WorldWideScience

Sample records for understorey species calluna

  1. Germination of native understorey species for revegetation of New South Wales coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, M.J.; Bellairs, S.M.; Mulligan, D.R. [University of Queensland, St. Lucia, Qld. (Australia). Dept. of Agriculture and Centre for Mined Land Rehabilitation

    1997-06-01

    This project investigates the suitability of a range of native understorey species for rehabilitation at several coal mines in New South Wales. The germination of seeds from 69 species representing 12 families was tested under controlled laboratory conditions. Germination occurred in all but two of the species tested and 50% germination was exceeded by 29 species. Species of the Mimosaceae, Fabaceae and Proteaceae tended to have above average germination; however species representing other families had variable germination results. A pre-germination heat treatment applied to all of the Acacia species increased germination in some but not all species. Seeds of these understorey species which were used in this trial, are native to the New South Wales coal fields and available commercially or are relatively easy to collect. Glasshouse and field trials are now being undertaken to assess establishment and growth on mine soil, spoil and coal reject materials. 9 refs., 5 figs.

  2. Antimicrobial activity of selected plant species of Genera arbutus l., Bruckenthalia rchb., Calluna salisb. and Erica l. (Ericaceae

    Directory of Open Access Journals (Sweden)

    Pavlović Dragana

    2014-03-01

    Full Text Available Najpoznatiji i najviše korišćeni biljni uroantiseptik je list uve, Uvaeursi folium (Arctostaphylos uva ursi, Ericaceae. U tradicionalnoj medicini često se i druge vrste familije Ericaceae spominju u lečenju urinarnih infekcija. Provera antimikrobne aktivnosti izvršena je za sledeće biljne vrste ove familije koje samostalno rastu u flori Balkanskog poluostrva: Arbutus unedo, Bruckentalia spiculifolia, Calluna vulgaris, Erica arborea i Erica carnea.

  3. Land-use history affects understorey plant species distributions in a large temperate-forest complex, Denmark

    DEFF Research Database (Denmark)

    Svenning, J.-C.; Baktoft, Karen H.; Balslev, Henrik

    2009-01-01

    In Europe, forests have been strongly influenced by human land-use for millennia. Here, we studied the importance of anthropogenic historical factors as determinants of understorey species distributions in a 967 ha Danish forest complex using 156 randomly placed 100-m2 plots, 15 environmental, 9...... dispersal and a strong literature record as ancient-forest species, were still concentrated in areas that were high forest in 1805. Among the younger forests, there were clear floristic differences between those on reclaimed bogs and those not. Apparently remnant populations of wet-soil plants were still...

  4. Transfer equations for cesium-137 for coniferous forest understorey plant species

    International Nuclear Information System (INIS)

    Wirth, E.; Hiersche, L.; Kammerer, L.; Krajewska, G.; Krestel, R.; Mahler, S.; Roemmelt, R.

    1994-01-01

    The transfer of cesium-137 from organic soil horizons to understorey vegetation has been studied on two coniferous tree sites. In total, 14 different plants preferably taking up their nutrients from organic soil layers were taken into account. A relatively good correlation was found to exist between the transfer factor (Bq/kg plant dry wt./Bq/kg O-horizons dry wt.) for dicotyledons (r=0.51) and berry plants (r=0.63), but there was no correlation for monocotyledons (r= 0 .15). The correlations could not be improved by additionally taking potassium in plant and soil into account. These results are discussed in respect to different parameters influencing the amount of cesium-137 uptake, including plants supported by mycorrhizal fungi

  5. Foliar responses of understorey Abies lasiocarpa to different degrees of release cutting of Betula papyrifera and conifer mixed species stand

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.R.; Letchford, T. [Ministry of Forests, Prince George, BC (Canada). Red Rock Research Station; Comeau, P.G. [BC Ministry of Forests, Victoria, BC (Canada); Coopersmith, D. [BC Ministry of Forests, Prince George, BC (Canada)

    2000-07-01

    Foliar responses of subalpine fir (Abies lasiocarpa (Hook.) Nutt.) to thinning were studied in a 35-yr-old mixed stand of paper birch (Betula papyrifera Marsh.) and conifers. The stand regenerated naturally after a wildfire with a canopy dominated by paper birch (average height 9.8 m) and an understorey dominated by subalpine fir (average height 1.6 m). The stand was thinned to four densities of birch: 0, 600 and 1200 stems ha{sup -1} and control (Unthinned at 2300-6400 stems ha{sup -1}) in the autumn of 1995. The understorey conifers, mainly subalpine fir, were thinned to 1200 stems ha{sup -1}. The study used a completely randomized split-plot design. Three sample trees were systematically selected from each treatment replicate and each tree stratum (upper, intermediate and lower understorey). One-year-old and older age class needles were collected from one south-facing branch within the fifth whorl from the tree top. Thinning of paper birch significantly (p<0.001) increased leaf area and dry weight per 100 needles for intermediate and short trees except in the 0 birch treatment. Understorey subalpine fir trees in 600 stems ha{sup -1} birch (T3) had the largest leaf area and leaf dry weight per 100 1-yr-old needles. Specific leaf area (SLA) decreased from unthinned (T1) to 0 birch (T4). Lower understorey trees had the largest SLA. One-year-old needles had significantly higher N, P and K concentrations in all the thinning treatments. These responses are consistent with the shade tolerance of subalpine fir. The results suggest that when managing a paper birch-conifers mixed wood forest it may be of benefit to understorey conifers to leave a birch canopy as a nursing crop.

  6. Species richness and distribution of understorey bryophytes in different forest types in Colombian Amazonia

    NARCIS (Netherlands)

    Benavides, J.C.; Duque, A.J.; Duivenvoorden, J.F.; Cleef, A.M.

    2006-01-01

    The first bryophyte survey results from Colombian Amazonia are presented. Bryophyte species, differentiated into mosses and liverworts, and further into four life-form classes, were sampled in 0.1-ha plots. These plots were distributed over four landscape units in the middle Caquetá area:

  7. Understorey bird abundance and diversity before and after a forest ...

    African Journals Online (AJOL)

    The understorey bird species diversity before the forest was burned was substantially higher than ..... Conservation interventions are necessary and measures against forest fires are ... I would like to thank the Ministry of Natural Resources and Tourism, Tanzania for permission ... package for education and data analysis.

  8. Seasonal variation in diversity and abundance of understorey birds ...

    African Journals Online (AJOL)

    Our findings suggest that in a situation where there is no natural forest, an exotic plantation with suitable indigenous understorey cover can help in protection of birds, including endemic and near-endemic species. Keywords: birds, conservation, Eastern Arc Mountains, plantation, seasonal altitudinal migration, seasons, ...

  9. Restoration of three forest herbs in the Liliaceae family by manipulating deer herbivory and overstorey and understorey vegetation

    Science.gov (United States)

    Cynthia D. Huebner; Kurt W. Gottschalk; Gary W. Miller; Patrick H. Brose

    2010-01-01

    Research on herbaceous vegetation restoration in forests characterised by overstorey tree harvests, excessive deer herbivory, and a dominant fern understorey is lacking. Most of the plant diversity found in Eastern hardwood forests in the United States is found in the herbaceous understorey layer. Loss of forest herbaceous species is an indicator of declining forest...

  10. Effects of Planting of Calluna Vulgaris for Stable Snow Accumulation in Winter

    Science.gov (United States)

    Ibuki, R.; Harada, K.

    2017-12-01

    Recent year climate of the winter season is changing and the period of snow accumulation is reduced compared with before. It affects the management of the ski resort. Snowfall had occurred in December 2016, but the snow accumulated after January 2017 at the ski resort located in the Pacific Ocean side of the Northeast region of Japan. This situation is thought to be originated from two reasons, one is snow thawing, another is to be blown away by the strong monsoon wind. We are considering utilizing planting to stabilize snow accumulation. Currently building rock gardens with shrubs, mainly Calluna Vulgaris in the ski resort for attracting customers in the summer. These are difficult to raise in the lowlands of Japan because they are too hot, but because of their good growth in relatively low-temperature highlands, it is rare for local residents to appreciate the value of these. In addition, it is excellent in low temperature resistance, and it will not die even under the snow. We investigated the pressure resistance performance due to snowfall and the appropriateness of growth under the weather conditions of the area. Regarding Calluna Vulgaris, Firefly, the plants were not damaged even under snow more than 1 m. In addition, three years have passed since planting, relatively good growth is shown, and the stock has been growing every year. Based on these results, we plan to stabilize the snow accumulation by carrying out planting of Calluna vulgaris inside the slope. The growth of the Calluna species is gentle and the tree height grows only about 50 cm even if 15 years have passed since planting. Therefore, it is considered that the plant body is hard to put out their head on the snow surface during the ski season. Next season will monitor the snow accumulation around the planting area through the snow season.

  11. Climbing plants in a temperate rainforest understorey: searching for high light or coping with deep shade?

    Science.gov (United States)

    Valladares, Fernando; Gianoli, Ernesto; Saldaña, Alfredo

    2011-08-01

    While the climbing habit allows vines to reach well-lit canopy areas with a minimum investment in support biomass, many of them have to survive under the dim understorey light during certain stages of their life cycle. But, if the growth/survival trade-off widely reported for trees hold for climbing plants, they cannot maximize both light-interception efficiency and shade avoidance (i.e. escaping from the understorey). The seven most important woody climbers occurring in a Chilean temperate evergreen rainforest were studied with the hypothesis that light-capture efficiency of climbers would be positively associated with their abundance in the understorey. Species abundance in the understorey was quantified from their relative frequency and density in field plots, the light environment was quantified by hemispherical photography, the photosynthetic response to light was measured with portable gas-exchange analyser, and the whole shoot light-interception efficiency and carbon gain was estimated with the 3-D computer model Y-plant. Species differed in specific leaf area, leaf mass fraction, above ground leaf area ratio, light-interception efficiency and potential carbon gain. Abundance of species in the understorey was related to whole shoot features but not to leaf level features such as specific leaf area. Potential carbon gain was inversely related to light-interception efficiency. Mutual shading among leaves within a shoot was very low (<20 %). The abundance of climbing plants in this southern rainforest understorey was directly related to their capacity to intercept light efficiently but not to their potential carbon gain. The most abundant climbers in this ecosystem match well with a shade-tolerance syndrome in contrast to the pioneer-like nature of climbers observed in tropical studies. The climbers studied seem to sacrifice high-light searching for coping with the dim understorey light.

  12. Avian distribution in treefall gaps and understorey of terra firme forest in the lowland Amazon

    Science.gov (United States)

    JR WUNDERLE; MICHAEL R. WILLIG; LUIZA MAGALLI PINTO HENRIQUES

    2005-01-01

    We compared the bird distributions in the understorey of treefall gaps and sites with intact canopy in Amazonian terra firme forest in Brazil. We compiled 2216 mist-net captures (116 species) in 32 gap and 32 forest sites over 22.3 months. Gap habitats differed from forest habitats in having higher capture rates, total captures, species richness and diversity....

  13. Severe dry winter affects plant phenology and carbon balance of a cork oak woodland understorey

    Science.gov (United States)

    Correia, A. C.; Costa-e-Silva, F.; Dubbert, M.; Piayda, A.; Pereira, J. S.

    2016-10-01

    Mediterranean climates are prone to a great variation in yearly precipitation. The effects on ecosystem will depend on the severity and timing of droughts. In this study we questioned how an extreme dry winter affects the carbon flux in the understorey of a cork oak woodland? What is the seasonal contribution of understorey vegetation to ecosystem productivity? We used closed-system portable chambers to measure CO2 exchange of the dominant shrub species (Cistus salviifolius, Cistus crispus and Ulex airensis), of the herbaceous layer and on bare soil in a cork oak woodland in central Portugal during the dry winter year of 2012. Shoot growth, leaf shedding, flower and fruit setting, above and belowground plant biomass were measured as well as seasonal leaf water potential. Eddy-covariance and micrometeorological data together with CO2 exchange measurements were used to access the understorey species contribution to ecosystem gross primary productivity (GPP). The herbaceous layer productivity was severely affected by the dry winter, with half of the yearly maximum aboveground biomass in comparison with the 6 years site average. The semi-deciduous and evergreen shrubs showed desynchronized phenophases and lagged carbon uptake maxima. Whereas shallow-root shrubs exhibited opportunistic characteristics in exploiting the understorey light and water resources, deep rooted shrubs showed better water status but considerably lower assimilation rates. The contribution of understorey vegetation to ecosystem GPP was lower during summer with 14% and maximum during late spring, concomitantly with the lowest tree productivity due to tree canopy renewal. The herbaceous vegetation contribution to ecosystem GPP never exceeded 6% during this dry year stressing its sensitivity to winter and spring precipitation. Although shrubs are more resilient to precipitation variability when compared with the herbaceous vegetation, the contribution of the understorey vegetation to ecosystem GPP can

  14. MAO-A inhibitory activity of quercetin from Calluna vulgaris (L.) Hull

    DEFF Research Database (Denmark)

    Saaby, Lasse; Rasmussen, Hasse Bonde; Jäger, Anna Katharina

    2009-01-01

    AIM OF THE STUDY: This study investigated MAO-A inhibitory activity of methanol extract of Calluna vulgaris (L.) Hull., which traditionally has been used as a nerve calming remedy. MATERIALS AND METHODS: A methanolic extract of Calluna vulgaris was partitioned against heptane, ethyl acetate...

  15. Spatial dynamics of understorey insectivorous birds and arthropods in a southeastern Brazilian Atlantic woodlot

    Directory of Open Access Journals (Sweden)

    MA. Manhães

    Full Text Available Spatial distribution and spatial relationships in capture rates of understorey insectivorous birds and density of arthropods were investigated in a patch of upper montane rain forest in Minas Gerais state, southeastern Brazil, from January to December 2004. The composition of the arthropod fauna collected was similar to that reported for other tropical forests, with predominance of Araneae, Coleoptera, Hymenoptera and Hemiptera non-Heteroptera. A total of 26 bird species were captured, among which the more common were Dysithamnus mentalis, Conopophaga lineata, Platyrinchus mystaceus, Basileuterus culicivorus and Sclerurus scansor. Variation in the bird capture rates among sampling net lines were not correlated with arthropod density. Rather, individual analyses of some bird species suggest that spatial distribution of understorey insectivorous birds is better explained by habitat type.

  16. Potential Propagation by Seed and Cuttings of the Azorean Native Calluna vulgaris (L. Hull

    Directory of Open Access Journals (Sweden)

    Maria João Pereira

    2014-01-01

    Full Text Available This work investigates the potential propagation by seed and cuttings of the Azorean native Calluna vulgaris (L. Hull. for landscape conservation. With that purpose we have performed several germination and cuttings trials, using plant material from wild populations of this species. In the germination trials, we tested the effects of photoperiod length (8 and 16 h, temperature (10, 15, 20, and 20–10°C, seed age (6, 108, and 270 days, temperature of seed storage (4°C and room temperature, and seed surface sterilization on the germination characteristics. In the cuttings trials, we tested the effects of stem cutting type, cultural conditions, cuttings’ harvest month, and rooting substrates on the rooting percentages. The best percentages of germination, 93 and 90%, were obtained with fresh seeds and surface sterilized and sown under an 8 h photoperiod and with temperatures of 10°C or 15°C, respectively; germination after seed storage during 270 days is significantly superior (71% when seeds are stored at 4°C. The best percentages of rooting were achieved for straight (96% or heel cuttings (90% harvested in March, planted on soil from natural stands of C. vulgaris and Erica azorica Hochst., outdoors in half shade, and partially covered with transparent polyethylene film.

  17. Shrubs tracing sea surface temperature--Calluna vulgaris on the Faroe Islands.

    Science.gov (United States)

    Beil, Ilka; Buras, Allan; Hallinger, Martin; Smiljanić, Marko; Wilmking, Martin

    2015-11-01

    The climate of Central and Northern Europe is highly influenced by the North Atlantic Ocean due to heat transfer from lower latitudes. Detailed knowledge about spatio-temporal variability of sea surface temperature (SST) in that region is thus of high interest for climate and environmental research. Because of the close relations between ocean and coastal climate and the climate sensitivity of plant growth, annual rings of woody plants in coastal regions might be used as a proxy for SST. We show here for the first time the proxy potential of the common and widespread evergreen dwarf shrub Calluna vulgaris (heather), using the Faroe Islands as our case study. Despite its small and irregular ring structure, the species seems suitable for dendroecological investigations. Ring width showed high and significant correlations with summer and winter air temperatures and SST. The C. vulgaris chronology from the Faroe Islands, placed directly within the North Atlantic Current, clearly reflects variations in summer SSTs over an area between Iceland and Scotland. Utilising shrubs like C. vulgaris as easy accessible and annually resolved proxies offers an interesting possibility for reconstruction of the coupled climate-ocean system at high latitudes.

  18. UNDERSTOREY OF PINE-PLANTATIONS ON DEGRADED SITES IN THE REGION OF DECIDUOUS FORESTS OF RIO GRANDE DO SUL

    Directory of Open Access Journals (Sweden)

    Franz H. Andrae

    2010-08-01

    Full Text Available In the central part of Rio Grande do Sul State understoreys of 12 stands of Pinus sp. and one of Araucaria angustifolia O.Ktze were studied, all growing on soils, degraded by agriculture. One pine stand, 10 years old, originated from a natural renovation, the others had been planted 25 to 30 years ago, Araucaria was seeded directly. A total of 575 plots were sampled, 25 m² each, distributed systematically within the stands. Measurements included pines overstorey, and all understorey woody species, separeted into layers of more than 1,3 m high and 1,3 to 0,3 m; the layer lower than 0,3 m included only natural renovation of pines. Understoreys were composed by 121 species, ocurring common and high value timber species, ornamental trees, native and exotic fruit tree species. A higher number of species was present with a very few individuals only. The presence of non woody species like grasses, herbs, ferns and lians also was quantified. The number of tree species and the presence of non woody species did not correlat with density of overstorey pines. Abundance and frequency of species showed no significant diferences, when samples were grouped according to their location in the center or close to stands edge. Distribution pattern of understorey trees within stands was quantified, using Cox’ index, species diversity was compared by means of Shannon-index. Similarity of stands was compared by Sörensen-Index. It was concluded, that exotic species planted on poor agricultural soil may not only be of farmers interest because of their high potential for wood production. These plantations also may be considered from conservationist point of view, since they show an unexpected high diversity, so contributing in a longer run to landscape improvement, possibly due to the small extension of stands.

  19. Primary forest dynamics in lowland dipterocarp forest at Danum Valley, Sabah, Malaysia, and the role of the understorey.

    Science.gov (United States)

    Newbery, D M; Kennedy, D N; Petol, G H; Madani, L; Ridsdale, C E

    1999-11-29

    Changes in species composition in two 4-ha plots of lowland dipterocarp rainforest at Danum, Sabah, were measured over ten years (1986-1996) for trees > or = 10 cm girth at breast height (gbh). Each included a lower-slope to ridge gradient. The period lay between two drought events of moderate intensity but the forest showed no large lasting responses, suggesting that its species were well adapted to this regime. Mortality and recruitment rates were not unusual in global or regional comparisons. The forest continued to aggrade from its relatively (for Sabah) low basal area in 1986 and, together with the very open upper canopy structure and an abundance of lianas, this suggests a forest in a late stage of recovery from a major disturbance, yet one continually affected by smaller recent setbacks. Mortality and recruitment rates were not related to population size in 1986, but across subplots recruitment was positively correlated with the density and basal area of small trees (10-change in mortality with increasing gbh: in the former it increased, in the latter it decreased. Forest processes are centred on this understorey quasi-stratum. The two replicate plots showed a high correspondence in the mortality, recruitment, population changes and growth rates of small trees for the 49 most abundant species in common to both. Overstorey species had higher rgrs than understorey ones, but both showed considerable ranges in mortality and recruitment rates. The supposed trade-off in traits, viz slower rgr, shade tolerance and lower population turnover in the understorey group versus faster potential growth rate, high light responsiveness and high turnover in the overstorey group, was only partly met, as some understorey species were also very dynamic. The forest at Danum, under such a disturbance-recovery regime, can be viewed as having a dynamic equilibrium in functional and structural terms. A second trade-off in shade-tolerance versus drought-tolerance is suggested for

  20. Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic forest.

    Science.gov (United States)

    Melo, Geruza L; Miotto, Barbara; Peres, Brisa; Cáceres, Nilton C

    2013-01-01

    Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus) and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus) were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003), particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.

  1. Stress responses of Calluna vulgaris to reduced and oxidised N applied under 'real world conditions'

    International Nuclear Information System (INIS)

    Sheppard, Lucy J.; Leith, Ian D.; Crossley, A.; Van Dijk, N.; Fowler, D.; Sutton, M.A.; Woods, C.

    2008-01-01

    Effects and implications of reduced and oxidised N, applied under 'real world' conditions, since May 2002, are reported for Calluna growing on an ombrotrophic bog. Ammonia has been released from a 10 m line source generating monthly concentrations of 180-6 μg m -3 , while ammonium chloride and sodium nitrate are applied in rainwater at nitrate and ammonium concentrations below 4 mM and providing up to 56 kg N ha -1 year -1 above a background deposition of 10 kg N ha -1 year -1 . Ammonia concentrations, >8 μg m -3 have significantly enhanced foliar N concentrations, increased sensitivity to drought, frost and winter desiccation, spring frost damage and increased the incidence of pathogen outbreaks. The mature Calluna bushes nearest the NH 3 source have turned bleached and moribund. By comparison the Calluna receiving reduced and oxidised N in rain has shown no significant visible or stress related effects with no significant increase in N status. - Exposure to NH 3 reduces stress resistance and increases visible damage in mature Calluna

  2. Short- and medium-term effects of experimental nitrogen fertilization on arthropods associated with Calluna vulgaris heathlands in north-west Spain

    International Nuclear Information System (INIS)

    Cuesta, D.; Taboada, A.; Calvo, L.; Salgado, J.M.

    2008-01-01

    We studied the short- and medium-term effects of experimental nitrogen fertilization (3 and 15 months after the treatment) on the arthropods of Calluna vulgaris heathlands in NW Spain. Three heathland sites were selected with two permanent plots per site: control and fertilized. Ammonium nitrate fertilizer (56 kg N ha -1 yr -1 ) was applied monthly and insects were caught using pitfall traps. We found mainly species-level responses to nitrogen addition. Seven species (e.g. Lochmaea suturalis) showed a consistent trend (benefited or harmed) in both periods and were proposed as possible reliable indicators of the effects of nitrogen deposition in these ecosystems. We also found variable arthropod trophic-group responses: (a) herbivores (leaf beetles, true bugs) increased in abundance on a short-term scale; (b) predators (carabid beetles, true bugs) showed opposite and less clear responses in both periods. Further long-term studies are needed to determine the mechanisms underlying the observed arthropod responses. - We observed consistent species-level and variable trophic-group responses to nitrogen addition in one of the southern-most locations for Calluna vulgaris heathlands within Europe

  3. Ecophysiological and foliar nitrogen concentration responses of understorey Acacia spp. and Eucalyptus sp. to prescribed burning.

    Science.gov (United States)

    Ma, Ling; Rao, Xingquan; Lu, Ping; Bai, Shahla Hosseini; Xu, Zhihong; Chen, Xiaoyang; Blumfield, Timothy; Xie, Jun

    2015-07-01

    Eucalyptus spp. is a dominant tree genus in Australia and most Eucalyptus spp. are canopy dominant species. In Australian natural forests, Eucalyptus spp. commonly are associated with understorey legumes which play a crucial role for ecological restoration owing to their nitrogen (N) fixing ability for replenishing the soil N lost after frequent prescribed burning. This study aimed to explore to what extent physiological responses of these species differ 7 and 12 years after last fire. Two most common understorey Acacia spp., Acacia leiocalyx and A. disparrima, as well as one non-leguminous Eucalyptus resinifera, were studied due to their dominance in the forest. Both A. leiocalyx and A. disparrima showed higher carbon (C) assimilation capacity, maximum photosynthetic capacity, and moderate foliar C/N ratio compared with E. resinifera. A. leiocalyx showed various advantages compared to A. disparrima such as higher photosynthetic capacity, adaptation to wider light range and higher foliar total N (TNmass). A. leiocalyx also relied on N2-fixing ability for longer time compared to A. disparrima. The results suggested that the two Acacia spp. were more beneficial to C and N cycles for the post burning ecosystem than the non-N2-fixing species E. resinifera. A. leiocalyx had greater contribution to complementing soil N cycle long after burning compared to A. disparrima.

  4. The influence of coniferous canopies on understorey vegetation and soils in mountain forests of the northern Calcareous Alps

    International Nuclear Information System (INIS)

    Ewald, Joerg

    2000-01-01

    Compositional and edaphic gradients were studied in montane forests of the Bavarian Alps (Germany), in which natural mixed deciduous-coniferous tree layers have been altered by past management in favour of Picea abies. Data on species composition and ecological factors were collected in a stratified random sample of 84 quadrats comprising a gradient from pure Picea to pure Fagus sylvatica stands. Data about the understorey composition were subjected to indirect (DCA) and direct gradient analysis (RDA) with the proportion of Picea in the canopy as a constraining variable. Three principal components of a matrix containing seven descriptors of mineral soil, relief and tree layer cover were included as covariables describing the variability of primary ecological factors. Gradients of organic topsoil morphology and chemistry were extracted correspondingly. Responses of individual species, species group and topsoil attributes were studied by simple and partial correlation analysis. Mosses were significantly more abundant and diverse under Picea stands. Few graminoid and herb species were partially associated with Picea, and total understorey richness and cover did not differ systematically by stand type. No relationship between tree layer and understorey diversity was detected at the studied scale. Juvenile Fagus sylvatica was the only woody species significantly less abundant under Picea. In the topsoil lower base saturation, lower pH and larger C/N ratios in the litter layer were partially attributable to the proportion of Picea, only for base saturation a relationship was detected in greater soil depth also. The frequency of broad humus form types did not differ by tree species, nor was overall depth of organic forest floor attributable to canopy composition

  5. Compositional stability of boreal understorey vegetation after overstorey harvesting across a riparian ecotone

    Science.gov (United States)

    Rebecca L. MacDonald; Han Y.H. Chen; Samuel F. Bartels; Brian J. Palik; Ellie E. Prepas; Frank Gilliam

    2015-01-01

    Questions: Understanding factors that contribute to the stability of an ecosystem following harvesting is central to predicting responses of boreal ecosystems to increasing human disturbances.While the response of understorey vegetation to harvesting is well understood for upland sites, little is known about compositional stability of riparian understorey vegetation....

  6. Experimental restoration of coppice-with-standards: Response of understorey vegetation from the conservation perspective.

    Science.gov (United States)

    Vild, Ondřej; Roleček, Jan; Hédl, Radim; Kopecký, Martin; Utinek, Dušan

    2013-12-15

    A substantial part of European lowland woodlands was managed as coppices or wood pastures for millennia. However, traditional management forms were almost completely abandoned in Central Europe by the middle of the 20th century. Combined with the effects of nitrogen deposition and herbivore pressure, shifts in management resulted in biodiversity loss affecting particularly light-demanding oligotrophic plant species. Experimental thinning was applied in a former oak coppice-with-standards in an attempt to restore vanishing understorey plant communities. Two levels of thinning intensity and zero management as control were used on 90 plots. Ten years after the treatment, significant changes in species composition and diversity were observed in heavily thinned plots, while moderate thinning had mostly insignificant effects. Light-demanding oligotrophic species significantly increased, indicating positive consequences of restoration. However, heavy thinning also brought about the expansion of native ruderal species. Alien species remained unchanged. We conclude that the restoration of coppice-with-standards can be an efficient tool to support vanishing light-demanding woodland species. Combined with biodiversity benefits, the increasing demand for biofuel may contribute to the renaissance of traditional management forms in forestry.

  7. Modelling Carbon Emissions in Calluna vulgaris–Dominated Ecosystems when Prescribed Burning and Wildfires Interact

    Science.gov (United States)

    Santana, Victor M.; Alday, Josu G.; Lee, HyoHyeMi; Allen, Katherine A.; Marrs, Rob H.

    2016-01-01

    A present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we modeled the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north-south gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads and annual C emissions under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with a decreasing wildfire return intervals. We observed that litter accumulation patterns varied between sites. Northern sites (colder and wetter) accumulated lower amounts of litter with time than southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon emissions also differed between sites: the optimal rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for minimum C emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C emissions. PMID:27880840

  8. Modelling Carbon Emissions in Calluna vulgaris-Dominated Ecosystems when Prescribed Burning and Wildfires Interact.

    Science.gov (United States)

    Santana, Victor M; Alday, Josu G; Lee, HyoHyeMi; Allen, Katherine A; Marrs, Rob H

    2016-01-01

    A present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we modeled the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north-south gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads and annual C emissions under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with a decreasing wildfire return intervals. We observed that litter accumulation patterns varied between sites. Northern sites (colder and wetter) accumulated lower amounts of litter with time than southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon emissions also differed between sites: the optimal rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for minimum C emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C emissions.

  9. Isometric scaling of above- and below-ground biomass at the individual and community levels in the understorey of a sub-tropical forest.

    Science.gov (United States)

    Cheng, Dongliang; Zhong, Quanlin; Niklas, Karl J; Ma, Yuzhu; Yang, Yusheng; Zhang, Jianhua

    2015-02-01

    Empirical studies and allometric partitioning (AP) theory indicate that plant above-ground biomass (MA) scales, on average, one-to-one (isometrically) with below-ground biomass (MR) at the level of individual trees and at the level of entire forest communities. However, the ability of the AP theory to predict the biomass allocation patterns of understorey plants has not been established because most previous empirical tests have focused on canopy tree species or very large shrubs. In order to test the AP theory further, 1586 understorey sub-tropical forest plants from 30 sites in south-east China were harvested and examined. The numerical values of the scaling exponents and normalization constants (i.e. slopes and y-intercepts, respectively) of log-log linear MA vs. MR relationships were determined for all individual plants, for each site, across the entire data set, and for data sorted into a total of 19 sub-sets of forest types and successional stages. Similar comparisons of MA/MR were also made. The data revealed that the mean MA/MR of understorey plants was 2·44 and 1·57 across all 1586 plants and for all communities, respectively, and MA scaled nearly isometrically with respect to MR, with scaling exponents of 1·01 for all individual plants and 0·99 for all communities. The scaling exponents did not differ significantly among different forest types or successional stages, but the normalization constants did, and were positively correlated with MA/MR and negatively correlated with scaling exponents across all 1586 plants. The results support the AP theory's prediction that MA scales nearly one-to-one with MR (i.e. MA ∝ MR (≈1·0)) and that plant biomass partitioning for individual plants and at the community level share a strikingly similar pattern, at least for the understorey plants examined in this study. Furthermore, variation in environmental conditions appears to affect the numerical values of normalization constants, but not the scaling exponents

  10. Effects of high-frequency understorey fires on woody plant regeneration in southeastern Amazonian forests

    Science.gov (United States)

    Balch, Jennifer K.; Massad, Tara J.; Brando, Paulo M.; Nepstad, Daniel C.; Curran, Lisa M.

    2013-01-01

    Anthropogenic understorey fires affect large areas of tropical forest, yet their effects on woody plant regeneration post-fire remain poorly understood. We examined the effects of repeated experimental fires on woody stem (less than 1 cm at base) mortality, recruitment, species diversity, community similarity and regeneration mode (seed versus sprout) in Mato Grosso, Brazil. From 2004 to 2010, forest plots (50 ha) were burned twice (B2) or five times (B5), and compared with an unburned control (B0). Stem density recovered within a year after the first burn (initial density: 12.4–13.2 stems m−2), but after 6 years, increased mortality and decreased regeneration—primarily of seedlings—led to a 63 per cent and 85 per cent reduction in stem density in B2 and B5, respectively. Seedlings and sprouts across plots in 2010 displayed remarkable community similarity owing to shared abundant species. Although the dominant surviving species were similar across plots, a major increase in sprouting occurred—almost three- and fourfold greater in B2 and B5 than in B0. In B5, 29 species disappeared and were replaced by 11 new species often present along fragmented forest edges. By 2010, the annual burn regime created substantial divergence between the seedling community and the initial adult tree community (greater than or equal to 20 cm dbh). Increased droughts and continued anthropogenic ignitions associated with frontier land uses may promote high-frequency fire regimes that may substantially alter regeneration and therefore successional processes. PMID:23610167

  11. Impact of global climate change and fire on the occurrence and function of understorey legumes in forest ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Reverchon, Frederique; Xu, Zhihong; Blumfield, Timothy J.; Chen, Chengrong; Abdullah, Kadum M. [Griffith Univ., Nathan, QLD (Australia). Environmental Futures Centre and School of Biomolecular and Physical Sciences

    2012-02-15

    The objective of this review was to provide a better understanding of how global climate change and fire influence the occurrence of understorey legumes and thereby biological nitrogen (N) fixation rates in forest ecosystems. Legumes are interesting models since they represent an interface between the soil, plant, and microbial compartments, and are directly linked to nutrient cycles through their ability to fix N. As such, they are likely to be affected by environmental changes. Biological N fixation has been shown to increase under enriched CO{sub 2} conditions, but is constrained by the availability of phosphorus and water. Climate change can also influence the species composition of legumes and their symbionts through warming, altered rainfall patterns, or changes in soil physicochemistry, which could modify the effectiveness of the symbiosis. Additionally, global climate change may increase the occurrence and intensity of forest wildfires thereby further influencing the distribution of legumes. The establishment of leguminous species is generally favored by fire, as is N{sub 2} fixation. This fixed N could therefore replenish the N lost through volatilization during the fire. However, fire may also generate shifts in the associated microbial community which could affect the outcome of the symbiosis. Understorey legumes are important functional species, and even when they cannot reasonably be expected to reestablish the nutrient balance in forest soils, they may be used as indicators to monitor nutrient fluxes and the response of forest ecosystems to changing environmental conditions. This would be helpful to accurately model ecosystem N budgets, and since N is often a limiting factor to plant growth and a major constraint on C storage in ecosystems, would allow us to assess more precisely the potential of these forests for C sequestration. (orig.)

  12. Use of Calluna vulgaris to detect signals of nitrogen deposition across an urban-rural gradient

    Science.gov (United States)

    Power, S. A.; Collins, C. M.

    2010-05-01

    Densely populated cities can experience high concentrations of traffic-derived pollutants, with oxides of nitrogen and ammonia contributing significantly to the overall nitrogen (N) budget of urban ecosystems. This study investigated changes in the biochemistry of in situ Calluna vulgaris plants to detect signals of N deposition across an urban-rural gradient from central London to rural Surrey, UK. Foliar N concentrations and δ 15N signatures were higher, and C/N ratios lower, in urban areas receiving the highest rates of N deposition. Plant phosphorus (P) concentrations were also highest in these areas, suggesting that elevated rates of N deposition are unlikely to result in progressive P-limitation in urban habitats. Free amino acid concentrations were positively related to N deposition for asparagine, glutamine, glycine, phenylalanine, isoleucine, leucine and lysine. Overall, relationships between tissue chemistry and N deposition were similar for oxidised, reduced and total N, although the strength of relationships varied with the different biochemical indicators. The results of this study indicate that current rates of N deposition are having substantial effects on plant biochemistry in urban areas, with likely implications for the biodiversity and functioning of urban ecosystems.

  13. Nitrogen deposition increases the acquisition of phosphorus and potassium by heather Calluna vulgaris

    International Nuclear Information System (INIS)

    Rowe, Edwin C.; Smart, Simon M.; Kennedy, Valerie H.; Emmett, Bridget A.; Evans, Christopher D.

    2008-01-01

    Increased plant productivity due to nitrogen pollution increases the strength of the global carbon sink, but is implicated in plant diversity loss. However, modelling and experimental studies have suggested that these effects are constrained by availability of other nutrients. In a survey of element concentrations in Calluna vulgaris across an N deposition gradient in the UK, shoot concentrations of N and more surprisingly phosphorus and potassium were positively correlated with N deposition; tissue N/P ratio even decreased with N deposition. Elevated P and K concentrations possibly resulted from improved acquisition due to additional enzyme production or mycorrhizal activity. Heather occurs on organic soils where nutrient limitations are likely due to availability constraints rather than small stocks. However, if this effect extends to other plant and soil types, effects of N deposition on C sinks and plant competition may not be as constrained by availability of other nutrients as previously proposed. - Heather tissue phosphorus and potassium concentrations increased across a nitrogen deposition gradient, implying that nitrogen limited acquisition of other plant nutrients

  14. Understorey fire frequency and the fate of burned forests in southern Amazonia.

    Science.gov (United States)

    Morton, D C; Le Page, Y; DeFries, R; Collatz, G J; Hurtt, G C

    2013-06-05

    Recent drought events underscore the vulnerability of Amazon forests to understorey fires. The long-term impact of fires on biodiversity and forest carbon stocks depends on the frequency of fire damages and deforestation rates of burned forests. Here, we characterized the spatial and temporal dynamics of understorey fires (1999-2010) and deforestation (2001-2010) in southern Amazonia using new satellite-based estimates of annual fire activity (greater than 50 ha) and deforestation (greater than 10 ha). Understorey forest fires burned more than 85 500 km(2) between 1999 and 2010 (2.8% of all forests). Forests that burned more than once accounted for 16 per cent of all understorey fires. Repeated fire activity was concentrated in Mato Grosso and eastern Pará, whereas single fires were widespread across the arc of deforestation. Routine fire activity in Mato Grosso coincided with annual periods of low night-time relative humidity, suggesting a strong climate control on both single and repeated fires. Understorey fires occurred in regions with active deforestation, yet the interannual variability of fire and deforestation were uncorrelated, and only 2.6 per cent of forests that burned between 1999 and 2008 were deforested for agricultural use by 2010. Evidence from the past decade suggests that future projections of frontier landscapes in Amazonia should separately consider economic drivers to project future deforestation and climate to project fire risk.

  15. Feeding resource partitioning between two understorey insectivorous birds in a fragment of Neotropical cloud forest

    Directory of Open Access Journals (Sweden)

    M. A. Manhães

    Full Text Available Abstract The food habits and niche overlap based on diet composition and prey size of two species of understorey insectivorous birds were investigated in an area of montane rain forest in the state of Minas Gerais, southeastern Brazil. A total of 43 birds were captured: 33 individuals of Conopophaga lineata (Conopophagidae with 13 recaptures, and 10 individuals of Myiothlypis leucoblephara (Parulidae with 12 recaptures, from which were obtained respectively 33 and 10 fecal samples. Fragments of 16 groups of arthropods, plus insect eggs, were identified in these samples. Conopophaga lineata predominantly consumed Formicidae (32% and Isoptera (23.6%. However, the index of alimentary importance (AI of Isoptera (3.53 was lower than other groups such as Formicidae (AI = 61.88, Coleoptera (AI = 16.17, insect larvae (AI = 6.95 and Araneae (AI = 6.6. Myiothlypis leucoblephara predominantly consumed Formicidae (28.2% and Coleoptera (24.4%, although Coleoptera and Hymenoptera non-Formicidae had the highest values of AI (38.71 and 22.98 respectively. Differences in the proportions of the types of arthropods consumed by birds were not enough to reveal their separation into feeding niches (overlap = 0.618, p observed ≤ expected = 0.934, whereas differences in the use of resources was mainly due to the size of the prey (p<0.001, where C lineata, the species with the highest body mass (p<0.001 consumed larger prey. It is plausible that prey size is an axis of niche dimension that allows the coexistence of these species.

  16. Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic Forest

    Directory of Open Access Journals (Sweden)

    GERUZA L. MELO

    2013-06-01

    Full Text Available Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003, particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.Cada espécie animal pode apresentar seletividade por micro-habitats priorizando proteção, forrageio ou microclima. Para compreender os padrões de distribuição de pequenos mamíferos ao nível do solo e de sub-bosque, nós analisamos o uso de micro-habitat por pequenos mamíferos em uma floresta estacional no sul do Brasil. Dez estações amostrais com sete pontos de captura foram usadas para amostragem dos seguintes microhabitats: liana, tronco caído, solo apenas coberto por folhiço, solo coberto por samambaias, árvore com tronco simples, árvore com bifurcações e arbustos do g

  17. Reproductive isolation of sympatric forms of the understorey palm Geonoma macrostachys in western Amazonia

    DEFF Research Database (Denmark)

    Borchsenius, Finn; Lozada, Tannya; Knudsen, Jette T.

    2016-01-01

    The evolution of a mechanism for attaining reproductive isolation between two diverging populations is a key step in the speciation process. We studied phenotypic variation, genetic differentiation, spatial distribution and reproductive ecology in two sympatric forms of the understorey palm Geonoma...

  18. The contribution of nitrogen deposition to the eutrophication signal in understorey plant communities of European forests

    NARCIS (Netherlands)

    Dobben, van H.F.; Vries, de W.

    2017-01-01

    We evaluated effects of atmospheric deposition of nitrogen on the composition of forest understorey vegetation both in space and time, using repeated data from the European wide monitoring program ICP-Forests, which focuses on normally managed forest. Our aim was to assess whether both spatial and

  19. Understorey fire propagation and tree mortality on adjacent areas to an Amazonian deforestation fire

    Science.gov (United States)

    J.A. Carvalho; C.A. Gurgel Veras; E.C. Alvarado; D.V. Sandberg; S.J. Leite; R. Gielow; E.R.C. Rabelo; J.C. Santos

    2010-01-01

    Fire characteristics in tropical ecosystems are poorly documented quantitatively in the literature. This paper describes an understorey fire propagating across the edges of a biomass burn of a cleared primary forest. The experiment was carried out in 2001 in the Amazon forest near Alta Floresta, state of Mato Grosso, Brazil, as part of biomass burning experiments...

  20. Improved understorey bamboo cover mapping using a novel hybrid neural network and expert system

    NARCIS (Netherlands)

    Wang, T.; Skidmore, A.K.; Toxopeus, A.G.

    2009-01-01

    The giant panda is an obligate bamboo grazer. Therefore, the availability and abundance of understorey bamboo determines the quantity and quality of panda habitat. However, there is little or no information about the spatial distribution or abundance of bamboo underneath the forest canopy, due to

  1. Carbon allocation and decomposition of root-derived organic matter in a plant-soil system of Calluna vulgaris as affected by elevated CO2.

    NARCIS (Netherlands)

    Verburg, P.S.J.; Gorissenand, A.; Arp, W.J.

    1998-01-01

    The effect of elevated CO2 on C allocation in plant and soil was assessed using soil cores planted with 1-y-old heather (Calluna vulgaris (L.) Hull). Plants were pulse-labeled with 14CO2 at ambient and elevated CO2 and two nitrogen regimes (low and high). After harvesting the plants, the soil was

  2. THE CANOPY EFFECTS OF Prosopis juliflora (DC. AND Acacia tortilis (HAYNE TREES ON HERBACEOUS PLANTS SPECIES AND SOIL PHYSICO-CHEMICAL PROPERTIES IN NJEMPS FLATS, KENYA

    Directory of Open Access Journals (Sweden)

    Henry C. Kahi

    2009-03-01

    Full Text Available The canopy effects of an exotic and indigenous tree species on soil properties and understorey herbaceous plant species were investigated on the Njemps Flats, Baringo district, Kenya. Samples of soil and herbaceous plant species were obtained within the canopies of systematically selected P. juliflora (exotic and A. tortilis (indigenous trees, and from adjacent open areas. Standing biomass, frequency and cover of understorey plant species were significantly (P

  3. The effect of potassium nutrition on sup 137 Cs uptake in two upland species

    Energy Technology Data Exchange (ETDEWEB)

    Jones, H E; Harrison, A F; Poskitt, J M; Roberts, J D; Clint, G [Institute for Terrestrial Ecology, Grange-over-Sands (UK)

    1991-01-01

    Agrostis capillaris (Agrostis) and Calluna vulgaris (Calluna), two species with differing phenologies and widespread presence in upland areas of Britain where high Chernobyl fallout occurred, were grown in pot culture with varying concentrations of potassium in the rooting medium. Tissue content of potassium increased with increasing supply in both species. Roots, excised from these plants, were placed in a solution of {sup 137}Cs-labelled caesium chloride for 15 min to determine uptake potential. There were clear negative relationships between the rate of uptake of {sup 137}Cs by both species and (a) the concentration of potassium supplied and (b) plant issue potassium concentrations. With Agrotis, there was an approximately ten-fold difference in {sup 137}Cs uptake between potassium-deficient and optimum plants; with Calluna, it was approximately eight-fold. These results demonstrate the suppression of {sup 137}Cs uptake into plants by potassium supply. (author).

