WorldWideScience

Sample records for coastal plant populations

  1. Twelve years of repeated wild hog activity promotes population maintenance of an invasive clonal plant in a coastal dune ecosystem.

    Science.gov (United States)

    Oldfield, Callie A; Evans, Jonathan P

    2016-04-01

    Invasive animals can facilitate the success of invasive plant populations through disturbance. We examined the relationship between the repeated foraging disturbance of an invasive animal and the population maintenance of an invasive plant in a coastal dune ecosystem. We hypothesized that feral wild hog (Sus scrofa) populations repeatedly utilized tubers of the clonal perennial, yellow nutsedge (Cyperus esculentus) as a food source and evaluated whether hog activity promoted the long-term maintenance of yellow nutsedge populations on St. Catherine's Island, Georgia, United States. Using generalized linear mixed models, we tested the effect of wild hog disturbance on permanent sites for yellow nutsedge culm density, tuber density, and percent cover of native plant species over a 12-year period. We found that disturbance plots had a higher number of culms and tubers and a lower percentage of native live plant cover than undisturbed control plots. Wild hogs redisturbed the disturbed plots approximately every 5 years. Our research provides demographic evidence that repeated foraging disturbances by an invasive animal promote the long-term population maintenance of an invasive clonal plant. Opportunistic facultative interactions such as we demonstrate in this study are likely to become more commonplace as greater numbers of introduced species are integrated into ecological communities around the world.

  2. Experimental and genetic analyses reveal that inbreeding depression declines with increased self-fertilization among populations of a coastal dune plant.

    Science.gov (United States)

    Dart, S; Eckert, C G

    2013-03-01

    Theory predicts that inbreeding depression (ID) should decline via purging in self-fertilizing populations. Yet, intraspecific comparisons between selfing and outcrossing populations are few and provide only mixed support for this key evolutionary process. We estimated ID for large-flowered (LF), predominantly outcrossing vs. small-flowered (SF), predominantly selfing populations of the dune endemic Camissoniopsis cheiranthifolia by comparing selfed and crossed progeny in glasshouse environments differing in soil moisture, and by comparing allozyme-based estimates of the proportion of seeds selfed and inbreeding coefficient of mature plants. Based on lifetime measures of dry mass and flower production, ID was stronger in nine LF populations [mean δ = 1-(fitness of selfed seed/fitness of outcrossed seed) = 0.39] than 16 SF populations (mean δ = 0.03). However, predispersal ID during seed maturation was not stronger for LF populations, and ID was not more pronounced under simulated drought, a pervasive stress in sand dune habitat. Genetic estimates of δ were also higher for four LF (δ = 1.23) than five SF (δ = 0.66) populations; however, broad confidence intervals around these estimates overlapped. These results are consistent with purging, but selective interference among loci may be required to maintain strong ID in partially selfing LF populations, and trade-offs between selfed and outcrossed fitness are likely required to maintain outcrossing in SF populations.

  3. Extended Shared Socioeconomic Pathways for Coastal Impact Assessment: Spatial Coastal Population Scenarios

    Science.gov (United States)

    Merkens, Jan-Ludolf; Reimann, Lena; Hinkel, Jochen; Vafeidis, Athanasios T.

    2016-04-01

    This work extends the Shared Socioeconomic Pathways (SSPs) by developing spatial projections of global coastal population distribution for the five basic SSPs. Based on a series of coastal migration drivers, which were identified from existing literature, we develop coastal narratives for the five basic SSPs (SSP1-5). These narratives account for differences in coastal versus inland population development in urban and rural areas. To spatially distribute population we use the International Institute for Applied Systems Analysis (IIASA) national population and urbanisation projections and employ country-specific growth rates which differ for coastal and inland as well as for urban and rural regions. These rates are derived from spatial analysis of historical population data. We then adjust these rates for each SSP based on the coastal narratives. The resulting global population grids depict the projected distribution of coastal population for each SSP, until the end of the 21st century, at a spatial resolution of 30 arc seconds. These grids exhibit a three- to four-fold increase in coastal population compared to the basic SSPs. Across all SSPs, except for SSP3, coastal population peaks by the middle of the 21st century and declines afterwards. In SSP3 the coastal population grows continuously until 2100. Compared to the base year 2000 the coastal population increases considerably in all SSPs. The extended SSPs are intended to be utilised in Impact, Adaptation and Vulnerability (IAV) assessments as they allow for improved analysis of exposure to sea-level rise and coastal flooding under different physical and socioeconomic scenarios.

  4. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes

    NARCIS (Netherlands)

    Piskiewicz, A.M.; Duyts, H.; Berg, M.P.; Costa, S.R.; Putten, van der W.H.

    2007-01-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis

  5. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes

    NARCIS (Netherlands)

    Piskiewicz, A.M.; Duyts, H.; Berg, M.P.; Costa, S.R.; Putten, van der W.H.

    2007-01-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis

  6. Municipal wastewater treatment plants in Mediterranean coastal cities [electronic resource]: inventory of treatment plants in cities of between 2,000 and 10,000 inhabitatnts

    National Research Council Canada - National Science Library

    2008-01-01

    The present document contains information on the municipal wastewater treatment plants in Mediterranean coastal cities with population between 2,000 and 10,000 inhabitants, respective to the MAP Technical Report Series...

  7. Future coastal population growth and exposure to sea-level rise and coastal flooding--a global assessment

    National Research Council Canada - National Science Library

    Neumann, Barbara; Vafeidis, Athanasios T; Zimmermann, Juliane; Nicholls, Robert J

    2015-01-01

    .... Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four...

  8. China's coastal population and economic development: summary of the symposium.

    Science.gov (United States)

    Song, R

    1992-01-01

    China's coastal areas have led the rest of China in economic development and low fertility rates; migration from inland areas and urbanization are well advanced. A symposium on China's coastal population and economic development was conducted in 1990 by the Population Research Institute of the Chinese Academy of Sciences, the Liaoning Population Institute, and the Dalian Population Institute at the request of the China Population Institute. There were 50 people in attendance representing major research institutes and family planning associations and media organizations. 26 papers were submitted. The opening speaker addressed developing the economy as a positive cycle of population and development, and accelerating change. Discussion focused on the following topics: the relationship between fertility rate changes and coastal economic development, population mobility and migration to coast areas, population urbanization, and related problems. In the summation by Professor Tian Xueyuan, 7 trends were identified: continued coastal population growth, a two-directional change in natural population growth, an increase in the rate of coastal population migration, rapid urban population growth, productive age population growth and changes in the employment structure, improvements in economic and technological progess and quality of life, and rapid population aging. The symposium was considered particularly timely in highlighting the current problems and strengths, integrating theorists with field workers, and maintaining an open exchange of ideas and information. Problems were identified as regional open areas in Heihai in Guangxi, Heihe in Heilongjiang, and Dalian in Liaoning Province. Although the population is considered professionally better qualified than in other regions, there is still a lack of technicians and skilled workers and an excess of untrained workers. Development is being slowed and mismanaged due to deficiencies in the job allocation and personnel

  9. Uncertainties in measuring populations potentially impacted by sea level rise and coastal flooding

    National Research Council Canada - National Science Library

    Mondal, Pinki; Tatem, Andrew J

    2012-01-01

    ... the size of vulnerable coastal populations. Many previous studies have undertaken this by quantifying the size of populations residing in low elevation coastal zones using one of two global spatial population datasets available - LandScan...

  10. Efficiency of plant growth promoting rhizobacteria isolated from sand dunes of Chennai coastal area.

    Science.gov (United States)

    Muthezhilan, R; Sindhuja, B S; Hussain, A Jaffar; Jayaprakashvel, M

    2012-08-15

    Plant Growth Promoting Rhizobacteria (PGPR) are beneficial bacteria that colonize the plant root and enhance the plant growth. The use of PGPR is steadily increasing in agriculture and offers an attractive way to replace chemical fertilizers, pesticides and supplements. In the present study, PGPR were isolated from 18 different rhizosphere soil samples of coastal sand dune plants, belonging to the genus Ipomoea sp. collected from the Chennai coastal area. For isolation of bacteria from soil samples, pour plate technique was followed. The rhizobacterial population was ranged from 4.4 x 10(6)-7.5 x 10(7) CFU g(-1). From that, 46 morphologically different bacterial strains were isolated. Among 46, 18 strains exhibited the production of Indole Acetic Acid. (IAA). When screened for phosphate solubilzing activity, six strains showed maximum activity. All these selected six strains were screened for seed germination among which these two strains (AMET1136 and AMET 1148) showed remarkable increase in the seed germination of black gram and green gram. For plant growth promotion, three types of treatments namely, seed bacterization, soil drenching and mixed (seed+soil) were carried out to check the potential of these two strains. Among that one strain which was identified as Pseudomonas sp. AMET1148 showed remarkable and significant increase in shoot length and root length of the tested plants. The study concluded that PGPR from coastal sand dund plants can be developed as plant growth promoters in agricultural crops.

  11. Plant-feeding nematodes in coastal sand dunes: occurrence, host specificity and effects on plant growth

    NARCIS (Netherlands)

    Brinkman, E.P.; Duyts, H.; Karssen, G.; Stoel, C.D.; Putten, van der W.H.

    2015-01-01

    Aims Coastal sand dunes have a well-established abiotic gradient from beach to land and a corresponding spatial gradient of plant species representing succession in time. Here, we relate the distribution of plant-feeding nematodes with dominant plant species in the field to host specialization and

  12. Diversity and use of ethnomedicinal plants in coastal Karnataka, India

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    M. JAYAKARA BHANDARY

    2014-04-01

    Full Text Available Bhandary MJ, Chandrashekar KR. 2014. Diversity and use of ethnomedicinal plants in coastal Karnataka, India. Biodiversitas 15: 89-93. A study was undertaken in Coastal Karnataka, a culturally and floristically diverse region between the Western Ghats and the Arabian sea in India, to document the diversity and uses of ethnomedicinal plants of the area. This study resulted in the documentation of ethnomedicinal uses of 342 species of plants belonging to 34 families. The dominant families of ethnomedicinal plants were: Fabaceae (38 species, Euphorbiaceae (22 species, Rubiaceae (11 species, Acanthaceae, Asteraceae, Apocynaceae and Rutaceae (10 species each. Among the plants used, 30% are herbs, 27% trees, 25% climbers and 18% shrubs. Majority of the plants are used against several diseases, either alone or in combination with other plants. The most popular medicinal plants, in terms of the number of diseases against which they are used, are Cyclea peltata, Aristolochia indica, Cuminum cyminum, Curcuma longa, Tamarindus indica, Asparagus racemosus, Ficus racemosa, Hemidesmus indicus, Ficus religiosa, Calotropis gigantea, Vitex negundo, Aegle marmelos and Leucas aspera. A list of 50 important ethnomedicinal plants of the region which are used in the treatment of 5 or more disorders is provided.

  13. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes.

    Science.gov (United States)

    Piśkiewicz, Anna M; Duyts, Henk; Berg, Matty P; Costa, Sofia R; van der Putten, Wim H

    2007-06-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis is capable of reducing the performance of the dominant grass Ammophila arenaria (Marram grass). However, field surveys show that populations of this nematode usually are controlled to nondamaging densities, but the control mechanism is unknown. In the present study, we first established that T. ventralis populations are top-down controlled by soil biota. Then, selective removal of soil fauna suggested that soil microorganisms play an important role in controlling T. ventralis. This result was confirmed by an experiment where selective inoculation of microarthropods, nematodes and microbes together with T. ventralis into sterilized dune soil resulted in nematode control when microbes were present. Adding nematodes had some effect, whereas microarthropods did not have a significant effect on T. ventralis. Our results have important implications for the appreciation of herbivore controls in natural soils. Soil food web models assume that herbivorous nematodes are controlled by predaceous invertebrates, whereas many biological control studies focus on managing nematode abundance by soil microorganisms. We propose that soil microorganisms play a more important role than do carnivorous soil invertebrates in the top-down control of herbivorous ectoparasitic nematodes in natural ecosystems. This is opposite to many studies on factors controlling root-feeding insects, which are supposed to be controlled by carnivorous invertebrates, parasitoids, or entomopathogenic nematodes. Our conclusion is that the ectoparasitic nematode T. ventralis is potentially able to limit productivity of the dune grass A. arenaria but that soil organisms, mostly microorganisms, usually prevent the

  14. Tracking the source of mercury in coastal populations of California Cougars (puma concolor)

    Science.gov (United States)

    Weiss-Penzias, P. S.; Wilmers, C.; Yovovich, V.; Houghtaling, P.; Torregrosa, A.

    2015-12-01

    As part of a project on the cycling of mercury (Hg) from the ocean to fog and deposition to land in coastal California, the whiskers of pumas from coastal and inland populations in California were analyzed for total Hg (HgT). Previous studies have shown that fog water in coastal California contains enhanced concentrations of monomethyl Hg (MMHg) compared to rain water. The likely source of fog MMHg is from evasion and demethylation of dimethyl Hg (DMHg) from coastal ocean upwelling. The California coast receives seasonal inputs of fog drip, and we hypothesized that if fog water deposition of MMHg was making an impact, the observable effects might be seen in high trophic level predators of the terrestrial ecosystem. Puma whiskers from 88 individuals from the Santa Cruz Mountains, a sub-range of the California Coast Range, were obtained and compared with puma whiskers from 12 individuals from the foothills of the Sierra Nevada Mountains. Mean total Hg in puma whiskers from the coastal population is 1.0 ± 1.5 ug Hg / g whisker (ppm), whereas mean HgT from the inland puma population is 0.13 ± 0.09 ppm. The difference between these means is significant to the 95% confidence level. For the coastal puma population, the whiskers from 10 individuals had HgT concentrations > 2.0 ppm and 3 individuals had HgT > 4 ppm, which exceeds the U.S. EPA reference dose for humans (1 ppm) approaches a level of concern found for other large mammals such as polar bears (5 ppm). The study is ongoing and HgT concentrations will be determined in the fur and flesh of deer from the same locations as the puma whiskers, since deer comprise ~95% of the puma diet. Samples of plants that are likely fed upon by deer that span the coastal-inland transect will also be analyzed for HgT. Estimates of fog frequency spatial patterns, derived from weather satellite observations and topographic modeling, will be compared with the HgT content of plant and animal tissue in coastal California to quantify

  15. PLANT COMMUNITIES ON COASTAL DUNES IN LAZIO (ITALY

    Directory of Open Access Journals (Sweden)

    A. STANISCI

    2004-05-01

    Full Text Available Aim of the paper is to describe the conservation state of the dune plant communities of Lazio (central Italy, using both original and already published phytosociological relevés. This case study in particular analyses the effects of human disturbance on the species composition and the vegetation zonation in coastal sandy landscape, already classified in three land facets. 13 plant associations were recognised and 9 of them were identified as potential natural vegetation types for the sandy coastal ecosystems of Lazio. Incidence of ruderal species and alien taxa were calculated for each plant community and for each land facet. The results have produced evidence that, even if Lazio coastline is largely occupied by human settlements or infrastructures, several sites still preserve an high plant communities diversity and few alien taxa inside the natural habitats occur. On the contrary where the human impact is intense, dune plant communities disappear or if they are still present, the vegetation zonation is incomplete, ruderals are abundant and alien species are locally common. A data-base of dune plant diversity was realised for a monitoring purpose.

  16. Population vulnerability to storm surge flooding in coastal Virginia, USA.

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    Liu, Hua; Behr, Joshua G; Diaz, Rafael

    2016-07-01

    This study aims to assess the vulnerability of populations to storm surge flooding in 12 coastal localities of Virginia, USA. Population vulnerability is assessed by way of 3 physical factors (elevation, slope, and storm surge category), 3 built-up components (road availability, access to hospitals, and access to shelters), and 3 household conditions (storm preparedness, financial constraints to recovering from severe weather events, and health fragility). Fuzzy analysis is used to generate maps illustrating variation in several types of population vulnerability across the region. When considering physical factors and household conditions, the most vulnerable neighborhoods to sea level rise and storm surge flooding are largely found in urban areas. However, when considering access to critical infrastructure, we find rural residents to be more vulnerable than nonrural residents. These detailed assessments can inform both local and state governments in catastrophic planning. In addition, the methodology may be generalized to assess vulnerability in other coastal corridors and communities. The originality is highlighted by evaluating socioeconomic conditions at refined scale, incorporating a broader range of human perceptions and predispositions, and employing a geoinformatics approach combining physical, built-up, and socioeconomic conditions for population vulnerability assessment. Integr Environ Assess Manag 2016;12:500-509. © 2015 SETAC. © 2015 SETAC.

  17. Effects of trampling limitation on coastal dune plant communities.

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    Santoro, Riccardo; Jucker, Tommaso; Prisco, Irene; Carboni, Marta; Battisti, Corrado; Acosta, Alicia T R

    2012-03-01

    Sandy coastlines are sensitive ecosystems where human activities can have considerable negative impacts. In particular, trampling by beach visitors is a disturbance that affects dune vegetation both at the species and community level. In this study we assess the effects of the limitation of human trampling on dune vegetation in a coastal protected area of Central Italy. We compare plant species diversity in two recently fenced sectors with that of an unfenced area (and therefore subject to human trampling) using rarefaction curves and a diversity/dominance approach during a two year study period. Our results indicate that limiting human trampling seems to be a key factor in driving changes in the plant diversity of dune systems. In 2007 the regression lines of species abundance as a function of rank showed steep slopes and high Y-intercept values in all sectors, indicating a comparable level of stress and dominance across the entire study site. On the contrary, in 2009 the regression lines of the two fenced sectors clearly diverge from that of the open sector, showing less steep slopes. This change in the slopes of the tendency lines, evidenced by the diversity/dominance diagrams and related to an increase in species diversity, suggests the recovery of plant communities in the two fences between 2007 and 2009. In general, plant communities subject to trampling tended to be poorer in species and less structured, since only dominant and tolerant plant species persisted. Furthermore, limiting trampling appears to have produced positive changes in the dune vegetation assemblage after a period of only two years. These results are encouraging for the management of coastal dune systems. They highlight how a simple and cost-effective management strategy, based on passive recovery conservation measures (i.e., fence building), can be a quick (1–2 years) and effective method for improving and safeguarding the diversity of dune plant communities.

  18. Gridded population projections for the coastal zone under the Shared Socioeconomic Pathways

    Science.gov (United States)

    Merkens, Jan-Ludolf; Reimann, Lena; Hinkel, Jochen; Vafeidis, Athanasios T.

    2016-10-01

    Existing quantifications of the Shared Socioeconomic Pathways (SSP) used for climate impact assessment do not account for subnational population dynamics such as coastward-migration that can be critical for coastal impact assessment. This paper extends the SSPs by developing spatial projections of global coastal population distribution for the five basic SSPs. Based on a series of coastal migration drivers we develop coastal narratives for each SSP. These narratives account for differences in coastal and inland population developments in urban and rural areas. To spatially distribute population, we use the International Institute for Applied Systems Analysis (IIASA) national population and urbanisation projections and employ country-specific growth rates, which differ for coastal and inland as well as for urban and rural regions, to project coastal population for each SSP. These rates are derived from spatial analysis of historical population data and adjusted for each SSP based on the coastal narratives. Our results show that, compared to the year 2000 (638 million), the population living in the Low Elevated Coastal Zone (LECZ) increases by 58% to 71% until 2050 and exceeds one billion in all SSPs. By the end of the 21st century, global coastal population declines to 830-907 million in all SSPs except for SSP3, where coastal population growth continues and reaches 1.184 billion. Overall, the population living in the LECZ is higher by 85 to 239 million compared to the original IIASA projections. Asia expects the highest absolute growth (238-303 million), Africa the highest relative growth (153% to 218%). Our results highlight regions where high coastal population growth is expected and will therefore face an increased exposure to coastal flooding.

  19. Future coastal population growth and exposure to sea-level rise and coastal flooding--a global assessment.

    Directory of Open Access Journals (Sweden)

    Barbara Neumann

    Full Text Available Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential

  20. Future coastal population growth and exposure to sea-level rise and coastal flooding--a global assessment.

    Science.gov (United States)

    Neumann, Barbara; Vafeidis, Athanasios T; Zimmermann, Juliane; Nicholls, Robert J

    2015-01-01

    Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential. Furthermore, we

  1. Future Coastal Population Growth and Exposure to Sea-Level Rise and Coastal Flooding - A Global Assessment

    Science.gov (United States)

    Neumann, Barbara; Vafeidis, Athanasios T.; Zimmermann, Juliane; Nicholls, Robert J.

    2015-01-01

    Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential. Furthermore, we

  2. Allometry data and equations for coastal marsh plants.

    Science.gov (United States)

    Lu, Meng; Caplan, Joshua S; Bakker, Jonathan D; Adam Langley, J; Mozdzer, Thomas J; Drake, Bert G; Patrick Megonigal, J

    2016-12-01

    Coastal marshes are highly valued for ecosystem services such as protecting inland habitats from storms, sequestering carbon, removing nutrients and other pollutants from surface water, and providing habitat for fish, shellfish, and birds. Because plants largely determine the structure and function of coastal marshes, quantifying plant biomass is essential for evaluating these ecosystem services, understanding the biogeochemical processes that regulate ecosystem function, and forecasting tidal wetland responses to accelerated sea level rise. Allometry is a convenient and efficient technique for nondestructive estimation of plant biomass, and it is commonly used in studies of carbon and nitrogen cycles, energy flows, and marsh surface elevation change. We present plant allometry data and models developed for three long-term experiments at the Smithsonian Global Change Research Wetland, a brackish marsh in the Rhode River subestuary of the Chesapeake Bay. The dataset contains 9,771 measurements of stem height, dry mass, and (in 9638 cases) stem width across 11 plant species. The vast majority of observations are for Schoenoplectus americanus (8430) and Phragmites australis (311), with fewer observations for other common species: Amaranthus cannabinus, Atriplex patula, Iva frutescens, Kosteletzkya virginica, Polygonum hydropiper, Solidago sempervirens, Spartina alterniflora, Spartina cynosuroides, and Typha angustifolia. Allometric relationships take the form of linear regressions of biomass (transformed using the Box-Cox procedure) on either stem height and width, or on stem height alone. Allometric relationships for Schoenoplectus americanus were not meaningfully altered by elevated CO2 , N enrichment, the community context, interannual variation in climate, or year, showing that a single equation can be used across a broad range of conditions for this species. Archived files include: (1) raw data used to derive allometric equations for each species, (2) reports and

  3. Selection in coastal Synechococcus (cyanobacteria populations evaluated from environmental metagenomes.

    Directory of Open Access Journals (Sweden)

    Vera Tai

    Full Text Available Environmental metagenomics provides snippets of genomic sequences from all organisms in an environmental sample and are an unprecedented resource of information for investigating microbial population genetics. Current analytical methods, however, are poorly equipped to handle metagenomic data, particularly of short, unlinked sequences. A custom analytical pipeline was developed to calculate dN/dS ratios, a common metric to evaluate the role of selection in the evolution of a gene, from environmental metagenomes sequenced using 454 technology of flow-sorted populations of marine Synechococcus, the dominant cyanobacteria in coastal environments. The large majority of genes (98% have evolved under purifying selection (dN/dS1, 77 out of 83 (93% were hypothetical. Notable among annotated genes, ribosomal protein L35 appears to be under positive selection in one Synechococcus population. Other annotated genes, in particular a possible porin, a large-conductance mechanosensitive channel, an ATP binding component of an ABC transporter, and a homologue of a pilus retraction protein had regions of the gene with elevated dN/dS. With the increasing use of next-generation sequencing in metagenomic investigations of microbial diversity and ecology, analytical methods need to accommodate the peculiarities of these data streams. By developing a means to analyze population diversity data from these environmental metagenomes, we have provided the first insight into the role of selection in the evolution of Synechococcus, a globally significant primary producer.

  4. Early successional microhabitats allow the persistence of endangered plants in coastal sand dunes.

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    Pardini, Eleanor A; Vickstrom, Kyle E; Knight, Tiffany M

    2015-01-01

    Many species are adapted to disturbance and occur within dynamic, mosaic landscapes that contain early and late successional microhabitats. Human modification of disturbance regimes alters the availability of microhabitats and may affect the viability of species in these ecosystems. Because restoring historical disturbance regimes is typically expensive and requires action at large spatial scales, such restoration projects must be justified by linking the persistence of species with successional microhabitats. Coastal sand dune ecosystems worldwide are characterized by their endemic biodiversity and frequent disturbance. Dune-stabilizing invasive plants alter successional dynamics and may threaten species in these ecosystems. We examined the distribution and population dynamics of two federally endangered plant species, the annual Layia carnosa and the perennial Lupinus tidestromii, within a dune ecosystem in northern California, USA. We parameterized a matrix population model for L. tidestromii and examined the magnitude by which the successional stage of the habitat (early or late) influenced population dynamics. Both species had higher frequencies and L. tidestromii had higher frequency of seedlings in early successional habitats. Lupinus tidestromii plants in early successional microhabitats had higher projected rates of population growth than those associated with stabilized, late successional habitats, due primarily to higher rates of recruitment in early successional microhabitats. These results support the idea that restoration of disturbance is critical in historically dynamic landscapes. Our results suggest that large-scale restorations are necessary to allow persistence of the endemic plant species that characterize these ecosystems.

  5. Strong genetic differentiation but not local adaptation toward the range limit of a coastal dune plant.

    Science.gov (United States)

    Samis, Karen E; López-Villalobos, Adriana; Eckert, Christopher G

    2016-11-01

    All species have limited geographic distributions; but the ecological and evolutionary mechanisms causing range limits are largely unknown. That many species' geographic range limits are coincident with niche limits suggests limited evolutionary potential of marginal populations to adapt to conditions experienced beyond the range. We provide a test of range limit theory by combining population genetic analysis of microsatellite polymorphisms with a transplant experiment within, at the edge of, and 60 km beyond the northern range of a coastal dune plant. Contrary to expectations, lifetime fitness increased toward the range limit with highest fitness achieved by most populations at and beyond the range edge. Genetic differentiation among populations was strong, with very low, nondirectional gene flow suggesting range limitation via constraints to dispersal. In contrast, however, local adaptation was negligible, and a distance-dependent decline in fitness only occurred for those populations furthest from home when planted beyond the range limit. These results challenge a commonly held assumption that stable range limits match niche limits, but also raise questions about the unique value of peripheral populations in expanding species' geographical ranges.

  6. Arthropods associated with medicinal plants in coastal South Carolina

    Institute of Scientific and Technical Information of China (English)

    ROLANDO LOPEZ; B. MERLE SHEPARD

    2007-01-01

    Arthropods were sampled from feverfew [Tanacetum parthenium (L.) SchultzBip], Echinaceapurpurea (L.) Moench, Echinaceapallida (Nutt.) Nutt., Valeriana officinalis L., and St. John's wort (Hypericum perforatum L.) during 1998-2001. In addition,arthropods were sampled on tansy (Tanacetum vulgare L.) from 2001-2004. In general,50-60 arthropod species where collected and identified among all of the medicinal plant species. Among the predators, Orius insidiosus (Say) (Hemiptera: Anthocoridae), Geocoris punctipes (Say) (Hemiptera: Lygaeidae) and spiders were most abundant from 1998-2004.The three-cornered alfalfa hopper, Spissistilus festinus (Say), was the most abundant herbivore found from 1998 to 2001. Orius insidiosus and G. punctipes were 3-4 times more abundant on T. parthenium than on any other medicinal plant species. Based on the numbers of predatory arthropods found on T. parthenium, this crop could be suitable as a companion or "banker" plant to attract and maintain populations of predators, especially O. insidiosus and G. punctipes. Whitefly nymphs attacked by predators with piercing/sucking mouthparts are easily identified using a microscope because of the general appearance of the carcass left by the predators. Thus, populations of predators on T. parthenium suppressed Bemisia tabaci populations on E. purpurea when these crops were planted as companion crops.

  7. Competition-density effect in plant populations

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The competition-density effect of plant populations is of significance in theory and practice of forest management and has been studied for long time. The differences between the two reciprocal equations of the competition-density effect in nonself-thinning populations and self-thinning populations were analyzed theoretically. This supplies a theoretical basis for analyzing the dynamics of forest populations and evaluating the effect of forest management.

  8. Influence of geographic setting on thermal discharge from coastal power plants.

    Science.gov (United States)

    Jia, Hou-Lei; Zheng, Shu; Xie, Jian; Ying, Xiao-Ming; Zhang, Cui-Ping

    2016-10-15

    Characteristics of thermal discharge from three coastal power plants were studied in China. The three plants, Zhuhai Power Plant, Chaozhou Power Plant and Huilai Power Plant, are located in estuary, bay and open sea, respectively. The water temperatures and ocean currents surrounding the outlet of the three power plants were monitored. The results show that the temperature rise became smaller as the spread of thermal discharge moved toward the open sea, which confirms the results of previous studies. The results also indicated that the influence range of thermal discharge from a coastal power plant is determined by geographic setting. The temperature rise range of the Chaozhou Plant, which is located in a bay, was the largest, followed by that of the Zhuhai Plant located in an estuary, and the temperature rise range of the Huilai Plant located in an open sea was the smallest. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Coastal Freshwater Wetland Plant Community Response to Seasonal Drought and Flooding in Northwestern Costa Rica

    Science.gov (United States)

    In tropical wet-dry climates, seasonal hydrologic cycles drive wetland plant community change and produce distinct seasonal plant assemblages. In this study, we examined the plant community response to seasonal flooding and drought in a large coastal freshwater wetland in northwe...

  10. Matrix population models from 20 studies of perennial plant populations

    Science.gov (United States)

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  11. Transcriptional variation associated with cactus host plant adaptation in Drosophila mettleri populations.

    Science.gov (United States)

    Hoang, Kim; Matzkin, Luciano M; Bono, Jeremy M

    2015-10-01

    Although the importance of host plant chemistry in plant-insect interactions is widely accepted, the genetic basis of adaptation to host plants is not well understood. Here, we investigate transcriptional changes associated with a host plant shift in Drosophila mettleri. While D. mettleri is distributed mainly throughout the Sonoran Desert where it specializes on columnar cacti (Carnegiea gigantea and Pachycereus pringleii), a population on Santa Catalina Island has shifted to chemically divergent coastal prickly pear cactus (Opuntia littoralis). We compared gene expression of larvae from the Sonoran Desert and Santa Catalina Island when reared on saguaro (C. gigantea), coastal prickly pear and laboratory food. Consistent with expectations based on the complexity and toxicity of cactus relative to laboratory food, within-population comparisons between larvae reared on these food sources revealed transcriptional differences in detoxification and other metabolic pathways. The majority of transcriptional differences between populations on the cactus hosts were independent of the rearing environment and included a disproportionate number of genes involved in processes relevant to host plant adaptation (e.g. detoxification, central metabolism and chemosensory pathways). Comparisons of transcriptional reaction norms between the two populations revealed extensive shared plasticity that likely allowed colonization of coastal prickly pear on Santa Catalina Island. We also found that while plasticity may have facilitated subsequent adaptive divergence in gene expression between populations, the majority of genes that differed in expression on the novel host were not transcriptionally plastic in the presumed ancestral state.

  12. Bird populations in coastal habitats, Arctic National Wildlife Range, Alaska: Results of 1978 and 1979 surveys

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Within the coastal zone of the Arctic National Wildlife Range, the highest breeding populations of birds occurred in wet and flooded sedge tundra areas surrounded by...

  13. Terrestrial bird populations and habitat use on coastal plain tundra of the Arctic National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers terrestrial bird populations and habitat use on the coastal plain tundra of the Arctic National Wildlife Refuge. Bird census plots were monitored....

  14. Constraints on coastal dune invasion for a notorious plant invader.

    Science.gov (United States)

    Griffith, Alden B; Ahmed, Tania; Hildner, Abigail L G; Kuckreja, Shivani; Long, Shuangxou

    2015-11-10

    Although most biological invasions are not successful, relatively few studies have examined otherwise notorious invaders in systems where they are not highly problematic. The annual grass Bromus tectorum is a dominant invader in western North America, but is usually confined to human-dominated and disturbed systems (e.g. roadsides and parking lots) in the East where it remains virtually unstudied. This study aims to address fundamental ecological questions regarding B. tectorum in a Cape Cod dune ecosystem. (i) What is the range of variation in population dynamics and the potential for population growth? (ii) Which factors influence its local abundance and distribution? We observed substantial variation in population dynamics over 3 years, with the number of adult B. tectorum individuals increasing substantially between the first 2 years (λ = 9.24) and then decreasing (λ = 0.43). Population growth in terms of total seeds was similarly variable, but to a lesser extent (λ = 2.32 followed by λ = 0.32). Experimental soil disturbance led to a more than 10-fold increase in mean seedling emergence, and high sensitivity to differences in emergence carried this effect through the life cycle. In contrast, barriers to seed dispersal had no effect on population dynamics, suggesting limited dispersal in this system. Across the landscape, the presence of B. tectorum was associated with areas of higher plant diversity as opposed to those with a strong dominant (e.g. the foredune, dominated by Ammophila breviligulata, or low heathlands, characterized by Hudsonia tomentosa and Arctostaphylos uva-ursi). Overall, we find that B. tectorum is capable of both substantial population growth and decline in a dune ecosystem, but is likely limited without disturbance and dispersal agents. Thus, management actions that restrict dune access (e.g. for nesting habitat) likely have the co-benefit of limiting the invasive potential of B. tectorum.

  15. Genetic isolation between coastal and fishery-impacted, offshore bottlenose dolphin (Tursiops spp.) populations.

    Science.gov (United States)

    Allen, Simon J; Bryant, Kate A; Kraus, Robert H S; Loneragan, Neil R; Kopps, Anna M; Brown, Alexander M; Gerber, Livia; Krützen, Michael

    2016-06-01

    The identification of species and population boundaries is important in both evolutionary and conservation biology. In recent years, new population genetic and computational methods for estimating population parameters and testing hypotheses in a quantitative manner have emerged. Using a Bayesian framework and a quantitative model-testing approach, we evaluated the species status and genetic connectedness of bottlenose dolphin (Tursiops spp.) populations off remote northwestern Australia, with a focus on pelagic 'offshore' dolphins subject to incidental capture in a trawl fishery. We analysed 71 dolphin samples from three sites beyond the 50 m depth contour (the inshore boundary of the fishery) and up to 170 km offshore, including incidentally caught and free-ranging individuals associating with trawl vessels, and 273 dolphins sampled at 12 coastal sites inshore of the 50 m depth contour and within 10 km of the coast. Results from 19 nuclear microsatellite markers showed significant population structure between dolphins from within the fishery and coastal sites, but also among dolphins from coastal sites, identifying three coastal populations. Moreover, we found no current or historic gene flow into the offshore population in the region of the fishery, indicating a complete lack of recruitment from coastal sites. Mitochondrial DNA corroborated our findings of genetic isolation between dolphins from the offshore population and coastal sites. Most offshore individuals formed a monophyletic clade with common bottlenose dolphins (T. truncatus), while all 273 individuals sampled coastally formed a well-supported clade of Indo-Pacific bottlenose dolphins (T. aduncus). By including a quantitative modelling approach, our study explicitly took evolutionary processes into account for informing the conservation and management of protected species. As such, it may serve as a template for other, similarly inaccessible study populations.

  16. Predicting Effects of Coastal Acidification on Marine Bivalve Populations

    Science.gov (United States)

    The partial pressure of carbon dioxide (pCO2) is increasing in the oceans and causing changes in seawater pH commonly described as ocean or coastal acidification. It is now well-established that, when reproduced in laboratory experiments, these increases in pCO2 can reduce survi...

  17. Host plant adaptation in Drosophila mettleri populations.

    Directory of Open Access Journals (Sweden)

    Sergio Castrezana

    Full Text Available The process of local adaptation creates diversity among allopatric populations, and may eventually lead to speciation. Plant-feeding insect populations that specialize on different host species provide an excellent opportunity to evaluate the causes of ecological specialization and the subsequent consequences for diversity. In this study, we used geographically separated Drosophila mettleri populations that specialize on different host cacti to examine oviposition preference for and larval performance on an array of natural and non-natural hosts (eight total. We found evidence of local adaptation in performance on saguaro cactus (Carnegiea gigantea for populations that are typically associated with this host, and to chemically divergent prickly pear species (Opuntia spp. in a genetically isolated population on Santa Catalina Island. Moreover, each population exhibited reduced performance on the alternative host. This finding is consistent with trade-offs associated with adaptation to these chemically divergent hosts, although we also discuss alternative explanations for this pattern. For oviposition preference, Santa Catalina Island flies were more likely to oviposit on some prickly pear species, but all populations readily laid eggs on saguaro. Experiments with non-natural hosts suggest that factors such as ecological opportunity may play a more important role than host plant chemistry in explaining the lack of natural associations with some hosts.

  18. A Comparative study on the prevalence of HCC seromarkers among tribal and coastal population

    Directory of Open Access Journals (Sweden)

    Joseph Selvin

    2010-03-01

    Full Text Available An extensive study on the prevalence of seromarkers (HBsAg and AFP of hepatocellular carcinoma among two low socioeconomic groups of Karumanthurai tribes and Kanyakumari coastal population was carried out. The results obtained suggest that the mean HBsAg value of tribal was more than that of the coastal population. The mean AFP of elevated and normal cases was found to be invariably significant (P< 0.01 over the two areas. Coastal patients tended to be significantly older than the tribal patients (P < 0.005, Wilcoxon rank sum test. All two racial/geographic regions showed a preponderance of male patients but this tendency was significantly more marked (P < 0.05 in the tribal group than in the coastal sample. Liquor habit and lack of personal hygienic practices were associated with the prevalence of HBsAg and AFP in both the areas. Surprisingly a positive association has been found between the consumption of marine foods and reduced risk of HCC. Thus the reduced risk of HCC among coastal population can probably be due to the development of immunity against HBV due to the dietary pattern of marine food consumption by coastal population.

  19. Uncertainties in measuring populations potentially impacted by sea level rise and coastal flooding.

    Directory of Open Access Journals (Sweden)

    Pinki Mondal

    Full Text Available A better understanding of the impact of global climate change requires information on the locations and characteristics of populations affected. For instance, with global sea level predicted to rise and coastal flooding set to become more frequent and intense, high-resolution spatial population datasets are increasingly being used to estimate the size of vulnerable coastal populations. Many previous studies have undertaken this by quantifying the size of populations residing in low elevation coastal zones using one of two global spatial population datasets available - LandScan and the Global Rural Urban Mapping Project (GRUMP. This has been undertaken without consideration of the effects of this choice, which are a function of the quality of input datasets and differences in methods used to construct each spatial population dataset. Here we calculate estimated low elevation coastal zone resident population sizes from LandScan and GRUMP using previously adopted approaches, and quantify the absolute and relative differences achieved through switching datasets. Our findings suggest that the choice of one particular dataset over another can translate to a difference of more than 7.5 million vulnerable people for countries with extensive coastal populations, such as Indonesia and Japan. Our findings also show variations in estimates of proportions of national populations at risk range from <0.1% to 45% differences when switching between datasets, with large differences predominantly for countries where coarse and outdated input data were used in the construction of the spatial population datasets. The results highlight the need for the construction of spatial population datasets built on accurate, contemporary and detailed census data for use in climate change impact studies and the importance of acknowledging uncertainties inherent in existing spatial population datasets when estimating the demographic impacts of climate change.

  20. Uncertainties in measuring populations potentially impacted by sea level rise and coastal flooding.

    Science.gov (United States)

    Mondal, Pinki; Tatem, Andrew J

    2012-01-01

    A better understanding of the impact of global climate change requires information on the locations and characteristics of populations affected. For instance, with global sea level predicted to rise and coastal flooding set to become more frequent and intense, high-resolution spatial population datasets are increasingly being used to estimate the size of vulnerable coastal populations. Many previous studies have undertaken this by quantifying the size of populations residing in low elevation coastal zones using one of two global spatial population datasets available - LandScan and the Global Rural Urban Mapping Project (GRUMP). This has been undertaken without consideration of the effects of this choice, which are a function of the quality of input datasets and differences in methods used to construct each spatial population dataset. Here we calculate estimated low elevation coastal zone resident population sizes from LandScan and GRUMP using previously adopted approaches, and quantify the absolute and relative differences achieved through switching datasets. Our findings suggest that the choice of one particular dataset over another can translate to a difference of more than 7.5 million vulnerable people for countries with extensive coastal populations, such as Indonesia and Japan. Our findings also show variations in estimates of proportions of national populations at risk range from population datasets. The results highlight the need for the construction of spatial population datasets built on accurate, contemporary and detailed census data for use in climate change impact studies and the importance of acknowledging uncertainties inherent in existing spatial population datasets when estimating the demographic impacts of climate change.

  1. A meta-analysis of plant facilitation in coastal dune systems: responses, regions, and research gaps.

    Science.gov (United States)

    Castanho, Camila de Toledo; Lortie, Christopher J; Zaitchik, Benjamin; Prado, Paulo Inácio

    2015-01-01

    Empirical studies in salt marshes, arid, and alpine systems support the hypothesis that facilitation between plants is an important ecological process in severe or 'stressful' environments. Coastal dunes are both abiotically stressful and frequently disturbed systems. Facilitation has been documented, but the evidence to date has not been synthesized. We did a systematic review with meta-analysis to highlight general research gaps in the study of plant interactions in coastal dunes and examine if regional and local factors influence the magnitude of facilitation in these systems. The 32 studies included in the systematic review were done in coastal dunes located in 13 countries around the world but the majority was in the temperate zone (63%). Most of the studies adopt only an observational approach to make inferences about facilitative interactions, whereas only 28% of the studies used both observational and experimental approaches. Among the factors we tested, only geographic region mediates the occurrence of facilitation more broadly in coastal dune systems. The presence of a neighbor positively influenced growth and survival in the tropics, whereas in temperate and subartic regions the effect was neutral for both response variables. We found no evidence that climatic and local factors, such as life-form and life stage of interacting plants, affect the magnitude of facilitation in coastal dunes. Overall, conclusions about plant facilitation in coastal dunes depend on the response variable measured and, more broadly, on the geographic region examined. However, the high variability and the limited number of studies, especially in tropical region, indicate we need to be cautious in the generalization of the conclusions. Anyway, coastal dunes provide an important means to explore topical issues in facilitation research including context dependency, local versus regional drivers of community structure, and the importance of gradients in shaping the outcome of net

  2. On the importance of coastal areas in the survival of Neanderthal populations during the Late Pleistocene

    Science.gov (United States)

    Finlayson, Clive

    2008-11-01

    This paper examines the distribution of Neanderthal populations across Europe and the Middle East. Key geographical variables are used to identify major population strongholds. Four are identified: southern Iberia, Atlantic Europe, Black Sea-Aegean and coastal Italy. Neanderthal site density in each stronghold was found to correspond closely with the predicted suitability of each area. A strong correlation was found between area suitability and last Neanderthal dates and the process of population fragmentation and extinction was found to affect continental areas first and coastal ones last. Oceanic influence, inter-area connectivity and proximity to coasts were found to be key variables in the Neanderthal extinction process. The functional ecological significance of coastal areas to Neanderthals is discussed.

  3. Global change and response of coastal dune plants to the combined effects of increased sand accretion (burial) and nutrient availability.

    Science.gov (United States)

    Frosini, Silvia; Lardicci, Claudio; Balestri, Elena

    2012-01-01

    Coastal dune plants are subjected to natural multiple stresses and vulnerable to global change. Some changes associated with global change could interact in their effects on vegetation. As vegetation plays a fundamental role in building and stabilizing dune systems, effective coastal habitat management requires a better understanding of the combined effects of such changes on plant populations. A manipulative experiment was conducted along a Mediterranean dune system to examine the individual and combined effects of increased sediment accretion (burial) and nitrogen enrichment associated with predicted global change on the performance of young clones of Sporobolus virginicus, a widespread dune stabilizing species. Increased burial severity resulted in the production of taller but thinner shoots, while nutrient enrichment stimulated rhizome production. Nutrient enrichment increased total plant biomass up to moderate burial levels (50% of plant height), but it had not effect at the highest burial level (100% of plant height). The effects of such factors on total biomass, shoot biomass and branching were influenced by spatial variation in natural factors at the scale of hundreds of metres. These results indicate that the effects of burial and nutrient enrichment on plant performance were not independent. Their combined effects may not be predicted by knowing the individual effects, at least under the study conditions. Under global change scenarios, increased nutrient input could alleviate nutrient stress in S. virginicus, enhancing clonal expansion and productivity, but this benefit could be offset by increased sand accretion levels equal or exceeding 100% of plant height. Depletion of stored reserves for emerging from sand could increase plant vulnerability to other stresses in the long-term. The results emphasize the need to incorporate statistical designs for detecting non-independent effects of multiple changes and adequate spatial replication in future works to

  4. Cesium-137 in deer: Savannah River Plant vs. southeastern coastal plain herds

    Energy Technology Data Exchange (ETDEWEB)

    Watts, J.R.; Rabon, E.W.; Dicks, A.S.

    1979-01-01

    The /sup 137/Cs content in deer killed during programmed hunts at the Savannah River Plant (SRP) has averaged 9.0 pCi/g. This value, based on measurements of 13,907 deer taken over 14 years (1965 to 1978), similar to the value obtained for 552 deer from other southeastern Coastal Plain locations, indicating the /sup 137/Cs content is due to fallout from the atmospheric testing of nuclear weapons rather than from SRP operations. The computerized SRP data base for each harvested deer includes age, sex, weight, cesium content, kill location, date, and the hunter's name. Analysis of these data enables the estimation of population dose from ingestion of the edible meat. Consumption of all edible meat from deer killed at SRP from 1965 to 1978 gives a whole body population dose of 196 man-rem from /sup 137/Cs. Assuming an annual consumption rate of 20 kg gives an average individual whole body dose of 13 mrem, about 10% of local annual background level. The radiation dose from /sup 40/K of natural potassium content of deer is comparable to the radiation dose from /sup 137/Cs.

  5. Documentation of hypoglycemic and wound healing plants in Kodiyampalayam coastal village (southeast coast of India

    Directory of Open Access Journals (Sweden)

    Satyavani Kaliamurthi

    2014-08-01

    Full Text Available Objective: To document the hypoglycemic and wound healing plant species especially halophytes and associates were carried out in the coastal village of Kodiyampalayam (Southeast coast of India. Methods: The data were collected during the month of December 2011 to November 2012 with personal interviews and group discussion of local coastal fisher women community and traditional practitioner. Results: The results indicated the traditional knowledge of 33 medicinal plant species, photographs, vernacular name, habit, active part and their mode of action. Among these, Citrullus colocynthis, Coccinia grandis, Rhizophora apiculata, Rhizophora mucronata, Bruguiera cylindrica, Excoecaria agallocha and Andrographis paniculata were discovered in huge number. Conclusions: This study concludes medicinal uses of halophytes and associates in the coastal area. It will be needed scientific validation for development of novel therapeutic agents.

  6. Documentation of hypoglycemic and wound healing plants in Kodiyampalayam coastal village (southeast coast of India)

    Institute of Scientific and Technical Information of China (English)

    Satyavani Kaliamurthi; Gurudeeban Selvaraj; Ramanathan Thirugnanasambandam

    2014-01-01

    Objective: To document the hypoglycemic and wound healing plant species especially halophytes and associates were carried out in the coastal village of Kodiyampalayam (Southeast coast of India). Methods: The data were collected during the month of December 2011 to November 2012 with personal interviews and group discussion of local coastal fisher women community and traditional practitioner. Results: The results indicated the traditional knowledge of 33 medicinal plant species, photographs, vernacular name, habit, active part and their mode of action. Among these, Citrullus colocynthis, Coccinia grandis, Rhizophora apiculata, Rhizophora mucronata, Bruguiera cylindrica, Excoecaria agallocha and Andrographis paniculata were discovered in huge number. Conclusions: This study concludes medicinal uses of halophytes and associates in the coastal area. It will be needed scientific validation for development of novel therapeutic agents.

  7. Utilization and Management of Small Fishery Population Resources in Coastal and Offshore Areas of China

    Institute of Scientific and Technical Information of China (English)

    Jiahua LE; Xiangguo ZHANG; Yingqi ZHOU

    2016-01-01

    There are numerous types of living resources in coastal and offshore areas of China. In recent years,both the population type and quantity structure have significant changes,and the stock of small fishery population resources is increasing. This population is precious protein resource. It is urgent to study how to take prompt and effective fishing and take full advantage of processing,utilization and management. Traditional utilization methods are limited by many factors. The utilization efficiency is extremely low. The feed conversion rate of some mariculture fishes with fresh small trash fishes as feeds is even as low as 0. 2. Innovative production and management organization model with aquatic enterprises as leaders greatly increases the utilization efficiency of small fish resources with the aid of marine processing mother ship. In order to further accelerate developing and utilizing small fishery population resources in coastal and offshore areas,China should launch survey and utilization researches of small fishery population resources in coastal and offshore areas,formulate practical and feasible laws,regulations and policies,actively encourage and support autonomous innovative management mode of enterprises,and promote effective utilization and management of coastal and offshore fishery resources.

  8. 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

    2015-01-01

    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. PMID:25750408

  9. Patterns of alien plant invasion across coastal bay areas in southern China

    Science.gov (United States)

    Hai Ren; Qinfeng Guo; Hong Liu; Jing Li; Qianmei Zhang; Hualin Xu; Fanghong Xu

    2014-01-01

    An understanding of the ways in which levels of invasions by alien species are correlated with environmental factors is helpful to manage the negative impacts of these invasive species. Two tropical coastal areas in South China, Shenzhen Bay and Leizhou Bay, are national nature reserves, but they are threatened by invasive plants. Here, we investigated the level of...

  10. First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae in the coastal valleys of northern Chile

    Directory of Open Access Journals (Sweden)

    Héctor A. Vargas

    2014-03-01

    Full Text Available First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae in the coastal valleys of northern Chile. The trees Haplorhus peruviana Engl. and Schinus molle L. (Anacardiaceae are mentioned as the first host plant records for the little known native moth Iridopsis hausmanni Vargas, 2007 (Lepidoptera, Geometridae, Ennominae in the coastal valleys of the northern Chilean Atacama Desert. This is also the first record of Anacardiaceae as host plant for a Neotropical species of Iridopsis Warren, 1894.

  11. Urban habitat fragmentation and genetic population structure of bobcats in coastal southern California

    Science.gov (United States)

    Ruell, E.W.; Riley, S.P.D.; Douglas, M.R.; Antolin, M.F.; Pollinger, J.R.; Tracey, J.A.; Lyren, L.M.; Boydston, E.E.; Fisher, R.N.; Crooks, K.R.

    2012-01-01

    Although habitat fragmentation is recognized as a primary threat to biodiversity, the effects of urban development on genetic population structure vary among species and landscapes and are not yet well understood. Here we use non-invasive genetic sampling to compare the effects of fragmentation by major roads and urban development on levels of dispersal, genetic diversity, and relatedness between paired bobcat populations in replicate landscapes in coastal southern California. We hypothesized that bobcat populations in sites surrounded by urbanization would experience reduced functional connectivity relative to less isolated nearby populations. Our results show that bobcat genetic population structure is affected by roads and development but not always as predicted by the degree that these landscape features surround fragments. Instead, we suggest that urban development may affect functional connectivity between bobcat populations more by limiting the number and genetic diversity of source populations of migrants than by creating impermeable barriers to dispersal.

  12. Are coastal protected areas always effective in achieving population recovery for nesting sea turtles?

    Directory of Open Access Journals (Sweden)

    Ronel Nel

    Full Text Available Sea turtles are highly migratory and usually dispersed, but aggregate off beaches during the nesting season, rendering them vulnerable to coastal threats. Consequently, coastal Marine Protection Areas (MPAs have been used to facilitate the recovery of turtle populations, but the effectiveness of these programs is uncertain as most have been operating for less than a single turtle generation (or1700 nests pa (index area especially over the last decade, while leatherback abundance increased initially∼10 to 70 nests pa (index area, but then stabilized. Although leatherbacks have higher reproductive output per female and comparable remigration periods and hatching success to loggerheads, the leatherback population failed to expand. Our results suggest that coastal MPAs can work but do not guarantee the recovery of sea turtle populations as pressures change over time. Causes considered for the lack of population growth include factors in the MPA (expansion into unmonitored areas or incubation environment of outside of the MPA (including carrying capacity and fishing mortality. Conservation areas for migratory species thus require careful design to account for species-specific needs, and need to be monitored to keep track of changing pressures.

  13. Investigation of the radiological impact on the coastal environment surrounding a fertilizer plant.

    Science.gov (United States)

    El Samad, O; Aoun, M; Nsouli, B; Khalaf, G; Hamze, M

    2014-07-01

    This investigation was carried out in order to assess the marine environmental radioactive pollution and the radiological impact caused by a large production plant of phosphate fertilizer, located in the Lebanese coastal zone. Natural radionuclides ((238)U, (235)U, (232)Th, (226)Ra, (210)Po, (210)Pb, (40)K) and anthropogenic (137)Cs were measured by alpha and gamma spectrometry in seawater, sediment, biota and coastal soil samples collected from the area impacted by this industry. The limited environmental monitoring program within 2 km of the plant indicates localized contamination with radionuclides of the uranium decay chain mainly due to the transport, the storage of raw materials and the free release of phosphogypsum waste.

  14. Invasive Plants in the Coastal Vegetal Communities in Valencia (Spain

    Directory of Open Access Journals (Sweden)

    Francisco FERRER MERINO

    2011-05-01

    Full Text Available A botanical survey has been conducted to determine the influence of invasive species on the main indigenous communities in the Spanish Mediterranean coast and evaluate the current status of these communities in the eastern coast of Spain. The work was done in about 35 km of coastline located in Valencia (Spain. A total of 361 species cataloged are present in the study area, belonging to 79 different families. 49 of them have been inventoried invasive species which currently affect 38 plant communities. For this cause, we have developed a map of location finding out the area occupied by the same at every point and key to indigenous communities it affects. The plant communities characteristic of semi-mobile dunes Centaureo maritimae-Echietum sabulicolae and Medicagini marinae-Ammophiletum australis have turned out to have a greater degree of invasion. Carpobrotus edulis, Agave americana, Arundo donax, Oxalis pes-caprae and Cortaderia sellowiana are invasive species that cause further encroachment, both in area as a number of vegetation communities they affect.

  15. Predictive occurrence models for coastal wetland plant communities: delineating hydrologic response surfaces with multinomial logistic regression

    Science.gov (United States)

    Snedden, Gregg A.; Steyer, Gregory D.

    2013-01-01

    Understanding plant community zonation along estuarine stress gradients is critical for effective conservation and restoration of coastal wetland ecosystems. We related the presence of plant community types to estuarine hydrology at 173 sites across coastal Louisiana. Percent relative cover by species was assessed at each site near the end of the growing season in 2008, and hourly water level and salinity were recorded at each site Oct 2007–Sep 2008. Nine plant community types were delineated with k-means clustering, and indicator species were identified for each of the community types with indicator species analysis. An inverse relation between salinity and species diversity was observed. Canonical correspondence analysis (CCA) effectively segregated the sites across ordination space by community type, and indicated that salinity and tidal amplitude were both important drivers of vegetation composition. Multinomial logistic regression (MLR) and Akaike's Information Criterion (AIC) were used to predict the probability of occurrence of the nine vegetation communities as a function of salinity and tidal amplitude, and probability surfaces obtained from the MLR model corroborated the CCA results. The weighted kappa statistic, calculated from the confusion matrix of predicted versus actual community types, was 0.7 and indicated good agreement between observed community types and model predictions. Our results suggest that models based on a few key hydrologic variables can be valuable tools for predicting vegetation community development when restoring and managing coastal wetlands.

  16. Positive responses of coastal dune plants to soil conditioning by the invasive Lupinus nootkatensis

    Science.gov (United States)

    Hanslin, Hans Martin; Kollmann, Johannes

    2016-11-01

    Invasive nitrogen-fixing plants drive vegetation dynamics and may cause irreversible changes in nutrient-limited ecosystems through increased soil resources. We studied how soil conditioning by the invasive alien Lupinus nootkatensis affected the seedling growth of co-occurring native plant species in coastal dunes, and whether responses to lupin-conditioned soil could be explained by fertilisation effects interacting with specific ecological strategies of the native dune species. Seedling performance of dune species was compared in a greenhouse experiment using field-collected soil from within or outside coastal lupin stands. In associated experiments, we quantified the response to nutrient supply of each species and tested how addition of specific nutrients affected growth of the native grass Festuca arundinacea in control and lupin-conditioned soil. We found that lupin-conditioned soil increased seedling biomass in 30 out of 32 native species; the conditioned soil also had a positive effect on seedling biomass of the invasive lupin itself. Increased phosphorus mobilisation by lupins was the major factor driving these positive seedling responses, based both on growth responses to addition of specific elements and analyses of plant available soil nutrients. There were large differences in growth responses to lupin-conditioned soil among species, but they were unrelated to selected autecological indicators or plant strategies. We conclude that Lupinus nootkatensis removes the phosphorus limitation for growth of native plants in coastal dunes, and that it increases cycling of other nutrients, promoting the growth of its own seedlings and a wide range of dune species. Finally, our study indicates that there are no negative soil legacies that prevent re-establishment of native plant species after removal of lupins.

  17. Ecological niche modeling of coastal dune plants and future potential distribution in response to climate change and sea level rise.

    Science.gov (United States)

    Mendoza-González, Gabriela; Martínez, M Luisa; Rojas-Soto, Octavio R; Vázquez, Gabriela; Gallego-Fernández, Juan B

    2013-08-01

    Climate change (CC) and sea level rise (SLR) are phenomena that could have severe impacts on the distribution of coastal dune vegetation. To explore this we modeled the climatic niches of six coastal dunes plant species that grow along the shoreline of the Gulf of Mexico and the Yucatan Peninsula, and projected climatic niches to future potential distributions based on two CC scenarios and SLR projections. Our analyses suggest that distribution of coastal plants will be severely limited, and more so in the case of local endemics (Chamaecrista chamaecristoides, Palafoxia lindenii, Cakile edentula). The possibilities of inland migration to the potential 'new shoreline' will be limited by human infrastructure and ecosystem alteration that will lead to a 'coastal squeeze' of the coastal habitats. Finally, we identified areas as future potential refuges for the six species in central Gulf of Mexico, and northern Yucatán Peninsula especially under CC and SLR scenarios.

  18. Traditional ethno-botanical uses of medicinal plants from coastal areas of Pakistan

    Institute of Scientific and Technical Information of China (English)

    Muhammad Qasim; Zainul Abideen; Muhammad Yousuf Adnan; Raziuddin Ansari; Bilquees Gul; Muhammad Ajmal Khan

    2014-01-01

    Objective: To document the traditional uses of wild plants as medicine by the villagers along the coastal highway from Karachi to Uthal. Methods: Information presented in this research was gathered from the local people using an integrated approach of floral collections, discussions with the elderly people and traditional medicinal practitioners using semi-structured questionnaire.Results:27 families in the targeted area. Majority of the plants (54%) from this coastal plant diversity were xerophytes followed by halophytes/xero-halophytes (40%) and glycophytes (6%). The most important uses included gastrointestinal diseases, pain killer, arthritis, skin and sexual disorders, asthma and expectorant. The above-ground parts of plants i.e. leaf, stem and fruit/seed as decoction are used most commonly to cure 23 ailments but root was also used in some cases.Conclusions:Ethno-medicinal surveys indicated the medicinal importance of 54 plant species from phyto-medicinal claim and it is hoped that it will lead to detailed chemical and pharmacological evaluations. This may also lead to a discovery of novel bioactive compounds for food and pharmaceutical industries. This study helps in documenting therapeutic uses of herbal remedies with new pevhayltou-amtioendsic. iTnhali sc lmaiamy aanldso i tl iesa hdo tpoe da tdhiastc iot vweirlyl loeaf dn otov edle tbaiioleadc tcihveem ciocmalp aonudn pdhs afromr afcoooldog aicnadl pharmaceutical industries.

  19. Lower Miocene plant assemblage with coastal-marsh herbaceous monocots from the Vienna Basin (Slovakia)

    Science.gov (United States)

    Kvaček, Zlatko; Teodoridis, Vasilis; Kováčová, Marianna; Schlögl, Ján; Sitár, Viliam

    2014-06-01

    A new plant assemblage of Cerová-Lieskové from Lower Miocene (Karpatian) deposits in the Vienna Basin (western Slovakia) is preserved in a relatively deep, upper-slope marine environment. Depositional conditions with high sedimentation rates allowed exceptional preservation of plant remains. The plant assemblage consists of (1) conifers represented by foliage of Pinus hepios and Tetraclinis salicornioides, a seed cone of Pinus cf. ornata, and by pollen of the Cupressaceae, Pinaceae, Pinus sp. and Cathaya sp., and (2) angiosperms represented by Cinnamomum polymorphum, Platanus neptuni, Potamogeton sp. and lauroid foliage, by pollen of Liquidambar sp., Engelhardia sp. and Craigia sp., and in particular by infructescences (so far interpreted as belonging to cereal ears). We validate genus and species assignments of the infructescences: they belong to Palaeotriticum Sitár, including P. mockii Sitár and P. carpaticum Sitár, and probably represent herbaceous monocots that inhabited coastal marshes, similar to the living grass Spartina. Similar infructescences occur in the Lower and Middle Miocene deposits of the Carpathian Foredeep (Slup in Moravia), Tunjice Hills (Žale in Slovenia), and probably also in the Swiss Molasse (Lausanne). This plant assemblage demonstrates that the paleovegetation was represented by evergreen woodland with pines and grasses in undergrowth, similar to vegetation inhabiting coastal brackish marshes today. It also indicates subtropical climatic conditions in the Vienna Basin (central Paratethys), similar to those implied by other coeval plant assemblages from Central Europe

  20. Lower Miocene plant assemblage with coastal-marsh herbaceous monocots from the Vienna Basin (Slovakia

    Directory of Open Access Journals (Sweden)

    Kvaček Zlatko

    2014-06-01

    Full Text Available A new plant assemblage of Cerová-Lieskové from Lower Miocene (Karpatian deposits in the Vienna Basin (western Slovakia is preserved in a relatively deep, upper-slope marine environment. Depositional conditions with high sedimentation rates allowed exceptional preservation of plant remains. The plant assemblage consists of (1 conifers represented by foliage of Pinus hepios and Tetraclinis salicornioides, a seed cone of Pinus cf. ornata, and by pollen of the Cupressaceae, Pinaceae, Pinus sp. and Cathaya sp., and (2 angiosperms represented by Cinnamomum polymorphum, Platanus neptuni, Potamogeton sp. and lauroid foliage, by pollen of Liquidambar sp., Engelhardia sp. and Craigia sp., and in particular by infructescences (so far interpreted as belonging to cereal ears. We validate genus and species assignments of the infructescences: they belong to Palaeotriticum Sitár, including P. mockii Sitár and P. carpaticum Sitár, and probably represent herbaceous monocots that inhabited coastal marshes, similar to the living grass Spartina. Similar infructescences occur in the Lower and Middle Miocene deposits of the Carpathian Foredeep (Slup in Moravia, Tunjice Hills (Žale in Slovenia, and probably also in the Swiss Molasse (Lausanne. This plant assemblage demonstrates that the paleovegetation was represented by evergreen woodland with pines and grasses in undergrowth, similar to vegetation inhabiting coastal brackish marshes today. It also indicates subtropical climatic conditions in the Vienna Basin (central Paratethys, similar to those implied by other coeval plant assemblages from Central Europe

  1. Traditional ethno-botanical uses of medicinal plants from coastal areas of Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Qasim

    2014-01-01

    Full Text Available Objective: To document the traditional uses of wild plants as medicine by the villagers along the coastal highway from Karachi to Uthal. Methods: Information presented in this research was gathered from the local people using an integrated approach of floral collections, discussions with the elderly people and traditional medicinal practitioners using semi-structured questionnaire. Results: Ethno-medicinal surveys indicated the medicinal importance of 54 plant species from 27 families in the targeted area. Majority of the plants (54% from this coastal plant diversity were xerophytes followed by halophytes/xero-halophytes (40% and glycophytes (6%. The most important uses included gastrointestinal diseases, pain killer, arthritis, skin and sexual disorders, asthma and expectorant. The above-ground parts of plants i.e. leaf, stem and fruit/seed as decoction are used most commonly to cure 23 ailments but root was also used in some cases. Conclusions: This study helps in documenting therapeutic uses of herbal remedies with new phyto-medicinal claim and it is hoped that it will lead to detailed chemical and pharmacological evaluations. This may also lead to a discovery of novel bioactive compounds for food and pharmaceutical industries.

  2. Gene Flow and the Measurement of Dispersal in Plant Populations.

    Science.gov (United States)

    Nicholls, Marc S.

    1986-01-01

    Reviews methods of estimating pollen and seed dispersals and discusses the extent and frequency of gene exchange within and between populations. Offers suggestions for designing exercises suitable for estimating dispersal distances in natural plant populations. (ML)

  3. Association of TSHR gene polymorphisms and haplotypes with Graves’ disease in Han population from coastal areas in Shandong province

    Institute of Scientific and Technical Information of China (English)

    王海丽

    2013-01-01

    Objective To investigate the association of thyroid stimulating hormone receptor(TSHR)gene polymorphisms and haplotypes with Graves’disease(GD)in Han population from coastal areas in Shandong province

  4. Purple Pitcher Plant (Sarracenia rosea) Dieback and Partial Community Disassembly following Experimental Storm Surge in a Coastal Pitcher Plant Bog

    Science.gov (United States)

    Abbott, Matthew J.; Battaglia, Loretta L.

    2015-01-01

    Sea-level rise and frequent intense hurricanes associated with climate change will result in recurrent flooding of inland systems such as Gulf Coastal pitcher plant bogs by storm surges. These surges can transport salt water and sediment to freshwater bogs, greatly affecting their biological integrity. Purple pitcher plants (Sarracenia rosea) are Gulf Coast pitcher plant bog inhabitants that could be at a disadvantage under this scenario because their pitcher morphology may leave them prone to collection of saline water and sediment after a surge. We investigated the effects of storm surge water salinity and sediment type on S. rosea vitality, plant community structure, and bog soil-water conductivity. Plots (containing ≥1 ramet of S. rosea) were experimentally flooded with fresh or saline water crossed with one of three sediment types (local, foreign, or no sediment). There were no treatment effects on soil-water conductivity; nevertheless, direct exposure to saline water resulted in significantly lower S. rosea cover until the following season when a prescribed fire and regional drought contributed to the decline of all the S. rosea to near zero percent cover. There were also significant differences in plant community structure between treatments over time, reflecting how numerous species increased in abundance and a few species decreased in abundance. However, in contrast to S. rosea, most of the other species in the community appeared resilient to the effects of storm surge. Thus, although the community may be somewhat affected by storm surge, those few species that are particularly sensitive to the storm surge disturbance will likely drop out of the community and be replaced by more resilient species. Depending on the longevity of these biological legacies, Gulf Coastal pitcher plant bogs may be incapable of fully recovering if they become exposed to storm surge more frequently due to climate change. PMID:25874369

  5. The influence of coastal topography, circulation patterns, and rafting in structuring populations of an intertidal alga.

