenokee National Wildlife Refuge, Charlton, Clinch, and Ware Counties GA

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This spreadsheet contains up-to-date (2016) information on the occurrence of vascular plant species observed within the Okefenokee NWR since 1932. This list should...

  1. Threatened plant species in the river ports of Central Europe: a potential for nature conservation

    Czech Academy of Sciences Publication Activity Database

    Jehlík, V.; Dostálek, J.; Frantík, Tomáš

    2016-01-01

    Roč. 19, č. 2 (2016), s. 999-1012 ISSN 1083-8155 Institutional support: RVO:67985939 Keywords : Central Europe * plant species richness * waterway Subject RIV: EH - Ecology, Behaviour Impact factor: 1.970, year: 2016

  2. Species richness of both native and invasive aquatic plants influenced by environmental conditions and human activity

    National Research Council Canada - National Science Library

    Capers, Robert S; Selsky, Roslyn; Bugbee, Gregory J; White, Jason C

    2009-01-01

    ...) lakes and ponds, collecting quantitative data on abundance and frequency. We used multiple linear and logistic regression to determine which environmental conditions were correlated with species richness of invasive and native plants...

  3. Palyonological studies of the semi-desert plant species from Pakistan

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... The detailed palynological description of 40 angiospermic plant species, belonging to 22 families and 38 ... under light microscope and scanning electron micro- scope, each ... The potential uses of pollen are steadily growing.

  4. Rapid plant identification using species- and group-specific primers targeting chloroplast DNA.

    Directory of Open Access Journals (Sweden)

    Corinna Wallinger

    Full Text Available Plant identification is challenging when no morphologically assignable parts are available. There is a lack of broadly applicable methods for identifying plants in this situation, for example when roots grow in mixture and for decayed or semi-digested plant material. These difficulties have also impeded the progress made in ecological disciplines such as soil- and trophic ecology. Here, a PCR-based approach is presented which allows identifying a variety of plant taxa commonly occurring in Central European agricultural land. Based on the trnT-F cpDNA region, PCR assays were developed to identify two plant families (Poaceae and Apiaceae, the genera Trifolium and Plantago, and nine plant species: Achillea millefolium, Fagopyrum esculentum, Lolium perenne, Lupinus angustifolius, Phaseolus coccineus, Sinapis alba, Taraxacum officinale, Triticum aestivum, and Zea mays. These assays allowed identification of plants based on size-specific amplicons ranging from 116 bp to 381 bp. Their specificity and sensitivity was consistently high, enabling the detection of small amounts of plant DNA, for example, in decaying plant material and in the intestine or faeces of herbivores. To increase the efficacy of identifying plant species from large number of samples, specific primers were combined in multiplex PCRs, allowing screening for multiple species within a single reaction. The molecular assays outlined here will be applicable manifold, such as for root- and leaf litter identification, botanical trace evidence, and the analysis of herbivory.

  5. 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.

  6. The plant economics spectrum is structured by leaf habits and growth forms across subtropical species.

    Science.gov (United States)

    Zhao, Yan-Tao; Ali, Arshad; Yan, En-Rong

    2017-02-01

    The plant economics spectrum that integrates the combination of leaf and wood syndromes provides a useful framework for the examination of species strategies at the whole-plant level. However, it remains unclear how species that differ in leaf habits and growth forms are integrated within the plant economics spectrum in subtropical forests. We measured five leaf and six wood traits across 58 subtropical plant species, which represented two leaf habits (evergreen vs deciduous) and two growth forms (tree vs shrub) in eastern China. Principal component analysis (PCA) was employed separately to construct the leaf (LES), wood (WES) and whole-plant (WPES) economics spectra. Leaf and wood traits are highly intra- and intercorrelated, thus defining not only the LES and WES, but also a WPES. Multi-trait variations in PCAs revealed that the traits which were representative of the acquisitive strategy, i.e., cheap tissue investment and rapid returns on that investment, were clustered at one end, while traits that represented the conservative strategy, i.e., expensive tissue investment and slower returns, were clustered at other end in each of the axes of the leaf and wood syndromes (PC1-axis) and the plant height strategy (PC2-axis). The local WPES, LES and WES were tightly correlated with each other. Evergreens shaped the conservative side, while deciduous species structured the acquisitive side of the WPES and LES. With respect to plant height strategies, trees formulated the acquisitive side and shrub species made up the conservative side of the WPES, LES and WES. In conclusion, our results suggested that the LES and WES were coordinated to a WPES for subtropical species. The finding of this local spectrum of plant form and function would be beneficial for modeling nutrient fluxes and species compositions in the changing climate, but also for understanding species strategies in an evolutionary context. © The Author 2016. Published by Oxford University Press. All rights

  7. 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.