  4. Microhabitat amelioration and reduced competition among understorey plants as drivers of facilitation across environmental gradients: towards a unifying framework

    Science.gov (United States)

    Soliveres, Santiago; Eldridge, David J.; Maestre, Fernando T.; Bowker, Matthew A.; Tighe, Matthew; Escudero, Adrián

    2015-01-01

    Studies of facilitative interactions as drivers of plant richness along environmental gradients often assume the existence of an overarching stress gradient equally affecting the performance of all the species in a given community. However, co-existing species differ in their ecophysiological adaptations, and do not experience the same stress level under particular environmental conditions. Moreover, these studies assume a unimodal richness-biomass curve, which is not as general as previously thought. We ignored these assumptions to assess changes in plant-plant interactions, and their effect on local species richness, across environmental gradients in semi-arid areas of Spain and Australia. We aimed to understand the relative importance of direct (microhabitat amelioration) and indirect (changes in the competitive relationships among the understorey species: niche segregation, competitive exclusion or intransitivity) mechanisms that might underlie the effects of nurse plants on local species richness. By jointly studying these direct and indirect mechanisms using a unifying framework, we were able to see how our nurse plants (trees, shrubs and tussock grasses) not only increased local richness by expanding the niche of neighbouring species, but also by increasing niche segregation among them, though the latter was not important in all cases. The outcome of the competition-facilitation continuum changed depending on the study area, likely because the different types of stress gradient considered. When driven by both rainfall and temperature, or rainfall alone, the community-wide importance of nurse plants remained constant (Spanish sites), or showed a unimodal relationship along the gradient (Australian sites). This study expands our understanding of the relative roles of plant-plant interactions and environmental conditions as drivers of local species richness in semi-arid environments. These results can also be used to refine predictions about the response of

  5. Microhabitat amelioration and reduced competition among understorey plants as drivers of facilitation across environmental gradients: towards a unifying framework.

    Science.gov (United States)

    Soliveres, Santiago; Eldridge, David J; Maestre, Fernando T; Bowker, Matthew A; Tighe, Matthew; Escudero, Adrián

    2011-11-20

    Studies of facilitative interactions as drivers of plant richness along environmental gradients often assume the existence of an overarching stress gradient equally affecting the performance of all the species in a given community. However, co-existing species differ in their ecophysiological adaptations, and do not experience the same stress level under particular environmental conditions. Moreover, these studies assume a unimodal richness-biomass curve, which is not as general as previously thought. We ignored these assumptions to assess changes in plant-plant interactions, and their effect on local species richness, across environmental gradients in semi-arid areas of Spain and Australia. We aimed to understand the relative importance of direct (microhabitat amelioration) and indirect (changes in the competitive relationships among the understorey species: niche segregation, competitive exclusion or intransitivity) mechanisms that might underlie the effects of nurse plants on local species richness. By jointly studying these direct and indirect mechanisms using a unifying framework, we were able to see how our nurse plants (trees, shrubs and tussock grasses) not only increased local richness by expanding the niche of neighbouring species, but also by increasing niche segregation among them, though the latter was not important in all cases. The outcome of the competition-facilitation continuum changed depending on the study area, likely because the different types of stress gradient considered. When driven by both rainfall and temperature, or rainfall alone, the community-wide importance of nurse plants remained constant (Spanish sites), or showed a unimodal relationship along the gradient (Australian sites). This study expands our understanding of the relative roles of plant-plant interactions and environmental conditions as drivers of local species richness in semi-arid environments. These results can also be used to refine predictions about the response of

  6. Do changes in grazing pressure and the degree of shrub encroachment alter the effects of individual shrubs on understorey plant communities and soil function?

    Science.gov (United States)

    Soliveres, Santiago; Eldridge, David J

    2014-04-01

    Shrub canopies in semi-arid environments often produce positive effects on soil fertility, and on the richness and biomass of understorey plant communities. However, both positive and negative effects of shrub encroachment on plant and soil attributes have been reported at the landscape-level. The contrasting results between patch- and landscape-level effects in shrublands could be caused by differences in the degree of shrub encroachment or grazing pressure, both of which are likely to reduce the ability of individual shrubs to ameliorate their understorey environment.We examined how grazing and shrub encroachment (measured as landscape-level shrub cover) influence patch-level effects of shrubs on plant density, biomass and similarity in species composition between shrub understories and open areas, and on soil stability, nutrient cycling, and infiltration in two semi-arid Australian woodlands.Individual shrubs had consistently positive effects on all plant and soil variables (average increase of 23% for all variables). These positive patch-level effects persisted with increasing shrub cover up to our maximum of 50% cover. Heavy grazing negatively affected most of the variables studied (average decline of 11%). It also altered, for some variables, how individual shrubs affected their sub-canopy environment with increasing shrub cover. Thus for species density, biomass and soil infiltration, the positive effect of individual shrubs with increasing shrub cover diminished under heavy grazing. Our study refines predictions of the effects of woody encroachment on ecosystem structure and functioning by showing that heavy grazing, rather than differences in shrub cover, explains the contrasting effects on ecosystem structure and function between individual shrubs and those in dense aggregations. We also discuss how species-specific traits of the encroaching species, such as their height or its ability to fix N, might influence the relationship between their patch

  7. Transpiration and stomatal conductance in a young secondary tropical montane forest: contrasts between native trees and invasive understorey shrubs.

    Science.gov (United States)

    Ghimire, Chandra Prasad; Bruijnzeel, L Adrian; Lubczynski, Maciek W; Zwartendijk, Bob W; Odongo, Vincent Omondi; Ravelona, Maafaka; van Meerveld, H J Ilja

    2018-04-21

    It has been suggested that vigorous secondary tropical forests can have very high transpiration rates, but sap flow and stomatal conductance dynamics of trees and shrubs in these forests are understudied. In an effort to address this knowledge gap, sap flow (thermal dissipation method, 12 trees) and stomatal conductance (porometry, six trees) were measured for young (5-7 years) Psiadia altissima (DC.) Drake trees, a widely occurring species dominating young regrowth following abandonment of swidden agriculture in upland eastern Madagascar. In addition, stomatal conductance (gs) was determined for three individuals of two locally common invasive shrubs (Lantana camara L. and Rubus moluccanus L.) during three periods with contrasting soil moisture conditions. Values of gs for the three investigated species were significantly higher and more sensitive to climatic conditions during the wet period compared with the dry period. Further, gs of the understorey shrubs was much more sensitive to soil moisture content than that of the trees. Tree transpiration rates (Ec) were relatively stable during the dry season and were only affected somewhat by soil water content at the end of the dry season, suggesting the trees had continued access to soil water despite drying out of the topsoil. The Ec exhibited a plateau-shaped relation with vapour pressure deficit (VPD), which was attributed to stomatal closure at high VPD. Vapour pressure deficit was the major driver of variation in Ec, during both the wet and the dry season. Overall water use of the trees was modest, possibly reflecting low site fertility after three swidden cultivation cycles. The observed contrast in gs response to soil water and climatic conditions for the trees and shrubs underscores the need to take root distributions into account when modelling transpiration from regenerating tropical forests.

  8. The effect of interspecific variation in photosynthetic plasticity on 4-year growth rate and 8-year survival of understorey tree seedlings in response to gap formations in a cool-temperate deciduous forest.

    Science.gov (United States)

    Oguchi, Riichi; Hiura, Tsutom; Hikosaka, Kouki

    2017-08-01

    Gap formation increases the light intensity in the forest understorey. The growth responses of seedlings to the increase in light availability show interspecific variation, which is considered to promote biodiversity in forests. At the leaf level, some species increase their photosynthetic capacity in response to gap formation, whereas others do not. Here we address the question of whether the interspecific difference in the photosynthetic response results in the interspecific variation in the growth response. If so, the interspecific difference in photosynthetic response would also contribute to species coexistence in forests. We also address the further relevant question of why some species do not increase their photosynthetic capacity. We assumed that some cost of photosynthetic plasticity may constrain acquisition of the plasticity in some species, and hypothesized that species with larger photosynthetic plasticity exhibit better growth after gap formation and lower survivorship in the shade understorey of a cool-temperate deciduous forest. We created gaps by felling canopy trees and studied the relationship between the photosynthetic response and the subsequent growth rate of seedlings. Naturally growing seedlings of six deciduous woody species were used and their mortality was examined for 8 years. The light-saturated rate of photosynthesis (Pmax) and the relative growth rate (RGR) of the seedlings of all study species increased at gap plots. The extent of these increases varied among the species. The stimulation of RGR over 4 years after gap formation was strongly correlated with change in photosynthetic capacity of newly expanded leaves. The increase in RGR and Pmax correlated with the 8-year mortality at control plots. These results suggest a trade-off between photosynthetic plasticity and the understorey shade tolerance. Gap-demanding species may acquire photosynthetic plasticity, sacrificing shade tolerances, whereas gap-independent species may acquire

  9. Understorey productivity in temperate grassy woodland responds to soil water availability but not to elevated [CO2 ].

    Science.gov (United States)

    Collins, Luke; Bradstock, Ross A; Resco de Dios, Victor; Duursma, Remko A; Velasco, Sabrina; Boer, Matthias M

    2018-06-01

    Rising atmospheric [CO 2 ] and associated climate change are expected to modify primary productivity across a range of ecosystems globally. Increasing aridity is predicted to reduce grassland productivity, although rising [CO 2 ] and associated increases in plant water use efficiency may partially offset the effect of drying on growth. Difficulties arise in predicting the direction and magnitude of future changes in ecosystem productivity, due to limited field experimentation investigating climate and CO 2 interactions. We use repeat near-surface digital photography to quantify the effects of water availability and experimentally manipulated elevated [CO 2 ] (eCO 2 ) on understorey live foliage cover and biomass over three growing seasons in a temperate grassy woodland in south-eastern Australia. We hypothesised that (i) understorey herbaceous productivity is dependent upon soil water availability, and (ii) that eCO 2 will increase productivity, with greatest stimulation occurring under conditions of low water availability. Soil volumetric water content (VWC) determined foliage cover and growth rates over the length of the growing season (August to March), with low VWC (productivity. However, eCO 2 did not increase herbaceous cover and biomass over the duration of the experiment, or mitigate the effects of low water availability on understorey growth rates and cover. Our findings suggest that projected increases in aridity in temperate woodlands are likely to lead to reduced understorey productivity, with little scope for eCO 2 to offset these changes. © 2018 John Wiley & Sons Ltd.

  10. Chemical and physical environmental conditions underneath mat- and canopy-forming macroalgae, and their effects on understorey corals.

    Science.gov (United States)

    Hauri, Claudine; Fabricius, Katharina E; Schaffelke, Britta; Humphrey, Craig

    2010-09-13

    Disturbed coral reefs are often dominated by dense mat- or canopy-forming assemblages of macroalgae. This study investigated how such dense macroalgal assemblages change the chemical and physical microenvironment for understorey corals, and how the altered environmental conditions affect the physiological performance of corals. Field measurements were conducted on macroalgal-dominated inshore reefs in the Great Barrier Reef in quadrats with macroalgal biomass ranging from 235 to 1029 g DW m(-2) dry weight. Underneath mat-forming assemblages, the mean concentration of dissolved oxygen was reduced by 26% and irradiance by 96% compared with conditions above the mat, while concentrations of dissolved organic carbon and soluble reactive phosphorous increased by 26% and 267%, respectively. The difference was significant but less pronounced under canopy-forming assemblages. Dissolved oxygen declined and dissolved inorganic carbon and alkalinity increased with increasing algal biomass underneath mat-forming but not under canopy-forming assemblages. The responses of corals to conditions similar to those found underneath algal assemblages were investigated in an aquarium experiment. Coral nubbins of the species Acropora millepora showed reduced photosynthetic yields and increased RNA/DNA ratios when exposed to conditions simulating those underneath assemblages (pre-incubating seawater with macroalgae, and shading). The magnitude of these stress responses increased with increasing proportion of pre-incubated algal water. Our study shows that mat-forming and, to a lesser extent, canopy-forming macroalgal assemblages alter the physical and chemical microenvironment sufficiently to directly and detrimentally affect the metabolism of corals, potentially impeding reef recovery from algal to coral-dominated states after disturbance. Macroalgal dominance on coral reefs therefore simultaneously represents a consequence and cause of coral reef degradation.

  11. Chemical and physical environmental conditions underneath mat- and canopy-forming macroalgae, and their effects on understorey corals.

    Directory of Open Access Journals (Sweden)

    Claudine Hauri

    2010-09-01

    Full Text Available Disturbed coral reefs are often dominated by dense mat- or canopy-forming assemblages of macroalgae. This study investigated how such dense macroalgal assemblages change the chemical and physical microenvironment for understorey corals, and how the altered environmental conditions affect the physiological performance of corals. Field measurements were conducted on macroalgal-dominated inshore reefs in the Great Barrier Reef in quadrats with macroalgal biomass ranging from 235 to 1029 g DW m(-2 dry weight. Underneath mat-forming assemblages, the mean concentration of dissolved oxygen was reduced by 26% and irradiance by 96% compared with conditions above the mat, while concentrations of dissolved organic carbon and soluble reactive phosphorous increased by 26% and 267%, respectively. The difference was significant but less pronounced under canopy-forming assemblages. Dissolved oxygen declined and dissolved inorganic carbon and alkalinity increased with increasing algal biomass underneath mat-forming but not under canopy-forming assemblages. The responses of corals to conditions similar to those found underneath algal assemblages were investigated in an aquarium experiment. Coral nubbins of the species Acropora millepora showed reduced photosynthetic yields and increased RNA/DNA ratios when exposed to conditions simulating those underneath assemblages (pre-incubating seawater with macroalgae, and shading. The magnitude of these stress responses increased with increasing proportion of pre-incubated algal water. Our study shows that mat-forming and, to a lesser extent, canopy-forming macroalgal assemblages alter the physical and chemical microenvironment sufficiently to directly and detrimentally affect the metabolism of corals, potentially impeding reef recovery from algal to coral-dominated states after disturbance. Macroalgal dominance on coral reefs therefore simultaneously represents a consequence and cause of coral reef degradation.

  12. DYNAMICS STRUCTURE OF THE UNDERSTOREY VEGETATION INFLUENCED BY LOGGING IN A SOLID GROUND FOREST, IN THE MUNICIPALITY OF MOJU, PARÁ STATE

    Directory of Open Access Journals (Sweden)

    Fernanda da Silva Mendes

    2013-06-01

    Full Text Available http://dx.doi.org/10.5902/198050989283The structure dynamics of an understorey vegetation influenced by gaps caused by reduced impact logging was analyzed during 12 years in a solid ground rain forest in the municipality of Moju, Pará state, eastern Brazilian Amazon forest. Angiosperm individuals from 10 cm height up to 5 cm DBH were surveyed in a 468 m² sample area in six occasions (1998, 1999, 2000, 2001, 2007 and 2010, they were analyzed considering their life-forms (trees, shrub, lianas, herbs and palms, abundance, frequency, size classes (CT1 = 10 cm ≤ HT < 50 cm; CT2 = 50 cm ≤ HT < 130 cm; CT3 = 130 cm < HT and DAP < 2 cm; and CT4 = 2 cm ≤ DAP < 5 cm and relative natural regeneration Burseraceae, Marantaceae, Violaceae and Lecythidaceae were the most important families in the study area in every occasions, while the most representative species were Monotagma sp1., Monotagma sp2., Rinorea guianensis, Lecythis idatimon e Protium pilosum. The most frequent life forms were trees, herbs and lianas in all occasions. The dynamics of life forms depended on light intensity. The establishment of commercial and potentially commercial species was favored by gaps, suggesting that natural regeneration of those species do not need to be assisted for guaranteeing timber stocks for future harvests.

  13. Integrating conventional classifiers with a GIS expert system to increase the accuracy of invasive species mapping

    NARCIS (Netherlands)

    Masocha, M.; Skidmore, A.K.

    2011-01-01

    Mapping the cover of invasive species using remotely sensed data alone is challenging, because many invaders occur as mid-level canopy species or as subtle understorey species and therefore contribute little to the spectral signatures captured by passive remote sensing devices. In this study, two

  14. Effect of industrial pollution on the distribution dynamics of radionuclides in boreal understorey ecosystems (EPORA). Final report

    International Nuclear Information System (INIS)

    Suomela, M.; Rahola, T.; Bergman, R.; Bunzl, K.; Jaakkola, T.

    1999-08-01

    The project EPORA 'Effects of Industrial Pollution on Distribution Dynamics of Radionuclides in Boreal Understorey Ecosystems' is a part of the Nuclear Fission Safety Research programme of the European Union. A suitable environment for the study was found in the surroundings of the Cu-Ni smelter in Monchegorsk, in NW Russia where the huge atmospheric emissions from the smelter have polluted the environment since the 1930's. Samples of soil, litter, plants and runoff water were taken. Total concentrations of the main pollutants, Ni and Cu, in the organic soil increased from about 10 mg kg -1 at the reference site in Finland to about 5000 mg kg -1 at the most polluted site in Russia. Similar trends were observed for exchangeable fractions and plant concentrations of the same elements. Concentrations of exchangeable K, Ca, and Mg in the organic soil decreased strongly with increased input of chemical pollutants. The radionuclides studied were 137 Cs, 90 Sr and 239+240 Pu, mainly originating from the atmospheric nuclear weapons tests. The contribution of the Chernobyl derived 137 Cs deposition was about 10% but insignificant for the other nuclides. The activity distribution of all three radionuclides in the soil, their corresponding residence half-times as well as their aggregated trencher factors for various plants depended on the degree of pollution: Activity distribution: in the litter layer, the activity of all three radionuclides increased continually from the reference site to the most polluted site. This effect was most pronounced for 239+240 Pu and least for 90 Sr and could, at least partly, be explained by the increase of the thickness of this layer. In the root zone, the opposite effect was observed: the largest fraction of all radionuclides was found at the reference site. In the organic layer, the exchangeable fractions of 137 Cs, 90 Sr and 239+240 Pu decreased with increasing pollution. Residence half-times: in the root zone, the residence half-times of 90

  15. Changes of Species Richness in Heathland Communities over 15 Years following Disturbances

    Directory of Open Access Journals (Sweden)

    L. Calvo

    2012-01-01

    Full Text Available The aim of this study was to define the species richness patterns over a period of 15 years during the vegetation recovery process after disturbances (burning, cutting and ploughing in heathlands. Three communities were selected: two dominated by Erica australis and one dominated by Calluna vulgaris. The alpha and gamma diversity patterns were site specific and influenced by the ecological traits of dominant shrub species. The shrubland dominated by Erica australis, typical resprouters with a fast regeneration, showed the highest values of alpha and gamma diversity during the first 7 years of regeneration. The heathland dominated by Calluna vulgaris, an obligate seeder, had a contrasting pattern of alpha and gamma diversity, as the highest values appeared from year 7 until year 14. Thus, the speed of regeneration of the dominant shrub species could be the main factor affecting structural parameters in these communities. Species richness patterns did not vary in relation to the different types of perturbation. Cutting and burning would be the most suitable forestry management strategies to conserve Erica australis heathlands, but burning is more appropriate in Calluna vulgaris ones because cutting modified this community.

  16. Effect of industrial pollution on the distribution dynamics of radionuclides in boreal understorey ecosystems (EPORA). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Suomela, M.; Rahola, T. [Radiation and Nuclear Safety Authority, Helsinki (Finland); Bergman, R. [National Defence Research Establishment (Sweden); Bunzl, K. [National Research Center for Environmental and Health (Germany); Jaakkola, T. [Helsinki Univ. (Finland). Radiochemical Lab.; Steinnes, E. [Norwegian University of Science and Technology (Norway)

    1999-08-01

    The project EPORA 'Effects of Industrial Pollution on Distribution Dynamics of Radionuclides in Boreal Understorey Ecosystems' is a part of the Nuclear Fission Safety Research programme of the European Union. A suitable environment for the study was found in the surroundings of the Cu-Ni smelter in Monchegorsk, in NW Russia where the huge atmospheric emissions from the smelter have polluted the environment since the 1930's. Samples of soil, litter, plants and runoff water were taken. Total concentrations of the mainpollutants, Ni and Cu, in the organic soil increased from about 10 mg kg{sup -1} at the reference site in Finland to about 5000 mg kg{sup -1} at the most polluted site in Russia. Similar trends were observed for exchangeable fractions and plant concentrations of the same elements. Concentrations of exchangeable K, Ca, and Mg in the organic soil decreased strongly with increased input of chemical pollutants. The radionuclides studied were {sup 137}Cs, {sup 90}Sr and {sup 239+240}Pu, mainly originating from the atmospheric nuclear weapons tests. The contribution of the Chernobyl derived {sup 137}Cs deposition was about 10% but insignificant for the other nuclides. The activity distribution of all three radionuclides in the soil, their corresponding residence half-times as well as their aggregated trencher factors for various plants depended on the degree of pollution: Activity distribution: in the litter layer, the activity of all three radionuclides increased continually from the reference site to the most polluted site. This effect was most pronounced for {sup 239+240}Pu and least for {sup 90}Sr and could, at least partly, be explained by the increase of the thickness of this layer. In the root zone, the opposite effect was observed: the largest fraction of all radionuclides was found at the reference site. In the organic layer, the exchangeable fractions of {sup 137}Cs, {sup 90}Sr and {sup 239+240}Pu decreased with increasing pollution

  17. Plasticity influencing the light compensation point offsets the specialization for light niches across shrub species in a tropical forest understorey

    NARCIS (Netherlands)

    Sterck, F.J.; Duursma, R.A.; Pearcy, R.W.; Valladares, F.; Cieslak, M.; Weemstra, M.

    2013-01-01

    1.Shade tolerance can be defined as the light level at which plants can survive and possibly grow. This light level is referred to as the whole-plant light compensation point (LCP). The LCP depends on multiple leaf and architectural traits. We are still uncertain how often interspecific trait

  18. The influence of savanna trees on nutrient, water and light availability and the understorey vegetation

    NARCIS (Netherlands)

    Ludwig, F.; Kroon, de H.; Berendse, F.; Prins, H.H.T.

    2004-01-01

    In an East African savanna herbaceous layer productivity and species composition were studied around Acacia tortilis trees of three different age classes, as well as around dead trees and in open grassland patches. The effects of trees on nutrient, light and water availability were measured to

  19. Effects of simulated historical tree litter raking on the understorey vegetation in a central European forest

    Czech Academy of Sciences Publication Activity Database

    Vild, Ondřej; Kalwij, Jesse; Hédl, Radim

    2015-01-01

    Roč. 18, č. 4 (2015), s. 569-578 ISSN 1402-2001 R&D Projects: GA AV ČR IAA600050812 EU Projects: European Commission(XE) 278065 - LONGWOOD Institutional support: RVO:67985939 Keywords : conservation management * litter raking * species diversity Subject RIV: EF - Botanics Impact factor: 2.308, year: 2015

  20. Experimental restoration of coppice-with-standards: Response of understorey vegetation from the conservation perspective

    Czech Academy of Sciences Publication Activity Database

    Vild, Ondřej; Roleček, Jan; Hédl, Radim; Kopecký, Martin; Utinek, D.

    2013-01-01

    Roč. 310, Dec 2013 (2013), s. 234-241 ISSN 0378-1127 R&D Projects: GA AV ČR IAA600050812; GA MŠk EE2.3.20.0267 Institutional support: RVO:67985939 Keywords : restoration experiment * endangered species * traditional woodland management Subject RIV: EF - Botanics Impact factor: 2.667, year: 2013

  1. Growth responses of low-alpine dwarf-shrub heath species to nitrogen deposition and management

    International Nuclear Information System (INIS)

    Britton, Andrea J.; Fisher, Julia M.

    2008-01-01

    Nitrogen deposition is a continuing problem in European alpine regions. We hypothesised that, despite climatic limitations, low-alpine Calluna heathland would respond to nitrogen addition with increased shoot growth and flowering and that fire and grazing would modify responses. In a five-year study, 0-50 kg N ha -1 y -1 were added, combined with burning (+/-) and clipping (+/-). Calluna vulgaris responded with increased shoot extension, but effects on flowering were variable. Burning enhanced the positive effect of nitrogen addition and negative effects of clipping. Sub-dominant shrubs generally did not respond to nitrogen. C. vulgaris shoot extension was stimulated by nitrogen addition of 10 kg N ha -1 y -1 (above background) supporting suggestions that alpine heathlands are sensitive to low levels of nitrogen deposition. Increased C. vulgaris growth could negatively impact on important lichen components of this vegetation through increased shading and competition. Climatic factors constrain productivity in this community, but do not prevent rapid responses to nitrogen deposition by some species. - Low levels of N deposition increase productivity in alpine dwarf-shrub heath despite strong climatic constraints

  2. Changes in the onset of spring growth in shrubland species in response to experimental warming along a north-south gradient in Europe

    DEFF Research Database (Denmark)

    Prieto, Patricia; Penuelas, Josep; Niinemets, Üelo

    2009-01-01

    Species responsive to increased temperatures were Vaccinium myrtillus and Empetrum nigrum in Wales, Deschampsia flexuosa in Denmark, Calluna vulgaris in Netherlands, Populus alba in Hungary and Erica multiflora in Spain. Although the acceleration of spring growth was the commonest response to warming...... gradient with average annual temperatures (8.2–15.6 °C) and precipitation (511–1427 mm). Methods 'Bud break' was monitored in eight shrub and grass species in six European sites under control and experimentally warmer conditions generated by automatic roofs covering vegetation during the night. Results...... treatments, the responses at each site were species specific and year dependent. Under experimental warming 25% of cases exhibited a significantly earlier onset of the growing season and 10% had a significantly delayed onset of vegetative growth. No geographical gradient was detected in the experimental...

  3. Beneath the veil: Plant growth form influences the strength of species richness-productivity relationships in forests

    Science.gov (United States)

    Oberle, B.; Grace, J.B.; Chase, J.M.

    2009-01-01

    Aim: Species richness has been observed to increase with productivity at large spatial scales, though the strength of this relationship varies among functional groups. In forests, canopy trees shade understorey plants, and for this reason we hypothesize that species richness of canopy trees will depend on macroclimate, while species richness of shorter growth forms will additionally be affected by shading from the canopy. In this study we test for differences in species richness-productivity relationships (SRPRs) among growth forms (canopy trees, shrubs, herbaceous species) in small forest plots. Location: We analysed 231 plots ranging from 34.0?? to 48.3?? N latitude and from 75.0?? to 124.2?? W longitude in the United States. Methods: We analysed data collected by the USDA Forest Inventory and Analysis program for plant species richness partitioned into different growth forms, in small plots. We used actual evapotranspiration as a macroclimatic estimate of regional productivity and calculated the area of light-blocking tissue in the immediate area surrounding plots for an estimate of the intensity of local shading. We estimated and compared SRPRs for different partitions of the species richness dataset using generalized linear models and we incorporated the possible indirect effects of shading using a structural equation model. Results: Canopy tree species richness increased strongly with regional productivity, while local shading primarily explained the variation in herbaceous plant richness. Shrub species richness was related to both regional productivity and local shading. Main conclusions: The relationship between total forest plant species richness and productivity at large scales belies strong effects of local interactions. Counter to the pattern for overall richness, we found that understorey herbaceous plant species richness does not respond to regional productivity gradients, and instead is strongly influenced by canopy density, while shrub species

  4. The Species Richness of Vascular Plants and Amphibia in Major Plant Communities in Temperate to Tropical Australia: Relationship with Annual Biomass Production

    International Nuclear Information System (INIS)

    Specht, R. L.; Tyler, M.J.

    2010-01-01

    Aerodynamic fluxes (frictional, thermal, evaporative) in the atmosphere as it flows over and through a plant community determine the Foliage Projective Covers and eco-morphological attributes of new leaves developed annually in overstorey and understorey strata. The number of leaves produced on vertical foliage shoots depends on available soil water and nutrients, also ambient temperature, during this short growth season. Stem density (number of stems per hectare) and species richness (number of species per hectare) in the overstorey of major Floristic Groups are correlated with annual shoot growth (ASG, t ha-1) in that stratum. Species richness in the overstorey increases in the climatic gradient from the arid to the humid zone as well as with increasing air temperatures (about 10 degree C) from temperate to tropical Australia. Species richness in the understorey is highest in plant communities in temperate Australia, decreasing in the temperature gradient towards the tropics. As with other major plant and animal groups within an ecosystem, the species richness of Amphibia is correlated with the amount of solar energy fixed (per annum) by the major plant formation in the regional photosynthetic potential determined by the foliage shoots (ASG, t ha-1) produced annually in the overstorey.

  5. The Species Richness of Vascular Plants and Amphibia in Major Plant Communities in Temperate to Tropical Australia: Relationship with Annual Biomass Production

    Directory of Open Access Journals (Sweden)

    R. L. Specht

    2010-01-01

    Full Text Available Aerodynamic fluxes (frictional, thermal, evaporative in the atmosphere as it flows over and through a plant community determine the Foliage Projective Covers and eco-morphological attributes of new leaves developed annually in overstorey and understorey strata. The number of leaves produced on vertical foliage shoots depends on available soil water and nutrients, also ambient temperature, during this short growth season. Stem density (number of stems per hectare and species richness (number of species per hectare in the overstorey of major Floristic Groups are correlated with annual shoot growth (ASG, t ha−1 in that stratum. Species richness in the overstorey increases in the climatic gradient from the arid to the humid zone as well as with increasing air temperatures (about 10oC from temperate to tropical Australia. Species richness in the understorey is highest in plant communities in temperate Australia, decreasing in the temperature gradient towards the tropics. As with other major plant and animal groups within an ecosystem, the species richness of Amphibia is correlated with the amount of solar energy fixed (per annum by the major plant formation in the region—a photosynthetic potential determined by the foliage shoots (ASG, t ha−1 produced annually in the overstorey.

  6. General characterisation of study area and definition of experimental protocols. WP 1 in the project 'Effect of industrial pollution on the distribution dynamics of radionuclides in boreal understorey ecosystems'

    Energy Technology Data Exchange (ETDEWEB)

    Rahola, T. [Radiation and Nuclear Safety Authority, Helsinki (Finland); Albers, B. [National Research Center for Environmental and Health (Georgia); Bergman, R. [National Defence Research Establishment (Germany)] [and others

    1999-08-01

    The research project EPORA (Effects of Industrial Pollution on the Distribution Dynamics of Radionuclides in Boreal Understorey Ecosystems) is part of the EU Nuclear Fission Safety Programme 1994 - 1998. The main purpose of EPORA is to study the influence of strong chemical pollution on the behaviour of artificial radionuclides ({sup 137}Cs,{sup 90}Sr, {sup 239},{sup 240}{sub Pu}) in a northern boreal ecosystem and subsequently to assess the significance of the findings to the radiation exposure of the population in such areas. The present report is a documentation of the selection of study areas based on the assessment of available information on pollution in the Kola Peninsula and Northern Fennoscandia and of sampling and analysing methods. (orig.)

  7. General characterisation of study area and definition of experimental protocols. WP 1 in the project 'Effect of industrial pollution on the distribution dynamics of radionuclides in boreal understorey ecosystems'

    International Nuclear Information System (INIS)

    Rahola, T.; Albers, B.; Bergman, R.

    1999-08-01

    The research project EPORA (Effects of Industrial Pollution on the Distribution Dynamics of Radionuclides in Boreal Understorey Ecosystems) is part of the EU Nuclear Fission Safety Programme 1994 - 1998. The main purpose of EPORA is to study the influence of strong chemical pollution on the behaviour of artificial radionuclides ( 137 Cs, 90 Sr, 239 , 240 Pu ) in a northern boreal ecosystem and subsequently to assess the significance of the findings to the radiation exposure of the population in such areas. The present report is a documentation of the selection of study areas based on the assessment of available information on pollution in the Kola Peninsula and Northern Fennoscandia and of sampling and analysing methods. (orig.)

  8. Arbutin content and antioxidant activity of some Ericaceae species.

    Science.gov (United States)

    Pavlović, R D; Lakusić, B; Doslov-Kokorus, Z; Kovacević, N

    2009-10-01

    Quantitative analyses and investigation of antioxidant activity of herb and dry ethanolic extracts of five species from Ericaceae family (Arbutus unedo L., Bruckentalia spiculifolia Rchb., Calluna vulgaris Salisb., Erica arborea L. and Erica carnea L.) were performed. Total polyphenols, tannins and flavonoids were determined spectrophotometrically and arbutin content was measured both spectrophotometrically and by HPLC coupled with DAD detection. Antioxidative properites of the ethanolic extracts were tested by means of FRAP (total antioxidant capacity), lipid peroxidation and DPPH free radical scavenging activity. A significant amount of arbutin was detected only in Arbutus unedo. All samples investigated showed excellent antioxidant activity. The best inhibition of lipid peroxidation has been shown by Bruckentalia spiculifolia herb extract (62.5 microg/ml; more than 95%), which contained the highest amount of flavonoids (11.79%). The highest scavenging activity was obtained with leave extract of Arbutus unedo (IC50 = 7.14 microg/ml). The leaves of A. unedo contained a small amount of flavonoids but high content of non-tannins polyphenols.

  9. Effects of past burning frequency on plant species structure and composition in dry dipterocarp forest

    Science.gov (United States)

    Wanthongchai, Dr.; Bauhus, Prof.; Goldammer, Prof.

    2009-04-01

    Anthropogenic burning in dry dipterocarp forests (DDF) has become a common phenomenon throughout Thailand. It is feared that too frequent fires may affect vegetation structure and composition and thus impact on ecosystem productivity. The aim of this study was to quantify the effects of prescribed fires on sites with different past burning regimes on vegetation structure and composition in the Huay Kha Khaeng Wildlife Sanctuary (HKK), Thailand. Fire frequency was determined from satellite images and ranged from frequent, infrequent, rare and unburned with fire occurrences of 7, 2, 1 and 0 out of the past 10 years, respectively. The pre-burn fuel loads, the overstorey and understorey vegetation structure and composition were determined to investigate the effects of the contrasting past burning regimes. The burning experiment was carried out, applying a three-strip head-fire burning technique. The vegetation structure and composition were sampled again one year after the fire to assess the fire impacts. Aboveground fine fuel loads increased with the length of fire-free interval. The woody plant structures of the frequently burned stand differed from those of the other less frequently burned stands. The species composition of the overstorey on the frequently burned site, in particular that of small sized trees (4.5-10 cm dbh), also differed significantly from that of the other sites. Whilst the ground vegetation including shrubs and herbs did not differ between the past burning regimes, frequent burning obviously promoted the proliferation of graminoid vegetation. There was no clear evidence showing that the prescribed fires affected the mortality of trees (dbh> 4.5 cm) on the sites of the different past burning regimes. The effects of prescribed burning on the understorey vegetation structures varied between the past burning regimes and the understorey vegetation type. Therefore, it is recommended that the DDF at HKK should be subjected to a prescribed fire frequency

  10. The discovery of Kerivoula krauensis (Chiroptera: Vespertilionidae in southern peninsular Thailand provides new information on the distribution and conservation status of this data deficient species

    Directory of Open Access Journals (Sweden)

    Bounsavane Douangboubpha

    2014-10-01

    Full Text Available In August 2013, an adult male Kerivoula krauensis was captured in a harp trap set in forest understorey in Bala Forest, Hala-Bala Wildlife Sanctuary, Narathiwat Province, Thailand. This is only the second locality recorded for the species, the first outside Malaysia, and represents a range extension of 254 km, northwards from Krau Wildlife Reserve, Malaysia. This discovery has important conservation implications suggesting that the species is more widespread than previously thought but also confirms previous findings that it appears to live in very low population densities as compared to other Kerivoula found in the same habitat. Information on its taxonomy, echolocation call, distribution and ecology is included. In addition, the new material from Thailand is briefly compared to other known species from the country

  11. Estimation of carbon flow in a Calluna heath system

    International Nuclear Information System (INIS)

    Roesberg, I.; Oevstedal, D.O.; Seljelid, R.; Schreiner, Oe.; Goksoeyr, J.

    1981-01-01

    In a Culluna heath, plots of 1 m 2 were pulse labelled with 14 CO 2 , and the radioactivity in vegetation above ground, roots, litter and soil organic matter followed for almost two years. In a separate experiment, radioactivity in above ground and root respiration and in soil microbial biomass was determined. A kinetic model for the carbon transfer reaction is presented, and shown to give a satisfactory agreement with the experimental data. The results demonstrate that a major part of the assimilated carbon passes through the roots and into the soil, where it is rapidly mineralized. (author)

  12. Endangered Species

    Science.gov (United States)

    EPA's Endangered Species Protection Program helps promote recovery of listed species. The ESPP determines if pesticide use in a geographic area may affect any listed species. Find needed limits on pesticide use in Endangered Species Protection Bulletins.

  13. Assessing the impact of revegetation and weed control on urban sensitive bird species.

    Science.gov (United States)

    Archibald, Carla L; McKinney, Matthew; Mustin, Karen; Shanahan, Danielle F; Possingham, Hugh P

    2017-06-01

    Nature in cities is concentrated in urban green spaces, which are key areas for urban biodiversity and also important areas to connect people with nature. To conserve urban biodiversity within these natural refugia, habitat restoration such as weed control and revegetation is often implemented. These actions are expected to benefit biodiversity, although species known to be affected by urbanization may not be interacting with restoration in the ways we anticipate. In this study, we use a case study to explore how urban restoration activities impact different bird species. Birds were grouped into urban sensitivity categories and species abundance, and richness was then calculated using a hierarchical species community model for individual species responses, with "urban class" used as the hierarchical parameter. We highlight variable responses of birds to revegetation and weed control based on their level of urban sensitivity. Revegetation of open grassy areas delivers significant bird conservation outcomes, but the effects of weed control are neutral or in some cases negative. Specifically, the species most reliant on remnant vegetation in cities seem to remain stable or decline in abundance in areas with weed control, which we suspect is the result of a simplification of the understorey. The literature reports mixed benefits of weed control between taxa and between locations. We recommend, in our case study site, that weed control be implemented in concert with replanting of native vegetation to provide the understory structure preferred by urban sensitive birds. Understanding the impacts of revegetation and weed control on different bird species is important information for practitioners to make restoration decisions about the allocation of funds for conservation action. This new knowledge can be used both for threatened species and invasive species management.

  14. Spatial Patterns and Interspecific Associations of Three Canopy Species at Different Life Stages in a Subtropical Forest,China

    Institute of Scientific and Technical Information of China (English)

    Lin Li; Shi-Guang Wei; Zhong-Liang Huang; Wan-Hui Ye; Hong-Lin Cao

    2008-01-01

    Spatial patterns of species at different life stages are an important aspect for understanding causal mechanisms that facilitate species co-existence.Using Ripley's univariate L(t) and bivariate L12(t) functions,we analyzed the spatial patterns and interspecific associations of three canopy species at different life history stages in a 20-ha subtropical forest plot in Dinghushan Nature Reserve.Based on diameter at breast height (DBH),four life stages were distinguished.Castanopsis chinensis and Schima superba showed a unimodal DBH distribution.Engelhardtia roxburghiana showed a bimodal curve.L(t) function analysis showed significantly aggregated distributions of all three species at later life stages and random distribution at early life stages at some scales.From the analysis of L12(t) function,the results showed the positive association was a dominant pattern for most species pairs at most scales but the intensity of association decreases with the increase of life stages.Juveniles of the three species had no negative intra- and interspecific associations with the older life stages.Only premature trees were suppressed by overmature trees at some scales.Considering these results,we found three canopy-dominant species that lacked regeneration.There was no direct competition occurring between understorey individuals.Young trees can grow well under conspecific species with two other species.Longevity and lack of regeneration led to a large number of trees stored in mature and overmature stages,therefore,intra-and inter-competition can be strong at later life stages.

  15. SALMONELLA SPECIES

    African Journals Online (AJOL)

    DR. AMINU

    ... of Salmonella species serotypes in relation to age and sex among children, ..... However, most antimicrobials show sufficient selective toxicity to be of value in ... salmonellosis should be given good attention (Barrow et al., 2007). To reduce ...

  16. Species interactions can maintain resistance of subtidal algal habitats to an increasingly modified world

    Directory of Open Access Journals (Sweden)

    Laura J. Falkenberg

    2015-07-01

    Full Text Available Current trends in habitat loss have been forecast to accelerate under anticipated global change, thereby focusing conservation attention on identifying the circumstances under which key species interactions retard habitat loss. Urbanised coastlines are associated with broad-scale loss of kelp canopies and their replacement by less productive mats of algal turf, a trend predicted to accelerate under ocean acidification and warming (i.e. enhanced CO2 and temperature. Here we use kelp forests as a model system to test whether efforts to maintain key species interactions can maintain habitat integrity under forecasted conditions. First, we assessed whether increasing intensity of local human activity is associated with more extensive turf mats and sparser canopies via structured field observations. Second, we experimentally tested the hypothesis that intact canopies can resist turf expansion under enhanced CO2 and temperature in large mesocosms. In the field, there was a greater proportion of turf patches on urbanised coasts of South Australia than in agricultural and urban catchments in which there was a greater proportion of canopy-forming algae. Mesocosm experiments revealed this expansion of turfs is likely to accelerate under increases in CO2 and temperature, but may be limited by the presence of intact canopies. We note that even in the presence of canopy, increases in CO2 and temperature facilitate greater turf covers than occurs under contemporary conditions. The influence of canopy would likely be due to shading of the understorey turfs which, in turn, can modify their photosynthetic activity. These results suggest that resistance of habitat to change under human-dominated conditions may be managed via the retention of key species and their interactions. Management that directly reduces the disturbance of habitat-forming organisms (e.g. harvesting or reverses loss through restoration may, therefore, reinforce habitat resistance in an

  17. Light-related variation in sapling architecture of three shade-tolerant tree species of the Mexican rain forest Variación arquitectural de árboles juveniles en relación con la luz en tres especies tolerantes a la sombra en una selva húmeda mexicana

    Directory of Open Access Journals (Sweden)

    JOSÉ LUIS MARTÍNEZ-SÁNCHEZ

    2008-09-01

    Full Text Available The crown architecture of three shade-tolerant tree species (two subcanopy and one mid-canopy was analyzed in relation to the light regime of the forest understorey. The aim was to examine to which extent shade-tolerant species variate in their crown architecture. Tree saplings (265 between 50 and 300 cm height, and distributed from understorey to variously-sized canopy gaps, were measured for 13 architectural traits in the lowland rain forest of Los Tuxtlas, México. The analysis showed that the three species changed their architecture as light increased but in a different way. No species conformed to the typical wide-crown type expected for shade-tolerant species, and in contrast they presented some traits of light demanding species. The two sub-canopy species tended to adopt a crown form between a narrow- and wide-crown type, and the mid-canopy species showed more traits of a narrow-crown type. The horizontal crown area appeared as the more related trait to the light and sapling height. It is concluded that despite being shade-tolerant, the studied species make use of better-lit environments in the forest understorey. The crown architecture of shade-tolerant species is not as rigid as originally conceived.Se analizó la arquitectura de la copa de tres especies tolerantes a la sombra (dos del sotobosque y una del dosel medio en relación con el ambiente lumínico del sotobosque de la selva. El objetivo fue examinar el grado de variación que presenta la arquitectura de la copa de especies tolerantes a la sombra. Para esto, se midieron 13 variables arquitecturales en 265 árboles juveniles (50-300 cm de altura distribuidos desde sitios de selva madura hasta claros de diversos tamaños, en la selva húmeda tropical de Los Tuxtlas, México. El análisis mostró que las tres especies cambian la arquitectura de su copa a medida que aumenta la disponibilidad de luz, pero de diferente forma. Ninguna especie presentó el típico modelo de copa plana

  18. Species composition and forest structure explain the temperature sensitivity patterns of productivity in temperate forests

    Directory of Open Access Journals (Sweden)

    F. J. Bohn

    2018-03-01

    development, one could plant below the closed canopy of even-aged, pioneer trees a climax-species-rich understorey that will build the canopy of the mature forest. This study highlights that forest structure and species composition are both relevant for understanding the temperature sensitivity of wood production.

