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Sample records for alien annual plants

  1. Competition between alien annual grasses and native annual plants in the Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.

    2000-01-01

    Alien annual grasses in the genera Bromus and Schismus are widespread and abundant in the Mojave Desert, and negative correlations between these aliens and native annual plants suggest that competition may occur between them. Effects of competition were evaluated by thinning alien annual grass seedlings and measuring the responses of native annual plants at three sites in the central, southcentral and southwestern Mojave Desert during 2 y of contrasting plant productivity. Effects of Bromus and Schismus were evaluated separately in the microhabitat where each was most abundant, beneath the north side of creosote bushes (Larrea tridentata) for Bromus and in the open interspace between shrubs for Schismus. Thinning of Bromus and Schismus significantly increased density and biomass of native annuals at all three sites, only during a year of high annual plant productivity and species richness. Effects of thinning were greatest for Amsinckia tesselata and for a group of relatively uncommon native annuals. Thinning also significantly increased the density and biomass of the alien forb, Erodium cicutarium. These results show that alien annual grasses can compete with native annual plants and an alien forb in the Mojave Desert and that effects can vary among years.

  2. Dominance and environmental correlates of alien annual plants in the Mojave Desert, USA

    USGS Publications Warehouse

    Brooks, M.L.; Berry, K.H.

    2006-01-01

    Land managers are concerned about the negative effects of alien annual plants on native plants, threatened and endangered species such as the desert tortoise (Gopherus agassizii), and ecosystem integrity in the Mojave Desert. Management of alien plants is hampered by a lack of information regarding the dominance and environmental correlates of these species. The results of this study indicate that alien plant species comprised a small fraction of the total annual plant flora, but most of the annual plant community biomass. When rainfall was high in 1995, aliens comprised 6% of the flora and 66% of the biomass. When rainfall was low in 1999, aliens comprised 27% of the flora and 91% of the biomass. Bromus rubens, Schismus spp. (S. arabicus and S. barbatus), and Erodium cicutarium were the predominant alien species during both years, comprising 99% of the alien biomass. B. rubens was more abundant in relatively mesic microhabitats beneath shrub canopies and at higher elevations above 800-1000 m, whereas Schismus spp. and E. cicutarium were more abundant in the relatively arid interspaces between shrubs, and, for Schismus spp., at lower elevations as well. Disturbance variables were more reliable indicators of alien dominance than were productivity or native plant diversity variables, although relationships often varied between years of contrasting rainfall. The strongest environmental correlates occurred between dirt road density and alien species richness and biomass of E. cicutarium, and between frequency and size of fires and biomass of B. rubens.

  3. Effects of increased soil nitrogen on the dominance of alien annual plants in the Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.

    2003-01-01

    1. Deserts are one of the least invaded ecosystems by plants, possibly due to naturally low levels of soil nitrogen. Increased levels of soil nitrogen caused by atmospheric nitrogen deposition may increase the dominance of invasive alien plants and decrease the diversity of plant communities in desert regions, as it has in other ecosystems. Deserts should be particularly susceptible to even small increases in soil nitrogen levels because the ratio of increased nitrogen to plant biomass is higher compared with most other ecosystems. 2. The hypothesis that increased soil nitrogen will lead to increased dominance by alien plants and decreased plant species diversity was tested in field experiments using nitrogen additions at three sites in the in the Mojave Desert of western North America. 3. Responses of alien and native annual plants to soil nitrogen additions were measured in terms of density, biomass and species richness. Effects of nitrogen additions were evaluated during 2 years of contrasting rainfall and annual plant productivity. The rate of nitrogen addition was similar to published rates of atmospheric nitrogen deposition in urban areas adjacent to the Mojave Desert (3.2 g N m-2 year-1). The dominant alien species included the grasses Bromus madritensis ssp. rubens and Schismus spp. (S. arabicus and S. barbatus) and the forb Erodium cicutarium. 4. Soil nitrogen addition increased the density and biomass of alien annual plants during both years, but decreased density, biomass and species richness of native species only during the year of highest annual plant productivity. The negative response of natives may have been due to increased competitive stress for soil water and other nutrients caused by the increased productivity of aliens. 5. The effects of nitrogen additions were significant at both ends of a natural nutrient gradient, beneath creosote bush Larrea tridentata canopies and in the interspaces between them, although responses varied among individual

  4. Habitat invasibility and dominance by alien annual plants in the western Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.

    1999-01-01

    Patterns of habitat invasibility and alien dominance, respectively measured as species richness and biomass of alien annual plants, were evaluated in association with four habitat factors at the Desert Tortoise Research Natural Area (DTNA) in the western Mojave Desert, USA. Habitat factors varied in levels of disturbance outside (high) and inside (low) the DTNA, and in levels of soil nutrients in washlet (high) and hummock (low) topographic positions, in Larrea-north (high), Larrea-south (medium), and interspace (low) microhabitats near creosote bushes (Larrea tridentata), and during 1995 when rainfall was 207% (high) and 1994 when rainfall was 52% (low) of the long-term average. Dominant alien plants included the annual grasses Bromus rubens, Bromus trinii, and Schismus spp., and the forb Erodium cicutarium. Species richness and dominance of alien annual plants were slightly higher where disturbance was high, and much higher where soil nutrients were high. B. rubens and B. trinii were most dominant in washlets and in the Larrea-north microhabitats during both years. These two species evolved in mesic ecosystems, and appeared to be particularly limited by soil nutrients at this site. Schismus spp. and E. cicutarium were also most dominant in washlets, but their dominance varied between interspaces in 1994 and the Larrea-south microhabitat in 1995. Monitoring to detect the invasion of new annual plants should focus on regions of high rainfall and nitrogen deposition and on washes and beneath-canopy microhabitats. The ecological range of each alien species should be evaluated separately, because their evolutionary origins may greatly affect their patterns of invasion and dominance in the Mojave Desert.

  5. Characteristics of successful alien plants.

    PubMed

    van Kleunen, M; Dawson, W; Maurel, N

    2015-05-01

    Herbert Baker arguably initiated the search for species characteristics determining alien plant invasion success, with his formulation of the 'ideal weed'. Today, a profusion of studies has tested a myriad of traits for their importance in explaining success of alien plants, but the multiple, not always appropriate, approaches used have led to some confusion and criticism. We argue that a greater understanding of the characteristics explaining alien plant success requires a refined approach that respects the multistage, multiscale nature of the invasion process. We present a schema of questions we can ask regarding the success of alien species, with the answering of one question in the schema being conditional on the answer of preceding questions (thus acknowledging the nested nature of invasion stages). For each question, we identify traits and attributes of species we believe are likely to be most important in explaining species success, and we make predictions as to how we expect successful aliens to differ from natives and from unsuccessful aliens in their characteristics. We organize the findings of empirical studies according to the questions in our schema that they have addressed, to assess the extent to which they support our predictions. We believe that research on plant traits of alien species has already told us a lot about why some alien species become successful after introduction. However, if we ask the right questions at the appropriate scale and use appropriate comparators, research on traits may tell us whether they are really important or not, and if so under which conditions. PMID:25421056

  6. Effects of livestock watering sites on alien and native plants in the Mojave Desert, USA

    USGS Publications Warehouse

    Brooks, M.L.; Matchett, J.R.; Berry, K.H.

    2006-01-01

    Increased livestock densities near artificial watering sites create disturbance gradients called piospheres. We studied responses of alien and native annual plants and native perennial plants within 9 piospheres in the Mojave Desert of North America. Absolute and proportional cover of alien annual plants increased with proximity to watering sites, whereas cover and species richness of native annual plants decreased. Not all alien species responded the same, as the alien forb Erodium cicutarium and the alien grass Schismus spp. increased with proximity to watering sites, and the alien annual grass Bromus madritensis ssp. rubens decreased. Perennial plant cover and species richness also declined with proximity to watering sites, as did the structural diversity of perennial plant cover classes. Significant effects were focused within 200 m of the watering sites, suggesting that control efforts for alien annual plants and restoration efforts for native plants should optimally be focused within this central part of the piosphere gradient.

  7. Fire and grazing impacts on plant diversity and alien plant invasions in the southern Sierra Nevada

    USGS Publications Warehouse

    Keeley, J.E.; Lubin, D.; Fotheringham, C.J.

    2003-01-01

    Patterns of native and alien plant diversity in response to disturbance were examined along an elevational gradient in blue oak savanna, chaparral, and coniferous forests. Total species richness, alien species richness, and alien cover declined with elevation, at scales from 1 to 1000 m2. We found no support for the hypothesis that community diversity inhibits alien invasion. At the 1-m2 point scale, where we would expect competitive interactions between the largely herbaceous flora to be most intense, alien species richness as well as alien cover increased with increasing native species richness in all communities. This suggests that aliens are limited not by the number of native competitors, but by resources that affect establishment of both natives and aliens. Blue oak savannas were heavily dominated by alien species and consistently had more alien than native species at the 1-m 2 scale. All of these aliens are annuals, and it is widely thought that they have displaced native bunchgrasses. If true, this means that aliens have greatly increased species richness. Alternatively, there is a rich regional flora of native annual forbs that could have dominated these grasslands prior to displacement by alien grasses. On our sites, livestock grazing increased the number of alien species and alien cover only slightly over that of sites free of livestock grazing for more than a century, indicating some level of permanency to this invasion. In chaparral, both diversity and aliens increased markedly several years after fire. Invasive species are rare in undisturbed shrublands, and alien propagules fail to survive the natural crown fires in these ecosystems. Thus, aliens necessarily must colonize after fire and, as a consequence, time since fire is an important determinant of invasive presence. Blue oak savannas are an important propagule source for alien species because they maintain permanent populations of all alien species encountered in postfire chaparral, and because

  8. Index of Alien Impact: A method for evaluating potential ecological impact of alien plant species

    EPA Science Inventory

    Alien plant species are stressors to ecosystems and indicators of reduced ecosystem integrity. The magnitude of the stress reflects not only the quantity of aliens present, but also the quality of their interactions with native ecosystems. We develop an Index of Alien Impact (IAI...

  9. Alien plant dynamics following fire in mediterranean-climate California shrublands

    USGS Publications Warehouse

    Keeley, J.E.; Baer-Keeley, M.; Fotheringham, C.J.

    2005-01-01

    Over 75 species of alien plants were recorded during the first five years after fire in southern California shrublands, most of which were European annuals. Both cover and richness of aliens varied between years and plant association. Alien cover was lowest in the first postfire year in all plant associations and remained low during succession in chaparral but increased in sage scrub. Alien cover and richness were significantly correlated with year (time since disturbance) and with precipitation in both coastal and interior sage scrub associations. Hypothesized factors determining alien dominance were tested with structural equation modeling. Models that included nitrogen deposition and distance from the coast were not significant, but with those variables removed we obtained a significant model that gave an R2 = 0.60 for the response variable of fifth year alien dominance. Factors directly affecting alien dominance were (1) woody canopy closure and (2) alien seed banks. Significant indirect effects were (3) fire intensity, (4) fire history, (5) prefire stand structure, (6) aridity, and (7) community type. According to this model the most critical factor influencing aliens is the rapid return of the shrub and subshrub canopy. Thus, in these communities a single functional type (woody plants) appears to the most critical element controlling alien invasion and persistence. Fire history is an important indirect factor because it affects both prefire stand structure and postfire alien seed banks. Despite being fire-prone ecosystems, these shrublands are not adapted to fire per se, but rather to a particular fire regime. Alterations in the fire regime produce a very different selective environment, and high fire frequency changes the selective regime to favor aliens. This study does not support the widely held belief that prescription burning is a viable management practice for controlling alien species on semiarid landscapes. ?? 2005 by the Ecological Society of

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

    USGS Publications Warehouse

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

    2011-01-01

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

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

    USGS Publications Warehouse

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

    2011-01-01

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

  12. Index of Alien Impact: A Method for Evaluating Potential Ecological Impact of Alien Plant Species

    NASA Astrophysics Data System (ADS)

    Magee, Teresa K.; Ringold, Paul L.; Bollman, Michael A.; Ernst, Ted L.

    2010-04-01

    Alien plant species are stressors to ecosystems and indicators of reduced ecosystem integrity. The magnitude of the stress reflects not only the quantity of aliens present, but also the quality of their interactions with native ecosystems. We develop an Index of Alien Impact ( IAI) to estimate the collective ecological impact of in situ alien species. IAI summarizes the frequency of occurrence and potential ecological impact ( Invasiveness-Impact Score ( I i )) of individual alien species for all aliens present in a particular location or community type. A component metric, I i , is based on ecological species traits (life history, ecological amplitude, and ability to alter ecosystem processes) that reflect mechanisms, which can increase impact to ecosystem structure and function. While I i is less complex than some other multi-metric rankings of alien impact, it compares well to these metrics and to qualitative judgments. IAI can be adapted for different ecological settings by modifying the set of species traits incorporated in I i to reflect properties likely to breach biotic and abiotic barriers or alter ecosystem function in a particular region or community type of interest. To demonstrate our approach, we created versions of IAI and I i , applicable to the diverse streamside vegetation of a river basin (19,631 km2) spanning low-elevation arid to mesic montane habitats in eastern Oregon, USA. In this demonstration effort, we (1) evaluate relationships of IAI to metrics describing invasion level, and (2) illustrate the potential utility of IAI for prioritizing alien species management activities and informing restoration goals.

  13. The impact of an alien plant on a native plant-pollinator network: an experimental approach.

    PubMed

    Lopezaraiza-Mikel, Martha E; Hayes, Richard B; Whalley, Martin R; Memmott, Jane

    2007-07-01

    Studies of pairwise interactions have shown that an alien plant can affect the pollination of a native plant, this effect being mediated by shared pollinators. Here we use a manipulative field experiment, to investigate the impact of the alien plant Impatiens glandulifera on an entire community of coflowering native plants. Visitation and pollen transport networks were constructed to compare replicated I. glandulifera invaded and I. glandulifera removal plots. Invaded plots had significantly higher visitor species richness, visitor abundance and flower visitation. However, the pollen transport networks were dominated by alien pollen grains in the invaded plots and consequently higher visitation may not translate in facilitation for pollination. The more generalized insects were more likely to visit the alien plant, and Hymenoptera and Hemiptera were more likely to visit the alien than Coleoptera. Our data indicate that generalized native pollinators can provide a pathway of integration for alien plants into native visitation systems. PMID:17542933

  14. Modelling Hotspots for Invasive Alien Plants in India.

    PubMed

    Adhikari, Dibyendu; Tiwary, Raghuvar; Barik, Saroj Kanta

    2015-01-01

    Identification of invasion hotspots that support multiple invasive alien species (IAS) is a pre-requisite for control and management of invasion. However, till recently it remained a methodological challenge to precisely determine such invasive hotspots. We identified the hotspots of alien species invasion in India through Ecological Niche Modelling (ENM) using species occurrence data from the Global Biodiversity Information Facility (GBIF). The predicted area of invasion for selected species were classified into 4 categories based on number of model agreements for a region i.e. high, medium, low and very low. About 49% of the total geographical area of India was predicted to be prone to invasion at moderate to high levels of climatic suitability. The intersection of anthropogenic biomes and ecoregions with the regions of 'high' climatic suitability was classified as hotspot of alien plant invasion. Nineteen of 47 ecoregions of India, harboured such hotspots. Most ecologically sensitive regions of India, including the 'biodiversity hotspots' and coastal regions coincide with invasion hotspots, indicating their vulnerability to alien plant invasion. Besides demonstrating the usefulness of ENM and open source data for IAS management, the present study provides a knowledge base for guiding the formulation of an effective policy and management strategy for controlling the invasive alien species. PMID:26230513

  15. Modelling Hotspots for Invasive Alien Plants in India

    PubMed Central

    Adhikari, Dibyendu; Tiwary, Raghuvar; Barik, Saroj Kanta

    2015-01-01

    Identification of invasion hotspots that support multiple invasive alien species (IAS) is a pre-requisite for control and management of invasion. However, till recently it remained a methodological challenge to precisely determine such invasive hotspots. We identified the hotspots of alien species invasion in India through Ecological Niche Modelling (ENM) using species occurrence data from the Global Biodiversity Information Facility (GBIF). The predicted area of invasion for selected species were classified into 4 categories based on number of model agreements for a region i.e. high, medium, low and very low. About 49% of the total geographical area of India was predicted to be prone to invasion at moderate to high levels of climatic suitability. The intersection of anthropogenic biomes and ecoregions with the regions of 'high' climatic suitability was classified as hotspot of alien plant invasion. Nineteen of 47 ecoregions of India, harboured such hotspots. Most ecologically sensitive regions of India, including the 'biodiversity hotspots' and coastal regions coincide with invasion hotspots, indicating their vulnerability to alien plant invasion. Besides demonstrating the usefulness of ENM and open source data for IAS management, the present study provides a knowledge base for guiding the formulation of an effective policy and management strategy for controlling the invasive alien species. PMID:26230513

  16. Recreational trails as corridors for alien plants in the Rocky Mountains, USA

    USGS Publications Warehouse

    Wells, Floye H.; Lauenroth, William K.; Bradford, John B.

    2012-01-01

    Alien plant species often use areas of heavy human activity for habitat and dispersal. Roads and utility corridors have been shown to harbor more alien species than the surrounding vegetation and are therefore believed to contribute to alien plant persistence and spread. Recreational trails represent another corridor that could harbor alien species and aid their spread. Effective management of invasive species requires understanding how alien plants are distributed at trailheads and trails and how their dispersal may be influenced by native vegetation. Our overall goal was to investigate the distribution of alien plants at trailheads and trails in the Rocky Mountains of Colorado. At trailheads, we found that although the number of alien species was less than the number of native species, alien plant cover ( x̄=50%) did not differ from native plant cover, and we observed a large number of alien seedlings in the soil seed bank, suggesting that alien plants are a large component of trailhead communities and will continue to be so in the future. Along trails, we found higher alien species richness and cover on trail (as opposed to 4 m from the trail) in 3 out of 4 vegetation types, and we observed higher alien richness and cover in meadows than in other vegetation types. Plant communities at both trailheads and trails, as well as seed banks at trailheads, contain substantial diversity and abundance of alien plants. These results suggest that recreational trails in the Rocky Mountains of Colorado may function as corridors that facilitate the spread of alien species into wildlands. Our results suggest that control of alien plants should begin at trailheads where there are large numbers of aliens and that control efforts on trails should be prioritized by vegetation type.

  17. New records in vascular plants alien to Kyrgyzstan

    PubMed Central

    2014-01-01

    Abstract A series of brief notes on distribution of vascular plants alien to Kyrgyzstan is presented. A further expansion of Anthemis ruthenica (Asteraceae), Crambe orientalis (Brassicaceae) and Salvia aethiopis (Lamiaceae) in northern and northwestern Kyrgyzstan is recorded. The first record of Chenopodium vulvaria (Amaranthaceae) from the northern side of Kyrgyz Range is confirmed, and the species was found for the second time in Alay Range. The ephemerous occurrence of Hirschfeldia incana (Brassicaceae) in Central Asia is recorded for the first time from Fergana Range. Tragus racemosus (Poaceae) is first recorded from the Chüy Depression as an ephemerous alien. Arrhenatherum elatius, escaped from cultivation and locally established, is new to the country. The second record of established occurrence of Centaurea solstitialis (Asteraceae) and an ephemerous occurrence of Glaucium corniculatum (Papaveraceae) are presented. Complete information is collected about the occurrence of every mentioned species in Kyrgyzstan. PMID:24855435

  18. Alien plant invasion in mixed-grass prairie: Effects of vegetation type and anthropogenic disturbance

    USGS Publications Warehouse

    Larson, D.L.; Anderson, P.J.; Newton, W.

    2001-01-01

    The ability of alien plant species to invade a region depends not only on attributes of the plant, but on characteristics of the habitat being invaded. Here, we examine characteristics that may influence the success of alien plant invasion in mixed-grass prairie at Theodore Roosevelt National Park, in western North Dakota, USA. The park consists of two geographically separate units with similar vegetation types and management history, which allowed us to examine the effects of native vegetation type, anthropogenic disturbance, and the separate park units on the invasion of native plant communities by alien plant species common to counties surrounding both park units. If matters of chance related to availability of propagules and transient establishment opportunities determine the success of invasion, park unit and anthropogenic disturbance should better explain the variation in alien plant frequency. If invasibility is more strongly related to biotic or physical characteristics of the native plant communities, models of alien plant occurrence should include vegetation type as an explanatory variable. We examined >1300 transects across all vegetation types in both units of the park. Akaike's Information Criterion (AIC) indicated that the fully parameterized model, including the interaction among vegetation type, disturbance, and park unit, best described the distribution of both total number of alien plants per transect and frequency of alien plants on transects where they occurred. Although all vegetation types were invaded by alien plants, mesic communities had both greater numbers and higher frequencies of alien plants than did drier communities. A strong element of stochasticity, reflected in differences in frequencies of individual species between the two park units, suggests that prediction of risk of invasion will always involve uncertainty. In addition, despite well-documented associations between anthropogenic disturbance and alien plant invasion, five of

  19. Seed dispersal networks in the Galápagos and the consequences of alien plant invasions

    PubMed Central

    Heleno, Ruben H.; Olesen, Jens M.; Nogales, Manuel; Vargas, Pablo; Traveset, Anna

    2013-01-01

    Alien plants are a growing threat to the Galápagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most dispersed invaders were Lantana camara, Rubus niveus and Psidium guajava, the latter two likely benefiting from an asynchronous fruit production with most native plants, which facilitate their consumption and spread. Lava lizards dispersed the seeds of 27 species, being the most important dispersers, followed by small ground finch, two mockingbirds, the giant tortoise and two insectivorous birds. Most animals dispersed alien seeds, but these formed a relatively small proportion of the interactions. Nevertheless, the integration of aliens was higher in the island that has been invaded for longest, suggesting a time-lag between alien plant introductions and their impacts on seed dispersal networks. Alien plants become more specialized with advancing invasion, favouring more simplified plant and disperser communities. However, only habitat type significantly affected the overall network structure. Alien plants were dispersed via two pathways: dry-fruited plants were preferentially dispersed by finches, while fleshy fruited species were mostly dispersed by other birds and reptiles. PMID:23173203

  20. Seed dispersal networks in the Galápagos and the consequences of alien plant invasions.

    PubMed

    Heleno, Ruben H; Olesen, Jens M; Nogales, Manuel; Vargas, Pablo; Traveset, Anna

    2013-01-01

    Alien plants are a growing threat to the Galápagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most dispersed invaders were Lantana camara, Rubus niveus and Psidium guajava, the latter two likely benefiting from an asynchronous fruit production with most native plants, which facilitate their consumption and spread. Lava lizards dispersed the seeds of 27 species, being the most important dispersers, followed by small ground finch, two mockingbirds, the giant tortoise and two insectivorous birds. Most animals dispersed alien seeds, but these formed a relatively small proportion of the interactions. Nevertheless, the integration of aliens was higher in the island that has been invaded for longest, suggesting a time-lag between alien plant introductions and their impacts on seed dispersal networks. Alien plants become more specialized with advancing invasion, favouring more simplified plant and disperser communities. However, only habitat type significantly affected the overall network structure. Alien plants were dispersed via two pathways: dry-fruited plants were preferentially dispersed by finches, while fleshy fruited species were mostly dispersed by other birds and reptiles. PMID:23173203

  1. Applications of remote sensing to alien invasive plant studies.

    PubMed

    Huang, Cho-Ying; Asner, Gregory P

    2009-01-01

    Biological invasions can affect ecosystems across a wide spectrum of bioclimatic conditions. Therefore, it is often important to systematically monitor the spread of species over a broad region. Remote sensing has been an important tool for large-scale ecological studies in the past three decades, but it was not commonly used to study alien invasive plants until the mid 1990s. We synthesize previous research efforts on remote sensing of invasive plants from spatial, temporal and spectral perspectives. We also highlight a recently developed state-of-the-art image fusion technique that integrates passive and active energies concurrently collected by an imaging spectrometer and a scanning-waveform light detection and ranging (LiDAR) system, respectively. This approach provides a means to detect the structure and functional properties of invasive plants of different canopy levels. Finally, we summarize regional studies of biological invasions using remote sensing, discuss the limitations of remote sensing approaches, and highlight current research needs and future directions. PMID:22408558

  2. Applications of Remote Sensing to Alien Invasive Plant Studies

    PubMed Central

    Huang, Cho-ying; Asner, Gregory P.

    2009-01-01

    Biological invasions can affect ecosystems across a wide spectrum of bioclimatic conditions. Therefore, it is often important to systematically monitor the spread of species over a broad region. Remote sensing has been an important tool for large-scale ecological studies in the past three decades, but it was not commonly used to study alien invasive plants until the mid 1990s. We synthesize previous research efforts on remote sensing of invasive plants from spatial, temporal and spectral perspectives. We also highlight a recently developed state-of-the-art image fusion technique that integrates passive and active energies concurrently collected by an imaging spectrometer and a scanning-waveform light detection and ranging (LiDAR) system, respectively. This approach provides a means to detect the structure and functional properties of invasive plants of different canopy levels. Finally, we summarize regional studies of biological invasions using remote sensing, discuss the limitations of remote sensing approaches, and highlight current research needs and future directions. PMID:22408558

  3. How do alien plants fit in the space-phylogeny matrix?

    PubMed

    Procheş, Şerban; Forest, Félix; Jose, Sarah; De Dominicis, Michela; Ramdhani, Syd; Wiggill, Timothy

    2015-01-01

    Recent advances in the field of plant community phylogenetics and invasion phylogenetics are mostly based on plot-level data, which do not take into consideration the spatial arrangement of individual plants within the plot. Here we use within-plot plant coordinates to investigate the link between the physical distance separating plants, and their phylogenetic relatedness. We look at two vegetation types (forest and grassland, similar in species richness and in the proportion of alien invasive plants) in subtropical coastal KwaZulu-Natal, South Africa. The relationship between phylogenetic distance and physical distance is weak in grassland (characterised by higher plant densities and low phylogenetic diversity), and varies substantially in forest vegetation (variable plant density, higher phylogenetic diversity). There is no significant relationship between the proportion of alien plants in the plots and the strength of the physical-phylogenetic distance relationship, suggesting that alien plants are well integrated in the local spatial-phylogenetic landscape. PMID:25893962

  4. How Do Alien Plants Fit in the Space-Phylogeny Matrix?

    PubMed Central

    Procheş, Şerban; Forest, Félix; Jose, Sarah; De Dominicis, Michela; Ramdhani, Syd; Wiggill, Timothy

    2015-01-01

    Recent advances in the field of plant community phylogenetics and invasion phylogenetics are mostly based on plot-level data, which do not take into consideration the spatial arrangement of individual plants within the plot. Here we use within-plot plant coordinates to investigate the link between the physical distance separating plants, and their phylogenetic relatedness. We look at two vegetation types (forest and grassland, similar in species richness and in the proportion of alien invasive plants) in subtropical coastal KwaZulu-Natal, South Africa. The relationship between phylogenetic distance and physical distance is weak in grassland (characterised by higher plant densities and low phylogenetic diversity), and varies substantially in forest vegetation (variable plant density, higher phylogenetic diversity). There is no significant relationship between the proportion of alien plants in the plots and the strength of the physical-phylogenetic distance relationship, suggesting that alien plants are well integrated in the local spatial-phylogenetic landscape. PMID:25893962

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

    PubMed

    Le Maitre, D C; Gush, M B; Dzikiti, S

    2015-01-01

    There have been many studies of the diverse impacts of invasions by alien plants but few have assessed impacts on water resources. We reviewed the information on the impacts of invasions on surface runoff and groundwater resources at stand to catchment scales and covering a full annual cycle. Most of the research is South African so the emphasis is on South Africa's major invaders with data from commercial forest plantations where relevant. Catchment studies worldwide have shown that changes in vegetation structure and the physiology of the dominant plant species result in changes in surface runoff and groundwater discharge, whether they involve native or alien plant species. Where there is little change in vegetation structure [e.g. leaf area (index), height, rooting depth and seasonality] the effects of invasions generally are small or undetectable. In South Africa, the most important woody invaders typically are taller and deeper rooted than the native species. The impacts of changes in evaporation (and thus runoff) in dryland settings are constrained by water availability to the plants and, thus, by rainfall. Where the dryland invaders are evergreen and the native vegetation (grass) is seasonal, the increases can reach 300-400 mm/year. Where the native vegetation is evergreen (shrublands) the increases are ∼200-300 mm/year. Where water availability is greater (riparian settings or shallow water tables), invading tree water-use can reach 1.5-2.0 times that of the same species in a dryland setting. So, riparian invasions have a much greater impact per unit area invaded than dryland invasions. The available data are scattered and incomplete, and there are many gaps and issues that must be addressed before a thorough understanding of the impacts at the site scale can be gained and used in extrapolating to watershed scales, and in converting changes in flows to water supply system yields. PMID:25935861

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

    PubMed Central

    Le Maitre, D. C.; Gush, M. B.; Dzikiti, S.

    2015-01-01

    There have been many studies of the diverse impacts of invasions by alien plants but few have assessed impacts on water resources. We reviewed the information on the impacts of invasions on surface runoff and groundwater resources at stand to catchment scales and covering a full annual cycle. Most of the research is South African so the emphasis is on South Africa's major invaders with data from commercial forest plantations where relevant. Catchment studies worldwide have shown that changes in vegetation structure and the physiology of the dominant plant species result in changes in surface runoff and groundwater discharge, whether they involve native or alien plant species. Where there is little change in vegetation structure [e.g. leaf area (index), height, rooting depth and seasonality] the effects of invasions generally are small or undetectable. In South Africa, the most important woody invaders typically are taller and deeper rooted than the native species. The impacts of changes in evaporation (and thus runoff) in dryland settings are constrained by water availability to the plants and, thus, by rainfall. Where the dryland invaders are evergreen and the native vegetation (grass) is seasonal, the increases can reach 300–400 mm/year. Where the native vegetation is evergreen (shrublands) the increases are ∼200–300 mm/year. Where water availability is greater (riparian settings or shallow water tables), invading tree water-use can reach 1.5–2.0 times that of the same species in a dryland setting. So, riparian invasions have a much greater impact per unit area invaded than dryland invasions. The available data are scattered and incomplete, and there are many gaps and issues that must be addressed before a thorough understanding of the impacts at the site scale can be gained and used in extrapolating to watershed scales, and in converting changes in flows to water supply system yields. PMID:25935861

  7. Spatial risk assessment of alien invasive plants in China.

    PubMed

    Bai, Fan; Chisholm, Ryan; Sang, Weiguo; Dong, Ming

    2013-07-16

    The large-scale distribution patterns of alien invasive plants (AIP) can provide key information and a theoretical basis for management strategies, including the prevention of invasions, the control and eradication of established AIPs, and the identification of areas at high risk of invasion. This study aims to quantify distribution patterns of AIP in China, to develop approaches that measure the social, economic, and ecological impacts, and to identify areas that are at higher risk of plant invasion. Based on published literature, there were 384 AIPs in China, representing 233 genera from 66 families. Climatic factors were among the primary factors determining AIPs' overall distribution patterns. The majority of AIPs were tropically distributed in China, meaning that they were mainly restricted to southern China. Temperate-distributed AIPs, those distributed only or predominantly in northern China, were fewer but had higher average rates of spread than tropically distributed AIPs. Average ecological and economic impact per AIP was negatively correlated with AIP richness, meaning that areas with relatively few AIPs nevertheless have some of the most detrimental ones. Our comparative evaluation showed that the risk of invasion differed among regions of China, with high-risk areas in southern China (Yunnan, Guangxi, and Guangdong) and central coastal areas of eastern China (Shandong, Hebei, and Jiangsu). In the context of climate change, areas around latitudes of 33° N, including Hebei, Shandong, Henan, and Jiangsu, should be given more attention for the control and prevention of plant invasions. Predictions of high-risk areas for future invasions differed depending on the scale of aggregation and the evaluation index, indicating that invasive risk assessments should be based on multiple factors. PMID:23738912

  8. An Assessment of Stakeholder Perceptions and Management of Noxious Alien Plants in Spain

    NASA Astrophysics Data System (ADS)

    Andreu, Jara; Vilà, Montserrat; Hulme, Philip E.

    2009-06-01

    Despite biological invasions being a worldwide phenomenon causing significant ecological, economic, and human welfare impacts, there is limited understanding regarding how environmental managers perceive the problem and subsequently manage alien species. Spanish environmental managers were surveyed using questionnaires to (1) analyze the extent to which they perceive plant invasions as a problem; (2) identify the status, occurrence, and impacts of noxious alien plant species; (3) assess current effort and expenditure targeting alien plant management; and, finally, (4) identify the criteria they use to set priorities for management. In comparison to other environmental concerns, plant invasions are perceived as only moderately problematic and mechanical control is the most valued and frequently used strategy to cope with plant invasions in Spain. Based on 70 questionnaires received, 193 species are considered noxious, 109 of which have been the subject of management activities. More than 90% of species are found in at least one protected area. According to respondents, the most frequently managed species are the most widespread across administrative regions and the ones perceived as causing the highest impacts. The perception of impact seems to be independent of their invasion status, since only half of the species identified as noxious are believed to be invasive in Spain, while 43% of species thought to only be casual aliens are causing a high impact. Records of management costs are poor and the few data indicate that the total actual expenditure amounted to 50,492,437 € in the last decade. The majority of respondents stated that management measures are insufficient to control alien plants due to limited economic resources, lack of public awareness and support, and an absence of coordination among different public administrations. Managers also expressed their concern about the fact that much scientific research is concerned with the ecology of alien plants

  9. Ecological Risk Assessment with MCDM of Some Invasive Alien Plants in China

    NASA Astrophysics Data System (ADS)

    Xie, Guowen; Chen, Weiguang; Lin, Meizhen; Zheng, Yanling; Guo, Peiguo; Zheng, Yisheng

    Alien plant invasion is an urgent global issue that threatens the sustainable development of the ecosystem health. The study of its ecological risk assessment (ERA) could help us to prevent and reduce the invasion risk more effectively. Based on the theory of ERA and methods of the analytic hierarchy process (AHP) of multi-criteria decision-making (MCDM), and through the analyses of the characteristics and processes of alien plant invasion, this paper discusses the methodologies of ERA of alien plant invasion. The assessment procedure consisted of risk source analysis, receptor analysis, exposure and hazard assessment, integral assessment, and countermeasure of risk management. The indicator system of risk source assessment as well as the indices and formulas applied to measure the ecological loss and risk were established, and the method for comprehensively assessing the ecological risk of alien plant invasion was worked out. The result of ecological risk analysis to 9 representative invasive alien plants in China shows that the ecological risk of Erigeron annuus, Ageratum conyzoides, Alternanthera philoxeroides and Mikania midrantha is high (grade1-2), that of Oxalis corymbosa and Wedelia chinensis comes next (grade3), while Mirabilis jalapa, Pilea microphylla and Calendula officinalis of the last (grade 4). Risk strategies are put forward on this basis.

  10. Ornamental Plants as Invasive Aliens: Problems and Solutions in Kruger National Park, South Africa

    NASA Astrophysics Data System (ADS)

    Foxcroft, Llewellyn C.; Richardson, David M.; Wilson, John R. U.

    2008-01-01

    The most widespread invasive alien plant species in South Africa’s Kruger National Park (KNP) were either introduced unintentionally along rivers and roads, or intentionally for use as ornamentals. We examine the spatial distribution of ornamental alien plants in KNP, look at the link between human population size, history, and species richness, and show how the distribution of particular species reflects the likely history of ornamental plantings. Results are used to assess whether past management actions have been appropriately directed. Two hundred and fifty-eight alien species have been recorded in the 36 tourist camps and staff villages. The number of staff housed in villages explains much of the diversity of cultivated alien plant species. Older camps also tend to have more ornamental alien plant species. However, the lack of a strong link between camp age and number of cultivated species suggests that ornamental plants have been widely spread around the KNP by humans. We also show that increased camp activity (either size or age) has led to more ornamental species, while, with the notable exception of Skukuza, camp activity has had a much smaller effect on the number of noncultivated species. Noncultivated species tend to be naturally dispersed, as opposed to directly spread by humans between camps. Past management prioritized certain species on the basis of their potential to invade KNP and on the prevailing national legislation. These species were removed manually and follow-up control was carried out. Once the priority species were deemed to be under control, less invasive species were targeted. All alien species were removed from vacated houses, regardless of the potential invasiveness of the species.

  11. Alien Roadside Species More Easily Invade Alpine than Lowland Plant Communities in a Subarctic Mountain Ecosystem

    PubMed Central

    Lembrechts, Jonas J.; Milbau, Ann; Nijs, Ivan

    2014-01-01

    Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment. PMID:24586947

  12. Alien plant invasions and native plant extinctions: a six-threshold framework

    PubMed Central

    Downey, Paul O.; Richardson, David M.

    2016-01-01

    Biological invasions are widely acknowledged as a major threat to global biodiversity. Species from all major taxonomic groups have become invasive. The range of impacts of invasive taxa and the overall magnitude of the threat is increasing. Plants comprise the biggest and best-studied group of invasive species. There is a growing debate; however, regarding the nature of the alien plant threat—in particular whether the outcome is likely to be the widespread extinction of native plant species. The debate has raised questions on whether the threat posed by invasive plants to native plants has been overstated. We provide a conceptual framework to guide discussion on this topic, in which the threat posed by invasive plants is considered in the context of a progression from no impact through to extinction. We define six thresholds along the ‘extinction trajectory’, global extinction being the final threshold. Although there are no documented examples of either ‘in the wild’ (Threshold 5) or global extinctions (Threshold 6) of native plants that are attributable solely to plant invasions, there is evidence that native plants have crossed or breached other thresholds along the extinction trajectory due to the impacts associated with plant invasions. Several factors may be masking where native species are on the trajectory; these include a lack of appropriate data to accurately map the position of species on the trajectory, the timeframe required to definitively state that extinctions have occurred and management interventions. Such interventions, focussing mainly on Thresholds 1–3 (a declining population through to the local extinction of a population), are likely to alter the extinction trajectory of some species. The critical issue for conservation managers is the trend, because interventions must be implemented before extinctions occur. Thus the lack of evidence for extinctions attributable to plant invasions does not mean we should disregard the broader

  13. Alien plant invasions and native plant extinctions: a six-threshold framework.

    PubMed

    Downey, Paul O; Richardson, David M

    2016-01-01

    Biological invasions are widely acknowledged as a major threat to global biodiversity. Species from all major taxonomic groups have become invasive. The range of impacts of invasive taxa and the overall magnitude of the threat is increasing. Plants comprise the biggest and best-studied group of invasive species. There is a growing debate; however, regarding the nature of the alien plant threat-in particular whether the outcome is likely to be the widespread extinction of native plant species. The debate has raised questions on whether the threat posed by invasive plants to native plants has been overstated. We provide a conceptual framework to guide discussion on this topic, in which the threat posed by invasive plants is considered in the context of a progression from no impact through to extinction. We define six thresholds along the 'extinction trajectory', global extinction being the final threshold. Although there are no documented examples of either 'in the wild' (Threshold 5) or global extinctions (Threshold 6) of native plants that are attributable solely to plant invasions, there is evidence that native plants have crossed or breached other thresholds along the extinction trajectory due to the impacts associated with plant invasions. Several factors may be masking where native species are on the trajectory; these include a lack of appropriate data to accurately map the position of species on the trajectory, the timeframe required to definitively state that extinctions have occurred and management interventions. Such interventions, focussing mainly on Thresholds 1-3 (a declining population through to the local extinction of a population), are likely to alter the extinction trajectory of some species. The critical issue for conservation managers is the trend, because interventions must be implemented before extinctions occur. Thus the lack of evidence for extinctions attributable to plant invasions does not mean we should disregard the broader threat. PMID

  14. No evidence for local adaptation in an invasive alien plant: field and greenhouse experiments tracing a colonization sequence

    PubMed Central

    Pahl, Anna T.; Kollmann, Johannes; Mayer, Andreas; Haider, Sylvia

    2013-01-01

    Background and Aims Local adaptation enables plant species to persist under different environmental conditions. Evolutionary change can occur rapidly in invasive annual species and has been shown to lead to local adaptation. However, the patterns and mechanisms of local adaptation in invasive species along colonization sequences are not yet understood. Thus, in this study the alien annual Impatiens glandulifera was used to investigate local adaptation to distinct habitats that have been consecutively invaded in central Europe. Methods A reciprocal transplant experiment was performed using 15 populations from alluvial deciduous forests, fallow meadows and coniferous upland forests, and a greenhouse experiment was performed in which plants from these habitats were grown under treatments reflecting the main habitat differentiators (shade, soil acidity, competition). Key Results Biomass production, specific leaf area, plant height and relative growth rate differed between habitats in the field experiment and between treatments in the greenhouse, but not between seed origins. Overall, there was no indication of local adaptation in either experiment. Conclusions Since I. glandulifera is a successful invader in many habitats without showing local adaptation, it is suggested that the species is coping with environmental variation by means of high phenotypic plasticity. The species seems to follow a ‘jack-and-master’ strategy, i.e. it is able to maintain high fitness under a wide range of environmental conditions, but performs particularly well in favourable habitats. Therefore, the proposed colonization sequence is likely to be based primarily on changes in propagule pressure. It is concluded that invasive alien plants can become dominant in distinct habitats without local adaptation. PMID:24214934

  15. Putative linkages between below- and aboveground mutualisms during alien plant invasions.

    PubMed

    Rodríguez-Echeverría, Susana; Traveset, Anna

    2015-01-01

    Evidence of the fundamental role of below-aboveground links in controlling ecosystem processes is mostly based on studies done with soil herbivores or mutualists and aboveground herbivores. Much less is known about the links between belowground and aboveground mutualisms, which have been studied separately for decades. It has not been until recently that these mutualisms-mycorrhizas and legume-rhizobia on one hand, and pollinators and seed dispersers on the other hand-have been found to influence each other, with potential ecological and evolutionary consequences. Here we review the mechanisms that may link these two-level mutualisms, mostly reported for native plant species, and make predictions about their relevance during alien plant invasions. We propose that alien plants establishing effective mutualisms with belowground microbes might improve their reproductive success through positive interactions between those mutualists and pollinators and seed dispersers. On the other hand, changes in the abundance and diversity of soil mutualists induced by invasion can also interfere with below-aboveground links for native plant species. We conclude that further research on this topic is needed in the field of invasion ecology as it can provide interesting clues on synergistic interactions and invasional meltdowns during alien plant invasions. PMID:26034049

  16. Putative linkages between below- and aboveground mutualisms during alien plant invasions

    PubMed Central

    Rodríguez-Echeverría, Susana; Traveset, Anna

    2015-01-01

    Evidence of the fundamental role of below–aboveground links in controlling ecosystem processes is mostly based on studies done with soil herbivores or mutualists and aboveground herbivores. Much less is known about the links between belowground and aboveground mutualisms, which have been studied separately for decades. It has not been until recently that these mutualisms—mycorrhizas and legume–rhizobia on one hand, and pollinators and seed dispersers on the other hand—have been found to influence each other, with potential ecological and evolutionary consequences. Here we review the mechanisms that may link these two-level mutualisms, mostly reported for native plant species, and make predictions about their relevance during alien plant invasions. We propose that alien plants establishing effective mutualisms with belowground microbes might improve their reproductive success through positive interactions between those mutualists and pollinators and seed dispersers. On the other hand, changes in the abundance and diversity of soil mutualists induced by invasion can also interfere with below–aboveground links for native plant species. We conclude that further research on this topic is needed in the field of invasion ecology as it can provide interesting clues on synergistic interactions and invasional meltdowns during alien plant invasions. PMID:26034049

  17. An Extensive Alien Plant Inventory from the Inhabited Areas of Galapagos

    PubMed Central

    Guézou, Anne; Trueman, Mandy; Buddenhagen, Christopher Evan; Chamorro, Susana; Guerrero, Ana Mireya; Pozo, Paola; Atkinson, Rachel

    2010-01-01

    Background Plant invasions are causing habitat degradation in Galapagos. Problems are concentrated on the four inhabited islands. Plants introduced to rural areas in the humid highlands and urban areas on the arid coast act as foci for invasion of the surrounding Galapagos National Park. Methodology/Principal Findings Here we present results of the most comprehensive inventory to date of alien vascular plants in the inhabited areas of Galapagos. The survey was conducted between 2002 and 2007, in 6031 properties (97% of the total) on Floreana, Isabela, San Cristobal and Santa Cruz Islands. In total 754 alien vascular plant taxa were recorded, representing 468 genera in 123 families. Dicotyledons represented 554 taxa, monocotyledons 183, there were 7 gymnosperms and 10 pteridophytes. Almost half (363) of the taxa were herbaceous. The most represented families were Fabaceae (sensu lato), Asteraceae and Poaceae. The three most recorded species in the humid rural areas were Psidium guajava, Passiflora edulis and Bryophyllum pinnatum, and in the dry urban areas, Aloe vera, Portulaca oleracea and Carica papaya. In total, 264 (35%) taxa were recorded as naturalized. The most common use for taxa was ornamental (52%). Conclusions/Significance This extensive survey has increased the known alien vascular flora of Galapagos by 257 species, giving a ratio of alien to native taxa of 1.57∶1. It provides a crucial baseline for plant invasion management in the archipelago and contributes data for meta analyses of invasion processes worldwide. A repeat of the survey in the future would act as an effective early detection tool to help avoid further invasion of the Galapagos National Park. PMID:20421999

  18. Long-term differences in annual litter production between alien (Sonneratia apetala) and native (Kandelia obovata) mangrove species in Futian, Shenzhen, China.