    Science.gov (United States)

    Muhlin, J F; Engel, C R; Stessel, R; Weatherbee, R A; Brawley, S H

    2008-03-01

    Understanding the dispersal processes that influence genetic structure in marine species requires estimating gene flow in a dynamic, fluid environment that is often poorly characterized at scales relevant to multiple dispersive stages (e.g. spores, gametes, zygotes, larvae, adults). We examine genetic structure in the marine alga Fucus vesiculosus L., which inhabits moderately exposed shores in the northern Atlantic but releases gametes only under sunny, calm conditions. We predicted genetic structure would correlate with coastal topography because weather frequently varies across coastal promontories on the Maine shore when F. vesiculosus is reproductive, which causes one side to experience high levels of water motion (= no gamete release) while one side is calm (= gamete release). Furthermore, we expected that the effect of low dispersal capacities of gametes and zygotes would result in spatial genetic structure over short distances. Using surface drifters, we characterized near-shore circulation patterns around the study sites to investigate whether directionality of gene flow was correlated with directionality of currents. We found significant genetic differentiation among sites sampled at two different peninsulas, but patterns of differentiation were unrelated to coastal topography and there was no within-site spatial structuring. Our genetic and near-shore circulation data, combined with an examination of gamete longevity, support the dependency of gene flow on storm-detached, rafting, reproductive adults. This study highlights the significance of rafting as a mechanism for structuring established populations of macroalgae and associated biota and demonstrates the importance of coupling population genetics' research with relevant hydrodynamic studies.

  6. Bulinus globosus (Planorbidae; Gastropoda) populations in the Lake Victoria basin and coastal Kenya show extreme nuclear genetic differentiation

    DEFF Research Database (Denmark)

    Nyakaana, Silvester; Stothard, J. Russell; Nalugwa, Allen

    2013-01-01

    -fertilizing, this species has been reported to be preferentially out crossing. In this study, we characterized the population genetic structure of 19 B. globosus populations sampled across the Lake Victoria basin and coastal Kenya using four polymorphic microsatellite loci. Population genetic structure was characterized...

  7. Ecological Effects of Roads on the Plant Diversity of Coastal Wetland in the Yellow River Delta

    Directory of Open Access Journals (Sweden)

    Yunzhao Li

    2014-01-01

    Full Text Available The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of βT and Jaccard’s coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing β-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion.

  8. Effects of flooding, salinity and herbivory on coastal plant communities, Louisiana, United States

    Science.gov (United States)

    Gough, L.; Grace, J.B.

    1998-01-01

    Flooding and salinity stress are predicted to increase in coastal Louisiana as relative sea level rise (RSLR) continues in the Gulf of Mexico region. Although wetland plant species are adapted to these stressors, questions persist as to how marshes may respond to changed abiotic variables caused by RSLR, and how herbivory by native and non-native mammals may affect this response. The effects of altered flooding and salinity on coastal marsh communities were examined in two field experiments that simultaneously manipulated herbivore pressure. Marsh sods subjected to increased or decreased flooding (by lowering or raising sods, respectively), and increased or decreased salinity (by reciprocally transplanting sods between a brackish and fresh marsh), were monitored inside and outside mammalian herbivore exclosures for three growing seasons. Increased flooding stress reduced species numbers and biomass; alleviating flooding stress did not significantly alter species numbers while community biomass increased. Increased salinity reduced species numbers and biomass, more so if herbivores were present. Decreasing salinity had an unexpected effect: herbivores selectively consumed plants transplanted from the higher-salinity site. In plots protected from herbivory, decreased salinity had little effect on species numbers or biomass, but community composition changed. Overall, herbivore pressure further reduced species richness and biomass under conditions of increased flooding and increased salinity, supporting other findings that coastal marsh species can tolerate increasingly stressful conditions unless another factor, e.g., herbivory, is also present. Also, species dropped out of more stressful treatments much faster than they were added when stresses were alleviated, likely due to restrictions on dispersal. The rate at which plant communities will shift as a result of changed abiotic variables will determine if marshes remain viable when subjected to RSLR.

  9. Gene flow between insular, coastal and interior populations of brown bears in Alaska.

    Science.gov (United States)

    Paetkau, D; Shields, G F; Strobeck, C

    1998-10-01

    The brown bears of coastal Alaska have been recently regarded as comprising from one to three distinct genetic groups. We sampled brown bears from each of the regions for which hypotheses of genetic uniqueness have been made, including the bears of the Kodiak Archipelago and the bears of Admiralty, Baranof and Chichagof (ABC) Islands in southeast Alaska. These samples were analysed with a suite of nuclear microsatellite markers. The 'big brown bears' of coastal Alaska were found to be part of the continuous continental distribution of brown bears, and not genetically isolated from the physically smaller 'grizzly bears' of the interior. By contrast, Kodiak brown bears appear to have experienced little or no genetic exchange with continental populations in recent generations. The bears of the ABC Islands, which have previously been shown to undergo little or no female-mediated gene flow with mainland populations, were found not to be genetically isolated from mainland bears. The data from the four insular populations indicate that female and male dispersal can be reduced or eliminated by water barriers of 2-4 km and 7 km in width, respectively.

  10. Bay-scale population structure in coastal Atlantic cod in Labrador and Newfoundland, Canada

    DEFF Research Database (Denmark)

    Ruzzante, D.E.; Wroblewski, J.S.; Taggart, C.T.;

    2000-01-01

    of population structure suggest that important barriers to gene flow exist among five components that include two inshore (Gilbert and Trinity Bay) and three offshore cod aggregations on the north-east Newfoundland Shelf and the Grand Bank. D-A and D-SW estimates of genetic distance that involve Gilbert Bay cod...... fishery collapse. Harvesting strategies for northern cod should recognize the existence of genetic diversity between inshore and offshore components as well as among coastal components. (C) 2000 The Fisheries Society of the British Isles...

  11. Effect of an invasive plant and moonlight on rodent foraging behavior in a coastal dune ecosystem.

    Science.gov (United States)

    Johnson, Matthew D; De León, Yesenia L

    2015-01-01

    Understanding how invasive plants may alter predator avoidance behaviors is important for granivorous rodents because their foraging can trigger ripple effects in trophic webs. Previous research has shown that European beach grass Ammophila arenaria, an invasive species in coastal California, affects the predation of other seeds by the rodents Microtus californicus, Peromyscus maniculatus, and Reithrodontomys megalotis. This may be due to lower perceived predation risk by rodents foraging in close proximity to the cover provided by Ammophila, but this mechanism has not yet been tested. We examined the perceived predation risk of rodents by measuring the 'giving up density' of food left behind in experimental patches of food in areas with and without abundant cover from Ammophila and under varying amount of moonlight. We found strong evidence that giving up density was lower in the thick uniform vegetation on Ammophila-dominated habitat than it was in the more sparsely and diversely vegetated restored habitat. There was also evidence that moonlight affected giving up density and that it mediated the effects of habitat, although with our design we were unable to distinguish the effects of lunar illumination and moon phase. Our findings illustrate that foraging rodents, well known to be risk-averse during moonlit nights, are also affected by the presence of an invasive plant. This result has implications for granivory and perhaps plant demography in invaded and restored coastal habitats. Future research in this system should work to unravel the complex trophic links formed by a non-native invasive plant (i.e., Ammophila) providing cover favored by native rodents, which likely forage on and potentially limit the recruitment of native and non-native plants, some of which have ecosystem consequences of their own.

  12. Effect of an invasive plant and moonlight on rodent foraging behavior in a coastal dune ecosystem.

    Directory of Open Access Journals (Sweden)

    Matthew D Johnson

    Full Text Available Understanding how invasive plants may alter predator avoidance behaviors is important for granivorous rodents because their foraging can trigger ripple effects in trophic webs. Previous research has shown that European beach grass Ammophila arenaria, an invasive species in coastal California, affects the predation of other seeds by the rodents Microtus californicus, Peromyscus maniculatus, and Reithrodontomys megalotis. This may be due to lower perceived predation risk by rodents foraging in close proximity to the cover provided by Ammophila, but this mechanism has not yet been tested. We examined the perceived predation risk of rodents by measuring the 'giving up density' of food left behind in experimental patches of food in areas with and without abundant cover from Ammophila and under varying amount of moonlight. We found strong evidence that giving up density was lower in the thick uniform vegetation on Ammophila-dominated habitat than it was in the more sparsely and diversely vegetated restored habitat. There was also evidence that moonlight affected giving up density and that it mediated the effects of habitat, although with our design we were unable to distinguish the effects of lunar illumination and moon phase. Our findings illustrate that foraging rodents, well known to be risk-averse during moonlit nights, are also affected by the presence of an invasive plant. This result has implications for granivory and perhaps plant demography in invaded and restored coastal habitats. Future research in this system should work to unravel the complex trophic links formed by a non-native invasive plant (i.e., Ammophila providing cover favored by native rodents, which likely forage on and potentially limit the recruitment of native and non-native plants, some of which have ecosystem consequences of their own.

  13. Models of plant populations and communities

    Energy Technology Data Exchange (ETDEWEB)

    Huston, M.

    1990-01-01

    This document is the overview of the plant section in the book, {und Individual-Based Models and Approaches in Ecology}. A brief description of each of the chapters is provided, as well as a comparison of the models presented in each chapter. Four of the six chapters deal with single species interactions, one dealt with a two species system (plants and pollinators) and one deals with multispecies interactions. Both i-state distribution models and i-state configuration models are discussed. (MHB)

  14. Disturbance in dry coastal dunes in Denmark promotes diversity of plants and arthropods

    DEFF Research Database (Denmark)

    Brunbjerg, Ane Kirstine; Jørgensen, Gorm Pilgaard; Nielsen, Kristian Mandsberg;

    2015-01-01

    Naturally disturbed coastal dunes have become strongly reduced during the last century due to the cessation of grazing by domestic herbivores, dune stabilization initiatives, and increasing nitrogen deposition, all promoting encroachment by grasses, shrubs and woody plants. We assessed the effects......, trampled paths and their paired controls. We used Nonmetric Multidimensional Scaling (NMDS) ordination to assess differences in species composition of disturbed areas and controls. Ordination scores were used as response variables in Linear Mixed Effect (LME) models to test for the effects of disturbances...... responded differently to different disturbances. Arthropod communities were more diverse in disturbed plots and hosted species often found in early successional habitats of potential conservation value. Disturbance promoted β-diversity, but affected plants more than arthropods, likely because...

  15. Model calculating annual mean atmospheric dispersion factor for coastal site of nuclear power plant

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper describes an atmospheric dispersion field experiment performed on the coastal site of nuclear power plant in the east part of China during 1995 to 1996. The three-dimension joint frequency are obtained by hourly observation of wind and temperature on a 100m high tower; the frequency of the “event day of land and sea breezes” are given by observation of surface wind and land and sea breezes; the diffusion parameters are got from measurements of turbulent and wind tunnel simulation test.A new model calculating the annual mean atmospheric dispersion factor for coastal site of nuclear power plant is developed and established.This model considers not only the effect from mixing release and mixed layer but also the effect from the internal boundary layer and variation of diffusion parameters due to the distance from coast.The comparison between results obtained by the new model and current model shows that the ratio of annual mean atmospheric dispersion factor gained by the new model and the current one is about 2.0.

  16. Transplanting native dominant plants to facilitate community development in restored coastal plain wetlands.

    Energy Technology Data Exchange (ETDEWEB)

    De Steven, Diane; Sharitz, Rebecca R.

    2007-12-01

    Abstract: Drained depressional wetlands are typically restored by plugging ditches or breaking drainage tiles to allow recovery of natural ponding regimes, while relying on passive recolonization from seed banks and dispersal to establish emergent vegetation. However, in restored depressions of the southeastern United States Coastal Plain, certain characteristic rhizomatous graminoid species may not recolonize because they are dispersal-limited and uncommon or absent in the seed banks of disturbed sites. We tested whether selectively planting such wetland dominants could facilitate restoration by accelerating vegetative cover development and suppressing non-wetland species. In an operational-scale project in a South Carolina forested landscape, drained depressional wetlands were restored in early 2001 by completely removing woody vegetation and plugging surface ditches. After forest removal, tillers of two rhizomatous wetland grasses (Panicum hemitomon, Leersia hexandra) were transplanted into singlespecies blocks in 12 restored depressions that otherwise were revegetating passively. Presence and cover of all plant species appearing in planted plots and unplanted control plots were recorded annually. We analyzed vegetation composition after two and four years, during a severe drought (2002) and after hydrologic recovery (2004). Most grass plantings established successfully, attaining 15%–85% cover in two years. Planted plots had fewer total species and fewer wetland species compared to control plots, but differences were small. Planted plots achieved greater total vegetative cover during the drought and greater combined cover of wetland species in both years. By 2004, planted grasses appeared to reduce cover of non-wetland species in some cases, but wetter hydrologic conditions contributed more strongly to suppression of non-wetland species. Because these two grasses typically form a dominant cover matrix in herbaceous depressions, our results indicated that

  17. Highly diverse recombining populations of Vibrio cholerae and Vibrio parahaemolyticus in French Mediterranean coastal lagoons

    Directory of Open Access Journals (Sweden)

    Kevin eEsteves

    2015-07-01

    Full Text Available Vibrio parahaemolyticus and Vibrio cholerae are ubiquitous to estuarine and marine environments. These two species can induce infections in humans. Therefore understanding the structure and dynamics of non-pandemic environmental populations in temperate regions, such as Mediterranean coastal systems, is important if we are to evaluate the risks of infection to humans.Environmental isolates of V. cholerae (n=109 and V. parahaemolyticus (n=89 sampled at different dates, stations and water salinities were investigated for virulence genes and by a multilocus sequence-based analysis (MLSA. V. cholerae isolates were all ctxA negative and only one isolate of V. parahaemolyticus displayed trh2 gene. Most Sequence Types (ST corresponded to unique ST isolated at one date or one station. Frequent recombination events were detected among different pathogenic species, V. parahaemolyticus, V. cholerae, Vibrio mimicus and Vibrio metoecus. Recombination had a major impact on the diversification of lineages. The genetic diversity assessed by the number of ST/strain was higher in low salinity conditions for V. parahaemolyticus and V. cholerae whereas the frequency of recombination events in V. cholerae was lower in low salinity. Mediterranean coastal lagoon systems housed V. cholerae and V. parahaemolyticus with genetic diversities equivalent to the worldwide diversity described so far. The presence of STs found in human infections as well as the frequency of recombination events in environmental vibrios populations could predict a potential epidemiological risk.

  18. Palatal changes of reverse smokers in a rural coastal Andhra population with review of literature

    Directory of Open Access Journals (Sweden)

    T Sreenivasa Bharath

    2015-01-01

    Full Text Available Aim: To investigate and record the palatal changes in individuals habituated to reverse chutta smoking in rural coastal Andhra population. Materials and Methods: Sixty individuals out of whom 47 females and 13 males habituated to reverse smoking with no other tobacco and alcohol habits and no other systemic disturbances were selected. The palatal changes were recorded by six examiners. Database were searched for the following terms "reverse smokers," "nicotina palatini" and "palatal lesions." Results: The mean and percentage prevalence of the each lesion recorded and agreed by six examiners among 60 subjects showed presence of 87.77% hyperpigmented areas, 64.44% depigmented areas, 51.66% excrescences, 32.22% potentially malignant lesions and 9.72% frank ulcerations. Conclusion: Reverse smoking is an endemic tobacco habit still practiced in the coastal rural Andhra Pradesh. It is a well-established and socially acceptable habit among adult females. The changes recorded clinically shows characteristic features that are unique among this population group.

  19. Floristic survey of traditional herbal medicinal plants for treatments of various diseases from coastal diversity in Pudhukkottai District, Tamilnadu, India

    Institute of Scientific and Technical Information of China (English)

    Rameshkumar S; Ramakritinan CM

    2013-01-01

    Objective: To conduct ethno medicinal survey in coastal plant species in Pudhukkottai district and collect information on medicinal plants used for the treatment of various diseases such as pneumonia, asthma, rheumatism, piles, diarrhea, skin diseases, spleen diseases and several other ailments.Methods:The study was conducted during November 2012 to April 2013 by visiting regularly fishery communities and local peoples with the help of interviews. Traditional herbal medicine information was collected as per the described methods.Results:A total of 52 plant species, 28 were herbs, 8 trees, 8 climbers, 7 shrubs and one species of aquatic creeper.Conclusions:The study revealed that local communities and fishery communities have a great species representing 31 families have been reported. Of the 52 plant faith in the traditional healing system and they rely on medicinal plants for treatment of various diseases. Now, the coastal plants have been extensively modified by human activity. Further studies on phytochemistry, pharmacology and pharmacognosy on these species may lead to the invention of novel bioactive compounds to treat pathogenic diseases. Due to continuous loss of coastal vegetation, the associated indigenous knowledge is also gradually disappearing. So, it is imperative to protect and restore the coastal vegetation, as an immediate priority.

  20. Nutritive Equilibrium in Rice Plant Populations for High Yield

    Institute of Scientific and Technical Information of China (English)

    WANGBOLUN; LIUXINAN; 等

    1999-01-01

    The effects of nitrogen,phosphorus and potassium application level,seed rate and transplanting density on the growth and development of rice plants were studied to find out nutrient status in high-yielding rice plants and to increase grain yield by adequate fertilization.There was an equilibrium relationship among nutrient elements for high-yielding rice plant populations.The equilibrium index of nutrient amount ,content and distribution in high-yielding rice plants should be generally greater than-2 but less than 2.The optimum nutritive proportion of nitrogen:phosphorus:potassium assimilated by the plants was about 10:2:9 at the ripening stage.But the content and the proportion varied with the growth stages,Therefore,the nutrient in rice plant populations should be in a dynamic equilibrium.So as to achieve high yield.

  1. Coupling bacterioplankton populations and environment to community function in coastal temperate waters

    DEFF Research Database (Denmark)

    Traving, S. J.; Bentzon-Tilia, Mikkel; Knudsen-Leerbeck, H.

    2016-01-01

    Bacterioplankton play a key role in marine waters facilitating processes important for carbon cycling. However, the influence of specific bacterial populations and environmental conditions on bacterioplankton community performance remains unclear. The aim of the present study was to identify...... drivers of bacterioplankton community functions, taking into account the variability in community composition and environmental conditions over seasons, in two contrasting coastal systems. A Least Absolute Shrinkage and Selection Operator (LASSO) analysis of the biological and chemical data obtained from...... surface waters over a full year indicated that specific bacterial populations were linked to measured functions. Namely, Synechococcus (Cyanobacteria) was strongly correlated with protease activity. Both function and community composition showed seasonal variation. However, the pattern of substrate...

  2. Transcriptome analysis deciphers evolutionary mechanisms underlying genetic differentiation between coastal and offshore anchovy populations in the Bay of Biscay

    KAUST Repository

    Montes, Iratxe

    2016-09-13

    Morphometry and otolith microchemistry point to the existence of two populations of the European anchovy (Engraulis encrasicolus) in the Bay of Biscay: one in open seawaters, and a yet unidentified population in coastal waters. To test this hypothesis, we assembled a large number of samples from the region, including 587 juveniles and spawning adults from offshore and coastal waters, and 264 fish from other locations covering most of the species’ European range. These samples were genotyped for 456 exonic SNPs that provide a robust way to decipher adaptive processes in these populations. Two genetically differentiated populations of anchovy inhabit the Bay of Biscay with different population dynamics: (1) a large offshore population associated with marine waters included in the wide-shelf group, and (2) a coastal metapopulation adapted to estuarine environments in the Bay of Biscay and North Sea included in the narrow-shelf group. Transcriptome analysis identified neutral and adaptive evolutionary processes underlying differentiation between these populations. Reduced gene flow between offshore and coastal populations in the Bay of Biscay appears to result from divergence between two previously isolated gene pools adapted to contrasting habitats and now in secondary contact. Eleven molecular markers appear to mark divergent selection between the ecotypes, and a majority of these markers are associated with salinity variability. Ecotype differences at two outlier genes, TSSK6 and basigin, may hinder gamete compatibility between the ecotypes and reinforce reproductive isolation. Additionally, possible convergent evolution between offshore and coastal populations in the Bay of Biscay has been detected for the syntaxin1B-otoferlin gene system, which is involved in the control of larval buoyancy. Further study of exonic markers opens the possibility of understanding the mechanisms of adaptive divergence between European anchovy populations. © 2016, Springer

  3. Do plant population and planting date make a difference in corn production?

    Science.gov (United States)

    One management practice that can positively or negatively impact corn yield is plant population. Yield potential can also be influenced by the date of planting, which is strongly linked to the at-planting and in-season weather and climatic conditions. Even when considering management changes, we nee...

  4. Biofouling evaluation in the seawater cooling circuit of an operating coastal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Murthy, P.S.; Veeramani, P.; Ershath, M.I.M.; Venugopalan, V.P. [BARC Facilities, Water and Steam Chemistry Div., Kalpakkam, Tamil Nadu (India)

    2010-07-01

    Chlorination is the most commonly used method of biofouling control in cooling water systems of coastal power stations. In the present study, we report results of extensive sampling in different sections of the cooling water system of an operating power station undertaken during three consecutive maintenance shutdowns. The power plant employed continuous low level chlorination (0.2 ± 0.1 mg L{sup -1} TRO) with twice-a-week booster dosing (0.4 ± 0.1 mg L-1 TRO for 8 hours). In addition, the process seawater heat exchangers received supplementary dosing of bromide treatment (0.2 ± 0.1 mg L{sup -1} TRO for 1 hour in every 8 h shift). Biofouling samples were collected from the cooling water conduits, heat exchanger water boxes, pipelines, heated discharge conduits and outfall section during the annual maintenance shutdown of the plant in the years 2007, 2008 and 2009. Simultaneous monitoring of biofouling on test coupons in coastal waters enabled direct comparison of fouling situation on test panels and that in the cooling system. The data showed significant reduction in biofouling inside the cooling circuit as compared to the coastal waters. However, significant amount of fouling was still evident at several places, indicating inadequacy of the biocide treatment regime. The maximum load of 31.3 kg m{sup 2} y{sup -1} was observed in the conduits leading to the process seawater heat exchangers (PSW-HX) and the minimum of 1.3 kg m{sup 2} y{sup -1} was observed in the outfall section. Fouling loads of 12.2 - 14.7 kg m{sup 2} y{sup -1} were observed in the concrete conduits feeding the main condensers. Bromide treatment ahead of the PSW-HX could marginally reduce the fouling load in the downstream section of the dosing point; the HX inlets still showed good biofouling. Species diversity across the cooling water system showed the pre-condenser section to be dominated by green mussels (Perna viridis), pearl oysters (Pinctada sp.) and edible oysters (Crassostrea sp

  5. The population structure of Glossina palpalis gambiensis from island and continental locations in Coastal Guinea.

    Directory of Open Access Journals (Sweden)

    Philippe Solano

    Full Text Available BACKGROUND: We undertook a population genetics analysis of the tsetse fly Glossina palpalis gambiensis, a major vector of sleeping sickness in West Africa, using microsatellite and mitochondrial DNA markers. Our aims were to estimate effective population size and the degree of isolation between coastal sites on the mainland of Guinea and Loos Islands. The sampling locations encompassed Dubréka, the area with the highest Human African Trypanosomosis (HAT prevalence in West Africa, mangrove and savannah sites on the mainland, and two islands, Fotoba and Kassa, within the Loos archipelago. These data are discussed with respect to the feasibility and sustainability of control strategies in those sites currently experiencing, or at risk of, sleeping sickness. PRINCIPAL FINDINGS: We found very low migration rates between sites except between those sampled around the Dubréka area that seems to contain a widely dispersed and panmictic population. In the Kassa island samples, various effective population size estimates all converged on surprisingly small values (10population sizes suggest high levels of inbreeding in tsetse flies within the island samples in marked contrast to the large diffuse deme in Dubréka zones. We discuss how these genetic results suggest that different tsetse control strategies should be applied on the mainland and islands.

  6. The population structure of Glossina palpalis gambiensis from island and continental locations in Coastal Guinea.

    Science.gov (United States)

    Solano, Philippe; Ravel, Sophie; Bouyer, Jeremy; Camara, Mamadou; Kagbadouno, Moise S; Dyer, Naomi; Gardes, Laetitia; Herault, Damien; Donnelly, Martin J; De Meeûs, Thierry

    2009-01-01

    We undertook a population genetics analysis of the tsetse fly Glossina palpalis gambiensis, a major vector of sleeping sickness in West Africa, using microsatellite and mitochondrial DNA markers. Our aims were to estimate effective population size and the degree of isolation between coastal sites on the mainland of Guinea and Loos Islands. The sampling locations encompassed Dubréka, the area with the highest Human African Trypanosomosis (HAT) prevalence in West Africa, mangrove and savannah sites on the mainland, and two islands, Fotoba and Kassa, within the Loos archipelago. These data are discussed with respect to the feasibility and sustainability of control strategies in those sites currently experiencing, or at risk of, sleeping sickness. We found very low migration rates between sites except between those sampled around the Dubréka area that seems to contain a widely dispersed and panmictic population. In the Kassa island samples, various effective population size estimates all converged on surprisingly small values (10population sizes suggest high levels of inbreeding in tsetse flies within the island samples in marked contrast to the large diffuse deme in Dubréka zones. We discuss how these genetic results suggest that different tsetse control strategies should be applied on the mainland and islands.

  7. Investigation of Metal Uptake and Translocation in Wetland Plants from Urban Coastal Areas

    Science.gov (United States)

    Feng, H.; Zhang, W.; Qian, Y.; Liu, W.; Yu, L.; Jones, K. W.; Liu, C.; Tappero, R.

    2013-12-01

    This research mainly focused on the use of synchrotron micro XRF technique to study the mechanisms of metal uptake by plants in conjunction with other measurements to provide insight metal concentrations and distributions in the rhizosphere root system. Many urban-industrial areas exhibit environmental degradation. One of the most common issues is sediment metal contamination resulting from past industrial land uses. The wetland ecosystem in urban coastal areas, such as New Jersey, USA, and Shanghai, China, is a unique laboratory for investigating sediment remediation and wetland ecological rehabilitations. Understanding the natural processes that control the mobility of metals in wetland plants is important to understand the metal biochemical cycle. Wetland plants can uptake metals from rhizosphere soils through their root system and store these metals within the plant biomass. The accumulation of metals in wetland plants provides a potential approach for brownfield remediation and wetland restoration. In the rhizosphere, the role of Fe plaque, which forms on the surface of wetland plant roots, has been an issue of debate in controlling metal biogeochemical cycle. It was reported that due to the large specific surface area of iron-oxides for metal sequestration, Fe plaque can provide a reactive substrate to scavenge metals. Several early studies suggest that the Fe plaque serves as a barrier preventing heavy metals from entering plant roots. However, others suggest that Fe plaque is not the main barrier. Therefore, investigation of the natural processes that control the mobility of metals from sediment to wetland plants is a critical step in understanding metal translocation and geochemical cycling in wetlands. In this study we found that metal concentrations and distributions in the root cross section from the epidermis to the vascular cylinder were apparently different. Two clusters of metal distributions were seen with Fe and Pb mainly distributed in the

  8. Highly diverse recombining populations of Vibrio cholerae and Vibrio parahaemolyticus in French Mediterranean coastal lagoons.

    Science.gov (United States)

    Esteves, Kévin; Mosser, Thomas; Aujoulat, Fabien; Hervio-Heath, Dominique; Monfort, Patrick; Jumas-Bilak, Estelle

    2015-01-01

    Vibrio parahaemolyticus and Vibrio cholerae are ubiquitous to estuarine and marine environments. These two species found in Mediterranean coastal systems can induce infections in humans. Environmental isolates of V. cholerae (n = 109) and V. parahaemolyticus (n = 89) sampled at different dates, stations and water salinities were investigated for virulence genes and by a multilocus sequence-based analysis (MLSA). V. cholerae isolates were all ctxA negative and only one isolate of V. parahaemolyticus displayed trh2 gene. Most Sequence Types (ST) corresponded to unique ST isolated at one date or one station. Frequent recombination events were detected among different pathogenic species, V. parahaemolyticus, V. cholerae, Vibrio mimicus, and Vibrio metoecus. Recombination had a major impact on the diversification of lineages. The genetic diversity assessed by the number of ST/strain was higher in low salinity condition for V. parahaemolyticus and V. cholerae whereas the frequency of recombination events in V. cholerae was lower in low salinity condition. Mediterranean coastal lagoon systems housed V. cholerae and V. parahaemolyticus with genetic diversities equivalent to the worldwide diversity described so far. The presence of STs found in human infections as well as the frequency of recombination events in environmental vibrios populations could predict a potential epidemiological risk.

  9. Highly diverse recombining populations of Vibrio cholerae and Vibrio parahaemolyticus in French Mediterranean coastal lagoons

    Science.gov (United States)

    Esteves, Kévin; Mosser, Thomas; Aujoulat, Fabien; Hervio-Heath, Dominique; Monfort, Patrick; Jumas-Bilak, Estelle

    2015-01-01

    Vibrio parahaemolyticus and Vibrio cholerae are ubiquitous to estuarine and marine environments. These two species found in Mediterranean coastal systems can induce infections in humans. Environmental isolates of V. cholerae (n = 109) and V. parahaemolyticus (n = 89) sampled at different dates, stations and water salinities were investigated for virulence genes and by a multilocus sequence-based analysis (MLSA). V. cholerae isolates were all ctxA negative and only one isolate of V. parahaemolyticus displayed trh2 gene. Most Sequence Types (ST) corresponded to unique ST isolated at one date or one station. Frequent recombination events were detected among different pathogenic species, V. parahaemolyticus, V. cholerae, Vibrio mimicus, and Vibrio metoecus. Recombination had a major impact on the diversification of lineages. The genetic diversity assessed by the number of ST/strain was higher in low salinity condition for V. parahaemolyticus and V. cholerae whereas the frequency of recombination events in V. cholerae was lower in low salinity condition. Mediterranean coastal lagoon systems housed V. cholerae and V. parahaemolyticus with genetic diversities equivalent to the worldwide diversity described so far. The presence of STs found in human infections as well as the frequency of recombination events in environmental vibrios populations could predict a potential epidemiological risk. PMID:26236294

  10. 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.

  11. Natural persistence of the coastal plant Glehnia littoralis along temperate sandy coasts

    Science.gov (United States)

    Yang, Hong-Xiao; Chu, Jian-Min; Liu, Xiao-Shan

    2017-01-01

    We studied germination behaviors and persistence mechanism of wild Glehnia littoralis, a typical coastal species at temperate sandy coasts of the North Pacific Ocean, and tested the hypothesis that the coastal plants may have evolved special seeds adapting to the coasts, by which they recruit and persist easily, occupying the coasts as ideal habitats. In the Shandong Peninsula, China, we investigated temperature and moisture conditions of coast sand in relation to germination and evaluated effects of sand burial, seawater immersion and sowing time on germination. When germination began, daily dawn temperatures of sand were about 10 °C and daily noon temperatures were about 25 °C; the temperatures were not different in the sand seeds exhibited large germination rates if sand burial was at depths >= 3 cm and winter freezing was kept longer than 2.5 months. Seeds experiencing seawater immersion were able to germinate well. These evidences suggest that G. littoralis has evolved special seeds adapting to seawater dispersal and specific season rhythm. By the seeds, G. littoralis occupies temperate sandy coasts as ideal habitats to persist. PMID:28211487

  12. Does extreme environmental severity promote plant facilitation? An experimental field test in a subtropical coastal dune.

    Science.gov (United States)

    Castanho, Camila T; Oliveira, Alexandre A; Prado, Paulo Inácio K L

    2015-07-01

    The stress gradient hypothesis (SGH) postulates how the balance between plant competition and facilitation shifts along environmental gradients. Early formulations of the SGH predicted that facilitation should increase monotonically with stress. However, a recent theoretical refinement of the SGH postulates stronger facilitation under moderate stress, followed by a decreasing role of facilitation in the most severe environments. We conducted field experiments along the most severe part of a coastal dune gradient in southeast Brazil to test the effect of stress on the intensity and importance of the net interactions between two tree species. First, we compared the performance of distinct life stages of Ternstroemia brasiliensis in the presence and absence of Guapira opposita adults along a beach-to-inland gradient, a gradient of environmental severity. To test the effect of one stress factor in particular, we also manipulated water availability, a limiting resource due to the sandy soils. At the most severe part of the coastal gradient (i.e. closest to the seashore), both intensity and importance of the interaction between G. opposita and T. brasiliensis were negatively related to stress, with a pattern consistent across distinct life stages of the target species. However, the sign of the net interaction depended on the life stage of the target species. Our results provide empirical evidence that the role of facilitation tends to wane, leading to neutral or even negative net interactions between species as stress reaches its maximum, as predicted by the recent refinements of the SGH.

  13. Winter Activity of Coastal Plain Populations of Bat Species Affected by White-Nose Syndrome and Wind Energy Facilities.

    Science.gov (United States)

    Grider, John F; Larsen, Angela L; Homyack, Jessica A; Kalcounis-Rueppell, Matina C

    2016-01-01

    Across the entire distribution of a species, populations may have variable responses to environmental perturbations. Many bat species experience mortality in large portions of their range during hibernation and along migratory paths to and from wintering grounds, from White-nose syndrome (WNS) and wind energy development, respectively. In some areas, warm temperatures may allow bats to remain active through winter, thus decreasing their susceptibility to WNS and/or mortality associated with migration to wintering grounds. These areas could act as a refugia and be important for the persistence of local populations. To determine if warmer temperatures affect bat activity, we compared year-round activity of bat populations in the Coastal Plain and Piedmont of North Carolina, USA, two regions that differ in winter temperature. We established six recording stations, four along a 295-kilometer north-south transect in the Coastal Plain, and two in the Piedmont of North Carolina. We recorded bat activity over two years. We supplemented our recordings with mist-net data. Although bat activity was lower during winter at all sites, the odds of recording a bat during winter were higher at Coastal Plain sites when compared with Piedmont sites. Further, bats in the Piedmont had a lower level of winter activity compared to summer activity than bats in the Coastal Plain that had more similar levels of activity in the winter and summer. We found high bat species richness on the Coastal Plain in winter, with winter-active species including those known to hibernate throughout most of their range and others known to be long distance migrants. In particular, two species impacted by WNS, the northern long-eared bat (Myotis septentrionalis) and tricolored bat (Perimyotis subflavus), were present year round in the Coastal Plain. The tricolored bat was also present year-round in the Piedmont. In the Coastal Plain, the long distance migratory hoary bat (Lasiurus cinereus) was active in the

  14. A STUDY OF METABOLIC PARAMETER AND MORBIDITY PROFILE AMONG ELDERLY POPULATION IN RURAL COASTAL ANDHRA PRADESH

    Directory of Open Access Journals (Sweden)

    Shakeela

    2016-01-01

    Full Text Available Global population ageing is an important challenge and opportunity faced by all countries. With advances in medicine helping more people to live longer lives, the number of people over age 60 years is expected to double by 2050 and will require radical social change according to a new report released by the WHO for the international day. Present study is designed to evaluate metabolic parameter and morbidity profile in elderly people in rural coastal Andhra Pradesh; 30% of male and 31% of the female was diabetic; 26.4% of the male and 37.5% of the female was having osteoarthritis; 41.18% of the male and 37.5% of the female have acid peptic disease; 10.1% of male and 12.75% of the female have ischemic heart disease. So it is required to provide promotional, preventive, curative and rehabilitative services in an integrated manner for the elderly

  15. Characterization and Photoprotector Activity of Endophytic Fungal Pigments from Coastal Plant Sarang Semut (Hydnophytum formicarum

    Directory of Open Access Journals (Sweden)

    Mada Triandala Sibero

    2016-04-01

    Full Text Available Endophytic fungus RS3 isolated from coastal plant sarang semut (Hydnophytum formicarum produced extracellular black pigment. The aims of this research were to obtain the pigment, to characterize and to determine the photoprotector activity. This research was conducted into several steps, that were determination of the best precipitating agent, characterization using instrument and solubility analysis, and analysis of Sun Protection Factor (SPF. Results showed the pigment was precipitated using acid solvent with pH ≤ 2.5. Functional groups of pigment were hydroxyl, aromatic ring, phenol and amine. According to its characteristics, black pigment produced by RS3 isolate was proposed as melanin. The photoprotector analysis showed the SPF value was 11.33.

  16. Enhanced growth of halophyte plants in biochar-amended coastal soil: roles of nutrient availability and rhizosphere microbial modulation.

    Science.gov (United States)

    Zheng, Hao; Wang, Xiao; Chen, Lei; Wang, Zhenyu; Xia, Yang; Zhang, Yipeng; Wang, Hefang; Luo, Xianxiang; Xing, Baoshan

    2017-03-27

    Soil health is essential and irreplaceable for plant growth and global food production, which has been threatened by climate change and soil degradation. Degraded coastal soils are urgently required to reclaim using new sustainable technologies. Interest in applying biochar to improve soil health and promote crop yield has rapidly increased because of its multiple benefits. However, effects of biochar addition on the saline-sodic coastal soil health and halophyte growth were poorly understood. Response of two halophytes, Sesbania (Sesbania cannabina) and Seashore mallow (Kosteletzkya virginica), to the individual or co-application of biochar and inorganic fertilizer into a coastal soil was investigated using a 52-day pot experiment. The biochar alone or co-application stimulated the plant growth (germination, root development, biomass), primarily attributed to the enhanced nutrients availability from the biochar-improved soil health. Additionally, the promoted microbial activities and bacterial community shift towards the beneficial taxa (e.g., Pseudomonas and Bacillus) in the rhizosphere also contributed to the enhanced plant growth and biomass. Our findings showed the promising significance because biochar added at an optimal level (≤5%) could be a feasible option to reclaim the degraded coastal soil, enhance plant growth and production, and increase soil health and food security.

  17. The east-west-north colonization history of the Mediterranean and Europe by the coastal plant Carex extensa (Cyperaceae)

    NARCIS (Netherlands)

    Escudero, M.; Vargas, P.; Arens, P.; Ouborg, N.J.; Luceno, M.

    2010-01-01

    Coastal plants are ideal models for studying the colonization routes of species because of the simple linear distributions of these species. Carex extensa occurs mainly in salt marshes along the Mediterranean and European coasts. Variation in cpDNA sequences, amplified fragment length polymorphisms

  18. Effects of an invasive plant on population dynamics in toads.

    Science.gov (United States)

    Greenberg, Daniel A; Green, David M

    2013-10-01

    When populations decline in response to unfavorable environmental change, the dynamics of their population growth shift. In populations that normally exhibit high levels of variation in recruitment and abundance, as do many amphibians, declines may be difficult to identify from natural fluctuations in abundance. However, the onset of declines may be evident from changes in population growth rate in sufficiently long time series of population data. With data from 23 years of study of a population of Fowler's toad (Anaxyrus [ = Bufo] fowleri) at Long Point, Ontario (1989-2011), we sought to identify such a shift in dynamics. We tested for trends in abundance to detect a change point in population dynamics and then tested among competing population models to identify associated intrinsic and extrinsic factors. The most informative models of population growth included terms for toad abundance and the extent of an invasive marsh plant, the common reed (Phragmites australis), throughout the toads' marshland breeding areas. Our results showed density-dependent growth in the toad population from 1989 through 2002. After 2002, however, we found progressive population decline in the toads associated with the spread of common reeds and consequent loss of toad breeding habitat. This resulted in reduced recruitment and population growth despite the lack of significant loss of adult habitat. Our results underscore the value of using long-term time series to identify shifts in population dynamics coincident with the advent of population decline. © 2013 Society for Conservation Biology.

  19. Cancer mortality in the indigenous population of coastal Chukotka, 1961–1990

    Directory of Open Access Journals (Sweden)

    Alexey A. Dudarev

    2013-03-01

    Full Text Available Objectives. The general aim was to assess the pattern and trend in cancer mortality among the indigenous people of coastal Chukotka during the period 1961–1990. Methods. All cases of cancer deaths of indigenous residents of the Chukotsky district in the north-easternmost coast of Chukotka Autonomous Okrug were copied from personal death certificates. There were a total of 219 cancer deaths during the study period. The average annual number of cases, percent, crude, and age-standardized cancer mortality rates (ASMR per 100,000 among men and women for all sites combined and selected sites were calculated. Data were aggregated into six 5-year periods to assess temporal trends. Direct age-standardization was performed with the Segi-Doll world standard population used by the International Agency for Research on Cancer. Results. The indigenous Chukchi and Eskimo people living in Chukotsky district were at higher risk of death from cancer during the 30-year period between 1961 and 1990, with ASMR among men twice that of Russia, and among women 3.5 times higher. The excess can be attributed to the extremely high mortality from oesophageal cancer and lung cancer. Conclusions. The indigenous people of coastal Chukotka were at very high risk of death from cancer relative to the Russian population nationally. The mortality data from this study correspond to the pattern of incidence reported among other indigenous people of the Russian Arctic. Little information is available since 1990, and the feasibility of ethnic-specific health data is now severely limited.

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

    Science.gov (United States)

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

  1. Prediction of plant vulnerability to salinity increase in a coastal ecosystem by stable isotopic composition (δ18O) of plant stem water: a model study

    Science.gov (United States)

    Zhai, Lu; Jiang, Jiang; DeAngelis, Don; Sternberg, Leonel d.S.L

    2016-01-01

    Sea level rise and the subsequent intrusion of saline seawater can result in an increase in soil salinity, and potentially cause coastal salinity-intolerant vegetation (for example, hardwood hammocks or pines) to be replaced by salinity-tolerant vegetation (for example, mangroves or salt marshes). Although the vegetation shifts can be easily monitored by satellite imagery, it is hard to predict a particular area or even a particular tree that is vulnerable to such a shift. To find an appropriate indicator for the potential vegetation shift, we incorporated stable isotope 18O abundance as a tracer in various hydrologic components (for example, vadose zone, water table) in a previously published model describing ecosystem shifts between hammock and mangrove communities in southern Florida. Our simulations showed that (1) there was a linear relationship between salinity and the δ18O value in the water table, whereas this relationship was curvilinear in the vadose zone; (2) hammock trees with higher probability of being replaced by mangroves had higher δ18O values of plant stem water, and this difference could be detected 2 years before the trees reached a tipping point, beyond which future replacement became certain; and (3) individuals that were eventually replaced by mangroves from the hammock tree population with a 50% replacement probability had higher stem water δ18O values 3 years before their replacement became certain compared to those from the same population which were not replaced. Overall, these simulation results suggest that it is promising to track the yearly δ18O values of plant stem water in hammock forests to predict impending salinity stress and mortality.

  2. Genetic analysis of threatened Australian grayling Prototroctes maraena suggests recruitment to coastal rivers from an unstructured marine larval source population.

    Science.gov (United States)

    Schmidt, D J; Crook, D A; O'Connor, J P; Hughes, J M

    2011-01-01

    Population genetic variation of Australian grayling Prototroctes maraena was examined to determine whether the dispersal strategy of this amphidromous species favours retention of larvae and juveniles in close proximity to their natal river, or mixing of populations via marine dispersal. Variation in microsatellite and mitochondrial DNA markers was unstructured and differentiation was indistinguishable from zero across four coastal rivers spanning approximately one-quarter of the continental range of the species. This result indicates that the marine larval and juvenile phase probably facilitates extensive gene flow among coastal rivers and agrees with a previous analysis of otolith chemistry that suggested larvae probably move into the sea rather than remain in estuaries. It appears likely that the dispersal strategy of P. maraena would enable recolonization of rivers that experience localized extinction provided that connectivity between freshwater habitats and the sea is sufficient to permit migration and that enough source populations remain intact to support viability of the wider population.

  3. Effect of pre-planting irrigation, maize planting pattern and nitrogen on weed seed bank population.

    Science.gov (United States)

    Hemmati, E; Vazan, S; Oveisi, M

    2011-01-01

    Pre-planting irrigation and planting patterns are important factors in weed management that effect on seed bank. Additionally, the nitrogen is the most important factor in plant growth that affects weed-crop competition and ultimately, seed rain into the soil. A field experiment was conducted to study the effect of nitrogen application rates, pre-planting irrigation and maize planting patterns on weed seed bank population. Experimental factors were nitrogen rates at 4 levels (200, 300, 400 and 500 kg per hectare) as main plot; and pre-planting irrigation at 2 levels (irrigation before planting plus weeding emerged seedlings and, irrigation after sowing), and maize planting patterns (one-row and two-row planting of maize with same density per square of row length) that were assigned in a factorial arrangement to the sub plots. Soil samples were taken at the beginning of the season (before planting of maize) and at the end of the season (after harvest) at depth of 0-5 cm in the fixed quadrates (60 cm x 60 cm). The weed seeds were extracted from the soil samples and were identified using standard methods. The majority of weed seed bank populations included 6 weed species: Portulaca oleracea, Chenopodium album, Amaranthus retroflexus, Sorghum halepense, Daturea stramonium, Xanthium strumarium. Results showed that population of weed seed bank increased significantly with increasing nitrogen rate. The increasing rate was different between one-row and two-row planting patterns. The parameters indicated that seed bank population was much higher in a one row planting pattern of maize. With two-row planting, seed bank was decreased by 34, 26, 20 and 5% at 200, 300, 400 and 500 kg N/ha, respectively. Pre-planting irrigation was also found an effective implement to reduce the weed seed bank. When pre-planting irrigation was applied, seed bank was decreased by 57, 43, 34 and 9% at 200, 300, 400 and 500 kg N/ha. Increasing nitrogen because of weed's better growth and higher seed

  4. Effects of diesel and kerosene on germination and growth of coastal wetland plant species.

    Science.gov (United States)

    Kim, Kee Dae

    2014-11-01

    This study aims to investigate effects of diesel and kerosene on seed germination and seedling growth among coastal wetland plants to select species that can be used for the restoration and revegetation of oil-polluted habitats. Tests on 51 species were performed in Petri dishes containing 0 %, 6 %, 12 %, and 18 % diesel, 20 %, 40 %, and 60 % kerosene; each treatment combination was replicated five times with 20 seeds in each Petri dish. All dishes were held in a growth chamber with 20°C day of 12 h/15°C night of 12 h in 80 % humidity for 20 days for calculating the germination percentage, seedling weight, and seedling vitality. The germination percentage of Rumex stenophyllus decreased significantly in diesel and kerosene treatments. The weights of seedlings treated with diesel and kerosene either increased or decreased in comparison with controls depending on the species. Vitality percentage values were high for seedlings of Chenopodium ficifolium. Thus, herbaceous plant responses to oil treatments are species-specific.

  5. Mapping an invasive plant, Phragmites australis, in coastal wetlands using the EO-1 Hyperion hyperspectral sensor

    Science.gov (United States)

    Pengra, B.W.; Johnston, C.A.; Loveland, T.R.

    2007-01-01

    Mapping tools are needed to document the location and extent of Phragmites australis, a tall grass that invades coastal marshes throughout North America, displacing native plant species and degrading wetland habitat. Mapping Phragmites is particularly challenging in the freshwater Great Lakes coastal wetlands due to dynamic lake levels and vegetation diversity. We tested the applicability of Hyperion hyperspectral satellite imagery for mapping Phragmites in wetlands of the west coast of Green Bay in Wisconsin, U.S.A. A reference spectrum created using Hyperion data from several pure Phragmites stands within the image was used with a Spectral Correlation Mapper (SCM) algorithm to create a raster map with values ranging from 0 to 1, where 0 represented the greatest similarity between the reference spectrum and the image spectrum and 1 the least similarity. The final two-class thematic classification predicted monodominant Phragmites covering 3.4% of the study area. Most of this was concentrated in long linear features parallel to the Green Bay shoreline, particularly in areas that had been under water only six years earlier when lake levels were 66??cm higher. An error matrix using spring 2005 field validation points (n = 129) showed good overall accuracy-81.4%. The small size and linear arrangement of Phragmites stands was less than optimal relative to the sensor resolution, and Hyperion's 30??m resolution captured few if any pure pixels. Contemporary Phragmites maps prepared with Hyperion imagery would provide wetland managers with a tool that they currently lack, which could aid attempts to stem the spread of this invasive species. ?? 2006 Elsevier Inc. All rights reserved.

  6. Plant population and row spacing on biomass sorghum yield performance

    Directory of Open Access Journals (Sweden)

    Andre May

    2015-01-01

    Full Text Available ABSTRACT: Biomass sorghum is one of the most promising crops for the production of electricity through the burning in high-pressure boilers, due to its high calorific value, high yield, seed propagation, short cycle, and to the possibility of full mechanization of its agricultural processes. However, there is still a lack of information about its cultural practices. To this end, this research aimed to evaluate the influence of row spacing and plant population on the yield performance of biomass sorghum. The experimental design was a randomized block, in factorial scheme of 4 x 4, with four row spacings (0.5, 0.7, 0.9 and 1.1m, and four plant populations (80,000; 100,000; 120,000 and 140,000 plants ha-1, with three replications. The characteristics evaluated were: plant height, stem diameter, number of leaves, number of tillers per plant, fresh weight per plant and biomass. Total biomass yield was greatly influenced by the row spacing, showing a sharp reduction when row spacing increased, in the two years of study, changing from 180.27 to 114.42t ha-1 in the 2012/13 crop year, and from 146.50 to 102.56t ha-1 in the 2013/14 crop year, for 0.5 and 1.1m between rows, respectively. The lowest yields observed in the second year of the study were due to unfavorable weather conditions in the period.

  7. Analysis of nutrient content and assessment of economic value for major salt-tolerant plants in coastal areas: a case study of Dongying City,Shandong Province

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Salinization of soil is a worldwide problem concerning resources and ecology,especially serious in coastal areas.Testing of 26 sorts of data or parameters are carried out on leaves of 22 plant species (in 24 plant variety) of existing main salt-tolerant plant of the Yellow River Delta region.Data or parameters include the following elements:contents of K+,Na+,Ca2+,Mg2+ and Cl-,contents of protein,fat,total energy,ash and contents of 17 amino acids.The results show that these tested plants have economic values.For example,according to their uses,they can be divided into edible plants,forage plants,medicine or health plants,and some of them can be used for multipurposes.These plants have played important roles in the sustainable utilization of plant resources in coastal areas.This paper has taken evaluations on the economic uses of salt-tolerant plants and given suggestions for saline soil improvement and resource utilization in coastal areas.Based on the results of investigation and experiments,we suppose that the salt-tolerant plants in coastal areas can be grouped into 9 main groups according to their eeonomic value:pioneer plants for saline land improvement,medicine,edible and forage plants,industry material forestation,breeding material,energy plants and eco-tourism resources.

  8. Variation in plant defences among populations of a range-expanding plant: consequences for trophic interactions.

    Science.gov (United States)

    Fortuna, Taiadjana M; Eckert, Silvia; Harvey, Jeffrey A; Vet, Louise E M; Müller, Caroline; Gols, Rieta

    2014-12-01

    Although plant-herbivore-enemy interactions have been studied extensively in cross-continental plant invasions, little is known about intra-continental range expanders, despite their rapid spread globally. Using an ecological and metabolomics approach, we compared the insect performance of a generalist and specialist herbivore and a parasitoid, as well as plant defence traits, among native, exotic invasive and exotic non-invasive populations of the Turkish rocket, Bunias orientalis, a range-expanding species across parts of Eurasia. In the glasshouse, the generalist herbivore, Mamestra brassicae, and its parasitoid, Microplitis mediator, performed better on non-native than on native plant populations. Insect performance did not differ between the two non-native origins. By contrast, the specialist herbivore, Pieris brassicae, developed poorly on all populations. Differences in trichome densities and in the metabolome, particularly in the family-specific secondary metabolites (i.e. glucosinolates), may explain population-related variation in the performance of the generalist herbivore and its parasitoid. Total glucosinolate concentrations were significantly induced by herbivory, particularly in native populations. Native populations of B. orientalis are generally better defended than non-native populations. The role of insect herbivores and dietary specialization as a selection force on defence traits in the range-expanding B. orientalis is discussed.

  9. Plant diversity, species turnover and shifts in functional traits in coastal dune vegetation: Results from permanent plots over a 52-year period

    NARCIS (Netherlands)

    Kuiters, A.T.; Kramer, K.; Hagen, van der H.G.J.M.; Schaminée, J.H.J.

    2009-01-01

    Question: What is the relationship between plant diversity and species turnover in coastal dune vegetation plots? How is the long-term change in species composition of vegetation plots related to shifts in functional traits, and what does it tell us about the dominant processes? Location: Coastal du

  10. Survey of fish impingement at power plants in the United States. Volume III. Estuaries and coastal waters

    Energy Technology Data Exchange (ETDEWEB)

    Stupka, Richard C.; Sharma, Rajendra K.

    1977-03-01

    Impingement of fish at cooling-water intakes of 32 power plants, located on estuaries and coastal waters has been surveyed and data are presented. Descriptions of site, plant, and intake design and operation are provided. Reports in this volume summarize impingement data for individual plants in tabular and histogram formats. Information was available from differing sources such as the utilities themselves, public documents, regulatory agencies, and others. Thus, the extent of detail in the reports varies greatly from plant to plant. Histogram preparation involved an extrapolation procedure that has inadequacies. The reader is cautioned in the use of information presented in this volume to determine intake-design acceptability or intensity of impacts on ecosystems. No conclusions are presented herein; data comparisons are made in Volume IV.

  11. Habitats and plant communities in the Nile Delta of Egypt I. Deltaic Mediterranean coastal habitat.

    Science.gov (United States)

    Mashaly, I A; El-Habashy, I E; El-Halawany, E F; Omar, G

    2008-11-15

    The present study aims at investigating the vegetation-soil relationships in the Deltaic Mediterranean coastal land of Egypt. The Deltaic coast of the Mediterranean Sea of Egypt can be distinguished into five habitat types, namely: sand dunes, salt marshes, sand sheets, sandy fertile lands and lake shorelines (Manzala, Burullus and Idku). These habitats are categorized into four vegetation groups namely, group A dominated by Rumex pictus, group B codominated by Pancratium maritimum-Cyperus capitatus-Lolium perenne, group C codominated by Arthrocnemum macrostachyum-Atriplex portulacoides-Typha domingensis and group D codominated by Echinochloa stagnina-Typha domingensis-Phragmites australis. One hundred and thirty plant species are recorded in this coast and belonging to 38 families. Out of the recorded species, about 41.54% are annuals, 2.31% biennials and 56.15% perennials. The percentages of the life-form indicated that, therophytes attained the highest representation (43.85%). The floristic analysis revealed that, 55.38% of the recorded species are Mediterranean elements. The ecological amplitudes of the leading species along the gradient of edaphic factors are discussed.

  12. Integrated coastal monitoring of a gas processing plant using native and caged mussels

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, Steven, E-mail: sbr@niva.no [Norwegian Institute for Water Research (NIVA), Gaustadalleen 21, NO-0349 Oslo (Norway); Harman, Christopher [Norwegian Institute for Water Research (NIVA), Gaustadalleen 21, NO-0349 Oslo (Norway); Soto, Manu; Cancio, Ibon [CBET Res Grp, R and D Centre for Experimental Marine Biology and Biotechnology (PIE), Univ Basque Country, Areatza Z/G, Plentzia-Bizkaia, E-48620 Basque Country (Spain); Glette, Tormod [Det Norske Veritas (DNV), Veritasveien 1, 1363 Hovik (Norway); Marigomez, Ionan [CBET Res Grp, R and D Centre for Experimental Marine Biology and Biotechnology (PIE), Univ Basque Country, Areatza Z/G, Plentzia-Bizkaia, E-48620 Basque Country (Spain)

    2012-06-01

    The biological effects of a coastal process water (PW) discharge on native and caged mussels (Mytilus edulis) were assessed. Chemical analyses of mussel tissues and semi permeable membrane devices, along with a suite of biomarkers of different levels of biological complexity were measured. These were lysosomal membrane stability in haemocytes and digestive cells; micronuclei formation in haemocytes; changes in cell-type composition in the digestive gland epithelium; integrity of digestive gland tissue; peroxisome proliferation; and oxidative stress. Additionally the Integrative Biological Response (IBR/n) index was calculated. This integrative biomarker approach distinguished mussels, both native and caged, exhibiting different stress conditions not identified from the contaminant exposure. Mussels exhibiting higher stress responses were found with increased proximity to the PW discharge outlet. However, the biological effects reported could not be entirely attributed to the PW discharge based on the chemicals measured, but were likely due to either other chemicals in the discharge that were not measured, the general impact of the processing plant and or other activities in the local vicinity. - Highlights: Black-Right-Pointing-Pointer Good agreement between biomarkers for the different mussel groups. Black-Right-Pointing-Pointer IBR/n was able to differentiate between exposed and reference mussels. Black-Right-Pointing-Pointer Mussels closest to the PW outlet were in poorest health. Black-Right-Pointing-Pointer Chemical concentrations were low or undetected in all SPMD and mussel samples. Black-Right-Pointing-Pointer Biomarker responses could not be entirely attributed to the PW discharge.

  13. Influence of Seeding Rate on Weed Density in Soybean Planting System for Southeastern Coastal Plains

    Directory of Open Access Journals (Sweden)

    Pawel Wiatrak

    2011-01-01

    Full Text Available Problem statement: Increasing seeding rates may help decrease weed pressure in soybean [Glycine max (L. Merr.] wide row spacing. Approach: The objective of this study was to evaluate the influence of five glyphosate-resistant soybean Maturity Groups (MG (IV, V, VI, VII and VIII and six seeding rates (68,000,136,000, 204,000, 272,000, 340,000 and 408,000 seeds ha-1 on weed density under dryland conditions on the Southeastern coastal plain in 2007-2009. Results: Weed decrease with increasing seeding rate varied over years. Weed density was generally lower at higher seeding rates for most MG soybeans at 30 and 60 DAP, except MG IV and VIII at 30 DAP in 2007 and MG VI at 30 DAP in 2008. At 60 DAP, soybean leaf area index (LAI and normalized difference vegetation index (NDVI were greater with lower weed density. Conclusion: Additionally, negative correlations were observed between weed density and plant LAI/NDVI for all MG in 2008 and MG IV through VI in 2009. These results suggest that increased seeding rates may help decrease weed pressure and improve soybean growth at early growth stages. However the response of weed pressure to seeding rate may vary over years and depend on MG soybean.

  14. Rapid evolution accelerates plant population spread in fragmented experimental landscapes.

    Science.gov (United States)

    Williams, Jennifer L; Kendall, Bruce E; Levine, Jonathan M

    2016-07-29

    Predicting the speed of biological invasions and native species migrations requires an understanding of the ecological and evolutionary dynamics of spreading populations. Theory predicts that evolution can accelerate species' spread velocity, but how landscape patchiness--an important control over traits under selection--influences this process is unknown. We manipulated the response to selection in populations of a model plant species spreading through replicated experimental landscapes of varying patchiness. After six generations of change, evolving populations spread 11% farther than nonevolving populations in continuously favorable landscapes and 200% farther in the most fragmented landscapes. The greater effect of evolution on spread in patchier landscapes was consistent with the evolution of dispersal and competitive ability. Accounting for evolutionary change may be critical when predicting the velocity of range expansions.

  15. Individualism in plant populations: using stochastic differential equations to model individual neighbourhood-dependent plant growth.

    Science.gov (United States)

    Lv, Qiming; Schneider, Manuel K; Pitchford, Jonathan W

    2008-08-01

    We study individual plant growth and size hierarchy formation in an experimental population of Arabidopsis thaliana, within an integrated analysis that explicitly accounts for size-dependent growth, size- and space-dependent competition, and environmental stochasticity. It is shown that a Gompertz-type stochastic differential equation (SDE) model, involving asymmetric competition kernels and a stochastic term which decreases with the logarithm of plant weight, efficiently describes individual plant growth, competition, and variability in the studied population. The model is evaluated within a Bayesian framework and compared to its deterministic counterpart, and to several simplified stochastic models, using distributional validation. We show that stochasticity is an important determinant of size hierarchy and that SDE models outperform the deterministic model if and only if structural components of competition (asymmetry; size- and space-dependence) are accounted for. Implications of these results are discussed in the context of plant ecology and in more general modelling situations.

  16. Human Stressors Are Driving Coastal Benthic Long-Lived Sessile Fan Mussel Pinna nobilis Population Structure More than Environmental Stressors.

    OpenAIRE

    Salud Deudero; Maite Vázquez-Luis; Elvira Álvarez

    2015-01-01

    Coastal degradation and habitat disruption are severely compromising sessile marine species. The fan shell Pinna nobilis is an endemic, vulnerable species and the largest bivalve in the Mediterranean basin. In spite of species legal protection, fan shell populations are declining. Models analyzed the contributions of environmental (mean depth, wave height, maximum wave height, period of waves with high energy and mean direction of wave source) versus human-derived stressors (anchoring, protec...

  17. Rhizobium halophytocola sp. nov., isolated from the root of a coastal dune plant.

    Science.gov (United States)

    Bibi, Fehmida; Chung, Eu Jin; Khan, Ajmal; Jeon, Che Ok; Chung, Young Ryun

    2012-08-01

    During a study of endophytic bacteria from coastal dune plants, a bacterial strain, designated YC6881(T), was isolated from the root of Rosa rugosa collected from the coastal dune areas of Namhae Island, Korea. The bacterium was found to be Gram-staining-negative, motile, halophilic and heterotrophic with a single polar flagellum. Strain YC6881(T) grew at temperatures of 4-37 °C (optimum, 28-32 °C), at pH 6.0-9.0 (optimum, pH 7.0-8.0), and at NaCl concentrations in the range of 0-7.5% (w/v) (optimum, 4-5% NaCl). Strain YC6881(T) was catalase- and oxidase-positive and negative for nitrate reduction. According to phylogenetic analysis using 16S rRNA gene sequences, strain YC6881(T) belonged to the genus Rhizobium and showed the highest 16S rRNA gene sequence similarity of 96.9% to Rhizobium rosettiformans, followed by Rhizobium borbori (96.3%), Rhizobium radiobacter (96.1%), Rhizobium daejeonense (95.9%), Rhizobium larrymoorei (95.6%) and Rhizobium giardinii (95.4%). Phylogenetic analysis of strain YC6881(T) by recA, atpD, glnII and 16S-23S intergenic spacer (IGS) sequences all confirmed the phylogenetic arrangements obtained by using 16S rRNA gene sequences. Cross-nodulation tests showed that strain YC6881(T) was a symbiotic bacterium that nodulated Vigna unguiculata and Pisum sativum. The major components of the cellular fatty acids were C(18:1)ω7c (53.7%), C(19:0) cyclo ω8c (12.6%) and C(12:0) (8.1%). The DNA G+C content was 52.8 mol%. Phenotypic and physiological tests with respect to carbon source utilization, antibiotic resistance, growth conditions, phylogenetic analyses of housekeeping genes recA, atpD and glnII, and fatty acid composition could be used to discriminate strain YC6881(T) from other species of the genus Rhizobium in the same sublineage. Based on the results obtained in this study, strain YC6881(T) is considered to represent a novel species of the genus Rhizobium, for which the name Rhizobium halophytocola sp. nov. is proposed. The type

  18. Potential impacts of sea level rise on native plant communities and associated cultural sites in coastal areas of the main Hawaiian Islands

    Science.gov (United States)

    Jacobi, James D.; Warshauer, Frederick R.

    2017-01-01

    Hawaiian coastal vegetation is comprised of plant species that are adapted to growing in extremely harsh conditions (salt spray, wave wash, wind, and substrates with limited nutrients) found in this habitat zone. Prior to human colonization of Hawai‘i coastal vegetation extended as a continuous ring around each of the islands, broken only by stretches of recent lava flows or unstable cliff faces. However, since humans arrived in Hawai‘i many areas that originally supported native coastal plant communities have been highly altered or the native vegetation totally removed for agriculture, housing, or resort development, destroyed by fire, displaced by invasive plants, eaten by introduced mammals, or damaged by recreational use. This study was focused on identifying sites that still retain relatively intact and highly diverse native coastal plant communities throughout the main Hawaiian Islands that may be further impacted by projected sea level rise. Approximately 40 percent of Hawai‘i’s coastlines were found to still contain high quality native coastal plant communities. Most of these sites were located in areas where the coastal vegetation can still migrate inshore in response to rising sea level and associated inundation by waves. However, six sites with high-quality native coastal vegetation were found on low-lying offshore islets that will be totally inundated with a one meter increase in sea level and thirty sites were found to have some type of fixed barrier, such as a paved road or structure, which would restrict the plants from colonizing the adjacent inland areas. Many of these sites also have other cultural resources that are fixed in place and will definitely be impacted by rising sea level. The results of this study can help refine our understanding of Hawai‘i’s remaining native coastal vegetation and aid with the development of management and restoration strategies to ensure the long-term survival of these unique plant communities.

  19. Coastal Wetland Dynamics and Wildlife Populations: Modeling the Effects of Sea Level Rise and Landscape Change

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Assess the potential impacts of sea level rise on coastal ecosystems and related wildlife resources. Develop a Bayesian Belief network that projects the impact of...

  20. Population structure, length-weight and length-length relationships of six populations of the Bartail Flathead Platycephalus indicus (Scorpaeniformes: Platycephalidae along the Persian Gulf coastal waters

    Directory of Open Access Journals (Sweden)

    Hamed Mousavi-Sabet

    2015-01-01

    Full Text Available The size frequency distribution for age structure, length-weight (LWR and length-length (LLR relationships of six populations of Platycephalus indicus along the Persian Gulf coastal waters in Iran are reported.  A total of 180 P. indicus specimens were studied from six localities including Charak, Bandar-Abbas, Shif, Motaf, Khur-Musa and Bahrekan.  The maximum standard length recorded for the studied populations ranged between 300 to 510 mm and the b values of the length-weight relationships ranged between 3.0 and 3.2.  The obtained results indicated isometric growth patterns for all these populations with the exception of the Bahrekan population which showed a positive allometric growth pattern.  The LLR between the total and standard lengths in these populations were found to be highly significant.  The results would be useful for further studies on population assessment and sustainable conservation of the fish along the Persian Gulf coastal waters.

  1. Population growth, trophic level, and reproductive biology of two congeneric archer fishes (Toxotes chatareus, Hamilton 1822 and Toxotes jaculatrix, Pallas 1767) inhabiting Malaysian coastal waters

    National Research Council Canada - National Science Library

    Simon, K D; Bakar, Y; Samat, A; Zaidi, C C; Aziz, A; Mazlan, A G

    2009-01-01

    Population growth, trophic level, and some aspects of reproductive biology of two congeneric archer fish species, Toxotes chatareus and Toxotes jaculatrix, collected from Johor coastal waters, Malaysia, were studied...

  2. Survival, nesting success, and habitat selection in wild turkey populations in the Upper Coastal Plain of South Carolina.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, William F.

    2007-07-01

    ABSRACT. We compared survival rates between hunted and unhunted wild turkey (Meleagris gallopavo) gobblers in the upper coastal plain of South Carolina to assess the impact of spring gobbler-only hunts on populations. Gobblers were captured on the Savannah River Site (SRS), which contains long-established populations that have never been hunted, and on Crackerneck Wildlife Management Area and Ecological reserve (CWMA), which has held spring hunts since 1983. In January-March of 1998-2000, 46 gobblers were captured on SRS and 19 were captured no CWMA. Each turkey was fitted with a backpack radio transmitter and monitored 3 times per week.