  19. Species composition and forest structure explain the temperature sensitivity patterns of productivity in temperate forests

    Science.gov (United States)

    Bohn, Friedrich J.; May, Felix; Huth, Andreas

    2018-03-01

    below the closed canopy of even-aged, pioneer trees a climax-species-rich understorey that will build the canopy of the mature forest. This study highlights that forest structure and species composition are both relevant for understanding the temperature sensitivity of wood production.

  20. First typology of cacao (Theobroma cacao L.) systems in Colombian Amazonia, based on tree species richness, canopy structure and light availability.

    Science.gov (United States)

    Suárez Salazar, Juan Carlos; Ngo Bieng, Marie Ange; Melgarejo, Luz Marina; Di Rienzo, Julio A; Casanoves, Fernando

    2018-01-01

    We present a typology of cacao agroforest systems in Colombian Amazonia. These systems had yet to be described in the literature, especially their potential in terms of biodiversity conservation. The systems studied are located in a post-conflict area, and a deforestation front in Colombian Amazonia. Cacao cropping systems are of key importance in Colombia: cacao plays a prime role in post conflict resolution, as cacao is a legal crop to replace illegal crops; cacao agroforests are expected to be a sustainable practice, promoting forest-friendly land use. We worked in 50 x 2000 m2 agroforest plots, in Colombian Amazonia. A cluster analysis was used to build a typology based on 28 variables characterised in each plot, and related to diversity, composition, spatial structure and light availability for the cacao trees. We included variables related to light availability to evaluate the amount of transmitted radiation to the cacao trees in each type, and its suitability for cacao ecophysiological development. We identified 4 types of cacao agroforests based on differences concerning tree species diversity and the impact of canopy spatial structure on light availability for the cacao trees in the understorey. We found 127 tree species in the dataset, with some exclusive species in each type. We also found that 3 out of the 4 types identified displayed an erosion of tree species diversity. This reduction in shade tree species may have been linked to the desire to reduce shade, but we also found that all the types described were compatible with good ecophysiological development of the cacao trees. Cacao agroforest systems may actually be achieving biodiversity conservation goals in Colombian Amazonia. One challenging prospect will be to monitor and encourage the conservation of tree species diversity in cacao agroforest systems during the development of these cropping systems, as a form of forest-friendly management enhancing sustainable peace building in Colombia.

  1. First typology of cacao (Theobroma cacao L.) systems in Colombian Amazonia, based on tree species richness, canopy structure and light availability

    Science.gov (United States)

    Suárez Salazar, Juan Carlos; Melgarejo, Luz Marina; Di Rienzo, Julio A.; Casanoves, Fernando

    2018-01-01

    Aim and background We present a typology of cacao agroforest systems in Colombian Amazonia. These systems had yet to be described in the literature, especially their potential in terms of biodiversity conservation. The systems studied are located in a post-conflict area, and a deforestation front in Colombian Amazonia. Cacao cropping systems are of key importance in Colombia: cacao plays a prime role in post conflict resolution, as cacao is a legal crop to replace illegal crops; cacao agroforests are expected to be a sustainable practice, promoting forest-friendly land use. Material and methods We worked in 50 x 2000 m2 agroforest plots, in Colombian Amazonia. A cluster analysis was used to build a typology based on 28 variables characterised in each plot, and related to diversity, composition, spatial structure and light availability for the cacao trees. We included variables related to light availability to evaluate the amount of transmitted radiation to the cacao trees in each type, and its suitability for cacao ecophysiological development. Main results We identified 4 types of cacao agroforests based on differences concerning tree species diversity and the impact of canopy spatial structure on light availability for the cacao trees in the understorey. We found 127 tree species in the dataset, with some exclusive species in each type. We also found that 3 out of the 4 types identified displayed an erosion of tree species diversity. This reduction in shade tree species may have been linked to the desire to reduce shade, but we also found that all the types described were compatible with good ecophysiological development of the cacao trees. Main conclusions and prospects Cacao agroforest systems may actually be achieving biodiversity conservation goals in Colombian Amazonia. One challenging prospect will be to monitor and encourage the conservation of tree species diversity in cacao agroforest systems during the development of these cropping systems, as a form of

  2. First typology of cacao (Theobroma cacao L. systems in Colombian Amazonia, based on tree species richness, canopy structure and light availability.

    Directory of Open Access Journals (Sweden)

    Juan Carlos Suárez Salazar

    Full Text Available We present a typology of cacao agroforest systems in Colombian Amazonia. These systems had yet to be described in the literature, especially their potential in terms of biodiversity conservation. The systems studied are located in a post-conflict area, and a deforestation front in Colombian Amazonia. Cacao cropping systems are of key importance in Colombia: cacao plays a prime role in post conflict resolution, as cacao is a legal crop to replace illegal crops; cacao agroforests are expected to be a sustainable practice, promoting forest-friendly land use.We worked in 50 x 2000 m2 agroforest plots, in Colombian Amazonia. A cluster analysis was used to build a typology based on 28 variables characterised in each plot, and related to diversity, composition, spatial structure and light availability for the cacao trees. We included variables related to light availability to evaluate the amount of transmitted radiation to the cacao trees in each type, and its suitability for cacao ecophysiological development.We identified 4 types of cacao agroforests based on differences concerning tree species diversity and the impact of canopy spatial structure on light availability for the cacao trees in the understorey. We found 127 tree species in the dataset, with some exclusive species in each type. We also found that 3 out of the 4 types identified displayed an erosion of tree species diversity. This reduction in shade tree species may have been linked to the desire to reduce shade, but we also found that all the types described were compatible with good ecophysiological development of the cacao trees.Cacao agroforest systems may actually be achieving biodiversity conservation goals in Colombian Amazonia. One challenging prospect will be to monitor and encourage the conservation of tree species diversity in cacao agroforest systems during the development of these cropping systems, as a form of forest-friendly management enhancing sustainable peace building in

  3. Endangered Species Day | Endangered Species Coalition

    Science.gov (United States)

    Annual Top 10 Report Protecting the Endangered Species Act Wildlife Voices Stand for Wolves Endangered Campaigns Wildlife Voices Protecting the Endangered Species Act Annual Top 10 Report Endangered Species Day Stand for Wolves Vanishing BOOK: A Wild Success The Endangered Species Act at 40 Endangered Species The

  4. Effects of an experimental increase of temperature and drought on the photosynthetic performance of two ericaceous shrub species along a north-south European gradient

    DEFF Research Database (Denmark)

    Llorens, L.; Penuelas, J.; Beier, C.

    2004-01-01

    ericaceous shrubs (Erica multiflora and Calluna vulgaris) along a European gradient of temperature and precipitation (UK, Denmark, The Netherlands, and Spain). At each site, a passive warming treatment was applied during the night throughout the whole year, whereas the drought treatment excluded rain events...

  5. Understorey bird abundance and diversity before and after a forest ...

    African Journals Online (AJOL)

    Scopus: Journal of East African Ornithology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 34 (2015) >. Log in or Register to get access to full text downloads.

  6. Species concept and speciation

    Directory of Open Access Journals (Sweden)

    Amal Y. Aldhebiani

    2018-03-01

    Full Text Available Defining and recognizing a species has been a controversial issue for a long time. To determine the variation and the limitation between species, many concepts have been proposed. When a taxonomist study a particular taxa, he/she must adopted a species concept and provide a species limitation to define this taxa. In this paper some of species concepts are discussed starting from the typological species concepts to the phylogenetic concept. Positive and negative aspects of these concepts are represented in addition to their application. Keywords: Species concept, Species limitation, Species, Taxonomy, Classification

  7. Development of floristic diversity in 10-year-old restoration forests on a bauxite mined site in Amazonia.

    Science.gov (United States)

    J. A. Parrotta; O. H. Knowles; J.M. Wunderle Jr.

    1997-01-01

    Patterns of plant and animal diversity were studied in a 10-year-old native species reforestation area at a bauxite-mined site at porto Trombetas in western Para State, Brazil. Understorey and overstorey floristic composition and structure, understorey light conditions, forest floor development and soil properties were evaluated in a total of 38 78.5-m2

  8. Species accounts. Chapter 4

    Science.gov (United States)

    Margaret K. Trani; W. Mark Ford; Brian R., eds. Chapman

    2007-01-01

    Narrative accounts for each species are presented by several authors in a consistent format to convey specific information relative to that mammal. The orders are arranged phylogenetically; families and species are arranged alphabetically to facilitate finding a particular species.

  9. Translocation of 14C in adventitiously rooting Calluna vulgaris on peat

    International Nuclear Information System (INIS)

    Wallen, B.

    1983-01-01

    Seasonal variation in translocation of 14 C-labelled assimilates showed that 14 C-translocation within woody tissue was mainly limited to the phytomass produced during the last eight years. Independent of overgrowth of basal stem segments or decumbent sections by Sphagnum, or of subsequent adventitious rooting, the allocation followed a negative exponential from the assimilating units down the plant, and reached negligible values in 8-yr-old wood. Translocation to fine roots was however, mainly restricted to the shallow roots. Already at ca. 10 cm depth, the fine roots contained only about 5% of the concentration in the fine roots in the surface. During spring and autumn translocation to below ground parts dominated. During summer the main translocation was within the above ground green shoots and flowers. Here most of the allocated 14 C was irreversibly bound. There were only weak indications of accumulation of moblie 14 C-compounds in the woody parts near the soil surface. (author)

  10. Agroforestry Species Switchboard

    DEFF Research Database (Denmark)

    Kindt, R.; John, I.; Ordonez, J.

    2016-01-01

    The current version of the Agroforestry Species Switchboard documents the presence of a total of 26,135 plant species (33,813 species including synonyms) across 19 web-based databases. When available, hyperlinks to information on the selected species in particular databases are provided. In total...

  11. Endangered Species Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of the Endangered Species Act (ESA) is to protect and recover imperiled species and the ecosystems upon which they depend. The U.S. Fish and Wildlife...

  12. Endangered Species Protection Bulletins

    Science.gov (United States)

    Endangered Species Protection Bulletins set forth geographically specific pesticide use limitations for the protection of threatened and endangered (listed) species and their designated critical habitat. Find out how to get and use Bulletins.

  13. Species diversity modulates predation

    NARCIS (Netherlands)

    Kratina, P.; Vos, M.; Anholt, B.R.

    2007-01-01

    Predation occurs in a context defined by both prey and non-prey species. At present it is largely unknown how species diversity in general, and species that are not included in a predator's diet in particular, modify predator–prey interactions.Therefore we studied how both the density and diversity

  14. Species choice, provenance and species trials among native Brazilian species

    Energy Technology Data Exchange (ETDEWEB)

    Drumond, M A

    1982-01-01

    Six papers from the conference are presented. Drumond, M.A., Potential of species native to the semi-arid tropics, 766-781, (Refs. 18), reports on Anadenanthera macrocarpa, Mimosa species, Schinopsis brasiliensis, Spondias tuberosa, Ziziphus joazeiro, Cnidoscolus phyllacanthus, Bursera leptophleos (leptophloeos), Tabebuia impetiginosa, Astronium urundeuva, and Mimosa caesalpinia. Monteiro, R.F.R., Speltz, R.M., Gurgel, J.T. do A.; Silvicultural performance of 24 provenances of Araucaria angustifolia in Parana, 814-824, (Refs. 8). Pires, C.L. da S., Kalil Filho, A.N., Rosa, P.R.F. da, Parente, P.R., Zanatto, A.C.S.; Provenance trials of Cordia alliodora in the State of Sao Paulo, 988-995, (Refs. 9). Nogueira, J.C.B., Siqueira, A.C.M.F., Garrido, M.A.O., Gurgel Garrido, L.M. do A., Rosa, P.R.F., Moraes, J.L. de, Zandarin, M.A., Gurgel Filho, O.A., Trials of some native species in various regions of the State of Sao Paulo, 1051-1063, (Refs. 9) describes Centrolobium tomentosum, Peltophorum dubium, Tabebuia vellosoi, Cariniana legalis, and Balfourodendron riedelianum. Batista, M.P., Borges, J.F., Franco, M.A.B.; Early growth of a native species in comparison with exotics in northeastern Para, Brazil, 1105-1110, (Refs. 3). Jacaranda copaia is compared with Gmelina arborea, Pinus caribaea various hondurensis, Eucalyptus deglupta, and E. urophylla. Lima, P.C.F., Souza, S.M. de, Drumond, M.A.; Trials of native forest species at Petrolina, Pernambuco, 1139-1148, (Refs. 8), deals with Anadenanthera macrocarpa, Piptadenia obliqua, Pithecellobium foliolosum, Astronium urundeuva, Schinopsis brasiliensis, Cassia excelsa, Caesalpinia pyramidalis, Parkia platycephala, Pseudobombax simplicifolium, Tabebuia impetiginosa, Caesalpinia ferrea, and Aspidosperma pyrifolium. 18 references.

  15. Separation of chemical species

    International Nuclear Information System (INIS)

    Rentzepis, P.M.

    1977-01-01

    Isotopic separation is accomplished by (1) a second photon irradiation step for selective ionization of a first isotopic species and (2) selective precipitation of a generally immiscible liquid from the saturating vapor phase on the ionized species. The first photon corresponds with a sharply defined spectral portion of the irradiation which exclusively excites the first species to a vibrational level. The second photon further excites this species to its ionization level. Selective precipitation is by coulombic attraction between the ionized species and the vapor. The procedure is applicable to any vapor phase ionizable material

  16. Detection of cryptic species

    International Nuclear Information System (INIS)

    Cockburn, A.F.; Jensen, T.; Seawright, J.A.

    1998-01-01

    Morphologically similar cryptic species are common in insects. In Anopheles mosquitoes morphologically described species are complexes of cryptic species. Cryptic species are of great practical importance for two reasons: first, one or more species of the complex might not be a pest and control efforts directed at the complex as a whole would therefore be partly wasted; and second, genetic (and perhaps biological) control strategies directed against one species of the complex would not affect other species of the complex. At least one SIT effort has failed because the released sterile insect were of a different species and therefore did not mate with the wild insects being targeted. We use a multidisciplinary approach for detection of cryptic species complexes, focusing first on identifying variability in wild populations using RFLPs of mitochondrial and ribosomal RNA genes (mtDNA and rDNA); followed by confirmation using a variety of other techniques. For rapid identification of wild individuals of field collections, we use a DNA dot blot assay. DNA probes can be isolated by differential screening, however we are currently focusing on the sequencing of the rDNA extragenic spacers. These regions are repeated several hundred times per genome in mosquitoes and evolve rapidly. Molecular drive tends to keen the individual genes homogeneous within a species. (author)

  17. Detection of cryptic species

    Energy Technology Data Exchange (ETDEWEB)

    Cockburn, A F; Jensen, T; Seawright, J A [United States Dept. of Agriculture, Agricultural Research Service, Medical and Veterinary Entomology Research Lab., Gainesville, FL (United States)

    1998-01-01

    Morphologically similar cryptic species are common in insects. In Anopheles mosquitoes morphologically described species are complexes of cryptic species. Cryptic species are of great practical importance for two reasons: first, one or more species of the complex might not be a pest and control efforts directed at the complex as a whole would therefore be partly wasted; and second, genetic (and perhaps biological) control strategies directed against one species of the complex would not affect other species of the complex. At least one SIT effort has failed because the released sterile insect were of a different species and therefore did not mate with the wild insects being targeted. We use a multidisciplinary approach for detection of cryptic species complexes, focusing first on identifying variability in wild populations using RFLPs of mitochondrial and ribosomal RNA genes (mtDNA and rDNA); followed by confirmation using a variety of other techniques. For rapid identification of wild individuals of field collections, we use a DNA dot blot assay. DNA probes can be isolated by differential screening, however we are currently focusing on the sequencing of the rDNA extragenic spacers. These regions are repeated several hundred times per genome in mosquitoes and evolve rapidly. Molecular drive tends to keen the individual genes homogeneous within a species. (author). 11 refs, 2 figs, 2 tabs.

  18. Chapter 16: Species Diversity

    African Journals Online (AJOL)

    zargaran

    2012-05-03

    May 3, 2012 ... rarefaction method was recorded in Pardanan, with 28 oak gall wasps species. Furthermore, the highest amount of Gini-Simpson and Shannon entropy index were recorded in Sardasht, while the highest evenness was recorded in Shalmash. Differences in the local distribution of oak species, especially.

  19. The Origin of Species

    NARCIS (Netherlands)

    Darwin, Charles

    2005-01-01

    In The Origin of Species Darwin outlined his theory of evolution, which proposed that species had been evolving and differentiating over time under the influence of natural selection. On its publication it became hugely influential, bringing about a seismic shift in the scientific view of humanitys

  20. Aquatic species and habitats

    Science.gov (United States)

    Danny C. Lee; James R. Sedell; Bruce E. Rieman; Russell F. Thurow; Jack E. Williams

    1998-01-01

    Continuing human activities threaten the highly prized aquatic resources of the interior Columbia basin. Precipitous declines in native species, particularly Pacific salmon, and a large influx of introduced species have radically altered the composition and distribution of native fishes. Fortunately, areas of relatively high aquatic integrity remain, much of it on...

  1. Support your local species

    DEFF Research Database (Denmark)

    Stärk, Johanna

    Nearly a quarter of all animal species within the European Union are threatened with extinction. Protecting many of these species will require the full spectrum of conservation actions from in-situ to ex-situ management. Holding an estimated 44% of EU Red Listed terrestrial vertebrates, zoos hereby...

  2. Extragastric Helicobacter species

    DEFF Research Database (Denmark)

    On, Stephen L.W.; Hynes, S.; Wadstrom, T.

    2002-01-01

    The genus Helicobacter has expanded at a rapid pace and no fewer than 31 species have been named since the proposal of the genus in 1989. Of these 31 species, 22 are principally associated with extragastric niches and there is increasing interest in the role of these taxa in diseases of humans...... and animals. Substantial evidence attests to certain species playing a role in the pathogenesis of enteric, hepatic and biliary disorders and some taxa demonstrate zoonotic potential. The importance of extragastric Helicobacters is likely to be an important topic for research in the near future. Here...

  3. The species in primatology.

    Science.gov (United States)

    Groves, Colin

    2014-01-01

    Biologists of the late eighteenth and early nineteenth centuries all bandied about the term "species," but very rarely actually said what they meant by it. Often, however, one can get inside their thinking by piecing together some of their remarks. One of the most nearly explicit-appropriately, for the man who wrote a book called The Origin of Species - was Charles Darwin: "Practically, when a naturalist can unite two forms together by others having intermediate characters, he treats the one as a variety of the other… He later translated this into evolutionary terms: "Hereafter, we shall be compelled to acknowledge that the only distinction between species and well-marked varieties is, that the latter are known, or believed, to be connected at the present day by intermediate gradations, whereas species were formerly thus connected"(1:484-5.) Copyright © 2014 Wiley Periodicals, Inc.

  4. Hierarchical species distribution models

    Science.gov (United States)

    Hefley, Trevor J.; Hooten, Mevin B.

    2016-01-01

    Determining the distribution pattern of a species is important to increase scientific knowledge, inform management decisions, and conserve biodiversity. To infer spatial and temporal patterns, species distribution models have been developed for use with many sampling designs and types of data. Recently, it has been shown that count, presence-absence, and presence-only data can be conceptualized as arising from a point process distribution. Therefore, it is important to understand properties of the point process distribution. We examine how the hierarchical species distribution modeling framework has been used to incorporate a wide array of regression and theory-based components while accounting for the data collection process and making use of auxiliary information. The hierarchical modeling framework allows us to demonstrate how several commonly used species distribution models can be derived from the point process distribution, highlight areas of potential overlap between different models, and suggest areas where further research is needed.

  5. Endangered Species: Pesticide Restrictions

    Science.gov (United States)

    Our goal is to protect threatened and endangered species and their habitats, without placing unnecessary burden on agriculture and pesticide users. Pesticide limitations are developed to ensure safe use of pesticides in order to meet this goal.

  6. Threatened & Endangered Species Occurrences

    Data.gov (United States)

    Kansas Data Access and Support Center — The database consists of a single statewide coverage of location records for 54 species contained in the Kansas Natural Heritage Inventory database of the Kansas...

  7. Sub specie aeternitatis

    Directory of Open Access Journals (Sweden)

    Laura Gioeni

    2012-10-01

    Full Text Available Per delineare il rapporto tra etica ed estetica nell'architettura e rispondere alla domanda principale «che cosa è o dovrebbe essere un buon architetto?», il saggio discute la tesi di Wittgenstein secondo cui «l'opera d'arte è l'oggetto visto sub specie aeternitatis e la vita buona è il mondo visto sub specie aeternitatis. Questa è la connessione tra arte ed etica».

  8. Genomic definition of species

    Energy Technology Data Exchange (ETDEWEB)

    Crkvenjakov, R.; Drmanac, R.

    1991-07-01

    The subject of this paper is the definition of species based on the assumption that genome is the fundamental level for the origin and maintenance of biological diversity. For this view to be logically consistent it is necessary to assume the existence and operation of the new law which we call genome law. For this reason the genome law is included in the explanation of species phenomenon presented here even if its precise formulation and elaboration are left for the future. The intellectual underpinnings of this definition can be traced to Goldschmidt. We wish to explore some philosophical aspects of the definition of species in terms of the genome. The point of proposing the definition on these grounds is that any real advance in evolutionary theory has to be correct in both its philosophy and its science.

  9. Bounding species distribution models

    Directory of Open Access Journals (Sweden)

    Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE

    2011-10-01

    Full Text Available Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for “clamping” model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART and maximum entropy (Maxent models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5: 642–647, 2011].

  10. Bounding Species Distribution Models

    Science.gov (United States)

    Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].

  11. Aquatic Nuisance Species Locator

    Science.gov (United States)

    Data in this map has been collected by the United States Geological Survey's Nonindigenous Aquatic Species program located in Gainesville, Florida (http://nas.er.usgs.gov/default.aspx). This dataset may have some inaccuracies and is only current to June 15, 2012. The species identified in this dataset are not inclusive of all aquatic nuisance species, but rather a subset identified to be at risk for transport by recreational activities such as boating and angling. Additionally, the locations where organisims have been identified are also not inclusive and should be treated as a guide. Organisms are limited to the following: American bullfrog, Asian clam, Asian shore crab, Asian tunicate, Australian spotted jellyfish, Chinese mitten crab, New Zealand mudsnail, Colonial sea squirt, Alewife, Bighead carp, Black carp, Flathead catfish, Grass carp, Green crab, Lionfish, Northern snakehead, Quagga mussel, Round Goby, Ruffe, Rusty crayfish, Sea lamprey, Silver carp, Spiny water flea, Veined rapa whelk, Zebra mussel

  12. Man as a Species.

    Science.gov (United States)

    Solem, Alan; And Others

    Written in 1964, the document represents experimental material of the Anthropology Curriculum Study Project. The objectives of the project were to discuss the evolution of man as distinguished from the evolution of other species and as related to culture, and to emphasize human diversity. Three brief essays are presented. The first, "The…

  13. Coevolution of Symbiotic Species

    OpenAIRE

    Leok, Boon Tiong Melvin

    1996-01-01

    This paper will consider the coevolution of species which are symbiotic in their interaction. In particular, we shall analyse the interaction of squirrels and oak trees, and develop a mathematical framework for determining the coevolutionary equilibrium for consumption and production patterns.

  14. Positive feedback in species communities

    NARCIS (Netherlands)

    Gerla, D.J.

    2012-01-01

    Sometimes the eventual population densities in a species community depend on the initial densities or the arrival times of species. If arrival times determine species composition, a priority effect has occurred. Priority effects may occur if the species community exhibits alternative stable states

  15. The functional biogeography of species

    DEFF Research Database (Denmark)

    Carstensen, Daniel W.; Dalsgaard, Bo; Svenning, Jens-Christian

    2013-01-01

    Biogeographical systems can be analyzed as networks of species and geographical units. Within such a biogeographical network, individual species may differ fundamentally in their linkage pattern, and therefore hold different topological roles. To advance our understanding of the relationship betw...... to distributions at the local community level. We finally discuss how our biogeographical species roles may correspond to the stages of the taxon cycle and other prominent theories of species assembly.......Biogeographical systems can be analyzed as networks of species and geographical units. Within such a biogeographical network, individual species may differ fundamentally in their linkage pattern, and therefore hold different topological roles. To advance our understanding of the relationship...... between species traits and large-scale species distribution patterns in archipelagos, we use a network approach to classify birds as one of four biogeographical species roles: peripherals, connectors, module hubs, and network hubs. These roles are based upon the position of species within the modular...

  16. Autecology of broadleaved species

    OpenAIRE

    Gonin, Pierre; Larrieu, Laurent; Coello, Jaime; Marty, Pauline; Lestrade , Marine; Becquey, Jacques; Claessens, Hugues

    2013-01-01

    Anyone involved in timber production needs some knowledge of autecology. With the renewed interest in hardwoods in the last 20 years, they are increasingly being introduced by planting or encouraged in natural stands. The results in terms of growth have not always met foresters’ expectations, due to technical problems and especially because the species are not always suited to the different sites. While the principle of establishing hardwoods is not in question, it is important to be aware of...

  17. Prior indigenous technological species

    Science.gov (United States)

    Wright, Jason T.

    2018-01-01

    One of the primary open questions of astrobiology is whether there is extant or extinct life elsewhere the solar system. Implicit in much of this work is that we are looking for microbial or, at best, unintelligent life, even though technological artefacts might be much easier to find. Search for Extraterrestrial Intelligence (SETI) work on searches for alien artefacts in the solar system typically presumes that such artefacts would be of extrasolar origin, even though life is known to have existed in the solar system, on Earth, for eons. But if a prior technological, perhaps spacefaring, species ever arose in the solar system, it might have produced artefacts or other technosignatures that have survived to present day, meaning solar system artefact SETI provides a potential path to resolving astrobiology's question. Here, I discuss the origins and possible locations for technosignatures of such a prior indigenous technological species, which might have arisen on ancient Earth or another body, such as a pre-greenhouse Venus or a wet Mars. In the case of Venus, the arrival of its global greenhouse and potential resurfacing might have erased all evidence of its existence on the Venusian surface. In the case of Earth, erosion and, ultimately, plate tectonics may have erased most such evidence if the species lived Gyr ago. Remaining indigenous technosignatures might be expected to be extremely old, limiting the places they might still be found to beneath the surfaces of Mars and the Moon, or in the outer solar system.

  18. Estimating Effects of Species Interactions on Populations of Endangered Species.

    Science.gov (United States)

    Roth, Tobias; Bühler, Christoph; Amrhein, Valentin

    2016-04-01

    Global change causes community composition to change considerably through time, with ever-new combinations of interacting species. To study the consequences of newly established species interactions, one available source of data could be observational surveys from biodiversity monitoring. However, approaches using observational data would need to account for niche differences between species and for imperfect detection of individuals. To estimate population sizes of interacting species, we extended N-mixture models that were developed to estimate true population sizes in single species. Simulations revealed that our model is able to disentangle direct effects of dominant on subordinate species from indirect effects of dominant species on detection probability of subordinate species. For illustration, we applied our model to data from a Swiss amphibian monitoring program and showed that sizes of expanding water frog populations were negatively related to population sizes of endangered yellow-bellied toads and common midwife toads and partly of natterjack toads. Unlike other studies that analyzed presence and absence of species, our model suggests that the spread of water frogs in Central Europe is one of the reasons for the decline of endangered toad species. Thus, studying population impacts of dominant species on population sizes of endangered species using data from biodiversity monitoring programs should help to inform conservation policy and to decide whether competing species should be subject to population management.

  19. CHROMOSOMES OF WOODY SPECIES

    Directory of Open Access Journals (Sweden)

    Julio R Daviña

    2000-01-01

    Full Text Available Chromosome numbers of nine subtropical woody species collected in Argentina and Paraguay are reported. The counts tor Coutarea hexandra (2n=52, Inga vera subsp. affinis 2n=26 (Fabaceae and Chorisia speciosa 2n=86 (Bombacaceae are reported for the first time. The chromosome number given for Inga semialata 2n=52 is a new cytotype different from the previously reported. Somatic chromosome numbers of the other taxa studied are: Sesbania punicea 2n=12, S. virgata 2n=12 and Pilocarpus pennatifolius 2n=44 from Argentina

  20. Save Our Species: Protecting Endangered Species from Pesticides.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    This full-size poster profiles 11 wildlife species that are endangered. Color illustrations of animals and plants are accompanied by narrative describing their habitats and reasons for endangerment. The reverse side of the poster contains information on the Endangered Species Act, why protecting endangered and threatened species is important, how…

  1. Vertical stratification of bat assemblages in flooded and unflooded Amazonian forests

    Directory of Open Access Journals (Sweden)

    Maria João Ramos PEREIRA, João Tiago MARQUES, Jorge M. PALMEIRIM

    2010-08-01

    Full Text Available Tropical rainforests usually have multiple strata that results in a vertical stratification of ecological opportunities for animals. We investigated if this stratification influences the way bats use the vertical space in flooded and unflooded forests of the Central Amazon. Using mist-nets set in the canopy (17 to 35 m high and in the understorey (0 to 3 m high we sampled four sites in upland unflooded forests (terra firme, three in forests seasonally flooded by nutrient-rich water (várzea, and three in forests seasonally flooded by nutrient-poor water (igapó. Using rarefaction curves we found that species richness in the understorey and canopy were very similar. An ordination analysis clearly separated the bat assemblages of the canopy from those of the understorey in both flooded and unflooded habitats. Gleaning carnivores were clearly associated with the understorey, whereas frugivores were abundant in both strata. Of the frugivores, Carollinae and some Stenodermatinae were understorey specialists, but several Stenodermatinae mostly used the canopy. The first group mainly includes species that, in general, feed on fruits of understorey shrubs, whereas the second group feed on figs and other canopy fruits. We conclude that vertical stratification in bat communities occurs even within forests with lower canopy heights, such as Amazonian seasonally flooded forests, and that the vertical distribution of bat species is closely related to their diet and foraging behaviour [Current Zoology 56 (4: 469–478, 2010].

  2. New species of Malaysian ferns

    NARCIS (Netherlands)

    Holttum, R.E.

    1962-01-01

    The present paper includes descriptions of several new species of ferns found among recent collections from various parts of Malaysia; also two new combinations of names of species which are of interest on account of their taxonomic history.

  3. Endangered Species Act Critical Habitat

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Critical habitat (CH) is designated for the survival and recovery of species listed as threatened or endangered under the Endangered Species Act (ESA). Critical...

  4. Plant nutrient mobilization in temperate heathland responds to elevated CO2, temperature and drought

    DEFF Research Database (Denmark)

    Andresen, Louise C.; Michelsen, Anders; Jonasson, Sven

    2010-01-01

    Temperate terrestrial ecosystems are currently exposed to increased atmospheric CO2 and progressive climatic changes with increased temperature and periodical drought. We here present results from a field experiment, where the effects of these three main climate change related factors...... decreased in response to drought. These complex changes in availability and release of nutrients from soil organic matter turnover and mineralization in response to elevated CO2 and climate change may influence the future plant carbon sequestration and species composition at temperate heathlands....... in Deschampsia soil, and microbial immobilization of N and P decreased in warmed Calluna soil. Warming tended to increase microbial N and P in Calluna but not in Deschampsia soil in fall, and more microbial C was accumulated under drought in Calluna soil. The effects of warming were often counteracted or erased...

  5. New Malesian species of Viscaceae

    NARCIS (Netherlands)

    Barlow, Bryan A.

    1996-01-01

    Three new Malesian species of Viscaceae are described. Ginalloa flagellaris Barlow is distinguished as a species from New Guinea and New Britain, previously included within G. arnottiana Korthals. Viscum exile Barlow is recognized as a new species endemic to Celebes, related to V. ovalifolium.

  6. Lichen species preference by reindeer

    Energy Technology Data Exchange (ETDEWEB)

    Holleman, D F; Luick, J R

    1977-08-01

    The preference by reindeer for five species of lichens commonly found on Central Alaska rangelands was tested under controlled laboratory conditions. Results indicate that reindeer are strongly selective species in their lichen grazing habits. The five tested species ranged as follows in order of decreasing acceptibility: Caldonia alpestris, C. rangiferina, Stereocaulon paschale, Cetraria richardsonii, and Peltigera aphthosa.

  7. 75 FR 78974 - Endangered Species

    Science.gov (United States)

    2010-12-17

    ...-XA086 Endangered Species AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.) and the regulations governing the taking, importing, and exporting of endangered and threatened species (50 CFR 222-226). Permit...

  8. California Endangered Species Resource Guide.

    Science.gov (United States)

    California State Dept. of Education, Los Angeles.

    This document was developed in response to California Senate Bill No. 885, "The Endangered Species Education Project," that called for a statewide program in which schools adopt a local endangered species, research past and current efforts to preserve the species' habitat, develop and implement an action plan to educate the community…

  9. 76 FR 2348 - Endangered Species

    Science.gov (United States)

    2011-01-13

    .... 15596] Endangered Species AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... requested permit has been issued under the authority of the Endangered Species Act of 1973, as amended (ESA... endangered and threatened species (50 CFR parts 222-226). The North Carolina Aquarium at Fort Fisher has been...

  10. Electrosmog and species conservation

    Energy Technology Data Exchange (ETDEWEB)

    Balmori, Alfonso, E-mail: abalmorimartinez@gmail.com

    2014-10-15

    Despite the widespread use of wireless telephone networks around the world, authorities and researchers have paid little attention to the potential harmful effects of mobile phone radiation on wildlife. This paper briefly reviews the available scientific information on this topic and recommends further studies and specific lines of research to confirm or refute the experimental results to date. Controls must be introduced and technology rendered safe for the environment, particularly, threatened species. - Highlights: • Studies have shown effects in both animals and plants. • Two thirds of the studies reported ecological effects. • There is little research in this area and further research is needed. • The technology must be safe. • Controls should be introduced to mitigate the possible effects.

  11. Management of invasive species

    DEFF Research Database (Denmark)

    Schou, Jesper Sølver; Jensen, Frank

    impact of the establishment of this invasive species is a substantial increase in the number of allergy cases, which we use as a measure of the physical damage. As valuation methods, we use both the cost-of-illness method and the benefit transfer method to quantify the total gross benefits of the two...... policy actions. Based on the idea of an invasion function, we identify the total and average net benefit under both prevention and mitigation. For both policy actions, the total and average net benefits are significantly positive irrespective of the valuation method used; therefore, both prevention...... and mitigation are beneficial policy actions. However, the total and average net benefits under mitigation are larger than the benefits under prevention, implying that the former policy action is more beneficial. Despite this result, we conclude that prevention, not mitigation, shall be used because...

  12. Prices and species diversity

    DEFF Research Database (Denmark)

    Sauer, Johannes

    of biodiversity and the appropriate incorporation in stochastic fron-tier models to achieve more realistic measures of production efficiency. We use the empirical example of tobacco production drawing from as well as affecting species diversity in the surrounding forests. We apply a shadow profit distance......In recent decades a significant amount of literature has been produced concerned with establishing a link between production efficiency and environmental efficiency with respect to quantitative modelling. This has been mainly addressed by focusing on the incorporation of undesirable outputs...... or the incorporation of environmentally det-rimental inputs. However, while the debate with respect to linear programming based DEA modelling is already at an advanced stage the corresponding one with respect to stochastic frontier modelling still needs considerable efforts. This contribution fo-cuses on the case...

  13. Reactive Oxygen Species

    DEFF Research Database (Denmark)

    Franchina, Davide G.; Dostert, Catherine; Brenner, Dirk

    2018-01-01

    T cells are a central component of defenses against pathogens and tumors. Their effector functions are sustained by specific metabolic changes that occur upon activation, and these have been the focus of renewed interest. Energy production inevitably generates unwanted products, namely reactive...... and transcription factors, influencing the outcome of the T cell response. We discuss here how ROS can directly fine-tune metabolism and effector functions of T cells....... oxygen species (ROS), which have long been known to trigger cell death. However, there is now evidence that ROS also act as intracellular signaling molecules both in steady-state and upon antigen recognition. The levels and localization of ROS contribute to the redox modeling of effector proteins...

  14. Introduced species as evolutionary traps

    Science.gov (United States)

    Schlaepfer, Martin A.; Sherman, P.W.; Blossey, B.; Runge, M.C.

    2005-01-01

    Invasive species can alter environments in such a way that normal behavioural decision-making rules of native species are no longer adaptive. The evolutionary trap concept provides a useful framework for predicting and managing the impact of harmful invasive species. We discuss how native species can respond to changes in their selective regime via evolution or learning. We also propose novel management strategies to promote the long-term co-existence of native and introduced species in cases where the eradication of the latter is either economically or biologically unrealistic.

  15. Insular species swarm goes underground

    DEFF Research Database (Denmark)

    P. S. Reboleira, Ana Sofia; Enghoff, Henrik

    2014-01-01

    Two new species of the genus Cylindroiulus Verhoeff, 1894, C. julesvernei and C. oromii, are described from the subterranean ecosystem of Madeira Island, Portugal. Species are illustrated with photographs and diagrammatic drawings. The new species belong to the Cylindroiulus madeirae......-group, an insular species swarm distributed in the archipelagos of Madeira and the Canary Islands. We discuss the differences between the new species and their relatives and present information on the subterranean environment of Madeira. An updated overview of the subterranean biodiversity of millipedes...

  16. Addition of ash on drained forested peatlands in southern Sweden. Effects on forest production, fluxes of greenhouse gases, peat properties, understorey vegetation and groundwater chemistry; Tillfoersel av aska i skog paa dikad torvmark i soedra Sverige. Effekter paa skogsproduktion, floeden av vaexthusgaser, torvegenskaper, markvegetation och grundvattenkemi

    Energy Technology Data Exchange (ETDEWEB)

    Sikstroem, Ulf; Bjoerk, Robert G; Ring, Eva; Ernfors, Maria; Jacobson, Staffan; Nilsson, Mats; Klemedtsson, Leif

    2009-02-15

    The objective of the present study was to evaluate effects of wood-ash addition on drained peatlands in southern Sweden. Tree growth, greenhouse gases, peat properties, microbial biomass and processes, understory vegetation and groundwater chemistry were measured in three field experiments (some variables were not measured in all experiments): (i) 168 Perstorp, an oligotrophic mire with Scotch pine (Pinus sylvestris L.), where 2.5 tonnes d.w. of wood ash/ha (2.5WA) was added in 1982; (ii) 273 Anderstorp, also an oligotrophic mire with Scots pine, where 3.3 tonnes d.w. crushed ash/ha (3.3KA) and 6.6 tonnes d.w. crushed/ha (6.6KA) was added in 2003; (iii) 278 Skogaryd, a minerotrophic mire with Norway spruce (Picea abies L. Karst.), where the same doses of crushed ash as in Anderstorp were added in 2006. Untreated controls were included in all experiments. At Anderstorp, increased tree growth was indicated, at least in the treatment with the highest ash dose during the first five years after treatment. The annual emissions of CO{sub 2}, CH4 and N{sub 2}O from the peat were unaffected. At Skogaryd, the growth was unaffected and the emissions of both CO{sub 2} and N{sub 2}O were reduced during the first two years after treatment. In general, the significant ash effects (2.5WA and 3.3KA evaluated) on peat characteristics, microbial biomass and processes were found in the upper soil (0-5 cm) at the recently treated sites (Anderstorp and Skogaryd), and at greater depths (5-30 cm) at Perstorp, where the ash was added 25 years ago. In the ash treatment at Perstorp, there was a shift in the plant community structure and a decrease in species diversity of the understory vegetation. However, at this point of time, the forest stand had become substantially denser than on the control plots. Hence, these effects on the understory vegetation may have been an indirect effect of the ash-induced altered tree stand properties. In Skogaryd, no shift in the plant community was found

  17. Ring species as demonstrations of the continuum of species formation

    DEFF Research Database (Denmark)

    Pereira, Ricardo José Do Nascimento; Wake, David B.

    2015-01-01

    In the mid-20th century, Ernst Mayr (1942) and Theodosius Dobzhansky (1958) championed the significance of 'circular overlaps' or 'ring species' as the perfect demonstration of the gradual nature of species formation. As an ancestral species expands its range, wrapping around a geographic barrier......? What conditions favour their formation? Modelling studies have attempted to address these knowledge gaps by estimating the biological parameters that result in stable ring species (Martins et al. 2013), and determining the necessary topographic parameters of the barriers encircled (Monahan et al. 2012......). However, any generalization is undermined by a major limitation: only a handful of ring species are known to exist in nature. In addition, many of them have been broken into multiple species presumed to be evolving independently, usually obscuring the evolutionary dynamics that generate diversity. A paper...

  18. Species of Wadicosa (Araneae, Lycosidae): a new species from Madagascar.

    Science.gov (United States)

    Kronestedt, Torbjörn

    2017-05-10

    Since establishing the wolf spider genus Wadicosa Zyuzin, 1985 (Zyuzin 1985), eleven species have been accepted in it, either by transfer from Lycosa Latreille, 1804 or Pardosa C.L. Koch, 1847 or by original designation (WSC 2017). However, according to Kronestedt (1987), additional species wait to be formally transferred to Wadicosa. The genus is restricted to the Old World, with one species, Wadicosa jocquei Kronestedt, 2015, recently described from Madagascar and surrounding islands.

  19. Native species that can replace exotic species in landscaping

    Directory of Open Access Journals (Sweden)

    Elisabeth Regina Tempel Stumpf

    2015-08-01

    Full Text Available Beyond aesthetics, the contemporary landscaping intends to provide other benefits for humans and environment, especially related to the environmental quality of urban spaces and conservation of the species. A trend in this direction is the reduction in the use of exotic plants in their designs, since, over time, they can become agents of replacement of native flora, as it has occurred in Rio Grande do Sul with many species introduced by settlers. However, the use of exotic species is unjustifiable, because the flora diversity of the Bioma Pampa offers many native species with appropriate features to the ornamental use. The commercial cultivation and the implantation of native species in landscaped areas constitute innovations for plant nurseries and landscapers and can provide a positive reduction in extractivism, contributing to dissemination, exploitation and preservation of native flora, and also decrease the impact of chemical products on environment. So, this work intends to identify native species of Bioma Pampa with features and uses similar to the most used exotic species at Brazilian landscaping. The species were selected from consulting books about native plants of Bioma Pampa and plants used at Brazilian landscaping, considering the similarity on habit and architecture, as well as characteristics of leafs, flowers and/or fruits and environmental conditions of occurrence and cultivation. There were identified 34 native species able to properly replace exotic species commonly used. The results show that many native species of Bioma Pampa have interesting ornamental features to landscape gardening, allowing them to replace exotic species that are traditionally cultivated.