  8. A simple and efficient method for isolating small RNAs from different plant species

    OpenAIRE

    Rosas-Cárdenas, Flor de Fátima; Durán-Figueroa, Noé; Vielle-Calzada, Jean-Philippe; Cruz-Hernández, Andrés; Marsch-Martínez, Nayelli; de Folter, Stefan

    2011-01-01

    Abstract Background Small RNAs emerged over the last decade as key regulators in diverse biological processes in eukaryotic organisms. To identify and study small RNAs, good and efficient protocols are necessary to isolate them, which sometimes may be challenging due to the composition of specific tissues of certain plant species. Here we describe a simple and efficient method to isolate small RNAs from different plant species. Results We developed a simple and efficient method to isolate sma...

  9. 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,...

  10. Using habitat suitability models to target invasive plant species surveys.

    Science.gov (United States)

    Crall, Alycia W; Jarnevich, Catherine S; Panke, Brendon; Young, Nick; Renz, Mark; Morisette, Jeffrey

    2013-01-01

    Managers need new tools for detecting the movement and spread of nonnative, invasive species. Habitat suitability models are a popular tool for mapping the potential distribution of current invaders, but the ability of these models to prioritize monitoring efforts has not been tested in the field. We tested the utility of an iterative sampling design (i.e., models based on field observations used to guide subsequent field data collection to improve the model), hypothesizing that model performance would increase when new data were gathered from targeted sampling using criteria based on the initial model results. We also tested the ability of habitat suitability models to predict the spread of invasive species, hypothesizing that models would accurately predict occurrences in the field, and that the use of targeted sampling would detect more species with less sampling effort than a nontargeted approach. We tested these hypotheses on two species at the state scale (Centaurea stoebe and Pastinaca sativa) in Wisconsin (USA), and one genus at the regional scale (Tamarix) in the western United States. These initial data were merged with environmental data at 30-m2 resolution for Wisconsin and 1-km2 resolution for the western United States to produce our first iteration models. We stratified these initial models to target field sampling and compared our models and success at detecting our species of interest to other surveys being conducted during the same field season (i.e., nontargeted sampling). Although more data did not always improve our models based on correct classification rate (CCR), sensitivity, specificity, kappa, or area under the curve (AUC), our models generated from targeted sampling data always performed better than models generated from nontargeted data. For Wisconsin species, the model described actual locations in the field fairly well (kappa = 0.51, 0.19, P sampling did detect more species than nontargeted sampling with less sampling effort (chi2 = 47

  11. Studies on the chalcone synthase gene of two higher plants: petroselinum hortense and matthiola incana

    Energy Technology Data Exchange (ETDEWEB)

    Hemleben, V.; Frey, M.; Rall, S.; Koch, M.; Kittel, M.; Kreuzaler, F.; Ragg, H.; Fautz, E.; Hahlbrock, K.

    1982-01-01

    Two higher plant systems are presented which allow to study coordinated gene expression of the light-induced metabolic pathway of flavonoid biosynthesis: tissue culture cells of Petroselinum hortense (Apiaceae) and different developmental stages of various genotypes of Matthiola incana (Brassicaceae). The gene structure of the chalcone synthase is mainly studied. A cDNA clone (pLF56) of parsley has been constructed and characterized conferring the chalcone synthase gene sequence. Strong cross hybridization between the parsley cDNA and Matthiola DNA allowed to identify a HindIII fragment (6000 bp) identical in size for parsley and different Matthiola wild type lines and a mutant line.

  12. Interference of Cd2+ in functioning of the photosynthetic apparatus of higher plants

    Directory of Open Access Journals (Sweden)

    Tadeusz Baszyński

    2014-01-01

    Full Text Available The actual opinions concerning the role of Cd2+ in inhibition of photosynthesis have been reviewed. The light phase of photosynthesis, particularly the site of Cd2+ action in the photosynthetic transport chain has been given the greatest attention. Cd2+-induced inhibition of Photosystem II activity as the result of thylakoid membrane degradation has been discussed. The present studies on Cd2+-inhibited dark reactions occurring in stroma has been analysed. Attention has been drawn to the fact that the results of studies in vitro are not always compatible with the changes found in the photosynthetic apparatus of higher plants growing in a Cd2 containing medium.