    PubMed

    Liu, Lina; Li, Fenglan; Yang, Qiong; Tam, Nora F Y; Liao, Wenbo; Zan, Qijie

    2014-08-30

    Annual litter production in alien (Sonneratia apetala) and native (Kandelia obovata) mangrove forests in Shenzhen, China were compared from 1999 to 2010. S. apetala had significantly higher litter production than K. obovata, with mean annual total litter of 18.1 t ha(-1) yr(-1) and 15.2 t ha(-1) yr(-1), respectively. The higher litter production in S. apetala forest indicates higher productivity and consequently more nutrient supply to the estuarine ecosystems but may be more invasive due to positive plant-soil feedbacks and nutrient availability to this alien species. Two peaks were recorded in S. apetala (May and October), while only one peak was observed in K. obovata, in early spring (March and April). Leaf and reproductive materials were the main contributors to litter production (>80%) in both forests. These results suggest that the ecological function of S. apetala and its invasive potential can be better understood based on a long-term litter fall analysis. PMID:24841715

  19. Relative abundance of an invasive alien plant affects insect-flower interaction networks in Ireland

    NASA Astrophysics Data System (ADS)

    Stout, Jane C.; Casey, Leanne M.

    2014-02-01

    Invasive alien flowering plants may affect native plant pollinator interactions and have knock on impacts on populations of native plants and animals. The magnitude of these impacts, however, may be modified by the relative abundance of the invasive plant and the number of flowers it presents.We tested this by examining the structure of insect-flower interaction networks in six sites with increasing levels of invasion by Rhododendron ponticum in Ireland.Neither flower-visiting insect abundance, species richness nor diversity were related to R. ponticum flower abundance, but the composition of insect communities was. The total number of flowers in a site increased with the relative abundance of R. ponticum flowers but the number of co-flowering native plant species in these sites was low (<6), making interaction networks relatively small.As a result, changes in interaction network properties (connectance, interaction evenness and network level specialisation), which correlated with R. ponticum flower abundance, were a result of the small network size rather than due to changes in the resilience of networks.Overall, we conclude that the impacts of invasive alien plants on native plant-pollinator interactions are not only species specific, but site specific, according to the abundance of flowers produced by both the invasive and the native plants.

  20. Sentinel Trees as a Tool to Forecast Invasions of Alien Plant Pathogens

    PubMed Central

    Vettraino, AnnaMaria; Roques, Alain; Yart, Annie; Fan, Jian-ting; Sun, Jiang-hua; Vannini, Andrea

    2015-01-01

    Recent disease outbreaks caused by alien invasive pathogens into European forests posed a serious threat to forest sustainability with relevant environmental and economic effects. Many of the alien tree pathogens recently introduced into Europe were not previously included on any quarantine lists, thus they were not subject to phytosanitary inspections. The identification and description of alien fungi potentially pathogenic to native European flora before their introduction in Europe, is a paramount need in order to limit the risk of invasion and the impact to forest ecosystems. To determine the potential invasive fungi, a sentinel trees plot was established in Fuyang, China, using healthy seedlings of European tree species including Quercus petreae, Q. suber, and Q. ilex. The fungal assemblage associated with symptomatic specimens was studied using the tag-encoded 454 pyrosequencing of the nuclear ribosomal internal transcribed spacer-1 (ITS 1). Taxa with probable Asiatic origin were identified and included plant pathogenic genera. These results indicate that sentinel plants may be a strategic tool to improve the prevention of bioinvasions. PMID:25826684

  1. Alien plant monitoring with ultralight airborne imaging spectroscopy.

    PubMed

    Calviño-Cancela, María; Méndez-Rial, Roi; Reguera-Salgado, Javier; Martín-Herrero, Julio

    2014-01-01

    Effective management of invasive plants requires a precise determination of their distribution. Remote sensing techniques constitute a promising alternative to field surveys and hyperspectral sensors (also known as imaging spectrometers, with a large number of spectral bands and high spectral resolution) are especially suitable when very similar categories are to be distinguished (e.g. plant species). A main priority in the development of this technology is to lower its cost and simplify its use, so that its demonstrated aptitude for many environmental applications can be truly realized. With this aim, we have developed a system for hyperspectral imaging (200 spectral bands in the 380-1000 nm range and circa 3 nm spectral resolution) operated on board ultralight aircraft (namely a gyrocopter), which allows a drastic reduction of the running costs and operational complexity of image acquisition, and also increases the spatial resolution of the images (circa 5-8 pixels/m(2) at circa 65 km/h and 300 m height). The detection system proved useful for the species tested (Acacia melanoxylon, Oxalis pes-caprae, and Carpobrotus aff. edulis and acinaciformis), with user's and producer's accuracy always exceeding 90%. The detection accuracy reported corresponds to patches down to 0.125 m(2) (50% of pixels 0.5 × 0.5 m in size), a very small size for many plant species, making it very effective for initial stages of invasive plant spread. In addition, its low operating costs, similar to those of a 4WD ground vehicle, facilitate frequent image acquisition. Acquired images constitute a permanent record of the status of the study area, with great amount of information that can be analyzed in the future for other purposes, thus greatly facilitating the monitoring of natural areas at detailed spatial and temporal scales for improved management. PMID:25010601

  2. Alien Plant Monitoring with Ultralight Airborne Imaging Spectroscopy

    PubMed Central

    Calviño-Cancela, María; Méndez-Rial, Roi; Reguera-Salgado, Javier; Martín-Herrero, Julio

    2014-01-01

    Effective management of invasive plants requires a precise determination of their distribution. Remote sensing techniques constitute a promising alternative to field surveys and hyperspectral sensors (also known as imaging spectrometers, with a large number of spectral bands and high spectral resolution) are especially suitable when very similar categories are to be distinguished (e.g. plant species). A main priority in the development of this technology is to lower its cost and simplify its use, so that its demonstrated aptitude for many environmental applications can be truly realized. With this aim, we have developed a system for hyperspectral imaging (200 spectral bands in the 380–1000 nm range and circa 3 nm spectral resolution) operated on board ultralight aircraft (namely a gyrocopter), which allows a drastic reduction of the running costs and operational complexity of image acquisition, and also increases the spatial resolution of the images (circa 5–8 pixels/m2 at circa 65 km/h and 300 m height). The detection system proved useful for the species tested (Acacia melanoxylon, Oxalis pes-caprae, and Carpobrotus aff. edulis and acinaciformis), with user’s and producer’s accuracy always exceeding 90%. The detection accuracy reported corresponds to patches down to 0.125 m2 (50% of pixels 0.5×0.5 m in size), a very small size for many plant species, making it very effective for initial stages of invasive plant spread. In addition, its low operating costs, similar to those of a 4WD ground vehicle, facilitate frequent image acquisition. Acquired images constitute a permanent record of the status of the study area, with great amount of information that can be analyzed in the future for other purposes, thus greatly facilitating the monitoring of natural areas at detailed spatial and temporal scales for improved management. PMID:25010601

  3. Urban Power Line Corridors as Novel Habitats for Grassland and Alien Plant Species in South-Western Finland.

    PubMed

    Lampinen, Jussi; Ruokolainen, Kalle; Huhta, Ari-Pekka

    2015-01-01

    Regularly managed electric power line corridors may provide habitats for both early-successional grassland plant species and disturbance-dependent alien plant species. These habitats are especially important in urban areas, where they can help conserve native grassland species and communities in urban greenspace. However, they can also provide further footholds for potentially invasive alien species that already characterize urban areas. In order to implement power line corridors into urban conservation, it is important to understand which environmental conditions in the corridors favor grassland species and which alien species. Likewise it is important to know whether similar environmental factors in the corridors control the species composition of the two groups. We conducted a vegetation study in a 43 kilometer long urban power line corridor network in south-western Finland, and used generalized linear models and distance-based redundancy analysis to determine which environmental factors best predict the occurrence and composition of grassland and alien plant species in the corridors. The results imply that old corridors on dry soils and steep slopes characterized by a history as open areas and pastures are especially suitable for grassland species. Corridors suitable for alien species, in turn, are characterized by productive soils and abundant light and are surrounded by a dense urban fabric. Factors controlling species composition in the two groups are somewhat correlated, with the most important factors including light abundance, soil moisture, soil calcium concentration and soil productivity. The results have implications for grassland conservation and invasive alien species control in urban areas. PMID:26565700

  4. Urban Power Line Corridors as Novel Habitats for Grassland and Alien Plant Species in South-Western Finland

    PubMed Central

    Lampinen, Jussi; Ruokolainen, Kalle; Huhta, Ari-Pekka

    2015-01-01

    Regularly managed electric power line corridors may provide habitats for both early-successional grassland plant species and disturbance-dependent alien plant species. These habitats are especially important in urban areas, where they can help conserve native grassland species and communities in urban greenspace. However, they can also provide further footholds for potentially invasive alien species that already characterize urban areas. In order to implement power line corridors into urban conservation, it is important to understand which environmental conditions in the corridors favor grassland species and which alien species. Likewise it is important to know whether similar environmental factors in the corridors control the species composition of the two groups. We conducted a vegetation study in a 43 kilometer long urban power line corridor network in south-western Finland, and used generalized linear models and distance-based redundancy analysis to determine which environmental factors best predict the occurrence and composition of grassland and alien plant species in the corridors. The results imply that old corridors on dry soils and steep slopes characterized by a history as open areas and pastures are especially suitable for grassland species. Corridors suitable for alien species, in turn, are characterized by productive soils and abundant light and are surrounded by a dense urban fabric. Factors controlling species composition in the two groups are somewhat correlated, with the most important factors including light abundance, soil moisture, soil calcium concentration and soil productivity. The results have implications for grassland conservation and invasive alien species control in urban areas. PMID:26565700

  5. Unmanned Aerial Vehicles for Alien Plant Species Detection and Monitoring

    NASA Astrophysics Data System (ADS)

    Dvořák, P.; Müllerová, J.; Bartaloš, T.; Brůna, J.

    2015-08-01

    Invasive species spread rapidly and their eradication is difficult. New methods enabling fast and efficient monitoring are urgently needed for their successful control. Remote sensing can improve early detection of invading plants and make their management more efficient and less expensive. In an ongoing project in the Czech Republic, we aim at developing innovative methods of mapping invasive plant species (semi-automatic detection algorithms) by using purposely designed unmanned aircraft (UAV). We examine possibilities for detection of two tree and two herb invasive species. Our aim is to establish fast, repeatable and efficient computer-assisted method of timely monitoring, reducing the costs of extensive field campaigns. For finding the best detection algorithm we test various classification approaches (object-, pixel-based and hybrid). Thanks to its flexibility and low cost, UAV enables assessing the effect of phenological stage and spatial resolution, and is most suitable for monitoring the efficiency of eradication efforts. However, several challenges exist in UAV application, such as geometrical and radiometric distortions, high amount of data to be processed and legal constrains for the UAV flight missions over urban areas (often highly invaded). The newly proposed UAV approach shall serve invasive species researchers, management practitioners and policy makers.

  6. Release from belowground enemies and shifts in root traits as interrelated drivers of alien plant invasion success: a hypothesis.

    PubMed

    Dawson, Wayne

    2015-10-01

    Our understanding of the interrelated mechanisms driving plant invasions, such as the interplay between enemy release and resource-acquisition traits, is biased by an aboveground perspective. To address this bias, I hypothesize that plant release from belowground enemies (especially fungal pathogens) will give invasive plant species a fitness advantage in the alien range, via shifts in root traits (e.g., increased specific root length and branching intensity) that increase resource uptake and competitive ability compared to native species in the alien range, and compared to plants of the invader in its native range. Such root-trait changes could be ecological or evolutionary in nature. I explain how shifts in root traits could occur as a consequence of enemy release and contribute to invasion success of alien plants, and how they could be interrelated with other potential belowground drivers of invasion success (allelopathy, mutualist enhancement). Finally, I outline the approaches that could be taken to test whether belowground enemy release results in increased competitive ability and nutrient uptake by invasive alien plants, via changes in root traits in the alien range. PMID:26668717

  7. Dispersal limitation does not control high elevational distribution of alien plant species in the southern Sierra Nevada, California

    USGS Publications Warehouse

    Rundel, Philip W.; Keeley, Jon E.

    2016-01-01

    Patterns of elevational distribution of alien plant species in the southern Sierra Nevada of California were used to test the hypothesis that alien plant species invading high elevations around the world are typically climate generalists capable of growing across a wide elevational range. The Sierra Nevada has been heavily impacted for more than a century and a half, first by heavy grazing up into high elevation meadows, followed by major logging, and finally, by impacts associated with recreational use. The comparative elevational patterns of distribution and growth form were compared for native and alien plant species in the four families (Asteraceae, Brassicaceae, Fabaceae, and Poaceae) that contribute the majority of naturalized aliens in the study area. The distribution of realized climatic niche breadth, as measured by elevational range of occurrence, was virtually identical for alien and native species, with both groups showing a roughly Gaussian distribution peaking with species whose range covers a span of 1500–1999 m. In contrast to alien species, which only rarely occurred at higher elevations, native species showed a distribution of upper elevation limits peaking at 3000–3499 m, an elevation that corresponds to the zone of upper montane and subalpine forests. Consistent with a hypothesis of abiotic limitations, only a few alien species have been ecologically successful invaders at subalpine and alpine elevations above 2500 m. The low diversity of aliens able to become established in these habitats is unlikely due to dispersal limitations, given the long history of heavy grazing pressure at high elevations across this region. Instead, this low diversity is hypothesized to be a function of life history traits and multiple abiotic stresses that include extremes of cold air and soil temperature, heavy snowfall, short growing seasons, and low resource availability. These findings have significant implications for resource managers.

  8. Separating habitat invasibility by alien plants from the actual level of invasion.

    PubMed

    Chytrý, Milan; Jarosik, Vojtech; Pysek, Petr; Hájek, Ondrej; Knollová, Ilona; Tichý, Lubomír; Danihelka, Jií

    2008-06-01

    Habitats vary considerably in the level of invasion (number or proportion of alien plant species they contain), which depends on local habitat properties, propagule pressure, and climate. To determine the invasibility (susceptibility to invasions) of different habitats, it is necessary to factor out the effects of any confounding variables such as propagule pressure and climate on the level of invasion. We used 20 468 vegetation plots from 32 habitats in the Czech Republic to compare the invasibility of different habitats. Using regression trees, the proportion of alien plants, including archaeophytes (prehistoric to medieval invaders) and neophytes (recent invaders), was related to variables representing habitat properties, propagule pressure, and climate. The propagule pressure was expressed as the proportion of surrounding urban and industrial or agricultural land, human population density, distance from a river, and history of human colonization in the region. Urban and industrial land use had a positive effect on the proportion of both archaeophytes and neophytes. Agricultural land use, higher population density, and longer history of human impact positively affected the proportion of archaeophytes. Disturbed human-made habitats with herbaceous vegetation were most invaded by both groups of aliens. Neophytes were also relatively common in disturbed woody vegetation, such as broad-leaved plantations, forest clearings, and riverine scrub. These habitats also had the highest proportion of aliens after removing the effect of propagule pressure and climate, indicating that they are not only the most invaded, but also most invasible. These habitats experience recurrent disturbances and are rich, at least temporarily, in available nutrients, which supports the hypothesis that fluctuating resources are the major cause of habitat invasibility. The least invaded habitats were mires and alpine-subalpine grasslands and scrub. After removing the effect of propagule

  9. Survey of roadside alien plants in Hawai`i Volcanoes National Park and adjacent residential areas 2001-2005

    USGS Publications Warehouse

    Bio, Keali'i F.; Pratt, Linda W.; Jacobi, James D.

    2012-01-01

    The sides of all paved roads of Hawai`i Volcanoes National Park (HAVO) were surveyed on foot in 2001 to 2005, and the roadside presence of 240 target invasive and potentially invasive alien plant species was recorded in mile-long increments. Buffer zones 5–10 miles (8–16 km) long along Highway 11 on either side of the Kīlauea and Kahuku Units of the park, as well as Wright Road that passed by the disjunct `Ōla`a Tract Unit, were included in the survey. Highway 11 is the primary road through the park and a major island thoroughfare. Three residential subdivisions adjacent to the park were similarly surveyed in 0.5–1 mile (0.8–1.6 km) intervals in 2003, and data were analyzed separately. Two roads to the east and northeast were also surveyed, but data from these disjunct areas were analyzed separately from park roads. In total, 174 of the target alien species were observed along HAVO roads and buffers, exclusive of residential areas, and the mean number of target aliens per mile surveyed was 20.6. Highway 11 and its buffer zones had the highest mean number of target alien plants per mile (26.7) of all park roads, and the Mauna Loa Strip Road had the lowest mean (11.7). Segments of Highway 11 adjacent to HAVO and Wright Road next to `Ōla`a Tract had mean numbers of target alien per mile (24–47) higher than those of any internal road. Alien plant frequencies were summarized for each road in HAVO. Fifteen new records of vascular plants for HAVO were observed and collected along park roads. An additional 28 alien plant species not known from HAVO were observed along the buffer segments of Highway 11 adjacent to the park. Within the adjacent residential subdivisions, 65 target alien plant species were sighted along roadsides. At least 15 potentially invasive species not currently found within HAVO were observed along residential roads, and several other species found there have been previously eliminated from the park or controlled to remnant populations

  10. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks.

    PubMed

    Emer, Carine; Vaughan, Ian P; Hiscock, Simon; Memmott, Jane

    2015-01-01

    Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae) affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet) and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam) and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward. PMID:26633170

  11. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks

    PubMed Central

    Emer, Carine; Vaughan, Ian P.; Hiscock, Simon; Memmott, Jane

    2015-01-01

    Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae) affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet) and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam) and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward. PMID:26633170

  12. Niche dynamics of alien species do not differ among sexual and apomictic flowering plants.

    PubMed

    Dellinger, Agnes S; Essl, Franz; Hojsgaard, Diego; Kirchheimer, Bernhard; Klatt, Simone; Dawson, Wayne; Pergl, Jan; Pyšek, Petr; van Kleunen, Mark; Weber, Ewald; Winter, Marten; Hörandl, Elvira; Dullinger, Stefan

    2016-02-01

    Biological invasions can be associated with shifts of the species' climatic niches but the incidence of such shifts is under debate. The reproductive system might be a key factor controlling such shifts because it influences a species' evolutionary flexibility. However, the link between reproductive systems and niche dynamics in plant invasions has been little studied so far. We compiled global occurrence data sets of 13 congeneric sexual and apomictic species pairs, and used principal components analysis (PCA) and kernel smoothers to compare changes in climatic niche optima, breadths and unfilling/expansion between native and alien ranges. Niche change metrics were compared between sexual and apomictic species. All 26 species showed changes in niche optima and/or breadth and 14 species significantly expanded their climatic niches. However, we found no effect of the reproductive system on niche dynamics. Instead, species with narrower native niches showed higher rates of niche expansion in the alien ranges. Our results suggest that niche shifts are frequent in plant invasions but evolutionary potential may not be of major importance for such shifts. Niche dynamics rather appear to be driven by changes of the realized niche without adaptive change of the fundamental climatic niche. PMID:26508329

  13. RELATIONSHIPS OF ALIEN PLANT SPECIES ABUNDANCE TO RIPARIAN VEGETATION, ENVIRONMENT, AND DISTURBANCE

    EPA Science Inventory

    Riparian ecosystems are often invaded by alien species. We evaluated vegetation, environment, and disturbance conditions and their interrelationships with alien species abundance along reaches of 29 streams in eastern Oregon, USA. Using flexible-BETA clustering, indicator species...

  14. Invasion trajectory of alien trees: the role of introduction pathway and planting history.

    PubMed

    Donaldson, Jason E; Hui, Cang; Richardson, David M; Robertson, Mark P; Webber, Bruce L; Wilson, John R U

    2014-05-01

    Global change is driving a massive rearrangement of the world's biota. Trajectories of distributional shifts are shaped by species traits, the recipient environment and driving forces with many of the driving forces directly due to human activities. The relative importance of each in determining the distributions of introduced species is poorly understood. We consider 11 Australian Acacia species introduced to South Africa for different reasons (commercial forestry, dune stabilization and ornamentation) to determine how features of the introduction pathway have shaped their invasion history. Projections from species distribution models (SDMs) were developed to assess how the reason for introduction influences the similarity between climatic envelopes in native and alien ranges. A lattice model for an idealized invasion was developed to assess the relative contribution of intrinsic traits and introduction dynamics on the abundance and extent over the course of simulated invasions. SDMs show that alien populations of ornamental species in South Africa occupy substantially different climate space from their native ranges, whereas species introduced for forestry occupy a similar climate space in native and introduced ranges. This may partly explain the slow spread rates observed for some alien ornamental plants. Such mismatches are likely to become less pronounced with the current drive towards 'eco gardens' resulting in more introductions of ornamental species with a close climate match between native and newly introduced regions. The results from the lattice model showed that the conditions associated with the introduction pathway (especially introduction pressure) dominate early invasion dynamics. The placement of introduction foci in urban areas limited the extent and abundance of invasive populations. Features of introduction events appear to initially mask the influence of intrinsic species traits on invasions and help to explain the relative success of species

  15. Impact of Alien Plant Invaders on Pollination Networks in Two Archipelagos

    PubMed Central

    Padrón, Benigno; Traveset, Anna; Biedenweg, Tine; Díaz, Diana; Nogales, Manuel; Olesen, Jens M.

    2009-01-01

    Mutualistic interactions between plants and animals promote integration of invasive species into native communities. In turn, the integrated invaders may alter existing patterns of mutualistic interactions. Here we simultaneously map in detail effects of invaders on parameters describing the topology of both plant-pollinator (bi-modal) and plant-plant (uni-modal) networks. We focus on the invader Opuntia spp., a cosmopolitan alien cactus. We compare two island systems: Tenerife (Canary Islands) and Menorca (Balearic Islands). Opuntia was found to modify the number of links between plants and pollinators, and was integrated into the new communities via the most generalist pollinators, but did not affect the general network pattern. The plant uni-modal networks showed disassortative linkage, i.e. species with many links tended to connect to species with few links. Thus, by linking to generalist natives, Opuntia remained peripheral to network topology, and this is probably why native network properties were not affected at least in one of the islands. We conclude that the network analytical approach is indeed a valuable tool to evaluate the effect of invaders on native communities. PMID:19609437

  16. Effects of invasive alien kahili ginger (Hedychium gardnerianum) on native plant species regeneration in a Hawaiian rainforest

    USGS Publications Warehouse

    Minden, V.; Jacobi, J.D.; Porembski, S.; Boehmer, H.J.

    2010-01-01

    Questions: Does the invasive alien Hedychium gardnerianum (1) replace native understory species, (2) suppress natural regeneration of native plant species, (3) increase the invasiveness of other non-native plants and (4) are native forests are able to recover after removal of H. gardnerianum. Location: A mature rainforest in Hawai'i Volcanoes National Park on the island of Hawai'i (about 1200 m. a.s.l.; precipitation approximately 2770mm yr-1). Study sites included natural plots without effects of alien plants, ginger plots with a H. gardnerianum-domimted herb layer and cleared plots treated with herbicide to remove alien plants. Methods: Counting mature trees, saplings and seedlings of native and alien plant species. Using nonparametric H-tests to compare impact of H. gardnerianum on the structure of different sites. Results: Results confirmed the hypothesis that H. gardnerianum has negative effects on natural forest dynamics. Lower numbers of native tree seedlings and saplings were found on ginger-dominated plots. Furthermore, H. gardnerianum did not show negative effects on the invasive alien tree species Psidium cattleianum. Conclusions: This study reveals that where dominance of H. gardnerianum persists, regeneration of the forest by native species will be inhibited. Furthermore, these areas might experience invasion by P. cattleianum, resulting in displacement of native canopy species in the future, leading to a change in forest structure and loss of other species dependent on natural rainforest, such as endemic birds. However, if H. gardnerianum is removed the native Hawaiian forest is likely to regenerate and regain its natural structure. ?? 2009 International Association for Vegetation Science.

  17. [Effects of nitrogen and carbon addition and arbuscular mycorrhiza on alien invasive plant Ambrosia artemisiifolia].

    PubMed

    Huang, Dong; Sang, Wei-guo; Zhu, Li; Song, Ying-ying; Wang, Jin-ping

    2010-12-01

    A greenhouse control experiment was conducted to explore the effects of nitrogen and carbon addition and arbuscular mycorrhiza (AM) on the growth of alien invasive plant Ambrosia artemisiifolia (common ragweed). Nitrogen addition had no significant effects on the morphological indices, biomass and its allocation, and absolute growth rate of A. artemisiifolia, but increased the nitrogen content in the aboveground and underground parts of the plant significantly. Carbon addition increased the content of soil available nitrogen. In this case, the biomass allocation in root system for nutrient (nitrogen) absorption promoted, resulting in a remarkable decrease of branch number, total leaf area, specific leaf area (SLA), and leaf mass ratio. As a result, the total biomass decreased significantly. The symbiosis of A. artemisiifolia and AM fungi had great influence on the common ragweed's soil nitrogen acclimation, which enhanced its resource-capture by the increase of SLA, and this effect was more significant when the soil nitrogen content was low. AM fungi played an important role in the growth of A. artemisiifolia in low-nitrogen environment. PMID:21442989

  18. Contrasting impacts of climate-driven flowering phenology on changes in alien and native plant species distributions.

    PubMed

    Hulme, Philip E

    2011-01-01

    Plant phenology is particularly sensitive to climate and a key indicator of environmental change. Globally, first flowering dates (FFDs) have advanced by several days per decade in response to recent climate warming, but, while earlier flowering should allow plant distributions to increase, a link between FFD and range changes has not been observed. • Here I show for 347 species that the extent to which FFD has responded to climate warming is linked to the degree to which their relative distributions have changed over 30 yr across the British Isles. • Native plant species whose phenology did not track climate change declined in distribution, whereas species that became more widespread all exhibited earlier flowering. In contrast, alien neophytes showed both a stronger phenological response to warming and a more marked increase in distribution, but no link between the two. • These trends were consistent both for relative changes in the national distribution and for local abundance. At the national scale, the more recently an alien species became established in Britain, the more likely it was to increase in distribution irrespective of FFD, suggesting that recent changes in alien species distributions are decoupled from climate and driven by other factors. PMID:20807339

  19. Some Perspectives on the Risks and Benefits of Biological Control of Invasive Alien Plants in the Management of Natural Ecosystems

    NASA Astrophysics Data System (ADS)

    van Wilgen, B. W.; Moran, V. C.; Hoffmann, J. H.

    2013-09-01

    Globally, invasions by alien plants are rapidly increasing in extent and severity, leading to large-scale ecosystem degradation. Weed biological control offers opportunities to arrest or even reverse these trends and, although it is not always effective or appropriate as a management strategy, this practice has an excellent record of safety and many notable successes over two centuries. In recent years, growing concerns about the potential for unintended, non-target damage by biological control agents, and fears about other unpredictable effects on ecosystems, have created an increasingly demanding risk-averse regulatory environment. This development may be counter-productive because it tends to overemphasize potential problems and ignores or underestimates the benefits of weed biological control; it offers no viable alternatives; and it overlooks the inherent risks of a decision not to use biological control. The restoration of badly degraded ecosystems to a former pristine condition is not a realistic objective, but the protection of un-invaded or partial restoration of invaded ecosystems can be achieved safely, at low cost and sustainably through the informed and responsible application of biological control. This practice should therefore be given due consideration when management of invasive alien plants is being planned. This discussion paper provides a perspective on the risks and benefits of classical weed biological control, and it is aimed at assisting environmental managers in their deliberations on whether or not to use this strategy in preference, or as a supplement to other alien invasive plant control practices.

  20. Life under alien skies

    NASA Astrophysics Data System (ADS)

    Dartnell, Lewis

    2012-04-01

    As the number of confirmed extrasolar planets increases, so does the likelihood that some of them will harbour life. Lewis Dartnell describes some preliminary - but increasingly well founded - efforts to predict what alien plants and animals might look like.

  1. Flowering phenology of invasive alien plant species compared with native species in three Mediterranean-type ecosystems

    PubMed Central

    Godoy, Oscar; Richardson, David M.; Valladares, Fernando; Castro-Díez, Pilar

    2009-01-01

    Background and Aims Flowering phenology is a potentially important component of success of alien species, since elevated fecundity may enhance invasiveness. The flowering patterns of invasive alien plant species and related natives were studied in three regions with Mediterranean-type climate: California, Spain and South Africa's Cape region. Methods A total of 227 invasive–native pairs were compared for seven character types across the regions, with each pair selected on the basis that they shared the same habitat type within a region, had a common growth form and pollination type, and belonged to the same family or genus. Key Results Invasive alien plant species have different patterns of flowering phenology from native species in the three regions. Whether the alien species flower earlier, later or at the same time as natives depends on the climatic regime in the native range of the aliens and the proportion of species in the invasive floras originating from different regions. Species invading at least two of the regions displayed the same flowering pattern, showing that flowering phenology is a conservative trait. Invasive species with native ranges in temperate climates flower earlier than natives, those from Mediterranean-type climates at the same time, and species from tropical climates flower later. In California, where the proportion of invaders from the Mediterranean Basin is high, the flowering pattern did not differ between invasive and native species, whereas in Spain the high proportion of tropical species results in a later flowering than natives, and in the Cape region early flowering than natives was the result of a high proportion of temperate invaders. Conclusions Observed patterns are due to the human-induced sympatry of species with different evolutionary histories whose flowering phenology evolved under different climatic regimes. The severity of the main abiotic filters imposed by the invaded regions (e.g. summer drought) has not been

  2. Nonrandom Composition of Flower Colors in a Plant Community: Mutually Different Co-Flowering Natives and Disturbance by Aliens

    PubMed Central

    Makino, Takashi T.; Yokoyama, Jun

    2015-01-01

    When pollinators use flower color to locate food sources, a distinct color can serve as a reproductive barrier against co-flowering species. This anti-interference function of flower color may result in a community assembly of plant species displaying mutually different flower colors. However, such color dispersion is not ubiquitous, suggesting a variable selection across communities and existence of some opposing factors. We conducted a 30-week study in a plant community and measured the floral reflectances of 244 species. The reflectances were evaluated in insect color spaces (bees, swallowtails, and flies), and the dispersion was compared with random expectations. We found that co-existing colors were overdispersed for each analyzed pollinator type, and this overdispersion was statistically significant for bees. Furthermore, we showed that exclusion of 32 aliens from the analysis significantly increased the color dispersion of native flowers in every color space. This result indicated that aliens disturbed a native plant–pollinator network via similarly colored flowers. Our results demonstrate the masking effects of aliens in the detection of color dispersion of native flowers and that variations in pollinator vision yield different outcomes. Our results also support the hypothesis that co-flowering species are one of the drivers of color diversification and affect the community assembly. PMID:26650121

  3. Alien Plants Introduced by Different Pathways Differ in Invasion Success: Unintentional Introductions as a Threat to Natural Areas

    PubMed Central

    Pyšek, Petr; Jarošík, Vojtěch; Pergl, Jan

    2011-01-01

    Background Understanding the dimensions of pathways of introduction of alien plants is important for regulating species invasions, but how particular pathways differ in terms of post-invasion success of species they deliver has never been rigorously tested. We asked whether invasion status, distribution and habitat range of 1,007 alien plant species introduced after 1500 A.D. to the Czech Republic differ among four basic pathways of introduction recognized for plants. Principal Findings Pathways introducing alien species deliberately as commodities (direct release into the wild; escape from cultivation) result in easier naturalization and invasion than pathways of unintentional introduction (contaminant of a commodity; stowaway arriving without association with it). The proportion of naturalized and invasive species among all introductions delivered by a particular pathway decreases with a decreasing level of direct assistance from humans associated with that pathway, from release and escape to contaminant and stowaway. However, those species that are introduced via unintentional pathways and become invasive are as widely distributed as deliberately introduced species, and those introduced as contaminants invade an even wider range of seminatural habitats. Conclusions Pathways associated with deliberate species introductions with commodities and pathways whereby species are unintentionally introduced are contrasting modes of introductions in terms of invasion success. However, various measures of the outcome of the invasion process, in terms of species' invasion success, need to be considered to accurately evaluate the role of and threat imposed by individual pathways. By employing various measures we show that invasions by unintentionally introduced plant species need to be considered by management as seriously as those introduced by horticulture, because they invade a wide range of seminatural habitats, hence representing even a greater threat to natural areas

  4. Peak fire temperatures and effects on annual plants in the Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.

    2002-01-01

    Very little is known about the behavior and effects of fire in the Mojave Desert, because fire was historically uncommon. However, fire has become more frequent since the 1970s with increased dominance of the invasive annual grasses Bromus rubens and Schismus spp., and land managers are concerned about its ecological effect. In this paper, I describe patterns of peak fire temperature and their effect on annual plants in creosote bush scrub vegetation of the Mojave Desert. Temperatures were monitored among microhabitats and distances from the soil surface, and between spring and summer. Microhabitats ranged from high amounts of fuel beneath creosote bush (Larrea tridentata) canopies, to intermediate amounts at the canopy drip line, to low amounts in the interspaces between them. Distances from the soil surface were within the vertical range where most annual plant seeds occur (-2, 0, 5, and 10 cm). I also compare temperature patterns with postfire changes in soil properties and annual plant biomass and species richness to infer potential mechanisms by which fires affect annual plants. Peak fire temperatures were most affected by the microhabitat fuel gradient, and the effects of fire on annual plants varied among microhabitats. Beneath creosote bushes, lethal fire temperatures for annual plant seeds occurred above- and belowground, resulting in four postfire years of reduced annual plant biomass and species richness due most likely to seed mortality, especially of Bromus rubens and native forbs. At the canopy drip line, lethal fire temperatures occurred only aboveground, reducing annual plant biomass for 1 yr and species richness for 2 yr, and increasing biomass of Schismus sp., the alien forb Erodium cicutarium, and native annuals after 3 yr. Negligible changes were caused by fire in interspaces or between spring and summer. Fire effects models for creosote bush scrub vegetation must account for patterns of peak fire temperature along the shrub-intershrub gradient

  5. Rainfall effects on rare annual plants

    USGS Publications Warehouse

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

    2008-01-01

    1. Variation in climate is predicted to increase over much of the planet this century. Forecasting species persistence with climate change thus requires understanding of how populations respond to climate variability, and the mechanisms underlying this response. Variable rainfall is well known to drive fluctuations in annual plant populations, yet the degree to which population response is driven by between-year variation in germination cueing, water limitation or competitive suppression is poorly understood. 2. We used demographic monitoring and population models to examine how three seed banking, rare annual plants of the California Channel Islands respond to natural variation in precipitation and their competitive environments. Island plants are particularly threatened by climate change because their current ranges are unlikely to overlap regions that are climatically favourable in the future. 3. Species showed 9 to 100-fold between-year variation in plant density over the 5-12 years of censusing, including a severe drought and a wet El Nin??o year. During the drought, population sizes were low for all species. However, even in non-drought years, population sizes and per capita growth rates showed considerable temporal variation, variation that was uncorrelated with total rainfall. These population fluctuations were instead correlated with the temperature after the first major storm event of the season, a germination cue for annual plants. 4. Temporal variation in the density of the focal species was uncorrelated with the total vegetative cover in the surrounding community, suggesting that variation in competitive environments does not strongly determine population fluctuations. At the same time, the uncorrelated responses of the focal species and their competitors to environmental variation may favour persistence via the storage effect. 5. Population growth rate analyses suggested differential endangerment of the focal annuals. Elasticity analyses and life

  6. Distinct invasion strategies operating within a natural annual plant system.

    PubMed

    Lai, Hao Ran; Mayfield, Margaret M; Gay-des-Combes, Justine M; Spiegelberger, Thomas; Dwyer, John M

    2015-04-01

    Alien plant species are known to have a wide range of impacts on recipient communities, from resident species' exclusions to coexistence with resident species. It remains unclear; however, if this variety of impacts is due to different invader strategies, features of recipient communities or both. To test this, we examined multiple plant invasions of a single ecosystem in southwestern Australia. We used extensive community data to calculate pairwise segregation between target alien species and many co-occurring species. We related segregation to species' positions along community trait hierarchies and identified at least two distinct invasion strategies: 'exploiters' which occupy high positions along key trait hierarchies and reduce local native species diversity (particularly in nutrient-enriched situations), and 'coexisters' who occupy intermediate trait positions and have no discernable impact on native diversity. We conclude that trait hierarchies, linked to measures of competition, can provide valuable insights about the processes driving different invasion outcomes. PMID:25728390

  7. Impacts of alien invasive plants on soil nutrients are correlated with initial site conditions in NW Europe.

    PubMed

    Dassonville, Nicolas; Vanderhoeven, Sonia; Vanparys, Valérie; Hayez, Mathieu; Gruber, Wolf; Meerts, Pierre

    2008-08-01

    Alien invasive plants are capable of modifying ecosystem function. However, it is difficult to make generalisations because impacts often appear to be species- and site-specific. In this study, we examined the impacts of seven highly invasive plant species in NW Europe (Fallopia japonica, Heracleum mantegazzianum, Impatiens glandulifera, Prunus serotina, Rosa rugosa, Senecio inaequidens, Solidago gigantea) on nutrient pools in the topsoil and the standing biomass. We tested if the impacts follow predictable patterns, across species and sites or, alternatively, if they are entirely idiosyncratic. To that end, we compared invaded and adjacent uninvaded plots in a total of 36 sites with widely divergent soil chemistry and vegetation composition. For all species, invaded plots had increased aboveground biomass and nutrient stocks in standing biomass compared to uninvaded vegetation. This suggests that enhanced nutrient uptake may be a key trait of highly invasive plant species. The magnitude and direction of the impact on topsoil chemical properties were strongly site-specific. A striking finding is that the direction of change in soil properties followed a predictable pattern. Thus, strong positive impacts (higher topsoil nutrient concentrations in invaded plots compared to uninvaded ones) were most often found in sites with initially low nutrient concentrations in the topsoil, while negative impacts were generally found under the opposite conditions. This pattern was significant for potassium, magnesium, phosphorus, manganese and nitrogen. The particular site-specific pattern in the impacts that we observed provides the first evidence that alien invasive species may contribute to a homogenisation of soil conditions in invaded landscapes. PMID:18491146

  8. Torrefaction of invasive alien plants: Influence of heating rate and other conversion parameters on mass yield and higher heating value.

    PubMed

    Mundike, Jhonnah; Collard, François-Xavier; Görgens, Johann F

    2016-06-01

    With the aim of controlling their proliferation, two invasive alien plants, Lantana camara (LC) and Mimosa pigra (MP), both widespread in Africa, were considered for torrefaction for renewable energy applications. Using thermogravimetric analysis, the influence of heating rate (HR: 2.18-19.82°Cmin(-1)) together with variable temperature and hold time on char yield and HHV (in a bomb calorimeter) were determined. Statistically significant effects of HR on HHV with optima at 10.5°Cmin(-1) for LC and 20°Cmin(-1) for MP were obtained. Increases of HHV up to 0.8MJkg(-1) or energy yield greater than 10%, together with a 3-fold reduction in torrefaction conversion time could be achieved by optimisation of HR. Analysis of the torrefaction volatiles by TG-MS showed that not only hemicelluloses, but also lignin conversion, could influence the optimum HR value. PMID:26954309

  9. Alienation Incident.

    ERIC Educational Resources Information Center

    Wasserman, Louis

    1979-01-01

    Critiques Marxian "cures" for alienation as discussed in Karl Marx's "Economic and Philosophical Manuscripts." Also traces the activity of a former student who joined the revolution in Cuba. Journal available from 7 Harwood Drive, Amherst, New York, 14226. (KC)

  10. In Defense of the Alien. Volume I. Immigration Law and Legal Representation. Proceedings of the Annual Legal Conference on the Representation of Aliens (Washington, D.C., March 2-3, 1978). First Edition.

    ERIC Educational Resources Information Center

    Fragomen, Austin T., Jr., Ed.; Tomasi, Lydio F., Ed.

    The articles in this volume present the views of government representatives and others on law and policy affecting aliens, especially undocumented aliens, in the United States. Part 1 of the volume deals with legal rights and legal representation. Individual papers discuss the role and activities of the Immigration and Naturalization Service;…

  11. In Defense of the Alien. Volume II. Immigration Law and Legal Representation. Proceedings of the Annual Legal Conference on Alien's Rights: Options for the 1980s (Washington, D.C., March 29-30, 1979). First Edition.

    ERIC Educational Resources Information Center

    Fragomen, Austin T., Jr., Ed.; Tomasi, Lydio F., Ed.