  20. Population genetics and cryptic species

    International Nuclear Information System (INIS)

    McPheron, Bruce A.

    2000-01-01

    Does the definition of a species matter for pest management purposes? Taxonomists provide us with tools - usually morphological characters - to identify a group of organisms that we call a species. The implication of this identification is that all of the individuals that fit the provided description are members of the species in question. The taxonomists have considered the range of variation among individuals in defining the species, but this variation is often forgotten when we take the concept of species to the level of management. Just as there is morphological variation among individuals, there is also variation in practically any character we might imagine, which has implications for the short and long term success of our management tactics. The rich literature on insecticide resistance should be a constant reminder of the fact that the pressure on pest survival and reproduction applied by our management approaches frequently leads to evolutionary changes within the pest species. The degree of variation within a particular species is a defining characteristic of that species. This level of variability may have very important implications for successful management, so it is very important to measure variation and, whenever possible, the genetic basis of that variation, in a target species. Population genetic approaches can provide evidence of genetic structure (or lack thereof) among populations of a species. These types of data can be used to discuss the movement of pest populations on a local or global scale. In other cases, we may have a complex of species that share some, but not all, characteristics. Species complexes that share morphological characters (i.e., cannot be easily distinguished) but not biological characters are referred to as sibling or cryptic species

  1. Confronting species distribution model predictions with species functional traits.

    Science.gov (United States)

    Wittmann, Marion E; Barnes, Matthew A; Jerde, Christopher L; Jones, Lisa A; Lodge, David M

    2016-02-01

    Species distribution models are valuable tools in studies of biogeography, ecology, and climate change and have been used to inform conservation and ecosystem management. However, species distribution models typically incorporate only climatic variables and species presence data. Model development or validation rarely considers functional components of species traits or other types of biological data. We implemented a species distribution model (Maxent) to predict global climate habitat suitability for Grass Carp (Ctenopharyngodon idella). We then tested the relationship between the degree of climate habitat suitability predicted by Maxent and the individual growth rates of both wild (N = 17) and stocked (N = 51) Grass Carp populations using correlation analysis. The Grass Carp Maxent model accurately reflected the global occurrence data (AUC = 0.904). Observations of Grass Carp growth rate covered six continents and ranged from 0.19 to 20.1 g day(-1). Species distribution model predictions were correlated (r = 0.5, 95% CI (0.03, 0.79)) with observed growth rates for wild Grass Carp populations but were not correlated (r = -0.26, 95% CI (-0.5, 0.012)) with stocked populations. Further, a review of the literature indicates that the few studies for other species that have previously assessed the relationship between the degree of predicted climate habitat suitability and species functional traits have also discovered significant relationships. Thus, species distribution models may provide inferences beyond just where a species may occur, providing a useful tool to understand the linkage between species distributions and underlying biological mechanisms.

  2. Balance of bacterial species in the gut

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Balance of bacterial species in the gut. Protective. Lactobacillus species. Bifidobacterium species. Selected E. coli. Saccharomyces boulardii. Clostridium butyricum.

  3. Quantifying the invasiveness of species

    Directory of Open Access Journals (Sweden)

    Robert Colautti

    2014-04-01

    Full Text Available The success of invasive species has been explained by two contrasting but non-exclusive views: (i intrinsic factors make some species inherently good invaders; (ii species become invasive as a result of extrinsic ecological and genetic influences such as release from natural enemies, hybridization or other novel ecological and evolutionary interactions. These viewpoints are rarely distinguished but hinge on distinct mechanisms leading to different management scenarios. To improve tests of these hypotheses of invasion success we introduce a simple mathematical framework to quantify the invasiveness of species along two axes: (i interspecific differences in performance among native and introduced species within a region, and (ii intraspecific differences between populations of a species in its native and introduced ranges. Applying these equations to a sample dataset of occurrences of 1,416 plant species across Europe, Argentina, and South Africa, we found that many species are common in their native range but become rare following introduction; only a few introduced species become more common. Biogeographical factors limiting spread (e.g. biotic resistance, time of invasion therefore appear more common than those promoting invasion (e.g. enemy release. Invasiveness, as measured by occurrence data, is better explained by inter-specific variation in invasion potential than biogeographical changes in performance. We discuss how applying these comparisons to more detailed performance data would improve hypothesis testing in invasion biology and potentially lead to more efficient management strategies.

  4. Uncommon Species and Other Features

    Data.gov (United States)

    Vermont Center for Geographic Information — The Vermont Fish and Wildlife Department's Natural Heritage Inventory (NHI) maintains a database of uncommon, rare, threatened and endangered species and natural...

  5. Incorporating Context Dependency of Species Interactions in Species Distribution Models.

    Science.gov (United States)

    Lany, Nina K; Zarnetske, Phoebe L; Gouhier, Tarik C; Menge, Bruce A

    2017-07-01

    Species distribution models typically use correlative approaches that characterize the species-environment relationship using occurrence or abundance data for a single species. However, species distributions are determined by both abiotic conditions and biotic interactions with other species in the community. Therefore, climate change is expected to impact species through direct effects on their physiology and indirect effects propagated through their resources, predators, competitors, or mutualists. Furthermore, the sign and strength of species interactions can change according to abiotic conditions, resulting in context-dependent species interactions that may change across space or with climate change. Here, we incorporated the context dependency of species interactions into a dynamic species distribution model. We developed a multi-species model that uses a time-series of observational survey data to evaluate how abiotic conditions and species interactions affect the dynamics of three rocky intertidal species. The model further distinguishes between the direct effects of abiotic conditions on abundance and the indirect effects propagated through interactions with other species. We apply the model to keystone predation by the sea star Pisaster ochraceus on the mussel Mytilus californianus and the barnacle Balanus glandula in the rocky intertidal zone of the Pacific coast, USA. Our method indicated that biotic interactions between P. ochraceus and B. glandula affected B. glandula dynamics across >1000 km of coastline. Consistent with patterns from keystone predation, the growth rate of B. glandula varied according to the abundance of P. ochraceus in the previous year. The data and the model did not indicate that the strength of keystone predation by P. ochraceus varied with a mean annual upwelling index. Balanus glandula cover increased following years with high phytoplankton abundance measured as mean annual chlorophyll-a. M. californianus exhibited the same

  6. Experimental manipulation of succession in heathland ecosystems.

    NARCIS (Netherlands)

    Berendse, F.; Schmitz, M.; Visser, de W.

    1994-01-01

    An experiment was carried out in two heathland ecosystems, one dominated by Calluna vulgaris and the other by Molinia caerulea, to analyse the effects of soil organic matter accumulation and nutrient mineralization on plant species dynamics during succession. The experiment included one treatment

  7. Previously unknown species of Aspergillus.

    Science.gov (United States)

    Gautier, M; Normand, A-C; Ranque, S

    2016-08-01

    The use of multi-locus DNA sequence analysis has led to the description of previously unknown 'cryptic' Aspergillus species, whereas classical morphology-based identification of Aspergillus remains limited to the section or species-complex level. The current literature highlights two main features concerning these 'cryptic' Aspergillus species. First, the prevalence of such species in clinical samples is relatively high compared with emergent filamentous fungal taxa such as Mucorales, Scedosporium or Fusarium. Second, it is clearly important to identify these species in the clinical laboratory because of the high frequency of antifungal drug-resistant isolates of such Aspergillus species. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been shown to enable the identification of filamentous fungi with an accuracy similar to that of DNA sequence-based methods. As MALDI-TOF MS is well suited to the routine clinical laboratory workflow, it facilitates the identification of these 'cryptic' Aspergillus species at the routine mycology bench. The rapid establishment of enhanced filamentous fungi identification facilities will lead to a better understanding of the epidemiology and clinical importance of these emerging Aspergillus species. Based on routine MALDI-TOF MS-based identification results, we provide original insights into the key interpretation issues of a positive Aspergillus culture from a clinical sample. Which ubiquitous species that are frequently isolated from air samples are rarely involved in human invasive disease? Can both the species and the type of biological sample indicate Aspergillus carriage, colonization or infection in a patient? Highly accurate routine filamentous fungi identification is central to enhance the understanding of these previously unknown Aspergillus species, with a vital impact on further improved patient care. Copyright © 2016 European Society of Clinical Microbiology and

  8. Fuzzy species among recombinogenic bacteria

    Directory of Open Access Journals (Sweden)

    Fraser Christophe

    2005-03-01

    Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

  9. 76 FR 74778 - Endangered Species

    Science.gov (United States)

    2011-12-01

    .... 16439] Endangered Species AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... has been issued under the authority of the Endangered Species Act of 1973, as amended (ESA; 16 U.S.C. 1531 et seq.) and the regulations governing the taking, importing, and exporting of endangered and...

  10. [Yeast species in vulvovaginitis candidosa].

    Science.gov (United States)

    Nemes-Nikodém, Éva; Tamási, Béla; Mihalik, Noémi; Ostorházi, Eszter

    2015-01-04

    Vulvovaginal candidiasis is the most common mycosis, however, the available information about antifungal susceptibilities of these yeasts is limited. To compare the gold standard fungal culture with a new molecular identification method and report the incidence of yeast species in vulvovaginitis candidosa. The authors studied 370 yeasts isolated from vulvovaginal candidiasis and identified them by phenotypic and molecular methods. The most common species was Candida albicans (85%), followed by Candida glabrata, and other Candida species. At present there are no recommendations for the evaluation of antifungal susceptibility of pathogenic fungal species occurring in vulvovaginal candidiasis and the natural antifungal resistance of the different species is known only. Matrix Assisted Laser Desorption Ionization Time of Flight identification can be used to differentiate the fluconazole resistant Candida dubliniensis and the sensitive Candida albicans strains.

  11. Enolonium Species-Umpoled Enolates

    DEFF Research Database (Denmark)

    Arava, Shlomy; Kumar, Jayprakash N.; Maksymenko, Shimon

    2017-01-01

    Enolonium species/iodo(III) enolates of carbonyl compounds have been suggested to be intermediates in a wide variety of hypervalent iodine induced chemical transformations of ketones, including α-C-O, α-C-N, α-C-C, and alpha-carbon- halide bond formation, but they have never been characterized. We...... report that these elusive umpoled enolates may be made as discrete species that are stable for several minutes at-78 degrees C, and report the first spectroscopic identification of such species. It is shown that enolonium species are direct intermediates in C-O, C-N, C-Cl, and C-C bond forming reactions....... Our results open up chemical space for designing a variety of new transformations. We showcase the ability of enolonium species to react with prenyl, crotyl, cinnamyl, and allyl silanes with absolute regioselectivity in up to 92% yield....

  12. Evaluating barriers to native seedling establishment in an invaded Hawaiian lowland wet forest

    Science.gov (United States)

    S. Cordell; R. Ostertag; B. Rowe; L. Sweinhart; L. Vasquez-Radonic; J. Michaud; T.C. Cole; J.R. Schulten

    2009-01-01

    Many tropical island forest ecosystems are dominated by non-native plant species and lack native species regeneration in the understorey. Comparison of replicated control and removal plots offers an opportunity to examine not only invasive species impacts but also the restoration potential of native species. In lowland Hawaiian wet forests little is known about native...

  13. Species concepts, species delimitation and the inherent limitations

    Indian Academy of Sciences (India)

    Frank Zachos

    synchrony and to sexually reproducing organisms would not be a problem anymore ... approach to species delimitation that combines genetic data with .... The datasets or algorithms could then be modified so that the groups yielded conform.

  14. Genome Sequences of Oryza Species

    KAUST Repository

    Kumagai, Masahiko; Tanaka, Tsuyoshi; Ohyanagi, Hajime; Hsing, Yue-Ie C.; Itoh, Takeshi

    2018-01-01

    This chapter summarizes recent data obtained from genome sequencing, annotation projects, and studies on the genome diversity of Oryza sativa and related Oryza species. O. sativa, commonly known as Asian rice, is the first monocot species whose complete genome sequence was deciphered based on physical mapping by an international collaborative effort. This genome, along with its accurate and comprehensive annotation, has become an indispensable foundation for crop genomics and breeding. With the development of innovative sequencing technologies, genomic studies of O. sativa have dramatically increased; in particular, a large number of cultivars and wild accessions have been sequenced and compared with the reference rice genome. Since de novo genome sequencing has become cost-effective, the genome of African cultivated rice, O. glaberrima, has also been determined. Comparative genomic studies have highlighted the independent domestication processes of different rice species, but it also turned out that Asian and African rice share a common gene set that has experienced similar artificial selection. An international project aimed at constructing reference genomes and examining the genome diversity of wild Oryza species is currently underway, and the genomes of some species are publicly available. This project provides a platform for investigations such as the evolution, development, polyploidization, and improvement of crops. Studies on the genomic diversity of Oryza species, including wild species, should provide new insights to solve the problem of growing food demands in the face of rapid climatic changes.

  15. Genome Sequences of Oryza Species

    KAUST Repository

    Kumagai, Masahiko

    2018-02-14

    This chapter summarizes recent data obtained from genome sequencing, annotation projects, and studies on the genome diversity of Oryza sativa and related Oryza species. O. sativa, commonly known as Asian rice, is the first monocot species whose complete genome sequence was deciphered based on physical mapping by an international collaborative effort. This genome, along with its accurate and comprehensive annotation, has become an indispensable foundation for crop genomics and breeding. With the development of innovative sequencing technologies, genomic studies of O. sativa have dramatically increased; in particular, a large number of cultivars and wild accessions have been sequenced and compared with the reference rice genome. Since de novo genome sequencing has become cost-effective, the genome of African cultivated rice, O. glaberrima, has also been determined. Comparative genomic studies have highlighted the independent domestication processes of different rice species, but it also turned out that Asian and African rice share a common gene set that has experienced similar artificial selection. An international project aimed at constructing reference genomes and examining the genome diversity of wild Oryza species is currently underway, and the genomes of some species are publicly available. This project provides a platform for investigations such as the evolution, development, polyploidization, and improvement of crops. Studies on the genomic diversity of Oryza species, including wild species, should provide new insights to solve the problem of growing food demands in the face of rapid climatic changes.

  16. Species interactions and plant polyploidy.

    Science.gov (United States)

    Segraves, Kari A; Anneberg, Thomas J

    2016-07-01

    Polyploidy is a common mode of speciation that can have far-reaching consequences for plant ecology and evolution. Because polyploidy can induce an array of phenotypic changes, there can be cascading effects on interactions with other species. These interactions, in turn, can have reciprocal effects on polyploid plants, potentially impacting their establishment and persistence. Although there is a wealth of information on the genetic and phenotypic effects of polyploidy, the study of species interactions in polyploid plants remains a comparatively young field. Here we reviewed the available evidence for how polyploidy may impact many types of species interactions that range from mutualism to antagonism. Specifically, we focused on three main questions: (1) Does polyploidy directly cause the formation of novel interactions not experienced by diploids, or does it create an opportunity for natural selection to then form novel interactions? (2) Does polyploidy cause consistent, predictable changes in species interactions vs. the evolution of idiosyncratic differences? (3) Does polyploidy lead to greater evolvability in species interactions? From the scarce evidence available, we found that novel interactions are rare but that polyploidy can induce changes in pollinator, herbivore, and pathogen interactions. Although further tests are needed, it is likely that selection following whole-genome duplication is important in all types of species interaction and that there are circumstances in which polyploidy can enhance the evolvability of interactions with other species. © 2016 Botanical Society of America.

  17. Scale dependence in species turnover reflects variance in species occupancy.

    Science.gov (United States)

    McGlinn, Daniel J; Hurlbert, Allen H

    2012-02-01

    Patterns of species turnover may reflect the processes driving community dynamics across scales. While the majority of studies on species turnover have examined pairwise comparison metrics (e.g., the average Jaccard dissimilarity), it has been proposed that the species-area relationship (SAR) also offers insight into patterns of species turnover because these two patterns may be analytically linked. However, these previous links only apply in a special case where turnover is scale invariant, and we demonstrate across three different plant communities that over 90% of the pairwise turnover values are larger than expected based on scale-invariant predictions from the SAR. Furthermore, the degree of scale dependence in turnover was negatively related to the degree of variance in the occupancy frequency distribution (OFD). These findings suggest that species turnover diverges from scale invariance, and as such pairwise turnover and the slope of the SAR are not redundant. Furthermore, models developed to explain the OFD should be linked with those developed to explain species turnover to achieve a more unified understanding of community structure.

  18. Species-area relationships are controlled by species traits.

    Science.gov (United States)

    Franzén, Markus; Schweiger, Oliver; Betzholtz, Per-Eric

    2012-01-01

    The species-area relationship (SAR) is one of the most thoroughly investigated empirical relationships in ecology. Two theories have been proposed to explain SARs: classical island biogeography theory and niche theory. Classical island biogeography theory considers the processes of persistence, extinction, and colonization, whereas niche theory focuses on species requirements, such as habitat and resource use. Recent studies have called for the unification of these two theories to better explain the underlying mechanisms that generates SARs. In this context, species traits that can be related to each theory seem promising. Here we analyzed the SARs of butterfly and moth assemblages on islands differing in size and isolation. We tested whether species traits modify the SAR and the response to isolation. In addition to the expected overall effects on the area, traits related to each of the two theories increased the model fit, from 69% up to 90%. Steeper slopes have been shown to have a particularly higher sensitivity to area, which was indicated by species with restricted range (slope = 0.82), narrow dietary niche (slope= 0.59), low abundance (slope= 0.52), and low reproductive potential (slope = 0.51). We concluded that considering species traits by analyzing SARs yields considerable potential for unifying island biogeography theory and niche theory, and that the systematic and predictable effects observed when considering traits can help to guide conservation and management actions.

  19. Multiple mechanisms enable invasive species to suppress native species.

    Science.gov (United States)

    Bennett, Alison E; Thomsen, Meredith; Strauss, Sharon Y

    2011-07-01

    Invasive plants represent a significant threat to ecosystem biodiversity. To decrease the impacts of invasive species, a major scientific undertaking of the last few decades has been aimed at understanding the mechanisms that drive invasive plant success. Most studies and theories have focused on a single mechanism for predicting the success of invasive plants and therefore cannot provide insight as to the relative importance of multiple interactions in predicting invasive species' success. We examine four mechanisms that potentially contribute to the success of invasive velvetgrass Holcus lanatus: direct competition, indirect competition mediated by mammalian herbivores, interference competition via allelopathy, and indirect competition mediated by changes in the soil community. Using a combination of field and greenhouse approaches, we focus on the effects of H. lanatus on a common species in California coastal prairies, Erigeron glaucus, where the invasion is most intense. We found that H. lanatus had the strongest effects on E. glaucus via direct competition, but it also influenced the soil community in ways that feed back to negatively influence E. glaucus and other native species after H. lanatus removal. This approach provided evidence for multiple mechanisms contributing to negative effects of invasive species, and it identified when particular strategies were most likely to be important. These mechanisms can be applied to eradication of H. lanatus and conservation of California coastal prairie systems, and they illustrate the utility of an integrated set of experiments for determining the potential mechanisms of invasive species' success.

  20. Evolution of mutualism between species

    Energy Technology Data Exchange (ETDEWEB)

    Post, W.M.; Travis, C.C.; DeAngelis, D.L.

    1980-01-01

    Recent theoretical work on mutualism, the interaction between species populations that is mutually beneficial, is reviewed. Several ecological facts that should be addressed in the construction of dynamic models for mutualism are examined. Basic terminology is clarified. (PSB)

  1. Phase Two Protected Species Valuation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nonmarket valuation research has produced economic value estimates for a variety of threatened, endangered, and rare species around the world. Although over 40 value...

  2. 76 FR 1405 - Endangered Species

    Science.gov (United States)

    2011-01-10

    ... the understanding of the pelagic ecology of these species and allow more reliable assessments of... permit: (1) Was applied for in good faith, (2) will not operate to the disadvantage of such endangered or...

  3. Infrared spectra of mineral species

    CERN Document Server

    Chukanov, Nikita V

    2014-01-01

    This book details more than 3,000 IR spectra of more than 2,000 mineral species collected during last 30 years. It features full descriptions and analytical data of each sample for which IR spectrum was obtained.

  4. THE USE OF CASSAVA SPECIES

    African Journals Online (AJOL)

    User

    The plant is propagated from mature stems, which .... USE OF CASSAVA SPECIES AND ALUM IN WASTE WATER TREATMENT, .... acidity, total suspended solids, dissolved oxygen and ..... Rural Areas, MSc Thesis, Department of Water.

  5. Achromobacter species in cystic fibrosis

    DEFF Research Database (Denmark)

    Hansen, C R; Pressler, T; Ridderberg, W

    2013-01-01

    Achromobacter species leads to chronic infection in an increasing number of CF patients. We report 2 cases of Achromobacter ruhlandii cross-infection between patients after well-described indirect contact....

  6. Species Typing in Dermal Leishmaniasis

    Science.gov (United States)

    Dujardin, Jean-Claude

    2015-01-01

    SUMMARY Leishmania is an infectious protozoan parasite related to African and American trypanosomes. All Leishmania species that are pathogenic to humans can cause dermal disease. When one is confronted with cutaneous leishmaniasis, identification of the causative species is relevant in both clinical and epidemiological studies, case management, and control. This review gives an overview of the currently existing and most used assays for species discrimination, with a critical appraisal of the limitations of each technique. The consensus taxonomy for the genus is outlined, including debatable species designations. Finally, a numerical literature analysis is presented that describes which methods are most used in various countries and regions in the world, and for which purposes. PMID:25672782

  7. The Candida Pathogenic Species Complex

    Science.gov (United States)

    Turner, Siobhán A.; Butler, Geraldine

    2014-01-01

    Candida species are the most common causes of fungal infection. Approximately 90% of infections are caused by five species: Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei. Three (C. albicans, C. tropicalis, and C. parapsilosis) belong to the CTG clade, in which the CTG codon is translated as serine and not leucine. C. albicans remains the most commonly isolated but is decreasing relative to the other species. The increasing incidence of C. glabrata is related to its reduced susceptibility to azole drugs. Genome analysis suggests that virulence in the CTG clade is associated with expansion of gene families, particularly of cell wall genes. Similar independent processes took place in the C. glabrata species group. Gene loss and expansion in an ancestor of C. glabrata may have resulted in preadaptations that enabled pathogenicity. PMID:25183855

  8. Phase One Protected Species Valuation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nonmarket valuation research has produced economic value estimates for a variety of threatened, endangered, and rare species around the world. Although over 40 value...

  9. Theoretical microbial ecology without species

    Science.gov (United States)

    Tikhonov, Mikhail

    2017-09-01

    Ecosystems are commonly conceptualized as networks of interacting species. However, partitioning natural diversity of organisms into discrete units is notoriously problematic and mounting experimental evidence raises the intriguing question whether this perspective is appropriate for the microbial world. Here an alternative formalism is proposed that does not require postulating the existence of species as fundamental ecological variables and provides a naturally hierarchical description of community dynamics. This formalism allows approaching the species problem from the opposite direction. While the classical models treat a world of imperfectly clustered organism types as a perturbation around well-clustered species, the presented approach allows gradually adding structure to a fully disordered background. The relevance of this theoretical construct for describing highly diverse natural ecosystems is discussed.

  10. Species delimitation in the Stenocereus griseus (Cactaceae) species complex reveals a new species, S. huastecorum.

    Science.gov (United States)

    Alvarado-Sizzo, Hernán; Casas, Alejandro; Parra, Fabiola; Arreola-Nava, Hilda Julieta; Terrazas, Teresa; Sánchez, Cristian

    2018-01-01

    The Stenocereus griseus species complex (SGSC) has long been considered taxonomically challenging because the number of taxa belonging to the complex and their geographical boundaries remain poorly understood. Bayesian clustering and genetic distance-based methods were used based on nine microsatellite loci in 377 individuals of three main putative species of the complex. The resulting genetic clusters were assessed for ecological niche divergence and areolar morphology, particularly spination patterns. We based our species boundaries on concordance between genetic, ecological, and morphological data, and were able to resolve four species, three of them corresponding to S. pruinosus from central Mexico, S. laevigatus from southern Mexico, and S. griseus from northern South America. A fourth species, previously considered to be S. griseus and commonly misidentified as S. pruinosus in northern Mexico showed significant genetic, ecological, and morphological differentiation suggesting that it should be considered a new species, S. huastecorum, which we describe here. We show that population genetic analyses, ecological niche modeling, and morphological studies are complementary approaches for delimiting species in taxonomically challenging plant groups such as the SGSC.

  11. Species delimitation in the Stenocereus griseus (Cactaceae species complex reveals a new species, S. huastecorum.

    Directory of Open Access Journals (Sweden)

    Hernán Alvarado-Sizzo

    Full Text Available The Stenocereus griseus species complex (SGSC has long been considered taxonomically challenging because the number of taxa belonging to the complex and their geographical boundaries remain poorly understood. Bayesian clustering and genetic distance-based methods were used based on nine microsatellite loci in 377 individuals of three main putative species of the complex. The resulting genetic clusters were assessed for ecological niche divergence and areolar morphology, particularly spination patterns. We based our species boundaries on concordance between genetic, ecological, and morphological data, and were able to resolve four species, three of them corresponding to S. pruinosus from central Mexico, S. laevigatus from southern Mexico, and S. griseus from northern South America. A fourth species, previously considered to be S. griseus and commonly misidentified as S. pruinosus in northern Mexico showed significant genetic, ecological, and morphological differentiation suggesting that it should be considered a new species, S. huastecorum, which we describe here. We show that population genetic analyses, ecological niche modeling, and morphological studies are complementary approaches for delimiting species in taxonomically challenging plant groups such as the SGSC.

  12. Species selection for smallholder aquaculture

    OpenAIRE

    Brummett, R.E.

    1996-01-01

    Systems for selection of species for smallholder aquaculture are presented. These are: food fits; management decisions; and economic criteria. Food fits suggests categorizing pond food resources into a few categories based loosely on the instrinsic traits of food which effect their selectivity by predators. Using management decision techniques, potential polycultures might also be compared with each other and with monoculture. Under economic criteria (and for species known in local markets), ...

  13. Endangered Lilium Species of Turkey

    Directory of Open Access Journals (Sweden)

    Sevim Demir

    2018-01-01

    Full Text Available Turkey, which is among the major gene centers of the world and has a special place in plant genetic diversity. However, many plant genetic resources, including geophytes, are under genetic erosion because of the environmental and other problems and therefore face with the danger of extinction. Lilium ciliatum is endemic to North East Anatolia. IUCN (International Union for the Conservation of Natural Resources Red List Category of this species is Endangered (EN. Lilium ciliatum naturally grown in Zigana pass, Bayburt, Trabzon, Bulancak, Giresun and Gümüşhane is endangered and major threats of L. ciliatum are road construction and human disturbance related to ecotourism and recreation. It was reported that Lilium carniolicum naturally grown in Turkey is endangered although it isn’t in the IUCN Red List. Distribution areas of L. carniolicum are Trabzon, Rize, Artvin and it is also endemic to North East Anatolia. These species have high potential for use as ornamental plants with their colorful big flowers. In addition, the bulbs of these species are also used in the cosmetic industry and medicine. These are the main properties that increase the importance of L. ciliatum and L. carniolicum species. Therefore it is very important to protect the habitats of these species, ensure the continuity of their generations. The disappearance of these endemic species from our country means to disappear from the world. This review has been given in order to give some information about the endangered Lilium species of Turkey and conservation actions on these species in Turkey flora and take attention to the issue.

  14. Collective behaviour across animal species.

    Science.gov (United States)

    DeLellis, Pietro; Polverino, Giovanni; Ustuner, Gozde; Abaid, Nicole; Macrì, Simone; Bollt, Erik M; Porfiri, Maurizio

    2014-01-16

    We posit a new geometric perspective to define, detect, and classify inherent patterns of collective behaviour across a variety of animal species. We show that machine learning techniques, and specifically the isometric mapping algorithm, allow the identification and interpretation of different types of collective behaviour in five social animal species. These results offer a first glimpse at the transformative potential of machine learning for ethology, similar to its impact on robotics, where it enabled robots to recognize objects and navigate the environment.

  15. Thromboelastography in Selected Avian Species

    DEFF Research Database (Denmark)

    Andersen, Sophie Susanna Strindberg; Nielsen, Tenna W; Ribeiro, Ângela M

    2015-01-01

    Currently available assay methods and reagents are not optimized for evaluating avian hemostasis; therefore, assessing avian coagulopathies is challenging. Recently, thromboelastography (TEG), which measures the viscoelastic properties of blood, has been used clinically in mammalian species...... to diagnose and characterize hemostatic disorders. To evaluate TEG in healthy individuals of 6 avian species, we modified existing mammalian TEG protocols to allow analysis of citrated, avian whole-blood samples collected from scarlet ibis (Eudocimus ruber) (n = 13), American flamingos ( Phoenicopterus ruber...

  16. The nature of plant species.

    Science.gov (United States)

    Rieseberg, Loren H; Wood, Troy E; Baack, Eric J

    2006-03-23

    Many botanists doubt the existence of plant species, viewing them as arbitrary constructs of the human mind, as opposed to discrete, objective entities that represent reproductively independent lineages or 'units of evolution'. However, the discreteness of plant species and their correspondence with reproductive communities have not been tested quantitatively, allowing zoologists to argue that botanists have been overly influenced by a few 'botanical horror stories', such as dandelions, blackberries and oaks. Here we analyse phenetic and/or crossing relationships in over 400 genera of plants and animals. We show that although discrete phenotypic clusters exist in most genera (> 80%), the correspondence of taxonomic species to these clusters is poor (< 60%) and no different between plants and animals. Lack of congruence is caused by polyploidy, asexual reproduction and over-differentiation by taxonomists, but not by contemporary hybridization. Nonetheless, crossability data indicate that 70% of taxonomic species and 75% of phenotypic clusters in plants correspond to reproductively independent lineages (as measured by postmating isolation), and thus represent biologically real entities. Contrary to conventional wisdom, plant species are more likely than animal species to represent reproductively independent lineages.

  17. The Colletotrichum gloeosporioides species complex.

    Science.gov (United States)

    Weir, B S; Johnston, P R; Damm, U

    2012-09-15

    The limit of the Colletotrichum gloeosporioides species complex is defined genetically, based on a strongly supported clade within the Colletotrichum ITS gene tree. All taxa accepted within this clade are morphologically more or less typical of the broadly defined C. gloeosporioides, as it has been applied in the literature for the past 50 years. We accept 22 species plus one subspecies within the C. gloeosporioides complex. These include C. asianum, C. cordylinicola, C. fructicola, C. gloeosporioides, C. horii, C. kahawae subsp. kahawae, C. musae, C. nupharicola, C. psidii, C. siamense, C. theobromicola, C. tropicale, and C. xanthorrhoeae, along with the taxa described here as new, C. aenigma, C. aeschynomenes, C. alatae, C. alienum, C. aotearoa, C. clidemiae, C. kahawae subsp. ciggaro, C. salsolae, and C. ti, plus the nom. nov. C. queenslandicum (for C. gloeosporioides var. minus). All of the taxa are defined genetically on the basis of multi-gene phylogenies. Brief morphological descriptions are provided for species where no modern description is available. Many of the species are unable to be reliably distinguished using ITS, the official barcoding gene for fungi. Particularly problematic are a set of species genetically close to C. musae and another set of species genetically close to C. kahawae, referred to here as the Musae clade and the Kahawae clade, respectively. Each clade contains several species that are phylogenetically well supported in multi-gene analyses, but within the clades branch lengths are short because of the small number of phylogenetically informative characters, and in a few cases individual gene trees are incongruent. Some single genes or combinations of genes, such as glyceraldehyde-3-phosphate dehydrogenase and glutamine synthetase, can be used to reliably distinguish most taxa and will need to be developed as secondary barcodes for species level identification, which is important because many of these fungi are of biosecurity

  18. Terrestrial animals as invasive species and as species at risk from invasions

    Science.gov (United States)

    Deborah M. Finch; Dean Pearson; Joseph Wunderle; Wayne Arendt

    2010-01-01

    Including terrestrial animal species in the invasive species strategy plan is an important step in invasive species management. Invasions by nonindigenous species threaten nearly 50 percent of imperiled native species in the United States and are the Nation's second leading cause of species endangerment. Invasion and conversion of native habitats by exotic species...

  19. Strong persistent growth differences govern individual performance and population dynamics in a tropical forest understorey palm

    NARCIS (Netherlands)

    Jansen, M.; Zuidema, P.A.; Anten, N.P.R.; Martínez-Ramos, M.

    2012-01-01

    1. Persistent variation in growth rate between individual plants can have strong effects on population dynamics as fast growers reach the reproductive size at an earlier age and thus potentially contribute more to population growth than slow growers. In tropical forests, such persistent growth

  20. Driving factors behind the eutrophication signal in understorey plant communities of deciduous temperate forests

    Czech Academy of Sciences Publication Activity Database

    Verheyen, E.; Baeten, L.; De Frenne, P.; Brnhardt-Römermann, M.; Brunet, J.; Cornelis, J.; Decocq, G.; Dierschke, H.; Eriksson, O.; Hédl, Radim; Heinken, T.; Hermy, M.; Hommel, P.; Kirby, K.; Naaf, T.; Peterken, G.; Petřík, Petr; Pfadenhauer, J.; Van Calster, H.; Walther, G.-R.; Wulf, M.; Verstraeten, G.

    2012-01-01

    Roč. 100, č. 2 (2012), s. 352-365 ISSN 0022-0477 R&D Projects: GA AV ČR IAA600050812 Institutional research plan: CEZ:AV0Z60050516 Keywords : Ellenberg indicator values * forest management * large herbivores Subject RIV: EF - Botanics Impact factor: 5.431, year: 2012

  1. Reduced-impact logging and temporal activity of understorey bats in lowland Amazonia

    Science.gov (United States)

    Ivan Castro Arellano; Steven J. Presley; Michael R. Willig; Joseph M. Wunderle; Luiz N. Saldanha

    2009-01-01

    Because global timber demands continue to threaten tropical rain forests, identification of sustainable use forest management protocols that meet human needs while preserving biodiversity is critical. Reduced-impact logging (RIL) protocols are increasingly common in the tropics and may be a viable option for sustainable forest use; however, few studies have documented...

  2. Malassezia Species and Pityriasis Versicolor

    Directory of Open Access Journals (Sweden)

    Gulin Rodoplu

    2016-01-01

    Full Text Available Malassezia species are found in part of the normal human cutaneous commensal flora, however it has been known for many years that the Malassezia yeasts are associated with a number of different human diseases ranging from pityriasis versicolor to seborrhoeic dermatitis. In addition, since the 1980s, they have been reported as causing opportunistic systemic infections. The taxonomy of Malassezia spp. has recently been modified to include 13 obligatorily lipophilic species, plus one non-obligatorily lipophilic species, which only rarely colonizes human hosts and currently the genus consist 14 species as M. furfur, M. pachydermatis, M. sympodialis, M. globosa, M. obtusa, M. slooffiae, M. restricta, M. dermatis, M. japonica, M. nana, M. yamatoensis, M. caprae, M. equina, M. cuniculi. Fastidious growth requirements of Malassezia yeasts defied the initial attempts to culture these organisms and their true identification and the relationship between different species only became apparent with the application of modern molecular techniques. The causative fungus is seen especially in such seborrheic areas as the scalp, face, trunk and upper back. Under the influence of various exogenous or endogenous predisposing factors, these yeasts change from the blastospore form to the mycelial form and become pathogenic. Diagnosis of pityriasis versicolor which is caused by Malassezia species is generally easy and lies on the basis of its clinical appearance and can be confirmed by mycological examination. The diagnosisis is mainly based on direct examination with potassium hydroxide (KOH and demonstration that represents pseudohyphae and blastoconidia as the typical %u201Cspaghetti and meatballs%u201D pattern. Characteristic features of the genus Malassezia include a distinctive morphology and an affinity for lipids in culture. Culture is necessary to recover the infecting strain, especially for epidemiologic purposes and also to test its antifungal susceptibility

  3. Phenotypic covariance at species' borders.

    Science.gov (United States)

    Caley, M Julian; Cripps, Edward; Game, Edward T

    2013-05-28

    Understanding the evolution of species limits is important in ecology, evolution, and conservation biology. Despite its likely importance in the evolution of these limits, little is known about phenotypic covariance in geographically marginal populations, and the degree to which it constrains, or facilitates, responses to selection. We investigated phenotypic covariance in morphological traits at species' borders by comparing phenotypic covariance matrices (P), including the degree of shared structure, the distribution of strengths of pair-wise correlations between traits, the degree of morphological integration of traits, and the ranks of matricies, between central and marginal populations of three species-pairs of coral reef fishes. Greater structural differences in P were observed between populations close to range margins and conspecific populations toward range centres, than between pairs of conspecific populations that were both more centrally located within their ranges. Approximately 80% of all pair-wise trait correlations within populations were greater in the north, but these differences were unrelated to the position of the sampled population with respect to the geographic range of the species. Neither the degree of morphological integration, nor ranks of P, indicated greater evolutionary constraint at range edges. Characteristics of P observed here provide no support for constraint contributing to the formation of these species' borders, but may instead reflect structural change in P caused by selection or drift, and their potential to evolve in the future.

  4. Aspergillus fumigatus and Related Species

    Science.gov (United States)

    Sugui, Janyce A.; Kwon-Chung, Kyung J.; Juvvadi, Praveen R.; Latgé, Jean-Paul; Steinbach, William J.

    2015-01-01

    The genus Aspergillus contains etiologic agents of aspergillosis. The clinical manifestations of the disease range from allergic reaction to invasive pulmonary infection. Among the pathogenic aspergilli, Aspergillus fumigatus is most ubiquitous in the environment and is the major cause of the disease, followed by Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Aspergillus nidulans, and several species in the section Fumigati that morphologically resemble A. fumigatus. Patients that are at risk for acquiring aspergillosis are those with an altered immune system. Early diagnosis, species identification, and adequate antifungal therapy are key elements for treatment of the disease, especially in cases of pulmonary invasive aspergillosis that often advance very rapidly. Incorporating knowledge of the basic biology of Aspergillus species to that of the diseases that they cause is fundamental for further progress in the field. PMID:25377144

  5. What is a Species? An Endless Debate

    Indian Academy of Sciences (India)

    Srimath

    a research scholar in ... perspectives are collectively termed as Phylogenetic Species ... tors view the origin of the species they study”. ..... explosion of molecular data has been the major driving force in unearthing cryptic species, it is no ...

  6. Vegetation composition and structure influences bird species ...

    African Journals Online (AJOL)

    Vegetation composition and structure influences bird species community ... variables on bird species diversity and richness of respective foraging guilds, and ... of the species assessed: (1) increasing closed cover due to woody plant density, ...

  7. Alien species recorded in the United Arab Emirates: an initial list of terrestrial and freshwater species

    Directory of Open Access Journals (Sweden)

    Pritpal Soorae

    2015-10-01

    Full Text Available Little is documented on the alien terrestrial and freshwater species in the United Arab Emirates. To address this, an assessment of terrestrial and freshwater alien species was conducted using various techniques such as a questionnaire, fieldwork data, networking with relevant people, and a detailed literature review. The results of the initial assessment show that there are 146 alien species recorded in the following seven major taxonomic groups: invertebrates 49 species, freshwater fish five species, amphibian one species, reptiles six species, birds 71 species, mammals six species and plants eight species. To inform decision makers a full list of the 146 species identified in this assessment is presented. 

  8. Man...An Endangered Species?

    Science.gov (United States)

    Department of the Interior, Washington, DC.

    The general theme of this 1968 yearbook is that man is a threatened species, facing overpopulation and unbridled technology - both self induced. The presentation is broad, relating to many aspects of conservation and natural resources in the United States in a descriptive, non-technical style. The yearbook is divided into major topics: Land…

  9. Phylogenetic relationships among Maloideae species

    Science.gov (United States)

    The Maloideae is a highly diverse sub-family of the Rosaceae containing several agronomically important species (Malus sp. and Pyrus sp.) and their wild relatives. Previous phylogenetic work within the group has revealed extensive intergeneric hybridization and polyploidization. In order to develop...

  10. Botrytis species on bulb crops

    NARCIS (Netherlands)

    Lorbeer, J.W.; Seyb, A.M.; Boer, de M.; Ende, van den J.E.

    2007-01-01

    Abstract. A number of Botrytis species are pathogens of bulb crops. Botrytis squamosa (teleomorph=Botrytotinia squamosa) causal agent of botrytis leaf blight and B. allii the causal agent of botrytis neck rotare two of the most important fungal diseases of onion. The taxonomics of several of the

  11. Endangered Species: An Educator's Handbook.

    Science.gov (United States)

    Smith, Jean, M., Comp.

    Presented are two articles, an annotated bibliography, and other information useful in teaching about endangered species, especially those found in Florida. The articles provide an ethical rationale, teaching suggestions, and a discussion of the value of wildlife. Descriptions of over 100 pertinent books, periodicals, movies, and filmstrips are in…

  12. Molecular Epidemiology of Fonsecaea Species

    NARCIS (Netherlands)

    Najafzadeh, M.J.; Sun, J.; Vicente, V.A.; Klaassen, C.H.W.; Bonifaz, A.; Gerrits van den Ende, A.H.G.; Menken, S.B.J.; de Hoog, G.S.

    2011-01-01

    To assess population diversities among 81 strains of fungi in the genus Fonsecaea that had been identified down to species level, we applied amplified fragment-length polymorphism (AFLP) technology and sequenced the internal transcribed spacer regions and the partial cell division cycle, β-tubulin,

  13. SARS – virus jumps species

    Indian Academy of Sciences (India)

    SARS – virus jumps species. Coronavirus reshuffles genes; Rotteir et al, Rotterdam showed the virus to jump from cats to mouse cells after single gene mutation ? Human disease due to virus jumping from wild or domestic animals; Present favourite animal - the cat; - edible or domestic.

  14. Species recovery in the United States: Increasing the effectiveness of the Endangered Species Act

    Science.gov (United States)

    Daniel M. Evans; Judy P. Che-Castaldo; Deborah Crouse; Frank W. Davis; Rebecca Epanchin-Niell; Curtis H. Flather; R. Kipp Frohlich; Dale D. Goble; Ya-Wei Li; Timothy D. Male; Lawrence L. Master; Matthew P. Moskwik; Maile C. Neel; Barry R. Noon; Camille Parmesan; Mark W. Schwartz; J. Michael Scott; Byron K. Williams

    2016-01-01

    The Endangered Species Act (ESA) has succeeded in shielding hundreds of species from extinction and improving species recovery over time. However, recovery for most species officially protected by the ESA - i.e., listed species - has been harder to achieve than initially envisioned. Threats to species are persistent and pervasive, funding has been insufficient...

