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Sample records for assess plant diversity

  1. PLANT DIVERSITY

    EPA Science Inventory

    Habitat change statistics and species-area curves were used to estimate the effects of alternative future scenarios for agriculture on plant diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future s...

  2. Assessing the diversity of bacterial communities associated with plants

    PubMed Central

    Andreote, Fernando Dini; Azevedo, João Lúcio; Araújo, Welington Luiz

    2009-01-01

    Plant–bacteria interactions result from reciprocal recognition between both species. These interactions are responsible for essential biological processes in plant development and health status. Here, we present a review of the methodologies applied to investigate shifts in bacterial communities associated with plants. A description of techniques is made from initial isolations to culture-independent approaches focusing on quantitative Polymerase Chain Reaction in real time (qPCR), Denaturing Gradient Gel Electrophoresis (DGGE), clone library construction and analysis, the application of multivariate analyses to microbial ecology data and the upcoming high throughput methodologies such as microarrays and pyrosequencing. This review supplies information about the development of traditional methods and a general overview about the new insights into bacterial communities associated with plants. PMID:24031382

  3. Evolution & Diversity in Plants.

    ERIC Educational Resources Information Center

    Pearson, Lorentz C.

    1988-01-01

    Summarizes recent findings that help in understanding how evolution has brought about the diversity of plant life that presently exists. Discusses basic concepts of evolution, diversity and classification, the three-line hypothesis of plant evolution, the origin of fungi, and the geologic time table. Included are 31 references. (CW)

  4. Palaeo plant diversity in subtropical Africa - ecological assessment of a conceptual model of climate-vegetation interaction

    NASA Astrophysics Data System (ADS)

    Groner, V. P.; Claussen, M.; Reick, C.

    2015-07-01

    We here critically re-assess a conceptual model dealing with the potential effect of plant diversity on climate-vegetation feedback, and provide an improved version adjusted to plant types that prevailed during the African Humid Period (AHP). Our work contributes to the understanding of the timing and abruptness of vegetation decline at the end of the AHP, investigated by various working groups during the past two decades using a wide range of model and palaeoproxy reconstruction approaches. While some studies indicated an abrupt collapse of vegetation at the end of the AHP, others suggested a gradual decline. Claussen et al. (2013) introduced a new aspect in the discussion, proposing that plant diversity in terms of moisture requirements could affect the strength of climate-vegetation feedback. In a conceptual model study, the authors illustrated that high plant diversity could stabilize an ecosystem, whereas a reduction in plant diversity might allow for an abrupt regime shift under gradually changing environmental conditions. Based on recently published pollen data and the current state of ecological literature, we evaluate the representation of climate-vegetation feedback in this conceptual approach, and put the suggested conclusions into an ecological context. In principle, the original model reproduces the main features of different plant types interacting together with climate although vegetation determinants other than precipitation are neglected. However, the model cannot capture the diversity of AHP vegetation. Especially tropical gallery forest taxa, indirectly linked to local precipitation, are not appropriately represented. In order to fill the gaps in the description of plant types regarding AHP diversity, we modify the original model in four main aspects. First, the growth ranges in terms of moisture requirements are extended by upper limits to represent full environmental envelopes. Second, data-based AHP plant types replace the hypothetical plant types. Third, the tropical gallery forest type follows the gradual insolation forcing with a linear approximation because it relies more on large scale climate than on regional precipitation amounts. Fourth, we replace the dimensionless vegetation cover fractions with individual effective leaf areas to capture different contributions to climate-vegetation feedback. These adjustments allow for the consideration of a broader spectrum of plant types, plant-climate feedbacks, and implicitly for plant-plant interactions. With the consideration of full environmental envelopes and the prescribed retreat of the tropical gallery forest type we can simulate a diverse mosaic-like environment as it was reconstructed from pollen. Transient simulations of this diverse environment support the buffering effect of high functional diversity on ecosystem performance and precipitation, concluded by Claussen et al. (2013) from the simple approach. Sensitivity studies with different combinations of plant types highlight the importance of plant composition on system stability, and the stabilizing or destabilizing potential a single functional type may inherit. In a broader view, the adjusted model provides a useful tool to study the roles of real plant types in an ecosystem and their combined climate-vegetation feedback under changing precipitation regimes.

  5. Importance of Genetic Diversity Assessment in Crop Plants and Its Recent Advances: An Overview of Its Analytical Perspectives

    PubMed Central

    Govindaraj, M.; Vetriventhan, M.; Srinivasan, M.

    2015-01-01

    The importance of plant genetic diversity (PGD) is now being recognized as a specific area since exploding population with urbanization and decreasing cultivable lands are the critical factors contributing to food insecurity in developing world. Agricultural scientists realized that PGD can be captured and stored in the form of plant genetic resources (PGR) such as gene bank, DNA library, and so forth, in the biorepository which preserve genetic material for long period. However, conserved PGR must be utilized for crop improvement in order to meet future global challenges in relation to food and nutritional security. This paper comprehensively reviews four important areas; (i) the significance of plant genetic diversity (PGD) and PGR especially on agriculturally important crops (mostly field crops); (ii) risk associated with narrowing the genetic base of current commercial cultivars and climate change; (iii) analysis of existing PGD analytical methods in pregenomic and genomic era; and (iv) modern tools available for PGD analysis in postgenomic era. This discussion benefits the plant scientist community in order to use the new methods and technology for better and rapid assessment, for utilization of germplasm from gene banks to their applied breeding programs. With the advent of new biotechnological techniques, this process of genetic manipulation is now being accelerated and carried out with more precision (neglecting environmental effects) and fast-track manner than the classical breeding techniques. It is also to note that gene banks look into several issues in order to improve levels of germplasm distribution and its utilization, duplication of plant identity, and access to database, for prebreeding activities. Since plant breeding research and cultivar development are integral components of improving food production, therefore, availability of and access to diverse genetic sources will ensure that the global food production network becomes more sustainable. The pros and cons of the basic and advanced statistical tools available for measuring genetic diversity are briefly discussed and their source links (mostly) were provided to get easy access; thus, it improves the understanding of tools and its practical applicability to the researchers. PMID:25874132

  6. Geographic information system method for assessing chemo-diversity in medicinal plants.

    PubMed

    Moraes, Rita M; Momm, Henrique G; Silva, Bladimiro; Maddox, Victor; Easson, Gregory L; Lata, Hemant; Ferreira, Daneel

    2005-12-01

    The spatial distribution of wild germplasm of Podophyllum peltatum L. (American mayapple) has been analyzed using the Geographic Information System (GIS) with the objective to develop a method and a database for evaluation of biotic and abiotic factors influencing drug yield, and to map elite genotypes for propagation and improvement. The field assessment followed a standard procedure including geographical coordinates of each accession, leaf biomass randomly harvested, identification of associate species, collection of herbarium specimen, soil sample and digital pictures of the site. By overlaying morphological and chemical data with geomorphic information, a thematic map was created locating the podophyllotoxin-rich accessions and the uniqueness of each site was recorded for post-collection analysis. This work has enabled the establishment of a database of P. peltatum germplasm in Mississippi with drug yield linked to spatial locations for rational utilization of our natural resources. While this method integrates information of well-characterized diverse in situ P. peltatum germplasm, it might become a strategy for curators to reduce cost for establishing and maintaining ex situ collections since the genetic material is geo-referenced. PMID:16395654

  7. Palaeo plant diversity in subtropical Africa - ecological assessment of a conceptual model of climate-vegetation interaction

    NASA Astrophysics Data System (ADS)

    Groner, V. P.; Claussen, M.; Reick, C.

    2015-10-01

    We critically reassess a conceptual model here, dealing with the potential effect of plant diversity on climate-vegetation feedback, and we provide an improved version adjusted to plant types that prevailed during the African Humid Period (AHP). Our work contributes to the understanding of the timing and abruptness of vegetation decline at the end of the AHP, investigated by various working groups during the past 2 decades using a wide range of model and palaeo-proxy reconstruction approaches. While some studies indicated an abrupt collapse of vegetation at the end of the AHP, others suggested a gradual decline. Claussen et al. (2013) introduced a new aspect in the discussion, proposing that plant diversity in terms of moisture requirements could affect the strength of climate-vegetation feedback. In a conceptual model study, the authors illustrated that high plant diversity could stabilize an ecosystem, whereas a reduction in plant diversity might allow for an abrupt regime shift under gradually changing environmental conditions. In the light of recently published pollen data and the current state of ecological literature, the conceptual model by Claussen et al. (2013) reproduces the main features of different plant types interacting together with climate, but it does not capture the reconstructed diversity of AHP vegetation. Especially tropical gallery forest taxa, indirectly linked to local precipitation, are not appropriately represented. With a new model version adjusted to AHP vegetation, we can simulate a diverse mosaic-like environment as reconstructed from pollen, and we observe a stabilizing effect of high functional diversity on vegetation cover and precipitation. Sensitivity studies with different combinations of plant types highlight the importance of plant composition on system stability, and the stabilizing or destabilizing potential a single plant type may inherit. The model's simplicity limits its application; however, it provides a useful tool to study the roles of real plant types in an ecosystem and their combined climate-vegetation feedback under changing precipitation regimes.

  8. Socioeconomics drive urban plant diversity.

    PubMed

    Hope, Diane; Gries, Corinna; Zhu, Weixing; Fagan, William F; Redman, Charles L; Grimm, Nancy B; Nelson, Amy L; Martin, Chris; Kinzig, Ann

    2003-07-22

    Spatial variation in plant diversity has been attributed to heterogeneity in resource availability for many ecosystems. However, urbanization has resulted in entire landscapes that are now occupied by plant communities wholly created by humans, in which diversity may reflect social, economic, and cultural influences in addition to those recognized by traditional ecological theory. Here we use data from a probability-based survey to explore the variation in plant diversity across a large metropolitan area using spatial statistical analyses that incorporate biotic, abiotic, and human variables. Our prediction for the city was that land use, along with distance from urban center, would replace the dominantly geomorphic controls on spatial variation in plant diversity in the surrounding undeveloped Sonoran desert. However, in addition to elevation and current and former land use, family income and housing age best explained the observed variation in plant diversity across the city. We conclude that a functional relationship, which we term the "luxury effect," may link human resource abundance (wealth) and plant diversity in urban ecosystems. This connection may be influenced by education, institutional control, and culture, and merits further study. PMID:12847293

  9. COURSE INFORMATION Plant Diversity and Evolution

    E-print Network

    Chen, Kuang-Yu

    plant diversity. 2. The major features and evolutionary origins of vascular plants. 3. The analytical of terminology) 5. Identification of plants using keys 6. Recognition of important vascular plant families (seeCOURSE INFORMATION Fall 2009 Plant Diversity and Evolution (11:704:411) and Advanced Plant

  10. Diversity protects plant communities against generalist molluscan herbivores

    PubMed Central

    Fabian, Yvonne; Sandau, Nadine; Bruggisser, Odile T; Kehrli, Patrik; Aebi, Alexandre; Rohr, Rudolf P; Naisbit, Russell E; Bersier, Louis-Félix

    2012-01-01

    Wildflower strips are used to increase natural enemies of crop pests and to conserve insect diversity on farmland. Mollusks, especially slugs, can affect the vegetation development in these strips considerably. Although recent theoretical work suggests that more diverse plant communities will exhibit greater resistance against herbivore pressure, empirical studies are scarce. We conducted a semi-natural experiment in wildflower strips, manipulating trophic structure (reduction in herbivorous mollusks and reduction in major predators) and plant diversity (2, 6, 12, 20 and 24 sown species). This design allowed us to assess the effect of plant diversity, biomass and composition on mollusks, and vice versa, the effect of mollusc abundance on vegetation. Seven species of mollusks were found in the strips, with the slugs Arion lusitanicus, Deroceras reticulatum and Deroceras panormitanum being most frequent. We found a negative relationship between plant diversity and mollusk abundance, which was due predominantly to a decrease in the agricultural pest species A. lusitanicus. These results are consistent with the hypothesis that plant diversity can reduce the impact of herbivores. However, plant identity also had an effect on mollusks, and accounted for a much larger fraction of the variation in mollusk communities than biodiversity effects. While overall plant diversity decreased during the 3 years of the study, in the final year the highest plant diversity was found in the plots where mollusk populations were experimentally reduced. We conclude that selective feeding by generalist herbivores leads to changes in plant community composition and hence reduced plant diversity. Our results highlight the importance of plant biodiversity as protection against generalist herbivores, which if abundant can in the long term negatively impact plant diversity, driving the system along a “low plant diversity – high mollusk abundance” trajectory. PMID:23145332

  11. Curvilinear effects of invasive plants on plant diversity: plant community invaded by Sphagneticola trilobata.

    PubMed

    Qi, Shan-Shan; Dai, Zhi-Cong; Zhai, De-Li; Chen, Si-Chong; Si, Chun-Can; Huang, Ping; Wang, Rui-Ping; Zhong, Qiong-Xin; Du, Dao-Lin

    2014-01-01

    The effects of invasive plants on the species diversity of plant communities are controversial, showing either a positive or negative linear relationship. Based on community data collected from forty 5 m×5 m plots invaded by Sphagneticola trilobata in eight cities across Hainan Island, China, we found S. trilobata decreased plant community diversity once its cover was beyond 10%. We demonstrated that the effects of invasive/native plants on the plant diversity of communities invaded by S. trilobata were curvilinear. These effects, which showed peaks under different degrees of vegetation cover, appeared not only for S. trilobata and all invasive plants, but also for all native plants. Invasive plants primarily had negative effects on plant diversity when they became abundant at a much lower cover level (less than 35%), compared with the native plants (over 60%). Thus, it is necessary to distinguish a range for assessing the effects of plants, especially invasive plants. Our results also confirmed that the invasion intensity of invasive alien plants increased with the intensity of local economic development. We highlight and further discuss the critical importance of curvilinear effects of biological invasion to provide ideas regarding the conservation of local biodiversity and the management of invasive plants. PMID:25426856

  12. Curvilinear Effects of Invasive Plants on Plant Diversity: Plant Community Invaded by Sphagneticola trilobata

    PubMed Central

    Zhai, De-Li; Chen, Si-Chong; Si, Chun-Can; Huang, Ping; Wang, Rui-Ping; Zhong, Qiong-Xin; Du, Dao-Lin

    2014-01-01

    The effects of invasive plants on the species diversity of plant communities are controversial, showing either a positive or negative linear relationship. Based on community data collected from forty 5 m×5 m plots invaded by Sphagneticola trilobata in eight cities across Hainan Island, China, we found S. trilobata decreased plant community diversity once its cover was beyond 10%. We demonstrated that the effects of invasive/native plants on the plant diversity of communities invaded by S. trilobata were curvilinear. These effects, which showed peaks under different degrees of vegetation cover, appeared not only for S. trilobata and all invasive plants, but also for all native plants. Invasive plants primarily had negative effects on plant diversity when they became abundant at a much lower cover level (less than 35%), compared with the native plants (over 60%). Thus, it is necessary to distinguish a range for assessing the effects of plants, especially invasive plants. Our results also confirmed that the invasion intensity of invasive alien plants increased with the intensity of local economic development. We highlight and further discuss the critical importance of curvilinear effects of biological invasion to provide ideas regarding the conservation of local biodiversity and the management of invasive plants. PMID:25426856

  13. How does pedogenesis drive plant diversity?

    USGS Publications Warehouse

    Laliberté, Etienne; Grace, James B.; Huston, Michael A.; Lambers, Hans; Teste, François P.; Turner, Benjamin L.; Wardle, David A.

    2013-01-01

    Some of the most species-rich plant communities occur on ancient, strongly weathered soils, whereas those on recently developed soils tend to be less diverse. Mechanisms underlying this well-known pattern, however, remain unresolved. Here, we present a conceptual model describing alternative mechanisms by which pedogenesis (the process of soil formation) might drive plant diversity. We suggest that long-term soil chronosequences offer great, yet largely untapped, potential as 'natural experiments' to determine edaphic controls over plant diversity. Finally, we discuss how our conceptual model can be evaluated quantitatively using structural equation modeling to advance multivariate theories about the determinants of local plant diversity. This should help us to understand broader-scale diversity patterns, such as the latitudinal gradient of plant diversity.

  14. How does pedogenesis drive plant diversity?

    PubMed

    Laliberté, Etienne; Grace, James B; Huston, Michael A; Lambers, Hans; Teste, François P; Turner, Benjamin L; Wardle, David A

    2013-06-01

    Some of the most species-rich plant communities occur on ancient, strongly weathered soils, whereas those on recently developed soils tend to be less diverse. Mechanisms underlying this well-known pattern, however, remain unresolved. Here, we present a conceptual model describing alternative mechanisms by which pedogenesis (the process of soil formation) might drive plant diversity. We suggest that long-term soil chronosequences offer great, yet largely untapped, potential as 'natural experiments' to determine edaphic controls over plant diversity. Finally, we discuss how our conceptual model can be evaluated quantitatively using structural equation modeling to advance multivariate theories about the determinants of local plant diversity. This should help us to understand broader-scale diversity patterns, such as the latitudinal gradient of plant diversity. PMID:23561322

  15. Rapid plant diversity assessment using a pixel nested plot design: A case study in Beaver Meadows, Rocky Mountain National Park, Colorado, USA

    USGS Publications Warehouse

    Kalkhan, M.A.; Stafford, E.J.; Stohlgren, T.J.

    2007-01-01

    Geospatial statistical modelling and thematic maps have recently emerged as effective tools for the management of natural areas at the landscape scale. Traditional methods for the collection of field data pertaining to questions of landscape were developed without consideration for the parameters of these applications. We introduce an alternative field sampling design based on smaller unbiased random plot and subplot locations called the pixel nested plot (PNP). We demonstrate the applicability of the PNP design of 15 m x 15 m to assess patterns of plant diversity and species richness across the landscape at Rocky Mountain National Park (RMNP), Colorado, USA in a time (cost)-efficient manner for field data collection. Our results produced comparable results to a previous study in the Beaver Meadow study (BMS) area within RMNP, where there was a demonstrated focus of plant diversity. Our study used the smaller PNP sampling design for field data collection which could be linked to geospatial information data and could be used for landscape-scale analyses and assessment applications. In 2003, we established 61 PNP in the eastern region of RMNP. We present a comparison between this approach using a sub-sample of 19 PNP from this data set and 20 of Modified Whittaker nested plots (MWNP) of 20 m x 50 m that were collected in the BMS area. The PNP captured 266 unique plant species while the MWNP captured 275 unique species. Based on a comparison of PNP and MWNP in the Beaver Meadows area, RMNP, the PNP required less time and area sampled to achieve a similar number of species sampled. Using the PNP approach for data collection can facilitate the ecological monitoring of these vulnerable areas at the landscape scale in a time- and therefore cost-effective manner. ?? 2007 The Authors.

  16. Genetic diversity is positively associated with plant fitness, stability, and the provision of ecosystem services. Typically, diversity is lost with disturbance and is not completely

    E-print Network

    Lawrence, Deborah

    #12;i Abstract Genetic diversity is positively associated with plant fitness, stability recovered by restoration. Therefore, there is concern about the state of seagrass genetic diversity Chesapeake Bay seeds. This dissertation assesses the genetic diversity of Virginia seagrass meadows

  17. Relationships between Spatial Metrics and Plant Diversity in Constructed Freshwater Wetlands

    PubMed Central

    Grossman, Jake J.; Allen, George A.; Benzing, David H.

    2015-01-01

    The diversity of plant species and their distribution in space are both thought to have important effects on the function of wetland ecosystems. However, knowledge of the relationships between plant species and spatial diversity remains incomplete. In this study, we investigated relationships between spatial pattern and plant species diversity over a five year period following the initial restoration of experimental wetland ecosystems. In 2003, six identical and hydrologically-isolated 0.18 ha wetland “cells” were constructed in former farmland in northeast Ohio. The systems were subjected to planting treatments that resulted in different levels of vascular plant species diversity among cells. Plant species diversity was assessed through annual inventories. Plant spatial pattern was assessed by digitizing low-altitude aerial photographs taken at the same time as the inventories. Diversity metrics derived from the inventories were significantly related to certain spatial metrics derived from the photographs, including cover type diversity and contagion. We found that wetlands with high cover type diversity harbor higher plant species diversity than wetlands with fewer types of patches. We also found significant relationships between plant species diversity and spatial patterning of patch types, but the direction of the effect differed depending on the diversity metric used. Links between diversity and spatial pattern observed in this study suggest that high-resolution aerial imagery may provide wetland scientists with a useful tool for assessing plant diversity. PMID:26296205

  18. Flower diversity and plant mating strategies 1 Flower diversity and plant mating

    E-print Network

    Barrett, Spencer C.H.

    Flower diversity and plant mating strategies 1 Flower diversity and plant mating strategies The diversification in form and function of flowers, the reproductive structures of angiosperms (flower- ing plants), provides some of the most compelling examples of adaptation by natural selection. Flowers vary enormously

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

    EPA Science Inventory

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

  20. Reconciling Harvest Intensity and Plant Diversity in Boreal Ecosystems: Does Intensification Influence Understory Plant Diversity?

    PubMed

    Kershaw, H Maureen; Morris, Dave M; Fleming, Robert L; Luckai, Nancy J

    2015-11-01

    Overall demand for forest products in the boreal forest is increasing to supply growing bio-energy demands in addition to traditional forest products. As a result, there is a need to refine current forest policies to reconcile production and ecosystem function within the context of ecologically sustainable management. This study assessed understory plants' richness, evenness, and diversity in six harvested boreal black spruce-dominated stands situated on loam, sand, and peat site types 15 years after the application of four harvest treatments of increasing biomass removals. Treatments included uncut, stem-only harvest, full-tree harvest, and full-tree harvest + blading of O horizon. Following canopy removal, species richness and diversity (Shannon's and Simpson's indices) increased on all soil types. The more than doubling of slash loading on the stem-only treatment plots compared to the full-tree plots led to significantly lower species diversity on loam sites; however, the reverse was observed on peat sites where the slash provided warmer, drier microsites facilitating the establishment of a broader array of species. Preexisting ericaceous shrub and sphagnum components continued to dominate on the peat sites. Compositional shifts were most evident for the full-tree + bladed treatment on all soil types, with increases in herbaceous cover including ruderal species. The results suggest that the intensification of harvesting on plant diversity varies with soil type, and these differential results should be considered in the refinement of forest biomass-harvesting guidelines to ensure ecological sustainability and biodiversity conservation over a broad suite of soil types. PMID:26092048

  1. Reconciling Harvest Intensity and Plant Diversity in Boreal Ecosystems: Does Intensification Influence Understory Plant Diversity?

    NASA Astrophysics Data System (ADS)

    Kershaw, H. Maureen; Morris, Dave M.; Fleming, Robert L.; Luckai, Nancy J.

    2015-11-01

    Overall demand for forest products in the boreal forest is increasing to supply growing bio-energy demands in addition to traditional forest products. As a result, there is a need to refine current forest policies to reconcile production and ecosystem function within the context of ecologically sustainable management. This study assessed understory plants' richness, evenness, and diversity in six harvested boreal black spruce-dominated stands situated on loam, sand, and peat site types 15 years after the application of four harvest treatments of increasing biomass removals. Treatments included uncut, stem-only harvest, full-tree harvest, and full-tree harvest + blading of O horizon. Following canopy removal, species richness and diversity (Shannon's and Simpson's indices) increased on all soil types. The more than doubling of slash loading on the stem-only treatment plots compared to the full-tree plots led to significantly lower species diversity on loam sites; however, the reverse was observed on peat sites where the slash provided warmer, drier microsites facilitating the establishment of a broader array of species. Preexisting ericaceous shrub and sphagnum components continued to dominate on the peat sites. Compositional shifts were most evident for the full-tree + bladed treatment on all soil types, with increases in herbaceous cover including ruderal species. The results suggest that the intensification of harvesting on plant diversity varies with soil type, and these differential results should be considered in the refinement of forest biomass-harvesting guidelines to ensure ecological sustainability and biodiversity conservation over a broad suite of soil types.

  2. A hierarchical perspective of plant diversity

    USGS Publications Warehouse

    Sarr, Daniel; Hibbs, D.E.; Huston, M.

    2005-01-01

    Predictive models of plant diversity have typically focused on either a landscapea??s capacity for richness (equilibrium models), or on the processes that regulate competitive exclusion, and thus allow species to coexist (nonequilibrium models). Here, we review the concepts and purposes of a hierarchical, multiscale model of the controls of plant diversity that incorporates the equilibrium model of climatic favorability at macroscales, nonequilibrium models of competition at microscales, and a mixed model emphasizing environmental heterogeneity at mesoscales. We evaluate the conceptual model using published data from three spatially nested datasets: (1) a macroscale analysis of ecoregions in the continental and western U.S.; (2) a mesoscale study in California; and (3) a microscale study in the Siskiyou Mountains of Oregon and California. At the macroscale (areas from 3889 km2 to 638,300 km2), climate (actual evaporation) was a strong predictor of tree diversity (R2 = 0.80), as predicted by the conceptual model, but area was a better predictor for vascular plant diversity overall (R2 = 0.38), which suggests different types of plants differ in their sensitivity to climatic controls. At mesoscales (areas from 1111 km2 to 15,833 km2 ), climate was still an important predictor of richness (R2 = 0.52), but, as expected, topographic heterogeneity explained an important share of the variance (R2 = 0.19), showed positive correlations with diversity of trees, shrubs, and annual and perennial herbs, and was the primary predictor of shrub and annual plant species richness. At microscales (0.1 ha plots), spatial patterns of diversity showed a clear unimodal pattern along a climatea??driven productivity gradient and a negative relationship with soil fertility. The strong decline in understory and total diversity at the most productive sites suggests that competitive controls, as predicted, can override climatic controls at this scale. We conclude that this hierarchical, multiscale model provides a sound basis to understand and analyze plant species diversity. Specifically, future research should employ the principles in this paper to explore climatic controls on species richness of different life forms, better quantify environmental heterogeneity in landscapes, and analyze how these largea??scale factors interact with local nonequilibrium dynamics to maintain plant diversity.

  3. An Inventory of Peer Assessment Diversity

    ERIC Educational Resources Information Center

    Gielen, Sarah; Dochy, Filip; Onghena, Patrick

    2011-01-01

    Since Topping published his literature review on peer assessment in 1998, the number of studies on this subject has doubled, if not tripled. However, along with this expansion, the diversity of peer assessment applications increased equally fast. Based on recent literature, this contribution focuses specifically on the diversity that has come to…

  4. ASSESSING PLANTING STOCK QUALITY Comprehensive assessments of planting stock

    E-print Network

    high- quality stock for Pacific Slope forests. THE PROGRAM DESIGN Planting stock quality was assessedASSESSING PLANTING STOCK QUALITY Comprehensive assessments of planting stock quality are essential to evaluate planting stock quality and nursery practice. Field tests provide proof of the nursery's ability

  5. Diverse roles of strigolactones in plant development.

    PubMed

    Brewer, Philip B; Koltai, Hinanit; Beveridge, Christine A

    2013-01-01

    With the discovery of strigolactones as root exudate signals that trigger parasitic weed seed germination, and then as a branching inhibitor and plant hormone, the next phase of strigolactone research has quickly revealed this hormone class as a major player in optimizing plant growth and development. From the early stages of plant evolution, it seems that strigolactones were involved in enabling plants to modify growth in order to gain advantage in competition with neighboring organisms for limited resources. For example, a moss plant can alter its growth in response to strigolactones emanating from a neighbor. Within a higher plant, strigolactones appear to be involved in controlling the balance of resource distribution via strategic modification of growth and development. Most notably, higher plants that encounter phosphate deficiency increase strigolactone production, which changes root growth and promotes fungal symbiosis to enhance phosphate intake. The shoot also changes by channeling resources away from unessential leaves and branches and into the main stem and root system. This hormonal response is a key adaption that radically alters whole-plant architecture in order to optimize growth and development under diverse environmental conditions. PMID:23155045

  6. Diverse urban plantings managed with sufficient resource availability can increase plant productivity and arthropod diversity.

    PubMed

    Muller, Jonathon N; Loh, Susan; Braggion, Ligia; Cameron, Stephen; Firn, Jennifer L

    2014-01-01

    Buildings structures and surfaces are explicitly being used to grow plants, and these "urban plantings" are generally designed for aesthetic value. Urban plantings also have the potential to contribute significant "ecological values" by increasing urban habitat for animals such as arthropods and by increasing plant productivity. In this study, we evaluated how the provision of these additional ecological values is affected by plant species richness; the availability of essential resources for plants, such as water, light, space; and soil characteristics. We sampled 33 plantings located on the exterior of three buildings in the urban center of Brisbane, Australia (subtropical climatic region) over 2, 6 week sampling periods characterized by different temperature and rainfall conditions. Plant cover was estimated as a surrogate for productivity as destructive sampling of biomass was not possible. We measured weekly light levels (photosynthetically active radiation), plant CO2 assimilation, soil CO2 efflux, and arthropod diversity. Differences in plant cover were best explained by a three-way interaction of plant species richness, management water regime and sampling period. As the richness of plant species increased in a planter, productivity and total arthropod richness also increased significantly-likely due to greater habitat heterogeneity and quality. Overall we found urban plantings can provide additional ecological values if essential resources are maintained within a planter such as water, light and soil temperature. Diverse urban plantings that are managed with these principles in mind can contribute to the attraction of diverse arthropod communities, and lead to increased plant productivity within a dense urban context. PMID:25400642

  7. Diverse urban plantings managed with sufficient resource availability can increase plant productivity and arthropod diversity

    PubMed Central

    Muller, Jonathon N.; Loh, Susan; Braggion, Ligia; Cameron, Stephen; Firn, Jennifer L.

    2014-01-01

    Buildings structures and surfaces are explicitly being used to grow plants, and these “urban plantings” are generally designed for aesthetic value. Urban plantings also have the potential to contribute significant “ecological values” by increasing urban habitat for animals such as arthropods and by increasing plant productivity. In this study, we evaluated how the provision of these additional ecological values is affected by plant species richness; the availability of essential resources for plants, such as water, light, space; and soil characteristics. We sampled 33 plantings located on the exterior of three buildings in the urban center of Brisbane, Australia (subtropical climatic region) over 2, 6 week sampling periods characterized by different temperature and rainfall conditions. Plant cover was estimated as a surrogate for productivity as destructive sampling of biomass was not possible. We measured weekly light levels (photosynthetically active radiation), plant CO2 assimilation, soil CO2 efflux, and arthropod diversity. Differences in plant cover were best explained by a three-way interaction of plant species richness, management water regime and sampling period. As the richness of plant species increased in a planter, productivity and total arthropod richness also increased significantly—likely due to greater habitat heterogeneity and quality. Overall we found urban plantings can provide additional ecological values if essential resources are maintained within a planter such as water, light and soil temperature. Diverse urban plantings that are managed with these principles in mind can contribute to the attraction of diverse arthropod communities, and lead to increased plant productivity within a dense urban context. PMID:25400642

  8. Plant diversity predicts beta but not alpha diversity of soil microbes across grasslands worldwide

    USGS Publications Warehouse

    Prober, Suzanne M.; Leff, Jonathan W.; Bates, Scott T.; Borer, Elizabeth T.; Firn, Jennifer; Harpole, W. Stanley; Lind, Eric M.; Seabloom, Eric W.; Adler, Peter B.; Bakker, Jonathan D.; Cleland, Elsa E.; DeCrappeo, Nicole; DeLorenze, Elizabeth; Hagenah, Nicole; Hautier, Yann; Hofmockel, Kirsten S.; Kirkman, Kevin P.; Knops, Johannes M. H.; La Pierre, Kimberly J.; MacDougall, Andrew S.; McCulley, Rebecca L.; Mitchell, Charles E.; Risch, Anita C.; Schuetz, Martin; Stevens, Carly J.; Williams, Ryan J.; Fierer, Noah

    2015-01-01

    Aboveground–belowground interactions exert critical controls on the composition and function of terrestrial ecosystems, yet the fundamental relationships between plant diversity and soil microbial diversity remain elusive. Theory predicts predominantly positive associations but tests within single sites have shown variable relationships, and associations between plant and microbial diversity across broad spatial scales remain largely unexplored. We compared the diversity of plant, bacterial, archaeal and fungal communities in one hundred and forty-five 1 m2 plots across 25 temperate grassland sites from four continents. Across sites, the plant alpha diversity patterns were poorly related to those observed for any soil microbial group. However, plant beta diversity (compositional dissimilarity between sites) was significantly correlated with the beta diversity of bacterial and fungal communities, even after controlling for environmental factors. Thus, across a global range of temperate grasslands, plant diversity can predict patterns in the composition of soil microbial communities, but not patterns in alpha diversity.

  9. Pasture Condition Score Indicators: Controls on Plant and Forage Diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA-NRCS Pasture Condition Score (PCS) system was developed for evaluating pastures and making management recommendations. Four of the ten rating criteria relate to plant species diversity and composition: percent desirable plants, plant cover, plant diversity, and percent legume. Baseline data...

  10. Patterns of Plant Diversity in Georgia and Texas Salt Marshes

    E-print Network

    Pennings, Steven C.

    Patterns of Plant Diversity in Georgia and Texas Salt Marshes Amy E. Kunza & Steven C. Pennings quantified patterns of plant species diversity on transects across elevation at 59 salt marsh sites. Salt marsh . Species diversity Introduction Ecologists have long been interested in understanding

  11. Species interaction mechanisms maintain grassland plant species diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Theory has outpaced empirical research in pursuit of identifying mechanisms maintaining species diversity. Here we demonstrate how data from diversity-ecosystem functioning experiments can be used to test maintenance of diversity theory. We predict that grassland plant diversity can be maintained by...

  12. Herbivory enhances positive effects of plant genotypic diversity

    E-print Network

    Agrawal, Anurag

    functioning, community genetics, diffuse selection, genetic diversity and herbivory, Oenothera biennis that an often-overlooked compo- nent of biological diversity, intraspecific genetic diversity, can have wide). Genetically diverse plant communities, for example, are more productive (Crutsinger et al. 2006), support more

  13. Environmental correlates of plant diversity in Korean temperate forests

    NASA Astrophysics Data System (ADS)

    ?erný, Tomáš; Doležal, Ji?í; Jane?ek, Št?pán; Šr?tek, Miroslav; Valachovi?, Milan; Pet?ík, Petr; Altman, Jan; Bartoš, Michael; Song, Jong-Suk

    2013-02-01

    Mountainous areas of the Korean Peninsula are among the biodiversity hotspots of the world's temperate forests. Understanding patterns in spatial distribution of their species richness requires explicit consideration of different environmental drivers and their effects on functionally differing components. In this study, we assess the impact of both geographical and soil variables on the fine-scale (400 m2) pattern of plant diversity using field data from six national parks, spanning a 1300 m altitudinal gradient. Species richness and the slopes of species-area curves were calculated separately for the tree, shrub and herb layer and used as response variables in regression tree analyses. A cluster analysis distinguished three dominant forest communities with specific patterns in the diversity-environment relationship. The most widespread middle-altitude oak forests had the highest tree richness but the lowest richness of herbaceous plants due to a dense bamboo understory. Total richness was positively associated with soil reaction and negatively associated with soluble phosphorus and solar radiation (site dryness). Tree richness was associated mainly with soil factors, although trees are frequently assumed to be controlled mainly by factors with large-scale impact. A U-shaped relationship was found between herbaceous plant richness and altitude, caused by a distribution pattern of dwarf bamboo in understory. No correlation between the degree of canopy openness and herb layer richness was detected. Slopes of the species-area curves indicated the various origins of forest communities. Variable diversity-environment responses in different layers and communities reinforce the necessity of context-dependent differentiation for the assessment of impacts of climate and land-use changes in these diverse but intensively exploited regions.

  14. Assessing Nutritional Diversity of Cropping Systems in African Villages

    PubMed Central

    DeClerck, Fabrice; Diru, Willy; Fanzo, Jessica; Gaynor, Kaitlyn; Lambrecht, Isabel; Mudiope, Joseph; Mutuo, Patrick K.; Nkhoma, Phelire; Siriri, David; Sullivan, Clare; Palm, Cheryl A.

    2011-01-01

    Background In Sub-Saharan Africa, 40% of children under five years in age are chronically undernourished. As new investments and attention galvanize action on African agriculture to reduce hunger, there is an urgent need for metrics that monitor agricultural progress beyond calories produced per capita and address nutritional diversity essential for human health. In this study we demonstrate how an ecological tool, functional diversity (FD), has potential to address this need and provide new insights on nutritional diversity of cropping systems in rural Africa. Methods and Findings Data on edible plant species diversity, food security and diet diversity were collected for 170 farms in three rural settings in Sub-Saharan Africa. Nutritional FD metrics were calculated based on farm species composition and species nutritional composition. Iron and vitamin A deficiency were determined from blood samples of 90 adult women. Nutritional FD metrics summarized the diversity of nutrients provided by the farm and showed variability between farms and villages. Regression of nutritional FD against species richness and expected FD enabled identification of key species that add nutrient diversity to the system and assessed the degree of redundancy for nutrient traits. Nutritional FD analysis demonstrated that depending on the original composition of species on farm or village, adding or removing individual species can have radically different outcomes for nutritional diversity. While correlations between nutritional FD, food and nutrition indicators were not significant at household level, associations between these variables were observed at village level. Conclusion This study provides novel metrics to address nutritional diversity in farming systems and examples of how these metrics can help guide agricultural interventions towards adequate nutrient diversity. New hypotheses on the link between agro-diversity, food security and human nutrition are generated and strategies for future research are suggested calling for integration of agriculture, ecology, nutrition, and socio-economics. PMID:21698127

  15. Plant diversity increases soil microbial activity and soil carbon storage.

    PubMed

    Lange, Markus; Eisenhauer, Nico; Sierra, Carlos A; Bessler, Holger; Engels, Christoph; Griffiths, Robert I; Mellado-Vázquez, Perla G; Malik, Ashish A; Roy, Jacques; Scheu, Stefan; Steinbeiss, Sibylle; Thomson, Bruce C; Trumbore, Susan E; Gleixner, Gerd

    2015-01-01

    Plant diversity strongly influences ecosystem functions and services, such as soil carbon storage. However, the mechanisms underlying the positive plant diversity effects on soil carbon storage are poorly understood. We explored this relationship using long-term data from a grassland biodiversity experiment (The Jena Experiment) and radiocarbon ((14)C) modelling. Here we show that higher plant diversity increases rhizosphere carbon inputs into the microbial community resulting in both increased microbial activity and carbon storage. Increases in soil carbon were related to the enhanced accumulation of recently fixed carbon in high-diversity plots, while plant diversity had less pronounced effects on the decomposition rate of existing carbon. The present study shows that elevated carbon storage at high plant diversity is a direct function of the soil microbial community, indicating that the increase in carbon storage is mainly limited by the integration of new carbon into soil and less by the decomposition of existing soil carbon. PMID:25848862

  16. Exotic plant species invade hot spots of native plant diversity

    USGS Publications Warehouse

    Stohlgren, T.J.; Binkley, D.; Chong, G.W.; Kalkhan, M.A.; Schell, L.D.; Bull, K.A.; Otsuki, Y.; Newman, G.; Bashkin, M.; Yowhan, S.

    1999-01-01

    Some theories and experimental studies suggest that areas of low plant species richness may be invaded more easily than areas of high plant species richness. We gathered nested-scale vegetation data on plant species richness, foliar cover, and frequency from 200 1-m2 subplots (20 1000-m2 modified-Whittaker plots) in the Colorado Rockies (USA), and 160 1-m2 subplots (16 1000-m2 plots) in the Central Grasslands in Colorado, Wyoming, South Dakota, and Minnesota (USA) to test the generality of this paradigm. At the 1-m2 scale, the paradigm was supported in four prairie types in the Central Grasslands, where exotic species richness declined with increasing plant species richness and cover. At the 1-m2 scale, five forest and meadow vegetation types in the Colorado Rockies contradicted the paradigm; exotic species richness increased with native-plant species richness and foliar cover. At the 1000-m2 plot scale (among vegetation types), 83% of the variance in exotic species richness in the Central Grasslands was explained by the total percentage of nitrogen in the soil and the cover of native plant species. In the Colorado Rockies, 69% of the variance in exotic species richness in 1000-m2 plots was explained by the number of native plant species and the total percentage of soil carbon. At landscape and biome scales, exotic species primarily invaded areas of high species richness in the four Central Grasslands sites and in the five Colorado Rockies vegetation types. For the nine vegetation types in both biomes, exotic species cover was positively correlated with mean foliar cover, mean soil percentage N, and the total number of exotic species. These patterns of invasibility depend on spatial scale, biome and vegetation type, spatial autocorrelation effects, availability of resources, and species-specific responses to grazing and other disturbances. We conclude that: (1) sites high in herbaceous foliar cover and soil fertility, and hot spots of plant diversity (and biodiversity), are invasible in many landscapes; and (2) this pattern may be more closely related to the degree resources are available in native plant communities, independent of species richness. Exotic plant invasions in rare habitats and distinctive plant communities pose a significant challenge to land managers and conservation biologists.

  17. Microbes on mountainsides: Contrasting elevational patterns of bacterial and plant diversity

    PubMed Central

    Bryant, Jessica A.; Lamanna, Christine; Morlon, Hélène; Kerkhoff, Andrew J.; Enquist, Brian J.; Green, Jessica L.

    2008-01-01

    The study of elevational diversity gradients dates back to the foundation of biogeography. Although elevational patterns of plant and animal diversity have been studied for centuries, such patterns have not been reported for microorganisms and remain poorly understood. Here, in an effort to assess the generality of elevational diversity patterns, we examined soil bacterial and plant diversity along an elevation gradient. To gain insight into the forces that structure these patterns, we adopted a multifaceted approach to incorporate information about the structure, diversity, and spatial turnover of montane communities in a phylogenetic context. We found that observed patterns of plant and bacterial diversity were fundamentally different. While bacterial taxon richness and phylogenetic diversity decreased monotonically from the lowest to highest elevations, plants followed a unimodal pattern, with a peak in richness and phylogenetic diversity at mid-elevations. At all elevations bacterial communities had a tendency to be phylogenetically clustered, containing closely related taxa. In contrast, plant communities did not exhibit a uniform phylogenetic structure across the gradient: they became more overdispersed with increasing elevation, containing distantly related taxa. Finally, a metric of phylogenetic beta-diversity showed that bacterial lineages were not randomly distributed, but rather exhibited significant spatial structure across the gradient, whereas plant lineages did not exhibit a significant phylogenetic signal. Quantifying the influence of sample scale in intertaxonomic comparisons remains a challenge. Nevertheless, our findings suggest that the forces structuring microorganism and macroorganism communities along elevational gradients differ. PMID:18695215

  18. High Plant Diversity in Eocene South America: Evidence from

    E-print Network

    Lyons, S. Kathleen

    an ancient history of high plant diversity in warm areas of South America. There is little evidence but much and relative importance of geologically recent speciation are disputed (8­12). Evidence for or against earlierHigh Plant Diversity in Eocene South America: Evidence from Patagonia Peter Wilf,1,2,3 * N. Rube

  19. Plant species richness drives the density and diversity of Collembola in temperate grassland

    NASA Astrophysics Data System (ADS)

    Sabais, Alexander C. W.; Scheu, Stefan; Eisenhauer, Nico

    2011-05-01

    Declining biodiversity is one of the most important aspects of anthropogenic global change phenomena, but the implications of plant species loss for soil decomposers are little understood. We used the experimental grassland community of the Jena Experiment to assess the response of density and diversity of Collembola to varying plant species richness, plant functional group richness and plant functional group identity. We sampled the experimental plots in spring and autumn four years after establishment of the experimental plant communities. Collembola density and diversity significantly increased with plant species and plant functional group richness highlighting the importance of the singular hypothesis for soil invertebrates. Generally, grasses and legumes beneficially affected Collembola density and diversity, whereas effects of small herbs usually were detrimental. These impacts were largely consistent in spring and autumn. By contrast, in the presence of small herbs the density of hemiedaphic Collembola and the diversity of Isotomidae increased in spring whereas they decreased in autumn. Beneficial impacts of plant diversity as well as those of grasses and legumes were likely due to increased root and microbial biomass, and elevated quantity and quality of plant residues serving as food resources for Collembola. By contrast, beneficial impacts of small herbs in spring probably reflect differences in microclimatic conditions, and detrimental effects in autumn likely were due to low quantity and quality of resources. The results point to an intimate relationship between plants and the diversity of belowground biota, even at small spatial scales, contrasting the findings of previous studies. The pronounced response of soil animals in the present study was presumably due to the fact that plant communities had established over several years. As decomposer invertebrates significantly impact plant performance, changes in soil biota density and diversity are likely to have major feedbacks on plant community productivity and composition.

  20. Plant monocultures produce more antagonistic soil Streptomyces communities than high-diversity plant communities

    E-print Network

    Thomas, David D.

    bacteria, the Streptomyces possess particularly strong antagonistic activities and inhibit diverse plant the potential of soil Streptomyces to antagonize plant pathogens, using an in vitro plate assay with indicatorPlant monocultures produce more antagonistic soil Streptomyces communities than high

  1. Assessment of genetic diversity and relationships among caladium cultivars and species using molecular markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caladium (Caladium hortulanum Birdsey) is an important aroid widely used in the ornamental plant industry. Concerns have been raised about possible loss of genetic diversity due to a drastic decline in the number of cultivars in the last century. This study assessed genetic diversity and relationshi...

  2. Global patterns and determinants of vascular plant diversity

    E-print Network

    Kreft, Holger

    Global patterns and determinants of vascular plant diversity Holger Kreft* and Walter Jetz *Nees data. Here, we investigate the global-scale species-richness pattern of vascular plants and examine its, such as vascular plants, will long remain elusive. Thus, the method of choice is analyzing the species

  3. Positive interactions between herbivores and plant diversity shape forest regeneration

    PubMed Central

    Cook-Patton, Susan C.; LaForgia, Marina; Parker, John D.

    2014-01-01

    The effects of herbivores and diversity on plant communities have been studied separately but rarely in combination. We conducted two concurrent experiments over 3 years to examine how tree seedling diversity, density and herbivory affected forest regeneration. One experiment factorially manipulated plant diversity (one versus 15 species) and the presence/absence of deer (Odocoileus virginianus). We found that mixtures outperformed monocultures only in the presence of deer. Selective browsing on competitive dominants and associational protection from less palatable species appear responsible for this herbivore-driven diversity effect. The other experiment manipulated monospecific plant density and found little evidence for negative density dependence. Combined, these experiments suggest that the higher performance in mixture was owing to the acquisition of positive interspecific interactions rather than the loss of negative intraspecific interactions. Overall, we emphasize that realistic predictions about the consequences of changing biodiversity will require a deeper understanding of the interaction between plant diversity and higher trophic levels. If we had manipulated only plant diversity, we would have missed an important positive interaction across trophic levels: diverse seedling communities better resist herbivores, and herbivores help to maintain seedling diversity. PMID:24718763

  4. Endophytic actinobacteria of medicinal plants: diversity and bioactivity.

    PubMed

    Golinska, Patrycja; Wypij, Magdalena; Agarkar, Gauravi; Rathod, Dnyaneshwar; Dahm, Hanna; Rai, Mahendra

    2015-08-01

    Endophytes are the microorganisms that exist inside the plant tissues without having any negative impact on the host plant. Medicinal plants constitute the huge diversity of endophytic actinobacteria of economical importance. These microbes have huge potential to synthesis of numerous novel compounds that can be exploited in pharmaceutical, agricultural and other industries. It is of prime importance to focus the present research on practical utilization of this microbial group in order to find out the solutions to the problems related to health, environment and agriculture. An extensive characterization of diverse population of endophytic actinobacteria associated with medicinal plants can provide a greater insight into the plant-endophyte interactions and evolution of mutualism. In the present review, we have discussed the diversity of endophytic actinobacteria of from medicinal plants their multiple bioactivities. PMID:26093915

  5. Power Plant Water Intake Assessment.

    ERIC Educational Resources Information Center

    Zeitoun, Ibrahim H.; And Others

    1980-01-01

    In order to adequately assess the impact of power plant cooling water intake on an aquatic ecosystem, total ecosystem effects must be considered, rather than merely numbers of impinged or entrained organisms. (Author/RE)

  6. Soil microbes drive the classic plant diversity­ productivity pattern

    E-print Network

    Schnitzer, Stefan A.; Klironomos, John N.; HilleRisLambers, Jannek; Kinkel, Linda L.; Reich, Peter B.; Xiao, Kun; Rillig, Matthias C.; Sikes, Benjamin A.; Callaway, Ragan M.; Mangan, Scott A.; van Nes, Egbert H.; Scheffer, Marten

    2011-02-01

    Ecosystem productivity commonly increases asymptotically with plant species diversity, and determining the mechanisms responsible for this well-known pattern is essential to predict potential changes in ecosystem productivity ...

  7. In the footsteps of Vavilov: plant diversity then and now

    Technology Transfer Automated Retrieval System (TEKTRAN)

    N. I. Vavilov’s theories direct present day global activities in plant science, breeding, and conservation. His expeditions around the world located centers of diversity of crop evolution. Vavilov was one of the earliest scientists to realize that wild genetic diversity could be lost, through geneti...

  8. Plant Diversity Impacts Decomposition and Herbivory via Changes in Aboveground Arthropods

    PubMed Central

    Ebeling, Anne; Meyer, Sebastian T.; Abbas, Maike; Eisenhauer, Nico; Hillebrand, Helmut; Lange, Markus; Scherber, Christoph; Vogel, Anja; Weigelt, Alexandra; Weisser, Wolfgang W.

    2014-01-01

    Loss of plant diversity influences essential ecosystem processes as aboveground productivity, and can have cascading effects on the arthropod communities in adjacent trophic levels. However, few studies have examined how those changes in arthropod communities can have additional impacts on ecosystem processes caused by them (e.g. pollination, bioturbation, predation, decomposition, herbivory). Therefore, including arthropod effects in predictions of the impact of plant diversity loss on such ecosystem processes is an important but little studied piece of information. In a grassland biodiversity experiment, we addressed this gap by assessing aboveground decomposer and herbivore communities and linking their abundance and diversity to rates of decomposition and herbivory. Path analyses showed that increasing plant diversity led to higher abundance and diversity of decomposing arthropods through higher plant biomass. Higher species richness of decomposers, in turn, enhanced decomposition. Similarly, species-rich plant communities hosted a higher abundance and diversity of herbivores through elevated plant biomass and C:N ratio, leading to higher herbivory rates. Integrating trophic interactions into the study of biodiversity effects is required to understand the multiple pathways by which biodiversity affects ecosystem functioning. PMID:25226237

  9. Plant diversity impacts decomposition and herbivory via changes in aboveground arthropods.

    PubMed

    Ebeling, Anne; Meyer, Sebastian T; Abbas, Maike; Eisenhauer, Nico; Hillebrand, Helmut; Lange, Markus; Scherber, Christoph; Vogel, Anja; Weigelt, Alexandra; Weisser, Wolfgang W

    2014-01-01

    Loss of plant diversity influences essential ecosystem processes as aboveground productivity, and can have cascading effects on the arthropod communities in adjacent trophic levels. However, few studies have examined how those changes in arthropod communities can have additional impacts on ecosystem processes caused by them (e.g. pollination, bioturbation, predation, decomposition, herbivory). Therefore, including arthropod effects in predictions of the impact of plant diversity loss on such ecosystem processes is an important but little studied piece of information. In a grassland biodiversity experiment, we addressed this gap by assessing aboveground decomposer and herbivore communities and linking their abundance and diversity to rates of decomposition and herbivory. Path analyses showed that increasing plant diversity led to higher abundance and diversity of decomposing arthropods through higher plant biomass. Higher species richness of decomposers, in turn, enhanced decomposition. Similarly, species-rich plant communities hosted a higher abundance and diversity of herbivores through elevated plant biomass and C:N ratio, leading to higher herbivory rates. Integrating trophic interactions into the study of biodiversity effects is required to understand the multiple pathways by which biodiversity affects ecosystem functioning. PMID:25226237

  10. Plant genotypic diversity reduces the rate of consumer resource utilization

    PubMed Central

    McArt, Scott H.; Thaler, Jennifer S.

    2013-01-01

    While plant species diversity can reduce herbivore densities and herbivory, little is known regarding how plant genotypic diversity alters resource utilization by herbivores. Here, we show that an invasive folivore—the Japanese beetle (Popillia japonica)—increases 28 per cent in abundance, but consumes 24 per cent less foliage in genotypic polycultures compared with monocultures of the common evening primrose (Oenothera biennis). We found strong complementarity for reduced herbivore damage among plant genotypes growing in polycultures and a weak dominance effect of particularly resistant genotypes. Sequential feeding by P. japonica on different genotypes from polycultures resulted in reduced consumption compared with feeding on different plants of the same genotype from monocultures. Thus, diet mixing among plant genotypes reduced herbivore consumption efficiency. Despite positive complementarity driving an increase in fruit production in polycultures, we observed a trade-off between complementarity for increased plant productivity and resistance to herbivory, suggesting costs in the complementary use of resources by plant genotypes may manifest across trophic levels. These results elucidate mechanisms for how plant genotypic diversity simultaneously alters resource utilization by both producers and consumers, and show that population genotypic diversity can increase the resistance of a native plant to an invasive herbivore. PMID:23658201

  11. Coevolution can explain defensive secondary metabolite diversity in plants.

    PubMed

    Speed, Michael P; Fenton, Andy; Jones, Meriel G; Ruxton, Graeme D; Brockhurst, Michael A

    2015-12-01

    Many plant species produce defensive compounds that are often highly diverse within and between populations. The genetic and cellular mechanisms by which metabolite diversity is produced are increasingly understood, but the evolutionary explanations for persistent diversification in plant secondary metabolites have received less attention. Here we consider the role of plant-herbivore coevolution in the maintenance and characteristics of diversity in plant secondary metabolites. We present a simple model in which plants can evolve to invest in a range of defensive toxins, and herbivores can evolve resistance to these toxins. We allow either single-species evolution or reciprocal coevolution. Our model shows that coevolution maintains toxin diversity within populations. Furthermore, there is a fundamental coevolutionary asymmetry between plants and their herbivores, because herbivores must resist all plant toxins, whereas plants need to challenge and nullify only one resistance trait. As a consequence, average plant fitness increases and insect fitness decreases as number of toxins increases. When costs apply, the model showed both arms race escalation and strong coevolutionary fluctuation in toxin concentrations across time. We discuss the results in the context of other evolutionary explanations for secondary metabolite diversification. PMID:26243527

  12. T Plant hazards assessment

    SciTech Connect

    Broz, R.E.

    1994-09-27

    This document establishes the technical basis in support of Emergency Planning activities for the T Plant on the Hanford Site. The document represents an acceptable interpretation of the implementing guidance document for DOE ORDER 5500.3A. Through this document, the technical basis for the development of facility specific Emergency Action Levels and the Emergency Planning Zone is demonstrated.

  13. B Plant hazards assessment

    SciTech Connect

    Broz, R.E.

    1994-09-23

    This document establishes the technical basis in support of Emergency Planning Activities for B Plant on the Hanford Site. The document represents an acceptable interpretation of the implementing guidance document for DOE Order 5500.3A. Through this document, the technical basis for the development of facility specific , Emergency Action Levels and the Emergency Planning Zone is demonstrated.

  14. Nutritive value in relation to plant species diversity of pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Planting forage mixtures may benefit pasture herbage production; however, changes in botanical composition could cause unstable nutritive value. Data from two grazing studies and a farm survey were used to examine how plant species diversity influenced herbage nutritive value. In one grazing study,...

  15. IS PLANT SPECIES DIVERSITY WORTH MANAGING IN GRAZING LANDS?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this symposium is to present the latest concepts in plant biodiversity in grazing land ecosystems and discuss their potential application to management of forage and grazing lands. The symposium begins with an overview of plant diversity in grassland ecosystems, then addresses topics ...

  16. Stability of production and plant species diversity in managed grasslands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant biodiversity theory suggests that increased plant species diversity contributes to the stability of ecosystems. In managed grasslands, such as pastures, greater stability of herbage production would be beneficial. In this retrospective study, I used data from three reports from the 1930s, 1940...

  17. Combined use of a new SNP-based assay and multilocus SSR markers to assess genetic diversity of Xylella fastidiosa subsp. pauca infecting citrus and coffee plants.

    PubMed

    Montes-Borrego, Miguel; Lopes, Joao R S; Jiménez-Díaz, Rafael M; Landa, Blanca B

    2015-03-01

    Two haplotypes of Xylella fastidiosa subsp. pauca (Xfp) that correlated with their host of origin were identified in a collection of 90 isolates infecting citrus and coffee plants in Brazil, based on a single-nucleotide polymorphism in the gyrB sequence. A new single-nucleotide primer extension (SNuPE) protocol was designed for rapid identification of Xfp according to the host source. The protocol proved to be robust for the prediction of the Xfp host source in blind tests using DNA from cultures of the bacterium, infected plants, and insect vectors allowed to feed on Xfp-infected citrus plants. AMOVA and STRUCTURE analyses of microsatellite data separated most Xfp populations on the basis of their host source, indicating that they were genetically distinct. The combined use of the SNaPshot protocol and three previously developed multilocus SSR markers showed that two haplotypes and distinct isolates of Xfp infect citrus and coffee in Brazil and that multiple, genetically different isolates can be present in a single orchard or infect a single tree. This combined approach will be very useful in studies of the epidemiology of Xfp-induced diseases, host specificity of bacterial genotypes, the occurrence of Xfp host jumping, vector feeding habits, etc., in economically important cultivated plants or weed host reservoirs of Xfp in Brazil and elsewhere. PMID:26415663

  18. Phytochrome diversity in green plants and the origin of canonical plant phytochromes.

    PubMed

    Li, Fay-Wei; Melkonian, Michael; Rothfels, Carl J; Villarreal, Juan Carlos; Stevenson, Dennis W; Graham, Sean W; Wong, Gane Ka-Shu; Pryer, Kathleen M; Mathews, Sarah

    2015-01-01

    Phytochromes are red/far-red photoreceptors that play essential roles in diverse plant morphogenetic and physiological responses to light. Despite their functional significance, phytochrome diversity and evolution across photosynthetic eukaryotes remain poorly understood. Using newly available transcriptomic and genomic data we show that canonical plant phytochromes originated in a common ancestor of streptophytes (charophyte algae and land plants). Phytochromes in charophyte algae are structurally diverse, including canonical and non-canonical forms, whereas in land plants, phytochrome structure is highly conserved. Liverworts, hornworts and Selaginella apparently possess a single phytochrome, whereas independent gene duplications occurred within mosses, lycopods, ferns and seed plants, leading to diverse phytochrome families in these clades. Surprisingly, the phytochrome portions of algal and land plant neochromes, a chimera of phytochrome and phototropin, appear to share a common origin. Our results reveal novel phytochrome clades and establish the basis for understanding phytochrome functional evolution in land plants and their algal relatives. PMID:26215968

  19. Phytochrome diversity in green plants and the origin of canonical plant phytochromes

    PubMed Central

    Li, Fay-Wei; Melkonian, Michael; Rothfels, Carl J.; Villarreal, Juan Carlos; Stevenson, Dennis W.; Graham, Sean W.; Wong, Gane Ka-Shu; Pryer, Kathleen M.; Mathews, Sarah

    2015-01-01

    Phytochromes are red/far-red photoreceptors that play essential roles in diverse plant morphogenetic and physiological responses to light. Despite their functional significance, phytochrome diversity and evolution across photosynthetic eukaryotes remain poorly understood. Using newly available transcriptomic and genomic data we show that canonical plant phytochromes originated in a common ancestor of streptophytes (charophyte algae and land plants). Phytochromes in charophyte algae are structurally diverse, including canonical and non-canonical forms, whereas in land plants, phytochrome structure is highly conserved. Liverworts, hornworts and Selaginella apparently possess a single phytochrome, whereas independent gene duplications occurred within mosses, lycopods, ferns and seed plants, leading to diverse phytochrome families in these clades. Surprisingly, the phytochrome portions of algal and land plant neochromes, a chimera of phytochrome and phototropin, appear to share a common origin. Our results reveal novel phytochrome clades and establish the basis for understanding phytochrome functional evolution in land plants and their algal relatives. PMID:26215968

  20. Assessing Dispositions toward Cultural Diversity among Preservice Teachers.

    ERIC Educational Resources Information Center

    Dee, Jay R.; Henkin, Alan B.

    2002-01-01

    Assessed preservice teachers' attitudes toward cultural diversity prior to entering into multicultural education courses at an urban university. Respondents indicated strong support for implementing diversity issues in the classroom and high levels of agreement with equity beliefs and the social value of diversity. They did not agree that…

  1. Diversity begets diversity: host expansions and the diversification of plant-feeding insects

    PubMed Central

    Janz, Niklas; Nylin, Sören; Wahlberg, Niklas

    2006-01-01

    Background Plant-feeding insects make up a large part of earth's total biodiversity. While it has been shown that herbivory has repeatedly led to increased diversification rates in insects, there has been no compelling explanation for how plant-feeding has promoted speciation rates. There is a growing awareness that ecological factors can lead to rapid diversification and, as one of the most prominent features of most insect-plant interactions, specialization onto a diverse resource has often been assumed to be the main process behind this diversification. However, specialization is mainly a pruning process, and is not able to actually generate diversity by itself. Here we investigate the role of host colonizations in generating insect diversity, by testing if insect speciation rate is correlated with resource diversity. Results By applying a variant of independent contrast analysis, specially tailored for use on questions of species richness (MacroCAIC), we show that species richness is strongly correlated with diversity of host use in the butterfly family Nymphalidae. Furthermore, by comparing the results from reciprocal sister group selection, where sister groups were selected either on the basis of diversity of host use or species richness, we find that it is likely that diversity of host use is driving species richness, rather than vice versa. Conclusion We conclude that resource diversity is correlated with species richness in the Nymphalidae and suggest a scenario based on recurring oscillations between host expansions – the incorporation of new plants into the repertoire – and specialization, as an important driving force behind the diversification of plant-feeding insects. PMID:16420707

  2. Diversity Strategies for Nuclear Power Plant Instrumentation and Control Systems

    SciTech Connect

    Wood, Richard Thomas; Belles, Randy; Cetiner, Mustafa Sacit; Holcomb, David Eugene; Korsah, Kofi; Loebl, Andy; Mays, Gary T; Muhlheim, Michael David; Mullens, James Allen; Poore III, Willis P; Qualls, A L; Wilson, Thomas L; Waterman, Michael E.

    2010-02-01

    This report presents the technical basis for establishing acceptable mitigating strategies that resolve diversity and defense-in-depth (D3) assessment findings and conform to U.S. Nuclear Regulatory Commission (NRC) requirements. The research approach employed to establish appropriate diversity strategies involves investigation of available documentation on D3 methods and experience from nuclear power and nonnuclear industries, capture of expert knowledge and lessons learned, determination of best practices, and assessment of the nature of common-cause failures (CCFs) and compensating diversity attributes. The research described in this report does not provide guidance on how to determine the need for diversity in a safety system to mitigate the consequences of potential CCFs. Rather, the scope of this report provides guidance to the staff and nuclear industry after a licensee or applicant has performed a D3 assessment per NUREG/CR-6303 and determined that diversity in a safety system is needed for mitigating the consequences of potential CCFs identified in the evaluation of the safety system design features. Succinctly, the purpose of the research described in this report was to answer the question, 'If diversity is required in a safety system to mitigate the consequences of potential CCFs, how much diversity is enough?' The principal results of this research effort have identified and developed diversity strategies, which consist of combinations of diversity attributes and their associated criteria. Technology, which corresponds to design diversity, is chosen as the principal system characteristic by which diversity criteria are grouped to form strategies. The rationale for this classification framework involves consideration of the profound impact that technology-focused design diversity provides. Consequently, the diversity usage classification scheme involves three families of strategies: (1) different technologies, (2) different approaches within the same technology, and (3) different architectures within the same technology. Using this convention, the first diversity usage family, designated Strategy A, is characterized by fundamentally diverse technologies. Strategy A at the system or platform level is illustrated by the example of analog and digital implementations. The second diversity usage family, designated Strategy B, is achieved through the use of distinctly different technologies. Strategy B can be described in terms of different digital technologies, such as the distinct approaches represented by general-purpose microprocessors and field-programmable gate arrays. The third diversity usage family, designated Strategy C, involves the use of variations within a technology. An example of Strategy C involves different digital architectures within the same technology, such as that provided by different microprocessors (e.g., Pentium and Power PC). The grouping of diversity criteria combinations according to Strategies A, B, and C establishes baseline diversity usage and facilitates a systematic organization of strategic approaches for coping with CCF vulnerabilities. Effectively, these baseline sets of diversity criteria constitute appropriate CCF mitigating strategies for digital safety systems. The strategies represent guidance on acceptable diversity usage and can be applied directly to ensure that CCF vulnerabilities identified through a D3 assessment have been adequately resolved. Additionally, a framework has been generated for capturing practices regarding diversity usage and a tool has been developed for the systematic assessment of the comparative effect of proposed diversity strategies (see Appendix A).

  3. Modeling Forest Structure and Vascular Plant Diversity in Piedmont Forests

    NASA Astrophysics Data System (ADS)

    Hakkenberg, C.

    2014-12-01

    When the interacting stressors of climate change and land cover/land use change (LCLUC) overwhelm ecosystem resilience to environmental and climatic variability, forest ecosystems are at increased risk of regime shifts and hyperdynamism in process rates. To meet the growing range of novel biotic and environmental stressors on human-impacted ecosystems, the maintenance of taxonomic diversity and functional redundancy in metacommunities has been proposed as a risk spreading measure ensuring that species critical to landscape ecosystem functioning are available for recruitment as local systems respond to novel conditions. This research is the first in a multi-part study to establish a dynamic, predictive model of the spatio-temporal dynamics of vascular plant diversity in North Carolina Piedmont mixed forests using remotely sensed data inputs. While remote sensing technologies are optimally suited to monitor LCLUC over large areas, direct approaches to the remote measurement of plant diversity remain a challenge. This study tests the efficacy of predicting indices of vascular plant diversity using remotely derived measures of forest structural heterogeneity from aerial LiDAR and high spatial resolution broadband optical imagery in addition to derived topo-environmental variables. Diversity distribution modelling of this sort is predicated upon the idea that environmental filtering of dispersing species help define fine-scale (permeable) environmental envelopes within which biotic structural and compositional factors drive competitive interactions that, in addition to background stochasticity, determine fine-scale alpha diversity. Results reveal that over a range of Piedmont forest communities, increasing structural complexity is positively correlated with measures of plant diversity, though the nature of this relationship varies by environmental conditions and community type. The diversity distribution model is parameterized and cross-validated using three high quality vegetation survey datasets, including Duke Forest Korstian permanent plots, Forest Inventory Analysis (FIA), and the scale transgressive, nested module Carolina Vegetation Survey (CVS).

  4. Assessment of molecular diversity and population structure of the Ethiopian sorghum [Sorghum bicolor L. (Moench)] germplasm collection maintained by the USDA-ARS National Plant Germplasm System using SSR markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic diversity and population structure present in the Ethiopian sorghum collection maintained at the USDA-ARS National Plant Germplasm System (NPGS) has not been studied. In addition, 83% of the accessions in the Ethiopian collection lack passport information which has constrained their eval...

  5. Herbivores and nutrients control grassland plant diversity via light limitation

    USGS Publications Warehouse

    Borer, Elizabeth T.; Seabloom, Eric W.; Gruner, Daniel S.; Harpole, W. Stanley; Hillebrand, Helmut; Lind, Eric M.; Alder, Peter B.; Alberti, Juan; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori; Blumenthal, Dana; Brown, Cynthia S.; Brudvig, Lars A.; Buckley, Yvonne M.; Cadotte, Marc; Chu, Cheng-Jin; Cleland, Elsa E.; Crawley, Michael J.; Daleo, Pedro; Damschen, Ellen Ingman; Davies, Kendi F.; DeCrappeo, Nicole M.; Du, Guozhen; Firn, Jennifer; Hautier, Yann; Heckman, Robert W.; Hector, Andy; HilleRisLambers, Janneke; Iribarne, Oscar; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Leakey, Andrew D.B.; Li, Wei; MacDougall, Andrew S.; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Mortensen, Brent; O'Halloran, Lydia R.; Orrock, John L.; Pascual, Jesús; Prober, Suzanne M.; Pyke, David A.; Risch, Anita C.; Schuetz, Martin; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren L.; Williams, Ryan J.; Wragg, Peter D.; Wright, Justin P.; Yang, Louie H.