  13. Seed sprout production: Consumables and a foundation for higher plant growth in space

    Science.gov (United States)

    Day, Michelle; Thomas, Terri; Johnson, Steve; Luttges, Marvin

    1990-01-01

    Seed sprouts can be produced as a source of fresh vegetable materials and as higher plant seedlings in space. Sprout production was undertaken to evaluate the mass accumulations possible, the technologies needed, and the reliability of the overall process. Baseline experiments corroborated the utility of sprout production protocols for a variety of seed types. The automated delivery of saturated humidity effectively supplants labor intensive manual soaking techniques. Automated humidification also lend itself to modest centrifugal sprout growth environments. A small amount of ultraviolet radiation effectively suppressed bacterial and fungal contamination, and the sprouts were suitable for consumption.

  14. Studies on the chalcone synthase gene of two higher plants: petroselinum hortense and matthiola incana.

    Science.gov (United States)

    Hemleben, V; Frey, M; Rall, S; Koch, M; Kittel, M; Kreuzaler, F; Ragg, H; Fautz, E; Hahlbrock, K

    1982-01-01

    Two higher plant systems are presented which allow to study coordinated gene expression of the light-induced metabolic pathway of flavonoid biosynthesis: tissue culture cells of Petroselinum hortense (Apiaceae) and different developmental stages of various genotypes of Matthiola incana (Brassicaceae). The gene structure of the chalcone synthase is mainly studied. A cDNA clone (pLF56) of parsley has been constructed and characterized conferring the chalcone synthase gene sequence. Strong cross hybridization between the parsley cDNA and Matthiola DNA allowed to identify a HindIII fragment (6000 bp) identical in size for parsley and different Matthiola wild type lines and a mutant line.

  15. Variation in habitat suitability does not always relate to variation in species' plant functional traits.

    Science.gov (United States)

    Thuiller, Wilfried; Albert, Cécile H; Dubuis, Anne; Randin, Christophe; Guisan, Antoine

    2010-02-23

    Habitat suitability models, which relate species occurrences to environmental variables, are assumed to predict suitable conditions for a given species. If these models are reliable, they should relate to change in plant growth and function. In this paper, we ask the question whether habitat suitability models are able to predict variation in plant functional traits, often assumed to be a good surrogate for a species' overall health and vigour. Using a thorough sampling design, we show a tight link between variation in plant functional traits and habitat suitability for some species, but not for others. Our contrasting results pave the way towards a better understanding of how species cope with varying habitat conditions and demonstrate that habitat suitability models can provide meaningful descriptions of the functional niche in some cases, but not in others.

  16. Mapping plant species ranges in the Hawaiian Islands: developing a methodology and associated GIS layers

    Science.gov (United States)

    Price, Jonathan P.; Jacobi, James D.; Gon, Samuel M.; Matsuwaki, Dwight; Mehrhoff, Loyal; Wagner, Warren; Lucas, Matthew; Rowe, Barbara

    2012-01-01

    This report documents a methodology for projecting the geographic ranges of plant species in the Hawaiian Islands. The methodology consists primarily of the creation of several geographic information system (GIS) data layers depicting attributes related to the geographic ranges of plant species. The most important spatial-data layer generated here is an objectively defined classification of climate as it pertains to the distribution of plant species. By examining previous zonal-vegetation classifications in light of spatially detailed climate data, broad zones of climate relevant to contemporary concepts of vegetation in the Hawaiian Islands can be explicitly defined. Other spatial-data layers presented here include the following: substrate age, as large areas of the island of Hawai'i, in particular, are covered by very young lava flows inimical to the growth of many plant species; biogeographic regions of the larger islands that are composites of multiple volcanoes, as many of their species are restricted to a given topographically isolated mountain or a specified group of them; and human impact, which can reduce the range of many species relative to where they formerly were found. Other factors influencing the geographic ranges of species that are discussed here but not developed further, owing to limitations in rendering them spatially, include topography, soils, and disturbance. A method is described for analyzing these layers in a GIS, in conjunction with a database of species distributions, to project the ranges of plant species, which include both the potential range prior to human disturbance and the projected present range. Examples of range maps for several species are given as case studies that demonstrate different spatial characteristics of range. Several potential applications of species-range maps are discussed, including facilitating field surveys, informing restoration efforts, studying range size and rarity, studying biodiversity, managing

  17. Plant species differ in early seedling growth and tissue nutrient responses to arbuscular and ectomycorrhizal fungi.

    Science.gov (United States)