  15. Optimal conservation of migratory species.

    Directory of Open Access Journals (Sweden)

    Tara G Martin

    Full Text Available BACKGROUND: Migratory animals comprise a significant portion of biodiversity worldwide with annual investment for their conservation exceeding several billion dollars. Designing effective conservation plans presents enormous challenges. Migratory species are influenced by multiple events across land and sea-regions that are often separated by thousands of kilometres and span international borders. To date, conservation strategies for migratory species fail to take into account how migratory animals are spatially connected between different periods of the annual cycle (i.e. migratory connectivity bringing into question the utility and efficiency of current conservation efforts. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the first framework for determining an optimal conservation strategy for a migratory species. Employing a decision theoretic approach using dynamic optimization, we address the problem of how to allocate resources for habitat conservation for a Neotropical-Nearctic migratory bird, the American redstart Setophaga ruticilla, whose winter habitat is under threat. Our first conservation strategy used the acquisition of winter habitat based on land cost, relative bird density, and the rate of habitat loss to maximize the abundance of birds on the wintering grounds. Our second strategy maximized bird abundance across the entire range of the species by adding the constraint of maintaining a minimum percentage of birds within each breeding region in North America using information on migratory connectivity as estimated from stable-hydrogen isotopes in feathers. We show that failure to take into account migratory connectivity may doom some regional populations to extinction, whereas including information on migratory connectivity results in the protection of the species across its entire range. CONCLUSIONS/SIGNIFICANCE: We demonstrate that conservation strategies for migratory animals depend critically upon two factors: knowledge of

  16. Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species (Trichoptera, Hydroptilidae

    Directory of Open Access Journals (Sweden)

    Oláh, J.

    2013-06-01

    Full Text Available A brief synopsis of the Oxyethira flavicornis species group is produced by the examination of type materials. Diagrammatic drawings with similar style were prepared for all the known and for the new species. Short description of genus Oxyethira, subgenus Oxyethira, species group of Oxyethira flavicornis are presented together with the description of five species clusters: O. datra new species cluster, O. ecornuta new species cluster, O. flavicornis new species cluster, O. hiroshima new species cluster, O. tiunovae new species cluster. Five new species are described from the O. flavicornis species group: O chitosea sp. n., O. hena sp. n., O. hiroshima sp. n., O. kakida sp. n., O. mekunna sp. n. One new species is described from the Oxyethira grisea species group: Oxyethira ozea sp. n. and two new species from the Oxyethira ramosa species group: Oxyethira miea sp. n., Oxyethira okinawa sp. n.

  17. Floral reward in Ranunculaceae species

    Directory of Open Access Journals (Sweden)

    Bożena Denisow

    2016-04-01

    Full Text Available Floral reward is important in ecological and evolutionary perspectives and essential in pollination biology. For example, floral traits, nectar and pollen features are essential for understanding the functional ecology, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant–pollinator interactions. We believe to present a synthetic description in the field of floral reward in Ranunculaceae family important in pollination biology and indicating connections between ecological and evolutionary approaches. The links between insect visitors’ behaviour and floral reward type and characteristics exist. Ranunculaceae is a family of aboot 1700 species (aboot 60 genera, distributed worldwide, however the most abundant representatives are in temperate and cool regions of the northern and southern hemispheres. The flowers are usually radially symmetric (zygomorphic and bisexual, but in Aconitum, Aquilegia are bilaterally symmetric (zygomorphic. Most Ranunculaceae flowers offer no nectar, only pollen (e.g., Ranunculus, Adonis vernalis, Thalictrum, but numerous species create trophic niches for different wild pollinators (e.g. Osmia, Megachile, Bombus, Andrena (Denisow et al. 2008. Pollen is a source of protein, vitamins, mineral salts, organic acids and hormones, but the nutritional value varies greatly between different plant species. The pollen production can differ significantly between Ranunculacea species. The mass of pollen produced in anthers differ due to variations in the number of developed anthers. For example, interspecies differences are considerable, 49 anthers are noted in Aquilegia vulgaris, 70 anthers in Ranunculus lanuginosus, 120 in Adonis vernalis. A significant intra-species differences’ in the number of anthers are also noted (e.g. 41 to 61 in Aquilegia vulgaris, 23-45 in Ranunculus cassubicus. Pollen production can be up to 62 kg per ha for Ranunculus acer

  18. ICRAF Species Switchboard. Version 1.2

    DEFF Research Database (Denmark)

    Kindt, R.; Ordonez, J.; Smith, E.

    2015-01-01

    The current version of the Agroforestry Species Switchboard documents the presence of a total of 26,135 plant species (33,813 species including synonyms) across 19 web-based databases. When available, hyperlinks to information on the selected species in particular databases are provided. In total...

  19. Ranking species in mutualistic networks

    Science.gov (United States)

    Domínguez-García, Virginia; Muñoz, Miguel A.

    2015-02-01

    Understanding the architectural subtleties of ecological networks, believed to confer them enhanced stability and robustness, is a subject of outmost relevance. Mutualistic interactions have been profusely studied and their corresponding bipartite networks, such as plant-pollinator networks, have been reported to exhibit a characteristic ``nested'' structure. Assessing the importance of any given species in mutualistic networks is a key task when evaluating extinction risks and possible cascade effects. Inspired in a recently introduced algorithm -similar in spirit to Google's PageRank but with a built-in non-linearity- here we propose a method which -by exploiting their nested architecture- allows us to derive a sound ranking of species importance in mutualistic networks. This method clearly outperforms other existing ranking schemes and can become very useful for ecosystem management and biodiversity preservation, where decisions on what aspects of ecosystems to explicitly protect need to be made.

  20. Competitive intransitivity promotes species coexistence.

    Science.gov (United States)

    Laird, Robert A; Schamp, Brandon S

    2006-08-01

    Using a spatially explicit cellular automaton model with local competition, we investigate the potential for varied levels of competitive intransitivity (i.e., nonhierarchical competition) to promote species coexistence. As predicted, on average, increased levels of intransitivity result in more sustained coexistence within simulated communities, although the outcome of competition also becomes increasingly unpredictable. Interestingly, even a moderate degree of intransitivity within a community can promote coexistence, in terms of both the length of time until the first competitive exclusion and the number of species remaining in the community after 500 simulated generations. These results suggest that modest levels of intransitivity in nature, such as those that are thought to be characteristic of plant communities, can contribute to coexistence and, therefore, community-scale biodiversity. We explore a potential connection between competitive intransitivity and neutral theory, whereby competitive intransitivity may represent an important mechanism for "ecological equivalence."

  1. Charcoal anatomy of forest species

    Directory of Open Access Journals (Sweden)

    Graciela Inés Bolzon de Muñiz1

    2012-09-01

    Full Text Available Vegetal charcoal retains the anatomical structure of the wood and may permit its botanical identification, which depends on species characteristics, the charcoal fragments size and preservation state. Anatomical characterization of ten forest species charcoal was done envisaging the identification and control of illegal charcoal. Differences between gymnosperms and angiosperms are evident in carbonized wood. Vessel diameter was statistically different between wood and charcoal in Vatairea guianensis, Mezilaurus itauba, Calophyllum brasiliense e Qualea cf. acuminata, and vessel frequency in Vatairea guianensis, Manilkara huberi, Qualea cf. acuminata e Simarouba amara. The anatomical structure from wood, in general aspects, is constant during carbonization process using temperature of 450°C, being possible to identify the material by using its cellular components.

  2. Population Genomics of Paramecium Species.

    Science.gov (United States)

    Johri, Parul; Krenek, Sascha; Marinov, Georgi K; Doak, Thomas G; Berendonk, Thomas U; Lynch, Michael

    2017-05-01

    Population-genomic analyses are essential to understanding factors shaping genomic variation and lineage-specific sequence constraints. The dearth of such analyses for unicellular eukaryotes prompted us to assess genomic variation in Paramecium, one of the most well-studied ciliate genera. The Paramecium aurelia complex consists of ∼15 morphologically indistinguishable species that diverged subsequent to two rounds of whole-genome duplications (WGDs, as long as 320 MYA) and possess extremely streamlined genomes. We examine patterns of both nuclear and mitochondrial polymorphism, by sequencing whole genomes of 10-13 worldwide isolates of each of three species belonging to the P. aurelia complex: P. tetraurelia, P. biaurelia, P. sexaurelia, as well as two outgroup species that do not share the WGDs: P. caudatum and P. multimicronucleatum. An apparent absence of global geographic population structure suggests continuous or recent dispersal of Paramecium over long distances. Intergenic regions are highly constrained relative to coding sequences, especially in P. caudatum and P. multimicronucleatum that have shorter intergenic distances. Sequence diversity and divergence are reduced up to ∼100-150 bp both upstream and downstream of genes, suggesting strong constraints imposed by the presence of densely packed regulatory modules. In addition, comparison of sequence variation at non-synonymous and synonymous sites suggests similar recent selective pressures on paralogs within and orthologs across the deeply diverging species. This study presents the first genome-wide population-genomic analysis in ciliates and provides a valuable resource for future studies in evolutionary and functional genetics in Paramecium. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Haemolytic glycoglycerolipids from Gymnodinium species.

    Science.gov (United States)

    Parrish, C C; Bodennec, G; Gentien, P

    1998-03-01

    Glycoglycerolipids derived from microalgae can be a source of biologically active substances including toxins. Such glycolipids were analysed in two isolates of toxic marine dinoflagellates from European waters. The lipids of Gymnodinium mikimotoi contained 17% of monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG), while in Gymnodinium sp. the proportion was 35%. MGDG and DGDG from both species were haemolytic. The major unsaturated fatty acid in both algal glycolipids was 18:5 omega 3.

  4. Chemokines in teleost fish species.

    Science.gov (United States)

    Alejo, Alí; Tafalla, Carolina

    2011-12-01

    Chemokines are chemoattractant cytokines defined by the presence of four conserved cysteine residues which in mammals can be divided into four subfamilies depending on the arrangement of the first two conserved cysteines in their sequence: CXC (α), CC (β), C and CX(3)C classes. Evolutionarily, fish can be considered as an intermediate step between species which possess only innate immunity (invertebrates) and species with a fully developed acquired immune network such as mammals. Therefore, the functionality of their different immune cell types and molecules is sometimes also intermediate between innate and acquired responses. The first chemokine gene identified in a teleost was a rainbow trout (Oncorhynchus mykiss) chemokine designated as CK1 in 1998. Since then, many different chemokine genes have been identified in several fish species, but their role in homeostasis and immune response remains largely unknown. Extensive genomic duplication events and the fact that chemokines evolve more quickly than other immune genes, make it very difficult to establish true orthologues between fish and mammalian chemokines that would help us with the ascription of immune roles. In this review, we describe the current state of knowledge of chemokine biology in teleost fish, focusing mainly on which genes have been identified so far and highlighting the most important aspects of their expression regulation, due to the great lack of functional information available for them. As the number of chemokine genes begins to close down for some teleost species, there is an important need for functional assays that may elucidate the role of each of these molecules within the fish immune response. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Candida Species Biofilms’ Antifungal Resistance

    Science.gov (United States)

    Silva, Sónia; Rodrigues, Célia F.; Araújo, Daniela; Rodrigues, Maria Elisa; Henriques, Mariana

    2017-01-01

    Candida infections (candidiasis) are the most prevalent opportunistic fungal infection on humans and, as such, a major public health problem. In recent decades, candidiasis has been associated to Candida species other than Candida albicans. Moreover, biofilms have been considered the most prevalent growth form of Candida cells and a strong causative agent of the intensification of antifungal resistance. As yet, no specific resistance factor has been identified as the sole responsible for the increased recalcitrance to antifungal agents exhibited by biofilms. Instead, biofilm antifungal resistance is a complex multifactorial phenomenon, which still remains to be fully elucidated and understood. The different mechanisms, which may be responsible for the intrinsic resistance of Candida species biofilms, include the high density of cells within the biofilm, the growth and nutrient limitation, the effects of the biofilm matrix, the presence of persister cells, the antifungal resistance gene expression and the increase of sterols on the membrane of biofilm cells. Thus, this review intends to provide information on the recent advances about Candida species biofilm antifungal resistance and its implication on intensification of the candidiasis. PMID:29371527

  6. Linking Keystone Species and Functional Groups: A New Operational Definition of the Keystone Species Concept

    OpenAIRE

    Robert D. Davic

    2003-01-01

    The concept of the "keystone species" is redefined to allow for the a priori prediction of these species within ecosystems. A keystone species is held to be a strongly interacting species whose top-down effect on species diversity and competition is large relative to its biomass dominance within a functional group. This operational definition links the community importance of keystone species to a specific ecosystem process, e.g., the regulation of species diversity, within functional groups ...

  7. Community structure informs species geographic distributions

    KAUST Repository

    Montesinos-Navarro, Alicia

    2018-05-23

    Understanding what determines species\\' geographic distributions is crucial for assessing global change threats to biodiversity. Measuring limits on distributions is usually, and necessarily, done with data at large geographic extents and coarse spatial resolution. However, survival of individuals is determined by processes that happen at small spatial scales. The relative abundance of coexisting species (i.e. \\'community structure\\') reflects assembly processes occurring at small scales, and are often available for relatively extensive areas, so could be useful for explaining species distributions. We demonstrate that Bayesian Network Inference (BNI) can overcome several challenges to including community structure into studies of species distributions, despite having been little used to date. We hypothesized that the relative abundance of coexisting species can improve predictions of species distributions. In 1570 assemblages of 68 Mediterranean woody plant species we used BNI to incorporate community structure into Species Distribution Models (SDMs), alongside environmental information. Information on species associations improved SDM predictions of community structure and species distributions moderately, though for some habitat specialists the deviance explained increased by up to 15%. We demonstrate that most species associations (95%) were positive and occurred between species with ecologically similar traits. This suggests that SDM improvement could be because species co-occurrences are a proxy for local ecological processes. Our study shows that Bayesian Networks, when interpreted carefully, can be used to include local conditions into measurements of species\\' large-scale distributions, and this information can improve the predictions of species distributions.

  8. Alien species in the Finnish weed flora

    Directory of Open Access Journals (Sweden)

    T. HYVÖNEN

    2008-12-01

    Full Text Available The present study aimed at assessing the invasion of alien weed species in Finland based on a review of their occurrence in the Finnish weed flora. The evaluation was conducted for the three phases of the invasion process, i.e. introduction, naturalization and invasion. The literature review revealed that 815 alien weed species occur in Finland of which 314 are regarded as naturalized. Based on their occurrence in different climate zones, the risk of naturalization of new harmful alien weed species was deemed low for those species not currently found in Finland, but higher for species occurring as casual aliens in Finland. In the latter group, 10 species of concern were detected. Exploration of the distribution patterns of naturalized species within Finland revealed species occupancy to be dependent on the residence time of the species. Established neophytes can be expected to extend their ranges and to increase occupation of agricultural habitats in the future.;

  9. Sporulation of Phytophthora ramorum and P. kernoviae on asymptomatic foliage and fruit

    Science.gov (United States)

    S. Denman; E. Moralejo; S.A. Kirk; E. Orton; A. Whybrow

    2008-01-01

    Phytophthora ramorum and P. kernoviae are newly discovered invasive Phytophthoras causing leaf necrosis, shoot tip dieback (mostly on ornamental and forest understorey host species) and bleeding cankers on tree trunks of a wide range of plant species. Both pathogens are now present in south-west England....

  10. Natural Constraints to Species Diversification.

    Directory of Open Access Journals (Sweden)

    Eric Lewitus

    2016-08-01

    Full Text Available Identifying modes of species diversification is fundamental to our understanding of how biodiversity changes over evolutionary time. Diversification modes are captured in species phylogenies, but characterizing the landscape of diversification has been limited by the analytical tools available for directly comparing phylogenetic trees of groups of organisms. Here, we use a novel, non-parametric approach and 214 family-level phylogenies of vertebrates representing over 500 million years of evolution to identify major diversification modes, to characterize phylogenetic space, and to evaluate the bounds and central tendencies of species diversification. We identify five principal patterns of diversification to which all vertebrate families hold. These patterns, mapped onto multidimensional space, constitute a phylogenetic space with distinct properties. Firstly, phylogenetic space occupies only a portion of all possible tree space, showing family-level phylogenies to be constrained to a limited range of diversification patterns. Secondly, the geometry of phylogenetic space is delimited by quantifiable trade-offs in tree size and the heterogeneity and stem-to-tip distribution of branching events. These trade-offs are indicative of the instability of certain diversification patterns and effectively bound speciation rates (for successful clades within upper and lower limits. Finally, both the constrained range and geometry of phylogenetic space are established by the differential effects of macroevolutionary processes on patterns of diversification. Given these properties, we show that the average path through phylogenetic space over evolutionary time traverses several diversification stages, each of which is defined by a different principal pattern of diversification and directed by a different macroevolutionary process. The identification of universal patterns and natural constraints to diversification provides a foundation for understanding the

  11. Natural Constraints to Species Diversification.

    Science.gov (United States)

    Lewitus, Eric; Morlon, Hélène

    2016-08-01

    Identifying modes of species diversification is fundamental to our understanding of how biodiversity changes over evolutionary time. Diversification modes are captured in species phylogenies, but characterizing the landscape of diversification has been limited by the analytical tools available for directly comparing phylogenetic trees of groups of organisms. Here, we use a novel, non-parametric approach and 214 family-level phylogenies of vertebrates representing over 500 million years of evolution to identify major diversification modes, to characterize phylogenetic space, and to evaluate the bounds and central tendencies of species diversification. We identify five principal patterns of diversification to which all vertebrate families hold. These patterns, mapped onto multidimensional space, constitute a phylogenetic space with distinct properties. Firstly, phylogenetic space occupies only a portion of all possible tree space, showing family-level phylogenies to be constrained to a limited range of diversification patterns. Secondly, the geometry of phylogenetic space is delimited by quantifiable trade-offs in tree size and the heterogeneity and stem-to-tip distribution of branching events. These trade-offs are indicative of the instability of certain diversification patterns and effectively bound speciation rates (for successful clades) within upper and lower limits. Finally, both the constrained range and geometry of phylogenetic space are established by the differential effects of macroevolutionary processes on patterns of diversification. Given these properties, we show that the average path through phylogenetic space over evolutionary time traverses several diversification stages, each of which is defined by a different principal pattern of diversification and directed by a different macroevolutionary process. The identification of universal patterns and natural constraints to diversification provides a foundation for understanding the deep-time evolution of

  12. Natural Constraints to Species Diversification

    Science.gov (United States)

    Lewitus, Eric; Morlon, Hélène

    2016-01-01

    Identifying modes of species diversification is fundamental to our understanding of how biodiversity changes over evolutionary time. Diversification modes are captured in species phylogenies, but characterizing the landscape of diversification has been limited by the analytical tools available for directly comparing phylogenetic trees of groups of organisms. Here, we use a novel, non-parametric approach and 214 family-level phylogenies of vertebrates representing over 500 million years of evolution to identify major diversification modes, to characterize phylogenetic space, and to evaluate the bounds and central tendencies of species diversification. We identify five principal patterns of diversification to which all vertebrate families hold. These patterns, mapped onto multidimensional space, constitute a phylogenetic space with distinct properties. Firstly, phylogenetic space occupies only a portion of all possible tree space, showing family-level phylogenies to be constrained to a limited range of diversification patterns. Secondly, the geometry of phylogenetic space is delimited by quantifiable trade-offs in tree size and the heterogeneity and stem-to-tip distribution of branching events. These trade-offs are indicative of the instability of certain diversification patterns and effectively bound speciation rates (for successful clades) within upper and lower limits. Finally, both the constrained range and geometry of phylogenetic space are established by the differential effects of macroevolutionary processes on patterns of diversification. Given these properties, we show that the average path through phylogenetic space over evolutionary time traverses several diversification stages, each of which is defined by a different principal pattern of diversification and directed by a different macroevolutionary process. The identification of universal patterns and natural constraints to diversification provides a foundation for understanding the deep-time evolution of

  13. The Invasive Species Forecasting System

    Science.gov (United States)

    Schnase, John; Most, Neal; Gill, Roger; Ma, Peter

    2011-01-01

    The Invasive Species Forecasting System (ISFS) provides computational support for the generic work processes found in many regional-scale ecosystem modeling applications. Decision support tools built using ISFS allow a user to load point occurrence field sample data for a plant species of interest and quickly generate habitat suitability maps for geographic regions of management concern, such as a national park, monument, forest, or refuge. This type of decision product helps resource managers plan invasive species protection, monitoring, and control strategies for the lands they manage. Until now, scientists and resource managers have lacked the data-assembly and computing capabilities to produce these maps quickly and cost efficiently. ISFS focuses on regional-scale habitat suitability modeling for invasive terrestrial plants. ISFS s component architecture emphasizes simplicity and adaptability. Its core services can be easily adapted to produce model-based decision support tools tailored to particular parks, monuments, forests, refuges, and related management units. ISFS can be used to build standalone run-time tools that require no connection to the Internet, as well as fully Internet-based decision support applications. ISFS provides the core data structures, operating system interfaces, network interfaces, and inter-component constraints comprising the canonical workflow for habitat suitability modeling. The predictors, analysis methods, and geographic extents involved in any particular model run are elements of the user space and arbitrarily configurable by the user. ISFS provides small, lightweight, readily hardened core components of general utility. These components can be adapted to unanticipated uses, are tailorable, and require at most a loosely coupled, nonproprietary connection to the Web. Users can invoke capabilities from a command line; programmers can integrate ISFS's core components into more complex systems and services. Taken together, these

  14. Litter decomposition rate and soil organic matter quality in a patchwork heathland of Southern Norway

    Science.gov (United States)

    Certini, G.; Vestgarden, L. S.; Forte, C.; Tau Strand, L.

    2014-07-01

    Norwegian heathland soils, although scant and shallow, are major reservoirs of carbon (C). We aimed at assessing whether vegetation cover and, indirectly, its driving factor soil drainage are good proxies for soil organic matter (SOM) composition and dynamics in a typical heathland area of Southern Norway consisting in a patchwork of three different types of vegetation, dominated by Calluna, Molinia, or Sphagnum. Such vegetation covers were clearly associated to microtopographic differences, which in turn dictated differences in soil moisture regime, Calluna growing in the driest sites, Sphagnum in the wettest, and Molinia in sites with intermediate moisture. Litter decomposition was followed over a period of 1 year, by placing litterbags filled with biomass from each dominant species under each type of vegetation cover. The composition of the living biomass, the bulk SOM and some extractable fractions of SOM were investigated by chemical methods and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Litter decomposition was faster for Molinia and Calluna, irrespective of the vegetation cover of the site where they were placed. Sphagnum litter decomposed very slowly, especially under Calluna, where the soil environment is by far more oxidising than under itself. In terms of SOM quality, Calluna covered areas showed the greatest differences from the others, in particular a much higher contribution from lipids and aliphatic biopolymers, apparently related to biomass composition. Our findings showed that in the studied environment litter decomposition rate and SOM composition are actually dependent on vegetation cover and/or soil drainage. On this basis, monitoring changes in the patchwork of vegetation types in boreal heathlands could be a reliable cost-effective way to account for modifications in the SOM potential to last induced by climate change.

  15. Why some plant species are rare.

    Science.gov (United States)

    Wieger Wamelink, G W; Wamelink, G W Weiger; Goedhart, Paul W; Frissel, Joep; Frissel, Josep Y

    2014-01-01

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

  16. SIS - Species and Stock Administrative Data Set

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Species and Stock Administrative data set within the Species Information System (SIS) defines entities within the database that serve as the basis for recording...

  17. Assessing Pesticides under the Endangered Species Act

    Science.gov (United States)

    EPA’s pesticide risk assessment and regulatory processes ensure that protections are in place for all populations of non-target species. We have developed risk assessment procedures to determine potential for harm to individuals of a listed species.

  18. Molecular Diagnosis of Pathogenic Sporothrix Species

    NARCIS (Netherlands)

    Rodrigues, Anderson Messias; de Hoog, G Sybren; de Camargo, Zoilo Pires

    2015-01-01

    BACKGROUND: Sporotrichosis is a chronic (sub)cutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species

  19. 76 FR 68776 - Invasive Species Advisory Committee

    Science.gov (United States)

    2011-11-07

    ... broad array of issues related to preventing the introduction of invasive species and providing for their...-2012 Invasive Species National Management Plan. The meeting is open to the public. An orientation...

  20. Species coextinctions and the biodiversity crisis.

    Science.gov (United States)

    Koh, Lian Pin; Dunn, Robert R; Sodhi, Navjot S; Colwell, Robert K; Proctor, Heather C; Smith, Vincent S

    2004-09-10

    To assess the coextinction of species (the loss of a species upon the loss of another), we present a probabilistic model, scaled with empirical data. The model examines the relationship between coextinction levels (proportion of species extinct) of affiliates and their hosts across a wide range of coevolved interspecific systems: pollinating Ficus wasps and Ficus, parasites and their hosts, butterflies and their larval host plants, and ant butterflies and their host ants. Applying a nomographic method based on mean host specificity (number of host species per affiliate species), we estimate that 6300 affiliate species are "coendangered" with host species currently listed as endangered. Current extinction estimates need to be recalibrated by taking species coextinctions into account.

  1. 77 FR 23740 - Invasive Species Advisory Committee

    Science.gov (United States)

    2012-04-20

    ... broad array of issues related to preventing the introduction of invasive species and providing for their... both ecological and management contexts, will center on topics that: (1) Pertain to invasive species...

  2. Endangered species toxicity extrapolation using ICE models

    Science.gov (United States)

    The National Research Council’s (NRC) report on assessing pesticide risks to threatened and endangered species (T&E) included the recommendation of using interspecies correlation models (ICE) as an alternative to general safety factors for extrapolating across species. ...

  3. Foliar flavonoids of nine species of Bauhinia

    OpenAIRE

    SALATINO, ANTONIO; BLATT, CECÍLIA T.T.; SANTOS, DÉBORAH Y.A.C. DOS; VAZ, ANGELA M.S.F.

    1999-01-01

    Foliar flavonoids of nine species of Bauhinia were isolated and identified. All the compounds correspond to glycosides derived from kaempferol, quercetin, isorhamnetin and myricetin. Derivatives of the latter aglyconhe seem to be rare in Bauhinia. Derivatives of isorhamnetin are commonly found in species of subgenus Bauhinia and were not detected in the two species of subgenus Phanera. Flavonoid patterns of species of the former subgenus are in general more complex than those of the latter. ...

  4. New species of Cystolepiota from China

    Directory of Open Access Journals (Sweden)

    Meng-Lin Xu

    2016-10-01

    Full Text Available In this paper, a new species, Cystolepiota pseudofumosifolia, is introduced. C. pseudofumosifolia is characterized by granulose or powdery pileus with an anatomic structure that is loosely globose, as well as ellipsoid cells in chains in the pileus covering the cheilocystidia. This new species is compared to the related and similar Cystolepiota species in morphology and molecular phylogeny based on Internal transcribed spacer sequences. Both types of data support our specimens as a new species in the genus Cystolepiota.

  5. Biodiversity in the cyclic competition system of three species according to the emergence of mutant species

    Science.gov (United States)

    Park, Junpyo

    2018-05-01

    Understanding mechanisms which promote or hinder existing ecosystems are important issues in ecological sciences. In addition to fundamental interactions such as competition and migration among native species, existing ecosystems can be easily disturbed by external factors, and the emergence of new species may be an example in such cases. The new species which does not exist in a current ecosystem can be regarded as either alien species entered from outside or mutant species born by mutation in existing normal species. Recently, as existing ecosystems are getting influenced by various physical/chemical external factors, mutation due to anthropogenic and environmental factors can occur more frequently and is thus attracting much attention for the maintenance of ecosystems. In this paper, we consider emergences of mutant species among self-competing three species in the cyclic dominance. By defining mutation as the birth of mutant species, we investigate how mutant species can affect biodiversity in the existing ecosystem. Through microscopic and macroscopic approaches, we have found that the society of existing normal species can be disturbed by mutant species either the society is maintained accompanying with the coexistence of all species or jeopardized by occupying of mutant species. Due to the birth of mutant species, the existing society may be more complex by constituting two different groups of normal and mutant species, and our results can be contributed to analyze complex ecosystems of many species. We hope our findings may propose a new insight on mutation in cyclic competition systems of many species.

  6. Linking Keystone Species and Functional Groups: A New Operational Definition of the Keystone Species Concept

    Directory of Open Access Journals (Sweden)

    Robert D. Davic

    2003-07-01

    Full Text Available The concept of the "keystone species" is redefined to allow for the a priori prediction of these species within ecosystems. A keystone species is held to be a strongly interacting species whose top-down effect on species diversity and competition is large relative to its biomass dominance within a functional group. This operational definition links the community importance of keystone species to a specific ecosystem process, e.g., the regulation of species diversity, within functional groups at lower trophic levels that are structured by competition for a limited resource. The a priori prediction of keystone species has applied value for the conservation of natural areas.

  7. Unimodal models to relate species to environment

    NARCIS (Netherlands)

    Braak, ter C.J.F.

    1987-01-01

    To assess the impact of environmental change on biological communities knowledge about species-environment relationships is indispensable. Ecologists attempt to uncover the relationships between species and environment from data obtained from field surveys. In the survey, species are scored on their

  8. 3 CFR - The Endangered Species Act

    Science.gov (United States)

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false The Endangered Species Act Presidential Documents Other Presidential Documents Memorandum of March 3, 2009 The Endangered Species Act Memorandum for the Heads of Executive Departments and Agencies The Endangered Species Act (ESA), 16 U.S.C. 1531 et seq...

  9. 75 FR 29359 - Invasive Species Advisory Committee

    Science.gov (United States)

    2010-05-25

    ... Council is co-chaired by the Secretary of the Interior, the Secretary of Agriculture, and the Secretary of... of the most invaded marine/coastal environments in the world, with over 50 invasive species that... development of state invasive species councils. DATES: Meeting of the Invasive Species Advisory Committee...

  10. Endangered Species & Biodiversity: A Classroom Project & Theme

    Science.gov (United States)

    Lauro, Brook

    2012-01-01

    Students discover the factors contributing to species losses worldwide by conducting a project about endangered species as a component of a larger classroom theme of biodiversity. Groups conduct research using online endangered- species databases and present results to the class using PowerPoint. Students will improve computer research abilities…

  11. The Gilbertiodendron ogoouense species complex (Leguminosae

    NARCIS (Netherlands)

    Burgt, van der X.M.; Mackinder, B.A.; Wieringa, J.J.; Estrella, de la Manuel

    2015-01-01

    The Gilbertiodendron ogoouense species complex consists of 14 tree species. Eight species are here newly described and one is here reinstated: G. bambolense Burgt; G. breteleri Burgt; G. ebo Burgt & Mackinder; G. ecoukense (Pellegr.) Burgt; G. maximum Burgt & Wieringa; G. minkebense Burgt

  12. Brachyspira Species and Gastroenteritis in Humans

    NARCIS (Netherlands)

    Westerman, L.J.; Boer, de R.F.; Roelfsema, J.H.; Friesema, I.H.M.; Kortbeek, L.M.; Wagenaar, J.A.; Bonten, M.J.M.; Kusters, J.G.

    2013-01-01

    Brachyspira species have been implicated as a potential cause of gastroenteritis in humans; this is, however, controversial. In 733 gastroenteritis cases and 464 controls, we found 29 samples positive for Brachyspira species (2.3% of cases and 2.6% of controls; P = 0.77). Brachyspira species were

  13. Brachyspira Species and Gastroenteritis in Humans

    NARCIS (Netherlands)

    Westerman, L J; de Boer, R F; Roelfsema, J H; Friesema, I H M; Kortbeek, L M; Wagenaar, J A; Bonten, M J M; Kusters, J G

    Brachyspira species have been implicated as a potential cause of gastroenteritis in humans; this is, however, controversial. In 733 gastroenteritis cases and 464 controls, we found 29 samples positive for Brachyspira species (2.3% of cases and 2.6% of controls; P = 0.77). Brachyspira species were

  14. 22 CFR 216.5 - Endangered species.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Endangered species. 216.5 Section 216.5 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ENVIRONMENTAL PROCEDURES § 216.5 Endangered species. It is A... endangered or threatened species and their critical habitats. The Initial Environmental Examination for each...

  15. Invasive Species Science Update (No. 7)

    Science.gov (United States)

    Dean Pearson; Yvette Ortega; Jack Butler

    2014-01-01

    Invasive Species Science Updates are designed to keep managers and other users up-to-date with recently completed and ongoing research by RMRS scientists, as well as highlight breaking news related to invasive species issues. The newsletter is produced by the RMRS Invasive Species Working Group (ISWG), which is a core group of scientists who volunteer to coordinate...

  16. Do invasive plant species alter soil health?

    Science.gov (United States)

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

  17. Options in dealing with marine alien species

    NARCIS (Netherlands)

    Pelt-Heerschap, van H.M.L.; Sneekes, A.C.; Foekema, E.M.

    2015-01-01

    Invasive species can have strong impact on the local ecosystem, not only substantial impact on the local ecosystem, but also on economy and human health. This review on marine alien species outlines aspects of prevention, eradication and control strategies. When managing invasive species, prevention

  18. Species rarity: definition, causes, and classification

    Science.gov (United States)

    Curtis H. Flather; Carolyn Hull Sieg

    2007-01-01

    In virtually all ecological communities around the world, most species are represented by few individuals, and most individuals come from only a few of the most common species. Why this distribution of species abundances is so regularly observed among different taxonomic sets in geographically diverse systems is a question that has received considerable theoretical and...

  19. New french uranium mineral species

    International Nuclear Information System (INIS)

    Branche, G.; Chervet, J.; Guillemin, C.

    1952-01-01

    In this work, the authors study the french new uranium minerals: parsonsite and renardite, hydrated phosphates of lead and uranium; kasolite: silicate hydrated of uranium and lead uranopilite: sulphate of uranium hydrated; bayleyite: carbonate of uranium and of hydrated magnesium; β uranolite: silicate of uranium and of calcium hydrated. For all these minerals, the authors give the crystallographic, optic characters, and the quantitative chemical analyses. On the other hand, the following species, very rare in the french lodgings, didn't permit to do quantitative analyses. These are: the lanthinite: hydrated uranate oxide; the α uranotile: silicate of uranium and of calcium hydrated; the bassetite: uranium phosphate and of hydrated iron; the hosphuranylite: hydrated uranium phosphate; the becquerelite: hydrated uranium oxide; the curite: oxide of uranium and lead hydrated. Finally, the authors present at the end of this survey a primary mineral: the brannerite, complex of uranium titanate. (author) [fr

  20. Satellite tracking of threatened species

    Science.gov (United States)

    Williams, M.; Lunsford, A.; Ellis, D.; Robinson, J.; Coronado, P.; Campbell, W.

    1998-01-01

    In 1990, a joint effort of two U.S. federal agencies, NASA Goddard Space Flight Center (GSFC) and the Patuxent Wildlife Research Center, began. We initially joined forces in a project that used satellite telemetry to discover the winter home of a tiny dwindling population of Siberian Cranes. Since then several projects have emerged, and a web site was created to follow some of these activities. This web site is called the Satellite Tracking of Threatened Species and its location is http://sdcd.gsfc.nasa.gov/ISTO/satellite_tracking. It describes the overall program, and links you to three subsections that describe the projects in more detail: Satellite Direct Readout, Birdtracks, and Birdworld.

  1. Ensemble forecasting of species distributions.

    Science.gov (United States)

    Araújo, Miguel B; New, Mark

    2007-01-01

    Concern over implications of climate change for biodiversity has led to the use of bioclimatic models to forecast the range shifts of species under future climate-change scenarios. Recent studies have demonstrated that projections by alternative models can be so variable as to compromise their usefulness for guiding policy decisions. Here, we advocate the use of multiple models within an ensemble forecasting framework and describe alternative approaches to the analysis of bioclimatic ensembles, including bounding box, consensus and probabilistic techniques. We argue that, although improved accuracy can be delivered through the traditional tasks of trying to build better models with improved data, more robust forecasts can also be achieved if ensemble forecasts are produced and analysed appropriately.

  2. Core-satellite species hypothesis and native versus exotic species in secondary succession

    Science.gov (United States)

    Martinez, Kelsey A.; Gibson, David J.; Middleton, Beth A.

    2015-01-01

    A number of hypotheses exist to explain species’ distributions in a landscape, but these hypotheses are not frequently utilized to explain the differences in native and exotic species distributions. The core-satellite species (CSS) hypothesis predicts species occupancy will be bimodally distributed, i.e., many species will be common and many species will be rare, but does not explicitly consider exotic species distributions. The parallel dynamics (PD) hypothesis predicts that regional occurrence patterns of exotic species will be similar to native species. Together, the CSS and PD hypotheses may increase our understanding of exotic species’ distribution relative to natives. We selected an old field undergoing secondary succession to study the CSS and PD hypotheses in conjunction with each other. The ratio of exotic to native species (richness and abundance) was observed through 17 years of secondary succession. We predicted species would be bimodally distributed and that exotic:native species ratios would remain steady or decrease through time under frequent disturbance. In contrast to the CSS and PD hypotheses, native species occupancies were not bimodally distributed at the site, but exotic species were. The exotic:native species ratios for both richness (E:Nrichness) and abundance (E:Ncover) generally decreased or remained constant throughout supporting the PD hypothesis. Our results suggest exotic species exhibit metapopulation structure in old field landscapes, but that metapopulation structures of native species are disrupted, perhaps because these species are dispersal limited in the fragmented landscape.

  3. The nuclear question: rethinking species importance in multi-species animal groups.

    Science.gov (United States)

    Srinivasan, Umesh; Raza, Rashid Hasnain; Quader, Suhel

    2010-09-01

    1. Animals group for various benefits, and may form either simple single-species groups, or more complex multi-species associations. Multi-species groups are thought to provide anti-predator and foraging benefits to participant individuals. 2. Despite detailed studies on multi-species animal groups, the importance of species in group initiation and maintenance is still rated qualitatively as 'nuclear' (maintaining groups) or 'attendant' (species following nuclear species) based on species-specific traits. This overly simplifies and limits understanding of inherently complex associations, and is biologically unrealistic, because species roles in multi-species groups are: (i) likely to be context-specific and not simply a fixed species property, and (ii) much more variable than this dichotomy indicates. 3. We propose a new view of species importance (measured as number of inter-species associations), along a continuum from 'most nuclear' to 'least nuclear'. Using mixed-species bird flocks from a tropical rainforest in India as an example, we derive inter-species association measures from randomizations on bird species abundance data (which takes into account species 'availability') and data on 86 mixed-species flocks from two different flock types. Our results show that the number and average strength of inter-species associations covary positively, and we argue that species with many, strong associations are the most nuclear. 4. From our data, group size and foraging method are ecological and behavioural traits of species that best explain nuclearity in mixed-species bird flocks. Parallels have been observed in multi-species fish shoals, in which group size and foraging method, as well as diet, have been shown to correlate with nuclearity. Further, the context in which multi-species groups occur, in conjunction with species-specific traits, influences the role played by a species in a multi-species group, and this highlights the importance of extrinsic factors in

  4. Ecological impacts of non-native species

    Science.gov (United States)

    Wilkinson, John W.

    2012-01-01

    Non-native species are considered one of the greatest threats to freshwater biodiversity worldwide (Drake et al. 1989; Allen and Flecker 1993; Dudgeon et al. 2005). Some of the first hypotheses proposed to explain global patterns of amphibian declines included the effects of non-native species (Barinaga 1990; Blaustein and Wake 1990; Wake and Morowitz 1991). Evidence for the impact of non-native species on amphibians stems (1) from correlative research that relates the distribution or abundance of a species to that of a putative non-native species, and (2) from experimental tests of the effects of a non-native species on survival, growth, development or behaviour of a target species (Kats and Ferrer 2003). Over the past two decades, research on the effects of non-native species on amphibians has mostly focused on introduced aquatic predators, particularly fish. Recent research has shifted to more complex ecological relationships such as influences of sub-lethal stressors (e.g. contaminants) on the effects of non-native species (Linder et al. 2003; Sih et al. 2004), non-native species as vectors of disease (Daszak et al. 2004; Garner et al. 2006), hybridization between non-natives and native congeners (Riley et al. 2003; Storfer et al. 2004), and the alteration of food-webs by non-native species (Nystrom et al. 2001). Other research has examined the interaction of non-native species in terms of facilitation (i.e. one non-native enabling another to become established or spread) or the synergistic effects of multiple non-native species on native amphibians, the so-called invasional meltdown hypothesis (Simerloff and Von Holle 1999). Although there is evidence that some non-native species may interact (Ricciardi 2001), there has yet to be convincing evidence that such interactions have led to an accelerated increase in the number of non-native species and cumulative impacts are still uncertain (Simberloff 2006). Applied research on the control, eradication, and

  5. Microbial species delineation using whole genome sequences.

    Science.gov (United States)

    Varghese, Neha J; Mukherjee, Supratim; Ivanova, Natalia; Konstantinidis, Konstantinos T; Mavrommatis, Kostas; Kyrpides, Nikos C; Pati, Amrita

    2015-08-18

    Increased sequencing of microbial genomes has revealed that prevailing prokaryotic species assignments can be inconsistent with whole genome information for a significant number of species. The long-standing need for a systematic and scalable species assignment technique can be met by the genome-wide Average Nucleotide Identity (gANI) metric, which is widely acknowledged as a robust measure of genomic relatedness. In this work, we demonstrate that the combination of gANI and the alignment fraction (AF) between two genomes accurately reflects their genomic relatedness. We introduce an efficient implementation of AF,gANI and discuss its successful application to 86.5M genome pairs between 13,151 prokaryotic genomes assigned to 3032 species. Subsequently, by comparing the genome clusters obtained from complete linkage clustering of these pairs to existing taxonomy, we observed that nearly 18% of all prokaryotic species suffer from anomalies in species definition. Our results can be used to explore central questions such as whether microorganisms form a continuum of genetic diversity or distinct species represented by distinct genetic signatures. We propose that this precise and objective AF,gANI-based species definition: the MiSI (Microbial Species Identifier) method, be used to address previous inconsistencies in species classification and as the primary guide for new taxonomic species assignment, supplemented by the traditional polyphasic approach, as required. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Alien species on the coasts of Turkey

    Directory of Open Access Journals (Sweden)

    M.E. CINAR

    2005-12-01

    Full Text Available The compilation of data on alien species reported from the Turkish coasts yielded a total of 263 species belonging to 11 systematic groups, of which Mollusca had the highest number of species (85 species, followed by Crustacea (51, fishes (43 and phytobenthos (39. The Black Sea is represented by a total of 20 alien species, the Sea of Marmara by 48 species, the Aegean Sea by 98 species and the Levantine Sea by 202 species. The majority of aliens found in the Black Sea and the Sea of Marmara were transported via shipping, whereas the Levantine coast is extensively subjected to Lessepsian migration. Benthic habitats (soft and hard substrata comprise 76% of the total alien species and the pelagic environment is inhabited by thirty-nine species. Almost 50% of aliens collected from the Turkish coasts were found only at 0-10 m depth. Eight species occur at depths deeper than 100 m. The impacts of aliens on the benthic and pelagic ecosystems are presented.

  7. Genomic definition of species. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Crkvenjakov, R.; Drmanac, R.

    1993-03-01

    A genome is the sum total of the DNA sequences in the cells of an individual organism. The common usage that species possess genomes comes naturally to biochemists, who have shown that all protein and nucleic acid molecules are at the same time species- and individual-specific, with minor individual variations being superimposed on a consensus sequence that is constant for a species. By extension, this property is attributed to the common features of DNA in the chromosomes of members of a given species and is called species genome. Our proposal for the definition of a biological species is as follows: A species comprises a group of actual and potential biological organisms built according to a unique genome program that is recorded, and at least in part expressed, in the structures of their genomic nucleic acid molecule(s), having intragroup sequence differences which can be fully interconverted in the process of organismal reproduction.

  8. Genomic definition of species. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Crkvenjakov, R.; Dramanac, R.

    1992-06-01

    A genome is the sum total of the DNA sequences in the cells of an individual organism. The common usage that species possess genomes comes naturally to biochemists, who have shown that all protein and nucleic acid molecules are at the same time species and individual-specific, with minor individual variations being superimposed on a consensus sequence that is constant for a species. By extension, this property is attributed to the common features of DNA in the chromosomes of members of a given species and is called (species) genome. The definition of species based on chromosomes, genes, or genome common to its member organisms has been implied or mentioned in passing numerous times. Some population biologists think that members of species have similar ``homeostatic genotypes,`` which are to a degree resistant to mutation or environmental change in the production of a basic phenotype.