    This collection of papers from a 1979 legal symposium presents the views of government representatives and experts from the private sector concerning the rights of legal and illegal aliens in the United States, international trends in aliens' rights, and immigration/refugee policy options and issues for the l980s. Issues considered include: (1)…

  12. Alien Abductions

    NASA Astrophysics Data System (ADS)

    Nickell, Joe

    2000-03-01

    Since the beginning of the modern UFO craze in 1947, an elaborate mythology has developed concerning alleged extraterrestrial visitations. ``Flying saucer" sightings (typically involving misperceptions of such mundane phenomena as meteors and research balloons) began to be accompanied in the 1950s by reports from ``contactees," persons who claimed to have had close encounters with, even to have been transported to distant planets by, UFO occupants. By the 1960s came reports of sporadic ``abductions" which have proliferated in correlation with media interest. (Indeed, by interaction between claimants and media the portrayal of aliens has evolved from a multiplicity of types into the rather standardized big-eyed humanoid model.) While evidence of alien contact has often been faked--as by spurious photos, ``crop circles," and the notorious ``Alien Autopsy" film--few alien abduction reports appear to be hoaxes. Most seem instead to come from sincere, sane individuals. Nevertheless, not one has been authenticated, and serious investigation shows that such claims can be explained as sleep-related phenomena (notably ``waking dreams"), hypnotic confabulation, and other psychological factors. As is typical of other mythologies, the alien myth involves supernormal beings that may interact with humans, and it purports to explain the workings of the universe and humanity's place within it.

  13. Neighbour Origin and Ploidy Level Drive Impact of an Alien Invasive Plant Species in a Competitive Environment

    PubMed Central

    Sun, Yan; Müller-Schärer, Heinz; Schaffner, Urs

    2016-01-01

    Our understanding of the potential mechanisms driving the spread and naturalization of alien plant species has increased over the past decades, but specific knowledge on the factors contributing to their increased impact in the introduced range is still urgently needed. The native European plant Centaurea stoebe occurs as two cytotypes with different life histories (monocarpic diploids, allo-polycarpic tetraploids). However, only tetraploids have been found in its introduced range in North America, where C. stoebe has become a most prominent plant invader. Here, we focus on the ploidy level of C. stoebe and origin of neighbouring community in explaining the high impact during the invasion of new sites in the introduced range. We conducted a mesocosm experiment under open-field conditions with the diploid (EU2x) and tetraploid (EU4x) cytotype of Centaurea stoebe from its native European (EU) range, and with the invasive tetraploid (NA4x) cytotype from the introduced North American (NA) range in competition with EU (old) or NA (new) neighbouring plant communities. In the presence of competition, the biomass of EU neighbouring community was reduced to a comparable level by all three geo-cytotypes of C. stoebe. In contrast, the biomass of the NA neighbouring community was reduced beyond when competing with tetraploid, but not with diploid C. stoebe. The fact that the biomass of all three geo-cytotypes of C. stoebe was correlated with the biomass of the EU neighbouring community, but not with that of the NA neighbouring community suggests that different mechanisms underlie the competitive interactions between C. stoebe and its old vs. new neighbouring communities, such as competition for the same limiting resources at home vs competition through novel allelo-chemicals or differential resource uptake strategies in the introduced range. We therefore caution to simply use the ecosystem impact assessed at home to predict impact in the introduced range. PMID:27203687

  14. Neighbour Origin and Ploidy Level Drive Impact of an Alien Invasive Plant Species in a Competitive Environment.

    PubMed

    Sun, Yan; Müller-Schärer, Heinz; Schaffner, Urs

    2016-01-01

    Our understanding of the potential mechanisms driving the spread and naturalization of alien plant species has increased over the past decades, but specific knowledge on the factors contributing to their increased impact in the introduced range is still urgently needed. The native European plant Centaurea stoebe occurs as two cytotypes with different life histories (monocarpic diploids, allo-polycarpic tetraploids). However, only tetraploids have been found in its introduced range in North America, where C. stoebe has become a most prominent plant invader. Here, we focus on the ploidy level of C. stoebe and origin of neighbouring community in explaining the high impact during the invasion of new sites in the introduced range. We conducted a mesocosm experiment under open-field conditions with the diploid (EU2x) and tetraploid (EU4x) cytotype of Centaurea stoebe from its native European (EU) range, and with the invasive tetraploid (NA4x) cytotype from the introduced North American (NA) range in competition with EU (old) or NA (new) neighbouring plant communities. In the presence of competition, the biomass of EU neighbouring community was reduced to a comparable level by all three geo-cytotypes of C. stoebe. In contrast, the biomass of the NA neighbouring community was reduced beyond when competing with tetraploid, but not with diploid C. stoebe. The fact that the biomass of all three geo-cytotypes of C. stoebe was correlated with the biomass of the EU neighbouring community, but not with that of the NA neighbouring community suggests that different mechanisms underlie the competitive interactions between C. stoebe and its old vs. new neighbouring communities, such as competition for the same limiting resources at home vs competition through novel allelo-chemicals or differential resource uptake strategies in the introduced range. We therefore caution to simply use the ecosystem impact assessed at home to predict impact in the introduced range. PMID:27203687

  15. Ornamental Annual Plants and Their Uses. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with ornamental annual plants and their uses. Included in the script are narrations for use with a total of 254 slides illustrating 97 different plants. At least two slides are provided for each plant: one shows the growth habits of the…

  16. Fire-driven alien invasion in a fire-adapted ecosystem.

    PubMed

    Keeley, Jon E; Brennan, Teresa J

    2012-08-01

    Disturbance plays a key role in many alien plant invasions. However, often the main driver of invasion is not disturbance per se but alterations in the disturbance regime. In some fire-adapted shrublands, the community is highly resilient to infrequent, high-intensity fires, but changes in the fire regime that result in shorter fire intervals may make these communities more susceptible to alien plant invasions. This study examines several wildfire events that resulted in short fire intervals in California chaparral shrublands. In one study, we compared postfire recovery patterns in sites with different prefire stand ages (3 and 24 years), and in another study we compared sites that had burned once in four years with sites that had burned twice in this period. The population size of the dominant native shrub Adenostoma fasciculatum was drastically reduced following fire in the 3-year sites relative to the 24-year sites. The 3-year sites had much greater alien plant cover and significantly lower plant diversity than the 24-year sites. In a separate study, repeat fires four years apart on the same sites showed that annual species increased significantly after the second fire, and alien annuals far outnumbered native annuals. Aliens included both annual grasses and annual forbs and were negatively correlated with woody plant cover. Native woody species regenerated well after the first fire but declined after the second fire, and one obligate seeding shrub was extirpated from two sites by the repeat fires. It is concluded that some fire-adapted shrublands are vulnerable to changes in fire regime, and this can lead to a loss of native diversity and put the community on a trajectory towards type conversion from a woody to an herbaceous system. Such changes result in alterations in the proportion of natives to non-natives, changes in functional types from deeply rooted shrubs to shallow rooted grasses and forbs, increased fire frequency due to the increase in fine fuels

  17. Fire-driven alien invasion in a fire-adapted ecosystem

    USGS Publications Warehouse

    Keeley, Jon E.; Brennan, Teresa J.

    2012-01-01

    Disturbance plays a key role in many alien plant invasions. However, often the main driver of invasion is not disturbance per se but alterations in the disturbance regime. In some fire-adapted shrublands, the community is highly resilient to infrequent, high-intensity fires, but changes in the fire regime that result in shorter fire intervals may make these communities more susceptible to alien plant invasions. This study examines several wildfire events that resulted in short fire intervals in California chaparral shrublands. In one study, we compared postfire recovery patterns in sites with different prefire stand ages (3 and 24 years), and in another study we compared sites that had burned once in four years with sites that had burned twice in this period. The population size of the dominant native shrub Adenostoma fasciculatum was drastically reduced following fire in the 3-year sites relative to the 24-year sites. The 3-year sites had much greater alien plant cover and significantly lower plant diversity than the 24-year sites. In a separate study, repeat fires four years apart on the same sites showed that annual species increased significantly after the second fire, and alien annuals far outnumbered native annuals. Aliens included both annual grasses and annual forbs and were negatively correlated with woody plant cover. Native woody species regenerated well after the first fire but declined after the second fire, and one obligate seeding shrub was extirpated from two sites by the repeat fires. It is concluded that some fire-adapted shrublands are vulnerable to changes in fire regime, and this can lead to a loss of native diversity and put the community on a trajectory towards type conversion from a woody to an herbaceous system. Such changes result in alterations in the proportion of natives to non-natives, changes in functional types from deeply rooted shrubs to shallow rooted grasses and forbs, increased fire frequency due to the increase in fine fuels

  18. Aliens in Your Classroom? Plants and EE in the Classroom and in the Field.

    ERIC Educational Resources Information Center

    Raymond, Stephanie

    1999-01-01

    Finds that many restoration projects have attempted to replace the native species, but project planners often have an imperfect understanding of the plant communities they are trying to re-create. Argues that when students join these projects, they may receive an inaccurate impression of local ecosystems. (Author/CCM)

  19. The role of habitat factors in successful invasion of alien plant Acer negundo in riparian zones.

    NASA Astrophysics Data System (ADS)

    Sikorski, Piotr; Sikorska, Daria

    2016-04-01

    Ash-leaved maple (Acer negundo) is one of the most invasive species occurring in riparian zones. The invasion is especially effective in disturbed areas, as the plant favours anthropogenic sites. The plant was also observed to be able to penetrate into sandy bars, also those separated from the land, inaccessible to people. It's removal is time-consuming and laborious, often involves damage done to sensitive vegetation and the results are doubtful, as the plant quickly regenerates. The invasion patterns and establishment of ash-leaved maple in natural ecosystems are poorly investigated. The aim of this study was to test how habitat factors such as: light availability, soil characteristics and competition contribute to ash-leaved maple effective colonization of natural sand bars free from anthropogenic pressure. In 2014 sand bars located in Vistula River Valley in Warsaw were inventoried and classified basing on their development stage as 1 - initial, 2 - unstable, 3 - stable. Apart from the occurrence of the invasive ash-leaved maple the plants competing with it were recognized and the percentage of the shoots of shrubs and herbaceous plants was estimated. PAR was measured at ground level and 1 meter above ground, the thickness of organic layer formed on the top of the sand was also measured as the indicator of sand bar development stage. The maple's survival in extremely difficult conditions resembles the strategy of willows and poplars naturally occurring in the riparian zones, which are well adapted to this environment. The success of invasion strongly depends on the plants establishment during sand bars initial stage of development. The seedlings growth correlates with the age of the sand bar (r1=0,41, r2=0,42 i r3=0,57). The colonization lasts for 4-6 years and the individuals start to cluster in bigger parches. After that period the maple turns into the phase of competition for space. Habitat factors such as shading (r2=0,41 i r3=0,51) and organic layer

  20. Site-specific conditions influence plant naturalization: The case of alien Proteaceae in South Africa

    NASA Astrophysics Data System (ADS)

    Moodley, Desika; Geerts, Sjirk; Rebelo, Tony; Richardson, David M.; Wilson, John R. U.

    2014-08-01

    The outcome of plant introductions is often considered in binary terms (invasive or non-invasive). However, most species experience a time lag before naturalization occurs, and many species become naturalized at some sites but not at others. It is therefore important to understand the site-specific mechanisms underlying naturalization. Proteaceae is an interesting case as some species are widespread invaders, while others, despite a long history of cultivation, show no signs of naturalization. At least 26 non-native Proteaceae species have been introduced to, and are cultivated in, South Africa. We mapped populations and examined differences between naturalized and non-naturalized populations (e.g. propagule pressure, land use and bioclimatic suitability). Of the 15 species surveyed, 6 were naturalized at one or more sites. Of these, Hakea salicifolia is most widely cultivated, but is only naturalizing in some areas (32 naturalized populations out of 62 populations that were surveyed). We found propagule pressure to be the most important determinant of naturalization for H. salicifolia. However, in suboptimal climatic conditions, naturalization only occurred if micro-site conditions were suitable, i.e. there was some disturbance and water available. For the other naturalized species there were few sites to compare, but we came to similar conclusions - Banksia integrifolia only naturalized at the site where it was planted the longest; Banksia serrata only naturalized at a site influenced by fire regimes; while Banksia formosa naturalized at sites with high propagule pressure, absence of fires and where there is no active clearing of the plants. Naturalization of Proteaceae in South Africa appears to be strongly mediated by site-specific anthropogenic activities (e.g. many planted individuals and water availability). More broadly, we argue that invasion biology needs to focus more closely on the mechanisms by which species and pathways interact to determine the

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  2. Pinellas Plant annual site environmental report for calendar year 1993

    SciTech Connect

    Not Available

    1994-06-10

    Martin Marietta Specialty Components, Inc., and the US Department of Energy are committed to successfully administering a high quality Environmental Management Program at the Pinellas Plant in Pinellas County, Florida. Part of this commitment includes accurately documenting and communicating to the Pinellas Plant stakeholder the results of their environmental compliance and monitoring activities. The Annual Site Environmental Report presents a comprehensive summary of the results of the environmental monitoring, waste management, and environmental restoration programs at the Pinellas Plant for 1993. This report also includes the plant`s performance in the areas of compliance with applicable regulatory requirements and standards and identifies major environmental management program initiatives and accomplishments for 1993.

  3. Changes in defense of an alien plant Ambrosia artemisiifolia before and after the invasion of a native specialist enemy Ophraella communa.

    PubMed

    Fukano, Yuya; Yahara, Tetsukazu

    2012-01-01

    The evolution of increased competitive ability hypothesis (EICA) predicts that when alien plants are free from their natural enemies they evolve lower allocation to defense in order to achieve a higher growth rate. If this hypothesis is true, the converse implication would be that the defense against herbivory could be restored if a natural enemy also becomes present in the introduced range. We tested this scenario in the case of Ambrosia artemisiifolia (common ragweed) - a species that invaded Japan from North America. We collected seeds from five North American populations, three populations in enemy free areas of Japan and four populations in Japan where the specialist herbivore Ophraella communa naturalized recently. Using plants grown in a common garden in Japan, we compared performance of O. communa with a bioassay experiment. Consistent with the EICA hypothesis, invasive Japanese populations of A. artemisiifolia exhibited a weakened defense against the specialist herbivores and higher growth rate than native populations. Conversely, in locations where the herbivore O. communa appeared during the past decade, populations of A. artemisiifolia exhibited stronger defensive capabilities. These results strengthen the case for EICA and suggest that defense levels of alien populations can be recuperated rapidly after the native specialist becomes present in the introduced range. Our study implies that the plant defense is evolutionary labile depending on plant-herbivore interactions. PMID:23145089

  4. Changes in Defense of an Alien Plant Ambrosia artemisiifolia before and after the Invasion of a Native Specialist Enemy Ophraella communa

    PubMed Central

    Fukano, Yuya; Yahara, Tetsukazu

    2012-01-01

    The evolution of increased competitive ability hypothesis (EICA) predicts that when alien plants are free from their natural enemies they evolve lower allocation to defense in order to achieve a higher growth rate. If this hypothesis is true, the converse implication would be that the defense against herbivory could be restored if a natural enemy also becomes present in the introduced range. We tested this scenario in the case of Ambrosia artemisiifolia (common ragweed) – a species that invaded Japan from North America. We collected seeds from five North American populations, three populations in enemy free areas of Japan and four populations in Japan where the specialist herbivore Ophraella communa naturalized recently. Using plants grown in a common garden in Japan, we compared performance of O. communa with a bioassay experiment. Consistent with the EICA hypothesis, invasive Japanese populations of A. artemisiifolia exhibited a weakened defense against the specialist herbivores and higher growth rate than native populations. Conversely, in locations where the herbivore O. communa appeared during the past decade, populations of A. artemisiifolia exhibited stronger defensive capabilities. These results strengthen the case for EICA and suggest that defense levels of alien populations can be recuperated rapidly after the native specialist becomes present in the introduced range. Our study implies that the plant defense is evolutionary labile depending on plant-herbivore interactions. PMID:23145089

  5. Pinellas Plant annual site environmental report for calendar year 1995

    SciTech Connect

    1996-05-01

    Lockheed Martin Specialty Components, Inc., and the US Department of Energy are committed to successfully administering a high-quality Environmental, Safety and Health Program at the Pinellas Plant in Pinellas County, Florida. Part of this commitment includes accurately documenting and communicating to the Pinellas Plant stakeholders the results of the Pinellas Plant`s environmental compliance and monitoring activities. The Annual Site Environmental Report presents a comprehensive summary of the results of the Environmental Monitoring, Waste Management, and Environmental Restoration Programs at the Pinellas Plant for 1995. This report also includes the plant`s performance in the areas of compliance with applicable regulatory requirements and standards and identifies major Environmental, Safety and Health Program initiatives and accomplishments for 1995. As a result of the end of the Department of Energy`s Defense Programs mission (weapons production) on September 30, 1994, considerable changes at the Pinellas Plant are occurring. The Department of Energy`s Environmental Management is now the landlord of the Pinellas Plant to facilitate the plant`s new mission of transition to alternate use in support of economic development and safe shutdown. The Department of Energy sold the Pinellas Plant to the Pinellas County Industry Council in March 1995, and it is leasing back a portion of the plant through September 1997, to complete the safe shutdown and transition activities.

  6. ALIENS IN WESTERN STREAM ECOSYSTEMS

    EPA Science Inventory

    The USEPA's Environmental Monitoring and Assessment Program conducted a five year probability sample of permanent mapped streams in 12 western US states. The study design enables us to determine the extent of selected riparian invasive plants, alien aquatic vertebrates, and some ...

  7. Effects of Alien Plants on Ecosystem Structure and Functioning and Implications for Restoration: Insights from Three Degraded Sites in South African Fynbos

    NASA Astrophysics Data System (ADS)

    Gaertner, Mirijam; Richardson, David M.; Privett, Sean D. J.

    2011-07-01

    We investigated the type and extent of degradation at three sites on the Agulhas Plain, South Africa: an old field dominated by the alien grass Pennisetum clandestinum Pers . (kikuyu), an abandoned Eucalyptus plantation, and a natural fynbos community invaded by nitrogen fixing—Australian Acacia species. These forms of degradation are representative of many areas in the region. By identifying the nature and degree of ecosystem degradation we aimed to determine appropriate strategies for restoration in this biodiversity hotspot. Vegetation surveys were conducted at degraded sites and carefully selected reference sites. Soil-stored propagule seed banks and macro- and micro-soil nutrients were determined. Species richness, diversity and native cover under Eucalyptus were extremely low compared to the reference site and alterations of the soil nutrients were the most severe. The cover of indigenous species under Acacia did not differ significantly from that in reference sites, but species richness was lower under Acacia and soils were considerably enriched. Native species richness was much lower in the kikuyu site, but soil nutrient status was similar to the reference site. Removal of the alien species alone may be sufficient to re-initiate ecosystem recovery at the kikuyu site, whereas active restoration is required to restore functioning ecosystems dominated by native species in the Acacia thicket and the Eucalyptus plantation. To restore native plant communities we suggest burning, mulching with sawdust and sowing of native species.

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

    NASA Astrophysics Data System (ADS)

    Bailey, Joseph; Field, Richard; Boyd, Doreen

    2016-04-01

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

  9. Portsmouth Gaseous Diffusion Plant annual site environmental report for 1993

    SciTech Connect

    Horak, C.M.

    1994-11-01

    This calendar year (CY) 1993 annual report on environmental monitoring of the US Department of Energy`s (DOE`s) Portsmouth Gaseous Diffusion Plant (Portsmouth) and its environs consists of three separate documents: a summary pamphlet for the general public; a more detail discussion and of compliance status, data, and environmental impacts (this document); and a volume of detailed data that is available on request. The objectives of this report are to report compliance status during 1993; provide information about the plant site and plant operations; report 1993 monitoring data for the installation and its environs that may have been affected by operations on the plant site; document information on input and assumptions used in calculations; provide trend analyses (where appropriate) to indicate increases and decreases in environmental impact, and provide general information on quality assurance for the environmental monitoring program.

  10. Alienation, Dogmatism and Acquiescence.

    ERIC Educational Resources Information Center

    Ray, John J.

    1984-01-01

    Examined the issue of acquiescence by administering a balanced dogmatism scale and a balanced alienation scale to a random sample of Australians (N=118). Results showed that dogmatism and alienation did not correlate when acquiescence was controlled. (LLL)

  11. 76 FR 26302 - Submission for OMB Review; Comment Request; Reunification Procedures for Unaccompanied Alien...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

    ...; Reunification Procedures for Unaccompanied Alien Children Description Following the passage of the 2002 Homeland... Resettlement (ORR), is charged with the care and placement of unaccompanied alien children in Federal custody... unaccompanied alien. Annual Burden Estimates Number of Average Instrument Number of responses per burden...

  12. The coregulator Alien

    PubMed Central

    Papaioannou, Maria; Melle, Christian; Baniahmad, Aria

    2007-01-01

    Alien has characteristics of a corepressor for selected members of the nuclear hormone receptor (NHR) superfamily and also for transcription factors involved in cell cycle regulation and DNA repair. Alien mediates gene silencing and represses the transactivation of specific NHRs and other transcription factors to modulate hormone response and cell proliferation. Alien is a highly conserved protein and is expressed in a wide variety of tissues. Knockout of the gene encoding Alien in mice is embryonic lethal at a very early stage, indicating an important evolutionary role in multicellular organisms. From a mechanistic perspective, the corepressor function of Alien is in part mediated by histone deacetylase (HDAC) activity. In addition, Alien seems to modulate nucleosome assembly activity. This suggests that Alien is acting on chromatin not only through recruitment of histone-modifying activities, but also through enhancing nucleosome assembly. PMID:18174916

  13. Waste Isolation Pilot Plant Annual Site Environmental Report for 2012

    SciTech Connect

    2013-09-01

    The purpose of the Waste Isolation Pilot Plant (WIPP) Annual Site Environmental Report for 2012 (ASER) is to provide information required by U.S. Department of Energy (DOE) Order 231.1B, Environment, Safety, and Health Reporting. Specifically, the ASER presents summary environmental data to: Characterize site environmental management performance; Summarize environmental occurrences and responses reported during the calendar year; Confirm compliance with environmental standards and requirements; Highlight significant environmental accomplishments, including progress toward the DOE Environmental Sustainability Goals made through implementation of the WIPP Environmental Management System (EMS).

  14. Alien species as a driver of recent extinctions.

    PubMed

    Bellard, Céline; Cassey, Phillip; Blackburn, Tim M

    2016-02-01

    We assessed the prevalence of alien species as a driver of recent extinctions in five major taxa (plants, amphibians, reptiles, birds and mammals), using data from the IUCN Red List. Our results show that alien species are the second most common threat associated with species that have gone completely extinct from these taxa since AD 1500. Aliens are the most common threat associated with extinctions in three of the five taxa analysed, and for vertebrate extinctions overall. PMID:26888913

  15. Incorporating stakeholder preferences in the selection of technologies for using invasive alien plants as a bio-energy feedstock: applying the analytical hierarchy process.

    PubMed

    De Lange, W J; Stafford, W H L; Forsyth, G G; Le Maitre, D C

    2012-05-30

    Invasive alien plants (IAPs) impose significant social costs on the population of the Agulhas Plain region in South Africa due to their adverse impacts on ecosystem goods and services (decreased water supply and increased fire risk). While the cost of clearing IAPs is considerable, this paper assesses opportunities to reduce some of the social and environmental burdens (e.g. disruptions of ecosystems which have negative impacts on livelihoods) by using IAP biomass to produce bio-energy. However, such an initiative could increase financial dependency on these plants and is thus considered to be a major risk factor which could create adverse incentives to illegally grow these plants. A participatory decision-making process with active stakeholder participation is a key element in managing such an initiative. We used a multi-stakeholder engagement process and the analytical hierarchy process to define and weigh suitable criteria for the assessment of different "IAP biomass to bio-energy" technology scenarios on the Agulhas Plain. Feasible scenarios were constructed by means of an expert panel which were then ranked according to stakeholder preference. The six criteria were: minimising impacts on natural resources; job creation; certainty of benefits to local people in the study area; development of skills for life; technology performance and cost efficiency. This ranking was largely determined by the preference for resource efficiency in terms of minimising impacts on natural ecosystems and the localisation of benefits. The smaller, modular technologies were consequently preferred since these realise direct local benefits while developing local skills and capacity in their manufacture, sales and maintenance. The rankings as obtained in this study are context-bound, which implies that the findings only have limited application to areas with similar biophysical and socio-economic characteristics. However, the method itself is fully generalisable, and the same

  16. Will climate change drive alien invasive plants into areas of high protection value? An improved model-based regional assessment to prioritise the management of invasions.

    PubMed

    Vicente, J R; Fernandes, R F; Randin, C F; Broennimann, O; Gonçalves, J; Marcos, B; Pôças, I; Alves, P; Guisan, A; Honrado, J P

    2013-12-15

    Species distribution models (SDMs) studies suggest that, without control measures, the distribution of many alien invasive plant species (AIS) will increase under climate and land-use changes. Due to limited resources and large areas colonised by invaders, management and monitoring resources must be prioritised. Choices depend on the conservation value of the invaded areas and can be guided by SDM predictions. Here, we use a hierarchical SDM framework, complemented by connectivity analysis of AIS distributions, to evaluate current and future conflicts between AIS and high conservation value areas. We illustrate the framework with three Australian wattle (Acacia) species and patterns of conservation value in Northern Portugal. Results show that protected areas will likely suffer higher pressure from all three Acacia species under future climatic conditions. Due to this higher predicted conflict in protected areas, management might be prioritised for Acacia dealbata and Acacia melanoxylon. Connectivity of AIS suitable areas inside protected areas is currently lower than across the full study area, but this would change under future environmental conditions. Coupled SDM and connectivity analysis can support resource prioritisation for anticipation and monitoring of AIS impacts. However, further tests of this framework over a wide range of regions and organisms are still required before wide application. PMID:24161807

  17. Alienation and Illness.

    ERIC Educational Resources Information Center

    Kobasa, Suzanne C.

    Reviews of studies of four groups (business executives, lawyers, Army officers, and working women) which demonstrate the health-damaging effects of alienation in certain life situations show that, when under stress, members of these groups who feel alienated fall ill, medically and/or psychiatrically. Three models are described which may explain…

  18. The aliens are hiding

    NASA Astrophysics Data System (ADS)

    2015-06-01

    In reply to the physicsworld.com news story “Trail goes cold on alien hotspots, for now” (28 April, http://ow.ly/MeOpZ; see also p5), which described the results of a survey that looked for unexplained pockets of infrared radiation that could have been produced by advanced alien civilizations.

  19. Alienation from School

    ERIC Educational Resources Information Center

    Hascher, Tina; Hagenauer, Gerda

    2010-01-01

    Two studies aimed at understanding the time course of alienation from school and school factors that may influence alienation from school during early adolescence. In Study 1, 434 students from grade 5-8 participated (cross-sectional design). In Study 2, we followed 356 students from grade 6-7 (longitudinal design). The results confirm the…

  20. The negative effect of biocrusts upon annual-plant growth on sand dunes during extreme droughts

    NASA Astrophysics Data System (ADS)

    Kidron, Giora J.

    2014-01-01

    The moisture content of crusted and non-crusted habitats on sand was measured.Higher available water characterized the non-crusted habitats during drought years.Non-crusted habitats had higher species diversity, density and biomass.Crusts exert a negative effect on annual plants during droughts.Mobile sand serve as fertility belts for annual plants during drought years.

  1. Alienation Attitudes and Exploratory Behavior.

    ERIC Educational Resources Information Center

    Maddi, Salvatore R.

    In order to give the psychological conception of alienation greater cogency relative to the influence of sociological alienation, research is needed that ties alienation attitudes to individual personal behavior. It was hypothesized that the stronger the alienation attitudes of people, the weaker will be their exploratory behavior. Thus,…

  2. Plant community patterns in unburned and burned blackbrush (Coleogyne ramosissima Torr.) shrublands in the Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.; Matchett, J.R.

    2003-01-01

    The blackbrush vegetation type is dominated by Coleogyne ramossisima, which is thought to preclude the coexistence of many other plant species. Fire can remove blackbrush cover and possibly increase plant species richness and evenness. Fire also may increase the frequency and cover of alien annual grasses, thereby intensifying landscape flammability. We tested these predictions in unburned and burned (6-14 years postfire) blackbrush at 3 sites spanning the range of this vegetation type in the Mojave Desert. Species richness in unburned blackbrush was similar to published values for other vegetation types in western North America, but richness varied significantly among the 3 sites and 4 spatial scales (1, 10, 100, and 1000 m2). Richness values declined in order from annual forbs, woody perennials, herbaceous perennials, annual grasses, cacti, to perennial grasses. Fire reduced Coleogyne cover, thus boosting species evenness. In contrast, species richness decreased after burning, although the results varied among spatial scales. Total cover was unaffected by fire because cover of woody perennials decreased, while cover of annual forbs, annual grasses, herbaceous perennials, and perennial grasses increased. Native species richness and cover decreased, whereas alien richness and cover increased after burning, especially where the alien forb Erodium cicutarium was present. Fire had no effect on frequency and variable effects on cover of alien annual grasses. These results indicate that in blackbrush species richness can vary among sites and local spatial scales, and effects of fire can vary among plant life-forms and between natives and aliens.

  3. Increasing Seriousness of Plant Invasions in Croplands of Eastern China in Relation to Changing Farming Practices: A Case Study

    PubMed Central

    Chen, Guo-Qi; He, Yun-He; Qiang, Sheng

    2013-01-01

    Arable areas are commonly susceptible to alien plant invasion because they experience dramatic environmental influences and intense anthropogenic activity. However, the limited reports on relevant factors in plant invasion of croplands have addressed single or a few invasive species and environmental factors. To elucidate key factors affecting plant invasions in croplands, we analyzed the relationship between 11 effective factors and changes in composition of alien plants, using field surveys of crop fields in Anhui Province conducted during 1987–1990 (historical dataset) and 2005–2010 (recent dataset), when rapid urbanization was occurring in China. We found that in the past few decades, the dominance and richness of alien plant populations approximately doubled, despite differences among the 4 regions of Anhui Province. Among the 38 alien invasive plant species observed in the sites, the dominance values of 11 species increased significantly, while the dominance of 4 species decreased significantly. The quantity of chemical fertilizer and herbicide applied, population density, agricultural machinery use, traffic frequency, and annual mean temperature were significantly related to increased richness and annual dominance values of alien plant species. Our findings suggest that the increase in alien plant invasions during the past few decades is primarily a result of increased application of chemical fertilizer and herbicides. PMID:24066105

  4. Waset Isolation Pilot Plant Annual Site Environmental Report for 2006

    SciTech Connect

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2007-09-26

    The purpose of the Waste Isolation Pilot Plant Annual Site Environmental Report for 2006 (ASER) is to provide information required by U.S. Department of Energy (DOE) Order 231.1A, Environment, Safety, and Health Reporting. Specifically, the ASER presents summary environmental data that: (a) Characterize site environmental management performance; (b) Summarize environmental occurrences and responses reported during the calendar year; (c) Confirm compliance with environmental standards and requirements; and (d) Highlight significant facility programs and efforts. The DOE Carlsbad Field Office (CBFO) and Washington TRU Solutions LLC (WTS) maintain and preserve the environmental resources at the WIPP site. DOE Order 231.1A; DOE Order 450.1, Environmental Protection Program; and DOE Order 5400.5, Radiation Protection of the Public and Environment, require that the affected environment at and near DOE facilities be monitored to ensure the safety and health of the public and the environment. This report was prepared in accordance with DOE Order 231.1A. This order requires that DOE facilities submit an ASER to the DOE Headquarters Office of the Assistant Secretary for Environment, Safety, and Health. The WIPP Hazardous Waste Facility Permit (HWFP) (No. NM4890139088-TSDF [treatment, storage, and disposal facility]) further requires that the ASER be provided to the New Mexico Environment Department (NMED).

  5. Waste Isolation Pilot Plant Annual Site Environmental Report for 2010

    SciTech Connect

    2011-09-01

    The purpose of the Waste Isolation Pilot Plant (WIPP) Annual Site Environmental Report for 2010 (ASER) is to provide information required by U.S. Department of Energy (DOE) Order 231.1A, Environment, Safety, and Health Reporting. Specifically, the ASER presents summary environmental data to: (1) Characterize site environmental management performance. (2) Summarize environmental occurrences and responses reported during the calendar year. (3) Confirm compliance with environmental standards and requirements. (4) Highlight significant environmental accomplishments, including progress toward the DOE Environmental Sustainability Goals made through implementation of the WIPP Environmental Management System (EMS). The DOE Carlsbad Field Office (CBFO) and the management and operating contractor (MOC), Washington TRU Solutions LLC (WTS), maintain and preserve the environmental resources at the WIPP. DOE Order 231.1A; DOE Order 450.1A, Environmental Protection Program; and DOE Order 5400.5, Radiation Protection of the Public and the Environment, require that the affected environment at and near DOE facilities be monitored to ensure the safety and health of the public and workers, and preservation of the environment. This report was prepared in accordance with DOE Order 231.1A, which requires that DOE facilities submit an ASER to the DOE Headquarters Chief Health, Safety, and Security Officer. The WIPP Hazardous Waste Facility Permit Number NM4890139088-TSDF (Permit) further requires that the ASER be provided to the New Mexico Environment Department (NMED).

  6. Phenotypic selection favors missing trait combinations in coexisting annual plants.

    PubMed

    Kimball, Sarah; Gremer, Jennifer R; Huxman, Travis E; Lawrence Venable, D; Angert, Amy L

    2013-08-01

    Trade-offs among traits are important for maintaining biodiversity, but the role of natural selection in their construction is not often known. It is possible that trade-offs reflect fundamental constraints, negative correlational selection, or directional selection operating on costly, redundant traits. In a Sonoran Desert community of winter annual plants, we have identified a trade-off between relative growth rate and water-use efficiency among species, such that species with high relative growth rate have low water-use efficiency and vice versa. We measured selection on water-use efficiency, relative growth rate, and underlying traits within populations of four species at two study sites with different average climates. Phenotypic trait correlations within species did not match the among-species trade-off. In fact, for two species with high water-use efficiency, individuals with high relative growth rate also had high water-use efficiency. All populations experienced positive directional selection for water-use efficiency and relative growth rate. Selection tended to be stronger on water-use efficiency at the warmer and drier site, and selection on relative growth rate tended to be stronger at the cooler and wetter site. Our results indicate that directional natural selection favors a phenotype not observed among species in the community, suggesting that the among-species trade-off could be due to pervasive genetic constraints, perhaps acting in concert with processes of community assembly. PMID:23852354

  7. Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola

    PubMed Central

    Leinaas, Hans Petter; Bengtsson, Jan; Janion-Scheepers, Charlene; Chown, Steven L

    2015-01-01

    Biological invasions are major threats to biodiversity, with impacts that may be compounded by other forms of environmental change. Observations of high density of the invasive springtail (Collembola), Hypogastrura manubrialis in heavily grazed renosterveld vegetation in the Western Cape, South Africa, raised the question of whether the invasion was favored by changes in plant litter quality associated with habitat disturbance in this vegetation type. To examine the likely mechanisms underlying the high abundance of H. manubrialis, cages with three types of naturally occurring litter with different nutrient content were placed out in the area and collected after different periods of time. Hypogastrura manubrialis was mainly found in the nutrient-rich litter of the yellowbush (Galenia africana), which responds positively to disturbance in the form of overgrazing. This suggests that invasion may have been facilitated by a positive interaction with this grazing resistant plant. By contrast, indigenous Collembola were least abundant in yellowbush litter. Negative correlations between high abundance of H. manubrialis and the abundance and diversity of other species suggest that competitive interactions might underlie low abundance of these other species at the patch level. Group behavior enables H. manubrialis to utilize efficiently this ephemeral, high quality resource, and might improve its competitive ability. The results suggest that interactions among environmental change drivers may lead to unforeseen invasion effects. H. manubrialis is not likely to be very successful in un-grazed renosterveld, but in combination with grazing, favoring the nutrient-rich yellowbush, it may become highly invasive. Field manipulations are required to fully verify these conclusions. PMID:26380678

  8. Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola.

    PubMed

    Leinaas, Hans Petter; Bengtsson, Jan; Janion-Scheepers, Charlene; Chown, Steven L

    2015-08-01

    Biological invasions are major threats to biodiversity, with impacts that may be compounded by other forms of environmental change. Observations of high density of the invasive springtail (Collembola), Hypogastrura manubrialis in heavily grazed renosterveld vegetation in the Western Cape, South Africa, raised the question of whether the invasion was favored by changes in plant litter quality associated with habitat disturbance in this vegetation type. To examine the likely mechanisms underlying the high abundance of H. manubrialis, cages with three types of naturally occurring litter with different nutrient content were placed out in the area and collected after different periods of time. Hypogastrura manubrialis was mainly found in the nutrient-rich litter of the yellowbush (Galenia africana), which responds positively to disturbance in the form of overgrazing. This suggests that invasion may have been facilitated by a positive interaction with this grazing resistant plant. By contrast, indigenous Collembola were least abundant in yellowbush litter. Negative correlations between high abundance of H. manubrialis and the abundance and diversity of other species suggest that competitive interactions might underlie low abundance of these other species at the patch level. Group behavior enables H. manubrialis to utilize efficiently this ephemeral, high quality resource, and might improve its competitive ability. The results suggest that interactions among environmental change drivers may lead to unforeseen invasion effects. H. manubrialis is not likely to be very successful in un-grazed renosterveld, but in combination with grazing, favoring the nutrient-rich yellowbush, it may become highly invasive. Field manipulations are required to fully verify these conclusions. PMID:26380678

  9. Waste Isolation Pilot Plant Annual Site Enviromental Report for 2008

    SciTech Connect

    Washington Regulatory and Enviromnetal Services

    2009-09-21

    The purpose of the Waste Isolation Pilot Plant Annual Site Environmental Report for 2008 (ASER) is to provide information required by U.S. Department of Energy (DOE) Order 231.1A, Environment, Safety, and Health Reporting. Specifically, the ASER presents summary environmental data to characterize site environmental management performance; summarize environmental occurrences and responses reported during the calendar year; confirm compliance with environmental standards and requirements; highlight significant facility programs and efforts; and describe how compliance and environmental improvement is accomplished through the WIPP Environmental Management System (EMS). The DOE Carlsbad Field Office (CBFO) and the management and operating contractor (MOC), Washington TRU Solutions LLC (WTS), maintain and preserve the environmental resources at the Waste Isolation Pilot Plant (WIPP). DOE Order 231.1A; DOE Order 450.1A, Environmental Protection Program; and DOE Order 5400.5, Radiation Protection of the Public and the Environment, require that the affected environment at and near DOE facilities be monitored to ensure the safety and health of the public and workers, and preservation of the environment. This report was prepared in accordance with DOE Order 231.1A, which requires that DOE facilities submit an ASER to the DOE Headquarters Chief Health, Safety, and Security Officer. The WIPP Hazardous Waste Facility Permit (HWFP) Number NM4890139088-TSDF (treatment, storage, and disposal facility) further requires that the ASER be provided to the New Mexico Environment Department (NMED). The WIPP mission is to safely dispose of transuranic (TRU) radioactive waste generated by the production of nuclear weapons and other activities related to the national defense of the United States. In 2008, 5,265 cubic meters (m3) of TRU waste were disposed of at the WIPP facility, including 5,216 m3 of contact-handled (CH) TRU waste and 49 m3 of remote-handled (RH) TRU waste. From the first

  10. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent residence.... An alien commuter engaged in seasonal work will be presumed to have taken up residence in the...

  11. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent residence.... An alien commuter engaged in seasonal work will be presumed to have taken up residence in the...

  12. An annual plant growth proxy in the Mojave Desert using MODIS-EVI data

    USGS Publications Warehouse

    Wallace, C.S.A.; Thomas, K.A.

    2008-01-01

    In the arid Mojave Desert, the phenological response of vegetation is largely dependent upon the timing and amount of rainfall, and maps of annual plant cover at any one point in time can vary widely. Our study developed relative annual plant growth models as proxies for annual plant cover using metrics that captured phenological variability in Moderate-Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) satellite images. We used landscape phenologies revealed in MODIS data together with ecological knowledge of annual plant seasonality to develop a suite of metrics to describe annual growth on a yearly basis. Each of these metrics was applied to temporally-composited MODIS-EVI images to develop a relative model of annual growth. Each model was evaluated by testing how well it predicted field estimates of annual cover collected during 2003 and 2005 at the Mojave National Preserve. The best performing metric was the spring difference metric, which compared the average of three spring MODIS-EVI composites of a given year to that of 2002, a year of record drought. The spring difference metric showed correlations with annual plant cover of R2 = 0.61 for 2005 and R 2 = 0.47 for 2003. Although the correlation is moderate, we consider it supportive given the characteristics of the field data, which were collected for a different study in a localized area and are not ideal for calibration to MODIS pixels. A proxy for annual growth potential was developed from the spring difference metric of 2005 for use as an environmental data layer in desert tortoise habitat modeling. The application of the spring difference metric to other imagery years presents potential for other applications such as fuels, invasive species, and dust-emission monitoring in the Mojave Desert.

  13. An Annual Plant Growth Proxy in the Mojave Desert Using MODIS-EVI Data

    PubMed Central

    Wallace, Cynthia S.A.; Thomas, Kathryn A.

    2008-01-01

    In the arid Mojave Desert, the phenological response of vegetation is largely dependent upon the timing and amount of rainfall, and maps of annual plant cover at any one point in time can vary widely. Our study developed relative annual plant growth models as proxies for annual plant cover using metrics that captured phenological variability in Moderate-Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) satellite images. We used landscape phenologies revealed in MODIS data together with ecological knowledge of annual plant seasonality to develop a suite of metrics to describe annual growth on a yearly basis. Each of these metrics was applied to temporally-composited MODIS-EVI images to develop a relative model of annual growth. Each model was evaluated by testing how well it predicted field estimates of annual cover collected during 2003 and 2005 at the Mojave National Preserve. The best performing metric was the spring difference metric, which compared the average of three spring MODIS-EVI composites of a given year to that of 2002, a year of record drought. The spring difference metric showed correlations with annual plant cover of R2 = 0.61 for 2005 and R2 = 0.47 for 2003. Although the correlation is moderate, we consider it supportive given the characteristics of the field data, which were collected for a different study in a localized area and are not ideal for calibration to MODIS pixels. A proxy for annual growth potential was developed from the spring difference metric of 2005 for use as an environmental data layer in desert tortoise habitat modeling. The application of the spring difference metric to other imagery years presents potential for other applications such as fuels, invasive species, and dust-emission monitoring in the Mojave Desert.

  14. Alien Life Imagined

    NASA Astrophysics Data System (ADS)

    Brake, Mark

    2012-11-01

    1. Kosmos: aliens in ancient Greece; 2. The world turned upside down: Copernicanism and the voyages of discovery; 3. In Newton's train: pluralism and the system of the world; 4. Extraterrestrials in the early machine age; 5. After Darwin: the war of the worlds; 6. Einstein's sky: life in the new universe; 7. Ever since SETI: astrobiology in the space age; References; Index.