    2014-01-01

    Human alterations to nutrient cycles and herbivore communities are affecting global biodiversity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.

  6. Plant Diversity Surpasses Plant Functional Groups and Plant Productivity as Driver of Soil Biota in the Long Term

    PubMed Central

    Eisenhauer, Nico; Milcu, Alexandru; Sabais, Alexander C. W.; Bessler, Holger; Brenner, Johanna; Engels, Christof; Klarner, Bernhard; Maraun, Mark; Partsch, Stephan; Roscher, Christiane; Schonert, Felix; Temperton, Vicky M.; Thomisch, Karolin; Weigelt, Alexandra; Weisser, Wolfgang W.; Scheu, Stefan

    2011-01-01

    Background One of the most significant consequences of contemporary global change is the rapid decline of biodiversity in many ecosystems. Knowledge of the consequences of biodiversity loss in terrestrial ecosystems is largely restricted to single ecosystem functions. Impacts of key plant functional groups on soil biota are considered to be more important than those of plant diversity; however, current knowledge mainly relies on short-term experiments. Methodology/Principal Findings We studied changes in the impacts of plant diversity and presence of key functional groups on soil biota by investigating the performance of soil microorganisms and soil fauna two, four and six years after the establishment of model grasslands. The results indicate that temporal changes of plant community effects depend on the trophic affiliation of soil animals: plant diversity effects on decomposers only occurred after six years, changed little in herbivores, but occurred in predators after two years. The results suggest that plant diversity, in terms of species and functional group richness, is the most important plant community property affecting soil biota, exceeding the relevance of plant above- and belowground productivity and the presence of key plant functional groups, i.e. grasses and legumes, with the relevance of the latter decreasing in time. Conclusions/Significance Plant diversity effects on biota are not only due to the presence of key plant functional groups or plant productivity highlighting the importance of diverse and high-quality plant derived resources, and supporting the validity of the singular hypothesis for soil biota. Our results demonstrate that in the long term plant diversity essentially drives the performance of soil biota questioning the paradigm that belowground communities are not affected by plant diversity and reinforcing the importance of biodiversity for ecosystem functioning. PMID:21249208

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

    NASA Astrophysics Data System (ADS)

    Picard, Christine; Bosco, Marco

    2008-01-01

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

  8. Nematicide impacts on nematodes and feedbacks on plant productivity in a plant diversity gradient

    NASA Astrophysics Data System (ADS)

    Eisenhauer, Nico; Ackermann, Michael; Gass, Svenja; Klier, Matthias; Migunova, Varvara; Nitschke, Norma; Ruess, Liliane; Sabais, Alexander C. W.; Weisser, Wolfgang W.; Scheu, Stefan

    2010-09-01

    A major issue in current ecological research is the effect of biodiversity on ecosystem functioning. Although several studies reported a positive diversity - productivity relationship, the role of soil animals has been largely neglected. Nematodes are among the most widespread and important herbivores causing substantial yield losses in agriculture; however, impacts of nematodes on the diversity - productivity relationship in semi-natural plant communities have not been investigated until today. In the framework of the Jena Experiment (Thuringia, Germany) we established control and nematicide treated subplots to manipulate nematode densities on plots varying in plant species (1-16) and functional group richness (1-4). We explored the interacting effects of nematicide application and plant diversity on the main trophic groups of nematodes and on aboveground plant productivity. Nematicide application reduced the number of nematodes significantly, particularly that of plant feeders and predators. The negative impact of nematicide application on plant and bacterial feeders depended however on the diversity of the plant community. Total plant shoot biomass tended to decrease in the presence of ambient nematode densities. In detail, nematode effects varied however with plant functional group identity by reducing only the shoot biomass of herbs significantly but not that of legumes. Furthermore, the shoot biomass of grasses tended to decrease in the presence of ambient nematode densities. In contrast to total shoot biomass, nematodes decreased grass shoot biomass only in high diverse but not in low diverse plant communities. Thus, the present study for the first time highlights that nematodes likely modify the community structure und functions of semi-natural plant communities by altering the competition between plant functional groups and by attenuating the diversity - productivity relationship.

  9. THE EFFECTIVENESS OF QUADRATS FOR MEASURING VASCULAR PLANT DIVERSITY

    EPA Science Inventory

    Quadrats are widely used for measuring characteristics of vascular plant communities. It is well recognized that quadrat size affects measurements of frequency and cover. The ability of quadrats of varying sizes to adequately measure diversity has not been established. An exha...

  10. PLANT SPECIES DIVERSITY, ECOSYSTEM FUNCTION, AND PASTURE MANAGEMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grassland farmers face new challenges in pasture management including improving sustainability, reducing inputs of fertilizers and pesticides, and protecting soil resources. Managing plant diversity within and among pastures may be one tool to aid producers in meeting these new challenges. Pasture e...

  11. Plant Ecology & Diversity Vol. 1, No. 2, November 2008, 197207

    E-print Network

    DeChaine, Eric

    ://www.informaworld.com TPED A bridge or a barrier? Beringia's influence on the distribution and diversity of tundra plants strongly suggests that Beringia was a refugium for tundra taxa throughout the Quaternary (the last 2 environmental history of Beringia played in the diversification of tundra flora. Methods: I adopted

  12. STEM Diversity Postdoctoral Research Associate Department of Plant Biology

    E-print Network

    Kent, Angela

    .inclusiveillinois.illinois.edu). The University of Illinois conducts criminal background checks on all job candidates upon acceptanceSTEM Diversity Postdoctoral Research Associate Department of Plant Biology University of Illinois mentor will be assigned. Minimum Qualifications: Ph.D. or equivalent terminal degree is required

  13. ORIGINAL ARTICLE Accuracy of protist diversity assessments

    E-print Network

    Dolan, John

    . The 18S ribosomal DNA (rDNA) pyrosequencing has revealed a vast diversity of infrequent sequences classical cloning and sequencing and pyrosequencing of twoQ1 different markers, the 18S rDNA pyrosequencing, which produces thousands of 18S ribosomal DNA (rDNA) amplicon sequence reads from a single sample

  14. Fostering Respect Creating Community DIVERSITY ASSESSMENT

    E-print Network

    Pittendrigh, Barry

    ­06 Strategic Plan and its goal of "enhancing human and intellectual diversity to build a student body, fac's 2001­06 Strategic Plan laid the foundation for effective, cooper- ative, and efficient exchange of infor- mation and alignment of resources. The plan encouraged an array of collaborative efforts

  15. Using Plant Functional Traits to Explain Diversity–Productivity Relationships

    PubMed Central

    Roscher, Christiane; Schumacher, Jens; Gubsch, Marlén; Lipowsky, Annett; Weigelt, Alexandra; Buchmann, Nina; Schmid, Bernhard; Schulze, Ernst-Detlef

    2012-01-01

    Background The different hypotheses proposed to explain positive species richness–productivity relationships, i.e. selection effect and complementarity effect, imply that plant functional characteristics are at the core of a mechanistic understanding of biodiversity effects. Methodology/Principal Findings We used two community-wide measures of plant functional composition, (1) community-weighted means of trait values (CWM) and (2) functional trait diversity based on Rao’s quadratic diversity (FDQ) to predict biomass production and measures of biodiversity effects in experimental grasslands (Jena Experiment) with different species richness (2, 4, 8, 16 and 60) and different functional group number and composition (1 to 4; legumes, grasses, small herbs, tall herbs) four years after establishment. Functional trait composition had a larger predictive power for community biomass and measures of biodiversitity effects (40–82% of explained variation) than species richness per se (<1–13% of explained variation). CWM explained a larger amount of variation in community biomass (80%) and net biodiversity effects (70%) than FDQ (36 and 38% of explained variation respectively). FDQ explained similar proportions of variation in complementarity effects (24%, positive relationship) and selection effects (28%, negative relationship) as CWM (27% of explained variation for both complementarity and selection effects), but for all response variables the combination of CWM and FDQ led to significant model improvement compared to a separate consideration of different components of functional trait composition. Effects of FDQ were mainly attributable to diversity in nutrient acquisition and life-history strategies. The large spectrum of traits contributing to positive effects of CWM on biomass production and net biodiversity effects indicated that effects of dominant species were associated with different trait combinations. Conclusions/Significance Our results suggest that the identification of relevant traits and the relative impacts of functional identity of dominant species and functional diversity are essential for a mechanistic understanding of the role of plant diversity for ecosystem processes such as aboveground biomass production. PMID:22623961

  16. The microbiome of medicinal plants: diversity and importance for plant growth, quality and health

    PubMed Central

    Köberl, Martina; Schmidt, Ruth; Ramadan, Elshahat M.; Bauer, Rudolf; Berg, Gabriele

    2013-01-01

    Past medicinal plant research primarily focused on bioactive phytochemicals, however, the focus is currently shifting due to the recognition that a significant number of phytotherapeutic compounds are actually produced by associated microbes or through interaction with their host. Medicinal plants provide an enormous bioresource of potential use in modern medicine and agriculture, yet their microbiome is largely unknown. The objective of this review is (i) to introduce novel insights into the plant microbiome with a focus on medicinal plants, (ii) to provide details about plant- and microbe-derived ingredients of medicinal plants, and (iii) to discuss possibilities for plant growth promotion and plant protection for commercial cultivation of medicinal plants. In addition, we also present a case study performed both to analyse the microbiome of three medicinal plants (Matricaria chamomilla L., Calendula officinalis L., and Solanum distichum Schumach. and Thonn.) cultivated on organically managed Egyptian desert farm and to develop biological control strategies. The soil microbiome of the desert ecosystem was comprised of a high abundance of Gram-positive bacteria of prime importance for pathogen suppression under arid soil conditions. For all three plants, we observed a clearly plant-specific selection of the microbes as well as highly specific diazotrophic communities that overall identify plant species as important drivers in structural and functional diversity. Lastly, native Bacillus spec. div. strains were able to promote plant growth and elevate the plants’ flavonoid production. These results underline the numerous links between the plant-associated microbiome and the plant metabolome. PMID:24391634

  17. 36 CFR 219.9 - Diversity of plant and animal communities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Diversity of plant and animal... PLANNING National Forest System Land Management Planning § 219.9 Diversity of plant and animal communities... diversity of plant and animal communities and the persistence of native species in the plan area....

  18. 36 CFR 219.9 - Diversity of plant and animal communities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Diversity of plant and animal... PLANNING National Forest System Land Management Planning § 219.9 Diversity of plant and animal communities... diversity of plant and animal communities and the persistence of native species in the plan area....

  19. Herbivores and nutrients control grassland plant diversity via light limitation.

    SciTech Connect

    Borer, Elizabeth T.; et al, et al

    2014-01-01

    Human alterations to nutrient cycles1,2 and herbivore communities3–7 are affecting global biodiversity dramatically2. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems8,9. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.

  20. Endophytic Fungal Communities Associated with Vascular Plants in the High Arctic Zone Are Highly Diverse and Host-Plant Specific

    PubMed Central

    Zhang, Tao; Yao, Yi-Feng

    2015-01-01

    This study assessed the diversity and distribution of endophytic fungal communities associated with the leaves and stems of four vascular plant species in the High Arctic using 454 pyrosequencing with fungal-specific primers targeting the ITS region. Endophytic fungal communities showed high diversity. The 76,691 sequences obtained belonged to 250 operational taxonomic units (OTUs). Of these OTUs, 190 belonged to Ascomycota, 50 to Basidiomycota, 1 to Chytridiomycota, and 9 to unknown fungi. The dominant orders were Helotiales, Pleosporales, Capnodiales, and Tremellales, whereas the common known fungal genera were Cryptococcus, Rhizosphaera, Mycopappus, Melampsora, Tetracladium, Phaeosphaeria, Mrakia, Venturia, and Leptosphaeria. Both the climate and host-related factors might shape the fungal communities associated with the four Arctic plant species in this region. These results suggested the presence of an interesting endophytic fungal community and could improve our understanding of fungal evolution and ecology in the Arctic terrestrial ecosystems. PMID:26067836

  1. Nova Acta Leopoldina NF 92, Nr. 342, 6183 (2005) Global Centers of Vascular Plant Diversity

    E-print Network

    Kreft, Holger

    2005-01-01

    Nova Acta Leopoldina NF 92, Nr. 342, 61­83 (2005) Global Centers of Vascular Plant Diversity) With 2 Figures and 1 Table Abstract The diversity of vascular plants is very unevenly distributed across.2 % of all vascular plant species. A world map of vascular plant richness is presented based

  2. Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-12-01

    Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional diversity and its consequences for ecosystem functioning are assessed here using a 6-year rainfall manipulation experiment. Five precipitation treatments were switched annually resulting in increased levels of precipitation variability while maintaining average precipitation constant. Functional diversity showed a positive response to increased variability due to increased evenness. Dominant grasses decreased and rare plant functional types increased in abundance because grasses showed a hump-shaped response to precipitation with a maximum around modal precipitation, whereas rare species peaked at high precipitation values. Increased functional diversity ameliorated negative effects of precipitation variability on primary production. Rare species buffered the effect of precipitation variability on the variability in total productivity because their variance decreases with increasing precipitation variance. PMID:26437913

  3. Alpha and beta diversity of plants and animals along a tropical land-use gradient.

    PubMed

    Kessler, Michael; Abrahamczyk, Stefan; Bos, Merijn; Buchori, Damayanti; Putra, Dadang Dwi; Gradstein, S Robbert; Höhn, Patrick; Kluge, Jürgen; Orend, Friederike; Pitopang, Ramadhaniel; Saleh, Shahabuddin; Schulze, Christian H; Sporn, Simone G; Steffan-Dewenter, Ingolf; Tjitrosoedirdjo, Sri S; Tscharntke, Teja

    2009-12-01

    Assessing the overall biological diversity of tropical rain forests is a seemingly insurmountable task for ecologists. Therefore, researchers frequently sample selected taxa that they believe reflect general biodiversity patterns. Usually, these studies focus on the congruence of alpha diversity (the number of species found per sampling unit) between taxa rather than on beta diversity (turnover of species assemblages between sampling units). Such approaches ignore the potential role of habitat heterogeneity that, depending on the taxonomic group considered, can greatly enhance beta diversity at local and landscape scales. We compared alpha and beta diversity of four plant groups (trees, lianas, terrestrial herbs, epiphytic liverworts) and eight animal groups (birds, butterflies, lower canopy ants, lower canopy beetles, dung beetles, bees, wasps, and the parasitoids of the latter two) at 15 sites in Sulawesi, Indonesia, that represented natural rain forest and three types of cacao agroforests differing in management intensity. In total, we recorded 863 species. Patterns of species richness per study site varied strongly between taxonomic groups. Only 13-17% of the variance in species richness of one taxonomic group could be predicted from the species richness of another, and on average 12-18% of the variance of beta diversity of a given group was predicted by that in other groups, although some taxon pairs had higher values (up to 76% for wasps and their parasitoids). The degree of congruence of patterns of alpha diversity was not influenced by sampling completeness, whereas the indicator value for beta diversity improved when using a similarity index that accounts for incomplete sampling. The indication potential of alpha diversity for beta diversity and vice versa was limited within taxa (7-20%) and virtually nil between them (0-4%). We conclude that different taxa can have largely independent patterns of alpha diversity and that patterns of beta diversity can be more congruent. Thus, conservation plans on a landscape scale need to put more emphasis on the high heterogeneity of agroforests and the overarching role of beta diversity shaping overall diversity patterns. PMID:20014584

  4. Application of diversity to regional ecological assessment: a review with recommendations

    SciTech Connect

    Levenson, J.B.; Stearns, F.W.

    1980-03-01

    Species diversity is frequently considered a primary indicator of ecosystem health, stability, and resilience. As such, species diversity is commonly the major criterion upon which environmental impact statements and ecological assessments are based. This report describes the theoretical development and refinement of the concept of ecological diversity and the various mathematical expressions of diversity. Advantages and disadvantages of each diversity expression are discussed. The application and interpretation of diversity indices for different spatial scales (e.g., specific sites and regional assessments) and variables (e.g., species diversity, habitat diversity, landscape diversity) are contrasted. Recommendations indicate the appropriate diversity indices for regional ecological assessments.

  5. Plant diversity hotspots in the Atlantic coastal forests of Brazil.

    PubMed

    Murray-Smith, Charlotte; Brummitt, Neil A; Oliveira-Filho, Ary T; Bachman, Steven; Moat, Justin; Lughadha, Eimear M Nic; Lucas, Eve J

    2009-02-01

    Plant-diversity hotspots on a global scale are well established, but smaller local hotspots within these must be identified for effective conservation of plants at the global and local scales. We used the distributions of endemic and endemic-threatened species of Myrtaceae to indicate areas of plant diversity and conservation importance within the Atlantic coastal forests (Mata Atlântica) of Brazil. We applied 3 simple, inexpensive geographic information system (GIS) techniques to a herbarium specimen database: predictive species-distribution modeling (Maxent); complementarity analysis (DIVA-GIS); and mapping of herbarium specimen collection locations. We also considered collecting intensity, which is an inherent limitation of use of natural history records for biodiversity studies. Two separate areas of endemism were evident: the Serra do Mar mountain range from Paraná to Rio de Janeiro and the coastal forests of northern Espírito Santo and southern Bahia. We identified 12 areas of approximately 35 km(2) each as priority areas for conservation. These areas had the highest species richness and were highly threatened by urban and agricultural expansion. Observed species occurrences, species occurrences predicted from the model, and results of our complementarity analysis were congruent in identifying those areas with the most endemic species. These areas were then prioritized for conservation importance by comparing ecological data for each. PMID:18950472

  6. Diversity of endophytic enterobacteria associated with different host plants.

    PubMed

    Torres, Adalgisa Ribeiro; Araújo, Welington Luiz; Cursino, Luciana; Hungria, Mariangela; Plotegher, Fábio; Mostasso, Fábio Luís; Azevedo, João Lúcio

    2008-08-01

    Fifty-three endophytic enterobacteria isolates from citrus, cocoa, eucalyptus, soybean, and sugar cane were evaluated for susceptibility to the antibiotics ampicillin and kanamycin, and cellulase production. Susceptibility was found on both tested antibiotics. However, in the case of ampicillin susceptibility changed according to the host plant, while all isolates were susceptible to kanamycin. Cellulase production also changed according to host plants. The diversity of these isolates was estimated by employing BOX-PCR genomic fingerprints and 16S rDNA sequencing. In total, twenty-three distinct operational taxonomic units (OTUs) were identified by employing a criterion of 60% fingerprint similarity as a surrogate for an OTU. The 23 OTUs belong to the Pantoea and Enterobacter genera, while their high diversity could be an indication of paraphyletic classification. Isolates representing nine different OTUs belong to Pantoea agglomerans, P. ananatis, P. stewartii, Enterobacter sp., and E. homaechei. The results of this study suggest that plant species may select endophytic bacterial genotypes. It has also become apparent that a review of the Pantoea/Enterobacter genera may be necessary. PMID:18758726

  7. Promontory Facility Plant-wide Energy Assessment

    SciTech Connect

    Weir, Roger M.; Bebb, Deanna, Brown, Herman E.

    2008-03-28

    A 1-year plant-wide assessment at the ATK Promontory manufacturing facility utilizing innovative assessment technologies to identify energy savings opportunities in: steam, water, compressed air, HVAC, utility, production, and building systems.

  8. Plant and bird diversity in natural forests and in native and exotic plantations in NW Portugal

    NASA Astrophysics Data System (ADS)

    Proença, Vânia M.; Pereira, Henrique M.; Guilherme, João; Vicente, Luís

    2010-03-01

    Forest ecosystems have been subjected to continuous dynamics between deforestation and forestation. Assessing the effects of these processes on biodiversity could be essential for conservation planning. We analyzed patterns of species richness, diversity and evenness of plants and birds in patches of natural forest of Quercus spp. and in stands of native Pinus pinaster and exotic Eucalyptus globulus in NW Portugal. We analyzed data of forest and non-forest species separately, at the intra-patch, patch and inter-patch scales. Forest plant richness, diversity and evenness were higher in oak forest than in pine and eucalypt plantations. In total, 52 species of forest plants were observed in oak forest, 33 in pine plantation and 28 in eucalypt plantation. Some forest species, such as Euphorbia dulcis, Omphalodes nitida and Eryngium juresianum, were exclusively or mostly observed in oak forest. Forest bird richness and diversity were higher in both oak and pine forests than in eucalypt forest; evenness did not differ among forests. In total, 16 species of forest birds were observed in oak forest, 18 in pine forest and 11 in eucalypt forest. Species such as Certhia brachydactyla, Sitta europaea and Dendrocopos major were common in oak and/or pine patches but were absent from eucalypt stands. Species-area relationships of forest plants and forest birds in oak patches had consistently a higher slope, at both the intra and inter-patch scales, than species-area relationships of forest species in plantations and non-forest species in oak forest. These findings demonstrate the importance of oak forest for the conservation of forest species diversity, pointing the need to conserve large areas of oak forest due to the apparent vulnerability of forest species to area loss. Additionally, diversity patterns in pine forest were intermediate between oak forest and eucalypt forest, suggesting that forest species patterns may be affected by forest naturalness.

  9. Impacts of weather on long-term patterns of plant richness and diversity vary with location and management.

    PubMed

    Jonas, Jayne L; Buhl, Deborah A; Symstad, Amy J

    2015-09-01

    Better understanding the influence of precipitation and temperature on plant assemblages is needed to predict the effects of climate change. Many studies have examined the relationship between plant productivity and weather (primarily precipitation), but few have directly assessed the relationship between plant richness or diversity and weather despite their increased use as metrics of ecosystem condition. We focus on the grasslands of central North America, which are characterized by high temporal climatic variability. Over the next 100 years, these grasslands are predicted to experience further increased variability in growing season precipitation, as well as increased temperatures, due to global climate change. We assess the portion of interannual variability of richness and diversity explained by weather, how relationships between these metrics and weather vary among plant assemblages, and which aspects of weather best explain temporal variability. We used an information-theoretic approach to assess relationships between long-term plant richness and diversity patterns and a priori weather covariates using six data sets from four grasslands. Weather explained up to 49% and 63% of interannual variability in total plant species richness and diversity, respectively. However, richness and diversity responses to specific weather variables varied both among sites and among experimental treatments within sites. In general, we found many instances in which temperature was of equal or greater importance as precipitation, as well as evidence of the importance of lagged effects and precipitation or temperature variability. Although precipitation has been shown to be a key driver of productivity in grasslands, our results indicate that increasing temperatures alone, without substantial changes in precipitation patterns, could have measurable effects on Great Plains grassland plant assemblages and biodiversity metrics. Our results also suggest that richness and diversity will respond in unique ways to changing climate and management can affect these responses; additional research and monitoring will be essential for further understanding of these complex relationships. PMID:26594699

  10. Plant diterpene synthases: exploring modularity and metabolic diversity for bioengineering.

    PubMed

    Zerbe, Philipp; Bohlmann, Jörg

    2015-07-01

    Plants produce thousands of diterpenoid natural products; some of which are of significant industrial value as biobased pharmaceuticals (taxol), fragrances (sclareol), food additives (steviosides), and commodity chemicals (diterpene resin acids). In nature, diterpene synthase (diTPS) enzymes are essential for generating diverse diterpene hydrocarbon scaffolds. While some diTPSs also form oxygenated compounds, more commonly, oxygenation is achieved by cytochrome P450-dependent mono-oxygenases. Recent genome-, transcriptome-, and metabolome-guided gene discovery and enzyme characterization identified novel diTPS functions that form the core of complex modular pathway systems. Insights into diterpene metabolism may translate into the development of new bioengineered microbial and plant-based production systems. PMID:26003209

  11. Development and Initial Psychometric Assessment of the Plant Attitude Questionnaire

    NASA Astrophysics Data System (ADS)

    Fan?ovi?ová, Jana; Prokop, Pavol

    2010-10-01

    Plants are integral parts of ecosystems which determine life on Earth. People's attitudes toward them are however, largely overlooked. Here we present initial psychometric assessment of self-constructed Plant Attitude Scale (PAS) that was administered to a sample of 310 Slovakian students living in rural areas aged 10-15 years. The final version of PAS consists from 29 Likert-scale items that were loaded to four distinct dimensions (Interest, Importance, Urban trees and Utilization). Mean scores revealed that Slovakian students lack positive attitudes toward plants and that gender had no effect on their mean attitude scores. Living in a family with a garden was associated with a more positive attitude toward plants. Further correlative research on diverse samples containing urban children and experimental research examining the impact of gardening in schools on student attitudes toward plants is required.

  12. Diversity, classification and function of the plant protein kinase superfamily

    PubMed Central

    Lehti-Shiu, Melissa D.; Shiu, Shin-Han

    2012-01-01

    Eukaryotic protein kinases belong to a large superfamily with hundreds to thousands of copies and are components of essentially all cellular functions. The goals of this study are to classify protein kinases from 25 plant species and to assess their evolutionary history in conjunction with consideration of their molecular functions. The protein kinase superfamily has expanded in the flowering plant lineage, in part through recent duplications. As a result, the flowering plant protein kinase repertoire, or kinome, is in general significantly larger than other eukaryotes, ranging in size from 600 to 2500 members. This large variation in kinome size is mainly due to the expansion and contraction of a few families, particularly the receptor-like kinase/Pelle family. A number of protein kinases reside in highly conserved, low copy number families and often play broadly conserved regulatory roles in metabolism and cell division, although functions of plant homologues have often diverged from their metazoan counterparts. Members of expanded plant kinase families often have roles in plant-specific processes and some may have contributed to adaptive evolution. Nonetheless, non-adaptive explanations, such as kinase duplicate subfunctionalization and insufficient time for pseudogenization, may also contribute to the large number of seemingly functional protein kinases in plants. PMID:22889912

  13. Plant diversity drives soil microbial biomass carbon in grasslands irrespective of global environmental change factors.

    PubMed

    Thakur, Madhav Prakash; Milcu, Alexandru; Manning, Pete; Niklaus, Pascal A; Roscher, Christiane; Power, Sally; Reich, Peter B; Scheu, Stefan; Tilman, David; Ai, Fuxun; Guo, Hongyan; Ji, Rong; Pierce, Sarah; Ramirez, Nathaly Guerrero; Richter, Annabell Nicola; Steinauer, Katja; Strecker, Tanja; Vogel, Anja; Eisenhauer, Nico

    2015-11-01

    Soil microbial biomass is a key determinant of carbon dynamics in the soil. Several studies have shown that soil microbial biomass significantly increases with plant species diversity, but it remains unclear whether plant species diversity can also stabilize soil microbial biomass in a changing environment. This question is particularly relevant as many global environmental change (GEC) factors, such as drought and nutrient enrichment, have been shown to reduce soil microbial biomass. Experiments with orthogonal manipulations of plant diversity and GEC factors can provide insights whether plant diversity can attenuate such detrimental effects on soil microbial biomass. Here, we present the analysis of 12 different studies with 14 unique orthogonal plant diversity × GEC manipulations in grasslands, where plant diversity and at least one GEC factor (elevated CO2 , nutrient enrichment, drought, earthworm presence, or warming) were manipulated. Our results show that higher plant diversity significantly enhances soil microbial biomass with the strongest effects in long-term field experiments. In contrast, GEC factors had inconsistent effects with only drought having a significant negative effect. Importantly, we report consistent non-significant effects for all 14 interactions between plant diversity and GEC factors, which indicates a limited potential of plant diversity to attenuate the effects of GEC factors on soil microbial biomass. We highlight that plant diversity is a major determinant of soil microbial biomass in experimental grasslands that can influence soil carbon dynamics irrespective of GEC. PMID:26118993

  14. Plant and algal cell walls: diversity and functionality

    PubMed Central

    Popper, Zoë A.; Ralet, Marie-Christine; Domozych, David S.

    2014-01-01

    Background Although plants and many algae (e.g. the Phaeophyceae, brown, and Rhodophyceae, red) are only very distantly related they are united in their possession of carbohydrate-rich cell walls, which are of integral importance being involved in many physiological processes. Furthermore, wall components have applications within food, fuel, pharmaceuticals, fibres (e.g. for textiles and paper) and building materials and have long been an active topic of research. As shown in the 27 papers in this Special Issue, as the major deposit of photosynthetically fixed carbon, and therefore energy investment, cell walls are of undisputed importance to the organisms that possess them, the photosynthetic eukaryotes (plants and algae). The complexities of cell wall components along with their interactions with the biotic and abiotic environment are becoming increasingly revealed. Scope The importance of plant and algal cell walls and their individual components to the function and survival of the organism, and for a number of industrial applications, are illustrated by the breadth of topics covered in this issue, which includes papers concentrating on various plants and algae, developmental stages, organs, cell wall components, and techniques. Although we acknowledge that there are many alternative ways in which the papers could be categorized (and many would fit within several topics), we have organized them as follows: (1) cell wall biosynthesis and remodelling, (2) cell wall diversity, and (3) application of new technologies to cell walls. Finally, we will consider future directions within plant cell wall research. Expansion of the industrial uses of cell walls and potentially novel uses of cell wall components are both avenues likely to direct future research activities. Fundamentally, it is the continued progression from characterization (structure, metabolism, properties and localization) of individual cell wall components through to defining their roles in almost every aspect of plant and algal physiology that will present many of the major challenges in future cell wall research. PMID:25453142

  15. Acts of Diversity: Assessing the Impact of Service-Learning

    ERIC Educational Resources Information Center

    Paoletti, Jo B.; Segal, Eden; Totino, Christina

    2007-01-01

    Teaching--and assessing learning--about diversity through service-learning is full of challenges, especially if the learning goals are affective. The teacher has no good way of knowing exactly where the starting point is for each student. The student may only know where the starting point was once he or she has moved beyond it and sees it in…

  16. Assessment of a Diversity Assignment in a PR Principles Course

    ERIC Educational Resources Information Center

    Gallicano, Tiffany Derville; Stansberry, Kathleen

    2012-01-01

    This study assesses an assignment for incorporating diversity into the principles of public relations course. The assignment is tailored to the challenges of using an active learning approach in a large lecture class. For the assignment, students write a goal, objectives, strategies, an identification of tactics, and evaluation plans for either…

  17. Assessing genetic diversity in Valencia peanut germplasm using SSR markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Valencia peanuts (Arachis hypogaea L.ssp. fastigiata var. fastigiata) are well known for their in-shell market value. Assessment of genetic diversity of the available Valencia germplasm is key to the success of developing improved cultivars with desirable agronomic and quality traits. In the pres...

  18. How generalist herbivores exploit belowground plant diversity in temperate grasslands

    PubMed Central

    Wallinger, Corinna; Staudacher, Karin; Schallhart, Nikolaus; Mitterrutzner, Evi; Steiner, Eva-Maria; Juen, Anita; Traugott, Michael

    2014-01-01

    Belowground herbivores impact plant performance, thereby inducing changes in plant community composition, which potentially leads to cascading effects onto higher trophic levels and ecosystem processes and productivity. Among soil-living insects, external root-chewing generalist herbivores have the strongest impact on plants. However, the lack of knowledge on their feeding behaviour under field conditions considerably hampers achieving a comprehensive understanding of how they affect plant communities. Here, we address this gap of knowledge by investigating the feeding behaviour of Agriotes click beetle larvae, which are common generalist external root-chewers in temperate grassland soils. Utilizing diagnostic multiplex PCR to assess the larval diet, we examined the seasonal patterns in feeding activity, putative preferences for specific plant taxa, and whether species identity and larval instar affect food choices of the herbivores. Contrary to our hypothesis, most of the larvae were feeding-active throughout the entire vegetation period, indicating that the grassland plants are subjected to constant belowground feeding pressure. Feeding was selective, with members of Plantaginaceae and Asteraceae being preferred; Apiaceae were avoided. Poaceae, although assumed to be most preferred, had an intermediate position. The food preferences exhibited seasonal changes, indicating a fluctuation in plant traits important for wireworm feeding choice. Species- and instar-specific differences in dietary choice of the Agriotes larvae were small, suggesting that species and larval instars occupy the same trophic niche. According to the current findings, the food choice of these larvae is primarily driven by plant identity, exhibiting seasonal changes. This needs to be considered when analysing soil herbivore–plant interactions. PMID:24188592

  19. How generalist herbivores exploit belowground plant diversity in temperate grasslands.

    PubMed

    Wallinger, Corinna; Staudacher, Karin; Schallhart, Nikolaus; Mitterrutzner, Evi; Steiner, Eva-Maria; Juen, Anita; Traugott, Michael

    2014-08-01

    Belowground herbivores impact plant performance, thereby inducing changes in plant community composition, which potentially leads to cascading effects onto higher trophic levels and ecosystem processes and productivity. Among soil-living insects, external root-chewing generalist herbivores have the strongest impact on plants. However, the lack of knowledge on their feeding behaviour under field conditions considerably hampers achieving a comprehensive understanding of how they affect plant communities. Here, we address this gap of knowledge by investigating the feeding behaviour of Agriotes click beetle larvae, which are common generalist external root-chewers in temperate grassland soils. Utilizing diagnostic multiplex PCR to assess the larval diet, we examined the seasonal patterns in feeding activity, putative preferences for specific plant taxa, and whether species identity and larval instar affect food choices of the herbivores. Contrary to our hypothesis, most of the larvae were feeding-active throughout the entire vegetation period, indicating that the grassland plants are subjected to constant belowground feeding pressure. Feeding was selective, with members of Plantaginaceae and Asteraceae being preferred; Apiaceae were avoided. Poaceae, although assumed to be most preferred, had an intermediate position. The food preferences exhibited seasonal changes, indicating a fluctuation in plant traits important for wireworm feeding choice. Species- and instar-specific differences in dietary choice of the Agriotes larvae were small, suggesting that species and larval instars occupy the same trophic niche. According to the current findings, the food choice of these larvae is primarily driven by plant identity, exhibiting seasonal changes. This needs to be considered when analysing soil herbivore-plant interactions. PMID:24188592

  20. Antimicrobial plant metabolites: structural diversity and mechanism of action.

    PubMed

    Radulovi?, N S; Blagojevi?, P D; Stojanovi?-Radi?, Z Z; Stojanovi?, N M

    2013-01-01

    Microbial infectious diseases continue to be one of the leading causes of morbidity and mortality. It has been estimated that microbial species comprise about 60% of the Earth's biomass. This, together with the fact that their genetic, metabolic and physiological diversity is extraordinary, makes them a major threat to the health and development of populations across the world. Widespread antibiotic resistance, the emergence of new pathogens in addition to the resurgence of old ones, and the lack of effective new therapeutics exacerbate the problems. Thus, the need to discover and develop new antimicrobial agents is critical to improve mankind's future health. Plant secondary metabolites (PSMs) offer particular promise in this sense. Plant Kingdom could be considered a rich source of the most diverse structures (e.g. there are more than 12,000 known alkaloids, more than 8,000 phenolic compounds and over 25,000 different terpenoids), many of which were proven to possess strong antimicrobial properties (e.g. thymol, eurabienol, etc.). In many instances, PSMs can be easily isolated from the plant matrix, either in pure state or in the form of mixtures of chemically related compounds. What is also important is that the development of bacterial resistance toward natural plant products (that are generally regarded as eco-friendly) has been thus far documented in a very limited number of cases (e.g. for reserpine). Having all of the mentioned advantages of PSMs as potential antimicrobials in mind, a major question arises: why is it that there are still no commercially available or commonly used antibiotics of plant origin? This review tries to give a critical answer to this question by considering potential mechanisms of antimicrobial action of PSMs (inhibition of cell wall or protein synthesis, inducing leakage from the cells by tampering with the function of the membranes, interfering with intermediary metabolisms or DNA/RNA synthesis/function), as well as their physical and chemical properties (e.g. hydrophilicity/lipophilicity, chemical stability). To address the possible synergistic/antagonistic effects between PSMs and with standard antibiotics, special attention has been given to the antimicrobial activity of PSM-mixtures (e.g. essential oils, plant extracts). Moreover, possible ways of overcoming some of PSMs molecular limitations in respect to their usage as potential antibiotics were also discussed (e.g. derivatization that would enable fine tuning of certain molecular characteristics). PMID:23210781

  1. Diversity cascades in alfalfa fields: from plant quality to agroecosystem diversity.

    PubMed

    Pearson, Clark V; Massad, Tara J; Dyer, Lee A

    2008-08-01

    To examine top-down and bottom-up influences on managed terrestrial communities, we manipulated plant resources and arthropod abundance in alfalfa (Medicago sativa L.) fields. We modified arthropod communities using three nonfactorial manipulations: pitfall traps to remove selected arthropods, wooden crates to create habitat heterogeneity, and an arthropod removal treatment using a reversible leaf blower. These manipulations were crossed with fertilizer additions, which were applied to half of the plots. We found strong effects of fertilizer on plant quality and biomass, and these effects cascaded up to increase herbivore abundance and diversity. The predator community also exhibited a consistent positive effect on the maintenance of herbivore species richness and abundance. These top-down changes in arthropods did not cascade down to affect plant biomass; however, plant quality (saponin content) increased with higher herbivore densities. These results corroborate previous studies in alfalfa that show complex indirect effects, such as trophic cascades, can operate in agricultural systems, but the specifics of the interactions depend on the assemblages of arthropods involved. PMID:18801260

  2. Bacterial diversity and composition in the fluid of pitcher plants of the genus Nepenthes.

    PubMed

    Takeuchi, Yayoi; Chaffron, Samuel; Salcher, Michaela M; Shimizu-Inatsugi, Rie; Kobayashi, Masaki J; Diway, Bibian; von Mering, Christian; Pernthaler, Jakob; Shimizu, Kentaro K

    2015-07-01

    Pitchers are modified leaves used by carnivorous plants for trapping prey. Their fluids contain digestive enzymes from the plant and they harbor abundant microbes. In this study, the diversity of bacterial communities was assessed in Nepenthes pitcher fluids and the composition of the bacterial community was compared to that in other environments, including the phyllosphere of Arabidopsis, animal guts and another pitcher plant, Sarracenia. Diversity was measured by 454 pyrosequencing of 16S rRNA gene amplicons. A total of 232,823 sequences were obtained after chimera and singleton removal that clustered into 3260 distinct operational taxonomic units (OTUs) (3% dissimilarity), which were taxonomically distributed over 17 phyla, 25 classes, 45 orders, 100 families, and 195 genera. Pyrosequencing and fluorescence in situ hybridization yielded similar estimates of community composition. Most pitchers contained high proportions of unique OTUs, and only 22 OTUs (<0.6%) were shared by ?14/16 samples, suggesting a unique bacterial assemblage in each pitcher at the OTU level. Diversity analysis at the class level revealed that the bacterial communities of both opened and unopened pitchers were most similar to that of Sarracenia and to that in the phyllosphere. Therefore, the bacterial community in pitchers may be formed by environmental filtering and/or by phyllosphere bacteria. PMID:26138047

  3. Genomic diversity of Pseudomonas spp. isolated from aerial or root surfaces of plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Among the diverse strains of Pseudomonas fluorescens and Pseudomonas chlororaphis inhabiting plant surfaces are those that protect plants from infection by pathogens. To explore the diversity of these bacteria, we derived genomic sequences of seven strains that suppress plant disease. Along with t...

  4. Tiger Team assessment of the Pinellas Plant

    SciTech Connect

    Not Available

    1990-05-01

    This Document contains findings identified during the Tiger Team Compliance Assessment of the Department of Energy's (DOE's) Pinellas Plant, Pinellas County, Florida. The assessment wa directed by the Department's Office of Environment, Safety, and Health (ES H) from January 15 to February 2, 1990. The Pinellas Tiger Team Compliance Assessment is comprehensive in scope. It covers the Environment Safety and Health, and Management areas and determines the plant's compliance with applicable Federal (including DOE), State, and local regulations and requirements.

  5. Diversity and distribution of Listeria monocytogenes in meat processing plants.

    PubMed

    Martín, Belén; Perich, Adriana; Gómez, Diego; Yangüela, Javier; Rodríguez, Alicia; Garriga, Margarita; Aymerich, Teresa

    2014-12-01

    Listeria monocytogenes is a major concern for the meat processing industry because many listeriosis outbreaks have been linked to meat product consumption. The aim of this study was to elucidate L. monocytogenes diversity and distribution across different Spanish meat processing plants. L. monocytogenes isolates (N = 106) collected from food contact surfaces of meat processing plants and meat products were serotyped and then characterised by multilocus sequence typing (MLST). The isolates were serotyped as 1/2a (36.8%), 1/2c (34%), 1/2b (17.9%) and 4b (11.3%). MLST identified ST9 as the most predominant allelic profile (33% of isolates) followed by ST121 (16%), both of which were detected from several processing plants and meat products sampled in different years, suggesting that those STs are highly adapted to the meat processing environment. Food contact surfaces during processing were established as an important source of L. monocytogenes in meat products because the same STs were obtained in isolates recovered from surfaces and products. L. monocytogenes was recovered after cleaning and disinfection procedures in two processing plants, highlighting the importance of thorough cleaning and disinfection procedures. Epidemic clone (EC) marker ECI was identified in 8.5%, ECIII was identified in 2.8%, and ECV was identified in 7.5% of the 106 isolates. Furthermore, a selection of presumably unrelated ST9 isolates was analysed by multi-virulence-locus sequence typing (MVLST). Most ST9 isolates had the same virulence type (VT11), confirming the clonal origin of ST9 isolates; however, one ST9 isolate was assigned to a new VT (VT95). Consequently, MLST is a reliable tool for identification of contamination routes and niches in processing plants, and MVLST clearly differentiates EC strains, which both contribute to the improvement of L. monocytogenes control programs in the meat industry. PMID:25084653

  6. Green Plants in the Red: A Baseline Global Assessment for the IUCN Sampled Red List Index for Plants.

    PubMed

    Brummitt, Neil A; Bachman, Steven P; Griffiths-Lee, Janine; Lutz, Maiko; Moat, Justin F; Farjon, Aljos; Donaldson, John S; Hilton-Taylor, Craig; Meagher, Thomas R; Albuquerque, Sara; Aletrari, Elina; Andrews, A Kei; Atchison, Guy; Baloch, Elisabeth; Barlozzini, Barbara; Brunazzi, Alice; Carretero, Julia; Celesti, Marco; Chadburn, Helen; Cianfoni, Eduardo; Cockel, Chris; Coldwell, Vanessa; Concetti, Benedetta; Contu, Sara; Crook, Vicki; Dyson, Philippa; Gardiner, Lauren; Ghanim, Nadia; Greene, Hannah; Groom, Alice; Harker, Ruth; Hopkins, Della; Khela, Sonia; Lakeman-Fraser, Poppy; Lindon, Heather; Lockwood, Helen; Loftus, Christine; Lombrici, Debora; Lopez-Poveda, Lucia; Lyon, James; Malcolm-Tompkins, Patricia; McGregor, Kirsty; Moreno, Laura; Murray, Linda; Nazar, Keara; Power, Emily; Quiton Tuijtelaars, Mireya; Salter, Ruth; Segrott, Robert; Thacker, Hannah; Thomas, Leighton J; Tingvoll, Sarah; Watkinson, Gemma; Wojtaszekova, Katerina; Nic Lughadha, Eimear M

    2015-01-01

    Plants provide fundamental support systems for life on Earth and are the basis for all terrestrial ecosystems; a decline in plant diversity will be detrimental to all other groups of organisms including humans. Decline in plant diversity has been hard to quantify, due to the huge numbers of known and yet to be discovered species and the lack of an adequate baseline assessment of extinction risk against which to track changes. The biodiversity of many remote parts of the world remains poorly known, and the rate of new assessments of extinction risk for individual plant species approximates the rate at which new plant species are described. Thus the question 'How threatened are plants?' is still very difficult to answer accurately. While completing assessments for each species of plant remains a distant prospect, by assessing a randomly selected sample of species the Sampled Red List Index for Plants gives, for the first time, an accurate view of how threatened plants are across the world. It represents the first key phase of ongoing efforts to monitor the status of the world's plants. More than 20% of plant species assessed are threatened with extinction, and the habitat with the most threatened species is overwhelmingly tropical rain forest, where the greatest threat to plants is anthropogenic habitat conversion, for arable and livestock agriculture, and harvesting of natural resources. Gymnosperms (e.g. conifers and cycads) are the most threatened group, while a third of plant species included in this study have yet to receive an assessment or are so poorly known that we cannot yet ascertain whether they are threatened or not. This study provides a baseline assessment from which trends in the status of plant biodiversity can be measured and periodically reassessed. PMID:26252495

  7. Green Plants in the Red: A Baseline Global Assessment for the IUCN Sampled Red List Index for Plants

    PubMed Central

    Griffiths-Lee, Janine; Lutz, Maiko; Moat, Justin F.; Farjon, Aljos; Donaldson, John S.; Hilton-Taylor, Craig; Meagher, Thomas R.; Albuquerque, Sara; Aletrari, Elina; Andrews, A. Kei; Atchison, Guy; Baloch, Elisabeth; Barlozzini, Barbara; Brunazzi, Alice; Carretero, Julia; Celesti, Marco; Chadburn, Helen; Cianfoni, Eduardo; Cockel, Chris; Coldwell, Vanessa; Concetti, Benedetta; Contu, Sara; Crook, Vicki; Dyson, Philippa; Gardiner, Lauren; Ghanim, Nadia; Greene, Hannah; Groom, Alice; Harker, Ruth; Hopkins, Della; Khela, Sonia; Lakeman-Fraser, Poppy; Lindon, Heather; Lockwood, Helen; Loftus, Christine; Lombrici, Debora; Lopez-Poveda, Lucia; Lyon, James; Malcolm-Tompkins, Patricia; McGregor, Kirsty; Moreno, Laura; Murray, Linda; Nazar, Keara; Power, Emily; Quiton Tuijtelaars, Mireya; Salter, Ruth; Segrott, Robert; Thacker, Hannah; Thomas, Leighton J.; Tingvoll, Sarah; Watkinson, Gemma; Wojtaszekova, Katerina; Nic Lughadha, Eimear M.

    2015-01-01

    Plants provide fundamental support systems for life on Earth and are the basis for all terrestrial ecosystems; a decline in plant diversity will be detrimental to all other groups of organisms including humans. Decline in plant diversity has been hard to quantify, due to the huge numbers of known and yet to be discovered species and the lack of an adequate baseline assessment of extinction risk against which to track changes. The biodiversity of many remote parts of the world remains poorly known, and the rate of new assessments of extinction risk for individual plant species approximates the rate at which new plant species are described. Thus the question ‘How threatened are plants?’ is still very difficult to answer accurately. While completing assessments for each species of plant remains a distant prospect, by assessing a randomly selected sample of species the Sampled Red List Index for Plants gives, for the first time, an accurate view of how threatened plants are across the world. It represents the first key phase of ongoing efforts to monitor the status of the world’s plants. More than 20% of plant species assessed are threatened with extinction, and the habitat with the most threatened species is overwhelmingly tropical rain forest, where the greatest threat to plants is anthropogenic habitat conversion, for arable and livestock agriculture, and harvesting of natural resources. Gymnosperms (e.g. conifers and cycads) are the most threatened group, while a third of plant species included in this study have yet to receive an assessment or are so poorly known that we cannot yet ascertain whether they are threatened or not. This study provides a baseline assessment from which trends in the status of plant biodiversity can be measured and periodically reassessed. PMID:26252495

  8. Gene regulation networks generate diverse pigmentation patterns in plants

    PubMed Central

    Albert, Nick W; Davies, Kevin M; Schwinn, Kathy E

    2014-01-01

    The diversity of pigmentation patterns observed in plants occurs due to the spatial distribution and accumulation of colored compounds, which may also be associated with structural changes to the tissue. Anthocyanins are flavonoids that provide red/purple/blue coloration to plants, often forming complex patterns such as spots, stripes, and vein-associated pigmentation, particularly in flowers. These patterns are determined by the activity of MYB-bHLH-WDR (MBW) transcription factor complexes, which activate the anthocyanin biosynthesis genes, resulting in anthocyanin pigment accumulation. Recently, we established that the MBW complex controlling anthocyanin synthesis acts within a gene regulation network that is conserved within at least the Eudicots. This network involves hierarchy, reinforcement, and feedback mechanisms that allow for stringent and responsive regulation of the anthocyanin biosynthesis genes. The gene network and mobile nature of the WDR and R3-MYB proteins provide exciting new opportunities to explore the basis of pigmentation patterning, and to investigate the evolutionary history of the MBW components in land plants. PMID:25763693

  9. Gene regulation networks generate diverse pigmentation patterns in plants.

    PubMed

    Albert, Nick W; Davies, Kevin M; Schwinn, Kathy E

    2014-01-01

    The diversity of pigmentation patterns observed in plants occurs due to the spatial distribution and accumulation of colored compounds, which may also be associated with structural changes to the tissue. Anthocyanins are flavonoids that provide red/purple/blue coloration to plants, often forming complex patterns such as spots, stripes, and vein-associated pigmentation, particularly in flowers. These patterns are determined by the activity of MYB-bHLH-WDR (MBW) transcription factor complexes, which activate the anthocyanin biosynthesis genes, resulting in anthocyanin pigment accumulation. Recently, we established that the MBW complex controlling anthocyanin synthesis acts within a gene regulation network that is conserved within at least the Eudicots. This network involves hierarchy, reinforcement, and feedback mechanisms that allow for stringent and responsive regulation of the anthocyanin biosynthesis genes. The gene network and mobile nature of the WDR and R3-MYB proteins provide exciting new opportunities to explore the basis of pigmentation patterning, and to investigate the evolutionary history of the MBW components in land plants. PMID:25763693

  10. Gene regulation networks generate diverse pigmentation patterns in plants.

    PubMed

    Albert, Nick; Davies, Kevin; Schwinn, Kathy

    2014-06-13

    The diversity of pigmentation patterns observed in plants occurs due to the spatial distribution and accumulation of colored compounds, which may also be associated with structural changes to the tissue. Anthocyanins are flavonoids that provide red/purple/blue coloration to plants, often forming complex patterns such as spots, stripes, and vein-associated pigmentation, particularly in flowers. These patterns are determined by the activity of MYB-bHLH-WDR (MBW) transcription factor complexes, which activate the anthocyanin biosynthesis genes, resulting in anthocyanin pigment accumulation. Recently, we established that the MBW complex controlling anthocyanin synthesis acts within a gene regulation network that is conserved within at least the Eudicots. This network involves hierarchy, reinforcement, and feedback mechanisms that allow for stringent and responsive regulation of the anthocyanin biosynthesis genes. The gene network and mobile nature of the WDR and R3-MYB proteins provide exciting new opportunities to explore the basis of pigmentation patterning, and to investigate the evolutionary history of the MBW components in land plants. PMID:24926872

  11. Long-term effects of sowing high or low diverse seed mixtures on plant and gastropod diversity

    NASA Astrophysics Data System (ADS)

    Dedov, Ivailo; Stoyanov, Ivailo L.; Penev, Lyubomir; Harvey, Jeffrey A.; Van der Putten, Wim H.; Bezemer, T. Martijn

    2006-09-01

    A number of studies have reported that consumers affect a range of community-level processes, and in turn their diversity and abundance is influenced by the structure and diversity of the plant community. Although gastropods are important generalist herbivores in many environments, few studies have examined the effects of plant species richness and plant community structure on gastropods. This study investigated gastropod species richness and interactions with various above-ground parameters of the vegetation on an experimental field with four plant treatments: low and high diversity of sown later succession plant species, natural colonization at the start of the experiment and natural colonization after 3 years of continued agricultural practice. The investigated gastropod assemblage contained only seven species and was highly dominated by two of them. Both in pitfalls and with hand-sorting the number of species collected per plot was highest in plots with natural plant colonization. Multivariate analysis revealed that overall gastropod abundance was positively associated with plant height and percentage cover of plants, and negatively with percentage grass cover. The same pattern holds for one of the dominant species-complex ( Cochlicopa lubrica/ lubricella). The other dominant gastropod species ( Deroceras reticulatum) was more abundant in samples with higher percentages of moss cover and higher plant diversity, while less abundant at samples with higher plant cover, indicating that the gastropod species preferences may matter more than just their response to plant diversity. Two plant-gastropod species-level associations were observed: Senecio jacobaea with D. reticulatum and Tanacetum vulgare with Cochlicopa spp. The present study also demonstrated that pitfall-traps are suitable for collecting terrestrial gastropods, at least for species-poor grassland habitats.

  12. Diversity and use of ethno-medicinal plants in the region of Swat, North Pakistan

    PubMed Central

    2013-01-01

    Background Due to its diverse geographical and habitat conditions, northern Pakistan harbors a wealth of medicinal plants. The plants and their traditional use are part of the natural and cultural heritage of the region. This study was carried out to document which medicinal plant species and which plant parts are used in the region of Swat, which syndrome categories are particularly concerned, and which habitat spectrum is frequented by collectors. Finally, we assessed to which extent medicinal plants are vulnerable due to collection and habitat destruction. Methods An ethnobotanical survey was undertaken in the Miandam area of Swat, North Pakistan. Data were collected through field assessment as well as from traditional healers and locals by means of personal interviews and semi-structured questionnaires. Results A total of 106 ethno-medicinal plant species belonging to 54 plant families were recorded. The most common growth forms were perennial (43%) and short-lived herbs (23%), shrubs (16%), and trees (15%). Most frequently used plant parts were leaves (24%), fruits (18%) and subterranean parts (15%). A considerable proportion of the ethno-medicinal plant species and remedies concerns gastro-intestinal disorders. The remedies were mostly prepared in the form of decoction or powder and were mainly taken orally. Eighty out of 106 ethno-medicinal plants were indigenous. Almost 50% of the plants occurred in synanthropic vegetation while slightly more than 50% were found in semi-natural, though extensively grazed, woodland and grassland vegetation. Three species (Aconitum violaceum, Colchicum luteum, Jasminum humile) must be considered vulnerable due to excessive collection. Woodlands are the main source for non-synanthropic indigenous medicinal plants. The latter include many range-restricted taxa and plants of which rhizomes and other subterranean parts are dug out for further processing as medicine. Conclusion Medicinal plants are still widely used for treatment in the area of Swat. Some species of woodlands seem to be adapted to wood-pasture, but vulnerable to overcollecting, and in particular to deforestation. It is suggested to implement local small-scaled agroforestry systems to cultivate vulnerable and commercially valuable ethno-medicinal woodland plants under local self-government responsibility. PMID:23587127

  13. Comparative assessment of genetic diversity among Indian bamboo genotypes using RAPD and ISSR markers.

    PubMed

    Desai, Parth; Gajera, Bhavesh; Mankad, Mounil; Shah, Shikha; Patel, Armi; Patil, Ghanshyam; Narayanan, Subhash; Kumar, Nitish

    2015-08-01

    Bamboo is one of the important plant for pulp, paper and charcoal industries. After China, India is the second largest bamboo reserve in Asia. Around the globe, wide genetic diversity of bamboo is present which serves as the base for selection and improvement. DNA based molecular markers appears to be a striking substitute for systematic assessment of the genetic diversity in conservation and genetic improvement of plants. DNA based molecular markers such as RAPD and ISSR were used to assess the genetic diversity in 13 bamboo genotypes. Total 120 RAPD and 63 ISSR primers were tested, of which only 42 polymorphic primers (30 RAPD and 12 ISSR), gave reproducible amplification profile and were used in this study. 30 RAPD primers yielded total 645 amplified fragments, of which 623 were polymorphic, and 20.76 polymorphic bands per primer were observed across 13 genotypes. 12 ISSR primers produced 246 amplified fragments, of which 241 were polymorphic, and 20.08 polymorphic bands per primer was observed across 13 different genotypes. The Jaccard's coefficient of RAPD, ISSR and pooled RAPD and ISSR dendrograms ranged from 0.26 to 0.83, 0.23 to 0.86 and 0.26 to 0.84 respectively. The present study found the large genetic diversity present between different elite genotypes of bamboo. Such investigation can deliver a well understanding of the available genotypes, which might be further exploited for the paper industry. PMID:25761883

  14. Technology-Enhanced Formative Assessment of Plant Identification

    NASA Astrophysics Data System (ADS)

    Conejo, Ricardo; Garcia-Viñas, Juan Ignacio; Gastón, Aitor; Barros, Beatriz

    2015-10-01

    Developing plant identification skills is an important part of the curriculum of any botany course in higher education. Frequent practice with dried and fresh plants is necessary to recognize the diversity of forms, states, and details that a species can present. We have developed a web-based assessment system for mobile devices that is able to pose appropriate questions according to the location of the student. A student's location can be obtained using the device position or by scanning a QR code attached to a dried plant sheet in a herbarium or to a fresh plant in an arboretum. The assessment questions are complemented with elaborated feedback that, according to the students' responses, provides indications of possible mistakes and correct answers. Three experiments were designed to measure the effectiveness of the formative assessment using dried and fresh plants. Three questionnaires were used to evaluate the system performance from the students' perspective. The results clearly indicate that formative assessment is objectively effective compared to traditional methods and that the students' attitudes towards the system were very positive.

  15. Functional trait diversity across trophic levels determines herbivore impact on plant community biomass.

    PubMed

    Deraison, Hélène; Badenhausser, Isabelle; Loeuille, Nicolas; Scherber, Christoph; Gross, Nicolas

    2015-12-01

    Understanding the consequences of trophic interactions for ecosystem functioning is challenging, as contrasting effects of species and functional diversity can be expected across trophic levels. We experimentally manipulated functional identity and diversity of grassland insect herbivores and tested their impact on plant community biomass. Herbivore resource acquisition traits, i.e. mandible strength and the diversity of mandibular traits, had more important effects on plant biomass than body size. Higher herbivore functional diversity increased overall impact on plant biomass due to feeding niche complementarity. Higher plant functional diversity limited biomass pre-emption by herbivores. The functional diversity within and across trophic levels therefore regulates the impact of functionally contrasting consumers on primary producers. By experimentally manipulating the functional diversity across trophic levels, our study illustrates how trait-based approaches constitute a promising way to tackle existing links between trophic interactions and ecosystem functioning. PMID:26439435

  16. Bacterial Diversity of Active Sludge in Wastewater Treatment Plant

    NASA Astrophysics Data System (ADS)

    Jiang, Xin; Ma, Mingchao; Li, Jun; Lu, Anhuai; Zhong, Zuoshen

    A bacterial 16S rDNA gene clone library was constructed to analyze the bacterial diversity of active sludge in Gaobeidian Wastewater Treatment Plant, Beijing. The results indicated that the bacterial diversity of active sludge was very high, and the clones could be divided into 5 different groups. The dominant bacterial community was proteobacteria, which accounted for 76.7%. The dominant succession of bacterial community were as follows: the ?-proteobacteria (39.8%), the uncultured bacteria (22.33%), the ?-proteobacteria (20.15%), the ?-proteobacteria (6.79%), and the ?-proteobacteria (4.85%). Nitrosomonas-like and Nitrospira-like bacteria, such as Nitrosomonas sp. (1.94%) and uncultured Nitrospirae bacterium (11.65%) were also detected, which have played important roles in ammonia and nitrite oxidisers in the system. However, they were only a little amount because of their slow growth and less competitive advantage than heterotrophic bacteria. Denitrifying bacteria like Thauera sp. was at a high percentage, which implies a strong denitrification ability; Roseomonas sp. was also detected in the clone library, which could be related to the degradation of organophosphorus pesticide.

  17. Biotic and abiotic properties mediating plant diversity effects on soil microbial communities in an experimental grassland.

    PubMed

    Lange, Markus; Habekost, Maike; Eisenhauer, Nico; Roscher, Christiane; Bessler, Holger; Engels, Christof; Oelmann, Yvonne; Scheu, Stefan; Wilcke, Wolfgang; Schulze, Ernst-Detlef; Gleixner, Gerd

    2014-01-01

    Plant diversity drives changes in the soil microbial community which may result in alterations in ecosystem functions. However, the governing factors between the composition of soil microbial communities and plant diversity are not well understood. We investigated the impact of plant diversity (plant species richness and functional group richness) and plant functional group identity on soil microbial biomass and soil microbial community structure in experimental grassland ecosystems. Total microbial biomass and community structure were determined by phospholipid fatty acid (PLFA) analysis. The diversity gradient covered 1, 2, 4, 8, 16 and 60 plant species and 1, 2, 3 and 4 plant functional groups (grasses, legumes, small herbs and tall herbs). In May 2007, soil samples were taken from experimental plots and from nearby fields and meadows. Beside soil texture, plant species richness was the main driver of soil microbial biomass. Structural equation modeling revealed that the positive plant diversity effect was mainly mediated by higher leaf area index resulting in higher soil moisture in the top soil layer. The fungal-to-bacterial biomass ratio was positively affected by plant functional group richness and negatively by the presence of legumes. Bacteria were more closely related to abiotic differences caused by plant diversity, while fungi were more affected by plant-derived organic matter inputs. We found diverse plant communities promoted faster transition of soil microbial communities typical for arable land towards grassland communities. Although some mechanisms underlying the plant diversity effect on soil microorganisms could be identified, future studies have to determine plant traits shaping soil microbial community structure. We suspect differences in root traits among different plant communities, such as root turnover rates and chemical composition of root exudates, to structure soil microbial communities. PMID:24816860

  18. Biotic and Abiotic Properties Mediating Plant Diversity Effects on Soil Microbial Communities in an Experimental Grassland

    PubMed Central

    Lange, Markus; Habekost, Maike; Eisenhauer, Nico; Roscher, Christiane; Bessler, Holger; Engels, Christof; Oelmann, Yvonne; Scheu, Stefan; Wilcke, Wolfgang; Schulze, Ernst-Detlef; Gleixner, Gerd

    2014-01-01

    Plant diversity drives changes in the soil microbial community which may result in alterations in ecosystem functions. However, the governing factors between the composition of soil microbial communities and plant diversity are not well understood. We investigated the impact of plant diversity (plant species richness and functional group richness) and plant functional group identity on soil microbial biomass and soil microbial community structure in experimental grassland ecosystems. Total microbial biomass and community structure were determined by phospholipid fatty acid (PLFA) analysis. The diversity gradient covered 1, 2, 4, 8, 16 and 60 plant species and 1, 2, 3 and 4 plant functional groups (grasses, legumes, small herbs and tall herbs). In May 2007, soil samples were taken from experimental plots and from nearby fields and meadows. Beside soil texture, plant species richness was the main driver of soil microbial biomass. Structural equation modeling revealed that the positive plant diversity effect was mainly mediated by higher leaf area index resulting in higher soil moisture in the top soil layer. The fungal-to-bacterial biomass ratio was positively affected by plant functional group richness and negatively by the presence of legumes. Bacteria were more closely related to abiotic differences caused by plant diversity, while fungi were more affected by plant-derived organic matter inputs. We found diverse plant communities promoted faster transition of soil microbial communities typical for arable land towards grassland communities. Although some mechanisms underlying the plant diversity effect on soil microorganisms could be identified, future studies have to determine plant traits shaping soil microbial community structure. We suspect differences in root traits among different plant communities, such as root turnover rates and chemical composition of root exudates, to structure soil microbial communities. PMID:24816860

  19. AfroDb: A Select Highly Potent and Diverse Natural Product Library from African Medicinal Plants

    PubMed Central

    Ntie-Kang, Fidele; Zofou, Denis; Babiaka, Smith B.; Meudom, Rolande; Scharfe, Michael; Lifongo, Lydia L.; Mbah, James A.; Mbaze, Luc Meva’a; Sippl, Wolfgang; Efange, Simon M. N.

    2013-01-01

    Computer-aided drug design (CADD) often involves virtual screening (VS) of large compound datasets and the availability of such is vital for drug discovery protocols. We assess the bioactivity and “drug-likeness” of a relatively small but structurally diverse dataset (containing >1,000 compounds) from African medicinal plants, which have been tested and proven a wide range of biological activities. The geographical regions of collection of the medicinal plants cover the entire continent of Africa, based on data from literature sources and information from traditional healers. For each isolated compound, the three dimensional (3D) structure has been used to calculate physico-chemical properties used in the prediction of oral bioavailability on the basis of Lipinski’s “Rule of Five”. A comparative analysis has been carried out with the “drug-like”, “lead-like”, and “fragment-like” subsets, as well as with the Dictionary of Natural Products. A diversity analysis has been carried out in comparison with the ChemBridge diverse database. Furthermore, descriptors related to absorption, distribution, metabolism, excretion and toxicity (ADMET) have been used to predict the pharmacokinetic profile of the compounds within the dataset. Our results prove that drug discovery, beginning with natural products from the African flora, could be highly promising. The 3D structures are available and could be useful for virtual screening and natural product lead generation programs. PMID:24205103

  20. Effects of time since fire on birds in a plant diversity hotspot

    NASA Astrophysics Data System (ADS)

    Chalmandrier, Loïc; Midgley, Guy F.; Barnard, Phoebe; Sirami, Clélia

    2013-05-01

    Global changes are influencing fire regimes in many parts of the world. In the Fynbos plant diversity hotspot (Cape Floristic Region, South Africa), fire frequency has increased in protected areas where the mean fire interval went from 12-19 to 6-9 years between 1970 and 2000. Fire is one of the main drivers of plant diversity in the Cape Floristic Region. Too frequent fires threaten the persistence of slow-maturing plant species, and such insights have led to the adoption of fire management principles based on plant responses. The effects of fire on Fynbos fauna are much more poorly understood, and have not generally been considered in depth in Fynbos conservation policies, planning or management. We assessed the response of bird communities to long-term fire-induced vegetation changes using space-for-time substitution. We studied bird communities, vegetation structure and plant functional composition in 84 Fynbos plots burnt between two and 18 years before. Ten of the 14 bird species analysed showed a significant change in their abundance with time since fire. We observed a significant species turnover along the post-fire succession due to changes both in vegetation structure and plant functional composition, with a characteristic shift from non-Fynbos specialists and granivorous species to Fynbos specialists and nectarivorous species. If current trends of increasing fire frequency continue, Fynbos endemic birds such as nectarivores may become vulnerable. Conservation management should thus aim more carefully to maintain mosaics of Fynbos patches of different ages. Future research needs to estimate the proportion of vegetation of different ages and patch sizes needed to support dependent fauna, particularly endemics.

  1. PLANT SPECIES DIVERSITY IN NATIVE AND RESTORED TALLGRASS PRAIRIES: PATTERNS AND CONTROLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One goal of ecological restoration is to restore diversity of native vegetation, but mechanisms responsible for diversity in targeted communities often are poorly understood. We measured diversity (Simpson's index, 1/D) of plant species and functional groups of species in replicated 0.5-m2 plots wi...

  2. Plant diversity and identity effects on predatory nematodes and their prey.

    PubMed

    Kostenko, Olga; Duyts, Henk; Grootemaat, Saskia; De Deyn, Gerlinde B; Bezemer, T Martijn

    2015-02-01

    There is considerable evidence that both plant diversity and plant identity can influence the level of predation and predator abundance aboveground. However, how the level of predation in the soil and the abundance of predatory soil fauna are related to plant diversity and identity remains largely unknown. In a biodiversity field experiment, we examined the effects of plant diversity and identity on the infectivity of entomopathogenic nematodes (EPNs, Heterorhabditis and Steinernema spp.), which prey on soil arthropods, and abundance of carnivorous non-EPNs, which are predators of other nematode groups. To obtain a comprehensive view of the potential prey/food availability, we also quantified the abundance of soil insects and nonpredatory nematodes and the root biomass in the experimental plots. We used structural equation modeling (SEM) to investigate possible pathways by which plant diversity and identity may affect EPN infectivity and the abundance of carnivorous non-EPNs. Heterorhabditis spp. infectivity and the abundance of carnivorous non-EPNs were not directly related to plant diversity or the proportion of legumes, grasses and forbs in the plant community. However, Steinernema spp. infectivity was higher in monocultures of Festuca rubra and Trifolium pratense than in monocultures of the other six plant species. SEM revealed that legumes positively affected Steinernema infectivity, whereas plant diversity indirectly affected the infectivity of HeterorhabditisEPNs via effects on the abundance of soil insects. The abundance of prey (soil insects and root-feeding, bacterivorous, and fungivorous nematodes) increased with higher plant diversity. The abundance of prey nematodes was also positively affected by legumes. These plant community effects could not be explained by changes in root biomass. Our results show that plant diversity and identity effects on belowground biota (particularly soil nematode community) can differ between organisms that belong to the same feeding guild and that generalizations about plant diversity effects on soil organisms should be made with great caution. PMID:25750711

  3. Spatial patterns of plant diversity below-ground as revealed by DNA barcoding

    E-print Network

    Barrett, Spencer C.H.