  9. Sea Cucumber (Holothuroidea Species of Turkey

    Directory of Open Access Journals (Sweden)

    Mehmet AYDIN

    2016-11-01

    Full Text Available There are nearly 1200 sea cucumber species in the world oceans, while only 37 species from Holothuroidea class lives in the Mediterranean Sea. This preliminary study aims identification sea cucumbers species of the Turkish waters. The sea cucumber samples used in this study were obtained from a series of different studies between the years of 2008 and 2014. Identification of the species are mainly based on the morphometric characteristics while some of species are determined from their calcareous spicules. Eight sea species were identified in this research which are; Holothuria tubulosa, Holothuria polii, Holothuria mammata, Holothuria (Platyperona sanctori, Holothuria forskali, Stichopus regalis, Synaptula reciprocans and Stereoderma kirschbergi. There are limited number of studies in the literature focusing on the identification of the sea cucumber species spread in our seas. Therefore, this study is believed to play an important role in guiding future researches.

  10. Fisheries oceanography of northern pelagic fish species

    DEFF Research Database (Denmark)

    Tsoukali, Stavroula

    for marine organisms. One of the impacts will be the time that species start to spawn, and there is already evidence for earlier spawning in some North Sea fish species. A change like that may likely have a chain reaction, affecting larval stages and whether they will live in environments with high food...... of the species they consume now and increased availability of new species. In addition, there will likely be economic impacts on the local fishing communities. How species respond to climate change is a field of research that receives great attention because the responses will affect the management of fisheries......People are familiar with marine fish species and the great variety of different species that are available in the market, such as herring, cod and sole. What may not be well known is that every individual fish goes through a long, risky journey during its life before reaching maturity. Most...

  11. Four new species of Pteromalus Swederus (Hymenoptera: Chalcidoidea: Pteromalidae) and redescriptions of three other species

    NARCIS (Netherlands)

    Gijswijt, M.J.

    1999-01-01

    A key to the European species of the Pteromalus altus group is presented. The relationship between this group and species of the genus Euphorbia (Euphorbiaceae) is confirmed. One new species: P. villosae, associated with Euphorbia villosa Waldst. & Kit.is presented. Two new species of the albipennis

  12. Palpi aplenty: New species in the Chrysotus longipalpus species group (Diptera: Dolichopodidae)

    Science.gov (United States)

    Justin B. Runyon; Renato S. Capellari

    2018-01-01

    Four new Nearctic species belonging to the Chrysotus longipalpus species group are described: Chrysotus keyensis sp. nov. (Florida), Chrysotus mccreadiei sp. nov. (Alabama), Chrysotus mystax sp. nov. (Alabama), and Chrysotus plumarista sp. nov. (Alabama). This brings the number of known species in this group to twelve. A key to species of males of the C. longipalpus...

  13. A globally-distributed alien invasive species poses risks to United States imperiled species.

    Science.gov (United States)

    McClure, Meredith L; Burdett, Christopher L; Farnsworth, Matthew L; Sweeney, Steven J; Miller, Ryan S

    2018-03-28

    In the midst of Earth's sixth mass extinction event, non-native species are a driving factor in many imperiled species' declines. One of the most widespread and destructive alien invasive species in the world, wild pigs (Sus scrofa) threaten native species through predation, habitat destruction, competition, and disease transmission. We show that wild pigs co-occur with up to 87.2% of imperiled species in the contiguous U.S. identified as susceptible to their direct impacts, and we project increases in both the number of species at risk and the geographic extent of risks by 2025. Wild pigs may therefore present a severe threat to U.S. imperiled species, with serious implications for management of at-risk species throughout wild pigs' global distribution. We offer guidance for efficient allocation of research effort and conservation resources across species and regions using a simple approach that can be applied to wild pigs and other alien invasive species globally.

  14. Bacillus cereus and related species.

    Science.gov (United States)

    Drobniewski, F A

    1993-10-01

    Bacillus cereus is a gram-positive aerobic or facultatively anaerobic spore-forming rod. It is a cause of food poisoning, which is frequently associated with the consumption of rice-based dishes. The organism produces an emetic or diarrheal syndrome induced by an emetic toxin and enterotoxin, respectively. Other toxins are produced during growth, including phospholipases, proteases, and hemolysins, one of which, cereolysin, is a thiol-activated hemolysin. These toxins may contribute to the pathogenicity of B. cereus in nongastrointestinal disease. B. cereus isolated from clinical material other than feces or vomitus was commonly dismissed as a contaminant, but increasingly it is being recognized as a species with pathogenic potential. It is now recognized as an infrequent cause of serious nongastrointestinal infection, particularly in drug addicts, the immunosuppressed, neonates, and postsurgical patients, especially when prosthetic implants such as ventricular shunts are inserted. Ocular infections are the commonest types of severe infection, including endophthalmitis, panophthalmitis, and keratitis, usually with the characteristic formation of corneal ring abscesses. Even with prompt surgical and antimicrobial agent treatment, enucleation of the eye and blindness are common sequelae. Septicemia, meningitis, endocarditis, osteomyelitis, and surgical and traumatic wound infections are other manifestations of severe disease. B. cereus produces beta-lactamases, unlike Bacillus anthracis, and so is resistant to beta-lactam antibiotics; it is usually susceptible to treatment with clindamycin, vancomycin, gentamicin, chloramphenicol, and erythromycin. Simultaneous therapy via multiple routes may be required.

  15. Antibiotic resistance in Burkholderia species.

    Science.gov (United States)

    Rhodes, Katherine A; Schweizer, Herbert P

    2016-09-01

    The genus Burkholderia comprises metabolically diverse and adaptable Gram-negative bacteria, which thrive in often adversarial environments. A few members of the genus are prominent opportunistic pathogens. These include Burkholderia mallei and Burkholderia pseudomallei of the B. pseudomallei complex, which cause glanders and melioidosis, respectively. Burkholderia cenocepacia, Burkholderia multivorans, and Burkholderia vietnamiensis belong to the Burkholderia cepacia complex and affect mostly cystic fibrosis patients. Infections caused by these bacteria are difficult to treat because of significant antibiotic resistance. The first line of defense against antimicrobials in Burkholderia species is the outer membrane penetration barrier. Most Burkholderia contain a modified lipopolysaccharide that causes intrinsic polymyxin resistance. Contributing to reduced drug penetration are restrictive porin proteins. Efflux pumps of the resistance nodulation cell division family are major players in Burkholderia multidrug resistance. Third and fourth generation β-lactam antibiotics are seminal for treatment of Burkholderia infections, but therapeutic efficacy is compromised by expression of several β-lactamases and ceftazidime target mutations. Altered DNA gyrase and dihydrofolate reductase targets cause fluoroquinolone and trimethoprim resistance, respectively. Although antibiotic resistance hampers therapy of Burkholderia infections, the characterization of resistance mechanisms lags behind other non-enteric Gram-negative pathogens, especially ESKAPE bacteria such as Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Species longevity in North American fossil mammals.

    Science.gov (United States)

    Prothero, Donald R

    2014-08-01

    Species longevity in the fossil record is related to many paleoecological variables and is important to macroevolutionary studies, yet there are very few reliable data on average species durations in Cenozoic fossil mammals. Many of the online databases (such as the Paleobiology Database) use only genera of North American Cenozoic mammals and there are severe problems because key groups (e.g. camels, oreodonts, pronghorns and proboscideans) have no reliable updated taxonomy, with many invalid genera and species and/or many undescribed genera and species. Most of the published datasets yield species duration estimates of approximately 2.3-4.3 Myr for larger mammals, with small mammals tending to have shorter species durations. My own compilation of all the valid species durations in families with updated taxonomy (39 families, containing 431 genera and 998 species, averaging 2.3 species per genus) yields a mean duration of 3.21 Myr for larger mammals. This breaks down to 4.10-4.39 Myr for artiodactyls, 3.14-3.31 Myr for perissodactyls and 2.63-2.95 Myr for carnivorous mammals (carnivorans plus creodonts). These averages are based on a much larger, more robust dataset than most previous estimates, so they should be more reliable for any studies that need species longevity to be accurately estimated. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  17. A Theory of Flagship Species Action

    Directory of Open Access Journals (Sweden)

    Paul Jepson

    2015-01-01

    Full Text Available The flagship species approach is an enduring strategy in conservation. Academic discussion on flagship species has focussed on two dimensions: on what basis should they be selected and how have they been put to use. Here we consider a third dimension, namely the manner in which flagship species act and have the capacity to galvanise and influence conservation outcomes. Drawing on concepts from the social sciences, viz. affordance, framing, and actor-networks; we discuss examples of flagship species to propose a theory of flagship species action. In brief, our theory posits that a flagship species is one with traits that afford the assembly of relatively coherent networks of associations with ideational elements located in pre-existing cultural framings. These associations give rise to opportunities to align with deep cultural frames, contemporary cultural phenomena and political economy such that when a conservation action is introduced, forms of agency cause the species and human publics to change. The species becomes re-framed (or reinvigorated as a cultural asset speaking for a wider nature, publics and political agendas. Further our theory posits that species with traits that enrol in idea networks incorporating human fears, will have limited flagship capacity. This is because the ability of the representations produced to align with frames incorporating collective aspirations is constrained. In terms of applied conservation practice, our theory suggests that: a key criteria for selecting potential flagship species is presence in existing cultural frames, that effective deployment of flagship species requires an understanding of the species′ cultural associations, and a species ability to galvanise action may be limited to certain times and places. Furthermore, once deployed conservation interests will never have full control over the flagship species: it may act in uncertain and unexpected ways.

  18. Competition between species of small mammals

    International Nuclear Information System (INIS)

    Grant, P.R.

    1978-01-01

    Interspecific competition has often been inferred from its results. In evolutionary time it has been responsible for patterns of regularity in the structure of mammalian communities, and in the morphological and ecological characteristics of the constituent species. In contemporary time it gives rise to reciprocal (complementary) numbers and distributions of two or more species. These inferences are strengthened by recent experimental demonstrations of competition between species of North American rodents. Recent observations and experiments are reviewed. The most thoroughly studied competitors are two species of microtine rodents, Microtus pennsylvanicus and Clethrionomys gapperi. Species which compete for space have been studied experimentally more often than have food competitors. Overt aggression is frequently implicated, but its importance in nature in relation to other means of interaction (e.g. through vocal or scent communication) is not known. The definitive study of competition for food between mammal species has yet to be performed

  19. Radiation protection of non-human species

    International Nuclear Information System (INIS)

    Leith, I.S.

    1993-01-01

    The effects of radiation on non-human species, both animals and plants, have long been investigated. In the disposal of radioactive wastes, the protection of non-human species has been investigated. Yet no radiation protection standard for exposure of animals and plants per se has been agreed. The International Commission on Radiological Protection has long taken the view that, if human beings are properly protected from radiation, other species will thereby be protected to the extent necessary for their preservation. However, the International Atomic Energy Agency has found it necessary to investigate the protection of non-human species where radioactivity is released to an environment unpopulated by human beings. It is proposed that the basis of such protection, and the knowledge of radiation effects on non-human species on which it is based, suggest a practical radiation protection standard for non-human species. (1 tab.)

  20. On the Mass Distribution of Animal Species

    Science.gov (United States)

    Redner, Sidney; Clauset, Aaron; Schwab, David

    2009-03-01

    We develop a simple diffusion-reaction model to account for the broad and asymmetric distribution of adult body masses for species within related taxonomic groups. The model assumes three basic evolutionary features that control body mass: (i) a fixed lower limit that is set by metabolic constraints, (ii) a species extinction risk that is a weakly increasing function of body mass, and (iii) cladogenetic diffusion, in which daughter species have a slight tendency toward larger mass. The steady-state solution for the distribution of species masses in this model can be expressed in terms of the Airy function. This solution gives mass distributions that are in good agreement with data on 4002 terrestrial mammal species from the late Quaternary and 8617 extant bird species.

  1. Aging and immortality in unicellular species.

    Science.gov (United States)

    Florea, Michael

    2017-10-01

    It has been historically thought that in conditions that permit growth, most unicellular species do not to age. This was particularly thought to be the case for symmetrically dividing species, as such species lack a clear distinction between the soma and the germline. Despite this, studies of the symmetrically dividing species Escherichia coli and Schizosaccharomyces pombe have recently started to challenge this notion. They indicate that E. coli and S. pombe do age, but only when subjected to environmental stress. If true, this suggests that aging may be widespread among microbial species in general, and that studying aging in microbes may inform other long-standing questions in aging. This review examines the recent evidence for and against replicative aging in symmetrically dividing unicellular organisms, the mechanisms that underlie aging, why aging evolved in these species, and how microbial aging fits into the context of other questions in aging. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Costs Associated with Endangered Species Act Compliance

    Science.gov (United States)

    2013-08-01

    August 2013 2 on economic costs or values related to endangered species costs or values, focuses primarily on Contingent Valuation Method studies...of species preservation (Lew, Layton, and Rowe 2010; Wallmo 2006). Most studies consider public valuation of species preservation, and not costs of...2012, NMFS 2006, U.S. Army Engineer, Mississippi Valley Division 2012, Kozlowski 1993, PFMC 2002) and through development of expenditure categories

  3. The transformer species of the Ukrainian Polissya

    Directory of Open Access Journals (Sweden)

    Protopopova Vira V.

    2015-09-01

    Full Text Available The investigation results of the transformer species participation (Echinocystis lobata (Michx. Torr. & A. Gray, Heracleum sosnowskyi Manden., Impatiens glandulifera Royle, I. parviflora DC., Reynoutria japonica Houtt., Robinia pseudoacacia L. in different plant communities of the Ukrainian Polissya (Forest zone of Ukraine are presented. All the abovementioned species are strong edificators in the region that can significantly change important species composition parameters of communities and character of landscape.

  4. Species - San Diego Co. [ds121

    Data.gov (United States)

    California Natural Resource Agency — This is the Biological Observation Database point layer representing baseline observations of sensitive species (as defined by the MSCP) throughout San Diego County....

  5. Biological species in the viral world.

    Science.gov (United States)

    Bobay, Louis-Marie; Ochman, Howard

    2018-06-05

    Due to their dependence on cellular organisms for metabolism and replication, viruses are typically named and assigned to species according to their genome structure and the original host that they infect. But because viruses often infect multiple hosts and the numbers of distinct lineages within a host can be vast, their delineation into species is often dictated by arbitrary sequence thresholds, which are highly inconsistent across lineages. Here we apply an approach to determine the boundaries of viral species based on the detection of gene flow within populations, thereby defining viral species according to the biological species concept (BSC). Despite the potential for gene transfer between highly divergent genomes, viruses, like the cellular organisms they infect, assort into reproductively isolated groups and can be organized into biological species. This approach revealed that BSC-defined viral species are often congruent with the taxonomic partitioning based on shared gene contents and host tropism, and that bacteriophages can similarly be classified in biological species. These results open the possibility to use a single, universal definition of species that is applicable across cellular and acellular lifeforms.

  6. Use of species-specific PCR for the identification of 10 sea cucumber species

    Science.gov (United States)

    Wen, Jing; Zeng, Ling

    2014-11-01

    We developed a species-specific PCR method to identify species among dehydrated products of 10 sea cucumber species. Ten reverse species-specific primers designed from the 16S rRNA gene, in combination with one forward universal primer, generated PCR fragments of ca. 270 bp length for each species. The specificity of the PCR assay was tested with DNA of samples of 21 sea cucumber species. Amplification was observed in specific species only. The species-specific PCR method we developed was successfully applied to authenticate species of commercial products of dehydrated sea cucumber, and was proven to be a useful, rapid, and low-cost technique to identify the origin of the sea cucumber product.

  7. Relating species abundance distributions to species-area curves in two Mediterranean-type shrublands

    Science.gov (United States)

    Keeley, Jon E.

    2003-01-01

    Based on both theoretical and empirical studies there is evidence that different species abundance distributions underlie different species-area relationships. Here I show that Australian and Californian shrubland communities (at the scale from 1 to 1000 m2) exhibit different species-area relationships and different species abundance patterns. The species-area relationship in Australian heathlands best fits an exponential model and species abundance (based on both density and cover) follows a narrow log normal distribution. In contrast, the species-area relationship in Californian shrublands is best fit with the power model and, although species abundance appears to fit a log normal distribution, the distribution is much broader than in Australian heathlands. I hypothesize that the primary driver of these differences is the abundance of small-stature annual species in California and the lack of annuals in Australian heathlands. Species-area is best fit by an exponential model in Australian heathlands because the bulk of the species are common and thus the species-area curves initially rise rapidly between 1 and 100 m2. Annuals in Californian shrublands generate very broad species abundance distributions with many uncommon or rare species. The power function is a better model in these communities because richness increases slowly from 1 to 100 m2 but more rapidly between 100 and 1000 m2due to the abundance of rare or uncommon species that are more likely to be encountered at coarser spatial scales. The implications of this study are that both the exponential and power function models are legitimate representations of species-area relationships in different plant communities. Also, structural differences in community organization, arising from different species abundance distributions, may lead to different species-area curves, and this may be tied to patterns of life form distribution.

  8. Two new species of nocturnal bees of the genus Megalopta (Hymenoptera: Halictidae) with keys to species.

    Science.gov (United States)

    Gonzalez, Victor H; Griswold, Terry; Ayala, Ricardo

    2010-03-01

    Megalopta Smith, 1853, is a Neotropical genus of nocturnal or crepuscular bees. Two subgenera are recognized with most of its nearly 30 species placed in the nominate subgenus. Species of Megalopta s. str. are more commonly collected than species of Noctoraptor Engel et al. 1997, all presumably parasites of Megalopta s. str. Two new species of Megalopta are described here: M. (Megalopta) tetewana, n. sp., from Mexico and M. (Noctoraptor) huaoranii, n. sp., from Ecuador. Identification keys to the Central American species of Megalopta s. str. and the species of the parasitic subgenus Noctoraptor are presented.

  9. The species velocity of trees in Alaska

    Science.gov (United States)

    Morrison, B. D.; Napier, J.; de Lafontaine, G.; Heath, K.; Li, B.; Hu, F.; Greenberg, J. A.

    2017-12-01

    Anthropogenic climate change has motivated interest in the paleo record to enhance our knowledge about past vegetation responses to climate change and help understand potential responses in the future. Additionally, polar regions currently experience the most rapid rates of climate change globally, prompting concern over changes in the ecological composition of high latitude ecosystems. Recent analyses have attempted to construct methods to estimate a species' ability to track climate change by computing climate velocity; a measure of the rate of climate displacement across a landscape which may indicate the speed an organism must migrate to keep pace with climate change. However, a challenge to using climate velocity in understanding range shifts is a lack of species-specificity in the velocity calculations: climate velocity does not actually use any species data in its analysis. To solve the shortcomings of climate velocity in estimating species displacement rates, we computed the "species velocity" of white spruce, green and grey alder populations across the state of Alaska from the Last Glacial Maximum (LGM) to today. Species velocity represents the rate and direction a species is required to migrate to keep pace with a changing climate following the LGM. We used a species distribution model to determine past and present white spruce and alder distributions using statistically downscaled climate data at 60m. Species velocity was then derived from the change in species distribution per year by the change in distribution over Alaska (km/yr). High velocities indicate locations where the species environmental envelope is changing drastically and must disperse rapidly to survive climate change. As a result, high velocity regions are more vulnerable to distribution shifts and higher risk of local extinction. Conversely, low species velocities indicate locations where the local climate envelope is shifting relatively slowly, reducing the stress to disperse quickly

  10. Classification and dynamics of a Southern African subtropical coastal lowland forest

    CSIR Research Space (South Africa)

    Van Wyk, GF

    2006-01-01

    Full Text Available . Understorey composition in a particular community was often similar to the canopy composition in the next community in the hypothesized time sequence, than to the composition of its own canopy. Analysis of size-class distributions of canopy species for each...

  11. Evaluating species richness: biased ecological inference results from spatial heterogeneity in species detection probabilities

    Science.gov (United States)

    McNew, Lance B.; Handel, Colleen M.

    2015-01-01

    Accurate estimates of species richness are necessary to test predictions of ecological theory and evaluate biodiversity for conservation purposes. However, species richness is difficult to measure in the field because some species will almost always be overlooked due to their cryptic nature or the observer's failure to perceive their cues. Common measures of species richness that assume consistent observability across species are inviting because they may require only single counts of species at survey sites. Single-visit estimation methods ignore spatial and temporal variation in species detection probabilities related to survey or site conditions that may confound estimates of species richness. We used simulated and empirical data to evaluate the bias and precision of raw species counts, the limiting forms of jackknife and Chao estimators, and multi-species occupancy models when estimating species richness to evaluate whether the choice of estimator can affect inferences about the relationships between environmental conditions and community size under variable detection processes. Four simulated scenarios with realistic and variable detection processes were considered. Results of simulations indicated that (1) raw species counts were always biased low, (2) single-visit jackknife and Chao estimators were significantly biased regardless of detection process, (3) multispecies occupancy models were more precise and generally less biased than the jackknife and Chao estimators, and (4) spatial heterogeneity resulting from the effects of a site covariate on species detection probabilities had significant impacts on the inferred relationships between species richness and a spatially explicit environmental condition. For a real dataset of bird observations in northwestern Alaska, the four estimation methods produced different estimates of local species richness, which severely affected inferences about the effects of shrubs on local avian richness. Overall, our results

  12. Species-specific associations between overstory and understory tree species in a semideciduous tropical forest

    Directory of Open Access Journals (Sweden)

    Flaviana Maluf Souza

    2015-03-01

    Full Text Available We investigated the occurrence of associations between overstory and understory tree species in a semideciduous tropical forest. We identified and measured all trees of nine canopy species with diameter at breast height ≥4.8 cm in a 10.24 ha plot and recorded all individuals beneath their canopies ("understory individuals" within the same diameter class. The total density of understory individuals did not significantly differ under different overstory species. One overstory species (Ceiba speciosa showed higher understory species richness compared with five other species. There was a strong positive association between three overstory species (Esenbeckia leiocarpa, Savia dictyocarpa, and C. speciosa and the density of seven understory species (Balfourodendron riedelianum, Chrysophyllum gonocarpum, E. leiocarpa, Holocalyx balansae, Machaerium stipitatum, Rhaminidium elaeocarpum, and S. dictyocarpa. These results probably reflect the outcome of a complex set of interactions including facilitation and competition, and further studies are necessary to better understand the magnitude and type of the effects of individual overstory species on understory species. The occurrence of species-specific associations shown here reinforces the importance of non-random processes in structuring plant communities and suggest that the influence of overstory species on understory species in high-diversity forests may be more significant than previously thought.

  13. Effects of different nitrogen forms, ammonia gas and wet deposited ammonium and nitrate, on methane and nitrous oxide emissions from an ombrotrophic bog, Whim Moss, in the Scottish Borders

    OpenAIRE

    Sheppard, L. J.; Leith, I. D.; Field, C.; van Dijk, N.; Rung, M.; Skiba, U.

    2008-01-01

    Enhanced reactive nitrogen deposition may compromise the sustainability and functioning of bogs, with respect to carbon sequestration and greenhouse gas production. Since 2002, three N forms have been applied to an ombrotrophic bog growing Calluna, Sphagnum capillifolium and Eriophorum vaginatum in order to test this. Significant changes in species cover and soil chemistry, especially in response to elevated ammonia concentrations, have been recorded. Ammonia deposition has also increased nit...

  14. New Species of Orchids from Vietnam

    Directory of Open Access Journals (Sweden)

    Leonid V. Averyanov

    2007-12-01

    Full Text Available Identification of herbarium specimens collected in course of field exploration works in Vietnam during 2005-2007 revealed ten species of orchids new for science. Illustrated descriptions are provided for each discovered species, which are named as Anoectochilus papillosus, Arundina caespitosa, Bulbophyllum paraemarginatum, B. sinhoënse, Cheirostylis foliosa, Goodyera rhombodoides, Liparis rivularis, Oberonia multidentata, O. trichophora and Sunipia nigricans.

  15. Xanthomendoza borealis - a bipolar lichen species

    DEFF Research Database (Denmark)

    LIndblom, Louise; Søchting, Ulrik

    It has been uncertain whether the two xanthorioid taxa known as Xanthoria mawsonii and Xanthomen-doza borealis truly are distinct species or if they should best be treated as one species. They are morphologically very similar, but inhabit two disjunct geographical areas, that is, circumpolar on t...

  16. Rapid molecular technique to distinguish Fusarium species

    CSIR Research Space (South Africa)

    Lodolo, EJ

    1993-03-01

    Full Text Available The nuclear DNA (nDNA) of different isolates of three closely related, toxin-producing Fusarium species, F. moniliforme, F. nygamai and F. napiforme, was compared to ascertain the sensitivity of a molecular method to distinguish these three species...

  17. Antibiotic susceptibilities of Salmonella species prevalent among ...

    African Journals Online (AJOL)

    This study was conducted to assess the prevalence of Salmonella species among children having diarrhea in Katsina State, Nigeria. A total of 220 diarrhea stool samples of children aged five years and below (0-5 years) were collected and screened for Salmonella species using culture technique. Presumptively positive ...

  18. In vitro propagation of Fraxinus species

    Science.gov (United States)

    J.W. Van Sambeek; J.E. Preece

    2007-01-01

    The genus Fraxinus, a member of the Oleaceae family, includes over 65 ash species native to the temperate regions of the northern hemisphere (Miller, 1955). Several of the ash species are important forest trees noted for their tough, highly resistant to shock, straight grained wood as well as being excellent shade trees for parks and residential...

  19. Molecular characterization of thermophilic Campylobacter species ...

    African Journals Online (AJOL)

    We identified two species of thermophilic Campylobacter in companion dogs in Jos. Majority of C. jejuni were isolated from mucoid faeces while mixed infections of the two species were more common among diarrhoeic dogs. Pet owners should observe strict hand hygiene especially after handling dogs or their faeces to ...

  20. Two New American Species of Hordeum (Poaceae)

    DEFF Research Database (Denmark)

    Bothmer, Roland Von; Jacobsen, Niels; Bagger Jørgensen, Rikke

    1985-01-01

    Two new species of Hordeum are described, viz. the diploid H. erectifolium, native to Argentina, and H. guatemalense, native to Guatemala.......Two new species of Hordeum are described, viz. the diploid H. erectifolium, native to Argentina, and H. guatemalense, native to Guatemala....

  1. New and noteworthy Malesian species of Loranthaceae

    NARCIS (Netherlands)

    Barlow, Bryan A.

    1995-01-01

    Ten new or noteworthy Malesian species of Loranthaceae are discussed. The known area of the relictual Cecarria obtusifolia (Merrill) Barlow is increased to include Flores and Timor. Dendrophthoe curvata (Blume) Miquel is accepted as a distinct species. The status of Dendrophthoe falcata (L. f.)

  2. On two new species of Cercopithecus

    NARCIS (Netherlands)

    Jentink, F.A.

    1886-01-01

    In 1877 our Museum received a Cercopithecus died in the Zoological Garden at Rotterdam. Professor Schlegel thought it to be a new species and called it Cercopithecus signatus, but he never described it. As it seems to me to be a very good species I describe it under the name given by Schlegel. It

  3. Species diversity of Trichoderma in Poland

    Science.gov (United States)

    Fifteen species of Trichoderma were identified from among 118 strains originating from different regions and ecological niches in Poland. This low number indicates low species diversity of Trichoderma in this Central European region. Using the ITS1-ITS2 regions, 64 strains were positively identified...

  4. Prevalence of Cryptosporidium species and Giardia intestinalis ...

    African Journals Online (AJOL)

    Cryptosporidium species and Giardia intestinalis cause diarrheal infections in humans and other vertebrate animals globally and are considered to be of great public health importance. The study was conducted to determine the prevalence Cryptosporidium species and G. intestinalis infections among patients attending ...

  5. New species of haematozoa in Phalacrocoracidae and ...

    African Journals Online (AJOL)

    New species of haematozoa, namely Leucocytozoon ugwidi sp. nov. from the Cape Cormorant Phalacrocorax capensis and Haemoproteus skuae sp. nov. from the Subantarctic Skua Catharacta antarctica, are described. These are the first species to be recorded from the families Phalacrocoracidae and Stercorariidae, ...

  6. Metabolite production by differnt Ulocladium species

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Hollensted, Morten

    2008-01-01

    Ulocladium, which is phylogenetically related to Alternaria, contains species that are food spoilers and plant pathogens, but also species that have potential as enzyme producers and bio-control agents. Ulocladium spp. are often found on dead vegetation, in soil, air and dust, but also on food...

  7. Species hybridization in the genus Pinus

    Science.gov (United States)

    Peter W. Garrett

    1979-01-01

    Results of a breeding program in which a large number of pine species were tested indicate that a number of species and hybrids may be useful in the northeastern United States. Austrian black pine x Japanese black pine and hybrids containing Japanese red pine all had good growth rates. While none of the soft pines grew faster than eastern white pine, a number of...

  8. Toward reassessing data-deficient species.

    Science.gov (United States)

    Bland, Lucie M; Bielby, Jon; Kearney, Stephen; Orme, C David L; Watson, James E M; Collen, Ben

    2017-06-01

    One in 6 species (13,465 species) on the International Union for Conservation of Nature (IUCN) Red List is classified as data deficient due to lack of information on their taxonomy, population status, or impact of threats. Despite the chance that many are at high risk of extinction, data-deficient species are typically excluded from global and local conservation priorities, as well as funding schemes. The number of data-deficient species will greatly increase as the IUCN Red List becomes more inclusive of poorly known and speciose groups. A strategic approach is urgently needed to enhance the conservation value of data-deficient assessments. To develop this, we reviewed 2879 data-deficient assessments in 6 animal groups and identified 8 main justifications for assigning data-deficient status (type series, few records, old records, uncertain provenance, uncertain population status or distribution, uncertain threats, taxonomic uncertainty, and new species). Assigning a consistent set of justification tags (i.e., consistent assignment to assessment justifications) to species classified as data deficient is a simple way to achieve more strategic assessments. Such tags would clarify the causes of data deficiency; facilitate the prediction of extinction risk; facilitate comparisons of data deficiency among taxonomic groups; and help prioritize species for reassessment. With renewed efforts, it could be straightforward to prevent thousands of data-deficient species slipping unnoticed toward extinction. © 2016 Society for Conservation Biology.

  9. Preliminary observations on the species composition and ...

    African Journals Online (AJOL)

    Majority of the mushrooms appear during the rain season and are equally available during the short and long rains. This suggests that most species will grow well throughout the year whenever moisture level in the substrate is adequate irrespective of the season. Some of the species especially the Polypores (Ganoderma ...

  10. Taxonomy of Penicillium citrinum and related species

    NARCIS (Netherlands)

    Houbraken, J.; Frisvad, J.C.; Samson, R.A.

    2010-01-01

    Penicillium citrinum and related species have been examined using a combination of partial beta-tubulin, calmodulin and ITS sequence data, extrolite patterns and phenotypic characters. It is concluded that seven species belong to the series Citrina. Penicillium sizovae and Penicillium steckii are

  11. Some new or noteworthy species of Mortierella

    NARCIS (Netherlands)

    Gams, W.

    1976-01-01

    Twenty-two species of Mortierella are described and distributed over the sections defined by Gams (1970) which include the following new species: Section Pusilla: M. roseo-nana; Section Alpina: M. globalpina and M. polygonia Section Simplex: M. amoeboidea; Section Hygrophila : M. elongatula, M.

  12. DNA species surveillance: Monitoring bushmeat poaching and ...

    African Journals Online (AJOL)

    DNA species identification has applications in such areas as forensic science, systematics, conservation genetics and agriculture. One key anthropogenic activity threatening large wildlife fauna is illegal exploitation. In Kenya, species identification of raw and processed meat products remains a constraint to effective ...

  13. Distribution of crayfish species in Hungarian waters

    NARCIS (Netherlands)

    Mercédesz, Ludányi; Peeters, E.T.H.M.; Kiss, B.; Roessink, I.

    2016-01-01

    Three native crayfish species, i.e.~Astacus astacus, Astacus leptodactylus and Austropotamobius torrentium, occur in Hungary. Lately, however, non-indigenous crustaceans have also invaded the country Their most recent distribution and impact on the occurrences of the native species is not clear.

  14. Grain Unloading Of Arsenic Species In Rice

    Science.gov (United States)

    Rice (Oryza sativa) is the staple food for over half the world's population yet may represent a significant dietary source of inorganic arsenic (As), a nonthreshold, class 1 human carcinogen. Rice grain As is dominated by the inorganic species, and the organic species dim...

  15. SERI Aquatic Species Program: 1983 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    1984-03-01

    During 1983 research was carried out under three tasks: biological, engineering, and analysis. Biological research was aimed at screening for promising species of microalgae, macroalgae, and emergent plants that could be cultivated for energy products. Promising species were studied further to improve yields.

  16. ENDANGERED SPECIES SENSITIVITY AND ECOLOGICAL RISK ASSESSMENT

    Science.gov (United States)

    he U.S. Environmental Protection Agency (EPA), U.S. Fish & Wildlife Service, and National Marine Fisheries Service share a common responsibility for the protection of our nation's aquatic species under the Endangered Species Act (ESA) of 1973. The EPA, under the Federal Insectici...

  17. antimicrobial susceptibility pattern of Salmonella species

    African Journals Online (AJOL)

    user

    ABSTRACT. Treatment of enteric fever is increasingly becoming very challenging due to the increasing wave of antibiotic resistance. This study is a review of the contemporary antimicrobial susceptibility pattern of. Salmonella species. The antimicrobial susceptibility pattern of Salmonella species to a wide range of.

  18. Endangered Species (Plants). LC Science Tracer Bullet.

    Science.gov (United States)

    Niskern, Diana, Comp.

    This guide is intended for those who wish to study the literature dealing with various aspects of endangered plant species. This document includes the following sections, some of which are bibliographies: (1) "Introductions to the Topic"; (2) "Subject Headings" (for endangered species of plants used by the Library of Congress); (3) "General…

  19. Endangered Species: Real Life in Two Dimensions

    Science.gov (United States)

    Henderson, Lynette K.

    2012-01-01

    The focus of "Endangered Species: Real Life in Two Dimensions" is to create awareness about a critical environmental issue. There is a special urgency to this project because large numbers of animal species are currently endangered or on the brink of extinction. In addition to being enlightened about this important topic through research, students…

  20. Multiple bacterial species reside in chronic wounds

    DEFF Research Database (Denmark)

    Gjødsbøl, Kristine; Christensen, Jens Jørgen; Karlsmark, Tonny

    2006-01-01

    species present were identified. More than one bacterial species were detected in all the ulcers. The most common bacteria found were Staphylococcus aureus (found in 93.5% of the ulcers), Enterococcus faecalis (71.7%), Pseudomonas aeruginosa (52.2%), coagulase-negative staphylococci (45.7%), Proteus...

  1. Multiplexed microsatellite markers for seven Metarhizium species

    Science.gov (United States)

    Cross-species transferability of 41 previously published simple sequence repeat (SSR) markers was assessed for 11 species of the entomopathogenic fungus Metarhizium. A collection of 65 Metarhizium isolates including all 54 used in a recent phylogenetic revision of the genus were characterized. Betwe...

  2. The Invasive Plant Species Education Guide

    Science.gov (United States)

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

    2010-01-01

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

  3. The Drosophila bipectinata species complex: phylogenetic ...

    Indian Academy of Sciences (India)

    Navya

    *For Correspondence. e-mail: bashisthsingh2004@rediffmail.com, ... A species complex constitutes groups of closely related species which have diverged ..... there is a strong reproductive isolation too (See review by Singh and Banerjee 2016) .... figure both the loops touch the chromocenter and in our microphotograph ...

  4. CONSERVATION PROGRAMS THAT PROMOTE INVASIVE SPECIES

    Science.gov (United States)

    Invasive plant species are degrading the structure and function of ecosystems throughout the world. Although most state and federal conservation agencies in the U.S. attempt to reduce the impact of invasive species, some agency activities can contribute to the spread of invasive...

  5. Invasive plant species in hardwood tree plantations

    Science.gov (United States)

    Rochelle R. Beasley; Paula M. Pijut

    2010-01-01

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

  6. New species of Maerua (Capparaceae) from Angola

    NARCIS (Netherlands)

    Abreu, J.A.; Martins, E.S.; Catarino, L.

    2014-01-01

    Genus Maerua has around 60 species represented on the African continent, of which three have been reported for Angola. Two new species of Maerua (Capparaceae) from Angola are here described. Both are closely similar to M. juncea subsp. juncea, being distinguished by floral traits such as the

  7. 76 FR 30955 - Invasive Species Advisory Committee

    Science.gov (United States)

    2011-05-27

    ... Commerce. The duty of the Council is to provide national leadership regarding invasive species issues... broad array of issues related to preventing the introduction of invasive species and providing for their... with Western-based scientists and practitioners on problems and potential solutions, as well as...

  8. Fatal attraction: rare species in the spotlight.

    Science.gov (United States)

    Angulo, Elena; Deves, Anne-Laure; Saint Jalmes, Michel; Courchamp, Franck

    2009-04-07

    The exploitation of rare and endangered species can end in the species's extinction because the increased value people associate with rarity increases the economic incentive to exploit the last individuals, creating a positive feedback loop. This recently proposed concept, called the anthropogenic Allee effect (AAE), relies on the assumption that people do value rarity, but this remains to be established. Moreover, it also remains to be determined whether attraction to rarity is a trait confined to a minority of hobbyists (e.g. wildlife collectors, exotic pet owners) or characteristic of the general public. We estimated how much the general public valued rare species compared with common ones, using five different metrics related to personal investment: time spent, physical effort, unpleasantness, economic investment and risk. We surveyed the visitors of a zoo. To see the rare species, the visitors to the zoo invested more time in searching and contemplation, they were ready to expend more physical effort, they tolerated more unpleasant conditions, they were willing to pay more and, finally, they risked more to obtain (steal) a rare species. Our results provide substantial evidence of how the general public places more value on rare species, compared with common species. This confirms the AAE as an actual process, which in addition concerns a large part of the population. This has important consequences for the conservation of species that are rare now, or that could become so in the future.

  9. Characterization of Aspergillus species associated with ...

    African Journals Online (AJOL)

    About 82 triphala powder samples were analyzed for the association of different fungi. Results reveal the predominance of Aspergillus as the major genera with six predominant species namely, A. niger, A. flavus, A. fumigatus, A. terreus, A. nidulans and A. amstelodami. Therefore, these six isolated Aspergillus species were ...

  10. Novel Pestivirus Species in Pigs, Austria, 2015.

    Science.gov (United States)

    Lamp, Benjamin; Schwarz, Lukas; Högler, Sandra; Riedel, Christiane; Sinn, Leonie; Rebel-Bauder, Barbara; Weissenböck, Herbert; Ladinig, Andrea; Rümenapf, Till

    2017-07-01

    A novel pestivirus species was discovered in a piglet-producing farm in Austria during virologic examinations of congenital tremor cases. The emergence of this novel pestivirus species, provisionally termed Linda virus, in domestic pigs may have implications for classical swine fever virus surveillance and porcine health management.

  11. Emergent neutrality drives phytoplankton species coexistence

    Science.gov (United States)

    Segura, Angel M.; Calliari, Danilo; Kruk, Carla; Conde, Daniel; Bonilla, Sylvia; Fort, Hugo

    2011-01-01

    The mechanisms that drive species coexistence and community dynamics have long puzzled ecologists. Here, we explain species coexistence, size structure and diversity patterns in a phytoplankton community using a combination of four fundamental factors: organism traits, size-based constraints, hydrology and species competition. Using a ‘microscopic’ Lotka–Volterra competition (MLVC) model (i.e. with explicit recipes to compute its parameters), we provide a mechanistic explanation of species coexistence along a niche axis (i.e. organismic volume). We based our model on empirically measured quantities, minimal ecological assumptions and stochastic processes. In nature, we found aggregated patterns of species biovolume (i.e. clumps) along the volume axis and a peak in species richness. Both patterns were reproduced by the MLVC model. Observed clumps corresponded to niche zones (volumes) where species fitness was highest, or where fitness was equal among competing species. The latter implies the action of equalizing processes, which would suggest emergent neutrality as a plausible mechanism to explain community patterns. PMID:21177680

  12. Finessing atlas data for species distribution models

    NARCIS (Netherlands)

    Niamir, A.; Skidmore, A.K.; Toxopeus, A.G.; Munoz, A.R.; Real, R.

    2011-01-01

    Aim The spatial resolution of species atlases and therefore resulting model predictions are often too coarse for local applications. Collecting distribution data at a finer resolution for large numbers of species requires a comprehensive sampling effort, making it impractical and expensive. This

  13. 77 FR 70456 - Receipt of Applications for Endangered Species Permits

    Science.gov (United States)

    2012-11-26

    ...: TE-13844A Applicant: Aquatic Resources Management, Lexington, Kentucky. Applicant requests amendment... fish species, twelve (12) fresh-water mussel species, one (1) snake species, one (1) insect species and...

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

    Science.gov (United States)

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

  15. Biodiversity hotspots house most undiscovered plant species.

    Science.gov (United States)

    Joppa, Lucas N; Roberts, David L; Myers, Norman; Pimm, Stuart L

    2011-08-09

    For most organisms, the number of described species considerably underestimates how many exist. This is itself a problem and causes secondary complications given present high rates of species extinction. Known numbers of flowering plants form the basis of biodiversity "hotspots"--places where high levels of endemism and habitat loss coincide to produce high extinction rates. How different would conservation priorities be if the catalog were complete? Approximately 15% more species of flowering plant are likely still undiscovered. They are almost certainly rare, and depending on where they live, suffer high risks of extinction from habitat loss and global climate disruption. By using a model that incorporates taxonomic effort over time, regions predicted to contain large numbers of undiscovered species are already conservation priorities. Our results leave global conservation priorities more or less intact, but suggest considerably higher levels of species imperilment than previously acknowledged.

  16. New species in Aspergillus section Terrei

    DEFF Research Database (Denmark)

    Samson, R. A.; Peterson, S. W.; Frisvad, Jens Christian

    2011-01-01

    . clade including the type isolate of A. niveus (CBS 115.27) constitutes a lineage closely related to A. carneus. Fennellia nivea, the hypothesized teleomorph is not related to this clade. Aspergillus allahabadii, A. niveus var. indicus, and two species originally placed in section Versicolores, A......Section Terrei of Aspergillus was studied using a polyphasic approach including sequence analysis of parts of the beta-tubulin and calmodulin genes and the ITS region, macro- and micromorphological analyses and examination of extrolite profiles to describe three new species in this section. Based....... floccosus, A. terreus var. africanus, A. terreus var. aureus, while Aspergillus hortai is recognised at species level. Aspergillus terreus NRRL 4017 is described as the new species A. pseudoterreus. Also included in section Terrei are some species formerly placed in sections Flavipedes and Versicolores. A...

  17. Actinomyces Species Isolated from Breast Infections

    Science.gov (United States)

    Loh, S. F.; Morris, T.; Hughes, H.; Dixon, J. M.