  15. Aliens and atheism

    NASA Astrophysics Data System (ADS)

    Campos, Sergio; de Muynck, Willem; Virginia; Peerally, Abed; Tyler, David; Stephen

    2014-11-01

    In reply to the physicsworld.com blog post "Aliens and atheists" (2 October, http://ow.ly/CQzu4), about a survey that found that atheists are more likely than religious people to believe that life exists on other planets.

  16. Alien invasive birds.

    PubMed

    Brochier, B; Vangeluwe, D; van den Berg, T

    2010-08-01

    A bird species is regarded as alien invasive if it has been introduced, intentionally or accidentally, to a location where it did not previously occur naturally, becomes capable of establishing a breeding population without further intervention by humans, spreads and becomes a pest affecting the environment, the local biodiversity, the economy and/or society, including human health. European Starling (Sturnus vulgaris), Common Myna (Acridotheres tristis) and Red-vented Bulbul (Pycnonotus cafer) have been included on the list of '100 of the World's Worst Invasive Alien Species', a subset of the Global Invasive Species Database. The 'Delivering Alien Invasive Species Inventories for Europe' project has selected Canada Goose (Branta canadensis), Ruddy Duck (Oxyura jamaicensis), Rose-ringed Parakeet (Psittacula krameri) and Sacred Ibis (Threskiornis aethiopicus) as among 100 of the worst invasive species in Europe. For each of these alien bird species, the geographic range (native and introduced range), the introduction pathway, the general impacts and the management methods are presented. PMID:20919578

  17. Forgetting and remembering alienation theory.

    PubMed

    Yuill, Chris

    2011-01-01

    Alienation theory has acted as the stimulus for a great deal of research and writing in the history of sociology. It has formed the basis of many sociological "classics" focused on the workplace and the experiences of workers, and has also been mobilized to chart wider social malaise and individual troubles. Alienation theory usage has, however, declined significantly since its heyday of the 1960s and 1970s. Here, the reasons why alienation theory was "forgotten" and what can be gained by "remembering" alienation theory are explored. to realize this ambition this article proceeds by (1) briefly visiting differing definitions of alienation theory, before charting its high point, and the various debates and tensions of the time, during the 1960s and 1970s; (2) analysing the reasons why alienation theory fell from grace from the 1980s onwards; (3) elaborating how and why alienation theory is still relevant for sociology and the wider social sciences today. PMID:21809508

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  19. Radioactive materials released from nuclear power plants. Annual report 1978

    SciTech Connect

    Tichler, J.; Benkovitz, C.

    1981-03-01

    Releases of radioactive materials in airborne and liquid effluents from commerical light water reactors during 1978 have been compiled and reported. Data on soild waste shipments as well as selected operating information have been included. This report supplements earlier annual reports by the former Atomic Energy Commission and the Nuclear Regulatory Commission. The 1978 release data are compared with previous years releases in tabular form. Data covering specific radionuclides are summarized.

  20. Pinellas Plant Annual Site Environmental Report for calendar year 1994

    SciTech Connect

    1995-06-01

    This report presents a comprehensive summary of the results of the Environmental Monitoring, Waste Management, and Environmental Restoration Programs at the Pinellas Plant, in Pinellas County, Florida for 1994. This report also includes the plant`s performance in the areas of compliance with applicable regulatory requirements and standards and identifies major Environmental, Safety and Health Program initiatives and accomplishments for 1994. As a result of the end of Department of Energy Defense Programs mission production on September 30, 1994, considerable changes at the Pinellas Plant occurred. These changes, which included transitioning the plant toward alternate use in support of economic development and safe shutdown, both increased and heightened Environmental, Safety and Health responsibilities. In December 1994, the Department of Energy announced it had reached an agreement to sell the Pinellas Plant to the Pinellas County Industry Council in March 1995. The plant is being leased back by the Department of Energy through September 1997 to complete safe shutdown, reconfiguration, transfer of equipment to other Department of Energy production facilities, and transition to commercial ventures. Permit modifications and transfers will be completed during 1995 to reflect the new ownership by the Pinellas County Industry Council and to include new tenants as needed.

  1. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  2. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... shall be made in accordance with 8 CFR 264.5. ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent...

  3. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  4. 8 CFR 232.3 - Arriving aliens.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Arriving aliens. 232.3 Section 232.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS DETENTION OF ALIENS FOR PHYSICAL AND MENTAL EXAMINATION § 232.3 Arriving aliens. When a district director has reasonable...

  5. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for...

  6. 8 CFR 236.13 - Ineligible aliens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 236.13 Section 236.13 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS; REMOVAL OF ALIENS ORDERED REMOVED Family Unity Program §...

  7. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  8. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for...

  9. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... shall be made in accordance with 8 CFR 264.5. ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent...

  10. 8 CFR 236.13 - Ineligible aliens.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Ineligible aliens. 236.13 Section 236.13 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS; REMOVAL OF ALIENS ORDERED REMOVED Family Unity Program §...

  11. 8 CFR 232.3 - Arriving aliens.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Arriving aliens. 232.3 Section 232.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS DETENTION OF ALIENS FOR PHYSICAL AND MENTAL EXAMINATION § 232.3 Arriving aliens. When a district director has reasonable...

  12. 8 CFR 232.3 - Arriving aliens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Arriving aliens. 232.3 Section 232.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS DETENTION OF ALIENS FOR PHYSICAL AND MENTAL EXAMINATION § 232.3 Arriving aliens. When a district director has reasonable...

  13. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for...

  14. 8 CFR 236.13 - Ineligible aliens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Ineligible aliens. 236.13 Section 236.13 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS; REMOVAL OF ALIENS ORDERED REMOVED Family Unity Program §...

  15. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  16. 8 CFR 236.13 - Ineligible aliens.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Ineligible aliens. 236.13 Section 236.13 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS; REMOVAL OF ALIENS ORDERED REMOVED Family Unity Program §...

  17. 8 CFR 232.3 - Arriving aliens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Arriving aliens. 232.3 Section 232.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS DETENTION OF ALIENS FOR PHYSICAL AND MENTAL EXAMINATION § 232.3 Arriving aliens. When a district director has reasonable...

  18. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for...

  19. 8 CFR 232.3 - Arriving aliens.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Arriving aliens. 232.3 Section 232.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS DETENTION OF ALIENS FOR PHYSICAL AND MENTAL EXAMINATION § 232.3 Arriving aliens. When a district director has reasonable...

  20. 22 CFR 41.71 - Transit aliens.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  1. 8 CFR 236.13 - Ineligible aliens.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Ineligible aliens. 236.13 Section 236.13 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS; REMOVAL OF ALIENS ORDERED REMOVED Family Unity Program §...

  2. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... shall be made in accordance with 8 CFR 264.5. ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent...

  3. 8 CFR 244.4 - Ineligible aliens.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for...

  4. Czech alien flora and the historical pattern of its formation: what came first to Central Europe?

    PubMed

    Pysek, Petr; Sádlo, Jirí; Mandák, Bohumil; Jarosík, Vojtech

    2003-03-01

    Temporal patterns of immigration to the country were analysed using 668 alien species in the flora of the Czech Republic for which the dates of the first record were available (64.8% of the total number of 1031 so-called neophytes, i.e. aliens introduced after the year 1500). After a period of initial slow increase lasting to the 1840s, the accumulation of neophytes over time could be best fitted by a linear model that explained 97% of the variance. The intensity of floristic research, which varied between periods, did not significantly affect the overall increase in the number of aliens. The effect of species traits on the year of introduction was evaluated, with continent of origin, introduction type (deliberate or accidental), life history, Grime's life strategy, onset of flowering, mode of dispersal and propagule size as explanatory variables. Species of European origin and CSR strategists arrived earlier than those with other origins and strategies. Deliberately introduced species appeared earlier than accidental arrivals, and those cultivated for utilitary reasons on average arrived earlier than ornamentals. Species capable of early flowering were remarkably more prevalent among early newcomers. A separate analysis of accidentally introduced American species also identified life history as a significant predictor of immigration time, with annuals being introduced earlier than biennials and perennials. The data contribute to an understanding of a crucial stage of the invasion process that has received little attention in the literature. The model "early alien" to Central Europe is a European species with a CSR strategy deliberately brought for cultivation as a utilitary plant. Once it escaped from cultivation, its establishment in the wild was favoured by its ability to flower early and, therefore, complete the life cycle. PMID:12647111

  5. Captured by Aliens

    NASA Astrophysics Data System (ADS)

    Achenbach, Joel

    2000-03-01

    Captured by Aliens is a long and twisted voyage from science to the supernatural and back again. I hung out in Roswell, N.M., spent time with the Mars Society, met a guy who was figuring out the best way to build a spaceship to go to Alpha Centauri. I visited the set of the X-Files and talked to Mulder and Scully. One day over breakfast I was told by NASA administrator Dan Goldin, We live in a fog, man! He wants the big answers to the big questions. I spent a night in the base of a huge radio telescope in the boondocks of West Virginia, awaiting the signal from the aliens. I was hypnotized in a hotel room by someone who suspected that I'd been abducted by aliens and that this had triggered my interest in the topic. In the last months of his life, I talked to Carl Sagan, who believed that the galaxy riots with intelligent civilizations. He's my hero, for his steadfast adherence to the scientific method. What I found in all this is that the big question that needs immediate attention is not what's out THERE, but what's going on HERE, on Earth, and why we think the way we do, and how we came to be here in the first place.

  6. Belowground Water Dynamics Under Contrasting Annual and Perennial Plant Communities in an Agriculturally-Dominated Landscape

    NASA Astrophysics Data System (ADS)

    Mora, G.; Asbjornsen, H.; Helmers, M. J.; Shepherd, G. W.

    2005-12-01

    The conversion from grasslands and forests to row-crops in the Midwest has affected soil water cycling because plant characteristics are one of the main parameters determining soil storage capacity, infiltration rates, and surface runoff. Little is known, however, about the extent of modification of soil water dynamics under different plant communities. To address this important issue, we are documenting soil water dynamics under contrasting perennial and annual plant communities in an agriculturally-dominated landscape. Measurements of soil moisture and depths of uptake of source water were obtained for six vegetative cover types (corn and soybean field, brome pasture, degraded savanna, restored savanna, and restored prairie) at the Neal Smith National Wildlife Refuge in Prairie City, Iowa. The depths of uptake of soil water were determined on the basis of oxygen isotope composition of soil water and stem water. Measurements were performed once a month during an entire growing season. Preliminary results indicate that soil water present under the different vegetation types show similar profiles with depth during the dry months. Soil water in the upper 5 cm is enriched in oxygen-18 by about 5 per mil relative to soil water at 100 cm. Our preliminary results also indicate that the isotopic composition of stem water from annual plants is typically higher by about 2 per mil relative to that of stem water from perennial plants during the dry period. Whereas the oxygen isotopic composition for corn stem water is -5.49 per mil, that for elm and oak stem water is -7.62 and -7.51 per mil, respectively. The higher isotope values for corn suggest that annual crop plants are withdrawing water from shallower soil horizons relative to perennial plants. Moreover, our preliminary data suggest lower moisture content in soil under annual plant cover. We propose that the presence of deeper roots in the perennial vegetation allows these plants to tap into deeper water sources when

  7. Using flowering and heat-loss models for improving greenhouse energy-use efficiency in annual bedding plant production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In temperate climates, annual bedding plants are typically produced in heated greenhouses from late winter through early summer. Temperature, photoperiod, light intensity, and transplant date are commonly manipulated during commercial production so that plants are in flower for predetermined market ...

  8. ORGANIC PESTICIDE MODIFICATION OF SPECIES INTERACTIONS USING ANNUAL PLANT COMMUNITIES

    EPA Science Inventory

    A method is proposed and tested for assessing multispecies responses to three pesticides (atrazine, 2,4,D and malathion). Pesticides were applied at two concentrations, mon model plant communities grown in raised beds using soil containing a natural weed bank. over by species was...

  9. Radioactive Effluents from Nuclear Power Plants Annual Report 2008

    SciTech Connect

    U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation

    2010-12-10

    This report describes radioactive effluents from commercial nuclear power plants (NPPs) in the United States. This information was reported by the licensees for radioactive discharges that occurred in 2008. The report provides information relevant to the potential impact of NPPs on the environment and on public health.

  10. Radioactive Effluents from Nuclear Power Plants Annual Report 2007

    SciTech Connect

    U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation

    2010-12-10

    This report describes radioactive effluents from commercial nuclear power plants (NPPs) in the United States. This information was reported by the licensees for radioactive discharges that occurred in 2007. The report provides information relevant to the potential impact of NPPs on the environment and on public health.

  11. LIVESTOCK ACTIVITY AND CHIHUAHUAN DESERT ANNUAL-PLANT COMMUNITIES: BOUNDARY ANALYSIS OF DISTURBANCE GRADIENTS

    EPA Science Inventory

    The impact of domestic livestock on soil properties and perennial vegetation is greatest close to water points and generally decreases exponentially with distance from water. We hypothesized that the impact of livestock on annual-plant communities would be similar to that on per...

  12. Are early summer wildfires an opportunity to revegetate exotic annual grass-invaded plant communities?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Medusahead (Taeniatherum caput-medusae (L.) Nevski) is an exotic annual grass reducing biodiversity and altering ecosystem function and processes in rangelands. Revegetation of medusahead-invaded plant communities is needed to improve ecosystem function, increase livestock forage production, and im...

  13. Nongenetic Inheritance of Induced Resistance in a Wild Annual Plant.

    PubMed

    Lankinen, Åsa; Abreha, Kibrom B; Alexandersson, Erik; Andersson, Stefan; Andreasson, Erik

    2016-08-01

    Nongenetic inheritance (e.g., transgenerational epigenetic effects) has received increasing interest in recent years, particularly in plants. However, most studies have involved a few model species and relatively little is known about wild species in these respects. We investigated transgenerational induced resistance to infection by the devastating oomycete Phytophthora infestans in Solanum physalifolium, a wild relative of cultivated potato. We treated plants with β-aminobutyric acid (BABA), a nontoxic compound acting as an inducing agent, or infected plants with P. infestans. BABA treatment reduced lesion size in detached-leaf assays inoculated by P. infestans in two of three tested genotypes, suggesting that resistance to oomycetes can be induced by BABA within a generation not only in crops or model species but also in wild species directly collected from nature. Both BABA treatment and infection in the parental generation reduced lesions in the subsequent generation in one of two genotypes, indicating a transgenerational influence on resistance that varies among genotypes. We did not detect treatment effects on seed traits, indicating the involvement of a mechanism unrelated to maternal effects. In conclusion, our study provides data on BABA induction and nongenetic inheritance of induced resistance in a wild relative of cultivated potato, implying that this factor might be important in the ecological and agricultural landscape. PMID:27070426

  14. Regulation of polyamine synthesis in plants. Annual progress report

    SciTech Connect

    Malmberg, R.L.

    1993-02-09

    Polyamines are small positively charged compounds that have been hypothesized to be involved in a wide variety of plant physiological and development functions. The regulation of the polyamine synthesis pathway is uniquely interesting because of the existence of two pathways to putrescine synthesis, and the consequent questions of how these two pathways are compartmentalized and how they interact with each other. The specific directions our research is taking are: (1) A characterization of arginine decarboxylase regulation; we have discovered two post-translational mechanisms for regulating arginine decarboxylase activity. One of these is a novel protease that clips the arginine decarboxylase pre-protein to activate it. We would like to understand this activating protease better, determine its mechanism of action, and determine its importance in the overall scheme of arginine decarboxylase regulation. (2) We have begun a similar characterization of ornithine decarboxylase by purifying it from plants. (3) We are characterizing the polyamine mutant collection we have developed. (4) Finally, we have begun to characterize the evolution of arginine decarboxylase, as an additional approach that could shed light on its functions in plants. Our intent is to understand arginine decarboxylase structure and regulation in detail, and then to further explore regulatory differences between ornithine and arginine decarboxylases.

  15. 8 CFR 244.17 - Annual registration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Annual registration. 244.17 Section 244.17... FOR NATIONALS OF DESIGNATED STATES § 244.17 Annual registration. (a) Aliens granted Temporary... of residence. Such registration will apply to nationals of those foreign states designated...

  16. 8 CFR 244.17 - Annual registration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Annual registration. 244.17 Section 244.17... FOR NATIONALS OF DESIGNATED STATES § 244.17 Annual registration. (a) Aliens granted Temporary... of residence. Such registration will apply to nationals of those foreign states designated...

  17. Non-native plant litter enhances soil carbon dioxide emissions in an invaded annual grassland.

    PubMed

    Zhang, Ling; Wang, Hong; Zou, Jianwen; Rogers, William E; Siemann, Evan

    2014-01-01

    Litter decomposition is a fundamental ecosystem process in which breakdown and decay of plant detritus releases carbon and nutrients. Invasive exotic plants may produce litter that differs from native plant litter in quality and quantity. Such differences may impact litter decomposition and soil respiration in ways that depend on whether exotic and native plant litters decompose in mixtures. However, few field experiments have examined how exotic plants affect soil respiration via litter decomposition. Here, we conducted an in situ study of litter decomposition of an annual native grass (Eragrostis pilosa), a perennial exotic forb (Alternanthera philoxeroides), and their mixtures in an annual grassland in China to examine potential invasion effects on soil respiration. Alternanthera litter decomposed faster than Eragrostis litter when each was incubated separately. Mass loss in litter mixes was more rapid than predicted from rates in single species bags (only 35% of predicted mass remained at 8 months) showing synergistic effects. Notably, exotic plant litter decomposition rate was unchanged but native plant litter decomposition rate was accelerated in mixtures (decay constant k = 0.20 month(-1)) compared to in isolation (k = 0.10 month(-1)). On average, every litter type increased soil respiration compared to bare soil from which litter was removed. However, the increases were larger for mixed litter (1.82 times) than for Alternanthera litter (1.58 times) or Eragrostis litter (1.30 times). Carbon released as CO2 relative to litter carbon input was also higher for mixed litter (3.34) than for Alternathera litter (2.29) or Eragrostis litter (1.19). Our results indicated that exotic Alternanthera produces rapidly decomposing litter which also accelerates the decomposition of native plant litter in litter mixtures and enhances soil respiration rates. Thus, this exotic invasive plant species will likely accelerate carbon cycling and increase soil respiration

  18. Desperately seeking aliens

    NASA Astrophysics Data System (ADS)

    Aldiss, Brian W.

    2001-02-01

    Belief that intelligent life is commonplace in the Universe was taken for granted by scholars and scientists until well into the nineteenth century. Space travel since the late 1950s reignited the debate, which even now attracts discussion by serious, professional scientists. And although statisticians might lobby that life must surely exist somewhere in the Universe, the evolution of what we perceive as 'intelligent life' seems utterly improbable - elsewhere as well as on Earth. Can we free ourselves of our animist fantasies and accept that all alien forms of intelligent life are, and always have been, imaginary?

  19. 1995 Annual epidemiologic surveillance report for Pantex Plant

    SciTech Connect

    1998-06-01

    This report provides a summary of epidemiologic surveillance data collected from the Pantex Plant from January 1, 1995 through December 31,1995. The data were collected by a coordinator at Pantex and submitted to the Epidemiologic Surveillance Data Center,located at Oak Ridge Institute for Science and Education, where quality control procedures and data analyses were carried out. The data presented apply only to Pantex. The main sections of the report are the same as in previous years; the 1995 report provides additional information describing the work force by age and occupational groups.

  20. A Mechanistic Study of Plant and Microbial Controls over R* for Nitrogen in an Annual Grassland

    PubMed Central

    Levine, Jonathan M.; HilleRisLambers, Janneke

    2014-01-01

    Differences in species' abilities to capture resources can drive competitive hierarchies, successional dynamics, community diversity, and invasions. To investigate mechanisms of resource competition within a nitrogen (N) limited California grassland community, we established a manipulative experiment using an R* framework. R* theory holds that better competitors within a N limited community should better depress available N in monoculture plots and obtain higher abundance in mixture plots. We asked whether (1) plant uptake or (2) plant species influences on microbial dynamics were the primary drivers of available soil N levels in this system where N structures plant communities. To disentangle the relative roles of plant uptake and microbially-mediated processes in resource competition, we quantified soil N dynamics as well as N pools in plant and microbial biomass in monoculture plots of 11 native or exotic annual grassland plants over one growing season. We found a negative correlation between plant N content and soil dissolved inorganic nitrogen (DIN, our measure of R*), suggesting that plant uptake drives R*. In contrast, we found no relationship between microbial biomass N or potential net N mineralization and DIN. We conclude that while plant-microbial interactions may have altered the overall quantity of N that plants take up, the relationship between species' abundance and available N in monoculture was largely driven by plant N uptake in this first year of growth. PMID:25170943

  1. Paducah Gaseous Diffusion Plant Annual Site Environmental Report for 1993

    SciTech Connect

    Not Available

    1994-10-01

    The purpose of this document is to summarize effluent monitoring and environmental surveillance results and compliance with environmental laws, regulations, and orders at the Paducah Gaseous Diffusion Plant (PGDP). Environmental monitoring at PGDP consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring is direct measurement or the collection and analysis of samples of liquid and gaseous discharges to the environment. Environmental surveillance is direct measurement or the collection and analysis of samples of air, water, soil, foodstuff, biota, and other media. Environmental monitoring is performed to characterize and quantify contaminants, assess radiation exposures of members of the public, demonstrate compliance with applicable standards and permit requirements, and detect and assess the effects (if any) on the local environment. Multiple samples are collected throughout the year and are analyzed for radioactivity, chemical content, and various physical attributes.

  2. (Restriction of virus infection by plants: Annual report, 1986)

    SciTech Connect

    Bruening, G.

    1986-12-05

    This research concerns the strong resistance, or even immunity, against a specific virus that is exhibited by one or a few lines of a plant species, in contrast to the general susceptibility of most lines of that species. The contrast between the reactions to virus inoculation of different lines of one species implies that a single gene or a very few genes may mediate the resistance or immunity. The prospects for isolating, studying and transferring such a gene should be good for a system with these characteristics. Seedlings of a line Arlington of the cowpea (Vigna unguiculata) fail to support the replication of cowpea mosaic virus strain SB (CPMV-SB). Genetic crosses of Arlington cowpea to the systemic host Blackeye 5 cowpea show that the immunity is inherited as a simple dominant gene. In contrast to the seedlings, the protoplasts of the Arlington cowpea support CPMV-SB replication, but only to a very low level compared to protoplasts of Blackeye 5 cowpeas. From evidence reported earlier we concluded that Arlington cowpea protoplasts restrict the production of CPMV-SB proteins. We postulated, and obtained evidence for, a proteinase inhibitor that is specific for a CPMV-SB proteinase. This proteinase inhibitor is our prime candidate for the mediator of the resistance of Arlington protoplasts to CPMV-SB. Progress to date is described.

  3. [Restriction of virus infection by plants: Annual report, 1986

    SciTech Connect

    Bruening, G.

    1986-12-05

    This research concerns the strong resistance, or even immunity, against a specific virus that is exhibited by one or a few lines of a plant species, in contrast to the general susceptibility of most lines of that species. The contrast between the reactions to virus inoculation of different lines of one species implies that a single gene or a very few genes may mediate the resistance or immunity. The prospects for isolating, studying and transferring such a gene should be good for a system with these characteristics. Seedlings of a line Arlington of the cowpea (Vigna unguiculata) fail to support the replication of cowpea mosaic virus strain SB (CPMV-SB). Genetic crosses of Arlington cowpea to the systemic host Blackeye 5 cowpea show that the immunity is inherited as a simple dominant gene. In contrast to the seedlings, the protoplasts of the Arlington cowpea support CPMV-SB replication, but only to a very low level compared to protoplasts of Blackeye 5 cowpeas. From evidence reported earlier we concluded that Arlington cowpea protoplasts restrict the production of CPMV-SB proteins. We postulated, and obtained evidence for, a proteinase inhibitor that is specific for a CPMV-SB proteinase. This proteinase inhibitor is our prime candidate for the mediator of the resistance of Arlington protoplasts to CPMV-SB. Progress to date is described.

  4. 8 CFR 1244.4 - Ineligible aliens.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Ineligible aliens. 1244.4 Section 1244.4 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.4 Ineligible aliens. An...

  5. 8 CFR 1244.4 - Ineligible aliens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Ineligible aliens. 1244.4 Section 1244.4 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.4 Ineligible aliens. An...

  6. 8 CFR 245a.32 - Ineligible aliens.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Ineligible aliens. 245a.32 Section 245a.32 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS TO... IMMIGRATION AND NATIONALITY ACT LIFE Act Amendments Family Unity Provisions § 245a.32 Ineligible aliens....

  7. 8 CFR 245a.32 - Ineligible aliens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Ineligible aliens. 245a.32 Section 245a.32 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS TO... IMMIGRATION AND NATIONALITY ACT LIFE Act Amendments Family Unity Provisions § 245a.32 Ineligible aliens....

  8. 8 CFR 1244.4 - Ineligible aliens.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Ineligible aliens. 1244.4 Section 1244.4 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.4 Ineligible aliens. An...

  9. 28 CFR 21.3 - Aliens.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Aliens. 21.3 Section 21.3 Judicial Administration DEPARTMENT OF JUSTICE WITNESS FEES § 21.3 Aliens. (a) Aliens entitled to payment of $30 per day. The following aliens are entitled to witness fees and allowances provided in § 21.4: (1)...

  10. 8 CFR 245a.32 - Ineligible aliens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 245a.32 Section 245a.32 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS TO... IMMIGRATION AND NATIONALITY ACT LIFE Act Amendments Family Unity Provisions § 245a.32 Ineligible aliens....

  11. 8 CFR 245a.32 - Ineligible aliens.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Ineligible aliens. 245a.32 Section 245a.32 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS TO... IMMIGRATION AND NATIONALITY ACT LIFE Act Amendments Family Unity Provisions § 245a.32 Ineligible aliens....

  12. 28 CFR 21.3 - Aliens.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Aliens. 21.3 Section 21.3 Judicial Administration DEPARTMENT OF JUSTICE WITNESS FEES § 21.3 Aliens. (a) Aliens entitled to payment of $30 per day. The following aliens are entitled to witness fees and allowances provided in § 21.4: (1)...

  13. 8 CFR 1244.4 - Ineligible aliens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 1244.4 Section 1244.4 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.4 Ineligible aliens. An...

  14. 28 CFR 21.3 - Aliens.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Aliens. 21.3 Section 21.3 Judicial Administration DEPARTMENT OF JUSTICE WITNESS FEES § 21.3 Aliens. (a) Aliens entitled to payment of $30 per day. The following aliens are entitled to witness fees and allowances provided in § 21.4: (1)...

  15. 28 CFR 21.3 - Aliens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Aliens. 21.3 Section 21.3 Judicial Administration DEPARTMENT OF JUSTICE WITNESS FEES § 21.3 Aliens. (a) Aliens entitled to payment of $30 per day. The following aliens are entitled to witness fees and allowances provided in § 21.4: (1)...

  16. 8 CFR 1244.4 - Ineligible aliens.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Ineligible aliens. 1244.4 Section 1244.4 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.4 Ineligible aliens. An...

  17. 28 CFR 21.3 - Aliens.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Aliens. 21.3 Section 21.3 Judicial Administration DEPARTMENT OF JUSTICE WITNESS FEES § 21.3 Aliens. (a) Aliens entitled to payment of $30 per day. The following aliens are entitled to witness fees and allowances provided in § 21.4: (1)...

  18. 8 CFR 245a.32 - Ineligible aliens.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Ineligible aliens. 245a.32 Section 245a.32 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS TO... IMMIGRATION AND NATIONALITY ACT LIFE Act Amendments Family Unity Provisions § 245a.32 Ineligible aliens....

  19. Annual glyphosate treatments alter growth of unaffected bentgrass (Agrostis) weeds and plant community composition.

    PubMed

    Ahrens, Collin W; Auer, Carol A

    2012-01-01

    Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities. PMID:23226530

  20. Annual Glyphosate Treatments Alter Growth of Unaffected Bentgrass (Agrostis) Weeds and Plant Community Composition

    PubMed Central

    Ahrens, Collin W.; Auer, Carol A.

    2012-01-01

    Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities. PMID:23226530

  1. Seasonal changes in spatial patterns of two annual plants in the Chihuahuan Desert, USA

    USGS Publications Warehouse

    Yin, Z.-Y.; Guo, Q.; Ren, H.; Peng, S.-L.

    2005-01-01

    Spatial pattern of a biotic population may change over time as its component individuals grow or die out, but whether this is the case for desert annual plants is largely unknown. Here we examined seasonal changes in spatial patterns of two annuals, Eriogonum abertianum and Haplopappus gracilis, in initial (winter) and final (summer) densities. The density was measured as the number of individuals from 384 permanent quadrats (each 0.5 m ?? 0.5 m) in the Chihuahuan Desert near Portal, Arizona, USA. We used three probability distributions (binomial, Poisson, and negative binomial or NB) that represent three basic spatial patterns (regular, random, and clumped) to fit the observed frequency distributions of densities of the two annuals. Both species showed clear clumped patterns as characterized by the NB and had similar inverse J-shaped frequency distribution curves in two density categories. Also, both species displayed a reduced degree of aggregation from winter to summer after the spring drought (massive die-off), as indicated by the increased k-parameter of the NB and decreased values of another NB parameter p, variance/mean ratio, Lloyd's Index of Patchiness, and David and Moore's Index of Clumping. Further, we hypothesized that while the NB (i.e., Poisson-logarithmic) well fits the distribution of individuals per quadrat, its components, the Poisson and logarithmic, may describe the distributions of clumps per quadrat and of individuals per clump, respectively. We thus obtained the means and variances for (1) individuals per quadrat, (2) clumps per quadrat, and (3) individuals per clump. The results showed that the decrease of the density from winter to summer for each plant resulted from the decrease of individuals per clump, rather than from the decrease of clumps per quadrat. The great similarities between the two annuals indicate that our observed temporal changes in spatial patterns may be common among desert annual plants. ?? Springer 2005.

  2. Alien Hand Syndrome.

    PubMed

    Hassan, Anhar; Josephs, Keith A

    2016-08-01

    Alien hand syndrome (AHS) is a rare disorder of involuntary limb movement together with a sense of loss of limb ownership. It most commonly affects the hand, but can occur in the leg. The anterior (frontal, callosal) and posterior variants are recognized, with distinguishing clinical features and anatomical lesions. Initial descriptions were attributed to stroke and neurosurgical operations, but neurodegenerative causes are now recognized as most common. Structural and functional imaging and clinical studies have implicated the supplementary motor area, pre-supplementary motor area, and their network connections in the frontal variant of AHS, and the inferior parietal lobule and connections in the posterior variant. Several theories are proposed to explain the pathophysiology. Herein, we review the literature to update advances in the understanding of the classification, pathophysiology, etiology, and treatment of AHS. PMID:27315251

  3. Optimal allocation in annual plants and its implications for drought response

    NASA Astrophysics Data System (ADS)

    Caldararu, Silvia; Smith, Matthew; Purves, Drew

    2015-04-01

    The concept of plant optimality refers to the plastic behaviour of plants that results in lifetime and offspring fitness. Optimality concepts have been used in vegetation models for a variety of processes, including stomatal conductance, leaf phenology and biomass allocation. Including optimality in vegetation models has the advantages of creating process based models with a relatively low complexity in terms of parameter numbers but which are capable of reproducing complex plant behaviour. We present a general model of plant growth for annual plants based on the hypothesis that plants allocate biomass to aboveground and belowground vegetative organs in order to maintain an optimal C:N ratio. The model also represents reproductive growth through a second optimality criteria, which states that plants flower when they reach peak nitrogen uptake. We apply this model to wheat and maize crops at 15 locations corresponding to FLUXNET cropland sites. The model parameters are data constrained using a Bayesian fitting algorithm to eddy covariance data, satellite derived vegetation indices, specifically the MODIS fAPAR product and field level crop yield data. We use the model to simulate the plant drought response under the assumption of plant optimality and show that the plants maintain unstressed total biomass levels under drought for a reduction in precipitation of up to 40%. Beyond that level plant response stops being plastic and growth decreases sharply. This behaviour results simply from the optimal allocation criteria as the model includes no explicit drought sensitivity component. Models that use plant optimality concepts are a useful tool for simulation plant response to stress without the addition of artificial thresholds and parameters.

  4. Intraspecific and interspecific pair-wise seedling competition between exotic annual grasses and native perennials: Plant-soil relationships

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few studies have examined plant-soil relationships in competitive arenas between exotic and native plants in the western United States. A pair-wise competitive design was used to evaluate plant-soil relationships between seedings of the exotic annual grasses Bromus tectorum and Taentherium caput-med...

  5. 2003 Kansas City Plant Annual Illness and Injury Surveillance Report, Revised September 2007

    SciTech Connect

    U.S. Department of Energy, Office of Health, Safety and Security, Office of Illness and Injury Prevention Programs

    2007-10-04

    Annual Illness and Injury Surveillance Program report for 2003 for the Kansas City Plant. The U.S. Department of Energy’s (DOE) commitment to assuring the health and safety of its workers includes the conduct of epidemiologic surveillance activities that provide an early warning system for health problems among workers. The IISP monitors illnesses and health conditions that result in an absence of workdays, occupational injuries and illnesses, and disabilities and deaths among current workers.

  6. 2003 Pantex Plant Annual Illness and Injury Surveillance Report, Revised September 2007

    SciTech Connect

    U.S. Department of Energy, Office of Health, Safety and Security, Office of Illness and Injury Prevention Programs

    2007-10-05

    Annual Illness and Injury Surveillance Program report for 2003 for the Pantex Plant. DOE is commited to assuring the health and safety of its workers. This includes the conduct of epidemiologic surveillance activities that provide an early warning system for health problems among workers. The IISP monitors illnesses and health conditions that result in an absence of workdays, occupational injuries and illnesses, and disabilities and deaths among current workers.

  7. Usefulness of LANDSAT data for monitoring plant development and range conditions in California's annual grassland

    NASA Technical Reports Server (NTRS)

    Carneggie, D. M.; Degloria, S. D.; Colwell, R. N.

    1977-01-01

    A network of sampling sites throughout the annual grassland region was established to correlate plant growth in stages and forage production to climatic and other environmental factors. Plant growth and range conditions were further related to geographic location and seasonal variations. A sequence of LANDSAT data was obtained covering critical periods in the growth cycle. Data were analyzed by both photointerpretation and computer aided techniques. Image characteristics and spectral reflectance data were then related to forage production, range condition, range site, and changing growth conditions.

  8. Cotyledon damage affects seed number through final plant size in the annual grassland species Medicago lupulina

    PubMed Central

    Zhang, Shiting; Zhao, Chuan; Lamb, Eric G.

    2011-01-01

    Background and Aims The effects of cotyledon damage on seedling growth and survival are relatively well established, but little is known about the effects on aspects of plant fitness such as seed number and size. Here the direct and indirect mechanisms linking cotyledon damage and plant fitness in the annual species Medicago lupulina are examined. Methods Growth and reproductive traits, including mature plant size, time to first flowering, flower number, seed number and individual seed mass were monitored in M. lupulina plants when zero, one or two cotyledons were removed at 7 d old. Structural equation modelling (SEM) was used to examine the mechanisms linking cotyledon damage to seed number and seed mass. Key Results Cotyledon damage reduced seed number but not individual seed mass. The primary mechanism was a reduction in plant biomass with cotyledon damage that in turn reduced seed number primarily through a reduction in flower numbers. Although cotyledon damage delayed flower initiation, it had little effect on seed number. Individual seed mass was not affected by cotyledon removal, but there was a trade-off between seed number and seed mass. Conclusions It is shown how a network of indirect mechanisms link damage to cotyledons and fitness in M. lupulina. Cotyledon damage had strong direct effects on both plant size and flowering phenology, but an analysis of the causal relationships among plant traits and fitness components showed that a reduction in plant size associated with cotyledon damage was an important mechanism influencing fitness. PMID:21196450

  9. Impact of alien pines on local arbuscular mycorrhizal fungal communities-evidence from two continents.

    PubMed

    Gazol, Antonio; Zobel, Martin; Cantero, Juan José; Davison, John; Esler, Karen J; Jairus, Teele; Öpik, Maarja; Vasar, Martti; Moora, Mari

    2016-06-01

    The introduction of alien plants can influence biodiversity and ecosystems. However, its consequences for soil microbial communities remain poorly understood. We addressed the impact of alien ectomycorrhizal (EcM) pines on local arbuscular mycorrhizal (AM) fungal communities in two regions with contrasting biogeographic histories: in South Africa, where no native EcM plant species are present; and in Argentina, where EcM trees occur naturally. The effect of alien pines on AM fungal communities differed between these regions. In South Africa, plantations of alien EcM pines exhibited lower AM fungal richness and significantly altered community composition, compared with native fynbos. In Argentina, the richness and composition of local AM fungal communities were similar in plantations of alien EcM pines and native forest. However, the presence of alien pines resulted in slight changes to the phylogenetic structure of root AM fungal communities in both regions. In pine clearcut areas in South Africa, the richness and composition of AM fungal communities were intermediate between the native fynbos and the alien pine plantation, which is consistent with natural regeneration of former AM fungal communities following pine removal. We conclude that the response of local AM fungal communities to alien EcM pines differs between biogeographic regions with different histories of species coexistence. PMID:27056916

  10. PMI: Plant-Microbe Interfaces (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Schadt, Christopher

    2013-03-01

    Christopher Schadt of Oak Ridge National Laboratory on "Plant-Microbe Interactions" in the context of poplar trees at the 8th Annual Genomics of Energy & Environment Meeting on March 27, 2013 held in Walnut Creek, Calif.

  11. DEVELOPMENT OF AN INDEX OF ALIEN SPECIES INVASIVENESS: AN AID TO ASSESSING RIPARIAN VEGETATION CONDITION

    EPA Science Inventory

    Many riparian areas are invaded by alien plant species that negatively affect native species composition, community dynamics and ecosystem properties. We sampled vegetation along reaches of 31 low order streams in eastern Oregon, and characterized species assemblages at patch an...

  12. Physiological variation among native and exotic winter annual plants associated with microbiotic crusts in the Mojave Desert

    USGS Publications Warehouse

    DeFalco, L.A.; Detling, J.K.; Tracy, C.R.; Warren, S.D.

    2001-01-01

    Microbiotic crusts are important components of many aridland soils. Research on crusts typically focuses on the increase in soil fertility due to N-fixing micro-organisms, the stabilization of soils against water and wind erosion and the impact of disturbance on N-cycling. The effect of microbiotic crusts on the associated plant community has received little attention. We quantified the influence of crusts on the production, species diversity, nutrient content and water relations of winter annual plant species associated with microbiotic soil crusts in the northeast Mojave Desert. Shoot biomass of winter annuals was 37% greater and plant density was 77% greater on crusts than were biomass and density on soils lacking crust cover (=bare soils). This greater production of annuals on crusts was likely due to enhanced soil conditions including an almost two-fold increase in soil organic matter and inorganic N compared to bare soils. Crusted soils also had 53% greater volumetric water content than bare soils during November and December, the time when winter annuals become established. As plant development progressed into spring, however, soil water availability decreased: More negative plant xylem water potentials were associated with greater plant biomass on crusted soils. Plants associated with microbiotic soil crusts had lower concentrations of N in shoots (mg N g-1 dry mass). However, total shoot N (mg N m-2) was the same in plants growing on the different soil types when biomass production peaked in April. Shoots had similar patterns in their concentration and content of P. Species diversity of annuals was not statistically different between the two soil types. Yet, while native annuals comprised the greatest proportion of shoot biomass on bare soils, exotic forbs and grasses produced more biomass on crusts. Total shoot nutrient content (biomass x concentration) of the two exotic annual species examined was dramatically greater on crusts than bare soils; only one

  13. Bidirectional recovery patterns of Mojave Desert vegetation in an aqueduct pipeline corridor after 36 years: II. Annual plants

    USGS Publications Warehouse

    Berry, Kristin H.; Mack, Jeremy S.; Weigand, James F.; Gowan, Timothy A.; LaBerteaux, Denise

    2015-01-01

    We studied recovery of winter annual plants in a 97-m wide disturbed aqueduct corridor in the Mojave Desert 36 years after construction. We established plots at 0, 20, and 40 m from the road verge at the corridor center and at 100 m in undisturbed vegetation. We recorded 47 annual species, of which 41 were native and six were exotic. Exotic species composed from 64 to 91% of total biomass. We describe a bilateral process of recovery: from the road verge to the outward edge of the corridor and from undisturbed habitat into the corridor. Native annual plants significantly increased in richness from road verge to undisturbed vegetation, but not in density, biomass, or cover. In contrast, exotic annual plants increased in density, biomass, cover and richness with increasing distance from the road verge. The species of colonizing shrubs and type of canopy cover affected density, biomass, and richness of annuals. Species composition of native annuals differed significantly by distance, suggesting secondary succession. In general, native annuals were closer to achieving recovery on the 40-m plots than at the road verge. Recovery estimates were in centuries and dependent on location, canopy type, and whether considering all annuals or natives only.

  14. Comparative Functional Responses Predict the Invasiveness and Ecological Impacts of Alien Herbivorous Snails

    PubMed Central

    Xu, Meng; Mu, Xidong; Dick, Jaimie T. A.; Fang, Miao; Gu, Dangen; Luo, Du; Zhang, Jiaen; Luo, Jianren; Hu, Yinchang

    2016-01-01

    Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in “100 of the World's Worst Invasive Alien Species”; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest “attack rates” a, shortest “handling times” h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach. PMID:26771658

  15. Comparative Functional Responses Predict the Invasiveness and Ecological Impacts of Alien Herbivorous Snails.

    PubMed

    Xu, Meng; Mu, Xidong; Dick, Jaimie T A; Fang, Miao; Gu, Dangen; Luo, Du; Zhang, Jiaen; Luo, Jianren; Hu, Yinchang

    2016-01-01

    Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in "100 of the World's Worst Invasive Alien Species"; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest "attack rates" a, shortest "handling times" h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach. PMID:26771658

  16. F-box gene family is expanded in herbaceous annual plants Arabidopsis and rice relative to woody perennial plant Populus

    SciTech Connect

    Yang, Xiaohan; Kalluri, Udaya C; Jawdy, Sara; Gunter, Lee E; Yin, Tongming; Tschaplinski, Timothy J; Weston, David; Ranjan, Priya; Tuskan, Gerald A

    2008-01-01

    F-box proteins are generally responsible for substrate recognition in the Skp1-Cullin-F-box complexes that are involved in protein degradation via the ubiquitin-26S proteosome pathway. In plants, F-box genes influence a variety of biological processes such as leaf senescence, branching, self-incompatibility and responses to biotic and abiotic stresses. The number of F-box genes in Populus (~320) is less than half that found in Arabidopsis (~660) or rice (~680), even though the total number of genes in Populus is equivalent to that in rice and 1.5 times that in Arabidopsis. We performed comparative genomic analysis between the woody perennial plant Populus and the herbaceous annual plants Arabidopsis and rice in order to explicate the functional implications of this large gene family. Our analyses reveal interspecific differences in genomic distribution, orthologous relationship, intron evolution, protein domain structure and gene expression. The set of F-box genes shared by these three species appear to be involved in core biological processes essential for plant growth and development; lineage-specific differences primarily occurred because of an expansion of the F-box genes via tandem duplications in Arabidopsis and rice. The present study provides insights into the relationship between the structure and composition of the F-box gene family in herbaceous and woody species and their associated developmental and physiological features.