    Spatial patterns of plant diversity below-ground as revealed by DNA barcoding PRASAD R. KESANAKURTI and of the mechanisms of community assembly has been limited by our ability to identify plants based on root tissue barcoding marker, for investigating spatial patterns of root diversity, and relate observed patterns

  4. 36 CFR 219.9 - Diversity of plant and animal communities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Diversity of plant and animal communities. 219.9 Section 219.9 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PLANNING National Forest System Land Management Planning § 219.9 Diversity of plant and animal communities. This section adopts...

  5. Experimental warming causes rapid loss of plant diversity in New England salt marshes

    E-print Network

    Bertness, Mark D.

    LETTER Experimental warming causes rapid loss of plant diversity in New England salt marshes Keryn predict the decline of a diverse assemblage of mid-latitude salt marsh plants, based on an ecosystem warming experiment. In New England salt marshes, a guild of halophytic forbs occupies stressful

  6. Are herbage yield and yield stability affected by plant species diversity in sown pasture mixtures?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A tenet of plant biodiversity theory in grasslands is that increased diversity contributes to the stability of ecosystems. In managed grasslands, such as pastures, greater stability of herbage production as a result of increased plant species diversity would be beneficial. In this study, I combined ...

  7. Herbivore impact on grassland plant diversity depends on habitat productivity and herbivore size

    E-print Network

    Thomas, David D.

    LETTER Herbivore impact on grassland plant diversity depends on habitat productivity and herbivore-year field experiment at seven grassland sites in North America and Europe. We show that assemblages be key determinants of grassland plant species composition and diversity (McNaughton et al. 1989; Collins

  8. Agricultural and biofuel implications of a species diversity experiment with native perennial grassland plants

    E-print Network

    Thomas, David D.

    grassland plants Lee R. DeHaan a, *, Sanford Weisberg b , David Tilman c , Dario Fornara c a The Land exceeding those of less diverse plots composed of randomly selected grassland species (Tilman et al., 2001 diversity Biomass Biofuel Perennial Grassland Agriculture Plant breeding A B S T R A C T Two primary

  9. Climate-suitable planting as a strategy for maintaining forest productivity and functional diversity.

    PubMed

    Duveneck, Matthew J; Scheller, Robert M

    2015-09-01

    Within the time frame of the longevity of tree species, climate change will change faster than the ability of natural tree migration. Migration lags may result in reduced productivity and reduced diversity in forests under current management and climate change. We evaluated the efficacy of planting climate-suitable tree species (CSP), those tree species with current or historic distributions immediately south of a focal landscape, to maintain or increase aboveground biomass productivity, and species and functional diversity. We modeled forest change with the LANDIS-II forest simulation model for 100 years (2000-2100) at a 2-ha cell resolution and five-year time steps within two landscapes in the Great Lakes region (northeastern Minnesota and northern lower Michigan, USA). We compared current climate to low- and high-emission futures. We simulated a low-emission climate future with the Intergovernmental Panel on Climate Change (IPCC) 2007 B1 emission scenario and the Parallel Climate Model Global Circulation Model (GCM). We simulated a high-emission climate future with the IPCC A1FI emission scenario and the Geophysical Fluid Dynamics Laboratory (GFDL) GCM. We compared current forest management practices (business-as-usual) to CSP management. In the CSP scenario, we simulated a target planting of 5.28% and 4.97% of forested area per five-year time step in the Minnesota and Michigan landscapes, respectively. We found that simulated CSP species successfully established in both landscapes under all climate scenarios. The presence of CSP species generally increased simulated aboveground biomass. Species diversity increased due to CSP; however, the effect on functional diversity was variable. Because the planted species were functionally similar to many native species, CSP did not result in a consistent increase nor decrease in functional diversity. These results provide an assessment of the potential efficacy and limitations of CSP management. These results have management implications for sites where diversity and productivity are expected to decline. Future efforts to restore a specific species or forest type may not be possible, but CSP may sustain a more general ecosystem service (e.g., aboveground biomass). PMID:26552272

  10. Invertebrate herbivory increases along an experimental gradient of grassland plant diversity.

    PubMed

    Loranger, Hannah; Weisser, Wolfgang W; Ebeling, Anne; Eggers, Till; De Luca, Enrica; Loranger, Jessy; Roscher, Christiane; Meyer, Sebastian T

    2014-01-01

    Plant diversity is a key driver of ecosystem functioning best documented for its influence on plant productivity. The strength and direction of plant diversity effects on species interactions across trophic levels are less clear. For example, with respect to the interactions between herbivorous invertebrates and plants, a number of competing hypotheses have been proposed that predict either increasing or decreasing community herbivory with increasing plant species richness. We investigated foliar herbivory rates and consumed leaf biomass along an experimental grassland plant diversity gradient in year eight after establishment. The gradient ranged from one to 60 plant species and manipulated also functional group richness (from one to four functional groups-legumes, grasses, small herbs, and tall herbs) and plant community composition. Measurements in monocultures of each plant species showed that functional groups differed in the quantity and quality of herbivory damage they experienced, with legumes being more damaged than grasses or non-legume herbs. In mixed plant communities, herbivory increased with plant diversity and the presence of two key plant functional groups in mixtures had a positive (legumes) and a negative (grasses) effect on levels of herbivory. Further, plant community biomass had a strong positive impact on consumed leaf biomass, but little effect on herbivory rates. Our results contribute detailed data from a well-established biodiversity experiment to a growing body of evidence suggesting that an increase of herbivory with increasing plant diversity is the rule rather than an exception. Considering documented effects of herbivory on other ecosystem functions and the increase of herbivory with plant diversity, levels of herbivory damage might not only be a result, but also a trigger within the diversity-productivity relationship. PMID:23907703

  11. Invasive plant erodes local song diversity in a migratory passerine.

    PubMed

    Ortega, Yvette K; Benson, Aubree; Greene, Erick

    2014-02-01

    Exotic plant invasions threaten ecosystems globally, but we still know little about the specific consequences for animals. Invasive plants can alter the quality of breeding habitat for songbirds, thereby impacting important demographic traits such as dispersal, philopatry, and age structure. These demographic effects may in turn alter song-learning conditions to affect song structure and diversity. We studied Chipping Sparrows (Spizella passerina) breeding in six savannas that were either dominated by native vegetation or invaded by spotted knapweed (Centaurea stoebe), an exotic forb known to diminish food resources and reproductive success. Here, we report that the prevalence of older birds was relatively low in knapweed-invaded habitat, where recruitment of yearlings compensated for diminished site fidelity to sustain territory abundance. In both habitat types, yearling males tended to adopt songs similar to their neighbors and match the songs of older birds rather than introducing new song types, a pattern seen in many songbird species. As a consequence, in invaded habitat where age structure was skewed away from older birds serving as potential song models, yearlings converged on fewer song types. Similarity of songs among individuals was significantly higher and the overall number of song types averaged nearly 20% lower in invaded relative to native habitat. Degradation of habitat quality generally impacts site fidelity and age ratios in migratory songbirds and hence may commonly alter song-learning conditions. Associated shifts in song attributes known to influence reproductive success could in turn enforce demographic declines driven by habitat degradation. Local song structure may serve as an important indicator of habitat quality and population status for songbirds. PMID:24669738

  12. Plant Ecology & Diversity Vol. 3, No. 2, June 2010, 103108

    E-print Network

    Jiggins, Francis

    both deplete genetic diversity and increase genetic differentiation towards the margins of a species work showed that this colonisation resulted in a decrease of phenotypic and genetic diversity from on genetic differentiation may be independent of the effects on genetic diversity. They point

  13. Ground Layer Plant Species Turnover and Beta Diversity in Southern-European Old-Growth Forests

    PubMed Central

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

    2014-01-01

    Different assembly processes may simultaneously affect local-scale variation of species composition in temperate old-growth forests. Ground layer species diversity reflects chance colonization and persistence of low-dispersal species, as well as fine-scale environmental heterogeneity. The latter depends on both purely abiotic factors, such as soil properties and topography, and factors primarily determined by overstorey structure, such as light availability. Understanding the degree to which plant diversity in old-growth forests is associated with structural heterogeneity and/or to dispersal limitation will help assessing the effectiveness of silvicultural practices that recreate old-growth patterns and structures for the conservation or restoration of plant diversity. We used a nested sampling design to assess fine-scale species turnover, i.e. the proportion of species composition that changes among sampling units, across 11 beech-dominated old-growth forests in Southern Europe. For each stand, we also measured a wide range of environmental and structural variables that might explain ground layer species turnover. Our aim was to quantify the relative importance of dispersal limitation in comparison to that of stand structural heterogeneity while controlling for other sources of environmental heterogeneity. For this purpose, we used multiple regression on distance matrices at the within-stand extent, and mixed effect models at the extent of the whole dataset. Species turnover was best predicted by structural and environmental heterogeneity, especially by differences in light availability and in topsoil nutrient concentration and texture. Spatial distances were significant only in four out of eleven stands with a relatively low explanatory power. This suggests that structural heterogeneity is a more important driver of local-scale ground layer species turnover than dispersal limitation in southern European old-growth beech forests. PMID:24748155

  14. Differential effects of plant diversity on functional trait variation of grass species

    PubMed Central

    Gubsch, Marlén; Buchmann, Nina; Schmid, Bernhard; Schulze, Ernst-Detlef; Lipowsky, Annett; Roscher, Christiane

    2011-01-01

    Background and Aims Functional trait differences and trait adjustment in response to influences of the biotic environment could reflect niche partitioning among species. In this study, we tested how variation in above-ground plant traits, chosen as indicators for light and nitrogen acquisition and use, differs among taxonomically closely related species (Poaceae) to assess their potential for niche segregation at increasing plant diversity. Methods Traits of 12 grass species were measured in experimental grasslands (Jena Experiment) of varying species richness (from 1 to 60) and presence of particular functional groups (grasses, legumes, tall herbs and small herbs). Key Results Grass species increased shoot and leaf length, investment into supporting tissue (stem mass fraction) and specific leaf area as well as reduced foliar ?13C values with increasing species richness, indicating higher efforts for light acquisition. These species-richness effects could in part be explained by a higher probability of legume presence in more diverse communities. Leaf nitrogen concentrations increased and biomas s : N ratios in shoots decreased when grasses grew with legumes, indicating an improved nitrogen nutrition. Foliar ?15N values of grasses decreased when growing with legumes suggesting the use of depleted legume-derived N, while decreasing ?15N values with increasing species richness indicated a shift in the uptake of different N sources. However, efforts to optimize light and nitrogen acquisition by plastic adjustment of traits in response to species richness and legume presence, varied significantly among grass species. It was possible to show further that trait adjustment of grass species increased niche segregation in more diverse plant communities but that complementarity through niche separation may differ between light and nutrient acquisition. Conclusions The results suggest that even among closely related species such as grasses different strategies are used to cope with neighbours. This lack in redundancy in turn may facilitate complementary resource use and coexistence. PMID:21068024

  15. Disparate effects of plant genotypic diversity on foliage and litter arthropod communities

    SciTech Connect

    Crutsinger, Greg; Reynolds, Nicholas; Classen, Aimee T; Sanders, Dr. Nathan James

    2008-01-01

    Intraspecific diversity within plant species is increasingly recognized as an important influence on the structure of associated arthropod communities, though whether there are congruent responses of above- and belowground communities to intraspecific diversity remains unclear. In this study, we compare the effects of host-plant genotype and genotypic diversity of the perennial plant, Solidago altissima, on the arthropod community associated with living plant tissue (foliage-based community) and microarthropods associated with leaf litter (litter-based community). We found that variation among host-plant genotypes had strong effects on the diversity and composition of foliage-based arthropods, but only weak influence on litter-based microarthropods. Furthermore, host-plant genotypic diversity was positively related to the abundance and diversity of foliage-based arthropods, including herbivore and predator trophic levels. In contrast, there were minimal effects of genotypic diversity in litter on microarthropods. Our study illustrates that incorporating both above- and belowground perspective into community genetics studies leads to very different conclusions about the importance of intraspecific diversity, than when considering aboveground responses in isolation.

  16. Molecular assessment of genetic diversity in mung bean germplasm.

    PubMed

    Lavanya, G Roopa; Srivastava, Jyoti; Ranade, Shirish A

    2008-04-01

    RAPD profiles were used to identify the extent of diversity among 54 accessions of mung bean that included both improved and local land races. Out of the 40 primers screened, seven primers generated 174 amplification products with an average of 24.85 bands per primer. The RAPD profiles were analysed for Jaccard's similarity coefficients that was found to be in the range from 0 to 0.48, indicating the presence of wide range of genetic diversity at molecular level. Cluster analysis was carried out based on distances (1-similarity coefficient) using neighbour-joining method in Free Tree package. The dendrogram resolved all the accessions into two major clusters, I (with 11 accessions) and II (with 43 accessions). However, the cluster was further divided into four subclusters (II A with six, II B with nine, II C with 15 and II D with 13 accessions). The distribution of the accessions in different clusters and subclusters appears to be related to their performance in field conditions for 10 morphological traits that were scored. This study indicated that the RAPD profiles provide an easy and simple technique for preliminary genetic diversity assessment of mung bean accessions that may reflect morphological trait differences among them. PMID:18560176

  17. Slippery or sticky? Functional diversity in the trapping strategy of Nepenthes carnivorous plants

    E-print Network

    Forterre, Yoël

    Slippery or sticky? Functional diversity in the trapping strategy of Nepenthes carnivorous plants Paysages et Jardin Botanique de Plantes Carnivores, Peyrusse-Massas, France Author for correspondence words: biological trade-off, carnivorous pitcher plant, digestive fluid, leaf wax, Nepenthes, trapping

  18. Metabarcoding as a tool for investigating arthropod diversity in Nepenthes pitcher plants

    E-print Network

    Pierce, Naomi E.

    amplicon sequencing, carnivorous plant, insect, microcosm, network. INTRODUCTION Tropical rainforests house. 2011; Taberlet et al. 2012). Carnivorous plants have been recognized as hosts for insects sinceMetabarcoding as a tool for investigating arthropod diversity in Nepenthes pitcher plants LEONORA S

  19. A keystone predator controls bacterial diversity in the pitcher-plant (Sarracenia purpurea) microecosystem

    E-print Network

    Pringle, Anne

    - filled leaves of the carnivorous pitcher-plant Sarrace- nia purpurea includes arthropods, protozoa of such systems available for field studies. That makes the model ecosystem of the carnivorous pitcher- plantA keystone predator controls bacterial diversity in the pitcher-plant (Sarracenia purpurea

  20. NORTHEASTERN NATURALIST2002 9(3):267284 ANT DIVERSITY IN PITCHER-PLANT BOGS

    E-print Network

    Gotelli, Nicholas J.

    and the density of the carnivorous plant Sarracenia purpurea; and nutrient availability. Among Massachusetts bogs) at Hawley Bog in northwestern Massachusetts, we found that the dominant prey of this carnivorous plant wereNORTHEASTERN NATURALIST2002 9(3):267­284 ANT DIVERSITY IN PITCHER-PLANT BOGS OF MASSACHUSETTS AARON

  1. PLANT -MITE MUTUALISM IN COFFEA ARABICA: A COMPARISON OF MITE DIVERSITY BETWEEN COFFEE PLANTATION AND

    E-print Network

    associated with predatory mites. There were no spider mites inside domatia of coffee plants even thoughPLANT - MITE MUTUALISM IN COFFEA ARABICA: A COMPARISON OF MITE DIVERSITY BETWEEN COFFEE PLANTATION AND NATURAL FOREST Prepared by Sivu Situngu Plants species with structures known as leaf domatia are usually

  2. Seven years of carbon dioxide enrichment, nitrogen fertilization and plant diversity influence arbuscular

    E-print Network

    Thomas, David D.

    Seven years of carbon dioxide enrichment, nitrogen fertilization and plant diversity influence by examining the joint effects of carbon dioxide (CO2) enrichment, nitrogen (N) fertilization and plant. Increasing atmospheric carbon dioxide (CO2) influences plant water relations and often pref- erentially

  3. Habitats as Complex Odour Environments: How Does Plant Diversity Affect Herbivore and Parasitoid Orientation?

    PubMed Central

    Wäschke, Nicole; Hardge, Kristin; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2014-01-01

    Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weevi?s capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weevi?s foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts. PMID:24416354

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

    PubMed Central

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

    2014-01-01

    Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at high diversity may lead to reduced investment in defenses via growth-defense trade-offs. Alternatively, positive effects of plant diversity on plant growth may lead to increased herbivore abundance which in turn leads to a greater investment in plant defenses. The magnitude of trait variation underlying diversity effects is usually greater among species than among genotypes within a given species, so plant species diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects. Here we compared the relative importance of plant genotypic and species diversity on anti-herbivore defenses and whether such effects are mediated indirectly via diversity effects on plant growth and/or herbivore damage. To this end, we performed a large-scale field experiment where we manipulated genotypic diversity of big-leaf mahogany (Swietenia macrophylla) and tree species diversity, and measured effects on mahogany growth, damage by the stem-boring specialist caterpillar Hypsipyla grandella, and defensive traits (polyphenolics and condensed tannins in stem and leaves). We found that both forms of plant diversity had positive effects on stem (but not leaf) defenses. However, neither source of diversity influenced mahogany growth, and diversity effects on defenses were not mediated by either growth-defense trade-offs or changes in stem-borer damage. Although the mechanism(s) of diversity effects on plant defenses are yet to be determined, our study is one of the few to test for and show producer diversity effects on plant chemical defenses. PMID:25141305

  5. Single nucleotide polymorphisms for assessing genetic diversity in castor bean (Ricinus communis)

    PubMed Central

    2010-01-01

    Background Castor bean (Ricinus communis) is an agricultural crop and garden ornamental that is widely cultivated and has been introduced worldwide. Understanding population structure and the distribution of castor bean cultivars has been challenging because of limited genetic variability. We analyzed the population genetics of R. communis in a worldwide collection of plants from germplasm and from naturalized populations in Florida, U.S. To assess genetic diversity we conducted survey sequencing of the genomes of seven diverse cultivars and compared the data to a reference genome assembly of a widespread cultivar (Hale). We determined the population genetic structure of 676 samples using single nucleotide polymorphisms (SNPs) at 48 loci. Results Bayesian clustering indicated five main groups worldwide and a repeated pattern of mixed genotypes in most countries. High levels of population differentiation occurred between most populations but this structure was not geographically based. Most molecular variance occurred within populations (74%) followed by 22% among populations, and 4% among continents. Samples from naturalized populations in Florida indicated significant population structuring consistent with local demes. There was significant population differentiation for 56 of 78 comparisons in Florida (pairwise population ?PT values, p < 0.01). Conclusion Low levels of genetic diversity and mixing of genotypes have led to minimal geographic structuring of castor bean populations worldwide. Relatively few lineages occur and these are widely distributed. Our approach of determining population genetic structure using SNPs from genome-wide comparisons constitutes a framework for high-throughput analyses of genetic diversity in plants, particularly in species with limited genetic diversity. PMID:20082707

  6. Habitat Heterogeneity Affects Plant and Arthropod Species Diversity and Turnover in Traditional Cornfields

    PubMed Central

    Martínez, Eliana; Rös, Matthias; Bonilla, María Argenis; Dirzo, Rodolfo

    2015-01-01

    The expansion of the agricultural frontier by the clearing of remnant forests has led to human-dominated landscape mosaics. Previous studies have evaluated the effect of these landscape mosaics on arthropod diversity at local spatial scales in temperate and tropical regions, but little is known about fragmentation effects in crop systems, such as the complex tropical traditional crop systems that maintain a high diversity of weeds and arthropods in low-Andean regions. To understand the factors that influence patterns of diversity in human-dominated landscapes, we investigate the effect of land use types on plant and arthropod diversity in traditionally managed cornfields, via surveys of plants and arthropods in twelve traditional cornfields in the Colombian Andes. We estimated alpha and beta diversity to analyze changes in diversity related to land uses within a radius of 100 m to 1 km around each cornfield. We observed that forests influenced alpha diversity of plants, but not of arthropods. Agricultural lands had a positive relationship with plants and herbivores, but a negative relationship with predators. Pastures positively influenced the diversity of plants and arthropods. In addition, forest cover seemed to influence changes in plant species composition and species turnover of herbivore communities among cornfields. The dominant plant species varied among fields, resulting in high differentiation of plant communities. Predator communities also exhibited high turnover among cornfields, but differences in composition arose mainly among rare species. The crop system evaluated in this study represents a widespread situation in the tropics, therefore, our results can be of broad significance. Our findings suggest that traditional agriculture may not homogenize biological communities, but instead could maintain the regional pool of species through high beta diversity. PMID:26197473

  7. Protein change in plant evolution: tracing one thread connecting molecular and phenotypic diversity

    PubMed Central

    Bartlett, Madelaine E.; Whipple, Clinton J.

    2013-01-01

    Proteins change over the course of evolutionary time. New protein-coding genes and gene families emerge and diversify, ultimately affecting an organism’s phenotype and interactions with its environment. Here we survey the range of structural protein change observed in plants and review the role these changes have had in the evolution of plant form and function. Verified examples tying evolutionary change in protein structure to phenotypic change remain scarce. We will review the existing examples, as well as draw from investigations into domestication, and quantitative trait locus (QTL) cloning studies searching for the molecular underpinnings of natural variation. The evolutionary significance of many cloned QTL has not been assessed, but all the examples identified so far have begun to reveal the extent of protein structural diversity tolerated in natural systems. This molecular (and phenotypic) diversity could come to represent part of natural selection’s source material in the adaptive evolution of novel traits. Protein structure and function can change in many distinct ways, but the changes we identified in studies of natural diversity and protein evolution were predicted to fall primarily into one of six categories: altered active and binding sites; altered protein–protein interactions; altered domain content; altered activity as an activator or repressor; altered protein stability; and hypomorphic and hypermorphic alleles. There was also variability in the evolutionary scale at which particular changes were observed. Some changes were detected at both micro- and macroevolutionary timescales, while others were observed primarily at deep or shallow phylogenetic levels. This variation might be used to determine the trajectory of future investigations in structural molecular evolution. PMID:24124420

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

    PubMed Central

    Li, Yunzhao; Du, Siyao; Han, Guangxuan; Qu, Fanzhu; Wang, Guangmei; Fu, Yuqin; Zhan, Chao

    2014-01-01

    The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of ?T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20?m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing ?-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20?m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion. PMID:25147872

  9. Forest species diversity reduces disease risk in a generalist plant pathogen invasion

    USGS Publications Warehouse

    Haas, Sarah E.; Hooten, Mevin B.; Rizzo, David M.; Meentemeyer, Ross K.

    2011-01-01

    Empirical evidence suggests that biodiversity loss can increase disease transmission, yet our understanding of the 'diversity-disease hypothesis' for generalist pathogens in natural ecosystems is limited. We used a landscape epidemiological approach to examine two scenarios regarding diversity effects on the emerging plant pathogen Phytophthora ramorum across a broad, heterogeneous ecoregion: (1) an amplification effect exists where disease risk is greater in areas with higher plant diversity due to the pathogen's wide host range, or (2) a dilution effect where risk is reduced with increasing diversity due to lower competency of alternative hosts. We found evidence for pathogen dilution, whereby disease risk was lower in sites with higher species diversity, after accounting for potentially confounding effects of host density and landscape heterogeneity. Our results suggest that although nearly all plants in the ecosystem are hosts, alternative hosts may dilute disease transmission by competent hosts, thereby buffering forest health from infectious disease.

  10. -Plant diversity, biogeography, and environment in Iberia: Patterns and possible causal factors -245 Journal of Vegetation Science 13: 245-258, 2002

    E-print Network

    Rey Benayas, José María

    - Plant diversity, biogeography, and environment in Iberia: Patterns and possible causal factors evapotranspiration; WHC = Water holding capacity. Plant diversity, biogeography and environment in Iberia: Patterns

  11. Relationships between plant diversity and grasshopper diversity and abundance in the Little Missouri National Grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A continuing challenge in Orthoptera ecology is to understand what determines grasshopper species diversity at a given site. In this study, the objective was to determine if variation in grasshopper abundance and diversity between 23 sites in western North Dakota (USA) could be explained by variatio...

  12. Plant Wide Assessment for SIFCO Industries, Inc.

    SciTech Connect

    Kelly Kissock, Arvind Thekdi et. al.

    2005-07-06

    Sifco Industries carreid out a plant wide energy assessment under a collaborative program with the U.S. Department of Energy during October 2004 to September 2005. During the year, personnel from EIS, E3M, DPS, BuyCastings.Com, and Sifco plant facilities and maintenance personnel, as a team collected energy use, construction, process, equipment and operational information about the plant. Based on this information, the team identified 13 energy savings opportunities. Near term savings opportunities have a total potential savings of about $1,329,000 per year and a combined simple payback of about 11 months. Implementation of these recommendations would reduce CO2 emissions by about 16,000,000 pounds per year, which would reduce overall plant CO2 emissions by about 45%. These totals do not include another $830,000 per year in potential savings with an estimated 9-month payback, from converting the forging hammers from steam to compressed air.

  13. High plant diversity in Oregon tidal wetlands and multiple threats to its persistence

    EPA Science Inventory

    Tidal wetlands in the Pacific Northwest occur in coastal estuaries differing widely in size, relative freshwater inputs, and degree of watershed development. To better understand patterns of plant diversity in tidal wetlands across the region and potential climate change effects ...

  14. Microbiome interplay: plants alter microbial abundance and diversity within the built environment.

    PubMed

    Mahnert, Alexander; Moissl-Eichinger, Christine; Berg, Gabriele

    2015-01-01

    The built indoor microbiome has importance for human health. Residents leave their microbial fingerprint but nothing is known about the transfer from plants. Our hypothesis that indoor plants contribute substantially to the microbial abundance and diversity in the built environment was experimentally confirmed as proof of principle by analyzing the microbiome of the spider plant Chlorophytum comosum in relation to their surroundings. The abundance of Archaea, Bacteria, and Eukaryota (fungi) increased on surrounding floor and wall surfaces within 6 months of plant isolation in a cleaned indoor environment, whereas the microbial abundance on plant leaves and indoor air remained stable. We observed a microbiome shift: the bacterial diversity on surfaces increased significantly but fungal diversity decreased. The majority of cells were intact at the time of samplings and thus most probably alive including diverse Archaea as yet unknown phyllosphere inhabitants. LEfSe and network analysis showed that most microbes were dispersed from plant leaves to the surrounding surfaces. This led to an increase of specific taxa including spore-forming fungi with potential allergic potential but also beneficial plant-associated bacteria, e.g., Paenibacillus. This study demonstrates for the first time that plants can alter the microbiome of a built environment, which supports the significance of plants and provides insights into the complex interplay of plants, microbiomes and human beings. PMID:26379656

  15. Microbiome interplay: plants alter microbial abundance and diversity within the built environment

    PubMed Central

    Mahnert, Alexander; Moissl-Eichinger, Christine; Berg, Gabriele

    2015-01-01

    The built indoor microbiome has importance for human health. Residents leave their microbial fingerprint but nothing is known about the transfer from plants. Our hypothesis that indoor plants contribute substantially to the microbial abundance and diversity in the built environment was experimentally confirmed as proof of principle by analyzing the microbiome of the spider plant Chlorophytum comosum in relation to their surroundings. The abundance of Archaea, Bacteria, and Eukaryota (fungi) increased on surrounding floor and wall surfaces within 6 months of plant isolation in a cleaned indoor environment, whereas the microbial abundance on plant leaves and indoor air remained stable. We observed a microbiome shift: the bacterial diversity on surfaces increased significantly but fungal diversity decreased. The majority of cells were intact at the time of samplings and thus most probably alive including diverse Archaea as yet unknown phyllosphere inhabitants. LEfSe and network analysis showed that most microbes were dispersed from plant leaves to the surrounding surfaces. This led to an increase of specific taxa including spore-forming fungi with potential allergic potential but also beneficial plant-associated bacteria, e.g., Paenibacillus. This study demonstrates for the first time that plants can alter the microbiome of a built environment, which supports the significance of plants and provides insights into the complex interplay of plants, microbiomes and human beings. PMID:26379656

  16. Plant Diversity and Invasives in Blue Oak Savannas of the Southern Sierra Nevada1

    E-print Network

    Plant Diversity and Invasives in Blue Oak Savannas of the Southern Sierra Nevada1 Jon E. Keeley2 Abstract Blue oak savannas were found to be substantially more diverse at all scales from localized point of the understory flora in these blue oak savannas, comprising three- fourths of the species at the smallest scale

  17. Global Patterns of Liverwort Diversity, Distribution, and Floristic Knowledge EARLY LAND PLANTS TODAY: GLOBAL PATTERNS

    E-print Network

    Söderström, Lars

    425 Global Patterns of Liverwort Diversity, Distribution, and Floristic Knowledge EARLY LAND PLANTS TODAY: GLOBAL PATTERNS OF LIVERWORT DIVERSITY, DISTRIBUTION, AND FLORISTIC KNOWLEDGE MATT VON KONRAT1, Athens, U.S.A. * Corresponding author: mvonkonrat@fieldmuseum.org SUMMARY Liverworts (Marchantiophyta

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

    USGS Publications Warehouse

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

    2013-01-01

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

  19. Biodiversity assessment among two Nebraska prairies: a comparison between traditional and phylogenetic diversity indices

    PubMed Central

    Aust, Shelly K.; Ahrendsen, Dakota L.

    2015-01-01

    Abstract Background Conservation of the evolutionary diversity among organisms should be included in the selection of priority regions for preservation of Earth’s biodiversity. Traditionally, biodiversity has been determined from an assessment of species richness (S), abundance, evenness, rarity, etc. of organisms but not from variation in species’ evolutionary histories. Phylogenetic diversity (PD) measures evolutionary differences between taxa in a community and is gaining acceptance as a biodiversity assessment tool. However, with the increase in the number of ways to calculate PD, end-users and decision-makers are left wondering how metrics compare and what data are needed to calculate various metrics. New information In this study, we used massively parallel sequencing to generate over 65,000 DNA characters from three cellular compartments for over 60 species in the asterid clade of flowering plants. We estimated asterid phylogenies from character datasets of varying nucleotide quantities, and then assessed the effect of varying character datasets on resulting PD metric values. We also compared multiple PD metrics with traditional diversity indices (including S) among two endangered grassland prairies in Nebraska (U.S.A.). Our results revealed that PD metrics varied based on the quantity of genes used to infer the phylogenies; therefore, when comparing PD metrics between sites, it is vital to use comparable datasets. Additionally, various PD metrics and traditional diversity indices characterize biodiversity differently and should be chosen depending on the research question. Our study provides empirical results that reveal the value of measuring PD when considering sites for conservation, and it highlights the usefulness of using PD metrics in combination with other diversity indices when studying community assembly and ecosystem functioning. Ours is just one example of the types of investigations that need to be conducted across the tree of life and across varying ecosystems in order to build a database of phylogenetic diversity assessments that lead to a pool of results upon which a guide through the plethora of PD metrics may be prepared for use by ecologists and conservation planners. PMID:26312052

  20. Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Doethideomycetes Fungi

    SciTech Connect

    Ohm, Robin A.; Feau, Nicolas; Henrissat, Bernard; Schoch, Conrad L.; Horwitz, Benjamin A.; Barry, Kerrie W.; Condon, Bradford J.; Copeland, Alex C.; Dhillon, Braham; Glaser, Fabien; Hesse, Cedar N.; Kosti, Idit; LaButti, Kurt; Lindquist, Erika A.; Lucas, Susan; Salamov, Asaf A.; Bradshaw, Rosie E.; Ciuffetti, Lynda; Hamelin, Richard C.; Kema, Gert H. J.; Lawrence, Christopher; Scott, James A.; Spatafora, Joseph W.; Turgeon, B. Gillian; de Wit, Pierre J. G. M.; Zhong, Shaobin; Goodwin, Stephen B.; Grigoriev, Igor V.

    2012-03-13

    The class of Dothideomycetes is one of the largest and most diverse groups of fungi. Many are plant pathogens and pose a serious threat to agricultural crops grown for biofuel, food or feed. Most Dothideomycetes have only a single host and related species can have very diverse host plants. Eighteen genomes of Dothideomycetes have currently been sequenced by the Joint Genome Institute and other sequencing centers. Here we describe the results of comparative analyses of the fungi in this group.

  1. Evaluating Plant Functional Diversity in an Organic Intercropping System 

    E-print Network

    Franco, Jose

    2015-04-01

    Overyielding, a phenomenon whereby plant production in mixture exceeds that of production in monoculture, has been attributed to complementary use of resources by different plant functional types. Few studies have examined ...

  2. Plant Growth Promotion Potential Is Equally Represented in Diverse Grapevine Root-Associated Bacterial Communities from Different Biopedoclimatic Environments

    PubMed Central

    Fusi, Marco; Cherif, Ameur; Abou-Hadid, Ayman; El-Bahairy, Usama; Sorlini, Claudia; Daffonchio, Daniele

    2013-01-01

    Plant-associated bacteria provide important services to host plants. Environmental factors such as cultivar type and pedoclimatic conditions contribute to shape their diversity. However, whether these environmental factors may influence the plant growth promoting (PGP) potential of the root-associated bacteria is not widely understood. To address this issue, the diversity and PGP potential of the bacterial assemblage associated with the grapevine root system of different cultivars in three Mediterranean environments along a macrotransect identifying an aridity gradient were assessed by culture-dependent and independent approaches. According to 16S rRNA gene PCR-DGGE, the structure of endosphere and rhizosphere bacterial communities was highly diverse (P = 0.03) and was associated with a cultivar/latitudinal/climatic effect. Despite being diverse, the bacterial communities associated with Egyptian grapevines shared a higher similarity with the Tunisian grapevines than those cultivated in North Italy. A similar distribution, according to the cultivar/latitude/aridity gradients, was observed for the cultivable bacteria. Many isolates (23%) presented in vitro multiple stress resistance capabilities and PGP activities, the most frequent being auxin synthesis (82%), insoluble phosphate solubilisation (61%), and ammonia production (70%). The comparable numbers and types of potential PGP traits among the three different environmental settings indicate a strong functional homeostasis of beneficial bacteria associated with grape root. PMID:23878810

  3. Plant growth promotion potential is equally represented in diverse grapevine root-associated bacterial communities from different biopedoclimatic environments.

    PubMed

    Marasco, Ramona; Rolli, Eleonora; Fusi, Marco; Cherif, Ameur; Abou-Hadid, Ayman; El-Bahairy, Usama; Borin, Sara; Sorlini, Claudia; Daffonchio, Daniele

    2013-01-01

    Plant-associated bacteria provide important services to host plants. Environmental factors such as cultivar type and pedoclimatic conditions contribute to shape their diversity. However, whether these environmental factors may influence the plant growth promoting (PGP) potential of the root-associated bacteria is not widely understood. To address this issue, the diversity and PGP potential of the bacterial assemblage associated with the grapevine root system of different cultivars in three Mediterranean environments along a macrotransect identifying an aridity gradient were assessed by culture-dependent and independent approaches. According to 16S rRNA gene PCR-DGGE, the structure of endosphere and rhizosphere bacterial communities was highly diverse (P = 0.03) and was associated with a cultivar/latitudinal/climatic effect. Despite being diverse, the bacterial communities associated with Egyptian grapevines shared a higher similarity with the Tunisian grapevines than those cultivated in North Italy. A similar distribution, according to the cultivar/latitude/aridity gradients, was observed for the cultivable bacteria. Many isolates (23%) presented in vitro multiple stress resistance capabilities and PGP activities, the most frequent being auxin synthesis (82%), insoluble phosphate solubilisation (61%), and ammonia production (70%). The comparable numbers and types of potential PGP traits among the three different environmental settings indicate a strong functional homeostasis of beneficial bacteria associated with grape root. PMID:23878810

  4. Modeling terrestrial carbon and water dynamics across climatic gradients: does plant trait diversity matter?

    PubMed

    Pappas, Christoforos; Fatichi, Simone; Burlando, Paolo

    2016-01-01

    Plant trait diversity in many vegetation models is crudely represented using a discrete classification of a handful of 'plant types' (named plant functional types; PFTs). The parameterization of PFTs reflects mean properties of observed plant traits over broad categories ignoring most of the inter- and intraspecific plant trait variability. Taking advantage of a multivariate leaf-trait distribution (leaf economics spectrum), as well as documented plant drought strategies, we generate an ensemble of hypothetical species with coordinated attributes, rather than using few PFTs. The behavior of these proxy species is tested using a mechanistic ecohydrological model that translates plant traits into plant performance. Simulations are carried out for a range of climates representative of different elevations and wetness conditions in the European Alps. Using this framework we investigate the sensitivity of ecosystem response to plant trait diversity and compare it with the sensitivity to climate variability. Plant trait diversity leads to highly divergent vegetation carbon dynamics (fluxes and pools) and to a lesser extent water fluxes (transpiration). Abiotic variables, such as soil water content and evaporation, are only marginally affected. These results highlight the need for revising the representation of plant attributes in vegetation models. Probabilistic approaches, based on observed multivariate whole-plant trait distributions, provide a viable alternative. PMID:26389742

  5. EFB 435/635 Flowering Plants: Diversity, Evolution, & Systematics Fall 2014 08/25/14 Page 1 of 5

    E-print Network

    Hui, Bowen

    EFB 435/635 Flowering Plants: Diversity, Evolution, & Systematics Fall 2014 08/25/14 Page 1 of 5 of the diversity and evolution of flowering plants, including their ecological, economic and cultural significance. Half of the course topics cover major concepts in plant evolution and systematics, including plant

  6. Global patterns of plant diversity and floristic knowledge

    E-print Network

    Kreft, Holger

    @uni-bonn.de ABSTRACT Aims We present the first global map of vascular plant species richness by ecoregion and compare documents and pinpoint geographical gaps in our understanding of the global vascular plant flora. Finally studied than those poor in vascular plants. Similarly, only in a few biomes did we find significant

  7. ?-Diversity of Functional Groups of Woody Plants in a Tropical Dry Forest in Yucatan

    PubMed Central

    López-Martínez, Jorge Omar; Sanaphre-Villanueva, Lucía; Dupuy, Juan Manuel; Hernández-Stefanoni, José Luis; Meave, Jorge Arturo; Gallardo-Cruz, José Alberto

    2013-01-01

    Two main theories have attempted to explain variation in plant species composition (?-diversity). Niche theory proposes that most of the variation is related to environment (environmental filtering), whereas neutral theory posits that dispersal limitation is the main driver of ?-diversity. In this study, we first explored how ?- and ?-diversity of plant functional groups defined by growth form (trees, shrubs and lianas, which represent different strategies of resource partitioning), and dispersal syndrome (autochory, anemochory and zoochory, which represent differences in dispersal limitation) vary with successional age and topographic position in a tropical dry forest. Second, we examined the effects of environmental, spatial, and spatially-structured environmental factors on ?-diversity of functional groups; we used the spatial structure of sampling sites as a proxy for dispersal limitation, and elevation, soil properties and forest stand age as indicators of environmental filtering. We recorded 200 species and 22,245 individuals in 276 plots; 120 species were trees, 41 shrubs and 39 lianas. We found that ?-diversity was highest for shrubs, intermediate for lianas and lowest for trees, and was slightly higher for zoochorous than for autochorous and anemochorous species. All three dispersal syndromes, trees and shrubs varied in composition among vegetation classes (successional age and topographic position), whilst lianas did not. ?-diversity was influenced mostly by proxies of environmental filtering, except for shrubs, for which the influence of dispersal limitation was more important. Stand age and topography significantly influenced ?-diversity across functional groups, but showed a low influence on ?-diversity –possibly due to the counterbalancing effect of resprouting on plant distribution and composition. Our results show that considering different plant functional groups reveals important differences in both ?- and ?-diversity patterns and correlates that are not apparent when focusing on overall woody plant diversity, and that have important implications for ecological theory and biodiversity conservation. PMID:24040014

  8. On the factors that promote the diversity of herbivorous insects and plants in tropical forests

    PubMed Central

    Becerra, Judith X.

    2015-01-01

    Some of the most fascinating and challenging questions in ecology are why biodiversity is highest in tropical forests and whether the factors involved are unique to these habitats. I did a worldwide test of the hypotheses that plant community divergence in antiherbivore traits results in higher insect herbivore diversity, and that predominant attack by specialized herbivores promotes plant richness. I found strong correlative support for both ideas. Butterfly diversity was greatest in regions where the community average species-pairwise dissimilarity in antiherbivore traits among plant species was highest. There was also a strong positive relationship between specialized (insect) vs. generalized (mammal) herbivores and plant richness. Regions where herbivory impact by mammals was higher than that of insects tended to have lower plant diversities. In contrast, regions in which insects are the main consumers, particularly in the Central and South American tropics, had the highest plant richness. Latitude did not explain any residual variance in insect or plant richness. The strong connections found between insect specialization, plant defense divergence, and plant and insect diversities suggest that increasing our understanding of the ecology of biological communities can aid in considerations of how to preserve biodiversity in the future. PMID:25902509

  9. On the factors that promote the diversity of herbivorous insects and plants in tropical forests.

    PubMed

    Becerra, Judith X

    2015-05-12

    Some of the most fascinating and challenging questions in ecology are why biodiversity is highest in tropical forests and whether the factors involved are unique to these habitats. I did a worldwide test of the hypotheses that plant community divergence in antiherbivore traits results in higher insect herbivore diversity, and that predominant attack by specialized herbivores promotes plant richness. I found strong correlative support for both ideas. Butterfly diversity was greatest in regions where the community average species-pairwise dissimilarity in antiherbivore traits among plant species was highest. There was also a strong positive relationship between specialized (insect) vs. generalized (mammal) herbivores and plant richness. Regions where herbivory impact by mammals was higher than that of insects tended to have lower plant diversities. In contrast, regions in which insects are the main consumers, particularly in the Central and South American tropics, had the highest plant richness. Latitude did not explain any residual variance in insect or plant richness. The strong connections found between insect specialization, plant defense divergence, and plant and insect diversities suggest that increasing our understanding of the ecology of biological communities can aid in considerations of how to preserve biodiversity in the future. PMID:25902509

  10. Interactive effects of plant species diversity and elevated CO2 on soil biota and nutrient cycling.

    PubMed

    Niklaus, P A; Alphei, J; Kampichler, C; Kandeler, E; Körner, C; Tscherko, D; Wohlfender, M

    2007-12-01

    Terrestrial ecosystems consist of mutually dependent producer and decomposer subsystems, but not much is known on how their interactions are modified by plant diversity and elevated atmospheric CO2 concentrations. Factorially manipulating grassland plant species diversity and atmospheric CO2 concentrations for five years, we tested whether high diversity or elevated CO2 sustain larger or more active soil communities, affect soil aggregation, water dynamics, or nutrient cycling, and whether plant diversity and elevated CO2 interact. Nitrogen (N) and phosphorus (P) pools, symbiotic N2 fixation, plant litter quality, soil moisture, soil physical structure, soil nematode, collembola and acari communities, soil microbial biomass and microflora community structure (phospholipid fatty acid [PLFA] profiles), soil enzyme activities, and rates of C fluxes to soils were measured. No increases in soil C fluxes or the biomass, number, or activity of soil organisms were detected at high plant diversity; soil H2O and aggregation remained unaltered. Elevated CO2 affected the ecosystem primarily by improving plant and soil water status by reducing leaf conductance, whereas changes in C cycling appeared to be of subordinate importance. Slowed-down soil drying cycles resulted in lower soil aggregation under elevated CO2. Collembola benefited from extra soil moisture under elevated CO2, whereas other faunal groups did not respond. Diversity effects and interactions with elevated CO2 may have been absent because soil responses were mainly driven by community-level processes such as rates of organic C input and water use; these drivers were not changed by plant diversity manipulations, possibly because our species diversity gradient did not extend below five species and because functional type composition remained unaltered. Our findings demonstrate that global change can affect soil aggregation, and we advocate that soil aggregation should be considered as a dynamic property that may respond to environmental changes and feed back on other ecosystem functions. PMID:18229849

  11. Initial assessment of natural diversity in Mexican fig landraces.

    PubMed

    García-Ruiz, M T; Mendoza-Castillo, V M; Valadez-Moctezuma, E; Muratalla-Lúa, A

    2013-01-01

    The common fig (Ficus carica L.) was introduced into Mexico by Spanish Franciscan missionaries in the 16th century. It is widely assumed that Mexican figs are the Spanish cultivar Black Mission. We collected and propagated 12 fig plants from six landraces from different states in Central Mexico that represent different climate. All of them were grown in a greenhouse at Universidad Autónoma Chapingo, in the State of Mexico. During the experimental period, the greenhouse had an average temperature and relative humidity of 29.2° ± 5.4°C (SEM) and 78.1 ± 6.7% (SEM), respectively. Morphological characterization was done following a selected set of quantitative and qualitative descriptors established by the IPGRI. DNA analysis was based on a combination of ISSR and RFLP markers. We observed great diversity mainly in fruit weight (28.1-96.2 g), fruit shape (ovoid, pyriform), and neck length (0.97-3.80 cm), which could not be explained by environmental conditions such as temperature and relative humidity. The Nei and Li/Dice similarity coefficient between landraces was determined by cluster analysis using the UPGMA method. Based on the morphological characterization and DNA fingerprinting data presented in this study, our results showed that after hundreds of years, black figs have adapted to local environmental condition in Central Mexico, yielding at least six clearly distinct landraces that represent valuable and previously undescribed genetic diversity. We also suggested names for those landraces according to their location and established a basis for further agronomic and molecular characterization of fig landraces. PMID:24085455

  12. ENVIRONMENTAL ASSESSMENT FOR OTEC PILOT PLANTS

    SciTech Connect

    Wilde, P.

    1980-06-01

    Logical and orderly progression of the OTEC program from conceptual designs through component testing to the goal of commercially viable OTEC plants require that the socio-legal requirements be met and the proper operating permits be obtained and maintained. This function is accomplished in a series of activities including: (1) Development and annual revision of a published OTEC Environmental Development Plan (EDP); (2) Compliance with NEPA/EPA and other regulatory requirements; and (3) Studies and research in support of the above. The Environmental Development Plan (EDP) lists the concerns, outlines the program to consider the effects and validity of such concerns on the OTEC program, and gives the time-table to meet the schedule, integrated with that of the engineering and design programs. The schedules of compliance activities and, to a lesser degree, research also are governed by the development progress of the technology. However, because of the lead time necessary to insure proper review the appropriate regulatory agencies, the environmental assessment program for the OTEC pilot plants (initially starting with the 10/40 MWe unit) is founded on the strategy of progressive improvement of previously accepted documentation. Based on experience with OTEC-1, the procedure for pilot plants will be: (1) Produce generic Environmental Assessment (EA) at the appropriate level of technology in advance of hardware contract; (2) Produce generic Environmental Impact Statement (EIS) at approximately the same time as the hardware procurement; (3) Monitor production of site specific supplement to the generic EIS prepared by the hardware contractor; (4) Assist pilot plant operator in applying and obtaining permits by providing current research and modeling data; (5) Monitor environmental program as required by regulatory agency; and (6) Use new site data for refining models for future pilot plant. assessments.

  13. Diversity of use and local knowledge of wild edible plant resources in Nepal

    PubMed Central

    2012-01-01

    Background Wild edible plants (WEP) provide staple and supplement foods, as well as cash income to local communities, thus favouring food security. However, WEP are largely ignored in land use planning and implementation, economic development, and biodiversity conservation. Moreover, WEP-related traditional knowledge is rapidly eroding. Therefore, we designed this study to fulfill a part of the knowledge gap by providing data on diversity, traditional knowledge, economic potential, and conservation value of WEP from Nepal. Methods The information was collected through focus group discussions and key informant interviews. Percentage of general utility of the plants among the study communities was evaluated using the Chi-square (?2) test of homogeneity. High priority species were identified after consultation with the local stakeholders followed by scoring based on defined criteria. Pairwise ranking was used to assess ethnoecological knowledge to identify the threats to WEP. Results We documented 81 species belonging to Angiosperms (74), Pteridophytes (5), and Fungi (2). Most of the species were used as fruits (44 species) followed by vegetables (36). Almost half of the species (47%) were also used for purposes other than food. From the species with market value (37% of the total), 10 were identified as high priority species. Pairwise ranking revealed that WEP are threatened mostly by habitat destruction, land-use change and over-harvesting. Some of these plants are crop wild relatives and could thus be used for crop improvement. Interestingly, our study also revealed that young people who spend most of the time in the forest as herdsmen are particularly knowledgeable of wild fruit plants. Conclusion We provide empirical evidence from a relatively large area of Nepal about diversity and status of WEP, as well as methodological insights about the proper knowledge holders to consult. Regarding the unique and important knowledge they have on WEP, young people should be included when recruiting participants to ethnobotanical studies or to any type of consultation about WEP. The habit of using wild edible plants is still alive and is a traditional culinary practice that demonstrates rich traditional knowledge of local people. WEP were found to be important for livelihood as well as showing great potential for crop improvement. Priority species should be promoted for income generation activities through sustainable collection and trade. Communities should engage in minimizing the threats to these valuable resources. PMID:22546349

  14. Diversity Dynamics of Silurian–Early Carboniferous Land Plants in South China

    PubMed Central

    Xiong, Conghui; Wang, Deming; Wang, Qi; Benton, Michael J.; Xue, Jinzhuang; Meng, Meicen; Zhao, Qi; Zhang, Jing

    2013-01-01

    New megafossil and microfossil data indicate four episodes in the diversification of Silurian–Early Carboniferous land plants of South China, a relatively continuous regional record. Plant diversity increased throughout, but the rising curve was punctuated by three major falls. There were peaks of origination in the Ludlow–Pragian, Givetian, late Famennian and Visean and peaks of extinction in the Pragian–Emsian, Givetian and early Tournaisian. Speciation and extinction rates were highest in the Lochkovian–Pragian and became progressively lower in subsequent stages. High correlation coefficients indicate that these events are associated with the availability of land habitat contingent on eustatic variations and increasing numbers of cosmopolitan genera. Meanwhile, proportions of endemic genera declined gradually. Due to less endemism and more migrations, both speciation and species extinction rates reduced. The changes of diversity and the timing of the three extinctions of land plants in South China are similar to those known already from Laurussia. However, the largest events in the Lochkovian–Pragian and subsequent smaller ones have not been seen in the global pattern of plant evolution. These land plant events do not correspond well temporally with those affecting land vertebrates or marine invertebrates. In South China, the diversity curve of land plants is generally opposite to that of marine faunas, showing a strong effect of eustatic variations. The increasing diversity of both land vertebrates and plants was punctuated above the Devonian–Carboniferous boundary, known as Romer's Gap, implying common underlying constraints on macroevolution of land animals and plants. PMID:24073276

  15. The impact of genomic approaches on our understanding of diversity and taxonomy of plant pathogenic bacteria.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our understanding of the diversity of bacterial plant pathogens has changed dramatically over the past 100 years. Initially it was thought that each newly described disease was caused by a distinct plant pathogen species. Later, similarities in the physiology of these pathogens as well as inadequate...

  16. Plant Species Diversity and Distribution in Pastures of the Northeastern USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazed pastures in the northeastern United contain far more than planted forage species. These species may contribute to forage production, but they may also detract from forage production or palatability. As the first step toward identifying the role of plant diversity in forage systems, we collect...

  17. Genetic diversity and domestication origin of tea plant Camellia taliensis (Theaceae) as revealed by microsatellite markers

    PubMed Central

    2014-01-01

    Background Tea is one of the most popular beverages in the world. Many species in the Thea section of the Camellia genus can be processed for drinking and have been domesticated. However, few investigations have focused on the genetic consequence of domestication and geographic origin of landraces on tea plants using credible wild and planted populations of a single species. Here, C. taliensis provides us with a unique opportunity to explore these issues. Results Fourteen nuclear microsatellite loci were employed to determine the genetic diversity and domestication origin of C. taliensis, which were represented by 587 individuals from 25 wild, planted and recently domesticated populations. C. taliensis showed a moderate high level of overall genetic diversity. The greater reduction of genetic diversity and stronger genetic drift were detected in the wild group than in the recently domesticated group, indicating the loss of genetic diversity of wild populations due to overexploitation and habitat fragmentation. Instead of the endangered wild trees, recently domesticated individuals were used to compare with the planted trees for detecting the genetic consequence of domestication. A little and non-significant reduction in genetic diversity was found during domestication. The long life cycle, selection for leaf traits and gene flow between populations will delay the emergence of bottleneck in planted trees. Both phylogenetic and assignment analyses suggested that planted trees may have been domesticated from the adjacent central forest of western Yunnan and dispersed artificially to distant places. Conclusions This study contributes to the knowledge about levels and distribution of genetic diversity of C. taliensis and provides new insights into genetic consequence of domestication and geographic origin of planted trees of this species. As an endemic tea source plant, wild, planted and recently domesticated C. taliensis trees should all be protected for their unique genetic characteristics, which are valuable for tea breeding. PMID:24405939

  18. Plant Diversity in Live Fences and Pastures, Two Examples from the Mexican Humid Tropics

    NASA Astrophysics Data System (ADS)

    Ruiz-Guerra, Betsabé; Rosas, Noé Velázquez; López-Acosta, Juan Carlos

    2014-09-01

    This study analyzes the potential uses of live fences and pastures as reservoirs of plant diversity for two regions with different management histories, Los Tuxtlas (LT) and Uxpanapa (UX), Veracruz, México. We studied two habitats, live fences and pastures, analyzed their species richness, diversity, structure and plant composition and classified species according to plant regeneration modes (light-demanding and shade tolerant), seed dispersal syndrome and their local uses. We recorded 62 species of trees at LT and 48 at UX. Live fences were more diverse than pastures in both regions. The LT site showed to analyze the relationship a higher diversity of plants in regeneration stages than the one at UX. However, UX had higher diversity of adult plants in the pastures than LT. Composition and structure of live fences were different between regions, as well as within live fences and pastures, 53 % of species were light-demanding and 40 % were shade tolerant; 70 % of the species were dispersed by birds. Differences between sites are associated with the modifications in live fences structure, which changed according to managerial practices and the use of local species; this may influence plant regeneration modes as well as the visits of avian dispersal agents. In LT, all species found in live fences were useful to humans, whereas in UX, less than half were used by the local population. Our results underline the importance of live fences and isolated trees in pasture habitats as potential sites to host native and useful species from tropical rain forests in livestock landscapes.

  19. [Agrobacterium rubi strains from blueberry plants are highly diverse].

    PubMed

    Abrahamovich, Eliana; López, Ana C; Alippi, Adriana M

    2014-01-01

    The diversity of a collection of Agrobacterium rubi strains isolated from blueberries from different regions of Argentina was studied by conventional microbiological tests and molecular techniques. Results from biochemical and physiological reactions, as well as from rep-PCR and RFLP analysis of PCR-amplified 23S rDNA showed high phenotypic and genotypic intraspecific variation. PMID:25444133

  20. No Consistent Effect of Plant Diversity on Productivity

    E-print Network

    Fridley, Jason D.

    and Switzerland) included more species in their highest-diversity treatments than in the monocultures, so that was not evaluated in monoculture. Thus, the maxi- mum number of species in the highest-diver- sity mixture must in monoculture. The species assemblage codes in the BIODEPTH dataset show that only at the Portugal, Sweden,

  1. Non-native plants add to the British flora without negative consequences for native diversity.

    PubMed

    Thomas, Chris D; Palmer, G

    2015-04-01

    Plants are commonly listed as invasive species, presuming that they cause harm at both global and regional scales. Approximately 40% of all species listed as invasive within Britain are plants. However, invasive plants are rarely linked to the national or global extinction of native plant species. The possible explanation is that competitive exclusion takes place slowly and that invasive plants will eventually eliminate native species (the "time-to-exclusion hypothesis"). Using the extensive British Countryside Survey Data, we find that changes to plant occurrence and cover between 1990 and 2007 at 479 British sites do not differ between native and non-native plant species. More than 80% of the plant species that are widespread enough to be sampled are native species; hence, total cover changes have been dominated by native species (total cover increases by native species are more than nine times greater than those by non-native species). This implies that factors other than plant "invasions" are the key drivers of vegetation change. We also find that the diversity of native species is increasing in locations where the diversity of non-native species is increasing, suggesting that high diversities of native and non-native plant species are compatible with one another. We reject the time-to-exclusion hypothesis as the reason why extinctions have not been observed and suggest that non-native plant species are not a threat to floral diversity in Britain. Further research is needed in island-like environments, but we question whether it is appropriate that more than three-quarters of taxa listed globally as invasive species are plants. PMID:25831537

  2. Non-native plants add to the British flora without negative consequences for native diversity

    PubMed Central

    Thomas, Chris D.; Palmer, G.

    2015-01-01

    Plants are commonly listed as invasive species, presuming that they cause harm at both global and regional scales. Approximately 40% of all species listed as invasive within Britain are plants. However, invasive plants are rarely linked to the national or global extinction of native plant species. The possible explanation is that competitive exclusion takes place slowly and that invasive plants will eventually eliminate native species (the “time-to-exclusion hypothesis”). Using the extensive British Countryside Survey Data, we find that changes to plant occurrence and cover between 1990 and 2007 at 479 British sites do not differ between native and non-native plant species. More than 80% of the plant species that are widespread enough to be sampled are native species; hence, total cover changes have been dominated by native species (total cover increases by native species are more than nine times greater than those by non-native species). This implies that factors other than plant “invasions” are the key drivers of vegetation change. We also find that the diversity of native species is increasing in locations where the diversity of non-native species is increasing, suggesting that high diversities of native and non-native plant species are compatible with one another. We reject the time-to-exclusion hypothesis as the reason why extinctions have not been observed and suggest that non-native plant species are not a threat to floral diversity in Britain. Further research is needed in island-like environments, but we question whether it is appropriate that more than three-quarters of taxa listed globally as invasive species are plants. PMID:25831537

  3. Simulated climate-vegetation interaction in semi-arid regions affected by plant diversity

    NASA Astrophysics Data System (ADS)

    Claussen, M.; Bathiany, S.; Brovkin, V.; Kleinen, T.

    2013-11-01

    The end of the African Humid Period between 6,000 and 4,000 years ago was associated with large changes in precipitation and vegetation cover. Sediment records from Lake Yoa, Chad, show a gradual decline in precipitation and fluctuation in vegetation over this interval, and have been suggested to demonstrate a weak interaction between climate and vegetation. However, interpretation of these data has neglected the potential effects of plant diversity on the stability of the climate-vegetation system. Here we use a conceptual model that represents plant diversity in terms of moisture requirement. Some of the plant types simulated are sensitive to changes in precipitation, which alone would lead to an unstable system with the possibility of abrupt changes. Other plants are more resilient, resulting in a stable system that changes gradually. We demonstrate that plant diversity tends to attenuate the instability of the interaction between climate and sensitive plant types, whereas it reduces the stability of the interaction between climate and less-sensitive plant types. Hence, despite large sensitivities of individual plant types to precipitation, a gradual decline in precipitation and shift in mean vegetation cover can occur. However, we suggest that the system could become unstable if some plant types were removed or introduced, leading to an abrupt regime shift.

  4. Biomass and diversity of dry alpine plant communities along altitudinal gradients in the Himalayas

    USGS Publications Warehouse

    Namgail, T.; Rawat, G.S.; Mishra, C.; van Wieren, S.E.; Prins, H.H.T.

    2012-01-01

    A non-linear relationship between phytodiversity and altitude has widely been reported, but the relationship between phytomass and altitude remains little understood. We examined the phytomass and diversity of vascular plants along altitudinal gradients on the dry alpine rangelands of Ladakh, western Himalaya. We used generalized linear and generalized additive models to assess the relationship between these vegetation parameters and altitude. We found a hump-shaped relationship between aboveground phytomass and altitude. We suspect that this is engendered by low rainfall and trampling/excessive grazing at lower slopes by domestic livestock, and low temperature and low nutrient levels at higher slopes. We also found a unimodal relationship between plant species-richness and altitude at a single mountain as well as at the scale of entire Ladakh. The species-richness at the single mountain peaked between 5,000 and 5,200 m, while it peaked between 3,500 and 4,000 m at entire Ladakh level. Perhaps biotic factors such as grazing and precipitation are, respectively, important in generating this pattern at the single mountain and entire Ladakh. ?? 2011 The Author(s).

  5. Phylogenetic diversity of plants alters the effect of species richness on invertebrate herbivory

    PubMed Central

    2013-01-01

    Long-standing ecological theory proposes that diverse communities of plants should experience a decrease in herbivory. Yet previous empirical examinations of this hypothesis have revealed that plant species richness increases herbivory in just as many systems as it decreases it. In this study, I ask whether more insight into the role of plant diversity in promoting or suppressing herbivory can be gained by incorporating information about the evolutionary history of species in a community. In an old field system in southern Ontario, I surveyed communities of plants and measured levels of leaf damage on 27 species in 38 plots. I calculated a measure of phylogenetic diversity (PSE) that encapsulates information about the amount of evolutionary history represented in each of the plots and looked for a relationship between levels of herbivory and both species richness and phylogenetic diversity using a generalized linear mixed model (GLMM) that could account for variation in herbivory levels between species. I found that species richness was positively associated with herbivore damage at the plot-level, in keeping with the results from several other recent studies on this question. On the other hand, phylogenetic diversity was associated with decreased herbivory. Importantly, there was also an interaction between species richness and phylogenetic diversity, such that plots with the highest levels of herbivory were plots which had many species but only if those species tended to be closely related to one another. I propose that these results are the consequence of interactions with herbivores whose diets are phylogenetically specialized (for which I introduce the term cladophage), and how phylogenetic diversity may alter their realized host ranges. These results suggest that incorporating a phylogenetic perspective can add valuable additional insight into the role of plant diversity in explaining or predicting levels of herbivory at a whole-community scale. PMID:23825795

  6. Herbivores and nutrients control grassland plant diversity via light limitation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human alterations to nutrient cycles and herbivore communities are dramatically altering global biodiversity. Theory predicts these changes to be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive excl...

  7. Environmental Quality and Fertility: The Effects of Plant Density, Species Richness, and Plant Diversity on Fertility Limitation *

    PubMed Central

    Brauner-Otto, Sarah R.

    2013-01-01

    The relationship between the environment and population has been of concern for centuries and climate change is making this an even more pressing area of study. In poor rural areas declining environmental conditions may elicit changes in family related behaviors. This paper explores this relationship in rural Nepal looking specifically at how plant density, species richness, and plant diversity are related to women’s fertility limitation behavior. Taking advantage of a unique data set with detailed micro-level environmental measures and individual fertility behavior I link geographically weighted measures of flora at one point in time to women’s later contraceptive use as a way to examine this complex relationship. I find a significant, positive relationship between plant density, species richness, and plant diversity and the timing of contraceptive use. Women in poor environmental conditions are less likely to terminate childbearing, or do so later, and therefore more likely to have larger families. PMID:25593378

  8. Genetic diversity and networks of exchange: a combined approach to assess intra-breed diversity

    PubMed Central

    2012-01-01

    Background Cryopreservation of three endangered Belgian sheep breeds required to characterize their intra-breed genetic diversity. It is assumed that the genetic structure of a livestock breed depends mostly on gene flow due to exchanges between herds. To quantify this relation, molecular data and analyses of the exchanges were combined for three endangered Belgian breeds. Methods For each breed, between 91 and 225 sheep were genotyped with 19 microsatellites. Genetic differentiations between breeds and among herds within a breed were evaluated and the genetic structure of the breeds was described using Bayesian clustering (Structure). Exchanges of animals between 20, 46 and 95 herds according to breed were identified via semi-directed interviews and were analyzed using the concepts of the network theory to calculate average degrees and shortest path lengths between herds. Correlation between the Reynolds’ genetic distances and the shortest path lengths between each pair of herds was assessed by a Mantel test approach. Results Genetic differentiation between breeds was high (0.16). Overall Fst values among herds were high in each breed (0.17, 0.11 and 0.10). Use of the Bayesian approach made it possible to identify genetic groups of herds within a breed. Significant correlations between the shortest path lengths and the Reynolds’ genetic distances were found in each breed (0.87, 0.33 and 0.41), which demonstrate the influence of exchanges between herds on the genetic diversity. Correlation differences between breeds could be explained by differences in the average degree of the animal exchange networks, which is a measure of the number of exchanges per herd. The two breeds with the highest average degree showed the lowest correlation. Information from the exchange networks was used to assign individuals to the genetic groups when molecular information was incomplete or missing to identify donors for a cryobank. Conclusions A fine-scale picture of the population genetic structure at the herd level was obtained for the three breeds. Network analysis made it possible to highlight the influence of exchanges on genetic structure and to complete or replace molecular information in establishing a conservation program. PMID:22620856

  9. Assessing Racial Microaggression Distress in a Diverse Sample.

    PubMed

    Torres-Harding, Susan; Turner, Tasha

    2015-12-01

    Racial microaggressions are everyday subtle or ambiguous racially related insults, slights, mistreatment, or invalidations. Racial microaggressions are a type of perceived racism that may negatively impact the health and well-being of people of color in the United States. This study examined the reliability and validity of the Racial Microaggression Scale distress subscales, which measure the perceived stressfulness of six types of microaggression experiences in a racially and ethnically diverse sample. These subscales exhibited acceptable to good internal consistency. The distress subscales also evidenced good convergent validity; the distress subscales were positively correlated with additional measures of stressfulness due to experiencing microaggressions or everyday discrimination. When controlling for the frequency of one's exposure to microaggression incidents, some racial/ethnic group differences were found. Asian Americans reported comparatively lower distress and Latinos reporting comparatively higher distress in response to Foreigner, Low-Achieving, Invisibility, and Environmental microaggressions. African Americans reported higher distress than the other groups in response to Environmental microaggressions. Results suggest that the Racial Microaggressions Scale distress subscales may aid health professionals in assessing the distress elicited by different types of microaggressions. In turn, this may facilitate diagnosis and treatment planning in order to provide multiculturally competent care for African American, Latino, and Asian American clients. PMID:25237154

  10. Carbon storage potential by four macrophytes as affected by planting diversity in a created wetland.

    PubMed

    Means, Mary M; Ahn, Changwoo; Korol, Alicia R; Williams, Lisa D

    2016-01-01

    Wetland creation has become a commonplace method for mitigating the loss of natural wetlands. Often mitigation projects fail to restore ecosystem services of the impacted natural wetlands. One of the key ecosystem services of newly created wetlands is carbon accumulation/sequestration, but little is known about how planting diversity (PD) affects the ability of herbaceous wetland plants to store carbon in newly created wetlands. Most mitigation projects involve a planting regime, but PD, which may be critical in establishing biologically diverse and ecologically functioning wetlands, is seldom required. Using a set of 34 mesocosms (?1 m(2) each), we investigated the effects of planting diversity on carbon storage potential of four native wetland plant species that are commonly planted in created mitigation wetlands in Virginia - Carex vulpinoidea, Eleocharis obtusa, Juncus effusus, and Mimulus ringens. The plants were grown under the four distinctive PD treatments [i.e., monoculture (PD 1) through four different species mixture (PD 4)]. Plant biomass was harvested after two growing seasons and analyzed for tissue carbon content. Competition values (CV) were calculated to understand how the PD treatment affected the competitive ability of plants relative to their biomass production and thus carbon storage potentials. Aboveground biomass ranged from 988 g/m(2) - 1515 g/m(2), being greatest in monocultures, but only when compared to the most diverse mixture (p = 0.021). However, carbon storage potential estimates per mesocosm ranged between 344 g C/m(2) in the most diverse mesocosms (PD 4) to 610 g C/m(2) in monoculture ones with no significant difference (p = 0.089). CV of E. obtusa and C. vulpinoidea showed a declining trend when grown in the most diverse mixtures but J. effusus and M. ringens displayed no difference across the PD gradient (p = 0.910). In monocultures, both M. ringens, and J. effusus appeared to store carbon as biomass more effectively than the other species, suggesting that the choice of plant species may play an important role in facilitating the development of carbon accumulation/storage in created wetlands. Plant community diversity provides many ecosystem services (e.g., habitat and floristic quality) other than carbon storage function. Thus, a further study is needed that will focus on investigating how other design elements such as microtopography and hydrologic connectivity may interact with PD in terms of enhancing the carbon storage potential of newly created wetlands. PMID:26431640

  11. Assessment of genetic diversity among faba bean genotypes using agro-morphological and molecular markers

    PubMed Central

    Ammar, Megahed H.; Alghamdi, Salem S.; Migdadi, Hussein M.; Khan, Muhammad A.; El-Harty, Ehab H.; Al-Faifi, Sulieman A.