  3. Bulk elastic moduli and solute potentials in leaves of freshwater, coastal and marine hydrophytes. Are marine plants more rigid?

    Science.gov (United States)

    Touchette, Brant W; Marcus, Sarah E; Adams, Emily C

    2014-03-28

    Bulk modulus of elasticity (ɛ), depicting the flexibility of plant tissues, is recognized as an important component in maintaining internal water balance. Elevated ɛ and comparatively low osmotic potential (Ψπ) may work in concert to effectively maintain vital cellular water content. This concept, termed the 'cell water conservation hypothesis', may foster tolerance for lower soil-water potentials in plants while minimizing cell dehydration and shrinkage. Therefore, the accumulation of solutes in marine plants, causing decreases in Ψπ, play an important role in plant-water relations and likely works with higher ɛ to achieve favourable cell volumes. While it is generally held that plants residing in marine systems have higher leaf tissue ɛ, to our knowledge no study has specifically addressed this notion in aquatic and wetland plants residing in marine and freshwater systems. Therefore, we compared ɛ and Ψπ in leaf tissues of 38 freshwater, coastal and marine plant species using data collected in our laboratory, with additional values from the literature. Overall, 8 of the 10 highest ɛ values were observed in marine plants, and 20 of the lowest 25 ɛ values were recorded in freshwater plants. As expected, marine plants often had lower Ψπ, wherein the majority of marine plants were below -1.0 MPa and the majority of freshwater plants were above -1.0 MPa. While there were no differences among habitat type and symplastic water content (θsym), we did observe higher θsym in shrubs when compared with graminoids, and believe that the comparatively low θsym observed in aquatic grasses may be attributed to their tendency to develop aerenchyma that hold apoplastic water. These results, with few exceptions, support the premise that leaf tissues of plants acclimated to marine environments tend to have higher ɛ and lower Ψπ, and agree with the general tenets of the cell water conservation hypothesis.

  4. Planting geometry and plant population affect dryland maize grain yield and harvest index

    Science.gov (United States)

    Water for dryland grain production in the Texas panhandle is limited. Agronomic practices such as reduction in plant population or change in sowing time may help increase maize (Zea mays L.) yield potential. Tiller formation under dryland conditions leads to more vegetative growth and reduced yield....

  5. Leaf n-alkanes as characters differentiating coastal and continental Juniperus deltoides populations from the Balkan Peninsula.

    Science.gov (United States)

    Rajčević, Nemanja; Janaćković, Pedja; Dodoš, Tanja; Tešević, Vele; Bojović, Srdjan; Marin, Petar D

    2014-07-01

    The composition of the cuticular n-alkanes isolated from the leaves of nine populations of Juniperus deltoides R.P.Adams from continental and coastal areas of the Balkan Peninsula was characterized by GC-FID and GC/MS analyses. In the leaf waxes, 14 n-alkane homologues with chain-lengths ranging from C22 to C35 were identified. n-Tritriacontane (C33 ) was dominant in the waxes of all populations, but variations between the populations in the contents of all n-alkanes were observed. Several statistical methods (ANOVA, principal component, discriminant, and cluster analyses) were used to investigate the diversity and variability of the cuticular-leaf-n-alkane patterns of the nine J. deltoides populations. This is the first report on the n-alkane composition for this species. The multivariate statistical analyses evidenced a high correlation of the leaf-n-alkane pattern with the geographical distribution of the investigated samples, differentiating the coastal from the continental populations of this taxon.

  6. Effects in Plant Populations Resulting from Chronic Radiation Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Geras' kin, Stanislav A.; Volkova, Polina Yu.; Vasiliyev, Denis V.; Dikareva, Nina S.; Oudalova, Alla A. [Russian Institute of Agricultural Radiology and Agroecology, 249032, Obninsk (Russian Federation)

    2014-07-01

    Human industrial activities have left behind a legacy of ecosystems strongly impacted by a wide range of contaminants, including radionuclides. Phyto-toxic effects of acute impact are well known, but the consequences of long-term chronic exposure to low pollutant concentrations is neither well understood nor adequately included in risk assessments. To understand effects of real-world contaminant exposure properly we must pay attention to what is actually going on in the field. However, for many wildlife groups and endpoints, there are no, or very few, studies that link accumulation, chronic exposure and biological effects in natural settings. To fill the gaps, results of field studies carried out on different plant species (winter rye and wheat, spring barley, oats, Scots pine, wild vetch, crested hair-grass) in various radioecological situations (nuclear weapon testing, the Chernobyl accident, uranium and radium processing) to investigate effects of long-term chronic exposure to radionuclides are discussed. Because each impacted site developed in its own way due to a unique history of events, the experience from one case study is rarely directly applicable to another situation. In spite of high heterogeneity in response, we have detected several general patterns. Plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic alterations and genetic diversity. Accumulation of cellular alterations may afterward influence biological parameters important for populations such as health and reproduction. Presented data provide evidence that in plant populations inhabiting heavily contaminated territories cytogenetic damage were accompanied by decrease in reproductive ability. In less contaminated sites, because of the scarcity of data available, it is impossible to establish exactly the relationship between cytogenetic effects and reproductive ability. Radioactive contamination of the plants

  7. Effects of Posidonia oceanica beach-cast on germination, growth and nutrient uptake of coastal dune plants.

    Directory of Open Access Journals (Sweden)

    Silvia Del Vecchio

    Full Text Available Seagrass meadows play an important role in marine ecosystems. A part of seagrass production is also exported to adjacent coastal terrestrial systems, possibly influencing their functioning. In this work we experimentally analyzed the effect of Posidonia oceanica beach-cast on plant germination, growth, and nutrient uptake of two plant species (Cakile maritima and Elymus farctus that grow on upper beaches and fore dunes along the Mediterranean coasts. We compared plants growing in simple sand (control with those growing in a substrate enriched with P. oceanica wrack (treatment in laboratory. P. oceanica wrack doubled the N substrate pool and kept the substrate humid. Plants growing in the treated substrate grew faster, were twice as large as those growing in the control substrate, while tissues were enriched in N and P (Cakile by the 1.3 fold in N and 2.5 fold in P; Elymus by 1.5 fold in N and 2 fold in P. Our results suggest a positive effect of seagrass litter for the enhancing of dune species, highlighting its role for the conservation of coastal dune ecosystems.

  8. Effects of Posidonia oceanica beach-cast on germination, growth and nutrient uptake of coastal dune plants.

    Science.gov (United States)

    Del Vecchio, Silvia; Marbà, Núria; Acosta, Alicia; Vignolo, Clara; Traveset, Anna

    2013-01-01

    Seagrass meadows play an important role in marine ecosystems. A part of seagrass production is also exported to adjacent coastal terrestrial systems, possibly influencing their functioning. In this work we experimentally analyzed the effect of Posidonia oceanica beach-cast on plant germination, growth, and nutrient uptake of two plant species (Cakile maritima and Elymus farctus) that grow on upper beaches and fore dunes along the Mediterranean coasts. We compared plants growing in simple sand (control) with those growing in a substrate enriched with P. oceanica wrack (treatment) in laboratory. P. oceanica wrack doubled the N substrate pool and kept the substrate humid. Plants growing in the treated substrate grew faster, were twice as large as those growing in the control substrate, while tissues were enriched in N and P (Cakile by the 1.3 fold in N and 2.5 fold in P; Elymus by 1.5 fold in N and 2 fold in P). Our results suggest a positive effect of seagrass litter for the enhancing of dune species, highlighting its role for the conservation of coastal dune ecosystems.

  9. Bulinus globosus (Planorbidae; Gastropoda) populations in the Lake Victoria basin and coastal Kenya show extreme nuclear genetic differentiation.

    Science.gov (United States)

    Nyakaana, Silvester; Stothard, J Russell; Nalugwa, Allen; Webster, Bonnie L; Lange, Charles N; Jørgensen, Aslak; Rollinson, David; Kristensen, Thomas K

    2013-11-01

    Bulinus globosus, a key intermediate host for Schistosoma haematobium that causes urinary schistosomiasis, is a hermaphroditic freshwater Planorbid snail species that inhabits patchy and transient water bodies prone to large seasonal variations in water availability. Although capable of self-fertilizing, this species has been reported to be preferentially out crossing. In this study, we characterized the population genetic structure of 19 B. globosus populations sampled across the Lake Victoria basin and coastal Kenya using four polymorphic microsatellite loci. Population genetic structure was characterized and quantified using FST statistics and Bayesian clustering algorithms. The four loci used in this study contained sufficient statistical power to detect low levels of population genetic differentiation and were highly polymorphic with the number of alleles per locus across populations ranging from 16 to 22. Average observed and expected heterozygosities across loci in each population ranged from 0.13 to 0.69 and from 0.39 to 0.79, respectively. Twenty-five of the seventy-six possible population-locus comparisons significantly deviated from Hardy-Weinberg equilibrium proportions after Bonferroni corrections, mostly due to the deficiency of heterozygotes. Significant genetic differentiation was observed between populations and Bayesian inferences identified 15 genetic clusters. The excess homozygosity, significant inbreeding and population genetic differentiation observed in B. globosus populations are likely to be due to the habitat patchiness, mating system and the proneness to cyclic extinction and recolonization in transient habitats.

  10. Morphometric comparisons of plant-mimetic juvenile fish associated with plant debris observed in the coastal subtropical waters around Kuchierabu-jima Island, southern Japan

    Science.gov (United States)

    2016-01-01

    The general morphological shape of plant-resembling fish and plant parts were compared using a geometric morphometrics approach. Three plant-mimetic fish species, Lobotes surinamensis (Lobotidae), Platax orbicularis (Ephippidae) and Canthidermis maculata (Balistidae), were compared during their early developmental stages with accompanying plant debris (i.e., leaves of several taxa) in the coastal subtropical waters around Kuchierabu-jima Island, closely facing the Kuroshio Current. The degree of similarity shared between the plant parts and co-occurring fish species was quantified, however fish remained morphologically distinct from their plant models. Such similarities were corroborated by analysis of covariance and linear discriminant analysis, in which relative body areas of fish were strongly related to plant models. Our results strengthen the paradigm that morphological clues can lead to ecological evidence to allow predictions of behavioural and habitat choice by mimetic fish, according to the degree of similarity shared with their respective models. The resemblance to plant parts detected in the three fish species may provide fitness advantages via convergent evolutionary effects. PMID:27547571

  11. Morphometric comparisons of plant-mimetic juvenile fish associated with plant debris observed in the coastal subtropical waters around Kuchierabu-jima Island, southern Japan.

    Science.gov (United States)

    de Queiroz, Alexya Cunha; Sakai, Yoichi; Vallinoto, Marcelo; Barros, Breno

    2016-01-01

    The general morphological shape of plant-resembling fish and plant parts were compared using a geometric morphometrics approach. Three plant-mimetic fish species, Lobotes surinamensis (Lobotidae), Platax orbicularis (Ephippidae) and Canthidermis maculata (Balistidae), were compared during their early developmental stages with accompanying plant debris (i.e., leaves of several taxa) in the coastal subtropical waters around Kuchierabu-jima Island, closely facing the Kuroshio Current. The degree of similarity shared between the plant parts and co-occurring fish species was quantified, however fish remained morphologically distinct from their plant models. Such similarities were corroborated by analysis of covariance and linear discriminant analysis, in which relative body areas of fish were strongly related to plant models. Our results strengthen the paradigm that morphological clues can lead to ecological evidence to allow predictions of behavioural and habitat choice by mimetic fish, according to the degree of similarity shared with their respective models. The resemblance to plant parts detected in the three fish species may provide fitness advantages via convergent evolutionary effects.

  12. 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.

  13. Population and community ecology of the rare plant amsinckia grandiflora

    Energy Technology Data Exchange (ETDEWEB)

    Carlsen, T.M.

    1996-11-01

    Research was conducted between the fall of 1992 and the spring on the population and community ecology of the rare annual plant, Amsinckia glandiflora (Gray) Kleeb. ex Greene (Boraginaceae). The research goal was to investigate the causes of the species rarity, data useful to restorative efforts. The work focused on the examination of competitive suppression by exotic annual grasses; comparisons with common, weedy congener; and the role of litter cover and seed germination and seedling establishment. Annual exotic grasses reduced A. grandiflora reproductive output to a greater extent than did the native perennial bunch grass.

  14. Responses of dune plant communities to continental uplift from a major earthquake: sudden releases from coastal squeeze.

    Directory of Open Access Journals (Sweden)

    Iván F Rodil

    Full Text Available Vegetated dunes are recognized as important natural barriers that shelter inland ecosystems and coastlines suffering daily erosive impacts of the sea and extreme events, such as tsunamis. However, societal responses to erosion and shoreline retreat often result in man-made coastal defence structures that cover part of the intertidal and upper shore zones causing coastal squeeze and habitat loss, especially for upper shore biota, such as dune plants. Coseismic uplift of up to 2.0 m on the Peninsula de Arauco (South central Chile, ca. 37.5º S caused by the 2010 Maule earthquake drastically modified the coastal landscape, including major increases in the width of uplifted beaches and the immediate conversion of mid to low sandy intertidal habitat to supralittoral sandy habitat above the reach of average tides and waves. To investigate the early stage responses in species richness, cover and across-shore distribution of the hitherto absent dune plants, we surveyed two formerly intertidal armoured sites and a nearby intertidal unarmoured site on a sandy beach located on the uplifted coast of Llico (Peninsula de Arauco over two years. Almost 2 years after the 2010 earthquake, dune plants began to recruit, then rapidly grew and produced dune hummocks in the new upper beach habitats created by uplift at the three sites. Initial vegetation responses were very similar among sites. However, over the course of the study, the emerging vegetated dunes of the armoured sites suffered a slowdown in the development of the spatial distribution process, and remained impoverished in species richness and cover compared to the unarmoured site. Our results suggest that when released from the effects of coastal squeeze, vegetated dunes can recover without restoration actions. However, subsequent human activities and management of newly created beach and dune habitats can significantly alter the trajectory of vegetated dune development. Management that integrates the

  15. Responses of dune plant communities to continental uplift from a major earthquake: sudden releases from coastal squeeze.

    Science.gov (United States)

    Rodil, Iván F; Jaramillo, Eduardo; Hubbard, David M; Dugan, Jenifer E; Melnick, Daniel; Velasquez, Carlos

    2015-01-01

    Vegetated dunes are recognized as important natural barriers that shelter inland ecosystems and coastlines suffering daily erosive impacts of the sea and extreme events, such as tsunamis. However, societal responses to erosion and shoreline retreat often result in man-made coastal defence structures that cover part of the intertidal and upper shore zones causing coastal squeeze and habitat loss, especially for upper shore biota, such as dune plants. Coseismic uplift of up to 2.0 m on the Peninsula de Arauco (South central Chile, ca. 37.5º S) caused by the 2010 Maule earthquake drastically modified the coastal landscape, including major increases in the width of uplifted beaches and the immediate conversion of mid to low sandy intertidal habitat to supralittoral sandy habitat above the reach of average tides and waves. To investigate the early stage responses in species richness, cover and across-shore distribution of the hitherto absent dune plants, we surveyed two formerly intertidal armoured sites and a nearby intertidal unarmoured site on a sandy beach located on the uplifted coast of Llico (Peninsula de Arauco) over two years. Almost 2 years after the 2010 earthquake, dune plants began to recruit, then rapidly grew and produced dune hummocks in the new upper beach habitats created by uplift at the three sites. Initial vegetation responses were very similar among sites. However, over the course of the study, the emerging vegetated dunes of the armoured sites suffered a slowdown in the development of the spatial distribution process, and remained impoverished in species richness and cover compared to the unarmoured site. Our results suggest that when released from the effects of coastal squeeze, vegetated dunes can recover without restoration actions. However, subsequent human activities and management of newly created beach and dune habitats can significantly alter the trajectory of vegetated dune development. Management that integrates the effects of natural

  16. PRIAMO project: a feasibility study on Sicilian sites for sea power plants in coastal waters

    Science.gov (United States)

    Ribotti, A.; Borghini, M.; Cucco, A.; De Domenico, E.; Dibenedetto, V.; Fazioli, L.; Genovese, L.; Iaria, G.; Olita, A.; Raffa, F.; Schroeder, K.; Sorgente, R.; Spanò, N.

    2012-04-01

    The increasing demand for renewable energy sources has recently favoured the exploitation of wind energy and photovoltaic, with strong repercussions on the landscape due to the visual impact of wind turbines and of the photovoltaic panels. A policy protecting the landscape suggests to focus on innovative solutions that enable the use of renewable energy and a low visual impact. This can be done with extensive offshore diving equipment installed in the sea, formed by turbines that use ocean currents to produce electric energy. The accommodation at sea, as well as offering greater availability of sites, has the advantage of giving a better and relatively constant resource with maximum efficiency and productivity. The international scenario suggests the need to identify sites potentially suitable and safe for energy use, placed at a distance from the coast at depths with bathymetric characteristics that make the power plant installation safe and technologically and economically feasible. In this context, the project PRIAMO (Planning, Research and Innovation in a Oriented Marine Environment), funded by the European Commission through the Sicilian Regional Operational Programme (POR), aims to verify the potential suitability of two Sicilian coastal sites, i.e. the Strait of Messina and a stretch of coast near Capo Granitola (Strait of Sicily). The work is realised with a view to the exploitation of marine currents that will be studied through the use of existing or new numerical models from the open sea to the coastal scale, then evaluating its cost-effectiveness in collaboration with Atlantis Resources Corp. Pte. Ltd (UK), European manufacturer of underwater turbines. An environmental study is done through monitoring and remediation techniques to assess the potential size of the foundation structure: sedimentological and morpho-bathymetric characteristics of the bottom, depth, steepness of the seabed, benthic biocoenoses, and load-bearing capacity of the area affected

  17. Seasonal timing of first rain storms affects rare plant population dynamics

    Science.gov (United States)

    Levine, J.M.; McEachern, A.K.; Cowan, C.

    2011-01-01

    A major challenge in forecasting the ecological consequences of climate change is understanding the relative importance of changes to mean conditions vs. changes to discrete climatic events, such as storms, frosts, or droughts. Here we show that the first major storm of the growing season strongly influences the population dynamics of three rare and endangered annual plant species in a coastal California (USA) ecosystem. In a field experiment we used moisture barriers and water addition to manipulate the timing and temperature associated with first major rains of the season. The three focal species showed two- to fivefold variation in per capita population growth rates between the different storm treatments, comparable to variation found in a prior experiment imposing eightfold differences in season-long precipitation. Variation in germination was a major demographic driver of how two of three species responded to the first rains. For one of these species, the timing of the storm was the most critical determinant of its germination, while the other showed enhanced germination with colder storm temperatures. The role of temperature was further supported by laboratory trials showing enhanced germination in cooler treatments. Our work suggests that, because of species-specific cues for demographic transitions such as germination, changes to discrete climate events may be as, if not more, important than changes to season-long variables.

  18. Radioactivity and element concentrations in the coastal bottom sediments in the vicinity of Yonggwang nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Woong; Eun, Go-Yeo-Na; Cha, Jong Mun; Kim, In S.; Kim, Kyeong Hee; Kim, Ju Yong [Kwangju Institute if Science and Technology, Kwangju (Korea, Republic of); Hong, Kwang Phyo; Kim, Ki Nam [Korea Electric Power Corporation, Seoul (Korea, Republic of)

    1999-07-01

    In order to evaluate the influence of nuclear power plant operation on nearby coast, the radioactivity and element concentrations in coastal bottom sediments were investigated. The coastal bottom sediments were collected at 179 sampling stations around the Yonggwang nuclear power plant and analyzed for radioactivity by HP-Ge {upsilon}-spectrophotometer and Low Background {alpha}/{beta} Counter, and heavy metals by ICP-AES and AAS. In addition, particle size distribution in a number of sediments were measured and compared with other analytical results. According to the result of grain size distribution, most sediments are classified as silt loam with 23 percent sand, 65 percent silt and 12 percent clay contents. The radioactivities of most nuclides except {sup 137}Cs are below the limit of detection, and artificial nuclide of {sup 137} Cs may derived from past nuclear weapon tests. The heavy metal concentrations are within the normal range of marine sediments and the anomaly caused by the operation of nuclear power plant has not been monitored. (author). 7 refs., 2 tabs., 3 figs.

  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. Effects of host-plant population size and plant sex on a specialist leaf-miner

    DEFF Research Database (Denmark)

    Bañuelos, María-José; Kollmann, Johannes Christian

    2011-01-01

    Animal population density has been related to resource patch size through various hypotheses such as those derived from island biogeography and resource concentration theory. This theoretical framework can be also applied to planteherbivore interactions, and it can be modified by the sex of the h......Animal population density has been related to resource patch size through various hypotheses such as those derived from island biogeography and resource concentration theory. This theoretical framework can be also applied to planteherbivore interactions, and it can be modified by the sex...... of the host-plant, and density-dependent relationships. Leaf-miners are specialised herbivores that leave distinct traces on infested leaves in the form of egg scars, mines, signs of predation and emergence holes. This allows the life cycle of the insect to be reconstructed and the success at the different...... stages to be estimated. The main stages of the leaf-miner Phytomyza ilicis were recorded in eleven populations of the evergreen host Ilex aquifolium in Denmark. Survival rates were calculated and related to population size, sex of the host plant, and egg and mine densities. Host population size...

  1. Population dynamics in central and edge populations of a narrowly endemic plant.

    Science.gov (United States)

    Aikens, Melissa L; Roach, Deborah A

    2014-07-01

    Species' range limits can be caused by environmental gradients, and in such cases, abundance is thought to be highest in the center of a species range and decline towards the edge (the abundant-center model). Although in theory decreased abundance is caused by a decline in performance at the edge, it has been shown that performance and abundance are not necessarily related. Few studies have compared abundance and performance in center and edge populations of endemic species, whose ranges may be restricted by the availability of specialized habitat rather than environmental gradients across their range. Additionally, range-wide studies that examine both northern and southern edge populations are rare. We used Roan Mountain rattlesnake-root (Prenanthes roanensis), a perennial plant endemic to the Southern Appalachians (USA), to compare abundance and performance between central populations and populations at the northern and southern edges of the range. To account for multiple fitness components across the life cycle, we measured performance of edge populations as vital-rate contributions to population growth rate compared to the center. Abundance did not decline at the range edge, but some vital-rate contributions were lower in edge populations compared to central populations. However, each edge population differed in which vital-rate contributions were lower compared to the center. Our results do not support the abundant-center model, and it appears that local factors are important in structuring the range of this endemic species. It is important to recognize that when implementing conservation or management plans, populations in close proximity may have substantial variation in demographic rates due to differences in the local environment.

  2. Seasonal occurrence and population structure of the broadnose sevengill shark Notorynchus cepedianus in coastal habitats of south-east Tasmania.

    Science.gov (United States)

    Barnett, A; Stevens, J D; Frusher, S D; Semmens, J M

    2010-11-01

    Research longline sampling was conducted seasonally from December 2006 to February 2009 to investigate the occurrence and population structure of the broadnose sevengill shark Notorynchus cepedianus in coastal areas of south-east Tasmania. Notorynchus cepedianus showed a consistent temporal trend in seasonal occurrence in Norfolk Bay characterized by high abundances in summer to near absence in winter. This pattern was less pronounced in the Derwent Estuary, where fish were still caught during winter. The absence of smaller total length (L(T) ) classes (<80 cm) from the catches suggests that N. cepedianus are not using these coastal habitats as nursery areas. Of the 457 individuals tagged, 68 (15%) were recaptured. Time at liberty ranged from 6 days to almost 4 years and all but one of the recaptures were caught in its original tagging location, suggesting site fidelity. The large number of N. cepedianus in these coastal systems over summer indicates that these areas are important habitats for this species and that N. cepedianus may have a significant influence on community dynamics through both direct and indirect predator-prey interactions.

  3. Population structure of a vector-borne plant parasite.

    Science.gov (United States)

    Yule, Kelsey M; Koop, Jennifer A H; Alexandre, Nicolas M; Johnston, Lauren R; Whiteman, Noah K

    2016-07-01

    Parasites are among the most diverse groups of life on Earth, yet complex natural histories often preclude studies of their speciation processes. The biology of parasitic plants facilitates in situ collection of data on both genetic structure and the mechanisms responsible for that structure. Here, we studied the role of mating, dispersal and establishment in host race formation of a parasitic plant. We investigated the population genetics of a vector-borne desert mistletoe (Phoradendron californicum) across two legume host tree species (Senegalia greggii and Prosopis velutina) in the Sonoran desert using microsatellites. Consistent with host race formation, we found strong host-associated genetic structure in sympatry, little genetic variation due to geographic site and weak isolation by distance. We hypothesize that genetic differentiation results from differences in the timing of mistletoe flowering by host species, as we found initial flowering date of individual mistletoes correlated with genetic ancestry. Hybrids with intermediate ancestry were detected genetically. Individuals likely resulting from recent, successful establishment events following dispersal between the host species were detected at frequencies similar to hybrids between host races. Therefore, barriers to gene flow between the host races may have been stronger at mating than at dispersal. We also found higher inbreeding and within-host individual relatedness values for mistletoes on the more rare and isolated host species (S. greggii). Our study spanned spatial scales to address how interactions with both vectors and hosts influence parasitic plant structure with implications for parasite virulence evolution and speciation.

  4. Dominance of Lysobacter sp. in the rhizosphere of two coastal sand dune plant species, Calystegia soldanella and Elymus mollis.

    Science.gov (United States)

    Lee, Myoung Sook; Do, Jin Ok; Park, Myung Soo; Jung, Sera; Lee, Kang Hyun; Bae, Kyung Sook; Park, Seong Joo; Kim, Seung Bum

    2006-07-01

    Bacterial diversity in the rhizosphere of beach morning glory (Calystegia soldanella) and wild rye (Elymus mollis), two of the major plant species inhabiting the coastal sane dune in Tae-An, Korea, was studied by the analysis of community 16S rRNA gene clones. The amplified rDNA restriction analysis (ARDRA) of the clones using HaeIII exhibited significant differences in the community composition between the two plant species as well as regional differences, but also identified a specific ARDRA pattern that was most common among the clones regardless of plant species. Subsequent sequence analysis indicated that the pattern was that of Lysobacter spp., which is a member of the family Xanthomonadaceae, class Gamma proteobacteria. The Lysobacter clones comprised 50.6% of the clones derived from C. soldanella and 62.5% of those from E. mollis. Other minor patterns included those of Pseudomonas spp., species of Rhizobium, Chryseobacterium spp. and Pantoea spp. among C. soldanella clones, and Pseudomonas sp. and Aeromonas hydrophila among E. mollis clones. It is not yet clear what kind of roles Lysobacter plays in association with sand dune plants, but its universal presence in the rhizosphere, together with the potential of this taxon for antagonistic activity against plant pathogens, suggests that Lysobacter might form a symbiotic relationship with its host plants.

  5. MAPPING OF MARINE PLANTS DISTRIBUTIONS IN NORTH COASTAL AREA OF SUMBAWA REGENCY USING ALOS/AVNIR-2 DATA

    Directory of Open Access Journals (Sweden)

    S.P. Astuti

    2012-11-01

    Full Text Available The exploitation and management of water resource be more beneficial, if preceded by study which includes biological aspect besides physics and chemical parameter of waters. The biological aspects study can be conducted by monitoring the change of ecosystem (biomonitoring. One of study that entangles biomonitoring is the research concerning change of marine plants. Marine plants consists of seagrasses and seaweeds. Using ALOS/AVNIR-2 data in this research because it has 3 visible bands (blue, green, and red with 10 meter spacial resolutions can penetrate into water column. Aims of research were (1 to know combinations of bands in ALOS/AVNIR-2 data was better in Lyzenga method applying to mapping marine plants, (2 to know the general species of marine plants in north coastal area of Sumbawa regency. Lyzenga method was used in image processing process to know the combination of bands which have better for mapping marine plants. Preliminary steps of image processing were image cropping, geometric correction and radiometric correction. Water column effect was reduced by Lyzenga algorithm. Six classes were determined by multispectral classification process i.e. seagrass, seaweeds, coral, hard sand and rubble of coral, and substratum. Field surveys has done to identify the accuracy level. The accuracy method by Lillesand and Kiefer (1990 was used in this research.The result of accuracy test show for image band 1 and band 2 combination given better visual object benthic than another combinations of bands, with overall accuracy was 86.67%. Seagrass found in north coastal area of Sumbawa regency consist of four species there were Cymodocea rotundata, Enhalus acoroides, Syringodium isoetifolium, and Halophila ovalis with width equal to 835.37 ha, while seaweeds were found equal to five species there were Euchema cottoni, Euchema cottoni ssp sakul, Halimeda sp, Padina sp, and Sargasum duplicatum with width equal to 269,16 ha.

  6. Responses to invasion and invader removal differ between native and exotic plant groups in a coastal dune.

    Science.gov (United States)

    Magnoli, Susan M; Kleinhesselink, Andrew R; Cushman, J Hall

    2013-12-01

    The spread of exotic, invasive species is a global phenomenon that is recognized as a major source of environmental change. Although many studies have addressed the effects of exotic plants on the communities they invade, few have quantified the effects of invader removal on plant communities, or considered the degree to which different plant groups vary in response to invasion and invader removal. We evaluated the effects of an exotic succulent, iceplant (Carpobrotus edulis), on a coastal dune plant community in northern California, as well as the community responses to its removal. To assess possible mechanisms by which iceplant affects other plants, we also evaluated its above- and belowground influences on the germination and growth of a dominant exotic annual grass, Bromus diandrus. We found that iceplant invasion was associated with reduced native plant cover as well as increased cover and density of some exotic plants-especially exotic annual grasses. However, iceplant removal did not necessarily lead to a reversal of these effects: removal increased the cover and density of both native and exotic species. We also found that B. diandrus grown in iceplant patches, or in soil where iceplant had been removed, had poorer germination and growth than B. diandrus grown in soil not influenced by iceplant. This suggests that the influence of iceplant on this dune plant community occurs, at least in part, due to belowground effects, and that these effects remain after iceplant has been removed. Our study demonstrates the importance of considering how exotic invasive plants affect not only native species, but also co-occurring exotic taxa. It also shows that combining observational studies with removal experiments can lead to important insights into the influence of invaders and the mechanisms of their effects.

  7. The role of coastal plant communities for climate change mitigation and adaptation

    Science.gov (United States)

    Duarte, Carlos M.; Losada, Iñigo J.; Hendriks, Iris E.; Mazarrasa, Inés; Marbà, Núria

    2013-11-01

    Marine vegetated habitats (seagrasses, salt-marshes, macroalgae and mangroves) occupy 0.2% of the ocean surface, but contribute 50% of carbon burial in marine sediments. Their canopies dissipate wave energy and high burial rates raise the seafloor, buffering the impacts of rising sea level and wave action that are associated with climate change. The loss of a third of the global cover of these ecosystems involves a loss of CO2 sinks and the emission of 1 Pg CO2 annually. The conservation, restoration and use of vegetated coastal habitats in eco-engineering solutions for coastal protection provide a promising strategy, delivering significant capacity for climate change mitigation and adaption.

  8. Population viability analysis of plant and animal populations with stochastic integral projection models.

    Science.gov (United States)

    Jaffré, Malo; Le Galliard, Jean-François

    2016-12-01

    Integral projection models (IPM) make it possible to study populations structured by continuous traits. Recently, Vindenes et al. (Ecology 92:1146-1156, 2011) proposed an extended IPM to analyse the dynamics of small populations in stochastic environments, but this model has not yet been used to conduct population viability analyses. Here, we used the extended IPM to analyse the stochastic dynamics of IPM of small size-structured populations in one plant and one animal species (evening primrose and common lizard) including demographic stochasticity in both cases and environmental stochasticity in the lizard model. We also tested the accuracy of a diffusion approximation of the IPM for the two empirical systems. In both species, the elasticity for λ was higher with respect to parameters linked to body growth and size-dependent reproduction rather than survival. An analytical approach made it possible to quantify demographic and environmental variance to calculate the average stochastic growth rate. Demographic variance was further decomposed to gain insights into the most important size classes and demographic components. A diffusion approximation provided a remarkable fit to the stochastic dynamics and cumulative extinction risk, except for very small populations where stochastic growth rate was biased upward or downward depending on the model. These results confirm that the extended IPM provides a powerful tool to assess the conservation status and compare the stochastic demography of size-structured species, but should be complemented with individual based models to obtain unbiased estimates for very small populations of conservation concern.

  9. Population structure of an invasive parthenogenetic gastropod in coastal lakes and estuaries of northern KwaZulu-Natal, South Africa.

    Directory of Open Access Journals (Sweden)

    Nelson A F Miranda

    Full Text Available BACKGROUND: Estuaries and coastal lakes receive little attention despite being heavily invaded by non-indigenous invasive species (NIS. In these situations, studies of population dynamics in invaded habitats can provide valuable insights into how NIS interact with new environments. Tarebia granifera is a prosobranch gastropod from south-east Asia which has invaded other sub-tropical parts of the world. This study addresses whether a small number of key environmental factors influences gastropod communities, and specifically how the population density and size structure of T. granifera were influenced by environmental change in estuaries and coastal lakes in southern Africa. METHODOLOGY/PRINCIPAL FINDINGS: T. granifera's density, number of brooded juveniles and size structure were measured at the St. Lucia Estuary, Mgobozeleni Estuary, Lake Sibaya and Lake Nhlange. Size structure was classified according to shell height (SH. All dissected individuals were found to be female and free from trematode infection. Salinity, water depth, temperature, and pH were the main factors correlated with population density of gastropod communities. T. granifera often reached densities well over 1000 ind. m(-2, displacing indigenous gastropods and becoming a dominant component of the benthic community. T. granifera successfully invaded estuaries despite frequent exposure to high salinity and desiccation, which could together eliminate >97% of the population. The persistence of T. granifera was ensured due to its high fecundity and the environmental tolerance of large adults (20-30 mm SH which carried an average of 158±12.8 SD brooded juveniles. Repeat introductions were not essential for the success of this parthenogenetic NIS. CONCLUSION/SIGNIFICANCE: There is a need for a broader study on the reproductive biology of T. granifera (including the previously overlooked "brood pouch ecology", which affects population dynamics and may be relevant to other

  10. GC-MS and FT-IR analysis of a coastal medicinal plant-Hyptis suaveolens (L. Poit

    Directory of Open Access Journals (Sweden)

    Joselin Joseph

    2016-05-01

    Full Text Available Objective: To investigate the bioactive components of a coastal medicinal plant, Hyptis suaveolens (L. Poit. (H. suaveolens leaves using fourier transform-infrared spectroscopy and gas chromatography-mass spectrometer (GC-MS. Methods: The chemical compositions of the ethanol extract of whole plant of H. suaveolens was investigated using PerkinElmer GC-MS, while the mass spectra of the compounds found in the extract was matched with the National Institute of Standard and Technology library. Results: The results of fourier transform-infrared spectroscopy analysis confirmed the presence of secondary alcohols, phenols, alkanes, alkynes, aromatics, nitro compounds and aliphatic compounds. GC-MS analysis of the ethanolic extract revealed the existence of 30 phytochemical compounds. 5,5-Dimethylimidazolidin-2,4-diamine (20.35% was found to be the major compound. Conclusions: The results of this study offer a platform to use H. suaveolens leaves as herbal alternative for various diseases.

  11. GC-MS and FT-IR analysis of a coastal medicinal plant-Hyptis suaveolens (L.) Poit

    Institute of Scientific and Technical Information of China (English)

    Joselin Joseph; Solomon Jeeva

    2016-01-01

    Objective:To investigate the bioactive components of a coastal medicinal plant,Hyptis suaveolens (L.) Poit. (H. suaveolens) leaves using fourier transform-infrared spectroscopy and gas chromatography-mass spectrometer (GC-MS). Methods: The chemical compositions of the ethanol extract of whole plant ofH. suaveolens was investigated using PerkinElmerGC-MS, while the mass spectra of the compounds found in the extract was matched with the National Institute of Standard and Technology library. Results: The results of fourier transform-infrared spectroscopy analysis confirmed the presence of secondary alcohols, phenols, alkanes, alkynes, aromatics, nitro compounds and aliphatic compounds.GC-MS analysis of the ethanolic extract revealed the existence of 30 phytochemical compounds. 5,5-Dimethylimidazolidin-2,4-diamine (20.35%) was found to be the major compound. Conclusions: The results of this study offer a platform to useH. suaveolens leaves as herbal alternative for various diseases.

  12. Transplanting native dominant plants to facilitate community development in restored coastal plain wetlands

    Science.gov (United States)

    Diane De Steven; Rebecca R. Sharitz

    2007-01-01

    Drained depressional wetlands are typically restored by plugging ditches or breaking drainage tiles to allow recovery of natural ponding regimes, while relying on passive recolonization from seed banks and dispersal to establish emergent vegetation. However, in restored depressions of the southeastern United States Coastal Plain, certain characteristic rhizomatous...

  13. Regional patterns and controlling factors in plant species composition and diversity in Canadian lowland coastal bogs and laggs

    Directory of Open Access Journals (Sweden)

    S.A. Howie

    2016-11-01

    Full Text Available Inventories of natural assemblages of plant species are critical when planning ecological restoration of bogs. However, little is known about the regional variation in plant communities at the margins (laggs of bogs, even though they are an integral element of raised bog ecosystems. Therefore, we investigated the regional patterns in the plant communities of bogs and laggs, and the factors that control them, for thirteen bogs in coastal British Columbia, Canada. Species richness was significantly higher in the bogs and laggs of the cooler, wetter Pacific Oceanic wetland region. Beta Diversity analyses showed that bogs in the Pacific Oceanic wetland region often shared species with their respective laggs, whereas half of the laggs in the warmer, drier Pacific Temperate wetland region had no species in common with the adjacent bogs and were thus more ecologically distinct from the bog. Primary climatic variables, such as mean annual precipitation, mean annual temperature and latitude, as well as climate-influenced variables, such as pH, peat depth, and Na+ concentrations were the main correlates of plant species composition in the studied bogs. Site-specific factors, particularly depth to water table, and fraction of inorganic material in peat samples, were as strongly related to lagg plant communities as climate, while hydrochemistry appeared to have less influence.

  14. Peripatric differentiation among adjacent marine lake and lagoon populations of a coastal fish, Sphaeramia orbicularis (Apogonidae, Perciformes, Teleostei).

    Science.gov (United States)

    Gotoh, Ryo O; Sekimoto, Hidekatsu; Chiba, Satoru N; Hanzawa, Naoto

    2009-08-01

    The effect of geographical isolation on speciation, particularly within short geographical ranges, is poorly understood among marine organisms. Focusing on marine lakes of the Palau Islands, we investigated the effect of geographical isolation on Sphaeramia orbicularis, a coastal fish inhabiting marine lakes and lagoons. We collected a total of 157 individuals from three meromictic marine lakes and three lagoon sites, and analyzed the genetic diversity and differentiation of the populations based on complete sequences of the mitochondrial control region (824 bp). The analyses show that the genetic diversity of marine lake populations is much lower than that of lagoon populations. Moreover, a mismatch distribution analysis suggests that marine lake populations have experienced a decrease followed by a rapid expansion of their population size. These results reveal that marine lake populations have experienced severe founder and/or bottleneck events during the last thousand to tens of thousand years. Pairwise Phi(ST )values ranged from 0.531 to 0.848 between marine lake and lagoon populations and from 0.429 to 0.870 among marine lake populations, indicating a high degree of genetic differentiation. We speculate that such peripatric differentiation between marine lake and lagoon populations was caused by a small number of individuals colonizing the lakes from the lagoon (founder event) followed by repetitive bottleneck events, such as those generated by the El Niño-Southern Oscillation (ENSO). So far, such high genetic divergences in extremely short geographical ranges (approximately 150-250 m) have scarcely been reported for marine organisms. We suggest that the marine lake is one of the good model of geographical isolation in marine organisms and each marine lake population is in the early stages of speciation.

  15. Foliage maturity of Quercus ilex affects the larval development of a Croatian coastal population of Lymantria dispar (Lepidoptera: Erebidae

    Directory of Open Access Journals (Sweden)

    Lukić Ivan

    2017-02-01

    Full Text Available Gypsy moth (Lymantria dispar is one of the most important forest pests in the world. Numerous previous studies focused only on different host tree species, but small number of them on foliage age. Since recent genetic analyses showed that there are significant differences between Croatian continental and coastal population we investigated coastal population since there was no previous research. For this research juvenile and mature foliage of Holm oak (Quercus ilex was used. Larval development was investigated in two laboratory experiments. One experiment involved rearing trials consisting of 50 individual larvae per treatment while a parallel experiment investigated gregarious feeding conditions using 120 larvae in a rearing treatment. Larval mortality was lower and development time shorter for individuals reared on juvenile foliage. High pupation success in both the individual and group rearing experiment for larvae reared on juvenile foliage was also observed. To conclude, our results showed high mortality, poor larval development and low pupation success in larvae reared on mature foliage. This research is significant because in the aspect of ongoing climate changes there is a possibility that gypsy moth will move to the north and shift its distribution by expanding into new climatic area.

  16. Molecular insights into seed dispersal mutualisms driving plant population recruitment

    Science.gov (United States)

    García, Cristina; Grivet, Delphine

    2011-11-01

    Most plant species require mutualistic interactions with animals to fulfil their demographic cycle. In this regard frugivory (i.e., the intake of fruits by animals) enhances natural regeneration by mobilizing a large amount of seeds from source trees to deposition sites across the landscape. By doing so, frugivores move propagules, and the genotypes they harbour creating the spatial, ecological, and genetic environment under which subsequent recruitment proceeds. Recruitment patterns can be envisioned as the result of two density- and distance-dependent processes: seed dispersal and seed/seedling survival (the Janzen-Connell model). Population genetic studies add another layer of complexity for understanding the fate of dispersed propagules: the genetic relatedness among neighbouring seeds within a seed clump, a major outcome of frugivore activity, modifies their chances of germinating and surviving. Yet, we virtually ignore how the spatial distribution of maternal progenies and recruitment patterns relate with each other in frugivore-generated seed rains. Here we focus on the critical role of frugivore-mediated seed dispersal in shaping the spatial distribution of maternal progenies in the seed rain. We first examine which genetic mechanisms underlying recruitment are influenced by the spatial distribution of maternal progenies. Next, we examine those studies depicting the spatial distribution of maternal progenies in a frugivore-generated seed rain. In doing so, we briefly review the most suitable analytical approaches applied to track the contribution of fruiting trees to the seed rain based on molecular data. Then we look more specifically at the role of distinct frugivore guilds in determining maternal genetic correlations and their expected consequences for recruitment patterns. Finally we posit some general conclusions and suggest future research directions that would provide a more comprehensive understanding of the ecological and evolutionary consequences

  17. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Science.gov (United States)

    2010-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  18. Adaptation to sea level rise: does local adaptation influence the demography of coastal fish populations?

    Science.gov (United States)

    Purcell, K M; Klerks, P L; Leberg, P L

    2010-10-01

    This study compared the growth of two western mosquitofish Gambusia affinis populations that were previously demonstrated to have genetic adaptations that increased survival under lethal salinity exposures. The objective was to evaluate how genetic adaptations to lethal salinity stress affect population demography when exposed to sublethal salinity stress. Results indicate that chronic salinity exposure had a generally negative impact on population size, but fish originating from one of the two populations established with fish from a brackish site exhibited an increase in population size. Saltwater intrusion seems to result in reduced population size for most populations. Some populations inhabiting more saline sites, however, may develop localized adaptations, mitigating the consequences of increased salinity on population productivity.

  19. Plant Date, Yield, and Nitrogen Management for Strawberries in the Coastal Plain of Virignia

    OpenAIRE

    Deitch, Ursula

    2016-01-01

    Fresh market strawberry (Fragaria × ananassa) availability in mid to late -April signals the beginning of locally available fresh fruit and vegetables for the mid-Atlantic region. Of the 290 acres of fresh market strawberries grown in Virginia annually, the majority are produced in the coastal plain of Virginia using intensely managed annual hill production systems. The objective of this study was to evaluate the potential yield of strawberries, determine how yield components change with pl...

  20. Seasonal variations in virus-host populations in Norwegian coastal waters: focusing on the cyanophage community infecting marine Synechococcus spp.

    Science.gov (United States)

    Sandaa, Ruth-Anne; Larsen, Aud

    2006-07-01

    Viruses are ubiquitous components of the marine ecosystem. In the current study we investigated seasonal variations in the viral community in Norwegian coastal waters by pulsed-field gel electrophoresis (PFGE). The results demonstrated that the viral community was diverse, displaying dynamic seasonal variation, and that viral populations of 29 different sizes in the range from 26 to 500 kb were present. Virus populations from 260 to 500 kb and dominating autotrophic pico- and nanoeukaryotes showed similar dynamic variations. Using flow cytometry and real-time PCR, we focused in particular on one host-virus system: Synechococcus spp. and cyanophages. The two groups covaried throughout the year and were found in the highest amounts in fall with concentrations of 7.3 x 10(4) Synechococcus cells ml(-1) and 7.2 x 10(3) cyanophage ml(-1). By using primers targeting the g20 gene in PCRs on DNA extracted from PFGE bands, we demonstrated that cyanophages were found in a genomic size range of 26 to 380 kb. The genetic richness of the cyanophage community, determined by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified g20 gene fragments, revealed seasonal shifts in the populations, with one community dominating in spring and summer and a different one dominating in fall. Phylogenetic analysis of the sequences originating from PFGE and DGGE bands grouped the sequences into three groups, all with homology to cyanomyoviruses present in cultures. Our results show that the cyanophage community in Norwegian coastal waters is dynamic and genetically diverse and has a surprisingly wide genomic size range.

  1. Impact of cotton planting date and nitrogen fertilization on Bemisia argentifolii populations

    Institute of Scientific and Technical Information of China (English)

    JIAN-LONGBI; DONG-MEILIN; KEH-SHENLII; NICKC.TOSCANO

    2005-01-01

    The silverleaf whitefly (Bemisia argentifolii Bellows and Perring) is a widely distributed pest of cotton (Gossypium hirsutum L.) and the population levels may be affected by rates of nitrogen fertilization and planting date. Field experiments were conducted to investigate the impact of cotton planting date and nitrogen fertilization on silverleaf whitefly population dynamics. Cotton was planted on 26 April and 8 June, for the early and late plantings, respectively. Nitrogen treatments consisted of soil applications of 0, 112, 168 and 224 kg of nitrogen per hectare. The population levels of adult whiteflies were much higher on early-planted cotton than on late planting. Also, increased numbers of adult whiteflies on both early and late plantings occurred with increasing amounts of applied nitrogen.Applied nitrogen increased seed cotton yields of early plantings but had no effect on the yields of late plantings.

  2. Model of yield response of corn to plant population and absorption of solar energy.

    Directory of Open Access Journals (Sweden)

    Allen R Overman

    Full Text Available Biomass yield of agronomic crops is influenced by a number of factors, including crop species, soil type, applied nutrients, water availability, and plant population. This article is focused on dependence of biomass yield (Mg ha(-1 and g plant(-1 on plant population (plants m(-2. Analysis includes data from the literature for three independent studies with the warm-season annual corn (Zea mays L. grown in the United States. Data are analyzed with a simple exponential mathematical model which contains two parameters, viz. Y(m (Mg ha(-1 for maximum yield at high plant population and c (m(2 plant(-1 for the population response coefficient. This analysis leads to a new parameter called characteristic plant population, x(c = 1/c (plants m(-2. The model is shown to describe the data rather well for the three field studies. In one study measurements were made of solar radiation at different positions in the plant canopy. The coefficient of absorption of solar energy was assumed to be the same as c and provided a physical basis for the exponential model. The three studies showed no definitive peak in yield with plant population, but generally exhibited asymptotic approach to maximum yield with increased plant population. Values of x(c were very similar for the three field studies with the same crop species.

  3. Plant defences limit herbivore population growth by changing predator-prey interactions.

    Science.gov (United States)

    Kersch-Becker, Mônica F; Kessler, André; Thaler, Jennifer S

    2017-09-13

    Plant quality and predators are important factors affecting herbivore population growth, but how they interact to regulate herbivore populations is not well understood. We manipulated jasmonate-induced plant resistance, exposure to the natural predator community and herbivore density to test how these factors jointly and independently affect herbivore population growth. On low-resistance plants, the predator community was diverse and abundant, promoting high predator consumption rates. On high-resistance plants, the predator community was less diverse and abundant, resulting in low predator consumption rate. Plant resistance only directly regulated aphid population growth on predator-excluded plants. When predators were present, plant resistance indirectly regulated herbivore population growth by changing the impact of predators on the herbivorous prey. A possible mechanism for the interaction between plant resistance and predation is that methyl salicylate, a herbivore-induced plant volatile attractive to predators, was more strongly induced in low-resistance plants. Increased plant resistance reduced predator attractant lures, preventing predators from locating their prey. Low-resistance plants may regulate herbivore populations via predators by providing reliable information on prey availability and increasing the effectiveness of predators. © 2017 The Author(s).

  4. Trichomonas vaginalis Infection and Associated Risk Factors in a Socially-Marginalized Female Population in Coastal Peru

    Science.gov (United States)

    Leon, Segundo R.; Konda, Kelika A.; Bernstein, Kyle T.; Pajuelo, Jose B.; Rosasco, Ana M.; Caceres, Carlos F.; Coates, Thomas J.; Klausner, Jeffrey D.

    2009-01-01

    Objective. The epidemiology of Trichomonas vaginalis infection among sexually active socially-marginalized women in three urban, coastal Peruvian cities was examined in order to quantify the prevalence of trichomonas infection and identify associated risk factors. Methods. We conducted a cross-sectional, venue-based study of women from socially-marginalized populations in three coastal Peruvian cities. Results. Among the 319 women enrolled, the overall prevalence of trichomonal infection was 9.1% (95% CI, 5.9%–12.3%). The mean age was 26.3 years, and 35.5% reported having had unprotected intercourse with nonprimary partners and 19.8% reported two or more sex partners in the last three months. Trichomonal infection was associated with increased number of sex partners (PR 2.5, 95% CI 1.4–4.6) and unprotected sex with nonprimary partner in the last three months (PR 2.3, 95% CI 1.1–4.9). Conclusions. A moderately high prevalence of trichomonal infection was found among women in our study. Trichomonal infection was associated with unprotected sex and multiple sex partners. Efforts to control the continued spread of trichomonal infection are warranted. PMID:19584943

  5. Hypernatremia in Dice snakes (Natrix tessellata from a coastal population: implications for osmoregulation in marine snake prototypes.

    Directory of Open Access Journals (Sweden)

    François Brischoux

    Full Text Available The widespread relationship between salt excreting structures (e.g., salt glands and marine life strongly suggests that the ability to regulate salt balance has been crucial during the transition to marine life in tetrapods. Elevated natremia (plasma sodium recorded in several marine snakes species suggests that the development of a tolerance toward hypernatremia, in addition to salt gland development, has been a critical feature in the evolution of marine snakes. However, data from intermediate stage (species lacking salt glands but occasionally using salty environments are lacking to draw a comprehensive picture of the evolution of an euryhaline physiology in these organisms. In this study, we assessed natremia of free-ranging Dice snakes (Natrix tessellata, a predominantly fresh water natricine lacking salt glands from a coastal population in Bulgaria. Our results show that coastal N. tessellata can display hypernatremia (up to 195.5 mmol x l(-1 without any apparent effect on several physiological and behavioural traits (e.g., hematocrit, body condition, foraging. More generally, a review of natremia in species situated along a continuum of habitat use between fresh- and seawater shows that snake species display a concomitant tolerance toward hypernatremia, even in species lacking salt glands. Collectively, these data suggest that a physiological tolerance toward hypernatremia has been critical during the evolution of an euryhaline physiology, and may well have preceded the evolution of salt glands.

  6. Hypernatremia in Dice Snakes (Natrix tessellata) from a Coastal Population: Implications for Osmoregulation in Marine Snake Prototypes

    Science.gov (United States)

    Brischoux, François; Kornilev, Yurii V.

    2014-01-01

    The widespread relationship between salt excreting structures (e.g., salt glands) and marine life strongly suggests that the ability to regulate salt balance has been crucial during the transition to marine life in tetrapods. Elevated natremia (plasma sodium) recorded in several marine snakes species suggests that the development of a tolerance toward hypernatremia, in addition to salt gland development, has been a critical feature in the evolution of marine snakes. However, data from intermediate stage (species lacking salt glands but occasionally using salty environments) are lacking to draw a comprehensive picture of the evolution of an euryhaline physiology in these organisms. In this study, we assessed natremia of free-ranging Dice snakes (Natrix tessellata, a predominantly fresh water natricine lacking salt glands) from a coastal population in Bulgaria. Our results show that coastal N. tessellata can display hypernatremia (up to 195.5 mmol.l−1) without any apparent effect on several physiological and behavioural traits (e.g., hematocrit, body condition, foraging). More generally, a review of natremia in species situated along a continuum of habitat use between fresh- and seawater shows that snake species display a concomitant tolerance toward hypernatremia, even in species lacking salt glands. Collectively, these data suggest that a physiological tolerance toward hypernatremia has been critical during the evolution of an euryhaline physiology, and may well have preceded the evolution of salt glands. PMID:24658047

  7. Hypernatremia in Dice snakes (Natrix tessellata) from a coastal population: implications for osmoregulation in marine snake prototypes.

    Science.gov (United States)

    Brischoux, François; Kornilev, Yurii V

    2014-01-01

    The widespread relationship between salt excreting structures (e.g., salt glands) and marine life strongly suggests that the ability to regulate salt balance has been crucial during the transition to marine life in tetrapods. Elevated natremia (plasma sodium) recorded in several marine snakes species suggests that the development of a tolerance toward hypernatremia, in addition to salt gland development, has been a critical feature in the evolution of marine snakes. However, data from intermediate stage (species lacking salt glands but occasionally using salty environments) are lacking to draw a comprehensive picture of the evolution of an euryhaline physiology in these organisms. In this study, we assessed natremia of free-ranging Dice snakes (Natrix tessellata, a predominantly fresh water natricine lacking salt glands) from a coastal population in Bulgaria. Our results show that coastal N. tessellata can display hypernatremia (up to 195.5 mmol x l(-1)) without any apparent effect on several physiological and behavioural traits (e.g., hematocrit, body condition, foraging). More generally, a review of natremia in species situated along a continuum of habitat use between fresh- and seawater shows that snake species display a concomitant tolerance toward hypernatremia, even in species lacking salt glands. Collectively, these data suggest that a physiological tolerance toward hypernatremia has been critical during the evolution of an euryhaline physiology, and may well have preceded the evolution of salt glands.

  8. Trichomonas vaginalis Infection and Associated Risk Factors in a Socially-Marginalized Female Population in Coastal Peru

    Directory of Open Access Journals (Sweden)

    Segundo R. Leon

    2009-01-01

    Full Text Available Objective. The epidemiology of Trichomonas vaginalis infection among sexually active socially-marginalized women in three urban, coastal Peruvian cities was examined in order to quantify the prevalence of trichomonas infection and identify associated risk factors. Methods. We conducted a cross-sectional, venue-based study of women from socially-marginalized populations in three coastal Peruvian cities. Results. Among the 319 women enrolled, the overall prevalence of trichomonal infection was 9.1% (95% CI, 5.9%–12.3%. The mean age was 26.3 years, and 35.5% reported having had unprotected intercourse with nonprimary partners and 19.8% reported two or more sex partners in the last three months. Trichomonal infection was associated with increased number of sex partners (PR 2.5, 95% CI 1.4–4.6 and unprotected sex with nonprimary partner in the last three months (PR 2.3, 95% CI 1.1–4.9. Conclusions. A moderately high prevalence of trichomonal infection was found among women in our study. Trichomonal infection was associated with unprotected sex and multiple sex partners. Efforts to control the continued spread of trichomonal infection are warranted.

  9. Mitochondrial population genomics supports a single pre-Clovis origin with a coastal route for the peopling of the Americas.

    Science.gov (United States)

    Fagundes, Nelson J R; Kanitz, Ricardo; Eckert, Roberta; Valls, Ana C S; Bogo, Mauricio R; Salzano, Francisco M; Smith, David Glenn; Silva, Wilson A; Zago, Marco A; Ribeiro-dos-Santos, Andrea K; Santos, Sidney E B; Petzl-Erler, Maria Luiza; Bonatto, Sandro L

    2008-03-01

    It is well accepted that the Americas were the last continents reached by modern humans, most likely through Beringia. However, the precise time and mode of the colonization of the New World remain hotly disputed issues. Native American populations exhibit almost exclusively five mitochondrial DNA (mtDNA) haplogroups (A-D and X). Haplogroups A-D are also frequent in Asia, suggesting a northeastern Asian origin of these lineages. However, the differential pattern of distribution and frequency of haplogroup X led some to suggest that it may represent an independent migration to the Americas. Here we show, by using 86 complete mitochondrial genomes, that all Native American haplogroups, including haplogroup X, were part of a single founding population, thereby refuting multiple-migration models. A detailed demographic history of the mtDNA sequences estimated with a Bayesian coalescent method indicates a complex model for the peopling of the Americas, in which the initial differentiation from Asian populations ended with a moderate bottleneck in Beringia during the last glacial maximum (LGM), around approximately 23,000 to approximately 19,000 years ago. Toward the end of the LGM, a strong population expansion started approximately 18,000 and finished approximately 15,000 years ago. These results support a pre-Clovis occupation of the New World, suggesting a rapid settlement of the continent along a Pacific coastal route.

  10. Wet and dry atmospheric depositions of inorganic nitrogen during plant growing season in the coastal zone of Yellow River Delta.

    Science.gov (United States)

    Yu, Junbao; Ning, Kai; Li, Yunzhao; Du, Siyao; Han, Guangxuan; Xing, Qinghui; Wu, Huifeng; Wang, Guangmei; Gao, Yongjun

    2014-01-01

    The ecological problems caused by dry and wet deposition of atmospheric nitrogen have been widespread concern in the world. In this study, wet and dry atmospheric depositions were monitored in plant growing season in the coastal zone of the Yellow River Delta (YRD) using automatic sampling equipment. The results showed that SO4 (2-) and Na(+) were the predominant anion and cation, respectively, in both wet and dry atmospheric depositions. The total atmospheric nitrogen deposition was ~2264.24 mg m(-2), in which dry atmospheric nitrogen deposition was about 32.02%. The highest values of dry and wet atmospheric nitrogen deposition appeared in May and August, respectively. In the studied area, NO3 (-)-N was the main nitrogen form in dry deposition, while the predominant nitrogen in wet atmospheric deposition was NH4 (+)-N with ~56.51% of total wet atmospheric nitrogen deposition. The average monthly attribution rate of atmospheric deposition of NO3 (-)-N and NH4 (+)-N was ~31.38% and ~20.50% for the contents of NO3 (-)-N and NH4 (+)-N in 0-10 cm soil layer, respectively, suggested that the atmospheric nitrogen was one of main sources for soil nitrogen in coastal zone of the YRD.

  11. Fine-scale spatial variation in plant species richness and its relationship to environmental conditions in coastal marshlands

    Science.gov (United States)

    Mancera, J.E.; Meche, G.C.; Cardona-Olarte, P.P.; Castaneda-Moya, E.; Chiasson, R.L.; Geddes, N.A.; Schile, L.M.; Wang, H.G.; Guntenspergen, G.R.; Grace, J.B.

    2005-01-01

    Previous studies have shown that variations in environmental conditions play a major role in explaining variations in plant species richness at community and landscape scales. In this study, we considered the degree to which fine-scale spatial variations in richness could be related to fine-scale variations in abiotic and biotic factors. To examine spatial variation in richness, grids of 1 m(2) plots were laid out at five sites within a coastal riverine wetland landscape. At each site, a 5 x 7 array of plots was established adjacent to the river's edge with plots one meter apart. In addition to the estimation of species richness, environmental measurements included sediment salinity, plot microelevation, percent of plot recently disturbed, and estimated community biomass. Our analysis strategy was to combine the use of structural equation modeling (path modeling) with an assessment of spatial association. Mantel's tests revealed significant spatial autocorrelation in species richness at four of the five sites sampled, indicating that richness in a plot correlated with the richness of nearby plots. We subsequently considered the degree to which spatial autocorrelations in richness could be explained by spatial autocorrelations in environmental conditions. Once data were corrected for environmental correlations, spatial autocorrelation in residual species richness could not be detected at any site. Based on these results, we conclude that in this coastal wetland, there appears to be a fine-scale mapping of diversity to microgradients in environmental conditions.

  12. Seed Selection by the Harvester Ant Pogonomyrmex rugosus (Hymenoptera: Formicidae) in Coastal Sage Scrub: Interactions With Invasive Plant Species.

    Science.gov (United States)

    Briggs, C M; Redak, R A

    2016-08-01

    Harvester ants can be the dominant seed predators on plants by collecting and eating seeds and are known to influence plant communities. Harvester ants are abundant in coastal sage scrub (CSS), and CSS is frequently invaded by several exotic plant species. This study used observations of foraging and cafeteria-style experiments to test for seed species selection by the harvester ant Pogonomyrmex rugosus Emery (Hymenoptera: Formicidae) in CSS. Analysis of foraging behavior showed that P. rugosus carried seeds of exotic Erodium cicutarium (L.) and exotic Brassica tournefortii (Gouan) on 85 and 15% of return trips to the nest (respectively), and only a very few ants carried the native seeds found within the study areas. When compared with the availability of seeds in the field, P. rugosus selected exotic E. cicutarium and avoided both native Encelia farinosa (Torrey & A. Gray) and exotic B. tournefortii. Foraging by P. rugosus had no major effect on the seed bank in the field. Cafeteria-style experiments confirmed that P. rugosus selected E. cicutarium over other available seeds. Native Eriogonum fasciculatum (Bentham) seeds were even less selected than E. farinosa and B. tournefortii.

  13. Benefit of shading by nurse plant does not change along a stress gradient in a coastal dune.

    Science.gov (United States)

    Castanho, Camila de Toledo; Prado, Paulo Inácio

    2014-01-01

    The proximity of adult neighbors often increases the performance of woody seedlings under harsh environmental conditions but this nurse plant effect becomes less intense when abiotic stress is alleviated, as predicted by the stress gradient hypothesis (SGH). Although some studies have tested how the net nurse effect is changed by stress, few studies have tested how the mechanism that drives the facilitative effect of nurse responds to changes in stress. We conducted field experiments in a subtropical coastal dune to test if shading drives the known nurse effect of adults of the tree Guapira opposita on seedling performance of another tree species, Ternstroemia brasiliensis. We transplanted T. brasiliensis seedlings to three neighbor environments: under a G. opposita crown, under artificial shade and without neighbor as a control. Furthermore, assuming that proximity to the seashore correlates with stress intensity, we tested if the potential shade-driven facilitation became less intense as stress decreased. Regardless of the proximity to the seashore, after a year, the survival of T. brasiliensis seedlings was twice as high when the seedlings were under G. opposita or under artificial shade compared to the control, indicating that the nurse effect is driven by shade and that this facilitation mechanism is constant along the stress gradient. However, G. opposita and artificial shade had a negative effect on seedlings growth. Overall, our results showed that the facilitation mechanism behind the nurse effect did not wane as the stress was reduced. Furthermore, in spite of the potential costs in terms of biomass production, our study highlights the potential of nurse plants and artificial shade as techniques to improve the survival of transplanted seedlings used in the restoration of degraded shrubland coastal dunes.

  14. Trace element reference intervals in the blood of healthy green sea turtles to evaluate exposure of coastal populations.

    Science.gov (United States)

    Villa, C A; Flint, M; Bell, I; Hof, C; Limpus, C J; Gaus, C

    2017-01-01

    Exposure to essential and non-essential elements may be elevated for green sea turtles (Chelonia mydas) that forage close to shore. Biomonitoring of trace elements in turtle blood can identify temporal trends over repeated sampling events, but any interpretation of potential health risks due to an elevated exposure first requires a comparison against a baseline. This study aims to use clinical reference interval (RI) methods to produce exposure baseline limits for essential and non-essential elements (Na, Mg, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba, and Pb) using blood from healthy subadult turtles foraging in a remote and offshore part of the Great Barrier Reef. Subsequent blood biomonitoring of three additional coastal populations, which forage in areas dominated by agricultural, urban and military activities, showed clear habitat-specific differences in blood metal profiles relative to the those observed in the offshore population. Coastal turtles were most often found to have elevated concentrations of Co, Mo, Mn, Mg, Na, As, Sb, and Pb relative to the corresponding RIs. In particular, blood from turtles from the agricultural site had Co concentrations ranging from 160 to 840 μg/L (4-25 times above RI), which are within the order expected to elicit acute effects in many vertebrates. Additional clinical blood biochemistry and haematology results indicate signs of a systemic disease and the prevalence of an active inflammatory response in a high proportion (44%) of turtles from the agricultural site. Elevated Co, Sb, and Mn in the blood of these turtles significantly correlated with elevated markers of acute inflammation (total white cell counts) and liver dysfunction (alkaline phosphatase and total bilirubin). The results of this study support the notion that elevated trace element exposures may be adversely affecting the health of nearshore green sea turtles.

  15. Strong linkage between plant and soil fungal communities along a successional coastal dune system.

    Science.gov (United States)

    Roy-Bolduc, Alice; Laliberté, Etienne; Boudreau, Stéphane; Hijri, Mohamed

    2016-10-01

    Complex interactions between plants and soil microorganisms drive key ecosystem and community properties such as productivity and diversity. In nutrient-poor systems such as sand dunes, plant traits and fungal symbioses related to nutrient acquisition can strongly influence vegetation dynamics. We investigated plant and fungal communities in a relic foredune plain located on an archipelago in Québec, Canada. We detected distinct communities across the edaphic and successional gradient. Our results showed a clear increase in plant species richness, as well as in the diversity of nutrient-acquisition strategies. We also found a strong correlation between aboveground vegetation and soil fungal communities, and both responded similarly to soil physicochemical properties. Soil pH influenced the composition of plant and fungal communities, and could act as an important environmental filter along this relic foredune plain. The increasing functional diversity in plant nutrient-acquisition strategies across the gradient might favor resource partitioning and facilitation among co-occurring plant species. The coordinated changes in soil microbial and plant communities highlight the importance of aboveground-belowground linkages and positive biotic interactions during ecological succession in nutrient-poor environments.

  16. How sea level rise affects sedimentation, plant growth, and carbon accumulation on coastal salt marshes

    Science.gov (United States)

    Mudd, S. M.; Howell, S. M.; Morris, J. T.