    Holste, Ellen K; Kobe, Richard K; Gehring, Catherine A

    2017-04-01

    Experiments with plant species that can host both arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF) are important to separating the roles of fungal type and plant species and understanding the influence of the types of symbioses on plant growth and nutrient acquisition. We examined the effects of mycorrhizal fungal type on the growth and tissue nutrient content of two tree species (Eucalyptus grandis and Quercus costaricensis) grown under four nutrient treatments (combinations of low versus high nitrogen (N) and phosphorus (P) with different N:P ratios) in the greenhouse. Trees were inoculated with unidentified field mixtures of AMF or EMF species cultivated on root fragments of AMF- or EMF-specific bait plants. In E. grandis, inoculation with both AMF and EMF positively affected belowground plant dry weight and negatively affected aboveground dry weight, while only inoculation with AMF increased tissue nutrient content. Conversely, Q. costaricensis dry weight and nutrient content did not differ significantly among inoculation treatments, potentially due to its dependence on cotyledon reserves for growth. Mineral nutrition of both tree species differed with the ratio of N to P applied while growth did not. Our results demonstrate that both tree species' characteristics and the soil nutrient environment can affect how AMF and EMF interact with their host plants. This research highlights the importance of mycorrhizal fungal-tree-soil interactions during early seedling growth and suggests that differences between AMF and EMF associations may be crucial to understanding forest ecosystem functioning.

  18. Public attitude in the city of Belgrade towards invasive alien plant species

    Directory of Open Access Journals (Sweden)

    Tomićević Jelena

    2012-01-01

    Full Text Available Biological invasions are seen as a major threat to biodiversity at a global level, while the number of new invasions is increasing at an alarming rate. Raising the awareness of the public, academic world and policy makers about the dangers caused by invasive species, is essential for the creation of the support needed to implement and coordinate the policies necessary to address this problem. The aim of this study is to determine the level of local public awareness of the existence of these plant species, examine the public attitude towards alien invasive plant species and willingness to get involved in the prevention of their spreading. The survey was conducted in four nurseries on the territory of the City of Belgrade and the investigation dealt only with alien invasive woody plant species. Thirty customers were questioned in each of the four nurseries. The results show that local public is uninformed on the issue of invasive plant species. It is necessary to constantly and intensively raise their awareness of this issue, as well as the awareness of harmful consequences that may occur due to the uncontrolled spreading of alien invasive species. This refers not only to the population that visits the nurseries and buys the plants there and to those employed in plant production and selling, but also to the whole local public and decision makers.

  19. Plant species effects on soil nutrients and chemistry in arid ecological zones.

    Science.gov (United States)

    Johnson, Brittany G; Verburg, Paul S J; Arnone, John A

    2016-09-01

    The presence of vegetation strongly influences ecosystem function by controlling the distribution and transformation of nutrients across the landscape. The magnitude of vegetation effects on soil chemistry is largely dependent on the plant species and the background soil chemical properties of the site, but has not been well quantified along vegetation transects in the Great Basin. We studied the effects of plant canopy cover on soil chemistry within five different ecological zones, subalpine, montane, pinyon-juniper, sage/Mojave transition, and desert shrub, in the Great Basin of Nevada all with similar underlying geology. Although plant species differed in their effects on soil chemistry, the desert shrubs Sarcobatus vermiculatus, Atriplex spp., Coleogyne ramosissima, and Larrea tridentata typically exerted the most influence on soil chemistry, especially amounts of K(+) and total nitrogen, beneath their canopies. However, the extent to which vegetation affected soil nutrient status in any given location was not only highly dependent on the species present, and presumably the nutrient requirements and cycling patterns of the plant species, but also on the background soil characteristics (e.g., parent material, weathering rates, leaching) where plant species occurred. The results of this study indicate that the presence or absence of a plant species, especially desert shrubs, could significantly alter soil chemistry and subsequently ecosystem biogeochemistry and function.

  20. Root foraging for Patchy Phosphorus of Plant Species with Contrasting Foraging Strategy - Role of Roots and Mycorrhiza

    Science.gov (United States)

    Felderer, B.; Robinson, B. H.; Jansa, J.; Vontobel, P.; Frossard, E.; Schulin, R.