  17. Space, time and aliens: charting the dynamic structure of Galápagos pollination networks.

    PubMed

    Traveset, Anna; Chamorro, Susana; Olesen, Jens M; Heleno, Ruben

    2015-01-01

    Oceanic archipelagos are threatened by the introduction of alien species which can severely disrupt the structure, function and stability of native communities. Here we investigated the pollination interactions in the two most disturbed Galápagos Islands, comparing the three main habitats and the two seasons, and assessing the impacts of alien plant invasions on network structure. We found that the pollination network structure was rather consistent between the two islands, but differed across habitats and seasons. Overall, the arid zone had the largest networks and highest species generalization levels whereas either the transition between habitats or the humid habitat showed lower values. Our data suggest that alien plants integrate easily into the communities, but with low impact on overall network structure, except for an increase in network selectiveness. The humid zone showed the highest nestedness and the lowest modularity, which might be explained by the low species diversity and the higher incidence of alien plants in this habitat. Both pollinators and plants were also more generalized in the hot season, when networks showed to be more nested. Alien species (both plants and pollinators) represented a high fraction (∼56 %) of the total number of interactions in the networks. It is thus likely that, in spite of the overall weak effect we found of alien plant invasion on pollination network structure, these introduced species influence the reproductive success of native ones, and by doing so, they affect the functioning of the community. This certainly deserves further investigation. PMID:26104283

  18. Space, time and aliens: charting the dynamic structure of Galápagos pollination networks

    PubMed Central

    Traveset, Anna; Chamorro, Susana; Olesen, Jens M.; Heleno, Ruben

    2015-01-01

    Oceanic archipelagos are threatened by the introduction of alien species which can severely disrupt the structure, function and stability of native communities. Here we investigated the pollination interactions in the two most disturbed Galápagos Islands, comparing the three main habitats and the two seasons, and assessing the impacts of alien plant invasions on network structure. We found that the pollination network structure was rather consistent between the two islands, but differed across habitats and seasons. Overall, the arid zone had the largest networks and highest species generalization levels whereas either the transition between habitats or the humid habitat showed lower values. Our data suggest that alien plants integrate easily into the communities, but with low impact on overall network structure, except for an increase in network selectiveness. The humid zone showed the highest nestedness and the lowest modularity, which might be explained by the low species diversity and the higher incidence of alien plants in this habitat. Both pollinators and plants were also more generalized in the hot season, when networks showed to be more nested. Alien species (both plants and pollinators) represented a high fraction (∼56 %) of the total number of interactions in the networks. It is thus likely that, in spite of the overall weak effect we found of alien plant invasion on pollination network structure, these introduced species influence the reproductive success of native ones, and by doing so, they affect the functioning of the community. This certainly deserves further investigation. PMID:26104283

  19. Host Preferences of Arbuscular Mycorrhizal Fungi Colonizing Annual Herbaceous Plant Species in Semiarid Mediterranean Prairies

    PubMed Central

    Torrecillas, E.; Roldán, A.

    2012-01-01

    In this study, we have analyzed and compared the diversities of the arbuscular mycorrhizal fungi (AMF) colonizing the roots of five annual herbaceous species (Hieracium vulgare, Stipa capensis, Anagallis arvensis, Carduus tenuiflorus, and Avena barbata) and a perennial herbaceous species (Brachypodium retusum). Our goal was to determine the differences in the communities of the AMF among these six plant species belonging to different families, using B. retusum as a reference. The AMF small-subunit rRNA genes (SSU) were subjected to nested PCR, cloning, sequencing, and phylogenetic analysis. Thirty-six AMF phylotypes, belonging to Glomus group A, Glomus group B, Diversispora, Paraglomus, and Ambispora, were identified. Five sequence groups identified in this study clustered to known glomalean species or isolates: group Glomus G27 to Glomus intraradices, group Glomus G19 to Glomus iranicum, group Glomus G10 to Glomus mosseae, group Glomus G1 to Glomus lamellosum/etunicatum/luteum, and group Ambispora 1 to Ambispora fennica. The six plant species studied hosted different AMF communities. A certain trend of AMF specificity was observed when grouping plant species by taxonomic families, highlighting the importance of protecting and even promoting the native annual vegetation in order to maintain the biodiversity and productivity of these extreme ecosystems. PMID:22752164

  20. Risk-informed assessment of regulatory and design requirements for future nuclear power plants. Annual report

    SciTech Connect

    2000-08-01

    OAK B188 Risk-informed assessment of regulatory and design requirements for future nuclear power plants. Annual report. The overall goal of this research project is to support innovation in new nuclear power plant designs. This project is examining the implications, for future reactors and future safety regulation, of utilizing a new risk-informed regulatory system as a replacement for the current system. This innovation will be made possible through development of a scientific, highly risk-formed approach for the design and regulation of nuclear power plants. This approach will include the development and/or confirmation of corresponding regulatory requirements and industry standards. The major impediment to long term competitiveness of new nuclear plants in the U.S. is the capital cost component--which may need to be reduced on the order of 35% to 40% for Advanced Light Water Reactors (ALWRS) such as System 80+ and Advanced Boiling Water Reactor (ABWR). The required cost reduction for an ALWR such as AP600 or AP1000 would be expected to be less. Such reductions in capital cost will require a fundamental reevaluation of the industry standards and regulatory bases under which nuclear plants are designed and licensed. Fortunately, there is now an increasing awareness that many of the existing regulatory requirements and industry standards are not significantly contributing to safety and reliability and, therefore, are unnecessarily adding to nuclear plant costs. Not only does this degrade the economic competitiveness of nuclear energy, it results in unnecessary costs to the American electricity consumer. While addressing these concerns, this research project will be coordinated with current efforts of industry and NRC to develop risk-informed, performance-based regulations that affect the operation of the existing nuclear plants; however, this project will go further by focusing on the design of new plants.

  1. Waste Isolation Pilot Plant Annual Site Environmental Report for 2014. Emended

    SciTech Connect

    none,

    2015-09-01

    The purpose of the Waste Isolation Pilot Plant (WIPP) Annual Site Environmental Report for 2014 (ASER) is to provide information required by U.S. Department of Energy (DOE) Order 231.1B, Environment, Safety, and Health Reporting. Specifically, the ASER presents summary environmental data to: Characterize site environmental management performance; Summarize environmental occurrences and responses reported during the calendar year (CY); Confirm compliance with environmental standards and requirements; Highlight significant environmental accomplishments, including progress toward the DOE environmental sustainability goals made through implementation of the WIPP Environmental Management System (EMS).

  2. Comparison of signaling interactions determining annual and perennial plant growth in response to low temperature

    PubMed Central

    Wingler, Astrid

    2015-01-01

    Low temperature inhibits plant growth despite the fact that considerable rates of photosynthetic activity can be maintained. Instead of lower rates of photosynthesis, active inhibition of cell division and expansion is primarily responsible for reduced growth. This results in sink limitation and enables plants to accumulate carbohydrates that act as compatible solutes or are stored throughout the winter to enable re-growth in spring. Regulation of growth in response to temperature therefore requires coordination with carbon metabolism, e.g., via the signaling metabolite trehalose-6-phosphate. The phytohormones gibberellin (GA) and jasmonate (JA) play an important role in regulating growth in response to temperature. Growth restriction at low temperature is mainly mediated by DELLA proteins, whose degradation is promoted by GA. For annual plants, it has been shown that the GA/DELLA pathway interacts with JA signaling and C-repeat binding factor dependent cold acclimation, but these interactions have not been explored in detail for perennials. Growth regulation in response to seasonal factors is, however, particularly important in perennials, especially at high latitudes. In autumn, growth cessation in trees is caused by shortening of the daylength in interaction with phytohormone signaling. In perennial grasses seasonal differences in the sensitivity to GA may enable enhanced growth in spring. This review provides an overview of the signaling interactions that determine plant growth at low temperature and highlights gaps in our knowledge, especially concerning the seasonality of signaling responses in perennial plants. PMID:25628637

  3. 8 CFR 1214.2 - Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration proceedings. 1214.2 Section 1214.2 Aliens and... NONIMMIGRANT CLASSES § 1214.2 Review of alien victims of severe forms of trafficking in persons; aliens...

  4. 8 CFR 1214.2 - Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration proceedings. 1214.2 Section 1214.2 Aliens and... NONIMMIGRANT CLASSES § 1214.2 Review of alien victims of severe forms of trafficking in persons; aliens...

  5. 8 CFR 1214.2 - Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration proceedings. 1214.2 Section 1214.2 Aliens and... NONIMMIGRANT CLASSES § 1214.2 Review of alien victims of severe forms of trafficking in persons; aliens...

  6. 8 CFR 1214.2 - Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration proceedings. 1214.2 Section 1214.2 Aliens and... NONIMMIGRANT CLASSES § 1214.2 Review of alien victims of severe forms of trafficking in persons; aliens...

  7. 8 CFR 1214.2 - Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration proceedings. 1214.2 Section 1214.2 Aliens and... NONIMMIGRANT CLASSES § 1214.2 Review of alien victims of severe forms of trafficking in persons; aliens...

  8. Graffiti and "Film School" Culture: Displaying Alienation.

    ERIC Educational Resources Information Center

    Scheibel, Dean

    1994-01-01

    Examines graffiti created by students in "film school" as an organizational document. Finds themes related to alienation and the discourse that counters the sources of that alienation. Shows how the humorous communicative style of graffiti creates tension among cultural meanings that mediates between alienation and liberation. (SR)

  9. 33 CFR 125.25 - Aliens.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Aliens. 125.25 Section 125.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT....25 Aliens. Alien registration records together with other papers and documents which indicated...

  10. 33 CFR 125.25 - Aliens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Aliens. 125.25 Section 125.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT....25 Aliens. Alien registration records together with other papers and documents which indicated...

  11. 43 CFR 3102.2 - Aliens.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Aliens. 3102.2 Section 3102.2 Public Lands... INTERIOR MINERALS MANAGEMENT (3000) OIL AND GAS LEASING Qualifications of Lessees § 3102.2 Aliens. Leases or interests therein may be acquired and held by aliens only through stock ownership, holding...

  12. 33 CFR 125.25 - Aliens.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Aliens. 125.25 Section 125.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT....25 Aliens. Alien registration records together with other papers and documents which indicated...

  13. 22 CFR 62.27 - Alien physicians.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Alien physicians. 62.27 Section 62.27 Foreign... Provisions § 62.27 Alien physicians. (a) Purpose. Pursuant to the Mutual Educational and Cultural Exchange... Foreign Medical Graduates must sponsor alien physicians who wish to pursue programs of graduate...

  14. 22 CFR 62.27 - Alien physicians.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Alien physicians. 62.27 Section 62.27 Foreign... Provisions § 62.27 Alien physicians. (a) Purpose. Pursuant to the Mutual Educational and Cultural Exchange... Foreign Medical Graduates must sponsor alien physicians who wish to pursue programs of graduate...

  15. 43 CFR 3102.2 - Aliens.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Aliens. 3102.2 Section 3102.2 Public Lands... INTERIOR MINERALS MANAGEMENT (3000) OIL AND GAS LEASING Qualifications of Lessees § 3102.2 Aliens. Leases or interests therein may be acquired and held by aliens only through stock ownership, holding...

  16. 33 CFR 125.25 - Aliens.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Aliens. 125.25 Section 125.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT....25 Aliens. Alien registration records together with other papers and documents which indicated...

  17. 43 CFR 3102.2 - Aliens.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Aliens. 3102.2 Section 3102.2 Public Lands... INTERIOR MINERALS MANAGEMENT (3000) OIL AND GAS LEASING Qualifications of Lessees § 3102.2 Aliens. Leases or interests therein may be acquired and held by aliens only through stock ownership, holding...

  18. Alienation, Dogmatism, and Related Personality Characteristics.

    ERIC Educational Resources Information Center

    Sexton, Miriam E.

    1983-01-01

    Examined the relationship between alienation and dogmatism, as measured by shared personality characteristics. Scores from the Rokeach Dogmatism Scale, the Keniston Alienation Scale, the California Test of Personality, and the Omnibus Personality Inventory were obtained for 92 college freshmen. Alienation and dogmatism were positively related…

  19. 43 CFR 3102.2 - Aliens.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Aliens. 3102.2 Section 3102.2 Public Lands... INTERIOR MINERALS MANAGEMENT (3000) OIL AND GAS LEASING Qualifications of Lessees § 3102.2 Aliens. Leases or interests therein may be acquired and held by aliens only through stock ownership, holding...

  20. 22 CFR 62.27 - Alien physicians.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Alien physicians. 62.27 Section 62.27 Foreign... Provisions § 62.27 Alien physicians. (a) Purpose. Pursuant to the Mutual Educational and Cultural Exchange... Foreign Medical Graduates must sponsor alien physicians who wish to pursue programs of graduate...

  1. 33 CFR 125.25 - Aliens.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Aliens. 125.25 Section 125.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT....25 Aliens. Alien registration records together with other papers and documents which indicated...

  2. Usefulness of LANDSAT data for monitoring plant development and range conditions in California's annual grassland

    NASA Technical Reports Server (NTRS)

    Carneggie, D. M.; Degloria, S. D.; Colwell, R. N.

    1975-01-01

    A network of sampling sites throughout the annual grassland region of California was established to correlate plant growth stages and forage production to climatic and other environmental factors. Plant growth and range conditions were further related to geographic location and seasonal variations. A sequence of LANDSAT data was obtained covering critical periods in the growth cycle. This was analyzed by both photointerpretation and computer aided techniques. Image characteristics and spectral reflectance data were then related to forage production, range condition, range site and changing growth conditions. It was determined that repeat sequences with LANDSAT color composite images do provide a means for monitoring changes in range condition. Spectral radiance data obtained from magnetic tape can be used to determine quantitatively the critical stages in the forage growth cycle. A computer ratioing technique provided a sensitive indicator of changes in growth stages and an indication of the relative differences in forage production between range sites.

  3. Effect of the Internet Commerce on Dispersal Modes of Invasive Alien Species

    PubMed Central

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M. H.; Moroń, Dawid; Sutherland, William J.; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal. PMID:24932498

  4. Effect of the internet commerce on dispersal modes of invasive alien species.

    PubMed

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M H; Moroń, Dawid; Sutherland, William J; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal. PMID:24932498

  5. 8th Annual Glycoscience Symposium: Integrating Models of Plant Cell Wall Structure, Biosynthesis and Assembly

    SciTech Connect

    Azadi, Paratoo

    2015-09-24

    The Complex Carbohydrate Research Center (CCRC) of the University of Georgia holds a symposium yearly that highlights a broad range of carbohydrate research topics. The 8th Annual Georgia Glycoscience Symposium entitled “Integrating Models of Plant Cell Wall Structure, Biosynthesis and Assembly” was held on April 7, 2014 at the CCRC. The focus of symposium was on the role of glycans in plant cell wall structure and synthesis. The goal was to have world leaders in conjunction with graduate students, postdoctoral fellows and research scientists to propose the newest plant cell wall models. The symposium program closely followed the DOE’s mission and was specifically designed to highlight chemical and biochemical structures and processes important for the formation and modification of renewable plant cell walls which serve as the basis for biomaterial and biofuels. The symposium was attended by both senior investigators in the field as well as students including a total attendance of 103, which included 80 faculty/research scientists, 11 graduate students and 12 Postdoctoral students.

  6. A feasibility study of perennial/annual plant species to restore soils contaminated with heavy metals

    NASA Astrophysics Data System (ADS)

    Zacarías, Montserrat; Beltrán, Margarita; Gilberto Torres, Luis; González, Abelardo

    A feasibility study was carried out to evaluate the application of perennial/annual plant species in a phytoextraction process of a previously washed industrial urban soil contaminated by nickel, arsenic and cupper. The plant species selected for this study were Ipomea (Ipomea variada); grass (Poa pratensis); grass mixture (Festuca rubra, Cynodon dactylon, Lolium multiforum, Pennisetum sp.); Monks Cress (Tropaeolum majus); ficus (Ficus benajamina) and fern (Pteris cretica). Soil was characterized and it presented the following heavy metals concentrations (dry weight): 80 mg of Ni/kg, 456-656 mg of As/kg and 1684-3166 mg of Cu/kg. Germination and survival in contaminated soil tests were conducted, from these, P. pratensis was discarded and the rest of plant species tested were used for the phytoextraction selection test. After 4 months of growth, biomass production was determined, and content of Ni, As and Cu was analyzed in plant’s tissue. Metal biological absorption coefficient (BAC), bio-concentration factor (BCF) and translocation factor (TF), were calculated. Regarding to biomass generation it was observed, in every case, an inhibition of the plant growth compared with blanks sown in a non contaminated soil; inhibition ranged from 22.5% for the Monk cress to 98% for Ipomea. Even though the later presented high BAC, BCF and TF, its growth was severely inhibited, and therefore, due its low biomass generation, it is not recommended for phytoextraction under conditions for this study. Heavy metals concentrations in plant’s tissue (dry weight) were as high as 866 mg Cu/kg and 602 mg As/kg for grass mixture; and 825 mg As/kg was observed for Monks cress. Grass mixture and monks cress had high BAC, BCF and TF, also they had high metal concentrations in its plants tissues and the lowest growth inhibition rates; hence the application in phytoextraction processes of these plants is advisable.

  7. The Mexican "Illegal Alien" Commute.

    ERIC Educational Resources Information Center

    Decker, Phil

    1986-01-01

    A photo report of the following three treks by illegal aliens across the border from Mexico to work in Arizona reveals the dangers and disappointments the migrants are exposed to: (1) a "carpool" from Southern Mexico; (2) a train ride from Sinaloa; and (3) a 40-mile hike through the Arizona desert. (PS)

  8. The Creative Use of Alienation.

    ERIC Educational Resources Information Center

    Herrick, James E.

    The process of becoming a world citizen requires, as a first step, personal alienation from the cultural values and social arrangements of nation-states that stand in the way of such an effort. Three interrelated propositions underlie this thesis. First, prevailing cultural values and social arrangements severely limit opportunities for people to…

  9. SEASONALITY OF ANNUAL PLANT ESTABLISHMENT INFLUENCES THE INTERACTIONBETWEEN THE NON-NATIVE ANNUAL GRASS BROMUS MADRITENSIS SSP. RUBENS AND MOJAVE DESERT PERENNIALS

    SciTech Connect

    L A. DEFALCO; G. C. FERNANDEZ; R. S. NOWAK

    2004-01-01

    Competition between native and non-native species can change the composition and structure of plant communities, but in deserts the timing of non-native plant establishment can modulate their impacts to native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native perennials--Larrea iridentata, Achnatherum hymenoides, and Pleuraphis rigida--in either winter or spring. Additional plots were prepared for the Same perennial species and seasons, but with a mixture of native annual species. Relative growth rates of perennial shoots (RGRs) declined with increasing Bromus biomass when Bromus that was established in winter had 2-3 mo of growth and high water use before perennial growth began. However, this high water use did not significantly reduce water potentials for the perennials, suggesting Bromus that established earlier depleted other soil resources, such as N, otherwise used by perennial plants. Spring-established Bromus had low biomass even at higher densities and did not effectively reduce RGRs, resulting in an overall lower impact to perennials than when Bromus was established in winter. Similarly, growth and reproduction of perennials with mixed annuals as neighbors did not differ from those with Bromus neighbors of equivalent biomass, but densities of these annuals did not support the high biomass necessary to reduce perennial growth. Thus, impacts of native Mojave Desert annuals to perennials are expected to be lower than those of Bromus because seed dormancy and narrow requirements for seedling survivorship produce densities and biomass lower than those achieved by Bromus. In comparing the effects of Bromus among perennial species, the impact of increased Bromus biomass on RGR was lower for Larrea than for the two perennial grasses, probably because Lurrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This contrasts

  10. Searching for Alien Life Having Unearthly Biochemistry

    NASA Technical Reports Server (NTRS)

    Jones, Harry

    2003-01-01

    The search for alien life in the solar system should include exploring unearth-like environments for life having an unearthly biochemistry. We expect alien life to conform to the same basic chemical and ecological constraints as terrestrial life, since inorganic chemistry and the laws of ecosystems appear to be universal. Astrobiologists usually assume alien life will use familiar terrestrial biochemistry and therefore hope to find alien life by searching near water or by supplying hydrocarbons. The assumption that alien life is likely to be based on carbon and water is traditional and plausible. It justifies high priority for missions to search for alien life on Mars and Europa, but it unduly restricts the search for alien life. Terrestrial carbon-water biochemistry is not possible on most of the bodies of our solar system, but all alien life is not necessarily based on terrestrial biochemistry. If alien life has a separate origin from Earth life, and if can survive in an environment extremely different from Earth's, then alien life may have unearthly biochemistry. There may be other solvents than water that support alien life and other elements than carbon that form complex life enabling chain molecules. Rather than making the exploration-restricting assumption that all life requires carbon, water, and terrestrial biochemistry, we should make the exploration-friendly assumption that indigenous, environmentally adapted, alien life forms might flourish using unearthly biochemistry in many places in the solar system. Alien life might be found wherever there is free energy and a physical/chemical system capable of using that energy to build living structures. Alien life may be discovered by the detection of some general non-equilibrium chemistry rather than of terrestrial biochemistry. We should explore all the potential abodes of life in the solar system, including those where life based on terrestrial biochemistry can not exist.

  11. The Influence of Precipitation-Driven Annual Plant Growth on Dust Emission in the Mojave Desert, USA

    NASA Astrophysics Data System (ADS)

    Urban, F. E.; Reynolds, R. L.; Fulton, R. E.

    2009-12-01

    Sparsely vegetated drylands are an important source for dust emission. However, little detail is known about dust generation in response to timing of precipitation and the consequent effects on soil and vegetation dynamics in these settings. This deficiency is especially acute at intermediate landscape scales, tens of meters to several hundred meters. It is essential to consider dust emission at this scale, because it links dust generation at scales of grains and wind tunnels with regional-scale dust examined using remotely sensed data from satellites. Three sites of slightly different geomorphic settings in the vicinity of Soda (dry) Lake were instrumented (in 1999) with meteorological and sediment transport sensors to measure wind erosion through saltating particle detection during high winds. Changes in vegetation in close proximity to the instrumented sites were bi-annually documented through measurements of plant type, cover, and repeat photographic imagery. Whereas high wind events are the dominant driver of saltation and dust emission, emissive conditions prevail only when annual plants are sparse or absent. Results show that wind erosion and dust emission at two study sites are highly variable and that such variability is dominantly related to vegetation type and cover as influenced by the amount and timing of antecedent precipitation. Secondary controls on dust emission are availability of new sediment related to flood deposits at the sites and seasonally differential wind strength. At sites where annual plants respond quickly and advantageously to precipitation, emissive conditions typically shut down because of vegetation growth within two to three months. This cover of annual plants, even when dead, persists in the desert landscape as a stabilizing agent for varying amounts of time, ten months to three years depending on the amount and vegetation type and subsequent input of precipitation and further annual plant growth. The lasting stabilization effect

  12. Effect of ultraviolet radiation on chlorophyll, carotenoid, protein and proline contents of some annual desert plants.

    PubMed

    Salama, Hediat M H; Al Watban, Ahlam A; Al-Fughom, Anoud T

    2011-01-01

    Investigation was carried out to find whether enhanced ultraviolet radiation influences the Malva parviflora L., Plantago major L., Rumex vesicarius L. and Sismbrium erysimoids Desf. of some annual desert plants. The seeds were grown in plastic pots equally filled with a pre-sieved normal sandy soil for 1 month. The planted pots from each species were randomly divided into equal groups (three groups). Plants of the first group exposed to white-light tubes (400-700 nm) 60 w and UV (365 nm) 8 w tubes. The second group was exposed to white-light tubes (400-700 nm) 60 w and UV (302 nm) 8 w tubes. The third group was exposed to white-light tubes (400-700 nm) 60 w and UV (254 nm) 8 w tubes, respectively, for six days. The results indicated that the chlorophyll contents were affected by enhanced UV radiation. The chlorophyll a, b, and total contents were decreased compared with the control values and reduced with the enhanced UV radiation, but the carotenoid was increased compared with the control and also reduced with the enhanced UV radiation. So, the contents of chlorophylls varied considerably. M. parviflora showed the highest constitutive levels of accumulated chlorophyll a, b, and total chlorophyll (0.463, 0.307 and 0.774 mg g(-1) f w) among the investigated plant species. P. major showed the lowest constitutive levels of the chloroplast pigments, 0.0036, 0.0038 and 0.0075 mg g(-1) f w for chlorophyll a, b, and total chlorophyll at UV-365 nm, respectively. The protein content was decreased significantly in both root and shoot systems compared with the control values but, it was increased with increasing wave lengths of UV-radiation of all tested plants. R. vesicarius showed the highest protein contents among the investigated plants; its content was 3.8 mg g(-1) f w at UV-365 nm in shoot system. On the other hand, decreasing ultraviolet wave length induced a highly significant increase in the level of proline in both root and shoot of all

  13. Constrained growth flips the direction of optimal phenological responses among annual plants.

    PubMed

    Lindh, Magnus; Johansson, Jacob; Bolmgren, Kjell; Lundström, Niklas L P; Brännström, Åke; Jonzén, Niclas

    2016-03-01

    Phenological changes among plants due to climate change are well documented, but often hard to interpret. In order to assess the adaptive value of observed changes, we study how annual plants with and without growth constraints should optimize their flowering time when productivity and season length changes. We consider growth constraints that depend on the plant's vegetative mass: self-shading, costs for nonphotosynthetic structural tissue and sibling competition. We derive the optimal flowering time from a dynamic energy allocation model using optimal control theory. We prove that an immediate switch (bang-bang control) from vegetative to reproductive growth is optimal with constrained growth and constant mortality. Increasing mean productivity, while keeping season length constant and growth unconstrained, delayed the optimal flowering time. When growth was constrained and productivity was relatively high, the optimal flowering time advanced instead. When the growth season was extended equally at both ends, the optimal flowering time was advanced under constrained growth and delayed under unconstrained growth. Our results suggests that growth constraints are key factors to consider when interpreting phenological flowering responses. It can help to explain phenological patterns along productivity gradients, and links empirical observations made on calendar scales with life-history theory. PMID:26548947

  14. Effects of colonization processes on genetic diversity: differences between annual plants and tree species.

    PubMed Central

    Austerlitz, F; Mariette, S; Machon, N; Gouyon, P H; Godelle, B

    2000-01-01

    Tree species are striking for their high within-population diversity and low among-population differentiation for nuclear genes. In contrast, annual plants show much more differentiation for nuclear genes but much less diversity than trees. The usual explanation for this difference is that pollen flow, and therefore gene flow, is much higher for trees. This explanation is problematic because it relies on equilibrium hypotheses. Because trees have very recently recolonized temperate areas, they have experienced many foundation events, which usually reduce within-population diversity and increase differentiation. Only extremely high levels of gene flow could counterbalance these successive founder effects. We develop a model to study the impact of life cycle of forest trees, in particular of the length of their juvenile phase, on genetic diversity and differentiation during the glacial period and the following colonization period. We show that both a reasonably high level of pollen flow and the life-cycle characteristics of trees are needed to explain the observed structure of genetic diversity. We also show that gene flow and life cycle both have an impact on maternally inherited cytoplasmic genes, which are characterized both in trees and annual species by much less diversity and much more differentiation than nuclear genes. PMID:10757772

  15. 22 CFR 42.22 - Returning resident aliens.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Returning resident aliens. 42.22 Section 42.22... Returning resident aliens. (a) Requirements for returning resident status. An alien shall be classifiable as... presented that: (1) The alien had the status of an alien lawfully admitted for permanent residence at...

  16. 8 CFR 236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Confined aliens, incompetents, and minors. 236.2 Section 236.2 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS; REMOVAL OF ALIENS ORDERED REMOVED...

  17. 22 CFR 42.22 - Returning resident aliens.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Returning resident aliens. 42.22 Section 42.22... Returning resident aliens. (a) Requirements for returning resident status. An alien shall be classifiable as... presented that: (1) The alien had the status of an alien lawfully admitted for permanent residence at...

  18. 22 CFR 42.22 - Returning resident aliens.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Returning resident aliens. 42.22 Section 42.22... Returning resident aliens. (a) Requirements for returning resident status. An alien shall be classifiable as... presented that: (1) The alien had the status of an alien lawfully admitted for permanent residence at...

  19. 8 CFR 236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Confined aliens, incompetents, and minors. 236.2 Section 236.2 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS; REMOVAL OF ALIENS ORDERED REMOVED...

  20. 22 CFR 42.22 - Returning resident aliens.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Returning resident aliens. 42.22 Section 42.22... Returning resident aliens. (a) Requirements for returning resident status. An alien shall be classifiable as... presented that: (1) The alien had the status of an alien lawfully admitted for permanent residence at...

  1. 22 CFR 42.22 - Returning resident aliens.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Returning resident aliens. 42.22 Section 42.22... Returning resident aliens. (a) Requirements for returning resident status. An alien shall be classifiable as... presented that: (1) The alien had the status of an alien lawfully admitted for permanent residence at...

  2. Variation in photosynthetic response to temperature in a guild of winter annual plants.

    PubMed

    Gremer, Jennifer R; Kimball, Sarah; Angert, Amy L; Venable, D Lawrence; Huxman, Travis E

    2012-12-01

    How species respond to environmental variation can have important consequences for population and community dynamics. Temperature, in particular, is one source of variation expected to strongly influence plant performance. Here, we compared photosynthetic responses to temperature across a guild of winter annual plants. Previous work in this system identified a trade-off between relative growth rate (RGR) and water-use efficiency (WUE) that predicts species differences in population dynamics over time, which then contribute to long-term species coexistence. Interestingly, species with high WUE invest in photosynthetic processes that appear to maximize carbon assimilation, while high-RGR species appear to maximize carbon gain by increasing leaf area for photosynthesis. In high-WUE species, higher rates of carbon acquisition were associated with increased investment into light-driven electron transport (J(max)). We tested whether such allocation allows these plants to have greater photosynthetic performance at lower temperatures by comparing the temperature sensitivity of photosynthesis across species in the community. Six species were grown in buried pots in the field, allowing them to experience natural changes in seasonal temperature. Plants were taken from the field and placed in growth chambers where photosynthetic performance was measured following short-term exposure to a wide range of temperatures. These measurements were repeated throughout the season. Our results suggest that high-WUE species are more efficient at processing incoming light, as measured by chlorophyll fluorescence, and exhibit higher net photosynthetic rates (A(net)) than high-RGR species, and these advantages are greatest at low temperatures. Sampling date differentially affected fluorescence across species, while species had similar seasonal changes in A(net). Our results suggest that species-specific responses to temperature contribute to the WUE-RGR trade-off that has been shown to

  3. Understanding past, contemporary, and future dynamics of plants, populations, and communities using Sonoran Desert winter annuals.

    PubMed

    Huxman, Travis E; Kimball, Sarah; Angert, Amy L; Gremer, Jennifer R; Barron-Gafford, Greg A; Venable, D Lawrence

    2013-07-01

    Global change requires plant ecologists to predict future states of biological diversity to aid the management of natural communities, thus introducing a number of significant challenges. One major challenge is considering how the many interacting features of biological systems, including ecophysiological processes, plant life histories, and species interactions, relate to performance in the face of a changing environment. We have employed a functional trait approach to understand the individual, population, and community dynamics of a model system of Sonoran Desert winter annual plants. We have used a comprehensive approach that connects physiological ecology and comparative biology to population and community dynamics, while emphasizing both ecological and evolutionary processes. This approach has led to a fairly robust understanding of past and contemporary dynamics in response to changes in climate. In this community, there is striking variation in physiological and demographic responses to both precipitation and temperature that is described by a trade-off between water-use efficiency (WUE) and relative growth rate (RGR). This community-wide trade-off predicts both the demographic and life history variation that contribute to species coexistence. Our framework has provided a mechanistic explanation to the recent warming, drying, and climate variability that has driven a surprising shift in these communities: cold-adapted species with more buffered population dynamics have increased in relative abundance. These types of comprehensive approaches that acknowledge the hierarchical nature of biology may be especially useful in aiding prediction. The emerging, novel and nonstationary climate constrains our use of simplistic statistical representations of past plant behavior in predicting the future, without understanding the mechanistic basis of change. PMID:23838034

  4. [A case of parental alienation].

    PubMed

    Menz, Wolfgang

    2014-01-01

    The clinical term "Parental Alienation Syndrome" (PAS) was introduced in 1984 by Richard Gardner, an American psychiatrist. Gardner described PAS and its symptoms, as a personality disorder, which appears chiefly in connection to child custody disputes wherein a child turns suddenly and massively against the non-custodial parent without reasonable grounds for doing so. This action by the child is a result of the custodial parent's emotionally abusive attempts to incite the child against the non-custodial parent.Where the child's rejection is based on some real past experience, there is not PAS. PAS only occurs as a result of the custodial parent's actions. Despite intensive effort, PAS was not included in the new DSM-V. In this case, a particularly impressive case history of parental alienation is described and discussed. PMID:24464865

  5. Alien liquid detector and control

    SciTech Connect

    Potter, B.M.

    1980-09-02

    An alien liquid detector employs a monitoring element and an energizing circuit for maintaining the temperature of the monitoring element substantially above ambient temperature. For this purpose an electronic circit controls a flow of heating current to the monitoring element. The presence of an alien liquid is detected by sensing a predetermined change in heating current flow to the monitoring element, e.g., to distinguish between water and oil. In preferred embodiments the monitoring element is a thermistor whose resistance is compared with a reference resistance and heating current through the thermistor is controlled in accordance with the difference. In one embodiment a bridge circuit senses the resistance difference; the difference may be sensed by an operational amplifier arrangement. Features of the invention include positioning the monitoring element at the surface of water, slightly immersed, so that the power required to maintain the thermistor temperature substantially above ambient temperature serves to detect presence of oil pollution at the surface.

  6. Alien phytogeographic regions of southern Africa: numerical classification, possible drivers, and regional threats.

    PubMed

    Hugo, Sanet; Van Rensburg, Berndt J; Van Wyk, Abraham E; Steenkamp, Yolande

    2012-01-01

    The distributions of naturalised alien plant species that have invaded natural or semi-natural habitat are often geographically restricted by the environmental conditions in their new range, implying that alien species with similar environmental requirements and tolerances may form assemblages and characterise particular areas. The aim of this study was to use objective numerical techniques to reveal any possible alien phytogeographic regions (i.e. geographic areas with characteristic alien plant assemblages) in southern Africa. Quarter degree resolution presence records of naturalised alien plant species of South Africa, Lesotho, Swaziland, Namibia and Botswana were analysed through a divisive hierarchical classification technique, and the output was plotted on maps for further interpretation. The analyses revealed two main alien phytogeographic regions that could be subdivided into eight lower level phytogeographic regions. Along with knowledge of the environmental requirements of the characteristic species and supported by further statistical analyses, we hypothesised on the main drivers of alien phytogeographic regions, and suggest that environmental features such as climate and associated biomes were most important, followed by human activities that modify climatic and vegetation features, such as irrigation and agriculture. Most of the characteristic species are not currently well-known as invasive plant species, but many may have potential to become troublesome in the future. Considering the possibility of biotic homogenization, these findings have implications for predicting the characteristics of the plant assemblages of the future. However, the relatively low quality of the dataset necessitates further more in-depth studies with improved data before the findings could be directly beneficial for management. PMID:22574145

  7. Alien Phytogeographic Regions of Southern Africa: Numerical Classification, Possible Drivers, and Regional Threats

    PubMed Central

    Hugo, Sanet; Van Rensburg, Berndt J.; Van Wyk, Abraham E.; Steenkamp, Yolande

    2012-01-01

    The distributions of naturalised alien plant species that have invaded natural or semi-natural habitat are often geographically restricted by the environmental conditions in their new range, implying that alien species with similar environmental requirements and tolerances may form assemblages and characterise particular areas. The aim of this study was to use objective numerical techniques to reveal any possible alien phytogeographic regions (i.e. geographic areas with characteristic alien plant assemblages) in southern Africa. Quarter degree resolution presence records of naturalised alien plant species of South Africa, Lesotho, Swaziland, Namibia and Botswana were analysed through a divisive hierarchical classification technique, and the output was plotted on maps for further interpretation. The analyses revealed two main alien phytogeographic regions that could be subdivided into eight lower level phytogeographic regions. Along with knowledge of the environmental requirements of the characteristic species and supported by further statistical analyses, we hypothesised on the main drivers of alien phytogeographic regions, and suggest that environmental features such as climate and associated biomes were most important, followed by human activities that modify climatic and vegetation features, such as irrigation and agriculture. Most of the characteristic species are not currently well-known as invasive plant species, but many may have potential to become troublesome in the future. Considering the possibility of biotic homogenization, these findings have implications for predicting the characteristics of the plant assemblages of the future. However, the relatively low quality of the dataset necessitates further more in-depth studies with improved data before the findings could be directly beneficial for management. PMID:22574145

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

    SciTech Connect

    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.

  9. Asymmetrical alien hands in corticobasal degeneration.

    PubMed

    Fitzgerald, David B; Drago, Valeria; Jeong, Yong; Chang, Yu-Ling; White, Keith D; Heilman, Kenneth M

    2007-03-15

    There are several forms of alien limb, but alien limb in corticobasal degeneration (CBD) is not well understood. We studied a patient with CBD who demonstrated two different types of alien limb. With his right hand he demonstrated a tactile avoidance response with levitation. With his left hand, he demonstrated continuous tactile pursuit of the examiner's hand ("tactile mitgehen"). Mitgehen is often associated with frontal dysfunction, but avoidance response and levitation are often associated with parietal dysfunction. PMID:17230447

  10. Invasion and Management of Agricultural Alien Insects in China.

    PubMed

    Wan, Fang-Hao; Yang, Nian-Wan

    2016-01-01

    China is the world's fourth-largest country in terms of landmass. Its highly diverse biogeography presents opportunities for many invasive alien insects. However, physical and climate barriers sometimes prevent locally occurring species from spreading. China has 560 confirmed invasive alien species; 125 are insect pests, and 92 of these damage the agricultural ecosystem. The estimated annual economic loss due to alien invasive species is more than $18.9 billion. The most harmful invasive insects exhibit some common characteristics, such as high reproduction, competitive dominance, and high tolerance, and benefit from mutualist facilitation interactions. Regional cropping system structure adjustments have resulted in mono-agricultural ecosystems in cotton and other staple crops, providing opportunities for monophagous insect pests. Furthermore, human dietary shifts to fruits and vegetables and smallholder-based farming systems result in highly diverse agricultural ecosystems, which provide resource opportunities for polyphagous insects. Multiple cropping and widespread use of greenhouses provide continuous food and winter habitats for insect pests, greatly extending their geographic range. The current management system consists of early-warning, monitoring, eradication, and spread blocking technologies. This review provides valuable new synthetic information on integrated management practices based mainly on biological control for a number of invasive species. We encourage farmers and extension workers to be more involved in training and further research for novel protection methods that takes into consideration end users' needs. PMID:26527302

  11. In Defense of the Alien. Volume VII. Immigration Reform and Refugee Developments. Proceedings of the Center for Migration Studies Annual National Legal Conference on Immigration and Refugee Policy (7th, Washington, DC, March 29-30, 1984).

    ERIC Educational Resources Information Center

    Tomasi, Lydio F., Ed.

    The proceedings of the 1984 Annual National Legal Conference on Immigration and Refugee Policy are collected in this book. Following a brief introduction, 16 papers are presented under three major headings: Immigration Legislation Reform; Immigration Legislation Practice; and Refugees: Policy and Legal Developments. The papers (and their authors)…

  12. Flows, droughts, and aliens: factors affecting the fish assemblage in a Sierra Nevada, California, stream.

    PubMed

    Kiernan, Joseph D; Moyle, Peter B

    2012-06-01

    The fishes of Martis Creek, in the Sierra Nevada of California (USA), were sampled at four sites annually over 30 years, 1979-2008. This long-term data set was used to examine (1) the persistence and stability of the Martis Creek fish assemblage in the face of environmental stochasticity; (2) whether native and alien fishes responded differently to a natural hydrologic regime (e.g., timing and magnitude of high and low flows); and (3) the importance of various hydrologic and physical habitat variables in explaining the abundances of native and alien fish species through time. Our results showed that fish assemblages were persistent at all sample sites, but individual species exhibited marked interannual variability in density, biomass, and relative abundance. The density and biomass of native fishes generally declined over the period of study, whereas most alien species showed no significant long-term trends. Only alien rainbow trout increased in both density and biomass at all sites over time. Redundancy analysis identified three hydrologic variables (annual 7-day minimum discharge, maximum winter discharge, and number of distinct winter floods) and two habitat variables (percentage of pool habitat and percentage of gravel substrate) that each explained a significant portion of the annual variation in fish assemblage structure. For alien taxa, their proportional contribution to the total fish assemblage was inversely related to mean annual streamflow, one-day maximum discharge in both winter and spring, and the frequency of springtime floods. Results of this study highlight the need for continuous annual monitoring of streams with highly variable flow regimes to evaluate shifts in fish community structure. Apparent successes or failures in stream management may appear differently depending on the time series of available data. PMID:22827124

  13. Inter-annual changes in detritus-based food chains can enhance plant growth response to elevated atmospheric CO2.

    PubMed

    Hines, Jes; Eisenhauer, Nico; Drake, Bert G

    2015-12-01

    Elevated atmospheric CO2 generally enhances plant growth, but the magnitude of the effects depend, in part, on nutrient availability and plant photosynthetic pathway. Due to their pivotal role in nutrient cycling, changes in abundance of detritivores could influence the effects of elevated atmospheric CO2 on essential ecosystem processes, such as decomposition and primary production. We conducted a field survey and a microcosm experiment to test the influence of changes in detritus-based food chains on litter mass loss and plant growth response to elevated atmospheric CO2 using two wetland plants: a C3 sedge (Scirpus olneyi) and a C4 grass (Spartina patens). Our field study revealed that organism's sensitivity to climate increased with trophic level resulting in strong inter-annual variation in detritus-based food chain length. Our microcosm experiment demonstrated that increased detritivore abundance could not only enhance decomposition rates, but also enhance plant growth of S. olneyi in elevated atmospheric CO2 conditions. In contrast, we found no evidence that changes in the detritus-based food chains influenced the growth of S. patens. Considered together, these results emphasize the importance of approaches that unite traditionally subdivided food web compartments and plant physiological processes to understand inter-annual variation in plant production response to elevated atmospheric CO2. PMID:25953075

  14. Alien species in a warmer world: risks and opportunities.

    PubMed

    Walther, Gian-Reto; Roques, Alain; Hulme, Philip E; Sykes, Martin T; Pysek, Petr; Kühn, Ingolf; Zobel, Martin; Bacher, Sven; Botta-Dukát, Zoltán; Bugmann, Harald; Czúcz, Bálint; Dauber, Jens; Hickler, Thomas; Jarosík, Vojtech; Kenis, Marc; Klotz, Stefan; Minchin, Dan; Moora, Mari; Nentwig, Wolfgang; Ott, Jürgen; Panov, Vadim E; Reineking, Björn; Robinet, Christelle; Semenchenko, Vitaliy; Solarz, Wojciech; Thuiller, Wilfried; Vilà, Montserrat; Vohland, Katrin; Settele, Josef

    2009-12-01

    Climate change and biological invasions are key processes affecting global biodiversity, yet their effects have usually been considered separately. Here, we emphasise that global warming has enabled alien species to expand into regions in which they previously could not survive and reproduce. Based on a review of climate-mediated biological invasions of plants, invertebrates, fishes and birds, we discuss the ways in which climate change influences biological invasions. We emphasise the role of alien species in a more dynamic context of shifting species' ranges and changing communities. Under these circumstances, management practices regarding the occurrence of 'new' species could range from complete eradication to tolerance and even consideration of the 'new' species as an enrichment of local biodiversity and key elements to maintain ecosystem services. PMID:19712994

  15. Effects of simulated daily precipitation patterns on annual plant populations depend on life stage and climatic region

    PubMed Central

    Köchy, Martin

    2008-01-01

    Background To improve the understanding of consequences of climate change for annual plant communities, I used a detailed, grid-based model that simulates the effect of daily rainfall variability on individual plants in five climatic regions on a gradient from 100 to 800 mm mean annual precipitation (MAP). The model explicitly considers moisture storage in the soil. I manipulated daily rainfall variability by changing the daily mean rain (DMR, rain volume on rainy days averaged across years for each day of the year) by ± 20%. At the same time I adjusted intervals appropriately between rainy days for keeping the mean annual volume constant. In factorial combination with changing DMR I also changed MAP by ± 20%. Results Increasing MAP generally increased water availability, establishment, and peak shoot biomass. Increasing DMR increased the time that water was continuously available to plants in the upper 15 to 30 cm of the soil (longest wet period, LWP). The effect of DMR diminished with increasing humidity of the climate. An interaction between water availability and density-dependent germination increased the establishment of seedlings in the arid region, but in the more humid regions the establishment of seedlings decreased with increasing DMR. As plants matured, competition among individuals and their productivity increased, but the size of these effects decreased with the humidity of the regions. Therefore, peak shoot biomass generally increased with increasing DMR but the effect size diminished from the semiarid to the mesic Mediterranean region. Increasing DMR reduced via LWP the annual variability of biomass in the semiarid and dry Mediterranean regions. Conclusion More rainstorms (greater DMR) increased the recharge of soil water reservoirs in more arid sites with consequences for germination, establishment, productivity, and population persistence. The order of magnitudes of DMR and MAP overlapped partially so that their combined effect is important for

  16. Oscheius tipulae in Italy: Evidence of an Alien Isolate in the Integral Natural Reserve of Montecristo Island (Tuscany).