    2015-01-01

    Actinomycosis is a chronic infection caused by Actinomyces species characterized by abscess formation, tissue fibrosis, and draining sinuses. The spectrum of infections caused by Actinomyces species ranges from classical invasive actinomycosis to a less invasive form of superficial skin and soft tissue infection. We present a review detailing all Actinomyces species isolated from breast infections in NHS Lothian between 2005 and 2013, Actinomyces species isolated from breast infections referred to the United Kingdom Anaerobe Reference Unit between 1988 and 2014, and cases describing Actinomyces breast infections published in the medical literature since 1994. Actinomyces species are fastidious organisms which can be difficult to identify and are likely to be underascertained as a cause of breast infections. Due to improved diagnostic methods, they are increasingly associated with chronic, recurrent breast infections and may play a more significant role in these infections than has previously been appreciated. PMID:26224846

  18. Region effects influence local tree species diversity.

    Science.gov (United States)

    Ricklefs, Robert E; He, Fangliang

    2016-01-19

    Global patterns of biodiversity reflect both regional and local processes, but the relative importance of local ecological limits to species coexistence, as influenced by the physical environment, in contrast to regional processes including species production, dispersal, and extinction, is poorly understood. Failure to distinguish regional influences from local effects has been due, in part, to sampling limitations at small scales, environmental heterogeneity within local or regional samples, and incomplete geographic sampling of species. Here, we use a global dataset comprising 47 forest plots to demonstrate significant region effects on diversity, beyond the influence of local climate, which together explain more than 92% of the global variation in local forest tree species richness. Significant region effects imply that large-scale processes shaping the regional diversity of forest trees exert influence down to the local scale, where they interact with local processes to determine the number of coexisting species.

  19. The Porphyra species of Helgoland (Bangiales, Rhodophyta)

    Science.gov (United States)

    Kornmann, P.; Sahling, P.-H.

    1991-03-01

    This revision of seven Porphyra species of Helgoland was based on a study of the structure of their fertile thalli and the behaviour of their spores. Regarding the reproductive organization the species may be arranged in two groups. P. leucosticta and P. purpureo-violacea are obligate monoecious species. Asexual thalli have never been observed in the field. The other five species are generally dioecious. Isomorphic sexual thalli and asexually propagating ones are mixed in uniform populations. Carpospores originating from sexual fusion develop into the diploid Conchocelis phase. Sporangia of asexual plants, though homologous in formation, produce spores of different kinds: aplanospores that give rise to the vegetative thallus directly (in P. umbilicalis, P. insolita n. sp. and P. ochotensis) and spores that develop into haploid Conchocelis (in P. laciniata and in P. linearis). P. laciniata — formerly considered synonymous with P. purpurea — is an independent species.

  20. Stand-level variation in evapotranspiration in non-water-limited eucalypt forests

    Science.gov (United States)

    Benyon, Richard G.; Nolan, Rachael H.; Hawthorn, Sandra N. D.; Lane, Patrick N. J.

    2017-08-01

    To better understand water and energy cycles in forests over years to decades, measurements of spatial and long-term temporal variability in evapotranspiration (Ea) are needed. In mountainous terrain, plot-level measurements are important to achieving this. Forest inventory data including tree density and size measurements, often collected repeatedly over decades, sample the variability occurring within the geographic and topographic range of specific forest types. Using simple allometric relationships, tree stocking and size data can be used to estimate variables including sapwood area index (SAI), which may be strongly correlated with annual Ea. This study analysed plot-level variability in SAI and its relationship with overstorey and understorey transpiration, interception and evaporation over a 670 m elevation gradient, in non-water-limited, even-aged stands of Eucalyptus regnans F. Muell. to determine how well spatial variation in annual Ea from forests can be mapped using SAI. Over the 3 year study, mean sap velocity in five E. regnans stands was uncorrelated with overstorey sapwood area index (SAI) or elevation: annual transpiration was predicted well by SAI (R2 0.98). Overstorey and total annual interception were positively correlated with SAI (R2 0.90 and 0.75). Ea from the understorey was strongly correlated with vapour pressure deficit (VPD) and net radiation (Rn) measured just above the understorey, but relationships between understorey Ea and VPD and Rn differed between understorey types and understorey annual Ea was not correlated with SAI. Annual total Ea was also strongly correlated with SAI: the relationship being similar to two previous studies in the same region, despite differences in stand age and species. Thus, spatial variation in annual Ea can be reliably mapped using measurements of SAI.

  1. Effects of species' characteristics on nongovernmental organizations' attitudes toward species conservation policy

    NARCIS (Netherlands)

    Knegtering, E; Hendrickx, L.C W P; van der Windt, H.J.; Schoot Uiterkamp, A.J.M.

    The authors examined the willingness of nongovernmental organizations (NGOs) to support public species conservation measures as a function of species characteristics, NGOs' interests, and interests harmed by the measures. In an experiment, 39 policy makers from nature conservation, mobility and

  2. ConSpeciFix: Classifying prokaryotic species based on gene flow.

    Science.gov (United States)

    Bobay, Louis-Marie; Ellis, Brian Shin-Hua; Ochman, Howard

    2018-05-16

    Classification of prokaryotic species is usually based on sequence similarity thresholds, which are easy to apply but lack a biologically-relevant foundation. Here, we present ConSpeciFix, a program that classifies prokaryotes into species using criteria set forth by the Biological Species Concept, thereby unifying species definition in all domains of life. ConSpeciFix's webserver is freely available at www.conspecifix.com. The local version of the program can be freely downloaded from https://github.com/Bobay-Ochman/ConSpeciFix. ConSpeciFix is written in Python 2.7 and requires the following dependencies: Usearch, MCL, MAFFT and RAxML. ljbobay@uncg.edu.

  3. Genetic sorting of subordinate species in grassland modulated by intraspecific variation in dominant species.

    Directory of Open Access Journals (Sweden)

    Danny J Gustafson

    Full Text Available Genetic variation in a single species can have predictable and heritable effects on associated communities and ecosystem processes, however little is known about how genetic variation of a dominant species affects plant community assembly. We characterized the genetic structure of a dominant grass (Sorghastrum nutans and two subordinate species (Chamaecrista fasciculata, Silphium integrifolium, during the third growing season in grassland communities established with genetically distinct (cultivated varieties or local ecotypes seed sources of the dominant grasses. There were genetic differences between subordinate species growing in the cultivar versus local ecotype communities, indicating that intraspecific genetic variation in the dominant grasses affected the genetic composition of subordinate species during community assembly. A positive association between genetic diversity of S. nutans, C. fasciculata, and S. integrifolium and species diversity established the role of an intraspecific biotic filter during community assembly. Our results show that intraspecific variation in dominant species can significantly modulate the genetic composition of subordinate species.

  4. New species of Moenkhausia Eigenmann, 1903 (Characiformes: Characidae with comments on the Moenkhausia oligolepis species complex

    Directory of Open Access Journals (Sweden)

    Ricardo C. Benine

    Full Text Available A new species of Moenkhausia is described from tributaries of the rio Paraguay, Brazil. The new species is diagnosed from congeners by characters related to body coloration, the number of lateral line scales, the degree of poring of the lateral line, and number of scales rows above and below the lateral line. Molecular analyses using partial sequences of the mitochondrial gene Cytochrome Oxidase I from specimens of the new species and specimens belonging to morphologically similar species demonstrated that the new species is easily differentiated by their high genetic distance and by their position in the phylogenetic hypothesis obtained through the Maximum Parsimony methodology. The analyses of three samples of M. oligolepis also revealed that they have high genetic distances and belong to different monophyletic groups suggesting that this species corresponds to a species complex rather than a single species.

  5. 75 FR 38069 - Injurious Wildlife Species; Listing the Boa Constrictor, Four Python Species, and Four Anaconda...

    Science.gov (United States)

    2010-07-01

    ... Python Species, and Four Anaconda Species as Injurious Reptiles AGENCY: Fish and Wildlife Service... regulations to add Indian python (Python molurus, including Burmese python Python molurus bivittatus), reticulated python (Broghammerus reticulatus or Python reticulatus), Northern African python (Python sebae...

  6. Spatial Complementarity and the Coexistence of Species

    Science.gov (United States)

    Velázquez, Jorge; Garrahan, Juan P.; Eichhorn, Markus P.

    2014-01-01

    Coexistence of apparently similar species remains an enduring paradox in ecology. Spatial structure has been predicted to enable coexistence even when population-level models predict competitive exclusion if it causes each species to limit its own population more than that of its competitor. Nevertheless, existing hypotheses conflict with regard to whether clustering favours or precludes coexistence. The spatial segregation hypothesis predicts that in clustered populations the frequency of intra-specific interactions will be increased, causing each species to be self-limiting. Alternatively, individuals of the same species might compete over greater distances, known as heteromyopia, breaking down clusters and opening space for a second species to invade. In this study we create an individual-based model in homogeneous two-dimensional space for two putative sessile species differing only in their demographic rates and the range and strength of their competitive interactions. We fully characterise the parameter space within which coexistence occurs beyond population-level predictions, thereby revealing a region of coexistence generated by a previously-unrecognised process which we term the triadic mechanism. Here coexistence occurs due to the ability of a second generation of offspring of the rarer species to escape competition from their ancestors. We diagnose the conditions under which each of three spatial coexistence mechanisms operates and their characteristic spatial signatures. Deriving insights from a novel metric — ecological pressure — we demonstrate that coexistence is not solely determined by features of the numerically-dominant species. This results in a common framework for predicting, given any pair of species and knowledge of the relevant parameters, whether they will coexist, the mechanism by which they will do so, and the resultant spatial pattern of the community. Spatial coexistence arises from complementary combinations of traits in each

  7. Neosilba (Tephritoidea: Lonchaeidae) species reared from coffee in Brazil, with description of a new species

    Energy Technology Data Exchange (ETDEWEB)

    Striki, Pedro Carlos; Prado, Angelo Pires do, E-mail: apprado@unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Biologia. Dept. de Parasitologia

    2006-07-01

    Neosilba species are believed to be secondary invaders of fruit, so, little attention has been paid to its presence in coffee fruits. In this article we present a key to Neosilba species present in coffee fruits and describe a new species that is considered a primary invader. We hope this will help researchers working with coffee fruits to better quantify the economic importance of Neosilba species associated with coffee fruits. (author)

  8. Neosilba (Tephritoidea: Lonchaeidae) species reared from coffee in Brazil, with description of a new species

    International Nuclear Information System (INIS)

    Striki, Pedro Carlos; Prado, Angelo Pires do

    2006-01-01

    Neosilba species are believed to be secondary invaders of fruit, so, little attention has been paid to its presence in coffee fruits. In this article we present a key to Neosilba species present in coffee fruits and describe a new species that is considered a primary invader. We hope this will help researchers working with coffee fruits to better quantify the economic importance of Neosilba species associated with coffee fruits. (author)

  9. Two new species of nocturnal bees of the genus Megalopta (Hymenoptera: Halictidae) with keys to species

    OpenAIRE

    Gonzalez, Victor H; Griswold, Terry; Ayala, Ricardo

    2010-01-01

    Megalopta Smith, 1853, is a Neotropical genus of nocturnal or crepuscular bees. Two subgenera are recognized with most of its nearly 30 species placed in the nominate subgenus. Species of Megalopta s. str. are more commonly collected than species of Noctoraptor Engel et al. 1997, all presumably parasites of Megalopta s. str. Two new species of Megalopta are described here: M. (Megalopta) tetewana, n. sp., from Mexico and M. (Noctoraptor) huaoranii, n. sp., from Ecuador. Identification keys to...

  10. Dna c-values of 20 invasive alien species and 3 native species in south china

    OpenAIRE

    Gong Ni; Wang Yu-Tao; Björn Lars Olof; Li Shao-Shan

    2014-01-01

    Cultivated fields and forests in South China are experiencing serious damage due to invasive alien plants. We investigated the relation between DNA C-values and invasiveness. The DNA C-values of 23 species ranged from 0.39 pg to 3.37 pg. Herbs, perennials and native species had higher mean DNA C-values than shrubs, annuals and invasive alien species. DNA C-values decreased with increasing invasiveness. Paederia scandens, a harmful native species, has the lo...

  11. Invading species in the Eel River, California: Successes, failures, and relationships with resident species

    Science.gov (United States)

    Brown, L.R.; Moyle, P.B.

    1997-01-01

    We examined invasions of non-native fishes into the Eel River, California. At least 16 species of fish have been introduced into the drainage which originally supported 12-14 fish species. Our study was prompted by the unauthorized introduction in 1979 of Sacramento squawfish, Ptychocheilus grandis, a large predatory cyprinid. From 1986 to 1990, we conducted growth and diet studies of squaw fish, conducted intensive surveys of the distribution and habitat associations of both native and introduced species, and examined the nature of species-habitat and interspecies relationships. We found no evidence for increased growth or expanded feeding habits, compared to native populations, of Sacramento squawfish as they invaded the Eel River drainage. Ten of the introduced species were well established, with four species limited to a reservoir and six species established in streams. The success or failure of introductions of stream species appeared to be a function of the ability of a species to survive the fluctuating, highly seasonal, flow regime. The present mixture of native and exotic species has not formed stable fish assemblages but it seems likely that four habitat-associated assemblages will develop. The overall effect of the successful species introductions has been to assemble a group of species, with some exceptions, that are native to and occur together in many California streams. The assemblages now forming are similar to those found in other California streams. The assemblage characterized by squawfish and suckers is likely to be resistant to invasion, in the absence of human caused habitat modifications.

  12. Rare species contribute disproportionately to the functional structure of species assemblages.

    Science.gov (United States)

    Leitão, Rafael P; Zuanon, Jansen; Villéger, Sébastien; Williams, Stephen E; Baraloto, Christopher; Fortunel, Claire; Mendonça, Fernando P; Mouillot, David

    2016-04-13

    There is broad consensus that the diversity of functional traits within species assemblages drives several ecological processes. It is also widely recognized that rare species are the first to become extinct following human-induced disturbances. Surprisingly, however, the functional importance of rare species is still poorly understood, particularly in tropical species-rich assemblages where the majority of species are rare, and the rate of species extinction can be high. Here, we investigated the consequences of local and regional extinctions on the functional structure of species assemblages. We used three extensive datasets (stream fish from the Brazilian Amazon, rainforest trees from French Guiana, and birds from the Australian Wet Tropics) and built an integrative measure of species rarity versus commonness, combining local abundance, geographical range, and habitat breadth. Using different scenarios of species loss, we found a disproportionate impact of rare species extinction for the three groups, with significant reductions in levels of functional richness, specialization, and originality of assemblages, which may severely undermine the integrity of ecological processes. The whole breadth of functional abilities within species assemblages, which is disproportionately supported by rare species, is certainly critical in maintaining ecosystems particularly under the ongoing rapid environmental transitions. © 2016 The Author(s).

  13. Protectiveness of Species Sensitivity Distribution Hazard Concentrations for Acute Toxicity Used in Endangered Species Risk Assessment

    Science.gov (United States)

    A primary objective of threatened and endangered species conservation is to ensure that chemical contaminants and other stressors do not adversely affect listed species. Assessments of the ecological risks of chemical exposures to listed species often rely on the use of surrogate...

  14. Tree structural and species diversities in Okwangwo Forest, Cross ...

    African Journals Online (AJOL)

    Tree species were grouped into abundance classes. A total of 125 tree species belonging to 36 families and 96 genera were recorded in the area with Margaleffs index of species richness of 2.2754. Most (99) of the tree species encountered were threatened/endangered, 23 species were rare with only 3 tree species ...

  15. Estimating tree species richness from forest inventory plot data

    Science.gov (United States)

    Ronald E. McRoberts; Dacia M. Meneguzzo

    2007-01-01

    Montreal Process Criterion 1, Conservation of Biological Diversity, expresses species diversity in terms of number of forest dependent species. Species richness, defined as the total number of species present, is a common metric for analyzing species diversity. A crucial difficulty in estimating species richness from sample data obtained from sources such as inventory...

  16. Identifying ambassador species for conservation marketing

    Directory of Open Access Journals (Sweden)

    E.A. Macdonald

    2017-10-01

    Full Text Available Conservation relies heavily on external funding, much of it from a supportive public. Therefore it is important to know which species are most likely to catalyse such funding. Whilst previous work has looked at the physical attributes that contribute to a species' appeal, no previous studies have tried to examine the extent to which a species' sympatriots might contribute to it's potential as flagship for wider conservation. Therefore, here we estimate ‘flexibility’ and ‘appeal’ scores for all terrestrial mammals (n = 4320 and identify which of these might serve as ambassadors (defined as both highly appealing and flexible. Relatively few mammals (between 240 and 331 emerged as ambassadors, with carnivores featuring heavily in this group (representing 5% of terrestrial mammals but 39% of ambassadors. ‘Top ambassadors’ were defined as those with both flexibility and appeal scores greater than 1 standard deviation above the mean. Less than a quarter of the 20 most endangered and evolutionary distinct species in this study were classed as ambassadors, highlighting the need for surrogate species to catalyse conservation effort in areas with such priority species. This is the first global analysis bringing together flexibility and appeal for all terrestrial mammals, and demonstrates an approach for determining how best to market species in order to achieve maximal conservation gain in a world with urgent conservation need but limited resources.

  17. Design and construction of "synthetic species".

    Directory of Open Access Journals (Sweden)

    Eduardo Moreno

    Full Text Available Synthetic biology is an area of biological research that combines science and engineering. Here, I merge the principles of synthetic biology and regulatory evolution to create a new species with a minimal set of known elements. Using preexisting transgenes and recessive mutations of Drosophila melanogaster, a transgenic population arises with small eyes and a different venation pattern that fulfils the criteria of a new species according to Mayr's Biological Species Concept. The population described here is the first transgenic organism that cannot hybridize with the original wild type population but remains fertile when crossed with other identical transgenic animals. I therefore propose the term "synthetic species" to distinguish it from "natural species", not only because it has been created by genetic manipulation, but also because it may never be able to survive outside the laboratory environment. The use of genetic engineering to design artificial species barriers could help us understand natural speciation and may have practical applications. For instance, the transition from transgenic organisms towards synthetic species could constitute a safety mechanism to avoid the hybridization of genetically modified animals with wild type populations, preserving biodiversity.

  18. Fusarium Species and Their Associated Mycotoxins.

    Science.gov (United States)

    Munkvold, Gary P

    2017-01-01

    The genus Fusarium includes numerous toxigenic species that are pathogenic to plants or humans, and are able to colonize a wide range of environments on earth. The genus comprises around 70 well-known species, identified by using a polyphasic approach, and as many as 300 putative species, according to phylogenetic species concepts; many putative species do not yet have formal names. Fusarium is one of the most economically important fungal genera because of yield loss due to plant pathogenic activity; mycotoxin contamination of food and feed products which often render them unaccep for marketing; and health impacts to humans and livestock, due to consumption of mycotoxins. Among the most important mycotoxins produced by species of Fusarium are the trichothecenes and the fumonisins. Fumonisins cause fatal livestock diseases and are considered potentially carcinogenic mycotoxins for humans, while trichothecenes are potent inhibitors of protein synthesis. This chapter summarizes the main aspects of morphology, pathology, and toxigenicity of the main Fusarium species that colonize different agricultural crops and environments worldwide, and cause mycotoxin contamination of food and feed.

  19. Species coexistence in a changing world.

    Science.gov (United States)

    Valladares, Fernando; Bastias, Cristina C; Godoy, Oscar; Granda, Elena; Escudero, Adrián

    2015-01-01

    The consequences of global change for the maintenance of species diversity will depend on the sum of each species responses to the environment and on the interactions among them. A wide ecological literature supports that these species-specific responses can arise from factors related to life strategies, evolutionary history and intraspecific variation, and also from environmental variation in space and time. In the light of recent advances from coexistence theory combined with mechanistic explanations of diversity maintenance, we discuss how global change drivers can influence species coexistence. We revise the importance of both competition and facilitation for understanding coexistence in different ecosystems, address the influence of phylogenetic relatedness, functional traits, phenotypic plasticity and intraspecific variability, and discuss lessons learnt from invasion ecology. While most previous studies have focused their efforts on disentangling the mechanisms that maintain the biological diversity in species-rich ecosystems such as tropical forests, grasslands and coral reefs, we argue that much can be learnt from pauci-specific communities where functional variability within each species, together with demographic and stochastic processes becomes key to understand species interactions and eventually community responses to global change.

  20. Phylogenetic and Phylogenomic Definition of Rhizopus Species

    Directory of Open Access Journals (Sweden)

    Andrii P. Gryganskyi

    2018-06-01

    Full Text Available Phylogenomic approaches have the potential to improve confidence about the inter-relationships of species in the order Mucorales within the fungal tree of life. Rhizopus species are especially important as plant and animal pathogens and bioindustrial fermenters for food and metabolite production. A dataset of 192 orthologous genes was used to construct a phylogenetic tree of 21 Rhizopus strains, classified into four species isolated from habitats of industrial, medical and environmental importance. The phylogeny indicates that the genus Rhizopus consists of three major clades, with R. microsporus as the basal species and the sister lineage to R. stolonifer and two closely related species R. arrhizus and R. delemar. A comparative analysis of the mating type locus across Rhizopus reveals that its structure is flexible even between different species in the same genus, but shows similarities between Rhizopus and other mucoralean fungi. The topology of single-gene phylogenies built for two genes involved in mating is similar to the phylogenomic tree. Comparison of the total length of the genome assemblies showed that genome size varies by as much as threefold within a species and is driven by changes in transposable element copy numbers and genome duplications.

  1. Recent advances in probabilistic species pool delineations

    Directory of Open Access Journals (Sweden)

    Dirk Nikolaus Karger

    2016-07-01

    Full Text Available A species pool is the set of species that could potentially colonize and establish within a community. It has been a commonly used concept in biogeography since the early days of MacArthur and Wilson’s work on Island Biogeography. Despite their simple and appealing definition, an operational application of species pools is bundled with a multitude of problems, which have often resulted in arbitrary decisions and workarounds when defining species pools. Two recently published papers address the operational problems of species pool delineations, and show ways of delineating them in a probabilistic fashion. In both papers, species pools were delineated using a process-based, mechanistical approach, which opens the door for a multitude of new applications in biogeography. Such applications include detecting the hidden signature of biotic interactions, disentangling the geographical structure of community assembly processes, and incorporating a temporal extent into species pools. Although similar in their conclusions, both ‘probabilistic approaches’ differ in their implementation and definitions. Here I give a brief overview of the differences and similarities of both approaches, and identify the challenges and advantages in their application.

  2. Pushing the pace of tree species migration.

    Directory of Open Access Journals (Sweden)

    Eli D Lazarus

    Full Text Available Plants and animals have responded to past climate changes by migrating with habitable environments, sometimes shifting the boundaries of their geographic ranges by tens of kilometers per year or more. Species migrating in response to present climate conditions, however, must contend with landscapes fragmented by anthropogenic disturbance. We consider this problem in the context of wind-dispersed tree species. Mechanisms of long-distance seed dispersal make these species capable of rapid migration rates. Models of species-front migration suggest that even tree species with the capacity for long-distance dispersal will be unable to keep pace with future spatial changes in temperature gradients, exclusive of habitat fragmentation effects. Here we present a numerical model that captures the salient dynamics of migration by long-distance dispersal for a generic tree species. We then use the model to explore the possible effects of assisted colonization within a fragmented landscape under a simulated tree-planting scheme. Our results suggest that an assisted-colonization program could accelerate species-front migration rates enough to match the speed of climate change, but such a program would involve an environmental-sustainability intervention at a massive scale.

  3. Cryptic species as a window into the paradigm shift of the species concept.

    Science.gov (United States)

    Fišer, Cene; Robinson, Christopher T; Malard, Florian

    2018-02-01

    The species concept is the cornerstone of biodiversity science, and any paradigm shift in the delimitation of species affects many research fields. Many biologists now are embracing a new "species" paradigm as separately evolving populations using different delimitation criteria. Individual criteria can emerge during different periods of speciation; some may never evolve. As such, a paradigm shift in the species concept relates to this inherent heterogeneity in the speciation process and species category-which is fundamentally overlooked in biodiversity research. Cryptic species fall within this paradigm shift: they are continuously being reported from diverse animal phyla but are poorly considered in current tests of ecological and evolutionary theory. The aim of this review is to integrate cryptic species in biodiversity science. In the first section, we address that the absence of morphological diversification is an evolutionary phenomenon, a "process" counterpart to the long-studied mechanisms of morphological diversification. In the next section regarding taxonomy, we show that molecular delimitation of cryptic species is heavily biased towards distance-based methods. We also stress the importance of formally naming of cryptic species for better integration into research fields that use species as units of analysis. Finally, we show that incorporating cryptic species leads to novel insights regarding biodiversity patterns and processes, including large-scale biodiversity assessments, geographic variation in species distribution and species coexistence. It is time for incorporating multicriteria species approaches aiming to understand speciation across space and taxa, thus allowing integration into biodiversity conservation while accommodating for species uncertainty. © 2018 John Wiley & Sons Ltd.

  4. Review: Allee effects in social species.

    Science.gov (United States)

    Angulo, Elena; Luque, Gloria M; Gregory, Stephen D; Wenzel, John W; Bessa-Gomes, Carmen; Berec, Ludek; Courchamp, Franck

    2018-01-01

    Allee effects have important implications for many aspects of basic and applied ecology. The benefits of aggregation of conspecific individuals are central to Allee effects, which have led to the widely held assumption that social species are more prone to Allee effects. Robust evidence for this assumption, however, remains rare. Furthermore, previous research on Allee effects has failed to adequately address the consequences of the different levels of organisation within social species' populations. Here, we review available evidence of Allee effects and model the role of demographic and behavioural factors that may combine to dampen or strengthen Allee effects in social species. We use examples across various species with contrasting social structure, including carnivores, bats, primates and eusocial insects. Building on this, we provide a conceptual framework that allows for the integration of different Allee effects in social species. Social species are characterised by nested levels of organisation. The benefits of cooperation, measured by mean individual fitness, can be observed at both the population and group levels, giving rise to "population level" and "group level" Allee effects respectively. We also speculate on the possibility of a third level, reporting per capita benefits for different individuals within a group (e.g. castes in social insects). We show that group size heterogeneity and intergroup interactions affect the strength of population-level demographic Allee effects. Populations with higher group size heterogeneity and in which individual social groups cooperate demonstrate the weakest Allee effects and may thus provide an explanation for why extinctions due to Allee effects are rare in social species. More adequately accounting for Allee effects in social species will improve our understanding of the ecological and evolutionary implications of cooperation in social species. © 2017 The Authors. Journal of Animal Ecology © 2017 British

  5. Economics of Harmful Invasive Species: A Review

    Directory of Open Access Journals (Sweden)

    George Marbuah

    2014-07-01

    Full Text Available The purpose of this study is to review theoretical and empirical findings in economics with respect to the challenging question of how to manage invasive species. The review revealed a relatively large body of literature on the assessment of damage costs of invasive species; single species and groups of species at different geographical scales. However, the estimated damage costs show large variation, from less than 1 million USD to costs corresponding to 12% of gross domestic product, depending on the methods employed, geographical scale, and scope with respect to inclusion of different species. Decisions regarding optimal management strategies, when to act in the invasion chain and which policy to choose, have received much less attention in earlier years, but have been subject to increasing research during the last decade. More difficult, but also more relevant policy issues have been raised, which concern the targeting in time and space of strategies under conditions of uncertainty. In particular, the weighting of costs and benefits from early detection and mitigation against the uncertain avoidance of damage with later control, when the precision in targeting species is typically greater is identified as a key challenge. The role of improved monitoring for detecting species and their spread and damage has been emphasized, but questions remain on how to achieve this in practice. This is in contrast to the relatively large body of literature on policies for mitigating dispersal by trade, which is regarded as one of the most important vectors for the spread of invasive species. On the other hand, the literature on how to mitigate established species, by control or adaptation, is much more scant. Studies evaluating causes for success or failure of policies against invasive in practice are in principal non-existing.

  6. An updated checklist of mosquito species (Diptera: Culicidae) from Madagascar

    Science.gov (United States)

    Tantely, Michaël Luciano; Le Goff, Gilbert; Boyer, Sébastien; Fontenille, Didier

    2016-01-01

    An updated checklist of 235 mosquito species from Madagascar is presented. The number of species has increased considerably compared to previous checklists, particularly the last published in 2003 (178 species). This annotated checklist provides concise information on endemism, taxonomic position, developmental stages, larval habitats, distribution, behavior, and vector-borne diseases potentially transmitted. The 235 species belong to 14 genera: Aedeomyia (3 species), Aedes (35 species), Anopheles (26 species), Coquillettidia (3 species), Culex (at least 50 species), Eretmapodites (4 species), Ficalbia (2 species), Hodgesia (at least one species), Lutzia (one species), Mansonia (2 species), Mimomyia (22 species), Orthopodomyia (8 species), Toxorhynchites (6 species), and Uranotaenia (73 species). Due to non-deciphered species complexes, several species remain undescribed. The main remarkable characteristic of Malagasy mosquito fauna is the high biodiversity with 138 endemic species (59%). Presence and abundance of species, and their association, in a given location could be a bio-indicator of environmental particularities such as urban, rural, forested, deforested, and mountainous habitats. Finally, taking into account that Malagasy culicidian fauna includes 64 species (27%) with a known medical or veterinary interest in the world, knowledge of their biology and host preference summarized in this paper improves understanding of their involvement in pathogen transmission in Madagascar. PMID:27101839

  7. An updated checklist of mosquito species (Diptera: Culicidae from Madagascar

    Directory of Open Access Journals (Sweden)

    Tantely Michaël Luciano

    2016-01-01

    Full Text Available An updated checklist of 235 mosquito species from Madagascar is presented. The number of species has increased considerably compared to previous checklists, particularly the last published in 2003 (178 species. This annotated checklist provides concise information on endemism, taxonomic position, developmental stages, larval habitats, distribution, behavior, and vector-borne diseases potentially transmitted. The 235 species belong to 14 genera: Aedeomyia (3 species, Aedes (35 species, Anopheles (26 species, Coquillettidia (3 species, Culex (at least 50 species, Eretmapodites (4 species, Ficalbia (2 species, Hodgesia (at least one species, Lutzia (one species, Mansonia (2 species, Mimomyia (22 species, Orthopodomyia (8 species, Toxorhynchites (6 species, and Uranotaenia (73 species. Due to non-deciphered species complexes, several species remain undescribed. The main remarkable characteristic of Malagasy mosquito fauna is the high biodiversity with 138 endemic species (59%. Presence and abundance of species, and their association, in a given location could be a bio-indicator of environmental particularities such as urban, rural, forested, deforested, and mountainous habitats. Finally, taking into account that Malagasy culicidian fauna includes 64 species (27% with a known medical or veterinary interest in the world, knowledge of their biology and host preference summarized in this paper improves understanding of their involvement in pathogen transmission in Madagascar.

  8. Cross-species amplification of 105 Lolium perenne SSR loci in 23 species within the Poaceae

    DEFF Research Database (Denmark)

    Jensen, Louise Bach; Holm, Preben Bach; Lübberstedt, Thomas

    2007-01-01

    Amplification of 105 Lolium perenne SSR markers was studied in 23 grass species representing seven tribes from three subfamilies of Poaceae. Twelve of the SSR markers are published for the first time. Between 2% and 96% of the SSR markers could be amplified within a given species. A subset of eight...... SSR markers was evaluated for polymorphism across nine of the 23 grass species. Four to seven of the markers were polymorphic within each species, with an average detection of 2.4 alleles per species....

  9. Dna c-values of 20 invasive alien species and 3 native species in south china

    Directory of Open Access Journals (Sweden)

    Gong Ni

    2014-01-01

    Full Text Available Cultivated fields and forests in South China are experiencing serious damage due to invasive alien plants. We investigated the relation between DNA C-values and invasiveness. The DNA C-values of 23 species ranged from 0.39 pg to 3.37 pg. Herbs, perennials and native species had higher mean DNA C-values than shrubs, annuals and invasive alien species. DNA C-values decreased with increasing invasiveness. Paederia scandens, a harmful native species, has the lowest DNA C-value among the perennials, indicating that native species with low nuclear content may also possess an invasive potential.

  10. Metabolite production by species of Stemphylium

    DEFF Research Database (Denmark)

    Olsen, Kresten Jon Kromphardt; Rossman, Amy; Andersen, Birgitte

    2018-01-01

    metabolites were found to be important for distinguishing species, while some unknown metabolites were also found to have important roles in distinguishing species of Stemphylium. This study is the first of its kind to investigate the chemical potential of Stemphylium across the whole genus.......Morphology and phylogeny has been used to distinguish members of the plant pathogenic fungal genus Stemphylium. A third method for distinguishing species is by chemotaxonomy. The main goal of the present study was to investigate the chemical potential of Stemphylium via HPLC-UV-MS analysis, while...

  11. Reservoirs of Non-baumannii Acinetobacter Species

    Science.gov (United States)

    Al Atrouni, Ahmad; Joly-Guillou, Marie-Laure; Hamze, Monzer; Kempf, Marie

    2016-01-01

    Acinetobacter spp. are ubiquitous gram negative and non-fermenting coccobacilli that have the ability to occupy several ecological niches including environment, animals and human. Among the different species, Acinetobacter baumannii has evolved as global pathogen causing wide range of infection. Since the implementation of molecular techniques, the habitat and the role of non-baumannii Acinetobacter in human infection have been elucidated. In addition, several new species have been described. In the present review, we summarize the recent data about the natural reservoir of non-baumannii Acinetobacter including the novel species that have been described for the first time from environmental sources and reported during the last years. PMID:26870013

  12. Tree Species Identity Shapes Earthworm Communities

    DEFF Research Database (Denmark)

    Schelfhout, Stephanie; Mertens, Jan; Verheyen, Kris

    2017-01-01

    Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden...... of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer...

  13. Fort Collins Science Center: Invasive Species Science

    Science.gov (United States)

    Stohlgren, Tom

    2004-01-01

    Invasive, non-native species of plants, animals, and disease organisms adversely affect the ecosystems they enter. Like "biological wildfires," they can quickly spread, and they affect nearly all terrestrial and aquatic ecosystems. Invasive species have become the greatest environmental challenge of the 21st century in terms of economic, environmental, and human health costs, with an estimated impact in the U.S. of over $138 billion per year. Managers of Department of the Interior and other public and private lands and waters rank invasive species as their top resource management problem.

  14. Fatty acid composition of forage herb species

    DEFF Research Database (Denmark)

    Warner, D.; Jensen, Søren Krogh; Cone, J.W.

    2010-01-01

    The use of alternative forage species in grasslands for intensive livestock production is receiving renewed attention. Data on fatty acid composition of herbs are scarce, so four herbs (Plantago lanceolata, Achillea millefolium, Cichorium intybus, Pastinaca sativa) and one grass species (timothy......, Phleum pratense) were sown in a cutting trial. The chemical composition and concentration of fatty acids (FA) of individual species were determined during the growing season. Concentrations of crude protein and FA were generally higher in the herbs than in timothy. C. intybus had the highest nutritive...

  15. Species Diversity Enhances Predator Growth Rates

    International Nuclear Information System (INIS)

    Olson, M.H.; Jacobs, R.P.; O'Donnell, E.B.

    2007-01-01

    Predators can be important top-down regulators of community structure and are known to have both positive and negative effects on species diversity. However, little is known about the reciprocal effects of species diversity on predators. Across a set of 80 lakes in Connecticut, USA, we found a strong positive correlation between prey species diversity (using the Shannon-Weiner Diversity Index) and growth rates of largemouth bass (Micropterus salmoides). This correlation was strongest for small predators and decreased with body size. Although the underlying mechanisms are not known, the correlation is not driven by total fish abundance, predator abundance, or productivity.

  16. Predictions For New, Exotic Actinide Species

    International Nuclear Information System (INIS)

    Pyykko, P.

    2002-01-01

    The approach. New, simple chemical species can be predicted by studying isoelectronic series using ab initio quantum chemistry. We currently use in most cases relativistic pseudopotentials and handle the electron correlation using density functional theory (DFT) or wave-function-based methods, from MP2 to CCSD(T). Typical codes are Gaussian 98, Turbomole or MolCas. For full four-component Dirac-Fock calculations, the DREAMS code of K. G. Dyall has been utilized. For mapping out the possible new species, complete maps of all possibilities are made, whenever possible, and the new species typically occur along the coast-line of the 'island of stability' of already known species

  17. antimicrobial susceptibility pattern of Salmonella species

    African Journals Online (AJOL)

    user

    GLOBAL JOURNAL OF COMMUNITY MEDICINE VOL. 2 NO. 1 & 2 2009: 5 - ... This study is a review of the contemporary antimicrobial susceptibility pattern of. Salmonella species. ... south-east Asia, parts of Latin America, the. Caribbean, and ...

  18. Metabolomic analysis of three Mollicute species.

    Directory of Open Access Journals (Sweden)

    Anna A Vanyushkina

    Full Text Available We present a systematic study of three bacterial species that belong to the class Mollicutes, the smallest and simplest bacteria, Spiroplasma melliferum, Mycoplasma gallisepticum, and Acholeplasma laidlawii. To understand the difference in the basic principles of metabolism regulation and adaptation to environmental conditions in the three species, we analyzed the metabolome of these bacteria. Metabolic pathways were reconstructed using the proteogenomic annotation data provided by our lab. The results of metabolome, proteome and genome profiling suggest a fundamental difference in the adaptation of the three closely related Mollicute species to stress conditions. As the transaldolase is not annotated in Mollicutes, we propose variants of the pentose phosphate pathway catalyzed by annotated enzymes for three species. For metabolite detection we employed high performance liquid chromatography coupled with mass spectrometry. We used liquid chromatography method - hydrophilic interaction chromatography with silica column - as it effectively separates highly polar cellular metabolites prior to their detection by mass spectrometer.

  19. Luminescence properties of uranyl-acetate species

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, Hannes; Moll, Henry [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology; Stumpf, Thorsten [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry

    2017-06-01

    Time-resolved laser-induced fluorescence spectroscopy (TRLFS) was applied to characterize uranium(VI)- acetate species based on their luminescence properties. In contrast to previous interpretations, no indications were detected for the existence of the 1: 3 complex.

  20. Influence of estuaries on shelf foraminiferal species

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.

    Dabhol-bhatkal stretch of the west coast of India is marked by a number of estuaries. Cavarotalia annectens is selected to monitor the influence of these estuaries on the inner shelf foraminiferal fauna. The percentage distribution of this species...

  1. CONSERVATION METHODS OF ENDANGERED SPECIES GUNDU ...

    African Journals Online (AJOL)

    user

    Department of Forestry, Akperan Orshi College of Agriculture Yandev, Gboko ... conservation measure, an endangered species finally goes into extinction, that ... either for tourism, scientific studies/ .... economic, educational, scientific, cultural.

  2. New trends in species distribution modelling

    Science.gov (United States)

    Zimmermann, Niklaus E.; Edwards, Thomas C.; Graham, Catherine H.; Pearman, Peter B.; Svenning, Jens-Christian

    2010-01-01

    Species distribution modelling has its origin in the late 1970s when computing capacity was limited. Early work in the field concentrated mostly on the development of methods to model effectively the shape of a species' response to environmental gradients (Austin 1987, Austin et al. 1990). The methodology and its framework were summarized in reviews 10–15 yr ago (Franklin 1995, Guisan and Zimmermann 2000), and these syntheses are still widely used as reference landmarks in the current distribution modelling literature. However, enormous advancements have occurred over the last decade, with hundreds – if not thousands – of publications on species distribution model (SDM) methodologies and their application to a broad set of conservation, ecological and evolutionary questions. With this special issue, originating from the third of a set of specialized SDM workshops (2008 Riederalp) entitled 'The Utility of Species Distribution Models as Tools for Conservation Ecology', we reflect on current trends and the progress achieved over the last decade.

  3. Cooperation and the Endangered Species Act

    International Nuclear Information System (INIS)

    Palmer, S.C.

    1991-01-01

    Passage of the Endangered Species Act in 1973 set the stage for some of the nations most polemic environmental battles. One of these is in the Colorado River Basin which is home to four native and rare fish species. Acrimonious confrontation has characterized the consultations under the ESA regarding these fish species. In 1983, the U.S. Fish and Wildlife Service announced that no new water depletions such as for hydropower plants, from the Upper Colorado River Basin would be allowed. This created no small stir among basin states and water developers and a negotiated solution was sought. The result was the Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin. This paper reports that models of political negotiation indicate conceptually, that the Recovery Program with its decisions made by unanimity of consensus, its open process and sharing of information, its shared budget and users fees, is a vehicle of political compromise and cooperation

  4. Bioeconomic analysis supports the endangered species act.

    Science.gov (United States)

    Salau, Kehinde R; Fenichel, Eli P

    2015-10-01

    The United States Endangered Species Act (ESA) was enacted to protect and restore declining fish, wildlife, and plant populations. The ESA mandates endangered species protection irrespective of costs. This translates to the restriction of activities that harm endangered populations. We discuss criticisms of the ESA in the context of public land management and examine under what circumstance banning non-conservation activity on multiple use federal lands can be socially optimal. We develop a bioeconomic model to frame the species management problem under the ESA and identify scenarios where ESA-imposed regulations emerge as optimal strategies. Results suggest that banning harmful activities is a preferred strategy when valued endangered species are in decline or exposed to poor habitat quality. However, it is not optimal to sustain such a strategy in perpetuity. An optimal plan involves a switch to land-use practices characteristic of habitat conservation plans.

  5. The Drosophila bipectinata species complex: phylogenetic ...

    Indian Academy of Sciences (India)

    PARUL BANERJEE

    c Indian Academy of Sciences. RESEARCH ARTICLE. The Drosophila bipectinata species complex: phylogenetic relationship among different members based on chromosomal variations. PARUL BANERJEE and BASHISTH N. SINGH. ∗. Genetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi ...

  6. A cross-species alignment tool (CAT)

    DEFF Research Database (Denmark)

    Li, Heng; Guan, Liang; Liu, Tao

    2007-01-01

    BACKGROUND: The main two sorts of automatic gene annotation frameworks are ab initio and alignment-based, the latter splitting into two sub-groups. The first group is used for intra-species alignments, among which are successful ones with high specificity and speed. The other group contains more...... sensitive methods which are usually applied in aligning inter-species sequences. RESULTS: Here we present a new algorithm called CAT (for Cross-species Alignment Tool). It is designed to align mRNA sequences to mammalian-sized genomes. CAT is implemented using C scripts and is freely available on the web...... at http://xat.sourceforge.net/. CONCLUSIONS: Examined from different angles, CAT outperforms other extant alignment tools. Tested against all available mouse-human and zebrafish-human orthologs, we demonstrate that CAT combines the specificity and speed of the best intra-species algorithms, like BLAT...

  7. Marine linefish programme priority species list

    CSIR Research Space (South Africa)

    Wallace, JH

    1983-05-01

    Full Text Available in Durban in April 1982. For each species, information is presented on; distribution, angling status, preferred habitat, growth, reproduction, catch statistics and further research work required. The publication is intended to act as a working document...

  8. Germplasm characterization of three jabuticaba tree species

    Directory of Open Access Journals (Sweden)

    Moeses Andrigo Danner

    2011-09-01

    Full Text Available The purpose of this study was to characterize cultivated genotypes of three jabuticaba species (Plinia cauliflora, P. trunciflora, and P. jaboticaba. Phenology and fruit growth, as well as leaf, flower and fruit traits were evaluated. Variability in all traits was observed among genotypes of the three jabuticaba species. The trait peduncle size is indicated for differentiation of the three species under study. The leaf and fruit sizes of the genotypes P. trunciflora 3, P. trunciflora 4, P. trunciflora 5 and P. jaboticaba 1 differ from those described in the literature for these species, indicating the formation of ecotypes. Jabuticaba fruit skin contains high anthocyanin and flavonoid concentrations, with potential use in food and pharmaceutical industries.