    2015-01-01

    Forty faba bean (Vicia faba L.) genotypes were evaluated for their agro-morphological performance and molecular diversity under Central Region of Saudi Arabia conditions during 2010–11 and 2011–12 seasons. Field performance results showed that faba genotypes exhibited a significant amount of variation for their agro-morphological studied parameters. Giza40 recorded the tallest genotype (139.5 cm), highest number of seeds per plants (100.8), and the highest seed yield per plant (70.8 g). The best performing genotypes were Giza40, FLIP03-014FB, Gazira1 and Goff1. Genetic variability among genotypes was determined using Sequence Related Amplified Polymorphism (SRAP) and Amplified Fragment Length Polymorphism (AFLP) markers. A total of 183 amplified fragments (alleles) and 1758 polymorphic fragments (bands) in SRAP and 202 alleles and 716 bands in AFLP were obtained using six SRAP and four AFLP primer combinations respectively. Polymorphism information content (PIC) values for AFLP and SRAP markers were higher than 0.8, indicating the existence of a considerable amount of genetic diversity among faba tested genotypes. The UPGMA based clustering of faba genotypes was largely based on origin and/or genetic background. Result of cluster analysis based on SRAP showed weak and not significant correlation while, it was highly significant based on AFLP analysis with agro-morphological characters (r = 0.01, p > 0.54 and r = 0.26, p < 0.004 respectively). Combined SRAP and AFLP markers proved to be significantly useful for genetic diversity assessment at molecular level. They exhibited high discrimination power, and were able to distinguish the faba bean genotypes with high efficiency and accuracy levels. PMID:25972757

  12. Assessment of genetic diversity among faba bean genotypes using agro-morphological and molecular markers.

    PubMed

    Ammar, Megahed H; Alghamdi, Salem S; Migdadi, Hussein M; Khan, Muhammad A; El-Harty, Ehab H; Al-Faifi, Sulieman A

    2015-05-01

    Forty faba bean (Vicia faba L.) genotypes were evaluated for their agro-morphological performance and molecular diversity under Central Region of Saudi Arabia conditions during 2010-11 and 2011-12 seasons. Field performance results showed that faba genotypes exhibited a significant amount of variation for their agro-morphological studied parameters. Giza40 recorded the tallest genotype (139.5 cm), highest number of seeds per plants (100.8), and the highest seed yield per plant (70.8 g). The best performing genotypes were Giza40, FLIP03-014FB, Gazira1 and Goff1. Genetic variability among genotypes was determined using Sequence Related Amplified Polymorphism (SRAP) and Amplified Fragment Length Polymorphism (AFLP) markers. A total of 183 amplified fragments (alleles) and 1758 polymorphic fragments (bands) in SRAP and 202 alleles and 716 bands in AFLP were obtained using six SRAP and four AFLP primer combinations respectively. Polymorphism information content (PIC) values for AFLP and SRAP markers were higher than 0.8, indicating the existence of a considerable amount of genetic diversity among faba tested genotypes. The UPGMA based clustering of faba genotypes was largely based on origin and/or genetic background. Result of cluster analysis based on SRAP showed weak and not significant correlation while, it was highly significant based on AFLP analysis with agro-morphological characters (r = 0.01, p > 0.54 and r = 0.26, p < 0.004 respectively). Combined SRAP and AFLP markers proved to be significantly useful for genetic diversity assessment at molecular level. They exhibited high discrimination power, and were able to distinguish the faba bean genotypes with high efficiency and accuracy levels. PMID:25972757

  13. Effects of Plant Biomass, Plant Diversity, and Water Content on Bacterial Communities in Soil Lysimeters: Implications for the Determinants of Bacterial Diversity? †

    PubMed Central

    Zul, Delita; Denzel, Sabine; Kotz, Andrea; Overmann, Jörg

    2007-01-01

    Soils may comprise tens of thousands to millions of bacterial species. It is still unclear whether this high level of diversity is governed by functional redundancy or by a multitude of ecological niches. In order to address this question, we analyzed the reproducibility of bacterial community composition after different experimental manipulations. Soil lysimeters were planted with four different types of plant communities, and the water content was adjusted. Group-specific phylogenetic fingerprinting by PCR-denaturing gradient gel electrophoresis revealed clear differences in the composition of Alphaproteobacteria, Betaproteobacteria, Bacteroidetes, Chloroflexi, Planctomycetes, and Verrucomicrobia populations in soils without plants compared to that of populations in planted soils, whereas no influence of plant species composition on bacterial diversity could be discerned. These results indicate that the presence of higher plant species affects the species composition of bacterial groups in a reproducible manner and even outside of the rhizosphere. In contrast, the environmental factors tested did not affect the composition of Acidobacteria, Actinobacteria, Archaea, and Firmicutes populations. One-third (52 out of 160) of the sequence types were found to be specifically and reproducibly associated with the absence or presence of plants. Unexpectedly, this was also true for numerous minor constituents of the soil bacterial assemblage. Subsequently, one of the low-abundance phylotypes (beta10) was selected for studying the interdependence under particular experimental conditions and the underlying causes in more detail. This so-far-uncultured phylotype of the Betaproteobacteria species represented up to 0.18% of all bacterial cells in planted lysimeters compared to 0.017% in unplanted systems. A cultured representative of this phylotype exhibited high physiological flexibility and was capable of utilizing major constituents of root exudates. Our results suggest that the bacterial species composition in soil is determined to a significant extent by abiotic and biotic factors, rather than by mere chance, thereby reflecting a multitude of distinct ecological niches. PMID:17873072

  14. Moderate land use changes plant functional composition without loss of functional diversity in India's Western Ghats.

    PubMed

    Mandle, Lisa; Ticktin, Tamara

    2015-09-01

    The fields of ecology and conservation science increasingly recognize the importance of managing for functional composition and functional diversity to maintain critical ecosystem processes and services. However, little is known about the degree to which widespread but moderate forms of land use that maintain overall vegetation structure are compatible with the conservation of functional diversity. We assessed differences in plani functional composition and functional diversity across savanna woodlands in the Western Ghats, India, managed with varying degrees of biomass extraction, livestock grazing, and ground fire. Across the gradient of moderate land uses, we found shifts in functional composition but no overall decline in functional diversity with land, use intensification. Biomass extraction was associated with changes in dispersal mode, reduced seed mass, and lower overstory functional diversity. Livestock grazing was associated with shorter overstory species, reduced seed mass, and increased understory functional diversity. Nonnative invasive species contributed to shifts in understory functional composition with livestock grazing and increased functional diversity with more intensive land use. Our study highlights both the utility and some limitations of assessing conservation value with functional diversity. These results suggest that moderate-intensity local land use can be compatible with maintenance of functional diversity in savanna woodlands of the Western Ghats, and further efforts to maximize this compatibility would benefit conservation in South India's extensive human-managed landscapes. However, using functional diversity as the sole metric by which to gauge conservation value can mask threats from invasive species and loss of diversity within categories of biotic dispersal. Therefore, functional diversity metrics are likely to provide a valuable complement to, but not replacement for, other management targets such as species composition. PMID:26552276

  15. Modelling snow cover duration improves predictions of functional and taxonomic diversity for alpine plant communities

    PubMed Central

    Carlson, Bradley Z.; Choler, Philippe; Renaud, Julien; Dedieu, Jean-Pierre; Thuiller, Wilfried

    2015-01-01

    Background and Aims Quantifying relationships between snow cover duration and plant community properties remains an important challenge in alpine ecology. We developed a method to estimate spatial variation in energy availability in the context of a topographically complex, high-elevation watershed, which we used to test the explanatory power of environmental gradients both with and without snow cover in relation to taxonomic and functional plant diversity. Methods We mapped snow cover at 15 m resolution using Landsat imagery for five recent years and fitted a generalized additive model (GAM) for each year linking snow to time and topography. Predicted snow cover maps were combined with air temperature and solar radiation at daily resolution, summed for each year and averaged across years. Equivalent growing season energy gradients were also estimated without accounting for snow cover duration. Relationships were tested between environmental gradients and diversity metrics measured for 100 plots (including species richness, community weighted mean traits, functional diversity and hyperspectral estimates of canopy chlorophyll content). Key Results Accounting for snow cover in environmental variables consistently led to improved predictive power as well as more ecologically meaningful characterizations of plant diversity. Model parameters differed significantly when fitted with and without snow cover. Filtering solar radiation with snow as compared to without led to an average gain in R2 of 0.26 and also reversed slope direction to more intuitive relationships for several diversity metrics. Conclusions We show that in alpine environments, high-resolution data on snow cover duration are pivotal for capturing the spatial heterogeneity of both taxonomic and functional diversity. The use of climate variables without consideration of snow cover can lead to erroneous predictions of plant diversity. Our results further indicate that studies seeking to predict the response of alpine plant communities to climate change need to consider shifts in both temperature and nival regimes. PMID:25851138

  16. Assessing phenotypic, biochemical, and molecular diversity in coriander (Coriandrum sativum L.) germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research was conducted to elucidate phenotypic and biochemical diversity in 60 coriander (Coriandrum sativum L.) accessions maintained at the North Central Regional Plant Introduction Station and examine relationships between amplified fragment length polymorphisms (AFLP) and patterns of phenot...

  17. 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 the vegetation mosaic in this region places them in proximity to chaparral. The speed at which alien propagules reach a burned site and the speed at which the shrublands return to their former closed-canopy condition determine alien invasion. Frequent burning of this vegetation alters the balance in favor of alien invasion. In the higher-elevation coniferous forests, species diversity was a function of fire severity and time since fire. High-intensity fires create gaps that decrease canopy coverage and increase light levels and nutrients for an ephemeral successional flora. Few species have persistent seed banks, so the time since fire is an important determinant of colonization success. There was a highly significant interaction between fire severity and time since fire for understory cover, species richness, and alien richness and cover. Understory was sparse in the first year after fire, particularly in low-severity burns, and increased substantially several years after fire, particularly on high-severity burns. Both fire severity and time since fire affected alien species richness and dominance. Coniferous forests had about one-third as many alien species as the foothill oak savannas, and fewer than half of the species were shared between these communities. Unburned coniferous forests were largely free of alien species, whereas some burned sites had a significant alien presence, which presents a challenge for fire restoration of these forests.

  18. Vascular plant abundance and diversity in an alpine heath under observed and simulated global change.

    PubMed

    Alatalo, Juha M; Little, Chelsea J; Jägerbrand, Annika K; Molau, Ulf

    2015-01-01

    Global change is predicted to cause shifts in species distributions and biodiversity in arctic tundra. We applied factorial warming and nutrient manipulation to a nutrient and species poor alpine/arctic heath community for seven years. Vascular plant abundance in control plots increased by 31%. There were also notable changes in cover in the nutrient and combined nutrient and warming treatments, with deciduous and evergreen shrubs declining, grasses overgrowing these plots. Sedge abundance initially increased significantly with nutrient amendment and then declined, going below initial values in the combined nutrient and warming treatment. Nutrient addition resulted in a change in dominance hierarchy from deciduous shrubs to grasses. We found significant declines in vascular plant diversity and evenness in the warming treatment and a decline in diversity in the combined warming and nutrient addition treatment, while nutrient addition caused a decline in species richness. The results give some experimental support that species poor plant communities with low diversity may be more vulnerable to loss of species diversity than communities with higher initial diversity. The projected increase in nutrient deposition and warming may therefore have negative impacts on ecosystem processes, functioning and services due to loss of species diversity in an already impoverished environment. PMID:25950370

  19. Vascular plant abundance and diversity in an alpine heath under observed and simulated global change

    PubMed Central

    Alatalo, Juha M.; Little, Chelsea J.; Jägerbrand, Annika K.; Molau, Ulf

    2015-01-01

    Global change is predicted to cause shifts in species distributions and biodiversity in arctic tundra. We applied factorial warming and nutrient manipulation to a nutrient and species poor alpine/arctic heath community for seven years. Vascular plant abundance in control plots increased by 31%. There were also notable changes in cover in the nutrient and combined nutrient and warming treatments, with deciduous and evergreen shrubs declining, grasses overgrowing these plots. Sedge abundance initially increased significantly with nutrient amendment and then declined, going below initial values in the combined nutrient and warming treatment. Nutrient addition resulted in a change in dominance hierarchy from deciduous shrubs to grasses. We found significant declines in vascular plant diversity and evenness in the warming treatment and a decline in diversity in the combined warming and nutrient addition treatment, while nutrient addition caused a decline in species richness. The results give some experimental support that species poor plant communities with low diversity may be more vulnerable to loss of species diversity than communities with higher initial diversity. The projected increase in nutrient deposition and warming may therefore have negative impacts on ecosystem processes, functioning and services due to loss of species diversity in an already impoverished environment. PMID:25950370

  20. Pyrosequencing reveals a highly diverse and cultivar-specific bacterial endophyte community in plant roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is the first known pyrosequencing assessment of plant-endophyes residing within roots. The assessment suggests that the microbial assemblage residing within plant tissues is cultivar-specific and its phylotype richness is several orders of magnitude greater than previously believed. This new...

  1. The “Hidden Diversity” of Medicinal Plants in Northeastern Brazil: Diagnosis and Prospects for Conservation and Biological Prospecting

    PubMed Central

    Cavalcanti, Deyvson Rodrigues; Albuquerque, Ulysses Paulino

    2013-01-01

    Increases in ethnobotanical studies and knowledge in recent decades have led to a greater and more accurate interpretation of the overall patterns related to the use of medicinal plants, allowing for a clear identification of some ecological and cultural phenomena. “Hidden diversity” of medicinal plants refers in the present study to the existence of several species of medicinal plants known by the same vernacular name in a given region. Although this phenomenon has previously been observed in a localized and sporadic manner, its full dimensions have not yet been established. In the present study, we sought to assess the hidden diversity of medicinal plants in northeastern Brazil based on the ethnospecies catalogued by local studies. The results indicate that there are an average of at least 2.78 different species per cataloged ethnospecies in the region. Phylogenetic proximity and its attendant morphological similarity favor the interchangeable use of these species, resulting in serious ecological and sanitary implications as well as a wide range of options for conservation and bioprospecting. PMID:24228056

  2. Assessment Matters in Higher Education: Choosing and Using Diverse Approaches.

    ERIC Educational Resources Information Center

    Brown, Sally, Ed.; Glasner, Angela, Ed.

    This book presents 16 papers on assessment in higher education grouped into four sections on: first, systems approaches to assessment; second, the effectiveness of innovative assessment; third, assessing practice; and fourth, autonomous assessment. The included papers are: (1) "Institutional Strategies for Assessment" (Sally Brown); (2)…

  3. Relationships between Plant Diversity and the Abundance and ?-Diversity of Predatory Ground Beetles (Coleoptera: Carabidae) in a Mature Asian Temperate Forest Ecosystem

    PubMed Central

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

    2013-01-01

    A positive relationship between plant diversity and both abundance and diversity of predatory arthropods is postulated by the Enemies Hypothesis, a central ecological top-down control hypothesis. It has been supported by experimental studies and investigations of agricultural and grassland ecosystems, while evidence from more complex mature forest ecosystems is limited. Our study was conducted on Changbai Mountain in one of the last remaining large pristine temperate forest environments in China. We used predatory ground beetles (Coleoptera: Carabidae) as target taxon to establish the relationship between phytodiversity and their activity abundance and diversity. Results showed that elevation was the only variable included in both models predicting carabid activity abundance and ?-diversity. Shrub diversity was negatively and herb diversity positively correlated with beetle abundance, while shrub diversity was positively correlated with beetle ?-diversity. Within the different forest types, a negative relationship between plant diversity and carabid activity abundance was observed, which stands in direct contrast to the Enemies Hypothesis. Furthermore, plant species density did not predict carabid ?-diversity. In addition, the density of herbs, which is commonly believed to influence carabid movement, had little impact on the beetle activity abundance recorded on Changbai Mountain. Our study indicates that in a relatively large and heterogeneous mature forest area, relationships between plant and carabid diversity are driven by variations in environmental factors linked with altitudinal change. In addition, traditional top-down control theories that are suitable in explaining diversity patterns in ecosystems of low diversity appear to play a much less pronounced role in highly complex forest ecosystems. PMID:24376582

  4. Diversity of Riparian Plants among and within Species Shapes River Communities.

    PubMed

    Jackrel, Sara L; Wootton, J Timothy

    2015-01-01

    Organismal diversity among and within species may affect ecosystem function with effects transmitting across ecosystem boundaries. Whether recipient communities adjust their composition, in turn, to maximize their function in response to changes in donor composition at these two scales of diversity is unknown. We use small stream communities that rely on riparian subsidies as a model system. We used leaf pack experiments to ask how variation in plants growing beside streams in the Olympic Peninsula of Washington State, USA affects stream communities via leaf subsidies. Leaves from red alder (Alnus rubra), vine maple (Acer cinereus), bigleaf maple (Acer macrophyllum) and western hemlock (Tsuga heterophylla) were assembled in leaf packs to contrast low versus high diversity, and deployed in streams to compare local versus non-local leaf sources at the among and within species scales. Leaves from individuals within species decomposed at varying rates; most notably thin leaves decomposed rapidly. Among deciduous species, vine maple decomposed most rapidly, harbored the least algal abundance, and supported the greatest diversity of aquatic invertebrates, while bigleaf maple was at the opposite extreme for these three metrics. Recipient communities decomposed leaves from local species rapidly: leaves from early successional plants decomposed rapidly in stream reaches surrounded by early successional forest and leaves from later successional plants decomposed rapidly adjacent to later successional forest. The species diversity of leaves inconsistently affected decomposition, algal abundance and invertebrate metrics. Intraspecific diversity of leaf packs also did not affect decomposition or invertebrate diversity. However, locally sourced alder leaves decomposed more rapidly and harbored greater levels of algae than leaves sourced from conspecifics growing in other areas on the Olympic Peninsula, but did not harbor greater aquatic invertebrate diversity. In contrast to alder, local intraspecific differences via decomposition, algal or invertebrate metrics were not observed consistently among maples. These results emphasize that biodiversity of riparian subsidies at the within and across species scale have the potential to affect aquatic ecosystems, although there are complex species-specific effects. PMID:26539714

  5. Diversity of Riparian Plants among and within Species Shapes River Communities

    PubMed Central

    Jackrel, Sara L.; Wootton, J. Timothy

    2015-01-01

    Organismal diversity among and within species may affect ecosystem function with effects transmitting across ecosystem boundaries. Whether recipient communities adjust their composition, in turn, to maximize their function in response to changes in donor composition at these two scales of diversity is unknown. We use small stream communities that rely on riparian subsidies as a model system. We used leaf pack experiments to ask how variation in plants growing beside streams in the Olympic Peninsula of Washington State, USA affects stream communities via leaf subsidies. Leaves from red alder (Alnus rubra), vine maple (Acer cinereus), bigleaf maple (Acer macrophyllum) and western hemlock (Tsuga heterophylla) were assembled in leaf packs to contrast low versus high diversity, and deployed in streams to compare local versus non-local leaf sources at the among and within species scales. Leaves from individuals within species decomposed at varying rates; most notably thin leaves decomposed rapidly. Among deciduous species, vine maple decomposed most rapidly, harbored the least algal abundance, and supported the greatest diversity of aquatic invertebrates, while bigleaf maple was at the opposite extreme for these three metrics. Recipient communities decomposed leaves from local species rapidly: leaves from early successional plants decomposed rapidly in stream reaches surrounded by early successional forest and leaves from later successional plants decomposed rapidly adjacent to later successional forest. The species diversity of leaves inconsistently affected decomposition, algal abundance and invertebrate metrics. Intraspecific diversity of leaf packs also did not affect decomposition or invertebrate diversity. However, locally sourced alder leaves decomposed more rapidly and harbored greater levels of algae than leaves sourced from conspecifics growing in other areas on the Olympic Peninsula, but did not harbor greater aquatic invertebrate diversity. In contrast to alder, local intraspecific differences via decomposition, algal or invertebrate metrics were not observed consistently among maples. These results emphasize that biodiversity of riparian subsidies at the within and across species scale have the potential to affect aquatic ecosystems, although there are complex species-specific effects. PMID:26539714

  6. 76 FR 44891 - Monsanto Co.; Availability of Petition, Plant Pest Risk Assessment, and Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ...DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service [Docket No...Monsanto Co.; Availability of Petition, Plant Pest Risk Assessment, and Environmental...for Drought Tolerance AGENCY: Animal and Plant Health Inspection Service, USDA....

  7. Assessing Plants for Phytoremediation of Arsenic-Contaminated Soils

    E-print Network

    Ma, Lena

    by roots and translocation from roots to shoots. Specifically, how does a plant acquire and maintain24 Assessing Plants for Phytoremediation of Arsenic-Contaminated Soils Nandita Singh and Lena Q. Ma- chemistry of As in plants, (2) plant hyperaccumulation of inorganics including As, (3) the phenomenon

  8. [Effects of different removal disturbance intensity on plant diversity of Bursaphelenchus xylophilus-invaded Masson pine community].

    PubMed

    Shi, Juan; Luo, Youqing; Song, Jiying; Yan, Xiaosu; Jiang, Ping; Wang, Yijiao

    2006-07-01

    The study on the plant diversity of Bursaphelenchus xylophilus-invaded Masson pine community under effects of different removal disturbance intensity showed that the species diversity indices (richness, Shannon-Wiener index and evenness) of arbor layer decreased in the sequence of broad-leaved stand after the removal of all infected pine trees in the pure pine stand in Fuyang > lightly infected Masson pine - Schima superba mixed stand in Fuyang > uninfected stand mixture of Masson pine and Castanopsis fargessi as the control > lightly infected pure Masson pine stand in Fuyang > Quercus variables stand formed after selective removal of infected pine trees from a mixed Masson pine and Q. variables stand in Zhoushan Islands > pure young Masson pine stand formed after the removal of all infected pine trees from a pure Masson pine stand > pure Liquidambar formosana stand after the removal of infected pine trees from a pure pine stand in Zhoushan Islands > mixed stand consisted of Pinus thunbergii and the Masson pine in Zhoushan Islands > moderately infected Masson pine stand in Zhoushan Islands. All the three indices of shrub layer did not show any significant differences among different communities, except for the pure pine stand in Zhoushan Island, which were the lowest. The three indices of herb layer were higher in pure young Masson pine, Q. variables stand, and L. formosana stand than in other stands. The Masson pine forest at different geographical situation and with different harm extent had distinct disparity, as well as that in different disturbance degree and restoring manner. The "Index of Disturbing Intensity of Stump and Fallen Woods" or IDISF was created to represent the disturbance degree of tree removal on plant diversity. It was found that for both less and more removal disturbing degree, the relationship between species diversity indices and IDISF followed the "Mid-altitude bulge" theory. Specifically, both excessive and insufficient removal of infected trees would cause the decline of plant species diversity in certain degree. Covariance analysis of IDISF indicated that different IDISF had no significant effects on the species diversity of arbor layer, but had different effects on that of shrub and herb layers, which could be used to assess the changes in species diversity of different Masson pine communities after the invasion of pine wood nematode. PMID:17044484

  9. Rapid compositional change and significant loss of plant species diversity among Triassic-Jurassic palynofloras in East Greenland

    NASA Astrophysics Data System (ADS)

    Mander, Luke; Kürschner, Wolfram; McElwain, Jennifer

    2010-05-01

    The Triassic-Jurassic (Tr-J; 200Ma) transition coincides with the eruption of massive flood basalts associated with the opening of the Atlantic Ocean. This is thought to have lead to a fourfold increase in palaeoatmospheric carbon dioxide, a consequent rise in global temperatures of between 3 and 6 degrees Celsius, and a rise in atmospheric pollutants such as sulphur dioxide. Recent work has employed either plant macrofossils (mostly leaves) or sporomorphs (pollen and spores) to reconstruct the response of terrestrial vegetation to this episode of major environmental change. Investigations of the macrofossil record at Astartekloft in East Greenland indicate a rapid loss of plant diversity in the Late Rhaetian, culminating in an 80% species turnover at the Tr-J boundary interval. However, evidence for such catastrophic diversity loss is conspicuously absent from the sporomorph record. This fossil group indicates that the Tr-J boundary interval in central and northwest Europe is characterized by compositional change and a transient shift from gymnosperm forests to fern-dominated vegetation. In order to address this uncertainty regarding Tr-J vegetation change according to macrofossils versus sporomorphs, we present an analysis of sporomorph diversity and compositional change across the Tr-J at Astartekloft, East Greenland. Sporomorph diversity was estimated using individual and sample-based rarefaction techniques, and compositional differences between sporomorph samples were assessed using non-metric multidimensional scaling. These analyses reveal that sporomorph assemblages from the Tr-J boundary interval at Astartekloft are between 23 and 27% less taxonomically diverse than other Triassic assemblages, and that this interval is characterized by a dramatic shift in the composition of the standing vegetation. These results are statistically significant and are also unrelated to changes in the environment of deposition. These results indicate that the magnitude of plant diversity loss across the Tr-J in East Greenland is apparently greater in the macrofossil record than the sporomorph record. Comparison of these results with taphonomic work on the representation of different groups of plants in macrofossil and sporomorph records at Astartekloft is used to understand this discrepancy.

  10. Size, age and composition: characteristics of plant taxa as diversity predictors of gall-midges (Diptera: Cecidomyiidae).

    PubMed

    Araújo, Walter S

    2011-12-01

    Many hypotheses have been proposed to explain the diversity of gall-midge insects (Diptera: Cecidomyiidae), some of them taking into account plant diversity. This study aims to test the importance of size, age and composition of host plant taxa in the diversity of Cecidomyiidae. For this we used inventories data on the diversity of galling and host plants in Brazil. We found that Asterales, Myrtales and Malpighiales, were the most important orders, with 34, 33 and 25, gall morphotypes, respectively. The most representative host families were Asteraceae (34 morphotypes), Myrtaceae (23) and Fabaceae (22). In general, the order size and the plant family were good predictors of the galling diversity, but not the taxon age. The most diverse host genera for gall-midges were Mikania, Eugenia and Styrax, with 15, 13 and nine galler species, respectively. The size of plant genera showed no significant relationship with the richness of Cecidomyiidae, contrary to the prediction of the plant taxon size hypothesis. The plant genera with the greatest diversity of galling insects are not necessarily those with the greatest number of species. These results indicate that some plant taxa have a high intrinsic richness of galling insects, suggesting that the plant species composition may be equally or more important for the diversity of gall-midges than the size or age of the host taxon. PMID:22208077

  11. Celanese Chemicals Clear Lake Plant Energy Projects Assessment and Implementation 

    E-print Network

    Weber, J.

    2000-01-01

    Clear Lake Plant Energy Projects Assessment and Implementation Joel Weber Energy Coordinator, CLP Celanese Chemicals Pasadena, Texas ABSTRACT Tower and a Stripper Tower, with a process-to The Clear Lake Plant ofCelanese Chemicals process...

  12. Plant diversity in live fences and pastures, two examples from the Mexican humid tropics.

    PubMed

    Ruiz-Guerra, Betsabé; Rosas, Noé Velázquez; López-Acosta, Juan Carlos

    2014-09-01

    This study analyzes the potential uses of live fences and pastures as reservoirs of plant diversity for two regions with different management histories, Los Tuxtlas (LT) and Uxpanapa (UX), Veracruz, México. We studied two habitats, live fences and pastures, analyzed their species richness, diversity, structure and plant composition and classified species according to plant regeneration modes (light-demanding and shade tolerant), seed dispersal syndrome and their local uses. We recorded 62 species of trees at LT and 48 at UX. Live fences were more diverse than pastures in both regions. The LT site showed to analyze the relationship a higher diversity of plants in regeneration stages than the one at UX. However, UX had higher diversity of adult plants in the pastures than LT. Composition and structure of live fences were different between regions, as well as within live fences and pastures, 53 % of species were light-demanding and 40 % were shade tolerant; 70 % of the species were dispersed by birds. Differences between sites are associated with the modifications in live fences structure, which changed according to managerial practices and the use of local species; this may influence plant regeneration modes as well as the visits of avian dispersal agents. In LT, all species found in live fences were useful to humans, whereas in UX, less than half were used by the local population. Our results underline the importance of live fences and isolated trees in pasture habitats as potential sites to host native and useful species from tropical rain forests in livestock landscapes. PMID:24981271

  13. Plant Trait Diversity Buffers Variability in Denitrification Potential over Changes in Season and Soil Conditions

    PubMed Central

    McGill, Bonnie M.; Sutton-Grier, Ariana E.; Wright, Justin P.

    2010-01-01

    Background Denitrification is an important ecosystem service that removes nitrogen (N) from N-polluted watersheds, buffering soil, stream, and river water quality from excess N by returning N to the atmosphere before it reaches lakes or oceans and leads to eutrophication. The denitrification enzyme activity (DEA) assay is widely used for measuring denitrification potential. Because DEA is a function of enzyme levels in soils, most ecologists studying denitrification have assumed that DEA is less sensitive to ambient levels of nitrate (NO3?) and soil carbon and thus, less variable over time than field measurements. In addition, plant diversity has been shown to have strong effects on microbial communities and belowground processes and could potentially alter the functional capacity of denitrifiers. Here, we examined three questions: (1) Does DEA vary through the growing season? (2) If so, can we predict DEA variability with environmental variables? (3) Does plant functional diversity affect DEA variability? Methodology/Principal Findings The study site is a restored wetland in North Carolina, US with native wetland herbs planted in monocultures or mixes of four or eight species. We found that denitrification potentials for soils collected in July 2006 were significantly greater than for soils collected in May and late August 2006 (p<0.0001). Similarly, microbial biomass standardized DEA rates were significantly greater in July than May and August (p<0.0001). Of the soil variables measured—soil moisture, organic matter, total inorganic nitrogen, and microbial biomass—none consistently explained the pattern observed in DEA through time. There was no significant relationship between DEA and plant species richness or functional diversity. However, the seasonal variance in microbial biomass standardized DEA rates was significantly inversely related to plant species functional diversity (p<0.01). Conclusions/Significance These findings suggest that higher plant functional diversity may support a more constant level of DEA through time, buffering the ecosystem from changes in season and soil conditions. PMID:20661464

  14. Characteristics of START assessments completed in mental health jail diversion programs.

    PubMed

    Desmarais, Sarah L; Van Dorn, Richard A; Telford, Robin P; Petrila, John; Coffey, Tim

    2012-01-01

    Many different instruments have been developed to assist in the assessment of risk for violence and other criminal behavior. However, there is limited evidence regarding how these instruments work in the 'real world'. Even less is known about how these instruments might work for assessing risk in jail diversion populations, whether in research or practice. To address these knowledge gaps, the present study examined the characteristics of risk assessments completed by program staff (n=10) on 96 mental health jail diversion clients (72 men and 24 women) using the Short-Term Assessment of Risk and Treatability (START). The findings provide preliminary support for the reliability and validity of START assessments completed in jail diversion programs, the first evidence of the transportability of START outside psychiatric settings, and further evidence regarding the reliability and validity of START assessments completed in the field. They additionally support the consideration of an eighth, general offending risk domain in START assessments. PMID:22807034

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

    PubMed

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

    2015-01-01

    The diversity and genetic differentiation of populations of Fusarium oxysporum associated with tomato fields, both endophytes obtained from tomato plants and isolates obtained from soil surrounding the sampled plants, were investigated. A total of 609 isolates of F. oxysporum were obtained, 295 isolates from a total of 32 asymptomatic tomato plants in two fields and 314 isolates from eight soil cores sampled from the area surrounding the plants. Included in this total were 112 isolates from the stems of all 32 plants, a niche that has not been previously included in F. oxysporum population genetics studies. Isolates were characterized using the DNA sequence of the translation elongation factor 1? gene. A diverse population of 26 sequence types was found, although two sequence types represented nearly two-thirds of the isolates studied. The sequence types were placed in different phylogenetic clades within F. oxysporum, and endophytic isolates were not monophyletic. Multiple sequence types were found in all plants, with an average of 4.2 per plant. The population compositions differed between the two fields but not between soil samples within each field. A certain degree of differentiation was observed between populations associated with different tomato cultivars, suggesting that the host genotype may affect the composition of plant-associated F. oxysporum populations. No clear patterns of genetic differentiation were observed between endophyte populations and soil populations, suggesting a lack of specialization of endophytic isolates. PMID:25304514

  16. PATTERNS OF ALLOZYME DIVERSITY IN THE THREATENED PLANT ERIGERON PARISHII (ASTERACEAE). (R826102)

    EPA Science Inventory

    Thirty-one occurrences of Erigeron parishii, a narrowly endemic plant threatened by mining, were sampled for allozyme diversity. This taxon held considerable genetic variation at the [4 allozyme loci surveyed. Species (e.g., alleles per locus [A] = 4.3 and proportion of polymorph...

  17. Diverse lifestyles and strategies of plant pathogenesis encoded in the genomes of eighteen Dothideomycetes fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The class Dothideomycetes is one of the largest groups of fungi with a high level of ecological diversity including many plant pathogens infecting a broad range of hosts. Here for the first time we compare the sequenced genomes of 18 Dothideomycetes to analyze their evolution, genome organization, a...

  18. Diversity of Marine Plants. Man and the Gulf of Mexico Series.

    ERIC Educational Resources Information Center

    Irby, Bobby N., Comp.; And Others

    "Man and the Gulf of Mexico" (MGM) is a marine science curriculum series developed to meet the needs of 10th through 12th grade students in Mississippi and Alabama schools. This MGM unit on the diversity of marine plants is divided into 12 sections. The first section introduces the unit by providing objectives and activities on why people classify…

  19. NEUTRONICS ANALYSIS OF A SELF-COOLED BLANKET FOR A LASER FUSION PLANT WITH MAGNETIC DIVERSION

    E-print Network

    Raffray, A. René

    , San Diego, CA, rraffray@ucsd.edu A blanket concept made of the low electrical conductivity Si is used. An example blanket concept made of the low electrical conductivity SiCf/SiC composite (requiredNEUTRONICS ANALYSIS OF A SELF-COOLED BLANKET FOR A LASER FUSION PLANT WITH MAGNETIC DIVERSION M

  20. OIKOS 91: 97108. Copenhagen 2000 Plant diversity increases resistance to invasion in the absence of

    E-print Network

    Thomas, David D.

    91: 97­108. Biological invasion is a widespread, but poorly understood phenomenon. Elton's hypothesis of biological invasions has be- come a focal area of ecological study. Several volumes have surveyedOIKOS 91: 97­108. Copenhagen 2000 Plant diversity increases resistance to invasion in the absence

  1. Pollinating flies (Diptera): A major contribution to plant diversity and agricultural production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diptera are one of the three largest and most diverse animal groups of the world. As an often neglected, but important group of pollinators, they play a significant role in agrobiodiversity and biodiversity of plants everywhere. Flies are present in almost all habitats and biomes and for many food p...

  2. The effects of forest management on plant species diversity in a Sierran conifer forest

    E-print Network

    Battles, John

    The effects of forest management on plant species diversity in a Sierran conifer forest John J in the mixed conifer forest. In addition to the existing data, we conducted botanical inventories in 32 plots-seral stands. # 2001 Elsevier Science B.V. All rights reserved. Keywords: Species richness; Temperate conifer

  3. Diversity and biological activities of endophytic fungi associated with micropropagated medicinal plant Echinacea purpurea (L.) Moench

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Echinacea is one of the top ten selling medicinal herbs in Europe and United States. Commercially available formulations may contain different plant parts of three species (Echinacea purpurea, E. pallida, and E. angustifolia). Our study evaluates the diversity of microbial community associated with ...

  4. Plant Diversity: Effects of Grazing System and Stocking Rate in Northern Mixed-Grass Prairie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of grazing system, stocking rate, and grazing system X stocking rate interactions, on plant diversity are poorly understood in rangelands. A grazing system (season-long and short-duration rotational grazing) X stocking rate (light: 16 steers•80 ha-1, moderate: 4 steers•12 ha-1 and heavy: 4 s...

  5. Exotic plant traits lead to functional diversity decline in novel ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exotic species have become common and even dominant in some grasslands forming novel ecosystems because the species in them have no common evolutionary history. Recent work on these novel ecosystems suggest that exotic species contribute to diversity declines. In order to identify the plant traits...

  6. Functional microbial diversity dynamics in common effluent treatment plants of South Gujarat and hydrocarbon degradation.

    PubMed

    Zaveri, Purvi; Munshi, Nasreen; Vaidya, Alok; Jha, Sanjay; Kumar, G Naresh

    2015-06-01

    Common effluent treatment plants (CETPs) of South Gujarat region, India, process wastewater generated by more than 2500 industries because of the nonfeasibility of processing at the individual industrial unit. This study assessed functional microbial diversity in wastewater samples of CETPs over a geological belt using Ecoplate®, isolation of the most abundant bacteria, and screening for hydrocarbon degradation. The high evenness (EPielou) values (0.9) in almost all samples indicated a highly even community structure. Principal component analysis of carbon source utilization showed a cluster of all inlet samples except E1 and another cluster of all outlet samples; aeration tank community samples were dispersed. In spite of the high richness found in microbial communities, 60 morphologically similar organisms were observed and isolated; 46 out of them were subjected to amplified ribosomal DNA restriction analysis with MboI, HaeIII, and TaqI enzyme, followed by UPGMA clustering. In screening the most abundant bacteria from each cluster, one of the cultures showed a high potential for hydrocarbon degradation and was identified as Pseudomonas citronellolis by 16S rDNA sequencing. Because of its highly adapted inherent nature, this bacterium may help augment the conventional procedure in wastewater treatment and efficiently decrease the organic load. PMID:25925663

  7. 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

  8. Receding Water Line and Interspecific Competition Determines Plant Community Composition and Diversity in Wetlands in Beijing

    PubMed Central

    Wang, Zhengjun; Gong, Huili; Zhang, Jing

    2015-01-01

    Climate and human-induced wetland degradation has accelerated in recent years, not only resulting in reduced ecosystem services but also greatly affecting the composition and diversity of wetland plant communities. To date, the knowledge of the differences in community parameters and their successional trends in degraded wetlands remains scarce. Here based on remote sensing images, geographic information system technology, and statistical methods, we produced a successional gradient map of the Yeyahu Wetland Nature Reserve in Beijing, which has experienced a steady decline in water level in recent decades. In addition, we analyzed community composition and diversity along with each identified gradient. The results showed that community diversity decreases while dominance increases with the progress of succession, with the highest diversity occurring during the early stage of succession. Moreover, the community demonstrates greater similarity among subareas during later successional stages, and the similarity coefficients calculated from the important value (IV) of each species are more accurate. Correlation analysis showed that the impact of soil factors on diversity was not significant at a subarea scale, although these nutrients showed an increasing trend with the community succession. Furthermore, the IVs of the dominant species had a particularly significant impact on diversity, showing a significantly negative correlation with diversity indices and a significantly positive correlation with dominance indices. Further analysis showed that the retreat of water level resulted from sustained drought and local human activities was a major extrinsic driving force resulting in observed differences in the community successional stages, which resulted in differences in community composition and diversity. On the other hand, interspecific competition was the main intrinsic mechanism, which significantly influenced the IVs of the dominant species and community diversity. The results of this study could aid in improving the understanding of community composition, diversity, and its successional trends in degraded wetlands. PMID:25848799

  9. Assessment of species diversity from species abundance distributions at different localities

    E-print Network

    Engen, Steinar

    by analysing similarities of communities of rare and endangered species of oak-living beetles in southAssessment of species diversity from species abundance distributions at different localities, Norway. We show how the spatial structure of species diversity can be analyzed using the correlation

  10. Preliminary assessment of genetic diversity of Italian honey bees in the USA and Italy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Declining numbers of breeder queens and the concomitant loss of genetic diversity potentially could result in inbreeding and increased susceptibility to pests and disease in honey bees. Genetic diversity of commercial Italian bee colonies in the United States and Italy was assessed using microsatell...

  11. Changing Attitudes over Time: Assessing the Effectiveness of a Workplace Diversity Course

    ERIC Educational Resources Information Center

    Probst, Tahira M.

    2003-01-01

    Diversity is increasing within the United States, and higher education will likely play a key role in preparing people to function in this new environment. This study assessed the effectiveness of a semester-long psychology workplace diversity course at changing student levels of ethnocentrism and attitudes regarding gender roles; the disabled;…

  12. Genetic Structure and Molecular Diversity of Cacao Plants Established as Local Varieties for More than Two Centuries: The Genetic History of Cacao Plantations in Bahia, Brazil

    PubMed Central

    Santos, Elisa S. L.; Cerqueira-Silva, Carlos Bernard M.; Mori, Gustavo M.; Ahnert, Dário; Mello, Durval L. N.; Pires, José Luis; Corrêa, Ronan X.; de Souza, Anete P.

    2015-01-01

    Bahia is the most important cacao-producing state in Brazil, which is currently the sixth-largest country worldwide to produce cacao seeds. In the eighteenth century, the Comum, Pará and Maranhão varieties of cacao were introduced into southern Bahia, and their descendants, which are called ‘Bahian cacao’ or local Bahian varieties, have been cultivated for over 200 years. Comum plants have been used to start plantations in African countries and extended as far as countries in South Asia and Oceania. In Brazil, two sets of clones selected from Bahian varieties and their mutants, the Agronomic Institute of East (SIAL) and Bahian Cacao Institute (SIC) series, represent the diversity of Bahian cacao in germplasm banks. Because the genetic diversity of Bahian varieties, which is essential for breeding programs, remains unknown, the objective of this work was to assess the genetic structure and diversity of local Bahian varieties collected from farms and germplasm banks. To this end, 30 simple sequence repeat (SSR) markers were used to genotype 279 cacao plants from germplasm and local farms. The results facilitated the identification of 219 cacao plants of Bahian origin, and 51 of these were SIAL or SIC clones. Bahian cacao showed low genetic diversity. It could be verified that SIC and SIAL clones do not represent the true diversity of Bahian cacao, with the greatest amount of diversity found in cacao trees on the farms. Thus, a core collection to aid in prioritizing the plants to be sampled for Bahian cacao diversity is suggested. These results provide information that can be used to conserve Bahian cacao plants and applied in breeding programs to obtain more productive Bahian cacao with superior quality and tolerance to major diseases in tropical cacao plantations worldwide. PMID:26675449

  13. Patterns of genetic diversity in three plant lineages endemic to the Cape Verde Islands

    PubMed Central

    Romeiras, Maria M.; Monteiro, Filipa; Duarte, M. Cristina; Schaefer, Hanno; Carine, Mark

    2015-01-01

    Conservation of plant diversity on islands relies on a good knowledge of the taxonomy, distribution and genetic diversity of species. In recent decades, a combination of morphology- and DNA-based approaches has become the standard for investigating island plant lineages and this has led, in some cases, to the discovery of previously overlooked diversity, including ‘cryptic species’. The flora of the Cape Verde archipelago in the North Atlantic is currently thought to comprise ?740 vascular plant species, 92 of them endemics. Despite the fact that it is considered relatively well known, there has been a 12 % increase in the number of endemics in the last two decades. Relatively few of the Cape Verde plant lineages have been included in genetic studies so far and little is known about the patterns of diversification in the archipelago. Here we present an updated list for the endemic Cape Verde flora and analyse diversity patterns for three endemic plant lineages (Cynanchum, Globularia and Umbilicus) based on one nuclear (ITS) and four plastid DNA regions. In all three lineages, we find genetic variation. In Cynanchum, we find two distinct haplotypes with no clear geographical pattern, possibly reflecting different ploidy levels. In Globularia and Umbilicus, differentiation is evident between populations from northern and southern islands. Isolation and drift resulting from the small and fragmented distributions, coupled with the significant distances separating the northern and southern islands, could explain this pattern. Overall, our study suggests that the diversity in the endemic vascular flora of Cape Verde is higher than previously thought and further work is necessary to characterize the flora. PMID:25979965

  14. Assessing the extent and diversity of riparian ecosystems in Sonora, Mexico

    USGS Publications Warehouse

    Scott, M.L.; Nagler, P.L.; Glenn, E.P.; Valdes-Casillas, C.; Erker, J.A.; Reynolds, E.W.; Shafroth, P.B.; Gomez-Limon, E.; Jones, C.L.

    2009-01-01

    Conservation of forested riparian ecosystems is of international concern. Relatively little is known of the structure, composition, diversity, and extent of riparian ecosystems in Mexico. We used high- and low-resolution satellite imagery from 2000 to 2006, and ground-based sampling in 2006, to assess the spatial pattern, extent, and woody plant composition of riparian forests across a range of spatial scales for the state of Sonora, Mexico. For all 3rd and higher order streams, river bottomlands with riparian forests occupied a total area of 2,301 km2. Where forested bottomlands remained, on average, 34% of the area had been converted to agriculture while 39% remained forested. We estimated that the total area of riparian forest along the principal streams was 897 km2. Including fencerow trees, the total forested riparian area was 944 km2, or 0.5% of the total land area of Sonora. Ground-based sampling of woody riparian vegetation consisted of 92, 50 m radius circular plots. About 79 woody plant species were noted. The most important tree species, based on cover and frequency, were willow species Salix spp. (primarily S. goodingii and S. bonplandiana), mesquite species Prosopis spp. (primarily P. velutina), and Fremont cottonwood Populus fremontii. Woody riparian taxa at the reach scale showed a trend of increasing diversity from north to south within Sonora. Species richness was greatest in the willow-bald cypress Taxodium distichum var. mexicanum-Mexican cottonwood P. mexicana subsp. dimorphia ecosystem. The non-native tamarisk Tamarix spp. was rare, occurring at just three study reaches. Relatively natural stream flow patterns and fluvial disturbance regimes likely limit its establishment and spread. ?? 2008 Springer Science + Business Media BV.

  15. Assessing the Effects of Woody Plant Traits on Understory Herbaceous Cover in a Semiarid Rangeland

    NASA Astrophysics Data System (ADS)

    Belay, Tamrat A.; Moe, Stein R.

    2015-07-01

    The ecological impact of woody plant encroachment in rangeland ecosystems has traditionally been evaluated based on correlation studies between densities of dissimilar woody plants and various ecosystem properties. However, ecosystem properties respond differently to woody plant encroachment because of variations in adaptation of co-occurring woody plants. The objective of this study is to predict the impact of woody plant encroachment on understory herbaceous cover based on analysis of key traits of woody plants. We conducted a vegetation survey in 4 savanna sites in southwestern Ethiopia and compared 9 different key traits of 19 co-occurring woody plants with understory herbaceous cover. Our results show that low understory herbaceous cover is associated with evergreen leaf phenology, shrubby growth form, smaller relative crown-base height and larger relative crown diameter. However, the N2-fixing ability and density of woody plants did not influence the understory herbaceous cover. This shows that traits of individual woody plants can predict the impact of woody plant encroachment on understory herbaceous cover better than density does. The finding improves our ability to accurately predict the impact of woody plant encroachment on various ecosystem properties in highly diverse savanna systems. This plant trait-based approach could be also used as an important management exercise to assess and predict the impact of encroaching woody species in several rangeland ecosystems.

  16. Sampling and Complementarity Effects of Plant Diversity on Resource Use Increases the Invasion Resistance of Communities

    PubMed Central

    Zhu, Dan H.; Wang, Ping; Zhang, Wei Z.; Yuan, Yue; Li, Bin; Wang, Jiang

    2015-01-01

    Background Although plant diversity is postulated to resist invasion, studies have not provided consistent results, most of which were ascribed to the influences of other covariate environmental factors. Methodology/Principal Findings To explore the mechanisms by which plant diversity influences community invasibility, an experiment was conducted involving grassland sites varying in their species richness (one, two, four, eight, and sixteen species). Light interception efficiency and soil resources (total N, total P, and water content) were measured. The number of species, biomass, and the number of seedlings of the invading species decreased significantly with species richness. The presence of Patrinia scabiosaefolia Fisch. ex Trev. and Mosla dianthera (Buch.-Ham. ex Roxburgh) Maxim. significantly increased the resistance of the communities to invasion. A structural equation model showed that the richness of planted species had no direct and significant effect on invasion. Light interception efficiency had a negative effect on the invasion whereas soil water content had a positive effect. In monocultures, Antenoron filiforme (Thunb.) Rob. et Vaut. showed the highest light interception efficiency and P. scabiosaefolia recorded the lowest soil water content. With increased planted-species richness, a greater percentage of pots showed light use efficiency higher than that of A. filiforme and a lower soil water content than that in P. scabiosaefolia. Conclusions/Significance The results of this study suggest that plant diversity confers resistance to invasion, which is mainly ascribed to the sampling effect of particular species and the complementarity effect among species on resources use. PMID:26556713

  17. 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.

  18. Assessing the effect of disturbances on ectomycorrhiza diversity.

    PubMed

    Iordache, Virgil; Gherghel, Felicia; Kothe, Erika

    2009-02-01

    Ectomycorrhiza (ECM) communities can be described on a species level or on a larger scale at an ecosystem level. Here we show that the species level approach of successional processes in ECM communities is not appropriate for understanding the diversity patterns of ECM communities at contaminated sites. An ecosystem based approach improves predictability since different biotic and abiotic factors are included. However, it still does not take into account the hierarchical structure of the ecosystem. We suggest that diversity patterns of ECMs communities in forests can best be investigated at three levels. This hypothetical approach for investigation can be tested at sites of secondary succession in areas contaminated with metals. Once the diversity patterns are appropriately described by a hierarchical ecosystem approach, to the species level is used to explain these patterns by populational and ecotoxicological mechanisms. PMID:19440391

  19. Assessing the Effect of Disturbances on Ectomycorrhiza Diversity

    PubMed Central

    Iordache, Virgil; Gherghel, Felicia; Kothe, Erika

    2009-01-01

    Ectomycorrhiza (ECM) communities can be described on a species level or on a larger scale at an ecosystem level. Here we show that the species level approach of successional processes in ECM communities is not appropriate for understanding the diversity patterns of ECM communities at contaminated sites. An ecosystem based approach improves predictability since different biotic and abiotic factors are included. However, it still does not take into account the hierarchical structure of the ecosystem. We suggest that diversity patterns of ECMs communities in forests can best be investigated at three levels. This hypothetical approach for investigation can be tested at sites of secondary succession in areas contaminated with metals. Once the diversity patterns are appropriately described by a hierarchical ecosystem approach, to the species level is used to explain these patterns by populational and ecotoxicological mechanisms. PMID:19440391

  20. A new image of plantain diversity assessed by SSR, AFLP and MSAP markers.

    PubMed

    Noyer, J L; Causse, S; Tomekpe, K; Bouet, A; Baurens, F C

    2005-05-01

    Using both SSR and AFLP markers, the genetic diversity of 30 plantains constituting a representative sample of the phenotypic diversity was assessed. The results confirmed a very narrow genetic base of this cultivar group. SSR and AFLP data support the hypothesis that these cultivars may have arisen from vegetative multiplication of a single seed. MSAP were used to survey cytosine methylation status at CCGG sites in order to obtain an alternative source of diversity data. A higher degree of polymorphism was revealed allowing the classification of the samples into three clusters. No correlation was observed between the phenotypic classification and methylation diversity. Implications for breeding programs are discussed. PMID:16011003

  1. Paramagnetic cellulose DNA isolation improves DNA yield and quality among diverse plant taxa1

    PubMed Central

    Moeller, Jackson R.; Moehn, Nicholas R.; Waller, Donald M.; Givnish, Thomas J.

    2014-01-01

    • Premise of the study: The chemical diversity of land plants ensures that no single DNA isolation method results in high yield and purity with little effort for all species. Here we evaluate a new technique originally developed for forensic science, based on MagnaCel paramagnetic cellulose particles (PMC), to determine its efficacy in extracting DNA from 25 plant species representing 21 families and 15 orders. • Methods and Results: Yield and purity of DNA isolated by PMC, DNeasy Plant Mini Kit (silica column), and cetyltrimethylammonium bromide (CTAB) methods were compared among four individuals for each of 25 plant species. PMC gave a twofold advantage in average yield, and the relative advantage of the PMC method was greatest for samples with the lowest DNA yields. PMC also produced more consistent sample purity based on absorbance ratios at 260:280 and 260:230 nm. • Conclusions: PMC technology is a promising alternative for plant DNA isolation. PMID:25309836

  2. Biogeographical Interpretation of Elevational Patterns of Genus Diversity of Seed Plants in Nepal

    PubMed Central

    Li, Miao; Feng, Jianmeng

    2015-01-01

    This study tests if the biogeographical affinities of genera are relevant for explaining elevational plant diversity patterns in Nepal. We used simultaneous autoregressive (SAR) models to investigate the explanatory power of several predictors in explaining the diversity-elevation relationships shown in genera with different biogeographical affinities. Delta akaike information criterion (?AIC) was used for multi-model inferences and selections. Our results showed that both the total and tropical genus diversity peaked below the mid-point of the elevational gradient, whereas that of temperate genera had a nearly symmetrical, unimodal relationship with elevation. The proportion of temperate genera increased markedly with elevation, while that of tropical genera declined. Compared to tropical genera, temperate genera had wider elevational ranges and were observed at higher elevations. Water-related variables, rather than mid-domain effects (MDE), were the most significant predictors of elevational patterns of tropical genus diversity. The temperate genus diversity was influenced by energy availability, but only in quadratic terms of the models. Though climatic factors and mid-domain effects jointly explained most of the variation in the diversity of temperate genera with elevation, the former played stronger roles. Total genus diversity was most strongly influenced by climate and the floristic overlap of tropical and temperate floras, while the influences of mid-domain effects were relatively weak. The influences of water-related and energy-related variables may vary with biogeographical affinities. The elevational patterns may be most closely related to climatic factors, while MDE may somewhat modify the patterns. Caution is needed when investigating the causal factors underlying diversity patterns for large taxonomic groups composed of taxa of different biogeographical affinities. Right-skewed diversity-elevation patterns may be produced by the differential response of taxa with varying biogeographical affinities to climatic factors and MDE. PMID:26488164

  3. Nitrogen deposition and multi-dimensional plant diversity at the landscape scale

    PubMed Central

    Roth, Tobias; Kohli, Lukas; Rihm, Beat; Amrhein, Valentin; Achermann, Beat

    2015-01-01

    Estimating effects of nitrogen (N) deposition is essential for understanding human impacts on biodiversity. However, studies relating atmospheric N deposition to plant diversity are usually restricted to small plots of high conservation value. Here, we used data on 381 randomly selected 1?km2 plots covering most habitat types of Central Europe and an elevational range of 2900?m. We found that high atmospheric N deposition was associated with low values of six measures of plant diversity. The weakest negative relation to N deposition was found in the traditionally measured total species richness. The strongest relation to N deposition was in phylogenetic diversity, with an estimated loss of 19% due to atmospheric N deposition as compared with a homogeneously distributed historic N deposition without human influence, or of 11% as compared with a spatially varying N deposition for the year 1880, during industrialization in Europe. Because phylogenetic plant diversity is often related to ecosystem functioning, we suggest that atmospheric N deposition threatens functioning of ecosystems at the landscape scale. PMID:26064640

  4. Nitrogen deposition and multi-dimensional plant diversity at the landscape scale.

    PubMed

    Roth, Tobias; Kohli, Lukas; Rihm, Beat; Amrhein, Valentin; Achermann, Beat

    2015-04-01

    Estimating effects of nitrogen (N) deposition is essential for understanding human impacts on biodiversity. However, studies relating atmospheric N deposition to plant diversity are usually restricted to small plots of high conservation value. Here, we used data on 381 randomly selected 1?km(2) plots covering most habitat types of Central Europe and an elevational range of 2900?m. We found that high atmospheric N deposition was associated with low values of six measures of plant diversity. The weakest negative relation to N deposition was found in the traditionally measured total species richness. The strongest relation to N deposition was in phylogenetic diversity, with an estimated loss of 19% due to atmospheric N deposition as compared with a homogeneously distributed historic N deposition without human influence, or of 11% as compared with a spatially varying N deposition for the year 1880, during industrialization in Europe. Because phylogenetic plant diversity is often related to ecosystem functioning, we suggest that atmospheric N deposition threatens functioning of ecosystems at the landscape scale. PMID:26064640

  5. Plot shape effects on plant species diversity measurements

    USGS Publications Warehouse

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

    2005-01-01

    Question: Do rectangular sample plots record more plant species than square plots as suggested by both empirical and theoretical studies? Location: Grasslands, shrublands and forests in the Mediterranean-climate region of California, USA. Methods: We compared three 0.1-ha sampling designs that differed in the shape and dispersion of 1-m2 and 100-m2 nested subplots. We duplicated an earlier study that compared the Whittaker sample design, which had square clustered subplots, with the modified Whittaker design, which had dispersed rectangular subplots. To sort out effects of dispersion from shape we used a third design that overlaid square subplots on the modified Whittaker design. Also, using data from published studies we extracted species richness values for 400-m2 subplots that were either square or 1:4 rectangles partially overlaid on each other from desert scrub in high and low rainfall years, chaparral, sage scrub, oak savanna and coniferous forests with and without fire. Results: We found that earlier empirical reports of more than 30% greater richness with rectangles were due to the confusion of shape effects with spatial effects, coupled with the use of cumulative number of species as the metric for comparison. Average species richness was not significantly different between square and 1:4 rectangular sample plots at either 1-or 100-m2. Pairwise comparisons showed no significant difference between square and rectangular samples in all but one vegetation type, and that one exhibited significantly greater richness with squares. Our three intensive study sites appear to exhibit some level of self-similarity at the scale of 400 m2, but, contrary to theoretical expectations, we could not detect plot shape effects on species richness at this scale. Conclusions: At the 0.1-ha scale or lower there is no evidence that plot shape has predictable effects on number of species recorded from sample plots. We hypothesize that for the mediterranean-climate vegetation types studied here, the primary reason that 1:4 rectangles do not sample greater species richness than squares is because species turnover varies along complex environmental gradients that are both parallel and perpendicular to the long axis of rectangular plots. Reports in the literature of much greater species richness recorded for highly elongated rectangular strips than for squares of the same area are not likely to be fair comparisons because of the dramatically different periphery/area ratio, which includes a much greater proportion of species that are using both above and below-ground niche space outside the sample area. ?? IAVS; Opulus Press Uppsala.

  6. Mechanisms for increased soil C storage with increasing temporal and spatial plant diversity in Agroecosystems

    NASA Astrophysics Data System (ADS)

    Tiemann, L. K.; Grandy, S.; Marin-Spiotta, E.; Atkinson, E. E.

    2012-12-01

    Generally, there are positive relationships between plant species diversity and net primary production and other key ecosystem functions. However, the effects of aboveground diversity on soil microbial communities and ecosystem processes they mediate, such as soil C sequestration, remain unclear. In this study, we used an 11-y cropping diversity study where increases in diversity have increased crop yields. At the experimental site, temporal diversity is altered using combinations of annual crop rotations, while spatial diversity is altered using cover crop species. We used five treatments ranging in diversity from one to five species consisting of continuous corn with no cover crop or one cover crop and corn-soy-wheat rotations with no cover, one cover or two cover crop species. We collected soils from four replicate plots of each treatment and measured the distribution of mega- (>2 mm), macro- (0.25-2 mm), and micro- (0.053-0.25 mm) aggregates. Within each aggregate size class, we also measured total soil C and N, permanganate oxidizable C (POXC), extracellular enzyme activities (EEA), and microbial community structure with phospholipid fatty acid (PLFA) analysis. We use these data to address the impacts of both rotational and cover crop diversity on soil physical structure, associated microbial community structure and activity and soil C storage. As spatial diversity increased, we found concurrent increases in mega-aggregate abundance as well as increasing soil C in the mega- and micro-aggregates but not macro-aggregates. The proportion of total soil C in each aggregate size class that is relatively labile (POXC) was highest in the micro-aggregates, as was enzyme activity associated with labile C acquisition across all levels of diversity. Enzyme activity associated with more recalcitrant forms of soil C was highest in the mega-aggregate class, also across all diversity levels; however, the ratio of labile to recalcitrant EEA increased with increasing diversity in the mega- and micro-aggregates. In addition, soil N increased with diversity such that microbial C:N EEA simultaneously decreased in mega-aggregates. We also found that cropping diversity has created distinctive soil microbial communities, highlighted by variation in the abundance of gram positive bacteria and Actinomycetes. Further research will help us determine how these changes in community structure with increasing diversity are related to concomitant changes in aggregation and enzyme activities. We suggest that the additional organic matter inputs from cover crops in the high diversity treatments have increased aggregation processes and C pools. While microbial activity has also increased in association with this increased C availability, the activity of recalcitrant and N-acquiring enzymes has declined, suggesting an overall decrease in SOM mineralization with possible increased SOM stabilization. The addition of crop species in rotation (temporal diversity) had minimal influence on any of the measured parameters. We thus conclude that spatial diversity is a more important driver of soil structure and microbial activity, likely due to the high quality organic matter inputs derived from the leguminous cover crops; however, spatial diversity alone did not lead to the same level of C storage potential as mixtures of temporal and spatial diversity.

  7. Preparing Teachers for Diverse Learners: Assessing Teacher Candidates' Dispositions

    ERIC Educational Resources Information Center

    Northington, Vera Ann

    2011-01-01

    The National Council for Accreditation for Teacher Education (NCATE) recommended teacher preparation programs measure teacher candidates' disposition toward diverse learners. The conduction of the quantitative cross-sectional survey design utilized the Quick Discrimination Index Survey (QDI), a Likert-type tool that used reversed or negatively…

  8. Grazer exclusion alters plant spatial organization at multiple scales, increasing diversity

    PubMed Central

    Zhang, Hui; Gilbert, Benjamin; Wang, Wenbin; Liu, Junjie; Zhou, Shurong

    2013-01-01

    Grazing is one of the most important factors influencing community structure and productivity in natural grasslands. Understanding why and how grazing pressure changes species diversity is essential for the preservation and restoration of biodiversity in grasslands. We use heavily grazed subalpine meadows in the Qinghai-Tibetan Plateau to test the hypothesis that grazer exclusion alters plant diversity by changing inter- and intraspecific species distributions. Using recently developed spatial analyses combined with detailed ramet mapping of entire plant communities (91 species), we show striking differences between grazed and fenced areas that emerged at scales of just one meter. Species richness was similar at very small scales (0.0625 m2), but at larger scales diversity in grazed areas fell below 75% of corresponding fenced areas. These differences were explained by differences in spatial distributions; intra- and interspecific associations changed from aggregated at small scales to overdispersed in the fenced plots, but were consistently aggregated in the grazed ones. We conclude that grazing enhanced inter- and intraspecific aggregations and maintained high diversity at small scales, but caused decreased turnover in species at larger scales, resulting in lower species richness. Our study provides strong support to the theoretical prediction that inter- and intraspecific aggregation produces local spatial patterns that scale-up to affect species diversity in a community. It also demonstrates that the impacts of grazing can manifest through this mechanism, lowering diversity by reducing spatial turnover in species. Finally, it highlights the ecological and physiological plant processes that are likely responding to grazing and thereby altering aggregation patterns, providing new insights for monitoring, and mediating the impacts of grazing. PMID:24223294

  9. Nuclear power plant performance assessment pertaining to plant aging in France and the United States

    E-print Network

    Guyer, Brittany (Brittany Leigh)

    2013-01-01

    The effect of aging on nuclear power plant performance has come under increased scrutiny in recent years. The approaches used to make an assessment of this effect strongly influence the economics of nuclear power plant ...

  10. Are different facets of plant diversity well protected against climate and land cover changes? A test study in the French Alps

    PubMed Central

    Thuiller, Wilfried; Guéguen, Maya; Georges, Damien; Bonet, Richard; Chalmandrier, Loïc; Garraud, Luc; Renaud, Julien; Roquet, Cristina; Van Es, Jérémie; Zimmermann, Niklaus E.; Lavergne, Sébastien

    2014-01-01

    Climate and land cover changes are important drivers of the plant species distributions and diversity patterns in mountainous regions. Although the need for a multifaceted view of diversity based on taxonomic, functional and phylogenetic dimensions is now commonly recognized, there are no complete risk assessments concerning their expected changes. In this paper, we used a range of species distribution models in an ensemble-forecasting framework together with regional climate and land cover projections by 2080 to analyze the potential threat for more than 2,500 plant species at high resolution (2.5 km × 2.5 km) in the French Alps. We also decomposed taxonomic, functional and phylogenetic diversity facets into ? and ? components and analyzed their expected changes by 2080. Overall, plant species threats from climate and land cover changes in the French Alps were expected to vary depending on the species’ preferred altitudinal vegetation zone, rarity, and conservation status. Indeed, rare species and species of conservation concern were the ones projected to experience less severe change, and also the ones being the most efficiently preserved by the current network of protected areas. Conversely, the three facets of plant diversity were also projected to experience drastic spatial re-shuffling by 2080. In general, the mean ?-diversity of the three facets was projected to increase to the detriment of regional ?-diversity, although the latter was projected to remain high at the montane-alpine transition zones. Our results show that, due to a high-altitude distribution, the current protection network is efficient for rare species, and species predicted to migrate upward. Although our modeling framework may not capture all possible mechanisms of species range shifts, our work illustrates that a comprehensive risk assessment on an entire floristic region combined with functional and phylogenetic information can help delimitate future scenarios of biodiversity and better design its protection. PMID:25722539

  11. Terrestrial water and carbon fluxes across climatic gradients: does plant diversity matter?

    NASA Astrophysics Data System (ADS)

    Pappas, Christoforos; Fatichi, Simone; Burlando, Paolo

    2014-05-01

    Vegetation diversity in many land-surface, ecohydrological, and dynamic vegetation models is crudely represented using a discrete classification of a handful of "plant types" (named Plant Functional Types; PFTs). The parameterization of PFTs typically reflects mean properties of observed plant functional traits over broad categories (e.g., temperate broadleaf deciduous forest) ignoring most of the inter- and intra-specific trait variability. In the present study, taking advantage of well-established plant-trait cross-correlations described by the Leaf Economics Spectrum, we generated coordinated hypothetical species across a continuous spectrum of leaf traits, rather than using pre-defined categories. The behavior of these proxy species is then tested using a mechanistic ecohydrological model (T&C) that operates as a filter of their performance. Simulations are carried out for a range of climates representative of different elevations and wetness conditions in Switzerland. Using this framework the following questions are addressed: (i) how sensitive are the carbon and water dynamics to species diversity? and (ii) which is the correlation between plant physiological traits, plant performance and observed trait distribution across climatic gradients?

  12. The effects of plant diversity on nitrous oxide emissions in hydroponic microcosms

    NASA Astrophysics Data System (ADS)

    Sun, Hongying; Zhang, Chongbang; Song, Changchun; Chang, Scott X.; Gu, Baojing; Chen, Zhengxin; Peng, Changhui; Chang, Jie; Ge, Ying

    2013-10-01

    Previous studies have shown that plant diversity can improve the wastewater purification efficiency of constructed wetlands (CWs), but its effect on the nitrous oxide (N2O) emission in CWs has been unknown. To investigate the effect of plant diversity on the N2O emission, we established four plant species richness levels (each level containing 1, 2, 3 and 4 species, respectively) by using 96 hydroponic microcosms. Results showed that plant species richness enhanced the N2O emission, ranging from 27.1 to 115.4 ?g N2O m-2 d-1, and improved nitrate removal (P < 0.001). The presence of Phalaris arundinacea within a given plant community increased the N2O emission (P < 0.001). The presence of Rumex japonicas had no influence on the N2O emissions (P > 0.05), but improved nitrogen removal (P < 0.001). Hence, our study highlights the importance of both plant species richness and species identity in mediating the N2O emission and nitrogen removal in CWs.