    PubMed

    Torrini, Giulia; Mazza, Giuseppe; Strangi, Agostino; Barabaschi, Delfina; Landi, Silvia; Mori, Emiliano; Menchetti, Mattia; Sposimo, Paolo; Giuliani, Claudia; Zoccola, Antonio; Lazzaro, Lorenzo; Ferretti, Giulio; Foggi, Bruno; Roversi, Pio Federico

    2016-03-01

    Montecristo Island is an integral natural reserve of the Tuscan Archipelago National Park (Central Italy), characterized by a peculiar assemblage of flora and fauna, with several endemic taxa, and also with a high number of alien species. During a soil survey, we found an alien Oscheius tipulae Lam & Webster, 1971 isolate, phylogenetically close to others from South America. In this article, we examined the possible pathways of introduction of this nematode. Because of the high number of alien plants in this protected area and the low desiccation survival ability of O. tipulae, we hypothesized that the presence of this alien nematode isolate may be related to the soil of introduced plants, although historical association with plant-associated invertebrates is also possible. Further studies with more populations and marker molecules are necessary to investigate the distribution of O. tipulae and the possible impact on this natural reserve. PMID:27168647

  17. Oscheius tipulae in Italy: Evidence of an Alien Isolate in the Integral Natural Reserve of Montecristo Island (Tuscany)

    PubMed Central

    Torrini, Giulia; Mazza, Giuseppe; Strangi, Agostino; Barabaschi, Delfina; Landi, Silvia; Mori, Emiliano; Menchetti, Mattia; Sposimo, Paolo; Giuliani, Claudia; Zoccola, Antonio; Lazzaro, Lorenzo; Ferretti, Giulio; Foggi, Bruno; Roversi, Pio Federico

    2016-01-01

    Montecristo Island is an integral natural reserve of the Tuscan Archipelago National Park (Central Italy), characterized by a peculiar assemblage of flora and fauna, with several endemic taxa, and also with a high number of alien species. During a soil survey, we found an alien Oscheius tipulae Lam & Webster, 1971 isolate, phylogenetically close to others from South America. In this article, we examined the possible pathways of introduction of this nematode. Because of the high number of alien plants in this protected area and the low desiccation survival ability of O. tipulae, we hypothesized that the presence of this alien nematode isolate may be related to the soil of introduced plants, although historical association with plant-associated invertebrates is also possible. Further studies with more populations and marker molecules are necessary to investigate the distribution of O. tipulae and the possible impact on this natural reserve. PMID:27168647

  18. Impacts of Alien Tree Invasion on Evapotranspiration in Tropical Montane Cloud Forest in Hawai'i

    NASA Astrophysics Data System (ADS)

    Giambelluca, T. W.; Asner, G. P.; Martin, R. E.; Nullet, M. M.; Huang, M.; Delay, J. K.; Mudd, R. G.; Takahashi, M.

    2007-12-01

    Hawaiian tropical montane cloud forests (TMCFs) are ecologically and hydrologically valuable zones. TMCFs in Hawai'i serve as refugia for the remaining intact native terrestrial plant and animal ecosystems, and are major sources of hydrologic input to surface water and groundwater systems. Invasion of alien tree species, with obvious effects on the ecological integrity of TMCFs, also threatens to impact the hydrological services these forests provide. Much speculation has been made about the hydrological effects of replacing native forest tree species with alien trees in Hawai'i, but until now no measurements have been made to test these assertions. We established two study sites, each equipped with eddy covariance and other micrometeorological instrumentation, one within native Metrosideros polymorpha forest and the other at a site heavily invaded by Psidium cattleianum, in the cloud forest zone of Hawai'i Volcanoes National Park. We are conducting measurements of stand-level evapotranspiration, transpiration (using sapflow techniques), energy balance, throughfall, stemflow, and soil moisture at each site. Preliminary analysis of these measurements shows that the fraction of available energy used for evapotranspiration (ET Fraction) at the native site is much higher for wet canopy conditions. The ET Fraction at the native site has an annual cycle corresponding to the annual cycle in leaf area. Deviations from the annual cycle are more closely related to variations in canopy wetness than to variations in soil moisture. Overall, ET as a function of available energy is 27% higher at the invaded site than the native site. The difference in ET between the two sites is especially pronounced during dry canopy periods, during which the ET Fraction is 53% higher at the invaded site than the native site. Sapflow measurements using heat balance collars show that leaf-area-specific transpiration is much greater in invasive P. cattleianum trees than in remnant native M

  19. Alienation and Expectation in American Political Culture.

    ERIC Educational Resources Information Center

    Ranney, Austin

    The concept of political alienation in American culture is examined in light of evidence gathered by social scientists. Political alienation is interpreted to include a wide variety of attitudes and behaviors such as cynicism, outraged idealism, apathy, violent protest, powerlessness, and revolutionary zeal. To minimize conceptual ambiguities of…

  20. Alienating Students: Marxist Theory in Action

    ERIC Educational Resources Information Center

    Thiele, Megan; Pan, Yung-Yi Dian; Molina, Devin

    2016-01-01

    Karl Marx's revolutionary call, "Workers of the World Unite," resonates with many in today's society. This article describes and assesses an easily reproducible classroom activity that simulates both alienating, and perhaps more importantly, non-alienating states of production as described by Marx. This hands-on learning activity gives…

  1. Alienation and Use of the Mass Media.

    ERIC Educational Resources Information Center

    Pietila, Veikko

    Several studies in media viewing have examined the hypothesis that alienation correlates with the consumption of escape-type content from the mass media. In order to interpret this result, alienation was considered as a process beginning with difficiulties in situation definitions. It was assumed in this study that heavy information of the mass…

  2. Alienation, Mass Society and Mass Culture.

    ERIC Educational Resources Information Center

    Dam, Hari N.

    This monograph examines the nature of alienation in mass society and mass culture. Conceptually based on the "Gemeinschaft-Gesellschaft" paradigm of sociologist Ferdinand Tonnies, discussion traces the concept of alienation as it appears in the philosophies of Hegel, Marx, Kierkegaard, Sartre, and others. Dwight Macdonald's "A Theory of Mass…

  3. Alienation in the Barrio: Eastern New Mexico.

    ERIC Educational Resources Information Center

    Donnelly, Jerry D.

    Preliminary to a larger research project on Mexican American attitudes, this report focused on the extent to which feelings of alienation are present in the barrios of 5 eastern New Mexico population centers. The feelings of alienation were analyzed by the degree of powerlessness, normlessness, self-estrangement, and isolation expressed or…

  4. Alienation, dogmatism, and related personality characteristics.

    PubMed

    Sexton, M E

    1983-01-01

    Examined the relationship between alienation and dogmatism, as measured by shared personality characteristics. Scores from the Rokeach Dogmatism Scale, the Keniston Alienation Scale, the California Test of Personality, and the Omnibus Personality Inventory were obtained for a sample of 92 college freshmen. Alienation and dogmatism were found to be positively related concepts. The factors that best predicted alienation from dogmatic responses were intolerance expressed for opposing beliefs and compulsivity in the belief system. Alienation and dogmatism also were found to be associated with several commonly held personality traits, which center around anxiety, low self-esteem, and social estrangement manifested in feelings of hostility, aggression, loneliness, rejection, and isolation. These results were discussed and compared to previous research that explored the two concepts separately. PMID:6826758

  5. Soil sustainability study in Lithuanian alien forest stands

    NASA Astrophysics Data System (ADS)

    Čiuldiene, Dovile; Skridlaite, Grazina; Žalūdiene, Gaile; Askelsson, Cecilia; Armolaitis, Kestutis

    2016-04-01

    Tree species are shifting their natural ranges in response to climate changes (Saltré et al., 2013). Northern red oak has originated from North America, but was planted in Europe already in twentieth century. At present, it is considered as invasive species in Poland and at invasive stage in the Lithuanian forests (Riepsas and Straigyte, 2008). European larch naturally grows in Central Europe, but its range has been extended by planting it as far as the Nordic countries. According to a pollen study in peat soils, European larch naturally grew in Lithuania in the sixteenth century and was reintroduced 200 years ago (Jankauskas, 1954). Therefore, the global warming could accelerate the expansion of European larch and Northern red oak into Lithuanian forests. An urgent need appeared to evaluate an impact of those warmth-tolerant species on soil mineral chemistry and quality. New results on the determination of mineral weathering rates in alien forest stands using a PROFILE soil chemistry model were obtained during a doctoral study at the Institute of Forestry. Soil minerals were studied by a Scanning Electron Microscopy at the Institute of Geology and Geography. The results provided a lot of new information on soil weathering rates in Lithuania. The 47 and 157-year-old European larch (Larix decidua Mill.), 45 and 55-year-old Northern red oak (Quercus rubra L.) plantations and adjacent perennial grasslands were chosen for this study. The soils were classified as Luvisols and were developed from glaciofluvial deposits. The PROFILE model requires data of climate conditions (mean annual temperature and precipitation), chemical parameters of atmospheric deposition, forest plantation dendrometric and chemical (wood, foliage litter fall) characteristics, soil physical characteristics and mineral composition. A cation weathering rate (sum of Ca+Mg+ K) is 30% higher in a soil under the Northern red oak than in adjacent perennial grassland. Meanwhile, cation weathering rates

  6. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  7. 45 CFR 233.52 - Overpayment to aliens.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Overpayment to aliens. 233.52 Section 233.52... ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.52 Overpayment to aliens. A State Plan under title IV-A of the Social Security Act, shall provide that: (a) Any sponsor of an alien and the alien shall...

  8. 26 CFR 1.6654-6 - Nonresident alien individuals.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 13 2012-04-01 2012-04-01 false Nonresident alien individuals. 1.6654-6 Section... Penalties § 1.6654-6 Nonresident alien individuals. (a) In general. A nonresident alien individual is... the gross income of a nonresident alien individual is such as to require making a payment of...

  9. 22 CFR 40.91 - Certain aliens previously removed.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a...

  10. 47 CFR 90.115 - Foreign government and alien eligibility.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Foreign government and alien eligibility. 90... government and alien eligibility. (a) No station authorization in the radio services governed by this part....9(c) of this chapter) if such entity is: (1) An alien or the representative of any alien; (2)...

  11. 8 CFR 274a.3 - Continuing employment of unauthorized aliens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Continuing employment of unauthorized aliens. 274a.3 Section 274a.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS CONTROL OF EMPLOYMENT OF ALIENS Employer Requirements § 274a.3 Continuing employment...

  12. 22 CFR 40.92 - Aliens unlawfully present.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Aliens unlawfully present. 40.92 Section 40.92... UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.92 Aliens unlawfully present. (a) 3-year bar. An alien described in INA 212(a)(9)(B)(i)(I) shall be ineligible for...

  13. 45 CFR 233.52 - Overpayment to aliens.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true Overpayment to aliens. 233.52 Section 233.52 Public... ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.52 Overpayment to aliens. A State Plan under title IV-A of the Social Security Act, shall provide that: (a) Any sponsor of an alien and the alien shall...

  14. 8 CFR 1240.38 - Fingerprinting of excluded aliens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Fingerprinting of excluded aliens. 1240.38 Section 1240.38 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS PROCEEDINGS TO DETERMINE REMOVABILITY OF ALIENS IN THE UNITED STATES Exclusion...

  15. 45 CFR 1626.7 - Verification of eligible alien status.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 4 2012-10-01 2012-10-01 false Verification of eligible alien status. 1626.7... CORPORATION RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.7 Verification of eligible alien status. (a) An alien seeking representation shall submit appropriate documents to verify eligibility, unless the...

  16. 45 CFR 1626.5 - Alien status and eligibility.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 4 2012-10-01 2012-10-01 false Alien status and eligibility. 1626.5 Section 1626... RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.5 Alien status and eligibility. Subject to all other... may provide legal assistance to an alien who is present in the United States and who is within one...

  17. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  18. 26 CFR 1.871-3 - Residence of alien seamen.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Residence of alien seamen. 1.871-3 Section 1.871... (CONTINUED) INCOME TAXES Nonresident Aliens and Foreign Corporations § 1.871-3 Residence of alien seamen. In order to determine whether an alien seaman is a resident of the United States for purposes of the...

  19. 45 CFR 1626.5 - Alien status and eligibility.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Alien status and eligibility. 1626.5 Section 1626... RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.5 Alien status and eligibility. Subject to all other... may provide legal assistance to an alien who is present in the United States and who is within one...

  20. 8 CFR 1236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...(c) of 8 CFR chapter I. (b) Service custody and cost of maintenance. An alien confined because of... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Confined aliens, incompetents, and minors. 1236.2 Section 1236.2 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT...

  1. 26 CFR 1.6654-6 - Nonresident alien individuals.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 13 2013-04-01 2013-04-01 false Nonresident alien individuals. 1.6654-6 Section... Penalties § 1.6654-6 Nonresident alien individuals. (a) In general. A nonresident alien individual is... the gross income of a nonresident alien individual is such as to require making a payment of...

  2. 8 CFR 1240.38 - Fingerprinting of excluded aliens.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Fingerprinting of excluded aliens. 1240.38 Section 1240.38 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS PROCEEDINGS TO DETERMINE REMOVABILITY OF ALIENS IN THE UNITED STATES Exclusion...

  3. 8 CFR 1236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...(c) of 8 CFR chapter I. (b) Service custody and cost of maintenance. An alien confined because of... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Confined aliens, incompetents, and minors. 1236.2 Section 1236.2 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT...

  4. 26 CFR 1.871-3 - Residence of alien seamen.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 9 2013-04-01 2013-04-01 false Residence of alien seamen. 1.871-3 Section 1.871... (CONTINUED) INCOME TAXES (CONTINUED) Nonresident Aliens and Foreign Corporations § 1.871-3 Residence of alien seamen. In order to determine whether an alien seaman is a resident of the United States for purposes...

  5. 22 CFR 40.92 - Aliens unlawfully present.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens unlawfully present. 40.92 Section 40.92... UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.92 Aliens unlawfully present. (a) 3-year bar. An alien described in INA 212(a)(9)(B)(i)(I) shall be ineligible for...

  6. 26 CFR 1.871-3 - Residence of alien seamen.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 9 2012-04-01 2012-04-01 false Residence of alien seamen. 1.871-3 Section 1.871... (CONTINUED) INCOME TAXES (CONTINUED) Nonresident Aliens and Foreign Corporations § 1.871-3 Residence of alien seamen. In order to determine whether an alien seaman is a resident of the United States for purposes...

  7. 22 CFR 40.91 - Certain aliens previously removed.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a...

  8. 8 CFR 274a.3 - Continuing employment of unauthorized aliens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Continuing employment of unauthorized aliens. 274a.3 Section 274a.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS CONTROL OF EMPLOYMENT OF ALIENS Employer Requirements § 274a.3 Continuing employment...

  9. 8 CFR 1236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...(c) of 8 CFR chapter I. (b) Service custody and cost of maintenance. An alien confined because of... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Confined aliens, incompetents, and minors. 1236.2 Section 1236.2 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT...

  10. 26 CFR 1.6654-6 - Nonresident alien individuals.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Nonresident alien individuals. 1.6654-6 Section....6654-6 Nonresident alien individuals. (a) In general. A nonresident alien individual is required to... gross income of a nonresident alien individual is such as to require making a payment of...

  11. 8 CFR 1236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...(c) of 8 CFR chapter I. (b) Service custody and cost of maintenance. An alien confined because of... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Confined aliens, incompetents, and minors. 1236.2 Section 1236.2 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT...

  12. 26 CFR 1.6654-6 - Nonresident alien individuals.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 13 2011-04-01 2011-04-01 false Nonresident alien individuals. 1.6654-6 Section... Penalties § 1.6654-6 Nonresident alien individuals. (a) In general. A nonresident alien individual is... the gross income of a nonresident alien individual is such as to require making a payment of...

  13. 45 CFR 1626.5 - Alien status and eligibility.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Alien status and eligibility. 1626.5 Section 1626... RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.5 Alien status and eligibility. Subject to all other... may provide legal assistance to an alien who is present in the United States and who is within one...

  14. 26 CFR 1.871-3 - Residence of alien seamen.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 9 2011-04-01 2011-04-01 false Residence of alien seamen. 1.871-3 Section 1.871... (CONTINUED) INCOME TAXES (CONTINUED) Nonresident Aliens and Foreign Corporations § 1.871-3 Residence of alien seamen. In order to determine whether an alien seaman is a resident of the United States for purposes...

  15. 22 CFR 40.91 - Certain aliens previously removed.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a...

  16. 47 CFR 90.115 - Foreign government and alien eligibility.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Foreign government and alien eligibility. 90... government and alien eligibility. (a) No station authorization in the radio services governed by this part....9(c) of this chapter) if such entity is: (1) An alien or the representative of any alien; (2)...

  17. 8 CFR 1240.38 - Fingerprinting of excluded aliens.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Fingerprinting of excluded aliens. 1240.38 Section 1240.38 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS PROCEEDINGS TO DETERMINE REMOVABILITY OF ALIENS IN THE UNITED STATES Exclusion...

  18. 8 CFR 1240.38 - Fingerprinting of excluded aliens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Fingerprinting of excluded aliens. 1240.38 Section 1240.38 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS PROCEEDINGS TO DETERMINE REMOVABILITY OF ALIENS IN THE UNITED STATES Exclusion...

  19. 45 CFR 1626.7 - Verification of eligible alien status.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Verification of eligible alien status. 1626.7... CORPORATION RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.7 Verification of eligible alien status. (a) An alien seeking representation shall submit appropriate documents to verify eligibility, unless the...

  20. 22 CFR 40.92 - Aliens unlawfully present.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Aliens unlawfully present. 40.92 Section 40.92... UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.92 Aliens unlawfully present. (a) 3-year bar. An alien described in INA 212(a)(9)(B)(i)(I) shall be ineligible for...

  1. 8 CFR 274a.3 - Continuing employment of unauthorized aliens.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Continuing employment of unauthorized aliens. 274a.3 Section 274a.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS CONTROL OF EMPLOYMENT OF ALIENS Employer Requirements § 274a.3 Continuing employment...

  2. 47 CFR 90.115 - Foreign government and alien eligibility.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Foreign government and alien eligibility. 90... government and alien eligibility. (a) No station authorization in the radio services governed by this part....9(c) of this chapter) if such entity is: (1) An alien or the representative of any alien; (2)...

  3. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  4. 45 CFR 1626.5 - Alien status and eligibility.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 4 2013-10-01 2013-10-01 false Alien status and eligibility. 1626.5 Section 1626... RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.5 Alien status and eligibility. Subject to all other... may provide legal assistance to an alien who is present in the United States and who is within one...

  5. 45 CFR 233.52 - Overpayment to aliens.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false Overpayment to aliens. 233.52 Section 233.52... ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.52 Overpayment to aliens. A State Plan under title IV-A of the Social Security Act, shall provide that: (a) Any sponsor of an alien and the alien shall...

  6. 45 CFR 1626.7 - Verification of eligible alien status.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 4 2013-10-01 2013-10-01 false Verification of eligible alien status. 1626.7... CORPORATION RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.7 Verification of eligible alien status. (a) An alien seeking representation shall submit appropriate documents to verify eligibility, unless the...

  7. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  8. 45 CFR 1626.7 - Verification of eligible alien status.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Verification of eligible alien status. 1626.7... CORPORATION RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.7 Verification of eligible alien status. (a) An alien seeking representation shall submit appropriate documents to verify eligibility, unless the...

  9. 28 CFR 0.47 - Alien property matters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Alien property matters. 0.47 Section 0.47....47 Alien property matters. The Office of Alien Property shall be a part of the Civil Division: (a... Alien Property: (1) Exercising or performing all the authority, rights, privileges, powers, duties,...

  10. 22 CFR 40.92 - Aliens unlawfully present.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Aliens unlawfully present. 40.92 Section 40.92... UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.92 Aliens unlawfully present. (a) 3-year bar. An alien described in INA 212(a)(9)(B)(i)(I) shall be ineligible for...

  11. 45 CFR 233.52 - Overpayment to aliens.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Overpayment to aliens. 233.52 Section 233.52... ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.52 Overpayment to aliens. A State Plan under title IV-A of the Social Security Act, shall provide that: (a) Any sponsor of an alien and the alien shall...

  12. 22 CFR 40.91 - Certain aliens previously removed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a...

  13. 8 CFR 274a.3 - Continuing employment of unauthorized aliens.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Continuing employment of unauthorized aliens. 274a.3 Section 274a.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS CONTROL OF EMPLOYMENT OF ALIENS Employer Requirements § 274a.3 Continuing employment...

  14. 47 CFR 90.115 - Foreign government and alien eligibility.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Foreign government and alien eligibility. 90... government and alien eligibility. (a) No station authorization in the radio services governed by this part....9(c) of this chapter) if such entity is: (1) An alien or the representative of any alien; (2)...

  15. 7 CFR 273.4 - Citizenship and alien status.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... residing in the same household as the alien at the time of the abuse, an alien whose child has been... residing in the same household as the alien at the time of the abuse, an alien whose child has been... Laotian who is deceased, or (iii) An unmarried dependent child of such Hmong or Highland Laotian who...

  16. 7 CFR 273.4 - Citizenship and alien status.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... residing in the same household as the alien at the time of the abuse, an alien whose child has been... residing in the same household as the alien at the time of the abuse, an alien whose child has been... Laotian who is deceased, or (iii) An unmarried dependent child of such Hmong or Highland Laotian who...

  17. 7 CFR 273.4 - Citizenship and alien status.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... residing in the same household as the alien at the time of the abuse, an alien whose child has been... residing in the same household as the alien at the time of the abuse, an alien whose child has been... Laotian who is deceased, or (iii) An unmarried dependent child of such Hmong or Highland Laotian who...

  18. 7 CFR 273.4 - Citizenship and alien status.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... residing in the same household as the alien at the time of the abuse, an alien whose child has been... residing in the same household as the alien at the time of the abuse, an alien whose child has been... Laotian who is deceased, or (iii) An unmarried dependent child of such Hmong or Highland Laotian who...

  19. 26 CFR 1.871-3 - Residence of alien seamen.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 9 2014-04-01 2014-04-01 false Residence of alien seamen. 1.871-3 Section 1.871... (CONTINUED) INCOME TAXES (CONTINUED) Nonresident Aliens and Foreign Corporations § 1.871-3 Residence of alien seamen. In order to determine whether an alien seaman is a resident of the United States for purposes...

  20. 45 CFR 233.52 - Overpayment to aliens.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 2 2014-10-01 2012-10-01 true Overpayment to aliens. 233.52 Section 233.52 Public... ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.52 Overpayment to aliens. A State Plan under title IV-A of the Social Security Act, shall provide that: (a) Any sponsor of an alien and the alien shall...

  1. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  2. 8 CFR 1240.38 - Fingerprinting of excluded aliens.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Fingerprinting of excluded aliens. 1240.38 Section 1240.38 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS PROCEEDINGS TO DETERMINE REMOVABILITY OF ALIENS IN THE UNITED STATES Exclusion...

  3. 22 CFR 40.92 - Aliens unlawfully present.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Aliens unlawfully present. 40.92 Section 40.92... UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.92 Aliens unlawfully present. (a) 3-year bar. An alien described in INA 212(a)(9)(B)(i)(I) shall be ineligible for...

  4. 47 CFR 90.115 - Foreign government and alien eligibility.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Foreign government and alien eligibility. 90... government and alien eligibility. (a) No station authorization in the radio services governed by this part....9(c) of this chapter) if such entity is: (1) An alien or the representative of any alien; (2)...

  5. 8 CFR 274a.3 - Continuing employment of unauthorized aliens.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Continuing employment of unauthorized aliens. 274a.3 Section 274a.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS CONTROL OF EMPLOYMENT OF ALIENS Employer Requirements § 274a.3 Continuing employment...

  6. 45 CFR 1626.7 - Verification of eligible alien status.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 4 2014-10-01 2014-10-01 false Verification of eligible alien status. 1626.7... CORPORATION RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.7 Verification of eligible alien status. (a) An alien seeking representation shall submit appropriate documents to verify eligibility, unless the...

  7. 26 CFR 1.6654-6 - Nonresident alien individuals.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 13 2014-04-01 2014-04-01 false Nonresident alien individuals. 1.6654-6 Section... Penalties § 1.6654-6 Nonresident alien individuals. (a) In general. A nonresident alien individual is... the gross income of a nonresident alien individual is such as to require making a payment of...

  8. 8 CFR 1236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...(c) of 8 CFR chapter I. (b) Service custody and cost of maintenance. An alien confined because of... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Confined aliens, incompetents, and minors. 1236.2 Section 1236.2 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT...

  9. 22 CFR 40.91 - Certain aliens previously removed.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a...

  10. 1997 annual ground control operating plan for the Waste Isolation Pilot Plant

    SciTech Connect

    1997-02-01

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

  11. Photosynthetic resource-use efficiency and demographic variability in desert winter annual plants.

    PubMed

    Huxman, Travis E; Barron-Gafford, Greg; Gerst, Katharine L; Angert, Amy L; Tyler, Anna P; Venable, D Lawrence

    2008-06-01

    We studied a guild of desert winter annual plants that differ in long-term variation in per capita reproductive success (lb, the product of per capita survival from germination to reproduction, l, times per capita reproduction of survivors, b) to relate individual function to population and community dynamics. We hypothesized that variation in lb should be related to species' positions along a trade-off between relative growth rate (RGR) and photosynthetic water-use efficiency (WUE) because lb is a species-specific function of growing-season precipitation. We found that demographically variable species have greater RGR and greater leaf carbon isotope discrimination (Delta, a proxy inversely related to WUE). We examined leaf nitrogen and photosynthetic characteristics and found that, in this system, variation in Delta is a function of photosynthetic demand rather than stomatal regulation of water loss. The physiological characteristics that result in low Delta in some species may confer greater photosynthetic performance during the reliably moist but low temperature periods that immediately follow winter rainfall in the Sonoran Desert or alternatively during cool periods of the day or early growing season. Conversely, while species with high Delta and high RGR exhibit low leaf N, they have high biomass allocation to canopy leaf area display. Such trait associations may allow for greater performance during the infrequent conditions where high soil moisture persists into warmer conditions, resulting in high demographic variance. Alternatively, high variance could arise from specialization to warm periods of the day or season. Population dynamic buffering via stress tolerance (low RGR and Delta) correlates negatively with buffering via seed banks, as predicted by bet-hedging theory. By merging analyses of population dynamics with functional trait relationships, we develop a deeper understanding of the physiological, ecological, and evolutionary mechanisms involved in

  12. Annual water quality data report for the Waste Isolation Pilot Plant

    SciTech Connect

    Lyon, M.L. )

    1989-04-01

    This is the fourth Annual Water Quality Data Report for the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. The WIPP project is operated by the United States Department of Energy (DOE) for the purpose of providing a research and development facility to demonstrate the safe disposal of transuranic radioactive wastes generated by the defense activities of the United States Government. This report presents water quality data collected from January 1988 through December 1988 from 16 designated pre-operational (WIPP facility) monitoring wells, two additional wells, and 10 privately-owned wells in the vicinity of the WIPP. Additionally, water samples were collected from the Air Intake Shaft during shaft construction activities at the WIPP. This report lists pertinent information regarding the monitoring wells sampled, sampling zone, dates pumped, and types of samples collected during 1988. Comparative data from previous samplings of all wells can be found in Uhland and Randall (1986), Uhland et al. (1987), Randall et al. (1988), as well as in this report. The data reported by the Water Quality Sampling Program in this and previous reports indicate that serial sampling is a very useful tool in determining sample representativeness from wells in the WIPP vicinity. Serial sample field chemistry data are demonstrated to be highly accurate and precise as indicated by the excellent overall average percent spike recovery values and low RPD values reported for the sampling events. Serial sample field chemistry data and laboratory water quality parameter analyses gathered by the WQSP since January 1985 are the foundation for a pre-operational water quality baseline at the WIPP. 32 refs., 66 figs., 96 tabs.

  13. Tillage Requirments for integrating winter-annual grazing in peanut production: Plant water status and productivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of crop rotation systems involving winter-annual grazing can help peanut (Arachis hypogaea L.) producers increase profitability, although winter-annual grazing could result in excessive soil compaction, which can severely limit yields. We conducted a 3-yr field study on a Dothan loamy sand i...

  14. The Genome of Selaginella: A Remnant of an Ancient Vascular Plant Lineage (JGI Seventh Annual User Meeting, 2012: Genomics of Energy and Environment)

    ScienceCinema

    Banks, Jody [Purdue University

    2013-01-22

    Jody Banks from Purdue University on "The Genome of Selaginella, a Remnant of an Ancient Vascular Plant Lineage" at the 7th Annual Genomics of Energy & Environment Meeting on March 21, 2012 in Walnut Creek, Calif.

  15. The Challenges and Opportunities for Extending Plant Genomics to Climate (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Weston, David

    2013-03-01

    David Weston of Oak Ridge National Laboratory on "The challenges and opportunities for extending plant genomics to climate" at the 8th Annual Genomics of Energy & Environment Meeting on March 27, 2013 in Walnut Creek, Calif.

  16. Delineating Molecular Interaction Mechanisms in an In Vitro Microbial-Plant Community (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Larsen, Peter

    2013-03-01

    Peter Larsen of Argonne National Lab on "Delineating molecular interaction mechanisms in an in vitro microbial-plant community" at the 8th Annual Genomics of Energy & Environment Meeting in Walnut Creek, Calif.

  17. The Genome of Selaginella: A Remnant of an Ancient Vascular Plant Lineage (JGI Seventh Annual User Meeting, 2012: Genomics of Energy and Environment)

    SciTech Connect

    Banks, Jody

    2012-03-21

    Jody Banks from Purdue University on "The Genome of Selaginella, a Remnant of an Ancient Vascular Plant Lineage" at the 7th Annual Genomics of Energy & Environment Meeting on March 21, 2012 in Walnut Creek, Calif.

  18. Succession of Phylogeny and Function During Plant Litter Decomposition (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Brodie, Eoin

    2013-03-01

    Eoin Brodie of Berkeley Lab on "Succession of phylogeny and function during plant litter decomposition" at the 8th Annual Genomics of Energy & Environment Meeting on March 27, 2013 in Walnut Creek, Calif.

  19. Modulation of Root Microbiome Community Assembly by the Plant Immune Response (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Lebeis, Sarah

    2013-03-01

    Sarah Lebeis of University of North Carolina on "Modulation of root microbiome community assembly by the plant immune response" at the 8th Annual Genomics of Energy & Environment Meeting on March 28, 2013 in Walnut Creek, Calif.

  20. New Approaches and Technologies to Sequence de novo Plant reference Genomes (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect

    Schmutz, Jeremy

    2013-03-01

    Jeremy Schmutz of the HudsonAlpha Institute for Biotechnology on "New approaches and technologies to sequence de novo plant reference genomes" at the 8th Annual Genomics of Energy & Environment Meeting on March 27, 2013 in Walnut Creek, Calif.

  1. Hosts and parasites as aliens.

    PubMed

    Taraschewski, H

    2006-06-01

    Over the past decades, various free-living animals (hosts) and their parasites have invaded recipient areas in which they had not previously occurred, thus gaining the status of aliens or exotics. In general this happened to a low extent for hundreds of years. With variable frequency, invasions have been followed by the dispersal and establishment of non-indigenous species, whether host or parasite. In the literature thus far, colonizations by both hosts and parasites have not been treated and reviewed together, although both are usually interwoven in various ways. As to those factors permitting invasive success and colonization strength, various hypotheses have been put forward depending on the scientific background of respective authors and on the conspicuousness of certain invasions. Researchers who have tried to analyse characteristic developmental patterns, the speed of dispersal or the degree of genetic divergence in populations of alien species have come to different conclusions. Among parasitologists, the applied aspects of parasite invasions, such as the negative effects on economically important hosts, have long been at the centre of interest. In this contribution, invasions by hosts as well as parasites are considered comparatively, revealing many similarities and a few differences. Two helminths, the liver fluke, Fasciola hepatica, of cattle and sheep and the swimbladder nematode, Anguillicola crassus, of eels are shown to be useful as model parasites for the study of animal invasions and environmental global change. Introductions of F. hepatica have been associated with imports of cattle or other grazing animals. In various target areas, susceptible lymnaeid snails serving as intermediate hosts were either naturally present and/or were introduced from the donor continent of the parasite (Europe) and/or from other regions which were not within the original range of the parasite, partly reflecting progressive stages of a global biota change. In several

  2. Worker Alienation and Compensation at the Savannah River Site.

    PubMed

    Ashwood, Loka; Wing, Steve

    2016-05-01

    Corporations operating U.S. nuclear weapons plants for the federal government began tracking occupational exposures to ionizing radiation in 1943. However, workers, scholars, and policy makers have questioned the accuracy and completeness of radiation monitoring and its capacity to provide a basis for workers' compensation. We use interviews to explore the limitations of broad-scale, corporate epidemiological surveillance through worker accounts from the Savannah River Site nuclear weapons plant. Interviewees report inadequate monitoring, overbearing surveillance, limited venues to access medical support and exposure records, and administrative failure to report radiation and other exposures at the plant. The alienation of workers from their records and toil is relevant to worker compensation programs and the accuracy of radiation dose measurements used in epidemiologic studies of occupational radiation exposures at the Savannah River Site and other weapons plants. PMID:26956018

  3. 8 CFR 1244.17 - Annual registration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Annual registration. 1244.17 Section 1244... REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.17 Annual registration. (a... jurisdiction over their place of residence. Such registration will apply to nationals of those foreign...

  4. 8 CFR 1244.17 - Annual registration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Annual registration. 1244.17 Section 1244... REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.17 Annual registration. (a... jurisdiction over their place of residence. Such registration will apply to nationals of those foreign...

  5. Projecting changes in annual hydropower generation using regional runoff data: An assessment of the United States federal hydropower plants

    SciTech Connect

    Kao, Shih -Chieh; Sale, Michael J.; Ashfaq, Moetasim; Uria Martinez, Rocio; Kaiser, Dale Patrick; Wei, Yaxing; Diffenbaugh, Noah S.

    2014-12-18

    Federal hydropower plants account for approximately half of installed US conventional hydropower capacity, and are an important part of the national renewable energy portfolio. Utilizing the strong linear relationship between the US Geological Survey WaterWatch runoff and annual hydropower generation, a runoff-based assessment approach is introduced in this study to project changes in annual and regional hydropower generation in multiple power marketing areas. Future climate scenarios are developed with a series of global and regional climate models, and the model output is bias-corrected to be consistent with observed data for the recent past. Using this approach, the median decrease in annual generation at federal projects is projected to be less than –2 TWh, with an estimated ensemble uncertainty of ±9 TWh. Although these estimates are similar to the recently observed variability in annual hydropower generation, and may therefore appear to be manageable, significantly seasonal runoff changes are projected and it may pose significant challenges in water systems with higher limits on reservoir storage and operational flexibility. Lastly, future assessments will be improved by incorporating next-generation climate models, by closer examination of extreme events and longer-term change, and by addressing the interactions among hydropower and other water uses.

  6. Projecting changes in annual hydropower generation using regional runoff data: An assessment of the United States federal hydropower plants

    DOE PAGESBeta

    Kao, Shih -Chieh; Sale, Michael J.; Ashfaq, Moetasim; Uria Martinez, Rocio; Kaiser, Dale Patrick; Wei, Yaxing; Diffenbaugh, Noah S.

    2014-12-18

    Federal hydropower plants account for approximately half of installed US conventional hydropower capacity, and are an important part of the national renewable energy portfolio. Utilizing the strong linear relationship between the US Geological Survey WaterWatch runoff and annual hydropower generation, a runoff-based assessment approach is introduced in this study to project changes in annual and regional hydropower generation in multiple power marketing areas. Future climate scenarios are developed with a series of global and regional climate models, and the model output is bias-corrected to be consistent with observed data for the recent past. Using this approach, the median decrease inmore » annual generation at federal projects is projected to be less than –2 TWh, with an estimated ensemble uncertainty of ±9 TWh. Although these estimates are similar to the recently observed variability in annual hydropower generation, and may therefore appear to be manageable, significantly seasonal runoff changes are projected and it may pose significant challenges in water systems with higher limits on reservoir storage and operational flexibility. Lastly, future assessments will be improved by incorporating next-generation climate models, by closer examination of extreme events and longer-term change, and by addressing the interactions among hydropower and other water uses.« less

  7. Undocumented Aliens: A Study of Mexican Families.

    ERIC Educational Resources Information Center

    Salcido, Ramon M.

    1979-01-01

    The personal histories described here confirm that the primary impetus of undocumented aliens to emigrate is the desire for jobs and better socioeconomic opportunities. Amnesty, aid to families with dependent children, and increased social services are recommended. (Author/BEF)

  8. Large capacity, multi-fuel, and high temperature working fluid heaters to optimize CSP plant cost, complexity and annual generation

    NASA Astrophysics Data System (ADS)

    Peterseim, J. H.; Viscuso, L.; Hellwig, U.; McIntyre, P.

    2016-05-01

    This paper analyses the potential to optimize high temperature fluid back-up systems for concentrating solar power (CSP) plants by investigating the cost impact of component capacity and the impact of using multiple fuels on annual generation. Until now back-up heaters have been limited to 20MWth capacity but larger units have been realised in other industries. Installing larger units yields economy-of-scale benefits through improved manufacturing, optimised transport, and minimized on-site installation work. Halving the number of back-up boilers can yield cost reduction of 23% while minimizing plant complexity and on-site construction risk. However, to achieve these benefits it is important to adapt the back-up heaters to the plant's requirements (load change, capacity, minimum load, etc.) and design for manufacture, transport and assembly. Despite the fact that biomass availability is decreasing with increasing direct normal irradiance (DNI), some biomass is available in areas suitable for CSP plants. The use of these biomass resources is beneficial to maximise annual renewable energy generation, substitute natural gas, and use locally/seasonally available biomass resources that may not be used otherwise. Even small biomass quantities of only 50,000 t/a can increase the capacity factor of a 50MWe parabolic trough plant with 7h thermal energy storage from 40 to 49%. This is a valuable increase and such a concept is suitable for new plants and retrofit applications. However, similar to the capacity optimisation of back-up heaters, various design criteria have to be considered to ensure a successful project.

  9. Managing soil nitrogen to restore annual grass infested plant communities: an effective strategy or incomplete framework?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Theoretical and empirical work has established a positive relationship between resource availability and habitat invasibility. For invasive annual grasses, similar to other invasive species, invader success has been most often tied to increases in nitrogen (N) availability. These observations have...

  10. The 17th Annual Harry G. Armstrong Lecture. Cannabis: the plant, its drugs, and their effects.

    PubMed

    Turner, C E

    1983-04-01

    Marijuana is not a plant. It is a crude drug made from the Cannabis plant. Many other crude drugs are also made from this plant. Their chemical composition varies with the plant parts used in producing the particular drug. This paper describes the chemical composition of Cannabis, the uses to which these chemicals are put in the manufacture of crude drugs, and the effects of these drugs. PMID:6847576

  11. Alien Insects in Italy: Comparing Patterns from the Regional to European Level

    PubMed Central

    Inghilesi, Alberto F.; Mazza, Giuseppe; Cervo, Rita; Gherardi, Francesca; Sposimo, Paolo; Tricarico, Elena; Zapparoli, Marzio

    2013-01-01

    The introduction of species outside their native range contributes to the loss of biodiversity, alters the structure and functioning of ecosystems, and damages economy and human health. Insects are one of the taxa with the highest frequency of introduction due to their high diversity, biological properties, and close association with human activities. Here, the allodiversity of Italian entomofauna was analyzed, with a focus on Tuscany (Central Italy). A list of alien insects in Tuscany is included. The status of the alien entomofauna in Italy was updated. The number of alien insects amounts to 122 in Tuscany and 923 in Italy. An introduction rate of 98 species per decade was estimated in Italy. In Tuscany, alien insects belong to 10 orders, mostly Coleoptera (38%), Hemiptera (Sternorrhyncha and Auchenorrhyncha) (23%), and Hymenoptera (13%). They have been most often introduced through vegetable items (ornamental plants or crops). Most species come from the Nearctic region (26%) and are both phytophagous (63%) and amphigonic (80%). Differences and similarities in introduction patterns and in insect abundances across orders among regional, national, and European scales, also considering worldwide abundances, are discussed. Finally, a paucity of information regarding the negative impacts of many species, except for economic pests, phytosanitary threats, and vectors of disease, is underlined. A deeper understanding of the alien insects' ecological impact might help designate policies aimed at preventing further introductions and control the invasive populations of already established species. PMID:24219427

  12. Biodiversity and native plant abundance decline with increasing abundance of exotic annual grass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exotic plants are generally considered a serious problem in wildlands around the world. However, some argue that the impacts of exotic plants have been exaggerated and that biodiversity and other important plant community characteristics are commonly improved with invasion. Thus, disagreement exis...