    2009-04-01

    three species of arbuscular mycorrhizal fungi (AMF; Glomus intraradices, Glomus claroideum, Gigaspora margarita). Therefore, we will conduct a mesocosm experiment in a 2 x 2 x 5 factorial design, with two plant species, two P distribution patterns (homogeneous, heterogeneous) and five mycorrhizal treatments (three sterilized treatments inoculated with different AMF species, one sterilized inoculated control, one non-sterilized control). We will apply Neutron Radiography (NR)-technique to investigate root architecture on a time line. NR is a non-invasive technique that can be applied to image roots in sand or soil. In the soil-root system, neutrons are mainly retained or scattered by hydrogen. Because of the higher water content, roots appear darker on the image than the surrounding sand/soil. At the end of the experiment, above and belowground biomass will be harvested and P concentrations will be determined. Roots within and outside nutrient-rich patches will be sampled separately. Root architecture will be determined with WinRhizo. We will apply dual radioisotopic labeling of the soil P to investigate physiological plasticity of the roots and/or plant-mycorrhizal association with respect to the P uptake. Ten days before the end of the experiment we will inject carrier-free 32P-orthophosphate solution to the P-rich patch and 33P to the substrate outside the patch. At harvest, we will measure 32P and 33P availabilities in the substrate and the radioisotope contents in plants, and calculate P uptake per unit of root surface within and outside the P-rich patch. We will use real-time polymerase chain reaction assay targeting the species-specific motifs in the ribosomal large subunit to assess abundances of the different AMF species within the roots and in the soil enriched or not with P (i.e. plasticity of mycorrhiza-plant association).

  1. Transfer of knowledge about flowering and vegetative propagation from model species to bulbous plants

    NARCIS (Netherlands)

    Leeggangers, H.A.C.F.; Moreno Pachón, N.M.; Gude, H.; Immink, G.H.

    2013-01-01

    The extensive characterization of plant genes and genome sequences summed to the continuous development of biotechnology tools, has played a major role in understanding biological processes in plant model species. The challenge for the near future is to generate methods and pipelines for an

  2. Plant biomass and species composition along an environmental gradient in montane riparian meadows

    Science.gov (United States)

    Kathleen A. Dwire; J. Boone Kauffman; E. N. Jack Brookshire; John E. Baham

    2004-01-01

    In riparian meadows, narrow zonation of the dominant vegetation frequently occurs along the elevational gradient from the stream edge to the floodplain terrace. We measured plant species composition and above- and belowground biomass in three riparian plant communities - a priori defined as wet, moist, and dry meadow - along short streamside topographic gradients in...

  3. Accumulation of Cd, Pb and Zn by 19 wetland plant species in constructed wetland.

    Science.gov (United States)

    Liu, Jianguo; Dong, Yuan; Xu, Hai; Wang, Deke; Xu, Jiakuan

    2007-08-25

    Uptake and distribution of Cd, Pb and Zn by 19 wetland plant species were investigated with experiments in small-scale plot constructed wetlands, into which artificial wastewater dosed with Cd, Pb and Zn at concentrations of 0.5, 2.0 and 5.0mgl(-1) was irrigated. The results showed that the removal efficiency of Cd, Pb and Zn from the wastewater were more than 90%. Generally, there were tens differences among the 19 plant species in the concentrations and quantity accumulations of the heavy metals in aboveground part, underground part and whole plants. The distribution ratios into aboveground parts for the metals absorbed by plants varied also largely from about 30% to about 90%. All the plants accumulated, in one harvest, 19.85% of Cd, 22.55% of Pb and 23.75% of Zn that were added into the wastewater. Four plant species, e.g. Alternanthera philoxeroides, Zizania latifolia, Echinochloa crus-galli and Polygonum hydropiper, accumulated high amounts of Cd, Pb and Zn. Monochoria vaginalis was capable for accumulating Cd and Pb, Isachne globosa for Cd and Zn, and Digitaria sanguinalis and Fimbristylis miliacea for Zn. The results indicated that the plants, in constructed wetland for the treatment of wastewater polluted by heavy metals, can play important roles for removal of heavy metals through phytoextraction. Selection of plant species for use in constructed wetland will influence considerably removal efficiency and the function duration of the wetland.

  4. Initial soil development under pioneer plant species in metal mine waste deposits

    NARCIS (Netherlands)

    Arocena, J.M.; van Mourik, J.M.; Schilder, M.L.M.; Faz Cano, A.

    2010-01-01

    Mine waste materials are often inhospitable to plants due to extreme pH, high salinity, very low organic matter, elevated metal contents, and poor physical conditions. We investigated initial soil development in three study areas under different pioneer plant species in degraded landscapes left

  5. Plant cell walls: New insights from ancient species

    DEFF Research Database (Denmark)

    Sørensen, Iben; Willats, William George Tycho

    2008-01-01

    Cell walls are a defining feature of plants and have numerous crucial roles in growth and development. They are also the largest source of terrestrial biomass and have many important industrial applications - ranging from bulk products to functional food ingredients. There is considerable interest......-D-glucan is not unique to the Poales and is an abundant component of Equisetum arvense cell walls. Plant J 2008; 54:510-21....... in the structure and functions of cell walls, and in the evolution of their remarkably complex polysaccharide structures. The grasses and cereals (order Poales), have long been regarded as being unique in that their cell walls contain an unbranched homopolymer, (1¿3)(1¿4)-ß-D-glucan, in which short blocks of (1...