    2009-12-01

    The rate of accretion on coastal salt marshes depends on feedbacks between flow, macrophyte growth, and sedimentation. Under favourable conditions, marsh accretion rates will keep pace with the local rate of sea level rise. Marsh accretion is driven by both organic and inorganic sedimentation; mineral rich marshes will need less organic sedimentation to keep pace with sea level rise. Here we use a numerical model of marsh accretion, calibrated by sediment cores, to explore the relationship between sea level rise and carbon sequestration on salt marshes in the face of differing supplies of inorganic sediment. The model predicts that changes in carbon storage resulting from changing sediment supply or sea-level rise are strongly dependant on the background sediment supply: if inorganic sediment supply is reduced in an already sediment poor marsh the storage of organic carbon will increase to a far greater extent than in a sediment-rich marsh, provided that the rate of sea-level rise does not exceed a threshold. These results imply that altering sediment supply to estuaries (e.g., by damming upstream rivers or altering littoral sediment transport) could lead to significant changes in the carbon budgets of coastal salt marshes.

  17. Long-term impacts of nitrogen deposition on coastal plant communities.

    Science.gov (United States)

    Pakeman, Robin J; Alexander, Jim; Brooker, Rob; Cummins, Roger; Fielding, Debbie; Gore, Sarah; Hewison, Richard; Mitchell, Ruth; Moore, Emily; Orford, Katy; Pemberton, Clare; Trinder, Clare; Lewis, Rob

    2016-05-01

    Nitrogen deposition has been shown to have significant impacts on a range of vegetation types resulting in eutrophication and species compositional change. Data from a re-survey of 89 coastal sites in Scotland, UK, c. 34 years after the initial survey were examined to assess the degree of change in species composition that could be accounted for by nitrogen deposition. There was an overall increase in the Ellenberg Indicator Value for nitrogen (EIV-N) of 0.15 between the surveys, with a clear shift to species characteristic of more eutrophic situations. This was most evident for Acid grassland, Fixed dune, Heath, Slack and Tall grass mire communities and despite falls in EIV-N for Improved grass, Strand and Wet grassland. The increase in EIV-N was highly correlated to the cumulative deposition between the surveys, and for sites in south-east Scotland, eutrophication impacts appear severe. Unlike other studies, there appears to have been no decline in species richness associated with nitrogen deposition, though losses of species were observed on sites with the very highest levels of SOx deposition. It appears that dune vegetation (specifically Fixed dune) shows evidence of eutrophication above 4.1 kg N ha(-1) yr(-1), or 5.92 kg N ha(-1) yr(-1) if the lower 95% confidence interval is used. Coastal vegetation appears highly sensitive to nitrogen deposition, and it is suggested that major changes could have occurred prior to the first survey in 1976.

  18. Phylogenetics and population genetics of Plotosus canius (Siluriformes: Plotosidae from Malaysian coastal waters

    Directory of Open Access Journals (Sweden)

    Nima Khalili Samani

    2016-05-01

    Full Text Available Plotosus canius (Hamilton, 1822 is a significant marine species in Malaysia from nutritional and commercial perspectives. Despite numerous fundamental research on biological characteristics of P. canius, there are various concerns on the level of population differentiation, genomic structure, and the level of genetic variability among their populations due to deficiency of genetic-based studies. Deficiency on basic contexts such as stock identification, phylogenetic relationship and population genetic structure would negatively impact their sustainable conservation. Hence, this study was conducted to characterize the genetic structure of P. canius for the first time through the application of mitochondrial Cytochrome Oxidase I (COI gene, cross amplification of Tandanus tandanus microsatellites, and a total of 117 collected specimens across five selected populations of Malaysia. The experimental results of the mitochondrial analysis revealed that the haplotype diversity and nucleotide diversity varied from 0.395–0.771 and 0.033–0.65 respectively. Moreover, the statistical analysis of microsatellites addressed a considerable heterozygote insufficiency in all populations, with average observed heterozygosity (Ho value of 0.2168, which was lower than the standard heterozygosity in marine populations (Ho = 0.79. This alongside the high Fis values estimation, high pairwise differentiation among populations and low within population variations are supposed to be associated with small sample size, and inbreeding system. Besides, the significant finding of this study was the sharing of common haplotype KR086940, which reflects a historical genetic connectivity between Peninsular Malaysia and Borneo populations due to the geological history of Southeast Asia during Pleistocene era. Demographic analyses showed that all populations were in an equilibrium state with no significant evidence of population expansion. To put it briefly, the current study has

  19. Model of Yield Response of Corn to Plant Population and Absorption of Solar Energy

    Science.gov (United States)

    Overman, Allen R.; Scholtz, Richard V.

    2011-01-01

    Biomass yield of agronomic crops is influenced by a number of factors, including crop species, soil type, applied nutrients, water availability, and plant population. This article is focused on dependence of biomass yield (Mg ha−1 and g plant−1) on plant population (plants m−2). Analysis includes data from the literature for three independent studies with the warm-season annual corn (Zea mays L.) grown in the United States. Data are analyzed with a simple exponential mathematical model which contains two parameters, viz. Ym (Mg ha−1) for maximum yield at high plant population and c (m2 plant−1) for the population response coefficient. This analysis leads to a new parameter called characteristic plant population, xc = 1/c (plants m−2). The model is shown to describe the data rather well for the three field studies. In one study measurements were made of solar radiation at different positions in the plant canopy. The coefficient of absorption of solar energy was assumed to be the same as c and provided a physical basis for the exponential model. The three studies showed no definitive peak in yield with plant population, but generally exhibited asymptotic approach to maximum yield with increased plant population. Values of xc were very similar for the three field studies with the same crop species. PMID:21297960

  20. [Genetic effects in populations of plants growing in the zone of Kyshtym and Chernobyl accidents].

    Science.gov (United States)

    Shevchenko, V A; Kal'chenko, V A; Abramov, V I; Rubanovich, A V; Shevchenko, V V; Grinikh, L I

    1999-01-01

    Studies to analyze the genetic processes in natural populations of plants were started on the territory of the East-Ural Radioactive Trace (EURT) in 1962 and in the zone of the Chernobyl accident in May 1986. The main directions of the genetic studies in both radioactive areas were similar: 1) study of the mutation process intensity depending on the dose and dose rate and analysis of dose-effect relationships for different genetic changes (point mutations, chromosome aberrations in mitosis and meiosis) in irradiated plant populations; 2) study of the mutation process dynamics in generations of chronically (prolongly) irradiated populations of plants; 3) analysis of microevolutionary processes in irradiated plant populations. The report presents an analysis of observed dose-effect relationships under the action of radiation on populations of Arabidopsis thaliana, Pinus sylvestris and a number of other plant species. Analysis of the mutation processes dynamics in 8 Arabidopsis populations growing in the zone of the Chernobyl catastrophe has demonstrated that the level of the embryo lethal mutations 10 years after the accident in the irradiated populations significantly exceeds the control level. The following phenomena observed in chronically irradiated populations have also been considered: increased radioresistance of irradiated populations (radioadaptation), the appearance of abnormal karyotypes and selective markers upon chronic irradiation. The authors call attention to the high importance of monitoring of genetic processes in irradiated plant populations for understanding of the action of radiation on human populations.

  1. Competition between Plant-Populations with Different Rooting Depths. 2. Pot Experiments

    NARCIS (Netherlands)

    Berendse, F.

    1981-01-01

    In a previous paper in this series a model was proposed lor the competition between plant populations with different rooting depths. This model predicts that in mixtures of plant populations with different rooting depths the Relative Yield Total will exceed unity. Secondly it predicts that in these

  2. Highly diverse endophytic and soil Fusarium oxysporum populations associated with field-grown tomato plants.

    Science.gov (United States)

    Demers, Jill E; Gugino, Beth K; Jiménez-Gasco, María Del Mar

    2015-01-01

    The diversity and genetic differentiation of populations of Fusarium oxysporum associated with tomato fields, both endophytes obtained from tomato plants and isolates obtained from soil surrounding the sampled plants, were investigated. A total of 609 isolates of F. oxysporum were obtained, 295 isolates from a total of 32 asymptomatic tomato plants in two fields and 314 isolates from eight soil cores sampled from the area surrounding the plants. Included in this total were 112 isolates from the stems of all 32 plants, a niche that has not been previously included in F. oxysporum population genetics studies. Isolates were characterized using the DNA sequence of the translation elongation factor 1α gene. A diverse population of 26 sequence types was found, although two sequence types represented nearly two-thirds of the isolates studied. The sequence types were placed in different phylogenetic clades within F. oxysporum, and endophytic isolates were not monophyletic. Multiple sequence types were found in all plants, with an average of 4.2 per plant. The population compositions differed between the two fields but not between soil samples within each field. A certain degree of differentiation was observed between populations associated with different tomato cultivars, suggesting that the host genotype may affect the composition of plant-associated F. oxysporum populations. No clear patterns of genetic differentiation were observed between endophyte populations and soil populations, suggesting a lack of specialization of endophytic isolates. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  3. Ability of Matrix Models to Explain the Past and Predict the Future of Plant Populations

    NARCIS (Netherlands)

    E.E. Crone; M.M. Ellis; W.F. Morris; A. Stanley; T. Bell; P. Bierzychudek; J. Ehrlén; T.N. Kaye; T.M. Knight; P. Lesica; G. Oostermeijer; P.F. Quintana-Ascencio; T. Ticktin; T. Valverde; J.L. Williams; D.F. Doak; R. Ganesan; K.A. McEachern; A. Thorpe; E.S. Menges

    2013-01-01

    Uncertainty associated with ecological forecasts has long been recognized, but forecast accuracy is rarely quantified. We evaluated how well data on 82 populations of 20 species of plants spanning 3 continents explained and predicted plant population dynamics. We parameterized stage-based matrix mod

  4. Coupling bacterioplankton populations and environment to community function in coastal temperate waters

    DEFF Research Database (Denmark)

    Traving, S. J.; Bentzon-Tilia, Mikkel; Knudsen-Leerbeck, H.

    2016-01-01

    Bacterioplankton play a key role in marine waters facilitating processes important for carbon cycling. However, the influence of specific bacterial populations and environmental conditions on bacterioplankton community performance remains unclear. The aim of the present study was to identify driv...

  5. Application of plant growth regulators, a simple technique for improving the establishment success of plant cuttings in coastal dune restoration

    Science.gov (United States)

    Balestri, Elena; Vallerini, Flavia; Castelli, Alberto; Lardicci, Claudio

    2012-03-01

    Exogenous application of plant growth regulators (PGRs) may be an effective technique for increasing the rooting ability and the growth of vegetative fragments (cuttings) of plants used in dune restoration programs. Various concentrations (0, 50 and 100 mg l-1) of two auxins, alpha-naphtaleneacetic acid (NAA) and indole-3-butyric acid (IBA), and two cytokinins, 6-furfurylaminopurine (Kinetin) and 6-benzylaminopurine (BAP), were applied separately to cuttings of two widely used species for restoration, Ammophila arenaria and Sporobuls virginicus. Root development and production of new buds in cuttings were examined under laboratory conditions one month after application. Cuttings were also examined one year after transplanting into a sandy substratum under natural conditions, to test for possible long term effects of PGRs on plant establishment success and growth. The response of the two study species to PGRs differed substantially. In A. arenaria the auxin NAA at 100 mg l-1 reduced the time for root initiation and increased the rooting capacity of cuttings, while the cytokinin Kinetin at 50 mg l-1 facilitated root growth. No auxin had effect on rooting or growth of S. virginicus cuttings, but treatment with 100 mg l-1 Kinetin resulted in higher rooting success than the control. One year after planting, the cuttings of A. arenaria treated with 100 mg l-1 NAA showed a higher establishment success (90% vs. 55%) and produced more culms and longer roots than the control; those treated with cytokinins did not differ in the establishment success from the control, but had longer roots, more culms and rhizomes. On the other hand, the cuttings of S. virginicus treated with 100 mg l-1 Kinetin showed a higher establishment success (75% vs. 35%) and had more culms than the control. Therefore, in restoration activities that involved A. arenaria, a pre-treatment of cuttings with NAA would be beneficial, as it allows the production of a higher number of well-developed plants with

  6. Long-term impacts of nitrogen deposition on coastal plant communities

    DEFF Research Database (Denmark)

    Pakeman, Robin J.; Brooker, Rob; Alexander, Jim

    2016-01-01

    , Fixed dune, Heath, Slack and Tall grass mire communities and despite falls in EIV-N for Improved grass, Strand and Wet grassland. The increase in EIV-N was highly correlated to the cumulative deposition between the surveys, and for sites in south-east Scotland, eutrophication impacts appear severe....... Unlike other studies, there appears to have been no decline in species richness associated with nitrogen deposition, though losses of species were observed on sites with the very highest levels of SOx deposition. It appears that dune vegetation (specifically Fixed dune) shows evidence of eutrophication......Nitrogen deposition has been shown to have significant impacts on a range of vegetation types resulting in eutrophication and species compositional change. Data from a re-survey of 89 coastal sites in Scotland, UK, c. 34 years after the initial survey were examined to assess the degree of change...

  7. Genetic structure of colline and montane populations of an endangered plant species.

    Science.gov (United States)

    Maurice, Tiphaine; Matthies, Diethart; Muller, Serge; Colling, Guy

    2016-08-12

    Due to land-use intensification, lowland and colline populations of many plants of nutrient-poor grasslands have been strongly fragmented in the last decades, with potentially negative consequences for their genetic diversity and persistence. Populations in mountains might represent a genetic reservoir for grassland plants, because they have been less affected by land-use changes. We studied the genetic structure and diversity of colline and montane Vosges populations of the threatened perennial plant Arnica montana in western central Europe using AFLP markers. Our results indicate that in contrast to our expectation even strongly fragmented colline populations of A. montana have conserved a considerable amount of genetic diversity. However, mean seed mass increased with the proportion of polymorphic loci, suggesting inbreeding effects in low diversity populations. At a similar small geographical scale there was a clear IBD pattern for the montane Vosges but not for the colline populations. However, there was a strong IBD-pattern for the colline populations at a large geographical scale suggesting that this pattern is a legacy of historical gene flow, as most of the colline populations are today strongly isolated from each other. Genetic differentiation between colline and montane Vosges populations was strong. Moreover, results of a genome scan study indicated differences in loci under selection, suggesting that plants from montane Vosges populations might be maladapted to conditions at colline sites. Our results suggest caution in using material from montane populations of rare plants for the reinforcement of small genetically depauperate lowland populations.

  8. Genetic structure of colline and montane populations of an endangered plant species

    Science.gov (United States)

    Maurice, Tiphaine; Matthies, Diethart; Muller, Serge; Colling, Guy

    2016-01-01

    Due to land-use intensification, lowland and colline populations of many plants of nutrient-poor grasslands have been strongly fragmented in the last decades, with potentially negative consequences for their genetic diversity and persistence. Populations in mountains might represent a genetic reservoir for grassland plants, because they have been less affected by land-use changes. We studied the genetic structure and diversity of colline and montane Vosges populations of the threatened perennial plant Arnica montana in western central Europe using AFLP markers. Our results indicate that in contrast to our expectation even strongly fragmented colline populations of A. montana have conserved a considerable amount of genetic diversity. However, mean seed mass increased with the proportion of polymorphic loci, suggesting inbreeding effects in low diversity populations. At a similar small geographical scale, there was a clear IBD pattern for the montane Vosges but not for the colline populations. However, there was a strong IBD-pattern for the colline populations at a large geographical scale suggesting that this pattern is a legacy of historical gene flow, as most of the colline populations are today strongly isolated from each other. Genetic differentiation between colline and montane Vosges populations was strong. Moreover, results of a genome scan study indicated differences in loci under selection, suggesting that plants from montane Vosges populations might be maladapted to conditions at colline sites. Our results suggest caution in using material from montane populations of rare plants for the reinforcement of small genetically depauperate lowland populations. PMID:27519913

  9. Effects of tidal amplitude on intertidal resource availability and dispersal pressure in prehistoric human coastal populations: the Mediterranean Atlantic transition

    Science.gov (United States)

    Fa, Darren Andrew

    2008-11-01

    In this paper I argue that there is a growing body of evidence supporting an increasingly central position of coastal environments in human evolution and dispersals, rather than as merely peripheral habitats. Eustatic fluctuations during glacial cycles have meant that most prehistoric coastlines are now underwater, and lack of evidence to date of a close relationship between people and the coast can be most plausibly ascribed to the limited studies so far on submerged sites. Coastal environments provide high diversity in food resources, consisting of multiple ecotones in close proximity, which reduces the need to forage widely. One of the richest and most easily exploited coastal resources by human populations living on the coast are molluscs from marine rocky intertidal communities, which recent evidence has highlighted as important as far back as the Middle Palaeolithic. However, the density of these resources is limited by a number of factors, and this varies geographically. One of the main large-scale factors limiting rocky intertidal mollusc densities is tidal amplitude, beyond which smaller-scale local factors such as exposure to wave action and shore aspect, further affect species distributions. The area around the Strait of Gibraltar is used as a case study of an area, which is affected by large variations in tidal amplitudes thus allowing for quantitative comparisons between taxonomically and climatically similar regions. Shorelines along the Mediterranean coast, with reduced tidal amplitudes, exhibit compressed zonations and harbour fewer macro-mollusc individuals, with the reverse being the case along the Atlantic coast, which has significantly larger tides. Data from Middle and Upper Palaeolithic sites along the Strait are used to establish harvested species and present-day data are used to model the potential distributions and associated variables such as calorific returns of key food species. An optimal foraging model is used to explore the effects of

  10. Enhanced primary production in summer and winter-spring seasons in a populated NW Mediterranean coastal ecosystem

    Science.gov (United States)

    Guallar, Carles; Flos, Jordi

    2017-02-01

    Populated coastal ecosystems in the NW Mediterranean present three main characteristics that distinguish them from the open water ecosystem: a sea-land interaction, with freshwater influence from river mouths; a shallow seabed, which facilitates the interaction between the euphotic water column and the sediments; and high anthropogenic pressure, due to submarine sewage discharges. As a result, relatively high nutrient concentrations are measured in these ecosystems, with ammonia being an important fraction. These characteristics entail a different scenario from the open water ecosystem. Here, we present the distribution of phytoplankton primary production in the Barcelona coastal waters during summer and winter-spring seasons, by means of photosynthesis-irradiance experiments using the 14C technique. In winter-spring, stratification of the water column may begin earlier than in open water due to freshwater inputs. Therefore, with the water-column slightly stratified, chlorophyll-a and primary production become localised in the surface layers, due to the lower daily irradiance during this season. In these conditions, Total Primary Production (TPP) values measured ranged between 0.27 and 14.52 mgC m- 3 h- 1. As spring progresses and the stratification develops, surface waters tend to become nutrient depleted and nutrients are mainly localised in bottom waters between the thermocline and the seafloor. Under these conditions, high chlorophyll layers develop near the bottom. With the exception of their nutrient enrichment, these structures, referred to as coastal deep chlorophyll maxima, are comparable to the oceanic deep chlorophyll maxima in temperate oligotrophic seas. The nutrient enrichment is the result of the sediment resuspension from the seabed and the presence of sewage water discharged from the submarine outfall. These structures are highly productive (ca. 60% of water column primary production), comparable to the winter-spring bloom, and are sustained

  11. Review of water intake screening options for coastal water users with recommendations for Ocean Thermal Energy Conversion (OTEC) plants

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D.L.

    1979-05-01

    The large volumes of water withdrawn at both the warm and cold water intakes of an OTEC plant must be screened to remove organisms and debris which could clog the heat exchangers. The recent literature on screening technology is reviewed. In addition, various screen manufacturers and coastal facilities which use large volumes of seawater were visited to determine the operating experience with present screen technology. Static screens (particularly the Johnson Division, UOP profile wire screen and the Royce Equipment Company carrousel screen) have the potential advantage for OTEC for operating in a completely submerged state and of being cheaper to operate and maintain than traveling screens. However, there is no operational history with these static screens for large intake systems. The most promising traveling screen options for OTEC are the dual flow screens. They offer more screening surface and less head loss than through flow screens of similar size. They also have been operated in seawater for large intake systems. More detailed designs of potential OTEC plants, particurlarly screen wells, conduit and surge tank construction and head losses need to be determined before the best alternative intake screen can be selected. 38 references.

  12. The abundance of pink-pigmented facultative methylotrophs in the root zone of plant species in invaded coastal sage scrub habitat.

    Science.gov (United States)

    Irvine, Irina C; Brigham, Christy A; Suding, Katharine N; Martiny, Jennifer B H

    2012-01-01

    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.

  13. 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.

  14. Persistent organic pollutants (POPs) in populations of the clam Chione californiensis in coastal lagoons of the Gulf of California.

    Science.gov (United States)

    Vargas-González, Héctor H; Méndez-Rodríguez, Lía C; García-Hernández, Jaqueline; Mendoza-Salgado, Renato A; Zenteno-Savín, Tania; Arreola-Lizárraga, José A

    2016-07-02

    This study examines the potential public health risk due to the massive use of organochlorine pesticides (OCs) in agriculture in the Gulf of California. Specimens of the clam Chione californiensis were collected from three coastal lagoons (Yavaros, Altata and Reforma). Sites were classified as polluted/nonpolluted based on the presence/absence of OCs as an indicator of the persistence of these pollutants; in polluted sites, the time elapsed since pesticide application (past or recent) was estimated. Screening values (SV) for protecting human health as per the U.S. Environmental Protection Agency (EPA) were used for risk assessment. OCs detected were ranked according to frequency of occurrence as follows: γ-chlordane (75%) > endrin (54%) > aldrin (48%) > heptachlor, and dichlorodiphenyl-trichloroethane (DDE) (37%) > β-heptachlor epoxide (30%) > lindane (α-BHC, δ-BHC) and endosulphan I (≤ 6%). Specifically, OCs detected at the highest concentration were heptachlor in Yavaros (0.0168 µgg(-1)) and Altata (0.0046 µgg(-1)), and aldrin in Reforma (0.0019 µgg(-1)). β-Heptachlor epoxide in Altata and Reforma was the only OC with a concentration exceeding the EPA Screening Value. From our results and based on the monthly consumption limit set forth by EPA, the maximum safe consumption of clams to avoid a carcinogenic risk derived from β-heptachlor epoxide in the fishing villages of Yavaros and Altata is 4 servings per month (1 serving = 0.227 kg) by a 70-kg person. These findings suggest that concentrations of OCs and their isomers in C. californiensis populations reflect environmental persistence as well as recent inputs of OCs into coastal lagoons in the Gulf of California.

  15. Electrofishing as a sampling technique for coastal stream fish populations and communities in the Southeast of Brazil.

    Science.gov (United States)

    Mazzoni; Fenerich-Verani; Caramaschi

    2000-05-01

    Electrofishing adequacy was tested as a technique to obtain quantitative data of coastal stream fish populations and communities in the Southeast of Brazil. Seven field trips, between July/94 and July/95, were done in 5 localities of the Ubatiba fluvial system (Maricá, RJ). Seventeen species, among the 22 collected, had their numbers estimated through the Zipping method, the model used to test the sampling methodology. At each field trip, three removals with electrofishing were done in each locality and, according to the number of obtained species at each locality/field trip, we analysed 315 cases. Nineteen cases, among 315, showed failure condition. Estimates were significant (p catchability and the estimated number of individuals and/or environmental characteristics. High values for sampling efficiency (> 85%) were found for all estimates. An experimental analyses were done for one locality and, the comparison between the estimates for 3 and 6 successive removals showed a mean error and a standard deviation of 5.5% and 2.1% respectively. Therefore, it can be concluded that electrofishing was an efficient method for quantitative data analysis of fish populations and communities in the Ubatiba fluvial system.

  16. Quantifying age-related rates of social contact using diaries in a rural coastal population of Kenya.

    Directory of Open Access Journals (Sweden)

    Moses Chapa Kiti

    Full Text Available Improved understanding and quantification of social contact patterns that govern the transmission dynamics of respiratory viral infections has utility in the design of preventative and control measures such as vaccination and social distancing. The objective of this study was to quantify an age-specific matrix of contact rates for a predominantly rural low-income population that would support transmission dynamic modeling of respiratory viruses.From the population register of the Kilifi Health and Demographic Surveillance System, coastal Kenya, 150 individuals per age group (50 years exhibited the highest inter-generational contacts. Rural contact rates were higher than semiurban (18.8 vs 15.6, p = 0.002, with rural primary school students having twice as many assortative contacts as their semiurban peers.This is the first age-specific contact matrix to be defined for tropical Sub-Saharan Africa and has utility in age-structured models to assess the potential impact of interventions for directly transmitted respiratory infections.

  17. Quantifying Age-Related Rates of Social Contact Using Diaries in a Rural Coastal Population of Kenya

    Science.gov (United States)

    Kiti, Moses Chapa; Kinyanjui, Timothy Muiruri; Koech, Dorothy Chelagat; Munywoki, Patrick Kiio; Medley, Graham Francis; Nokes, David James

    2014-01-01

    Background Improved understanding and quantification of social contact patterns that govern the transmission dynamics of respiratory viral infections has utility in the design of preventative and control measures such as vaccination and social distancing. The objective of this study was to quantify an age-specific matrix of contact rates for a predominantly rural low-income population that would support transmission dynamic modeling of respiratory viruses. Methods and Findings From the population register of the Kilifi Health and Demographic Surveillance System, coastal Kenya, 150 individuals per age group (50 years) exhibited the highest inter-generational contacts. Rural contact rates were higher than semiurban (18.8 vs 15.6, p = 0.002), with rural primary school students having twice as many assortative contacts as their semiurban peers. Conclusions and Significance This is the first age-specific contact matrix to be defined for tropical Sub-Saharan Africa and has utility in age-structured models to assess the potential impact of interventions for directly transmitted respiratory infections. PMID:25127257

  18. Synthesis of silver nanoparticles by coastal plant Prosopis chilensis (L.) and their efficacy in controlling vibriosis in shrimp Penaeus monodon

    Science.gov (United States)

    Kandasamy, Kathiresan; Alikunhi, Nabeel M.; Manickaswami, Gayathridevi; Nabikhan, Asmathunisha; Ayyavu, Gopalakrishnan

    2013-02-01

    The present work investigated the effect of leaf extract from coastal plant Prosopis chilensis on synthesis of silver nanoparticles using AgNO3 as a substrate and to find their antibacterial potential on pathogenic Vibrio species in the shrimp, Penaeus monodon. The leaf extract could be able to produce silver nanoparticles, as evident by gradual change in colour of the reaction mixture consisted of the extract and 1 mM AgNO3 to dark brown. The silver nanoparticles exhibited 2 θ values corresponding to the presence of silver nanocrystal, as evident by X-ray diffraction spectrum. The peaks corresponding to flavanones and terpenoids were found to be stabilizing agents of the nanoparticles, as revealed by Fourier transform infrared spectroscopy. The size of silver nanoparticles ranged from 5 to 25 nm with an average of 11.3 ± 2.1 nm and was mostly of spherical in shape, as confirmed by transmission electron microscopy. The silver nanoparticles were found to inhibit Vibrio pathogens viz., Vibrio cholerae, V. harveyi, and V. parahaemolyticus and this antibacterial effect was better than that of leaf extract, as proved by disc diffusion assay. The nanoparticles were then tested in the shrimp Penaeus monodon challenged with the four species of Vibrio pathogens for 30 days. The shrimps fed with silver nanoparticles exhibited higher survival, associated with immunomodulation in terms of higher haemocyte counts, phenoloxidase and antibacterial activities of haemolymph of P. monodon which is on par with that of control. Thus, the present study proved the possibility of using silver nanoparticles produced by coastal Prosopis chilensis as antibacterial agent in controlling vibriosis.

  19. Forest fragmentation effects on patch occupancy and population viability of herbaceous plant species

    OpenAIRE

    Honnay, Olivier; Jacquemyn, Hans; Bossuyt, B; Hermy, Martin

    2005-01-01

    Habitat fragmentation is one of the major threats to species diversity. In this review, we discuss how the genetic and demographic structure of fragmented populations of herbaceous forest plant species is affected by increased genetic drift and inbreeding, reduced mate availability, altered interactions with pollinators, and changed environmental conditions through edge effects. Reported changes in population genetic and demographic structure of fragmented plant populations have, however, not...

  20. Reduced fecundity in small populations of the rare plant Gentianopsis ciliate (Gentianaceae)

    Science.gov (United States)

    Kery, M.; Matthies, D.

    2004-01-01

    Habitat destruction is the main cause for the biodiversity crisis. Surviving populations are often fragmented, i.e., small and isolated from each other. Reproduction of plants in small populations is often reduced, and this has been attributed to inbreeding depression, reduced attractiveness for pollinators, and reduced habitat quality in small populations. Here we present data on the effects of fragmentation on the rare, self-compatible perennial herb Gentianopsis ciliata (Gentianaceae), a species with very small and presumably well-dispersed seeds. We studied the relationship between population size, plant size, and the number of flowers produced in 63 populations from 1996-1998. In one of the years, leaf and flower size and the number of seeds produced per fruit was studied in a subset of 25 populations. Plant size, flower size, and the number of seeds per fruit and per plant increased with population size, whereas leaf length and the number of flowers per plant did not. The effects of population size on reproduction and on flower size remained significant if the effects were adjusted for differences in plant size, indicating that they could not be explained by differences in habitat quality. The strongly reduced reproduction in small populations may be due to pollination limitation, while the reduced flower size could indicate genetic effects.

  1. Implications of human induced changes on the distribution of important plant species in the northwestern coastal desert of Egypt

    Directory of Open Access Journals (Sweden)

    Marwa Waseem Halmy

    2015-12-01

    Full Text Available The application of species distribution modeling in deserts is a useful tool for mapping species and assessing the impact of human induced changes on individual species. Such applications are still rare, and this may be attributed to the fact that much of the arid lands and deserts around the world are located in inaccessible areas. Few studies have conducted spatially explicit modeling of plant species distribution in Egypt. The random forest modeling approach was applied to climatic and land-surface parameters to predict the distribution of ten important plant species in an arid landscape in the northwestern coastal desert of Egypt. The impact of changes in land use and climate on the distribution of the plant species was assessed. The results indicate that the changes in land use in the area have resulted in habitat loss for all the modeled species. Projected future changes in land use reveals that all the modeled species will continue to suffer habitat loss. The projected impact of modeled climate scenarios (A1B, A2A and B2A on the distribution of the modeled species by 2040 varied. Some of the species were projected to be adversely affected by the changes in climate, while other species are expected to benefit from these changes. The combined impact of the changes in land use and climate pose serious threats to most of the modeled species. The study found that all the species are expected to suffer loss in habitat, except Gymnocarpos decanderus. The study highlights the importance of assessing the impact of land use/climate change scenarios on other species of restricted distribution in the area and can help shape policy and mitigation measures directed toward biodiversity conservation in Egypt.

  2. Long-term persistence of a neotropical ant-plant population in the absence of obligate plant-ants.

    Science.gov (United States)

    Moraes, Sinara C; Vasconcelos, Heraldo L

    2009-09-01

    Interactions between ants and ant-plants are considered classic examples of obligate mutualisms. Previous studies have indicated that for many ant-plants the loss of ant colonies results in severe defoliation or mortality. Although individual plants can persist for some period of time without their mutualistic partners, to date populations of ant-free plants have only been recorded at high altitudes or on remote islands where herbivores are also scarce. We studied the interaction between ants, herbivores, and the ant-plant Tococa guianensis in the Cerrado region of central Brazil. Using a survey conducted across a large geographic region, we show that there is interpopulation variation in ant occupancy across sites and habitats. At most sites surveyed, plants were inhabited by Allomerus octoarticulatus, an obligate plant-ant. Plants with obligate ants had significantly lower standing levels of herbivore damage than plants with opportunistic ants and plants with no ant occupants. Furthermore, experimental removal of A. octoarticulatus resulted in increased levels of damage in both young and mature leaves. Despite the protection provided by obligate ants, populations of T. guianensis were found to persist without these ants in some areas. Plants without A. octoarticulatus had significantly greater leaf toughness and trichome density than those with A. octoarticulatus. Furthermore, trichome density in plants with A. octoarticulatus increased after ants were removed, probably as a response induced by increased levels of herbivore damage. To our knowledge, this is the first record of the occurrence of native myrmecophyte populations without their mutualistic ants in mainland low-elevation sites. Several factors may help to explain the long-term persistence of T. guianensis populations without plant-ants in some areas of the Brazilian Cerrado, including its potential for induced morphological defenses against insect herbivores and selection for increased levels of

  3. Density Effects on Plant Height Growth and Inequality in Sunflower Populations

    Institute of Scientific and Technical Information of China (English)

    Sa Xiao; Shu-Yan Chen; Lu-Qiang Zhao; Gang Wang

    2006-01-01

    Comparisons between competing and non-competing sunflower (Helianthus annuus L.) populations demonstrate pronounced effects of density on plant height growth, height-to-crown width ratio, and a population's height inequality. In the present study, non-destructive measurements of height and the projected crown area of sunflower plants were taken at seven times from emergence to fruit maturation in even-aged monospecific stands with initial densities of 1, 4, 16, and 64 plants/m2. The mean height of populations increased and then decreased with increasing population density; the height inequalities of uncrowded populations decreased during stand growth, whereas the height inequalities of crowded populations decreased first and then increased during stand development. The interindividual relationships between the relative height growth rate and height within uncrowded populations became significantly negative during population growth, whereas these relationships were negative first and then became positive during the development of crowded populations. In the uncrowded populations, the static interindividual relationship between height-to-crown width ratio and volume was positive, whereas for the crowded population these relationships became negative with increasing competition for light. The data suggest that the plastic responses of plant height and height-to-crown width ratio to light competition will become more intense with increasing competition intensity. The results of the present study argue strongly for the importance of size-dependent individual-level plastic responses due to size-asymmetric light competition in generating the variations in population height inequality.

  4. Transients drive the demographic dynamics of plant populations in variable environments

    DEFF Research Database (Denmark)

    McDonald, Jenni L; Stott, Iain; Townley, Stuart;

    2016-01-01

    clear patterns related to growth form. We find a surprising tendency for plant populations to boom rather than bust in response to temporal changes in vital rates and that stochastic growth rates increase with increasing tendency to boom. Synthesis. Transient dynamics contribute significantly......The dynamics of structured plant populations in variable environments can be decomposed into the ‘asymptotic’ growth contributed by vital rates, and ‘transient’ growth caused by deviation from stable stage structure. We apply this framework to a large, global data base of longitudinal studies...... of projection matrix models for plant populations. We ask, what is the relative contribution of transient boom and bust to the dynamic trajectories of plant populations in stochastic environments? Is this contribution patterned by phylogeny, growth form or the number of life stages per population and per...

  5. Genetic differentiation among Maconellicoccus hirsutus (Hemiptera: Pseudococcidae) populations living on different host plants.

    Science.gov (United States)

    Rosas-García, Ninfa M; Sarmiento-Benavides, Sandra L; Villegas-Mendoza, Jesús M; Hernández-Delgado, Sanjuana; Mayek-Pérez, Netzahualcoyotl

    2010-06-01

    The pink hibiscus mealybug Maconellicoccus hirsutus (Green) is a dangerous pest that damages a wide variety of agricultural, horticultural, and forestry crops. Amplified fragment length polymorphism (AFLP) fingerprints were used to characterize the genetic variation of 11 M. hirsutus populations infesting three plant species in Nayarit, Mexico. Analysis was carried out using four primers combinations, producing 590 polymorphic bands. Cluster analysis, as well as bootstrap dendrogram and nonmetric multidimensional scaling analysis, grouped M. hirsutus populations according to their host plant. The estimated F(ST) values indicated a high differentiation in M. hirsutus populations among the three host plant species. These results were also supported by a Bayesian analysis, which indicated a population clustering robustness according to their host plant. Genetic variation among populations is not caused by geographic distances, as shown by a Mantel test.

  6. Pleistocene glacial refugia across the Appalachian Mountains and coastal plain in the millipede genus Narceus: Evidence from population genetic, phylogeographic, and paleoclimatic data

    Directory of Open Access Journals (Sweden)

    Marek Paul E

    2009-01-01

    Full Text Available Abstract Background Species that are widespread throughout historically glaciated and currently non-glaciated areas provide excellent opportunities to investigate the role of Pleistocene climatic change on the distribution of North American biodiversity. Many studies indicate that northern animal populations exhibit low levels of genetic diversity over geographically widespread areas whereas southern populations exhibit relatively high levels. Recently, paleoclimatic data have been combined with niche-based distribution modeling to locate possible refugia during the Last Glacial Maximum. Using phylogeographic, population, and paleoclimatic data, we show that the distribution and mitochondrial data for the millipede genus Narceus are consistent with classical examples of Pleistocene refugia and subsequent post-glacial population expansion seen in other organismal groups. Results The phylogeographic structure of Narceus reveals a complex evolutionary history with signatures of multiple refugia in southeastern North America followed by two major northern expansions. Evidence for refugial populations were found in the southern Appalachian Mountains and in the coastal plain. The northern expansions appear to have radiated from two separate refugia, one from the Gulf Coastal Plain area and the other from the mid-Atlantic coastal region. Distributional models of Narceus during the Last Glacial Maximum show a dramatic reduction from the current distribution, with suitable ecological zones concentrated along the Gulf and Atlantic coastal plain. We found a strong correlation between these zones of ecological suitability inferred from our paleo-model with levels of genetic diversity derived from phylogenetic and population estimates of genetic structuring. Conclusion The signature of climatic change, during and after the Pleistocene, on the distribution of the millipede genus Narceus is evident in the genetic data presented. Niche-based historical

  7. Pleistocene glacial refugia across the Appalachian Mountains and coastal plain in the millipede genus Narceus: evidence from population genetic, phylogeographic, and paleoclimatic data.

    Science.gov (United States)

    Walker, Matt J; Stockman, Amy K; Marek, Paul E; Bond, Jason E

    2009-01-30

    Species that are widespread throughout historically glaciated and currently non-glaciated areas provide excellent opportunities to investigate the role of Pleistocene climatic change on the distribution of North American biodiversity. Many studies indicate that northern animal populations exhibit low levels of genetic diversity over geographically widespread areas whereas southern populations exhibit relatively high levels. Recently, paleoclimatic data have been combined with niche-based distribution modeling to locate possible refugia during the Last Glacial Maximum. Using phylogeographic, population, and paleoclimatic data, we show that the distribution and mitochondrial data for the millipede genus Narceus are consistent with classical examples of Pleistocene refugia and subsequent post-glacial population expansion seen in other organismal groups. The phylogeographic structure of Narceus reveals a complex evolutionary history with signatures of multiple refugia in southeastern North America followed by two major northern expansions. Evidence for refugial populations were found in the southern Appalachian Mountains and in the coastal plain. The northern expansions appear to have radiated from two separate refugia, one from the Gulf Coastal Plain area and the other from the mid-Atlantic coastal region. Distributional models of Narceus during the Last Glacial Maximum show a dramatic reduction from the current distribution, with suitable ecological zones concentrated along the Gulf and Atlantic coastal plain. We found a strong correlation between these zones of ecological suitability inferred from our paleo-model with levels of genetic diversity derived from phylogenetic and population estimates of genetic structuring. The signature of climatic change, during and after the Pleistocene, on the distribution of the millipede genus Narceus is evident in the genetic data presented. Niche-based historical distribution modeling strengthens the conclusions drawn from the

  8. The demographic consequences of mutualism: ants increase host-plant fruit production but not population growth.

    Science.gov (United States)

    Ford, Kevin R; Ness, Joshua H; Bronstein, Judith L; Morris, William F

    2015-10-01

    The impact of mutualists on a partner's demography depends on how they affect the partner's multiple vital rates and how those vital rates, in turn, affect population growth. However, mutualism studies rarely measure effects on multiple vital rates or integrate them to assess the ultimate impact on population growth. We used vital rate data, population models and simulations of long-term population dynamics to quantify the demographic impact of a guild of ant species on the plant Ferocactus wislizeni. The ants feed at the plant's extrafloral nectaries and attack herbivores attempting to consume reproductive organs. Ant-guarded plants produced significantly more fruit, but ants had no significant effect on individual growth or survival. After integrating ant effects across these vital rates, we found that projected population growth was not significantly different between unguarded and ant-guarded plants because population growth was only weakly influenced by differences in fruit production (though strongly influenced by differences in individual growth and survival). However, simulations showed that ants could positively affect long-term plant population dynamics through services provided during rare but important events (herbivore outbreaks that reduce survival or years of high seedling recruitment associated with abundant precipitation). Thus, in this seemingly clear example of mutualism, the interaction may actually yield no clear benefit to plant population growth, or if it does, may only do so through the actions of the ants during rare events. These insights demonstrate the value of taking a demographic approach to studying the consequences of mutualism.

  9. Ability of matrix models to explain the past and predict the future of plant populations.

    Science.gov (United States)

    Crone, Elizabeth E; Ellis, Martha M; Morris, William F; Stanley, Amanda; Bell, Timothy; Bierzychudek, Paulette; Ehrlén, Johan; Kaye, Thomas N; Knight, Tiffany M; Lesica, Peter; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F; Ticktin, Tamara; Valverde, Teresa; Williams, Jennifer L; Doak, Daniel F; Ganesan, Rengaian; McEachern, Kathyrn; Thorpe, Andrea S; Menges, Eric S

    2013-10-01

    Uncertainty associated with ecological forecasts has long been recognized, but forecast accuracy is rarely quantified. We evaluated how well data on 82 populations of 20 species of plants spanning 3 continents explained and predicted plant population dynamics. We parameterized stage-based matrix models with demographic data from individually marked plants and determined how well these models forecast population sizes observed at least 5 years into the future. Simple demographic models forecasted population dynamics poorly; only 40% of observed population sizes fell within our forecasts' 95% confidence limits. However, these models explained population dynamics during the years in which data were collected; observed changes in population size during the data-collection period were strongly positively correlated with population growth rate. Thus, these models are at least a sound way to quantify population status. Poor forecasts were not associated with the number of individual plants or years of data. We tested whether vital rates were density dependent and found both positive and negative density dependence. However, density dependence was not associated with forecast error. Forecast error was significantly associated with environmental differences between the data collection and forecast periods. To forecast population fates, more detailed models, such as those that project how environments are likely to change and how these changes will affect population dynamics, may be needed. Such detailed models are not always feasible. Thus, it may be wiser to make risk-averse decisions than to expect precise forecasts from models. © 2013 Society for Conservation Biology.

  10. Ability of matrix models to explain the past and predict the future of plant populations.

    Science.gov (United States)

    McEachern, Kathryn; Crone, Elizabeth E.; Ellis, Martha M.; Morris, William F.; Stanley, Amanda; Bell, Timothy; Bierzychudek, Paulette; Ehrlen, Johan; Kaye, Thomas N.; Knight, Tiffany M.; Lesica, Peter; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Ticktin, Tamara; Valverde, Teresa; Williams, Jennifer I.; Doak, Daniel F.; Ganesan, Rengaian; Thorpe, Andrea S.; Menges, Eric S.

    2013-01-01

    Uncertainty associated with ecological forecasts has long been recognized, but forecast accuracy is rarely quantified. We evaluated how well data on 82 populations of 20 species of plants spanning 3 continents explained and predicted plant population dynamics. We parameterized stage-based matrix models with demographic data from individually marked plants and determined how well these models forecast population sizes observed at least 5 years into the future. Simple demographic models forecasted population dynamics poorly; only 40% of observed population sizes fell within our forecasts' 95% confidence limits. However, these models explained population dynamics during the years in which data were collected; observed changes in population size during the data-collection period were strongly positively correlated with population growth rate. Thus, these models are at least a sound way to quantify population status. Poor forecasts were not associated with the number of individual plants or years of data. We tested whether vital rates were density dependent and found both positive and negative density dependence. However, density dependence was not associated with forecast error. Forecast error was significantly associated with environmental differences between the data collection and forecast periods. To forecast population fates, more detailed models, such as those that project how environments are likely to change and how these changes will affect population dynamics, may be needed. Such detailed models are not always feasible. Thus, it may be wiser to make risk-averse decisions than to expect precise forecasts from models.

  11. Biomarker measurements in a coastal fish-eating population environmentally exposed to organochlorines.

    Science.gov (United States)

    Ayotte, Pierre; Dewailly, Eric; Lambert, George H; Perkins, Sherry L; Poon, Raymond; Feeley, Mark; Larochelle, Christian; Pereg, Daria

    2005-10-01

    The Lower North Shore region of the St. Lawrence River is home to a fish-eating population that displays an unusually high body burden of several organochlorines, including polychlorinated biphenyls (PCBs) and dioxin-like compounds (DLCs). We measured biomarkers indicative of liver enzyme induction and investigated the relationship with organochlorine body burden in adult volunteers from this population. We determined plasma concentrations of PCBs and chlorinated pesticides by high-resolution gas chromatography (HRGC) with electron capture detection. DLC concentrations were measured by the dioxin-receptor chemically activated luciferase expression (DR-CALUX) assay and in a subset of participants, by HRGC/high-resolution mass spectrometry. We measured cotinine, d-glucaric acid, and porphyrins in morning urine samples and determined liver CYP1A2 activity in vivo using the caffeine breath test. Neither DLC concentrations as measured by the DR-CALUX nor PCB-153 concentrations, the latter representing total PCB exposure, were correlated with biomarkers of effects. Smoking (morning urinary cotinine concentration) was positively related to CYP1A2 activity as measured by the caffeine breath test (p biomarkers of hepatic enzyme induction. Our data are consistent with smoking-induced liver CYP1A2 activity altering heme metabolism and increasing the biotransformation of mono-ortho PCB congeners.

  12. Forest fragmentation effects on patch occupancy and population viability of herbaceous plant species.

    Science.gov (United States)

    Honnay, Olivier; Jacquemyn, Hans; Bossuyt, Beatrijs; Hermy, Martin

    2005-06-01

    Habitat fragmentation is one of the major threats to species diversity. In this review, we discuss how the genetic and demographic structure of fragmented populations of herbaceous forest plant species is affected by increased genetic drift and inbreeding, reduced mate availability, altered interactions with pollinators, and changed environmental conditions through edge effects. Reported changes in population genetic and demographic structure of fragmented plant populations have, however, not resulted in large-scale extinction of forest plants. The main reason for this is very likely the long-term persistence of small and isolated forest plant populations due to prolonged clonal growth and long generation times. Consequently, the persistence of small forest plant populations in a changing landscape may have resulted in an extinction debt, that is, in a distribution of forest plant species reflecting the historical landscape configuration rather than the present one. In some cases, fragmentation appears to affect ecosystem integrity rather than short-term population viability due to the opposition of different fragmentation-induced ecological effects. We finally discuss extinction and colonization dynamics of forest plant species at the regional scale and suggest that the use of the metapopulation concept, both because of its heuristic power and conservation applications, may be fruitful.

  13. A crab swarm at an ecological hotspot: patchiness and population density from AUV observations at a coastal, tropical seamount

    Science.gov (United States)

    Cho, Walter; Starczak, Victoria; Govindarajan, Annette F.; Guzman, Héctor M.; Girdhar, Yogesh; Holleman, Rusty C.; Churchill, James; Singh, Hanumant; Ralston, David K.

    2016-01-01

    A research cruise to Hannibal Bank, a seamount and an ecological hotspot in the coastal eastern tropical Pacific Ocean off Panama, explored the zonation, biodiversity, and the ecological processes that contribute to the seamount’s elevated biomass. Here we describe the spatial structure of a benthic anomuran red crab population, using submarine video and autonomous underwater vehicle (AUV) photographs. High density aggregations and a swarm of red crabs were associated with a dense turbid layer 4–10 m above the bottom. The high density aggregations were constrained to 355–385 m water depth over the Northwest flank of the seamount, although the crabs also occurred at lower densities in shallower waters (∼280 m) and in another location of the seamount. The crab aggregations occurred in hypoxic water, with oxygen levels of 0.04 ml/l. Barcoding of Hannibal red crabs, and pelagic red crabs sampled in a mass stranding event in 2015 at a beach in San Diego, California, USA, revealed that the Panamanian and the Californian crabs are likely the same species, Pleuroncodes planipes, and these findings represent an extension of the southern endrange of this species. Measurements along a 1.6 km transect revealed three high density aggregations, with the highest density up to 78 crabs/m2, and that the crabs were patchily distributed. Crab density peaked in the middle of the patch, a density structure similar to that of swarming insects. PMID:27114859

  14. A crab swarm at an ecological hotspot: patchiness and population density from AUV observations at a coastal, tropical seamount

    Directory of Open Access Journals (Sweden)

    Jesús Pineda

    2016-04-01

    Full Text Available A research cruise to Hannibal Bank, a seamount and an ecological hotspot in the coastal eastern tropical Pacific Ocean off Panama, explored the zonation, biodiversity, and the ecological processes that contribute to the seamount’s elevated biomass. Here we describe the spatial structure of a benthic anomuran red crab population, using submarine video and autonomous underwater vehicle (AUV photographs. High density aggregations and a swarm of red crabs were associated with a dense turbid layer 4–10 m above the bottom. The high density aggregations were constrained to 355–385 m water depth over the Northwest flank of the seamount, although the crabs also occurred at lower densities in shallower waters (∼280 m and in another location of the seamount. The crab aggregations occurred in hypoxic water, with oxygen levels of 0.04 ml/l. Barcoding of Hannibal red crabs, and pelagic red crabs sampled in a mass stranding event in 2015 at a beach in San Diego, California, USA, revealed that the Panamanian and the Californian crabs are likely the same species, Pleuroncodes planipes, and these findings represent an extension of the southern endrange of this species. Measurements along a 1.6 km transect revealed three high density aggregations, with the highest density up to 78 crabs/m2, and that the crabs were patchily distributed. Crab density peaked in the middle of the patch, a density structure similar to that of swarming insects.

  15. A crab swarm at an ecological hotspot: patchiness and population density from AUV observations at a coastal, tropical seamount.

    Science.gov (United States)

    Pineda, Jesús; Cho, Walter; Starczak, Victoria; Govindarajan, Annette F; Guzman, Héctor M; Girdhar, Yogesh; Holleman, Rusty C; Churchill, James; Singh, Hanumant; Ralston, David K

    2016-01-01

    A research cruise to Hannibal Bank, a seamount and an ecological hotspot in the coastal eastern tropical Pacific Ocean off Panama, explored the zonation, biodiversity, and the ecological processes that contribute to the seamount's elevated biomass. Here we describe the spatial structure of a benthic anomuran red crab population, using submarine video and autonomous underwater vehicle (AUV) photographs. High density aggregations and a swarm of red crabs were associated with a dense turbid layer 4-10 m above the bottom. The high density aggregations were constrained to 355-385 m water depth over the Northwest flank of the seamount, although the crabs also occurred at lower densities in shallower waters (∼280 m) and in another location of the seamount. The crab aggregations occurred in hypoxic water, with oxygen levels of 0.04 ml/l. Barcoding of Hannibal red crabs, and pelagic red crabs sampled in a mass stranding event in 2015 at a beach in San Diego, California, USA, revealed that the Panamanian and the Californian crabs are likely the same species, Pleuroncodes planipes, and these findings represent an extension of the southern endrange of this species. Measurements along a 1.6 km transect revealed three high density aggregations, with the highest density up to 78 crabs/m(2), and that the crabs were patchily distributed. Crab density peaked in the middle of the patch, a density structure similar to that of swarming insects.

  16. Genetic Diversity and Demographic History of Wild and Cultivated/Naturalised Plant Populations: Evidence from Dalmatian Sage (Salvia officinalis L., Lamiaceae).

    Science.gov (United States)

    Rešetnik, Ivana; Baričevič, Dea; Batîr Rusu, Diana; Carović-Stanko, Klaudija; Chatzopoulou, Paschalina; Dajić-Stevanović, Zora; Gonceariuc, Maria; Grdiša, Martina; Greguraš, Danijela; Ibraliu, Alban; Jug-Dujaković, Marija; Krasniqi, Elez; Liber, Zlatko; Murtić, Senad; Pećanac, Dragana; Radosavljević, Ivan; Stefkov, Gjoshe; Stešević, Danijela; Šoštarić, Ivan; Šatović, Zlatko

    2016-01-01

    Dalmatian sage (Salvia officinalis L., Lamiaceae) is a well-known aromatic and medicinal Mediterranean plant that is native in coastal regions of the western Balkan and southern Apennine Peninsulas and is commonly cultivated worldwide. It is widely used in the food, pharmaceutical and cosmetic industries. Knowledge of its genetic diversity and spatiotemporal patterns is important for plant breeding programmes and conservation. We used eight microsatellite markers to investigate evolutionary history of indigenous populations as well as genetic diversity and structure within and among indigenous and cultivated/naturalised populations distributed across the Balkan Peninsula. The results showed a clear separation between the indigenous and cultivated/naturalised groups, with the cultivated material originating from one restricted geographical area. Most of the genetic diversity in both groups was attributable to differences among individuals within populations, although spatial genetic analysis of indigenous populations indicated the existence of isolation by distance. Geographical structuring of indigenous populations was found using clustering analysis, with three sub-clusters of indigenous populations. The highest level of gene diversity and the greatest number of private alleles were found in the central part of the eastern Adriatic coast, while decreases in gene diversity and number of private alleles were evident towards the northwestern Adriatic coast and southern and eastern regions of the Balkan Peninsula. The results of Ecological Niche Modelling during Last Glacial Maximum and Approximate Bayesian Computation suggested two plausible evolutionary trajectories: 1) the species survived in the glacial refugium in southern Adriatic coastal region with subsequent colonization events towards northern, eastern and southern Balkan Peninsula; 2) species survived in several refugia exhibiting concurrent divergence into three genetic groups. The insight into genetic

  17. Genetic Diversity and Demographic History of Wild and Cultivated/Naturalised Plant Populations: Evidence from Dalmatian Sage (Salvia officinalis L., Lamiaceae.

    Directory of Open Access Journals (Sweden)

    Ivana Rešetnik

    Full Text Available Dalmatian sage (Salvia officinalis L., Lamiaceae is a well-known aromatic and medicinal Mediterranean plant that is native in coastal regions of the western Balkan and southern Apennine Peninsulas and is commonly cultivated worldwide. It is widely used in the food, pharmaceutical and cosmetic industries. Knowledge of its genetic diversity and spatiotemporal patterns is important for plant breeding programmes and conservation. We used eight microsatellite markers to investigate evolutionary history of indigenous populations as well as genetic diversity and structure within and among indigenous and cultivated/naturalised populations distributed across the Balkan Peninsula. The results showed a clear separation between the indigenous and cultivated/naturalised groups, with the cultivated material originating from one restricted geographical area. Most of the genetic diversity in both groups was attributable to differences among individuals within populations, although spatial genetic analysis of indigenous populations indicated the existence of isolation by distance. Geographical structuring of indigenous populations was found using clustering analysis, with three sub-clusters of indigenous populations. The highest level of gene diversity and the greatest number of private alleles were found in the central part of the eastern Adriatic coast, while decreases in gene diversity and number of private alleles were evident towards the northwestern Adriatic coast and southern and eastern regions of the Balkan Peninsula. The results of Ecological Niche Modelling during Last Glacial Maximum and Approximate Bayesian Computation suggested two plausible evolutionary trajectories: 1 the species survived in the glacial refugium in southern Adriatic coastal region with subsequent colonization events towards northern, eastern and southern Balkan Peninsula; 2 species survived in several refugia exhibiting concurrent divergence into three genetic groups. The insight

  18. Genetic Diversity and Demographic History of Wild and Cultivated/Naturalised Plant Populations: Evidence from Dalmatian Sage (Salvia officinalis L., Lamiaceae)

    Science.gov (United States)

    Rešetnik, Ivana; Baričevič, Dea; Batîr Rusu, Diana; Carović-Stanko, Klaudija; Chatzopoulou, Paschalina; Dajić-Stevanović, Zora; Gonceariuc, Maria; Grdiša, Martina; Greguraš, Danijela; Ibraliu, Alban; Jug-Dujaković, Marija; Krasniqi, Elez; Liber, Zlatko; Murtić, Senad; Pećanac, Dragana; Radosavljević, Ivan; Stefkov, Gjoshe; Stešević, Danijela; Šoštarić, Ivan; Šatović, Zlatko

    2016-01-01

    Dalmatian sage (Salvia officinalis L., Lamiaceae) is a well-known aromatic and medicinal Mediterranean plant that is native in coastal regions of the western Balkan and southern Apennine Peninsulas and is commonly cultivated worldwide. It is widely used in the food, pharmaceutical and cosmetic industries. Knowledge of its genetic diversity and spatiotemporal patterns is important for plant breeding programmes and conservation. We used eight microsatellite markers to investigate evolutionary history of indigenous populations as well as genetic diversity and structure within and among indigenous and cultivated/naturalised populations distributed across the Balkan Peninsula. The results showed a clear separation between the indigenous and cultivated/naturalised groups, with the cultivated material originating from one restricted geographical area. Most of the genetic diversity in both groups was attributable to differences among individuals within populations, although spatial genetic analysis of indigenous populations indicated the existence of isolation by distance. Geographical structuring of indigenous populations was found using clustering analysis, with three sub-clusters of indigenous populations. The highest level of gene diversity and the greatest number of private alleles were found in the central part of the eastern Adriatic coast, while decreases in gene diversity and number of private alleles were evident towards the northwestern Adriatic coast and southern and eastern regions of the Balkan Peninsula. The results of Ecological Niche Modelling during Last Glacial Maximum and Approximate Bayesian Computation suggested two plausible evolutionary trajectories: 1) the species survived in the glacial refugium in southern Adriatic coastal region with subsequent colonization events towards northern, eastern and southern Balkan Peninsula; 2) species survived in several refugia exhibiting concurrent divergence into three genetic groups. The insight into genetic

  19. Characteristics of coastal dune topography and vegetation in environments recently modified using beach fill and vegetation plantings, Veneto, Italy.

    Science.gov (United States)

    Nordstrom, Karl F; Gamper, Ulrike; Fontolan, Giorgio; Bezzi, Annelore; Jackson, Nancy L

    2009-12-01

    Human actions can contribute to degradation of coastal environments or they can increase the likelihood that these environments will be restored. Beach nourishment provides a basis for restoration, but ways must be found to add habitat improvement to projects designed for shore protection. This study examines how beach nourishment projects can help reinstate dune landscapes in locations where beaches and dunes had been replaced by static shore protection structures. Dune topography and vegetation on three nourished sites on the northern Adriatic Coast of Italy are compared to a reference site to evaluate changes after beach fill was emplaced. Results reveal how nourishment projects used for shore protection can restore the space available for dunes to form, increase the likelihood of sediment transfers inland and increase the diversity of topography and vegetation. Beach raking prevents formation and growth of hummocky, incipient backshore dunes that would otherwise evolve into a naturally functioning foredune. Sand-trapping fences can speed the process of foredune development but can be counterproductive if they interfere with transport to beach grass (Ammophila littoralis) planted landward of them. Shore protection structures can provide stability and more time for dune evolution on eroding shores, resulting in greater species richness and longer retention of ecological niches. These structures need not be required if re-nourishment occurs frequently enough to provide a beach wide enough to protect against storm wave uprush.

  20. Chemical defenses (glucosinolates) of native and invasive populations of the range expanding invasive plant Rorippa austriaca.

    Science.gov (United States)

    Huberty, Martine; Tielbörger, Katja; Harvey, Jeffrey A; Müller, Caroline; Macel, Mirka

    2014-04-01

    Due to global warming, species are expanding their range to higher latitudes. Some range expanding plants have become invasive in their new range. The Evolution of Increased Competitive Ability (EICA) hypothesis and the Shifting Defense Hypothesis (SDH) predict altered selection on plant defenses in the introduced range of invasive plants due to changes in herbivore pressures and communities. Here, we investigated chemical defenses (glucosinolates) of five native and seven invasive populations of the Eurasian invasive range expanding plant, Rorippa austriaca. Further, we studied feeding preferences of a generalist and a specialist herbivore among the populations. We detected eight glucosinolates in the leaves of R. austriaca. 8-Methylsulfinyloctyl glucosinolate was the most abundant glucosinolate in all plants. There were no overall differences between native and invasive plants in concentrations of glucosinolates. However, concentrations among populations within each range differed significantly. Feeding preference between the populations by a generalist herbivore was negatively correlated with glucosinolate concentrations. Feeding by a specialist did not differ between the populations and was not correlated with glucosinolates. Possibly, local differences in herbivore communities within each range may explain the differences in concentrations of glucosinolates among populations. Little support for the predictions of the EICA hypothesis or the SDH was found for the glucosinolate defenses of the studied native and invasive R. austriaca populations.

  1. Natural radionuclide of Po210 in the edible seafood affected by coal-fired power plant industry in Kapar coastal area of Malaysia

    OpenAIRE

    Mohamed Che Abd Rahim; Alam Lubna

    2011-01-01

    Abstract Background Po210 can be accumulated in various environmental materials, including marine organisms, and contributes to the dose of natural radiation in seafood. The concentration of this radionuclide in the marine environment can be influenced by the operation of a coal burning power plant but existing studies regarding this issue are not well documented. Therefore, the aim of this study was to estimate the Po210 concentration level in marine organisms from the coastal area of Kapar,...

  2. The role of advection in the distribution of plankton populations at a moored 1-D coastal observatory

    Science.gov (United States)

    Cross, Jaimie; Nimmo-Smith, W. Alex M.; Hosegood, Philip J.; Torres, Ricardo

    2015-09-01

    The degree to which advection modulates the distribution of plankton populations at a 1-D coastal observatory was assessed at station L4 in the western English Channel (50°15‧N 4°13‧W, depth 50 m), part of the Western Channel Observatory (WCO). Five tidal-cycle surveys were conducted, three in spring and two in summer 2010. Observations of the physical characteristics of L4 were obtained by using a moored acoustic doppler current profiler (ADCP) and a free-falling microstructure sensor (MSS). The moored ADCP highlighted the presence of vertical shear, with typical values of U during spring tides of ∼0.5 m s-1 at the surface and ∼0.2 m s-1 at the bed. The distribution of phyto- and zooplankton populations above a size threshold of 200 μm were examined using an in-line holographic imaging system, the Holocam. Variability in time as well as depth is a common feature throughout each of the surveys, with examples of recorded numbers of phytoplankton that ranged between 1300 L-1 and 2300 L-1 at the same depth but at different points within the tidal cycle. Further, at the same points in the tidal cycle the number of recorded zooplankton was also seen to vary, specifically with the identification of gelatinous planula in spring that increased the observed number to maximums of between 140 L-1 and 220 L-1 in the upper layer, considerably higher that the corresponding WP-2 net counts for a similar period. Specific aspects of the movement and transfer of plankton relating to advection and interaction with the pycnocline are identified, both across tidal cycles and seasons.

  3. Testing the importance of plant strategies on facilitation using congeners in a coastal community.

    Science.gov (United States)

    He, Qiang; Cui, Baoshan; Bertness, Mark D; An, Yuan

    2012-09-01

    Much is known about how environmental stress mediates the strength of facilitation, but less is known about how different plant traits affect facilitation. We examined interactions between the shrub Tamarix chinensis and two congeneric forbs (Suaeda salsa and S. glauca) on the Chinese coast. Although S. salsa and S. glauca are both annuals, morphologically similar, and have synchronous phenologies, they have contrasting adaptive strategies. S. glauca is salt intolerant but competitively superior, and S. salsa is salt tolerant but competitively inferior. Field surveys showed that S. glauca was associated with T. chinensis canopies while S. salsa was more abundant in open areas. A T. chinensis removal experiment showed that S. glauca cover was lower and soil salinity higher after two years in removal than in control plots. Transplant experiments showed that S. salsa performance under T. chinensis canopies was reduced by competition from S. glauca and T. chinensis, while in open areas S. glauca was not affected by S. salsa competition. Thus, contrasting competitive abilities and stress tolerances of S. glauca and S. salsa underlie their facilitative and competitive interactions with T. chinensis, suggesting that plant strategies are critical to the outcome of species interactions.

  4. Abundance pattern of wedge clam Donax cuneatus (L.) in different spatial scale in the vicinity of a coastal nuclear power plant.

    Science.gov (United States)

    Hussain, K Jahir; Mohanty, A K; Satpathy, K K; Prasad, M V R

    2010-04-01

    Impact of thermal discharge from a coastal power station (Madras Atomic Power Station, southeast coast of India) on the spatial variability of Donax cuneatus abundance was assessed to determine the impact boundary. Totally, 20 sites were selected both on south and north side in increasing spatial scale from mixing zone, 12 locations were selected toward south side at a distance from 0 (near mixing point) to 2,000 m and eight location were selected toward north from the effluent mixing zone. Mean water temperature along the coast ranged from 29.1 +/-0.15 degrees C to 31.2 +/- 0.15 degrees C. Total organic carbon content in the sediment ranged from 0.27% to 0.70%. D. cuneatus population on the swash zone was ranged between 1.3 +/- 1.5 and 88.3 +/- 9.6 m(-2). Meager population of wedge clam was observed up to 100 m (S100) south from mixing point and abundance gradually increased in different spatial scale. Comparatively high abundance was observed from S400 and reached maximum at S1000 (64.0 +/- 3.6 m(-2)). Similar pattern was observed on north side too but less abundance was observed only up to 80 m (N80). Maximum abundance was observed at control location C3-N500 (88.3 +/- 9.6 m(-2)). Forty meters on either side of discharge point was highly impacted, 80 to 100 m toward plume flow (south) was moderately impacted, and 80 m north of mixing point also witnessed moderate impact. After 100 m (N100), north was not affected by effluents, whereas between 100 and 400 m, south was influenced slightly. Multivariate clustering pattern on the environmental variables of all sampling locations and population trend of D. cuneatus at those stations showed similarity. Present investigation unambiguously showed that the abundance pattern of D. cuneatus on the sandy beach of east coast of Kalpakkam is not governed by single major factor but due to the result of multiple interacting factors. The population size of the wedge clam with reference to the effect of power plant effluents and

  5. Advancing environmentally explicit structured population models of plants

    DEFF Research Database (Denmark)

    Ehrlén, Johan; Morris, William; von Euler, Tove

    2016-01-01

    The relationship between the performance of individuals and the surrounding environment is fundamental in ecology and evolutionary biology. Assessing how abiotic and biotic environmental factors influence demographic processes is necessary to understand and predict population dynamics, as well as...

  6. Forest succession and population viability of grassland plants

    DEFF Research Database (Denmark)

    Lehtilä, Kari; Dahlgren, Johan; Garcia, Maria Begona

    2016-01-01

    Time lags in responses of organisms to deteriorating environmental conditions delay population declines and extinctions. We examined how local processes at the population level contribute to extinction debt, and how cycles of habitat deterioration and recovery may delay extinction. We carried out....... The simulations indicated that P. veris populations may have an extinction time of decades to centuries after a detrimental management change. A survey of the current incidence and abundance of P. veris in sites with different histories of afforestation confirmed the simulation results of low extinction rates. P....... veris had reduced incidence and abundance only at sites with at least 100 years of forest cover. Time to extinction in simulations was dependent on the duration of the periods with favourable and unfavourable conditions after management cessation, and the population sizes and growth rates...