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  14. Dynamic Response of Large Wind Power Plant Affected by Diverse Conditions at Individual Turbines

    SciTech Connect

    Elizondo, Marcelo A.; Lu, Shuai; Lin, Guang; Wang, Shaobu

    2014-07-31

    Diverse operating conditions at individual wind turbine generators (WTG) within wind power plants (WPPs) can affect the WPP dynamic response to system faults. For example, individual WTGs can experience diverse terminal voltage and power output caused by different wind direction and speed, affecting the response of protection and control limiters. In this paper, we present a study to investigate the dynamic response of a detailed WPP model under diverse power outputs of its individual WTGs. Wake effect is considered as the reason for diverse power outputs. The diverse WTG power output is evaluated in a test system where a large 168-machine test WPP is connected to the IEEE-39-bus system. The power output from each WTG is derived from a wake effect model that uses realistic statistical data for incoming wind speed and direction. The results show that diverse WTG output due to wake effect can affect the WPP dynamic response activating specialized control in some turbines. In addition, transient stability is affected by exhibiting uncertainty in critical clearing time calculation.

  15. 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

  16. Learning to Assess Science in Linguistically Diverse Classrooms: Tracking Growth in Secondary Science Preservice Teachers' Assessment Expertise

    ERIC Educational Resources Information Center

    Lyon, Edward G.

    2013-01-01

    Although studies have documented teachers' growth in assessing science resulting from professional development or science methods courses, little attention has been given to growth while being prepared to assess a linguistically diverse student population. In this study, the growth of 11 secondary science preservice teachers is documented by…

  17. ASSESSMENT OF TOKAMAK PLASMA OPERATION MODES AS FUSION POWER PLANTS

    E-print Network

    ASSESSMENT OF TOKAMAK PLASMA OPERATION MODES AS FUSION POWER PLANTS: THE STARLITE STUDY Farrokh plants. The research also has aimed at identifying both the trade-offs that lead to the optimal regime of operation for a tokamak power plant and the critical plasma physics and technology issues. During

  18. Quantitative phylogenetic assessment of microbial communities in diverse environments

    E-print Network

    2008-01-01

    cheddar mud, sludge, sewage, waste, silage, wastewater Tablesludge soil sponge spring subsurface termite termite.gut terrestrial treatment.plant Trough uranium.mill uranium.mining vent volcano waste wastewater

  19. Plant-Wide Assessment Report for Shaw Industries, Plant #78; Aiken, SC

    SciTech Connect

    Michael Brown PE, CEM; Matt Soderlund; Bill Meffert PE; Paolo Baldisserotto; Jerry Zolkowski PE, CEM

    2006-04-10

    A plant-wide energy assessment sponsored by the U.S. Department of Energy was conducted at Shaw Industries Group, plant #78 in Aiken, SC. The assessment team consisted of Georgia Tech faculty from the Energy & Environmental Management Center and Shaw personnel from plant #78 and the corporate energy group. The purpose of this assessment was to uncover as many opportunities for saving energy usage and costs using techniques that have been established as best practices in the energy engineering field. In addition, these findings are to be shared with similar plants in Shaw Industries Group to multiply the lessons learned. The findings from this assessment are included in this report.

  20. How do soil texture, plant community composition and earthworms affected the infiltration rate in a grassland plant diversity experiment depending on season?

    NASA Astrophysics Data System (ADS)

    Fischer, Christine; Britta, Merkel; Nico, Eisenhauer; Christiane, Roscher; Sabine, Attinger; Stefan, Scheu; Anke, Hildebrandt

    2013-04-01

    Background and aims: In this study we analyzed the influences of plant community characteristics, soil texture and earthworm presence on infiltration rates on a managed grassland plant diversity experiment assessing the role of biotic and abiotic factors on soil hydrology. Methods: We measured infiltration using a hood infiltrometer in subplots with ambient and reduced earthworm density (earthworm extraction) nested in plots of different plant species richness (1, 4, and 16), plant functional group number and composition (1 to 4; legumes, grasses, small herbs, tall herbs) in early summer (June) and autumn (September, October) 2011. Results: The presence of certain plant functional groups such as grasses and legumes influenced infiltration rates and this effect enhanced during the growing season. Infiltration was significantly higher in plots containing legumes than in plots without, and it was significantly lower in the presence of grasses than in their absence. In early summer, earthworm presence and biomass increased the infiltration rates, independently of plant species richness. In October, plant species richness only affected infiltration rates in reduced earthworm plots. At the end of the growing season earthworm populations were negatively influenced by grasses and positively by legumes. In September, infiltration rates were positive related to the proportion of finer grains. The correlation disappears when removing all plots containing legumes from the sample. For all measurements the infiltration rates decreases from early summer to autumn at the matric potentials at pressure zero and -0.02 m, but not for smaller macropores at matric potentials -0.04 and -0.06m. Conclusions: Considering infiltration rates as ecosystem function, this function will largely depend on the ecosystem composition and season, not on biodiversity per se. Our results indicate that biotic factors are of overriding influence for shaping infiltration rates mainly for larger macropores, and should be taken into account in hydrological applications.

  1. Genetic Structure, Diversity and Long Term Viability of a Medicinal Plant, Nothapodytes nimmoniana Graham. (Icacinaceae), in Protected and Non-Protected Areas in the Western Ghats Biodiversity Hotspot

    PubMed Central

    Shivaprakash, K. Nagaraju; Ramesha, B. Thimmappa; Uma Shaanker, Ramanan; Dayanandan, Selvadurai; Ravikanth, Gudasalamani

    2014-01-01

    Background and Question The harvesting of medicinal plants from wild sources is escalating in many parts of the world, compromising the long-term survival of natural populations of medicinally important plants and sustainability of sources of raw material to meet pharmaceutical industry needs. Although protected areas are considered to play a central role in conservation of plant genetic resources, the effectiveness of protected areas for maintaining medicinal plant populations subject to intense harvesting pressure remain largely unknown. We conducted genetic and demographic studies of Nothapodytes nimmoniana Graham, one of the extensively harvested medicinal plant species in the Western Ghats biodiversity hotspot, India to assess the effectiveness of protected areas in long-term maintenance of economically important plant species. Methodology/Principal Findings The analysis of adults and seedlings of N. nimmoniana in four protected and four non-protected areas using 7 nuclear microsatellite loci revealed that populations that are distributed within protected areas are subject to lower levels of harvesting and maintain higher genetic diversity (He?=?0.816, Ho?=?0.607, A?=?18.857) than populations in adjoining non-protected areas (He?=?0.781, Ho?=?0.511, A?=?15.571). Furthermore, seedlings in protected areas had significantly higher observed heterozygosity (Ho?=?0.630) and private alleles as compared to seedlings in adjoining non-protected areas (Ho?=?0.426). Most populations revealed signatures of recent genetic bottleneck. The prediction of long-term maintenance of genetic diversity using BOTTLESIM indicated that current population sizes of the species are not sufficient to maintain 90% of present genetic diversity for next 100 years. Conclusions/Significance Overall, these results highlight the need for establishing more protected areas encompassing a large number of adult plants in the Western Ghats to conserve genetic diversity of economically and medicinally important plant species. PMID:25493426

  2. Soil fertility and plant diversity enhance microbial performance in metal-polluted soils.

    PubMed

    Stefanowicz, Anna M; Kapusta, Pawe?; Szarek-?ukaszewska, Gra?yna; Grodzi?ska, Krystyna; Nikli?ska, Maria; Vogt, Rolf D

    2012-11-15

    This study examined the effects of soil physicochemical properties (including heavy metal pollution) and vegetation parameters on soil basal respiration, microbial biomass, and the activity and functional richness of culturable soil bacteria and fungi. In a zinc and lead mining area (S Poland), 49 sites were selected to represent all common plant communities and comprise the area's diverse soil types. Numerous variables describing habitat properties were reduced by PCA to 7 independent factors, mainly representing subsoil type (metal-rich mining waste vs. sand), soil fertility (exchangeable Ca, Mg and K, total C and N, organic C), plant species richness, phosphorus content, water-soluble heavy metals (Zn, Cd and Pb), clay content and plant functional diversity (based on graminoids, legumes and non-leguminous forbs). Multiple regression analysis including these factors explained much of the variation in most microbial parameters; in the case of microbial respiration and biomass, it was 86% and 71%, respectively. The activity of soil microbes was positively affected mainly by soil fertility and, apparently, by the presence of mining waste in the subsoil. The mining waste contained vast amounts of trace metals (total Zn, Cd and Pb), but it promoted microbial performance due to its inherently high content of macronutrients (total Ca, Mg, K and C). Plant species richness had a relatively strong positive effect on all microbial parameters, except for the fungal component. In contrast, plant functional diversity was practically negligible in its effect on microbes. Other explanatory variables had only a minor positive effect (clay content) or no significant influence (phosphorus content) on microbial communities. The main conclusion from this study is that high nutrient availability and plant species richness positively affected the soil microbes and that this apparently counteracted the toxic effects of metal contamination. PMID:23073370

  3. Should Exotic Eucalyptus be Planted in Subtropical China: Insights from Understory Plant Diversity in Two Contrasting Eucalyptus Chronosequences.

    PubMed

    Wu, Jianping; Fan, Houbao; Liu, Wenfei; Huang, Guomin; Tang, Jianfu; Zeng, Ruijin; Huang, Jing; Liu, Zhanfeng

    2015-11-01

    Although Eucalyptus is widely planted in South China, whose effects on native biodiversity are unclear. The objective of this study was to quantify the richness and composition of understory plants in two contrasting Eucalyptus chronosequences in South China. One was in Zhangzhou City with plantation age of 2, 4, and 6 years after clear-cutting Chinese fir forests, while the other was in Heshan City with plantation age of 2, 3, and 24 years that reforested on barren lands. Results showed that the richness of understory plants and functional groups was not significantly altered in the Zhangzhou chronosequence, while increased in the 24-year-old plantations, with a significantly larger proportion of woody plants than the younger plantations for the Heshan chronosequence. Moreover, a higher richness of woody plants accompanied by a lower richness of herbaceous species was detected in the Zhangzhou chronosequence compared with the Heshan one. To balance the need for pulp production and plant diversity conservation, we suggest that intercropping approaches between exotic Eucalyptus plantations and native forests should be considered in the fast rotation Eucalyptus plantations. However, Eucalyptus plantations may be used as pioneer species to sustain ecosystem functioning for the degraded lands. PMID:26239647

  4. Should Exotic Eucalyptus be Planted in Subtropical China: Insights from Understory Plant Diversity in Two Contrasting Eucalyptus Chronosequences

    NASA Astrophysics Data System (ADS)

    Wu, Jianping; Fan, Houbao; Liu, Wenfei; Huang, Guomin; Tang, Jianfu; Zeng, Ruijin; Huang, Jing; Liu, Zhanfeng

    2015-11-01

    Although Eucalyptus is widely planted in South China, whose effects on native biodiversity are unclear. The objective of this study was to quantify the richness and composition of understory plants in two contrasting Eucalyptus chronosequences in South China. One was in Zhangzhou City with plantation age of 2, 4, and 6 years after clear-cutting Chinese fir forests, while the other was in Heshan City with plantation age of 2, 3, and 24 years that reforested on barren lands. Results showed that the richness of understory plants and functional groups was not significantly altered in the Zhangzhou chronosequence, while increased in the 24-year-old plantations, with a significantly larger proportion of woody plants than the younger plantations for the Heshan chronosequence. Moreover, a higher richness of woody plants accompanied by a lower richness of herbaceous species was detected in the Zhangzhou chronosequence compared with the Heshan one. To balance the need for pulp production and plant diversity conservation, we suggest that intercropping approaches between exotic Eucalyptus plantations and native forests should be considered in the fast rotation Eucalyptus plantations. However, Eucalyptus plantations may be used as pioneer species to sustain ecosystem functioning for the degraded lands.

  5. KIPS: An Evidence-Based Tool for Assessing Parenting Strengths and Needs in Diverse Families

    ERIC Educational Resources Information Center

    Comfort, Marilee; Gordon, Philip R.; Naples, Denise

    2011-01-01

    The movement toward evidence-based practices has stimulated greater interest in assessing parenting outcomes. The purpose of these studies was to further validate the Keys to Interactive Parenting Scale (KIPS), a structured observational assessment of parenting quality, with 397 diverse families. Factor analysis demonstrated that the 12 KIPS items…

  6. Natural Products from Plant-associated Microorganisms: Distribution, Structural Diversity, Bioactivity, and Implications of Their Occurrence?

    PubMed Central

    Gunatilaka, A. A. Leslie

    2012-01-01

    A growing body of evidence suggests that plant-associated microorganisms, especially endophytic and rhizosphere bacteria and fungi, represent a huge and largely untapped resource of natural products with chemical structures that have been optimized by evolution for biological and ecological relevance. A diverse array of bioactive small molecule natural products has been encountered in these microorganisms. The structures of over 230 metabolites isolated and characterized from over 70 plant-associated microbial strains during the past four years are presented with information on their hosts, culture conditions, and biological activities. Some significant biological and ecological implications of their occurrence are also reviewed. PMID:16562864

  7. Diverse functions of KNOX transcription factors in the diploid body plan of plants.

    PubMed

    Tsuda, Katsutoshi; Hake, Sarah

    2015-10-01

    KNOX genes were initially found as shoot meristem regulators in angiosperms. Recent studies in diverse plant lineages however, have revealed the divergence of KNOX gene function during the evolution of diploid body plans. Using genomic approaches, class I KNOX transcription factors have been shown to regulate multiple hormone pathways including auxin and brassinosteroid as well as many transcription factors that play important roles in plant development. Class I KNOX proteins appear to be activators, whereas class II proteins act as repressors in transcriptional regulation of their target genes. PMID:26190742

  8. Incorporating biodiversity into rangeland health: Plant species richness and diversity in great plains grasslands

    USGS Publications Warehouse

    Symstad, A.J.; Jonas, J.L.

    2011-01-01

    Indicators of rangeland health generally do not include a measure of biodiversity. Increasing attention to maintaining biodiversity in rangelands suggests that this omission should be reconsidered, and plant species richness and diversity are two metrics that may be useful and appropriate. Ideally, their response to a variety of anthropogenic and natural drivers in the ecosystem of interest would be clearly understood, thereby providing a means to diagnose the cause of decline in an ecosystem. Conceptual ecological models based on ecological principles and hypotheses provide a framework for this understanding, but these models must be supported by empirical evidence if they are to be used for decision making. To that end, we synthesize results from published studies regarding the responses of plant species richness and diversity to drivers that are of management concern in Great Plains grasslands, one of North America's most imperiled ecosystems. In the published literature, moderate grazing generally has a positive effect on these metrics in tallgrass prairie and a neutral to negative effect in shortgrass prairie. The largest published effects on richness and diversity were caused by moderate grazing in tallgrass prairies and nitrogen fertilization in shortgrass prairies. Although weather is often cited as the reason for considerable annual fluctuations in richness and diversity, little information about the responses of these metrics to weather is available. Responses of the two metrics often diverged, reflecting differences in their sensitivity to different types of changes in the plant community. Although sufficient information has not yet been published for these metrics to meet all the criteria of a good indicator in Great Plains Grasslands, augmenting current methods of evaluating rangeland health with a measure of plant species richness would reduce these shortcomings and provide information critical to managing for biodiversity. ?? Society for Range Management.

  9. An explanation for conflicting records of Triassic-Jurassic plant diversity.

    PubMed

    Mander, Luke; Kürschner, Wolfram M; McElwain, Jennifer C

    2010-08-31

    Macrofossils (mostly leaves) and sporomorphs (pollen and spores) preserve conflicting records of plant biodiversity during the end-Permian (P-Tr), Triassic-Jurassic (Tr-J), and end-Cretaceous (K-T) mass extinctions. Estimates of diversity loss based on macrofossils are typically much higher than estimates of diversity loss based on sporomorphs. Macrofossils from the Tr-J of East Greenland indicate that standing species richness declined by as much as 85% in the Late Triassic, whereas sporomorph records from the same region, and from elsewhere in Europe, reveal little evidence of such catastrophic diversity loss. To understand this major discrepancy, we have used a new high-resolution dataset of sporomorph assemblages from Astartekløft, East Greenland, to directly compare the macrofossil and sporomorph records of Tr-J plant biodiversity. Our results show that sporomorph assemblages from the Tr-J boundary interval are 10-12% less taxonomically diverse than sporomorph assemblages from the Late Triassic, and that vegetation composition changed rapidly in the boundary interval as a result of emigration and/or extirpation of taxa rather than immigration and/or origination of taxa. An analysis of the representation of different plant groups in the macrofossil and sporomorph records at Astartekløft reveals that reproductively specialized plants, including cycads, bennettites and the seed-fern Lepidopteris are almost absent from the sporomorph record. These results provide a means of reconciling the macrofossil and sporomorph records of Tr-J vegetation change, and may help to understand vegetation change during the P-Tr and K-T mass extinctions and around the Paleocene-Eocene Thermal Maximum. PMID:20713737

  10. Plant Functional Diversity Can Be Independent of Species Diversity: Observations Based on the Impact of 4-Yrs of Nitrogen and Phosphorus Additions in an Alpine Meadow.

    PubMed

    Li, Wei; Cheng, Ji-Min; Yu, Kai-Liang; Epstein, Howard E; Guo, Liang; Jing, Guang-Hua; Zhao, Jie; Du, Guo-Zhen

    2015-01-01

    Past studies have widely documented the decrease in species diversity in response to addition of nutrients, however functional diversity is often independent from species diversity. In this study, we conducted a field experiment to examine the effect of nitrogen and phosphorus fertilization ((NH4)2 HPO4) at 0, 15, 30 and 60 g m-2 yr-1 (F0, F15, F30 and F60) after 4 years of continuous fertilization on functional diversity and species diversity, and its relationship with productivity in an alpine meadow community on the Tibetan Plateau. To this purpose, three community-weighted mean trait values (specific leaf area, SLA; mature plant height, MPH; and seed size, SS) for 30 common species in each fertilization level were determined; three components of functional diversity (functional richness, FRic; functional evenness, FEve; and Rao's index of quadratic entropy, FRao) were quantified. Our results showed that: (i) species diversity sharply decreased, but functional diversity remained stable with fertilization; (ii) community-weighted mean traits (SLA and MPH) had a significant increase along the fertilization level; (iii) aboveground biomass was not correlated with functional diversity, but it was significantly correlated with species diversity and MPH. Our results suggest that decreases in species diversity due to fertilization do not result in corresponding changes in functional diversity. Functional identity of species may be more important than functional diversity in influencing aboveground productivity in this alpine meadow community, and our results also support the mass ratio hypothesis; that is, the traits of the dominant species influenced the community biomass production. PMID:26295345

  11. Plant Functional Diversity Can Be Independent of Species Diversity: Observations Based on the Impact of 4-Yrs of Nitrogen and Phosphorus Additions in an Alpine Meadow

    PubMed Central

    Li, Wei; Cheng, Ji-Min; Yu, Kai-Liang; Epstein, Howard E.; Guo, Liang; Jing, Guang-Hua; Zhao, Jie; Du, Guo-Zhen

    2015-01-01

    Past studies have widely documented the decrease in species diversity in response to addition of nutrients, however functional diversity is often independent from species diversity. In this study, we conducted a field experiment to examine the effect of nitrogen and phosphorus fertilization ((NH4)2 HPO4) at 0, 15, 30 and 60 g m-2 yr-1 (F0, F15, F30 and F60) after 4 years of continuous fertilization on functional diversity and species diversity, and its relationship with productivity in an alpine meadow community on the Tibetan Plateau. To this purpose, three community-weighted mean trait values (specific leaf area, SLA; mature plant height, MPH; and seed size, SS) for 30 common species in each fertilization level were determined; three components of functional diversity (functional richness, FRic; functional evenness, FEve; and Rao’s index of quadratic entropy, FRao) were quantified. Our results showed that: (i) species diversity sharply decreased, but functional diversity remained stable with fertilization; (ii) community-weighted mean traits (SLA and MPH) had a significant increase along the fertilization level; (iii) aboveground biomass was not correlated with functional diversity, but it was significantly correlated with species diversity and MPH. Our results suggest that decreases in species diversity due to fertilization do not result in corresponding changes in functional diversity. Functional identity of species may be more important than functional diversity in influencing aboveground productivity in this alpine meadow community, and our results also support the mass ratio hypothesis; that is, the traits of the dominant species influenced the community biomass production. PMID:26295345

  12. Effects of Previous Land-Use on Plant Species Composition and Diversity in Mediterranean Forests

    PubMed Central

    Kouba, Yacine; Martínez-García, Felipe; de Frutos, Ángel; Alados, Concepción L.

    2015-01-01

    At some point in their history, most forests in the Mediterranean Basin have been subjected to intensive management or converted to agriculture land. Knowing how forest plant communities recovered after the abandonment of forest-management or agricultural practices (including livestock grazing) provides a basis for investigating how previous land management have affected plant species diversity and composition in forest ecosystems. Our study investigated the consequences of historical “land management” practices on present-day Mediterranean forests by comparing species assemblages and the diversity of (i) all plant species and (ii) each ecological group defined by species’ habitat preferences and successional status (i.e., early-, mid-, and late-successional species). We compared forest stands that differed both in land-use history and in successional stage. In addition, we evaluated the value of those stands for biodiversity conservation. The study revealed significant compositional differentiation among stands that was due to among-stand variations in the diversity (namely, species richness and evenness) of early-, intermediate-, and late-successional species. Historical land management has led to an increase in compositional divergences among forest stands and the loss of late-successional forest species. PMID:26397707

  13. Genetic diversity and population structure of cottons (Gossypium spp.) of the New World assessed by SSR markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A global analysis of cotton (Gossypium spp.) genetic diversity is the first step to understand its geographical distribution, dissemination, genetic relatedness, and population structure. To assess the genetic diversity and population structure in Gossypium species, 111 cotton accessions representin...

  14. Genetic diversity assessment of wild Malus sieversii populations in Kazakhstan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Malus sieversii is one of the major progenitor species of the dessert apple, Malus x domestica. Wild M. sieversii trees are found in the mountainous regions of Kazakhstan and other central Asian countries. The Plant Genetic Resources Unit (PGRU) in Geneva, NY maintains large field and seed collectio...

  15. Diversity of fungi associated with hair roots of ericaceous plants is affected by land use.

    PubMed

    Hazard, Christina; Gosling, Paul; Mitchell, Derek T; Doohan, Fiona M; Bending, Gary D

    2014-03-01

    Culture-independent molecular studies have provided new insights into the diversity of fungi associating with ericaceous plant roots. However, there is little understanding of the distribution of these fungi across landscapes, or the effects of environmental heterogeneity on ericoid mycorrhizal (ERM) fungal diversity and distribution. Terminal-restriction fragment length polymorphism and selective sequence analyses of the internal transcribed spacer regions of rDNA were used to infer fungal diversity of bait Vaccinium macrocarpon grown in soils from nine peatland sites in Ireland, representing three different land uses (bog, rough grazing and forest plantation) and the fungal communities of field-collected Calluna vulgaris for five of these nine sites. A diverse range of potential ERM fungi were found, and the sampling approach significantly affected the diversity of the fungal community. Despite significant site groupings of the fungal communities associated with V. macrocarpon and C. vulgaris, fungal communities were significantly dissimilar between sites with different land uses. Soil nitrogen content significantly explained 52% of the variation in the V. macrocarpon fungal communities. Evidence suggests that environmental heterogeneity has a role in shaping ERM fungal community composition at the landscape scale. PMID:24741702

  16. Assessing the Unseen Bacterial Diversity in Microbial Communities

    PubMed Central

    Caro-Quintero, Alejandro; Ochman, Howard

    2015-01-01

    For both historical and technical reasons, 16S ribosomal RNA has been the most common molecular marker used to analyze the contents of microbial communities. However, its slow rate of evolution hinders the resolution of closely related bacteria—individual 16S-phylotypes, particularly when clustered at 97% sequence identity, conceal vast amounts of species- and strain-level variation. Protein-coding genes, which evolve more quickly, are useful for differentiating among more recently diverged lineages, but their application is complicated by difficulties in designing low-redundancy primers that amplify homologous regions from distantly related taxa. Given the now-common practice of multiplexing hundreds of samples, adopting new genes usually entails the synthesis of large sets of barcoded primers. To circumvent problems associated with use of protein-coding genes to survey microbial communities, we develop an approach—termed phyloTAGs—that offers an automatic solution for primer design and can be easily adapted to target different taxonomic groups and/or different protein-coding regions. We applied this method to analyze diversity within the gorilla gut microbiome and recovered hundreds of strains that went undetected after deep-sequencing of 16S rDNA amplicons. PhyloTAGs provides a powerful way to recover the fine-level diversity within microbial communities and to study stability and dynamics of bacterial populations. PMID:26615218

  17. Roles of mesophyll conductance and plant functional diversities in tropical photosynthesis

    NASA Astrophysics Data System (ADS)

    Gu, L.

    2013-12-01

    Tropical photosynthesis dominates global terrestrial gross primary production (GPP) and will likely play a defining role in determining how global GPP will respond to climate change. Yet, our current understanding of biological, ecological, edaphic and environmental controls on tropical photosynthesis is poor. The overly simplistic schemes that current Earth System Models use to simulate tropical photosynthesis cannot capture the functional diversities associated with high species diversities in the tropics. New approaches that explicitly represent the functional diversities of tropical photosynthesis in Earth System Models are needed in order to realistically model responses of tropical photosynthesis to increased atmospheric CO2 concentrations and associated climate changes. To establish a basis for such approaches, we conducted intensive field measurements of leaf photosynthesis at three forest sites along a strong rainfall gradient in Panama in 2012-2013. The three sites are Parque Natural Metropolitano, Gamboa, and Parque Nacional San Lorenzo. The Parque Natural Metropolitano receives an annual precipitation of less than 1800mm and Parque Nacional San Lorenzo over 3300 mm with Gamboa in between. The three sites differ in species diversity with Parque Nacional San Lorenzo having the highest species diversity and Parque Nacional San Lorenzo the lowest. At the three contrasting sites, we measured A/Ci curves, leaf traits and leaf nutrient (N and P) contents of about 100 species. We determined mesophyll conductance with the LeafWeb approach. From these measurements, we developed practical but realistic parameterizations of functional diversities of tropical plant species at the three sites and implemented these parameterizations in the latest version of the Community Land Model. We found that mesophyll conductance is key to representing functional diversities of tropical forest species. Without it, responses of tropical photosynthesis to increased atmospheric CO2 concentrations may be underestimated. Interactive effects of mesophyll conductance, nutrient limitations, CO2 concentrations and climate change will be discussed in the context of new parameterizations enabled with our intensive measurements in Panama.

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

    PubMed

    Lange, Bernd Markus

    2015-01-01

    Secretory structures in terrestrial plants appear to have first emerged as intracellular oil bodies in liverworts. In vascular plants, internal secretory structures, such as resin ducts and laticifers, are usually found in conjunction with vascular bundles, whereas subepidermal secretory cavities and epidermal glandular trichomes generally have more complex tissue distribution patterns. The primary function of plant secretory structures is related to defense responses, both constitutive and induced, against herbivores and pathogens. The ability to sequester secondary (or specialized) metabolites and defense proteins in secretory structures was a critical adaptation that shaped plant-herbivore and plant-pathogen interactions. Although this review places particular emphasis on describing the evolution of pathways leading to terpenoids, it also assesses the emergence of other metabolite classes to outline the metabolic capabilities of different plant lineages. PMID:25621517

  19. Functional and genetic diversity of mycorrhizal fungi from single plants of Caladenia formosa (Orchidaceae)

    PubMed Central

    Huynh, Tien T.; Thomson, Richard; Mclean, Cassandra B.; Lawrie, Ann C.

    2009-01-01

    Background and Aims Mycorrhizal associations are essential to the plant kingdom. The largest flowering plant family, the Orchidaceae, relies on mycorrhizal fungi for germination, growth and survival. Evidence suggests varying degrees of fungal-host specificity based on a single fungal isolate from a single plant. This paper shows for the first time the diversity of endophytes colonizing in a single plant over consecutive years and the functional significance of this diversity. Methods Stem-collars of Caladenia formosa were collected in different seasons and years. Mycorrhizal fungi isolated were tested for their efficacy to induce leafing and genetically determined using ITS-RFLP and sequencing. Results Multiple mycorrhizal fungi were repeatedly isolated from a single collar that displayed varying effectiveness in germination percentages and adult leaf length. Additional factors contributed to the isolation of effective mycorrhizal fungi; fungal collection season, year of collection and individual isolates. Surface sterilization only improved the number of isolated mycorrhizal fungi. Dual inoculation did not increase germination. All 59 mycorrhizal fungi effective in germinating seed belonged to one clearly defined ITS (internal transcribed spacer) clade and clustered close to Sebacina vermifera (79–89 % homology). Isolates resulting in the greatest germination were not necessarily those resulting in the greatest survival and growth 1 year after germination. Conclusion Single orchid plants contained multiple mycorrhizal fungal strains of one species that had diverse functional differences. These results suggest that our current knowledge of fungal–host specificity may be incomplete due to experimental and analytical limitations. It also suggests that the long-term effectiveness of a mycorrhizal fungus or fungi could only be found by germination and longer-term growth tests rather than genetically. PMID:19561011

  20. Measuring plant diversity in the tall threetip sagebrush steppe: influence of previous grazing management practices.

    PubMed

    Seefeldt, Steven S; McCoy, Scott D

    2003-08-01

    In July 2000, a 490-ha wildfire burned a portion of a long-term grazing study that had been established in 1924 at the US Sheep Experiment Station north of Dubois, Idaho, USA. Earlier vegetation measurements in this tall threetip sagebrush (Artemisia tripartita spp. tripartita) bunchgrass plant community documented significant changes in vegetation due to grazing and the timing of grazing by sheep. A study was initiated in May 2001 using 12 multiscale modified Whittaker plots to determine the consequences of previous grazing practices on postfire vegetation composition. Because there was only one wildfire and it did not burn all of the original plots, the treatments are not replicated in time or space. We reduce the potential effects of psuedoreplication by confining our discussion to the sample area only. There were a total of 84 species in the sampled areas with 69 in the spring-grazed area and 70 each in the fall- and ungrazed areas. Vegetation within plots was equally rich and even with similar numbers of abundant species. The spring-grazed plots, however, had half as much plant cover as the fall- and ungrazed plots and the spring-grazed plots had the largest proportion of plant cover composed of introduced (27%) and annual (34%) plants. The fall-grazed plots had the highest proportion of native perennial grasses (43%) and the lowest proportion of native annual forbs (1%). The ungrazed plots had the lowest proportion of introduced plants (4%) and the highest proportion of native perennial forbs (66%). The vegetation of spring-grazed plots is in a degraded condition for the environment and further degradation may continue, with or without continued grazing or some other disturbance. If ecosystem condition was based solely on plant diversity and only a count of species numbers was used to determine plant diversity, this research would have falsely concluded that grazing and timing of grazing did not impact the condition of the ecosystem. PMID:14753648

  1. How Do Earthworms, Soil Texture and Plant Composition Affect Infiltration along an Experimental Plant Diversity Gradient in Grassland?

    PubMed Central

    Fischer, Christine; Roscher, Christiane; Jensen, Britta; Eisenhauer, Nico; Baade, Jussi; Attinger, Sabine; Scheu, Stefan; Weisser, Wolfgang W.; Schumacher, Jens; Hildebrandt, Anke

    2014-01-01

    Background Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. Methodology/Principal Findings We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species) and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs). In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i) direct, probably by modifying the pore spectrum and (ii) indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms. Conclusions/Significance Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications. PMID:24918943

  2. Quality assessment of plant transpiration water

    NASA Technical Reports Server (NTRS)

    Macler, Bruce A.; Janik, Daniel S.; Benson, Brian L.

    1990-01-01

    It has been proposed to use plants as elements of biologically-based life support systems for long-term space missions. Three roles have been brought forth for plants in this application: recycling of water, regeneration of air and production of food. This report discusses recycling of water and presents data from investigations of plant transpiration water quality. Aqueous nutrient solution was applied to several plant species and transpired water collected. The findings indicated that this water typically contained 0.3-6 ppm of total organic carbon, which meets hygiene water standards for NASA's space applications. It suggests that this method could be developed to achieve potable water standards.

  3. Biochemical survey of the polar head of plant glycosylinositolphosphoceramides unravels broad diversity.

    PubMed

    Cacas, Jean-Luc; Buré, Corinne; Furt, Fabienne; Maalouf, Jean-Paul; Badoc, Alain; Cluzet, Stéphanie; Schmitter, Jean-Marie; Antajan, Elvire; Mongrand, Sébastien

    2013-12-01

    Although Glycosyl-Inositol-Phospho-Ceramides (GIPCs) are the main sphingolipids of plant tissues, they remain poorly characterized in term of structures. This lack of information, notably with regard to polar heads, currently hampers the understanding of GIPC functions in biological systems. This situation prompted us to undertake a large scale-analysis of plant GIPCs: 23 plant species chosen in various phylogenetic groups were surveyed for their total GIPC content. GIPCs were extracted and their polar heads were characterized by negative ion MALDI and ESI mass spectrometry. Our data shed light on an unexpected broad diversity of GIPC distributions within Plantae, and the occurrence of yet-unreported GIPC structures in green and red algae. In monocots, GIPCs with three saccharides were apparently found to be major, whereas a series with two saccharides was dominant in Eudicots within a few notable exceptions. In plant cell cultures, GIPC polar heads appeared to bear a higher number of glycan units than in the tissue from which they originate. Perspectives are discussed in term of GIPC metabolism diversity and function of these lipids. PMID:23993446

  4. Variations in AOC and microbial diversity in an advanced water treatment plant

    NASA Astrophysics Data System (ADS)

    Yang, B. M.; Liu, J. K.; Chien, C. C.; Surampalli, R. Y.; Kao, C. M.

    2011-10-01

    SummaryThe objective of this study was to evaluate the variations in assimilable organic carbon (AOC) and microbial diversities in an advanced water treatment plant. The efficiency of biofiltration on AOC removal using anthracite and granular activated carbon (GAC) as the media was also evaluated through a pilot-scale column experiment. Effects of hydrological factors (seasonal effects and river flow) on AOC concentrations in raw water samples and hydraulic retention time (HRT) of biofiltration on AOC treatment were also evaluated. Results show that AOC concentrations in raw water and clear water of the plant were about 138 and 27 ?g acetate-C/L, respectively. Higher AOC concentrations were observed in wet seasons probably due to the resuspension of organic-contained sediments and discharges of non-point source (NPS) pollutants from the upper catchment. This reveals that seasonal effect played an important role in the variations in influent AOC concentrations. Approximately 82% and 70% of AOC removal efficiencies were observed in GAC and anthracite columns, respectively. Results from column experiment reveal that the applied treatment processes in the plant and biofiltration system were able to remove AOC effectively. Microbial colonization on GAC and anthracite were detected via the observation of scanning electron microscopic (SEM) images. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal significant decrease in microbial diversities after the ozonation process. Higher HRT caused higher microbial contact time, and thus, more microbial colonies and higher microbial diversity were observed in the latter part of the biofilters. Some of the dominant microbial species in the biofiltration columns belonged to the beta- proteobacterium, which might contribute to the AOC degradation. Results of this study provide us insight into the variations in AOC and microbial diversity in the advanced water treatment processes.

  5. Needs Assessment Among Diverse Groups: A Case Study.

    ERIC Educational Resources Information Center

    Pooler, Anne E.; Toner, James F.

    A Teacher Corps project to deliver staff development services focused on five educational settings: a correctional youth center, a high school, a junior high school, a youth group home consortium, and a college of education. It was felt that comparing the results of needs assessments conducted at each facility would enable useful analyses of…

  6. Chemical diversity of microbial volatiles and their potential for plant growth and productivity

    PubMed Central

    Kanchiswamy, Chidananda Nagamangala; Malnoy, Mickael; Maffei, Massimo E.

    2015-01-01

    Microbial volatile organic compounds (MVOCs) are produced by a wide array of microorganisms ranging from bacteria to fungi. A growing body of evidence indicates that MVOCs are ecofriendly and can be exploited as a cost-effective sustainable strategy for use in agricultural practice as agents that enhance plant growth, productivity, and disease resistance. As naturally occurring chemicals, MVOCs have potential as possible alternatives to harmful pesticides, fungicides, and bactericides as well as genetic modification. Recent studies performed under open field conditions demonstrate that efficiently adopting MVOCs may contribute to sustainable crop protection and production. We review here the chemical diversity of MVOCs by describing microbial–plants and microbial–microbial interactions. Furthermore, we discuss MVOCs role in inducing phenotypic plant responses and their potential physiological effects on crops. Finally, we analyze potential and actual limitations for MVOC use and deployment in field conditions as a sustainable strategy for improving productivity and reducing pesticide use. PMID:25821453

  7. Evolution and diversity of plant cell walls: from algae to flowering plants.

    PubMed

    Popper, Zoë A; Michel, Gurvan; Hervé, Cécile; Domozych, David S; Willats, William G T; Tuohy, Maria G; Kloareg, Bernard; Stengel, Dagmar B

    2011-01-01

    All photosynthetic multicellular Eukaryotes, including land plants and algae, have cells that are surrounded by a dynamic, complex, carbohydrate-rich cell wall. The cell wall exerts considerable biological and biomechanical control over individual cells and organisms, thus playing a key role in their environmental interactions. This has resulted in compositional variation that is dependent on developmental stage, cell type, and season. Further variation is evident that has a phylogenetic basis. Plants and algae have a complex phylogenetic history, including acquisition of genes responsible for carbohydrate synthesis and modification through a series of primary (leading to red algae, green algae, and land plants) and secondary (generating brown algae, diatoms, and dinoflagellates) endosymbiotic events. Therefore, organisms that have the shared features of photosynthesis and possession of a cell wall do not form a monophyletic group. Yet they contain some common wall components that can be explained increasingly by genetic and biochemical evidence. PMID:21351878

  8. High plant species diversity indirectly mitigates CO 2- and N-induced effects on grasshopper growth

    NASA Astrophysics Data System (ADS)

    Strengbom, Joachim; Reich, Peter B.; Ritchie, Mark E.

    2008-09-01

    We examined how elevated atmospheric [CO 2] and higher rate of nitrogen (N) input may influence grasshopper growth by changing food plant quality and how such effects may be modified by species diversity of the plant community. We reared grasshopper nymphs ( Melanoplus femurrubrum) on Poa pratensis from field-grown monocultures or polycultures (16 species) that were subjected to either ambient or elevated levels of CO 2 and N. Grasshopper growth rate was higher on P. pratensis leaves grown in monocultures than in polycultures, higher on P. pratensis grown under elevated than under ambient [CO 2], and higher on P. pratensis grown under elevated than under ambient [N]. The higher growth rate observed on P. pratensis exposed to elevated [CO 2] was, however, less pronounced for polyculture- than monoculture-grown P. pratensis. Growth rate of the grasshoppers was positively correlated with leaf [N], [C], and concentration of soluble carbohydrates + lipids. Concentration of non-structural carbohydrates + lipids was higher in leaves grown under elevated than under ambient [CO 2], and the difference between P. pratensis grown under ambient and elevated [CO 2] was greater for monoculture- than polyculture-grown P. pratensis. In addition, leaf N concentration was higher in P. pratensis grown in monocultures than in polycultures, suggesting that plant species richness, indirectly, may influence insect performance by changed nutritional value of the plants. Because we found interactive effects between all factors included ([CO 2], [N], and plant species diversity), our results suggest that these parameters may influence plant-insect interactions in a complex way that is not predictable from the sum of single factor manipulations.

  9. Risk management tools and the case study Brassica napus: evaluating possible effects of genetically modified plants on soil microbial diversity.

    PubMed

    Canfora, Loredana; Sbrana, Cristiana; Avio, Luciano; Felici, Barbara; Scatà, Maria Carmela; Neri, Ulderico; Benedetti, Anna

    2014-09-15

    The cultivation of GMPs in Europe raises many questions about the environmental risks, in particular about their ecological impact on non-target organisms and on soil properties. The aim of a multidisciplinary group engaged in a LIFE+project (MAN-GMP-ITA) was to validate and improve an existing environmental risk assessment (ERA) methodology on GMPs within the European legislative framework on GMOs. Given the impossibility of evaluating GMO impact directly, as GMPs are banned in Italy, GMPs have not been used at any stage of the project. The project thus specifically focused on the conditions for the implementation of ERA in different areas of Italy, with an emphasis on some sensitive and protected areas located in the North, Centre, and South of the country, in order to lay the necessary baseline for evaluating the possible effects of a GMP on soil communities. Our sub-group carried out soil analyses in order to obtain soil health and fertility indicators to be used as baselines in the ERA model. Using various methods of chemical, biochemical, functional and genetic analysis, our study assessed the changes in diversity and functionality of bacterial populations, and arbuscular mycorrhizal fungi. The results show that plant identity and growth, soil characteristics, and field site climatic parameters are key factors in contributing to variation in microbial community structure and diversity, thus validating our methodological approach. Our project has come to the conclusion that the uneven composition and biological-agronomical quality of soils need to be taken into consideration in a risk analysis within the framework of ERA for the release of genetically modified plants. PMID:25014185

  10. Life-cycle assessment of wastewater treatment plants

    E-print Network

    Dong, Bo, M. Eng. Massachusetts Institute of Technology

    2012-01-01

    This thesis presents a general model for the carbon footprints analysis of wastewater treatment plants (WWTPs), using a life cycle assessment (LCA) approach. In previous research, the issue of global warming is often related ...

  11. Elevated CO2 and plant species diversity interact to slow root decomposition

    SciTech Connect

    De Graaff, Marie-Anne; Schadt, Christopher Warren; Rula, Kelly L; Six, Johan W U A; Schweitzer, Jennifer A; Classen, Aimee T

    2011-01-01

    Changes in plant species diversity can result in synergistic increases in decomposition rates, while elevated atmospheric CO2 can slow the decomposition rates; yet it remains unclear how diversity and changes in atmospheric CO2 may interact to alter root decomposition. To investigate how elevated CO2 interacts with changes in root-litter diversity to alter decomposition rates, we conducted a 120-day laboratory incubation. Roots from three species (Trifolium repens, Lespedeza cuneata, and Festuca pratense) grown under ambient or elevated CO2 were incubated individually or in combination in soils that were exposed to ambient or elevated CO2 for five years. Our experiment resulted in two main findings: (1) Roots from T. repens and L. cuneata, both nitrogen (N) fixers, grown under elevated CO2 treatments had significantly slower decomposition rates than similar roots grown under ambient CO2 treatments; but the decomposition rate of F. pratense roots (a non-N-fixing species) was similar regardless of CO2 treatment. (2) Roots of the three species grown under ambient CO2 and decomposed in combination with each other had faster decomposition rates than when they were decomposed as single species. However, roots of the three species grown under elevated CO2 had similar decomposition rates when they were incubated alone or in combination with other species. These data suggest that if elevated CO2 reduces the root decomposition rate of even a few species in the community, it may slow root decomposition of the entire plant community.

  12. Endophytes in the plant Huperzia serrata: fungal diversity and discovery of a new pentapeptide.

    PubMed

    Xiong, Zhi-Qiang; Yang, Ying-Ying; Liu, Qiao-Xia; Sun, Cui-Cui; Jin, Yu; Wang, Yong

    2015-04-01

    Endophytic fungi are an underexploited resource of natural products and have a capacity to produce diverse classes of plant-derived secondary metabolites. Here, we investigated the diversity of endophytic fungi from Huperzia serrata and the potential for discovering novel fungal natural products. One hundred and fifty-five endophytic fungi isolates obtained from H. serrata, belonging to four classes Dothideomycetes (47.3 %), Sordariomycetes (36.8 %), Eurotiomycetes (10.6 %) and an undefined class (5.3 %, Mucoraceae), were grouped into nine genera based on morphological and molecular identification. Colletotrichum, Cladosporium, Sordariomycetes and Guignardia were the dominant genera, whereas the remaining genera were infrequent groups. To our knowledge, the fungal genera Mucor and Neurospora were first reported in Huperzia plant. Among these endophytic fungi isolates, strain B14, belonging to Penicillium oxalicum, gave a gray precipitate with Dragendorff's reagent. A new pentapeptide was isolated from the culture of strain B14, and its chemical structure was elucidated on the basis of spectroscopic data from (1)H NMR, (13)C NMR and ESI-MS/MS. Taken together, H. serrata has a significant diversity of endophytic fungi that could be a rich resource for the discovery of new natural products. PMID:25526853

  13. Beta Diversity of Plant-Pollinator Networks and the Spatial Turnover of Pairwise Interactions

    PubMed Central

    Carstensen, Daniel W.; Sabatino, Malena; Trøjelsgaard, Kristian; Morellato, Leonor Patricia C.

    2014-01-01

    Interactions between species form complex networks that vary across space and time. Even without spatial or temporal constraints mutualistic pairwise interactions may vary, or rewire, across space but this variability is not well understood. Here, we quantify the beta diversity of species and interactions and test factors influencing the probability of turnover of pairwise interactions across space. We ask: 1) whether beta diversity of plants, pollinators, and interactions follow a similar trend across space, and 2) which interaction properties and site characteristics are related to the probability of turnover of pairwise interactions. Geographical distance was positively correlated with plant and interaction beta diversity. We find that locally frequent interactions are more consistent across space and that local flower abundance is important for the realization of pairwise interactions. While the identity of pairwise interactions is highly variable across space, some species-pairs form interactions that are locally frequent and spatially consistent. Such interactions represent cornerstones of interacting communities and deserve special attention from ecologists and conservation planners alike. PMID:25384058

  14. Plant diversity does not buffer drought effects on early-stage litter mass loss rates and microbial properties.

    PubMed

    Vogel, Anja; Eisenhauer, Nico; Weigelt, Alexandra; Scherer-Lorenzen, Michael

    2013-09-01

    Human activities are decreasing biodiversity and changing the climate worldwide. Both global change drivers have been shown to affect ecosystem functioning, but they may also act in concert in a non-additive way. We studied early-stage litter mass loss rates and soil microbial properties (basal respiration and microbial biomass) during the summer season in response to plant species richness and summer drought in a large grassland biodiversity experiment, the Jena Experiment, Germany. In line with our expectations, decreasing plant diversity and summer drought decreased litter mass loss rates and soil microbial properties. In contrast to our hypotheses, however, this was only true for mass loss of standard litter (wheat straw) used in all plots, and not for plant community-specific litter mass loss. We found no interactive effects between global change drivers, that is, drought reduced litter mass loss rates and soil microbial properties irrespective of plant diversity. High mass loss rates of plant community-specific litter and low responsiveness to drought relative to the standard litter indicate that soil microbial communities were adapted to decomposing community-specific plant litter material including lower susceptibility to dry conditions during summer months. Moreover, higher microbial enzymatic diversity at high plant diversity may have caused elevated mass loss of standard litter. Our results indicate that plant diversity loss and summer drought independently impede soil processes. However, soil decomposer communities may be highly adapted to decomposing plant community-specific litter material, even in situations of environmental stress. Results of standard litter mass loss moreover suggest that decomposer communities under diverse plant communities are able to cope with a greater variety of plant inputs possibly making them less responsive to biotic changes. PMID:23606531

  15. Phylogenetic Exploration of Medicinal Plant Diversity MedPlant Research Assistant Fellowship

    E-print Network

    Zürich, Universität

    Fellowship Incense plants: phytochemistry and phylogeny The Institute of Systematic Botany, University deadline is November 1, 2015. The Institute of Systematic Botany, University of Zürich announces an opening in (ethno)botany or phytochemistry / pharmacology. According to the candidate's qualifications and interests

  16. [Diversity of plant in Jiaxing Shijiuyang ecological wetland for drinking water during operation].

    PubMed

    Shen, Ya-Qiang; Wei, Hong-Bin; Cheng, Wang-Da; Zhang, Hong-Mei; Wang, Wei-Dong; Yin, Cheng-Qing

    2011-10-01

    The Shijiuyang ecological wetland for drinking water of Jiaxing City, Zhejiang Province is one of the biggest constructed wetlands for water resource protection in China. To ensure a deep understanding of the present status of the wetland vegetation of Shijiuyang ecological wetland which has been run for 2.5 years and provide support for the vegetation management of ecological wetland, systematic investigation was carried out by using plot method and quadrat method in October to November, 2010. The species composition, dynamics of plant diversity and the biomass production during operation were analyzed. Altogether 70 species belonging to 28 families and 62 genera were recorded. Among them, there were 26 wetland plants, 20 mesophytes, 14 emergent, 4 submerged, 6 floating ones. Compared with the preliminary stage, the species numbers of wetland plants increased significantly from 15 species to 70 species. The spatial pattern of riparian species diversity was examined by adopting the Simpson index and Shannon-Wiener index as species diversity indices. The results showed that the riparian species diversity was higher in the west of the Beijiaohe river (Simpson index = 0.468 3, Shannon-Wiener index = 0.835 2) than that in the south of the Dongsheng Road (Simpson index = 0.357 6, Shannon-Wiener index = 0.660 4). The analyses of quantitative characteristics of wetland vegetation showed that the plants in the root-channel purification zone in the south of the Dongsheng Road grew better than those in the west of the Beijiaohe river. With regard to the riparian vegetation, the riparian plants in the west of the Beijiaohe river were more abundant. The mean biomass production (dry weight) in the root-channel purification zone was 1.73 kg x m(-2) and the total area was 9.12 x 10(4) m2, so the total biomass production was estimated to be 157.8 t. In the same way, the mean riparian vegetation biomass production(dry weight) was 0.83 kg x m(-2) and the total vegetation area was 3.75 x 10(4) m2, so the total riparian vegetation biomass production(dry weight) was estimated as 31.1 t. PMID:22279896

  17. Desert Farming Benefits from Microbial Potential in Arid Soils and Promotes Diversity and Plant Health

    PubMed Central

    Köberl, Martina; Müller, Henry; Ramadan, Elshahat M.; Berg, Gabriele

    2011-01-01

    Background To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. Methodology/Principal Findings We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt). Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90), and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37%) than in the desert (11%). Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%); disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. Conclusions/Significance After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural soil showed a higher diversity and a better ecosystem function for plant health but a loss of extremophilic bacteria. Interestingly, we detected that indigenous desert microorganisms promoted plant health in desert agro-ecosystems. PMID:21912695

  18. Plant metabolomics is not ripe for environmental risk assessment.

    PubMed

    Hall, Robert D; de Maagd, Ruud A

    2014-08-01

    Metabolomics separates and detects small molecules and helps determine the composition of plant materials. This makes it appear to be a possible contributor to environmental risk assessment (ERA) of transgenic plants. Here we argue that, despite important advances in the technology, limited annotation and our limited knowledge of the role of metabolites in plant-environment interactions means that metabolomics is not yet ripe for ERA. PMID:24908381

  19. Water treatment plants assessment at Talkha power plant.

    PubMed

    El-Sebaie, Olfat D; Abd El-Kerim, Ghazy E; Ramadan, Mohamed H; Abd El-Atey, Magda M; Taha, Sahr Ahmed

    2002-01-01

    Talkha power plant is the only power plant located in El-Mansoura. It generates electricity using two different methods by steam turbine and gas turbine. Both plants drew water from River Nile (208 m3 /h). The Nile raw water passes through different treatment processes to be suitable for drinking and operational uses. At Talkha power plant, there are two purification plants used for drinking water supply (100 m3/h) and for water demineralization supply (108 m3/h). This study aimed at studying the efficiency of the water purification plants. For drinking water purification plant, the annual River Nile water characterized by slightly alkaline pH (7.4-8), high annual mean values of turbidity (10.06 NTU), Standard Plate Count (SPC) (313.3 CFU/1 ml), total coliform (2717/100 ml), fecal coliform (0-2400/100 ml), and total algae (3 x 10(4) org/I). The dominant group of algae all over the study period was green algae. The blue green algae was abundant in Summer and Autumn seasons. The pH range, and the annual mean values of turbidity, TDS, total hardness, sulfates, chlorides, nitrates, nitrites, fluoride, and residual chlorine for purified water were in compliance with Egyptian drinking water standards. All the SPC recorded values with an annual mean value of 10.13 CFU/1 ml indicated that chlorine dose and contact time were not enough to kill the bacteria. However, they were in compliance with Egyptian decree (should not exceed 50 CFU/1 ml). Although the removal efficiency of the plant for total coliform and blue green algae was high (98.5% and 99.2%, respectively), the limits of the obtained results with an annual mean values of 40/100 ml and 15.6 org/l were not in compliance with the Egyptian decree (should be free from total coliform, fecal coliform and blue green algae). For water demineralization treatment plant, the raw water was characterized by slightly alkaline pH. The annual mean values of conductivity, turbidity, and TDS were 354.6 microS/cm, 10.84 NTU, and 214.6 mg/I, respectively. There was an increase in the results of conductivity, turbidity, total hardness, and TDS in carbon filter effluent which was attributed to the desorption of adsorbed ions on the carbon media. The removal efficiencies of turbidity, total hardness, and TDS indicated the high efficiency of the cationic filter. The annual removal efficiencies of conductivity, turbidity, chloride, and TDS proved the efficiency of the anionic filter for removing the dissolved and suspended ions. All of the recorded values of the pH, conductivity, turbidity, chlorides, hardness, and TDS of the mixed bed effluent indicated that the water at this stage was of high quality for boiler feed. The study recommended adjustment of coagulant and residual chlorine doses as well as contact time, and continuous monitoring and maintenance of the different units. PMID:17216967

  20. AQUATIC PLANT COMMUNITIES FOR IMPACT MONITORING AND ASSESSMENT

    EPA Science Inventory

    The studies revewed here suggest that both structural and functional assessments of aquatic plant communities are valuable tools in the determination of environmental impacts and water quality. I am not suggesting that aquatic plants be used in lieu of macronivertebrates or fish ...

  1. Development and Initial Psychometric Assessment of the Plant Attitude Questionnaire

    ERIC Educational Resources Information Center

    Fancovicova, Jana; Prokop, Pavol

    2010-01-01

    Plants are integral parts of ecosystems which determine life on Earth. People's attitudes toward them are however, largely overlooked. Here we present initial psychometric assessment of self-constructed Plant Attitude Scale (PAS) that was administered to a sample of 310 Slovakian students living in rural areas aged 10-15 years. The final version…

  2. ENVIRONMENTAL ASSESSMENT OF COKE BY-PRODUCT RECOVERY PLANTS

    EPA Science Inventory

    The report gives results of an initial screening study, initiating a multimedia environmental assessment of coke by-product recovery plants in the U.S. The study included both the gathering and analysis of existing data and sampling and analysis at one plant based on EPA's Indust...

  3. SOURCE ASSESSMENT: GLASS CONTAINER MANUFACTURING PLANTS

    EPA Science Inventory

    The report summarizes results of a study to gather and analyze background information and technical data related to air emissions from glass container manufacturing operations. It covers emissions from three plant areas: raw materials preparation and handling, glass melting, and ...

  4. Coastal plants : chemical sensitivities and risk assessments

    EPA Science Inventory

    The ability of plant-dominated ecosystems to improve water quality and provide habitat for biodiversity are important ecological services. These services are impacted by natural and anthropogenic stressors which includes contaminant toxicity. Scientific information describing the...

  5. Old and new challenges in using species diversity for assessing biodiversity

    PubMed Central

    Chiarucci, Alessandro; Bacaro, Giovanni; Scheiner, Samuel M.

    2011-01-01

    Although the maintenance of diversity of living systems is critical for ecosystem functioning, the accelerating pace of global change is threatening its preservation. Standardized methods for biodiversity assessment and monitoring are needed. Species diversity is one of the most widely adopted metrics for assessing patterns and processes of biodiversity, at both ecological and biogeographic scales. However, those perspectives differ because of the types of data that can be feasibly collected, resulting in differences in the questions that can be addressed. Despite a theoretical consensus on diversity metrics, standardized methods for its measurement are lacking, especially at the scales needed to monitor biodiversity for conservation and management purposes. We review the conceptual framework for species diversity, examine common metrics, and explore their use for biodiversity conservation and management. Key differences in diversity measures at ecological and biogeographic scales are the completeness of species lists and the ability to include information on species abundances. We analyse the major pitfalls and problems with quantitative measurement of species diversity, look at the use of weighting measures by phylogenetic distance, discuss potential solutions and propose a research agenda to solve the major existing problems. PMID:21768157

  6. Endophytic fungi from medicinal plant Bauhinia forficata : Diversity and biotechnological potential

    PubMed Central

    Bezerra, Jadson D.P.; Nascimento, Carlos C.F.; Barbosa, Renan do N.; da Silva, Dianny C.V.; Svedese, Virgínia M.; Silva-Nogueira, Eliane B.; Gomes, Bruno S.; Paiva, Laura M.; Souza-Motta, Cristina M.

    2015-01-01

    Bauhinia forficata is native to South America and used with relative success in the folk medicine in Brazil. The diversity, antibacterial activity, and extracellular hydrolytic enzymes of endophytic fungi associated with this plant were studied. Plant samples, which included leaves, sepals, stems, and seeds, were used. Ninety-five endophytic fungal were isolated (18 from leaves, 22 from sepals, 46 from stems, and nine from seeds), comprising 28 species. The most frequently isolated species were Acremonium curvulum (9.5%), Aspergillus ochraceus (7.37%), Gibberella fujikuroi (10.53%), Myrothecium verrucaria (10.53%) and Trichoderma piluliferum (7.37%). Diversity and species richness were higher in stem tissues, and Sorensen’s index of similarity between the tissues was low. Eleven fungi showed antibacterial activity. Aspergillus ochraceus , Gibberella baccata , Penicillium commune , and P. glabrum were those with the greatest antibacterial activity against Staphylococcus aureus and/or Streptococcus pyogenes . Thirteen species showed proteolytic activity, particularly Phoma putaminum . Fourteen species were cellulase positive, particularly the Penicillium species and Myrmecridium schulzeri . All isolates tested were xylanase positive and 10 showed lipolytic activity, especially Penicillium glabrum . It is clear that the endophytic fungi from B. forficata have potential for the production of bioactive compounds and may be a source of new therapeutic agents for the effective treatment of diseases in humans, other animals, and plants. To our knowledge, this is the first study of endophytic fungi from different tissues of B. forficata and their biotechnological potential. PMID:26221088

  7. Spatiotemporal patterns of induced resistance and susceptibility linking diverse plant parasites.

    PubMed

    Mouttet, Raphaëlle; Kaplan, Ian; Bearez, Philippe; Amiens-Desneux, Edwige; Desneux, Nicolas

    2013-12-01

    Induced defenses mediate interactions between parasites sharing the same host plant, but the outcomes of these interactions are challenging to predict because of spatiotemporal variation in plant responses and differences in defense pathways elicited by herbivores or pathogens. Dissecting these mediating factors necessitates an approach that encompasses a diversity of parasitic feeding styles and tracks interactions over space and time. We tested indirect plant-mediated relationships across three tomato (Solanum lycopersicum) consumers: (1) the fungal pathogen-powdery mildew, Oidium neolycopersici; (2) a sap-feeding insect-silverleaf whitefly, Bemisia tabaci; and (3) a chewing insect-the leaf miner, Tuta absoluta. Further, we evaluated insect/pathogen responses on local vs. systemic leaves and over short (1 day) vs. long (4 days) time scales. Overall, we documented: (1) a bi-directional negative effect between O. neolycopersici and B. tabaci; (2) an asymmetrical negative effect of B. tabaci on T. absoluta; and (3) an asymmetrical positive effect of T. absoluta on O. neolycopersici. Spatiotemporal patterns varied depending on the species pair (e.g., whitefly effects on leaf miner performance were highly localized to the induced leaf, whereas effects on pathogen growth were both local and systemic). These results highlight the context-dependent effects of induced defenses on a diverse community of tomato parasites. Notably, the outcomes correspond to those predicted by phytohormonal theory based on feeding guild differences with key implications for the recent European invasion by T. absoluta. PMID:23851986

  8. Diversity and regulation of plant Ca2+ pumps: insights from expression in yeast

    NASA Technical Reports Server (NTRS)

    Sze, H.; Liang, F.; Hwang, I.; Curran, A. C.; Harper, J. F.; Evans, M. L. (Principal Investigator)

    2000-01-01

    The spatial and temporal regulation of calcium concentration in plant cells depends on the coordinate activities of channels and active transporters located on different organelles and membranes. Several Ca2+ pumps have been identified and characterized by functional expression of plant genes in a yeast mutant (K616). This expression system has opened the way to a genetic and biochemical characterization of the regulatory and catalytic features of diverse Ca2+ pumps. Plant Ca(2+)-ATPases fall into two major types: AtECA1 represents one of four or more members of the type IIA (ER-type) Ca(2+)-ATPases in Arabidopsis, and AtACA2 is one of seven or more members of the type IIB (PM-type) Ca(2+)-ATPases that are regulated by a novel amino terminal domain. Type IIB pumps are widely distributed on membranes, including the PM (plasma membrane), vacuole, and ER (endoplasmic reticulum). The regulatory domain serves multiple functions, including autoinhibition, calmodulin binding, and sites for modification by phosphorylation. This domain, however, is considerably diverse among several type IIB ATPases, suggesting that the pumps are differentially regulated. Understanding of Ca2+ transporters at the molecular level is providing insights into their roles in signaling networks and in regulating fundamental processes of cell biology.

  9. A keystone predator controls bacterial diversity in the pitcher-plant (Sarracenia purpurea) microecosystem.

    PubMed

    Peterson, Celeste N; Day, Stephanie; Wolfe, Benjamin E; Ellison, Aaron M; Kolter, Roberto; Pringle, Anne

    2008-09-01

    The community of organisms inhabiting the water-filled leaves of the carnivorous pitcher-plant Sarracenia purpurea includes arthropods, protozoa and bacteria, and serves as a model system for studies of food web dynamics. Despite the wealth of data collected by ecologists and zoologists on this food web, very little is known about the bacterial assemblage in this microecosystem. We used terminal restriction fragment length polymorphism (T-RFLP) analysis to quantify bacterial diversity within the pitchers as a function of pitcher size, pH of the pitcher fluid and the presence of the keystone predator in this food web, larvae of the pitcher-plant mosquito Wyeomyia smithii. Results were analysed at two spatial scales: within a single bog and across three isolated bogs. Pitchers were sterile before they opened and composition of the bacterial assemblage was more variable between different bogs than within bogs. Measures of bacterial richness and diversity were greater in the presence of W. smithii and increased with increasing pitcher size. Our results suggest that fundamental ecological concepts derived from macroscopic food webs can also be used to predict the bacterial assemblages in pitcher plants. PMID:18479443

  10. [Effects of tourism disturbance on plant diversity in Qingshan Lake scenic area of Zhejiang Province].

    PubMed

    Lu, Qing-Bin; You, Wei-Yun; Zhao, Chang-Jie; Wang, Xiang-Wei; Meng-Xiang, Xiu

    2011-02-01

    From May 2007 to June 2008, an investigation was made on the changes of plant community in Qingshan Lake scenic area of Zhejiang Province under the effects of tourism disturbance. With the increase of tourism disturbance, the importance value of the plants was mainly fastened on a few species such as Pinus hwangshanensis, apt to decrease for tree and shrub species and to increase for herb species, and the individuals of the plants increased. The values of richness index (D) and diversity index (H) were in the order of medium disturbance > slight disturbance > severe disturbance, while the evenness index (J) value was in the order of medium disturbance > severe disturbance > slight disturbance. At the same vegetation layers, only a few species such as Cinnamomum camphora existed under different disturbances, and thereby, the similarity index values were smaller than 0.500. Slight disturbance affected coniferous forest most, with the average values of D, H, and J being the lowest (1.188, 1.056, and 0.697, respectively); severe disturbance affected broadleaf forest and shrub-herbage most, with the D value (2.013) of shrub-herbage and the H value (1.286) and J value (0.807) of broadleaf forest being the lowest; while medium disturbance was favorable to the increase of plant diversity and to the normal exertion of ecosystem function. The eco-safety of the structural elements of plant community in the scenic area was threatened to some extent, resulting in the reduction of indigenous species such as Sinocalycanthus chinensis and the incursion of exotic species as Setaria viridis. PMID:21608239

  11. Plant diversity effects on leaching of nitrate, ammonium, and dissolved organic nitrogen from an experimental grassland

    NASA Astrophysics Data System (ADS)

    Leimer, Sophia; Oelmann, Yvonne; Wirth, Christian; Wilcke, Wolfgang

    2014-05-01

    Leaching of nitrogen (N) from soil represents a resource loss and, in particular leaching of nitrate, can threaten drinking water quality. As plant diversity leads to a more exhaustive resource use, we investigated the effects of plant species richness, functional group richness, and the presence of specific functional groups on nitrate, ammonium, dissolved organic N (DON), and total dissolved N (TDN) leaching from an experimental grassland in the first 4 years after conversion from fertilized arable land to unfertilized grassland. The experiment is located in Jena, Germany, and consists of 82 plots with 1, 2, 4, 8, 16, or 60 plant species and 1-4 functional groups (legumes, grasses, non-leguminous tall herbs, non-leguminous small herbs). Nitrate, ammonium, and TDN concentrations in soil solution in the 0-0.3 m soil layer were measured every second week during 4 years on 62 plots and DON concentrations were calculated as difference between TDN and inorganic N. Missing concentrations in soil solution were estimated using a Bayesian statistical model. Downward water fluxes (DF) per plot from the 0-0.3 m soil layer were simulated in weekly resolution with a water balance model in connection with a Bayesian model for simulating missing soil water content measurements. To obtain annual nitrate, ammonium, and DON leaching from the 0-0.3 m soil layer per plot, we multiplied the respective concentrations in soil solution with DF and aggregated the data to annual sums. TDN leaching resulted from summation of nitrate, ammonium, and DON leaching. DON leaching contributed most to TDN leaching, particularly in plots without legumes. Dissolved inorganic N leaching in this grassland was dominated by nitrate. The amount of annual ammonium leaching was small and little influenced by plant diversity. Species richness affected DON leaching only in the fourth and last investigated year, possibly because of a delayed soil biota effect that increased microbial transformation of organic N to inorganic N in species-rich mixtures or because of complementary resource use of amino-acid DON of species-rich mixtures. Nitrate and TDN leaching generally decreased with increasing species richness likely because of more exhaustive resource use of more diverse plant mixtures. Functional group richness did not have a significant effect on nitrate, ammonium, DON, and TDN leaching. Legumes increased and grasses decreased nitrate, DON, and TDN leaching because of their N-fixing ability and their extensive rooting system, respectively. TDN leaching was highest in the first year after conversion from arable to grassland which can be related to former fertilization. Quantitative differences in nitrate leaching between plant diversity treatments were also highest in the first year after conversion. However, the percentage reduction of nitrate leaching by species richness, the presence of grasses, or the presence of small herbs increased with time since land-use change possibly because of a strengthening of diversity effects with time. We conclude that especially shortly after land-use change from fertilized arable land to unfertilized grassland, N leaching, in particular nitrate leaching, can be reduced considerably if highly diverse mixtures without legumes are established.

  12. Assessment of diversity indices for the characterization of the soil prokaryotic community by metagenomic analysis

    NASA Astrophysics Data System (ADS)

    Chernov, T. I.; Tkhakakhova, A. K.; Kutovaya, O. V.

    2015-04-01

    The diversity indices used in ecology for assessing the metagenomes of soil prokaryotic communities at different phylogenetic levels were compared. The following indices were considered: the number of detected taxa and the Shannon, Menhinick, Margalef, Simpson, Chao1, and ACE indices. The diversity analysis of the prokaryotic communities in the upper horizons of a typical chernozem (Haplic Chernozem (Pachic)), a dark chestnut soil (Haplic Kastanozem (Chromic)), and an extremely arid desert soil (Endosalic Calcisol (Yermic)) was based on the analysis of 16S rRNA genes. The Menhinick, Margalef, Chao1, and ACE indices gave similar results for the classification of the communities according to their diversity levels; the Simpson index gave good results only for the high-level taxa (phyla); the best results were obtained with the Shannon index. In general, all the indices used showed a decrease in the diversity of the soil prokaryotes in the following sequence: chernozem > dark chestnut soil > extremely arid desert soil.