  6. Growth responses to ozone in plant species from wetlands

    NARCIS (Netherlands)

    Franzaring, J.H.; Tonneijck, A.E.G.; Kooijman, A.W.N.; Dueck, Th.A.

    2000-01-01

    Ten wet grassland species were fumigated with four concentrations of ozone (charcoal-filtered air, non-filtered air and non-filtered air plus 25 or 50 nl 1-1 ozone) in open-top chambers during one growing season to investigate the long-term effect of this air pollutant on various growth variables.

  7. The assessment of invasive alien plant species removal programs ...

    African Journals Online (AJOL)

    Yusuf Adam

    include grasslands, thicket and forest vegetation. This region receives an ..... IAPs removal has been done, but on a national scale and was biome specific (van Wilgen et al., 2012) whereas this study .... 'Indirect remote sensing of a cryptic forest understorey invasive species', Forest Ecology and. Management, vol. 225, no.

  8. Sparse Distribution Pattern Of Some Plant Species In Two ...

    African Journals Online (AJOL)

    This study analysed species diversity and distribution patterns on two afromontane rain forests of the eastern Arc Mountains of Tanzania in the west Usambaras and Ulugurus to assess any possible threats to biodiversity conservation in this region. A hundred sample plots (0.02 ha) were established on each of the two ...

  9. Effect of soil-added cadmium on several plant species

    Energy Technology Data Exchange (ETDEWEB)

    Miles, L.J.; Parker, G.R.

    1979-04-01

    Several species (Andropogon scoparius, Rhus radicans, Rudbeckia hirta, Anemone cylindrica, Monarda fistulosa, Poa pratensis, and Liatris spicata) native to northwestern Indiana were grown from seed in the greenhouse for 6 weeks. An uncontaminated sandy soil was utilized as the substrate with four levels of soil-added Cd. The concentrations added ranged from 0 to 100 ..mu..g Cd/g soil and were comparable to surface soil Cd concentration levels found in the urban-industrial region of northwestern Indiana. Data on germination, survival, height, and dry weight were collected. Germination, survival, and weight were found to exhibit a negative response to increasing soil Cd concentration over all species. Height, however, was not found to be a consistently good indicator of Cd response. While overall species' differences were noted, no differences could be conclusively shown among the species for Cd tolerance, although there were indications that this was the case. All effects noted were of a low level for the soil-added Cd concentrations utilized.

  10. Productivity is a poor predictor of plant species richness

    Science.gov (United States)

    P.B. Adler; E.T. Borer; H. Hillebrand; Y. Hautier; A. Hector; S. Harpole; L.R. O’Halloran; J.B. Grace; M. Anderson; J.D. Bakker; L.A. Biederman; C.S. Brown; Y.M. Buckley; L.B. Calabrese; C.-J. Chu; E.E. Cleland; S.L. Collins; K.L. Cottingham; M.J. Crawley; E.I. Damschen; K.W. Davies; N.M. DeCrappeo; P.A. Fay; J. Firn; P. Frater; E.I. Gasarch; D.S. Gruner; N. Hagenah; J. Hille. Ris Lambers

    2011-01-01

    For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent...

  11. Ecotaxonmic baseline evaluation of the plant species in a ...

    African Journals Online (AJOL)

    Hence the envisaged event of uncontrolled and accidental hydrocarbon and effluent discharge, a preconceived knowledge of the vegetation could be helpful in the determination of the long and short term effects of such ecological problem. KEYWORDS: Environment, project area, vegetation sampling, species abundance, ...

  12. Migration potential of tundra plant species in a warming Arctic: Responses of southern ecotypes of three species to experimental warming in the High Arctic

    Science.gov (United States)