  13. Alcoa World Alumina: Plant-Wide Assessment at Arkansas Operations Reveals More than$900,000 in Potential Annual Savings

    SciTech Connect

    Not Available

    2003-07-01

    The plant-wide energy-efficiency assessment performed in 2001 at the Alcoa World Alumina Arkansas Operations in Bauxite, Arkansas, identified seven opportunities to save energy and reduce costs. By implementing five of these improvements, the facility can save 15,100 million British thermal units per year in natural gas and 8.76 million kilowatt-hours per year in electricity. This translates into approximate annual savings of$925,300 in direct energy costs and non-fuel operating and maintenance costs. The required capital investment is estimated at$271,200. The average payback period for all five projects would be approximately 8 months.

  14. Alcoa World Alumina: Plant Wide Assessment at Arkansas Operation Reveals More than $900,000 in Potential Annual Savings

    SciTech Connect

    2003-07-01

    The plant-wide energy-efficiency assessment performed in 2001 at the Alcoa World Alumina Arkansas Operations in Bauxite, Arkansas, identified seven opportunities to save energy and reduce costs. By implementing five of these improvements, the facility can save 15,100 million British thermal units per year in natural gas and 8.76 million kilowatt-hours per year in electricity. This translates into approximate annual savings of $925,300 in direct energy costs and non-fuel operating and maintenance costs. The required capital investment is estimated at $271,200. The average payback period for all five projects would be approximately 8 months.

  15. Molecular and biochemical identification of alien chromosome additions in shallot (Allium cepa L. Aggregatum group) carrying extra chromosome(s) of bunching onion (A. fistulosum L.).

    PubMed

    Yaguchi, Shigenori; Hang, Tran Thi Minh; Tsukazaki, Hikaru; Hoa, Vu Quynh; Masuzaki, Shin-ichi; Wako, Tadayuki; Masamura, Noriya; Onodera, Shuichi; Shiomi, Norio; Yamauchi, Naoki; Shigyo, Masayoshi

    2009-02-01

    To develop the bunching onion (Allium fistulosum L.; genomes, FF) chromosome-specific genetic markers for identifying extra chromosomes, eight shallot (A. cepa L. Aggregatum group; genomes, AA)--A. fistulosum monosomic addition plants (AA+nF) and 62 shallot--A. fistulosum single-alien deletion plants (AAF-nF) were analyzed by 23 different chromosome-specific genetic markers of shallot. The eight monosomic addition plants consisted of one AA+2F, two AA+6F, and five AA+8F. Of the 62 single-alien deletion plants, 60 could be identified as six different single-alien deletion lines (AAF-1F, -3F, -4F, -6F, -7F, and -8F) out of the eight possible types. Several single-alien deletion lines were classified on the basis of leaf and bulb characteristics. AAF-8F had the largest number of expanded leaves of five deletion plants. AAF-7F grew most vigorously, as expressed by its long leaf blade and biggest bulb size. AAF-4F had very small bulbs. AAF-7F and AAF-8F had different bulbs from those of shallot as well as other types of single-alien deletion lines in skin and outer scale color. Regarding the sugar content of the bulb tissues, the single-alien deletion lines showed higher fructan content than shallot. Moreover, shallot could not produce fructan with degree of polymerization (DP) 12 or higher, although the single-alien deletion lines showed DP 20 or higher. The content of S-alk(en)yl-L-cysteine sulfoxide (ACSO) in the single-alien deletion lines was significantly lower than that in shallot. These results indicated that chromosomes from A. fistulosum might carry anonymous factors to increase the highly polymerized fructan production and inhibit the synthesis of ACSO in shallot bulbs. Accordingly, alien chromosomes from A. fistulosum in shallot would contribute to modify the quality of shallot bulbs. PMID:19420800

  16. The influence of the annual invasive plant, Impatiens glandulifera, on the sediment dynamics of inland watercourses in temperate regions

    NASA Astrophysics Data System (ADS)

    Dalvi, Shrutika; Greenwood, Philip

    2016-04-01

    Impatiens glandulifera (Common English Name - Himalayan Balsam) is a non native annual and highly invasive plant that was introduced into parts of Europe from the Himalaya during the nineteenth century as a colourful adornment to parks and gardens. This Plant colonises areas along the river banks, preferably wet, depositional sites, and displaces natural vegetation. The plant is killed by cold weather. The leaves area of riverbank previously occupied by the plant extremely vulnerable to soil erosion until new plant germinates in the following spring. Research work undertaken in the northwest Switzerland and the soutwestern United Kingdom established s link between accelerated soil erosion caused by Impatiens glandulifera and its detrimental impact on native biodiversity of riparian zone of river catchment area. This study focueses on the potential impact of such erosion on sediment quality. A priory reasoning suggests that the preference of Impatiens glandulifera on young depsotional sites near watercourses affects sediment quality. In this study, the results of a soil quality analysis along Impatiens glandulifera-contaminated river banks is presented. Soil physical and chemical properties are compared to non-affected sites to assess the potential impact of preferential erosion on water quality. In addtiion, soil surface profile (SSP) measuring based on by erosion pins, a micro profile bridge and a digital calliper at different selected locations along the riparian zone of river catchment area is used to determine erosion rates and determine sediment transfer from the riparian zone into the rivers.

  17. Does Global Warming Increase Establishment Rates of Invasive Alien Species? A Centurial Time Series Analysis

    PubMed Central

    Huang, Dingcheng; Haack, Robert A.; Zhang, Runzhi

    2011-01-01

    Background The establishment rate of invasive alien insect species has been increasing worldwide during the past century. This trend has been widely attributed to increased rates of international trade and associated species introductions, but rarely linked to environmental change. To better understand and manage the bioinvasion process, it is crucial to understand the relationship between global warming and establishment rate of invasive alien species, especially for poikilothermic invaders such as insects. Methodology/Principal Findings We present data that demonstrate a significant positive relationship between the change in average annual surface air temperature and the establishment rate of invasive alien insects in mainland China during 1900–2005. This relationship was modeled by regression analysis, and indicated that a 1°C increase in average annual surface temperature in mainland China was associated with an increase in the establishment rate of invasive alien insects of about 0.5 species year−1. The relationship between rising surface air temperature and increasing establishment rate remained significant even after accounting for increases in international trade during the period 1950–2005. Moreover, similar relationships were detected using additional data from the United Kingdom and the contiguous United States. Conclusions/Significance These findings suggest that the perceived increase in establishments of invasive alien insects can be explained only in part by an increase in introduction rate or propagule pressure. Besides increasing propagule pressure, global warming is another driver that could favor worldwide bioinvasions. Our study highlights the need to consider global warming when designing strategies and policies to deal with bioinvasions. PMID:21931837

  18. Annual radiological environmental operating report: Browns Ferry Nuclear Plant, 1992. Operations Services/Technical Programs

    SciTech Connect

    Not Available

    1993-04-01

    This report describes the environmental radiological monitoring program conducted by TVA in the vicinity of Browns Ferry Nuclear Plant (BFN) in 1992. The program includes the collection of samples from the environment and the determination of the concentrations of radioactive materials in the samples. Samples are taken from stations in the general area of the plant and from areas not influenced by plant operations. Station locations are selected after careful consideration of the weather patterns and projected radiation doses to the various areas around the plant. Material sampled includes air, water, milk, foods, vegetation, soil, fish, sediment, and direct radiation levels. Results from stations near the plant are compared with concentrations from control stations and with preoperational measurements to determine potential impacts of plant operations. Small amounts of Co-60 and Cs-134 were found in sediment samples downstream from the plant. This activity in stream sediment would result in no measurable increase over background in the dose to the general public.

  19. Origin matters: diversity affects the performance of alien invasive species but not of native species.

    PubMed

    Sun, Yan; Müller-Schärer, Heinz; Maron, John L; Schaffner, Urs

    2015-06-01

    At local scales, it has often been found that invasibility decreases with increasing resident plant diversity. However, whether resident community diversity similarly resists invasion by alien versus native species is seldom studied. We examined this issue by invading constructed native plant assemblages that varied in species and functional richness with invasive alien or native Asteraceae species. Assemblages were also invaded with spotted knapweed, Centaurea stoebe, a native European aster that has been previously used in diversity-invasibility experiments in North America. We also conducted a field survey to explore the generality of the patterns generated from our experimental study. Both experimental and observational work revealed that increasing diversity reduced the performance of alien but not native invaders. Centaurea stoebe invading its native community performed poorly regardless of resident diversity, whereas in a parallel, previously published study conducted in North America, C. stoebe easily invaded low-diversity but not high-diversity assemblages. Our results suggest that diversity is an attribute of resident communities that makes them more or less susceptible to invasion by novel invasive alien but not native plant species. PMID:25996858

  20. Perennial grass dominance: creating a resilient plant community in an exotic annual grass invaded rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of western rangelands have been invaded by the exotic and invasive annual grass, cheatgrass (Bromus tectorum). Cheatgrass provides a fine-textured, early maturing fuel that has increased the chance, rate, spread and season of wildfire to public and private lands throughout the ...

  1. Regulation of polyamine synthesis in plants. Annual progress report, July 1, 1992--June 30, 1993

    SciTech Connect

    Malmberg, R.L.

    1995-07-01

    After isolation of a cDNA clone for the plant ARGdc, this research focused on unusual post-translational modifications occuring in a arginine decarboxylase cDNA clone in oats. A novel regulatory mechanism for polyamines was explored and an attempt was made to characterize it. A plant ornithine decarboxylase cDNA was identified in Arabidopsis. Further work remains on the mechanisms of polyamine regulation and function in plants.

  2. 8 CFR 274a.12 - Classes of aliens authorized to accept employment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Classes of aliens authorized to accept employment. 274a.12 Section 274a.12 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS CONTROL OF EMPLOYMENT OF ALIENS Employment Authorization § 274a.12 Classes of aliens authorized to accept employment. (a) Aliens...

  3. Population dynamics of Agriophyllum squarrosum, a pioneer annual plant endemic to mobile sand dunes, in response to global climate change

    PubMed Central

    Qian, Chaoju; Yin, Hengxia; Shi, Yong; Zhao, Jiecai; Yin, Chengliang; Luo, Wanyin; Dong, Zhibao; Chen, Guoxiong; Yan, Xia; Wang, Xiao-Ru; Ma, Xiao-Fei

    2016-01-01

    Climate change plays an important role in the transition of ecosystems. Stratigraphic investigations have suggested that the Asian interior experienced frequent transitions between grassland and desert ecosystems as a consequence of global climate change. Using maternally and bi-parentally inherited markers, we investigated the population dynamics of Agriophyllum squarrosum (Chenopodiaceae), an annual pioneer plant endemic to mobile sand dunes. Phylogeographic analysis revealed that A. squarrosum could originate from Gurbantunggut desert since ~1.6 Ma, and subsequently underwent three waves of colonisation into other deserts and sandy lands corresponding to several glaciations. The rapid population expansion and distribution range shifts of A. squarrosum from monsoonal climate zones suggested that the development of the monsoonal climate significantly enhanced the population growth and gene flow of A. squarrosum. These data also suggested that desertification of the fragile grassland ecosystems in the Qinghai-Tibetan Plateau was more ancient than previously suggested and will be aggravated under global warming in the future. This study provides new molecular phylogeographic insights into how pioneer annual plant species in desert ecosystems respond to global climate change, and facilitates evaluation of the ecological potential and genetic resources of future crops for non-arable dry lands to mitigate climate change. PMID:27210568

  4. Population dynamics of Agriophyllum squarrosum, a pioneer annual plant endemic to mobile sand dunes, in response to global climate change.

    PubMed

    Qian, Chaoju; Yin, Hengxia; Shi, Yong; Zhao, Jiecai; Yin, Chengliang; Luo, Wanyin; Dong, Zhibao; Chen, Guoxiong; Yan, Xia; Wang, Xiao-Ru; Ma, Xiao-Fei

    2016-01-01

    Climate change plays an important role in the transition of ecosystems. Stratigraphic investigations have suggested that the Asian interior experienced frequent transitions between grassland and desert ecosystems as a consequence of global climate change. Using maternally and bi-parentally inherited markers, we investigated the population dynamics of Agriophyllum squarrosum (Chenopodiaceae), an annual pioneer plant endemic to mobile sand dunes. Phylogeographic analysis revealed that A. squarrosum could originate from Gurbantunggut desert since ~1.6 Ma, and subsequently underwent three waves of colonisation into other deserts and sandy lands corresponding to several glaciations. The rapid population expansion and distribution range shifts of A. squarrosum from monsoonal climate zones suggested that the development of the monsoonal climate significantly enhanced the population growth and gene flow of A. squarrosum. These data also suggested that desertification of the fragile grassland ecosystems in the Qinghai-Tibetan Plateau was more ancient than previously suggested and will be aggravated under global warming in the future. This study provides new molecular phylogeographic insights into how pioneer annual plant species in desert ecosystems respond to global climate change, and facilitates evaluation of the ecological potential and genetic resources of future crops for non-arable dry lands to mitigate climate change. PMID:27210568

  5. ALIEN SPECIES: THEIR ROLE IN AMPHIBIAN POPULATION DECLINES AND RESTORATION

    EPA Science Inventory

    Alien species (also referred to as exotic, invasive, introduced, or normative species) have been implicated as causal agents in population declines of many amphibian species. Herein, we evaluate the relative contributions of alien species and other factors in adversely affecting ...

  6. Enhancement of nitrogen and phosphorus removal from eutrophic water by economic plant annual ryegrass (Lolium multiflorum) with ion implantation.

    PubMed

    Li, Miao; Sheng, Guo-ping; Wu, Yue-jin; Yu, Zeng-liang; Bañuelos, Gary S; Yu, Han-qing

    2014-01-01

    Severe eutrophication of surface water has been a major problem of increasing environmental concern worldwide. In the present study, economic plant annual ryegrass (Lolium multiflorum) was grown in floating mats as an economic plant-based treatment system to evaluate its potential after ion implantation for removing nutrients in simulated eutrophic water. The specific weight growth rate of L. multiflorum with ion implantation was significantly greater than that of the control, and the peroxidase, nitrate reductase, and acid phosphatase activities of the irradiated L. multiflorum were found to be greater than those plants without ion implantation. Higher total nitrogen (TN) and total phosphorus (TP) removal efficiencies were obtained for the L. multiflorum irradiated with 25 keV 5.2 × 10(16) N(+) ions/cm(2) and 30 keV 4.16 × 10(16) N(+) ions/cm(2), respectively (p < 0.05). Furthermore, the nitrogen and phosphorus contents in the plant biomass with ion implantation were also greater than those in the control and were positively correlated with TN and TP supplied. L. multiflorum itself was directly responsible for 39-49 and 47-58 % of the overall N and P removal in the experiment, respectively. The research results suggested that ion implantation could become a promising approach for increasing phytoremediation efficiency of nutrients from eutrophic water by L. multiflorum. PMID:24809498

  7. Small Variance in Growth Rate in Annual Plants has Large Effects on Genetic Drift

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When plant size is strongly correlated with plant reproduction, variance in growth rates results in a lognormal distribution of seed production within a population. Fecundity variance affects effective population size (Ne), which reflects the ability of a population to maintain beneficial mutations ...

  8. Radioactive materials released from nuclear power plants. Annual report 1991, Volume 12

    SciTech Connect

    Tichler, J.; Doty, K.; Congemi, J.

    1994-05-01

    Releases of radioactive materials in airborne and liquid effluents from commercial light water reactors during 1991 have been compiled and reported. Data on solid waste shipments as well as selected operating information have been included. This report supplements earlier annual reports issued by the former Atomic Energy Commission and the Nuclear Regulatory Commission. The 1991 release data are summarized in tabular form. Data Covering specific radionuclides are summarized.

  9. Radioactive materials released from nuclear power plants. Volume 11: Annual report, 1990

    SciTech Connect

    Tichler, J.; Doty, K.; Congemi, J.

    1993-10-01

    Releases of radioactive materials in airborne and liquid effluents from commercial light water reactors during 1990 have been compiled and reported. Data on solid waste shipments as well as selected operating information have been included. This report supplements earlier annual reports issued by the former Atomic Energy Commission and the Nuclear Regulatory Commission. The 1990 release data are summarized in tabular form. Data covering specific radionuclides are summarized.

  10. Radioactive materials released from nuclear power plants. Annual report 1989: Volume 10

    SciTech Connect

    Tichler, J.; Norden, K.; Congemi, J.

    1992-09-01

    Releases of radioactive materials in airborne and liquid effluents from commercial light water reactors during 1989 have been compiled and reported. The summary data for the years 1970 through 1988 are included for comparison. Data on solid waste shipments as well as selected operating information have been included. This report supplements earlier annual reports issued by the former Atomic Energy Commission and the Nuclear Regulatory Commission. The 1989 release data are summarized in tabular form. Data covering specific radionuclides are summarized.

  11. How does altered precipitation and annual grass invasion affect plant N uptake in a native semi-arid shrub community?

    NASA Astrophysics Data System (ADS)

    Mauritz, M.; Lipson, D.; Cleland, E. E.

    2012-12-01

    Climate change is expected to alter precipitation patterns, which will change the timing and amount of plant resources. Precipitation patterns determine water and nitrogen (N) availability, because water stimulates microbial N turnover and N transport. In order for plants to utilize water and N, they must coincide with the phenology and meet physiological requirements of the plant. As resource supply shifts, differences in species' ability to acquire resources will affect plant community composition. Semiarid ecosystems, such as shrublands in Southern California, are particularly sensitive to shifts in precipitation because they are severely water limited. This study takes advantage of the altered phenology and resource demands presented by invasive annual grasses in a native semiarid shrubland. The goal is to understand how altered precipitation patterns affect plant N uptake. Rainfall levels were manipulated to 50% and 150% of ambient levels. It is expected that higher rainfall levels promote annual grass invasion because grasses have higher water and N requirements and begin to grow earlier in the season than shrubs. A 15N tracer was added with the first rain event and plant samples were collected regularly to track the movement of N into the plants. Net soil N accumulation was determined using resin bags. Invasive grasses altered the timing and amount of N uptake but amount of rainfall had less effect on N distribution. 15N was detected sooner and at higher level in grasses than shrubs. 24hours after the first rain event 15N was detectable in grasses, 15N accumulated rapidly and peaked 2 months earlier than shrubs. Shrub 15N levels remained at pre-rain event levels for the first 2 months and began to increase at the beginning of spring, peak mid-spring and decline as the shrubs entered summer dormancy. One year later 15N levels in annual grass litter remained high, while 15N levels in shrubs returned to initial background levels as a result of resorption. 15N

  12. 32 CFR 1630.46 - Class 4-T: Treaty alien.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Class 4-T: Treaty alien. 1630.46 Section 1630.46 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM CLASSIFICATION RULES § 1630.46 Class 4-T: Treaty alien. In Class 4-T shall be placed any registrant who is an alien...

  13. 32 CFR 1602.3 - Aliens and nationals.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Aliens and nationals. 1602.3 Section 1602.3 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.3 Aliens and nationals. (a) The term alien means any person who is not a citizen or national of...

  14. 22 CFR 41.58 - Aliens in religious occupations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Aliens in religious occupations. 41.58 Section... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.58 Aliens in religious occupations. (a) Requirements for “R” classification. An alien shall be classifiable under the provisions of...

  15. 20 CFR 404.1036 - Certain nonresident aliens.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Certain nonresident aliens. 404.1036 Section... Employment § 404.1036 Certain nonresident aliens. (a) Foreign students. (1) Foreign students (nonimmigrant aliens) may be temporarily in the United States under subparagraph (F) of section 101(a)(15) of...

  16. 8 CFR 1241.20 - Aliens ordered excluded.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., see 8 CFR 241.20 through 241.25. ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Aliens ordered excluded. 1241.20 Section 1241.20 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  17. 42 CFR 436.330 - Coverage for certain aliens.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Coverage for certain aliens. 436.330 Section 436... Coverage of the Medically Needy § 436.330 Coverage for certain aliens. If an agency provides Medicaid to... condition, as defined in § 440.255(c) of this chapter to those aliens described in § 436.406(c) of...

  18. 45 CFR 233.51 - Eligibility of sponsored aliens.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false Eligibility of sponsored aliens. 233.51 Section... CONDITIONS OF ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.51 Eligibility of sponsored aliens... affidavit(s) of support or similar agreement on behalf of an alien (who is not the child of the sponsor...

  19. 8 CFR 236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ....1 of this chapter upon the person or persons specified by 8 CFR 103.8(c). (b) Service custody and... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Confined aliens, incompetents, and minors. 236.2 Section 236.2 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION...

  20. 32 CFR 1630.46 - Class 4-T: Treaty alien.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Class 4-T: Treaty alien. 1630.46 Section 1630.46 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM CLASSIFICATION RULES § 1630.46 Class 4-T: Treaty alien. In Class 4-T shall be placed any registrant who is an alien...

  1. 22 CFR 41.58 - Aliens in religious occupations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Aliens in religious occupations. 41.58 Section... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.58 Aliens in religious occupations. (a) Requirements for “R” classification. An alien shall be classifiable under the provisions of...

  2. 45 CFR 233.51 - Eligibility of sponsored aliens.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Eligibility of sponsored aliens. 233.51 Section... CONDITIONS OF ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.51 Eligibility of sponsored aliens... affidavit(s) of support or similar agreement on behalf of an alien (who is not the child of the sponsor...

  3. 32 CFR 1630.46 - Class 4-T: Treaty alien.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Class 4-T: Treaty alien. 1630.46 Section 1630.46 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM CLASSIFICATION RULES § 1630.46 Class 4-T: Treaty alien. In Class 4-T shall be placed any registrant who is an alien...

  4. 32 CFR 1630.46 - Class 4-T: Treaty alien.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Class 4-T: Treaty alien. 1630.46 Section 1630.46 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM CLASSIFICATION RULES § 1630.46 Class 4-T: Treaty alien. In Class 4-T shall be placed any registrant who is an alien...

  5. 8 CFR 1241.30 - Aliens ordered deported.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ordered deported, see 8 CFR 241.30 through 241.33. ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Aliens ordered deported. 1241.30 Section 1241.30 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  6. 22 CFR 41.55 - Aliens with extraordinary ability.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Aliens with extraordinary ability. 41.55... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.55 Aliens with extraordinary ability. (a) Requirements for O classification. An alien shall be classifiable under the provisions of INA...

  7. 45 CFR 233.51 - Eligibility of sponsored aliens.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true Eligibility of sponsored aliens. 233.51 Section 233... CONDITIONS OF ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.51 Eligibility of sponsored aliens... affidavit(s) of support or similar agreement on behalf of an alien (who is not the child of the sponsor...

  8. 8 CFR 1241.30 - Aliens ordered deported.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ordered deported, see 8 CFR 241.30 through 241.33. ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Aliens ordered deported. 1241.30 Section 1241.30 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  9. 8 CFR 1241.20 - Aliens ordered excluded.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., see 8 CFR 241.20 through 241.25. ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Aliens ordered excluded. 1241.20 Section 1241.20 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  10. 22 CFR 41.55 - Aliens with extraordinary ability.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens with extraordinary ability. 41.55... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.55 Aliens with extraordinary ability. (a) Requirements for O classification. An alien shall be classifiable under the provisions of INA...

  11. 20 CFR 404.1036 - Certain nonresident aliens.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Certain nonresident aliens. 404.1036 Section... Employment § 404.1036 Certain nonresident aliens. (a) Foreign students. (1) Foreign students (nonimmigrant aliens) may be temporarily in the United States under subparagraph (F) of section 101(a)(15) of...

  12. 42 CFR 436.128 - Coverage for certain qualified aliens.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Coverage for certain qualified aliens. 436.128... Mandatory Coverage of the Categorically Needy § 436.128 Coverage for certain qualified aliens. The agency... § 440.255(c) of this chapter to those aliens described in § 436.406(c) of this subpart....

  13. 42 CFR 436.128 - Coverage for certain qualified aliens.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Coverage for certain qualified aliens. 436.128... Mandatory Coverage of the Categorically Needy § 436.128 Coverage for certain qualified aliens. The agency... § 440.255(c) of this chapter to those aliens described in § 436.406(c) of this subpart....

  14. 45 CFR 233.51 - Eligibility of sponsored aliens.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Eligibility of sponsored aliens. 233.51 Section... CONDITIONS OF ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.51 Eligibility of sponsored aliens... affidavit(s) of support or similar agreement on behalf of an alien (who is not the child of the sponsor...

  15. 42 CFR 436.330 - Coverage for certain aliens.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Coverage for certain aliens. 436.330 Section 436... Coverage of the Medically Needy § 436.330 Coverage for certain aliens. If an agency provides Medicaid to... condition, as defined in § 440.255(c) of this chapter to those aliens described in § 436.406(c) of...

  16. 8 CFR 1241.30 - Aliens ordered deported.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ordered deported, see 8 CFR 241.30 through 241.33. ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Aliens ordered deported. 1241.30 Section 1241.30 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  17. 32 CFR 1602.3 - Aliens and nationals.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Aliens and nationals. 1602.3 Section 1602.3 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.3 Aliens and nationals. (a) The term alien means any person who is not a citizen or national of...

  18. 22 CFR 41.55 - Aliens with extraordinary ability.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Aliens with extraordinary ability. 41.55... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.55 Aliens with extraordinary ability. (a) Requirements for O classification. An alien shall be classifiable under the provisions of INA...

  19. 42 CFR 436.330 - Coverage for certain aliens.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Coverage for certain aliens. 436.330 Section 436... Coverage of the Medically Needy § 436.330 Coverage for certain aliens. If an agency provides Medicaid to... condition, as defined in § 440.255(c) of this chapter to those aliens described in § 436.406(c) of...

  20. 43 CFR 426.8 - Nonresident aliens and foreign entities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Nonresident aliens and foreign entities..., DEPARTMENT OF THE INTERIOR ACREAGE LIMITATION RULES AND REGULATIONS § 426.8 Nonresident aliens and foreign... reclamation law or these regulations, a nonresident alien or foreign entity that directly holds land in...

  1. 22 CFR 40.9 - Classes of inadmissible aliens.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Classes of inadmissible aliens. 40.9 Section 40.9 Foreign Relations DEPARTMENT OF STATE VISAS REGULATIONS PERTAINING TO BOTH NONIMMIGRANTS AND... inadmissible aliens. Subparts B through L describe classes of inadmissible aliens who are ineligible to...

  2. 42 CFR 436.128 - Coverage for certain qualified aliens.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Coverage for certain qualified aliens. 436.128... Mandatory Coverage of the Categorically Needy § 436.128 Coverage for certain qualified aliens. The agency... § 440.255(c) of this chapter to those aliens described in § 436.406(c) of this subpart....

  3. 43 CFR 426.8 - Nonresident aliens and foreign entities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Nonresident aliens and foreign entities..., DEPARTMENT OF THE INTERIOR ACREAGE LIMITATION RULES AND REGULATIONS § 426.8 Nonresident aliens and foreign... reclamation law or these regulations, a nonresident alien or foreign entity that directly holds land in...

  4. 42 CFR 435.139 - Coverage for certain aliens.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Coverage for certain aliens. 435.139 Section 435... Aliens § 435.139 Coverage for certain aliens. The agency must provide services necessary for the treatment of an emergency medical condition, as defined in § 440.255(c) of this chapter, to those...

  5. 22 CFR 41.58 - Aliens in religious occupations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Aliens in religious occupations. 41.58 Section... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.58 Aliens in religious occupations. (a) Requirements for “R” classification. An alien shall be classifiable under the provisions of...

  6. 42 CFR 436.330 - Coverage for certain aliens.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Coverage for certain aliens. 436.330 Section 436... Coverage of the Medically Needy § 436.330 Coverage for certain aliens. If an agency provides Medicaid to... condition, as defined in § 440.255(c) of this chapter to those aliens described in § 436.406(c) of...

  7. 20 CFR 404.1036 - Certain nonresident aliens.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Certain nonresident aliens. 404.1036 Section... Employment § 404.1036 Certain nonresident aliens. (a) Foreign students. (1) Foreign students (nonimmigrant aliens) may be temporarily in the United States under subparagraph (F) of section 101(a)(15) of...

  8. 22 CFR 40.9 - Classes of inadmissible aliens.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Classes of inadmissible aliens. 40.9 Section 40.9 Foreign Relations DEPARTMENT OF STATE VISAS REGULATIONS PERTAINING TO BOTH NONIMMIGRANTS AND... inadmissible aliens. Subparts B through L describe classes of inadmissible aliens who are ineligible to...

  9. 42 CFR 435.139 - Coverage for certain aliens.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Coverage for certain aliens. 435.139 Section 435... Aliens § 435.139 Coverage for certain aliens. The agency must provide services necessary for the treatment of an emergency medical condition, as defined in § 440.255(c) of this chapter, to those...

  10. 43 CFR 426.8 - Nonresident aliens and foreign entities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Nonresident aliens and foreign entities..., DEPARTMENT OF THE INTERIOR ACREAGE LIMITATION RULES AND REGULATIONS § 426.8 Nonresident aliens and foreign... reclamation law or these regulations, a nonresident alien or foreign entity that directly holds land in...

  11. 42 CFR 436.128 - Coverage for certain qualified aliens.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Coverage for certain qualified aliens. 436.128... Mandatory Coverage of the Categorically Needy § 436.128 Coverage for certain qualified aliens. The agency... § 440.255(c) of this chapter to those aliens described in § 436.406(c) of this subpart....

  12. 22 CFR 40.9 - Classes of inadmissible aliens.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Classes of inadmissible aliens. 40.9 Section 40.9 Foreign Relations DEPARTMENT OF STATE VISAS REGULATIONS PERTAINING TO BOTH NONIMMIGRANTS AND... inadmissible aliens. Subparts B through L describe classes of inadmissible aliens who are ineligible to...

  13. 8 CFR 236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ....1 of this chapter upon the person or persons specified by 8 CFR 103.8(c). (b) Service custody and... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Confined aliens, incompetents, and minors. 236.2 Section 236.2 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION...

  14. 42 CFR 435.139 - Coverage for certain aliens.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Coverage for certain aliens. 435.139 Section 435... ISLANDS, AND AMERICAN SAMOA Mandatory Coverage Mandatory Coverage of Certain Aliens § 435.139 Coverage for certain aliens. The agency must provide services necessary for the treatment of an emergency...

  15. 32 CFR 1602.3 - Aliens and nationals.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Aliens and nationals. 1602.3 Section 1602.3 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.3 Aliens and nationals. (a) The term alien means any person who is not a citizen or national of...

  16. 22 CFR 41.58 - Aliens in religious occupations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens in religious occupations. 41.58 Section... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.58 Aliens in religious occupations. (a) Requirements for “R” classification. An alien shall be classifiable under the provisions of...

  17. 8 CFR 1241.30 - Aliens ordered deported.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ordered deported, see 8 CFR 241.30 through 241.33. ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Aliens ordered deported. 1241.30 Section 1241.30 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  18. 42 CFR 435.139 - Coverage for certain aliens.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Coverage for certain aliens. 435.139 Section 435... Aliens § 435.139 Coverage for certain aliens. The agency must provide services necessary for the treatment of an emergency medical condition, as defined in § 440.255(c) of this chapter, to those...

  19. 8 CFR 1241.20 - Aliens ordered excluded.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., see 8 CFR 241.20 through 241.25. ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Aliens ordered excluded. 1241.20 Section 1241.20 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  20. 20 CFR 404.1036 - Certain nonresident aliens.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Certain nonresident aliens. 404.1036 Section... Employment § 404.1036 Certain nonresident aliens. (a) Foreign students. (1) Foreign students (nonimmigrant aliens) may be temporarily in the United States under subparagraph (F) of section 101(a)(15) of...

  1. 32 CFR 1602.3 - Aliens and nationals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Aliens and nationals. 1602.3 Section 1602.3 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.3 Aliens and nationals. (a) The term alien means any person who is not a citizen or national of...

  2. 22 CFR 40.9 - Classes of inadmissible aliens.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Classes of inadmissible aliens. 40.9 Section 40.9 Foreign Relations DEPARTMENT OF STATE VISAS REGULATIONS PERTAINING TO BOTH NONIMMIGRANTS AND... inadmissible aliens. Subparts B through L describe classes of inadmissible aliens who are ineligible to...

  3. 43 CFR 426.8 - Nonresident aliens and foreign entities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Nonresident aliens and foreign entities..., DEPARTMENT OF THE INTERIOR ACREAGE LIMITATION RULES AND REGULATIONS § 426.8 Nonresident aliens and foreign... reclamation law or these regulations, a nonresident alien or foreign entity that directly holds land in...

  4. 22 CFR 41.55 - Aliens with extraordinary ability.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Aliens with extraordinary ability. 41.55... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.55 Aliens with extraordinary ability. (a) Requirements for O classification. An alien shall be classifiable under the provisions of INA...

  5. 8 CFR 1241.20 - Aliens ordered excluded.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., see 8 CFR 241.20 through 241.25. ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Aliens ordered excluded. 1241.20 Section 1241.20 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  6. Socio-economic Predictors of Alienation among the Elderly.

    ERIC Educational Resources Information Center

    Durant, Thomas J., Jr.; Christian, Ollie

    1990-01-01

    Studied level of alienation and associations between socioeconomic variables and alienation in 200 older senior center clients. Found group isolation and powerlessness were more prevalent than personal isolation or normlessness; health, race, education, and income were strongest predictors of alienation; and older Blacks and those with lower…

  7. 28 CFR 0.47 - Alien property matters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Alien property matters. 0.47 Section 0.47....47 Alien property matters. The Office of Alien Property shall be a part of the Civil Division: (a) The following described matters are assigned to, and shall be conducted, handled, or supervised by...

  8. 28 CFR 0.47 - Alien property matters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Alien property matters. 0.47 Section 0.47....47 Alien property matters. The Office of Alien Property shall be a part of the Civil Division: (a) The following described matters are assigned to, and shall be conducted, handled, or supervised by...

  9. 28 CFR 0.47 - Alien property matters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Alien property matters. 0.47 Section 0.47....47 Alien property matters. The Office of Alien Property shall be a part of the Civil Division: (a) The following described matters are assigned to, and shall be conducted, handled, or supervised by...

  10. 28 CFR 0.47 - Alien property matters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Alien property matters. 0.47 Section 0.47....47 Alien property matters. The Office of Alien Property shall be a part of the Civil Division: (a) The following described matters are assigned to, and shall be conducted, handled, or supervised by...

  11. 8 CFR 1241.30 - Aliens ordered deported.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... ordered deported, see 8 CFR 241.30 through 241.33. ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Aliens ordered deported. 1241.30 Section 1241.30 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  12. 20 CFR 404.1036 - Certain nonresident aliens.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Certain nonresident aliens. 404.1036 Section... Employment § 404.1036 Certain nonresident aliens. (a) Foreign students. (1) Foreign students (nonimmigrant aliens) may be temporarily in the United States under subparagraph (F) of section 101(a)(15) of...

  13. 8 CFR 1241.20 - Aliens ordered excluded.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., see 8 CFR 241.20 through 241.25. ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Aliens ordered excluded. 1241.20 Section 1241.20 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF...

  14. 45 CFR 233.51 - Eligibility of sponsored aliens.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 2 2014-10-01 2012-10-01 true Eligibility of sponsored aliens. 233.51 Section 233... CONDITIONS OF ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.51 Eligibility of sponsored aliens... affidavit(s) of support or similar agreement on behalf of an alien (who is not the child of the sponsor...

  15. 43 CFR 426.8 - Nonresident aliens and foreign entities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Nonresident aliens and foreign entities..., DEPARTMENT OF THE INTERIOR ACREAGE LIMITATION RULES AND REGULATIONS § 426.8 Nonresident aliens and foreign... reclamation law or these regulations, a nonresident alien or foreign entity that directly holds land in...

  16. 22 CFR 41.55 - Aliens with extraordinary ability.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Aliens with extraordinary ability. 41.55... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.55 Aliens with extraordinary ability. (a) Requirements for O classification. An alien shall be classifiable under the provisions of INA...

  17. 32 CFR 1630.46 - Class 4-T: Treaty alien.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Class 4-T: Treaty alien. 1630.46 Section 1630.46 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM CLASSIFICATION RULES § 1630.46 Class 4-T: Treaty alien. In Class 4-T shall be placed any registrant who is an alien...

  18. 8 CFR 236.2 - Confined aliens, incompetents, and minors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ....1 of this chapter upon the person or persons specified by 8 CFR 103.8(c). (b) Service custody and... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Confined aliens, incompetents, and minors. 236.2 Section 236.2 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION...

  19. 22 CFR 41.58 - Aliens in religious occupations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Aliens in religious occupations. 41.58 Section... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.58 Aliens in religious occupations. (a) Requirements for “R” classification. An alien shall be classifiable under the provisions of...

  20. 32 CFR 1602.3 - Aliens and nationals.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Aliens and nationals. 1602.3 Section 1602.3 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.3 Aliens and nationals. (a) The term alien means any person who is not a citizen or national of...

  1. 22 CFR 40.9 - Classes of inadmissible aliens.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Classes of inadmissible aliens. 40.9 Section 40.9 Foreign Relations DEPARTMENT OF STATE VISAS REGULATIONS PERTAINING TO BOTH NONIMMIGRANTS AND... inadmissible aliens. Subparts B through L describe classes of inadmissible aliens who are ineligible to...

  2. 42 CFR 436.128 - Coverage for certain qualified aliens.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Coverage for certain qualified aliens. 436.128... Mandatory Coverage of the Categorically Needy § 436.128 Coverage for certain qualified aliens. The agency... § 440.255(c) of this chapter to those aliens described in § 436.406(c) of this subpart....

  3. 42 CFR 435.139 - Coverage for certain aliens.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Coverage for certain aliens. 435.139 Section 435... ISLANDS, AND AMERICAN SAMOA Mandatory Coverage Mandatory Coverage of Certain Aliens § 435.139 Coverage for certain aliens. The agency must provide services necessary for the treatment of an emergency...

  4. 42 CFR 436.330 - Coverage for certain aliens.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Coverage for certain aliens. 436.330 Section 436... Coverage of the Medically Needy § 436.330 Coverage for certain aliens. If an agency provides Medicaid to... condition, as defined in § 440.255(c) of this chapter to those aliens described in § 436.406(c) of...

  5. Systemic Disaffection: A Three-Factor Theory of Political Alienation.

    ERIC Educational Resources Information Center

    Long, Samuel

    The paper develops a theory of political alienation based upon interactions among three antecedent conditions. Political alienation is interpreted as combining feelings of inefficacy, discontent, cynicism, estrangement, and hopelessness. The factors evaluated for their contribution to political alienation are: (1) critical perceptions of…

  6. Alienation: A Concept for Understanding Low-Income, Urban Clients

    ERIC Educational Resources Information Center

    Holcomb-McCoy, Cheryl

    2004-01-01

    The author examines the concept of alienation and how it can be used to understand low-income, urban clients. A description is presented of 4 dimensions of alienation: powerlessness, meaninglessness, normlessness, and social isolation. Case illustrations are provided, and recommendations are made for counseling alienated clients. This article…

  7. Life-history traits of alien and native senecio species in the Mediterranean region

    NASA Astrophysics Data System (ADS)

    Sans, F. X.; Garcia-Serrano, H.; Afán, I.

    2004-12-01

    Two related shrubs, Senecio inaequidens and S. pterophorus, both introduced to western Mediterranean Europe from South Africa, were compared with a native Mediterranean shrub, S. malacitanus, to identify life-history traits that confer invasive ability. We examined ecological interactions that affect seedling emergence and establishment, flowering time, growth and reproduction and competitive ability in these three closely related species. Seeds were planted, the seedlings were then transplanted and individual performance was evaluated with respect to: (1) competition with plant neighbours and (2) resource addition. Senecio inaequidens had higher rates of seedling establishment and a shorter pre-reproductive period. Competition with neighbours had a considerable impact on S. malacitanus, delaying flowering time and reducing growth and reproduction. S. pterophorus showed inefficient seedling establishment compared to the other two species, but performed better in terms of growth and reproduction. The two alien species were markedly more competitive than the native one. However, differences in competitiveness among S. malacitanus and the two aliens varied depending on resource availability. Thus, Senecio inaequidens and S. pterophorus were more affected by competition in subplots with resource addition and by competition in those without addition, respectively. The latter showed a greater capacity to respond to additional resources in competitive environments and, in addition, its reproductive effort was unrelated to habitat conditions. The invasive potential of the alien species was higher than that of the native. This was a result of various biological characteristics and specific interactions between invader and environment, which made the invasiveness of alien species unpredictable.

  8. Grazing maintains native plant diversity and promotes community stability in an annual grassland.

    PubMed

    Beck, Jared J; Hernández, Daniel L; Pasari, Jae R; Zavaleta, Erika S

    2015-07-01

    Maintaining native biodiversity in grasslands requires management and mitigation of anthropogenic changes that have altered resource availability, grazing regimes, and community composition. In California (USA), high levels of atmospheric nitrogen (N) deposition have facilitated the invasion of exotic grasses, posing a threat to the diverse plant and insect communities endemic to serpentine grasslands. Cattle grazing has been employed to mitigate the consequences of exotic grass invasion, but the ecological effects of grazing in this system are not fully understood. To characterize the effects of realistic N deposition on serpentine plant communities and to evaluate the efficacy of grazing as a management tool, we performed a factorial experiment adding N and excluding large herbivores in California's largest serpentine grassland. Although we observed significant interannual variation in community composition related to climate in our six-year study, exotic cover was consistently and negatively correlated with native plant richness. Sustained low-level N addition did not influence plant community composition, but grazing reduced grass abundance while maintaining greater native forb cover, native plant diversity, and species richness in comparison to plots excluding large herbivores. Furthermore, grazing increased the temporal stability of plant communities by decreasing year-to-year variation in native forb cover, native plant diversity, and native species richness. Taken together, our findings demonstrate that moderate-intensity cattle grazing can be used to restrict the invasive potential of exotic grasses and maintain native plant communities in serpentine grasslands. We hypothesize that the reduced temporal variability in serpentine plant communities managed by grazing may directly benefit populations of the threatened Edith's Bay checkerspot butterfly (Euphydryas editha bayensis). PMID:26485954

  9. The influence of annual species composition and density on perennial seedling density in four plant communities in the Northern Mojave Desert

    SciTech Connect

    Hall, P.F.; Angerer, J.P.; Ostler, W.K.; Schultz, B.W.