  7. Local and global influences on population declines of coastal waders: Purple Sandpiper Calidris maritima numbers in the Moray Firth, Scotland

    Science.gov (United States)

    Summers, Ron W.; Foster, Simon; Swann, Bob; Etheridge, Brian

    2012-05-01

    Declines in numbers by several wader species in Britain have been linked to climate change, but the mechanism for the declines has rarely been explored. Britain lies at the northern end of the East Atlantic Flyway, and supports 1.3 million out of the Flyway's 8.5 million coastal waders (Charadrii) in winter and the Purple Sandpiper is one of the species whose numbers have declined. Here, we examine the dynamics of the decline as observed in the Moray Firth, northeast Scotland, investigating whether the decline was due to poorer apparent survival (return rate) or poorer recruitment of young birds. The maximum number in the Moray Firth declined from 860 in 1987/88 to 236 in 2006/07, with some increase during winters 2007/08 and 2008/09. At the three main high-tide roosts (Balintore, Lossiemouth and Buckie) the maximum combined number declined from 574 to 90. Changes in survival and recruitment (percentage of first-year birds) were examined at these roosts from captured samples, which were ringed and recaptured. There were no significant changes between winters in survival rates, nor were there differences between the survival rates of age groups (first-year and adult) or bill size groups, which represented birds of different sex and breeding origin. Annual survival estimates for the three roosts ranged from 72 to 77%. The percentage of first-year birds varied among roosts and years; the lowest values were during the late 1980s/early 1990s and early 2000s. A free-running population model incorporating varying percentages of first-year birds and constant mortality for each roost provided a plausible explanation for the decline. Although modelled numbers followed the observed pattern, a discrepancy in one year was carried forward in subsequent years, so that the fit with the observed numbers was parallel rather than similar. However, it seems that the decline in numbers was largely due to poorer recruitment. We discuss whether breeding success had declined, whether the

  8. Microbial populations responsible for specific soil suppressiveness to plant pathogens

    NARCIS (Netherlands)

    Weller, D.M.; Raaijmakers, J.M.; McSpadden Gardener, B.B.; Thomashow, L.S.

    2002-01-01

    Agricultural soils suppressive to soilborne plant pathogens occur worldwide, and for several of these soils the biological basis of suppressiveness has been described. Two classical types of suppressiveness are known. General suppression owes its activity to the total microbial biomass in soil and i

  9. Research progress of plant population genomics based on high-throughput sequencing.

    Science.gov (United States)

    Yunsheng, Wang

    2016-08-01

    Population genomics, a new paradigm for population genetics, combine the concepts and techniques of genomics with the theoretical system of population genetics and improve our understanding of microevolution through identification of site-specific effect and genome-wide effects using genome-wide polymorphic sites genotypeing. With the appearance and improvement of the next generation high-throughput sequencing technology, the numbers of plant species with complete genome sequences increased rapidly and large scale resequencing has also been carried out in recent years. Parallel sequencing has also been done in some plant species without complete genome sequences. These studies have greatly promoted the development of population genomics and deepened our understanding of the genetic diversity, level of linking disequilibium, selection effect, demographical history and molecular mechanism of complex traits of relevant plant population at a genomic level. In this review, I briely introduced the concept and research methods of population genomics and summarized the research progress of plant population genomics based on high-throughput sequencing. I also discussed the prospect as well as existing problems of plant population genomics in order to provide references for related studies.

  10. The urban populations behavior facing a performant project of incineration plant

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-01-01

    This work deals with the different reactions of populations facing a performant project of incineration plant. Fears and advanced arguments (fog, pollutants, trucks traffic, effects on grounds and on surrounding farmings, effects on human health) are described. (O.L.).

  11. Mangrove plants in coastal area of Central Java: 2. Floristic composition and vegetation structure

    Directory of Open Access Journals (Sweden)

    KUSUMO WINARNO

    2005-07-01

    Full Text Available The study was intended to observe the vegetation composition and structure of mangrove plants on southern and northern coast of Central Java Province. This research was conducted in July till December 2003, at 20 sites. Laboratory assay was done in Laboratory of Biology Department, Faculty of Mathematics and Natural Sciences, and Central Laboratory of Mathematics and Natural Sciences, Sebelas Maret University (UNS Surakarta. Data was collected by using belt transect method, from coast line into landward. The result indicated that in common, the trees strata which also have shoots strata and strata of germs (seedlings; and bushes strata which also have strata of germs (seedlings, if they were compared to the same species then their important value tend to be stable. So it was predictable that in the disturbance condition, the preservation of mangrove was guaranteed, as long as there was no great change on a broad scale.

  12. Volatile Constituents of Different Plant Parts and Populations of Malabaila aurea Boiss. from Montenegro

    OpenAIRE

    Ivan Vučković; Ljubodrag Vujisić; Marina Todosijević; Danijela Stešević; Slobodan Milosavljević; Sne žana Trifunović

    2014-01-01

    The volatile constituents of different plant parts and populations of Malabaila aurea Boiss. from Montenegro were obtained by simultaneous distillation-extraction and analyzed by GC-FID and GC-MS. A total of 12 samples were examined and 45 compounds were identified. The volatile content of different M. aurea populations was very similar, while the volatile fractions obtained from different plant parts showed significant qualitative and quantitative differences. The most abundant compounds fou...

  13. A whole plant approach to evaluate the water use of mediterranean maquis species in a coastal dune ecosystem

    Directory of Open Access Journals (Sweden)

    S. Mereu

    2009-02-01

    Full Text Available An integrated approach has been used to analyse the water relations of three Mediterranean species, A. unedo L., Q. ilex L. and P. latifolia L. co-occurring in a coastal dune ecosystem. The approach considered leaf level gas exchange, sap flow measurements and structural adaptations between 15 May and 31 July 2007, and was necessary to capture the different response of the three species to the same environment. The complexity of the response was proportional to the complexity of the system, characterized by a sandy soil with a low water retention capacity and the presence of a water table. The latter did not completely prevent the development of a drought response, and species differences in this responses have been partially attributed to a different root distribution. Sap flow of A. unedo decreased rapidly in response to the decline of Soil Water Content, while that of Q. ilex decreased only moderately. Midday leaf water potential of P. latifolia and A. unedo was between 2.2 and 2.7 MPa through the measuring period, while in Q. ilex it reached a value of 3.4 MPa at the end of the season. A. unedo was the only species to decrease the leaf area to sapwood area ratio from 23.9±1.2 (May to 15.2±1.5 (July, as a response to drought. A. unedo also underwent an almost stepwise loss on hydraulic conductivity, such a loss didn't occur for Q. ilex, while P. latifolia was able to slightly increase hydraulic conductivity, showing how different plant compartments coordinate differently between species as a response to drought. Such different coordination affects the gas exchange between vegetation and the atmosphere, and has implications for the response of the Mediterranean coastal dune ecosystems to climate change.

  14. Population dynamics of bacteria involved in enhanced biological phosphorus removal in Danish wastewater treatment plants.

    Science.gov (United States)

    Mielczarek, Artur Tomasz; Nguyen, Hien Thi Thu; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

    2013-03-15

    The enhanced biological phosphorus removal (EBPR) process is increasingly popular as a sustainable method for removal of phosphorus (P) from wastewater. This study consisted of a comprehensive three-year investigation of the identity and population dynamics of polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in 28 Danish municipal wastewater treatment plants with nutrient removal. Fluorescence in situ hybridization was applied to quantify ten probe-defined populations of PAO and GAO that in total constituted a large fraction (30% on average) of the entire microbial community targeted by the EUBmix probes. Two PAO genera, Accumulibacter and Tetrasphaera, were very abundant in all EBPR plants (average of 3.7% and 27% of all bacteria, respectively), and their abundance was relatively stable in the Danish full-scale plants without clear temporal variations. GAOs were occasionally present in some plants (Competibacter in 11 plants, Defluviicoccus in 6 plants) and were consistent in only a few plants. This shows that these were not core species in the EBPR communities. The total GAO abundance was always lower than that of Accumulibacter. In plants without EBPR design, the abundance of PAO and GAO was significantly lower. Competibacter correlated in general with high fraction of industrial wastewater. In specific plants Accumulibacter correlated with high C/P ratio of the wastewater and Tetrasphaera with high organic loading. Interestingly, the relative microbial composition of the PAO/GAO species was unique to each plant over time, which gives a characteristic plant-specific "fingerprint".

  15. Competition Between Plant Populations with Different Rooting Depths I. Theoretical Considerations

    NARCIS (Netherlands)

    Berendse, Frank

    1979-01-01

    As an extension of De Wit’s competition theory a theoretical description has been developed of competition between plant populations with different rooting depths. This model shows that in mixtures of plants with different rooting depths the value of the Relative Yield Total can be expected to excee

  16. Competition between Plant-Populations with Different Rooting Depths. 1. Theoretical Considerations

    NARCIS (Netherlands)

    Berendse, F.

    1979-01-01

    As an extension of De Wit's competition theory a theoretical description has been developed of competition between plant populations with different rooting depths. This model shows that in mixtures of plants with different rooting depths the value of the Relative Yield Total can be expected to excee

  17. 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

  18. Occupational hazard evaluation of working population in a select automotive industrial plant.

    Science.gov (United States)

    Wójcik, Alicja; Borzecki, Zdzisław; Kowalska, Edyta; Borzecki, Andrzej

    2004-01-01

    The research was conducted in the selected vehicle industry plant. Work conditions were assessed on the assembly line by measuring chemical and physical factors. Exposure to noise in the investigated plant exceeded the values of permissible standards. The pollution on the posts did not exceed the standards except singular concentrations. While assessing the values of chemical factors concentration, no toxicological danger was revealed in the investigated population. The work conditions of the investigated plant did not create the danger of professional diseases.

  19. [Monitoring the thermal plume from coastal nuclear power plant using satellite remote sensing data: modeling, and validation].

    Science.gov (United States)

    Zhu, Li; Zhao, Li-Min; Wang, Qiao; Zhang, Ai-Ling; Wu, Chuan-Qing; Li, Jia-Guo; Shi, Ji-Xiang

    2014-11-01

    Thermal plume from coastal nuclear power plant is a small-scale human activity, mornitoring of which requires high-frequency and high-spatial remote sensing data. The infrared scanner (IRS), on board of HJ-1B, has an infrared channel IRS4 with 300 m and 4-days as its spatial and temporal resolution. Remote sensing data aquired using IRS4 is an available source for mornitoring thermal plume. Retrieval pattern for coastal sea surface temperature (SST) was built to monitor the thermal plume from nuclear power plant. The research area is located near Guangdong Daya Bay Nuclear Power Station (GNPS), where synchronized validations were also implemented. The National Centers for Environmental Prediction (NCEP) data was interpolated spatially and temporally. The interpolated data as well as surface weather conditions were subsequently employed into radiative transfer model for the atmospheric correction of IRS4 thermal image. A look-up-table (LUT) was built for the inversion between IRS4 channel radiance and radiometric temperature, and a fitted function was also built from the LUT data for the same purpose. The SST was finally retrieved based on those preprocessing procedures mentioned above. The bulk temperature (BT) of 84 samples distributed near GNPS was shipboard collected synchronically using salinity-temperature-deepness (CTD) instruments. The discrete sample data was surface interpolated and compared with the satellite retrieved SST. Results show that the average BT over the study area is 0.47 degrees C higher than the retrieved skin temperature (ST). For areas far away from outfall, the ST is higher than BT, with differences less than 1.0 degrees C. The main driving force for temperature variations in these regions is solar radiation. For areas near outfall, on the contrary, the retrieved ST is lower than BT, and greater differences between the two (meaning > 1.0 degrees C) happen when it gets closer to the outfall. Unlike the former case, the convective heat

  20. Ecological behavior and effects of energy related pollutants. Progress report, June 1976--August 1977. [SO2 impact on survival and stability of plant species; fallout /sup 137/Cs transfer processes in Southeastern Coastal Plain ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Platt, R.B.; Ragsdale, H.L.; Murdy, W.H.; Shure, D.J.

    1977-10-25

    The impact of SO/sub 2/ on the survival and stability of plant populations and communities was studied. The results to date have an important bearing on the adequacy of current permissible ambient air levels for SO/sub 2/. Atmospheric SO/sub 2/ concentrations at near permissible levels had a significant adverse effect on sexual reproduction processes, which results in a reduced number of viable seeds, in all 8 populations tested. Implications for both natural and agricultural plant species and possible significant losses of fruit production are discussed. An ecological implication of the invisible effect of fruit and seed mortality is postulated since the life cycle of many insects and the trophic relations of numerous animals depend, at least in part, on fruit production by trees and shrubs. Hence, there is a potential for disruptive effects on ecosystem level processes. Results are also reported from four systems-oriented studies within the Lower Three Runs Creek Watershed, Savannah River Plant, to examine fallout /sup 137/Cs transfer processes in ecological systems characteristic of the Southeastern Coastal Plain. These studies were carried out within the stream and its floodplains, within floodplains along the stream gradient, in upland aquatic systems (Carolina Bays), and in the upland scrub-oak forest system. Results are discussed.

  1. Diversity and phosphate solubilization by bacteria isolated from Laki Island coastal ecosystem

    OpenAIRE

    SRI WIDAWATI

    2011-01-01

    Widawati S (2011) Diversity and phosphate solubilization by bacteria isolated from Laki Island coastal ecosystem. Biodiversitas 12: 17-21. Soil, water, sand, and plant rhizosphere samples collected from coastal ecosystem of Laki Island-Jakarta were screened for phosphate solubilizing bacteria (PSB). While the population was dependent on the cultivation media and the sample type, the highest bacterial population was observed in the rhizosphere of Ipomea aquatica. The PSB strains isolated from ...

  2. Aboveground Biomass Estimation of Individual Trees in a Coastal Planted Forest Using Full-Waveform Airborne Laser Scanning Data

    Directory of Open Access Journals (Sweden)

    Lin Cao

    2016-09-01

    Full Text Available The accurate estimation of individual tree level aboveground biomass (AGB is critical for understanding the carbon cycle, detecting potential biofuels and managing forest ecosystems. In this study, we assessed the capability of the metrics of point clouds, extracted from the full-waveform Airborne Laser Scanning (ALS data, and of composite waveforms, calculated based on a voxel-based approach, for estimating tree level AGB individually and in combination, over a planted forest in the coastal region of east China. To do so, we investigated the importance of point cloud and waveform metrics for estimating tree-level AGB by all subsets models and relative weight indices. We also assessed the capability of the point cloud and waveform metrics based models and combo model (including the combination of both point cloud and waveform metrics for tree-level AGB estimation and evaluated the accuracies of these models. The results demonstrated that most of the waveform metrics have relatively low correlation coefficients (<0.60 with other metrics. The combo models (Adjusted R2 = 0.78–0.89, including both point cloud and waveform metrics, have a relatively higher performance than the models fitted by point cloud metrics-only (Adjusted R2 = 0.74–0.86 and waveform metrics-only (Adjusted R2 = 0.72–0.84, with the mostly selected metrics of the 95th percentile height (H95, mean of height of median energy (HOMEμ and mean of the height/median ratio (HTMRμ. Based on the relative weights (i.e., the percentage of contribution for R2 of the mostly selected metrics for all subsets, the metric of 95th percentile height (H95 has the highest relative importance for AGB estimation (19.23%, followed by 75th percentile height (H75 (18.02% and coefficient of variation of heights (Hcv (15.18% in the point cloud metrics based models. For the waveform metrics based models, the metric of mean of height of median energy (HOMEμ has the highest relative importance for AGB

  3. Offsets in radiocarbon ages between plants and shells from same horizons of coastal sediments in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Toshimichi [Geologic Environment Division, Korea Institute of Geoscience & Mineral Resources, Gajeong-dong 30, Yuseong-gu, Daejeon (Korea, Republic of); Hong, Wan, E-mail: whong@kigam.re.kr [Geologic Environment Division, Korea Institute of Geoscience & Mineral Resources, Gajeong-dong 30, Yuseong-gu, Daejeon (Korea, Republic of); Sung, Ki Suk [Geologic Environment Division, Korea Institute of Geoscience & Mineral Resources, Gajeong-dong 30, Yuseong-gu, Daejeon (Korea, Republic of); Carbon Analysis Laboratory (CAL), 25, 114 Gil, Taejeon-ro, Dong-gu, Daejeon (Korea, Republic of); Sung, Kil Ho [Geologic Environment Division, Korea Institute of Geoscience & Mineral Resources, Gajeong-dong 30, Yuseong-gu, Daejeon (Korea, Republic of); University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon (Korea, Republic of); Nakashima, Rei [Institute of Geology & Geoinformation, Advanced Industrial Science & Technology, Higashi 1-1-1, Tsukuba, Ibaraki (Japan)

    2015-10-15

    To measure the spatial and chronological changes of the reservoir effect around the Korean Peninsula, the radiocarbon ages of 38 marine shell and terrestrial plant pairs from the same horizons of six cores of Holocene sediments collected from the southern coast and western coast sites of the peninsula were measured. These reservoir ages (R) were distributed in the range of 430 ± 190 yrs within 60 ± 60 to 1000 ± 60 yrs starting in 9000 cal BP. The average R values of the cores obtained from large rivers, such as the S13 and YAR-4 cores (340 and 190 yrs), were clearly smaller than the R values of the sites far from a large river, such as the S15 and W09 cores (470 and 650 yrs). This is thought to be associated with the mixing process of old brine and young freshwater. On the other hand, the R values of the S13, W17, and YAR-4 cores gradually increased during the time span from 6700 to 8200 cal BP. The R values for the S15 core also increased in the period from 2800 to 3800 cal BP. Such tendencies result from the mixing ratio increase of brine due to the rising sea level.

  4. Variation in plant defences among populations of a range-expanding plant: consequences for trophic interactions

    NARCIS (Netherlands)

    Fortuna, Taiadjana M.; Eckert, Silvia; Harvey, Jeffrey A.; Vet, Louise E. M.; Mueller, Caroline; Gols, Rieta

    2014-01-01

    Although plant-herbivore-enemy interactions have been studied extensively in cross-continental plant invasions, little is known about intra-continental range expanders, despite their rapid spread globally. Using an ecological and metabolomics approach, we compared the insect performance of a general

  5. Anthropometrics of mental foramen in dry dentate and edentulous mandibles in Coastal Andhra population of Andhra Pradesh State

    Directory of Open Access Journals (Sweden)

    Srinivas Moogala

    2014-01-01

    Full Text Available Aim: The aim of this study is to determine the morphological features and morphometrics of mental foramen with reference to surrounding anatomical landmarks in Coastal Andhra population of Andhra Pradesh State. Materials and Methods: Two-hundred and nineteen dry dentate and edentulous mandibles are examined in this study. Out of these 127 were dentate and 92 were edentulous. Various morphological and morphometrical parameters were measured by using digital Vernier caliper, metallic wire and metallic scale on both the right and left sides. Results: In the present study, the distance between most anterior margin of mental foramen and posterior border of ramus of the mandible is [MF-PR], MF-PR is 69.61 ± 6.03 mm on the right side and is 69.17 ± 6. 0 mm on left side in dentate mandible. In edentulous type, MF-PR is 68.39 ±6.4 mm on right side and 68.81 ± 6.55 mm on left side. In the present study, the distance between symphysis menti and most anterior margin of mental foramen [MF-SM] in dentate mandible is 28.24 ± 5.09 mm on right side and is 27.45 ± 3.7 mm on left side. In edentulous mandible (MF-SM is 28.51 ± 4.5 mm on right side and on left side is 27.99 ± 4.50 mm. Conclusion: Acquiring the knowledge and importance of anatomy of mental foramen is helpful in avoiding neurovascular complications, during regional anesthesia, peri apical surgeries, nerve repositioning and dental implant placement.

  6. Evolution of Wheat streak mosaic virus: dynamics of population growth within plants may explain limited variation.

    Science.gov (United States)

    French, Roy; Stenger, Drake C

    2003-01-01

    Like many other plant RNA viruses, Wheat streak mosaic virus (WSMV) sequence diversity within and among infected plants is low given the large number of virions produced. This may be explained by considering aspects of plant virus life history. Intracellular replication of RNA viruses is predominately linear, not exponential, which means that the rate at which mutations accumulate also is linear. Bottlenecks during systemic movement further limit diversity. Analysis of mixed infections with two WSMV isolates suggests that about four viral genomes participate in systemic invasion of each tiller. Low effective population size increases the role of stochastic processes on dynamics of plant virus population genetics and evolution. Despite low pair-wise diversity among isolates, the number of polymorphic sites within the U.S. population is about the same as between divergent strains or a sister species. Characteristics of polymorphism in the WSMV coat protein gene suggest that most variation appears neutral.

  7. Microbial populations responsible for specific soil suppressiveness to plant pathogens.

    Science.gov (United States)

    Weller, David M; Raaijmakers, Jos M; Gardener, Brian B McSpadden; Thomashow, Linda S

    2002-01-01

    Agricultural soils suppressive to soilborne plant pathogens occur worldwide, and for several of these soils the biological basis of suppressiveness has been described. Two classical types of suppressiveness are known. General suppression owes its activity to the total microbial biomass in soil and is not transferable between soils. Specific suppression owes its activity to the effects of individual or select groups of microorganisms and is transferable. The microbial basis of specific suppression to four diseases, Fusarium wilts, potato scab, apple replant disease, and take-all, is discussed. One of the best-described examples occurs in take-all decline soils. In Washington State, take-all decline results from the buildup of fluorescent Pseudomonas spp. that produce the antifungal metabolite 2,4-diacetylphloroglucinol. Producers of this metabolite may have a broader role in disease-suppressive soils worldwide. By coupling molecular technologies with traditional approaches used in plant pathology and microbiology, it is possible to dissect the microbial composition and complex interactions in suppressive soils.

  8. Genetic variability in chronic irradiated plant populations - Polymorphism and activity of antioxidant enzymes in chronic irradiated plant populations

    Energy Technology Data Exchange (ETDEWEB)

    Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)

    2014-07-01

    Introduction: The gene pool of natural population is constantly changing in order to provide the greatest fitness at this time. Ability of population to adapt to changing environmental conditions depends on genetic polymorphism of traits which are operates by selection. Chronic stress exposure can change amount or structure intra-population variability. Therefore, it is necessary to analyze the relationships between genetic polymorphism and stress factors, such as radiation exposure. This studies my assist in the development of new bio-indication methods. Materials and methods: Studying sites: Bryansk region is the most contaminated region of Russia as a result of Chernobyl accident. The initial activity by {sup 137}Cs on this territory reached 1 MBq/m{sup 2} above surface. Our study conducted in several districts of Bryansk region, which are characterized the most dose rate. Experimental sites similar to climate characteristics, stand of trees is homogeneous, pine trees take up a significant part of phytocenosis. Heavy metals content in soils and cones be within background. Dose rates vary from 0.14 to 130 mGy/year. Object: Pinus sylvestris L.,the dominant tree species in North European and Asian boreal forests. Scots pine has a long maturation period (18-20 month), which means that significant DNA damage may accumulate in the undifferentiated stem cells, even at low doses (or dose rates) during exposure to low concentrations of contaminants Isozyme analysis: We evaluated isozyme polymorphism of three antioxidant enzymes: superoxide dismutase, glutatione reductase and glutatione peroxidase. Analysis of enzymes activities: We chose key enzymes of antioxidant system for this experiment: superoxide dismutase, catalase and peroxidase. Results and conclusions: We estimated frequency of each allele in reference and experimental populations. based It was showed that frequency of rare alleles increase in chronic irradiated populations, i.e. increase the sampling variance

  9. Population Dynamics of Bean Leaf Beetle, Cerotoma trifurcata (Coleoptera: Chrysomelidae on Edamame Soybean Plants In Nebraska

    Directory of Open Access Journals (Sweden)

    Bamphitlhi Tiroesele

    2013-02-01

    Full Text Available Edamame soybeans are a speciality food item for fresh and processed markets and they are harvested at a physiologically immature (R6 stage. Bean leaf beetle, Cerotoma trifurcata, is a sporadic pest of soybean in Nebraska, however, its pest status and abundance has increased in the recent years due to an increase in soybean acreage. This was a field experiment aimed at determining the population growth rate of bean leaf beetle on two edamame soybean cultivars, ‘Butterbeans’ and ‘Envy,’ at two planting dates during 2004 and 2005 in Nebraska. The population growth of beetles was significantly higher on 'Butterbeans' than on 'Envy' for both the first and second planting periods in both 2004 and 2005 seasons. The beetle infestation differences were noticed on plants at the late reproductive growth stages, R5 and R6. Additionally, the beetle infestation on 'Butterbeans' growth stages in 2004 and 2005 was significantly different for the first and second planting dates. On average, the beetles were higher on plants at the late reproductive stages than the other stages for first and second planting periods. Similarly, ‘Envy’ growth stages showed significant difference in beetle infestation during the first and second planting dates. Significantly high beetle infestations were observed at the vegetative growth stages. The study revealed that population growth of bean leaf beetles on edamame soybeans is affected by the planting date, season and cultivar choice.

  10. The Effects of Rainfall on the Population Dynamics of an Endangered Aquatic Plant, Schoenoplectus gemmifer (Cyperaceae).

    Science.gov (United States)

    Kitamura, Koshi; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Tainaka, Kei-Ichi; Yoshimura, Jin

    2016-01-01

    The conservation of aquatic plants in river ecosystems should consider the wash-out (away) problem resulting from severe rainfall. The aquatic plant Schoenoplectus gemmifer is an endangered species endemic to Japan. Our previous study reported that the population size of S. gemmifer in Hamamatsu city, Japan, had decreased by one-tenth because many individuals had been washed out by a series of heavy rains in 2004. However, there is insufficient information on the ecological nature of this endangered aquatic plant for adequate conservation. In this paper, we report the population dynamics of one population in Hamamatsu city from 2004 to 2012 in relation to rainfall. We surveyed the number and growing location of all living individuals in the population 300 times during the study period. To examine the temporal changes of individual plants, we also counted the number of culms for 38 individuals in four observations among 300 records. Decreases and increases in the population size of this plant were associated with washing out and the settlement of gemmae (vegetative propagation), respectively. The major cause of the reduction in the population size was an increase in the number of washed-out individuals and not the decreased settlement of gemmae. The wash-out rates for small and large individuals were not significantly different. Small individuals having a stream form with linear leaves resisted flooding, and large individuals were often partially torn off by flooding events. Modification of river basins to reduce the flow velocity may be effective for the conservation of S. gemmifer.

  11. Correlations between wind flow and population location at 67 light water nuclear power plant sites. [USA

    Energy Technology Data Exchange (ETDEWEB)

    Sprung, J.L.; Steck, G.P.; Frazier, A.W.

    1978-10-01

    Because wind flow and population location are both likely to be influenced by topography, it has been suggested that wind distributions and population distributions ought to be correlated and that the neglect of these correlations in the calculations of the Reactor Safety Study could have resulted in significant underestimates of accident consequences. This paper presents the results of an investigation of correlations between wind roses and population locations at 67 of the 68 power plant sites included in the Reactor Safety Study.

  12. Managing breaches of containment and eradication of invasive plant populations.

    Science.gov (United States)

    Fletcher, Cameron S; Westcott, David A; Murphy, Helen T; Grice, Anthony C; Clarkson, John R

    2015-02-01

    Containment can be a viable strategy for managing invasive plants, but it is not always cheaper than eradication. In many cases, converting a failed eradication programme to a containment programme is not economically justified. Despite this, many contemporary invasive plant management strategies invoke containment as a fallback for failed eradication, often without detailing how containment would be implemented.We demonstrate a generalized analysis of the costs of eradication and containment, applicable to any plant invasion for which infestation size, dispersal distance, seed bank lifetime and the economic discount rate are specified. We estimate the costs of adapting eradication and containment in response to six types of breach and calculate under what conditions containment may provide a valid fallback to a breached eradication programme.We provide simple, general formulae and plots that can be applied to any invasion and show that containment will be cheaper than eradication only when the size of the occupied zone exceeds a multiple of the dispersal distance determined by seed bank longevity and the discount rate. Containment becomes proportionally cheaper than eradication for invaders with smaller dispersal distances, longer lived seed banks, or for larger discount rates.Both containment and eradication programmes are at risk of breach. Containment is less exposed to risk from reproduction in the 'occupied zone' and three types of breach that lead to a larger 'occupied zone', but more exposed to one type of breach that leads to a larger 'buffer zone'.For a well-specified eradication programme, only the three types of breach leading to reproduction in or just outside the buffer zone can justify falling back to containment, and only if the expected costs of eradication and containment were comparable before the breach.Synthesis and applications. Weed management plans must apply a consistent definition of containment and provide sufficient implementation detail

  13. Photosynthetic Characterization of Plant Functional Types from Coastal Tundra to Improve Representation of the Arctic in Earth System Models

    Science.gov (United States)

    Rogers, A.; Xu, C.; McDowell, N. G.; Sloan, V. L.; Norby, R. J.

    2012-12-01

    The primary goal of Earth System Models (ESMs) is to improve understanding and projection of future global change. In order to do this they must accurately represent the carbon fluxes associated with the terrestrial carbon cycle. Photosynthetic CO2 uptake is well described by the Farquhar, von Caemmerer and Berry model of photosynthesis, and most ESMs use a derivation of this model. One of the key parameters required by the Farquhar, von Caemmerer and Berry model is an estimate of the maximum rate of carboxylation by the enzyme Rubisco (Vc,max). In ESMs the parameter Vc,max is usually fixed for a given plant functional type (PFT) and often estimated from the empirical relationship between leaf N content and Vc,max. However, uncertainty in the estimation of Vc,max has been shown to account for significant variation in model estimation of gross primary production, particularly in the Arctic. As part of a new multidisciplinary project to improve the representation of the Arctic in ESMs (Next Generation Ecosystem Experiments - Arctic) we have begun to characterize photosynthetic parameters and N acquisition in the key Arctic PFTs. We measured the response of photosynthesis (A) to internal CO2 concentration (ci) in situ in two sedges (Carex aquatilis, Eriophorum angustifolium), a grass (Dupontia fisheri) and a forb (Petasites frigidus) growing on the Barrow Environmental Observatory, Barrow, AK. The values of Vc,max (normalized to 25oC) currently used to represent Arctic PFTs in ESMs are approximately half of the values we measured in these species in July, 2012, on the coastal tundra in Barrow. We hypothesize that these plants have a greater fraction of leaf N invested in Rubisco (FLNR) than is assumed by the models. The parameter Vc,max is used directly as a driver for respiration in some ESMs, and in other ESMs Vc,max is linked to leaf N content and N acquisition through FLNR. Therefore, these results have implications for ESMs beyond photosynthesis, and suggest that

  14. Proxy measures of fitness suggest coastal fish farms can act as population sources and not ecological traps for wild gadoid fish.

    Directory of Open Access Journals (Sweden)

    Tim Dempster

    Full Text Available BACKGROUND: Ecological traps form when artificial structures are added to natural habitats and induce mismatches between habitat preferences and fitness consequences. Their existence in terrestrial systems has been documented, yet little evidence suggests they occur in marine environments. Coastal fish farms are widespread artificial structures in coastal ecosystems and are highly attractive to wild fish. METHODOLOGY/PRINCIPAL FINDINGS: To investigate if coastal salmon farms act as ecological traps for wild Atlantic cod (Gadus morhua and saithe (Pollachius virens, we compared proxy measures of fitness between farm-associated fish and control fish caught distant from farms in nine locations throughout coastal Norway, the largest coastal fish farming industry in the world. Farms modified wild fish diets in both quality and quantity, thereby providing farm-associated wild fish with a strong trophic subsidy. This translated to greater somatic (saithe: 1.06-1.12 times; cod: 1.06-1.11 times and liver condition indices (saithe: 1.4-1.8 times; cod: 2.0-2.8 times than control fish caught distant from farms. Parasite loads of farm-associated wild fish were modified from control fish, with increased external and decreased internal parasites, however the strong effect of the trophic subsidy overrode any effects of altered loads upon condition. CONCLUSIONS AND SIGNIFICANCE: Proxy measures of fitness provided no evidence that salmon farms function as ecological traps for wild fish. We suggest fish farms may act as population sources for wild fish, provided they are protected from fishing while resident at farms to allow their increased condition to manifest as greater reproductive output.

  15. Starch Product of Wild Plants Species Jalawure (Tacca leontopetaloides L.) Kuntze as The Source of Food Security in The South Coastal West Java

    Science.gov (United States)

    Wardah; Sambas, E. N.; Ridwan; Ariani, D.

    2017-04-01

    Majority of people of South coast of West Java, from Sukabumi, Cianjur, Garut are fishermen. Natural conditions are very dry and the area of land for agriculture, particularly rice cultivation is minimal. So that the condition of the society is more directed to high enough levels of food insecurity. Because coastal areas tend to have a longer dry season from rainfall. Results of research conducted in the years 2013 - 2016 in the area of Pelabuhan Ratu, Cidaun (Cianjur), Coastal area of Jayanti, Ranca Buaya, Mekar Mukti, and along the coast until Pameungpeuk, Leuweung Sancang, is known that jalawure plant which grows wild at South-coast region of West Java is precisely the alternative solution to address food insecurity. The results of the starch flour is a source of carbohydrate that is high enough to be used as a substitute for rice and wheat. Another potential source of jalawure nutrition is also recommended for diabetics consumption.

  16. Influence of the Wax Lake Delta sediment diversion on aboveground plant productivity and carbon storage in deltaic island and mainland coastal marshes

    Science.gov (United States)

    DeLaune, R. D.; Sasser, C. E.; Evers-Hebert, E.; White, J. R.; Roberts, H. H.

    2016-08-01

    Coastal Louisiana is experiencing a significant loss of coastal wetland area due to increasing sea level rise, subsidence, sediment starvation and marsh collapse. The construction of large scale Mississippi River sediment diversions is currently being planned in an effort to help combat coastal wetlands losses at a rate of >50 km-2 y-1. The Wax Lake Delta (WLD) is currently being used as a model for evaluating potential land gain from large scale diversions of Mississippi River water and sediment. In this study, we determine the impact of the WLD diversion on plant production at newly formed islands within the delta and adjacent, mainland freshwater marshes. Plant aboveground productivity, sediment nutrient status and short term accretion were measured at three locations on a transect at each of three fresh water marsh sites along Hog Bayou and at six newly formed emerging island sites in the delta. Spring flooding has resulted in a greater increase in plant production and consequently, greater carbon sequestration potential in adjacent mainland marshes compared to the newly formed island sites, which contain less total carbon (C), nitrogen (N), and phosphorus (P) in the sediment. While sediment diversions are predicted to create land, as seen in island formation in the WLD, the greatest benefit of river sediment diversions from a carbon credit perspective might be to the adjacent freshwater mainland marshes for several reasons. Both greater plant production and sediment C accumulation are two important factors for marsh stability, while perhaps even more critical, is the prevention of the loss of stored sediment C in the marsh profile. This stored C would be lost without the introduction of freshwater, nutrients and sediment through river sediment diversion efforts.

  17. Population biology and habitat associations of benthic fish species in the shallow areas of a Mediterranean coastal lagoon (SE Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    David Verdiell Cubedo

    2008-06-01

    Full Text Available The present study investigates the seasonal variation in fish abundance, fish biomass, reproductive status and population structure of four dominant benthic fish species, Salaria pavo, Pomatoschistus marmoratus, Gobius cobitis and Gobius niger, in the shallow and littoral areas of the Mar Menor coastal lagoon. In addition, the seasonal habitat associations of each species were studied by assessing environmental variables related to the habitat structure: submerged vegetation cover, submerged vegetation density, water depth and substrate composition. The temporal variations in fish density, standing stock and size frequency distributions of these species can largely be attributed to the seasonality of their breeding and juvenile recruitment periods. Moreover, habitat associations for these species were similar to those obtained in other Mediterranean and Atlantic coastal lagoons.

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

    Directory of Open Access Journals (Sweden)

    Mohammad Saeed Emami

    2017-01-01

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

  19. Genotypic and phenotypic diversity in populations of plant-probiotic Pseudomonas spp. colonizing roots

    Science.gov (United States)

    Picard, Christine; Bosco, Marco

    2008-01-01

    Several soil microorganisms colonizing roots are known to naturally promote the health of plants by controlling a range of plant pathogens, including bacteria, fungi, and nematodes. The use of theses antagonistic microorganisms, recently named plant-probiotics, to control plant-pathogenic fungi is receiving increasing attention, as they may represent a sustainable alternative to chemical pesticides. Many years of research on plant-probiotic microorganisms (PPM) have indicated that fluorescent pseudomonads producing antimicrobial compounds are largely involved in the suppression of the most widespread soilborne pathogens. Phenotype and genotype analysis of plant-probiotic fluorescent pseudomonads (PFP) have shown considerable genetic variation among these types of strains. Such variability plays an important role in the rhizosphere competence and the biocontrol ability of PFP strains. Understanding the mechanisms by which genotypic and phenotypic diversity occurs in natural populations of PFP could be exploited to choose those agricultural practices which best exploit the indigenous PFP populations, or to isolate new plant-probiotic strains for using them as inoculants. A number of different methods have been used to study diversity within PFP populations. Because different resolutions of the existing microbial diversity can be revealed depending on the approach used, this review first describes the most important methods used for the assessment of fluorescent Pseudomonas diversity. Then, we focus on recent data relating how differences in genotypic and phenotypic diversity within PFP communities can be attributed to geographic location, climate, soil type, soil management regime, and interactions with other soil microorganisms and host plants. It becomes evident that plant-related parameters exert the strongest influence on the genotypic and phenotypic variations in PFP populations.

  20. Population status of the American alligator on the Savannah River Plant, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, T.M.

    1981-04-01

    Estimates are presented of alligator numbers, size distribution, sex ratios, reproductive effort, and population trends for all major components of the entire Savannah River Plant (SRP) alligator population. Savannah River Plant operations have impacted the alligator population in many different ways. The formation of man-made reservoirs has dramatically increased the amount of aquatic habitat available to alligators and has therefore increased the carrying capacity of the SRP site for this species. The thermal alteration of aquatic habitats on the SRP has also impacted the resident alligator population. Temperature elevations of aquatic habitat to greater than 38/sup 0/C result in the loss of this habitat to alligators. Moderate thermal increases on the other hand are responded to by alligator movement. The current information available on the alligators of the SRP suggests the following future trends: low density populations distant from thermally altered areas will continue at a low density with the exception of localized increases.

  1. Use of plants in oral health care by the population of Mahajanga, Madagascar.

    Science.gov (United States)

    Ranjarisoa, Lala Nirina; Razanamihaja, Noëline; Rafatro, Herintsoa

    2016-12-04

    The use of medicinal plants to address oral health problems is not well documented in Madagascar, yet the country is full of endemic flora. The aim of this study was to collect information on the use of plants in the region of Mahajanga, Madagascar, for the treatments of oral diseases mainly tooth decay. The ethnobotanical survey with respect to the use of plants for curing dental problems was carried out in 2012. A cluster sampling at three levels was applied when choosing the study sites. The target population was made up of heads of household. The following data were collected from a semi-structured questionnaire: name of plants, part used, mode of preparation, and administration. The Informant Consensus Factor and Fidelity Level indexes were calculated for each condition treated and used plants. The Results revealed that 93 per cent of the targeted population has used plants to calm dental pain, whereas 44.2% have reported using plants due to financial problems. About 65 species of plants are commonly used for oral health care and 63 of them treated caries. Cajanus cajan (L.) Millsp. was the most plant used. It was mostly used in crushed form of 5 to 9 leaves which were prepared and placed directly on the affected oral part or in the tooth cavity. In general, the treatment lasted about 5 days or minus. The ICF were 0.83 for caries and 0.81 for periodontal diseases. This ethnobotanical survey will serve as database for further phytochemical and pharmacological study of plants in order to identify their active components and advise the population on the most effective administration. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Causes and consequences of complex population dynamics in an annual plant, Cardamine pensylvanica

    Energy Technology Data Exchange (ETDEWEB)

    Crone, E.E.

    1995-11-08

    The relative importance of density-dependent and density-independent factors in determining the population dynamics of plants has been widely debated with little resolution. In this thesis, the author explores the effects of density-dependent population regulation on population dynamics in Cardamine pensylvanica, an annual plant. In the first chapter, she shows that experimental populations of C. pensylvanica cycled from high to low density in controlled constant-environment conditions. These cycles could not be explained by external environmental changes or simple models of direct density dependence (N{sub t+1} = f[N{sub t}]), but they could be explained by delayed density dependence (N{sub t+1} = f[N{sub t}, N{sub t+1}]). In the second chapter, she shows that the difference in the stability properties of population growth models with and without delayed density dependence is due to the presence of Hopf as well as slip bifurcations from stable to chaotic population dynamics. She also measures delayed density dependence due to effects of parental density on offspring quality in C. pensylvanica and shows that this is large enough to be the cause of the population dynamics observed in C. pensylvanica. In the third chapter, the author extends her analyses of density-dependent population growth models to include interactions between competing species. In the final chapter, she compares the effects of fixed spatial environmental variation and variation in population size on the evolutionary response of C. pensylvanica populations.

  3. Social-psychological well-being of rural population in the White Sea coastal area as a risk factor for the Russian Arctic policy

    Directory of Open Access Journals (Sweden)

    Andrey O. Podoplekin

    2016-10-01

    Full Text Available The article represents a generalized data from sociological survey of social-psychological well-being of the rural population of the coastal areas in Arkhangelsk region (included into the Russian Arctic zone held in 2015. The data shows a critical level of social pessimism, assurance of residents in continuation of negative social-economic dynamics, deficiency of motivation and readiness for active participation and inclusion into the development of territories. Such a status is based on a deep degradation of local industries, infrastructures and social sphere, which has been confirmed by statistic data. The revealed indicators explain high migration preparedness, especially in groups of working ages, proceeding, in the middle-term prospective, to the risk of depopulation and disintegration of social carcass in the coastal areas which, in their turn, possess a significant resource potential. At that, residential population on these areas considered as strategic factor from the perspective of Russian geopolitical interests in the Arctic. A positive trend may be provided through implementation of spatial approach to the social-economic development, which has been already applied in activities held by the Russian State Commission on the Arctic Development. With that there is obvious relevance of correction of the Russian legislation toward transformation of residential population into the beneficiary party of the macro-regional development, which may be provided by establishing of special regimes and preferences in spheres of natural resource use, tax assessment, entrepreneurship and crediting for all groups indigenous (resident population, including aboriginal people of the North.

  4. Impact of plant development on the rhizobacterial population of Arachis hypogaea: a multifactorial analysis.

    Science.gov (United States)

    Haldar, Shyamalina; Sengupta, Sanghamitra

    2015-07-01

    Present study investigates the impact of plant development on the structure and composition of root-associated bacterial community of groundnut (Arachis hypogaea) plant, an economically important oilseed legume. Relative abundance of total and active bacteria were studied in bulk soil and rhizosphere samples collected from different growth stages of groundnut plant by sequencing PCR-amplified 16S rRNA gene fragments from soil genomic DNA and reverse-transcribed soil community RNA. Plant growth promoting potential of cultivable rhizobacteria was evaluated using assays for inorganic phosphate solubilization and production of indole acetic acid, siderophores, biofilm, 1-amino-cyclopropane-1-carboxylate deaminase, laccase, and anti-fungal chemicals. Our study demonstrates that groundnut plant rhizosphere harbors a core microbiome populated by Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, and Acidobacteria. A distinct bacterial assemblage at nodulation stage due to predominance of Flavobacteria and Actinobacteria in DNA and RNA derived libraries respectively was also observed. Majority of cultivable isolates exhibiting plant growth promoting activities belonged to Proteobacteria and Firmicutes. Of them, Pseudomonas indica and Bacillus megaterium were detected in the rhizosphere samples from all the developmental stages of groundnut plant. This polyphasic study establishes the impact of plant development on rhizobacterial population of groundnut and underscores the applicability of soil isolates as a reliable component in sustainable agriculture.

  5. EFFECT OF PLANT DENSITY ON AGRONOMIC TRAITS AND PHOTOSYNTHETIC PERFORMANCE IN THE MAIZE IBM POPULATION

    Directory of Open Access Journals (Sweden)

    Mario Franić

    2015-12-01

    Full Text Available Photosynthesis is a vital process in plant physiology. Performance index is an indicator of plant vitality and is used as a main parameter in chlorophyll fluorescence measurements. Plant density is an important factor in maize production that can affect grain yield. Objective of this paper was to estimate the effect of plant density on agronomic traits and photosynthetic efficiency in the maize IBM population. The results showed a decrease in grain yield per plant basis (20 plants per plot in higher plant density (normal density - 3.88 kg per plot, high density - 2.95 kg per plot and an increase in grain yield per unit area (yield/ha in higher plant density (normal density - 11.03t ha-1, high density - 13.64 t ha-1. Performance index was decreased in higher plant density (normal density - 5.31, high density - 4.95. Statistical analysis showed highly significant effect (p<0.001 of density on performance index and highly significant effects (p<0.001 of plant density and genotype on maize yield. Low positive correlation was observed between grain yield per plot and performance index (r = 0.36, p<0.001.

  6. Herbivory and growth in terrestrial and aquatic populations of amphibious stream plants

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Jacobsen, Dean

    2002-01-01

    to evaluate advantages and disadvantages of aerial and submerged life. 2. Terrestrial populations had higher area shoot density, biomass and leaf production than aquatic populations, while leaf turnover rate and longevity were the same. Terrestrial populations experienced lower percentage grazing loss of leaf......1. Many amphibious plant species grow in the transition between terrestrial and submerged vegetation in small lowland streams. We determined biomass development, leaf turnover rate and invertebrate herbivory during summer in terrestrial and aquatic populations of three amphibious species...

  7. How to conserve threatened Chinese plant species with extremely small populations?

    Directory of Open Access Journals (Sweden)

    Sergei Volis

    2016-02-01

    Full Text Available The Chinese flora occupies a unique position in global plant diversity, but is severely threatened. Although biodiversity conservation in China has made significant progress over the past decades, many wild plant species have extremely small population sizes and therefore are in extreme danger of extinction. The concept of plant species with extremely small populations (PSESPs, recently adopted and widely accepted in China, lacks a detailed description of the methodology appropriate for conserving PSESPs. Strategies for seed sampling, reintroduction, protecting PSESP locations, managing interactions with the local human population, and other conservation aspects can substantially differ from those commonly applied to non-PSESPs. The present review is an attempt to provide a detailed conservation methodology with realistic and easy-to-follow guidelines for PSESPs in China.

  8. Genetic diversity of high-elevation populations of an endangered medicinal plant.

    Science.gov (United States)

    Nag, Akshay; Ahuja, Paramvir Singh; Sharma, Ram Kumar

    2014-11-21

    Intraspecific genetic variation in natural populations governs their potential to overcome challenging ecological and environmental conditions. In addition, knowledge of this variation is critical for the conservation and management of endangered plant taxa. Found in the Himalayas, Podophyllum hexandrum is an endangered high-elevation plant species that has great medicinal importance. Here we report on the genetic diversity analysis of 24 P. hexandrum populations (209 individuals), representing the whole of the Indian Himalayas. In the present study, seven amplified fragment length polymorphism (AFLP) primer pairs generated 1677 fragments, of which 866 were found to be polymorphic. Neighbour joining clustering, principal coordinate analysis and STRUCTURE analysis clustered 209 individuals from 24 populations of the Indian Himalayan mountains into two major groups with a significant amount of gene flow (Nm = 2.13) and moderate genetic differentiation Fst(0.196), G'st(0.20). This suggests that, regardless of geographical location, all of the populations from the Indian Himalayas are intermixed and are composed broadly of two types of genetic populations. High variance partitioned within populations (80 %) suggests that most of the diversity is restricted to the within-population level. These results suggest two possibilities about the ancient population structure of P. hexandrum: either all of the populations in the geographical region of the Indian Himalayas are remnants of a once-widespread ancient population, or they originated from two types of genetic populations, which coexisted a long time ago, but subsequently separated as a result of long-distance dispersal and natural selection. High variance partitioned within the populations indicates that these populations have evolved in response to their respective environments over time, but low levels of heterozygosity suggest the presence of historical population bottlenecks.

  9. Linking a Large-Watershed Hydrogeochemical Model to a Wetland Community-Ecosystem Model to Estimate Plant Invasion Risk in the Coastal Great Lakes Region, USA

    Science.gov (United States)

    Currie, W. S.; Bourgeau-Chavez, L. L.; Elgersma, K. J.; French, N. H. F.; Goldberg, D. E.; Hart, S.; Hyndman, D. W.; Kendall, A. D.; Martin, S. L.; Martina, J. P.

    2014-12-01

    In the Laurentian Great Lakes region of the Upper Midwest, USA, agricultural and urban land uses together with high N deposition are contributing to elevated flows of N in rivers and groundwater to coastal wetlands. The functioning of coastal wetlands, which provide a vital link between land and water, are imperative to maintaining the health of the entire Great Lakes Basin. Elevated N inflows are believed to facilitate the spread of large-stature invasive plants (cattails and Phragmites) that reduce biodiversity and have complex effects on other ecosystem services including wetland N retention and C accretion. We enhanced the ILHM (Integrated Landscape Hydrology Model) to simulate the effects of land use on N flows in streams, rivers, and groundwater throughout the Lower Peninsula of Michigan. We used the hydroperiods and N loading rates simulated by ILHM as inputs to the Mondrian model of wetland community-ecosystem processes to estimate invasion risk and other ecosystem services in coastal wetlands around the Michigan coast. Our linked models produced threshold behavior in the success of invasive plants in response to N loading, with the threshold ranging from ca. 8 to 12 g N/m2 y, depending on hydroperiod. Plant invasions increased wetland productivity 3-fold over historically oligotrophic native communities, decreased biodiversity but slightly increased wetland N retention. Regardless of invasion, elevated N loading resulted in significantly enhanced rates of C accretion, providing an important region-wide mechanism of C storage. The linked models predicted a general pattern of greater invasion risk in the southern basins of lakes Michigan and Huron relative to northern areas. The basic mechanisms of invasion have been partially validated in our field mesocosms constructed for this project. The general regional patterns of increased invasion risk have been validated through our field campaigns and remote sensing conducted for this project.

  10. Conservation state of populations of rare plant species in highly transformed meadow steppes of Southern Opillya

    Directory of Open Access Journals (Sweden)

    I. I. Dmytrash-Vatseba

    2016-09-01

    Full Text Available Degradation of natural habitats causes rapid extinction of rare plant populations. The diversity of rare plant species in the meadow steppes of Southern Opillya (Western Ukraine depends strongly on patch area, pasture digression of vegetation and a variety of eco-coenotical conditions. The main threats for the rare components of the meadow steppe flora are reduction of habitat and overgrazing. Spatial connections between sites are unable to support a constant rare plant population. The analysis of the composition of rare plant meadow-steppe species indicated that habitats with similar rare species composition usually have similar parameters of area, stages of pasture digression and eco-coenotical conditions. Spatial connectivity of patches does not ensure species similarity of rare components of the flora. Rare plant species were grouped according to their preferences for habitat , area and condition. In small patches subject to any stage of pasture digression grow populations of Adonis vernalis L., Pulsatilla patens (L. Mill., P. grandis Wender., Stipa capillata L., S. рennata L., Chamaecytisus blockianus (Pawł. Klásková etc. On the contrary, populations of other species (Carlina onopordifolia Besser. ex Szafer., Kuecz. et Pawł., Adenophora liliifolia (L. Ledeb. ex A. DC., Crambe tataria Sebeók, Euphorbia volhynica Besser ex Racib., Stipa tirsa Stev. etc. prefer large habitats, not changed by pasture digression. Prevention of reduction of rare species diversity requires preservation (also extension of patch area and regulation of grazing intensity.

  11. [Effects of host plants on the life table parameters of experimental populations of Aphis gossypii].

    Science.gov (United States)

    Li, Yan-Yan; Zhou, Xiao-Rong; Pang, Bao-Ping; Chang, Jing

    2013-05-01

    A comparative study was conducted on the life table parameters of Aphis gossypii reared on five host plant species at (25 +/- 1) degrees C in laboratory. There existed significant differences in the durations of various developmental stages, adult longevity, mean offspring number per day, net reproductive rate, intrinsic rate of increase, finite rate of increase, mean generation time, and population doubling time for the A. gossypii populations reared on the host plants. For the aphids on Lagenaria siceraria var. turbinate, they needed the longest time (5.84 days) to complete one generation, but for those on the other four plants, no significant differences were observed, with the time needed ranged from 5.24 to 5.45 days. The adult longevity was the longest (20.04 days) on Cucumis sativus, but had no significant differences on the other four host plants, being from 14.76 to 16.03 days. The populations' survival curves on all test host plants were of Deevey I, i. e., the death mainly occurred during late period. The survival rate on C. sativus was higher than those on the other four host plants. Based on the intrinsic rates of increase of A. gossypii, its host suitability was in the order of Cucumis melo var. saccharinus > Lagenaria siceraria var. turbinate > Cucurbita moschata var. melonaeformis > Cucumis sativus > Cucurbita pepo var. medullosa.

  12. Coastal Morphology and Coastal Protection

    NARCIS (Netherlands)

    Van de Graaff, J.

    2009-01-01

    Lecture notes ct5309. Tides, currents and water; coastal problems; sediment transport processes; coastal transport modes; longshore transport; cross-shore transport; fundamentals of mud; channels and trenches; coastal protection; application of structures; application of nourishments.

  13. Lead and zinc accumulation and tolerance in populations of six wetland plants

    Energy Technology Data Exchange (ETDEWEB)

    Deng, H. [Biology Department and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon, Hong Kong (China); Department of Environmental Science and Technology, East China Normal University, Shanghai (China); Ye, Z.H. [Biology Department and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon, Hong Kong (China); School of Life Sciences, Zhongshan (Sun Yat-sen) University, Guangzhou 510275 (China); Wong, M.H. [Biology Department and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon, Hong Kong (China)]. E-mail: mhwong@hkbu.edu.hk

    2006-05-15

    Wetland plants such as Typha latifolia and Phragmites australis have been indicated to show a lack of evolution of metal tolerance in metal-contaminated populations. The aim of the present study is to verify whether other common wetland plants such as Alternanthera philoxeroides and Beckmannia syzigachne, also possess the same characteristics. Lead and zinc tolerances in populations of six species collected from contaminated and clean sites were examined by hydroponics. In general, the contaminated populations did not show higher metal tolerance and accumulation than the controls. Similar growth responses and tolerance indices in the same metal treatment solution between contaminated and control populations suggest that metal tolerance in wetland plants are generally not further evolved by contaminated environment. The reasons may be related to the special root anatomy in wetland plants, the alleviated metal toxicity by the reduced rooting conditions and the relatively high innate metal tolerance in some species. - Populations from metal contaminated sites did not have significantly higher metal tolerance indices.

  14. Spatial distribution of populations of solitarious adult desert locust (Schistocerca gregaria Forsk.) on the coastal plain of Sudan

    NARCIS (Netherlands)

    Woldewahid, G.; Werf, van der W.; Huis, van A.; Stein, A.

    2004-01-01

    1 Densities of solitarious adult desert locusts were measured on regular grids of up to 126 sample sites in the southern part of the coastal plain of Sudan during the winters of 1999/2000 and 2000/2001. Geostatistical procedures were used to characterize spatial dependence of locust density, to eval

  15. Plant population and weeds influence stalk insects, soil moisture, and yield in rainfed sunflowers

    Institute of Scientific and Technical Information of China (English)

    JAWWAD A. QURESHI; PHILLIP W. STAHLMAN; J. P. MICHAUD

    2007-01-01

    Insect infestation, soil moisture, and yield were examined in populations of≈ 33 140 plants/ha (low) and ≈ 40 340 plants/ha (high) of an oilseed sunflower, Helianthus annuus L, cv. ' Triumph 660CL' with two levels of weediness. Less weedy plots resulted from the application of herbicide combination of S-metolachlor and sulfentrazone, whereas more weedy plots resulted from application of sulfentrazone alone. Among the 12 weed species recorded, neither plant numbers nor biomass differed between crop plant densities.Larvae of the stalk-boring insects Cylindrocopturus adspersus (Coleoptera: Curculionidae) and Mordellistena sp. (Coleoptera: Mordellidae) were less abundant in high density sunflowers, ostensibly due to reduced plant size. However, the same effect was not observed for Dectes texanus (Coleoptera: Cerambycidae) or Pelochrista womanana (Lepidoptera:Tortricidae), two other stalk-boring insects. Soil moisture was highest in low density and lowest in the high density sunflowers that were less weedy. Stalk circumference, head diameter, and seed weight were reduced for sunflower plants with short interplant distances (mean = 20 cm apart) compared to plants with long interplant distances (mean = 46 cm apart).These three variables were greater in less weedy plots compared with more weedy plots and positively correlated with interplant distance. Yields on a per-hectare basis paralleled those on a per-plant basis but were not different among treatments. The agronomic implications of planting density are discussed in the context of weed and insect management.

  16. Uncoupling the effects of seed predation and seed dispersal by granivorous ants on plant population dynamics.

    Directory of Open Access Journals (Sweden)

    Xavier Arnan

    Full Text Available Secondary seed dispersal is an important plant-animal interaction, which is central to understanding plant population and community dynamics. Very little information is still available on the effects of dispersal on plant demography and, particularly, for ant-seed dispersal interactions. As many other interactions, seed dispersal by animals involves costs (seed predation and benefits (seed dispersal, the balance of which determines the outcome of the interaction. Separate quantification of each of them is essential in order to understand the effects of this interaction. To address this issue, we have successfully separated and analyzed the costs and benefits of seed dispersal by seed-harvesting ants on the plant population dynamics of three shrub species with different traits. To that aim a stochastic, spatially-explicit individually-based simulation model has been implemented based on actual data sets. The results from our simulation model agree with theoretical models of plant response dependent on seed dispersal, for one plant species, and ant-mediated seed predation, for another one. In these cases, model predictions were close to the observed values at field. Nonetheless, these ecological processes did not affect in anyway a third species, for which the model predictions were far from the observed values. This indicates that the balance between costs and benefits associated to secondary seed dispersal is clearly related to specific traits. This study is one of the first works that analyze tradeoffs of secondary seed dispersal on plant population dynamics, by disentangling the effects of related costs and benefits. We suggest analyzing the effects of interactions on population dynamics as opposed to merely analyzing the partners and their interaction strength.

  17. Uncoupling the effects of seed predation and seed dispersal by granivorous ants on plant population dynamics.

    Science.gov (United States)

    Arnan, Xavier; Molowny-Horas, Roberto; Rodrigo, Anselm; Retana, Javier

    2012-01-01

    Secondary seed dispersal is an important plant-animal interaction, which is central to understanding plant population and community dynamics. Very little information is still available on the effects of dispersal on plant demography and, particularly, for ant-seed dispersal interactions. As many other interactions, seed dispersal by animals involves costs (seed predation) and benefits (seed dispersal), the balance of which determines the outcome of the interaction. Separate quantification of each of them is essential in order to understand the effects of this interaction. To address this issue, we have successfully separated and analyzed the costs and benefits of seed dispersal by seed-harvesting ants on the plant population dynamics of three shrub species with different traits. To that aim a stochastic, spatially-explicit individually-based simulation model has been implemented based on actual data sets. The results from our simulation model agree with theoretical models of plant response dependent on seed dispersal, for one plant species, and ant-mediated seed predation, for another one. In these cases, model predictions were close to the observed values at field. Nonetheless, these ecological processes did not affect in anyway a third species, for which the model predictions were far from the observed values. This indicates that the balance between costs and benefits associated to secondary seed dispersal is clearly related to specific traits. This study is one of the first works that analyze tradeoffs of secondary seed dispersal on plant population dynamics, by disentangling the effects of related costs and benefits. We suggest analyzing the effects of interactions on population dynamics as opposed to merely analyzing the partners and their interaction strength.

  18. Joint estimation of contemporary seed and pollen dispersal rates among plant populations.

    Science.gov (United States)

    Robledo-Arnuncio, J J

    2012-03-01

    There are few statistical methods for estimating contemporary dispersal among plant populations. A maximum-likelihood procedure is introduced here that uses pre- and post-dispersal population samples of biparentally inherited genetic markers to jointly estimate contemporary seed and pollen immigration rates from a set of discrete external sources into a target population. Monte Carlo simulations indicate that accurate estimates and reliable confidence intervals can be obtained using this method for both pollen and seed migration rates at modest sample sizes (100 parents/population and 100 offspring) when population differentiation is moderate (F(ST) ≥ 0.1), or by increasing pre-dispersal samples (to about 500 parents/population) when genetic divergence is weak (F(ST) = 0.01). The method exhibited low sensitivity to the number of source populations and achieved good accuracy at affordable genetic resolution (10 loci with 10 equifrequent alleles each). Unsampled source populations introduced positive biases in migration rate estimates from sampled sources, although they were minor when the proportion of immigration from the latter was comparatively low. A practical application of the method to a metapopulation of the Australian resprouter shrub Banksia attenuata revealed comparable levels of directional seed and pollen migration among dune groups, and the estimate of seed dispersal was higher than a previous estimate based on conservative assignment tests. The method should be of interest to researchers and managers assessing broad-scale nonequilibrium seed and pollen gene flow dynamics in plants.

  19. Pre-Columbian population dynamics in coastal southern Peru: A diachronic investigation of mtDNA patterns in the Palpa region by ancient DNA analysis.

    Science.gov (United States)

    Fehren-Schmitz, Lars; Reindel, Markus; Cagigao, Elsa Tomasto; Hummel, Susanne; Herrmann, Bernd

    2010-02-01

    Alternative models have been proposed to explain the formation and decline of the south Peruvian Nasca culture, ranging from migration or invasion to autochthonous development and ecological crisis. To reveal to what extent population dynamic processes accounted for cultural development in the Nasca mainland, or were influenced by them, we analyzed ancient mitochondrial DNA of 218 individuals, originating from chronologically successive archaeological sites in the Palpa region, the Paracas Peninsula, and the Andean highlands in southern Peru. The sampling strategy allowed a diachronic analysis in a time frame from approximately 800 BC to 800 AD. Mitochondrial coding region polymorphisms were successfully analyzed and replicated for 130 individuals and control region sequences (np 16021-16408) for 104 individuals to determine Native American mitochondrial DNA haplogroups and haplotypes. The results were compared with ancient and contemporary Peruvian populations to reveal genetic relations of the archaeological samples. Frequency data and statistics show clear proximity of the Nasca populations to the populations of the preceding Paracas culture from Palpa and the Peninsula, and suggest, along with archaeological data, that the Nasca culture developed autochthonously in the Rio Grande drainage. Furthermore, the influence of changes in socioeconomic complexity in the Palpa area on the genetic diversity of the local population could be observed. In all, a strong genetic affinity between pre-Columbian coastal populations from southern Peru could be determined, together with a significant differentiation from ancient highland and all present-day Peruvian reference populations, best shown in the differential distribution of mitochondrial haplogroups.

  20. Habitat-specific impacts of multiple consumers on plant population dynamics.

    Science.gov (United States)

    Maron, John L; Kauffman, Matthew J

    2006-01-01

    Multiple consumers often attack seeds, seedlings, and adult plants, but their population-level consequences remain uncertain. We examined how insect and small mammal consumers influenced the demography and abundance of the perennial shrub, bush lupine (Lupinus arboreus). In grassland and dune habitats we established replicate experimental lupine populations in 81-m2 plots that were either protected from, or exposed to, herbivorous voles and granivorous mice (via fencing) and/or root feeding insects (via insecticide treatment). Populations were initiated with transplanted seedlings in 1999 and 2000. We followed the demography of these cohorts, subsequent generations, and the seed bank for 5.5 years. Voles and insects killed many seedlings in dune (1999 only) and grassland (1999 and 2000) habitats. After 2000, insects and voles had minimal effects on seedling or adult survival. Seed predation by granivorous mice, however, greatly depressed seedling recruitment, resulting in lower adult lupine abundance in control plots vs. those protected from rodents. In grasslands, initial effects of voles and insects on seedling survival produced large differences among treatments in adult plant density and the cumulative number of seeds produced throughout the experiment. Differences among grassland populations in seed rain, however, had little influence on the magnitude of seedling recruitment into this habitat. Instead, recruitment out of a preexisting seed bank compensated for the lack of seed production in populations exposed to consumers. Shading by dense adults in plots protected from consumers limited seedling establishment within these populations. Although differences among populations in cumulative seed rain did not influence adult establishment, populations protected from consumers accumulated substantially larger seed banks than controls. These results illustrate how density dependence, habitat-specific seed dynamics, and particular demographic impacts of consumers

  1. Alarming plant dieback in the Outeniquas : is this an indication of global warming? Monitoring plant populations

    CSIR Research Space (South Africa)

    Rebelo, T

    2009-03-01

    Full Text Available is recommended, monitoring of this unusual Doring River species should be continued. More detailed investigations of the rainfall suggest that a cycle of dry years resulted in dry land plants invading wetlands following the 1999 fire at Doring River... very long time: wet algae and lichen were abundant and there were signs of iron accumulation. The dieback was in areas where water had accumulated due to slope differences, and areas outside the wetland that had stayed wet for longer than usual. A...

  2. 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...

  3. A Bioassay for Determining Resistance Levels in Tarnished Plant Bug Populations to Neonicotinoid Insecticides

    Science.gov (United States)

    A laboratory bioassay was developed and used to test field populations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), for resistance development to the neonicitinoid insecticides imidacloprid (Trimax®) and thiamethoxam (Centric®). The bioassay determined LC50 values by feeding...

  4. Computer aided data acquisition tool for high-throughput phenotyping of plant populations

    Science.gov (United States)

    2009-01-01

    Background The data generated during a course of a biological experiment/study can be sometimes be massive and its management becomes quite critical for the success of the investigation undertaken. The accumulation and analysis of such large datasets often becomes tedious for biologists and lab technicians. Most of the current phenotype data acquisition management systems do not cater to the specialized needs of large-scale data analysis. The successful application of genomic tools/strategies to introduce desired traits in plants requires extensive and precise phenotyping of plant populations or gene bank material, thus necessitating an efficient data acquisition system. Results Here we describe newly developed software "PHENOME" for high-throughput phenotyping, which allows researchers to accumulate, categorize, and manage large volume of phenotypic data. In this study, a large number of individual tomato plants were phenotyped with the "PHENOME" application using a Personal Digital Assistant (PDA) with built-in barcode scanner in concert with customized database specific for handling large populations. Conclusion The phenotyping of large population of plants both in the laboratory and in the field is very efficiently managed using PDA. The data is transferred to a specialized database(s) where it can be further analyzed and catalogued. The "PHENOME" aids collection and analysis of data obtained in large-scale mutagenesis, assessing quantitative trait loci (QTLs), raising mapping population, sampling of several individuals in one or more ecological niches etc. PMID:20003250

  5. HYPERSPECTRAL REMOTE SENSING, GPS, AND GIS APPLICATIONS IN OPPORTUNISTIC PLANT SPECIES MONITORING OF GREAT LAKES COASTAL WETLANDS

    Science.gov (United States)

    Coastal wetlands of the Laurentian Great Lakes (LGL) are among the most fragmented and disturbed ecosystems of the world, with a long history of human-induced disturbance. LGL wetlands have undergone losses in the biological diversity that coincides with an increase in the presen...