    Bjorkman, Anne; Henry, Greg; Vellend, Mark

    2013-04-01

    Climatic changes due to anthropogenic activity are predicted to have a profound effect on the world's biodiversity and ecosystem functioning. The response of natural communities to climate change will depend primarily on two factors: 1) the ability of species to adapt quickly to changing temperatures and precipitation trends, and 2) the ability of species and populations from southern latitudes to migrate northward and establish in new environments. The assumption is often made that species and populations will track their optimal climate northward as the earth warms, but this assumption ignores a host of other potentially important factors, including the lack of adaptation to photoperiod, soil moisture, and biotic interactions at higher latitudes. In this study, we aim to better understand the ability of southern populations to establish and grow at northern latitudes under warmer temperatures. We collected seeds or ramets of three Arctic plant species (Papaver radicatum, Oxyria digyna, and Arctagrostis latifolia) from Alexandra Fiord on Ellesmere Island, Canada and from southern populations at Cornwallis Island, Canada, Barrow, Alaska, and Latnjajaure, Sweden. These seeds were planted into experimentally warmed and control plots at Alexandra Fiord in 2011. We have tracked their survival, phenology, and growth over two growing seasons. Here, we will present the preliminary results of these experiments. In particular, we will discuss whether individuals originating from southern latitudes exhibit higher growth rates in warm plots than control plots, and whether southern populations survive and grow as well as or better than individuals from Alexandra Fiord in the warmed plots. In both cases, a positive response would indicate that a warming climate may facilitate a migration northward of more southerly species or populations, and that the lack of adaptation to local conditions (soil chemistry, microhabitat, etc.) will not limit this migration. Alternately, a

  13. Ecological modules and roles of species in heathland plant-insect flower visitor networks.

    Science.gov (United States)

    Dupont, Yoko L; Olesen, Jens M

    2009-03-01

    1. Co-existing plants and flower-visiting animals often form complex interaction networks. A long-standing question in ecology and evolutionary biology is how to detect nonrandom subsets (compartments, blocks, modules) of strongly interacting species within such networks. Here we use a network analytical approach to (i) detect modularity in pollination networks, (ii) investigate species composition of modules, and (iii) assess the stability of modules across sites. 2. Interactions between entomophilous plants and their flower-visitors were recorded throughout the flowering season at three heathland sites in Denmark, separated by >or= 10 km. Among sites, plant communities were similar, but composition of flower-visiting insect faunas differed. Visitation frequencies of visitor species were recorded as a measure of insect abundance. 3. Qualitative (presence-absence) interaction networks were tested for modularity. Modules were identified, and species classified into topological roles (peripherals, connectors, or hubs) using 'functional cartography by simulated annealing', a method recently developed by Guimerà & Amaral (2005a). 4. All networks were significantly modular. Each module consisted of 1-6 plant species and 18-54 insect species. Interactions aggregated around one or two hub plant species, which were largely identical at the three study sites. 5. Insect species were categorized in taxonomic groups, mostly at the level of orders. When weighted by visitation frequency, each module was dominated by one or few insect groups. This pattern was consistent across sites. 6. Our study adds support to the conclusion that certain plant species and flower-visitor groups are nonrandomly and repeatedly associated. Within a network, these strongly interacting subgroups of species may exert reciprocal selection pressures on each other. Thus, modules may be candidates for the long-sought key units of co-evolution.

  14. In vitro susceptibility testing of Yersinia species to eight plant ...

    African Journals Online (AJOL)

    AJL

    2012-05-24

    May 24, 2012 ... 10010 Afr. J. Biotechnol. Table 1. The inhibitory effect of neat ethanolic plant extracts and some natural antimicrobials against Yersinia sp. Extract. Diameter of zones of inhibition (mm). YPS. YE 0:3. YE 0:8. YK 0:11, 23. YI 0:52, 53 YIL 0:52, 53. Cymbopogon citratus (DC) staft leaves. 12.7. 16.5. 10.4*. 14.4.

  15. Higher diversity in fungal species discriminates children with type 1 diabetes mellitus from healthy control

    Directory of Open Access Journals (Sweden)