  13. Multiscale sampling of plant diversity: Effects of minimum mapping unit size

    USGS Publications Warehouse

    Stohlgren, T.J.; Chong, G.W.; Kalkhan, M.A.; Schell, L.D.

    1997-01-01

    Only a small portion of any landscape can be sampled for vascular plant diversity because of constraints of cost (salaries, travel time between sites, etc.). Often, the investigator decides to reduce the cost of creating a vegetation map by increasing the minimum mapping unit (MMU), and/or by reducing the number of vegetation classes to be considered. Questions arise about what information is sacrificed when map resolution is decreased. We compared plant diversity patterns from vegetation maps made with 100-ha, 50-ha, 2-ha, and 0.02-ha MMUs in a 754-ha study area in Rocky Mountain National Park, Colorado, United States, using four 0.025-ha and 21 0.1-ha multiscale vegetation plots. We developed and tested species-log(area) curves, correcting the curves for within-vegetation type heterogeneity with Jaccard's coefficients. Total species richness in the study area was estimated from vegetation maps at each resolution (MMU), based on the corrected species-area curves, total area of the vegetation type, and species overlap among vegetation types. With the 0.02-ha MMU, six vegetation types were recovered, resulting in an estimated 552 species (95% CI = 520-583 species) in the 754-ha study area (330 plant species were observed in the 25 plots). With the 2-ha MMU, five vegetation types were recognized, resulting in an estimated 473 species for the study area. With the 50-ha MMU, 439 plant species were estimated for the four vegetation types recognized in the study area. With the 100-ha MMU, only three vegetation types were recognized, resulting in an estimated 341 plant species for the study area. Locally rare species and keystone ecosystems (areas of high or unique plant diversity) were missed at the 2-ha, 50-ha, and 100-ha scales. To evaluate the effects of minimum mapping unit size requires: (1) an initial stratification of homogeneous, heterogeneous, and rare habitat types; and (2) an evaluation of within-type and between-type heterogeneity generated by environmental gradients and other factors. We suggest that at least some portions of vegetation maps created at a coarser level of resolution be validated at a higher level of resolution.

  14. Environmental risk assessment for plant pests: a procedure to evaluate their impacts on ecosystem services.

    PubMed

    Gilioli, G; Schrader, G; Baker, R H A; Ceglarska, E; Kertész, V K; Lövei, G; Navajas, M; Rossi, V; Tramontini, S; van Lenteren, J C

    2014-01-15

    The current methods to assess the environmental impacts of plant pests differ in their approaches and there is a lack of the standardized procedures necessary to provide accurate and consistent results, demonstrating the complexity of developing a commonly accepted scheme for this purpose. By including both the structural and functional components of the environment threatened by invasive alien species (IAS), in particular plant pests, we propose an environmental risk assessment scheme that addresses this complexity. Structural components are investigated by evaluating the impacts of the plant pest on genetic, species and landscape diversity. Functional components are evaluated by estimating how plant pests modify ecosystem services in order to determine the extent to which an IAS changes the functional traits that influence ecosystem services. A scenario study at a defined spatial and temporal resolution is then used to explore how an IAS, as an exogenous driving force, may trigger modifications in the target environment. The method presented here provides a standardized approach to generate comparable and reproducible results for environmental risk assessment as a component of Pest Risk Analysis. The method enables the assessment of overall environmental risk which integrates the impacts on different components of the environment and their probabilities of occurrence. The application of the proposed scheme is illustrated by evaluating the environmental impacts of the invasive citrus long-horn beetle, Anoplophora chinensis. PMID:24051446

  15. Consequences of plant-chemical diversity for domestic goat food preference in Mediterranean forests

    NASA Astrophysics Data System (ADS)

    Baraza, Elena; Hódar, José A.; Zamora, Regino

    2009-01-01

    The domestic goat, a major herbivore in the Mediterranean basin, has demonstrated a strong ability to adapt its feeding behaviour to the chemical characteristics of food, selecting plants according to their nutritive quality. In this study, we determine some chemical characteristics related to plant nutritional quality and its variability among and within five tree species, these being the main components of the mountain forests of SE Spain, with the aim of determining their influence on food selection by this generalist herbivore. We analyse nitrogen, total phenols, condensed tannins and fibre concentration as an indicator of the nutritive value of the different trees. To determine the preference by the domestic goat, we performed two types of feeding-choice assays, where goats had to select between different species or between branches of the same species but from trees of different nutritional quality. The analysis of the plant nutritional quality showed significant differences in the chemical characteristics between species, and a high variability within species. However, when faced with different tree species, the domestic goat selected some of them but showed striking individual differences between goats. When selecting between trees of the same species, the goats showed no differential selection. This limited effect of chemical plant characteristics, together with the variability in foraging behaviour, resulted in a widespread consumption of diverse plant species, which can potentially modulate the effect of the goat on vegetation composition, and open the way for the conservation of traditional livestock grazing on natural protected areas.

  16. Importance of Mediator complex in the regulation and integration of diverse signaling pathways in plants

    PubMed Central

    Samanta, Subhasis; Thakur, Jitendra K.

    2015-01-01

    Basic transcriptional machinery in eukaryotes is assisted by a number of cofactors, which either increase or decrease the rate of transcription. Mediator complex is one such cofactor, and recently has drawn a lot of interest because of its integrative power to converge different signaling pathways before channeling the transcription instructions to the RNA polymerase II machinery. Like yeast and metazoans, plants do possess the Mediator complex across the kingdom, and its isolation and subunit analyses have been reported from the model plant, Arabidopsis. Genetic, and molecular analyses have unraveled important regulatory roles of Mediator subunits at every stage of plant life cycle starting from flowering to embryo and organ development, to even size determination. It also contributes immensely to the survival of plants against different environmental vagaries by the timely activation of its resistance mechanisms. Here, we have provided an overview of plant Mediator complex starting from its discovery to regulation of stoichiometry of its subunits. We have also reviewed involvement of different Mediator subunits in different processes and pathways including defense response pathways evoked by diverse biotic cues. Wherever possible, attempts have been made to provide mechanistic insight of Mediator's involvement in these processes. PMID:26442070

  17. Plant diversity and ecosystem multifunctionality peak at intermediate levels of woody cover in global drylands

    PubMed Central

    Soliveres, Santiago; Maestre, Fernando T.; Eldridge, David J.; Delgado-Baquerizo, Manuel; Quero, José Luis; Bowker, Matthew A.; Gallardo, Antonio

    2015-01-01

    Aim The global spread of woody plants into grasslands is predicted to increase over the coming century. While there is general agreement regarding the anthropogenic causes of this phenomenon, its ecological consequences are less certain. We analyzed how woody vegetation of differing cover affects plant diversity (richness and evenness) and multiple ecosystem functions (multifunctionality) in global drylands, and how this changes with aridity. Location 224 dryland sites from all continents except Antarctica widely differing in their environmental conditions (from arid to dry-subhumid sites) and woody covers (from 0 to 100%). Methods Using a standardized field survey, we measured the cover, richness and evenness of perennial vegetation. At each site, we measured 14 ecosystem functions related to soil fertility and the build-up of nutrient pools. These functions are critical for maintaining ecosystem function in drylands. Results Species richness and ecosystem multifunctionality were strongly influenced by woody vegetation, with both variables peaking at relative woody covers (RWC) of 41-60%. This relationship shifted with aridity. We observed linear positive effects of RWC in dry-subhumid sites. These positive trends shifted to hump-shaped RWC-diversity and multifunctionality relationships under semiarid environments. Finally, hump-shaped (richness, evenness) or linear negative (multifunctionality) effects of RWC were found under the most arid conditions. Main conclusions Plant diversity and multifunctionality peaked at intermediate levels of woody cover, although this relationship became increasingly positive under wetter environments. This comprehensive study accounts for multiple ecosystem attributes across a range of woody covers and environmental conditions. Our results help us to reconcile contrasting views of woody encroachment found in current literature and can be used to improve predictions of the likely effects of encroachment on biodiversity and ecosystem services. PMID:25914607

  18. Diversity patterns of selected Andean plant groups correspond to topography and habitat dynamics, not orogeny.

    PubMed

    Mutke, Jens; Jacobs, Rana; Meyers, Katharina; Henning, Tilo; Weigend, Maximilian

    2014-01-01

    The tropical Andes are a hotspot of biodiversity, but detailed altitudinal and latitudinal distribution patterns of species are poorly understood. We compare the distribution and diversity patterns of four Andean plant groups on the basis of georeferenced specimen data: the genus Nasa (Loasaceae), the two South American sections of Ribes (sect. Parilla and sect. Andina, Grossulariaceae), and the American clade of Urtica (Urticaceae). In the tropical Andes, these often grow together, especially in (naturally or anthropogenically) disturbed or secondary vegetation at middle to upper elevations. The climatic niches of the tropical groups studied here are relatively similar in temperature and temperature seasonality, but do differ in moisture seasonality. The Amotape-Huancabamba Zone (AHZ) between 3 and 8° S shows a clear diversity peak of overall species richness as well as for narrowly endemic species across the groups studied. For Nasa, we also show a particular diversity of growth forms in the AHZ. This can be interpreted as proxy for a high diversity of ecological niches based on high spatial habitat heterogeneity in this zone. Latitudinal ranges are generally larger toward the margins of overall range of the group. Species number and number of endemic species of our taxa peak at elevations of 2,500-3,500 m in the tropical Andes. Altitudinal diversity patterns correspond well with the altitudinal distribution of slope inclination. We hypothesize that the likelihood and frequency of landslides at steeper slopes translate into temporal habitat heterogeneity. The frequency of landslides may be causally connected to diversification especially for the numerous early colonizing taxa, such as Urtica and annual species of Nasa. In contrast to earlier hypotheses, uplift history is not reflected in the pattern here retrieved, since the AHZ is the area of the most recent Andean uplift. Similarly, a barrier effect of the low-lying Huancabamba depression is not retrieved in our data. PMID:25346750

  19. Diversity patterns of selected Andean plant groups correspond to topography and habitat dynamics, not orogeny

    PubMed Central

    Mutke, Jens; Jacobs, Rana; Meyers, Katharina; Henning, Tilo; Weigend, Maximilian

    2014-01-01

    The tropical Andes are a hotspot of biodiversity, but detailed altitudinal and latitudinal distribution patterns of species are poorly understood. We compare the distribution and diversity patterns of four Andean plant groups on the basis of georeferenced specimen data: the genus Nasa (Loasaceae), the two South American sections of Ribes (sect. Parilla and sect. Andina, Grossulariaceae), and the American clade of Urtica (Urticaceae). In the tropical Andes, these often grow together, especially in (naturally or anthropogenically) disturbed or secondary vegetation at middle to upper elevations. The climatic niches of the tropical groups studied here are relatively similar in temperature and temperature seasonality, but do differ in moisture seasonality. The Amotape–Huancabamba Zone (AHZ) between 3 and 8° S shows a clear diversity peak of overall species richness as well as for narrowly endemic species across the groups studied. For Nasa, we also show a particular diversity of growth forms in the AHZ. This can be interpreted as proxy for a high diversity of ecological niches based on high spatial habitat heterogeneity in this zone. Latitudinal ranges are generally larger toward the margins of overall range of the group. Species number and number of endemic species of our taxa peak at elevations of 2,500–3,500 m in the tropical Andes. Altitudinal diversity patterns correspond well with the altitudinal distribution of slope inclination. We hypothesize that the likelihood and frequency of landslides at steeper slopes translate into temporal habitat heterogeneity. The frequency of landslides may be causally connected to diversification especially for the numerous early colonizing taxa, such as Urtica and annual species of Nasa. In contrast to earlier hypotheses, uplift history is not reflected in the pattern here retrieved, since the AHZ is the area of the most recent Andean uplift. Similarly, a barrier effect of the low-lying Huancabamba depression is not retrieved in our data. PMID:25346750

  20. Genetic and functional diversity of soil microbial communities associated to grapevine plants and wine quality

    NASA Astrophysics Data System (ADS)

    Mocali, Stefano; Fabiani, Arturo; Kuramae, Eiko; de Hollander, Mattias; Kowalchuk, George A.; Vignozzi, Nadia; Valboa, Giuseppe; Costantini, Edoardo

    2013-04-01

    Despite the economic importance of vineyards in Italy, the wine sector is facing severe challenges from increased global competition and climate changes. The quality of the grape at harvest has a strong direct impact on wine final quality and the strong relationship between wine composition, aroma, taste, and soil properties has been outlined in the "Terroir concept". However, information on the impact of soil microbial communities on soil functions, grapevine plants, and wine quality is generally lacking. In the current study, soils from two close sites in Central Tuscany (BRO11 and BRO12) cultivated with the same grapevine cultivar Sangiovese, but with contrasting wine quality, were examined. Although the BRO12 site provided a better wine quality than the BRO11, the two soils showed similar physical, chemical, and hydrological properties. Also soil humidity, as determined by FDR (Frequency Domain Reflectometry) sensors, indicated a similar water availability in the first 75 cm during a three years trial (2000-2010). Interestingly, the mean three years value of the ratio between the two stable carbon isotopes 13C/12C, measured in the alcohol of the wines, was significantly higher in BRO12 than in BRO11 (-28,3‰ and -24,4‰, respectively), indicating the presence of a relatively higher water stress in the BRO11 soil. Functional GeoChip microarray analyses revealed higher presence of Actinobacteria in the BRO12 than in the BRO11 soil, where the alfa-Proteobacteria were more abundant. Furthermore, a consistent difference in genes involved in S cycling, with a significant overrepresentation of sulphur-oxidation genes in BRO11 and increased levels of sulphate reduction genes BRO12 was detected. These results are consistent with the high content of sulphates and the abundance of Firmicutes such as Sulfobacillus thermosulfidooxidans in the BRO11 soil. Therefore, the different microbiology of the two soils could be related to the different redox conditions of the two soils. The structure of soil microbial communities was assessed using 16S and 18S rRNA genes pyrosequencing and the determination of some soil microbial properties such as microbial respiration, microbial C-biomass were also determined. The role of both genetic and functional diversity of soil bacterial community on grape physiology and wine quality will be discussed.

  1. Development of a Scale to Assess the Appropriateness of Curricula Materials for Diverse Populations

    ERIC Educational Resources Information Center

    Howard, Elissa M.; Weiler, Robert M.

    2003-01-01

    As America's public school population becomes more diverse, selecting culturally appropriate instructional materials becomes increasingly important. Though several existing scales assess the quality of curricula materials, most do not consider cultural relevance. The Curricula Appropriateness Scale (CAS) was designed to determine the…

  2. Sugarcane microsatellites for the assessment of genetic diversity in sugarcane germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of microsatellite or simple sequence repeat (SSR) markers to determine the genetic diversity between Saccharum (S. officinarum, S. spontaneum, S. sinense), Old World Erianthus Michx. sect. Ripidium, North American E. giganteus (S. giganteum), Sorghum and Miscanthus was assessed. Six SSR ...

  3. Phylogenetic placement of diverse amoebae inferred from multigene analyses and assessment of clade stability within

    E-print Network

    Katz, Laura

    Phylogenetic placement of diverse amoebae inferred from multigene analyses and assessment of clade relationships within the `Amoebozoa'. Ó 2007 Elsevier Inc. All rights reserved. Keywords: Amoeba; Sarcodina; Multigene analysis; SSU-rDNA; Unicellular eukaryote; Supergroups 1. Introduction The term amoeba is used

  4. Assessing the Crossdisciplinarity of Technology-Enhanced Learning with Science Overlay Maps and Diversity Measures

    ERIC Educational Resources Information Center

    Kalz, Marco; Specht, Marcus

    2014-01-01

    This paper deals with the assessment of the crossdisciplinarity of technology-enhanced learning (TEL). Based on a general discussion of the concept interdisciplinarity and a summary of the discussion in the field, two empirical methods from scientometrics are introduced and applied. Science overlay maps and the Rao-Stirling diversity index are…

  5. The Culture Audit: A Leadership Tool for Assessment and Strategic Planning in Diverse Schools and Colleges

    ERIC Educational Resources Information Center

    Bustamante, Rebecca M.

    2006-01-01

    This module is designed to introduce educational leaders to an organizational assessment tool called a "culture audit." Literature on organizational cultural competence suggests that culture audits are a valuable tool for determining how well school policies, programs, and practices respond to the needs of diverse groups and prepare…

  6. Looking Deeper than the Gradebook: Assessing Cultural Diversity Attitudes among Undergraduates

    ERIC Educational Resources Information Center

    Lake, Robert; Rittschof, Kent

    2012-01-01

    Identification of college students' attitudes about diversity issues is an important part of the assessment of student development across many fields of study. This article discusses an action research approach and classroom application strategies stemming from a survey of 88 pre-service teacher candidates on their attitudes toward homosexuality,…

  7. Assessing metabolomic and chemical diversity of a soybean lineage representing 35 years of breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information on crop genotype- and phenotype-metabolite associations can be of value to trait development as well as to food security and safety. The unique study presented here assessed seed metabolomic and ionomic diversity in a soybean lineage representing ~35 years of breeding (launch years 1972-...

  8. Constructing a questionnaire for assessment of awareness and acceptance of diversity in healthcare institutions

    PubMed Central

    2013-01-01

    Background To develop a healthcare environment that is congruent with diversity among care providers and care recipients and to eliminate ethnic discrimination, it’s important to map out and assess caregivers’ awareness and acceptance of diversity. Because of a lack of standardized questionnaires in the Swedish context, this study designed and standardized a questionnaire: the Assessment of Awareness and Acceptance of Diversity in Healthcare Institutions (AAAD, for short). Method The questionnaire was developed in four phases: a comprehensive literature review, face and content validity, construct validity by factor analysis, and a reliability test by internal consistency and stability assessments. Results Results of different validity and reliability analyses suggest high face, content, and construct validity as well as good reliability in internal consistency (Cronbach’s alpha: 0.68 to 0.8) and stability (test-retest: Spearman rank correlation coefficient: 0.60 to 0.76). The result of the factor analysis identified six dimensions in the questionnaire: 1) Attitude toward discrimination, 2) Interaction between staff, 3) Stereotypic attitude toward working with a person with a Swedish background, 4) Attitude toward working with a patient with a different background, 5) Attitude toward communication with persons with different backgrounds, 6) Attitude toward interaction between patients and staff. Conclusion This study introduces a newly developed questionnaire with good reliability and validity values that can assess healthcare workers’ awareness and acceptance of diversity in the healthcare environment and healthcare delivery. PMID:23607334

  9. Bat diversity and wind power investigations required for risk assessment in Denmark and Sweden

    E-print Network

    1 Bat diversity and wind power ­ investigations required for risk assessment in Denmark and Sweden) in Stockholm, February 5-7 2013. Field investigations of bat faunas were initiated with the use of ultrasound technique in 1978. Today we have an almost complete overview of bat distribution and species richness

  10. Catalogue of alien plants of the Czech Republic (2nd edition): checklist update, taxonomic diversity and invasion patterns

    E-print Network

    Kratochvíl, Lukas

    Catalogue of alien plants of the Czech Republic (2nd edition): checklist update, taxonomic): Catalogue of alien plants of the Czech Republic (2nd edition): checklist update, taxonomic diversity and invasion patterns. ­ Preslia 84: 155­255. A complete list of all alien taxa ever recorded in the flora

  11. Comparative genomics of plant-associated Pseudomonas spp.: Insights into diversity and inheritance of traits involved in multitrophic interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We provide here a comparative genome analysis of the Pseudomonas fluorescens group, including seven new genomic sequences for plant-associated strains. These strains exhibit a diverse spectrum of traits involved in biological control and other multitrophic interactions with plants, microbes, and ins...

  12. Diversity and clade ages of West Indian hummingbirds and the largest plant clades dependent on them: a

    E-print Network

    McGuire, Jimmy A.

    Diversity and clade ages of West Indian hummingbirds and the largest plant clades dependent on them November 2014 We analysed the geographical origins and divergence times of the West Indian hummingbirds biogeographical reconstruction. We also compiled a list of 101 West Indian plant species with hummingbird

  13. Assessing genetic structure and diversity of airborne bacterial communities by DNA fingerprinting and 16S rDNA clone library

    NASA Astrophysics Data System (ADS)

    Maron, Pierre-Alain; Lejon, David P. H.; Carvalho, Esmeralda; Bizet, Karine; Lemanceau, Philippe; Ranjard, Lionel; Mougel, Christophe

    The density, genetic structure and diversity of airborne bacterial communities were assessed in the outdoor atmosphere. Two air samples were collected on the same location (north of France) at two dates (March 2003 (sample1) and May 2003 (sample 2)). Molecular culture -independent methods were used to characterise airborne bacterial communities regardless of the cell culturability. The automated-ribosomal intergenic spacer analysis (A-RISA) was performed to characterise the community structure in each sample. For both sampling dates, complex A-RISA patterns were observed suggesting a highly diverse community structure, comparable to those found in soil, water or sediment environments. Furthermore, differences in the genetic structure of airborne bacterial communities were observed between samples 1 and 2 suggesting an important variability in time. A clone library of 16S rDNA directly amplified from air DNA of sample 1 was constructed and sequenced to analyse the community composition and diversity. The Proteobacteria group had the greatest representation (60%), with bacteria belonging to the different subdivisions ?- (19%), ?-(21%), ?-(12%) and ?-(8%). Firmicute and Actinobacteria were also well represented with 14% and 12%, respectively. Most of the identified bacteria are known to be commonly associated with soil or plant environments suggesting that the atmosphere is mainly colonised transiently by microorganisms from local sources, depending on air fluxes.

  14. Functional diversity of 2-oxoglutarate/Fe(II)-dependent dioxygenases in plant metabolism

    PubMed Central

    Farrow, Scott C.; Facchini, Peter J.

    2014-01-01

    Oxidative enzymes catalyze many different reactions in plant metabolism. Among this suite of enzymes are the 2-oxoglutarate/Fe(II)-dependent dioxygenases (2-ODDs). Cytochromes P450 (CYPs) as often considered the most versatile oxidative enzymes in nature, but the diversity and complexity of reactions catalyzed by 2-ODDs is superior to the CYPs. The list of oxidative reactions catalyzed by 2-ODDs includes hydroxylations, demethylations, desaturations, ring closure, ring cleavage, epimerization, rearrangement, halogenation, and demethylenation. Furthermore, recent work, including the discovery of 2-ODDs involved in epigenetic regulation, and others catalyzing several characteristic steps in specialized metabolic pathways, support the argument that 2-ODDs are among the most versatile and important oxidizing biological catalysts. In this review, we survey and summarize the pertinent literature with a focus on several key reactions catalyzed by 2-ODDs, and discuss the significance and impact of these enzymes in plant metabolism. PMID:25346740

  15. Phylogenetic diversity of dominant bacterial and archaeal communities in plant-microbial fuel cells using rice plants.

    PubMed

    Ahn, Jae-Hyung; Jeong, Woo-Suk; Choi, Min-Young; Kim, Byung-Yong; Song, Jaekyeong; Weon, Hang-Yeon

    2014-12-28

    In this study, the phylogenetic diversities of bacterial and archaeal communities in a plantmicrobial fuel cell (P-MFC) were investigated together with the environmental parameters, affecting its performance by using rice as a model plant. The beneficial effect of the plant appeared only during a certain period of the rice-growing season, at which point the maximum power density was approximately 3-fold higher with rice plants. The temperature, electrical conductivity (EC), and pH in the cathodic and anodic compartments changed considerably during the rice-growing season, and a higher temperature, reduced difference in pH between the cathodic and anodic compartments, and higher EC were advantageous to the performance of the P-MFC. A 16S rRNA pyrosequencing analysis showed that the 16S rRNAs of Deltaproteobacteria and those of Gammaproteobacteria were enriched on the anodes and the cathodes, respectively, when the electrical circuit was connected. At the species level, the operational taxonomic units (OTUs) related to Rhizobiales, Geobacter, Myxococcus, Deferrisoma, and Desulfobulbus were enriched on the anodes, while an OTU related to Acidiferrobacter thiooxydans occupied the highest proportion on the cathodes and occurred only when the circuit was connected. Furthermore, the connection of the electrical circuit decreased the abundance of 16S rRNAs of acetotrophic methanogens and increased that of hydrogenotrophic methanogens. The control of these physicochemical and microbiological factors is expected to be able to improve the performance of P-MFCs. PMID:25189409

  16. Pathogen threat assessment is predictive plant pathology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The American Society of Plant Pathologists has maintained a formal effort to prioritize threatening and emerging crop pathogens for over 70 years, and the APS Emerging Pathogens and Diseases Committee is continuing the process. In order to accomplish prioritization in a rigorous fashion, criteria mu...

  17. B Plant low level waste system integrity assessment report

    SciTech Connect

    Walter, E.J.

    1995-09-01

    This document provides the report of the integrity assessment activities for the B Plant low level waste system. The assessment activities were in response to requirements of the Washington State Dangerous Waste Regulations, Washington Administrative Code (WAC), 173-303-640. This integrity assessment report supports compliance with Hanford Federal Facility Agreement and Consent Order interim milestone target action M-32-07-T03.

  18. Not all non-natives are equally unequal: reductions in herbivore ?-diversity depend on phylogenetic similarity to native plant community.

    PubMed

    Burghardt, Karin T; Tallamy, Douglas W

    2015-10-01

    Effects of host plant ?- and ?-diversity often confound studies of herbivore ?-diversity, hindering our ability to predict the full impact of non-native plants on herbivores. Here, while controlling host plant diversity, we examined variation in herbivore communities between native and non-native plants, focusing on how plant relatedness and spatial scale alter the result. We found lower absolute magnitudes of ?-diversity among tree species and among sites on non-natives in all comparisons. However, lower relative ?-diversity only occurred for immature herbivores on phylogenetically distinct non-natives vs. natives. Locally in that comparison, non-native gardens had lower host specificity; while among sites, the herbivores supported were a redundant subset of species on natives. Therefore, when phylogenetically distinct non-natives replace native plants, the community of immature herbivores is likely to be homogenised across landscapes. Differences in communities on closely related non-natives were subtler, but displayed community shifts and increased generalisation on non-natives within certain feeding guilds. PMID:26271480

  19. Evaluating Methods for Isolating Total RNA and Predicting the Success of Sequencing Phylogenetically Diverse Plant Transcriptomes

    PubMed Central

    Bruskiewich, Richard; Burris, Jason N.; Carrigan, Charlotte T.; Chase, Mark W.; Clarke, Neil D.; Covshoff, Sarah; dePamphilis, Claude W.; Edger, Patrick P.; Goh, Falicia; Graham, Sean; Greiner, Stephan; Hibberd, Julian M.; Jordon-Thaden, Ingrid; Kutchan, Toni M.; Leebens-Mack, James; Melkonian, Michael; Miles, Nicholas; Myburg, Henrietta; Patterson, Jordan; Pires, J. Chris; Ralph, Paula; Rolf, Megan; Sage, Rowan F.; Soltis, Douglas; Soltis, Pamela; Stevenson, Dennis; Stewart, C. Neal; Surek, Barbara; Thomsen, Christina J. M.; Villarreal, Juan Carlos; Wu, Xiaolei; Zhang, Yong; Deyholos, Michael K.; Wong, Gane Ka-Shu

    2012-01-01

    Next-generation sequencing plays a central role in the characterization and quantification of transcriptomes. Although numerous metrics are purported to quantify the quality of RNA, there have been no large-scale empirical evaluations of the major determinants of sequencing success. We used a combination of existing and newly developed methods to isolate total RNA from 1115 samples from 695 plant species in 324 families, which represents >900 million years of phylogenetic diversity from green algae through flowering plants, including many plants of economic importance. We then sequenced 629 of these samples on Illumina GAIIx and HiSeq platforms and performed a large comparative analysis to identify predictors of RNA quality and the diversity of putative genes (scaffolds) expressed within samples. Tissue types (e.g., leaf vs. flower) varied in RNA quality, sequencing depth and the number of scaffolds. Tissue age also influenced RNA quality but not the number of scaffolds ?1000 bp. Overall, 36% of the variation in the number of scaffolds was explained by metrics of RNA integrity (RIN score), RNA purity (OD 260/230), sequencing platform (GAIIx vs HiSeq) and the amount of total RNA used for sequencing. However, our results show that the most commonly used measures of RNA quality (e.g., RIN) are weak predictors of the number of scaffolds because Illumina sequencing is robust to variation in RNA quality. These results provide novel insight into the methods that are most important in isolating high quality RNA for sequencing and assembling plant transcriptomes. The methods and recommendations provided here could increase the efficiency and decrease the cost of RNA sequencing for individual labs and genome centers. PMID:23185583

  20. The roles of community biomass and species pools in the regulation of plant diversity

    USGS Publications Warehouse

    Grace, J.B.

    2001-01-01

    Considerable debate has developed over the importance of community biomass and species pools in the regulation of community diversity. Attempts to explain patterns of plant diversity as a function of community biomass or productivity have been only partially successful and in general, have explained only a fraction of the observed variation in diversity. At the same time studies that have focused on the importance of species pools have led some to conclude that diversity is primarily regulated in the short term by the size of the species pool rather than by biotic interactions. In this paper, I explore how community biomass and species pools may work in combination to regulate diversity in herbaceous plant communities. To address this problem, I employ a simple model in which the dynamics of species richness are a function of aboveground community biomass and environmentally controlled gradients in species pools. Model results lead to two main predictions about the role of biomass regulation: (1) Seasonal dynamics of richness will tend to follow a regular oscillation, with richness rising to peak values during the early to middle portion of the growing season and then declining during the latter part of the season. (2.) Seasonal dieback of aboveground tissues facilitates the long-term maintenance of high levels of richness in the community. The persistence of aboveground tissues and accumulation of litter are especially important in limiting the number of species through the suppression of recruitment. Model results also lead to two main predictions about the role of species pools: (1) The height and position of peak richness relative to community biomass will be influenced by the rate at which the species pool increases as available soil resources increase. (2) Variations in nonresource environmental factors (e.g. soil pH or soil salinity) have the potential to regulate species pools in a way that is uncorrelated with aboveground biomass. Under extreme conditions, such nonresource effects can create a unimodal envelope of biomass-richness values. Available evidence from the literature provides partial support for these predictions, though additional data are needed to provide more convincing tests.

  1. Diversity and Taxonomy of Endophytic Xylariaceous Fungi from Medicinal Plants of Dendrobium (Orchidaceae)

    PubMed Central

    Chen, Juan; Zhang, Li-Chun; Xing, Yong-Mei; Wang, Yun-Qiang; Xing, Xiao-Ke; Zhang, Da-Wei; Liang, Han-Qiao; Guo, Shun-Xing

    2013-01-01

    Dendrobium spp. are traditional Chinese medicinal plants, and the main effective ingredients (polysaccharides and alkaloids) have pharmacologic effects on gastritis infection, cancer, and anti-aging. Previously, we confirmed endophytic xylariaceous fungi as the dominant fungi in several Dendrobium species of tropical regions from China. In the present study, the diversity, taxonomy, and distribution of culturable endophytic xylariaceous fungi associated with seven medicinal species of Dendrobium (Orchidaceae) were investigated. Among the 961 endophytes newly isolated, 217 xylariaceous fungi (morphotaxa) were identified using morphological and molecular methods. The phylogenetic tree constructed using nuclear ribosomal internal transcribed spacer (ITS), large subunit of ribosomal DNA (LSU), and beta-tubulin sequences divided these anamorphic xylariaceous isolates into at least 18 operational taxonomic units (OTUs). The diversity of the endophytic xylariaceous fungi in these seven Dendrobium species was estimated using Shannon and evenness indices, with the results indicating that the dominant Xylariaceae taxa in each Dendrobium species were greatly different, though common xylariaceous fungi were found in several Dendrobium species. These findings implied that different host plants in the same habitats exhibit a preference and selectivity for their fungal partners. Using culture-dependent approaches, these xylariaceous isolates may be important sources for the future screening of new natural products and drug discovery. PMID:23472167

  2. Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Dothideomycetes Fungi

    SciTech Connect

    Ohm, Robin A.; Feau, Nicolas; Henrissat, Bernard; Schoch, Conrad L.; Horwitz, Benjamin A.; Barry, Kerrie W.; Condon, Bradford J.; Copeland, Alex C.; Dhillon, Braham; Glaser, Fabian; Hesse, Cedar N.; Kosti, Idit; LaButti, Kurt; Lindquist, Erika A.; Lucas, Susan; Salamov, Asaf A.; Bradshaw, Rosie E.; Ciuffetti, Lynda; Hamelin, Richard C.; Kema, Gert H. J.; Lawrence, Christopher; Scott, James A.; Spatafora, Joseph W.; Turgeon, B. Gillian; Wit, Pierre J. G. M. de; Zhong, Shaobin; Goodwin, Stephen B.; Grigoriev, Igor V.

    2012-02-29

    The class Dothideomycetes is one of the largest groups of fungi with a high level of ecological diversity including many plant pathogens infecting a broad range of hosts. Here, we compare genome features of 18 members of this class, including 6 necrotrophs, 9 (hemi)biotrophs and 3 saprotrophs, to analyze genome structure, evolution, and the diverse strategies of pathogenesis. The Dothideomycetes most likely evolved from a common ancestor more than 280 million years ago. The 18 genome sequences differ dramatically in size due to variation in repetitive content, but show much less variation in number of (core) genes. Gene order appears to have been rearranged mostly within chromosomal boundaries by multiple inversions, in extant genomes frequently demarcated by adjacent simple repeats. Several Dothideomycetes contain one or more gene-poor, transposable element (TE)-rich putatively dispensable chromosomes of unknown function. The 18 Dothideomycetes offer an extensive catalogue of genes involved in cellulose degradation, proteolysis, secondary metabolism, and cysteine-rich small secreted proteins. Ancestors of the two major orders of plant pathogens in the Dothideomycetes, the Capnodiales and Pleosporales, may have had different modes of pathogenesis, with the former having fewer of these genes than the latter. Many of these genes are enriched in proximity to transposable elements, suggesting faster evolution because of the effects of repeat induced point (RIP) mutations. A syntenic block of genes, including oxidoreductases, is conserved in most Dothideomycetes and upregulated during infection in L. maculans, suggesting a possible function in response to oxidative stress.

  3. Diverse Lifestyles and Strategies of Plant Pathogenesis Encoded in the Genomes of Eighteen Dothideomycetes Fungi

    PubMed Central

    Ohm, Robin A.; Feau, Nicolas; Henrissat, Bernard; Schoch, Conrad L.; Horwitz, Benjamin A.; Barry, Kerrie W.; Condon, Bradford J.; Copeland, Alex C.; Dhillon, Braham; Glaser, Fabian; Hesse, Cedar N.; Kosti, Idit; LaButti, Kurt; Lindquist, Erika A.; Lucas, Susan; Salamov, Asaf A.; Bradshaw, Rosie E.; Ciuffetti, Lynda; Hamelin, Richard C.; Kema, Gert H. J.; Lawrence, Christopher; Scott, James A.; Spatafora, Joseph W.; Turgeon, B. Gillian; de Wit, Pierre J. G. M.; Zhong, Shaobin; Goodwin, Stephen B.; Grigoriev, Igor V.

    2012-01-01

    The class Dothideomycetes is one of the largest groups of fungi with a high level of ecological diversity including many plant pathogens infecting a broad range of hosts. Here, we compare genome features of 18 members of this class, including 6 necrotrophs, 9 (hemi)biotrophs and 3 saprotrophs, to analyze genome structure, evolution, and the diverse strategies of pathogenesis. The Dothideomycetes most likely evolved from a common ancestor more than 280 million years ago. The 18 genome sequences differ dramatically in size due to variation in repetitive content, but show much less variation in number of (core) genes. Gene order appears to have been rearranged mostly within chromosomal boundaries by multiple inversions, in extant genomes frequently demarcated by adjacent simple repeats. Several Dothideomycetes contain one or more gene-poor, transposable element (TE)-rich putatively dispensable chromosomes of unknown function. The 18 Dothideomycetes offer an extensive catalogue of genes involved in cellulose degradation, proteolysis, secondary metabolism, and cysteine-rich small secreted proteins. Ancestors of the two major orders of plant pathogens in the Dothideomycetes, the Capnodiales and Pleosporales, may have had different modes of pathogenesis, with the former having fewer of these genes than the latter. Many of these genes are enriched in proximity to transposable elements, suggesting faster evolution because of the effects of repeat induced point (RIP) mutations. A syntenic block of genes, including oxidoreductases, is conserved in most Dothideomycetes and upregulated during infection in L. maculans, suggesting a possible function in response to oxidative stress. PMID:23236275

  4. ASSESSING OFF-TARGET IMPACTS OF HERBICIDE DRIFT ON NATIVE PLANTS - IMPLICATIONS FOR PLANT COMMUNITIES AND WILDLIFE

    EPA Science Inventory

    The off target movement of herbicidess onto nontarget vegetation can affect native plants, plant communities and ecosystems. Within the agroecosystem, plants provide the basis for food and shelter for wildlife. The risk assessment process to determine potential pesticide impacts...

  5. Diverse evolutionary mechanisms shape the type III effector virulence factor repertoire in the plant pathogen Pseudomonas syringae.

    PubMed Central

    Rohmer, Laurence; Guttman, David S; Dangl, Jeffery L

    2004-01-01

    Many gram-negative pathogenic bacteria directly translocate effector proteins into eukaryotic host cells via type III delivery systems. Type III effector proteins are determinants of virulence on susceptible plant hosts; they are also the proteins that trigger specific disease resistance in resistant plant hosts. Evolution of type III effectors is dominated by competing forces: the likely requirement for conservation of virulence function, the avoidance of host defenses, and possible adaptation to new hosts. To understand the evolutionary history of type III effectors in Pseudomonas syringae, we searched for homologs to 44 known or candidate P. syringae type III effectors and two effector chaperones. We examined 24 gene families for distribution among bacterial species, amino acid sequence diversity, and features indicative of horizontal transfer. We assessed the role of diversifying and purifying selection in the evolution of these gene families. While some P. syringae type III effectors were acquired recently, others have evolved predominantly by descent. The majority of codons in most of these genes were subjected to purifying selection, suggesting selective pressure to maintain presumed virulence function. However, members of 7 families had domains subject to diversifying selection. PMID:15280247

  6. 7 CFR 319.40-11 - Plant pest risk assessment standards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Plant pest risk assessment standards. 319...of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...Unmanufactured Wood Articles § 319.40-11 Plant pest risk assessment...

  7. 7 CFR 319.40-11 - Plant pest risk assessment standards.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Plant pest risk assessment standards. 319...of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...Other Wood Articles § 319.40-11 Plant pest risk assessment...

  8. 7 CFR 319.40-11 - Plant pest risk assessment standards.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Plant pest risk assessment standards. 319...of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...Unmanufactured Wood Articles § 319.40-11 Plant pest risk assessment...

  9. 7 CFR 319.40-11 - Plant pest risk assessment standards.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Plant pest risk assessment standards. 319...of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...Other Wood Articles § 319.40-11 Plant pest risk assessment...

  10. 7 CFR 319.40-11 - Plant pest risk assessment standards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Plant pest risk assessment standards. 319...of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...Unmanufactured Wood Articles § 319.40-11 Plant pest risk assessment...

  11. The Arabidopsis synaptotagmin SYTA regulates the cell-to-cell movement of diverse plant viruses

    PubMed Central

    Uchiyama, Asako; Shimada-Beltran, Harumi; Levy, Amit; Zheng, Judy Y.; Javia, Parth A.; Lazarowitz, Sondra G.

    2014-01-01

    Synaptotagmins are a large gene family in animals that have been extensively characterized due to their role as calcium sensors to regulate synaptic vesicle exocytosis and endocytosis in neurons, and dense core vesicle exocytosis for hormone secretion from neuroendocrine cells. Thought to be exclusive to animals, synaptotagmins have recently been characterized in Arabidopsis thaliana, in which they comprise a five gene family. Using infectivity and leaf-based functional assays, we have shown that Arabidopsis SYTA regulates endocytosis and marks an endosomal vesicle recycling pathway to regulate movement protein-mediated trafficking of the Begomovirus Cabbage leaf curl virus (CaLCuV) and the Tobamovirus Tobacco mosaic virus (TMV) through plasmodesmata (Lewis and Lazarowitz, 2010). To determine whether SYTA has a central role in regulating the cell-to-cell trafficking of a wider range of diverse plant viruses, we extended our studies here to examine the role of SYTA in the cell-to-cell movement of additional plant viruses that employ different modes of movement, namely the Potyvirus Turnip mosaic virus (TuMV), the Caulimovirus Cauliflower mosaic virus (CaMV) and the Tobamovirus Turnip vein clearing virus (TVCV), which in contrast to TMV does efficiently infect Arabidopsis. We found that both TuMV and TVCV systemic infection, and the cell-to-cell trafficking of the their movement proteins, were delayed in the Arabidopsis Col-0 syta-1 knockdown mutant. In contrast, CaMV systemic infection was not inhibited in syta-1. Our studies show that SYTA is a key regulator of plant virus intercellular movement, being necessary for the ability of diverse cell-to-cell movement proteins encoded by Begomoviruses (CaLCuV MP), Tobamoviruses (TVCV and TMV 30K protein) and Potyviruses (TuMV P3N-PIPO) to alter PD and thereby mediate virus cell-to-cell spread. PMID:25414709

  12. Plant characterization of Roundup Ready 2 Yield ® soybean, MON 89788, for use in ecological risk assessment.

    PubMed

    Horak, Michael J; Rosenbaum, Eric W; Kendrick, Daniel L; Sammons, Bernard; Phillips, Samuel L; Nickson, Thomas E; Dobert, Raymond C; Perez, Tim

    2015-04-01

    During the development of a genetically modified (GM) crop product, extensive phenotypic and agronomic data are collected to characterize the plant in comparison to a conventional control with a similar genetic background. The data are evaluated for potential differences resulting from the genetic modification process or the GM trait, and the differences--if any--are subsequently considered in the context of contributing to the pest potential of the GM crop. Ultimately, these study results and those of other studies are used in an ecological risk assessment of the GM crop. In the studies reported here, seed germination, vegetative and reproductive growth, and pollen morphology of Roundup Ready 2 Yield(®) soybean, MON 89788, were compared to those of A3244, a conventional control soybean variety with the same genetic background. Any statistically significant differences were considered in the context of the genetic variation known to occur in soybean and were evaluated as indicators of an effect of the genetic modification process and assessed for impact on plant pest (weed) characteristics and adverse ecological impact (ecological risk). The results of these studies revealed no effects attributable to the genetic modification process or to the GM trait in the plant that would result in increased pest potential or adverse ecological impact of MON 89788 compared with A3244. These results and the associated risk assessments obtained from diverse geographic and environmental conditions in the United States and Argentina can be used by regulators in other countries to inform various assessments of ecological risk. PMID:25248506

  13. Assessment of the genetic and phenotypic diversity among rhizogenic Agrobacterium biovar 1 strains infecting solanaceous and cucurbit crops.

    PubMed

    Bosmans, Lien; Álvarez-Pérez, Sergio; Moerkens, Rob; Wittemans, Lieve; Van Calenberge, Bart; Kerckhove, Stefan Van; Paeleman, Anneleen; De Mot, René; Rediers, Hans; Lievens, Bart

    2015-08-01

    Rhizogenic Agrobacterium biovar 1 strains have been found to cause extensive root proliferation on hydroponically grown Cucurbitaceae and Solanaceae crops, resulting in substantial economic losses. As these agrobacteria live under similar ecological conditions, infecting a limited number of crops, it may be hypothesized that genetic and phenotypic variation among such strains is relatively low. In this study we assessed the phenotypic diversity as well as the phylogenetic and evolutionary relationships of several rhizogenic Agrobacterium biovar 1 strains from cucurbit and solanaceous crops. A collection of 41 isolates was subjected to a number of phenotypic assays and characterized by MLSA targeting four housekeeping genes (16S rRNA gene, recA, rpoB and trpE) and two loci from the root-inducing Ri-plasmid (part of rolB and virD2). Besides phenotypic variation, remarkable genotypic diversity was observed, especially for some chromosomal loci such as trpE. In contrast, genetic diversity was lower for the plasmid-borne loci, indicating that the studied chromosomal housekeeping genes and Ri-plasmid-borne loci might not exhibit the same evolutionary history. Furthermore, phylogenetic and network analyses and several recombination tests suggested that recombination could be contributing in some extent to the evolutionary dynamics of rhizogenic Agrobacterium populations. Finally, a genomospecies-level identification analysis revealed that at least four genomospecies may occur on cucurbit and tomato crops (G1, G3, G8 and G9). Together, this study gives a first glimpse at the genetic and phenotypic diversity within this economically important plant pathogenic bacterium. PMID:26187479

  14. Pinellas Plant final action plan: environmental, safety and health assessment of Pinellas Plant, Largo, Florida

    SciTech Connect

    Not Available

    1990-12-03

    This document contains responses and planned actions and their estimated costs for addressing the findings presented in the Tiger Team Environment, Safety, and Health Compliance Assessment of the Pinellas Plant. The assessment presented 170 findings in three general categories: environment, safety and health, and management and organization.

  15. Biotechnological uses of RNAi in plants: risk assessment considerations.

    PubMed

    Casacuberta, Josep M; Devos, Yann; du Jardin, Patrick; Ramon, Matthew; Vaucheret, Hervé; Nogué, Fabien

    2015-03-01

    RNAi offers opportunities to generate new traits in genetically modified (GM) plants. Instead of expressing novel proteins, RNAi-based GM plants reduce target gene expression. Silencing of off-target genes may trigger unintended effects, and identifying these genes would facilitate risk assessment. However, using bioinformatics alone is not reliable, due to the lack of genomic data and insufficient knowledge of mechanisms governing mRNA-small (s)RNA interactions. PMID:25721261

  16. Drivers of temporal changes in temperate forest plant diversity vary across spatial scales.

    PubMed

    Bernhardt-Römermann, Markus; Baeten, Lander; Craven, Dylan; De Frenne, Pieter; Hédl, Radim; Lenoir, Jonathan; Bert, Didier; Brunet, Jörg; Chudomelová, Markéta; Decocq, Guillaume; Dierschke, Hartmut; Dirnböck, Thomas; Dörfler, Inken; Heinken, Thilo; Hermy, Martin; Hommel, Patrick; Jaroszewicz, Bogdan; Keczy?ski, Andrzej; Kelly, Daniel L; Kirby, Keith J; Kopecký, Martin; Macek, Martin; Máliš, František; Mirtl, Michael; Mitchell, Fraser J G; Naaf, Tobias; Newman, Miles; Peterken, George; Pet?ík, Petr; Schmidt, Wolfgang; Standovár, Tibor; Tóth, Zoltán; Calster, Hans Van; Verstraeten, Gorik; Vladovi?, Jozef; Vild, Ond?ej; Wulf, Monika; Verheyen, Kris

    2015-10-01

    Global biodiversity is affected by numerous environmental drivers. Yet, the extent to which global environmental changes contribute to changes in local diversity is poorly understood. We investigated biodiversity changes in a meta-analysis of 39 resurvey studies in European temperate forests (3988 vegetation records in total, 17-75 years between the two surveys) by assessing the importance of (i) coarse-resolution (i.e., among sites) vs. fine-resolution (i.e., within sites) environmental differences and (ii) changing environmental conditions between surveys. Our results clarify the mechanisms underlying the direction and magnitude of local-scale biodiversity changes. While not detecting any net local diversity loss, we observed considerable among-site variation, partly explained by temporal changes in light availability (a local driver) and density of large herbivores (a regional driver). Furthermore, strong evidence was found that presurvey levels of nitrogen deposition determined subsequent diversity changes. We conclude that models forecasting future biodiversity changes should consider coarse-resolution environmental changes, account for differences in baseline environmental conditions and for local changes in fine-resolution environmental conditions. PMID:26212787

  17. 78 FR 66892 - BASF Plant Science LP; Availability of Plant Pest Risk Assessment and Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ...Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to...organisms and products altered or produced through genetic engineering that are plant pests or that there is reason...

  18. Draft environmental assessment: Ocean Thermal Energy Conversion (OTEC) Pilot Plants

    SciTech Connect

    Sullivan, S.M.; Sands, M.D.; Donat, J.R.; Jepsen, P.; Smookler, M.; Villa, J.F.

    1981-02-01

    This Environmental Assessment (EA) has been prepared, in accordance with the National Environmental Policy Act of 1969, for the deployment and operation of a commercial 40-Megawatt (MW) Ocean Thermal Energy Conversion (OTEC) Pilot Plant (hereafter called the Pilot Plant). A description of the proposed action is presented, and a generic environment typical of the candidate Pilot Plant siting regions is described. An assessment of the potential environmental impacts associated with the proposed action is given, and the risk of credible accidents and mitigating measures to reduce these risks are considered. The Federal and State plans and policies the proposed action will encompass are described. Alternatives to the proposed action are presented. Appendix A presents the navigation and environmental information contained in the US Coast Pilot for each of the candidate sites; Appendix B provides a brief description of the methods and calculations used in the EA. It is concluded that environmental disturbances associated with Pilot Plant activities could potentially cause significant environmental impacts; however, the magnitude of these potential impacts cannot presently be assessed, due to insufficient engineering and environmental information. A site- and design-specific OTEC Pilot Plant Environmental Impact Statement (EIS) is required to resolve the potentially significant environmental effects associated with Pilot Plant deployment and operation. (WHK)

  19. 78 FR 66892 - BASF Plant Science LP; Availability of Plant Pest Risk Assessment and Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ..., ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or... produced through genetic engineering that are plant pests or that there is reason to believe are plant... complete. In a notice \\2\\ published in ] the Federal Register on July 13, 2012, (77 FR 41363-41364,...

  20. Antimicrobial biosynthetic potential and genetic diversity of endophytic actinomycetes associated with medicinal plants.

    PubMed

    Gohain, Anwesha; Gogoi, Animesh; Debnath, Rajal; Yadav, Archana; Singh, Bhim P; Gupta, Vijai K; Sharma, Rajeev; Saikia, Ratul

    2015-10-01

    Endophytic actinomycetes are one of the primary groups that share symbiotic relationships with medicinal plants and are key reservoir of biologically active compounds. In this study, six selective medicinal plants were targeted for the first time for endophytic actinomycetes isolation from Gibbon Wild Life Sanctuary, Assam, India, during winter and summer and 76 isolates were obtained. The isolates were found to be prevalent in roots followed by stem and leaves. 16S rRNA gene sequence analysis revealed 16 genera, including rare genera, Verrucosispora, Isoptericola and Kytococcus, which have never been previously reported as endophytic. The genus Streptomyces (66%) was dominant in both seasons. Shannon's diversity index showed that Azadirachta indica (1.49), Rauwolfia serpentina (1.43) and Emblica officinalis (1.24) were relatively good habitat for endophytic actinomycetes. Antimicrobial strains showed prevalence of polyketide synthase (PKS) type-II (85%) followed by PKS type-I (14%) encoded in the genomes. Expression studies showed 12-fold upregulation of PKSII gene in seventh day of incubation for Streptomyces antibioticus (EAAG90). Our results emphasize that the actinomycetes assemblages within plant tissue exhibited biosynthetic systems encoding for important biologically active compounds. PMID:26347302

  1. Diversity of plant life cycles is generated by dynamic epigenetic regulation in response to vernalization.

    PubMed

    Satake, Akiko

    2010-10-21

    I developed a genetic-physiological model to investigate the molecular mechanisms regulating annual and perennial life histories, and theoretically explored local adaptation caused by environment-specific selection. The model integrates signal transmission in the vernalization pathway and physiological process regarding growth and resource accumulation. The transition from vegetative to reproductive growth was modeled as the process of accumulating the flowering signal, which is transported from leaves to meristems. The model predicted four distinct flowering behaviors, monocarpic annual/perennial and polycarpic-yearly or -intermittent flowering, depending on the epigenetic regulation of FLOWERING LOCUS C (FLC), a transcription factor that acts as a floral repressor. When FLC transcription was not activated after repression, plants always behaved monocarpically, while only a low activation rate of FLC allowed plants to become polycarpal. When mortality was high, rapid repression of FLC was evolutionarily favored, resulting in a summer annual phenotype. As mortality decreased, the evolutionarily favored phenotype shifted from summer to winter annuals, and further to polycarpic phenotypes in which FLC repression occurred slowly. Analysis of local adaptation demonstrated that sensitivity to low temperature increased from northern to southern habitats. These predictions provide important insights into the evolution of diversity in plant life cycles under rapid climate change. PMID:20659481

  2. Positive interactions between large herbivores and grasshoppers, and their consequences for grassland plant diversity.

    PubMed

    Zhong, Zhiwei; Wang, Deli; Zhu, Hui; Wang, Ling; Feng, Chao; Wang, Zhongnan

    2014-04-01

    Although the influence of positive interactions on plant and sessile communities has been well documented, surprisingly little is known about their role in structuring terrestrial animal communities. We evaluated beneficial interactions between two distantly related herbivore taxa, large vertebrate grazers (sheep) and smaller insect grazers (grasshoppers), using a set of field experiments in eastern Eurasian steppe of China. Grazing by large herbivores caused significantly higher grasshopper density, and this pattern persisted until the end of the experiment. Grasshoppers, in turn, increased the foraging time of larger herbivores, but such response occurred only during the peak of growing season (August). These reciprocal interactions were driven by differential herbivore foraging preferences for plant resources; namely, large herbivores preferred Artemisia forbs, whereas grasshoppers preferred Leymus grass. The enhancement of grasshopper density in areas grazed by large herbivores likely resulted from the selective consumption of Artemisia forbs by vertebrate grazers, which may potentially improve the host finding of grasshoppers. Likewise, grasshoppers appeared to benefit large herbivores by decreasing the cover and density of the dominant grass Leymus chinensis, which hampers large herbivores' access to palatable forbs. Moreover, we found that large herbivores grazing alone may significantly decrease plant diversity, yet grasshoppers appeared to mediate such negative effects when they grazed with large herbivores. Our results suggest that the positive, reciprocal interactions in terrestrial herbivore communities may be more prevalent and complex than previously thought. PMID:24933823

  3. Imprinting in plants as a mechanism to generate seed phenotypic diversity

    PubMed Central

    Bai, Fang; Settles, A. M.

    2015-01-01

    Normal plant development requires epigenetic regulation to enforce changes in developmental fate. Genomic imprinting is a type of epigenetic regulation in which identical alleles of genes are expressed in a parent-of-origin dependent manner. Deep sequencing of transcriptomes has identified hundreds of imprinted genes with scarce evidence for the developmental importance of individual imprinted loci. Imprinting is regulated through global DNA demethylation in the central cell prior to fertilization and directed repression of individual loci with the Polycomb Repressive Complex 2 (PRC2). There is significant evidence for transposable elements and repeat sequences near genes acting as cis-elements to determine imprinting status of a gene, implying that imprinted gene expression patterns may evolve randomly and at high frequency. Detailed genetic analysis of a few imprinted loci suggests an imprinted pattern of gene expression is often dispensable for seed development. Few genes show conserved imprinted expression within or between plant species. These data are not fully explained by current models for the evolution of imprinting in plant seeds. We suggest that imprinting may have evolved to provide a mechanism for rapid neofunctionalization of genes during seed development to increase phenotypic diversity of seeds. PMID:25674092

  4. Assessing the effectiveness of jail diversion programs for persons with serious mental illness and co-occurring substance use disorders.

    PubMed

    Steadman, Henry J; Naples, Michelle

    2005-01-01

    In recent years, jail diversion programs for people with serious mental illness and co-occurring substance use disorders have received increasing attention and have rapidly grown in number. Previous studies suggest that jail diversion programs have the potential to achieve positive outcomes. The present study reports findings from 6 jail diversion programs (3 pre-booking and 3 post-booking) participating in a federally-funded research initiative to assess the effectiveness of jail diversion programs for people with co-occurring disorders. Diverted and non-diverted groups were compared on self-reported outcomes at 12 months following diversion. The findings suggest that jail diversion reduces time spent in jail without increasing the public safety risk, while linking participants to community-based services. Jail diversion costs and the implications of these results for jail diversion programs and future research are discussed. PMID:15818607

  5. Plant-Wide Energy Efficiency Assessment at the Arizona Portland Cement Plant in Rillito, Arizona

    SciTech Connect

    Stephen J. Coppinger, P.E.; Bruce Colburn, Ph.D., P.E., CEM

    2007-05-17

    A Department of Energy Plant-wide Assessment was undertaken by Arizona Portland Cement (APC) beginning in May 2005. The assessment was performed at APC’s cement production facility in Rillito, Arizona. The assessment included a compressed air evaluation along with a detailed process audit of plant operations and equipment. The purpose of this Energy Survey was to identify a series of energy cost savings opportunities at the Plant, and provide preliminary cost and savings estimates for the work. The assessment was successful in identifying projects that could provide annual savings of over $2.7 million at an estimated capital cost of $4.3 million. If implemented, these projects could amount to a savings of over 4.9 million kWh/yr and 384,420 MMBtu/year.

  6. Genetic Diversity Analysis of Highly Incomplete SNP Genotype Data with Imputations: An Empirical Assessment

    PubMed Central

    Fu, Yong-Bi

    2014-01-01

    Genotyping by sequencing (GBS) recently has emerged as a promising genomic approach for assessing genetic diversity on a genome-wide scale. However, concerns are not lacking about the uniquely large unbalance in GBS genotype data. Although some genotype imputation has been proposed to infer missing observations, little is known about the reliability of a genetic diversity analysis of GBS data, with up to 90% of observations missing. Here we performed an empirical assessment of accuracy in genetic diversity analysis of highly incomplete single nucleotide polymorphism genotypes with imputations. Three large single-nucleotide polymorphism genotype data sets for corn, wheat, and rice were acquired, and missing data with up to 90% of missing observations were randomly generated and then imputed for missing genotypes with three map-independent imputation methods. Estimating heterozygosity and inbreeding coefficient from original, missing, and imputed data revealed variable patterns of bias from assessed levels of missingness and genotype imputation, but the estimation biases were smaller for missing data without genotype imputation. The estimates of genetic differentiation were rather robust up to 90% of missing observations but became substantially biased when missing genotypes were imputed. The estimates of topology accuracy for four representative samples of interested groups generally were reduced with increased levels of missing genotypes. Probabilistic principal component analysis based imputation performed better in terms of topology accuracy than those analyses of missing data without genotype imputation. These findings are not only significant for understanding the reliability of the genetic diversity analysis with respect to large missing data and genotype imputation but also are instructive for performing a proper genetic diversity analysis of highly incomplete GBS or other genotype data. PMID:24626289

  7. FUNGAL SYMBIONTS. Global assessment of arbuscular mycorrhizal fungus diversity reveals very low endemism.

    PubMed

    Davison, J; Moora, M; Öpik, M; Adholeya, A; Ainsaar, L; Bâ, A; Burla, S; Diedhiou, A G; Hiiesalu, I; Jairus, T; Johnson, N C; Kane, A; Koorem, K; Kochar, M; Ndiaye, C; Pärtel, M; Reier, Ü; Saks, Ü; Singh, R; Vasar, M; Zobel, M

    2015-08-28

    The global biogeography of microorganisms remains largely unknown, in contrast to the well-studied diversity patterns of macroorganisms. We used arbuscular mycorrhizal (AM) fungus DNA from 1014 plant-root samples collected worldwide to determine the global distribution of these plant symbionts. We found that AM fungal communities reflected local environmental conditions and the spatial distance between sites. However, despite AM fungi apparently possessing limited dispersal ability, we found 93% of taxa on multiple continents and 34% on all six continents surveyed. This contrasts with the high spatial turnover of other fungal taxa and with the endemism displayed by plants at the global scale. We suggest that the biogeography of AM fungi is driven by unexpectedly efficient dispersal, probably via both abiotic and biotic vectors, including humans. PMID:26315436

  8. Floristic Diversity and Distribution Pattern of Plant Communities along Altitudinal Gradient in Sangla Valley, Northwest Himalaya

    PubMed Central

    Rana, J. C.; Devi, Usha; Randhawa, S. S.; Kumar, Rajesh

    2014-01-01

    Himalayas are globally important biodiversity hotspots and are facing rapid loss in floristic diversity and changing pattern of vegetation due to various biotic and abiotic factors. This has necessitated the qualitative and quantitative assessment of vegetation here. The present study was conducted in Sangla Valley of northwest Himalaya aiming to assess the structure of vegetation and its trend in the valley along the altitudinal gradient. In the forest and alpine zones of the valley, 15 communities were recorded. Study revealed 320 species belonging to 199 genera and 75 families. Asteraceae, Rosaceae, Apiaceae, and Ranunculaceae were dominant. Among genera, Artemisia followed by Polygonum, Saussurea, Berberis, and Thalictrum were dominant. Tree and shrub's density ranged from 205 to 600 and from 105 to 1030 individual per hectare, respectively, whereas herbs ranged from 22.08 to 78.95 individual/m2. Nearly 182 species were native to the Himalaya. Maximum altitudinal distribution of few selected climate sensitive species was found to be highest in northeast and north aspects. This study gives an insight into the floristic diversity and community structure of the fragile Sangla Valley which was hitherto not available. PMID:25383363

  9. Martinez Refinery Completes Plant-Wide Energy Assessment

    SciTech Connect

    2002-11-01

    This OIT BestPractices Case Study describes how the Equilon Enterprises oil refinery in Martinez, California undertook a plant-wide energy assessment that focused on three key areas: waste minimization, process debottlenecking, and operations optimization. The assessment yielded recommendations, which, if implemented, can save more than 6,000,000 MMBtu per year and an estimated $52,000,000 per year, plus improve process control and reduce waste.

  10. Does Plant Diversity Affect Carbon and Water-Use Efficiency in Grasslands? Evidence from a Biodiversity and Ecosystem Functioning Experiment

    NASA Astrophysics Data System (ADS)

    Temperton, V. M.; Buchmann, N.; Steinbeiß, S.; Gleixner, G.; Schulze, D.

    2004-12-01

    In view of rapid species loss on a global scale it is imperative that we shed more light on how this loss of diversity will affect the functioning and functions of ecosystems. Previous research on biodiversity and ecosystem functioning has shown that plant biodiversity often has a positive relationship to net primary productivity (NPP), and/or net ecosystem productivity (NEP), particularly in temperate grassland systems (Hector et al 2002). One of the big ensuing questions is whether plant diversity also affects nutrient cycling and biogeochemical cycles in ecosystems. A more detailed look at the dynamics of carbon and water-use changes caused by plant diversity has only recently occurred (Caldeira et al 2001) but there is still much work to be done in this area. A large-scale grassland experiment entitled "The Jena Experiment" was started in spring 2002 in Germany in order to investigate the effect of plant diversity on ecosystem functioning, focussing mainly on element cycling and trophic interactions. Out of a total species pool of 60 species mixtures of 1 to 16 species and one to four functional groups were randomly selected and seeded as newly established communities on 82 plots of 20 x 20 m. The four functional groups consist of grasses, small and tall herbs, and legume species. With the use of natural abundance stable isotope ratios (?13C and ? 15N) in aboveground plant material, the relationship between plant diversity (both functional and species-driven) and productivity, water-use efficiency and nitrogen cycling was investigated. Results so far, show increased above-ground productivity with increasing species diversity as well as with increasing functional diversity of plants in a system. At community level, both carbon and nitrogen concentrations as well as ?13C in plants remained similar across the diversity gradient. In contrast we found a decrease in ? 15N values with increasing plant diversity. This suggests that bigger total carbon pools in more diverse systems can be attributed only to higher biomass, whereas some form of fractionation of ? 15N seems to be occurring during N uptake or in the soil in the most species-rich systems. Soil carbon also did not tend to respond to plant diversity levels. At the whole system scale there was no evidence for changes in water-use efficiency over the diversity gradient. Implications for the functioning of future grassland systems with reduced diversity will be discussed. References Caldeira, M. C., R. J. Ryel, et al. (2001) Mechanisms of positive biodiversity-production relationships: insights provided by delta C-13 analysis in experimental Mediterranean grassland plots. Ecology Letters 4(5): 439-443. Hector, A., E. Bazeley-White, et al. (2002). Overyielding in grassland communities: testing the sampling effect hypothesis with replicated biodiversity experiments. Ecology Letters 5(4): 502-511.

  11. Phylogenetic, Microbiological, and Glycoside Hydrolase Diversities within the Extremely Thermophilic, Plant Biomass-Degrading Genus Caldicellulosiruptor?

    PubMed Central

    Blumer-Schuette, Sara E.; Lewis, Derrick L.; Kelly, Robert M.

    2010-01-01

    Phylogenetic, microbiological, and comparative genomic analyses were used to examine the diversity among members of the genus Caldicellulosiruptor, with an eye toward the capacity of these extremely thermophilic bacteria to degrade the complex carbohydrate content of plant biomass. Seven species from this genus (C. saccharolyticus, C. bescii, C. hydrothermalis, C. owensensis, C. kronotskyensis, C. lactoaceticus, and C. kristjanssonii) were compared on the basis of 16S rRNA gene phylogeny and cross-species DNA-DNA hybridization to a whole-genome C. saccharolyticus oligonucleotide microarray, revealing that C. saccharolyticus was the most divergent within this group. Growth physiology of the seven Caldicellulosiruptor species on a range of carbohydrates showed that, while all could be cultivated on acid-pretreated switchgrass, only C. saccharolyticus, C. bescii, C. kronotskyensis, and C. lactoaceticus were capable of hydrolyzing Whatman no. 1 filter paper. Two-dimensional gel electrophoresis of the secretomes from cells grown on microcrystalline cellulose revealed that the cellulolytic species also had diverse secretome fingerprints. The C. saccharolyticus secretome contained a prominent S-layer protein that appears in the cellulolytic Caldicellulosiruptor species, suggesting a possible role in cell-substrate interactions. Growth physiology also correlated with glycoside hydrolase (GH) and carbohydrate-binding module (CBM) inventories for the seven bacteria, as deduced from draft genome sequence information. These inventories indicated that the absence of a single GH and CBM family was responsible for diminished cellulolytic capacity. Overall, the genus Caldicellulosiruptor appears to contain more genomic and physiological diversity than previously reported, and this argues for continued efforts to isolate new members from high-temperature terrestrial biotopes. PMID:20971878

  12. Cross-Scale Analysis of the Region Effect on Vascular Plant Species Diversity in Southern and Northern European Mountain Ranges

    PubMed Central

    Lenoir, Jonathan; Gégout, Jean-Claude; Guisan, Antoine; Vittoz, Pascal; Wohlgemuth, Thomas; Zimmermann, Niklaus E.; Dullinger, Stefan; Pauli, Harald; Willner, Wolfgang; Grytnes, John-Arvid; Virtanen, Risto; Svenning, Jens-Christian

    2010-01-01

    Background The divergent glacial histories of southern and northern Europe affect present-day species diversity at coarse-grained scales in these two regions, but do these effects also penetrate to the more fine-grained scales of local communities? Methodology/Principal Findings We carried out a cross-scale analysis to address this question for vascular plants in two mountain regions, the Alps in southern Europe and the Scandes in northern Europe, using environmentally paired vegetation plots in the two regions (n?=?403 in each region) to quantify four diversity components: (i) total number of species occurring in a region (total ?-diversity), (ii) number of species that could occur in a target plot after environmental filtering (habitat-specific ?-diversity), (iii) pair-wise species compositional turnover between plots (plot-to-plot ?-diversity) and (iv) number of species present per plot (plot ?-diversity). We found strong region effects on total ?-diversity, habitat-specific ?-diversity and plot-to-plot ?-diversity, with a greater diversity in the Alps even towards distances smaller than 50 m between plots. In contrast, there was a slightly greater plot ?-diversity in the Scandes, but with a tendency towards contrasting region effects on high and low soil-acidity plots. Conclusions/Significance We conclude that there are strong regional differences between coarse-grained (landscape- to regional-scale) diversity components of the flora in the Alps and the Scandes mountain ranges, but that these differences do not necessarily penetrate to the finest-grained (plot-scale) diversity component, at least not on acidic soils. Our findings are consistent with the contrasting regional Quaternary histories, but we also consider alternative explanatory models. Notably, ecological sorting and habitat connectivity may play a role in the unexpected limited or reversed region effect on plot ?-diversity, and may also affect the larger-scale diversity components. For instance, plot connectivity and/or selection for high dispersal ability may increase plot ?-diversity and compensate for low total ?-diversity. PMID:21203521

  13. Novel Symbiotic Protoplasts Formed by Endophytic Fungi Explain Their Hidden Existence, Lifestyle Switching, and Diversity within the Plant Kingdom

    PubMed Central

    Atsatt, Peter R.; Whiteside, Matthew D.