  6. Structure and dynamics of natural populations of the endangered plant Euryodendron excelsum H. T. Chang

    Institute of Scientific and Technical Information of China (English)

    Shikang SHEN; Haiying MA; Yuehua WANG; Boyi WANG; Guozhu SHEN

    2009-01-01

    Euryodendron excelsum H. T. Chang is an endangered species of the family Theaceae endemic to China. It is listed as a second-class endangered plant for state protection in the Red Data Book of Plants in the People's Republic of China. The species is restricted to one remnant population with less than 200 individuals in the Bajia region of Yangchun County, Guangdong Province.This study was conducted to determine the status of the population, analyze the past population structure and forecast the future population dynamics of E. excelsum.The size structure and height structure of the population of E. excelsum were tabulated and analyzed. Based on these data, we estimated the values of the parameters such as survival curve, mortality curve and life expectancy.Population dynamics was predicted by a time-sequence model. The size distribution of the whole population generally fit a reverse "J" type curve, suggesting a stable population. The number of young individuals was larger than that of middle-aged and old individuals. The analysis of life table and survival curves show that under environmental screening and human disturbance, the population had one peak of mortality in size class Ⅱ and only 11.43% individuals could survive from size class Ⅱ to size class III. The life expectancy of E. excelsum was the highest in size class IV. The survival curve of the population belongs to the Deevey-III type. Time-sequence models for E. excelsum population predict that the number of different size classes will increase after two and five years. As a result, the crucial factors for the natural regeneration and restoration of E. excelsum are the protection of living individuals and their habitat.

  7. Genetic variation in fitness within a clonal population of a plant RNA virus.

    Science.gov (United States)

    Cervera, Héctor; Elena, Santiago F

    2016-01-01

    A long-standing observation in evolutionary virology is that RNA virus populations are highly polymorphic, composed by a mixture of genotypes whose abundances in the population depend on complex interaction between fitness differences, mutational coupling and genetic drift. It was shown long ago, though in cell cultures, that most of these genotypes had lower fitness than the population they belong, an observation that explained why single-virion passages turned on Muller's ratchet while very large population passages resulted in fitness increases in novel environments. Here we report the results of an experiment specifically designed to evaluate in vivo the fitness differences among the subclonal components of a clonal population of the plant RNA virus tobacco etch potyvirus (TEV). Over 100 individual biological subclones from a TEV clonal population well adapted to the natural tobacco host were obtained by infectivity assays on a local lesion host. The replicative fitness of these subclones was then evaluated during infection of tobacco relative to the fitness of large random samples taken from the starting clonal population. Fitness was evaluated at increasing number of days post-inoculation. We found that at early days, the average fitness of subclones was significantly lower than the fitness of the clonal population, thus confirming previous observations that most subclones contained deleterious mutations. However, as the number of days of viral replication increases, population size expands exponentially, more beneficial and compensatory mutations are produced, and selection becomes more effective in optimizing fitness, the differences between subclones and the population disappeared.

  8. Drivers of Coastal Shoreline Change: Case Study of Hon Dat Coast, Kien Giang, Vietnam

    Science.gov (United States)

    Nguyen, Hai-Hoa; McAlpine, Clive; Pullar, David; Leisz, Stephen Joseph; Galina, Gramotnev

    2015-05-01

    Coastal shorelines are naturally dynamic, shifting in response to coastal geomorphological processes. Globally, land use change associated with coastal urban development and growing human population pressures is accelerating coastal shoreline change. In southern Vietnam, coastal erosion currently is posing considerable risks to shoreline land use and coastal inhabitants. The aim of this paper is to quantify historical shoreline changes along the Hon Dat coast between 1995 and 2009, and to document the relationships between coastal mangrove composition, width and density, and rates of shoreline change. The generalized linear mixed-effects models were used to quantify the major biophysical and land-use factors influencing shoreline change rates. Most significant drivers of the rates of change are cutting of mangroves, the dominant mangrove genus, changes in adjacent shoreline land use, changes of shoreline land cover, and width of fringing mangroves. We suggest that a possible and inexpensive strategy for robust mangrove shoreline defense is direct mangrove planting to promote mangrove density with the presence of breakwater structures. In the shorter term, construction of coastal barriers such as fence-structured melaleuca poles in combination with mangrove restoration schemes could help retain coastal sediments and increase the elevation of the accretion zone, thereby helping to stabilize eroding fringe shorelines. It also is recommended that implementation of a system of payments for mangrove ecosystem services and the stronger regulation of mangrove cutting and unsustainable land-use change to strengthen the effectiveness of mangrove conservation programs and coastal land-use management.

  9. Drivers of coastal shoreline change: case study of hon dat coast, Kien Giang, Vietnam.

    Science.gov (United States)

    Nguyen, Hai-Hoa; McAlpine, Clive; Pullar, David; Leisz, Stephen Joseph; Galina, Gramotnev

    2015-05-01

    Coastal shorelines are naturally dynamic, shifting in response to coastal geomorphological processes. Globally, land use change associated with coastal urban development and growing human population pressures is accelerating coastal shoreline change. In southern Vietnam, coastal erosion currently is posing considerable risks to shoreline land use and coastal inhabitants. The aim of this paper is to quantify historical shoreline changes along the Hon Dat coast between 1995 and 2009, and to document the relationships between coastal mangrove composition, width and density, and rates of shoreline change. The generalized linear mixed-effects models were used to quantify the major biophysical and land-use factors influencing shoreline change rates. Most significant drivers of the rates of change are cutting of mangroves, the dominant mangrove genus, changes in adjacent shoreline land use, changes of shoreline land cover, and width of fringing mangroves. We suggest that a possible and inexpensive strategy for robust mangrove shoreline defense is direct mangrove planting to promote mangrove density with the presence of breakwater structures. In the shorter term, construction of coastal barriers such as fence-structured melaleuca poles in combination with mangrove restoration schemes could help retain coastal sediments and increase the elevation of the accretion zone, thereby helping to stabilize eroding fringe shorelines. It also is recommended that implementation of a system of payments for mangrove ecosystem services and the stronger regulation of mangrove cutting and unsustainable land-use change to strengthen the effectiveness of mangrove conservation programs and coastal land-use management.

  10. Boom or bust? A comparative analysis of transient population dynamics in plants

    DEFF Research Database (Denmark)

    Stott, Iain; Franco, Miguel; Carslake, David

    2010-01-01

    researchers as further possible effectors of complicated dynamics. Previously published methods of transient analysis have tended to require knowledge of initial population structure. However, this has been overcome by the recent development of the parametric Kreiss bound (which describes how large...... a population must become before reaching its maximum possible transient amplification following a disturbance) and the extension of this and other transient indices to simultaneously describe both amplified and attenuated transient dynamics. We apply the Kreiss bound and other transient indices to a data base...... worrying artefact of basic model parameterization. Synthesis. Transient indices describe how big or how small plant populations can get, en route to long-term stable rates of increase or decline. The patterns we found in the potential for transient dynamics, across many species of plants, suggest...

  11. [Evaluation of non-host plant ethanol extracts against Plutella xylostella population].

    Science.gov (United States)

    Wei, Hui; Hou, Youming; Yang, Guang; Fu, Jianwei; You, Minsheng

    2005-06-01

    Through establishing experimental and natural population life tables, and by using the index of population trend (1) and interference index of population control (IIPC), this paper evaluated 8 kinds of non-host plant ethanol extracts against experimental population of Plutella xylostella, and 3 kinds of these extracts and their mixture against Plutella xylostella natural population. The experimental population life table of DBM showed that the index of population trend (I) was 69. 8964 in control, and decreased dramatically to 5.3702, 4.4842, 8.0945, 11.1382, 6.8937, 6.1609, 5.5199 and 9.8052, respectively in treatments of Zanthoxylum bungeanum, Eucalyptus tereticornis, Nicotiana tabacum, Broussonetia papyrifera, Bauhinia variegata, Duranta repens, Euphorbia hirta and Camellia oleifera ethanol extracts, while the corresponding IIPC was 0.0768, 0.0642, 0.1158, 0.1594, 0.0986, 0.0881, 0.0790 and 0. 1403, respectively. The natural population life tables of DBM showed that the index of population trend (I) was 21.6232 in control, and decreased dramatically to 5.1997, 7.4160, 7. 3644 and 3.1399, respectively in treatments of the ethanol extracts of E. tereticornis, N. tabacum, C. oleifera and their mixture, while the corresponding IIPC was 0.2405, 0.3695, 0.3549 and 0.1608, respectively. All of these indicated that the test plant extracts could interfere the development of P. xylostella population significantly, and had the potential as an effective measure for controlling insect pest.

  12. Medicinal plants profile used by the 3rd District population of Maceió-AL.

    Science.gov (United States)

    Griz, S A S; Matos-Rocha, T J; Santos, A F; Costa, J G; Mousinho, K C

    2017-05-04

    Herein the use of medicinal plants by the population of the 3rd Sanitary District of Maceió-AL city is reported. Transversal description was conducted from February 2013 to January 2014, with a sample of 116 individuals of both Gender Genders aged over 18 years. The ethnobotanical information interviews ethnobotanical information were obtained through semi - structured questionnaire featuring the use of medicinal plants and social and economical data. Descriptive statistics was applied for quantitative variables as mean and standard deviation and proportions for qualitative variables in the frequency table format. The results showed that 85.34% of the interviewees used plants for medicinal purposes. As the majority of these were (73.28%) females in the age group between 30-60 years of old. Among a total of 45 identified plant species, the highest use frequency were for Boldus Peumus (bilberry), Melissa officinalis (lemon balm), and Mentha piperita (mint). The most widely used plant foliage part was (53.53%) prepared as an infusion (55.5%). The use of medicinal plants in Maceió cityis widespread, highlighting the importance of ethnobotanical knowledge for the study of medicinal plants.

  13. Longevity can buffer plant and animal populations against changing climatic variability.

    Science.gov (United States)

    Morris, William F; Pfister, Catherine A; Tuljapurkar, Shripad; Haridas, Chirrakal V; Boggs, Carol L; Boyce, Mark S; Bruna, Emilio M; Church, Don R; Coulson, Tim; Doak, Daniel F; Forsyth, Stacey; Gaillard, Jean-Michel; Horvitz, Carol C; Kalisz, Susan; Kendall, Bruce E; Knight, Tiffany M; Lee, Charlotte T; Menges, Eric S

    2008-01-01

    Both means and year-to-year variances of climate variables such as temperature and precipitation are predicted to change. However, the potential impact of changing climatic variability on the fate of populations has been largely unexamined. We analyzed multiyear demographic data for 36 plant and animal species with a broad range of life histories and types of environment to ask how sensitive their long-term stochastic population growth rates are likely to be to changes in the means and standard deviations of vital rates (survival, reproduction, growth) in response to changing climate. We quantified responsiveness using elasticities of the long-term population growth rate predicted by stochastic projection matrix models. Short-lived species (insects and annual plants and algae) are predicted to be more strongly (and negatively) affected by increasing vital rate variability relative to longer-lived species (perennial plants, birds, ungulates). Taxonomic affiliation has little power to explain sensitivity to increasing variability once longevity has been taken into account. Our results highlight the potential vulnerability of short-lived species to an increasingly variable climate, but also suggest that problems associated with short-lived undesirable species (agricultural pests, disease vectors, invasive weedy plants) may be exacerbated in regions where climate variability decreases.

  14. Integrated approach to assessing the effects of soils polluted with heavy metals on a plant population.

    Science.gov (United States)

    Gutiérrez-Ginés, M J; Pastor, J; Hernández, A J

    2012-10-01

    This study addresses the effects of soil polluted with more than one heavy metal in a grass species. A 16-week bioassay with Avena sativa L. was conducted in microcosms using soils from two abandoned mines in central Spain that contained levels above World Health Organization (WHO) reference limits for soils of more than three heavy metals. Pollution effects were examined at cell, tissue, organ, plant and population levels. For this purpose, dry weight, maximum height and number of leaves were determined; leaf tissues were observed by low temperature scanning electron microscopy; the metal contents of roots and shoots were determined by plasma emission spectroscopy and their distribution in different tissues was analyzed by X-ray microanalysis using an environmental scanning electron microscope. The results explain the accumulation and translocation of soil metals by this plant species; their effects in cells, tissues and growth of plants; and allow inference on population effects. The discussion of the methodological approach leads us to propose a valid protocol to assess the effects of a set of heavy metals present in the topsoil of polluted sites on a plant population. We recommend its use for an ecotoxicological diagnosis and risk analysis of similarly polluted sites.

  15. Salt marsh dieback in coastal Louisiana: survey of plant and soil conditions in Barataria and Terrebonne basins, June 2000-September 2001

    Science.gov (United States)

    McKee, Karen L.; Mendelssohn, Irving A.; Materne, Michael D.

    2006-01-01

    Sudden and extensive dieback of the perennial marsh grass, Spartina alterniflora Loisel (smooth cordgrass), which dominates regularly flooded salt marshes along the Gulf of Mexico and Atlantic coastlines, occurred in the coastal zone of Louisiana. The objectives of this study were to assess soil and plant conditions in dieback areas of the Barataria-Terrebonne estuarine system as well as vegetative recovery during and after this dieback event. Multiple dieback sites were examined along 100 km of shoreline from the Atchafalaya River to the Mississippi River during the period from June 2000 through September 2001. The species primarily affected was S. alterniflora; sympatric species such as Avicennia germinans (L.) Stearn (black mangrove) and Juncus roemerianus Scheele (needlegrass rush) showed no visible signs of stress. The pattern of marsh dieback was distinctive with greatest mortality in the marsh interior, suggesting a correlation with local patterns of soil chemistry and/or hydrology. Little or no expansion of dieback occurred subsequent to the initial event, and areas with 50 percent or less mortality in the fall of 2000 had completely recovered by April 2001. Recovery was slower in interior marshes with 90 percent or greater mortality initially. However, regenerating plants in dieback areas showing some recovery were robust, and reproductive output was high, indicating that the causative agent was no longer present and that post-dieback soil conditions were actually promoting plant growth. Stands of other species within or near some dieback sites remained largely unchanged or expanded (A. germinans) into the dead salt marsh. The cause of the dieback is currently unknown. Biotic agents and excessive soil waterlogging/high sulfide were ruled out as primary causes of this acute event, although they could have contributed to overall plant stress and/or interacted with the primary agent to cause plant mortality. Our observations over the 15 month study

  16. Pollination biology of the urban populations of an ancient forest, spring ephemeral plant

    Directory of Open Access Journals (Sweden)

    Maciej A. Ziemiański

    2016-04-01

    Full Text Available Habitat fragmentation, caused by, among all, agriculture and urbanization, is one of the most important drivers of plant biodiversity decline worldwide. One of the signs of deteriorating zoogamous plant reproduction is pollen limitation, often associated with a decline in pollinator diversity and abundance. Various authors predict that the most vulnerable taxa are outbreeding plant species characterized by specialist pollination systems. We have, therefore, focused on self-incompatible Corydalis solida, an ancient forest, spring ephemeral plant, growing in three remnant urban populations in the city of Warsaw (Poland. Over two years, we checked for pollen limitation and recorded insect diversity and abundance for C. solida flowers. Our study populations composed of self-incompatible individuals were mainly visited by generalist pollinators, and produced more seeds when supplementally pollinated. Pollen limitation, however, was greater during 1 year with an early spring onset, when we observed a decline in floral visitors diversity and activity. This was probably an effect of phenological mismatch between plants and their pollinators, in this case, mostly social bees, i.e., over-wintered bumblebee queens and Apis mellifera. We conclude that for outbreeding zoogamous spring ephemerals, such as C. solida serviced by generalist pollinators, changing climatic conditions may override the effects of habitat fragmentation and influence their reproductive success.

  17. The Control Efficiency of Plant Alcohol Extracts on the Laboratory Populations of Myzus persicae (Sulzer)and Lipaphis erysimi (Kaltenbach)

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qiong; LIANG Guang-wen; ZENG Ling; SHEN Shu-ping

    2002-01-01

    The effects of semiochemicals extracted from 63 species of plants, on peach aphid (Myzus persicae) and mustard aphid (Lipaphis erysimi), were studied in laboratory. The deterrent rate, reproduction deterrent index and the interferential index of population control (ⅡPC) was used to evaluate the efficiency of semiochemicals on population control of the two target aphids. The results showed that the extracts of 34 species of common plants have noticeable effect on both aphid populations, especially, Xanthium sibiricum Petr.Et Widd. and Syngonium podophyllum Schott. These plant extracts could be used to construct the plant protectant to protect crops.

  18. Managing Natural and Reintroduced Rare Plant Populations within a Large Government Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Carlsen, T M; Paterson, L E; Alfaro, T M

    2009-07-15

    California is home to many large government reservations that have been in existence for decades. Many of these reservations were formed to support various Department of Defense and Department of Energy national defense activities. Often, only a very small percentage of the reservation is actively used for programmatic activities, resulting in large areas of intact habitat. In some cases, this has benefited rare plant populations, as surrounding lands have been developed for residential or industrial use. However, land management activities such as the suppression or active use of fire and other disturbance (such as fire trail grading) can also work to either the detriment or benefit of rare plant populations at these sites. A management regime that is beneficial to the rare plant populations of interest and is at best consistent with existing site programmatic activities, and at a minimum does not impact such activities, has the best potential for a positive outcome. As a result, some species may be 'difficult' while others may be 'easy' to manage in this context, depending on how closely the species biological requirements match the programmatic activities on the reservation. To illustrate, we compare and contrast two rare annual plant species found at Lawrence Livermore National Laboratory's Site 300. Although several populations of Amsinckia grandiflora have been restored on the site, and all populations are intensively managed, this species continues to decline. In contrast, Blepharizonia plumosa appears to take advantage of the annual controlled burns conducted on the site, and is thriving.

  19. Effects of Plant Extracts on Microbial Population, Methane Emission and Ruminal Fermentation Characteristics in

    Directory of Open Access Journals (Sweden)

    E. T. Kim

    2012-06-01

    Full Text Available This study was conducted to evaluate effects of plant extracts on methanogenesis and rumen microbial diversity in in vitro. Plant extracts (Artemisia princeps var. Orientalis; Wormwood, Allium sativum for. Pekinense; Garlic, Allium cepa; Onion, Zingiber officinale; Ginger, Citrus unshiu; Mandarin orange, Lonicera japonica; Honeysuckle were obtained from the Plant Extract Bank at Korea Research Institute of Bioscience and Biotechnology. The rumen fluid was collected before morning feeding from a fistulated Holstein cow fed timothy and commercial concentrate (TDN; 73.5%, crude protein; 19%, crude fat; 3%, crude fiber; 12%, crude ash; 10%, Ca; 0.8%, P; 1.2% in the ratio of 3 to 2. The 30 ml of mixture, comprising McDougall buffer and rumen liquor in the ratio of 4 to 1, was dispensed anaerobically into serum bottles containing 0.3 g of timothy substrate and plant extracts (1% of total volume, respectively filled with O2-free N2 gas and capped with a rubber stopper. The serum bottles were held in a shaking incubator at 39°C for 24 h. Total gas production in all plant extracts was higher (p<0.05 than that of the control, and total gas production of ginger extract was highest (p<0.05. The methane emission was highest (p<0.05 at control, but lowest (p<0.05 at garlic extract which was reduced to about 20% of methane emission (40.2 vs 32.5 ml/g DM. Other plant extracts also resulted in a decrease in methane emissions (wormwood; 8%, onion; 16%, ginger; 16.7%, mandarin orange; 12%, honeysuckle; 12.2%. Total VFAs concentration and pH were not influenced by the addition of plant extracts. Acetate to propionate ratios from garlic and ginger extracts addition samples were lower (p<0.05, 3.36 and 3.38 vs 3.53 than that of the control. Real-time PCR indicted that the ciliate-associated methanogen population in all added plant extracts decreased more than that of the control, while the fibrolytic bacteria population increased. In particular, the F. succinogens

  20. Analysis of ontogenetic spectra of populations of plants and lichens via ordinal regression

    Science.gov (United States)

    Sofronov, G. Yu.; Glotov, N. V.; Ivanov, S. M.

    2015-03-01

    Ontogenetic spectra of plants and lichens tend to vary across the populations. This means that if several subsamples within a sample (or a population) were collected, then the subsamples would not be homogeneous. Consequently, the statistical analysis of the aggregated data would not be correct, which could potentially lead to false biological conclusions. In order to take into account the heterogeneity of the subsamples, we propose to use ordinal regression, which is a type of generalized linear regression. In this paper, we study the populations of cowberry Vaccinium vitis-idaea L. and epiphytic lichens Hypogymnia physodes (L.) Nyl. and Pseudevernia furfuracea (L.) Zopf. We obtain estimates for the proportions of between-sample variability in the total variability of the ontogenetic spectra of the populations.

  1. Plant genetics affects arthropod community richness and composition: evidence from a synthetic eucalypt hybrid population.

    Science.gov (United States)

    Dungey, H S; Potts, B M; Whitham, T G; Li, H F

    2000-12-01

    To examine how genetic variation in a plant population affects arthropod community richness and composition, we quantified the arthropod communities on a synthetic population of Eucalyptus amygdalina, E. risdonii, and their F1 and advanced-generation hybrids. Five major patterns emerged. First, the pure species and hybrid populations supported significantly different communities. Second, species richness was significantly greatest on hybrids (F1 > F2 > E. amygdalina > E. risdonii). These results are similar to those from a wild population of the same species and represent the first case in which both synthetic and wild population studies confirm a genetic component to community structure. Hybrids also acted as centers of biodiversity by accumulating both the common and specialist taxa of both parental species (100% in the wild and 80% in the synthetic population). Third, species richness was significantly greater on F1s than the single F2 family, suggesting that the increased insect abundance on hybrids may not be caused by the breakup of coadapted gene complexes. Fourth, specialist arthropod taxa were most likely to show a dominance response to F1 hybrids, whereas generalist taxa exhibited a susceptible response. Fifth, in an analysis of 31 leaf terpenoids that are thought to play a role in plant defense, hybrids were generally intermediate to the parental chemotypes. Within the single F2 family, we found significant associations between the communities of individual trees and five individual oil components, including oil yield, demonstrating that there is a genetic effect on plant defensive chemistry that, in turn, may affect community structure. These studies argue that hybridization has important community-level consequences and that the genetic variation present in hybrid zones can be used to explore the genetic-based mechanisms that structure communities.

  2. A simulation study of dispersion of air borne radionuclides from a nuclear power plant under a hypothetical accidental scenario at a tropical coastal site

    Science.gov (United States)

    Srinivas, C. V.; Venkatesan, R.

    Meteorological condition in coastal regions is diurnally variable and spatially heterogeneous due to complex topography, land-sea interface, etc. A wide range of dispersion conditions is possible on a given day in the coastal regions. In case of inadvertent accidental situations, though unlikely, it would be necessary to examine the potentially severe case among different dynamically occurring local atmospheric conditions for dispersion and its range of impact around a nuclear power plant for safety analysis. In this context, dispersion of air borne radioactive effluents during a hypothetical accidental scenario from a proposed prototype fast breeder reactor (PFBR) at an Indian coastal site, Kalpakkam, is simulated using a 3-D meso-scale atmospheric model MM5 and a random walk particle dispersion model FLEXPART. A simulation carried out for a typical summer day predicted the development of land-sea breeze circulation and thermal internal boundary layer (TIBL) formation, which have been confirmed by meteorological observations. Analysis of dose distribution shows that the maximum dose for releases from a 100 m stack occurs at two places within 4 km distance during sea breeze/TIBL fumigation hours. Maximum dose also occurred during nighttime stable conditions. Results indicate that, on the day of present study, the highest concentrations occurred during periods of TIBL fumigation rather than during stable atmospheric conditions. Further, the area of impact (plume width at the surface) spreads up to a down wind distance of 4 km during fumigation condition. Simulation over a range of 25 km has shown turning of plume at the incidence of sea breeze circulation and two different dispersion patterns across the sea breeze front. These results are significant in comparison to the expected pattern shown by Gaussian plume model used for routine analysis.

  3. Effect of Three Plant Species on Population Densities of Xiphinema americanum and X. rivesi.

    Science.gov (United States)

    Georgi, L L

    1988-07-01

    A taxonomic revision of the Xiphinema americanum species complex has necessitated a reexamination of the host range of species in the complex before recommendations can be made with confidence on the likelihood that specific crops will be damaged. Toward this end, populations of X. americanum and X. rivesi collected from apple orchards in eastern and western New York state were evaluated after 3 months in pots planted with cucumber, apple, or dandelion seedlings. Eastern and western New York populations of both nematode species declined on cucumber but increased to similar final densities on apple and dandelion.

  4. ASSESSMENT OF THE FUKUSIMA NUCLEAR POWER PLANT ACCIDENT CONSEQUENCES BY THE POPULATION IN THE FAR EAST

    Directory of Open Access Journals (Sweden)

    G. V. Arkhangelskaya

    2012-01-01

    Full Text Available The article analyzes the attitude of the population in the five regions of the Far East to the consequences of the accident at the Fukushimai nuclear power plant, as well as the issues of informing about the accident. The analysis of public opinion is based on the data obtained by anonymous questionnaire survey performed in November 2011. In spite of the rather active informing and objective information on the absence of the contamination, most of the population of the Russian Far East believes that radioactive contamination is presented in the areas of their residence, and the main cause of this contamination is the nuclear accident in Japan.

  5. Population dose from indoor gamma exposure in the dwellings around Kudankulam nuclear power plant.

    Science.gov (United States)

    Brahmanandhan, G M; Selvasekarapandian, S; Malathi, J; Khanna, D; Jose, M T; Meenakshisundaram, V

    2008-01-01

    To assess the population dose due to the natural background radiation around the upcoming Kudankulam nuclear power plant, a systematic investigation has been carried out by measuring the indoor gamma dose. In total, 159 dwellings have been selected around the Kudankulam nuclear power plant area i.e. in Radhapuram and Nanguneri taluk (sub-districts) for the measurement. The geometric mean value of indoor gamma dose rate is 305 +/- 48 nGy h(-1) and 273 +/- 50 nGy h(-1) in Radhapuram and Nanguneri taluks (sub-districts), respectively. The annual effective dose due to indoor gamma radiation to the population has been found to be 1.5 mSv and 1.36 mSv in Radhapuram and Nanguneri taluks, respectively.

  6. Influence of small hydropower plants on brown trout (Salmo trutta L. population in Mislinja River

    Directory of Open Access Journals (Sweden)

    Blaž Cokan

    2013-12-01

    Full Text Available The brown trout (Salmo trutta L. in the Mislinja River has been endangered for years because of small hydroelectric power plants. To find out how they are affecting the population of the brown trout in the Mislinja River, we conducted a sampling of the brown trout, using a generating set. We measured the length and weight of all caught specimens and analysed the obtained data. The results are presented in this paper, e.g., biomass, estimations of abundance, average weight, average length and number of captured brown trout. We discovered that the population of the brown trout has decreased in all the sections where water has been taken away for small hydroelectric power plants.

  7. Coastal Engineering

    NARCIS (Netherlands)

    Van der Velden, E.T.J.M.

    1989-01-01

    Introduction, waves, sediment transport, littoral transport, lonshore sediment transport, onshore-offshore sediment transport, coastal changes, dune erosion and storm surges, sedimentation in channels and trenches, coastal engineering in practice.

  8. Medicinal plants used in some rural populations of Oaxaca, Puebla and Veracruz, Mexico.

    Science.gov (United States)

    Zamora-Martínez, M C; de Pascual Pola, C N

    1992-01-01

    Within Mexico's floristic abundance, plants with curative properties are outstanding due to their popularity in handling several illnesses, a fact that becomes specially important for the social groups of the tropical regions. In this paper the results of an ethnobotanical study carried out in 57 rural populations from the Mexican states of Oaxaca, Veracruz and Puebla are presented; questionnaire and interview methods were applied, with special attention to the use of plants for medical purposes. The most relevant results were: the taxonomic determination of 237 vegetal species from which 399 curative products are obtained, in order to combat 57 illnesses, the most frequent of which are those related to the digestive system, the skin, the reproductive system and those of supernatural origin, which can only be treated by the use of plants in special ceremonies known as 'limpias', due to their peculiar condition.

  9. Modeling spatial competition for light in plant populations with the porous medium equation.

    Science.gov (United States)

    Beyer, Robert; Etard, Octave; Cournède, Paul-Henry; Laurent-Gengoux, Pascal

    2015-02-01

    We consider a plant's local leaf area index as a spatially continuous variable, subject to particular reaction-diffusion dynamics of allocation, senescence and spatial propagation. The latter notably incorporates the plant's tendency to form new leaves in bright rather than shaded locations. Applying a generalized Beer-Lambert law allows to link existing foliage to production dynamics. The approach allows for inter-individual variability and competition for light while maintaining robustness-a key weakness of comparable existing models. The analysis of the single plant case leads to a significant simplification of the system's key equation when transforming it into the well studied porous medium equation. Confronting the theoretical model to experimental data of sugar beet populations, differing in configuration density, demonstrates its accuracy.

  10. Effect of Drought on Herbivore-Induced Plant Gene Expression: Population Comparison for Range Limit Inferences

    Directory of Open Access Journals (Sweden)

    Gunbharpur Singh Gill

    2016-03-01

    Full Text Available Low elevation “trailing edge” range margin populations typically face increases in both abiotic and biotic stressors that may contribute to range limit development. We hypothesize that selection may act on ABA and JA signaling pathways for more stable expression needed for range expansion, but that antagonistic crosstalk prevents their simultaneous co-option. To test this hypothesis, we compared high and low elevation populations of Boechera stricta that have diverged with respect to constitutive levels of glucosinolate defenses and root:shoot ratios; neither population has high levels of both traits. If constraints imposed by antagonistic signaling underlie this divergence, one would predict that high constitutive levels of traits would coincide with lower plasticity. To test this prediction, we compared the genetically diverged populations in a double challenge drought-herbivory growth chamber experiment. Although a glucosinolate defense response to the generalist insect herbivore Spodoptera exigua was attenuated under drought conditions, the plastic defense response did not differ significantly between populations. Similarly, although several potential drought tolerance traits were measured, only stomatal aperture behavior, as measured by carbon isotope ratios, was less plastic as predicted in the high elevation population. However, RNAseq results on a small subset of plants indicated differential expression of relevant genes between populations as predicted. We suggest that the ambiguity in our results stems from a weaker link between the pathways and the functional traits compared to transcripts.

  11. Effects of radiation exposure on plant populations and radiation protection of the environment

    Energy Technology Data Exchange (ETDEWEB)

    Geras' kin, St.A.; Dikarev, V.G.; Oudalova, A.A.; Vasiliev, D.V.; Dikareva, N.S.; Baykova, T.A. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation); Evseeva, T.I. [Institute of Biology, Komi Scientific Center, Ural Div. RAS, Syktyvkar (Russian Federation)

    2006-07-01

    The results of long-term field experiments in the 30-km Chernobyl NPP zone, In the vicinity of the radioactive wastes storage facility (Leningrad Region), at radium production industry storage cell (the Komi Republic), and in Bryansk Region affected by the ChNPP accident that have been carried out on different species of wild and agricultural plants are discussed. These findings indicate that plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic disturbances and genetic diversity. The chronic low-dose exposure appears to be an ecological factor creating preconditions for possible changes in the genetic structure of a population. These processes have a genetic basis; therefore, an understanding changes at the genetic level should help in an identifying more complex changes at higher levels. The presented findings add to filling an important gap in our knowledge on remote effects in plant populations and ecosystems from man-made impact. (author)

  12. Control of Xiphinema index populations by fallow plants under greenhouse and field conditions.

    Science.gov (United States)

    Villate, Laure; Morin, Elisa; Demangeat, Gérard; Van Helden, Maarten; Esmenjaud, Daniel

    2012-06-01

    The dagger nematode Xiphinema index has a high economic impact in vineyards by direct pathogenicity and above all by transmitting the Grapevine fanleaf virus (GFLV). Agrochemicals have been largely employed to restrict the spread of GFLV by reducing X. index populations but are now banned. As an alternative to nematicides, the use of fallow plants between two successive vine crops was assessed. We selected plant species adapted to vineyard soils and exhibiting negative impact on nematodes and we evaluated their antagonistic effect on X. index in greenhouse using artificially infested soil, and in naturally infested vineyard conditions. The screening was conducted with plants belonging to the families Asteraceae (sunflower, marigold, zinnia, and nyjer), Poaceae (sorghum and rye), Fabaceae (white lupin, white melilot, hairy vetch, and alfalfa), Brassicaceae (rapeseed and camelina), and Boraginaceae (phacelia). In the greenhouse controlled assay, white lupin, nyjer, and marigold significantly reduced X. index populations compared with that of bare soil. The vineyard assay, designed to take into account the aggregative pattern of X. index distribution, revealed that marigold and hairy vetch are good candidates as cover crops to reduce X. index populations in vineyard. Moreover, this original experimental design could be applied to manage other soilborne pathogens.

  13. Land crabs as key drivers in tropical coastal forest recruitment

    Science.gov (United States)

    Lindquist, E.S.; Krauss, K.W.; Green, P.T.; O'Dowd, D. J.; Sherman, P.M.; Smith, T. J.

    2009-01-01

    Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influence seed dispersal and viability, and seedling establishment and growth at the microsite. Rarely does one animal guild exert as significant an influence on different plant assemblages as land crabs. We review three tropical coastal ecosystems-mangroves, island maritime forests, and mainland coastal terrestrial forests-where land crabs directly influence forest composition by limiting tree establishment and recruitment. Land crabs differentially prey on seeds, propagules and seedlings along nutrient, chemical and physical environmental gradients. In all of these ecosystems, but especially mangroves, abiotic gradients are well studied, strong and influence plant species distributions. However, we suggest that crab predation has primacy over many of these environmental factors by acting as the first limiting factor of tropical tree recruitment to drive the potential structural and compositional organisation of coastal forests. We show that the influence of crabs varies relative to tidal gradient, shoreline distance, canopy position, time, season, tree species and fruiting periodicity. Crabs also facilitate forest growth and development through such activities as excavation of burrows, creation of soil mounds, aeration of soils, removal of leaf litter into burrows and creation of carbon-rich soil microhabitats. For all three systems, land crabs influence the distribution, density and size-class structure of tree populations. Indeed, crabs are among the major drivers of tree recruitment in tropical coastal forest ecosystems, and their conservation should be included in management plans of these forests. ?? 2009 Cambridge Philosophical Society.

  14. Plastid genomics in horticultural species: importance and applications for plant population genetics, evolution, and biotechnology

    Science.gov (United States)

    Rogalski, Marcelo; do Nascimento Vieira, Leila; Fraga, Hugo P.; Guerra, Miguel P.

    2015-01-01

    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 phylogeographical and plant population genetics analyses. 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. PMID:26284102

  15. Adaptive transgenerational plasticity in plants: case studies, mechanisms, and implications for natural populations

    Directory of Open Access Journals (Sweden)

    Jacob J. Herman

    2011-12-01

    Full Text Available Plants respond to environmental conditions not only by plastic changes to their own development and physiology, but also by altering the phenotypes expressed by their offspring. This transgenerational plasticity was initially considered to entail only negative effects of stressful parental environments, such as production of smaller seeds by resource- or temperature-stressed parent plants, and was therefore viewed as environmental noise. Recent evolutionary ecology studies have shown that in some cases, these inherited environmental effects can include specific growth adjustments that are functionally adaptive to the parental conditions that induced them, which can range from contrasting states of controlled laboratory environments to the complex habitat variation encountered by natural plant populations. Preliminary findings suggest that adaptive transgenerational effects can be transmitted by means of diverse mechanisms including changes to seed provisioning and biochemistry, and epigenetic modifications such as DNA methylation that can persist across multiple generations. These non-genetically inherited adaptations can influence the ecological breadth and evolutionary dynamics of plant taxa and promote the spread of invasive plants. Interdisciplinary studies that join mechanistic and evolutionary ecology approaches will be an important source of future insights.

  16. Effects of fertilization on population density and productivity of herbaceous plants in desert steppe

    Institute of Scientific and Technical Information of China (English)

    JieQiong Su; XinRong Li; HaoTian Yang

    2014-01-01

    In order to investigate the impacts of fertilization on population density and productivity on herbaceous plants in desert steppe, nitrogen (N), phosphorus (P), and N-P addition experiments were performed. Each fertilizer treatment included four addition levels, i.e., 0, 5, 10, and 20 g/m2. The results indicated that population density decreased as fertilization levels increased regardless of the sort of fertilizer. More specifically, total density as well as density of Artemisia capillaris, Al-lium polyrhizum, and Enneapogon brachystachyus decreased significantly in 20 g/m2 treated plots, as compared with the control plots. Fertilization effects on aboveground and root biomasses were extremely similar to that found in population density; that is, both total aboveground biomass and aboveground biomasses for A. capillaris, A. polyrhizum, and E. brachystachyus were negatively correlated with increasing fertilization levels, with all determination coefficients (R2) greater than 0.80. Therefore, in the case of desert regions (annual precipitation <180 mm), fertilization would inhibit population density and productivity of herbaceous plants.

  17. Epiphytic ferns in swamp forest remnants of the coastal plain of southern Brazil: latitudinal effects on the plant community

    Directory of Open Access Journals (Sweden)

    Letícia S. Machado

    Full Text Available ABSTRACT Community structure and spatial distribution of epiphytic ferns in swamp forest remnants along the coastal plain of the state of Rio Grande do Sul were analyzed. A total of 440 trees were sampled in fifty-seven 10 x 10 m plots. Each phorophyte was divided into five ecological zones (strata, where all species of epiphytic ferns were recorded. A total of 34 species representing 18 genera in six families were recorded. Polypodiaceae was the most represented family with 17 species, and Microgramma vacciniifolia had the highest epiphytic importance value. Characteristic holoepiphyte was the predominant ecological category, representing 70 % of the species. Ordination analysis showed a gradual change in floristic composition between ecological zones with richness differing significantly between strata. We observed that with increasing latitude there was a decrease in mean temperature and total rainfall, but an increase in frosts. These climatic and phytogeography changes result in a reduction in species richness and a change in the structure of epiphytic fern communities in a north-to-south direction. The importance of swamp forest remnants of the coastal plain to the diversity of epiphytic ferns is discussed.

  18. Developing population models: A systematic approach for pesticide risk assessment using herbaceous plants as an example.

    Science.gov (United States)

    Schmolke, Amelie; Kapo, Katherine E; Rueda-Cediel, Pamela; Thorbek, Pernille; Brain, Richard; Forbes, Valery

    2017-12-01

    Population models are used as tools in species management and conservation and are increasingly recognized as important tools in pesticide risk assessments. A wide variety of population model applications and resources on modeling techniques, evaluation and documentation can be found in the literature. In this paper, we add to these resources by introducing a systematic, transparent approach to developing population models. The decision guide that we propose is intended to help model developers systematically address data availability for their purpose and the steps that need to be taken in any model development. The resulting conceptual model includes the necessary complexity to address the model purpose on the basis of current understanding and available data. We provide specific guidance for the development of population models for herbaceous plant species in pesticide risk assessment and demonstrate the approach with an example of a conceptual model developed following the decision guide for herbicide risk assessment of Mead's milkweed (Asclepias meadii), a species listed as threatened under the US Endangered Species Act. The decision guide specific to herbaceous plants demonstrates the details, but the general approach can be adapted for other species groups and management objectives. Population models provide a tool to link population-level dynamics, species and habitat characteristics as well as information about stressors in a single approach. Developing such models in a systematic, transparent way will increase their applicability and credibility, reduce development efforts, and result in models that are readily available for use in species management and risk assessments. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Population dynamics of Gluconacetobacter diazotrophicus in sugarcane cultivars and its effect on plant growth.

    Science.gov (United States)

    Muñoz-Rojas, J; Caballero-Mellado, J

    2003-11-01

    Different experiments have estimated that the contribution of biological nitrogen fixation (BNF) is largely variable among sugarcane cultivars. Which bacteria are the most important in sugarcane-associated BNF is unknown. However, Gluconacetobacter diazotrophicus has been suggested as a strong candidate responsible for the BNF observed. In the present study, bacteria-free micropropagated plantlets of five sugarcane cultivars were inoculated with three G. diazotrophicus strains belonging to different genotypes. Bacterial colonization was monitored under different nitrogen fertilization levels and at different stages of plant growth. Analysis of the population dynamics of G. diazotrophicus strains in the different sugarcane varieties showed that the bacterial populations decreased drastically in relation to plant age, regardless of the nitrogen fertilization level, bacterial genotype or sugarcane cultivars. However, the persistence of the three strains was significantly longer in some cultivars (e.g., MEX 57-473) than in others (e.g., MY 55-14). In addition, some strains (e.g., PAl 5(T)) persisted for longer periods in higher numbers than other strains (e.g., PAl 3) inside plants of all the cultivars tested. Indeed, the study showed that the inoculation of G. diazotrophicus may be beneficial for sugarcane plant growth, but this response is dependent both on the G. diazotrophicus genotype and the sugarcane variety. The most positive response to inoculation was observed with the combination of strain PAl 5(T) and the variety MEX 57-473. Although the positive effect on sugarcane growth apparently occurred by mechanisms other than nitrogen fixation, the results show the importance of the sugarcane variety for the persistence of the plant-bacteria interaction, and it could explain the different rates of BNF estimated among sugarcane cultivars.

  20. Comparative spatial genetics and epigenetics of plant populations: heuristic value and a proof of concept.

    Science.gov (United States)

    Herrera, Carlos M; Medrano, Mónica; Bazaga, Pilar

    2016-04-01

    Despite the recent upsurge of interest on natural epigenetic variation of nonmodel organisms, factors conditioning the spatial structure of epigenetic diversity in wild plant populations remain virtually unexplored. We propose that information on processes shaping natural epigenetic variation can be gained using the spatial structure of genetic diversity as null model. Departures of epigenetic isolation-by-distance (IBD) patterns from genetic IBD patterns for the same sample, particularly differences in slope of similarity-distance regressions, will reflect the action of factors that operate specifically on epigenetic variation, including imperfect transgenerational inheritance and responsiveness to environmental factors of epigenetic marks. As a proof of concept, we provide a comparative analysis of spatial genetic and epigenetic structure of 200 mapped individuals of the perennial herb Helleborus foetidus. Plants were fingerprinted using nuclear microsatellites, amplified fragment length polymorphisms (AFLP) and methylation-sensitive AFLP markers. Expectations from individual-level IBD patterns were tested by means of kinship-distance regressions. Both genetic and epigenetic similarity between H. foetidus individuals conformed to theoretical expectations under individual-level IBD models. Irrespective of marker type, there were significant negative linear relationships between the kinship coefficient for plant pairs and their spatial separation. Regression slopes were significantly steeper for epigenetic markers. Epigenetic similarity between individuals was much greater than genetic similarity at shortest distances, such epigenetic 'kinship excess' tending to decrease as plant separation increased. Results suggest that moderate-to-high heritability and responsiveness to local environments are major drivers of epigenetic spatial structure in H. foetidus, and illustrate the heuristic value of comparing genetic and epigenetic spatial structure for formulating

  1. Genetic diversity and fitness in small populations of partially asexual, self-incompatible plants.

    Science.gov (United States)

    Navascués, M; Stoeckel, S; Mariette, S

    2010-05-01

    How self-incompatibility systems are maintained in plant populations is still a debated issue. Theoretical models predict that self-incompatibility systems break down according to the intensity of inbreeding depression and number of S-alleles. Other studies have explored the function of asexual reproduction in the maintenance of self-incompatibility. However, the population genetics of partially asexual, self-incompatible populations are poorly understood and previous studies have failed to consider all possible effects of asexual reproduction or could only speculate on those effects. In this study, we investigated how partial asexuality may affect genetic diversity at the S-locus and fitness in small self-incompatible populations. A genetic model including an S-locus and a viability locus was developed to perform forward simulations of the evolution of populations of various sizes. Drift combined with partial asexuality produced a decrease in the number of alleles at the S-locus. In addition, an excess of heterozygotes was present in the population, causing an increase in mutation load. This heterozygote excess was enhanced by the self-incompatibility system in small populations. In addition, in highly asexual populations, individuals produced asexually had some fitness advantages over individuals produced sexually, because sexual reproduction produces homozygotes of the deleterious allele, contrary to asexual reproduction. Our results suggest that future research on the function of asexuality for the maintenance of self-incompatibility will need to (1) account for whole-genome fitness (mutation load generated by asexuality, self-incompatibility and drift) and (2) acknowledge that the maintenance of self-incompatibility may not be independent of the maintenance of sex itself.

  2. Soybean morphophysiology and yield response to seeding systems and plant populations

    Directory of Open Access Journals (Sweden)

    Raniele Souza

    2016-03-01

    Full Text Available Soybean (Glicine max [L.] Merr. is recognized worldwide for its economic importance; it has the ability to adapt to environmental and management changes, particularly when using different spacing and plant populations. This study aimed to investigate the influence of morphological changes of the crisscross seeding system on grain growth and yield. Work was conducted at the Experimental Station of Anapolis, Goiás, Brazil, of the Technical Assistance Agency, Rural Extension and Agricultural Research of Goiás (EMATER for the 2013-2014 harvest. The experimental design was a randomized block and 2 x 3 x 3 factorial, with four replicates. Treatments consisted of two seeding systems (conventional-in line and crossed-crisscross, three soybean cultivars with different growth habits ('BRS Valiosa RR' determined, 'NA 7337 RR' semi-determined, and 'BMX Potencia RR' indeterminate and three sowing densities (245 000, 350 000, and 455 000 plants ha-1. Results showed that at 50 d after emergence the cross-seeding system showed higher closing among lines promoted by the increase in population. Leaf area and the leaf area index were not affected by the seeding system. Leaf area was lower with increasing plant density with no significant difference in relation to the leaf area index. The cross-system enabled a potential yield of 4504 kg ha-1 corresponding to an approximate 8% increase compared with conventional sowing using equidistant lines with 0.5 m spacing.

  3. Low crop plant population densities promote pollen-mediated gene flow in spring wheat (Triticum aestivum L.).

    Science.gov (United States)

    Willenborg, Christian J; Brûlé-Babel, Anita L; Van Acker, Rene C

    2009-12-01

    Transgenic wheat is currently being field tested with the intent of eventual commercialization. The development of wheat genotypes with novel traits has raised concerns regarding the presence of volunteer wheat populations and the role they may play in facilitating transgene movement. Here, we report the results of a field experiment that investigated the potential of spring wheat plant population density and crop height to minimize gene flow from a herbicide-resistant (HR) volunteer population to a non-HR crop. Pollen-mediated gene flow (PMGF) between the HR volunteer wheat population and four conventional spring wheat genotypes varying in height was assessed over a range of plant population densities. Natural hybridization events between the two cultivars were detected by phenotypically scoring plants in F(1) populations followed by verification with Mendelian segregation ratios in the F(1:2) families. PMGF was strongly associated with crop yield components, but showed no association with flowering synchrony. Maximum observed PMGF was always less than 0.6%, regardless of crop height and density. The frequency of PMGF in spring wheat decreased exponentially with increasing plant population density, but showed no dependence on either crop genotype or height. However, increasing plant densities beyond the recommended planting rate of 300 cropped wheat plants m(-2) provided no obvious benefit to reducing PMGF. Nevertheless, our results demonstrate a critical plant density of 175-200 cropped wheat plants m(-2) below which PMGF frequencies rise exponentially with decreasing plant density. These results will be useful in the development of mechanistic models and best management practices that collectively facilitate the coexistence of transgenic and nontransgenic wheat crops.

  4. Thermal Pollution by Nuclear Power Plants. A Learning Experience for Coastal and Oceanic Awareness Studies, No. 320. [Project COAST].

    Science.gov (United States)

    Delaware Univ., Newark. Coll. of Education.

    This publication includes several activities regarding the use of nuclear power plants and possible effects on the environment. The materials are designed for secondary school students and include reference materials and masters for transparencies. (RH)

  5. Thermal Pollution by Nuclear Power Plants. A Learning Experience for Coastal and Oceanic Awareness Studies, No. 320. [Project COAST].

    Science.gov (United States)

    Delaware Univ., Newark. Coll. of Education.

    This publication includes several activities regarding the use of nuclear power plants and possible effects on the environment. The materials are designed for secondary school students and include reference materials and masters for transparencies. (RH)

  6. Variation in tidal wetland plant diversity and composition within and among coastal estuaries: assessing the relative importance of environmental gradients

    Science.gov (United States)

    Question: Does wetland plant composition vary more by estuarine type (differentiated by the degree of riverine versus oceanic influence) or habitat type within estuaries (defined by US National Wetlands Inventory [NWI] marsh classes)? Location: Oregon estuaries: Netarts Bay, ...

  7. Plant Host Species and Geographic Distance Affect the Structure of Aboveground Fungal Symbiont Communities, and Environmental Filtering Affects Belowground Communities in a Coastal Dune Ecosystem.

    Science.gov (United States)

    David, Aaron S; Seabloom, Eric W; May, Georgiana

    2016-05-01

    Microbial symbionts inhabit tissues of all plants and animals. Their community composition depends largely on two ecological processes: (1) filtering by abiotic conditions and host species determining the environments that symbionts are able to colonize and (2) dispersal-limitation determining the pool of symbionts available to colonize a given host and community spatial structure. In plants, the above- and belowground tissues represent such distinct habitats for symbionts that we expect different effects of filtering and spatial structuring on their symbiont communities. In this study, we characterized above- and belowground communities of fungal endophytes--fungi living asymptomatically within plants--to understand the contributions of filtering and spatial structure to endophyte community composition. We used a culture-based approach to characterize endophytes growing in leaves and roots of three species of coastal beachgrasses in dunes of the USA Pacific Northwest. For leaves, endophyte isolation frequency and OTU richness depended primarily on plant host species. In comparison, for roots, both isolation frequency and OTU richness increased from the nutrient-poor front of the dune to the higher-nutrient backdune. Endophyte community composition in leaves exhibited a distance-decay relationship across the region. In a laboratory assay, faster growth rates and lower spore production were more often associated with leaf- than root-inhabiting endophytes. Overall, our results reveal a greater importance of biotic filtering by host species and dispersal-limitation over regional geographic distances for aboveground leaf endophyte communities and stronger effects of abiotic environmental filtering and locally patchy distributions for belowground root endophyte communities.

  8. Host plant use drives genetic differentiation in syntopic populations of Maculinea alcon

    Directory of Open Access Journals (Sweden)

    András Tartally

    2016-03-01

    Full Text Available The rare socially parasitic butterfly Maculinea alcon occurs in two forms, which are characteristic of hygric or xeric habitats and which exploit different host plants and host ants. The status of these two forms has been the subject of considerable controversy. Populations of the two forms are usually spatially distinct, but at Răscruci in Romania both forms occur on the same site (syntopically. We examined the genetic differentiation between the two forms using eight microsatellite markers, and compared with a nearby hygric site, Şardu. Our results showed that while the two forms are strongly differentiated at Răscruci, it is the xeric form there that is most similar to the hygric form at Şardu, and Bayesian clustering algorithms suggest that these two populations have exchanged genes relatively recently. We found strong evidence for population substructuring, caused by high within host ant nest relatedness, indicating very limited dispersal of most ovipositing females, but not association with particular host ant species. Our results are consistent with the results of larger scale phylogeographic studies that suggest that the two forms represent local ecotypes specialising on different host plants, each with a distinct flowering phenology, providing a temporal rather than spatial barrier to gene flow.

  9. A comparison of Aedes vigilax larval population densities and associated vegetation categories in a coastal wetland, Northern Territory, Australia.

    Science.gov (United States)

    Jacups, S P; Kurucz, N; Whelan, P I; Carter, J M

    2009-12-01

    Darwin's northern suburbs border an extensive coastal reed and upper mangrove wetland recognized as an important larval habitat for Aedes vigilax (Skuse), the northern salt marsh mosquito, an established vector for Ross River and Barmah Forest viruses and an appreciable pest species. We sought to identify the most important vegetation categories associated with Ae. vigilax breeding to maximize the efficiency of mosquito control efforts. Using a generalized linear model with negative binominal distribution and log link, this study compares larval densities, determined by focused dipping, between 13 discernable vegetation categories. The incidence rate ratios (RR) generated can be used to compare the magnitude of larval densities for each vegetation category, compared with the reference category. Aedes vigilax larval densities were almost ten times greater in artificial drainage areas (RR=9.82), followed by tide-affected reticulate (Sporobolus/Xerochloa) areas (RR=8.15), then Schoenoplectus/mangroves (RR=2.29), compared with the reference vegetation category "lower mangroves." Furthermore, larval densities were highest in May, due to tidal inundation, for drainage areas and tide-affected reticulates (RR=12.2, 11.7, respectively) compared with March, the reference month. Thus, to maximize the efficiency of aerial salt marsh mosquito control operations in this wetland, larval control is best accomplished by concentrating on drains, Schoenoplectus/mangroves, and tide-affected reticulate areas, commencing early after the wet season. These results should apply to other areas of salt marsh mosquito breeding across northern Australia.

  10. Dynamics of bacterial populations during bench-scale bioremediation of oily seawater and desert soil bioaugmented with coastal microbial mats.

    Science.gov (United States)

    Ali, Nidaa; Dashti, Narjes; Salamah, Samar; Sorkhoh, Naser; Al-Awadhi, Husain; Radwan, Samir

    2016-03-01

    This study describes a bench-scale attempt to bioremediate Kuwaiti, oily water and soil samples through bioaugmentation with coastal microbial mats rich in hydrocarbonoclastic bacterioflora. Seawater and desert soil samples were artificially polluted with 1% weathered oil, and bioaugmented with microbial mat suspensions. Oil removal and microbial community dynamics were monitored. In batch cultures, oil removal was more effective in soil than in seawater. Hydrocarbonoclastic bacteria associated with mat samples colonized soil more readily than seawater. The predominant oil degrading bacterium in seawater batches was the autochthonous seawater species Marinobacter hydrocarbonoclasticus. The main oil degraders in the inoculated soil samples, on the other hand, were a mixture of the autochthonous mat and desert soil bacteria; Xanthobacter tagetidis, Pseudomonas geniculata, Olivibacter ginsengisoli and others. More bacterial diversity prevailed in seawater during continuous than batch bioremediation. Out of seven hydrocarbonoclastic bacterial species isolated from those cultures, only one, Mycobacterium chlorophenolicum, was of mat origin. This result too confirms that most of the autochthonous mat bacteria failed to colonize seawater. Also culture-independent analysis of seawater from continuous cultures revealed high-bacterial diversity. Many of the bacteria belonged to the Alphaproteobacteria, Flavobacteria and Gammaproteobacteria, and were hydrocarbonoclastic. Optimal biostimulation practices for continuous culture bioremediation of seawater via mat bioaugmentation were adding the highest possible oil concentration as one lot in the beginning of bioremediation, addition of vitamins, and slowing down the seawater flow rate.

  11. Host mating system and the prevalence of a disease in a plant population

    Science.gov (United States)

    Koslow, Jennifer M.; DeAngelis, Donald L.

    2006-01-01

    A modified susceptible–infected–recovered (SIR) host–pathogen model is used to determine the influence of plant mating system on the outcome of a host–pathogen interaction. Unlike previous models describing how interactions between mating system and pathogen infection affect individual fitness, this model considers the potential consequences of varying mating systems on the prevalence of resistance alleles and disease within the population. If a single allele for disease resistance is sufficient to confer complete resistance in an individual and if both homozygote and heterozygote resistant individuals have the same mean birth and death rates, then, for any parameter set, the selfing rate does not affect the proportions of resistant, susceptible or infected individuals at equilibrium. If homozygote and heterozygote individual birth rates differ, however, the mating system can make a difference in these proportions. In that case, depending on other parameters, increased selfing can either increase or decrease the rate of infection in the population. Results from this model also predict higher frequencies of resistance alleles in predominantly selfing compared to predominantly outcrossing populations for most model conditions. In populations that have higher selfing rates, the resistance alleles are concentrated in homozygotes, whereas in more outcrossing populations, there are more resistant heterozygotes.

  12. General stabilizing effects of plant diversity on grassland productivity through population asynchrony and overyielding.

    Science.gov (United States)

    Hector, A; Hautier, Y; Saner, P; Wacker, L; Bagchi, R; Joshi, J; Scherer-Lorenzen, M; Spehn, E M; Bazeley-White, E; Weilenmann, M; Caldeira, M C; Dimitrakopoulos, P G; Finn, J A; Huss-Danell, K; Jumpponen, A; Mulder, C P H; Palmborg, C; Pereira, J S; Siamantziouras, A S D; Terry, A C; Troumbis, A Y; Schmid, B; Loreau, M

    2010-08-01

    Insurance effects of biodiversity can stabilize the functioning of multispecies ecosystems against environmental variability when differential species' responses lead to asynchronous population dynamics. When responses are not perfectly positively correlated, declines in some populations are compensated by increases in others, smoothing variability in ecosystem productivity. This variance reduction effect of biodiversity is analogous to the risk-spreading benefits of diverse investment portfolios in financial markets. We use data from the BIODEPTH network of grassland biodiversity experiments to perform a general test for stabilizing effects of plant diversity on the temporal variability of individual species, functional groups, and aggregate communities. We tested three potential mechanisms: reduction of temporal variability through population asynchrony; enhancement of long-term average performance through positive selection effects; and increases in the temporal mean due to overyielding. Our results support a stabilizing effect of diversity on the temporal variability of grassland aboveground annual net primary production through two mechanisms. Two-species communities with greater population asynchrony were more stable in their average production over time due to compensatory fluctuations. Overyielding also stabilized productivity by increasing levels of average biomass production relative to temporal variability. However, there was no evidence for a performance-enhancing effect on the temporal mean through positive selection effects. In combination with previous work, our results suggest that stabilizing effects of diversity on community productivity through population asynchrony and overyielding appear to be general in grassland ecosystems.

  13. 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.

  14. Population Status of Commercially Important Medicinal Plants in Dehradun Forest Division, Uttarakhand (India

    Directory of Open Access Journals (Sweden)

    Ninad B. RAUT

    2013-05-01

    Full Text Available The objective of forest management in the tropics, in recent decades, has shifted from timber production to biodiversity conservation and maintenance of life support system. However, past forestry practices have greatly influenced the structure of plant communities, preponderance of foreign invasive species, populations of high value medicinal plants as well as other non-wood forest products. We assessed the abundance and distribution of medicinal plants in managed and undisturbed forests of Dehradun Forest Division (DFD, Uttarakhand (India. A total of 80 transects (each 1 km long were laid in various categories of forest types in DFD. This paper deals with distribution, availability and regeneration status of five commercially important species viz., Justicia adhatoda, Aegle marmelos, Phyllanthus emblica, Terminalia bellirica and Terminalia chebula, across different forest types. The study reveals that open canopy forest patches, Lantana infested patches and Acacia catechu-Dalbergia sissoo (Khair -Shisam woodlands in the eastern part of the DFD have excellent potential for the production and sustainable harvest of Justicia adhatoda. Areas those are less suitable for timber production viz., open hill forests, have greater potential for conservation and development of Aegle marmelos, Phyllanthus emblica and Terminalia bellirica. For the production and management of high value medicinal plants in the DFD these ecological considerations need to be kept in mind.

  15. A stochastic model of chromatin modification: cell population coding of winter memory in plants.

    Science.gov (United States)

    Satake, Akiko; Iwasa, Yoh

    2012-06-07

    Biological memory, a sustained cellular response to a transient stimulus, has been found in many natural systems. The best example in plants is the winter memory by which plants can flower in favorable conditions in spring. For this winter memory, epigenetic regulation of FLOWERING LOCUS C (FLC), which acts as a floral repressor, plays a key role. Exposure to prolonged periods of cold results in the gradual suppression of FLC, which allows plants to measure the length of cold and to flower only after a sufficiently long winter. Although many genes involved in histone modifications have been isolated, molecular mechanisms of winter memory are not well understood. Here, we develop a model for chromatin modification, in which the dynamics of a single nucleosome are aggregated to on/off behavior of FLC expression at the cellular level and further integrated to a change of FLC expression at the whole-plant level. We propose cell-population coding of winter memory: each cell is described as a bistable system that shows heterogeneous timing of the transition from on to off in FLC expression under cold and measures the length of cold as the proportion of cells in the off state. This mechanism well explains robust FLC regulation and stable inheritance of winter memory after cell division in response to noisy signals. Winter memory lasts longer if deposition of the repressive histone mark occurs faster. A difference in deposition speed would discriminate between stable maintenance of FLC repression in annuals and transient expression in perennials.

  16. Realized gains from block-plot coastal Douglas-fir trials in the northern Oregon Cascades

    Science.gov (United States)

    Terrence Z. Ye; Keith J.S. Jayawickrama; J. Bradley. St. Clair

    2010-01-01

    Realized gains for coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) were evaluated using data collected from 15-year-old trees from five field trials planted in large block plots in the northern Oregon Cascades. Three populations with different genetic levels (elite--high predicted gain; intermediate--moderate predicted gain; and an...

  17. 热带滨海电厂腐蚀控制综合技术%The Corrosion Control Technic in Tropical Coastal Power Plant

    Institute of Scientific and Technical Information of China (English)

    王路东; 张鼎明; 李威力; 赵永韬

    2013-01-01

    Introduce the protect technic of buried pipe, flange, valve and stainless steel units in tropical coastal power plant. Using Mg anode to protect the buried pipeline in power plant, using Thermoplastic elastomer coating to protect the flange and valve, and using inhibitor and sacrificial anode to protect the sea water desalting equipment. Using comprehensive corrosion control methods to protect different steel structure in real flied.%本文主要介绍了热带滨海热电厂中埋地管道、法兰、阀门、不锈钢部件等部件腐蚀的综合防治。采用预组装镁合金牺牲阳极保护电厂中的埋地管道,采用热塑性弹性体涂层保护电厂中法兰及阀门等,采用缓蚀剂与牺牲阳极联合保护海水淡化设备,通过综合腐蚀控制方法对不同工况钢质结构进行防腐保护。

  18. Distinguishing plant population and variety with UAV-derived vegetation indices

    Science.gov (United States)

    Oakes, Joseph; Balota, Maria

    2017-05-01

    Variety selection and seeding rate are two important choice that a peanut grower must make. High yielding varieties can increase profit with no additional input costs, while seeding rate often determines input cost a grower will incur from seed costs. The overall purpose of this study was to examine the effect that seeding rate has on different peanut varieties. With the advent of new UAV technology, we now have the possibility to use indices collected with the UAV to measure emergence, seeding rate, growth rate, and perhaps make yield predictions. This information could enable growers to make management decisions early in the season based on low plant populations due to poor emergence, and could be a useful tool for growers to use to estimate plant population and growth rate in order to help achieve desired crop stands. Red-Green-Blue (RGB) and near-infrared (NIR) images were collected from a UAV platform starting two weeks after planting and continued weekly for the next six weeks. Ground NDVI was also collected each time aerial images were collected. Vegetation indices were derived from both the RGB and NIR images. Greener area (GGA- the proportion of green pixels with a hue angle from 80° to 120°) and a* (the average red/green color of the image) were derived from the RGB images while Normalized Differential Vegetative Index (NDVI) was derived from NIR images. Aerial indices were successful in distinguishing seeding rates and determining emergence during the first few weeks after planting, but not later in the season. Meanwhile, these aerial indices are not an adequate predictor of yield in peanut at this point.

  19. Estimating population exposure to power plant emissions using CALPUFF: a case study in Beijing, China

    Science.gov (United States)

    Zhou, Ying; Levy, Jonathan I.; Hammitt, James K.; Evans, John S.

    Epidemiological studies have shown a significant association between ambient particulate matter (PM) exposures and increased mortality and morbidity risk. Power plants are significant emitters of precursor gases of fine particulate matter. To evaluate the public health risk posed by power plants, it is necessary to evaluate population exposure to different pollutants. The concept of intake fraction (the fraction of a pollutant emitted that is eventually inhaled or ingested by a population) has been proposed to provide a simple summary measure of the relationship between emissions and exposure. Currently available intake fraction estimates from developing countries used models that look only at the near field impacts, which may not capture the full impact of a pollution source. This case study demonstrated how the intake fraction of power plant emissions in China can be calculated using a detailed long-range atmospheric dispersion model—CALPUFF. We found that the intake fraction of primary fine particles is roughly on the order of 10 -5, while the intake fractions of sulfur dioxide, sulfate and nitrate are on the order of 10 -6. These estimates are an order of magnitude higher than the US estimates. We also tested how sensitive the results were to key assumptions within the model. The size distribution of primary particles has a large impact on the intake fraction for primary particles while the background ammonia concentration is an important factor influencing the intake fraction of nitrate. The background ozone concentration has a moderate impact on the intake fraction of sulfate and nitrate. Our analysis shows that this approach is applicable to a developing country and it provides reasonable population exposure estimates.

  20. Diversity and population structure of sewage-derived microorganisms in wastewater treatment plant influent.

    Science.gov (United States)

    McLellan, S L; Huse, S M; Mueller-Spitz, S R; Andreishcheva, E N; Sogin, M L

    2010-02-01

    The release of untreated sewage introduces non-indigenous microbial populations of uncertain composition into surface waters. We used massively parallel 454 pyrosequencing of hypervariable regions in rRNA genes to profile microbial communities from eight untreated sewage influent samples of two wastewater treatment plants (WWTPs) in metropolitan Milwaukee. The sewage profiles included a discernible human faecal signature made up of several taxonomic groups including multiple Bifidobacteriaceae, Coriobacteriaceae, Bacteroidaceae, Lachnospiraceae and Ruminococcaceae genera. The faecal signature made up a small fraction of the taxa present in sewage but the relative abundance of these sequence tags mirrored the population structures of human faecal samples. These genera were much more prevalent in the sewage influent than standard indicators species. High-abundance sequences from taxonomic groups within the Beta- and Gammaproteobacteria dominated the sewage samples but occurred at very low levels in faecal and surface water samples, suggesting that these organisms proliferate within the sewer system. Samples from Jones Island (JI--servicing residential plus a combined sewer system) and South Shore (SS--servicing a residential area) WWTPs had very consistent community profiles, with greater similarity between WWTPs on a given collection day than the same plant collected on different days. Rainfall increased influent flows at SS and JI WWTPs, and this corresponded to greater diversity in the community at both plants. Overall, the sewer system appears to be a defined environment with both infiltration of rainwater and stormwater inputs modulating community composition. Microbial sewage communities represent a combination of inputs from human faecal microbes and enrichment of specific microbes from the environment to form a unique population structure.