    Kowalewska B

    2016-04-01

    Full Text Available Beata Kowalewska,1 Katarzyna Zorena,2 Małgorzata Szmigiero-Kawko,3 Piotr Wąż,4 Małgorzata Myśliwiec3 1Department of Tropical Medicine and Epidemiology, Institute of Maritime and Tropical Medicine, 2Department of Immunology and Environmental Microbiology, 3Clinic of Paediatrics, Diabetology and Endocrinology, 4Department of Nuclear Medicine, Medical University of Gdańsk, Gdańsk, Poland Objective: To conduct qualitative and quantitative assessment of yeast-like fungi in the feces of children and adolescents with type 1 diabetes mellitus (T1DM with respect to their metabolic control and duration of the disease.Materials and methods: The studied materials included samples of fresh feces collected from 53 children and adolescents with T1DM. Control group included 30 age- and sex-matched healthy individuals. Medical history was taken and physical examination was conducted in the two study arms. Prevalence of the yeast-like fungi in the feces was determined as well as their amounts, species diversity, drug susceptibility, and enzymatic activity.Results: The yeast-like fungi were found in the samples of feces from 75.4% of T1DM patients and 70% controls. In the group of T1DM patients, no correlation was found between age (Rs=0.253, P=0.068, duration of diabetes (Rs=−0.038, P=0.787, or body mass index (Rs=0.150, P=0.432 and the amount of the yeast-like fungi isolated in the feces. Moreover, no correlation was seen between the amount of the yeast-like fungi and glycated hemoglobin (Rs=0.0324, P=0.823, systolic blood pressure (Rs=0.102, P=0.483, or diastolic blood pressure (Rs=0.271, P=0.345.Conclusion: Our research has shown that children and adolescents with T1DM show higher species diversity of the yeast-like fungi, with Candida albicans being significantly less prevalent versus control subjects. Moreover, fungal species in patients with T1DM turn out to be more resistant to antifungal treatment. Keywords: children, diabetes mellitus type 1

  16. Phytotherapy of Polish migrants in Misiones, Argentina: legacy and acquired plant species.

    Science.gov (United States)

    Kujawska, Monika; Hilgert, Norma I

    2014-05-14

    Analyzing how and why phytotherapeutical practices survive a migratory process is important for understanding migrant health seeking behaviour and health demand. Contrary to most studies, which focus on migrants from warm climates who settle in European and American cities, this study explores continuations in the herbal pharmacopoeia of Eastern European peasants who settled down in rural subtropical areas of Argentina. The study also explores the pharmacopoeia among the descendants of the first generation born in Argentina. Primary and secondary sources were employed in the study. Data were collected during over 200 interviews (semi-structured, free lists and in-depth) with 94 study participants. Voucher specimens of species mentioned were gathered and identified. Illnesses were reported according to local ethnomedical terminology and classification. Only reports from informants' own experience were included in the analysis. The unit of analysis was a plant use report (plant species × plant part × ailment × informant). The frequency of mentions was calculated for plant parts used and modes of preparation and administration of herbal medicines, and the Informant Diversity Value was also estimated. Secondary information was obtained from ethnobotanical and ethnomedical literature concerning the whole of Poland. A list was made of medicinal plant species known from Poland available in the study area. Then, the similarity between the available species and those used by Polish migrants was evaluated by applying the Simpson index. An exhaustive list of 129 plant species used by the Polish community in Misiones, Argentina, was obtained. Among 37 species known form Poland and available in Misiones, 19 were used by the community. There was low consensus on the treatment of health conditions with legacy plants between Polish migrants and the Polish folk pharmacopoeia. The reasons for the relatively low use of legacy species are explained. More continuation has been

  17. Cross-talk of nitric oxide and reactive oxygen species in plant programed cell death

    OpenAIRE

    Yiqin eWang; Loake, Gary J.; Chengcai eChu

    2013-01-01

    In plants, programed cell death (PCD) is an important mechanism to regulate multiple aspects of growth and development, as well as to remove damaged or infected cells during responses to environmental stresses and pathogen attacks. Under biotic and abiotic stresses, plant cells exhibit a rapid synthesis of nitric oxide (NO) and a parallel accumulation of reactive oxygen species (ROS). Frequently, these responses trigger a PCD process leading to an intrinsic execution of plant cells. The accum...

  18. Are High Carbon Stocks in Agroforests and Forest Associated with High Plant Species Diversity?

    OpenAIRE

    Natalia, Depi; Arisoesilaningsih, Endang; Hairiah, Kurniatun

    2017-01-01

    Conserving plant diversity and retaining terrestrial carbon stocks are targets for environmental policy and appear to be generally compatible. However, detailed information on the way both respond to agroforestry management is lacking. Rubber and fruit tree agroforestry systems combine planted trees and trees that are tolerated or actively managed that derived from natural vegetation. The research aimed to evaluate plant species diversity, vegetation structure, and C stock in rubber agrofores...

  19. Pathogenicity of eight formae speciales of Fusarium oxysporum Schlecht. in relation to different plants species

    Directory of Open Access Journals (Sweden)

    Maria Wagner

    2014-08-01

    Full Text Available Eight formae speciales of Fusarium oxysporum were isolated from plants of aster, flax, bean, pea, tomato, carnation, yellow lupine and pine, showing visible symptoms of wilting. Plants of the eight species were inoculated with each of the studied formae speciales of F. oxysporum, F. oxysporum f. sp. lupini could be reisolated only from lupine, while the others were pathogenic for the hosts and showed ability to colonize another