    1993-12-31

    According to the Nuclear Waste Policy Act of 1982 (as amended in 1987), the US Department of Energy (DOE) must study and characterize Yucca Mountain as a potential site for long-term underground storage of high-level nuclear waste. Part of the overall site characterization program is to monitor potential impacts on the biological resources at Yucca Mountain. A part of the biological monitoring program, assessed vegetation parameters included density of annual and perennial seedlings. This data was used to evaluate: (1) seed germination and seed survival; and (2) if annual plant species density and cover influence perennial seedling survival. Twelve permanent 200 {times} 200-m ,study plots were established in each of four vegetation associations present in the Yucca Mountain Project area. During the spring of 1992, 20 to 60, 1-m{sup 2} randomly-located quadrats per study plot were measured for perennial seedling density, annual species density, and annual species composition. Perennial seedlings found in 1992 were relocated in the spring of 1993, and survival determined. Cover was measure in the spring of 1992. Annual plant density and cover was greatest in the Larrea-Lycium-Grayia vegetation association, and lowest in the Larrea-Ambrosia vegetation association. Annual seedling density had a negative exponential relationship with perennial seedling density in 1992. However, non-linear regression analysis indicated that 1992 annual seedling density had a greater impact on survival of pernnial seedlings from 1992 to 1993.

  10. HyPEP-FY 07 Annual Report: A Hydrogen Production Plant Efficiency Calculation Program

    SciTech Connect

    Chang Oh

    2007-09-01

    The Very High Temperature Gas-Cooled Reactor (VHTR) coupled to the High Temperature Steam Electrolysis (HTSE) process is one of two reference integrated systems being investigated by the U.S. Department of Energy and Idaho National Laboratory for the production of hydrogen. In this concept the VHTR outlet temperature of 900 °C provides thermal energy and high efficiency electricity for the electrolysis of steam in the HTSE process. In the second reference system the Sulfur Iodine (SI) process is coupled to the VHTR to produce hydrogen thermochemically. In the HyPEP project we are investigating and characterizing these two reference systems with respect to production, operability, and safety performance criteria. Under production, plant configuration and working fluids are being studied for their effect on efficiency. Under operability, control strategies are being developed with the goal of maintaining equipment within operating limits while meeting changes in demand. Safety studies are to investigate plant response for equipment failures. Specific objectives in FY07 were (1) to develop HyPEP Beta and verification and validation (V&V) plan, (2) to perform steady state system integration, (3) to perform parametric studies with various working fluids and power conversion unit (PCU) configurations, (4) the study of design options such as pressure, temperature, etc. (5) to develop a control strategy and (6) to perform transient analyses for plant upsets, control strategy, etc for hydrogen plant with PCU. This report describes the progress made in FY07 in each of the above areas. (1) The HyPEP code numeric scheme and Graphic User Interface have been tested and refined since the release of the alpha version a year ago. (2) The optimal size and design condition for the intermediate heat exchanger, one of the most important components for integration of the VHTR and HTSE plants, was estimated. (3) Efficiency calculations were performed for a variety of working fluids for

  11. Cucumis monosomic alien addition lines: morphological, cytological, and genotypic analyses.

    PubMed

    Chen, Jin-Feng; Luo, Xiang-Dong; Qian, Chun-Tao; Jahn, Molly M; Staub, Jack E; Zhuang, Fei-Yun; Lou, Qun-Feng; Ren, Gang

    2004-05-01

    Cucumis hystrix Chakr. (HH, 2n=24), a wild relative of the cultivated cucumber, possesses several potentially valuable disease-resistance and abiotic stress-tolerance traits for cucumber ( C. sativus L., CC, 2n=14) improvement. Numerous attempts have been made to transfer desirable traits since the successful interspecific hybridization between C. hystrix and C. sativus, one of which resulted in the production of an allotriploid (HCC, 2n=26: one genome of C. hystrix and two of C. sativus). When this genotype was treated with colchicine to induce polyploidy, two monosomic alien addition lines (MAALs) (plant nos. 87 and 517: 14 CC+1 H, 2n=15) were recovered among 252 viable plants. Each of these plants was morphologically distinct from allotriploids and cultivated cucumbers. Cytogenetic and molecular marker analyses were performed to confirm the genetic constitution and further characterize these two MAALs. Chromosome counts made from at least 30 meristematic cells from each plant confirmed 15 nuclear chromosomes. In pollen mother cells of plant nos. 87 and 517, seven bivalents and one univalent were observed at diakinesis and metaphase I; the frequency of trivalent formation was low (about 4-5%). At anaphase I and II, stochastic and asymmetric division led to the formation of two gamete classes: n=7 and n=8; however, pollen fertility was relatively high. Pollen stainability in plant no. 87 was 86.7% and in plant no. 517 was 93.2%. Random amplified polymorphic DNA analysis was performed using 100 random 10-base primers. Genotypes obtained with eight primers (A-9, A-11, AH-13, AI-19, AJ-18, AJ-20, E-19, and N-20) showed a band common to the two MAAL plants and C. hystrix that was absent in C. sativus, confirming that the alien chromosomes present in the MAALs were derived from C. hystrix. Morphological differences and differences in banding patterns were also observed between plant nos. 87 and 517 after amplification with primers AI-5, AJ-13, N-12, and N-20

  12. The generic impact scoring system (GISS): a standardized tool to quantify the impacts of alien species.

    PubMed

    Nentwig, Wolfgang; Bacher, Sven; Pyšek, Petr; Vilà, Montserrat; Kumschick, Sabrina

    2016-05-01

    Alien species can exert negative environmental and socio-economic impacts. Therefore, administrations from different sectors are trying to prevent further introductions, stop the spread of established species, and apply or develop programs to mitigate their impact, to contain the most harmful species, or to eradicate them if possible. Often it is not clear which of the numerous alien species are most important in terms of damage, and therefore, impact scoring systems have been developed to allow a comparison and thus prioritization of species. Here, we present the generic impact scoring system (GISS), which relies on published evidence of environmental and socio-economic impact of alien species. We developed a system of 12 impact categories, for environmental and socio-economic impact, comprising all kinds of impacts that an alien species may exert. In each category, the intensity of impact is quantified by a six-level scale ranging from 0 (no impact detectable) to 5 (the highest impact possible). Such an approach, where impacts are grouped based on mechanisms for environmental impacts and receiving sectors for socio-economy, allows for cross-taxa comparisons and prioritization of the most damaging species. The GISS is simple and transparent, can be conducted with limited funds, and can be applied to a large number of alien species across taxa and environments. Meanwhile, the system was applied to 349 alien animal and plant species. In a comparison with 22 other impact assessment methods, the combination of environmental and socio-economic impact, as well as the possibility of weighting and ranking of the scoring results make GISS the most broadly applicable system. PMID:27129597

  13. Alienation, recovered animism and altered states of consciousness.

    PubMed

    Charlton, Bruce G

    2007-01-01

    Alienation is the feeling that life is 'meaningless', that we do not belong in the world. But alienation is not an inevitable part of the human condition: some people do feel at one with the world as a consequence of the animistic way of thinking which is shared by children and hunter-gatherers. Animism considers all significant entities to have 'minds', to be 'alive', to be sentient agents. The animistic thinker inhabits a world populated by personal powers including not just other human beings, but also important animals and plants, and significant aspects of physical landscape. Humans belong in this world because it is a web of social relationships. Animism is therefore spontaneous, the 'natural' way of thinking for humans: all humans began as animistic children and for most of human evolutionary history would have grown into animistic adults. It requires sustained, prolonged and pervasive formal education to 'overwrite' animistic thinking with the rationalistic objectivity typical of the modern world. It is this learned abstraction that creates alienation--humans are no longer embedded in a world of social relations but become estranged, adrift in a world of indifferent things. Methods used to cure alienation and recover animistic modes of thinking involve detachment from the social systems that tend to maintain objectivity and rationality: for example, solitude, leisure, unstructured time and direct contact with nature. Many people also achieve similar results by deliberately inducing altered states of consciousness. Animistic thinking may emerge in meditation or contemplation, lucid dreaming, from self-hypnosis, when drowsy, in 'trance states' induced by repetitious rhythm or light, or when delirious due to illness, brain injury, psychoses, or intoxication with 'entheogenic' drugs--which is probably one reason for the perennial popularity of inducing intoxicated states. However, intoxication will typically damage memory processes making it harder to learn

  14. Alien seed beetles (Coleoptera: Chrysomelidae: Bruchinae) in Europe.

    PubMed

    Yus-Ramos, Rafael; Ventura, Daniel; Bensusan, Keith; Coello-García, Pedro; György, Zoltán; Stojanova, Anelia

    2014-01-01

    Under the framework of the DAISIE consortium, whose main mission is to make an inventory of the alien invasive species of Europe and its islands, we review the current state of knowledge and provide an up-to-date catalogue and distributional status for alien seed beetles (Coleoptera: Chrysomelidae: Bruchinae) in Europe. This work is based on studies of the species detected from the last century to the present, but with greater emphasis on the beginning of the 21st century, during which new biological studies have been carried out and findings made in European countries. The main objective of this paper is to focus on this last fact, which has promoted new views on the existing and potential threat of exotic bruchids in relation to climate change. This must now be regarded as a matter of concern for European agricultural and environmental policies. Only species of exotic origin introduced in European regions outside their native range were considered. Therefore, species of European origin spreading to new countries within Europe are not treated. Also, we provide a new approach to classifying alien seed beetle species according to their ability to become established, distinguishing between the well-established and those that may appear in seed stores but are not capable of invading natural and agricultural ecosystems. We present a taxonomic characterization of the alien bruchids found in Europe, providing an illustrated key based on external morphological characters of adults. The key facilitates the identification of the sixteen most frequently recorded genera, which represent 37 of the 42 species of exotic species recorded in Europe up to the present, whether established, not established or occasional. Finally, we provide a summary of the state of knowledge of the taxonomy and biology of the 20 most worrying species as pests, both established and non-established. This includes, where appropriate, an illustrated key for the identification of species. The study

  15. H-coal pilot plant. Phase II. Construction. Phase III. Operation. Annual report No. 3

    SciTech Connect

    Not Available

    1981-02-04

    At the request of DOE Oak Ridge, ASFI agreed to assume responsibility for completion of Plant construction in December, 1979, at which time Badger Plants' on-site work was ended. This construction effort consisted of electric heat tracing and insulation of piping and instrumentation. At the close of the reporting period the work was completed, or was projected to be completed, within the ASFI budgeted amounts and by dates that will not impact Plant operations. Engineering design solutions were completed for problems encountered with such equipment as the High Pressure Letdown Valves; Slurry Block Valves; Slurry Pumps; the Bowl Mill System; the Dowtherm System; and the Ebullating Pump. A Corrosion Monitoring Program was established. With the exception of Area 500, the Antisolvent Deashing Unit, all operating units were commissioned and operated during the reporting period. Coal was first introduced into the Plant on May 29, 1980, with coal operations continuing periodically through September 30, 1980. The longest continuous coal run was 119 hours. A total of 677 tons of Kentucky No. 11 Coal were processed during the reporting period. The problems encountered were mechanical, not process, in nature. Various Environmental and Health programs were implemented to assure worker safety and protection and to obtain data from Plant operations for scientific analysis. These comprehensive programs will contribute greatly in determining the acceptability of long term H-Coal Plant operations.

  16. Response of some common annual bedding plants to three species of meloidogyne.

    PubMed

    McSorley, R; Frederick, J J

    1994-12-01

    Twelve ornamental bedding plant cultivars were grown in soil infested with isolates of Meloidogyne incognita race 1, M. javanica, or M. arenaria race 1 in a series of tests in containers in a growth room. Root galling (0-5 scale) and eggs/plant were evaluated 8-10 weeks after soil infestation and seedling transplantation. Snapdragon, Antirrhinum majus cv. First Ladies, was extensively galled and highly susceptible (mean gall rating >/=4.2 and >/=14,500 eggs/plant), and Celosia argentea cv. Century Mix and Coleus blumei cv. Rainbow were susceptible (>1,500 eggs/plant) to all three Meloidogyne isolates. Response of Petunia x hybrida varied with cultivar and nematode isolate. Little or no galling or egg production from any Meloidogyne isolate was observed on Ageratum houstonianum cv. Blue Mink, Lobularia maritima cv. Rosie O'Day, or Tagetes patula cv. Dwarf Primrose. Galling was slight (mean rating 4.0 and >/=7,900 eggs/plant) by M. javanica and M. arenaria but was nearly free of galling from M. incognita. Zinna elegans cv. Scarlet was nearly free of galling from M. incognita and M. arenaria but was susceptible (mean gall rating = 2.9; 3,400 eggs/plant) to M. javanica. PMID:19279963

  17. Annual radiological environmental monitoring report: Watts Bar Nuclear Plant, 1992. Operations Services/Technical Programs

    SciTech Connect

    Not Available

    1993-04-01

    This report describes the preoperational environmental radiological monitoring program conducted by TVA in the vicinity of the Watts Bar Nuclear Plant (WBN) in 1992. The program includes the collection of samples from the environment and the determination of the concentrations of radioactive materials in the samples. Samples are taken from stations in the general area of the plant and from areas that will not be influenced by plant operations. Material sampled includes air, water, milk, foods, vegetation, soil, fish, sediment, and direct radiation levels. During plant operations, results from stations near the plant will be compared with concentrations from control stations and with preoperational measurements to determine potential impacts to the public. Exposures calculated from environmental samples were contributed by naturally occurring radioactive materials, from materials commonly found in the environment as a result of atmospheric fallout, or from the operation of other nuclear facilities in the area. Since WBN has not operated, there has been no contribution of radioactivity from the plant to the environment.

  18. The Lonely Consumer: Advertising and Alienation.

    ERIC Educational Resources Information Center

    Larson, Charles U.; Denton, Robert E.

    Advertising plays on the broad feelings of alienation (defined as an individual's frustrated or estranged responses to economic and sociological phenomena which affect that individual's place in society) which are endemic to the American consumer society and are, in Marxist views, symptomatic of any capitalist system. By generating anxieties and…

  19. Pathophysiology and Treatment of Alien Hand Syndrome

    PubMed Central

    Sarva, Harini; Deik, Andres; Severt, William Lawrence

    2014-01-01

    Background Alien hand syndrome (AHS) is a disorder of involuntary, yet purposeful, hand movements that may be accompanied by agnosia, aphasia, weakness, or sensory loss. We herein review the most reported cases, current understanding of the pathophysiology, and treatments. Methods We performed a PubMed search in July of 2014 using the phrases “alien hand syndrome,” “alien hand syndrome pathophysiology,” “alien hand syndrome treatment,” and “anarchic hand syndrome.” The search yielded 141 papers (reviews, case reports, case series, and clinical studies), of which we reviewed 109. Non-English reports without English abstracts were excluded. Results Accumulating evidence indicates that there are three AHS variants: frontal, callosal, and posterior. Patients may demonstrate symptoms of multiple types; there is a lack of correlation between phenomenology and neuroimaging findings. Most pathologic and functional imaging studies suggest network disruption causing loss of inhibition as the likely cause. Successful interventions include botulinum toxin injections, clonazepam, visuospatial coaching techniques, distracting the affected hand, and cognitive behavioral therapy. Discussion The available literature suggests that overlap between AHS subtypes is common. The evidence for effective treatments remains anecdotal, and, given the rarity of AHS, the possibility of performing randomized, placebo-controlled trials seems unlikely. As with many other interventions for movement disorders, identifying the specific functional impairments caused by AHS may provide the best guidance towards individualized supportive care. PMID:25506043

  20. Aliens Among Us : Are They Already Here ?

    NASA Astrophysics Data System (ADS)

    McGaha, J.

    2008-03-01

    Popular culture, science fiction and mainstream belief, says they are! What is the evidence? Astronomer, skeptic and retired USAF pilot James McGaha examines this "Space Age" Mythology. From years of investigation of the physical evidence of aliens and there spacecraft (UFO's) here on earth, McGaha presents the scientific facts.

  1. Processes of Alienation: Marx, Orff and Kodaly

    ERIC Educational Resources Information Center

    Benedict, Cathy

    2009-01-01

    Using Marx as a lens through which to interrogate music methodology, in particular those espoused by Orff and Kodaly, this article suggests that rather than the free play and creativity Orff and Kodaly intended, the implementation of these methods in a strict and unmindful manner, often alienates both teacher and student from musicking. Thus these…

  2. College as a Source of Black Alienation.

    ERIC Educational Resources Information Center

    Shingles, Richard D.

    1979-01-01

    This article summarizes college and precollege explanations of alienation and indicates how they intertwine in the case of Black college students. A multivariate analysis of Black students is then used to control for precollege experiences and isolate the independent impact of college life on Black students at a predominantly White university.…

  3. Student Drug Usage and Self-Alienation.

    ERIC Educational Resources Information Center

    Fischler, Michael L.

    Utilizing responses (a self administered, 15 item questionnaire) of a rural northeastern New England sample of junior high, senior high, and college students, correlation between legal and illegal drug use and perceived self-alienation was examined. Comparison was also made between users and nonusers. Legal users were defined as those who made at…

  4. The Alienating Influence of the Illusionogens

    ERIC Educational Resources Information Center

    Malcolm, Andrew I.

    1971-01-01

    The author, based on his discussion, hypothesizes that: (1) the use of marijuana may serve to intensify the tendency toward an adolescent's alienation and (2) attitudinal changes do occur in people who are exposed to the illusionogens and that these changes are more certainly fixed with continued use. (Author/BY)

  5. Invite an Alien to Astronomy Night

    ERIC Educational Resources Information Center

    Governor, Donna; Richwine, Pebble

    2007-01-01

    Dozens of inflatable aliens recently "descended" upon the authors' middle school to kick-off their first school-wide Astronomy night. With an estimated attendance of over 500, their eighth-grade students hosted over a dozen activity-rich sessions designed to entertain and educate students and their families about the wonders of the solar system…

  6. Creating Aliens: The Ultimate Life Sciences Activity.

    ERIC Educational Resources Information Center

    Beltramo, Dan

    2001-01-01

    Describes a seven-week project completed by the author's eighth-grade science students (as they studied "the chemistry of living things") in which they designed an alien and its world using the scientific concepts that they learned in class. Compares class presentations using PowerPoint software to presentations using posterboard. (SR)

  7. Combatives for Alienated Youth: Problems and Prospects.

    ERIC Educational Resources Information Center

    Hellison, Don

    Combative activities (boxing, wrestling, kung fu, etc.) are seen as having a positive influence on alienated inner city youth. Potential contributions of such activities in a school curriculum or recreation program include involvement, security, self-concept, and self-realization. Participants may be able to free themselves from such stereotype…

  8. 22 CFR 62.27 - Alien physicians.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... or academic medical center which has been designated an exchange visitor program by the Secretary of... Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM Specific Program Provisions § 62.27 Alien physicians. (a) Purpose. Pursuant to the Mutual Educational and Cultural...

  9. 22 CFR 62.27 - Alien physicians.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... or academic medical center which has been designated an exchange visitor program by the Secretary of... Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM Specific Program Provisions § 62.27 Alien physicians. (a) Purpose. Pursuant to the Mutual Educational and Cultural...

  10. Evaluation of annual efficiencies of high temperature central receiver concentrated solar power plants with thermal energy storage.

    SciTech Connect

    Ehrhart, Brian David; Gill, David Dennis

    2013-07-01

    The current study has examined four cases of a central receiver concentrated solar power plant with thermal energy storage using the DELSOL and SOLERGY computer codes. The current state-of-the-art base case was compared with a theoretical high temperature case which was based on the scaling of some input parameters and the estimation of other parameters based on performance targets from the Department of Energy SunShot Initiative. This comparison was done for both current and high temperature cases in two configurations: a surround field with an external cylindrical receiver and a north field with a single cavity receiver. There is a fairly dramatic difference between the design point and annual average performance, especially in the solar field and receiver subsystems, and also in energy losses due to the thermal energy storage being full to capacity. Additionally, there are relatively small differences (<2%) in annual average efficiencies between the Base and High Temperature cases, despite an increase in thermal to electric conversion efficiency of over 8%. This is due the increased thermal losses at higher temperature and operational losses due to subsystem start-up and shut-down. Thermal energy storage can mitigate some of these losses by utilizing larger thermal energy storage to ensure that the electric power production system does not need to stop and re-start as often, but solar energy is inherently transient. Economic and cost considerations were not considered here, but will have a significant impact on solar thermal electric power production strategy and sizing.

  11. Δ14C level of annual plants and fossil fuel derived CO2 distribution across different regions of China

    NASA Astrophysics Data System (ADS)

    Xi, X. T.; Ding, X. F.; Fu, D. P.; Zhou, L. P.; Liu, K. X.

    2013-01-01

    The 14C level in annual plants is a sensitive tracer for monitoring fossil fuel derived CO2 in the atmosphere. Corn leave samples were selected from different regions of China, including high mountains in the Tibetan Plateau, grassland in Inner Mongolia, and inland and coastal cities during the summer of 2010. The 14C/12C ratio of the samples was measured with the NEC compact AMS system at the Institute of Heavy Ion Physics, Peking University. The fossil fuel derived CO2 was estimated by comparing the measured Δ14C values of corn leave samples to background atmospheric Δ14C level. The influences of topography, meteorological conditions and carbon cycling processes on the fossil fuel derived CO2 concentration are considered when interpreting the data. Our results show a clear association of the low Δ14C values with regions where human activities are intensive.

  12. Plant rhizosphere effects on metal mobilization and transport. 1998 annual progress report

    SciTech Connect

    Fan, T.W.M.

    1998-06-01

    'Information on the mechanism of how plants mobilize, uptake, and metabolize metal ions is very limited. Especially deficient is the understanding of these processes involving pollutant metal ions and interactions among these ions. Based on the current knowledge regarding nutrient ions, it is clear that elucidation of rhizospheric processes such as exudation of organic ligands by plant roots and plant metabolism/adaptation involving these biogenic chelators is critically important. A mechanistic insight into these processes will advance knowledge in microbe-plant host interactions and how metal ions are mobilized, immobilized, and sequestered by these interactions. This, in turn, is essential to applications such as phytobioremediation and microbioremediation of metal ion pollution. Root exudation also serves many other important rhizosphere functions including energy supply for microbial degradation of organic pollutants, structuring of microbial community, and the formation of soil humic materials which are considered to be a major sink for both organic and inorganic pollutants. How root exudates function is critically dependent on the chemical nature of exudate components. Therefore, a comprehensive characterization of all major exudate components, regardless of their chemical class, should facilitate the development and implementation of bioremediation for both organic and inorganic pollutants. Therefore, the objectives of this project are: (1) To obtain a comprehensive composition of major organic components in plant root exudates as a function of different metal ions; (2) To examine plant metabolic response(s) to these metal ion treatments, with emphasis on biosynthetic pathways of organic ligands; and (3) To investigate the effect(s) of soil microbial (e.g. mycorrhizae) association on (1) and (2).'

  13. Cost and quality of fuels for electric utility plants: Energy data report. 1980 annual

    SciTech Connect

    Not Available

    1981-06-25

    In 1980 US electric utilities reported purchasng 594 million tons of coal, 408.5 million barrels of oil and 3568.7 billion ft/sup 3/ of gas. As compared with 1979 purchases, coal rose 6.7%, oil decreased 20.9%, and gas increased for the fourth year in a row. This volume presents tabulated and graphic data on the cost and quality of fossil fuel receipts to US electric utilities plants with a combined capacity of 25 MW or greater. Information is included on fuel origin and destination, fuel types, and sulfur content, plant types, capacity, and flue gas desulfurization method used, and fuel costs. (LCL)

  14. Annual Changes of Paddy Rice Planting Areas in Northeastern Asia from MODIS images in 2000-2014

    NASA Astrophysics Data System (ADS)

    Xiao, X.; Zhang, G.; Dong, J.; Menarguez, M. A.; Kou, W.; Jin, C.; Qin, Y.; Zhou, Y.; Wang, J.; Moore, B., III

    2014-12-01

    Knowledge of the area and spatial distribution of paddy rice is important for assessment of food security, management of water resources, estimation of greenhouse gas (methane) emissions, and understanding avian influenza virus transmission. Over the past two decades, paddy rice cultivation has expanded northward in temperate and cold temperate zones, particularly in Northeastern China. There is a need to quantify and map changes in paddy rice planting areas in Northeastern Asia (Japan, North and South Korea, and northeast China) at annual interval. We developed a pixel- and phenology-based image analysis system, MODIS-RICE, to map the paddy rice in Northeastern Asia by using multi-temporal MODIS thermal and surface reflectance imagery. Paddy rice fields during the flooding and transplanting phases have unique physical and spectral characteristics, which make it possible for the development of an automated and robust algorithm to track flooding and transplanting phases of paddy rice fields over time. In this presentation, we will show the MODIS-based annual maps of paddy rice planting area in the Northeastern Asia from 2000-2014 (500-m spatial resolution). Accuracy assessments using high-resolution images show that the resultant paddy rice map of Northeastern Asia had a comparable accuracy to the existing products, including 2010 Landsat-based National Land Cover Dataset (NLCD) of China, the 2010 RapidEye-based paddy rice map in North Korea, and the 2010 AVNIR-2-based National Land Cover Dataset in Japan in terms of both area and spatial pattern of paddy rice. This study has demonstrated that our novel MODIS-Rice system, which use both thermal and optical MODIS data over a year, are simple and robust tools to identify and map paddy rice fields in temperate and cold temperate zones.

  15. ANNUAL REPORT. MECHANISMS OF HEAVY METAL SEQUESTRATION IN SOILS: PLANT MICROBE INTERACTIONS AND ORGANIC MATTER AGING

    EPA Science Inventory

    Among the factors that influence metal availability to soil-grown plants, one of the least understood is the influence of root/soil interfaces on metal mobilization and subsequent transport into the root. These include root exudation for chelating and reducing metal ions, cell wa...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Structure, function, and biosynthesis of plant cell walls: proceedings of the seventh annual symposium in botany

    SciTech Connect

    Dugger, W.M.; Bartnicki-Garcia, S.

    1984-01-01

    Papers in the following areas were included in these symposium proceedings: (1) cell wall chemistry and biosynthesis; (2) cell wall hydrolysis and associated physiology; (3) cellular events associated with cell wall biosynthesis; and (4) interactions of plant cell walls with pathogens and related responses. Papers have been individually abstracted for the data base. (ACR)

  18. Neutron dosimetry at commercial nuclear plants. Annual report of Subtask D: TEPC feasibility

    SciTech Connect

    Cummings, F.M.; Endres, G.W.R.; McDonald, J.C.; Brackenbush, L.W.

    1984-06-01

    This study was designed to observe the feasibility of the use by NRC licensees of the tissue equivalent proportional counter (TEPC) system as a neutron monitoring instrument. Laboratory tissue equivalent proportional counters were irradiated using /sup 252/Cf sources at NBS and PNL and were irradiated inside containment of four operating nuclear power plants (two boiling water reactors and two pressurized water reactors). On the average, neutron dose-equivalent rates determined using the TEPC were 1.05 times the calculated dose-equivalent rates for the bare and moderated /sup 252/Cf sources and 0.86 times the dose-equivalent rates determined using the multispheres inside containment of nuclear power plants. Further, neutron dose equivalent rates determined using portable remmeters were an average of 1.71 times the dose equivalent determined using the multispheres inside the containment of nuclear power plants. It was observed that while electronic noise from temperature and vibrational effects inside containment prohibited an adequate measure of absorbed dose from gammas, the measurement of neutron absorbed dose was unaffected by these environmental parameters. It is recommended that for use inside containment at nuclear power plants: (1) the laboratory scale TEPC is the superior technique for accurate determination of neutron dose equivalent, (2) for remmeters similar to the one evaluated in this study, neutron dose equivalent response should be corrected to account for dependence of response on neutron energy or the remmeters should be calibrated using a moderated neutron source, and (3) at present, the TEPC should not be used to measure absorbed dose from gammas. Upon the advent of a proven miniaturized TEPC, this instrument may prove to be a desirable replacement for current portable neutron monitoring devices for the determination of dose equivalent inside containment of commercial nuclear power plants.

  19. Marine biomass program: plant breeding and genetics. Annual report, September 1984-December 1985

    SciTech Connect

    Neushul, M.; Harger, B.W.W.; Lewis, R.J.

    1986-03-01

    By building on past efforts and adding to the data base that has been assembled, and through collaborative research with others, progress has been made toward the long-term goal of growing macroalgae in the sea as a future source of substitute natural gas. It is encouraging that the authors program is being emulated in Japan and Sweden, and that there is growing interest in using the unique GRI kelp seedstock collection by workers in Germany, Japan, Alaska, Oregon, California, and elsewhere. This annual report discusses progress made in propagating kelps, and the floating gulf-weed, Sargassum. Work on kelp genetics has revealed high levels of compatability between species and genera, based on 166 hybridization tests.

  20. Systems Biology Approaches to Dissecting Plant Cell Wall Biosynthesis Genes in Poplus (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    ScienceCinema

    Glass, N Louise [UC Berkeley

    2013-01-25

    N. Louise Glass from the University of California, Berkeley, presents a talk titled "Systems Biology Approaches to Dissecting Plant Cell Wall Biosynthesis Genes in Poplus" at the JGI 7th Annual Users Meeting: Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, California.

  1. Systems Biology Approaches to Dissecting Plant Cell Wall Biosynthesis Genes in Poplus (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    SciTech Connect

    Glass, N Louise

    2012-03-22

    N. Louise Glass from the University of California, Berkeley, presents a talk titled "Systems Biology Approaches to Dissecting Plant Cell Wall Biosynthesis Genes in Poplus" at the JGI 7th Annual Users Meeting: Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, California.

  2. The role of plant litter on nutrient mineralization and vegetation dynamics in three sage-steppe communities with differing levels of annual grass invasion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant litter is an integral part of ecosystem nutrient cycling, which directly impacts vegetation dynamics. The net effects of litter are largely determined by the quantity and source material of the litter. Invasion of sage-steppe communities by annual grasses (e.g., Bromus tectorum) has caused dra...

  3. Portsmouth Gaseous Diffusion Plant Annual Site Environmental Report summary for 1993

    SciTech Connect

    Not Available

    1994-11-01

    This report contains summaries of the environmental programs at Paducah Gaseous Diffusion Plant, environmental monitoring and the results, and the impact of operations on the environment and the public for 1993. The environmental monitoring program at Paducah includes effluent monitoring and environmental surveillance. Effluent monitoring is measurement of releases as they occur. Contaminants are released through either airborne emissions or liquids discharged from the plant. These releases occur as part of normal site operations, such as cooling water discharged from the uranium enrichment cascade operations or airborne releases from ventilation systems. In the event of system failure, this monitoring provides timely warning so that corrective action can be taken before releases reach an unsafe level. Environmental surveillance tracks the dispersion of materials into the environment after they have been released. This involves the collection of samples from various media, such as water, soil, vegetation, and food crops, and the analysis of these samples for certain radionuclides, chemicals, and metals.

  4. Paducah Gaseous Diffusion Plant Annual Site Environmental Report summary for 1993

    SciTech Connect

    Not Available

    1994-11-01

    This report contains summaries of the environmental programs at Paducah Gaseous Diffusion Plant, environmental monitoring and the results, and the impact of operations on the environment and the public for 1993. The environmental monitoring program at Paducah includes effluent monitoring and environmental surveillance. Effluent monitoring is measurement of releases as they occur. Contaminants are released through either airborne emissions or liquids discharged from the plant. These releases occur as part of normal site operations, such as cooling water discharged from the uranium enrichment cascade operations or airborne releases from ventilation systems. In the event of system failure, this monitoring provides timely warning so that corrective action can be taken before releases reach an unsafe level. Environmental surveillance tracks the dispersion of materials into the environment after they have been released. This involves the collection of samples from various media, such as water, soil, vegetation, and food crops, and the analysis of these samples for certain radionuclides, chemicals, and metals.

  5. Enhancing nuclear power plant performance through the use of artifical intelligence. First annual report

    SciTech Connect

    Johnson, M.; Maren, A.; Miller, L.; Uhrig, R.; Upadhyaya, B.

    1989-06-15

    In the summer of 1988, the Department of Nuclear Engineering (NE) at the University of Tennessee (UT) in Knoxville was selected to carry out a research program in ``Enhancing the Operation of Nuclear Power plants through the use of Artificial Intelligence, This program is sponsored by the Department of Energy`s Office of Energy Research under 10CFR605 for Nuclear Engineering Research. The objective of the research is to advance the state-of-the-art of nuclear power plant control, safety, management, and instrumentation systems through the use of artificial intelligence (AI) techniques, including both expert systems and neural networks. The emphasis will be placed on methods that can be implemented on a rapid or real-time basis. A second, but equally important, objective is to build a broadly based critical mass of expertise in the artificial intelligence, field that can be brought to bear on the technology of nuclear power plants. Both of these goals are being met. This overview and the attached technical reports describe the work that is being carried out. Although in some cases, the scope of the work differs somewhat from the specific tasks described in the original proposal, all activities are clearly within the overall scope of the contract.

  6. SNP Discovery for mapping alien introgressions in wheat

    PubMed Central

    2014-01-01

    Background Monitoring alien introgressions in crop plants is difficult due to the lack of genetic and molecular mapping information on the wild crop relatives. The tertiary gene pool of wheat is a very important source of genetic variability for wheat improvement against biotic and abiotic stresses. By exploring the 5Mg short arm (5MgS) of Aegilops geniculata, we can apply chromosome genomics for the discovery of SNP markers and their use for monitoring alien introgressions in wheat (Triticum aestivum L). Results The short arm of chromosome 5Mg of Ae. geniculata Roth (syn. Ae. ovata L.; 2n = 4x = 28, UgUgMgMg) was flow-sorted from a wheat line in which it is maintained as a telocentric chromosome. DNA of the sorted arm was amplified and sequenced using an Illumina Hiseq 2000 with ~45x coverage. The sequence data was used for SNP discovery against wheat homoeologous group-5 assemblies. A total of 2,178 unique, 5MgS-specific SNPs were discovered. Randomly selected samples of 59 5MgS-specific SNPs were tested (44 by KASPar assay and 15 by Sanger sequencing) and 84% were validated. Of the selected SNPs, 97% mapped to a chromosome 5Mg addition to wheat (the source of t5MgS), and 94% to 5Mg introgressed from a different accession of Ae. geniculata substituting for chromosome 5D of wheat. The validated SNPs also identified chromosome segments of 5MgS origin in a set of T5D-5Mg translocation lines; eight SNPs (25%) mapped to TA5601 [T5DL · 5DS-5MgS(0.75)] and three (8%) to TA5602 [T5DL · 5DS-5MgS (0.95)]. SNPs (gsnp_5ms83 and gsnp_5ms94), tagging chromosome T5DL · 5DS-5MgS(0.95) with the smallest introgression carrying resistance to leaf rust (Lr57) and stripe rust (Yr40), were validated in two released germplasm lines with Lr57 and Yr40 genes. Conclusion This approach should be widely applicable for the identification of species/genome-specific SNPs. The development of a large number of SNP markers will facilitate the precise introgression and

  7. 8 CFR 241.21 - Stay of deportation of excluded alien.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Stay of deportation of excluded alien. 241.21 Section 241.21 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens (for Hearings...

  8. 8 CFR 241.24 - Notice to transportation line of alien's exclusion.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Notice to transportation line of alien's exclusion. 241.24 Section 241.24 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens (for...

  9. 8 CFR 241.21 - Stay of deportation of excluded alien.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Stay of deportation of excluded alien. 241.21 Section 241.21 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens (for Hearings...

  10. 8 CFR 241.21 - Stay of deportation of excluded alien.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Stay of deportation of excluded alien. 241.21 Section 241.21 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens (for Hearings...

  11. 8 CFR 241.21 - Stay of deportation of excluded alien.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Stay of deportation of excluded alien. 241.21 Section 241.21 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens (for Hearings...

  12. 8 CFR 241.21 - Stay of deportation of excluded alien.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Stay of deportation of excluded alien. 241.21 Section 241.21 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens (for Hearings...

  13. 45 CFR 1626.4 - Aliens eligible for assistance under anti-abuse laws.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 4 2014-10-01 2014-10-01 false Aliens eligible for assistance under anti-abuse... SERVICES CORPORATION RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.4 Aliens eligible for assistance... alien who is within one of the following categories: (i) An alien who has been battered or subjected...

  14. Microdissection and chromosome painting of the alien chromosome in an addition line of wheat-Thinopyrum intermedium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chromosome painting is an efficient tool for chromosome research. However, plant chromosome painting is relatively underdeveloped. In this study, chromosome painting was developed and used to identify alien chromosomes in TAi-27, a wheat-Thinopyrum intermedium addition line, and chromosomes of...

  15. Genetic variation of eggplant mottled dwarf virus from annual and perennial plant hosts.

    PubMed

    Pappi, Polyxeni G; Maliogka, Varvara I; Amoutzias, Gregory D; Katis, Nikolaos I

    2016-03-01

    The genetic diversity of eggplant mottled dwarf virus (EMDV), a member of the family Rhabdoviridae, was studied using isolates collected from different herbaceous and woody plant species and remote geographic areas. Sequences corresponding to the N, X, P, Y, M and G ORFs as well as the untranslated regions (UTRs) between ORFs were determined from all isolates. Low genetic diversity was found in almost all genomic regions studied except for the X ORF and the UTRs, which were more variable, while interestingly, an EMDV isolate from caper possessed a truncated G gene sequence. Furthermore, low d N /d S ratios, indicative of purifying selection, were calculated for all genes. Phylogenetic analysis showed that the EMDV isolates clustered in three distinct subgroups based on their geographical origin, with the exception of one subgroup that consisted of isolates from northern Greece and Cyprus. Overall, the level of genetic diversity of EMDV differed between seed- and asexually propagated plants in our collection, and this could be related to the mode of transmission. PMID:26660163

  16. Autoimmunity vs. cancer: predator vs. alien?

    PubMed

    Berens, Christian; Lauber, Kirsten; Herrmann, Martin

    2013-08-01

    "The enemy of my enemy is my friend." According to this motto, the human protagonists in Paul W. S. Anderson's science-fiction movie "Alien vs. Predator" (2004) solidarize with a predator in order to fight the aliens. Can this ancient and simple logic be transferred to the field of oncology and cancer immunotherapy? Can we utilize mechanisms known from the context of autoimmunity to fight cancer? Here, we summarize immune cell-mediated detection of danger and damage, central and peripheral tolerance, immunoregulation and immune privilege--processes known to be deregulated in the context of autoimmunity. We discuss them with special regard towards their misusage by tumors and pathogens and how they might be instrumentalized in the context of anti-cancer immunotherapy. PMID:23706137

  17. Evolutionary objections to "alien design" models.

    NASA Astrophysics Data System (ADS)

    Coffey, E. J.

    A previous paper demonstrated that the principal supporters of SETI have ignored the biological and evolutionary consequences of a creature's body form. In fact, the supporting evidence they provide actually contradicts their view. The approach they employ is that of the engineer: the process of "designing" a hypothetical creature to a specification irrespective of biological or evolutionary considerations. The principal types of "alien designs" which have been employed shall be discussed, and the evolutionary objections to them given.

  18. Short-term soil inorganic N pulse after experimental fire alters invasive and native annual plant production in a Mojave Desert shrubland.

    PubMed

    Esque, Todd C; Kaye, Jason P; Eckert, Sara E; Defalco, Lesley A; Tracy, C Richard

    2010-09-01

    Post-fire changes in desert vegetation patterns are known, but the mechanisms are poorly understood. Theory suggests that pulse dynamics of resource availability confer advantages to invasive annual species, and that pulse timing can influence survival and competition among species. Precipitation patterns in the American Southwest are predicted to shift toward a drier climate, potentially altering post-fire resource availability and consequent vegetation dynamics. We quantified post-fire inorganic N dynamics and determined how annual plants respond to soil inorganic nitrogen variability following experimental fires in a Mojave Desert shrub community. Soil inorganic N, soil net N mineralization, and production of annual plants were measured beneath shrubs and in interspaces during 6 months following fire. Soil inorganic N pools in burned plots were up to 1 g m(-2) greater than unburned plots for several weeks and increased under shrubs (0.5-1.0 g m(-2)) more than interspaces (0.1-0.2 g m(-2)). Soil NO(3) (-)-N (nitrate-N) increased more and persisted longer than soil NH(4) (+)-N (ammonium-N). Laboratory incubations simulating low soil moisture conditions, and consistent with field moisture during the study, suggest that soil net ammonification and net nitrification were low and mostly unaffected by shrub canopy or burning. After late season rains, and where soil inorganic N pools were elevated after fire, productivity of the predominant invasive Schismus spp. increased and native annuals declined. Results suggest that increased N availability following wildfire can favor invasive annuals over natives. Whether the short-term success of invasive species following fire will direct long-term species composition changes remains to be seen, yet predicted changes in precipitation variability will likely interact with N cycling to affect invasive annual plant dominance following wildfire. PMID:20419316

  19. Rapid regulatory control of plant cell expansion and wall relaxation. Annual technical progress report

    SciTech Connect

    Cosgrove, D.J.

    1991-08-14

    The aim of this project is to elucidate the biophysical and cellular mechanisms that control plant cell expansion. At present we are attempting to characterize the kinetics of the system(s) responsible for regulatory and compensatory behavior of growing cells and tissues. This work is significantly because it indicates that biochemical loosening and biophysical stress relaxation of the wall are part of a feedback loop controlling growth. This report briefly summarizes the efforts and results of the past 12 months. In large part, we have been trying to analyze the nature of growth rate ``noise,`` i.e. spontaneous and often erratic variations in growth rate. We are obtaining evidence that such ``noise`` is not random, but rather reveals an underlying growth mechanism with complex dynamics.

  20. [Plant growth with limited water]. [Annual report, December 15, 1992--December 14, 1993

    SciTech Connect

    Not Available

    1993-12-01

    We used a soybean seedling system to explore the mechanism of growth limitation by water deficiency (low {Psi}{sub W}). Our prior work had show that (low {Psi}{sub W} inhibited plant growth initially because of a physical limitation to water uptake that appeared to result from a decrease in the {Psi}{sub W} gradient feeding water to the enlarging cells. The gradient was shown to originate from cell wall yielding and was altered primarily at the vascular tissue. In the present grant, we reported the detailed shape of the gradient. We also found that growth could mobilize water from mature tissues in the complete absence of external water using the gradient in {Psi}{sub W}. Growth was maintained by this mobilization. After growth has been inhibited a few hours, metabolic changes occur and a 28kD protein accumulates in the wall fraction of the growth-affected cells. In the present grant, we showed that the mRNA for the protein accumulated in a tissue-specific manner similar to that of the protein, and the accumulation was correlated with the growth response. Other investigators working independently with an acid phosphatase found a deduced amino acid sequence similar to that for the 28kD protein we had published. Biochemical tests showed that the 28kD protein and a related 3lkD protein expressed acid phosphatase activity. We found that the acid phosphatase Of the 28kD protein was in the cell walls of intact plants (in addition to being in the cytoplasm). Current work focuses on the role of this protein. Efforts were made to reverse the growth inhibition at low {Phi}{sub W} by treating growing tissues with low pH buffer, but the protons apparently failed to penetrate the cuticle.