  1. Mites fluctuation population on peach tree (Prunus persica (L. Batsch and in associated plants

    Directory of Open Access Journals (Sweden)

    Carla Rosana Eichelberger

    2011-09-01

    Full Text Available Despite the importance of peach (Prunus persica (L. Batsch in Rio Grande do Sul, little is known about mites fluctuation population considered important to this crop. The objective of this study was to know the population diversity and fluctuation of mite species associated with Premier and Eldorado varieties in Roca Sales and Venâncio Aires counties, Rio Grande do Sul. The study was conducted from July 2008 to June 2009 when 15 plants were randomly chosen in each area. The plants were divided in quadrants and from each one a branch was chosen from which three leaves were removed: one collected in the apical region, another in the medium and the other in the basal region, totalizing 180 leaves/area. Five of the most abundant associated plants were collected monthly in enough amounts for the screening under the stereoscopic microscope during an hour. A total of 1,124 mites were found belonging to 14 families and 28 species. Tetranychus ludeni Zacher, 1913, Panonychus ulmi (Koch, 1836 and Mononychellus planki (McGregor, 1950 were the most abundant phytophagous mites, whereas Typhlodromalus aripo Deleon, 1967 and Phytoseiulus macropilis (Banks, 1904 the most common predatory mites. The period of one hour under stereoscopic microscope was enough to get a representative sample. In both places evaluated the ecologic indices were low, but little higherin Premier (H' 0.56; EqJ: 0.43 when compared to Eldorado (H' 0.53; EqJ 0.40. In Premier constant species were not observed and accessory only Brevipalpus phoenicis (Geijskes, 1939, T. ludeni and T. aripo. Higher abundance was observed in December and January and bigger amount in April. Already in Eldorado, T. ludeni and P. ulmi were constants. Greater abundance was observed in November and December, whereas grater richness in December and January. In both orchards were not found mites in buds. Tetranychus ludeni is the most abundant phytophagous mites with outbreak population in November, December and

  2. Modeling the population-level effects of hypoxia on a coastal fish: implications of a spatially-explicit individual-based model

    Science.gov (United States)

    Rose, K.; Creekmore, S.; Thomas, P.; Craig, K.; Neilan, R.; Rahman, S.; Wang, L.; Justic, D.

    2016-02-01

    The northwestern Gulf of Mexico (USA) currently experiences a large hypoxic area ("dead zone") during the summer. The population-level effects of hypoxia on coastal fish are largely unknown. We developed a spatially-explicit, individual-based model to analyze how hypoxia effects on reproduction, growth, and mortality of individual Atlantic croaker could lead to population-level responses. The model follows the hourly growth, mortality, reproduction, and movement of individuals on a 300 x 800 spatial grid of 1 km2 cells for 140 years. Chlorophyll-a concentration and water temperature were specified daily for each grid cell. Dissolved oxygen (DO) was obtained from a 3-D water quality model for four years that differed in their severity of hypoxia. A bioenergetics model was used to represent growth, mortality was assumed stage- and age-dependent, and movement behavior was based on temperature preferences and avoidance of low DO. Hypoxia effects were imposed using exposure-effects sub-models that converted time-varying exposure to DO to reductions in growth and fecundity, and increases in mortality. Using sequences of mild, intermediate, and severe hypoxia years, the model predicted a 20% decrease in population abundance. Additional simulations were performed under the assumption that river-based nutrients loadings that lead to more hypoxia also lead to higher primary production and more food for croaker. Twenty-five percent and 50% nutrient reduction scenarios were simulated by adjusting the cholorphyll-a concentrations used as food proxy for the croaker. We then incrementally increased the DO concentrations to determine how much hypoxia would need to be reduced to offset the lower food production resulting from reduced nutrients. We discuss the generality of our results, the hidden effects of hypoxia on fish, and our overall strategy of combining laboratory and field studies with modeling to produce robust predictions of population responses to stressors under

  3. Prevalence of Willis-Ekbom disease in rural coastal Ecuador. A two-phase, door-to-door, population-based survey.

    Science.gov (United States)

    Del Brutto, Oscar H; Del Brutto, Victor J; Zambrano, Mauricio; Castillo, Pablo R

    2014-09-15

    To estimate the prevalence of Willis-Ekbom disease (WED) in a racially homogeneous population of adults Amerindians living in rural coastal Ecuador, and to assess the reliability of the International Restless Legs Syndrome Study Group (IRLSSG) questionnaire when used in population-based studies. Two-phase, door-to-door, population-based survey. During Phase I, rural doctors screened all Atahualpa residents aged ≥40 years with the IRLSSG questionnaire. In Phase II, neurologists evaluated suspected WED cases and a matched sample of negative individuals. The census identified 665 persons aged ≥40 years. An affirmative response to the questionnaire was obtained in 94 persons. Medical history and neurological examination confirmed the diagnosis of WED in 40 of them. The evaluation of 188 non-suspected individuals revealed no further cases. The questionnaire had a sensitivity of 100% (95% CI, 89% to 100%), a specificity of 78% (95% CI, 72% to 83%), a positive predictive value of 0.43 (95% CI, 0.33 to 0.53), and a negative predictive value of 1 (95% CI, 0.98 to 1). The prevalence of WED in Atahualpa residents aged ≥40 years was 6%. The prevalence of WED in this adult Ecuadorian population is higher than that reported from most studies conducted in tropical countries, but similar to that found in Brazil. Specificity and positive predictive value of the IRLSSG questionnaire are poor, which reinforces the need for a second phase that should include an expert interview. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. A field test of the relationship between habitat area and population size for five perennial plant species

    Directory of Open Access Journals (Sweden)

    H. H. Bruun

    2005-03-01

    Full Text Available The population sizes of five perennial vascular plant species confined to old unimproved dry grasslands were assessed, viz. Anthericum ramosum, Filipendula vulgaris, Silene nutans, Thymus pulegioides, and Thymus serpyllum. All populations within the region were included. Only for Filipendula vulgaris and Thymus serpyllum, significant relationships between habitat area and population size were found. Thus, apparently perennial vascular plants have a limited ability to respond to large habitat areas by forming large populations. This puts a question mark on the use of incidence-function models for the study of plant metapopulations, because these models are based on an assumed positive relationship between habitat area and population size.

  5. Analysis of genetic diversity of a native population of Myrcia lundiana Kiaersk. plants using ISSR markers.

    Science.gov (United States)

    Alves, M F; Nizio, D A C; Brito, F A; Sampaio, T S; Silva, A V C; Arrigoni-Blank, M F; Carvalho, S V A; Blank, A F

    2016-12-02

    Myrcia lundiana Kiaersk. is a tree of the family Myrtaceae found in tropical and subtropical areas of the southern hemisphere that produces essential oil. The aim of this study was to characterize the genetic diversity of M. lundiana plants from a native population of Parque Nacional de Itabaiana, using inter-simple sequence repeat molecular markers. Thirty-five primers were tested, 20 of which were polymorphic, resulting in 135 polymorphic and informative bands. Results of the cluster analysis, obtained using the unweighted pair group method with arithmetic mean, grouped plants into three clusters: Cluster I - MLU001, MLU002, MLU003, MLU004, MLU005, MLU006, MLU018, MLU019, MLU020, MLU021, MLU022; MLU008, MLU011, MLU012, MLU014, MLU015, MLU017, MLU026, and MLU028; Cluster II - MLU007, MLU009, MLU010, MLU013, and MLU016; and Cluster III - MLU023, MLU024, MLU025, and MLU027. Jaccard similarity coefficients for pair-wise comparisons of plants ranged between 0.15 and 0.87. MLU014 and MLU015 presented low genetic diversity, with a similarity index of 0.87. Conversely, MLU007 and MLU019 presented high diversity, with a similarity index of 0.15. According to the structure analysis, three distinct clusters were formed. Genetic diversity of M. lundiana plants was intermediate, and expansion of its genetic diversity is necessary. MLU026 and MLU028 are the most suitable for selection in breeding programs, since they clearly represent all of the diversity present in these plants. Moreover, these results provide important information on the existing genetic variability, highlighting the importance of Parque Nacional de Itabaiana for the conservation of this species.

  6. Do changes in the frequency, magnitude and timing of extreme climatic events threaten the population viability of coastal birds?

    NARCIS (Netherlands)

    van de Pol, Martijn; Ens, Bruno J.; Heg, Dik; Brouwer, Lyanne; Krol, Johan; Maier, Martin; Exo, Klaus-Michael; Oosterbeek, Kees; Lok, Tamar; Eising, Corine M.; Koffijberg, Kees

    P>1. Climate change encompasses changes in both the means and the extremes of climatic variables, but the population consequences of the latter are intrinsically difficult to study. 2. We investigated whether the frequency, magnitude and timing of rare but catastrophic flooding events have changed

  7. Population dose commitments due to radioactive releases from nuclear power plant sites in 1984

    Energy Technology Data Exchange (ETDEWEB)

    Baker, D.A.

    1988-01-01

    Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1984. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 56 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 110 person-rem to a low of 0.002 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 5 person-rem. The total population dose for all sites was estimated at 280 person-rem for the 100 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 6 x 10/sup -6/ mrem to a high of 0.04 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.

  8. Drought tolerance in wild plant populations: the case of common beans (Phaseolus vulgaris L.).

    Science.gov (United States)

    Cortés, Andrés J; Monserrate, Fredy A; Ramírez-Villegas, Julián; Madriñán, Santiago; Blair, Matthew W

    2013-01-01

    Reliable estimations of drought tolerance in wild plant populations have proved to be challenging and more accessible alternatives are desirable. With that in mind, an ecological diversity study was conducted based on the geographical origin of 104 wild common bean accessions to estimate drought tolerance in their natural habitats. Our wild population sample covered a range of mesic to very dry habitats from Mexico to Argentina. Two potential evapotranspiration models that considered the effects of temperature and radiation were coupled with the precipitation regimes of the last fifty years for each collection site based on geographical information system analysis. We found that wild accessions were distributed among different precipitation regimes following a latitudinal gradient and that habitat ecological diversity of the collection sites was associated with natural sub-populations. We also detected a broader geographic distribution of wild beans across ecologies compared to cultivated common beans in a reference collection of 297 cultivars. Habitat drought stress index based on the Thornthwaite potential evapotranspiration model was equivalent to the Hamon estimator. Both ecological drought stress indexes would be useful together with population structure for the genealogical analysis of gene families in common bean, for genome-wide genetic-environmental associations, and for postulating the evolutionary history and diversification processes that have occurred for the species. Finally, we propose that wild common bean should be taken into account to exploit variation for drought tolerance in cultivated common bean which is generally considered susceptible as a crop to drought stress.

  9. Drought tolerance in wild plant populations: the case of common beans (Phaseolus vulgaris L..

    Directory of Open Access Journals (Sweden)

    Andrés J Cortés

    Full Text Available Reliable estimations of drought tolerance in wild plant populations have proved to be challenging and more accessible alternatives are desirable. With that in mind, an ecological diversity study was conducted based on the geographical origin of 104 wild common bean accessions to estimate drought tolerance in their natural habitats. Our wild population sample covered a range of mesic to very dry habitats from Mexico to Argentina. Two potential evapotranspiration models that considered the effects of temperature and radiation were coupled with the precipitation regimes of the last fifty years for each collection site based on geographical information system analysis. We found that wild accessions were distributed among different precipitation regimes following a latitudinal gradient and that habitat ecological diversity of the collection sites was associated with natural sub-populations. We also detected a broader geographic distribution of wild beans across ecologies compared to cultivated common beans in a reference collection of 297 cultivars. Habitat drought stress index based on the Thornthwaite potential evapotranspiration model was equivalent to the Hamon estimator. Both ecological drought stress indexes would be useful together with population structure for the genealogical analysis of gene families in common bean, for genome-wide genetic-environmental associations, and for postulating the evolutionary history and diversification processes that have occurred for the species. Finally, we propose that wild common bean should be taken into account to exploit variation for drought tolerance in cultivated common bean which is generally considered susceptible as a crop to drought stress.

  10. Population dose commitments due to radioactive releases from nuclear power plant sites in 1982. Volume 4

    Energy Technology Data Exchange (ETDEWEB)

    Baker, D.A.; Peloquin, R.A.

    1986-06-01

    Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1982. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 51 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments from both liquid and airborne pathways ranged from a high of 30 person-rem to a low of 0.007 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 130 person-rem for the 100 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 6 x 10/sup -7/ mrem to a high of 0.06 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.

  11. About a dynamic model of interaction of insect population with food plant

    Directory of Open Access Journals (Sweden)

    L.V. Nedorezov

    2011-12-01

    Full Text Available In present paper there is the consideration of mathematical model of food plant (resource - consumer (insect population - pathogen system dynamics which is constructed as a system of ordinary differential equations. The dynamic regimes of model are analyzed and, in particular, with the help of numerical methods it is shown that trigger regimes (regimes with two stable attractors can be realized in model under very simple assumptions about ecological and intra-population processes functioning. Within the framework of model it was assumed that the rate of food flow into the system is constant and functioning of intra-population selfregulative mechanisms can be described by Verhulst model. As it was found, trigger regimes are different with respect to their properties: in particular, in model the trigger regimes with one of stable stationary points on the coordinate plane can be realized (it corresponds to the situation when sick individuals in population are absent and their appearance in small volume leads to their asymptotic elimination; also the regimes with several nonzero stationary states and stable periodic fluctuations were found.

  12. A plant toxin mediated mechanism for the lag in snowshoe hare population recovery following cyclic declines

    Science.gov (United States)

    DeAngelis, Donald L.; Bryant, John P.; Liu, Rongsong; Gourley, Stephen A.; Krebs, Charles J; Reichardt, Paul B

    2015-01-01

    A necessary condition for a snowshoe hare population to cycle is reduced reproduction after the population declines. But the cause of a cyclic snowshoe hare population's reduced reproduction during the low phase of the cycle, when predator density collapses, is not completely understood. We propose that moderate-severe browsing by snowshoe hares upon preferred winter-foods could increase the toxicity of some of the hare's best winter-foods during the following hare low, with the result being a decline in hare nutrition that could reduce hare reproduction. We used a combination of modeling and experiments to explore this hypothesis. Using the shrub birch Betula glandulosa as the plant of interest, the model predicted that browsing by hares during a hare cycle peak, by increasing the toxicity B. glandulosa twigs during the following hare low, could cause a hare population to cycle. The model's assumptions were verified with assays of dammarane triterpenes in segments of B. glandulosa twigs and captive hare feeding experiments conducted in Alaska during February and March 1986. The model's predictions were tested with estimates of hare density and measurements of B. glandulosa twig growth made at Kluane, Yukon from 1988–2008. The empirical tests supported the model's predictions. Thus, we have concluded that a browsing-caused increase in twig toxicity that occurs during the hare cycle's low phase could reduce hare reproduction during the low phase of the hare cycle.

  13. Soil biota drive expression of genetic variation and development of population-specific feedbacks in an invasive plant.

    Science.gov (United States)

    Felker-Quinn, Emmi; Bailey, Joseph K; Schweitzer, Jennifer A

    2011-06-01

    Invasive plant species alter soils in ways that may affect the success of subsequent generations, creating plant-soil feedbacks. Ailanthus altissima is an invasive tree introduced two centuries ago to North America. We hypothesized that geographically distinct populations of A. altissima have established feedbacks specific to their local environment, due to soil communities cultivated by A. altissima. We collected seeds and soils from three populations in the eastern United States, and in the greenhouse reciprocally planted all families in all collected soils as well as in a control mixed soil, and in soils that had been irradiated for sterilization. There were positive plant-soil feedbacks for two populations in the live field-collected soils, but strong negative feedbacks for the third population. There were no population-level performance differences or feedbacks in the sterilized population locale soils, supporting a soil biotic basis for feedbacks and for the expression of genetic differentiation in A. altissima. If populations of Ailanthus altissima vary in the extent to which they benefit from and promote these plant-soil biota feedbacks, the interaction between invader and invaded community may be more important in determining the course of invasion than are the characteristics of either alone.

  14. Distribution of dominant arbuscular mycorrhizal fungi among five plant species in undisturbed vegetation of a coastal grassland

    DEFF Research Database (Denmark)

    Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

    2005-01-01

    Most plant species in mixed grassland vegetation are colonized by arbuscular mycorrhizal (AM) fungi. Previous studies have reported differences in host preferences among AM fungi, although the fungi are known to lack host specificity. In the present study, the distribution of phylogenetic groups...

  15. Influence of plant population and nitrogen-fertilizer at various levels on growth and growth efficiency of maize.

    Science.gov (United States)

    Tajul, M I; Alam, M M; Hossain, S M M; Naher, K; Rafii, M Y; Latif, M A

    2013-01-01

    Field experiments were conducted to evaluate plant population and N-fertilizer effects on yield and yield components of maize (Zea mays L.). Three levels of plant populations (53000, 66000, and 800,000 plants ha⁻¹ corresponding to spacings of 75 × 25, 60 × 25, and 50 × 25 cm) and 4 doses of N (100, 140, 180, and 220 kg ha⁻¹) were the treatment variables. Results revealed that plant growth, light interception (LI), yield attributes, and grain yield varied significantly due to the variations in population density and N-rates. Crop growth rate (CGR) was the highest with the population of 80,000 ha⁻¹ receiving 220 kg N ha⁻¹, while relative growth rate (RGR) showed an opposite trend of CGR. Light absorption was maximum when most of densely populated plant received the highest amount of N (220 kg N ha⁻¹). Response of soil-plant-analysis development (SPAD) value as well as N-content to N-rates was found significant. Plant height was the maximum at the lowest plant density with the highest amount of N. Plants that received 180 kg N ha⁻¹ with 80,000 plants ha⁻¹ had larger foliage, greater SPAD value, and higher amount of grains cob⁻¹ that contributed to the maximum yield (5.03 t ha⁻¹) and the maximum harvest index (HI) compared to the plants in other treatments.

  16. Influence of Plant Population and Nitrogen-Fertilizer at Various Levels on Growth and Growth Efficiency of Maize

    Directory of Open Access Journals (Sweden)

    M. I. Tajul

    2013-01-01

    Full Text Available Field experiments were conducted to evaluate plant population and N-fertilizer effects on yield and yield components of maize (Zea mays L.. Three levels of plant populations (53000, 66000, and 800000 plants ha−1 corresponding to spacings of 75 × 25, 60 × 25, and 50 × 25 cm and 4 doses of N (100, 140, 180, and 220 kg ha−1 were the treatment variables. Results revealed that plant growth, light interception (LI, yield attributes, and grain yield varied significantly due to the variations in population density and N-rates. Crop growth rate (CGR was the highest with the population of 80,000 ha−1 receiving 220 kg N ha−1, while relative growth rate (RGR showed an opposite trend of CGR. Light absorption was maximum when most of densely populated plant received the highest amount of N (220 kg N ha−1. Response of soil-plant-analysis development (SPAD value as well as N-content to N-rates was found significant. Plant height was the maximum at the lowest plant density with the highest amount of N. Plants that received 180 kg N ha−1 with 80,000 plants ha−1 had larger foliage, greater SPAD value, and higher amount of grains cob−1 that contributed to the maximum yield (5.03 t ha−1 and the maximum harvest index (HI compared to the plants in other treatments.

  17. Volatile Constituents of Different Plant Parts and Populations of Malabaila aurea Boiss. from Montenegro

    Directory of Open Access Journals (Sweden)

    Ivan Vučković

    2014-03-01

    Full Text Available The volatile constituents of different plant parts and populations of Malabaila aurea Boiss. from Montenegro were obtained by simultaneous distillation-extraction and analyzed by GC-FID and GC-MS. A total of 12 samples were examined and 45 compounds were identified. The volatile content of different M. aurea populations was very similar, while the volatile fractions obtained from different plant parts showed significant qualitative and quantitative differences. The most abundant compounds found in stems & leaves were apiole (51.0-56.3%, myristicin (16.3-25.4%, and falcarinol (4.1-10.7%. The roots showed the same major components, but with different relative abundances: 30.9-49.1% of apiole, 12.9-34.7% of falcarinol, and 9.9-31.1% of myristicin. The volatile constituents of fruits & flowers were remarkably different, containing up to 71.2-80.5% octyl butyrate, 11.4-18.0% octanol, and 2.7-6.8% octyl hexanoate. The results were discussed as possible indication of relatedness of Malabaila aurea and Pastinacasativa (parsnip .

  18. Hippopotamus (H. amphibius) diet change indicates herbaceous plant encroachment following megaherbivore population collapse

    Science.gov (United States)

    Chritz, Kendra L.; Blumenthal, Scott A.; Cerling, Thure E.; Klingel, Hans

    2016-01-01

    Megaherbivores (>1000 kg) are critical for ecosystem health and function, but face population collapse and extinction globally. The future of these megaherbivore-impoverished ecosystems is difficult to predict, though many studies have demonstrated increasing representation of C3 woody plants. These studies rely on direct observational data, however, and tools for assessing decadal-scale changes in African ecology without observation are lacking. We use isotopic records of historical common hippopotamus (Hippopotamus amphibius) canines to quantify herbaceous vegetation change in Queen Elizabeth National Park, Uganda following a period of civil unrest and poaching. This poaching event led to population collapse of two threatened African megaherbivore species: hippopotamus and African elephants (Loxodonta africana). Serial carbon isotope ratios (δ13C) in canine enamel from individuals that lived between 1960–2000 indicated substantial increases in C3 herbaceous plants in their diet (<20% C3 in the 1960s to 30–45% C3 in the 80s and 90s), supported by other observational and ecological data. These data indicate megaherbivore loss results in succession of both woody and herbaceous C3 vegetation and further reaching effects, such as decreased grazing capacity and herbivore biodiversity in the area. Given multiple lines of evidence, these individuals appear to accurately capture herbaceous vegetation change in Mweya. PMID:27616433

  19. ROLE OF PLANTS FOUND IN NORTH EAST INDIA AND BANGLADESH IN CONTROLLING POPULATION GROWTH

    Directory of Open Access Journals (Sweden)

    Jhimly Das

    2014-08-01

    Full Text Available Being part of the Indian subcontinent both the North Eastern region of India and the Bangladesh share a long common cultural, economic and political history. One of the most critical problems of developing countries like India as well as Bangladesh is their enormous increase in human population. Contraceptive Prevalence Rate (CPR of India is 48.3 and that of Bangladesh is 53.8. As the large majority of population of both the countries belong to rural area, the family planning programmes have largely remained unsuccessful because of many factors including lack of availability of contraceptive drugs in rural markets, lack of accessibility of rural people to medical personnel as well as the lack of acceptability of synthetic drugs due to various socio-cultural and religious perceptions prevailing among many ethnic communities. These contributed to a growing interest among researchers in developing contraceptives of natural origin and at present natural herbal contraception have become one of the major focuses of modern contraceptive research. Since time immemorial herbal drugs are being practiced by various rural communities and ethnic tribes in North East India as well as in Bangladesh, and hence the acceptability of herbal contraceptives is expected to be much higher among rural folk. In different parts of North East India and Bangladesh, ethnic communities are using plant based medicinal products till today. This study aims at highlighting the contraceptive property of some plants found in North-Eastern India as well as in Bangladesh.

  20. Hippopotamus (H. amphibius) diet change indicates herbaceous plant encroachment following megaherbivore population collapse.

    Science.gov (United States)

    Chritz, Kendra L; Blumenthal, Scott A; Cerling, Thure E; Klingel, Hans

    2016-01-01

    Megaherbivores (>1000 kg) are critical for ecosystem health and function, but face population collapse and extinction globally. The future of these megaherbivore-impoverished ecosystems is difficult to predict, though many studies have demonstrated increasing representation of C3 woody plants. These studies rely on direct observational data, however, and tools for assessing decadal-scale changes in African ecology without observation are lacking. We use isotopic records of historical common hippopotamus (Hippopotamus amphibius) canines to quantify herbaceous vegetation change in Queen Elizabeth National Park, Uganda following a period of civil unrest and poaching. This poaching event led to population collapse of two threatened African megaherbivore species: hippopotamus and African elephants (Loxodonta africana). Serial carbon isotope ratios (δ(13)C) in canine enamel from individuals that lived between 1960-2000 indicated substantial increases in C3 herbaceous plants in their diet (<20% C3 in the 1960s to 30-45% C3 in the 80s and 90s), supported by other observational and ecological data. These data indicate megaherbivore loss results in succession of both woody and herbaceous C3 vegetation and further reaching effects, such as decreased grazing capacity and herbivore biodiversity in the area. Given multiple lines of evidence, these individuals appear to accurately capture herbaceous vegetation change in Mweya.

  1. Hippopotamus (H. amphibius) diet change indicates herbaceous plant encroachment following megaherbivore population collapse

    Science.gov (United States)

    Chritz, Kendra L.; Blumenthal, Scott A.; Cerling, Thure E.; Klingel, Hans

    2016-09-01

    Megaherbivores (>1000 kg) are critical for ecosystem health and function, but face population collapse and extinction globally. The future of these megaherbivore-impoverished ecosystems is difficult to predict, though many studies have demonstrated increasing representation of C3 woody plants. These studies rely on direct observational data, however, and tools for assessing decadal-scale changes in African ecology without observation are lacking. We use isotopic records of historical common hippopotamus (Hippopotamus amphibius) canines to quantify herbaceous vegetation change in Queen Elizabeth National Park, Uganda following a period of civil unrest and poaching. This poaching event led to population collapse of two threatened African megaherbivore species: hippopotamus and African elephants (Loxodonta africana). Serial carbon isotope ratios (δ13C) in canine enamel from individuals that lived between 1960–2000 indicated substantial increases in C3 herbaceous plants in their diet (biodiversity in the area. Given multiple lines of evidence, these individuals appear to accurately capture herbaceous vegetation change in Mweya.

  2. Natural and traditional defense mechanisms to reduce climate risks in coastal zones of Bangladesh

    Directory of Open Access Journals (Sweden)

    Mohammed Ataur Rahman

    2015-03-01

    Full Text Available Substantially resourceful and densely populated coastal zones of Bangladesh experience numerous extreme events linked to hydro-meteorological processes viz. cyclones, tidal surges, floods, salinity intrusion and erosion etc. These hazards give rise to extensive damage to property and loss of lives every year. Further, anthropogenic activities in the coastal zones are accentuating environmental degradation causing widespread suffering. Cyclones and tornadoes in particular damage infrastructures and crops every year affecting the economy of the country negatively. Some naturally adapted plants as well as landscapes usually reduce the speed of cyclones and tornadoes and thus, protect the coastal zones. However, human activities have destroyed many of the forests and landscapes. Sundarbans and Chokoria Sundarbans mangrove forests of Bangladesh are under a great threat of extinction due to illicit logging and agricultural expansion. At least 34 plant species of tropical forest are on the verge of extinction. Many animals e.g., cats, bears, porcupines, wild boars, pythons and anteaters are in the process of being wiped out from the coastal areas. Among the marine and coastal species, Red crabs, jelly-fish, sharks, and dolphins are also rare but these were the major species prior to 1980s. This study revealed that during the recent decades there has been massive plantations and construction of embankment and polderization but these and other measures have been found to be impractical and ineffective in reducing disasters in coastal areas. There is a need for integration of traditional coping practices and wisdoms with modern approaches. Available knowledge on some of these traditional practices has been documented for establishing a sustainable policy for management of coastal zones of Bangladesh. By combining traditional and scientific management of coastal ecosystem with mangroves and other plants following triple-tier mechanism and habitat, it is

  3. Plant Community Richness Mediates Inhibitory Interactions and Resource Competition between Streptomyces and Fusarium Populations in the Rhizosphere.

    Science.gov (United States)

    Essarioui, Adil; LeBlanc, Nicholas; Kistler, Harold C; Kinkel, Linda L

    2017-07-01

    Plant community characteristics impact rhizosphere Streptomyces nutrient competition and antagonistic capacities. However, the effects of Streptomyces on, and their responses to, coexisting microorganisms as a function of plant host or plant species richness have received little attention. In this work, we characterized antagonistic activities and nutrient use among Streptomyces and Fusarium from the rhizosphere of Andropogon gerardii (Ag) and Lespedeza capitata (Lc) plants growing in communities of 1 (monoculture) or 16 (polyculture) plant species. Streptomyces from monoculture were more antagonistic against Fusarium than those from polyculture. In contrast, Fusarium isolates from polyculture had greater inhibitory capacities against Streptomyces than isolates from monoculture. Although Fusarium isolates had on average greater niche widths, the collection of Streptomyces isolates in total used a greater diversity of nutrients for growth. Plant richness, but not plant host, influenced the potential for resource competition between the two taxa. Fusarium isolates had greater niche overlap with Streptomyces in monoculture than polyculture, suggesting greater potential for Fusarium to competitively challenge Streptomyces in monoculture plant communities. In contrast, Streptomyces had greater niche overlap with Fusarium in polyculture than monoculture, suggesting that Fusarium experiences greater resource competition with Streptomyces in polyculture than monoculture. These patterns of competitive and inhibitory phenotypes among Streptomyces and Fusarium populations are consistent with selection for Fusarium-antagonistic Streptomyces populations in the presence of strong Fusarium resource competition in plant monocultures. Similarly, these results suggest selection for Streptomyces-inhibitory Fusarium populations in the presence of strong Streptomyces resource competition in more diverse plant communities. Thus, landscape-scale variation in plant species richness may be

  4. Estimating the cumulative effects of the nature-based tourism in a coastal dolphin population from southern Kenya

    Science.gov (United States)

    Pérez-Jorge, Sergi; Louzao, Maite; Oro, Daniel; Pereira, Thalia; Corne, Chloe; Wijtten, Zeno; Gomes, Inês; Wambua, John; Christiansen, Fredrik

    2017-06-01

    Due to the growth of nature-based tourism worldwide, behavioural studies are needed to assess the impact of this industry on wildlife populations and understand their short-term effect. Tourism impact on dolphin populations remain poorly documented in developing countries. This study investigates the effects of nature-based tourism on the behaviour of the Indo-Pacific bottlenose dolphins (Tursiops aduncus) in southern Kenya. We used Markov chain models to estimate transition probabilities between behavioural states in the presence and absence of tourist boats, and assess the overall behavioural budgets. Based on these data and the tourism intensity in the area, we quantified the potential tourist boat disturbance over the period 2006-2013. Our results demonstrated that tourist boat interactions affected dolphins' behavioural budgets, with a significant decrease in the overall amount of time travelling and an increase in diving. The average duration of travelling and resting decreased significantly in the presence of boats. Although the cumulative tourism exposure was not significant for the dolphin population at their current levels, these impacts should be taken into consideration with the potential tourism growth in the area. This is particularly important if tourism reaches periods of high intensity, as we have shown that these periods could have a significant impact for the species, particularly where home-range and core areas are highly overlap by this activity. Understanding the effect of human disturbance variations from previous years may help to predict the consequences on dolphin populations, towards achieving a more ecological and economic sustainability of the activity.

  5. Pacific Coastal Salmon Recovery Fund

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Congress established the Pacific Coastal Salmon Recovery Fund (PCSRF) to monitor the restoration and conservation of Pacific salmon and steelhead populations and...

  6. Regional gene flow and population structure of the wind-dispersed plant species Hypochaeris radicata (Asteraceae) in an agricultural landscape

    NARCIS (Netherlands)

    Mix, C.; Arens, P.F.P.; Rengelink, R.; Smulders, M.J.M.; Groenendael, van J.M.; Ouburg, J.

    2006-01-01

    Using microsatellites, we investigated population structure and gene flow of the short-lived, wind-dispersed plant species Hypochaeris radicata in a fragmented agricultural landscape where more than 99% of the nutrient-poor grasslands have disappeared over the last century. We sampled populations in

  7. Shoreline changes and Coastal Flooding impacts: South Gujarat coast (India)

    Science.gov (United States)

    Parihar, S. B.

    2016-12-01

    South Gujarat coast (India) is experiencing increased coastal inundation and erosion caused by sea-level rise affecting the population, infrastructure, and environment. The area falls under low elevation coastal zone (LEZ) and its topography of the area is also making coast highly susceptible to flooding, especially at high tides and during the rainy season. As part of studies on shoreline changes field trip carried on the coastal taluka's of South Gujarat coast i.e. Surat, Navsari and Valsad shows various temporal changes is taking place at coastal belt. There are ample of studies on coastal dynamics and impacts. The study focus on spatial temporal analysis shows the vulnerable zones covering various physical elements at risk. These coastal areas are attractive in nature for all kind of economic development and growth because of availability of the water & fertile land for house hold use, fishing and transportation. On the contrary, South Gujarat coast being tectonically active; makes this region high vulnerable for any kind of infrastructure development. The region had also witnessed loss of life and property, disruptions to transport & power and incidences of epidemics during the floods of 2006 in Surat. Coastal flooding would, under these scenarios, threaten region that are home of 370,000 approx (Census, 2011) people in seven coastal taluka's of Surat, Navsari and Valsad district. Among the people residing in the region, the most vulnerable communities are fishermen, farmer and industrial labours. The wide range of infrastructure such as roads, hospitals, schools, power plants, industries and port will also be at risk. Shoreline changes are inevitably changing the characteristics of south Gujarat coast; practices and policies should be put in place to mitigate the potentially adverse impacts on environment and human settlements. Key words: sea level rise, LEZ, vulnerable, erosion, inundation, spatial temporal analysis, landuse changes.

  8. Screening a coastal population in Southern Italy: iodine deficiency and prevalence of goitre, nutritional aspects and cardiovascular risk factors.

    Science.gov (United States)

    Valentino, R; Savastano, S; Tommaselli, A P; Di Biase, S; Calvanese, E; Carbone, D; Dorato, M; Orio, F; Lupoli, G; Lombardi, G

    2004-02-01

    To evaluate the prevalence of goitre by means of urinary iodine excretion, palpatory and ultrasonographic thyroid examinations in a heterogeneous population living by the sea. We used a special self-administered questionnaire to evaluate thyroid size, iodine intake, eating habits and cardiovascular risk factors in 600 subjects with a mean age of 45 +/- 17 years: 253 men (42.3%) and 347 women (57.7%). Urinary iodine excretion was low (72.1 +/- 15.7 microg/L; median 71.2) and associated with ultrasonographic evidence of an enlarged thyroid (16%) or structural thyroid abnormalities (30%), thus allowing us to define the Salerno Gulf as a mild-moderate area of endemic goitre. All of the subjects ate a Mediterranean diet, with a mean of two portions of fish/week. The cardiovascular risk factors considered were obesity, cigarette smoking, hypertension, hypercholesterolemia, hypertriglyceridemia and diabetes, the prevalences of which were in line with those reported in other studies of similar age-matched populations. The moderate intake of fish and the consumption of a Mediterranean diet did not prevent goitre. Iodine deficiency and subsequent goitre endemia are also present at sea level, probably because of a diet based on local products grown on soil with a low iodine content or possible seawater, soil and air environmental pollution that may interfere with the availability of iodine. The assessment of iodine deficiency should therefore involve the entire population and not only subjects living far from the sea.

  9. The spatial distribution of threats to plant species with extremely small populations

    Science.gov (United States)

    Wang, Chunjing; Zhang, Jing; Wan, Jizhong; Qu, Hong; Mu, Xianyun; Zhang, Zhixiang

    2016-04-01

    Many biological conservationists take actions to conserve plant species with extremely small populations (PSESP) in China; however, there have been few studies on the spatial distribution of threats to PSESP. Hence, we selected distribution data of PSESP and made a map of the spatial distribution of threats to PSESP in China. First, we used the weight assignment method to evaluate the threat risk to PSESP at both country and county scales. Second, we used a geographic information system to map the spatial distribution of threats to PSESP, and explored the threat factors based on linear regression analysis. Finally, we suggested some effective conservation options. We found that the PSESP with high values of protection, such as the plants with high scientific research values and ornamental plants, were threatened by over-exploitation and utilization, habitat fragmentation, and a small sized wild population in broad-leaved forests and bush fallows. We also identified some risk hotspots for PSESP in China. Regions with low elevation should be given priority for ex- and in-situ conservation. Moreover, climate change should be considered for conservation of PSESP. To avoid intensive over-exploitation or utilization and habitat fragmentation, in-situ conservation should be practiced in regions with high temperatures and low temperature seasonality, particularly in the high risk hotspots for PSESP that we proposed. Ex-situ conservation should be applied in these same regions, and over-exploitation and utilization of natural resources should be prevented. It is our goal to apply the concept of PSESP to the global scale in the future.

  10. The spatial distribution of threats to plant species with extremely small populations

    Science.gov (United States)

    Wang, Chunjing; Zhang, Jing; Wan, Jizhong; Qu, Hong; Mu, Xianyun; Zhang, Zhixiang

    2017-03-01

    Many biological conservationists take actions to conserve plant species with extremely small populations (PSESP) in China; however, there have been few studies on the spatial distribution of threats to PSESP. Hence, we selected distribution data of PSESP and made a map of the spatial distribution of threats to PSESP in China. First, we used the weight assignment method to evaluate the threat risk to PSESP at both country and county scales. Second, we used a geographic information system to map the spatial distribution of threats to PSESP, and explored the threat factors based on linear regression analysis. Finally, we suggested some effective conservation options. We found that the PSESP with high values of protection, such as the plants with high scientific research values and ornamental plants, were threatened by over-exploitation and utilization, habitat fragmentation, and a small sized wild population in broad-leaved forests and bush fallows. We also identified some risk hotspots for PSESP in China. Regions with low elevation should be given priority for ex- and in-situ conservation. Moreover, climate change should be considered for conservation of PSESP. To avoid intensive over-exploitation or utilization and habitat fragmentation, in-situ conservation should be practiced in regions with high temperatures and low temperature seasonality, particularly in the high risk hotspots for PSESP that we proposed. Ex-situ conservation should be applied in these same regions, and over-exploitation and utilization of natural resources should be prevented. It is our goal to apply the concept of PSESP to the global scale in the future.

  11. Detection of quantitative trait loci and heterotic loci for plant height using an immortalized F2 population in maize

    Institute of Scientific and Technical Information of China (English)

    TANG JiHua; MA XiQing; TENG WenTao; YAN JianBing; WU WeiRen; DAI JingRui; LI JianSheng

    2007-01-01

    A set of recombinant inbred lines (RIL) derived from Yuyu22, an elite hybrid widespread in China, was used to construct an immortalized F2 (IF2) population comprising 441 different crosses. Genetic linkage maps were constructed containing 10 linkages groups with 263 simple sequence repeat (SSR) molecular markers. Twelve and ten quantitative trait loci (QTL) were detected for plant height in the IF2 and RIL populations respectively, using the composite interval mapping method, and six same QTL were identified in the two populations. In addition, ten unique heterotic loci (HL) located on seven different chromosomes were revealed for plant height using the mid-parent heterosis as the input data. These HL explained 1.26%-8.41% of the genotypic variance in plant height heterosis and most expressed overdominant effects. Only three QTL and HL were located in the same chromosomal region, it implied that plant height and its heterosis might be controlled by two types of genetic mechanisms.

  12. Coastal Dynamics

    NARCIS (Netherlands)

    Bakker, W.T.

    1998-01-01

    This book deals on "Coastal Dynamics", which will be defined in a narrow sense as a mathematical theory, which starts from given equations of motion for the sediment, which leads with the continuity equation and given boundary conditions to a calculated (eventually schematized) coastal topography,

  13. A Survey of Plant Species Diversity and Ecological Species Group from the Coastal Zone Of Boujagh National Park, Guilan, Iran

    Directory of Open Access Journals (Sweden)

    Shahryar Saeidi Mehrvarz

    2016-06-01

    Full Text Available The aim of this study was to identify the ecological species groups and investigate the diversity among them. The research area comprises in a coastal system of Boujagh National Park, inNorthern of Guilan Province, Iran. Vegetation sampling was carried out along 6 shoreperpendicular transects, ween minimum 153 m and maximum 5562 m long. A total of 52 plot of 25square meters were taken in transects. In each sampled plot, the cover percentage value of eachspecies was estimated using Bran-Blanquet scales. Vegetation classified using Two-Way IndicatorSpecies Analysis (TWINSPAN. Classification of plots showed four vegetation groups: Convolvuluspersicus - Crepis foetida, Argusia sibirica, Eryngium caucasicum - Juncus acutus, Rubus sanctus. Plantdiversity in these vegetation groups have been evaluated. The comparison of diversity indicesamong groups were performed with ANOVA test. Results of analysis of variance in speciesdiversity indices showed significant differences among the groups in terms of biodiversity indices.The survey of variation in the groups showed that group 3 had the highest and group 2 had thelowest Shannon-Wiener’s, Simpson’s and Fisher’s diversity indices respectively. In Menhinink’sand Margalef’s richness indices group 2 and 3 had the highest and group 1 had the lowest measure.In Sheldon’s evenness index group 2 had the highest and group 3 had the lowest measure. Finally,the overall survey of indices showed that groups 1 and 2 had less diversity but had more evennessthan groups 3 and 4.This shows that despite suitable living conditions for the growth anddevelopment of vegetation in the groups 3 and 4, the abundance of species has declined Because ofthe destruction done in this section.

  14. Dissociation of a population of Pectobacterium atrosepticum SCRI1043 in tobacco plants: formation of bacterial emboli and dormant cells.

    Science.gov (United States)

    Gorshkov, Vladimir; Daminova, Amina; Ageeva, Marina; Petrova, Olga; Gogoleva, Natalya; Tarasova, Nadezhda; Gogolev, Yuri

    2014-05-01

    The population dynamics of Pectobacterium atrosepticum SCRI1043 (Pba) within tobacco plants was monitored from the time of inoculation until after long-term preservation of microorganisms in the remnants of dead plants. We found and characterised peculiar structures that totally occlude xylem vessels, which we have named bacterial emboli. Viable but non-culturable (VBN) Pba cells were identified in the remnants of dead plants, and the conditions for resuscitation of these VBN cells were established. Our investigation shows that dissociation of the integrated bacterial population during plant colonisation forms distinct subpopulations and cell morphotypes, which are likely to perform specific functions that ensure successful completion of the life cycle within the plant.

  15. Susceptibility of field populations of sugarcane borer from non-Bt and Bt maize plants to five individual Cry toxins

    Institute of Scientific and Technical Information of China (English)

    Fangneng Huang; Mukti N.Ghimire; B.Rogers Leonard; Yu-Cheng Zhu; Graham P.Head

    2012-01-01

    Sugarcane borer,Diatraea saccharalis (F.),is a major target of transgenic maize expressing Bacillus thuringiensis (Bt) proteins in South America and the US midsouth region.Resistance development in targct pest populations is a major threat to the sustainable use of Bt crops.In our field trials in 2009,a significant number of live borers and plant injury from D.saccharalis were observed in an experimental SmartStaxTM maize line.The objective of this study was to assess the relative susceptibility of two field populations ofD.saccharalis collected from non-Bt and Bt maize plants containing SmartStaxTM traits to five individual Cry proteins.The five Bt proteins included two proteins (Cry1A.105 and Cry2Ab2) that were expressed in SmartStaxTM maize plants and three other common Bt proteins (Cry1Aa,Cry1Ab and Cry1Ac) that were not produced in SmartStaxTM.Larval mortality and growth inhibition on Bt diet of the fourth gcneration after field collections were evaluated 7 days after release of neonates on the diet surface.The laboratory bioassays showed that 50% lethal concentration (LC50) values for Cry1 A.105 and Cry2Ab2 for the population originated from Bt plants were 3.55-and 1.34-fold greater,respectively,than those of the population collected from non-Bt plants.In contrast,relative to the population from non-Bt plants,the LC50 of the population sampled from Bt plants were 3.85-,2.5-and 1.64-fold more sensitive to Cry1Aa,Cry1Ab and Cry1Ac,respectively.The resuits did not provide clear evidence to conclude that the observed field survival of D.saccharalis on Bt plants was associated with increased levels of resistance.

  16. Ways of adaptation of the plant populations to chemical and radioactive contamination

    Energy Technology Data Exchange (ETDEWEB)

    Pozolotina, V.; Bezel' , V.; Zhuykova, T.; Severu' Khina, O.; Ulyanova, E. [Institute of Plant and Animal Ecology, Ural Division of Russian Academy of Sciences, Ekaterinburg (Russian Federation)

    2004-07-01

    Chemical agents (heavy metals, acids, etc.) and radiation render their influence upon biota being clearly distinct in primary mechanisms of action. However, lively organisms demonstrate one and the same set [arsenal] of response reactions, and thus it is important to reveal the ways of their realization caused by different types of techno-genic impacts. Our work was intended to examine the seed progeny of the dandelion, Taraxacum officinale, from radionuclides-contaminated coeno-populations (grown at the territories influenced by Eastern-Ural radioactive trace, in the Techa-river flood plain) and those situated in the nearest impact zone affected by a large metallurgical plant in the Urals. Plots, differently distanced from the enterprise, showed heavy metal contamination loads 8-33 times higher than the control site did. Radionuclides concentrations ({sup 90}Sr and {sup 137}Cs) within the contaminated zone exceeded the background values 4-40 times. The study allowed estimation of the seed progeny vitality level for different coeno-populations, comparison of their adaptive potential in regard to heavy metals tolerance and gamma radiation resistance, estimation of abnormal seedlings [sprouts] frequency values. It was shown [found] that under techno-genic pollution the dandelion coeno-populations usually demonstrate wider variations of different characteristics (vitality, mutability, root and leaf growth rates) as compared to those in the background zone. As a general regularity one can regard the phenomenon, that negative effects were not marked to be increased by heavier pollution loads, irrespectively of the agents nature. (author)

  17. Population structure, sex ratio and growth of the seabob shrimp Xiphopenaeus kroyeri (Decapoda, Penaeidae) from coastal waters of southern Brazil

    Science.gov (United States)

    Grabowski, Raphael Cezar; Simões, Sabrina Morilhas; Castilho, Antonio Leão

    2014-01-01

    Abstract This study evaluated the growth and population structure of Xiphopenaeus kroyeri in Babitonga Bay, southern Brazil. Monthly trawls were conducted from July 2010 through June 2011, using a shrimp boat outfitted with double-rig nets, at depths from 5 to 17 m. Differences from the expected 0.5 sex ratio were determined by applying a Binomial test. A von Bertalanffy growth model was used to estimate the individual growth, and longevity was calculated using its inverted formula. A total of 4,007 individuals were measured, including 1,106 juveniles (sexually immature) and 2,901 adults. Females predominated in the larger size classes. Males and females showed asymptotic lengths of 27.7 mm and 31.4 mm, growth constants of 0.0086 and 0.0070 per day, and longevities of 538 and 661 days, respectively. The predominance of females in larger size classes is the general rule in species of Penaeidae. The paradigm of latitudinal-effect does not appear to apply to seabob shrimp on the southern Brazilian coast, perhaps because of the small proportion of larger individuals, the occurrence of cryptic species, or the intense fishing pressure in this region. The longevity values are within the general range for species of Penaeidae. The higher estimates for longevity in populations at lower latitudes may have occurred because of the growth constants observed at these locations, resulting in overestimation of this parameter. PMID:25561841

  18. Creating new populations of Apium bermejoi (Apiaceae, a critically endangered endemic plant on Menorca (Balearic Islands

    Directory of Open Access Journals (Sweden)

    Rita, Juan

    2013-06-01

    Full Text Available Apium bermejoi is a stoloniferous plant endemic to the island of Menorca (Balearic Islands. It is found only at one locality, and it is listed as Critically Endangered (according to the IUCN criteria. We describe the main results of population restoration actions undertaken under the Recovery Plan for this species, including the following: 1 introduction at two new localities (2008, 2 reinforcement of the original wild and the introduced populations, and 3 a programme for monitoring population dynamics (including both wild and introduced populations spanning four years (2006-2010. The plant material for the introduction and reinforcement projects was generated from seeds gathered in the wild. We carried out a monthly census of all of the individuals/patches and emerged seedlings, from which we assessed their survival at 3-4months. The survival rates of the planted individuals in the two new localities after three months were found to be 59.0% and 56.3%, and more than 80% of the surviving plants produced fruits. A seasonal pattern was observed based on the minimum cover values recorded in the censuses taken at the end of summer, with an increase detected during autumn, and maximal cover values recorded during May/June. The A. bermejoi populations showed large inter-annual fluctuations in both the number of patches and area of occupancy. The number of seedlings varied across the study years, and their survival was linked to specific meteorological events, such as severe storms and dry and hot spells during autumn. The initial phase of introduction for this species has been overall successful, but a final evaluation can only be made on a longterm basis.Apium bermejoi, planta estolonífera endémica de Menorca (Islas Baleares, de la que se conoce una sola localidad en el medio natural, está considerada en Peligro Crítico de extinción (según criterios UICN. Se presentan los principales resultados de las acciones de restauración de las

  19. In vitro antiplasmodial effect of ethanolic extracts of coastal medicinal plants along Palk Strait against Plasmodium falciparum

    Institute of Scientific and Technical Information of China (English)

    Samuel Jacob Inbaneson; Sundaram Ravikumar; Palavesam Suganthi

    2012-01-01

    Objective: To identify the possible antiplasmodial compounds from Achyranthes aspera (A. aspera), Acalypha indica (A. indica), Jatropha glandulifera (J. glandulifera) and Phyllanthusamarus (P. amarus). Methods: The A. aspera, A. indica, J. glandulifera and P. amarus were collected along Palk Strait and the extraction was carried out in ethanol. The filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 μg/mL) of leaf, stem, root and flower extracts of A. aspera, A. indica, J. glandulifera and P. amarus were tested for antiplasmodial activity against Plasmodiumfalciparum. The potential extracts were also tested for their phytochemical constituents. Results:Of the selected plants species parts, the stem extract of A. indica showed excellent antiplasmodial activity (IC50= 43.81μg/mL) followed by stem extract of J. glandulifera (IC50= 49.14μg/mL). The stem extract of A. aspera, leaf and root extracts of A. indica, leaf, root and seed extracts of J.glandulifera and leaf and stem extracts of P. amarus showed IC 50 values between 50 and 100 μg/mL. Statistical analysis revealed that, significant antiplasmodial activity (P<0.01) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes was also carried out and it showed that there were no morphological changes in erythrocytes by the ethanolic extract of all the tested plant extracts. The in vitro antiplasmodial activity might be due to the presence of alkaloids, glycosides, flavonoids, phenols, saponins, triterpenoids, proteins, and tannins in the ethanolic extracts of tested plants. Conclusions: The ethanolic stem extracts of P. amarus and J. glandulifera possess lead compounds for the development of antiplasmodial drugs.

  20. Greenhouse gas emissions from coastal freshwater wetlands in Veracruz Mexico: Effect of plant community and seasonal dynamics

    Science.gov (United States)

    Marín-Muñiz, José Luis; Hernández, María E.; Moreno-Casasola, Patricia

    2015-04-01

    Wetlands play an important role in modulating atmospheric concentrations of Greenhouse Gases (GHGs), such as methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). Despite the fact that ∼30% of wetlands in the world occur in tropical latitudes, little is known about GHG emissions from these ecosystems and the variables that control such emissions. We investigated the CH4, N2O and CO2 emissions in tropical freshwater marshes (FM) and swamps (FS) on the coastal plain of Veracruz, Mexico. GHGs were measured every two months using the closed chamber technique from April 2010 to February 2012 (CH4 and N2O) and during the last year for CO2. The ranges of the emissions were 20-2000 mg C-CH4 m-2 d-1, -2-16 mg N-N2O m-2 d-1 and 0.5-18 g C-CO2 m-2d-1. There were not significant differences in the emissions between FM and FS (P = 0.314, 0.528 and 0.213 for CH4, N2O, and CO2, respectively). However, significant differences (P 364 mg m-2 d-1) than during dry season (<150 mg m-2 d-1). The opposite was observed for CO2 emissions, during dry season, wetland soils were more aerobic and CO2 fluxes increased (FM: 11 ± 2, FS: 12 ± 1 g m-2 d-1). N-N2O emissions (FM: 1.5 ± 0.96, FS: 2.4 ± 0.9 mg m-2 d-1) were similar during different climatic season (P = 0.056). Based on the global warming potential, CH4 was the main contributor to total GHGs emission during the rainy and windy seasons (75-93%), while CO2 was predominant during the dry season (79.6%) and N2O contributed with less than 7% in the three seasons. Water level and redox potential were found to be main factors influencing GHG emissions in these wetlands.

  1. A Comparative Study on Equilibrium Adsorption of Dyes on Adsorbents Prepared from Coastal Plant, C. equisetifolia Seeds via Green Modification and Activated Carbon

    Directory of Open Access Journals (Sweden)

    Jaafar Jazulhafiz Jefri

    2016-01-01

    Full Text Available Eco-friendly adsorbents were prepared from coastal plant, C. equisetifolia seeds treated with β-cyclodextrin (Rhusorbent for the removal of dyes. The study was carried out to determine the effectiveness of Rhusorbent to remove common dyes such as malachite green (MG and neutral red (NR dyes from aqueous solutions in batch experiments. The commercial activated carbon (AC was also used in this equilibrium absorption study which includes the effect of adsorbent dosage, initial dye concentration and contact time. The percentage of MG dye removal of about 92.4% and 88.4% was achieved for both Rhusorbent and AC respectively at concentration of 60mg/L and 0.4g absorbent. The equilibrium adsorption of about 91.1% and 79.1% was achieved for both Rhusorbent and AC respectively involving NR dye. The scanning electron micrographs of Rhusorbent show uneven and rough surface prompting evidence for the effective adsorption of MG and NR dyes on the surface of adsorbents. For both adsorption studies, Langmuir and Freundlich isotherm models fitted well the adsorption data involving both Rhusorbent and AC. C. equisetifolia seeds are a potential source for bio-inspired adsorbents for the removal of MG and NR dyes.

  2. Dune vegetation and coastal thicket plant communities in threatened limestone fynbos of Andrew’s Field and Tsaba-Tsaba Nature Reserve, Struisbaai, Western Cape

    Directory of Open Access Journals (Sweden)

    M.M. Zietsman

    2006-12-01

    Full Text Available The coastal thicket and dune vegetation of Andrew’s Field and Tsaba-Tsaba Nature Reserve was classified using Braun-Blanquet procedures and TWINSPAN. The vegetation was sampled using 74 randomly stratified sample plots. The floristic composition, cover- abundance of each species, and several environmental variables were recorded in each sample plot. Six plant communities were identified, namely, Rhus glauca - Euclea racemosa low to tall closed thicket community; Chrysanthemoides monilifera - Solanum africanum low closed dune shrub community; Chrysanthemoides monilifera - Ehrharta villosa var. maxima low to high closed dune shrub community; Ehrharta villosa var. maxima low to short closed dune grassland community; Ammophila arenaria low to short closed dune grassland community; and Arcthotheca populifolia - Thinopyrum distichum low to short open beach community. These were subdivided into eight subcommunities and four variants. All communities, sub-communities and variants were described and ecologically interpreted. The distribution of the communities, sub-communities and variants can mainly be ascribed to differences in landform, rockiness of the soil surface the degree of protection / exposure of the vegetation to the dominating winds of the area.

  3. 滨海电厂循环水系统海生物污染防治%Marine Biofouling Control in Circulating Water System of Coastal Power Plant

    Institute of Scientific and Technical Information of China (English)

    宋伟伟; 贾思洋; 周晓光; 张林

    2013-01-01

    The characteristic, damage and control methods of marine biofouling in circulating water system of coastal power plant were introduced in this paper, and the application of biocide was emphasized. Adopting alternatively non-oxidative biocide and oxidative biocide was an effective solution to marine biofouling, and the method of electrolyzing seawater antifouling technique was economic to large-scale circulating water system.%  要:本文介绍了滨海电厂循环水系统的海生物污染及危害,总结了滨海电厂循环水系统海生物污染的防治方法,并重点介绍了应用较广泛的杀生剂处理方法。非氧化性杀生剂与氧化性杀生剂交替使用是一种有效的防治海生物污染的方案,电解海水制氯防污技术对于大型循环水处理系统是经济合适的方案。

  4. Probabilistic estimation of dune erosion and coastal zone risk

    NARCIS (Netherlands)

    Li, F.

    2014-01-01

    Coastal erosion has gained global attention and has been studied for many decades. As a soft sea defence structure, coastal sandy dunes protect coastal zones all over the world, which usually are densely populated areas with tremendous economic value. The coastal zone of the Netherlands, one of the

  5. Population parameters and the relationships between environmental factors and abundance of the Acetes americanus shrimp (Dendrobranchiata: Sergestidae near a coastal upwelling region of Brazil

    Directory of Open Access Journals (Sweden)

    Ana Paula Freitas dos Santos

    2015-09-01

    Full Text Available AbstractThe population dynamics of Acetes americanus was investigated, focusing on the sex ratio, individual growth, longevity, recruitment and relationship between abundance and environmental factors in the region of Macaé, strongly influenced by coastal upwelling. Otter trawl net samplings were performed from July 2010 to June 2011 at two points (5 m and 15 m. Nearly 19,500 specimens, predominantly females (77.15%, were captured. Their sizes, larger than that of males, indicated sexual dimorphism. Shrimps at lower latitudes present larger sizes and longer longevity than those from higher latitudes. This difference is probably due to low temperatures and high primary productivity. Though no statistical correlation was found between abundance and environmental factors, the species was more abundant in temperatures closer to 20.0º C and in months with high chlorophyll-a levels. Due to the peculiar characteristics of this region, A. americanusshowed greater differences in size and longevity than individuals sampled in other studies undertaken in the continental shelf of Southeast Brazil.

  6. Adaptation as a potential response to sea-level rise: a genetic basis for salinity tolerance in populations of a coastal marsh fish.

    Science.gov (United States)

    Purcell, Kevin M; Hitch, Alan T; Klerks, Paul L; Leberg, Paul L

    2008-02-01

    Relative sea-level rise is resulting in the intrusion of saline waters into marshes historically dominated by fresh water. Saltwater intrusions can potentially affect resident marsh species, especially when storm-related tidal surges cause rapid changes in salinity. We examined the role of historical salinity exposure on the survival of Gambusia affinis from two locations in coastal Louisiana. At each location, we sampled fish populations from fresh, intermediate and brackish marshes. Individuals were then exposed to a salinity of 25‰ and survival time was measured. We found that fish from brackish and intermediate marshes had an increased tolerance to salinity stress relative to fish from freshwater environments. We then tested the descendents of fish from the fresh and brackish marshes, reared for two generation in fresh water, to determine if there was a genetic basis for differential survival. We found that descendents of individuals from brackish marshes showed elevated survivals relative to the descendents of fish with no historical exposure to salinity. The most reasonable mechanism to account for the differences in survival relative to historical exposure is genetic adaptation, suggesting that natural selection may play a role in the responses of resident marsh fishes to future increases in salinity.

  7. Population growth, trophic level, and reproductive biology of two congeneric archer fishes (Toxotes chatareus, Hamilton 1822 and Toxotes jaculatrix, Pallas 1767) inhabiting Malaysian coastal waters.

    Science.gov (United States)

    Simon, K D; Bakar, Y; Samat, A; Zaidi, C C; Aziz, A; Mazlan, A G

    2009-12-01

    Population growth, trophic level, and some aspects of reproductive biology of two congeneric archer fish species, Toxotes chatareus and Toxotes jaculatrix, collected from Johor coastal waters, Malaysia, were studied. Growth pattern by length-weight relationship (W=aL(b)) for the sexes differed, and exhibited positive allometric growth (male, female and combined sexes of T. chatareus; female and combined sexes of T. jaculatrix) and isometric growth (male samples of T. jaculatrix only). Trophic levels of both species were analyzed based on 128 specimens. The results show that, in both species, crustaceans and insects were the most abundant prey items, and among crustaceans the red clawed crab Sesarma bidens and Formicidae family insects were the most represented taxa. The estimated mean trophic levels for T. chatareus and T. jaculatrix were 3.422+/-0.009 and 3.420+/-0.020, respectively, indicating that they are largely carnivores. Fecundity of T. chatareus ranged from 38 354 to 147 185 eggs for females with total length ranging from 14.5 to 22.5 cm and total body weight from 48.7 to 270.2 g, and T. jaculatrix 25 251 to 150 456 eggs for females with total length ranging from 12.2 to 23.0 cm and total body weight from 25.7 to 275.0 g. Differences in values of gonadosomatic and hepatosomatic indexes calculated for both species in this study may have resulted from uneven sample size ranges.

  8. Genetic diversity of Ulva prolifera population in Qingdao coastal water during the green algal blooms revealed by microsatellite.

    Science.gov (United States)

    Li, Yue; Huang, Hong-Jia; Li, Hongye; Liu, Jiesheng; Yang, Weidong

    2016-10-15

    Green tides have occurred in Qingdao coast in China for seven consecutive years from 2007 to 2013. To provide information on the genetic structure of these blooms, 210 free-floating green algae samples isolated from the green tide in Qingdao coast on June 19, 2013 were identified based on the ITS, rbcL and 5S sequence, and genetic diversity was investigated by microsatellite markers. According to ITS, rbcL and 5S sequence, all the 210 samples belonged to Ulva prolifera. Nei's genetic diversity and Shannon index estimated using eight microsatellite markers indicated that the genetic diversity of U. prolifera population within Qingdao's green bloom in 2013 was low. Taking into account previous reports about life history and physiology of U. prolifera, we proposed that the limited origin area of the free-floating biomass and asexual reproduction of U. prolifera might be responsible for the lower diversity of free floating U. prolifera.

  9. The influence of extreme winds on coastal oceanography and its implications for coral population connectivity in the southern Arabian Gulf.

    Science.gov (United States)

    Cavalcante, Geórgenes H; Feary, David A; Burt, John A

    2016-04-30

    Using long-term oceanographic surveys and a 3-D hydrodynamic model we show that localized peak winds (known as shamals) cause fluctuation in water current speed and direction, and substantial oscillations in sea-bottom salinity and temperature in the southern Persian/Arabian Gulf. Results also demonstrate that short-term shamal winds have substantial impacts on oceanographic processes along the southern Persian/Arabian Gulf coastline, resulting in formation of large-scale (52 km diameter) eddies extending from the coast of the United Arab Emirates (UAE) to areas near the off-shore islands of Iran. Such eddies likely play an important role in transporting larvae from well-developed reefs of the off-shore islands to the degraded reef systems of the southern Persian/Arabian Gulf, potentially maintaining genetic and ecological connectivity of these geographically distant populations and enabling enhanced recovery of degraded coral communities in the UAE.

  10. Spatial and temporal assessment of the initial pattern of phytoplankton population in a newly built coastal reservoir

    Science.gov (United States)

    Ren, Xiangyu; Yang, Kai; Che, Yue; Wang, Mingwei; Zhou, Lili; Chen, Liqiao

    2016-09-01

    For decades, the main threat to the water security of a metropolis, such as the city of Shanghai, has been the rapidly growing demand for water and at the same time, the decrease in water quality, including eutrophication. Therefore Shanghai shifted the preferred freshwater source to the Yangtze Estuary and constructed the Qingcaosha Reservoir, which is subject to less eutrophic water from the Yangtze River. To assess the population of phytoplankton for the first time in the newly built reservoir, this study improved an integrated method to assess the phytoplankton pattern in large-water-area reservoirs and lakes, using partial triadic analysis and Geographic Information Systems. Monthly sampling and monitoring from 10 stations in the reservoir from July 2010 to December 2011 were conducted. The study examined the common pattern of the phytoplankton population structure and determined the differences in the specific composition of the phytoplankton community during the transition period of the reservoir. The results suggest that in all but three sampling stations in the upper parts of Qingcaosha Reservoir, there was a strong common compromise in 2011. The two most important periods occurred from late summer to autumn and from winter to early spring. The former was characterized by the dominance of cyanobacteria, whereas the latter was characterized by the dominance of both chlorophyta and diatoms. Cyanobacteria ( Microcystis spp. as the main genus) were the monopolistic dominant species in the summer after reservoir operation. The statistical analysis also indicated the necessity for regular monitoring to focus on the stations in the lower parts of the reservoir and on several limited species.

  11. Computer simulation model for the striped bass young-of-the-year population in the Hudson River. [Effects of entrainment and impingement at power plants on population dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Eraslan, A.H.; Van Winkle, W.; Sharp, R.D.; Christensen, S.W.; Goodyear, C.P.; Rush, R.M.; Fulkerson, W.

    1975-09-01

    This report presents a daily transient (tidal-averaged), longitudinally one-dimensional (cross-section-averaged) computer simulation model for the assessment of the entrainment and impingement impacts of power plant operations on young-of-the-year populations of the striped bass, Morone saxatilis, in the Hudson River.

  12. Genetic structure of coexisting wild and managed agave populations: implications for the evolution of plants under domestication.

    Science.gov (United States)

    Figueredo, Carmen Julia; Casas, Alejandro; González-Rodríguez, Antonio; Nassar, Jafet M; Colunga-GarcíaMarín, Patricia; Rocha-Ramírez, Víctor

    2015-10-03

    Domestication is a continuous evolutionary process guided by humans. This process leads to divergence in characteristics such as behaviour, morphology or genetics, between wild and managed populations. Agaves have been important resources for Mesoamerican peoples since prehistory. Some species are domesticated and others vary in degree of domestication. Agave inaequidens Koch is used in central Mexico to produce mescal, and a management gradient from gathered wild and silvicultural populations, as well as cultivated plantations, has been documented. Significant morphological differences were reported among wild and managed populations, and a high phenotypic variation in cultivated populations composed of plants from different populations. We evaluated levels of genetic diversity and structure associated with management, hypothesizing that high morphological variation would be accompanied by high genetic diversity in populations with high gene flow and low genetic structure among managed and unmanaged populations. Wild, silvicultural and cultivated populations were studied, collecting tissue of 19-30 plants per population. Through 10 nuclear microsatellite loci, we compared population genetic parameters. We analysed partition of variation associated with management categories to estimate gene flow among populations. Agave inaequidens exhibits high levels of genetic diversity (He = 0.707) and moderate genetic structure (FST = 0.112). No differences were found in levels of genetic diversity among wild (He = 0.704), silviculturally managed (He = 0.733) and cultivated (He = 0.698) populations. Bayesian analysis indicated that five genetic clusters best fit the data, with genetic groups corresponding to habitats where populations grow rather than to management. Migration rates ranged from zero between two populations to markedly high among others (M = 0.73-35.25). Natural mechanisms of gene flow and the dynamic management of agave propagules among populations favour gene

  13. Living in isolation - population structure, reproduction, and genetic variation of the endangered plant species Dianthus gratianopolitanus (Cheddar pink).

    Science.gov (United States)

    Putz, Christina M; Schmid, Christoph; Reisch, Christoph

    2015-09-01

    The endangered plant species Dianthus gratianopolitanus exhibits a highly fragmented distribution range comprising many isolated populations. Based upon this pattern of distribution, we selected a study region in Switzerland with a lower magnitude of isolation (Swiss Jura) and another study region in Germany with a higher degree of isolation (Franconian Jura). In each region, we chose ten populations to analyze population structure, reproduction, and genetic variation in a comparative approach. Therefore, we determined population density, cushion size, and cushion density to analyze population structure, investigated reproductive traits, including number of flowers, capsules, and germination rate, and analyzed amplified fragment length polymorphisms to study genetic variation. Population and cushion density were credibly higher in German than in Swiss populations, whereas reproductive traits and genetic variation within populations were similar in both study regions. However, genetic variation among populations and isolation by distance were stronger in Germany than in Switzerland. Generally, cushion size and density as well as flower and capsule production increased with population size and density, whereas genetic variation decreased with population density. In contrast to our assumptions, we observed denser populations and cushions in the region with the higher magnitude of isolation, whereas reproductive traits and genetic variation within populations were comparable in both regions. This corroborates the assumption that stronger isolation must not necessarily result in the loss of fitness and genetic variation. Furthermore, it supports our conclusion that the protection of strongly isolated populations contributes essentially to the conservation of a species' full evolutionary potential.