    2014-01-01

    Diverse fungi live all or part of their life cycle inside plants as asymptomatic endophytes. While endophytic fungi are increasingly recognized as significant components of plant fitness, it is unclear how they interact with plant cells; why they occur throughout the fungal kingdom; and why they are associated with most fungal lifestyles. Here we evaluate the diversity of endophytic fungi that are able to form novel protoplasts called mycosomes. We found that mycosomes cultured from plants and phylogenetically diverse endophytic fungi have common morphological characteristics, express similar developmental patterns, and can revert back to the free-living walled state. Observed with electron microscopy, mycosome ontogeny within Aureobasidium pullulans may involve two organelles: double membrane-bounded promycosome organelles (PMOs) that form mycosomes, and multivesicular bodies that may form plastid-infecting vesicles. Cultured mycosomes also contain a double membrane-bounded organelle, which may be homologous to the A. pullulans PMO. The mycosome PMO is often expressed as a vacuole-like organelle, which alternatively may contain a lipoid body or a starch grain. Mycosome reversion to walled cells occurs within the PMO, and by budding from lipid or starch-containing mycosomes. Mycosomes discovered in chicken egg yolk provided a plant-independent source for analysis: they formed typical protoplast stages, contained fungal ITS sequences and reverted to walled cells, suggesting mycosome symbiosis with animals as well as plants. Our results suggest that diverse endophytic fungi express a novel protoplast phase that can explain their hidden existence, lifestyle switching, and diversity within the plant kingdom. Importantly, our findings outline “what, where, when and how”, opening the way for cell and organelle-specific tests using in situ DNA hybridization and fluorescent labels. We discuss developmental, ecological and evolutionary contexts that provide a robust framework for continued tests of the mycosome phase hypothesis. PMID:24777121

  14. Mycorrhizal fungi of Vanilla: diversity, specificity and effects on seed germination and plant growth.

    PubMed

    Porras-Alfaro, Andrea; Bayman, Paul

    2007-01-01

    Mycorrhizal fungi are essential for the germination of orchid seeds. However, the specificity of orchids for their mycorrhizal fungi and the effects of the fungi on orchid growth are controversial. Mycorrhizal fungi have been studied in some temperate and tropical, epiphytic orchids, but the symbionts of tropical, terrestrial orchids are still unknown. Here we study diversity, specificity and function of mycorrhizal fungi in Vanilla, a pantropical genus that is both terrestrial and epiphytic. Mycorrhizal roots were collected from four Vanilla species in Puerto Rico, Costa Rica and Cuba. Cultured and uncultured mycorrhizal fungi were identified by sequencing the internal transcribed spacer region of nuclear rDNA (nrITS) and part of the mitochondrial ribosomal large subunit (mtLSU), and by counting number of nuclei in hyphae. Vanilla spp. were associated with a wide range of mycorrhizal fungi: Ceratobasidium, Thanatephorus and Tulasnella. Related fungi were found in different species of Vanilla, although at different relative frequencies. Ceratobasidium was more common in roots in soil and Tulasnella was more common in roots on tree bark, but several clades of fungi included strains from both substrates. Relative frequencies of genera of mycorrhizal fungi differed significantly between cultured fungi and those detected by direct amplification. Ceratobasidium and Tulasnella were tested for effects on seed germination of Vanilla and effects on growth of Vanilla and Dendrobium plants. We found significant differences among fungi in effects on seed germination and plant growth. Effects of mycorrhizal fungi on Vanilla and Dendrobium were similar: a clade of Ceratobasidium had a consistently positive effect on plant growth and seed germination. This clade has potential use in germination and propagation of orchids. Results confirmed that a single orchid species can be associated with several mycorrhizal fungi with different functional consequences for the plant. PMID:18065002

  15. Direct Anthelmintic Effects of Condensed Tannins from Diverse Plant Sources against Ascaris suum

    PubMed Central

    Williams, Andrew R.; Fryganas, Christos; Ramsay, Aina; Mueller-Harvey, Irene; Thamsborg, Stig M.

    2014-01-01

    Ascaris suum is one of the most prevalent nematode parasites in pigs and causes significant economic losses, and also serves as a good model for A. lumbricoides, the large roundworm of humans that is ubiquitous in developing countries and causes malnutrition, stunted growth and compromises immunity to other pathogens. New treatment options for Ascaris infections are urgently needed, to reduce reliance on the limited number of synthetic anthelmintic drugs. In areas where Ascaris infections are common, ethno-pharmacological practices such as treatment with natural plant extracts are still widely employed. However, scientific validation of these practices and identification of the active compounds are lacking, although observed effects are often ascribed to plant secondary metabolites such as tannins. Here, we extracted, purified and characterised a wide range of condensed tannins from diverse plant sources and investigated anthelmintic effects against A. suum in vitro. We show that condensed tannins can have potent, direct anthelmintic effects against A. suum, as evidenced by reduced migratory ability of newly hatched third-stage larvae and reduced motility and survival of fourth-stage larvae recovered from pigs. Transmission electron microscopy showed that CT caused significant damage to the cuticle and digestive tissues of the larvae. Furthermore, we provide evidence that the strength of the anthelmintic effect is related to the polymer size of the tannin molecule. Moreover, the identity of the monomeric structural units of tannin polymers may also have an influence as gallocatechin and epigallocatechin monomers exerted significant anthelmintic activity whereas catechin and epicatechin monomers did not. Therefore, our results clearly document direct anthelmintic effects of condensed tannins against Ascaris and encourage further in vivo investigation to determine optimal strategies for the use of these plant compounds for the prevention and/or treatment of ascariosis. PMID:24810761

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

    PubMed Central

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

    2012-01-01

    North Sinai deserts were surveyed for the predominant plant cover and for the culturable bacteria nesting their roots and shoots. Among 43 plant species reported, 13 are perennial (e.g. Fagonia spp., Pancratium spp.) and 30 annuals (e.g. Bromus spp., Erodium spp.). Eleven species possessed rhizo-sheath, e.g. Cyperus capitatus, Panicum turgidum and Trisetaria koelerioides. Microbiological analyses demonstrated: the great diversity and richness of associated culturable bacteria, in particular nitrogen-fixing bacteria (diazotrophs); the majority of bacterial residents were of true and/or putative diazotrophic nature; the bacterial populations followed an increasing density gradient towards the root surfaces; sizeable populations were able to reside inside the root (endorhizosphere) and shoot (endophyllosphere) tissues. Three hundred bacterial isolates were secured from studied spheres. The majority of nitrogen-fixing bacilli isolates belonged to Bacillus megaterium,Bacillus pumilus, Bacillus polymexa,Bacillus macerans,Bacillus circulans and Bacillus licheniformis. The family Enterobacteriaceae represented by Enterobacter agglomerans,Enterobacter sackazakii, Enterobacter cloacae, Serratia adorifera,Serratia liquefaciens and Klebsiella oxytoca. The non-Enterobacteriaceae population was rich in Pantoae spp., Agrobacterium rdiobacter, Pseudomonas vesicularis, Pseudomonas putida, Stenotrophomonas maltophilia, Ochrobactrum anthropi, Sphingomonas paucimobilis and Chrysemonas luteola.Gluconacetobacter diazotrophicus were reported inside root and shoot tissues of a number of tested plants. The dense bacterial populations reported speak well to the very possible significant role played by the endophytic bacterial populations in the survival, in respect of nutrition and health, of existing plants. Such groups of diazotrophs are good candidates, as bio-preparates, to support the growth of future field crops grown in deserts of north Sinai and irrigated by the water of El-Salam canal. PMID:25685397

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

    PubMed Central

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

    2015-01-01

    Intraspecific genetic variation in natural populations governs their potential to overcome challenging ecological and environmental conditions. In addition, knowledge of this variation is critical for the conservation and management of endangered plant taxa. Found in the Himalayas, Podophyllum hexandrum is an endangered high-elevation plant species that has great medicinal importance. Here we report on the genetic diversity analysis of 24 P. hexandrum populations (209 individuals), representing the whole of the Indian Himalayas. In the present study, seven amplified fragment length polymorphism (AFLP) primer pairs generated 1677 fragments, of which 866 were found to be polymorphic. Neighbour joining clustering, principal coordinate analysis and STRUCTURE analysis clustered 209 individuals from 24 populations of the Indian Himalayan mountains into two major groups with a significant amount of gene flow (Nm = 2.13) and moderate genetic differentiation Fst(0.196), G?st(0.20). This suggests that, regardless of geographical location, all of the populations from the Indian Himalayas are intermixed and are composed broadly of two types of genetic populations. High variance partitioned within populations (80 %) suggests that most of the diversity is restricted to the within-population level. These results suggest two possibilities about the ancient population structure of P. hexandrum: either all of the populations in the geographical region of the Indian Himalayas are remnants of a once-widespread ancient population, or they originated from two types of genetic populations, which coexisted a long time ago, but subsequently separated as a result of long-distance dispersal and natural selection. High variance partitioned within the populations indicates that these populations have evolved in response to their respective environments over time, but low levels of heterozygosity suggest the presence of historical population bottlenecks. PMID:25416728

  18. Temperature alone does not explain phenological variation of diverse temperate plants under experimental warming.

    PubMed

    Marchin, Renée M; Salk, Carl F; Hoffmann, William A; Dunn, Robert R

    2015-08-01

    Anthropogenic climate change has altered temperate forest phenology, but how these trends will play out in the future is controversial. We measured the effect of experimental warming of 0.6-5.0 °C on the phenology of a diverse suite of 11 plant species in the deciduous forest understory (Duke Forest, North Carolina, USA) in a relatively warm year (2011) and a colder year (2013). Our primary goal was to dissect how temperature affects timing of spring budburst, flowering, and autumn leaf coloring for functional groups with different growth habits, phenological niches, and xylem anatomy. Warming advanced budburst of six deciduous woody species by 5-15 days and delayed leaf coloring by 18-21 days, resulting in an extension of the growing season by as much as 20-29 days. Spring temperature accumulation was strongly correlated with budburst date, but temperature alone cannot explain the diverse budburst responses observed among plant functional types. Ring-porous trees showed a consistent temperature response pattern across years, suggesting these species are sensitive to photoperiod. Conversely, diffuse-porous species responded differently between years, suggesting winter chilling may be more important in regulating budburst. Budburst of the ring-porous Quercus alba responded nonlinearly to warming, suggesting evolutionary constraints may limit changes in phenology, and therefore productivity, in the future. Warming caused a divergence in flowering times among species in the forest community, resulting in a longer flowering season by 10-16 days. Temperature was a good predictor of flowering for only four of the seven species studied here. Observations of interannual temperature variability overpredicted flowering responses in spring-blooming species, relative to our warming experiment, and did not consistently predict even the direction of flowering shifts. Experiments that push temperatures beyond historic variation are indispensable for improving predictions of future changes in phenology. PMID:25736981

  19. An Assessment of Urea-Formaldehyde Fertilizer on the Diversity of Bacterial Communities in Onion and Sugar Beet

    PubMed Central

    Ikeda, Seishi; Suzuki, Keijiro; Kawahara, Makoto; Noshiro, Masao; Takahashi, Naokazu

    2014-01-01

    The impact of a urea-formaldehyde (UF) fertilizer on bacterial diversity in onion bulbs and main roots of sugar beet were examined using a 16S rRNA gene clone library. The UF fertilizer markedly increased bacterial diversity in both plants. The results of principal coordinates analysis (PCoA) revealed that nearly 30% of the variance observed in bacterial diversity in both the onion and sugar beet was attributed to the fertilization conditions and also that the community structures in both plants shifted unidirectionally in response to the UF fertilizer. PMID:24882062

  20. An assessment of urea-formaldehyde fertilizer on the diversity of bacterial communities in onion and sugar beet.

    PubMed

    Ikeda, Seishi; Suzuki, Keijiro; Kawahara, Makoto; Noshiro, Masao; Takahashi, Naokazu

    2014-01-01

    The impact of a urea-formaldehyde (UF) fertilizer on bacterial diversity in onion bulbs and main roots of sugar beet were examined using a 16S rRNA gene clone library. The UF fertilizer markedly increased bacterial diversity in both plants. The results of principal coordinates analysis (PCoA) revealed that nearly 30% of the variance observed in bacterial diversity in both the onion and sugar beet was attributed to the fertilization conditions and also that the community structures in both plants shifted unidirectionally in response to the UF fertilizer. PMID:24882062

  1. Exploring the Diversity of Plant DNA Viruses and Their Satellites Using Vector-Enabled Metagenomics on Whiteflies

    PubMed Central

    Ng, Terry Fei Fan; Duffy, Siobain; Polston, Jane E.; Bixby, Elise; Vallad, Gary E.; Breitbart, Mya

    2011-01-01

    Current knowledge of plant virus diversity is biased towards agents of visible and economically important diseases. Less is known about viruses that have not caused major diseases in crops, or viruses from native vegetation, which are a reservoir of biodiversity that can contribute to viral emergence. Discovery of these plant viruses is hindered by the traditional approach of sampling individual symptomatic plants. Since many damaging plant viruses are transmitted by insect vectors, we have developed “vector-enabled metagenomics” (VEM) to investigate the diversity of plant viruses. VEM involves sampling of insect vectors (in this case, whiteflies) from plants, followed by purification of viral particles and metagenomic sequencing. The VEM approach exploits the natural ability of highly mobile adult whiteflies to integrate viruses from many plants over time and space, and leverages the capability of metagenomics for discovering novel viruses. This study utilized VEM to describe the DNA viral community from whiteflies (Bemisia tabaci) collected from two important agricultural regions in Florida, USA. VEM successfully characterized the active and abundant viruses that produce disease symptoms in crops, as well as the less abundant viruses infecting adjacent native vegetation. PCR assays designed from the metagenomic sequences enabled the complete sequencing of four novel begomovirus genome components, as well as the first discovery of plant virus satellites in North America. One of the novel begomoviruses was subsequently identified in symptomatic Chenopodium ambrosiodes from the same field site, validating VEM as an effective method for proactive monitoring of plant viruses without a priori knowledge of the pathogens. This study demonstrates the power of VEM for describing the circulating viral community in a given region, which will enhance our understanding of plant viral diversity, and facilitate emerging plant virus surveillance and management of viral diseases. PMID:21544196

  2. ASSESSMENT REPORT FOR MPS IN PLANT PROTECTION OF AGRICULTURAL CROPS

    E-print Network

    Chen, Tsuhan

    ASSESSMENT REPORT FOR MPS IN PLANT PROTECTION OF AGRICULTURAL CROPS 1. Goals for Student Learning, and weed science. 2. Design and employ pest control strategies based on a thorough understanding of a crop of agricultural crops 5. Be able to convey pest management information to growers and advise them in making

  3. The Jena Diversity-Dynamic Global Vegetation Model (JeDi-DGVM): a diverse approach to representing terrestrial biogeography and biogeochemistry based on plant functional trade-offs

    NASA Astrophysics Data System (ADS)

    Pavlick, R.; Drewry, D. T.; Bohn, K.; Reu, B.; Kleidon, A.

    2013-06-01

    Terrestrial biosphere models typically abstract the immense diversity of vegetation forms and functioning into a relatively small set of predefined semi-empirical plant functional types (PFTs). There is growing evidence, however, from the field ecology community as well as from modelling studies that current PFT schemes may not adequately represent the observed variations in plant functional traits and their effect on ecosystem functioning. In this paper, we introduce the Jena Diversity-Dynamic Global Vegetation Model (JeDi-DGVM) as a new approach to terrestrial biosphere modelling with a richer representation of functional diversity than traditional modelling approaches based on a small number of fixed PFTs. JeDi-DGVM simulates the performance of a large number of randomly generated plant growth strategies, each defined by a set of 15 trait parameters which characterize various aspects of plant functioning including carbon allocation, ecophysiology and phenology. Each trait parameter is involved in one or more functional trade-offs. These trade-offs ultimately determine whether a strategy is able to survive under the climatic conditions in a given model grid cell and its performance relative to the other strategies. The biogeochemical fluxes and land surface properties of the individual strategies are aggregated to the grid-cell scale using a mass-based weighting scheme. We evaluate the simulated global biogeochemical patterns against a variety of field and satellite-based observations following a protocol established by the Carbon-Land Model Intercomparison Project. The land surface fluxes and vegetation structural properties are reasonably well simulated by JeDi-DGVM, and compare favourably with other state-of-the-art global vegetation models. We also evaluate the simulated patterns of functional diversity and the sensitivity of the JeDi-DGVM modelling approach to the number of sampled strategies. Altogether, the results demonstrate the parsimonious and flexible nature of a functional trade-off approach to global vegetation modelling, i.e. it can provide more types of testable outputs than standard PFT-based approaches and with fewer inputs. The approach implemented here in JeDi-DGVM sets the foundation for future applications that will explore the impacts of explicitly resolving diverse plant communities, allowing for a more flexible temporal and spatial representation of the structure and function of the terrestrial biosphere.

  4. Quantifying the importance of plant functional diversity for ecosystem functioning and resilience under scenarios of climate change (Invited)

    NASA Astrophysics Data System (ADS)

    Pavlick, R.; Drewry, D.; Kleidon, A.

    2013-12-01

    Dynamic Global Vegetation Models (DGVMs) typically employ only a small set of Plant Functional Types (PFTs) to represent the vast diversity of observed vegetation forms and functioning. There is growing evidence, however, that this abstraction may not adequately represent the observed variation in plant functional traits, which is thought to play an important role for many ecosystem functions and for ecosystem resilience to environmental change. The geographic distribution of PFTs in these models is also often based on empirical relationships between present-day climate and vegetation patterns. Projections of future climate change, however, point toward the possibility of novel regional climates, which could lead to no-analog vegetation compositions incompatible with the PFT paradigm. Here, we present results from the Jena Diversity-DGVM (JeDi-DGVM), a novel traits-based vegetation model, which simulates a large number of hypothetical plant growth strategies constrained by functional tradeoffs, thereby allowing for a more flexible temporal and spatial representation of the terrestrial biosphere. We run two sets of model experiments forced with the latest bias-corrected climate change scenarios from several different global climate models. In the first set, we simulate a diverse biosphere using a large number of plant growth strategies, allowing the modelled ecosystems to adapt through emergent changes in ecosystem composition. We then aggregate the surviving growth strategies from the first set of diverse simulations to a small number of biome-averaged growth strategies, recreating something akin to PFTs. We use this smaller set of PFT-like growth strategies to represent a sparse or low-diversity biosphere in the second set of model experiments. We quantify the importance of functional diversity by comparing key metrics of ecosystem functioning across the two sets of simulations. The results reveal the implications of using the common PFT vegetation modelling paradigm versus a more diverse approach and may help to quantify the value of biodiversity conservation efforts.

  5. Diversity of Endophytic Fungi Associated with the Roots of Four Aquatic Plants Inhabiting Two Wetlands in Korea

    PubMed Central

    You, Young-Hyun; Park, Jong Myong; Park, Jong-Han

    2015-01-01

    A total of 4 aquatic plants, Eleocharis kuroguwai Ohwi, Hydrocharis dubia Backer, Salvinia natans All., and Zizania latifolia Turcz., were sampled from representative two wetlands of South Korea. A total of 38 endophytic fungal strains were isolated from aquatic plants native to the Daepyeong wetland, and 27 strains were isolated from the Jilnal wetland. The internal transcribed spacer regions of fungal isolates were sequenced and a phylogenetic analysis was performed. In addition, endophytic fungal diversity from each wetland and host plant species was deduced. A total of 25 fungal genera were purely isolated, and 16 fungal genera were isolated from each of the two wetlands. Commonly isolated genera from both wetlands were Aspergillus, Cladosporium, Clonostachys, Fusarium, Leptosphaeria, Penicillium, and Talaromyces. This study revealed that fungal diversity varied with environmental conditions and by host plant in representative two wetlands. PMID:26539039

  6. Predicting Plant Diversity Patterns in Madagascar: Understanding the Effects of Climate and Land Cover Change in a Biodiversity Hotspot

    PubMed Central

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

    2015-01-01

    Climate and land cover change are driving a major reorganization of terrestrial biotic communities in tropical ecosystems. In an effort to understand how biodiversity patterns in the tropics will respond to individual and combined effects of these two drivers of environmental change, we use species distribution models (SDMs) calibrated for recent climate and land cover variables and projected to future scenarios to predict changes in diversity patterns in Madagascar. We collected occurrence records for 828 plant genera and 2186 plant species. We developed three scenarios, (i.e., climate only, land cover only and combined climate-land cover) based on recent and future climate and land cover variables. We used this modelling framework to investigate how the impacts of changes to climate and land cover influenced biodiversity across ecoregions and elevation bands. There were large-scale climate- and land cover-driven changes in plant biodiversity across Madagascar, including both losses and gains in diversity. The sharpest declines in biodiversity were projected for the eastern escarpment and high elevation ecosystems. Sharp declines in diversity were driven by the combined climate-land cover scenarios; however, there were subtle, region-specific differences in model outputs for each scenario, where certain regions experienced relatively higher species loss under climate or land cover only models. We strongly caution that predicted future gains in plant diversity will depend on the development and maintenance of dispersal pathways that connect current and future suitable habitats. The forecast for Madagascar’s plant diversity in the face of future environmental change is worrying: regional diversity will continue to decrease in response to the combined effects of climate and land cover change, with habitats such as ericoid thickets and eastern lowland and sub-humid forests particularly vulnerable into the future. PMID:25856241

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

    PubMed

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

    2015-01-01

    Climate and land cover change are driving a major reorganization of terrestrial biotic communities in tropical ecosystems. In an effort to understand how biodiversity patterns in the tropics will respond to individual and combined effects of these two drivers of environmental change, we use species distribution models (SDMs) calibrated for recent climate and land cover variables and projected to future scenarios to predict changes in diversity patterns in Madagascar. We collected occurrence records for 828 plant genera and 2186 plant species. We developed three scenarios, (i.e., climate only, land cover only and combined climate-land cover) based on recent and future climate and land cover variables. We used this modelling framework to investigate how the impacts of changes to climate and land cover influenced biodiversity across ecoregions and elevation bands. There were large-scale climate- and land cover-driven changes in plant biodiversity across Madagascar, including both losses and gains in diversity. The sharpest declines in biodiversity were projected for the eastern escarpment and high elevation ecosystems. Sharp declines in diversity were driven by the combined climate-land cover scenarios; however, there were subtle, region-specific differences in model outputs for each scenario, where certain regions experienced relatively higher species loss under climate or land cover only models. We strongly caution that predicted future gains in plant diversity will depend on the development and maintenance of dispersal pathways that connect current and future suitable habitats. The forecast for Madagascar's plant diversity in the face of future environmental change is worrying: regional diversity will continue to decrease in response to the combined effects of climate and land cover change, with habitats such as ericoid thickets and eastern lowland and sub-humid forests particularly vulnerable into the future. PMID:25856241

  8. Effects of plant diversity, N fertilization, and elevated carbon dioxide on grassland soil N cycling in a

    E-print Network

    Thomas, David D.

    Effects of plant diversity, N fertilization, and elevated carbon dioxide on grassland soil N cycling in a long-term experiment K E V I N E . M U E L L E R * , S A R A H E . H O B B I E * , D A V I D evaluated how elevated atmospheric carbon dioxide (CO2), N fertilization, and plant species richness alter

  9. Documenting and comparing plant species diversity by using numerical and parametric methods in Khaje Kalat, NE Iran.

    PubMed

    Ejtehadi, H; Soltani, R; Zahedi Pour, H

    2007-10-15

    The aim was to examine and document several aspects of numerical diversity such as species richness, species diversity and evenness and to compare diversity in different slope aspects of the area by using numerical and parametric methods. About 193 quadrats of 4 m2 were located according to the nature of vegetation. Species composition and their abundance were recorded in a two-year period (2005 to 2006). The result of field investigation was collecting and identifying of the total 225 plant species belonging to 154 genera and 37 families. The abundance data were subjected to analyses by specific diversity packages to characterize and obtain numerical indices (Shannon, Simpson, Brillouin, McIntosh, etc.,) and parametric families of species diversity. Numerical indices were calculated and documented for monitoring purposes. The results of diversity in main slope aspects (N, S, E, W) showed higher species richness and species diversity indices in the north aspect than in the others but it was not true with evenness indices. About 30 species such as Acanthophyllum glandulosum, Acroptilon repens, Alcea tiliacea, Bromus sericeous, Astragalus turbinatus, Centaurea balsamita etc., were detected exclusively in the north aspect. This can be important in reducing the evenness. Diversity comparing by using rank-abundance plot as well as diversity ordering of Hill, Renyi and Patil and Taillie confirmed high species diversity in the north yet the result of ANOVA showed no significant differences in the four aspects. The result of diversity based on the models revealed that the whole area, the south and the west aspects follow lognormal distribution, north aspect follows logarithmic whereas the east follows both lognormal and logarithmic distribution. In other word, a shift from being lognormal to logarithmic model was observed in the east aspect. PMID:19093482

  10. Tiger Team Assessment of the Pantex Plant, Amarillo, Texas

    SciTech Connect

    Not Available

    1990-02-01

    This document contains the findings and associated root causes identified during the Tiger Team Assessment of the Department of Energy's (DOE) Pantex Plant in Amarillo, Texas. This assessment was conducted by the Department's Office of Environment, Safety and Health between October 2 and 31, 1989. The scope of the assessment of the Pantex Plant covered all areas of environment, safety and health (ES H) activities, including compliance with federal, state, and local regulations, requirements, permits, agreements, orders and consent decrees, and DOE ES H Orders. The assessment also included an evaluation of the adequacy of DOE and site contractor ES H management programs. The draft findings were submitted to the Office of Defense Programs, the Albuquerque Operations Office, the Amarillo Area Office, and regulatory agencies at the conclusion of the on-site assessment activities for review and comment on technical accuracy. Final modifications and any other appropriate changes have been incorporated in the final report. The Tiger Team Assessment of the Pantex Plant is part of the larger Tiger Team Assessment program which will encompass over 100 DOE operating facilities. The assessment program is part of a 10-point initiative announced by Secretary of Energy James D. Watkins on June 27, 1989, to strengthen environmental protection and waste management activities in the Department. The results of the program will provide the Secretary with information on the compliance status of DOE facilities with regard to ES H requirements, root causes for noncompliance, adequacy of DOE and site contractor ES H management programs, and DOE-wide ES H compliance trends.

  11. Medicinal parasitic plants on diverse hosts with their usages and barcodes.

    PubMed

    Kwanda, Nantiya; Noikotr, Kowit; Sudmoon, Runglawan; Tanee, Tawatchai; Chaveerach, Arunrat

    2013-07-01

    Medicinal properties of parasitic plants were investigated by means of ethnobotanical study in some areas of northeastern Thailand. Important traditional usages are: Scurrula atropurpurea nourishes blood, Dendrophthoe pentandra decreases high blood pressure, and Helixanthera parasitica treats liver disease. Their systematics were also determined. The research is based on findings obtained from 100 parasite-host pairs. Of these, eight parasitic species were recorded; they are members of two families, viz. family Loranthaceae, namely D. lanosa, D. pentandra, H. parasitica, Macrosolen brandisianus, M. cochinchinensis and S. atropurpurea, and family Viscaceae, namely Viscum articulatum and V. ovalifolium. In addition, each parasitic species is found on diverse hosts, indicating non-host-parasitic specificity. Species-specific tagging of all species studied was carried out using the rbcL and psbA-trnH chloroplast regions. These tag sequences are submitted to GenBank databases under accession numbers JN687563-JN687578. Genetic distances calculated from nucleotide variations in a couple of species of each genus, Dendrophthoe, Macrosolen, and Viscum, were 0.032, 0.067 and 0.036 in the rbcL region, and 0.269, 0.073 and 0.264 in the psbA-trnH spacer region, respectively. These variations will be used for further identification of incomplete plant parts or other forms such as capsule, powder, dried or chopped pieces. PMID:22864809

  12. Fungal diversity in the rhizosphere of endemic plant species of Tenerife (Canary Islands): relationship to vegetation zones and environmental factors.

    PubMed

    Zachow, Christin; Berg, Christian; Müller, Henry; Meincke, Remo; Komon-Zelazowska, Monika; Druzhinina, Irina S; Kubicek, Christian P; Berg, Gabriele

    2009-01-01

    Knowledge about fungal diversity scaling relationships relative to that of plants is important to understand ecosystem functioning. Tenerife Island, a natural laboratory to study terrestrial biodiversity, is represented by six different vegetation zones characterized by specific abiotic conditions and plant communities with a high proportion of endemic plants. Little is known about the biodiversity of associated fungi. To understand the relationship between plant and fungal communities, we analysed soil/rhizosphere fungi from all vegetation zones. From 12 sampling points dispersed on the whole island, molecular analysis of fungal communities was determined by single-strand conformation polymorphism (SSCP) analysis using universal and specific primers for Trichoderma. The highly diverse fungal communities were mainly characterized by ectomycorrhiza-forming Basidiomycota and a high proportion of yet-unidentified species. Besides, Trichoderma-specific SSCP resulted in low diversity of mainly cosmopolitan species, for example Hypocrea lixii/T. harzianum. The dominance of T. harzianum was confirmed by cultivation. All Trichoderma isolates show an extraordinarily high antagonistic potential towards different groups of plant pathogens, supporting the hypothesis of extensive colonization by highly competitive Trichoderma species from the continent. In contrast, biodiversity patterns of the whole fungal and plant communities follow the same ecological rules. Furthermore, a high statistical correlation between fungal communities and the main environmental factors, temperature and precipitation, was found. PMID:18830279

  13. Biophysical methods for assessing plant responses to nanoparticle exposure.

    PubMed

    Ratnikova, Tatsiana A; Chen, Ran; Bhattacharya, Priyanka; Ke, Pu Chun

    2012-01-01

    As nanotechnology rapidly emerges into a new industry-driven by its enormous potential to revolutionize electronics, materials, and medicine-exposure of living species to discharged nanoparticles has become inevitable. Despite the increased effort on elucidating the environmental impact of nanotechnology, literature on higher plants exposure to nanoparticles remains scarce and often contradictory. Here we present our biophysical methodologies for the study of carbon nanoparticle uptake by Allium cepa cells and rice plants. We address the three essential aspects for such studies: identification of carbon nanoparticles in the plant species, quantification of nanotransport and aggregation in the plant compartments, and evaluation of plant responses to nanoparticle exposure on the cellular and organism level. Considering the close connection between plant and mammalian species in ecological systems especially in the food chain, we draw a direct comparison on the uptake of carbon nanoparticles in plant and mammalian cells. In addition to the above studies, we present methods for assessing the effects of quantum dot adsorption on algal photosynthesis. PMID:22975977

  14. Safety assessment: Pinellas Plant Child Development Center/Partnership School

    SciTech Connect

    Not Available

    1990-06-21

    This document describes the Child Development Center/Partnership School and its unique relationship to the Pinellas Plant. The school and its operation are described in detail, along with the administrative and engineering controls in place to ensure the safety of the facility. Special emphasis is placed on the analyses of potential risks to school operations and personnel which may be posed by their close proximity to the plant. A recent Safety Systems Management Assay (SSMA) was used as a guide in describing both routine operations and potential credible accident scenarios at the Pinellas Plant site. The Safety Assessment concluded that, although potential accidents at the Pinellas Plant could result in injury to personnel on the school site, the low probability of these incidents would make operation of the school an acceptable risk. The risks associated with routine operations at the plant are similar to those encountered at a large-scale electronics manufacturing plant. Numerous safeguards are in place to limit the effects of any credible accident on the Pinellas Plant and school site. 32 refs., 18 figs., 33 tabs.

  15. Fungal Endophyte Diversity and Bioactivity in the Indian Medicinal Plant Ocimum sanctum Linn

    PubMed Central

    Chowdhary, Kanika; Kaushik, Nutan

    2015-01-01

    Endophytic mycopopulation isolated from India’s Queen of herbs Tulsi (Ocimum sanctum) were explored and investigated for their diversity and antiphytopathogenic activity against widespread plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani and Fusarium oxysporum. 90 fungal isolates, representing 17 genera were recovered from 313 disease-free and surface sterilised plant segments (leaf and stem tissues) from three different geographic locations (Delhi, Hyderabad and Mukteshwar) during distinct sampling times in consequent years 2010 and 2011 in India. Fungal endophytes were subjected to molecular identification based on rDNA ITS sequence analysis. Plant pathogens such as F. verticillioides, B. maydis, C. coarctatum, R. bataticola, Hypoxylon sp., Diaporthe phaseolorum, Alternaria tenuissima and A. alternata have occurred as endophyte only during second sampling (second sampling in 2011) in the present study. Bi-plot generated by principal component analysis suggested tissue specificity of certain fungal endophytes. Dendrogram revealed species abundance as a function of mean temperature of the location at the time of sampling. Shannon diversity in the first collection is highest in Hyderabad leaf tissues (H' = 1.907) whereas in second collection it was highest from leaf tissues of Delhi (H' = 1.846). Mukteshwar (altitude: 7500 feet) reported least isolation rate in second collection. Nearly 23% of the total fungal isolates were considered as potent biocontrol agent. Hexane extract of M. phaseolina recovered from Hyderabad in first collection demonstrated highest activity against S. sclerotiorum with IC50 value of 0.38 mg/ml. Additionally, its components 2H-pyran-2-one, 5,6-dihydro-6-pentyl and palmitic acid, methyl ester as reported by GC-MS Chromatogram upon evaluation for their antiphytopathogenic activity exhibited IC50 value of 1.002 and 0.662 against respectively S. sclerotiorum indicating their significant role in antiphytopathogenic activity of hexane extract. The production of 2H-pyran-2-one, 5,6-dihydro-6-pentyl from M. phaseolina, an endophytic fungus is being reported for the first time. PMID:26529087

  16. Fungal Endophyte Diversity and Bioactivity in the Indian Medicinal Plant Ocimum sanctum Linn.

    PubMed

    Chowdhary, Kanika; Kaushik, Nutan

    2015-01-01

    Endophytic mycopopulation isolated from India's Queen of herbs Tulsi (Ocimum sanctum) were explored and investigated for their diversity and antiphytopathogenic activity against widespread plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani and Fusarium oxysporum. 90 fungal isolates, representing 17 genera were recovered from 313 disease-free and surface sterilised plant segments (leaf and stem tissues) from three different geographic locations (Delhi, Hyderabad and Mukteshwar) during distinct sampling times in consequent years 2010 and 2011 in India. Fungal endophytes were subjected to molecular identification based on rDNA ITS sequence analysis. Plant pathogens such as F. verticillioides, B. maydis, C. coarctatum, R. bataticola, Hypoxylon sp., Diaporthe phaseolorum, Alternaria tenuissima and A. alternata have occurred as endophyte only during second sampling (second sampling in 2011) in the present study. Bi-plot generated by principal component analysis suggested tissue specificity of certain fungal endophytes. Dendrogram revealed species abundance as a function of mean temperature of the location at the time of sampling. Shannon diversity in the first collection is highest in Hyderabad leaf tissues (H' = 1.907) whereas in second collection it was highest from leaf tissues of Delhi (H' = 1.846). Mukteshwar (altitude: 7500 feet) reported least isolation rate in second collection. Nearly 23% of the total fungal isolates were considered as potent biocontrol agent. Hexane extract of M. phaseolina recovered from Hyderabad in first collection demonstrated highest activity against S. sclerotiorum with IC50 value of 0.38 mg/ml. Additionally, its components 2H-pyran-2-one, 5,6-dihydro-6-pentyl and palmitic acid, methyl ester as reported by GC-MS Chromatogram upon evaluation for their antiphytopathogenic activity exhibited IC50 value of 1.002 and 0.662 against respectively S. sclerotiorum indicating their significant role in antiphytopathogenic activity of hexane extract. The production of 2H-pyran-2-one, 5,6-dihydro-6-pentyl from M. phaseolina, an endophytic fungus is being reported for the first time. PMID:26529087

  17. Genetic Diversity and Phylogenetic Relationships of the USDA Vigna Germplasm Collection Assessed by Gene-Derived Markers and Screening

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The phylogenetic relationships in the USDA Vigna germplasm collection were unclear and their genetic diversity had not been measured empirically. To reveal interspecific phylogenetic relationships and assess their genetic diversity, 48 accessions representing 12 Vigna species were selected, and 30 g...

  18. An engine for global plant diversity: highest evolutionary turnover and emigration in the American tropics

    PubMed Central

    Antonelli, Alexandre; Zizka, Alexander; Silvestro, Daniele; Scharn, Ruud; Cascales-Miñana, Borja; Bacon, Christine D.

    2015-01-01

    Understanding the processes that have generated the latitudinal biodiversity gradient and the continental differences in tropical biodiversity remains a major goal of evolutionary biology. Here we estimate the timing and direction of range shifts of extant flowering plants (angiosperms) between tropical and non-tropical zones, and into and out of the major tropical regions of the world. We then calculate rates of speciation and extinction taking into account incomplete taxonomic sampling. We use a recently published fossil calibrated phylogeny and apply novel bioinformatic tools to code species into user-defined polygons. We reconstruct biogeographic history using stochastic character mapping to compute relative numbers of range shifts in proportion to the number of available lineages through time. Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms. This suggests that at least in plants, the latitudinal biodiversity gradient primarily derives from other factors than differential rates of diversification. In contrast, the outstanding species richness found today in the American tropics (the Neotropics), as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates. This suggests an exceedingly rapid evolutionary turnover, i.e., Neotropical species being formed and replaced by one another at unparalleled rates. In addition, tropical America stands out from other continents by having “pumped out” more species than it received through most of the last 66 million years. These results imply that the Neotropics have acted as an engine for global plant diversity. PMID:25904934

  19. Traditional forest management has limited impact on plant diversity and composition in a tropical seasonal rainforest in SW China

    E-print Network

    Slik, Ferry

    a , Jing-Xin Liu d a Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical GardenTraditional forest management has limited impact on plant diversity and composition in a tropical Xishuangbanna a b s t r a c t In order to determine the impacts of different traditional forest management types

  20. Utilizing common-garden and genetic diversity structure analysis to determine strategies for releasing wildland plant germplasm for rangeland revegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Semi-arid rangelands in the western North America face many challenges due to invasive weedy species, wildfires, and past mismanagement. A diversity of plant species are needed to effectively revegetate degraded rangelands in this expansive area. Legumes native to western North America are of inte...

  1. The response of soil CO2 ux to changes in atmospheric CO2, nitrogen supply and plant diversity

    E-print Network

    Thomas, David D.

    plant diversity are three major global changes caused by human activities (Vitousek 1994; Sala et al three major anthropogenic global changes: atmos- pheric carbon dioxide (CO2) concentration, nitrogen (N most when soil moisture was low and soils were warm. Effects on soil CO2 ¯ux due to fertilization

  2. Plant diversity effects on soil food webs are stronger than those of elevated CO2 and N deposition

    E-print Network

    Thomas, David D.

    Plant diversity effects on soil food webs are stronger than those of elevated CO2 and N deposition examined the responses of soil food webs (soil microorganisms, nematodes, microarthropods) to 13-y was a strong driver of the structure and functioning of soil food webs through several bottom-up (resource

  3. Sampling Plant Diversity and Rarity at Landscape Scales: Importance of Sampling Time in Species Detectability

    PubMed Central

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

    2014-01-01

    Documenting and estimating species richness at regional or landscape scales has been a major emphasis for conservation efforts, as well as for the development and testing of evolutionary and ecological theory. Rarely, however, are sampling efforts assessed on how they affect detection and estimates of species richness and rarity. In this study, vascular plant richness was sampled in 356 quarter hectare time-unlimited survey plots in the boreal region of northeast Alberta. These surveys consisted of 15,856 observations of 499 vascular plant species (97 considered to be regionally rare) collected by 12 observers over a 2 year period. Average survey time for each quarter-hectare plot was 82 minutes, ranging from 20 to 194 minutes, with a positive relationship between total survey time and total plant richness. When survey time was limited to a 20-minute search, as in other Alberta biodiversity methods, 61 species were missed. Extending the survey time to 60 minutes, reduced the number of missed species to 20, while a 90-minute cut-off time resulted in the loss of 8 species. When surveys were separated by habitat type, 60 minutes of search effort sampled nearly 90% of total observed richness for all habitats. Relative to rare species, time-unlimited surveys had ?65% higher rare plant detections post-20 minutes than during the first 20 minutes of the survey. Although exhaustive sampling was attempted, observer bias was noted among observers when a subsample of plots was re-surveyed by different observers. Our findings suggest that sampling time, combined with sample size and observer effects, should be considered in landscape-scale plant biodiversity surveys. PMID:24740179

  4. Reliability of a Test Battery Designed for Quickly and Safely Assessing Diverse Indices of Neuromuscular Function

    NASA Technical Reports Server (NTRS)

    Spiering, Barry A.; Lee, Stuart M. C.; Mulavara, Ajitkumar P.; Bentley, Jason, R.; Buxton, Roxanne E.; Lawrence, Emily L.; Sinka, Joseph; Guilliams, Mark E.; Ploutz-Snyder, Lori L.; Bloomberg, Jacob J.

    2010-01-01

    Spaceflight affects nearly every physiological system. Spaceflight-induced alterations in physiological function translate to decrements in functional performance. Purpose: To develop a test battery for quickly and safely assessing diverse indices of neuromuscular performance. I. Quickly: Battery of tests can be completed in approx.30-40 min. II. Safely: a) No eccentric muscle actions or impact forces. b) Tests present little challenge to postural stability. III. Diverse indices: a) Strength: Excellent reliability (ICC = 0.99) b) Central activation: Very good reliability (ICC = 0.87) c) Power: Excellent reliability (ICC = 0.99) d) Endurance: Total work has excellent reliability (ICC = 0.99) e) Force steadiness: Poor reliability (ICC = 0.20 - 0.60) National

  5. PRESS RELEASE I PARIS I 14 OCTOBER 2015 Using data from 46 experiments on grassland plant diversity, an international team of

    E-print Network

    Matias, Catherine

    PRESS RELEASE I PARIS I 14 OCTOBER 2015 Using data from 46 experiments on grassland plant diversity study, the researchers therefore used data from 46 experiments on grassland plant diversity in order does indeed increase the resistance of grassland primary productivity1 for a broad range of climate

  6. Genetic diversity of Lagerstroemia (Lythraceae) species assessed by simple sequence repeat markers.

    PubMed

    He, D; Liu, Y; Cai, M; Pan, H T; Zhang, Q X; Wang, X Y; Wang, X J

    2012-01-01

    Lagerstroemia (crape myrtle) are famous ornamental plants with large pyramidal racemes, long flower duration, and diverse colors. However, little is known about the genetic structure and diversity of germplasm in Lagerstroemia. We genotyped 81 L. indica cultivars, five other species of Lagerstroemia, and 10 interspecific hybrids using 30 simple sequence repeat markers; 275 alleles were generated with a mean of nine alleles per locus. The mean polymorphism information content value, a measure of gene diversity, was 0.63, with a range from 0.25 to 0.86. The mean observed heterozygosity (0.51) tended to be lower than the mean expected heterozygosity (0.67). The mean F-statistics (F(ST), F(IS), and F(IT)) were 0.05, 0.20, and 0.24, respectively, indicating a high level of genetic variation among cultivars. Clustering analysis based on genetic distance divided the 96 genotypes into three distinct groups, which corresponded with their genetic backgrounds and geographic regions. L. indica cultivars and the other five L. species were grouped into different sub-clusters. Chinese and North American cultivars were divided into different clusters. These data about the genetic relationship among cultivars demonstrated the potential value of L. indica cultivars and other Lagerstroemia species for widening the genetic basis of breeding programs for this ornamental flower. PMID:23079847

  7. Aging assessment of large electric motors in nuclear power plants

    SciTech Connect

    Villaran, M.; Subudhi, M.

    1996-03-01

    Large electric motors serve as the prime movers to drive high capacity pumps, fans, compressors, and generators in a variety of nuclear plant systems. This study examined the stressors that cause degradation and aging in large electric motors operating in various plant locations and environments. The operating history of these machines in nuclear plant service was studied by review and analysis of failure reports in the NPRDS and LER databases. This was supplemented by a review of motor designs, and their nuclear and balance of plant applications, in order to characterize the failure mechanisms that cause degradation, aging, and failure in large electric motors. A generic failure modes and effects analysis for large squirrel cage induction motors was performed to identify the degradation and aging mechanisms affecting various components of these large motors, the failure modes that result, and their effects upon the function of the motor. The effects of large motor failures upon the systems in which they are operating, and on the plant as a whole, were analyzed from failure reports in the databases. The effectiveness of the industry`s large motor maintenance programs was assessed based upon the failure reports in the databases and reviews of plant maintenance procedures and programs.

  8. Tiger Team Assessment of the Paducah Gaseous Diffusion Plant

    SciTech Connect

    Not Available

    1990-07-01

    This document contains findings and concerns identified during the Tiger Team Assessment of the Department of Energy's (DOE's) Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky. The assessment was directed by the Department's Office of Environment, Safety and Health (ES H) and was conducted from June 18 to July 20, 1990. The PGDP Tiger Team Assessment is comprehensive in scope. It covers the Environmental, Safety and Health (including OSHA Compliance), and Management areas and determines the site's compliance with applicable federal (including DOE), state, and local regulations and requirements. The objective of the assessment program is to provide the Secretary with information on the current ES H compliance status of DOE facilities, root causation for noncompliance, adequacy of DOE and site contractor ES H management programs, response actions to address the identified problem areas, and DOE-wide ES H compliance trends and root causes. This volume contains appendices.

  9. Tiger Team Assessment of the Paducah Gaseous Diffusion Plant

    SciTech Connect

    Not Available

    1990-07-01

    This document contains findings and concerns identified during the Tiger Team Assessment of the Department of Energy's (DOE) Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky. The assessment was directed by the Department's Office of Environment, Safety and Health (ES H) and was conducted from June 18 to July 20, 1990. The PGDP Tiger Team Assessment is comprehensive in scope. It covers the Environmental, Safety and Health (including OSHA Compliance), and Management areas and determines the site's compliance with applicable federal (including DOE), state, and local regulations and requirements. The objective of the assessment program is to provide the Secretary with information on the current ES H compliance status of DOE facilities, root causation for noncompliance, adequacy of DOE and site contractor ES H management programs, response actions to address the identified problem areas, and DOE-wide ES H compliance trends and root causes.

  10. 78 FR 79658 - Okanagan Specialty Fruits, Inc.; Availability of Plant Pest Risk Assessment and Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-31

    ...DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service [Docket No...Specialty Fruits, Inc.; Availability of Plant Pest Risk Assessment and Environmental...To Resist Browning AGENCY: Animal and Plant Health Inspection Service, USDA....

  11. A framework for chemical plant safety assessment under uncertainty.

    SciTech Connect

    Zeng, X.; Anitescu, M.; Pereira, C.; Regalbuto, M.

    2009-03-01

    We construct a framework for assessing the risk that the uncertainty in the plant feed and physical parameters may mask the loss of a reaction product. To model the plant, we use a nonlinear, quasi-steady-state model with stochastic input and parameters. We compute the probability that more than a certain product amount is diverted, given the statistics of the uncertainty in the plant feed, in the values of the chemical parameters, and in the output measurement. The uncertainty in the physical parameters is based on the one provided by the recently developed concept of thermochemical tables. We use Monte Carlo methods to compute the probabilities, based on a Cauchy-theorem-like approach to avoid making anything but the safest asymptotic assumptions, as well as to avoid the excessive noise in the region of low-probability events.

  12. Tiered categorization of a diverse panel of HIV-1 Env pseudoviruses for assessment of neutralizing antibodies.

    PubMed

    Seaman, Michael S; Janes, Holly; Hawkins, Natalie; Grandpre, Lauren E; Devoy, Colleen; Giri, Ayush; Coffey, Rory T; Harris, Linda; Wood, Blake; Daniels, Marcus G; Bhattacharya, Tanmoy; Lapedes, Alan; Polonis, Victoria R; McCutchan, Francine E; Gilbert, Peter B; Self, Steve G; Korber, Bette T; Montefiori, David C; Mascola, John R

    2010-02-01

    The restricted neutralization breadth of vaccine-elicited antibodies is a major limitation of current human immunodeficiency virus-1 (HIV-1) candidate vaccines. In order to permit the efficient identification of vaccines with enhanced capacity for eliciting cross-reactive neutralizing antibodies (NAbs) and to assess the overall breadth and potency of vaccine-elicited NAb reactivity, we assembled a panel of 109 molecularly cloned HIV-1 Env pseudoviruses representing a broad range of genetic and geographic diversity. Viral isolates from all major circulating genetic subtypes were included, as were viruses derived shortly after transmission and during the early and chronic stages of infection. We assembled a panel of genetically diverse HIV-1-positive (HIV-1(+)) plasma pools to assess the neutralization sensitivities of the entire virus panel. When the viruses were rank ordered according to the average sensitivity to neutralization by the HIV-1(+) plasmas, a continuum of average sensitivity was observed. Clustering analysis of the patterns of sensitivity defined four subgroups of viruses: those having very high (tier 1A), above-average (tier 1B), moderate (tier 2), or low (tier 3) sensitivity to antibody-mediated neutralization. We also investigated potential associations between characteristics of the viral isolates (clade, stage of infection, and source of virus) and sensitivity to NAb. In particular, higher levels of NAb activity were observed when the virus and plasma pool were matched in clade. These data provide the first systematic assessment of the overall neutralization sensitivities of a genetically and geographically diverse panel of circulating HIV-1 strains. These reference viruses can facilitate the systematic characterization of NAb responses elicited by candidate vaccine immunogens. PMID:19939925

  13. DOE/OIT Plant-Wide Energy Assessment Experience Summary 

    E-print Network

    Olszewski, M.; Leach, R.; McElhaney, K.

    2001-01-01

    Cascade International Falls, Minnesota, mill; the Caraustar Rittman, Ohio, mill; the Crucible Utica, New York, plant; and the Inland Paperboard and Packaging Rome, Georgia, mill. Assessments have been com pleted and documented at all but Crucible...'s motor inventory. Inland Paperboard and Packaging Rome Mill Inland Box Corporation was fonned in 1925 as a producer ofcorrugated boxes. Two decades later, a joint venture fonned with Mead Corporation resulted in thc construction of the Rome, Georgia...

  14. Turbocharged PFBC Power Plant Technical and Economic Assessments 

    E-print Network

    Leppke, D.

    1988-01-01

    POWER PLANT TECHNICAL AND ECONOMIC ASSESSMENTS DELBERT M. LEPPKE Senior Technical Manager Fluor Daniel Chicago, Illinois Fluidized bed combustion (FBC) boilers are receiving considerable attention by the utility and industrial business.... The SOX remova 1 process is integral with the combustion process rather than a separate system subject to upsets during combustion transients. 3. NOX production is low because of the lower combustion temperatures. 4. Waste is in a dry form...

  15. Structural diversity: a multi-dimensional approach to assess recreational services in urban parks.

    PubMed

    Voigt, Annette; Kabisch, Nadja; Wurster, Daniel; Haase, Dagmar; Breuste, Jürgen

    2014-05-01

    Urban green spaces provide important recreational services for urban residents. In general, when park visitors enjoy "the green," they are in actuality appreciating a mix of biotic, abiotic, and man-made park infrastructure elements and qualities. We argue that these three dimensions of structural diversity have an influence on how people use and value urban parks. We present a straightforward approach for assessing urban parks that combines multi-dimensional landscape mapping and questionnaire surveys. We discuss the method as well the results from its application to differently sized parks in Berlin and Salzburg. PMID:24740619

  16. Growth phenology of coast Douglas-fir seed sources planted in diverse environments.

    PubMed

    Gould, Peter J; Harrington, Constance A; St Clair, J Bradley

    2012-12-01

    The timing of periodic life cycle events in plants (phenology) is an important factor determining how species and populations will react to climate change. We evaluated annual patterns of basal-area and height growth of coast Douglas-fir (Pseudotusga menziesii var. menziesii (Mirb.) Franco) seedlings from four seed sources that were planted in four diverse environments as part of the Douglas-fir Seed-Source Movement Trial. Stem diameters and heights were measured periodically during the 2010 growing season on 16 open-pollinated families at each study installation. Stem diameters were measured on a subset of trees with electronic dendrometers during the 2010 and 2011 growing seasons. Trees from the four seed sources differed in phenology metrics that described the timing of basal-area and height-growth initiation, growth cessation and growth rates. Differences in the height-growth metrics were generally larger than differences in the basal-area growth metrics and differences among installations were larger than differences among seed sources, highlighting the importance of environmental signals on growth phenology. Variations in the height- and basal-area growth metrics were correlated with different aspects of the seed-source environments: precipitation in the case of height growth and minimum temperature in the case of basal-area growth. The detailed dendrometer measurements revealed differences in growth patterns between seed sources during distinct periods in the growing season. Our results indicate that multiple aspects of growth phenology should be considered along with other traits when evaluating adaptation of populations to future climates. PMID:23135739

  17. Above- and below-ground effects of plant diversity depend on species origin: an experimental test with multiple invaders.

    PubMed

    Kuebbing, Sara E; Classen, Aimée T; Sanders, Nathan J; Simberloff, Daniel

    2015-11-01

    Although many plant communities are invaded by multiple nonnative species, we have limited information on how a species' origin affects ecosystem function. We tested how differences in species richness and origin affect productivity and seedling establishment. We created phylogenetically paired native and nonnative plant communities in a glasshouse experiment to test diversity-productivity relationships and responsible mechanisms (i.e. selection or complementarity effects). Additionally, we tested how productivity and associated mechanisms influenced seedling establishment. We used diversity-interaction models to describe how species' interactions influenced diversity-productivity relationships. Communities with more species had higher total biomass than did monoculture communities, but native and nonnative communities diverged in root : shoot ratios and the mechanism responsible for increased productivity: positive selection effect in nonnative communities and positive complementarity effect in native communities. Seedling establishment was 46% lower in nonnative than in native communities and was correlated with the average selection effect. Interspecific interactions contributed to productivity patterns, but the specific types of interactions differed between native and nonnative communities. These results reinforce findings that the diversity-productivity mechanisms in native and nonnative communities differ and are the first to show that these mechanisms can influence seedling establishment and that different types of interactions influence diversity-productivity relationships. PMID:26053089

  18. Metagenomic analyses reveal phylogenetic diversity of carboxypeptidase gene sequences in activated sludge of a wastewater treatment plant in Shanghai, China.

    PubMed

    Jin, Hao; Li, Bailin; Peng, Xu; Chen, Lanming

    2014-01-01

    Activated sludge of wastewater treatment plants carries a diverse microflora. However, up to 80-90 % of microorganisms in activated sludge cannot be cultured by current laboratory techniques, leaving an enzyme reservoir largely unexplored. In this study, we investigated carboxypeptidase diversity in activated sludge of a wastewater treatment plant in Shanghai, China, by a culture-independent metagenomic approach. Three sets of consensus degenerate hybrid oligonucleotide primers (CODEHOPs) targeting conserved domains of public carboxypeptidases have been designed to amplify carboxypeptidase gene sequences in the metagenomic DNA of activated sludge by PCR. The desired amplicons were evaluated by carboxypeptidase sequence clone libraries and phylogenetic analyses. We uncovered a significant diversity of carboxypeptidases present in the activated sludge. Deduced carboxypeptidase amino acid sequences (127-208 amino acids) were classified into three distinct clusters, ?, ?, and ?. Sequences belonging to clusters ? and ? shared 58-97 % identity to known carboxypeptidase sequences from diverse species, whereas sequences in the cluster ? were remarkably less related to public carboxypeptidase homologous in the GenBank database, strongly suggesting that novel carboxypeptidase families or microbial niches exist in the activated sludge. We also observed numerous carboxypeptidase sequences that were much closer to those from representative strains present in industrial and sewage treatment and bioremediation. Thermostable and halotolerant carboxypeptidase sequences were also detected in clusters ? and ?. Coexistence of various carboxypeptidases is evidence of a diverse microflora in the activated sludge, a feature suggesting a valuable gene resource to be further explored for biotechnology application. PMID:24860282

  19. Can diversity in root architecture explain plant water use efficiency? A modeling study

    PubMed Central

    Tron, Stefania; Bodner, Gernot; Laio, Francesco; Ridolfi, Luca; Leitner, Daniel

    2015-01-01

    Drought stress is a dominant constraint to crop production. Breeding crops with adapted root systems for effective uptake of water represents a novel strategy to increase crop drought resistance. Due to complex interaction between root traits and high diversity of hydrological conditions, modeling provides important information for trait based selection. In this work we use a root architecture model combined with a soil-hydrological model to analyze whether there is a root system ideotype of general adaptation to drought or water uptake efficiency of root systems is a function of specific hydrological conditions. This was done by modeling transpiration of 48 root architectures in 16 drought scenarios with distinct soil textures, rainfall distributions, and initial soil moisture availability. We find that the efficiency in water uptake of root architecture is strictly dependent on the hydrological scenario. Even dense and deep root systems are not superior in water uptake under all hydrological scenarios. Our results demonstrate that mere architectural description is insufficient to find root systems of optimum functionality. We find that in environments with sufficient rainfall before the growing season, root depth represents the key trait for the exploration of stored water, especially in fine soils. Root density, instead, especially near the soil surface, becomes the most relevant trait for exploiting soil moisture when plant water supply is mainly provided by rainfall events during the root system development. We therefore concluded that trait based root breeding has to consider root systems with specific adaptation to the hydrology of the target environment. PMID:26412932

  20. Diversity of sulfate-reducing bacteria in a plant using deep geothermal energy

    NASA Astrophysics Data System (ADS)

    Alawi, Mashal; Lerm, Stephanie; Vetter, Alexandra; Wolfgramm, Markus; Seibt, Andrea; Würdemann, Hilke

    2011-06-01

    Enhanced process understanding of engineered geothermal systems is a prerequisite to optimize plant reliability and economy. We investigated microbial, geochemical and mineralogical aspects of a geothermal groundwater system located in the Molasse Basin by fluid analysis. Fluids are characterized by temperatures ranging from 61°C to 103°C, salinities from 600 to 900 mg/l and a dissolved organic carbon content (DOC) between 6.4 to 19.3 mg C/l. The microbial population of fluid samples was analyzed by genetic fingerprinting techniques based on PCR-amplified 16S rRNA- and dissimilatory sulfite reductase genes. Despite of the high temperatures, microbes were detected in all investigated fluids. Fingerprinting and DNA sequencing enabled a correlation to metabolic classes and biogeochemical processes. The analysis revealed a broad diversity of sulfate-reducing bacteria. Overall, the detection of microbes known to be involved in biocorrosion and mineral precipitation indicates that microorganisms could play an important role for the understanding of processes in engineered geothermal systems.

  1. Genetic diversity of plant growth promoting rhizobacteria isolated from rhizospheric soil of wheat under saline condition.

    PubMed

    Upadhyay, Sudhir K; Singh, Devendra P; Saikia, Ratul

    2009-11-01

    In this study, a total of 130 rhizobacteria was isolated from a saline infested zone of wheat rhizosphere, and screened for plant growth promoting (PGP) traits at higher salt (NaCl) concentrations (2, 4, 6, and 8%). The results revealed that 24 rhizobacterial isolates were tolerant at 8% NaCl. Although all the 24 salt tolerable isolates produced indole-3-acetic acid (IAA), while 10 isolates solubilized phosphorus, eight produced siderophore, and six produced gibberellin. However, only three isolates showed the production of 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Diversity was analyzed through 16S rDNA-RFLP, and of these isolates with three tetra cutter restriction enzymes (HaeIII, AluI, and MspI), the representative cluster groups were identified by 16S rDNA sequencing. Bacillus and Bacillus-derived genera were dominant which showed PGP attributes at 8% NaCl concentration. Out of 24 isolates, nitrogen fixing ability (nif H gene) was detected in the two isolates, SU18 (Arthrobacter sp.) and SU48. PMID:19701667

  2. Prospecting cold deserts of north western Himalayas for microbial diversity and plant growth promoting attributes.

    PubMed

    Yadav, Ajar Nath; Sachan, Shashwati Ghosh; Verma, Priyanka; Saxena, Anil Kumar

    2015-06-01

    Microbial communities in different samples collected from cold deserts of north western Himalayas, India, were analyzed using 16S rRNA gene sequencing and phospholipid fatty acids (PLFA) analysis. A total of 232 bacterial isolates were characterized employing 16S rDNA-Amplified Ribosomal DNA Restriction Analysis with the three restriction endonucleases Alu I, Msp I and Hae III, which led to formation of 29-54 groups for the different sites, adding up to169 groups. 16S rRNA gene based phylogenetic analysis, revealed that 82 distinct species of 31 different genera, belonged to four phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. PLFA profiling was performed for concerned samples which gave an estimate of microbial communities without cultivating the microorganisms. PLFA analysis led to characterization of diverse group of microbes in different samples such as gram-negative, gram-positive bacteria, actinomycetes, cyanobacteria, anaerobic bacteria, sulphate reducing bacteria and fungi. The representative strains were screened for their plant growth promoting attributes, which included production of ammonia, HCN, gibberellic acid, IAA and siderophore; solubilization of phosphorus and activity of ACC deaminase. In vitro antifungal activity assay was performed against Rhizoctonia solani and Macrophomina phaseolina. Cold adapted microorganisms may serve as inoculants for crops growing under cold climatic conditions. To our knowledge, this is the first report for the presence of Arthrobacter nicotianae, Brevundimonas terrae, Paenibacillus tylopili and Pseudomonas cedrina in cold deserts and exhibit multifunctional PGP attributes at low temperatures. PMID:25575970

  3. Diversity and dynamics of Archaea in an activated sludge wastewater treatment plant

    PubMed Central

    2012-01-01

    Background The activated sludge process is one of the most widely used methods for treatment of wastewater and the microbial community composition in the sludge is important for the process operation. While the bacterial communities have been characterized in various activated sludge systems little is known about archaeal communities in activated sludge. The diversity and dynamics of the Archaea community in a full-scale activated sludge wastewater treatment plant were investigated by fluorescence in situ hybridization, terminal restriction fragment length polymorphism analysis and cloning and sequencing of 16S rRNA genes. Results The Archaea community was dominated by Methanosaeta-like species. During a 15?month period major changes in the community composition were only observed twice despite seasonal variations in environmental and operating conditions. Water temperature appeared to be the process parameter that affected the community composition the most. Several terminal restriction fragments also showed strong correlations with sludge properties and effluent water properties. The Archaea were estimated to make up 1.6% of total cell numbers in the activated sludge and were present both as single cells and colonies of varying sizes. Conclusions The results presented here show that Archaea can constitute a constant and integral part of the activated sludge and that it can therefore be useful to include Archaea in future studies of microbial communities in activated sludge. PMID:22784022

  4. Indicator organisms for assessing sanitization during composting of plant wastes.

    PubMed

    Noble, R; Dobrovin-Pennington, A; Pietravalle, S; Weekes, R; Henry, C M

    2011-08-01

    The potential for using plant pathogens and seeds as indicator organisms for assessing sanitization of plant wastes during composting was tested in bench-scale flask and large-scale systems. Plasmodiophora brassicae was unsuitable due to high temperature tolerance in dry to moist composts, and detection of viable inoculum post-composting using bioassay plants not corresponding with that using TaqMan® PCR, possibly due to preservation of nucleic acids at elevated temperatures. Several other plant pathogens (Sclerotinia sclerotiorum, Microdochium nivale, Phytophthora cinnamomi and Phytophthora nicotianae) were unsuitable due their low temperature tolerance. Fusarium oxysporum f.sp. cepae and f.sp. radicis-lycopersici chlamydospores and tomato seeds were suitable indicators due to their moderate temperature tolerance and ease of viability testing post-composting. Abutilon seeds were more tolerant than tomato seeds of compost temperatures ?52°C but more prone to degradation at lower temperatures and therefore less suitable as indicators. Relationships between compost temperature during exposures of 2-10 days and subsequent viability of the above chlamydospores or seeds enabled the sanitizing effect of composting processes to be predicted within 2-6 days. Plant waste type (woody or vegetable) had a small but significant effect on the relationship for tomato seeds but not for F. oxysporum chlamydospores. PMID:21546235

  5. Assessing Cd-induced stress from plant spectral response

    NASA Astrophysics Data System (ADS)

    Kancheva, Rumiana; Georgiev, Georgi

    2014-10-01

    Remote sensing plays a significant role in local, regional and global monitoring of land covers. Ecological concerns worldwide determine the importance of remote sensing applications for the assessment of soil conditions, vegetation health and identification of stress-induced changes. The extensive industrial growth and intensive agricultural land-use arise the serious ecological problem of environmental pollution associated with the increasing anthropogenic pressure on the environment. Soil contamination is a reason for degradation processes and temporary or permanent decrease of the productive capacity of land. Heavy metals are among the most dangerous pollutants because of their toxicity, persistent nature, easy up-take by plants and long biological half-life. This paper takes as its focus the study of crop species spectral response to Cd pollution. Ground-based experiments were performed, using alfalfa, spring barley and pea grown in Cd contaminated soils and in different hydroponic systems under varying concentrations of the heavy metal. Cd toxicity manifested itself by inhibition of plant growth and synthesis of photosynthetic pigments. Multispectral reflectance, absorbance and transmittance, as well as red and far red fluorescence were measured and examined for their suitability to detect differences in plant condition. Statistical analysis was performed and empirical relationships were established between Cd concentration, plant growth variables and spectral response Various spectral properties proved to be indicators of plant performance and quantitative estimators of the degree of the Cd-induced stress.

  6. Assessment of genetic and functional diversity of phosphate solubilizing fluorescent pseudomonads isolated from rhizospheric soil

    PubMed Central

    Naik, Popavath Ravindra; Raman, Gurusamy; Narayanan, Kannan Badri; Sakthivel, Natarajan

    2008-01-01

    Background Phosphorus is an essential macronutrient for the growth of plants. However, in most soils a large portion of phosphorus becomes insoluble and therefore, unavailable to plants. Knowledge on biodiversity of phosphate-solubilizing fluorescent pseudomonads is essential to understand their ecological role and their utilization in sustainable agriculture. Results Of 443 fluorescent pseudomonad strains tested, 80 strains (18%) showed positive for the solubilization of tri-calcium phosphate (Ca3(PO4)2) by the formation of visible dissolution halos on Pikovskaya's agar. These phosphate solubilizing strains showed high variability in utilizing various carbon sources. Numerical taxonomy of the phosphate solubilizing strains based on their carbon source utilization profiles resulted into three major phenons at a 0.76 similarity coefficient level. Genotypic analyses of strains by BOX (bacterial repetitive BOX element)-polymerase chain reaction (PCR) resulted into three distinct genomic clusters and 26 distinct BOX profiles at a 80% similarity level. On the basis of phenotypic characterization and 16S rRNA gene phylogenetic analyses strains were identified as Pseudomonas aeruginosa, P. mosselii, P. monteilii, P. plecoglossicida, P. putida, P. fulva and P. fluorescens. These phosphate solubilizing strains also showed the production of plant growth promoting enzymes, hormones and exhibited antagonism against phytopathogenic fungi that attack on various crops. Gene specific primers have identified the putative antibiotic producing strains. These putative strains were grown in fermentation media and production of antibiotics was confirmed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Conclusion Present study revealed a high degree of functional and genetic diversity among the phosphate solubilizing fluorescent pseudomonad bacteria. Due to their innate potential of producing an array of plant growth promoting enzymes, hormones and antifungal metabolites these phosphate solubilizing strains are considered to play a vital role in plant growth promotion, disease suppression and subsequent enhancement of yield. PMID:19099598

  7. Selenium hyperaccumulators harbor a diverse endophytic bacterial community characterized by high selenium resistance and plant growth promoting properties.

    PubMed

    Sura-de Jong, Martina; Reynolds, Ray J B; Richterova, Klara; Musilova, Lucie; Staicu, Lucian C; Chocholata, Iva; Cappa, Jennifer J; Taghavi, Safiyh; van der Lelie, Daniel; Frantik, Tomas; Dolinova, Iva; Strejcek, Michal; Cochran, Alyssa T; Lovecka, Petra; Pilon-Smits, Elizabeth A H

    2015-01-01

    Selenium (Se)-rich plants may be used to provide dietary Se to humans and livestock, and also to clean up Se-polluted soils or waters. This study focused on endophytic bacteria of plants that hyperaccumulate selenium (Se) to 0.5-1% of dry weight. Terminal restriction fragment length polymorphism (T-RFLP) analysis was used to compare the diversity of endophytic bacteria of hyperaccumulators Stanleya pinnata (Brassicaceae) and Astragalus bisulcatus (Fabaceae) with those from related non-accumulators Physaria bellii (Brassicaceae) and Medicago sativa (Fabaceae) collected on the same, seleniferous site. Hyperaccumulators and non-accumulators showed equal T-RF diversity. Parsimony analysis showed that T-RFs from individuals of the same species were more similar to each other than to those from other species, regardless of plant Se content or spatial proximity. Cultivable endophytes from hyperaccumulators S. pinnata and A. bisulcatus were further identified and characterized. The 66 bacterial morphotypes were shown by MS MALDI-TOF Biotyper analysis and 16S rRNA gene sequencing to include strains of Bacillus, Pseudomonas, Pantoea, Staphylococcus, Paenibacillus, Advenella, Arthrobacter, and Variovorax. Most isolates were highly resistant to selenate and selenite (up to 200 mM) and all could reduce selenite to red elemental Se, reduce nitrite and produce siderophores. Seven isolates were selected for plant inoculation and found to have plant growth promoting properties, both in pure culture and when co-cultivated with crop species Brassica juncea (Brassicaceae) or M. sativa. There were no effects on plant Se accumulation. We conclude that Se hyperaccumulators harbor an endophytic bacterial community in their natural seleniferous habitat that is equally diverse to that of comparable non-accumulators. The hyperaccumulator endophytes are characterized by high Se resistance, capacity to produce elemental Se and plant growth promoting properties. PMID:25784919

  8. Selenium hyperaccumulators harbor a diverse endophytic bacterial community characterized by high selenium resistance and plant growth promoting properties

    PubMed Central

    Sura-de Jong, Martina; Reynolds, Ray J. B.; Richterova, Klara; Musilova, Lucie; Staicu, Lucian C.; Chocholata, Iva; Cappa, Jennifer J.; Taghavi, Safiyh; van der Lelie, Daniel; Frantik, Tomas; Dolinova, Iva; Strejcek, Michal; Cochran, Alyssa T.; Lovecka, Petra; Pilon-Smits, Elizabeth A. H.

    2015-01-01

    Selenium (Se)-rich plants may be used to provide dietary Se to humans and livestock, and also to clean up Se-polluted soils or waters. This study focused on endophytic bacteria of plants that hyperaccumulate selenium (Se) to 0.5–1% of dry weight. Terminal restriction fragment length polymorphism (T-RFLP) analysis was used to compare the diversity of endophytic bacteria of hyperaccumulators Stanleya pinnata (Brassicaceae) and Astragalus bisulcatus (Fabaceae) with those from related non-accumulators Physaria bellii (Brassicaceae) and Medicago sativa (Fabaceae) collected on the same, seleniferous site. Hyperaccumulators and non-accumulators showed equal T-RF diversity. Parsimony analysis showed that T-RFs from individuals of the same species were more similar to each other than to those from other species, regardless of plant Se content or spatial proximity. Cultivable endophytes from hyperaccumulators S. pinnata and A. bisulcatus were further identified and characterized. The 66 bacterial morphotypes were shown by MS MALDI-TOF Biotyper analysis and 16S rRNA gene sequencing to include strains of Bacillus, Pseudomonas, Pantoea, Staphylococcus, Paenibacillus, Advenella, Arthrobacter, and Variovorax. Most isolates were highly resistant to selenate and selenite (up to 200 mM) and all could reduce selenite to red elemental Se, reduce nitrite and produce siderophores. Seven isolates were selected for plant inoculation and found to have plant growth promoting properties, both in pure culture and when co-cultivated with crop species Brassica juncea (Brassicaceae) or M. sativa. There were no effects on plant Se accumulation. We conclude that Se hyperaccumulators harbor an endophytic bacterial community in their natural seleniferous habitat that is equally diverse to that of comparable non-accumulators. The hyperaccumulator endophytes are characterized by high Se resistance, capacity to produce elemental Se and plant growth promoting properties. PMID:25784919

  9. Use of higher plants as screens for toxicity assessment.

    PubMed

    Kristen, U

    1997-01-01

    This review deals with the use of entire plants, seedlings, cell suspension cultures and pollen tubes for the estimation of potential toxicity in the environment, and for risk assessment of chemicals and formulations of human relevance. It is shown that the roots of onions and various crop seedlings, as well as in vitro growing pollen tubes of some mono- and dicotyledonous plants, are most frequently used to obtain toxicity data by determination of root and tube growth inhibition. Both roots and pollen tubes are chloroplast free, non-photosynthetic systems and, therefore, with regard to their cytotoxic reactions are closer to vertebrate tissues and cells than are chloroplast-containing plant organs. Root tips and anthers of flower buds are shown to be applicable to genotoxicity screening by microscopic analysis of mitotic or meiotic aberrations during cell division or microspore development, respectively. The processes of mitosis and meiosis are similar in plants and animals. Therefore, meristematic and sporogenic tissues of plants generally show patterns of cytotoxic response similar to those of embryogenic and spermatogenic tissues of vertebrates. The suitability of root tips, cell suspensions and pollen tubes for the investigation of mechanisms of toxic action and for the analysis of structure-activity relationships is also demonstrated. Two plant-based assays, the Allium test and the pollen tube growth test, both currently being evaluated alongside with established mammalian in vivo and in vitro protocols, are emphasized with regard to their potential use as alternatives to animal in vivo toxicity tests. For both assays, preliminary results indicate that the tips of growing roots and the rapidly elongating pollen tubes of certain higher plant species are as reliable as mammalian cell lines for detecting basal cytotoxicity. It is suggested that seeds and pollen grains, in particular, provide easily storable and convenient systems for inexpensive, relatively simple but precise toxicological assays. (c) 1997 Elsevier Science Ltd. PMID:20654304

  10. Methodology and Process for Condition Assessment at Existing Hydropower Plants

    SciTech Connect

    Zhang, Qin Fen; Smith, Brennan T; Cones, Marvin; March, Patrick; Dham, Rajesh; Spray, Michael

    2012-01-01

    Hydropower Advancement Project was initiated by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy to develop and implement a systematic process with a standard methodology to identify the opportunities of performance improvement at existing hydropower facilities and to predict and trend the overall condition and improvement opportunity within the U.S. hydropower fleet. The concept of performance for the HAP focuses on water use efficiency how well a plant or individual unit converts potential energy to electrical energy over a long-term averaging period of a year or more. The performance improvement involves not only optimization of plant dispatch and scheduling but also enhancement of efficiency and availability through advanced technology and asset upgrades, and thus requires inspection and condition assessment for equipment, control system, and other generating assets. This paper discusses the standard methodology and process for condition assessment of approximately 50 nationwide facilities, including sampling techniques to ensure valid expansion of the 50 assessment results to the entire hydropower fleet. The application and refining process and the results from three demonstration assessments are also presented in this paper.

  11. Traditional agroecosystems as conservatories and incubators of cultivated plant varietal diversity: the case of fig (Ficus carica L.) in Morocco

    PubMed Central

    2010-01-01

    Background Traditional agroecosystems are known to host both large crop species diversity and high within crop genetic diversity. In a context of global change, this diversity may be needed to feed the world. Are these agroecosystems museums (i.e. large core collections) or cradles of diversity? We investigated this question for a clonally propagated plant, fig (Ficus carica), within its native range, in Morocco, but as far away as possible from supposed centers of domestication. Results Fig varieties were locally numerous. They were found to be mainly highly local and corresponded to clones propagated vegetatively. Nevertheless these clones were often sufficiently old to have accumulated somatic mutations for selected traits (fig skin color) and at neutral loci (microsatellite markers). Further the pattern of spatial genetic structure was similar to the pattern expected in natural population for a mutation/drift/migration model at equilibrium, with homogeneous levels of local genetic diversity throughout Moroccan traditional agroecosystems. Conclusions We conclude that traditional agroecosystems constitue active incubators of varietal diversity even for clonally propagated crop species, and even when varieties correspond to clones that are often old. As only female fig is cultivated, wild fig and cultivated fig probably constitute a single evolutionary unit within these traditional agroecosystems. Core collections, however useful, are museums and hence cannot serve the same functions as traditional agroecosystems. PMID:20167055

  12. Assessment of endophytic yeast diversity in rice leaves by a culture-independent approach.

    PubMed

    Tantirungkij, Manee; Nasanit, Rujikan; Limtong, Savitree

    2015-09-01

    Endophytic microorganisms inhabit internal plant tissues in the host plant without causing any symptoms or negative effects. Although the diversity of endophytes has been evaluated by both culture-dependent and culture-independent methods, less information is available on yeast communities. Therefore, in this study a culture-independent method was used to examine endophytic yeasts associated with rice leaves based on the large subunit of ribosomal DNA using a semi-nested PCR technique. Sequence analysis indicated that the colonization frequency and the relative species frequency (RF) of endophytic yeast phylotypes were 0.41 and 0.06, respectively, and the majority of the yeast phylotypes were basidiomycetous yeasts. The phylotypes were designated as five known species (Cryptococcus victoriae, Debaryomyces hansenii, Debaryomyces vindobonensis, Meyerozyma guilliermondii and Pseudozyma antarctica), together with seventeen phylotypes closest to Candida metapsilosis, Cryp. foliicola, Cryp. laurentii, Pseudozyma abaconensis, Pseudozyma aphidis and Trichosporon asahii, among which some could be novel species. The most prevalent phylotypes were those closest to Cryp. foliicola (47.5 % RF) followed by D. hansenii (22.8 % RF) and P. antarctica (16.8 % RF). The presence of the phylotypes related to species known for their potential applications as biocontrol agents and plant growth promoting hormone producers suggests that they may have valuable applications. In addition, our findings revealed the occurrence of novel phylotypes at high frequency, which should encourage extensive studies to discover novel yeast species and to understand their roles in the rice leaves. PMID:26122889

  13. Comparative phylogeography of two related plant species with overlapping ranges in Europe, and the potential effects of climate change on their intraspecific genetic diversity

    PubMed Central

    2011-01-01

    Background The aim of the present study was to use a combined phylogeographic and species distribution modelling approach to compare the glacial histories of two plant species with overlapping distributions, Orthilia secunda (one-sided wintergreen) and Monotropa hypopitys (yellow bird's nest). Phylogeographic analysis was carried out to determine the distribution of genetic variation across the range of each species and to test whether both correspond to the "classic" model of high diversity in the south, with decreasing diversity at higher latitudes, or whether the cold-adapted O. secunda might retain more genetic variation in northern populations. In addition, projected species distributions based on a future climate scenario were modelled to assess how changes in the species ranges might impact on total intraspecific diversity in both cases. Results Palaeodistribution modelling and phylogeographic analysis using multiple genetic markers (chloroplast trnS-trnG region, nuclear ITS and microsatellites for O. secunda; chloroplast rps2, nuclear ITS and microsatellites for M. hypopitys) indicated that both species persisted throughout the Last Glacial Maximum in southern refugia. For both species, the majority of the genetic diversity was concentrated in these southerly populations, whereas those in recolonized areas generally exhibited lower levels of diversity, particularly in M. hypopitys. Species distribution modelling based on projected future climate indicated substantial changes in the ranges of both species, with a loss of southern and central populations, and a potential northward expansion for the temperate M. hypopitys. Conclusions Both Orthilia secunda and Monotropa hypopitys appear to have persisted through the LGM in Europe in southern refugia. The boreal O. secunda, however, has retained a larger proportion of its genetic diversity in more northerly populations outside these refugial areas than the temperate M. hypopitys. Given that future species distribution modelling suggests northern range shifts and loss of suitable habitat in the southern parts of the species' current distributions, extinction of genetically diverse rear edge populations could have a significant effect in the rangewide intraspecific diversity of both species, but particularly in M. hypopitys. PMID:21272309

  14. Inhalation risk assessment for existing Maryland power plants. Final report

    SciTech Connect

    Birks, A.; Zankel, K.; Corio, L.; Brower, R.

    1994-12-01

    An inhalation risk assessment was performed for all Maryland utility combustion sources, i.e., turbines, diesel engines, and coal and oil-fired boilers. This assessment involved 15 power plants sites comprising approximately 70 combustion units. The goal was to determine whether exposure to hazardous air pollutant (HAP) emissions (via inhalation) from any individual source or from all sources is likely to pose a significant health risk to the most exposed individuals (MEI). This assessment was based on conservative emissions and toxicological information, and is designed to be easily updated as new data become available. Existing unit-specific emissions data, accounting for furnace type, firing technique, and control technology, were used. Detailed dispersion modeling, accounting for site-specific effects such as structure downwash and terrain, was used to estimate potential inhalation exposure. Available toxicological data were used to estimate the risk posed by each utility combustion source in Maryland, and to identify any hazardous air pollutant emissions of concern.

  15. Molecular Diversity Assessment Using Sequence Related Amplified Polymorphism (SRAP) Markers in Vicia faba L.

    PubMed Central

    Alghamdi, Salem S.; Al-Faifi, Sulieman A.; Migdadi, Hussein M.; Khan, Muhammad Altaf; El-Harty, Ehab H.; Ammar, Megahed H.

    2012-01-01

    Sequence-related amplified polymorphism (SRAP) markers were used to assess the genetic diversity and relationship among 58 faba bean (Vicia faba L.) genotypes. Fourteen SRAP primer combinations amplified a total of 1036 differently sized well-resolved peaks (fragments), of which all were polymorphic with a 0.96 PIC value and discriminated all of the 58 faba bean genotypes. An average pairwise similarity of 21% was revealed among the genotypes ranging from 2% to 65%. At a similarity of 28%, UPGMA clustered the genotypes into three main groups comprising 78% of the genotypes. The local landraces and most of the Egyptian genotypes in addition to the Sudan genotypes were grouped in the first main cluster. The advanced breeding lines were scattered in the second and third main clusters with breeding lines from the ICARDA and genotypes introduced from Egypt. At a similarity of 47%, all the genotypes formed separated clusters with the exceptions of Hassawi 1 and Hassawi 2. Group analysis of the genotypes according to their geographic origin and type showed that the landraces were grouped according to their origin, while others were grouped according to their seed type. To our knowledge, this is the first application of SRAP markers for the assessment of genetic diversity in faba bean. Such information will be useful to determine optimal breeding strategies to allow continued progress in faba bean breeding. PMID:23211669

  16. Comparison of statistical methods for assessment of population genetic diversity by DNA fingerprinting

    SciTech Connect

    Leonard, T.; Roth, A.; Gordon, D.; Wessendarp, T.; Smith, M.K.; Silbiger, R.; Torsella, J.

    1995-12-31

    The advent of newer techniques for genomic characterization, e.g., Random Amplified Polymorphic DNA (RAPD) fingerprinting, has motivated development of a number of statistical approaches for creating hypothesis tests using this genetic information. The authors specific interest is methods for deriving relative genetic diversity measures of feral populations subjected to varying degrees of environmental impacts. Decreased polymorphism and loss of alleles have been documented in stressed populations of some species as assayed by allozyme analysis and, more recently, by DNA fingerprinting. Multilocus fingerprinting techniques (such as RAPDS) differ from allozyme analysis in that they do not explicitly yield information of allelism and heterozygosity. Therefore, in order to infer these parameters, assumptions must be made concerning the relationship of observed data to the underlying DNA architecture. In particular, assessments of population genetic diversity from DNA fingerprint data have employed at least three approaches based on different assumptions about the data. The authors compare different statistics, using a previously presented set of RAPD fingerprints of three populations of brown bullhead catfish. Furthermore, the behavior of these statistics is examined--as the sample sizes of fish/population and polymorphisms/fish are varied. Sample sizes are reduced either randomly or, in the case of polymorphisms (which are electrophoretic bands), systematically pruned using the criteria of high reproducibility between duplicate samples for inclusion of data. Implications for sampling individuals and loci in assessments of population genetic diversities are discussed. Concern about population N value and statistical power is very relevant to field situations where individuals available for sampling may be limited in number.

  17. Contrasting Taxonomic and Phylogenetic Diversity Responses to Forest Modifications: Comparisons of Taxa and Successive Plant Life Stages in South African Scarp Forest

    PubMed Central

    Grass, Ingo; Brandl, Roland; Botzat, Alexandra; Neuschulz, Eike Lena; Farwig, Nina

    2015-01-01

    The degradation of natural forests to modified forests threatens subtropical and tropical biodiversity worldwide. Yet, species responses to forest modification vary considerably. Furthermore, effects of forest modification can differ, whether with respect to diversity components (taxonomic or phylogenetic) or to local (?-diversity) and regional (?-diversity) spatial scales. This real-world complexity has so far hampered our understanding of subtropical and tropical biodiversity patterns in human-modified forest landscapes. In a subtropical South African forest landscape, we studied the responses of three successive plant life stages (adult trees, saplings, seedlings) and of birds to five different types of forest modification distinguished by the degree of within-forest disturbance and forest loss. Responses of the two taxa differed markedly. Thus, the taxonomic ?-diversity of birds was negatively correlated with the diversity of all plant life stages and, contrary to plant diversity, increased with forest disturbance. Conversely, forest disturbance reduced the phylogenetic ?-diversity of all plant life stages but not that of birds. Forest loss neither affected taxonomic nor phylogenetic diversity of any taxon. On the regional scale, taxonomic but not phylogenetic ?-diversity of both taxa was well predicted by variation in forest disturbance and forest loss. In contrast to adult trees, the phylogenetic diversity of saplings and seedlings showed signs of contemporary environmental filtering. In conclusion, forest modification in this subtropical landscape strongly shaped both local and regional biodiversity but with contrasting outcomes. Phylogenetic diversity of plants may be more threatened than that of mobile species such as birds. The reduced phylogenetic diversity of saplings and seedlings suggests losses in biodiversity that are not visible in adult trees, potentially indicating time-lags and contemporary shifts in forest regeneration. The different responses of taxonomic and phylogenetic diversity to forest modifications imply that biodiversity conservation in this subtropical landscape requires the preservation of natural and modified forests. PMID:25719204

  18. Value impact assessment: A preliminary assessment of improvement opportunities at the Quantico Central Heating Plant

    SciTech Connect

    Brambley, M.R.; Weakley, S.A.

    1990-09-01

    This report presents the results of a preliminary assessment of opportunities for improvement at the US Marine Corps (USMC) Quantico, Virginia, Central Heating Plant (CHP). This study is part of a program intended to provide the CHP staff with a computerized Artificial Intelligence (AI) decision support system that will assist in a more efficient, reliable, and safe operation of their plant. As part of the effort to provide the AI decision support system, a team of six scientists and engineers from the Pacific Northwest Laboratory (PNL) visited the plant to characterize the conditions and environment of the CHP. This assessment resulted in a list of potential performance improvement opportunities at the CHP. In this report, 12 of these opportunities are discussed and qualitatively analyzed. 70 refs., 7 figs., 6 tabs.

  19. Fungal endophytes in aboveground tissues of desert plants: infrequent in culture, but highly diverse and distinctive symbionts.

    PubMed

    Massimo, Nicholas C; Nandi Devan, M M; Arendt, Kayla R; Wilch, Margaret H; Riddle, Jakob M; Furr, Susan H; Steen, Cole; U'Ren, Jana M; Sandberg, Dustin C; Arnold, A Elizabeth

    2015-07-01

    In hot deserts, plants cope with aridity, high temperatures, and nutrient-poor soils with morphological and biochemical adaptations that encompass intimate microbial symbioses. Whereas the root microbiomes of arid-land plants have received increasing attention, factors influencing assemblages of symbionts in aboveground tissues have not been evaluated for many woody plants that flourish in desert environments. We evaluated the diversity, host affiliations, and distributions of endophytic fungi associated with photosynthetic tissues of desert trees and shrubs, focusing on nonsucculent woody plants in the species-rich Sonoran Desert. To inform our strength of inference, we evaluated the effects of two different nutrient media, incubation temperatures, and collection seasons on the apparent structure of endophyte assemblages. Analysis of >22,000 tissue segments revealed that endophytes were isolated four times more frequently from photosynthetic stems than leaves. Isolation frequency was lower than expected given the latitude of the study region and varied among species a function of sampling site and abiotic factors. However, endophytes were very species-rich and phylogenetically diverse, consistent with less arid sites of a similar latitudinal position. Community composition differed among host species, but not as a function of tissue type, sampling site, sampling month, or exposure. Estimates of abundance, diversity, and composition were not influenced by isolation medium or incubation temperature. Phylogenetic analyses of the most commonly isolated genus (Preussia) revealed multiple evolutionary origins of desert-plant endophytism and little phylogenetic structure with regard to seasonality, tissue preference, or optimal temperatures and nutrients for growth in vitro. Together, these results provide insight into endophytic symbioses in desert-plant communities and can be used to optimize strategies for capturing endophyte biodiversity at regional scales. PMID:25645243

  20. Prevalence and diversity of mycoviruses infecting the plant pathogen Ustilaginoidea virens.

    PubMed

    Jiang, Yinhui; Zhang, Tingting; Luo, Chaoxi; Jiang, Daohong; Li, Guoqing; Li, Qili; Hsiang, Tom; Huang, Junbin

    2015-01-01

    Rice false smut caused by Ustilaginoidea virens is a destructive disease in many rice-growing areas. Mycoviruses have been described in many fungal species, but there is little information regarding mycoviruses in U. virens. In this study, double-stranded (ds) RNA banding patterns were assessed in 198 wild-type isolates of U. virens obtained from different geographical regions in China. The presence of viral infections was unusually common in U. virens: 188 of the 198 isolates contained dsRNA elements with viral characteristics, and the presence of mixed infections with two or more related or unrelated mycoviruses was commonly detected. The GX-1 isolate contained four dsRNA mycoviruses: Ustilaginoidea virens RNA virus 1 (UvRV1) belonging to Totiviridae, Ustilaginoidea virens RNA virus 4 (UvRV4) belonging to an unclassified family which includes the Curvularia thermal tolerance virus, and the last two probably belonging to Partitiviridae. Biological comparisons of virus-free and infected fungal isolates revealed that UvRV1 strain GX-1 and UvRV4 were likely cryptic, since the infected strains did not show apparent symptoms or debilitation. Northern blotting experiments revealed that UvRV1 strain GX-1 and UvRV4 were frequently found in U. virens, irrespective of the place of origin, and similarly sized dsRNA bands were not always of similar sequence. Thus, our findings suggest that mycoviruses infecting U. virens in China are widespread and highly diverse. PMID:25200750

  1. Comparison of crenarchaeal consortia inhabiting the rhizosphere of diverse terrestrial plants with those in bulk soil in native environments.

    PubMed

    Sliwinski, Marek K; Goodman, Robert M

    2004-03-01

    To explore whether the crenarchaeal consortium found in the rhizosphere is distinct from the assemblage of crenarchaeotes inhabiting bulk soil, PCR-single-stranded-conformation polymorphism (PCR-SSCP) profiles were generated for 76 plant samples collected from native environments. Divergent terrestrial plant groups including bryophytes (mosses), lycopods (club mosses), pteridophytes (ferns), gymnosperms (conifers), and angiosperms (seed plants) were collected for this study. Statistical analysis revealed significant differences between rhizosphere and bulk soil PCR-SSCP profiles (Hotelling paired T(2) test, P < 0.0001), suggesting that a distinct crenarchaeal consortium is associated with plants. In general, phylotype richness increased in the rhizosphere compared to the corresponding bulk soil, although the range of this increase was variable. Examples of a major change in rhizosphere (versus bulk soil) PCR-SSCP profiles were detected for all plant groups, suggesting that crenarchaeotes form associations with phylogenetically diverse plants in native environments. In addition, examples of minor to no detectable difference were found for all terrestrial plant groups, suggesting that crenarchaeal associations with plants are mediated by environmental conditions. PMID:15006809

  2. Comparison of Crenarchaeal Consortia Inhabiting the Rhizosphere of Diverse Terrestrial Plants with Those in Bulk Soil in Native Environments

    PubMed Central

    Sliwinski, Marek K.; Goodman, Robert M.

    2004-01-01

    To explore whether the crenarchaeal consortium found in the rhizosphere is distinct from the assemblage of crenarchaeotes inhabiting bulk soil, PCR-single-stranded-conformation polymorphism (PCR-SSCP) profiles were generated for 76 plant samples collected from native environments. Divergent terrestrial plant groups including bryophytes (mosses), lycopods (club mosses), pteridophytes (ferns), gymnosperms (conifers), and angiosperms (seed plants) were collected for this study. Statistical analysis revealed significant differences between rhizosphere and bulk soil PCR-SSCP profiles (Hotelling paired T2 test, P < 0.0001), suggesting that a distinct crenarchaeal consortium is associated with plants. In general, phylotype richness increased in the rhizosphere compared to the corresponding bulk soil, although the range of this increase was variable. Examples of a major change in rhizosphere (versus bulk soil) PCR-SSCP profiles were detected for all plant groups, suggesting that crenarchaeotes form associations with phylogenetically diverse plants in native environments. In addition, examples of minor to no detectable difference were found for all terrestrial plant groups, suggesting that crenarchaeal associations with plants are mediated by environmental conditions. PMID:15006809

  3. Plant Diversity and Evolution (11:704:411) and Advanced Plant Systematics (16:215:507) Schedule 2009

    E-print Network

    Chen, Kuang-Yu

    in Plants (sexual reproduction) chapter 13 (pp. 465-472) Thu 15 Oct lecture Rosids: basal groups and Eurosid (pp. 252-259, 278-289) Mon 19 Oct lecture Non-Sex in Plants (vegetative reproduction) chapter 13 (pp

  4. Assessment of genome origins and genetic diversity in the genus Eleusine with DNA markers.

    PubMed

    Salimath, S S; de Oliveira, A C; Godwin, I D; Bennetzen, J L

    1995-08-01

    Finger millet (Eleusine coracana), an allotetraploid cereal, is widely cultivated in the arid and semiarid regions of the world. Three DNA marker techniques, restriction fragment length polymorphism (RFLP), randomly amplified polymorphic DNA (RAPD), and inter simple sequence repeat amplification (ISSR), were employed to analyze 22 accessions belonging to 5 species of Eleusine. An 8 probe--3 enzyme RFLP combination, 18 RAPD primers, and 6 ISSR primers, respectively, revealed 14, 10, and 26% polymorphism in 17 accessions of E. coracana from Africa and Asia. These results indicated a very low level of DNA sequence variability in the finger millets but did allow each line to be distinguished. The different Eleusine species could be easily identified by DNA marker technology and the 16% intraspecific polymorphism exhibited by the two analyzed accessions of E. floccifolia suggested a much higher level of diversity in this species than in E. coracana. Between species, E. coracana and E. indica shared the most markers, while E. indica and E. tristachya shared a considerable number of markers, indicating that these three species form a close genetic assemblage within the Eleusine. Eleusine floccifolia and E. compressa were found to be the most divergent among the species examined. Comparison of RFLP, RAPD, and ISSR technologies, in terms of the quantity and quality of data output, indicated that ISSRs are particularly promising for the analysis of plant genome diversity. PMID:7672607

  5. Spatially Informed Plant PRA Models for Security Assessment

    SciTech Connect

    Wheeler, Timothy A.; Thomas, Willard; Thornsbury, Eric

    2006-07-01

    Traditional risk models can be adapted to evaluate plant response for situations where plant systems and structures are intentionally damaged, such as from sabotage or terrorism. This paper describes a process by which traditional risk models can be spatially informed to analyze the effects of compound and widespread harsh environments through the use of 'damage footprints'. A 'damage footprint' is a spatial map of regions of the plant (zones) where equipment could be physically destroyed or disabled as a direct consequence of an intentional act. The use of 'damage footprints' requires that the basic events from the traditional probabilistic risk assessment (PRA) be spatially transformed so that the failure of individual components can be linked to the destruction of or damage to specific spatial zones within the plant. Given the nature of intentional acts, extensive modifications must be made to the risk models to account for the special nature of the 'initiating events' associated with deliberate adversary actions. Intentional acts might produce harsh environments that in turn could subject components and structures to one or more insults, such as structural, fire, flood, and/or vibration and shock damage. Furthermore, the potential for widespread damage from some of these insults requires an approach that addresses the impacts of these potentially severe insults even when they occur in locations distant from the actual physical location of a component or structure modeled in the traditional PRA. (authors)

  6. Genetic diversity in widespread species is not congruent with species richness in alpine plant communities.

    PubMed

    Taberlet, Pierre; Zimmermann, Niklaus E; Englisch, Thorsten; Tribsch, Andreas; Holderegger, Rolf; Alvarez, Nadir; Niklfeld, Harald; Coldea, Gheorghe; Mirek, Zbigniew; Moilanen, Atte; Ahlmer, Wolfgang; Marsan, Paolo Ajmone; Bona, Enzo; Bovio, Maurizio; Choler, Philippe; Cie?lak, El?bieta; Colli, Licia; Cristea, Vasile; Dalmas, Jean-Pierre; Frajman, Božo; Garraud, Luc; Gaudeul, Myriam; Gielly, Ludovic; Gutermann, Walter; Jogan, Nejc; Kagalo, Alexander A; Korbecka, Gra?yna; Küpfer, Philippe; Lequette, Benoît; Letz, Dominik Roman; Manel, Stéphanie; Mansion, Guilhem; Marhold, Karol; Martini, Fabrizio; Negrini, Riccardo; Niño, Fernando; Paun, Ovidiu; Pellecchia, Marco; Perico, Giovanni; Pi?ko?-Mirkowa, Halina; Prosser, Filippo; Pu?ca?, Mihai; Ronikier, Micha?; Scheuerer, Martin; Schneeweiss, Gerald M; Schönswetter, Peter; Schratt-Ehrendorfer, Luise; Schüpfer, Fanny; Selvaggi, Alberto; Steinmann, Katharina; Thiel-Egenter, Conny; van Loo, Marcela; Winkler, Manuela; Wohlgemuth, Thomas; Wraber, Tone; Gugerli, Felix; Vellend, Mark

    2012-12-01

    The Convention on Biological Diversity (CBD) aims at the conservation of all three levels of biodiversity, that is, ecosystems, species and genes. Genetic diversity represents evolutionary potential and is important for ecosystem functioning. Unfortunately, genetic diversity in natural populations is hardly considered in conservation strategies because it is difficult to measure and has been hypothesised to co-vary with species richness. This means that species richness is taken as a surrogate of genetic diversity in conservation planning, though their relationship has not been properly evaluated. We tested whether the genetic and species levels of biodiversity co-vary, using a large-scale and multi-species approach. We chose the high-mountain flora of the Alps and the Carpathians as study systems and demonstrate that species richness and genetic diversity are not correlated. Species richness thus cannot act as a surrogate for genetic diversity. Our results have important consequences for implementing the CBD when designing conservation strategies. PMID:23006492

  7. Structural and functional diversity of soil bacterial and fungal communities following woody plant encroachment in the southern Great Plains

    SciTech Connect

    Hollister, Emily B; Schadt, Christopher Warren; Palumbo, Anthony Vito; Ansley, R J; Boutton, Thomas W

    2010-01-01

    In the southern Great Plains (USA), encroachment of grassland ecosystems by Prosopis glandulosa (honey mesquite) is widespread. Mesquite encroachment alters net primary productivity, enhances stores of C and N in plants and soil, and leads to increased levels of soil microbial biomass and activity. While mesquite's impact on the biogeochemistry of the region is well established, it effects on soil microbial diversity and function are unknown. In this study, soils associated with four plant types (C{sub 3} perennial grasses, C{sub 4} midgrasses, C{sub 4} shortgrasses, and mesquite) from a mesquite-encroached mixed grass prairie were surveyed to in an attempt to characterize the structure, diversity, and functional capacity of their soil microbial communities. rRNA gene cloning and sequencing were used in conjunction with the GeoChip functional gene array to evaluate these potential differences. Mesquite soil supported increased bacterial and fungal diversity and harbored a distinct fungal community relative to other plant types. Despite differences in composition and diversity, few significant differences were detected with respect to the potential functional capacity of the soil microbial communities. These results may suggest that a high level of functional redundancy exists within the bacterial portion of the soil communities; however, given the bias of the GeoChip toward bacterial functional genes, potential functional differences among soil fungi could not be addressed. The results of this study illustrate the linkages shared between above- and belowground communities and demonstrate that soil microbial communities, and in particular soil fungi, may be altered by the process of woody plant encroachment.

  8. Plants with stacked genetically modified events: to assess or not to assess?

    PubMed

    Kok, Esther J; Pedersen, Jan; Onori, Roberta; Sowa, Slawomir; Schauzu, Marianna; De Schrijver, Adinda; Teeri, Teemu H

    2014-02-01

    The principles for the safety assessment of genetically modified (GM) organisms (GMOs) are harmonised worldwide to a large extent. There are, however, still differences between the European GMO regulations and the GMO regulations as they have been formulated in other parts of the world. One of these differences relates to the so-called 'stacked GM events', that is, GMOs, plants so far, where new traits are combined by conventional crossing of different GM plants. This paper advocates rethinking the current food/feed safety assessment of stacked GM events in Europe based on an analysis of different aspects that currently form the rationale for the safety assessment of stacked GM events. PMID:24418332

  9. Sown species richness and realized diversity can influence functioning of plant communities differently

    NASA Astrophysics Data System (ADS)

    Rychtecká, Terezie; Lanta, Vojt?ch; Weiterová, Iva; Lepš, Jan

    2014-08-01

    Biodiversity-ecosystem functioning experiments (BEF) typically manipulate sown species richness and composition of experimental communities to study ecosystem functioning as a response to changes in diversity. If sown species richness is taken as a measure of diversity and aboveground biomass production as a measure of community functioning, then this relationship is usually found to be positive. The sown species richness can be considered the equivalent of a local species pool in natural communities. However, in addition to species richness, realized diversity is also an important community diversity component. Realized diversity is affected by environmental filtering and biotic interactions operating within a community. As both sown species richness and the realized diversity in BEF studies (as well as local species pool vs observed realized richness in natural communities) can differ markedly, so can their effects on the community functioning. We tested this assumption using two data sets: data from a short-term pot experiment and data from the long-term Jena biodiversity plot experiment. We considered three possible predictors of community functioning (aboveground biomass production): sown species richness, realized diversity (defined as inverse of Simpson dominance index), and survivor species richness. Sown species richness affected biomass production positively in all cases. Realized diversity as well as survivor species richness had positive effects on biomass in approximately half of cases. When realized diversity or survivor species richness was tested together with sown species richness, their partial effects were none or negative. Our results suggest that we can expect positive diversity-productivity relationship when the local species pool size is the decisive factor determining realized observed diversity; in other cases, the shape of the diversity-functioning relationship may be quite opposite.

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

    PubMed Central

    Navascués, Miguel; Stoeckel, Solenn; Mariette, Stéphanie

    2010-01-01

    Summary How self-incompatibility systems are maintained in plant populations is still a debated issue. Theoretical models predict that self-incompatibility systems break down according to the intensity of inbreeding depression and number of S-alleles. Other studies have explored the role of asexual reproduction in the maintenance of self-incompatibility. However, the population genetics of partially asexual, self-incompatible populations are poorly understood and previous studies have failed to consider all possible effects of asexual reproduction or could only speculate on those effects. In the present study, we investigated how partial asexuality may affect genetic diversity at the S-locus and fitness in small self-incompatible populations. A genetic model including an S-locus and a viability locus was developed to perform forward simulations of the evolution of populations of various sizes. Drift combined with partial asexuality produced a decrease in the number of alleles at the S-locus. In addition, an excess of heterozygotes was present in the population, causing an increase in mutation load. This heterozygote excess was enhanced by the self-incompatibility system in small populations. In addition, in highly asexual populations, individuals produced asexually had some fitness advantages over individuals produced sexually (due to the increased heterozygosity, sex produces the homozygosis of deleterious alleles). Our results suggest that future research on the role of asexuality for the maintenance of self-incompatibility will need to (1) account for whole genome fitness (mutation load generated by asexuality, self-incompatibility and drift) and (2) acknowledge that the maintenance of self-incompatibility may not be independent of the maintenance of sex itself. PMID:19920857

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

    PubMed

    Navascués, M; Stoeckel, S; Mariette, S

    2010-05-01

    How self-incompatibility systems are maintained in plant populations is still a debated issue. Theoretical models predict that self-incompatibility systems break down according to the intensity of inbreeding depression and number of S-alleles. Other studies have explored the function of asexual reproduction in the maintenance of self-incompatibility. However, the population genetics of partially asexual, self-incompatible populations are poorly understood and previous studies have failed to consider all possible effects of asexual reproduction or could only speculate on those effects. In this study, we investigated how partial asexuality may affect genetic diversity at the S-locus and fitness in small self-incompatible populations. A genetic model including an S-locus and a viability locus was developed to perform forward simulations of the evolution of populations of various sizes. Drift combined with partial asexuality produced a decrease in the number of alleles at the S-locus. In addition, an excess of heterozygotes was present in the population, causing an increase in mutation load. This heterozygote excess was enhanced by the self-incompatibility system in small populations. In addition, in highly asexual populations, individuals produced asexually had some fitness advantages over individuals produced sexually, because sexual reproduction produces homozygotes of the deleterious allele, contrary to asexual reproduction. Our results suggest that future research on the function of asexuality for the maintenance of self-incompatibility will need to (1) account for whole-genome fitness (mutation load generated by asexuality, self-incompatibility and drift) and (2) acknowledge that the maintenance of self-incompatibility may not be independent of the maintenance of sex itself. PMID:19920857

  12. Microbes on mountainsides: Contrasting elevational patterns of bacterial and plant diversity

    E-print Network

    Enquist, Brian Joseph

    ecology phylogenetic diversity macroecology biogeography Roughly 250 years ago, Carolus Linnaeus (1 and biotic turnover over short geographic distances. The patterns observed by Linnaeus and his contemporaries

  13. Georgia-Pacific Palatka Plant Uses Thermal Pinch Analysis and Evaluates Water Reduction in Plant-Wide Energy Assessment

    SciTech Connect

    2002-12-01

    This OIT BestPractices Case Study describes the methods and results used in a plant-wide assessment at a Georgia-Pacific paper mill in Palatka, FL. Assessment personnel recommended several projects, which, if implemented, have the potential to save the plant more than 729,000 MMBtu per year and $2.9 million per year. In addition, the plant could reduce water use by 2,100 gallons per minute.

  14. High genetic diversity declines towards the geographic range periphery of Adonis vernalis, a Eurasian dry grassland plant.

    PubMed

    Hirsch, H; Wagner, V; Danihelka, J; Ruprecht, E; Sánchez-Gómez, P; Seifert, M; Hensen, I

    2015-11-01

    Genetic diversity is important for species' fitness and evolutionary processes but our knowledge on how it varies across a species' distribution range is limited. The abundant centre hypothesis (ACH) predicts that populations become smaller and more isolated towards the geographic range periphery - a pattern that in turn should be associated with decreasing genetic diversity and increasing genetic differentiation. We tested this hypothesis in Adonis vernalis, a dry grassland plant with an extensive Eurasian distribution. Its life-history traits and distribution characteristics suggest a low genetic diversity that decreases and a high genetic differentiation that increases towards the range edge. We analysed AFLP fingerprints in 28 populations along a 4698-km transect from the geographic range core in Russia to the western range periphery in Central and Western Europe. Contrary to our expectation, our analysis revealed high genetic diversity (range of proportion of polymorphic bands = 56-81%, He = 0.168-0.238) and low genetic differentiation across populations (?ST  = 0.18). However, in congruence with the genetic predictions of the ACH, genetic diversity decreased and genetic differentiation increased towards the range periphery. Spanish populations were genetically distinct, suggesting a divergent post-glacial history in this region. The high genetic diversity and low genetic differentiation in the remaining A. vernalis populations is surprising given the species' life-history traits and points to the possibility that the species has been widely distributed in the studied region or that it has migrated from a diverse source in an East-West direction, in the past. PMID:26122089

  15. Literature Review and Assessment of Plant and Animal Transfer Factors Used in Performance Assessment Modeling

    SciTech Connect

    Robertson, David E.; Cataldo, Dominic A.; Napier, Bruce A.; Krupka, Kenneth M.; Sasser, Lyle B.

    2003-07-20

    A literature review and assessment was conducted by Pacific Northwest National Laboratory (PNNL) to update information on plant and animal radionuclide transfer factors used in performance-assessment modeling. A group of 15 radionuclides was included in this review and assessment. The review is composed of four main sections, not including the Introduction. Section 2.0 provides a review of the critically important issue of physicochemical speciation and geochemistry of the radionuclides in natural soil-water systems as it relates to the bioavailability of the radionuclides. Section 3.0 provides an updated review of the parameters of importance in the uptake of radionuclides by plants, including root uptake via the soil-groundwater system and foliar uptake due to overhead irrigation. Section 3.0 also provides a compilation of concentration ratios (CRs) for soil-to-plant uptake for the 15 selected radionuclides. Section 4.0 provides an updated review on radionuclide uptake data for animal products related to absorption, homeostatic control, approach to equilibration, chemical and physical form, diet, and age. Compiled transfer coefficients are provided for cow’s milk, sheep’s milk, goat’s milk, beef, goat meat, pork, poultry, and eggs. Section 5.0 discusses the use of transfer coefficients in soil, plant, and animal modeling using regulatory models for evaluating radioactive waste disposal or decommissioned sites. Each section makes specific suggestions for future research in its area.

  16. Power plant system assessment. Final report. SP-100 Program

    SciTech Connect

    Anderson, R.V.; Atkins, D.F.; Bost, D.S.; Berman, B.; Clinger, D.A.; Determan, W.R.; Drucker, G.S.; Glasgow, L.E.; Hartung, J.A.; Harty, R.B.

    1983-10-31

    The purpose of this assessment was to provide system-level insights into 100-kWe-class space reactor electric systems. Using these insights, Rockwell was to select and perform conceptual design studies on a ''most attractive'' system that met the preliminary design goals and requirements of the SP-100 Program. About 4 of the 6 months were used in the selection process. The remaining 2 months were used for the system conceptual design studies. Rockwell completed these studies at the end of FY 1983. This report summarizes the results of the power plant system assessment and describes our choice for the most attractive system - the Rockwell SR-100G System (Space Reactor, 100 kWe, Growth) - a lithium-cooled UN-fueled fast reactor/Brayton turboelectric converter system.

  17. Environmental Assessment for decontamination and dismantlement, Pinellas Plant

    SciTech Connect

    1995-06-01

    The US Department of Energy (DOE) has prepared an Environmental Assessment (EA) (DOE/EA-1092) of the proposed decontamination and dismantlement of the Pinellas Plant in Largo, Florida. Under the Decontamination and Dismantlement EA, the DOE proposes to clean up facilities, structures, and utilities; dismantle specific structures; and mitigate or eliminate any environmental impacts associated with the cleanup, dismantlement, and related activities. Related activities include utilization of specific areas by new tenants prior to full-scale cleanup. Based on the analyses in the EA, the DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act of 1969. Therefore, the preparation of an environmental impact statement is not required. This report contains the Environmental Assessment, as well as the Finding of No Significant Impact (FONSI).

  18. Sharing of Diverse Mycorrhizal and Root-Endophytic Fungi among Plant Species in an Oak-Dominated Cool–Temperate Forest

    PubMed Central

    Toju, Hirokazu; Yamamoto, Satoshi; Sato, Hirotoshi; Tanabe, Akifumi S.

    2013-01-01

    Most terrestrial plants interact with diverse clades of mycorrhizal and root-endophytic fungi in their roots. Through belowground plant–fungal interactions, dominant plants can benefit by interacting with host-specific mutualistic fungi and proliferate in a community based on positive plant–mutualistic fungal feedback. On the other hand, subordinate plant species may persist in the community by sharing other sets (functional groups) of fungal symbionts with each other. Therefore, revealing how diverse clades of root-associated fungi are differentially hosted by dominant and subordinate plant species is essential for understanding plant community structure and dynamics. Based on 454-pyrosequencing, we determined the community composition of root-associated fungi on 36 co-occurring plant species in an oak-dominated forest in northern Japan and statistically evaluated the host preference phenotypes of diverse mycorrhizal and root-endophytic fungi. An analysis of 278 fungal taxa indicated that an ectomycorrhizal basidiomycete fungus in the genus Lactarius and a possibly endophytic ascomycete fungus in the order Helotiales significantly favored the dominant oak (Quercus) species. In contrast, arbuscular mycorrhizal fungi were generally shared among subordinate plant species. Although fungi with host preferences contributed to the compartmentalization of belowground plant–fungal associations, diverse clades of ectomycorrhizal fungi and possible root endophytes were associated not only with the dominant Quercus but also with the remaining plant species. Our findings suggest that dominant-ectomycorrhizal and subordinate plant species can host different subsets of root-associated fungi, and diverse clades of generalist fungi can counterbalance the compartmentalization of plant–fungal associations. Such insights into the overall structure of belowground plant–fungal associations will help us understand the mechanisms that facilitate the coexistence of plant species in natural communities. PMID:24250752

  19. Rapid Assessment of Octocoral Diversity and Habitat on Saba Bank, Netherlands Antilles

    PubMed Central

    Etnoyer, Peter J.; Wirshing, Herman H.; Sánchez, Juan A.

    2010-01-01

    Saba Bank is a large submerged platform (?2200 km2), average depth 30 m, located 4 km southwest of Saba Island in Netherlands Antilles, Caribbean Sea. Ships traveling to and from oil terminals on nearby St. Eustatius routinely anchor on the Bank, damaging benthic megafauna. Gorgonian octocorals are vulnerable to anchor damage, and they are common and conspicuous in shallow water (15–50 m) around the banks. This prompted a rapid assessment of octocoral habitat and diversity. The primary objectives were to estimate total species richness and to characterize habitats vis a vis gorgonians. Landsat imagery and multibeam bathymetry were employed to identify random sites for quantitative transects. A Seabotix LBV200L remotely operated vehicle (ROV) and SCUBA were used to collect and survey to 130 m. A total of 14 scuba dives and 3 ROV dives were completed in 10 days. During that time, 48 octocoral species were collected, including two likely undescribed species in the genera Pterogorgia and Lytreia. Gorgonian richness was exceptional, but not all species were collected, because the species accumulation curve remained steeply inclined after all surveys. Two shallow-water gorgonian habitat types were identified using multidimensional scaling and hierarchical cluster analyses: 1) a high diversity, high density fore-reef environment characterized by Eunicea spp., Gorgonia spp., and Pseudopterogorgia spp. and 2) a low diversity, low density plateau environment characterized by Pseudopterogorgia acerosa, Pterogorgia guadalupensis, and Gorgonia mariae. The analyses support hypotheses of broad (?15 km) habitat homogeneity (ANOSIM, P>0.05), but a significant difference between fore-reef and plateau environments (ANOSIM, P<0.05). However, there was some indication of habitat heterogeneity along the 15 km study section of the 50 km platform edge along the southeast rim. Our results highlight the complexity and biodiversity of the Saba Bank, and emphasize the need for more scientific exploration. PMID:20502636

  20. STOCHASTIC MODELS OF PLANT DIVERSITY: APPLICATION TO WHITE SANDS MISSILE RANGE

    EPA Science Inventory

    Diversity is an average property of a community and is identified as the species variety and abundance. The study of biodiversity is important because it is one of the central themes in ecology; the diversity of a system is often seen as an indicator of the well-being of the syst...

  1. Impact of agricultural land management systems on soil microbial diversity and plant disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased diversity of fungal rDNA ITS-1 amplicons, as measured by the Shannon-Weiner index, was associated with land management practices that minimise soil disturbance (bahiagrass pasture and undisturbed weed fallow) when compared with organic or conventional land management systems. Diversity de...

  2. Plant-Mediated Demographic Responses by Orius Insidiosus to Vegetational Diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1) Vegetational diversity is known to affect generalist predator populations, but the mechanisms that drive these natural enemy populations in vegetationally diverse systems are poorly understood. Here, we document how the demographics of an omnivorous bug, Orius insidiosus, respond to mono- and pol...

  3. Rapid assessment indicator of wetland integrity as an unintended predictor of avian diversity

    USGS Publications Warehouse

    Stapanian, Martin A.; Waite, Thomas A.; Krzys, Gregory; Mack, John J.; Micacchion, Mick

    2004-01-01

    Rapid assessment of aquatic ecosystems has been widely implemented, sometimes without thorough evaluation of the robustness of rapid assessment metrics as indicators of ecological integrity. Here, we evaluate whether the Ohio Rapid Assessment Method (ORAM) for Wetlands Version 5.0 is a useful indicator of ecological integrity beyond its intended purpose. ORAM was developed to categorize natural wetlands for regulatory purposes and to contribute to the development of indicators of biotic integrity. It was never intended for use as an index of the quality of habitat for wetland birds. Nonetheless, it is conceivable that ORAM scores could serve as adequate predictors of avian diversity. We evaluated whether avian species richness in wetlands could be reliably predicted from each of the following variables: (1) total ORAM score, (2) total score minus the score for one metric that did not apply to all wetlands, and (3) sum of scores for the four ORAM components (of 16 scored) with the highest potential point total. These four components corresponded to aquatic vegetation communities, microtopography, modifications to natural hydrologic regime, and sources of water. All three variables were significant predictors of both total species richness and mean species richness of birds of conservation concern. Variable (3) was a significant predictor of mean species richness of wetland-dependent birds. Variable (2) was a weak predictor of both total and mean species richness of all birds combined. These results extend the robustness of ORAM as an indicator of the ecological integrity of wetlands.

  4. Grain Diversity Effects on Banker Plant Growth and Parasitism by Aphidius colemani.

    PubMed

    McClure, Travis; Frank, Steven D

    2015-01-01

    Green peach aphid (Myzus persicae Sulzer) (Hemiptera: Aphididae) is a serious greenhouse pest with a short generation time, parthenogenetic reproduction and a broad host range. Banker plant systems are becoming a more common form of biological control for this pest. This system consists of grain "banker plants" infested with R. padi, an alternative hosts for the parasitoid Aphidius colemani. Thus A. colemani can reproduce on the banker plant when M. persicae populations are low. This system can increase pest suppression; however, like other biological control tools, efficacy is inconsistent. One reason is because several different grain species have been used. Our studies determined if there were benefits to planting interspecific mixture banker plants, similar to when open agricultural systems use mixed cropping. Our study found that although banker plants grow larger when planted as mixtures this added plant growth does not increase in the number of aphids, or mummies an individual banker plant can sustain. Rye banker plants grew larger, and sustained more mummies than the other species we tested, but barley banker plants resulted in a similar number of aphids in a more condensed area. Ultimately, we did not see any differences in pest suppression between monoculture banker plants, mixture banker plants, or our augmentative release treatment. However, using banker plants resulted in more female parasitoids than the augmentative release, a benefit to using banker plant systems. PMID:26463416

  5. Grain Diversity Effects on Banker Plant Growth and Parasitism by Aphidius colemani

    PubMed Central

    McClure, Travis; Frank, Steven D.

    2015-01-01

    Green peach aphid (Myzus persicae Sulzer) (Hemiptera: Aphididae) is a serious greenhouse pest with a short generation time, parthenogenetic reproduction and a broad host range. Banker plant systems are becoming a more common form of biological control for this pest. This system consists of grain “banker plants” infested with R. padi, an alternative hosts for the parasitoid Aphidius colemani. Thus A. colemani can reproduce on the banker plant when M. persicae populations are low. This system can increase pest suppression; however, like other biological control tools, efficacy is inconsistent. One reason is because several different grain species have been used. Our studies determined if there were benefits to planting interspecific mixture banker plants, similar to when open agricultural systems use mixed cropping. Our study found that although banker plants grow larger when planted as mixtures this added plant growth does not increase in the number of aphids, or mummies an individual banker plant can sustain. Rye banker plants grew larger, and sustained more mummies than the other species we tested, but barley banker plants resulted in a similar number of aphids in a more condensed area. Ultimately, we did not see any differences in pest suppression between monoculture banker plants, mixture banker plants, or our augmentative release treatment. However, using banker plants resulted in more female parasitoids than the augmentative release, a benefit to using banker plant systems. PMID:26463416

  6. Diversity patterns amongst herbivorous dinosaurs and plants during the Cretaceous: implications for hypotheses of dinosaur/angiosperm co-evolution.

    PubMed

    Butler, R J; Barrett, P M; Kenrick, P; Penn, M G

    2009-03-01

    Palaeobiologists frequently attempt to identify examples of co-evolutionary interactions over extended geological timescales. These hypotheses are often intuitively appealing, as co-evolution is so prevalent in extant ecosystems, and are easy to formulate; however, they are much more difficult to test than their modern analogues. Among the more intriguing deep time co-evolutionary scenarios are those that relate changes in Cretaceous dinosaur faunas to the primary radiation of flowering plants. Demonstration of temporal congruence between the diversifications of co-evolving groups is necessary to establish whether co-evolution could have occurred in such cases, but is insufficient to prove whether it actually did take place. Diversity patterns do, however, provide a means for falsifying such hypotheses. We have compiled a new database of Cretaceous dinosaur and plant distributions from information in the primary literature. This is used as the basis for plotting taxonomic diversity and occurrence curves for herbivorous dinosaurs (Sauropodomorpha, Stegosauria, Ankylosauria, Ornithopoda, Ceratopsia, Pachycephalosauria and herbivorous theropods) and major groups of plants (angiosperms, Bennettitales, cycads, cycadophytes, conifers, Filicales and Ginkgoales) that co-occur in dinosaur-bearing formations. Pairwise statistical comparisons were made between various floral and faunal groups to test for any significant similarities in the shapes of their diversity curves through time. We show that, with one possible exception, diversity patterns for major groups of herbivorous dinosaurs are not positively correlated with angiosperm diversity. In other words, at the level of major clades, there is no support for any diffuse co-evolutionary relationship between herbivorous dinosaurs and flowering plants. The diversification of Late Cretaceous pachycephalosaurs (excluding the problematic taxon Stenopelix) shows a positive correlation, but this might be spuriously related to poor sampling in the Turonian-Santonian interval. Stegosauria shows a significant negative correlation with flowering plants and a significant positive correlation with the nonflowering cycadophytes (cycads, Bennettitales). This interesting pattern is worthy of further investigation, and it reflects the decline of both stegosaurs and cycadophytes during the Early Cretaceous. PMID:19210589

  7. Covering chemical diversity of genetically-modified tomatoes using metabolomics for objective substantial equivalence assessment.

    PubMed

    Kusano, Miyako; Redestig, Henning; Hirai, Tadayoshi; Oikawa, Akira; Matsuda, Fumio; Fukushima, Atsushi; Arita, Masanori; Watanabe, Shin; Yano, Megumu; Hiwasa-Tanase, Kyoko; Ezura, Hiroshi; Saito, Kazuki

    2011-01-01

    As metabolomics can provide a biochemical snapshot of an organism's phenotype it is a promising approach for charting the unintended effects of genetic modification. A critical obstacle for this application is the inherently limited metabolomic coverage of any single analytical platform. We propose using multiple analytical platforms for the direct acquisition of an interpretable data set of estimable chemical diversity. As an example, we report an application of our multi-platform approach that assesses the substantial equivalence of tomatoes over-expressing the taste-modifying protein miraculin. In combination, the chosen platforms detected compounds that represent 86% of the estimated chemical diversity of the metabolites listed in the LycoCyc database. Following a proof-of-safety approach, we show that % had an acceptable range of variation while simultaneously indicating a reproducible transformation-related metabolic signature. We conclude that multi-platform metabolomics is an approach that is both sensitive and robust and that it constitutes a good starting point for characterizing genetically modified organisms. PMID:21359231

  8. Genetic diversity assessment of Vitis ficifolia Bge. populations from Henan province of China by SRAP markers

    PubMed Central

    Fan, Xiucai; Jiang, Jianfu; Zhang, Ying; Sun, Haisheng; Jiao, Jian; Liu, Chonghuai

    2015-01-01

    Eighteen sequence-related amplified polymorphism (SRAP) primer combinations were used to assess the genetic diversity of 126 individuals from five different geographical populations of Vitis ficifolia Bge. The numbers of bands scored per primer combination ranged from 8 to 27, with an average of 18.6 bands. At the population level, the percentage of polymorphic bands (PPB), Nei's gene diversity index (H) and Shannon's information index (I) were the highest in the Shihe (Xinyang) population (77.31%, 0.1987, 0.2805) and the lowest in the Linzhou (Anyang) population (55.82%, 0.1112, 0.1727). At the species level, PPB, H and I were 80.56%, 0.2129 and 0.3075, respectively. The genetic differentiation coefficient (G ST) was 0.2055 and the gene flow (Nm) was 1.9328, indicating strong intra-population genetic differentiation. Based on the unweighted pair group method based arithmetic average clustering diagram, the five studied populations may be divided into three groups. The clustering results were almost in accordance with the populations’ geographical distribution. PMID:26019614

  9. Assessing The Evolutionary Diversity Of Exon Skipping Events In Human, Mouse And Rat

    NASA Astrophysics Data System (ADS)

    Hsu, Fang-Rong; Chen, Chao-Jung; Kuo, Min-Chieh; Chang, Hwan-You; Shia, Wei-Chung

    2008-01-01

    This study is to research on the cross-species comparative analysis of homologous genetic sequence among human, mouse and rat by bioinformatics method, hopefully assessing the evolutionary diversity through exon length, reading frame preservation and KA/KS ratio test of alternative splicing events. Alternative splicing (AS) is an important mechanism in eukaryotic organism. We choose the "exon skipping events" from AS events for research. In the data of "conserved exon skipping events", we get 668 human-mouse conserved events, 179 human-rat conserved events and 266 conserved mouse-rat events. There are some extra data such as "non-conserved exon skipping events" and "species-specific events". We found out that the length of AS exon is shorter in conserved exon skipping event, but the ratio of reading frame preservation is higher. Among them, the minor form is the most special. We even got the same result in non-conserved exon skipping events. We calculated the KA/KS value by KA/KS ratio test and found out that the human-mouse KA/KS ratio is 0.158, the human-rat is 0.182 and the mouse-rat is 0.190. This represents that the human-mouse conserved events have the highest purifying selection pressure. In the end, we adopt KA/KS ratio test to do a further analysis between conserved and non-conserved exon skipping events and evaluate the evolutionary diversity of cross-species comparation.

  10. Prevalence, distribution, and diversity of Escherichia coli, Staphylococcus aureus, and Salmonella in kiwifruit orchards and processing plants.

    PubMed

    Feng, Yuqing; Li, Guanghui; Lv, Xiaoying; Xu, Yunfeng; Wu, Qian; Shi, Chao; Li, Qiong; Yang, Baowei; Wang, Xin; Xi, Meili; Xia, Xiaodong

    2014-10-01

    The aim of the study was to investigate the prevalence, distribution, and diversity of three foodborne bacteria in kiwifruit orchards and processing plants. Fourteen kiwifruit orchards and two processing plants in Shaanxi province were visited for sampling in 2012. Fruit samples and environmental samples in orchards and plants were taken for isolation of Escherichia coli, Staphylococcus aureus, and Salmonella. All isolates were characterized by antimicrobial susceptibility testing and detection of virulence genes. Selected isolates were further examined by pulsed-field gel electrophoresis (PFGE) analysis. In total, 160 E. coli isolates and 14 S. aureus isolates were recovered from 407 samples from orchards and plants, while no Salmonella was recovered. E. coli isolates displayed resistance most frequently to streptomycin (65.6%), and S. aureus isolates displayed resistance most frequently to erythromycin (21.4%). Three E. coli isolates (1.9%) were positive for stx2 and two S. aureus isolates (14.3%) were positive for both seb and seh. Seventy-seven E. coli isolates and 14 S. aureus isolates were analyzed by PFGE. PFGE results showed that both E. coli and S. aureus isolates were diverse, and blades for slicing during the processing could be an important contamination source. This study could provide useful information for kiwifruit growers and industry to establish proper management practices that help minimize the chance of microbial contamination from farm to table. PMID:25054781

  11. Coevolution Pattern and Functional Conservation or Divergence of miR167s and their targets across Diverse Plant Species

    PubMed Central

    Barik, Suvakanta; Kumar, Ashutosh; Sarkar Das, Shabari; Yadav, Sandeep; Gautam, Vibhav; Singh, Archita; Singh, Sharmila; Sarkar, Ananda K.

    2015-01-01

    microRNAs (miRNAs), a class of endogenously produced small non-coding RNAs of 20–21 nt length, processed from precursor miRNAs, regulate many developmental processes by negatively regulating the target genes in both animals and plants. The coevolutionary pattern of a miRNA family and their targets underscores its functional conservation or diversification. The miR167 regulates various aspects of plant development in Arabidopsis by targeting ARF6 and ARF8. The evolutionary conservation or divergence of miR167s and their target genes are poorly understood till now. Here we show the evolutionary relationship among 153 MIR167 genes obtained from 33 diverse plant species. We found that out of the 153 of miR167 sequences retrieved from the “miRBase”, 27 have been annotated to be processed from the 3? end, and have diverged distinctively from the other miR167s produced from 5? end. Our analysis reveals that gma-miR167h/i and mdm-miR167a are processed from 3? end and have evolved separately, diverged most resulting in novel targets other than their known ones, and thus led to functional diversification, especially in apple and soybean. We also show that mostly conserved miR167 sequences and their target AUXIN RESPONSE FACTORS (ARFs) have gone through parallel evolution leading to functional diversification among diverse plant species. PMID:26459056

  12. Aalborg Universitet An assessment of converter modelling needs for offshore wind power plants

    E-print Network

    Bak, Claus Leth

    Aalborg Universitet An assessment of converter modelling needs for offshore wind power plants). An assessment of converter modelling needs for offshore wind power plants connected via VSC-HVDC networks Power into Power Systems as well as on Transmission Networks for Offshore Wind Plants. Energynautics

  13. 7 CFR 319.40-11 - Plant pest risk assessment standards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Plant pest risk assessment standards. 319.40-11... Unmanufactured Wood Articles § 319.40-11 Plant pest risk assessment standards. When evaluating a request to... analysis to determine the plant pest risks associated with each requested importation in order to...

  14. 7 CFR 319.40-11 - Plant pest risk assessment standards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Plant pest risk assessment standards. 319.40-11... Unmanufactured Wood Articles § 319.40-11 Plant pest risk assessment standards. When evaluating a request to... analysis to determine the plant pest risks associated with each requested importation in order to...

  15. North Star Steel Company: Iowa Mini-Mill Conducts Plant-Wide Energy Assessment Using a Total Assessment Audit

    SciTech Connect

    2004-08-01

    North Star Steel completed a plant-wide energy assessment at its plant in Wilton, Iowa. The assessment identified potential annual savings of 140,000 MMBtu in natural gas, nearly 39 million kWh in electricity, and more than $2.6 million.

  16. Deciphering the Diversities of Astroviruses and Noroviruses in Wastewater Treatment Plant Effluents by a High-Throughput Sequencing Method.

    PubMed

    Prevost, B; Lucas, F S; Ambert-Balay, K; Pothier, P; Moulin, L; Wurtzer, S

    2015-10-01

    Although clinical epidemiology lists human enteric viruses to be among the primary causes of acute gastroenteritis in the human population, their circulation in the environment remains poorly investigated. These viruses are excreted by the human population into sewers and may be released into rivers through the effluents of wastewater treatment plants (WWTPs). In order to evaluate the viral diversity and loads in WWTP effluents of the Paris, France, urban area, which includes about 9 million inhabitants (approximately 15% of the French population), the seasonal occurrence of astroviruses and noroviruses in 100 WWTP effluent samples was investigated over 1 year. The coupling of these measurements with a high-throughput sequencing approach allowed the specific estimation of the diversity of human astroviruses (human astrovirus genotype 1 [HAstV-1], HAstV-2, HAstV-5, and HAstV-6), 7 genotypes of noroviruses (NoVs) of genogroup I (NoV GI.1 to NoV GI.6 and NoV GI.8), and 16 genotypes of NoVs of genogroup II (NoV GII.1 to NoV GII.7, NoV GII.9, NoV GII.12 to NoV GII.17, NoV GII.20, and NoV GII.21) in effluent samples. Comparison of the viral diversity in WWTP effluents to the viral diversity found by analysis of clinical data obtained throughout France underlined the consistency between the identified genotypes. However, some genotypes were locally present in effluents and were not found in the analysis of the clinical data. These findings could highlight an underestimation of the diversity of enteric viruses circulating in the human population. Consequently, analysis of WWTP effluents could allow the exploration of viral diversity not only in environmental waters but also in a human population linked to a sewerage network in order to better comprehend viral epidemiology and to forecast seasonal outbreaks. PMID:26253673

  17. A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers.

    PubMed

    Aronson, Myla F J; La Sorte, Frank A; Nilon, Charles H; Katti, Madhusudan; Goddard, Mark A; Lepczyk, Christopher A; Warren, Paige S; Williams, Nicholas S G; Cilliers, Sarel; Clarkson, Bruce; Dobbs, Cynnamon; Dolan, Rebecca; Hedblom, Marcus; Klotz, Stefan; Kooijmans, Jip Louwe; Kühn, Ingolf; Macgregor-Fors, Ian; McDonnell, Mark; Mörtberg, Ulla; Pysek, Petr; Siebert, Stefan; Sushinsky, Jessica; Werner, Peter; Winter, Marten

    2014-04-01

    Urbanization contributes to the loss of the world's biodiversity and the homogenization of its biota. However, comparative studies of urban biodiversity leading to robust generalities of the status and drivers of biodiversity in cities at the global scale are lacking. Here, we compiled the largest global dataset to date of two diverse taxa in cities: birds (54 cities) and plants (110 cities). We found that the majority of urban bird and plant species are native in the world's cities. Few plants and birds are cosmopolitan, the most common being Columba livia and Poa annua. The density of bird and plant species (the number of species per km(2)) has declined substantially: only 8% of native bird and 25% of native plant species are currently present compared with estimates of non-urban density of species. The current density of species in cities and the loss in density of species was best explained by anthropogenic features (landcover, city age) rather than by non-anthropogenic factors (geography, climate, topography). As urbanization continues to expand, efforts directed towards the conservation of intact vegetation within urban landscapes could support higher concentrations of both bird and plant species. Despite declines in the density of species, cities still retain endemic native species, thus providing opportunities for regional and global biodiversity conservation, restoration and education. PMID:24523278

  18. A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers

    PubMed Central

    Aronson, Myla F. J.; La Sorte, Frank A.; Nilon, Charles H.; Katti, Madhusudan; Goddard, Mark A.; Lepczyk, Christopher A.; Warren, Paige S.; Williams, Nicholas S. G.; Cilliers, Sarel; Clarkson, Bruce; Dobbs, Cynnamon; Dolan, Rebecca; Hedblom, Marcus; Klotz, Stefan; Kooijmans, Jip Louwe; Kühn, Ingolf; MacGregor-Fors, Ian; McDonnell, Mark; Mörtberg, Ulla; Pyšek, Petr; Siebert, Stefan; Sushinsky, Jessica; Werner, Peter; Winter, Marten

    2014-01-01

    Urbanization contributes to the loss of the world's biodiversity and the homogenization of its biota. However, comparative studies of urban biodiversity leading to robust generalities of the status and drivers of biodiversity in cities at the global scale are lacking. Here, we compiled the largest global dataset to date of two diverse taxa in cities: birds (54 cities) and plants (110 cities). We found that the majority of urban bird and plant species are native in the world's cities. Few plants and birds are cosmopolitan, the most common being Columba livia and Poa annua. The density of bird and plant species (the number of species per km2) has declined substantially: only 8% o