  14. Parentage versus two-generation analyses for estimating pollen-mediated gene flow in plant populations.

    Science.gov (United States)

    Burczyk, Jaroslaw; Koralewski, Tomasz E

    2005-07-01

    Assessment of contemporary pollen-mediated gene flow in plants is important for various aspects of plant population biology, genetic conservation and breeding. Here, through simulations we compare the two alternative approaches for measuring pollen-mediated gene flow: (i) the NEIGHBORHOOD model--a representative of parentage analyses, and (ii) the recently developed TWOGENER analysis of pollen pool structure. We investigate their properties in estimating the effective number of pollen parents (N(ep)) and the mean pollen dispersal distance (delta). We demonstrate that both methods provide very congruent estimates of N(ep) and delta, when the methods' assumptions considering the shape of pollen dispersal curve and the mating system follow those used in data simulations, although the NEIGHBORHOOD model exhibits generally lower variances of the estimates. The violations of the assumptions, especially increased selfing or long-distance pollen dispersal, affect the two methods to a different degree; however, they are still capable to provide comparable estimates of N(ep). The NEIGHBORHOOD model inherently allows to estimate both self-fertilization and outcrossing due to the long-distance pollen dispersal; however, the TWOGENER method is particularly sensitive to inflated selfing levels, which in turn may confound and suppress the effects of distant pollen movement. As a solution we demonstrate that in case of TWOGENER it is possible to extract the fraction of intraclass correlation that results from outcrossing only, which seems to be very relevant for measuring pollen-mediated gene flow. The two approaches differ in estimation precision and experimental efforts but they seem to be complementary depending on the main research focus and type of a population studied.

  15. Genetic Population Structure of Cacao Plantings within a Young Production Area in Nicaragua

    Science.gov (United States)

    Trognitz, Bodo; Scheldeman, Xavier; Hansel-Hohl, Karin; Kuant, Aldo; Grebe, Hans; Hermann, Michael

    2011-01-01

    Significant cocoa production in the municipality of Waslala, Nicaragua, began in 1961. Since the 1980s, its economic importance to rural smallholders increased, and the region now contributes more than 50% of national cocoa bean production. This research aimed to assist local farmers to develop production of high-value cocoa based on optimal use of cacao biodiversity. Using microsatellite markers, the allelic composition and genetic structure of cacao was assessed from 44 representative plantings and two unmanaged trees. The population at Waslala consists of only three putative founder genotype spectra (lineages). Two (B and R) were introduced during the past 50 years and occur in >95% of all trees sampled, indicating high rates of outcrossing. Based on intermediate allelic diversity, there was large farm-to-farm multilocus genotypic variation. GIS analysis revealed unequal distribution of the genotype spectra, with R being frequent within a 2 km corridor along roads, and B at more remote sites with lower precipitation. The third lineage, Y, was detected in the two forest trees. For explaining the spatial stratification of the genotype spectra, both human intervention and a combination of management and selection driven by environmental conditions, appear responsible. Genotypes of individual trees were highly diverse across plantings, thus enabling selection for farm-specific qualities. On-farm populations can currently be most clearly recognized by the degree of the contribution of the three genotype spectra. Of two possible strategies for future development of cacao in Waslala, i.e. introducing more unrelated germplasm, or working with existing on-site diversity, the latter seems most appropriate. Superior genotypes could be selected by their specific composite genotype spectra as soon as associations with desired quality traits are established, and clonally multiplied. The two Y trees from the forest share a single multilocus genotype, possibly representing the

  16. Genetic population structure of cacao plantings within a young production area in Nicaragua.

    Science.gov (United States)

    Trognitz, Bodo; Scheldeman, Xavier; Hansel-Hohl, Karin; Kuant, Aldo; Grebe, Hans; Hermann, Michael

    2011-01-14

    Significant cocoa production in the municipality of Waslala, Nicaragua, began in 1961. Since the 1980s, its economic importance to rural smallholders increased, and the region now contributes more than 50% of national cocoa bean production. This research aimed to assist local farmers to develop production of high-value cocoa based on optimal use of cacao biodiversity. Using microsatellite markers, the allelic composition and genetic structure of cacao was assessed from 44 representative plantings and two unmanaged trees. The population at Waslala consists of only three putative founder genotype spectra (lineages). Two (B and R) were introduced during the past 50 years and occur in >95% of all trees sampled, indicating high rates of outcrossing. Based on intermediate allelic diversity, there was large farm-to-farm multilocus genotypic variation. GIS analysis revealed unequal distribution of the genotype spectra, with R being frequent within a 2 km corridor along roads, and B at more remote sites with lower precipitation. The third lineage, Y, was detected in the two forest trees. For explaining the spatial stratification of the genotype spectra, both human intervention and a combination of management and selection driven by environmental conditions, appear responsible. Genotypes of individual trees were highly diverse across plantings, thus enabling selection for farm-specific qualities. On-farm populations can currently be most clearly recognized by the degree of the contribution of the three genotype spectra. Of two possible strategies for future development of cacao in Waslala, i.e. introducing more unrelated germplasm, or working with existing on-site diversity, the latter seems most appropriate. Superior genotypes could be selected by their specific composite genotype spectra as soon as associations with desired quality traits are established, and clonally multiplied. The two Y trees from the forest share a single multilocus genotype, possibly representing the

  17. The effects of vertebrate herbivory on plant community structure in the coastal marshes of the Pearl River, Louisiana, USA

    Science.gov (United States)

    Taylor, K.L.; Grace, J.B.

    1995-01-01

    In this study, we investigated the impacts of herbivory by the introduced aquatic herbivore, nutria (Myocastor coypus), on three marsh communities of the Pearl River using fenced exclosures and control plots. Although total community above-ground biomass was reduced by 30% in the plots exposed to herbivory as compared to those protected from herbivory, we found species richness to be unaffected. When individual species were examined within each community,Panicum virgatum andAster subulatus were found to be significantly reduced by herbivory in the freshwater community,Panicum virgatum andVigna luteola were significantly increased by herbivory in the oligohaline community, and no species were significantly affected in the mesohaline community. We conclude that this herbivory has some specific effects on some plant species as well as having a general community effect.

  18. Demographic population structure and fungal associations of plants colonizing High Arctic glacier forelands, Petuniabukta, Svalbard

    Directory of Open Access Journals (Sweden)

    Jakub Těšitel

    2014-04-01

    Full Text Available The development of vegetation in Arctic glacier forelands has been described as unidirectional, non-replacement succession characterized by the gradual establishment of species typical for mature tundra with no species turnover. Our study focused on two early colonizers of High Arctic glacier forelands: Saxifraga oppositifolia (Saxifragaceae and Braya purpurascens (Brassicaceae. While the first species is a common generalist also found in mature old growth tundra communities, the second specializes on disturbed substrate. The demographic population structures of the two study species were investigated along four glacier forelands in Petuniabukta, north Billefjorden, in central Spitsbergen, Svalbard. Young plants of both species occurred exclusively on young substrate, implying that soil conditions are favourable for establishment only before soil crusts develop. We show that while S. oppositifolia persists from pioneer successional stages and is characterized by increased size and flowering, B. purpurascens specializes on disturbed young substrate and does not follow the typical unidirectional, non-replacement succession pattern. Plants at two of the forelands were examined for the presence of root-associated fungi. Fungal genus Olpidium (Fungus incertae sedis was found along a whole successional gradient in one of the forelands.

  19. Plant extracts, metaldehyde and saline solutions on the population control of Bradybaena similaris

    Directory of Open Access Journals (Sweden)

    Junir Antonio Lutinski

    2016-08-01

    Full Text Available ABSTRACT: This study aimed to test the efficiency of plant extracts, metaldehyde and saline solutions, as alternatives to the population control of the snail Bradybaena similaris , and to investigate the effect of the plant extracts in reducing the damage of the snail on Brassica oleracea . The experiments were performed at the Entomology Laboratory of the Universidade Comunitária da Região de Chapecó (Unochapecó, using a random experimental design with nine treatments in triplicate. Five adult individuals of B. similaris were subjected to each trial, totaling 135 snails. The following treatments were tested: cinnamon ( Melia azedarach , timbó ( Ateleia glazioveana , rosemary ( Rosmarinus officinalis , mate herb ( Ilex paraguariensis , two concentrations of metaldehyde (3% and 5%, two concentrations of salt solution (5% and 10 %, and a control treatment (distilled water. To evaluate the survival of B. similaris it was checked the treatments every 24 hours, over four consecutive days. The results revealed that the two concentrations of metaldehyde were fully efficient, that the saline solution (10% had and intermediate efficiency, and that all other treatments were not effective. The treatment with the M. azedarach extract induced a higher consumption of B. oleracea , while the saline solution at 10% and the extracts of R. officinalis and I. paraguariensis inhibited leaf consumption.

  20. Portfolio effects, climate change, and the persistence of small populations: analyses on the rare plant Saussurea weberi.

    Science.gov (United States)

    Abbott, Ronald E; Doak, Daniel F; Peterson, Megan L

    2017-04-01

    The mechanisms that stabilize small populations in the face of environmental variation are crucial to their long-term persistence. Building from diversity-stability concepts in community ecology, within-population diversity is gaining attention as an important component of population stability. Genetic and microhabitat variation within populations can generate diverse responses to common environmental fluctuations, dampening temporal variability across the population as a whole through portfolio effects. Yet, the potential for portfolio effects to operate at small scales within populations or to change with systematic environmental shifts, such as climate change, remain largely unexplored. We tracked the abundance of a rare alpine perennial plant, Saussurea weberi, in 49 1-m(2) plots within a single population over 20 yr. We estimated among-plot correlations in log annual growth rate to test for population-level synchrony and quantify portfolio effects across the 20-yr study period and also in 5-yr subsets based on June temperature quartiles. Asynchrony among plots, due to different plot-level responses to June temperature, reduced overall fluctuations in abundance and the probability of decline in population models, even when accounting for the effects of density dependence on dynamics. However, plots became more synchronous and portfolio effects decreased during the warmest years of the study, suggesting that future climate warming may erode stabilizing mechanisms in populations of this rare plant.

  1. Adaptive Potential for the Invasion of Novel Host Plants in the Bean Weevil: Patterns of the Reproductive Behavior in Populations That Used Different Host Plants

    Directory of Open Access Journals (Sweden)

    Dragana Milanović

    2007-01-01

    Full Text Available The goal of this work was to examine interpopulation patterns in the reproductive behavior of populations of bean weevil (Acanthoscelides obtectus Say; Coleoptera: Bruchidae that had different levels of specialization on their native host plant – the bean (Phaseolus vulgaris L., as well as on a novel host plant – the chickpea (Cicer arietinum Thorn. The obtained pattern of interpopulation mating behavior seemed exactly as if the males on chickpea had evolved a specific odor and/or a courtship ritual that females of populationson bean found repulsive. Unlike females, the males of bean populations seemed to be willing to mate with females from the population on chickpea equally as with their own females. Such an asymmetric pattern of reproductive isolation between populations ofa species has been often considered an initial phase of a process of speciation. Thus, our results could be a good starting point for further, thorough examination of both the role of the level of host specialization in females and the role of biochemical characteristics of male pheromone (and/or their cuticular hydrocarbones in the evolution of pre-reproductive isolation between insect populations.As the results of this study, together those of previous studies on A. obtectus, suggest great evolutionary potential for invasions of and fast specialization on novel host plants, they could provide valuable information for the development of long-term strategiesunder the programmes of Integrated Pest Management.

  2. Are sunscreens a new environmental risk associated with coastal tourism?

    Science.gov (United States)

    Sánchez-Quiles, David; Tovar-Sánchez, Antonio

    2015-10-01

    The world coastal-zone population and coastal tourism are expected to grow during this century. Associated with that, there will be an increase in the use of sunscreens and cosmetics with UV-filters in their formulation, which will make coastal regions worldwide susceptible to the impact of these cosmetics. Recent investigations indicate that organic and inorganic UV-filters, as well as many other components that are constituents of the sunscreens, reach the marine environment--directly as a consequence of water recreational activities and/or indirectly from wastewater treatment plants (WWTP) effluents. Toxicity of organic and inorganic UV filters has been demonstrated in aquatic organism. UV-filters inhibit growth in marine phytoplankton and tend to bioaccumulate in the food webs. These findings together with coastal tourism data records highlight the potential risk that the increasing use of these cosmetics would have in coastal marine areas. Nevertheless, future investigations into distribution, residence time, aging, partitioning and speciation of their main components and by-products in the water column, persistence, accumulation and toxicity in the trophic chain, are needed to understand the magnitude and real impact of these emerging pollutants in the marine system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Occurrence of amphibians in northern California coastal dune drainages

    Science.gov (United States)

    Halstead, Brian J.; Kleeman, Patrick M.

    2017-01-01

    Many coastal dune ecosystems have been degraded by non-native dune vegetation, but these systems might still provide valuable habitat for some taxa, including amphibians. Because restoration of degraded dune systems is occurring and likely to continue, we examined the occurrence of amphibians in drainages associated with a coastal dune ecosystem degraded by invasive plants (European Beachgrass, Ammophila arenaria, and Iceplant, Carpobrotus edulis). We found that occupancy of 3 amphibian species (California Red-legged Frog, Rana draytonii; Sierran Treefrog, Hyliola sierra; and Rough-skinned Newt, Taricha granulosa) among 21 coastal-dune drainages was high, with most coastal-dune drainages occupied by all 3 species. Furthermore, reproduction of Sierran Treefrogs and California Red-legged Frogs was estimated to occur in approximately ½ and ⅓ of the drainages, respectively. The probability of occurrence of Rough-skinned Newts and pre-metamorphic life stages of both anurans decreased during the study, perhaps because of ongoing drought in California or precipitation-induced changes in phenology during the final year of the study. Maintaining structural cover and moist features during dune restoration will likely benefit native amphibian populations inhabiting coastal-dune ecosystems.

  4. Arsenic in the water-soil-plant system and the potential health risks in the coastal part of Chianan Plain, Southwestern Taiwan

    Science.gov (United States)

    Kar, Sandeep; Das, Suvendu; Jean, Jiin-Shuh; Chakraborty, Sukalyan; Liu, Chia-Chuan

    2013-11-01

    The present study investigates the bioavailability, soil to plant transfer and health risks of arsenic (As) in the coastal part of Chianan Plain in southwestern Taiwan. Groundwater used for irrigation, surface soils from agricultural lands and locally grown foodstuffs were collected from eight locations and analyzed for As to assess the risks associated with consuming these items. The concentration of As in groundwater ranged from 13.8 to 881 μg/L, whereas surface soil showed total As content in the range of 7.92-12.7 mg/kg. The available As content in surface soil accounted for 0.06-6.71% of the total As content, and was significantly correlated with it (R2 = 0.65, p < 0.05). Among the leachable fraction, the organic matter (3.23-54.8%) and exchangeable portions of oxides (6.03-38.4%) appear to be the major binding phases of As. The average As content in fourteen studied crops and vegetables varied from 10.3 to 151 μg/kg with maximum in mustard and minimum in radish. All the plants showed considerably higher As content (21.5 ± 3.64-262 ± 36.2 μg/kg) in their roots compared to the edible parts (9.15 ± 1.44-75.8 ± 22.9 μg/kg). The bioaccumulation factor (BAF) based on total As (ranging from 0.0009 to 0.144) and available As in soil (ranging from 0.039 to 0.571) indicate that mustard, rice, amaranth and spinach are the highest accumulators of As. Although the health risk index (HRI) of the studied crops and vegetables ranged from only 0.0068-0.454, with the maximum in rice, the combined HRI indicates an alarming value of 0.88. Therefore, the possible health risks due to long-term consumption of rice and other As-rich foodstuffs could be overcome by controlling the contamination pathways in the water-soil-plant system.

  5. A theoretical analysis of population genetics of plants on restored habitats

    Energy Technology Data Exchange (ETDEWEB)

    Bogoliubov, A.G. [Botanical Institute, Russian Academy of Science, St. Petersburg (Russian Federation); Loehle, C. [Argonne National Lab., IL (United States)

    1995-02-01

    Seed and propagules used for habitat restoration are not likely to be closely adapted to local site conditions. Rapid changes of genotypes frequencies on local microsites and/or microevolution would allow plants to become better adapted to a site. These same factors would help to maintain genetic diversity and ensure the survival of small endangered populations. We used population genetics models to examine the selection of genotypes during establishment on restored sites. Vegetative spread was shown to affect selection and significantly reduce genetic diversity. To study general microevolution, we linked a model of resource usage with a genetics model and analyzed competition between genotypes. A complex suite of feasible ecogenetic states was shown to result. The state actually resulting would depend strongly on initial conditions. This analysis indicated that genetic structure can vary locally and can produce overall genetic variability that is not simply the result of microsite adaptations. For restoration activities, the implication is that small differences in seed source could lead to large differences in local genetic structure after selection.

  6. A theoretical analysis of population genetics of plants on restored habitats

    Energy Technology Data Exchange (ETDEWEB)

    Bogoliubov, A.G. [Russian Academy of Science, St. Petersburg (Russian Federation). Botanical Inst.; Loehle, C. [Argonne National Lab., IL (United States). Environmental Research Div.

    1997-07-01

    Seed and propagules used for habitat restoration are not likely to be closely adapted to local site conditions. Rapid changes of genotypes frequencies on local microsites and/or microevolution would allow plants to become better adapted to a site. These same factors would help to maintain genetic diversity and ensure the survival of small endangered populations. The authors used population genetics models to examine the selection of genotypes during establishment on restored sites. Vegetative spread was shown to affect selection and significantly reduce genetic diversity. To study general microevolution, the authors linked a model of resource usage with a genetics model and analyzed competition between genotypes. A complex suite of feasible ecogenetic states was shown to result. The state actually resulting would depend strongly on initial conditions. This analysis indicated that genetic structure can vary locally and can produce overall genetic variability that is not simply the result of microsite adaptations. For restoration activities, the implication is that small differences in seed source could lead to large differences in local genetic structure after selection.

  7. Factors affecting population of filamentous bacteria in wastewater treatment plants with nutrients removal.

    Science.gov (United States)

    Miłobędzka, Aleksandra; Witeska, Anna; Muszyński, Adam

    2016-01-01

    Filamentous population in activated sludge and key operational parameters of full-scale municipal wastewater treatment plants (WWTPs) with bulking problems representative for Poland were investigated with quantitative fluorescence in situ hybridization. Statistical analyses revealed few relationships between operational parameters and biovolume of filamentous bacteria. Sludge age was not only positively correlated with abundance of Chloroflexi (parametric correlation and principal component analysis (PCA)), but also differentiated Microthrix population (analysis of variance (ANOVA)). Phylum Chloroflexi and pH presented a negative relation during the study (PCA). ANOVA showed that pH of influent and sludge volume index (SVI) differentiated abundance of types 0803 and 1851 of Chloroflexi and candidate division TM7. SVI increased along with higher abundance of Microthrix (positive parametric and non-parametric correlations and positive relation in PCA). Biovolumes of morphotypes 0803 and 1851 of Chloroflexi were differentiated by organic matter in influent, also by nutrients in the case of Chloroflexi type 1851. Chemical and biological oxygen demands (COD and BOD5, respectively) were negatively correlated with Microthrix. COD also differentiated the abundance of Haliscomenobacter hydrossis. Results of the study can be used to prevent WWTPs from excessive proliferation of filamentous bacteria and operational problems caused by them--bulking and foaming of activated sludge.

  8. Waterfowl breeding population survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Waterfowl breeding population surveys have been completed annually on the Arctic Coastal Plain of Alaska since 1986. Methods for the 2011 Arctic Coastal Plain...

  9. Waterfowl breeding population survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Waterfowl breeding population surveys have been completed annually on the Arctic Coastal Plain of Alaska since 1986. Methods for the 2010 Arctic Coastal Plain...

  10. Coexistence of trichome variation in a natural plant population: a combined study using ecological and candidate gene approaches.

    Directory of Open Access Journals (Sweden)

    Tetsuhiro Kawagoe

    Full Text Available The coexistence of distinct phenotypes within populations has long been investigated in evolutionary ecology. Recent studies have identified the genetic basis of distinct phenotypes, but it is poorly understood how the variation in candidate loci is maintained in natural environments. In this study, we examined fitness consequences and genetic basis of variation in trichome production in a natural population of Arabidopsis halleri subsp. gemmifera. Half of the individuals in the study population produced trichomes while the other half were glabrous, and the leaf beetle Phaedon brassicae imposed intensive damage to both phenotypes. The fitness of hairy and glabrous plants showed no significant differences in the field during two years. A similar result was obtained when sibling hairy and glabrous plants were transplanted at the same field site, whereas a fitness cost of trichome production was detected under a weak herbivory condition. Thus, equivalent fitness of hairy and glabrous plants under natural herbivory allows their coexistence in the contemporary population. The pattern of polymorphism of the candidate trichome gene GLABROUS1 (GL1 showed no evidence of long-term maintenance of trichome variation within the population. Although balancing selection under fluctuating biotic environments is often proposed to explain the maintenance of defense variation, the lack of clear evidence of balancing selection in the study population suggests that other factors such as gene flow and neutral process may have played relatively large roles in shaping trichome variation at least for the single population level.

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

    Science.gov (United States)

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

    2016-01-01

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

  12. Assessment of endocrine-disrupting chemicals attenuation in a coastal plain stream prior to wastewater treatment plant closure

    Science.gov (United States)

    Bradley, Paul M.; Journey, Celeste

    2014-01-01

    The U.S. Geological Survey is conducting a combined pre/post-closure assessment at a long-term wastewater treatment plant (WWTP) site at Fort Gordon near Augusta, Georgia. Here, we assess select endocrine-active chemicals and benthic macroinvertebrate community structure prior to closure of the WWTP. Substantial downstream transport and limited instream attenuation of endocrine-disrupting chemicals (EDCs) was observed in Spirit Creek over a 2.2-km stream segment downstream of the WWTP outfall. A modest decline (less than 20% in all cases) in surface water detections was observed with increasing distance downstream of the WWTP and attributed to partitioning to the sediment. Estrogens detected in surface water in this study included estrone (E1), 17β-estradiol (E2), and estriol (E3). The 5 ng/l and higher mean estrogen concentrations observed in downstream locations indicated that the potential for endocrine disruption was substantial. Concentrations of alkylphenol ethoxylate (APE) metabolite EDCs also remained statistically elevated above levels observed at the upstream control site. Wastewater-derived pharmaceutical and APE metabolites were detected in the outflow of Spirit Lake, indicating the potential for EDC transport to aquatic ecosystems downstream of Fort Gordon. The results indicate substantial EDC occurrence, downstream transport, and persistence under continuous supply conditions and provide a baseline for a rare evaluation of ecosystem response to WWTP closure.

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

    Science.gov (United States)

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

    2016-10-01

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

  14. Salinity-related variation in gene expression in wild populations of the black-chinned tilapia from various West African coastal marine, estuarine and freshwater habitats

    Science.gov (United States)

    Tine, Mbaye; McKenzie, David J.; Bonhomme, François; Durand, Jean-Dominique

    2011-01-01

    This study measured the relative expression of the genes coding for Na +, K +-ATPase 1α(NAKA), voltage-dependent anion channel (VDAC), cytochrome c oxidase-1 (COX), and NADH dehydrogenase (NDH), in gills of six wild populations of a West African tilapia species, acclimatised to a range of seasonal (rainy or dry) salinities in coastal, estuarine and freshwater sites. Previous laboratory experiments have demonstrated that these genes, involved in active ion transport, oxidative phosphorylation, and intra-cellular ATP transport, are relatively over-expressed in gill tissues of this species acclimated to high salinity. Positive correlations between relative expression and ambient salinity were found for all genes in the wild populations (Spearman rank correlation, p < 0.05), although for some genes these were only significant in either the rainy season or dry season. Most significantly, however, relative expression was positively correlated amongst the four genes, indicating that they are functionally interrelated in adaptation of Sarotherodon melanotheron to salinity variations in its natural environment. In the rainy season, when salinity was unstable and ranged between zero and 37 psu across the sites, overall mean expression of the genes was higher than in the dry season, which may have reflected more variable particularly sudden fluctuations in salinity and poorer overall water quality. In the dry season, when the salinity is more stable but ranged between zero and 100 psu across the sites, NAKA, NDH and VDAC expression revealed U-shaped relationships with lowest relative expression at salinities approaching seawater, between 25 and 45 psu. Although it is not simple to establish direct relationship between gene expression levels and energy requirement for osmoregulation, these results may indicate that costs of adaptation to salinity are lowest in seawater, the natural environment of this species. While S. melanotheron can colonise environments with extremely

  15. Going coastal: shared evolutionary history between coastal British Columbia and Southeast Alaska wolves (Canis lupus.

    Directory of Open Access Journals (Sweden)

    Byron V Weckworth

    Full Text Available BACKGROUND: Many coastal species occupying the temperate rainforests of the Pacific Northwest in North America comprise endemic populations genetically and ecologically distinct from interior continental conspecifics. Morphological variation previously identified among wolf populations resulted in recognition of multiple subspecies of wolves in the Pacific Northwest. Recently, separate genetic studies have identified diverged populations of wolves in coastal British Columbia and coastal Southeast Alaska, providing support for hypotheses of distinct coastal subspecies. These two regions are geographically and ecologically contiguous, however, there is no comprehensive analysis across all wolf populations in this coastal rainforest. METHODOLOGY/PRINCIPAL FINDINGS: By combining mitochondrial DNA datasets from throughout the Pacific Northwest, we examined the genetic relationship between coastal British Columbia and Southeast Alaska wolf populations and compared them with adjacent continental populations. Phylogenetic analysis indicates complete overlap in the genetic diversity of coastal British Columbia and Southeast Alaska wolves, but these populations are distinct from interior continental wolves. Analyses of molecular variation support the separation of all coastal wolves in a group divergent from continental populations, as predicted based on hypothesized subspecies designations. Two novel haplotypes also were uncovered in a newly assayed continental population of interior Alaska wolves. CONCLUSIONS/SIGNIFICANCE: We found evidence that coastal wolves endemic to these temperate rainforests are diverged from neighbouring, interior continental wolves; a finding that necessitates new international strategies associated with the management of this species.

  16. Going coastal: Shared evolutionary history between coastal British Columbia and Southeast Alaska wolves (canis lupus)

    Science.gov (United States)

    Weckworth, B.V.; Dawson, N.G.; Talbot, S.L.; Flamme, M.J.; Cook, J.A.

    2011-01-01

    Background: Many coastal species occupying the temperate rainforests of the Pacific Northwest in North America comprise endemic populations genetically and ecologically distinct from interior continental conspecifics. Morphological variation previously identified among wolf populations resulted in recognition of multiple subspecies of wolves in the Pacific Northwest. Recently, separate genetic studies have identified diverged populations of wolves in coastal British Columbia and coastal Southeast Alaska, providing support for hypotheses of distinct coastal subspecies. These two regions are geographically and ecologically contiguous, however, there is no comprehensive analysis across all wolf populations in this coastal rainforest. Methodology/Principal Findings: By combining mitochondrial DNA datasets from throughout the Pacific Northwest, we examined the genetic relationship between coastal British Columbia and Southeast Alaska wolf populations and compared them with adjacent continental populations. Phylogenetic analysis indicates complete overlap in the genetic diversity of coastal British Columbia and Southeast Alaska wolves, but these populations are distinct from interior continental wolves. Analyses of molecular variation support the separation of all coastal wolves in a group divergent from continental populations, as predicted based on hypothesized subspecies designations. Two novel haplotypes also were uncovered in a newly assayed continental population of interior Alaska wolves. Conclusions/Significance: We found evidence that coastal wolves endemic to these temperate rainforests are diverged from neighbouring, interior continental wolves; a finding that necessitates new international strategies associated with the management of this species. ?? 2011 This is an open-access article.

  17. Going coastal: shared evolutionary history between coastal British Columbia and Southeast Alaska wolves (Canis lupus).

    Science.gov (United States)

    Weckworth, Byron V; Dawson, Natalie G; Talbot, Sandra L; Flamme, Melanie J; Cook, Joseph A

    2011-05-04

    Many coastal species occupying the temperate rainforests of the Pacific Northwest in North America comprise endemic populations genetically and ecologically distinct from interior continental conspecifics. Morphological variation previously identified among wolf populations resulted in recognition of multiple subspecies of wolves in the Pacific Northwest. Recently, separate genetic studies have identified diverged populations of wolves in coastal British Columbia and coastal Southeast Alaska, providing support for hypotheses of distinct coastal subspecies. These two regions are geographically and ecologically contiguous, however, there is no comprehensive analysis across all wolf populations in this coastal rainforest. By combining mitochondrial DNA datasets from throughout the Pacific Northwest, we examined the genetic relationship between coastal British Columbia and Southeast Alaska wolf populations and compared them with adjacent continental populations. Phylogenetic analysis indicates complete overlap in the genetic diversity of coastal British Columbia and Southeast Alaska wolves, but these populations are distinct from interior continental wolves. Analyses of molecular variation support the separation of all coastal wolves in a group divergent from continental populations, as predicted based on hypothesized subspecies designations. Two novel haplotypes also were uncovered in a newly assayed continental population of interior Alaska wolves. We found evidence that coastal wolves endemic to these temperate rainforests are diverged from neighbouring, interior continental wolves; a finding that necessitates new international strategies associated with the management of this species.

  18. 我国沿海核电发展态势、致灾因素分析及研究建议%Development Trend, Disaster Threats of Nuclear Power Plants in China’s Coastal Zone and Suggestions for Further Studies

    Institute of Scientific and Technical Information of China (English)

    侯西勇; 于良巨; 骆永明

    2014-01-01

    China’s energy demand has increased dramatically as the rapid social and economic development since the beginning of the Reform and opening-up policy. The problem of energy shortages in China’s eastern coastal area is more serious than that in the central and western China because more population and industries have been concentrated in the eastern coastal area. As a result, almost all the nuclear power plants have been built or under construction are locating in China’s coastal zone. However, the coastal zone has been suffered and will go on suffering more natural hazards than the central and western China, such as earthquake, tsunami, hurricane, storm surge, sea ice. A magnitude 9.0 earthquake took place near Japan’s northeast coast and triggered a large tsunami on March 2011, which led to the Fukushima nuclear leak. This major hazard brought about the intense discussion and controversy on nuclear security and future development of nuclear power plants globally. This paper reviewed the development of nuclear power and nuclear security at home and abroad, and analyzed the development tendency, conditions and disaster sources of nuclear power plants in China’s coastal zone;ifnally, some suggestions with respect to management strategy and academic studies were put forward in order to improve the security of nuclear power plants in China’s coastal zone.%改革开放以来,我国经济社会发展迅速,能源需求日益增加,尤其是东部沿海人口和产业不断积聚,能源不足问题的严重性远远超过中西部,这总体上决定了我国已建和在建核电厂全部位于海岸带区域的基本特征。但是,东部沿海遭受地震、海啸、台风、风暴潮等灾害的威胁十分突出,2011年3月,日本东北部海域9.0级地震引发巨大海啸,并导致福岛核电站的核泄漏,这一重大事件在全球范围引发了对核电安全及其未来发展的深入思考和争论。因此,本文从全球

  19. Radiological impact of TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident on invertebrates in the coastal benthic food web.

    Science.gov (United States)

    Sohtome, Tadahiro; Wada, Toshihiro; Mizuno, Takuji; Nemoto, Yoshiharu; Igarashi, Satoshi; Nishimune, Atsushi; Aono, Tatsuo; Ito, Yukari; Kanda, Jota; Ishimaru, Takashi

    2014-12-01

    Radioactive cesium ((134)Cs and (137)Cs) concentrations in invertebrates of benthic food web (10 taxonomic classes with 46 identified families) collected from wide areas off Fukushima Prefecture (3-500 m depth) were inspected from July 2011, four months after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, to August 2013 to elucidate time-series trends among taxa and areas. Cesium-137 was detected in seven classes (77% of 592 specimens). Higher (137)Cs concentrations within detected data were often found in areas near or south of the FDNPP, which is consistent with the reported spatial distribution of (137)Cs concentrations in highly contaminated seawater and sediments after the FDNPP accident. Overall (137)Cs concentrations in invertebrates, the maxima of which (290 Bq kg(-1)-wet in the sea urchin Glyptocidaris crenularis) were lower than in many demersal fishes, had decreased exponentially with time, and exhibited taxon-specific decreasing trends. Concentrations in Bivalvia and Gastropoda decreased clearly with respective ecological half-lives of 188 d and 102 d. In contrast, decreasing trends in Malacostraca and Polychaeta were more gradual, with longer respective ecological half-lives of 208 d and 487 d. Echinoidea showed no consistent trend, presumably because of effects of contaminated sediments taken into their digestive tract. Comparison of (137)Cs concentrations in the invertebrates and those in seawater and sediments suggest that contaminated sediments are the major source of continuing contamination in benthic invertebrates, especially in Malacostraca and Polychaeta.

  20. A field experiment demonstrating plant life-history evolution and its eco-evolutionary feedback to seed predator populations.

    Science.gov (United States)

    Agrawal, Anurag A; Johnson, Marc T J; Hastings, Amy P; Maron, John L

    2013-05-01

    The extent to which evolutionary change occurs in a predictable manner under field conditions and how evolutionary changes feed back to influence ecological dynamics are fundamental, yet unresolved, questions. To address these issues, we established eight replicate populations of native common evening primrose (Oenothera biennis). Each population was planted with 18 genotypes in identical frequency. By tracking genotype frequencies with microsatellite DNA markers over the subsequent three years (up to three generations, ≈5,000 genotyped plants), we show rapid and consistent evolution of two heritable plant life-history traits (shorter life span and later flowering time). This rapid evolution was only partially the result of differential seed production; genotypic variation in seed germination also contributed to the observed evolutionary response. Since evening primrose genotypes exhibited heritable variation for resistance to insect herbivores, which was related to flowering time, we predicted that evolutionary changes in genotype frequencies would feed back to influence populations of a seed predator moth that specializes on O. biennis. By the conclusion of the experiment, variation in the genotypic composition among our eight replicate field populations was highly predictive of moth abundance. These results demonstrate how rapid evolution in field populations of a native plant can influence ecological interactions.

  1. Plant population and habitat characteristics of the endemic Sonoran Desert cactus Peniocereus striatus in Organ Pipe Cactus National Monument, Arizona

    Science.gov (United States)

    Anderson, Greta; Rutman, Sue; Munson, Seth M.

    2010-01-01

    Peniocereus striatus (Brandegee) Buxb. (Cactaceae) is an endemic Sonoran Desert cactus that reaches its northern range limit in southwestern Arizona. One U.S. population occupies a small area of Organ Pipe Cactus National Monument near the U.S./Mexico international boundary, which has been monitored since 1939. An extensive survey conducted in 2002, covering 177 ha, resulted in the discovery of 88 new plants, in addition to the relocation of 57 plants found in previous surveys. Despite potential increases in population size and spatial distribution, mean plant height and number of basal stems has not significantly changed in recent years. Bud scars revealed that a majority of the population was sexually mature. Peniocereus striatus occurrence increased with decreasing slope, spanned every slope aspect, and was highest on rocky soils, but was noticeably low on west and northwest slopes and areas where severe land degradation had previously occurred. Over half of P. striatus plants were nursed by shrubs and subshrubs, while 40% occurred under leguminous trees. A severe frost in January 2002 top-killed 19% of the population, with the greatest damage in drainage bottoms. However, long-term (1944–2002) climate records show that there has been an overall increase in the number of frost free days in the region, which, coupled with land use change, has implications for the future health of this population.

  2. Interactions between a pollinating seed predator and its host plant: the role of environmental context within a population.

    Science.gov (United States)

    Kula, Abigail A R; Castillo, Dean M; Dudash, Michele R; Fenster, Charles B

    2014-07-01

    Plant-insect interactions often are important for plant reproduction, but the outcome of these interactions may vary with environmental context. Pollinating seed predators have positive and negative effects on host plant reproduction, and the interaction outcome is predicted to vary with density or abundance of the partners. We studied the interaction between Silene stellata, an herbaceous perennial, and Hadena ectypa, its specialized pollinating seed predator. Silene stellata is only facultatively dependent upon H. ectypa for pollination because other nocturnal moth co-pollinators are equally effective at pollen transfer. We hypothesized that for plants without conspecific neighbors, H. ectypa would have higher visitation rates compared to co-pollinators, and the plants would experience lower levels of H. ectypa pollen deposition. We predicted similar oviposition throughout the study site but greater H. ectypa predation in the area without conspecific neighbors compared to plants embedded in a naturally high density area. We found that H. ectypa had consistently higher visitation than moth co-pollinators in all host plant contexts. However, H. ectypa pollinator importance declined in areas with low conspecific density because of reduced pollen deposition, resulting in lower seed set. Conversely, oviposition was similar across the study site independent of host plant density. Greater likelihood of very high fruit predation combined with lower pollination by H. ectypa resulted in reduced S. stellata female reproductive success in areas with low conspecific density. Our results demonstrate local context dependency of the outcomes of pollinating seed predator interactions with conspecific host plant density within a population.

  3. Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton

    Directory of Open Access Journals (Sweden)

    Martin D. Oliveira

    2014-03-01

    Full Text Available Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton. The striped mealybug, Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae, is a widely distributed and polyphagous pest species, which naturally occurs on cotton plants in Brazil. This study evaluated the establishment and population growth as well as the within-plant distribution of F. virgata on four cotton cultivars: CNPA 7H (white fibers, BRS Verde, BRS Safira, and BRS Rubi (colored fibers. The experiment was conducted in a complete randomized design with four treatments (cultivars and 18 replications of each. Thus, cotton plants of each cultivar were infested with 100 newly hatched nymphs of F. virgata. The number of adult female mealybugs and the total number of mealybugs per plant were quantified, respectively, at 25 and 50 days after infestation. The developmental and pre-reproductive periods were also determined. Furthermore, we verified the distribution of F. virgata on the plant parts at 25 and 50 days after infestation. Ferrisia virgata showed similar growth of 412-fold in the four cotton cultivars studied. Also, the nymphs were spread on infested leaves; the secondgeneration nymphs were spread and established in all plant parts. Our results characterize F. virgata as having much potential as an important cotton pest in Brazil.

  4. Natural radionuclide of Po210 in the edible seafood affected by coal-fired power plant industry in Kapar coastal area of Malaysia

    Directory of Open Access Journals (Sweden)

    Mohamed Che Abd Rahim

    2011-05-01

    Full Text Available Abstract Background Po210 can be accumulated in various environmental materials, including marine organisms, and contributes to the dose of natural radiation in seafood. The concentration of this radionuclide in the marine environment can be influenced by the operation of a coal burning power plant but existing studies regarding this issue are not well documented. Therefore, the aim of this study was to estimate the Po210 concentration level in marine organisms from the coastal area of Kapar, Malaysia which is very near to a coal burning power plant station and to assess its impact on seafood consumers. Methods Concentration of Po210 was determined in the edible muscle of seafood and water from the coastal area of Kapar, Malaysia using radiochemical separation and the Alpha Spectrometry technique. Results The activities of Po210 in the dissolved phase of water samples ranged between 0.51 ± 0.21 and 0.71 ± 0.24 mBql-1 whereas the particulate phase registered a range of 50.34 ± 11.40 to 72.07 ± 21.20 Bqkg-1. The ranges of Po210 activities in the organism samples were 4.4 ± 0.12 to 6.4 ± 0.95 Bqkg-1 dry wt in fish (Arius maculatus, 45.7 ± 0.86 to 54.4 ± 1.58 Bqkg-1 dry wt in shrimp (Penaeus merguiensis and 104.3 ± 3.44 to 293.8 ± 10.04 Bqkg-1 dry wt in cockle (Anadara granosa. The variation of Po210 in organisms is dependent on the mode of their life style, ambient water concentration and seasonal changes. The concentration factors calculated for fish and molluscs were higher than the recommended values by the IAEA. An assessment of daily intake and received dose due to the consumption of seafood was also carried out and found to be 2083.85 mBqday-1person-1 and 249.30 μSvyr-1 respectively. These values are comparatively higher than reported values in other countries. Moreover, the transformation of Po210 in the human body was calculated and revealed that a considerable amount of Po210 can be absorbed in the internal organs. The

  5. 75 FR 13012 - Endangered and Threatened Wildlife and Plants: Threatened Status for Southern Distinct Population...

    Science.gov (United States)

    2010-03-18

    ... abundance of predatory birds and marine mammals that accompany these runs, in coastal rivers such as the... `` disappeared completely for years at a time, for approximately three decades, in the 1800s'' and that eulachon... 1830s 1860s, the record does not support the contention that eulachon ``disappeared'' completely...

  6. Human and crab exposure to mercury in the Caribbean coastal shoreline of Colombia: impact from an abandoned chlor-alkali plant.

    Science.gov (United States)

    Olivero-Verbel, Jesus; Johnson-Restrepo, Boris; Baldiris-Avila, Rosa; Güette-Fernández, Jorge; Magallanes-Carreazo, Elizabeth; Vanegas-Ramírez, Lenis; Kunihiko, Nakamura

    2008-05-01

    Human hair samples from male and female people aged 6-85 years, as well as muscle of crabs (Callinectes sapidus and Callinectes bocourti) were collected from different fishing places along the Caribbean coastal shoreline of Colombia and analyzed for total mercury (T-Hg) in order to establish the impact of mercury-polluted sediments in Cartagena bay on the ecosystem. Hair T-Hg in inhabitants varied between 0.1 and 21.8 microg/g, with average and median of 1.52 microg/g and 1.1 microg/g, respectively. Differences between sampling locations were significant (P<0.01) and median values decreased in the order: Caño del Oro (1.5 microg/g)plant. Although the T-Hg median for these people is equal to the threshold risk level recommended by U.S. EPA, this study highlights the fact that contaminated sediments are still driving the distribution of mercury through the food chain, allowing its accumulation in fishermen whose diet includes marine products as sources of protein.

  7. Numerical Modelling of Arctic Coastal Hydrodynamics and Sediment Transport

    OpenAIRE

    Borgersen, Benedicte T

    2016-01-01

    Coastal areas are experiencing an increase in human population and activities, both in temperate and in Arctic areas. This change in the coastal areas requires that the areas are safe and reliable in order to not put human lives and economical values in danger. To be about to protect the coastal areas it is important to know the hydrodynamics and sediment transport and their effect on coastal areas. Numerical modeling of coastal hydrodynamics and sediment transport is a normal approach to...

  8. Regional gene flow and population structure of the wind-dispersed plant species Hypochaeris radicata (Asteraceae) in an agricultural landscape.

    Science.gov (United States)

    Mix, C; Arens, P F P; Rengelink, R; Smulders, M J M; Van Groenendael, J M; Ouborg, N J

    2006-06-01

    Using microsatellites, we investigated population structure and gene flow of the short-lived, wind-dispersed plant species Hypochaeris radicata in a fragmented agricultural landscape where more than 99% of the nutrient-poor grasslands have disappeared over the last century. We sampled populations in the few remaining high density populations in conservation areas, as well as individuals that occurred, with lower densities, in linear landscape elements, at two spatial scales. In a re-inventory of the landscape, after 3 years, both extinctions and colonizations of populations were observed. Contrary to expectations, no differences in genetic diversity between high and low density populations were observed. Both types of populations had relatively high levels of diversity. Overall genetic differentiation (theta) was 0.04 and significantly different from zero (P aerodynamic models on seed dispersal of H. radicata. We discuss the consequences of these results for an evaluation of the probability of persistence of this species in the fragmented landscape.

  9. A survey of integrated coastal zone management experiences

    NARCIS (Netherlands)

    Stive, M.J.F.

    1995-01-01

    Coastal problems that stem from human activities are almost always rooted in resource use conflicts. Since the majority of the world's population lives in coastal areas, such conflicts can only be expected to increase. As population growth continues, the pressure to develop coastal areas for housing

  10. Influence of effluents from a Wastewater Treatment Plant on nutrient distribution in a coastal creek from southern Brazil

    Directory of Open Access Journals (Sweden)

    Isaac Rodrigues Santos

    2008-02-01

    Full Text Available The hypothesis that effluents treated through activated sludge process cause changes in nutrient biogeochemistry of receiving water bodies was investigated in Vieira creek, southern Brazil. Dissolved oxygen, suspended matter, and pH did not vary among the sampling stations. Nutrient, biochemical oxygen demand, and conductivity values were significantly higher downstream from the Wastewater Treatment Plant (WWTP effluents. Further downstream, nitrate concentrations were higher due to ammonium nitrification, organic matter remineralization and/or the occurrence of unidentified sources. Per capita nutrient emission factors were estimated to be 0.16 kg P.yr-1 and 4.14 kg N.yr-1. Under pristine conditions, low N:P ratios were observed, which were significantly increased downstream due to the high ammonium input. The mixing zone of the nitrogen-rich waters from Vieira creek with the phosphorus-enriched waters from Patos lagoon estuary was considered under high risk of eutrophication. The results could be useful for planning and management of WWTP-effluent receiving waters in temperate regions from developing countries.A hipótese de que efluentes urbanos tratados através de um sistema de lodo ativado causam alterações na qualidade de água de ambientes aquáticos foi investigada no Arroio Vieira, Rio Grande, RS. Amostras de água foram coletadas a montante e a jusante dos emissários de uma estação de tratamento de esgoto (ETE. Oxigênio, material em suspensão e pH não variaram espacialmente. Já os valores para os nutrientes e para a demanda bioquímica do oxigênio foram significativamente maiores a jusante dos efluentes. Mais a jusante, as concentrações de nitrato aumentam devido à nitrificação do nitrogênio amoniacal, remineralização da matéria orgânica e/ou ocorrência de outros aportes não-identificados. A emissão de nutrientes per capita após o tratamento dos efluentes domésticos (0.16 kg P ano-1 e 4.14 kg N ano-1

  11. Neotropical coastal wetlands

    Science.gov (United States)

    McKee, Karen L.; Batzer, Darold P.; Baldwin, Andrew H.

    2012-01-01

    The Neotropical region, which includes the tropical Americas, is one of the world's eight biogeographic zones. It contains some of the most diverse and unique wetlands in the world, some of which are still relatively undisturbed by humans. This chapter focuses on the northern segment of the Neotropics (south Florida, the Caribbean islands, Mexico, and Central America), an area that spans a latitudinal gradient from about 7 N to 29 N and 60 W to 112 W. Examples of coastal wetlands in this realm include the Everglades (Florida, USA), Ten Thousand Islands (Florida, USA), Laguna de Terminos (Mexico), Twin Cays (Belize), and Zapata Swamp (Cuba). Coastal wetlands are dominated by mangroves, which will be emphasized here, but also include freshwater swamps and marshes, saline marshes, and seagrass beds. The aim of this chapter is to provide a broad overview of Neotropical coastal wetlands of the North American continent, with an emphasis on mangroves, since this is the dominant vegetation type and because in-depth coverage of all wetland types is impossible here. Instead, the goal is to describe the environmental settings, plant and animal communities, key ecological controls, and some conservation concerns, with specific examples. Because this book deals with wetlands of North America, this chapter excludes coastal wetlands of South America. However, much of the information is applicable to mangrove, marsh, and seagrass communities of other tropicaI regions.

  12. Survey of population health in towns with nuclear and fossil fuel power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, E.; Shubik, V. M.

    2004-07-01

    Comparative assessment of population health in Sosnovy Bor with nuclear power plant and Kirovsk with fossil fuel power station was made for public and administration information. Both towns are located in Leningrad administrative region at 150 km distance from each other. In nuclear power town radiological situation was assessed as normal and in Kirovsk up to 1995 yr. with coal fuel, maximum permissible levels of suspended particle of sulfur oxide in atmosphere were exceeded in 6-9% of samples. After 1995 yr. the natural gas was used as fuel. Demographic data for 1991-2000 yrs indicate that mortality including infants mortality and stillborns was lower in Sosnovy Bor (NOS) then in Kirovsk (fossil fuel) and on average Leningrad administrative region. Birth rate and population growth was higher in Sosnovy Bor at the same time surprisingly the recorded morbidity was higher in Sosnovy Bor which might be explained by extensive medical supervision and improved diagnostics. However, cancer and tuberculosis morbidity was lower in Sosnovy Bor. In Kirovsk in 1997-2000 yrs. oncological morbidity was higher on average comparing to Leningrad administrative region. Oncological mortality in Sosnovy Bor in 1997-2000 yrs. was lower than in Kirovsk and Leningrad region Standardized annual mortality in Sosnovy Bor, Kirovsk and Leningrad administrative region was 128.3, 209.6 and 211.7 on 100 000 respectively. Health state of pregnant women, deliveries, new-born condition were all in normal range in Sosnovy Bor, contrary to higher increased abortion rate and pregnancy complications in Kirovsk. These findings need further studies. (Author)

  13. Permanent colonization of creek sediments, creek water and limnic water plants by four Listeria species in low population densities.

    Science.gov (United States)

    Lang-Halter, Evi; Schober, Steffen; Scherer, Siegfried

    2016-09-01

    During a 1-year longitudinal study, water, sediment and water plants from two creeks and one pond were sampled monthly and analyzed for the presence of Listeria species. A total of 90 % of 30 sediment samples, 84 % of 31 water plant samples and 67 % of 36 water samples were tested positive. Generally, most probable number counts ranged between 1 and 40 g-1, only occasionally >110 cfu g-1 were detected. Species differentiation based on FT-IR spectroscopy and multiplex PCR of a total of 1220 isolates revealed L. innocua (46 %), L. seeligeri (27 %), L. monocytogenes (25 %) and L. ivanovii (2 %). Titers and species compositions were similar during all seasons. While the species distributions in sediments and associated Ranunculus fluitans plants appeared to be similar in both creeks, RAPD typing did not provide conclusive evidence that the populations of these environments were connected. It is concluded that (i) the fresh-water sediments and water plants are year-round populated by Listeria, (ii) no clear preference for growth in habitats as different as sediments and water plants was found and (iii) the RAPD-based intraspecific biodiversity is high compared to the low population density.

  14. Current use of wild plants with edible underground storage organs in a rural population of Patagonia: between tradition and change.

    Science.gov (United States)

    Ochoa, Juan José; Ladio, Ana Haydee

    2015-09-25

    Edible plants with underground storage organs (USOs) are neglected resources. We studied the local ecological knowledge edible plants with (USOs) in rural populations of North-Patagonia in order to establish how people are utilizing these plants. Some aspect of corpus-praxis-cosmos complex associated to the local ecological knowledge was documented and discussed. In addition, variation in this ecological knowledge due to age, gender, family structure, ethnic self-determination was also evaluated. Semi-structured interviews were conducted with 51 inhabitants in order to study the relationship between the current use of plants with USOs and the age, sex, family group composition and ethnic self-identification of interviewees. In addition, the Cultural Importance Index for each species was calculated. The current richness of known species in these populations is a total of 9 plants. Plants with USOs tend to be used more frequently as the age of the interviewee increases. Women and men showed no differences in the average richness of species cited. The interviewees who share their homes with other generations use these plants more frequently than those who live alone. Our results indicate that the interviewees who identified themselves as belonging to the Mapuche people use these plants more frequently. For the Mapuche people, wild plants have constituted material and symbolic resources of great importance in their historical subsistence. In addition, they are currently being redefined as elements which present a connection with ancestral practices, produce a strong relationship with the 'land', and become markers which identify the 'natural' (historical) ways of their people; these are key elements in the current political processes of identity revaluation. This research is valuable to stimulate cultural revival and health promotion programs in the communities with their own local, cultural food.

  15. EPR pilot study on the population of Stepnogorsk city living in the vicinity of a uranium processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Zhumadilov, Kassym; Akilbekov, Abdirash; Morzabayev, Aidar [L.N. Gumilyov Eurasian National University, Astana (Kazakhstan); Ivannikov, Alexander; Stepanenko, Valeriy [Medical Radiological Research Center, Obninsk (Russian Federation); Abralina, Sholpan; Sadvokasova, Lyazzat; Rakhypbekov, Tolebay [Semey State Medical University, Semey (Kazakhstan); Hoshi, Masaharu [Hiroshima University, Research Institute for Radiation Biology and Medicine, Hiroshima (Japan)

    2015-03-15

    The aim of this pilot study was to evaluate possible doses in teeth received by workers of a uranium processing plant, in excess to the natural background dose. For this, the electron paramagnetic resonance dosimetry method was applied. Absorbed doses in teeth from the workers were compared with those measured in teeth from the Stepnogorsk city population and a control pool population from Astana city. The measured tooth samples were extracted according to medical indications. In total, 32 tooth enamel samples were analyzed, 5 from Astana city, Kazakhstan (control population), 21 from the residents of Stepnogorsk city (180 km from Astana city), and 6 from the workers of a uranium processing plant. The estimated doses in tooth enamel from the uranium processing plant workers were not significantly different to those measured in enamel from the control population. In teeth from the workers, the maximum dose in excess to background dose was 33 mGy. In two teeth from residents of Stepnogorsk city, however, somewhat larger doses were measured. The results of this pilot study encourage further investigations in an effort to receiving a final conclusion on the exposure situation of the uranium processing plant workers and the residents of Stepnogorsk city. (orig.)

  16. Emergence of Competitive Dominant Ammonia-Oxidizing Bacterial Populations in a Full-Scale Industrial Wastewater Treatment Plant

    Science.gov (United States)

    Layton, Alice C.; Dionisi, Hebe; Kuo, H.-W.; Robinson, Kevin G.; Garrett, Victoria M.; Meyers, Arthur; Sayler, Gary S.

    2005-01-01

    Ammonia-oxidizing bacterial populations in an industrial wastewater treatment plant were investigated with amoA and 16S rRNA gene real-time PCR assays. Nitrosomonas nitrosa initially dominated, but over time RI-27-type ammonia oxidizers, also within the Nitrosomonas communis lineage, increased from below detection to codominance. This shift occurred even though nitrification remained constant. PMID:15691975

  17. Population dynamics in wastewater treatment plants with enhanced biological phosphorus removal operated with and without nitrogen removal

    DEFF Research Database (Denmark)

    Lee, N.; Jansen, J.l.C.; Aspegren, H.

    2002-01-01

    The population dynamics of activated sludge in a pilot plant with two activated sludge systems, both designed for enhanced biological phosphorus removal (EBPR), but one of them with (BNP) and the other without (BP) nitrogen removal, was monitored during a period of 2.5 years. The influent water...

  18. Emergence of Competitive Dominant Ammonia-Oxidizing Bacterial Populations in a Full-Scale Industrial Wastewater Treatment Plant

    OpenAIRE

    Layton, Alice C.; Dionisi, Hebe; Kuo, H.-W.; Robinson, Kevin G; Garrett, Victoria M.; Meyers, Arthur; Sayler, Gary S.

    2005-01-01

    Ammonia-oxidizing bacterial populations in an industrial wastewater treatment plant were investigated with amoA and 16S rRNA gene real-time PCR assays. Nitrosomonas nitrosa initially dominated, but over time RI-27-type ammonia oxidizers, also within the Nitrosomonas communis lineage, increased from below detection to codominance. This shift occurred even though nitrification remained constant.

  19. How TK-TD and population models for aquatic macrophytes could support the risk assessment for plant protection products

    NARCIS (Netherlands)

    Hommen, U.; Schmitt, W.; Heine, S.; Brock, T.C.M.; Duquesne, S.; Manson, P.; Meregali, G.; Ochoa-Acuna, H.; Vliet, van P.; Arts, G.H.P.

    2016-01-01

    This case study of the SETAC workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field wat

  20. Trends in Coastal Development and Land Cover Change: The Case ...

    African Journals Online (AJOL)

    South Africa. Keywords: Land cover change, coastal management, coastal development, ... population growth, social and economic development and climate-induced factors. The results ... changing in response to human demands and needs ...

  1. Degradation of marine habitats and coastal management framework

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.

    environmental degradation. Major driving forces for coastal degradation include (1) high rate of growth in population leading to reclamation of coastal areas and release of wastes, (2) over-fishing due to lack of alternative livelihoods, (3) large commercial...

  2. Population Genetic Structure of the Medicinal Plant Vitex rotundifolia in China: Implications for its Use and Conservation

    Institute of Scientific and Technical Information of China (English)

    Yuan Hu; Yu Zhu; Qiao-Yan Zhang; Hai-Liang Xin; Lu-Ping Qin; Bao-Rong Lu; Khalid Rahman; Han-Chen Zheng

    2008-01-01

    Vitexrotundifolia L.is an important plant species used in traditional Chinese medicine.For its efficient use and conservation,genetic diversity and clonal variation of V.rotundifolia populations in China were investigated using inter-simple sequence repeat markers.Fourteen natural populations were included to estimate genetic diversity,and a large population with 135 individuals was used to analyze clonal variation and fine-scale spatial genetic structure.The overall genetic diversity (GD) of V.rotundifolia populations in China was moderate (GD=0.190),with about 40% within-population variation.Across all populations surveyed,the average within-population diversity was moderate (P = 22.6%; GD = 0.086).A relatively high genetic differentiation (Gst=0.587)among populations was detected based on the analysis of molecular variance data.Such characteristics of V.rotundifolia are likely attributed to its sexual/asexual reproduction and limited gene flow.The genotypic diversity (D=0.992) was greater than the average values of a clonal plant,indicating its significant reproduction through seedlings.Spatial autocorrelation analysis showed a clear within-population structure with gene clusters of approximately 20 m.Genetic diversity patterns of V.rotundifolia in China provide a useful guide for its efficient use and conservation by selecting particular populations displaying greater variation that may contain required medicinal compounds,and by sampling individuals in a population at >20 m spatial intervals to avoid collecting individuals with identical or similar genotypes.

  3. Pseudohypericin and Hyperforin in Hypericum perforatum from Northern Turkey: Variation among Populations, Plant Parts and Phenological Stages

    Institute of Scientific and Technical Information of China (English)

    Cüneyt ?irak; Jolita Radusiene; Valdimaras Janulis; Liudas Ivanauskas

    2008-01-01

    Hypericum perforatum is a perennial medicinal plant known as "St. John's wort" in Western Europe and has been used in the treatment of several diseases for centuries. In the present study, morphologic, phenologic and population variability in pseudohypericin and hyperforin concentrations among H. perforatum populations from Northern Turkey was investigated for the first time. The aerial parts of H. perforatum plants representing a total of 30 individuals were collected at full flowering from 10 sites of Northern Turkey to search the regional variation in the secondary metabolits concentrations. For morphologic and phenologic sampling, plants from one site were gathered in five phenological stages: vegetative,floral budding, full flowering, fresh fruiting and mature fruiting. The plant materials were air-dried at room temperature and subsequently assayed for chemical concentrations by high performance liquid chromatography. Secondary metabolite concentrations ranged from traces to 2.94mg/g dry weight (DW) for pseudohypedcin and traces -6.29mg/g DW for hyperforin. The differences in the secondary metabolite concentrations among populations of H. perforatum were found to be significant. The populations varied greatly in hyperforin concentrations, whereas they produced a similar amount of pseudohypericin. Concentrations of both secondary metabolites in all tissues increased with advancing of plant development and higher accumulation levels were reached at flowering. Among different tissues, full opened flowers were found to be superior to stems, leaves and the other reproductive parts with regard to pseudohypericin and hyperforin accumulations. The present findings might be useful to optimize the processing methodology of wild-harvested plant material and obtain Increased concentrations of these secondary metabolites.

  4. 磁暴对沿海核电站变压器安全影响的研究%Study on the Impact of Magnetic Storm on Security of Transformers in Coastal Nuclear Plants

    Institute of Scientific and Technical Information of China (English)

    刘连光; 原丽; 王智冬; 郑宽; 冯学尚

    2011-01-01

    The geomagnetically induced current (CIC) caused by magnetic storm would damage transformers directly and disturb relay protections or some other equipments indirectly, and strong magnetic storm could threaten the security of power system. For verifying the magnetic storm impact on the transformers in coastal nuclear plants, a mass of GIC data was collected and statistically analyzed, which included the measured GIC data in Guangdong Lingao nuclear power plant and Jiangsu Shanghe substation and the calculated GIC data in Northwest 750 kV power grid ( all the data above happened at the peak of 23rd solar cycle during the strong magnetic storm). The differences of the transformer's GIC between coastal nuclear power plant and inland substation and their reasons were mainly studied. The result indicates that the transformers in coastal nuclear power plants are more vulnerable to the magnetic storm impact due to the influence of the coastal effect. On this basis, the possible impacts and risks of extreme magnetic storm on the large-scale power system are assessed preliminarily, and it is suggested that the impact of magnetic storm should be assessed while selecting nuclear power plants location and transformers type.%磁暴产生的地磁感应电流(GIC)直接损伤变压器和间接干扰继电保护等设备,强磁暴可能威胁到电网的安全运行.为探明磁暴对沿海核电站变压器的影响,对第23太阳周峰年强磁暴侵害广东岭澳核电站、江苏上河变电站的GIC测量数据,以及西北陕甘青宁750 kV电网计算数据进行统计分析,研究沿海核电站与内陆变电站变压器GIC大小及其差异原因.结果表明,由于受海岸效应现象的影响,沿海核电站的变压器更容易遭受磁暴的侵害.在此基础上,对极端磁暴的可能危害、灾害风险以及沿海核电站的磁暴灾害进行评估,并建议核电站选址和变压器选型时应评估磁暴的影响.

  5. Genetic Diversity and Population Structure of the Rare and Endangered Plant Species Pulsatilla patens (L.) Mill in East Central Europe.

    Science.gov (United States)

    Szczecińska, Monika; Sramko, Gabor; Wołosz, Katarzyna; Sawicki, Jakub

    2016-01-01

    Pulsatilla patens s.s. is a one of the most endangered plant species in Europe. The present range of this species in Europe is highly fragmented and the size of the populations has been dramatically reduced in the past 50 years. The rapid disappearance of P. patens localities in Europe has prompted the European Commission to initiate active protection of this critically endangered species. The aim of this study was to estimate the degree and distribution of genetic diversity within European populations of this endangered species. We screened 29 populations of P. patens using a set of six microsatellite primers. The results of our study indicate that the analyzed populations are characterized by low levels of genetic diversity (Ho = 0.005) and very high levels of inbreeding (FIS = 0.90). These results suggest that genetic erosion could be partially responsible for the lower fitness in smaller populations of this species. Private allelic richness was very low, being as low as 0.00 for most populations. Average genetic diversity over loci and mean number of alleles in P. patens populations were significantly correlated with population size, suggesting severe genetic drift. The results of AMOVA point to higher levels of variation within populations than between populations.The results of Structure and PCoA analyses suggest that the genetic structure of the studied P. patens populations fall into three clusters corresponding to geographical regions. The most isolated populations (mostly from Romania) formed a separate group with a homogeneous gene pool located at the southern, steppic part of the distribution range. Baltic, mostly Polish, populations fall into two genetic groups which were not fully compatible with their geographic distribution.Our results indicate the serious genetic depauperation of P. patens in the western part of its range, even hinting at an ongoing extinction vortex. Therefore, special conservation attention is required to maintain the populations

  6. Molecular Genetic Variation in a Clonal Plant Population of Leymus chinensis (Trin.) Tzvel.

    Institute of Scientific and Technical Information of China (English)

    Yu-Sheng WANG; Li-Ming ZHAO; Hua WANG; Jie WANG; Da-Ming HUANG; Rui-Min HONG; Xiao-Hua TENG; Nakamura MIKI

    2005-01-01

    Randomly amplified polymorphic DNA (RAPD) analysis was used to investigate the genetic variation among populations, between populations, and within populations, relationships between genetic distance and geographic distance, and the molecular variation and population size. The effects of geographic and genetic distances, as well as of genetic differentiation and population size, on genetic variations of Leymus chinensis (Trin.) Tzvel. are discussed. The present study showed that there was significant RAPD variation between the Baicheng region population and the Daqing region population, with a molecular variance of 6.35% (P < 0.04), and for differentiation among area populations of the Daqing region, with a molecular variance of 8.78% (P < 0.002). A 21.06% RAPD variation among all 16 populations among two regions was found (P < 0.001), as well as 72.59% variation within populations (P < 0.001). Molecular variation within populations was significantly different among 16 populations.

  7. Mixing plants from different origins to restore a declining population: ecological outcomes and local perceptions 10 years later.

    Science.gov (United States)

    Maurice, Anne-Claire; Abdelkrim, Jawad; Cisel, Matthieu; Zavodna, Monika; Bardin, Philippe; Matamoro, Alexis; Dumez, Richard; Machon, Nathalie

    2013-01-01

    Populations of the Large-flowered Sandwort (Arenaria grandiflora L.) in the Fontainebleau forest (France) have declined rapidly during the last century. Despite the initiation of a protection program in 1991, less than twenty individuals remained by the late 1990s. The low fitness of these last plants, which is likely associated with genetic disorders and inbreeding depression, highlighted the need for the introduction of non-local genetic material to increase genetic diversity and thus restore Fontainebleau populations. Consequently, A. grandiflora was introduced at three distant sites in the Fontainebleau forest in 1999. Each of these populations was composed of an identical mix of individuals of both local and non-local origin that were obtained through in vitro multiplication. After establishment, the population status (number of individuals, diameter of the plants, and number of flowers) of the introduced populations was monitored. At present, two populations (one of which is much larger than the other) persist, while the third one became extinct in 2004. Analyses of the ecological parameters of the introduction sites indicated that differences in soil pH and moisture might have contributed to the differences in population dynamics. This introduction plan and its outcome attracted interest of local community, with those who supported the plan and regarded its 10-year result as a biological success (i.e., persistent populations were created), but also those who expressed reservations or disapproval of the plan and its outcome. To understand this controversy, a sociological study involving 27 semi-structured interviews was carried out. From these interviews emerged three areas of controversy: alteration of the identity of the plant, alteration of the identity of its territory, and the biological and ethical consequences of the techniques used for the experimental conservation.

  8. Mixing plants from different origins to restore a declining population: ecological outcomes and local perceptions 10 years later.

    Directory of Open Access Journals (Sweden)

    Anne-Claire Maurice

    Full Text Available Populations of the Large-flowered Sandwort (Arenaria grandiflora L. in the Fontainebleau forest (France have declined rapidly during the last century. Despite the initiation of a protection program in 1991, less than twenty individuals remained by the late 1990s. The low fitness of these last plants, which is likely associated with genetic disorders and inbreeding depression, highlighted the need for the introduction of non-local genetic material to increase genetic diversity and thus restore Fontainebleau populations. Consequently, A. grandiflora was introduced at three distant sites in the Fontainebleau forest in 1999. Each of these populations was composed of an identical mix of individuals of both local and non-local origin that were obtained through in vitro multiplication. After establishment, the population status (number of individuals, diameter of the plants, and number of flowers of the introduced populations was monitored. At present, two populations (one of which is much larger than the other persist, while the third one became extinct in 2004. Analyses of the ecological parameters of the introduction sites indicated that differences in soil pH and moisture might have contributed to the differences in population dynamics. This introduction plan and its outcome attracted interest of local community, with those who supported the plan and regarded its 10-year result as a biological success (i.e., persistent populations were created, but also those who expressed reservations or disapproval of the plan and its outcome. To understand this controversy, a sociological study involving 27 semi-structured interviews was carried out. From these interviews emerged three areas of controversy: alteration of the identity of the plant, alteration of the identity of its territory, and the biological and ethical consequences of the techniques used for the experimental conservation.

  9. Genetic rescue persists beyond first-generation outbreeding in small populations of a rare plant

    National Research Council Canada - National Science Library

    Yvonne Willi; Mark van Kleunen; Stefan Dietrich; Markus Fischer

    2007-01-01

    .... St