  9. Density of Threatened and Endangered Species

    Data.gov (United States)

    California Natural Resource Agency — A compiled density of threatened and endangered species built around 2000m wide hexagonal cells. The dataset was created by generating a blank hex grid, intersecting...

  10. Invasive species unchecked by climate - response

    DEFF Research Database (Denmark)

    Burrows, Michael T.; Schoeman, David S.; Duarte, Carlos M.

    2012-01-01

    environments. This may be particularly true in the world's boreal oceans as melting sea ice facilitates new migratory passages between the Atlantic and Pacific Oceans. Moreover, as the ebb and flow of biodiversity intensifies under anthropogenic climate change, novel climates and communities of species......Hulme points out that observed rates of range expansion by invasive alien species are higher than the median speed of isotherm movement over the past 50 years, which in turn has outpaced the rates of climate-associated range changes of marine and terrestrial species. This is not surprising, given...... of climate-change-induced range shifts between native and alien species are meaningful only after the initial invasive spread has reached a stable range boundary. A focus on regions with high velocities of climate change, and on regions such as the tropics where novel thermal niches are being created, should...

  11. Osmoregulation in three species of Ambassidae (Osteichthyes ...

    African Journals Online (AJOL)

    1989-07-25

    Jul 25, 1989 ... the temperature tolerance ranges of the three species (Martin. 1988) suggest that ..... dependent on the period spent in freshwater (Holliday 1971;. Nordlie 1985). .... GILLES, R. 1975. Mechanisms of ion and osmoregulation.

  12. Community structure informs species geographic distributions

    KAUST Repository

    Montesinos-Navarro, Alicia; Estrada, Alba; Font, Xavier; Matias, Miguel G.; Meireles, Catarina; Mendoza, Manuel; Honrado, Joao P.; Prasad, Hari D.; Vicente, Joana R.; Early, Regan

    2018-01-01

    spatial resolution. However, survival of individuals is determined by processes that happen at small spatial scales. The relative abundance of coexisting species (i.e. 'community structure') reflects assembly processes occurring at small scales

  13. Sensory quality criteria for five fish species

    DEFF Research Database (Denmark)

    Warm, Karin; Nielsen, Jette; Hyldig, Grethe

    2000-01-01

    Sensory profiling has been used to develop one sensory vocabulary for five fish species: cod (Gadus morhua), saithe (Pollachius virens), rainbow trout (Salmo gardineri), herring (Clupea harengus) and flounder (Platichthys flessus). A nine- member trained panel assessed 18 samples with variation i...... variation and by presenting references, panel discussions and interpreting plots from multivariate data analysis. The developed profile can be used as a sensory wheel for these species, and with minor changes it may be adapted to similar species......Sensory profiling has been used to develop one sensory vocabulary for five fish species: cod (Gadus morhua), saithe (Pollachius virens), rainbow trout (Salmo gardineri), herring (Clupea harengus) and flounder (Platichthys flessus). A nine- member trained panel assessed 18 samples with variation...

  14. On two new species of Siriella (Mysidacea)

    Digital Repository Service at National Institute of Oceanography (India)

    Panampunnayil, S.U.

    Descriptions of two new mysids, Siriella africana ap. nov. collected from Agulhas Bank and S. intermedia sp. nov. collected from Laccadives are given. The present paper contains observations on two species of mysidacea collected from the Indian...

  15. Quantifying Temporal Genomic Erosion in Endangered Species.

    Science.gov (United States)

    Díez-Del-Molino, David; Sánchez-Barreiro, Fatima; Barnes, Ian; Gilbert, M Thomas P; Dalén, Love

    2018-03-01

    Many species have undergone dramatic population size declines over the past centuries. Although stochastic genetic processes during and after such declines are thought to elevate the risk of extinction, comparative analyses of genomic data from several endangered species suggest little concordance between genome-wide diversity and current population sizes. This is likely because species-specific life-history traits and ancient bottlenecks overshadow the genetic effect of recent demographic declines. Therefore, we advocate that temporal sampling of genomic data provides a more accurate approach to quantify genetic threats in endangered species. Specifically, genomic data from predecline museum specimens will provide valuable baseline data that enable accurate estimation of recent decreases in genome-wide diversity, increases in inbreeding levels, and accumulation of deleterious genetic variation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Endangered Species Litigation and Associated Pesticide Limitations

    Science.gov (United States)

    EPA has been subject to several citizen suits. As a result we have conducted scientific assessments and made effects determinations for various pesticide products as related to specific species of concern.

  17. ESUSA: US endangered species distribution file

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, J.; Calef, C.E.

    1979-10-01

    This report describes a file containing distribution data on endangered species of the United States of Federal concern pursuant to the Endangered Species Act of 1973. Included for each species are (a) the common name, (b) the scientific name, (c) the family, (d) the group (mammal, bird, etc.), (e) Fish and Wildlife Service (FWS) listing and recovery priorities, (f) the Federal legal status, (g) the geographic distribution by counties or islands, (h) Federal Register citations and (i) the sources of the information on distribution of the species. Status types are endangered, threatened, proposed, formally under review, candidate, deleted, and rejected. Distribution is by Federal Information Processing Standard (FIPS) county code and is of four types: designated critical habitat, present range, potential range, and historic range.

  18. EXTRACTION AND ANTIOXIDANT ACTIVITIES OF TWO SPECIES ...

    African Journals Online (AJOL)

    2013-06-30

    Jun 30, 2013 ... Origanum vulgare were investigated and also the total phenolic and ... species majorana, and vulgare respectively; also the DPPH of essential oil of Origanum ... inflammatory, antimicrobial and antioxidant activities[10] .

  19. Clonal growth and plant species abundance.

    Science.gov (United States)

    Herben, Tomáš; Nováková, Zuzana; Klimešová, Jitka

    2014-08-01

    Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf-height-seed) traits and by actual performance in the botanical garden. Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area - height - seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially underlying clonal growth effects on abundance. Garden

  20. The Endangered Species Act and Sound Science

    Science.gov (United States)

    2006-10-05

    population segment” under ESA? ! If a species is wide-ranging and begins, on its own, to reappear in an area it once occupied (as with a few wolves in... Yellowstone ), should these animals be regarded as a “resident population” for purposes of ESA? ! Should a formerly widely-distributed species (such as bald... wolves ), and is delisted as soon as possible (as with bald eagles and Florida panthers). Representatives of many scientific or environmental

  1. Invasive Species - A Threat to the Homeland?

    Science.gov (United States)

    2003-04-07

    species of weeds, diseases and organisms on both my farm and the surrounding woodlands. Some of these species include soybean cyst nematode, soybean aphid ...natural enemies in their new environment. Parasites, pathogens , or predators that would inhibit or limit their spread are few or non-existent. In...tested, and fielded to control the genetically modified organism. Serums would be less effective, and diagnosis of human pathogens could change and

  2. Isoprene emission from tropical tree species

    International Nuclear Information System (INIS)

    Padhy, P.K.; Varshney, C.K.

    2005-01-01

    Foliar emission of isoprene was measured in nine commonly growing tree species of Delhi, India. Dynamic flow enclosure technique was used and gas samples were collected onto Tenax-GC/Carboseive cartridges, which were then attached to the sample injection system in the gas chromatograph (GC). Eluting compounds were analysed using a flame ionisation detector (FID). Out of the nine tree species, isoprene emission was found in six species (Eucalyptus sp., Ficus benghalensis, Ficus religiosa, Mangifera indica, Melia azedarach, and Syzygium jambolanum), whereas, in the remaining three tree species (Alstonia scholaris, Azadirachta indica, and Cassia fistula) no isoprene emission was detected or the levels of emission were negligible or below the detection limit (BDL). Among six tree species, the highest hourly emission (10.2±6.8 μg g -1 leaf dry weight, average of five seasons) was observed in Ficus religiosa, while minimum emission was from Melia azedarach (2.2±4.9 μg g -1 leaf dry weight, average of five seasons). Isoprene emission (average of six species), over five seasons, was found to vary between 3.9 and 8.5 μg g -1 leaf dry weight during the rainy season. In addition, significant diurnal variation in isoprene emission was observed in each species. The preliminary estimate made in this study on the annual biogenic VOC emission from India may probably be the first of its kind from this part of the world. - Isoprene flux (diurnal and seasonal) from some tropical tree species was estimated and a regional comparison was made

  3. Isoprene emission from tropical tree species

    Energy Technology Data Exchange (ETDEWEB)

    Padhy, P.K. [School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India)]. E-mail: padhypk2003@yahoo.com; Varshney, C.K. [School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India)

    2005-05-01

    Foliar emission of isoprene was measured in nine commonly growing tree species of Delhi, India. Dynamic flow enclosure technique was used and gas samples were collected onto Tenax-GC/Carboseive cartridges, which were then attached to the sample injection system in the gas chromatograph (GC). Eluting compounds were analysed using a flame ionisation detector (FID). Out of the nine tree species, isoprene emission was found in six species (Eucalyptus sp., Ficus benghalensis, Ficus religiosa, Mangifera indica, Melia azedarach, and Syzygium jambolanum), whereas, in the remaining three tree species (Alstonia scholaris, Azadirachta indica, and Cassia fistula) no isoprene emission was detected or the levels of emission were negligible or below the detection limit (BDL). Among six tree species, the highest hourly emission (10.2{+-}6.8 {mu}g g{sup -1} leaf dry weight, average of five seasons) was observed in Ficus religiosa, while minimum emission was from Melia azedarach (2.2{+-}4.9 {mu}g g{sup -1} leaf dry weight, average of five seasons). Isoprene emission (average of six species), over five seasons, was found to vary between 3.9 and 8.5 {mu}g g{sup -1} leaf dry weight during the rainy season. In addition, significant diurnal variation in isoprene emission was observed in each species. The preliminary estimate made in this study on the annual biogenic VOC emission from India may probably be the first of its kind from this part of the world. - Isoprene flux (diurnal and seasonal) from some tropical tree species was estimated and a regional comparison was made.

  4. The ethics of reviving long extinct species.

    Science.gov (United States)

    Sandler, Ronald

    2014-04-01

    There now appears to be a plausible pathway for reviving species that have been extinct for several decades, centuries, or even millennia. I conducted an ethical analysis of de-extinction of long extinct species. I assessed several possible ethical considerations in favor of pursuing de-extinction: that it is a matter of justice; that it would reestablish lost value; that it would create new value; and that society needs it as a conservation last resort. I also assessed several possible ethical arguments against pursuing de-extinction: that it is unnatural; that it could cause animal suffering; that it could be ecologically problematic or detrimental to human health; and that it is hubristic. There are reasons in favor of reviving long extinct species, and it can be ethically acceptable to do so. However, the reasons in favor of pursuing de-extinction do not have to do with its usefulness in species conservation; rather, they concern the status of revived species as scientific and technological achievements, and it would be ethically problematic to promote de-extinction as a significant conservation strategy, because it does not prevent species extinctions, does not address the causes of extinction, and could be detrimental to some species conservation efforts. Moreover, humanity does not have a responsibility or obligation to pursue de-extinction of long extinct species, and reviving them does not address any urgent problem. Therefore, legitimate ecological, political, animal welfare, legal, or human health concerns associated with a de-extinction (and reintroduction) must be thoroughly addressed for it to be ethically acceptable. © 2013 Society for Conservation Biology.

  5. Relation of chironomids with Aeromonas species

    Directory of Open Access Journals (Sweden)

    Sivan eLaviad

    2016-05-01

    Full Text Available Chironomids (Diptera: Chironomidae, also known as non-biting midges, are one of the most abundant groups of insects in aquatic habitats. They undergo a complete metamorphosis of four life stages of which three are aquatic (egg, larva, pupa, and the adult emerges into the air. Chironomids serve as a natural reservoir of Aeromonas and Vibrio cholerae species. Here we review existing knowledge about the mutual relations between Aeromonas species and chironomids. Using 454-pyrosequencing of the 16S rRNA gene, we found that the prevalence of Aeromonas species in the insects’ egg masses and larvae was 1.6% and 3.3% of the insects’ endogenous microbiota, respectively. Aeromonas abundance per egg mass remained stable during a six-month period of bacterial monitoring. Different Aeromonas species were isolated and some demonstrated the ability to degrade the insect’s egg masses and to prevent eggs hatching. Chitinase was identified as the enzyme responsible for the egg mass degradation. Different Aeromonas species isolated from chironomids demonstrated the potential to protect their host from toxic metals. Aeromonas is a causative agent of fish infections. Fish are frequently recorded as feeding on chironomids. Thus, fish might be infected with Aeromonas species via chironomid consumption. Aeromonas strains are also responsible for causing gastroenteritis and wound infections in humans. Different virulence genes were identified in Aeromonas species isolated from chironomids. Chironomids may infest drinking water reservoirs, hence be the source of pathogenic Aeromonas strains in drinking water. Chironomids and Aeromonas species have a complicated mutual relationship.

  6. Phylogeny and species traits predict bird detectability

    Science.gov (United States)

    Solymos, Peter; Matsuoka, Steven M.; Stralberg, Diana; Barker, Nicole K. S.; Bayne, Erin M.

    2018-01-01

    Avian acoustic communication has resulted from evolutionary pressures and ecological constraints. We therefore expect that auditory detectability in birds might be predictable by species traits and phylogenetic relatedness. We evaluated the relationship between phylogeny, species traits, and field‐based estimates of the two processes that determine species detectability (singing rate and detection distance) for 141 bird species breeding in boreal North America. We used phylogenetic mixed models and cross‐validation to compare the relative merits of using trait data only, phylogeny only, or the combination of both to predict detectability. We found a strong phylogenetic signal in both singing rates and detection distances; however the strength of phylogenetic effects was less than expected under Brownian motion evolution. The evolution of behavioural traits that determine singing rates was found to be more labile, leaving more room for species to evolve independently, whereas detection distance was mostly determined by anatomy (i.e. body size) and thus the laws of physics. Our findings can help in disentangling how complex ecological and evolutionary mechanisms have shaped different aspects of detectability in boreal birds. Such information can greatly inform single‐ and multi‐species models but more work is required to better understand how to best correct possible biases in phylogenetic diversity and other community metrics.

  7. The temporal variability of species densities

    International Nuclear Information System (INIS)

    Redfearn, A.; Pimm, S.L.

    1993-01-01

    Ecologists use the term 'stability' to mean to number of different things (Pimm 1984a). One use is to equate stability with low variability in population density over time (henceforth, temporal variability). Temporal variability varies greatly from species to species, so what effects it? There are at least three sets of factors: the variability of extrinsic abiotic factors, food web structure, and the intrinsic features of the species themselves. We can measure temporal variability using at least three statistics: the coefficient of variation of density (CV); the standard deviation of the logarithms of density (SDL); and the variance in the differences between logarithms of density for pairs of consecutive years (called annual variability, hence AV, b y Wolda 1978). There are advantages and disadvantages to each measure (Williamson 1984), though in our experience, the measures are strongly correlated across sets of taxonomically related species. The increasing availability of long-term data sets allows one to calculate these statistics for many species and so to begin to understand the various causes of species differences in temporal variability

  8. Malaria vector species in Colombia: a review

    Directory of Open Access Journals (Sweden)

    James Montoya-Lerma

    2011-08-01

    Full Text Available Here we present a comprehensive review of the literature on the vectorial importance of the major Anopheles malaria vectors in Colombia. We provide basic information on the geographical distribution, altitudinal range, immature habitats, adult behaviour, feeding preferences and anthropophily, endophily and infectivity rates. We additionally review information on the life cycle, longevity and population fluctuation of Colombian Anopheles species. Emphasis was placed on the primary vectors that have been epidemiologically incriminated in malaria transmission: Anopheles darlingi, Anopheles albimanus and Anopheles nuneztovari. The role of a selection of local, regional or secondary vectors (e.g., Anopheles pseudopunctipennis and Anopheles neivai is also discussed. We highlight the importance of combining biological, morphological and molecular data for the correct taxonomical determination of a given species, particularly for members of the species complexes. We likewise emphasise the importance of studying the bionomics of primary and secondary vectors along with an examination of the local conditions affecting the transmission of malaria. The presence and spread of the major vectors and the emergence of secondary species capable of transmitting human Plasmodia are of great interest. When selecting control measures, the anopheline diversity in the region must be considered. Variation in macroclimate conditions over a species' geographical range must be well understood and targeted to plan effective control measures based on the population dynamics of the local Anopheles species.

  9. Inducible Clindamycin Resistance in Staphylococcus Species

    International Nuclear Information System (INIS)

    Afridi, F. I.; Zeb, M.; Farooqi, B. J.; Murtaza, G.; Hussain, A.

    2014-01-01

    Objective: To determine the frequency of inducible clindamycin resistance in clinical isolates of Staphylococcus species by phenotypic D-test. Study Design: Observational study. Place and Duration of Study: Ziauddin University Hospital, Karachi, from July to December 2011. Methodology: Consecutive clinical isolates of Staphylococcus species were collected and identified by conventional microbiological techniques. Antimicrobial susceptibility testing and inducible clindamycin resistance was carried out by performing D-test using CLSI criteria. Methicillin resistance was detected by using Cefoxitin disk as a surrogate marker. Statistical analysis was performed by SPSS version-17. Results: A total of 667 clinical isolates of Staphylococcus species were obtained during the study period. In these isolates, 177 (26.5%) were Staphylococcus aureus, and 490 (73.5%) were coagulase negative Staphylococci. The total frequency of inducible clindamycin resistance among isolates of Staphylococcus species was 120/667 (18%). Frequency of inducible clindamycin resistance among coagulase negative Staphylococci group and Staphylococcus aureus group were 18.57% and 16.38% respectively. Median age of patients in D-test positive group was 19.5 (1 - 54) years. Conclusion: The frequency of inducible clindamycin resistance among Staphylococcus species may differ in different hospital setup. Clinical microbiology laboratories should implement testing simple and effective D-test on all Staphylococcus species. D-test positive isolates should be reported clindamycin resistant to decrease treatment failure. (author)

  10. Chilli anthracnose disease caused by Colletotrichum species.

    Science.gov (United States)

    Than, Po Po; Prihastuti, Haryudian; Phoulivong, Sitthisack; Taylor, Paul W J; Hyde, Kevin D

    2008-10-01

    Anthracnose disease is one of the major economic constraints to chilli production worldwide, especially in tropical and subtropical regions. Accurate taxonomic information is necessary for effective disease control management. In the Colletotrichum patho-system, different Colletotrichum species can be associated with anthracnose of the same host. Little information is known concerning the interactions of the species associated with the chilli anthracnose although several Colletotrichum species have been reported as causal agents of chilli anthracnose disease worldwide. The ambiguous taxonomic status of Colletotrichum species has resulted in inaccurate identification which may cause practical problems in plant breeding and disease management. Although the management and control of anthracnose disease are still being extensively researched, commercial cultivars of Capsicum annuum that are resistant to the pathogens that cause chilli anthracnose have not yet been developed. This paper reviews the causal agents of chilli anthracnose, the disease cycle, conventional methods in identification of the pathogen and molecular approaches that have been used for the identification of Colletotrichum species. Pathogenetic variation and population structure of the causal agents of chilli anthracnose along with the current taxonomic status of Colletotrichum species are discussed. Future developments leading to the disease management strategies are suggested.

  11. Phytochemistry and Pharmacology of Berberis Species

    Science.gov (United States)

    Mokhber-Dezfuli, Najmeh; Saeidnia, Soodabeh; Gohari, Ahmad Reza; Kurepaz-Mahmoodabadi, Mahdieh

    2014-01-01

    The genus Berberis (Berberidaceae) includes about 500 species worldwide, some of which are widely cultivated in the north-eastern regions of Iran. This genus consists of spiny deciduous evergreen shrubs, characterized by yellow wood and flowers. The cultivation of seedless barberry in South Khorasan goes back to two hundred years ago. Medicinal properties for all parts of these plants have been reported, including: Antimicrobial, antiemetic, antipyretic, antioxidant, anti-inflammatory, anti-arrhythmic, sedative, anti-cholinergic, cholagogic, anti-leishmaniasis, and anti-malaria. The main compounds found in various species of Berberis, are berberine and berbamine. Phytochemical analysis of various species of this genus revealed the presence of alkaloids, tannins, phenolic compounds, sterols and triterpenes. Although there are some review articles on Berberis vulgaris (as the most applied species), there is no review on the phytochemical and pharmacological activities of other well-known species of the genus Berberis. For this reason, the present review mainly focused on the diverse secondary metabolites of various species of this genus and the considerable pharmacological and biological activities together with a concise story of the botany and cultivation. PMID:24600191

  12. Rare species are valued big time.

    Directory of Open Access Journals (Sweden)

    Elena Angulo

    Full Text Available BACKGROUND: It has recently been postulated that the value humans place on rarity could cause the extinction of rare species. This is because people are willing to pay the high costs of exploiting the last individuals. Many hobbies, such as ecotourism or the keeping of exotic pets may cause this effect--known as the anthropogenic Allee effect. However, the entire theory relies on the insofar undemonstrated assumption that people do value rarity. METHODOLOGY/PRINCIPAL FINDINGS: In order to quantify how much people valued rare species relative to common ones, we created online slideshows of photographs of either rare or common species on an Internet web site. The slideshow with photographs of rare species attracted more visitors, and visitors spent, in general, more time waiting to view it. CONCLUSIONS/SIGNIFICANCE: We provide evidence that people value rare more than common species. As we did not target consumers of a specific market, this finding suggests that the anthropogenic Allee effect is likely be driven by a large part of the population. Given the substantial participation in our online experiment, we highlight the potential of the world wide web resource as a tool for conservation action. However, the evidence presented here that the general public value rare species, combined with the assumption that anthropogenic Allee effect is operating, implies that conservationists should be prudent when using rarity to promote conservation.

  13. Assessing species saturation: conceptual and methodological challenges.

    Science.gov (United States)

    Olivares, Ingrid; Karger, Dirk N; Kessler, Michael

    2018-05-07

    Is there a maximum number of species that can coexist? Intuitively, we assume an upper limit to the number of species in a given assemblage, or that a lineage can produce, but defining and testing this limit has proven problematic. Herein, we first outline seven general challenges of studies on species saturation, most of which are independent of the actual method used to assess saturation. Among these are the challenge of defining saturation conceptually and operationally, the importance of setting an appropriate referential system, and the need to discriminate among patterns, processes and mechanisms. Second, we list and discuss the methodological approaches that have been used to study species saturation. These approaches vary in time and spatial scales, and in the variables and assumptions needed to assess saturation. We argue that assessing species saturation is possible, but that many studies conducted to date have conceptual and methodological flaws that prevent us from currently attaining a good idea of the occurrence of species saturation. © 2018 Cambridge Philosophical Society.

  14. Reptilian reovirus: a new fusogenic orthoreovirus species

    International Nuclear Information System (INIS)

    Duncan, Roy.; Corcoran, Jennifer; Shou Jingyun; Stoltz, Don

    2004-01-01

    The fusogenic subgroup of orthoreoviruses contains most of the few known examples of non-enveloped viruses capable of inducing syncytium formation. The only unclassified orthoreoviruses at the species level represent several fusogenic reptilian isolates. To clarify the relationship of reptilian reoviruses (RRV) to the existing fusogenic and nonfusogenic orthoreovirus species, we undertook a characterization of a python reovirus isolate. Biochemical, biophysical, and biological analyses confirmed the designation of this reptilian reovirus (RRV) isolate as an unclassified fusogenic orthoreovirus. Sequence analysis revealed that the RRV S1 and S3 genome segments contain a novel conserved 5'-terminal sequence not found in other orthoreovirus species. In addition, the gene arrangement and the coding potential of the bicistronic RRV S1 genome segment differ from that of established orthoreovirus species, encoding a predicted homologue of the reovirus cell attachment protein and a unique 125 residue p14 protein. The RRV S3 genome segment encodes a homologue of the reovirus sigma-class major outer capsid protein, although it is highly diverged from that of other orthoreovirus species (amino acid identities of only 16-25%). Based on sequence analysis, biological properties, and phylogenetic analysis, we propose this python reovirus be designated as the prototype strain of a fifth species of orthoreoviruses, the reptilian reoviruses

  15. Diversity of cuticular wax among Salix species and Populus species hybrids.

    Science.gov (United States)

    Cameron, Kimberly D; Teece, Mark A; Bevilacqua, Eddie; Smart, Lawrence B

    2002-08-01

    The leaf cuticular waxes of three Salix species and two Populus species hybrids, selected for their ability to produce high amounts of biomass, were characterized. Samples were extracted in CH(2)Cl(2) three times over the growing season. Low kV SEM was utilized to observe differences in the ultrastructure of leaf surfaces from each clone. Homologous series of wax components were classified into organic groups, and the variation in wax components due to clone, sample time, and their interaction was identified. All Salix species and Populus species hybrids showed differences in total wax load at each sampling period, whereas the pattern of wax deposition over time differed only between the Salix species. A strong positive relationship was identified between the entire homologous series of alcohols and total wax load in all clones. Similarly strong relationships were observed between fatty acids and total wax load as well as fatty acids and alcohols in two Salix species and one Populus species hybrid. One Salix species, S. dasyclados, also displayed a strong positive relationship between alcohols and alkanes. These data indicate that species grown under the same environmental conditions produce measurably different cuticular waxes and that regulation of wax production appears to be different in each species. The important roles cuticular waxes play in drought tolerance, pest, and pathogen resistance, as well as the ease of wax extraction and analysis, strongly suggest that the characteristics of the cuticular wax may prove to be useful selectable traits in a breeding program.

  16. Long-term Responses of Canopy-understorey Interactions to Disturbance Severity in Primary Picea abies Forests

    Czech Academy of Sciences Publication Activity Database

    Bače, R.; Schurman, J.S.; Brabec, Marek; Čada, V.; Deprés, T.; Janda, P.; Lábusová, J.; Mikoláš, M.; Morrissey, R. C.; Mrhalová, H.; Nagel, T.A.; Nováková, M. H.; Seedre, M.; Synek, M.; Trotsiuk, V.; Svoboda, M.

    2017-01-01

    Roč. 28, č. 6 (2017), s. 1128-1139 ISSN 1100-9233 Grant - others:GA ČR(CZ) GA15-14840S Institutional support: RVO:67985807 Keywords : Disturbance regime * Natural regeneration * Primary forest * Picea abies (L.) Karst * Windstorms * Bark beetle * Understory light availability * Saplings and poles * Canopy openness * Mountain forest Subject RIV: BB - Applied Statistics, Operational Research OBOR OECD: Statistics and probability Impact factor: 2.924, year: 2016

  17. Reconciliation with non-binary species trees.

    Science.gov (United States)

    Vernot, Benjamin; Stolzer, Maureen; Goldman, Aiton; Durand, Dannie

    2008-10-01

    Reconciliation extracts information from the topological incongruence between gene and species trees to infer duplications and losses in the history of a gene family. The inferred duplication-loss histories provide valuable information for a broad range of biological applications, including ortholog identification, estimating gene duplication times, and rooting and correcting gene trees. While reconciliation for binary trees is a tractable and well studied problem, there are no algorithms for reconciliation with non-binary species trees. Yet a striking proportion of species trees are non-binary. For example, 64% of branch points in the NCBI taxonomy have three or more children. When applied to non-binary species trees, current algorithms overestimate the number of duplications because they cannot distinguish between duplication and incomplete lineage sorting. We present the first algorithms for reconciling binary gene trees with non-binary species trees under a duplication-loss parsimony model. Our algorithms utilize an efficient mapping from gene to species trees to infer the minimum number of duplications in O(|V(G) | x (k(S) + h(S))) time, where |V(G)| is the number of nodes in the gene tree, h(S) is the height of the species tree and k(S) is the size of its largest polytomy. We present a dynamic programming algorithm which also minimizes the total number of losses. Although this algorithm is exponential in the size of the largest polytomy, it performs well in practice for polytomies with outdegree of 12 or less. We also present a heuristic which estimates the minimal number of losses in polynomial time. In empirical tests, this algorithm finds an optimal loss history 99% of the time. Our algorithms have been implemented in NOTUNG, a robust, production quality, tree-fitting program, which provides a graphical user interface for exploratory analysis and also supports automated, high-throughput analysis of large data sets.

  18. The status of Botryosphaeriaceae species infecting grapevines

    Directory of Open Access Journals (Sweden)

    Jose Ramón URBEZ-TORRES

    2011-12-01

    Full Text Available Normal 0 MicrosoftInternetExplorer4 Normal 0 MicrosoftInternetExplorer4 Species in the Botryosphaeriaceae have a cosmopolitan distribution, and occur on a wide range of annual and perennial hosts including grapevines. To date, morphological and taxonomic studies, as well as analyses of nucleotide sequences of multiple genes, have allowed the identification of at least 21 different species in the Botryosphaeriaceae occurring in grapevines worldwide. Grapevine disease symptoms caused by members of this family include leaf spots, fruit rots, shoot dieback, bud necrosis, vascular discoloration of the wood, and perennial cankers, and their current status as pathogens is reviewed. Additionally, the disease name Botryosphaeria dieback is proposed here to describe the different grapevine trunk disease symptoms caused by species of Botryosphaeriaceae. Much has been written during the last decade about the association between species in the Botryosphaeriaceae and grapevine trunk diseases, which has contributed to a better understanding of the role that these fungal taxa play in grapevine diseases. Although virulence has been shown to vary between species and isolates of the same species in different countries, these fungi have become well-recognized as important grapevine pathogens worldwide. Latest and novel findings from studies conducted in different countries, on disease etiology and species distribution, epidemiology and biology are discussed. Much progress has been achieved in the development and implementation of novel diagnostic and detection techniques.Vineyard sanitation techniques, as well as chemical, biological, and cultural control strategies available at the present time to reduce the infection caused by botryosphaeriaceous fungi, are presented in this review. 

  19. New species of Auritella (Inocybaceae) from Cameroon, with a worldwide key to the known species.

    Science.gov (United States)

    Matheny, P Brandon; Henkel, Terry W; Séné, Olivier; Korotkin, Hailee B; Dentinger, Bryn T M; Aime, M Catherine

    2017-12-01

    Two new species in the genus Auritella ( Inocybaceae ) are described as new from tropical rainforest in Cameroon. Descriptions, photographs, line drawings, and a worldwide taxonomic key to the described species of Auritella are presented. Phylogenetic analysis of 28S rDNA and rpb2 nucleotide sequence data suggests at least five phylogenetic species that can be ascribed to Auritella occur in the region comprising Cameroon and Gabon and constitute a strongly supported monophyletic subgroup within the genus. Phylogenetic analysis of ITS data supports the conspecificity of numerous collections attributed to the two new species as well as the monophyly of Australian species of Auritella . This work raises the known number of described species of Auritella to thirteen worldwide, four of which occur in tropical Africa, one in tropical India, and eight in temperate and tropical regions of Australia. This is the first study to confirm an ectomycorrhizal status of Auritella using molecular data.

  20. Molluscan indicator species and their potential use in ecological status assessment using species distribution modeling.

    Science.gov (United States)

    Moraitis, Manos L; Tsikopoulou, Irini; Geropoulos, Antonios; Dimitriou, Panagiotis D; Papageorgiou, Nafsika; Giannoulaki, Marianna; Valavanis, Vasilis D; Karakassis, Ioannis

    2018-05-24

    Marine habitat assessment using indicator species through Species Distribution Modeling (SDM) was investigated. The bivalves: Corbula gibba and Flexopecten hyalinus were the indicator species characterizing disturbed and undisturbed areas respectively in terms of chlorophyll a concentration in Greece. The habitat suitability maps of these species reflected the overall ecological status of the area. The C. gibba model successfully predicted the occurrence of this species in areas with increased physical disturbance driven by chlorophyll a concentration, whereas the habitat map for F. hyalinus showed an increased probability of occurrence in chlorophyll-poor areas, affected mainly by salinity. We advocate the use of C. gibba as a proxy for eutrophication and the incorporation of this species in monitoring studies through SDM methods. For the Mediterranean Sea we suggest the use of F. hyalinus in SDM as an indicator of environmental stability and a possible forecasting tool for salinity fluctuations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Reproductive Impacts of Endocrine-Disrupting Chemicals on Wildlife Species: Implications for Conservation of Endangered Species.

    Science.gov (United States)

    Tubbs, Christopher W; McDonough, Caitlin E

    2018-02-15

    Wildlife have proven valuable to our understanding of the potential effects of endocrine-disrupting chemicals (EDCs) on human health by contributing considerably to our understanding of the mechanisms and consequences of EDC exposure. But the threats EDCs present to populations of wildlife species themselves are significant, particularly for endangered species whose existence is vulnerable to any reproductive perturbation. However, few studies address the threats EDCs pose to endangered species owing to challenges associated with their study. Here, we highlight those barriers and review the available literature concerning EDC effects on endangered species. Drawing from other investigations into nonthreatened wildlife species, we highlight opportunities for new approaches to advance our understanding and potentially mitigate the effects of EDCs on endangered species to enhance their fertility.

  2. Biological review of 82 species of coral petitioned to be included in the Endangered Species Act

    Science.gov (United States)

    Brainard, Russell E.; Birkeland, Charles; Eakin, C. Mark; McElhany, Paul; Miller, Margaret W.; Patterson, Matt; Piniak, G.A.

    2011-01-01

    list 83 coral species as threatened or endangered under the U.S. Endangered Species Act. The petition was based on a predicted decline in available habitat for the species, citing anthropogenic climate change and ocean acidification as the lead factors among the various stressors responsible for the potential decline. The NMFS identified 82 of the corals as candidate species, finding that the petition provided substantive information for a potential listing of these species. The NMFS established a Biological Review Team (BRT) to prepare this Status Review Report that examines the status of these 82 candidate coral species and evaluates extinction risk for each of them. This document makes no recommendations for listing, as that is a separate evaluation to be conducted by the NMFS.

  3. Proactive Conservation Program: Species of Concern :: NOAA Fisheries

    Science.gov (United States)

    Invertebrates & Plants Species of Concern Threatened & Endangered Health & Stranding Marine Mammals : Species of Concern Species of Concern List | Grants and Technical Resources/Links bluefin tuna Bluefin Tuna (Thunnus thynnus) Photo: NOAA Species of Concern are those species about which we have some

  4. Effects of habitat structure and altitudinal gradients on avian species ...

    African Journals Online (AJOL)

    ... effect on bird species diversity. Bird species diversity increased with increase in tree height. A significant decline in bird species diversity with increased number of trees and canopy cover was noted. This result probably suggests an accumulation of forest edge species and generalist species in the less forested habitat.

  5. Delineating probabilistic species pools in ecology and biogeography

    OpenAIRE

    Karger, Dirk Nikolaus; Cord, Anna F; Kessler, Michael; Kreft, Holger; Kühn, Ingolf; Pompe, Sven; Sandel, Brody; Sarmento Cabral, Juliano; Smith, Adam B; Svenning, Jens-Christian; Tuomisto, Hanna; Weigelt, Patrick; Wesche, Karsten

    2016-01-01

    Aim To provide a mechanistic and probabilistic framework for defining the species pool based on species-specific probabilities of dispersal, environmental suitability and biotic interactions within a specific temporal extent, and to show how probabilistic species pools can help disentangle the geographical structure of different community assembly processes. Innovation Probabilistic species pools provide an improved species pool definition based on probabilities in conjuncti...

  6. Two new species of the Phanaeus endymion species group (Coleoptera, Scarabaeidae, Scarabaeinae).

    Science.gov (United States)

    Moctezuma, Victor; Sánchez-Huerta, José Luis; Halffter, Gonzalo

    2017-01-01

    Phanaeus bravoensis sp. n. is described from the coniferous-oak forests in the state of Guerrero, and P. huichol sp. n. from coniferous-oak forests and cloud forests in Jalisco and Nayarit. The new species are closely related to P. halffterorum and P. zoque respectively. Morphological trait combination, geographic distribution, and trophic habits show important differences among the studied species. A distribution map and an updated key to separate the species are included.

  7. Discordance between morphological and molecular species boundaries among Caribbean species of the reef sponge Callyspongia

    OpenAIRE

    DeBiasse, Melissa B; Hellberg, Michael E

    2015-01-01

    Sponges are among the most species-rich and ecologically important taxa on coral reefs, yet documenting their diversity is difficult due to the simplicity and plasticity of their morphological characters. Genetic attempts to identify species are hampered by the slow rate of mitochondrial sequence evolution characteristic of sponges and some other basal metazoans. Here we determine species boundaries of the Caribbean coral reef sponge genus Callyspongia using a multilocus, model-based approach...

  8. Indicator species of essential forest tree species in the Burdur district.

    Science.gov (United States)

    Negiz, Mehmet Güvenç; Eser, Yunus; Kuzugüdenll, Emre; Izkan, Kürşad

    2015-01-01

    The forests of Burdur district for long have been subjected to over grazing and individual selection. As a result of this, majority of the forest areas in the district were degraded. In the district, afforestation efforts included majority of forestry implementations. It is well known that selecting suitable species plays an important role for achieving afforestation efforts. In this context, knowing the indicator species among the target species would be used in afforestation efforts, studies on the interrelationships between environmental factors and target species distribution is vital for selecting suitable species for a given area. In this study, Anatolian Black pine (Pinus nigra), Red pine (Pinus brutia), Crimean juniper (Juniperus excelsa) and Taurus cedar (Cedrus libani), essential tree species, were considered as target species. The data taken from 100 sample plots in Burdur district was used. Interspecific correlation analysis was performed to determine the positive and negative indicator species among each of the target species. As a result of ICA, 2 positive (Berberis crataegina, Juniperus oxycedrus), 2 negative (Phillyrea latifolia, Quercus coccifera) for Crimean Juniper, I positive (Juniperus oxycedrus), 3 negative (Onopordium acanthium, Fraxinus ornus, Phillyrea latifolia) for Anatolian black pine, 3 positive (Paliurus spina-christi, Quercus coccifer, Crataegus orientalis), 2 negative (Berberis crataegina, Astragalus nanus) for Red pine and 3 positive (Berberis crataegina, Rhamnus oleoides, Astragalus prusianus) 2 negative (Paliurus spina-christi, Quercus cerris) for Taurus cedarwere defined as indicator plant species. In this way, practical information was obtained for selecting the most suitable species, among the target species, for afforestation efforts in Burdur district.

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

    Directory of Open Access Journals (Sweden)

    Alexander Bjarnason

    2017-08-01

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

  10. Two-species occupancy modeling accounting for species misidentification and nondetection

    Science.gov (United States)

    Chambert, Thierry; Grant, Evan H. Campbell; Miller, David A. W.; Nichols, James; Mulder, Kevin P.; Brand, Adrianne B,

    2018-01-01

    1. In occupancy studies, species misidentification can lead to false positive detections, which can cause severe estimator biases. Currently, all models that account for false positive errors only consider omnibus sources of false detections and are limited to single species occupancy. 2. However, false detections for a given species often occur because of the misidentification with another, closely-related species. To exploit this explicit source of false positive detection error, we develop a two-species occupancy model that accounts for misidentifications between two species of interest. As with other false positive models, identifiability is greatly improved by the availability of unambiguous detections at a subset of site-occasions. Here, we consider the case where some of the field observations can be confirmed using laboratory or other independent identification methods (“confirmatory data”). 3. We performed three simulation studies to (1) assess the model’s performance under various realistic scenarios, (2) investigate the influence of the proportion of confirmatory data on estimator accuracy, and (3) compare the performance of this two-species model with that of the single-species false positive model. The model shows good performance under all scenarios, even when only small proportions of detections are confirmed (e.g., 5%). It also clearly outperforms the single-species model.

  11. Bias correction in species distribution models: pooling survey and collection data for multiple species.

    Science.gov (United States)

    Fithian, William; Elith, Jane; Hastie, Trevor; Keith, David A

    2015-04-01

    Presence-only records may provide data on the distributions of rare species, but commonly suffer from large, unknown biases due to their typically haphazard collection schemes. Presence-absence or count data collected in systematic, planned surveys are more reliable but typically less abundant.We proposed a probabilistic model to allow for joint analysis of presence-only and survey data to exploit their complementary strengths. Our method pools presence-only and presence-absence data for many species and maximizes a joint likelihood, simultaneously estimating and adjusting for the sampling bias affecting the presence-only data. By assuming that the sampling bias is the same for all species, we can borrow strength across species to efficiently estimate the bias and improve our inference from presence-only data.We evaluate our model's performance on data for 36 eucalypt species in south-eastern Australia. We find that presence-only records exhibit a strong sampling bias towards the coast and towards Sydney, the largest city. Our data-pooling technique substantially improves the out-of-sample predictive performance of our model when the amount of available presence-absence data for a given species is scarceIf we have only presence-only data and no presence-absence data for a given species, but both types of data for several other species that suffer from the same spatial sampling bias, then our method can obtain an unbiased estimate of the first species' geographic range.

  12. Seasonal species interactions minimize the impact of species turnover on the likelihood of community persistence.

    Science.gov (United States)

    Saavedra, Serguei; Rohr, Rudolf P; Fortuna, Miguel A; Selva, Nuria; Bascompte, Jordi

    2016-04-01

    Many of the observed species interactions embedded in ecological communities are not permanent, but are characterized by temporal changes that are observed along with abiotic and biotic variations. While work has been done describing and quantifying these changes, little is known about their consequences for species coexistence. Here, we investigate the extent to which changes of species composition impact the likelihood of persistence of the predator-prey community in the highly seasonal Białowieza Primeval Forest (northeast Poland), and the extent to which seasonal changes of species interactions (predator diet) modulate the expected impact. This likelihood is estimated extending recent developments on the study of structural stability in ecological communities. We find that the observed species turnover strongly varies the likelihood of community persistence between summer and winter. Importantly, we demonstrate that the observed seasonal interaction changes minimize the variation in the likelihood of persistence associated with species turnover across the year. We find that these community dynamics can be explained as the coupling of individual species to their environment by minimizing both the variation in persistence conditions and the interaction changes between seasons. Our results provide a homeostatic explanation for seasonal species interactions and suggest that monitoring the association of interactions changes with the level of variation in community dynamics can provide a good indicator of the response of species to environmental pressures.

  13. Socially-parasitic Myrmica species (Hymenoptera, Formicidae) of Himalaya, with the description of a new species.

    Science.gov (United States)

    Bharti, Himender; Radchenko, Alexander; Sasi, Sishal

    2016-01-01

    A new socially-parasitic species, Myrmica latra sp. n. is described based on a queen and male from Indian Himalaya. Its queen differs from other species by the distinctly narrower petiole and postpetiole, blunt and non-divergent propodeal spines, and a darker body colour. The taxonomic position of the three known Himalayan socially-parasitic Myrmica species is discussed, and Myrmica ereptrix Bolton 1988 is transferred to the smythiesii species-group. It is supposed that Myrmica nefaria Bharti 2012 is a temporary social parasite, but Myrmica ereptrix and Myrmica latra sp. n. are permanent social parasites, and a key for their identification is provided.

  14. Onychiurid species from Wanda Mountains in China, with descriptions of two new species (Collembola, Onychiuridae)

    Science.gov (United States)

    Sun, Xin; Wu, Donghui

    2014-01-01

    Abstract A checklist of onychiurid species from the Wanda Mountains in China is presented. Eighteen species belonging to twelve genera have been found, including two new species. Bionychiurus qinglongensis sp. n. can be easily distinguished from other known species of the genus by the absence of pseudocelli on Th. I tergum and fewer number of vesicles in postantennal organ. Onychiurus heilongjiangensis sp. n. is diagnosed by pseudocellar formulae as 32/133/33352 dorsally and 3/011/31120 ventrally, parapseudocellar formula as 0/000/111001+1m, ratio of anal spine/unguis as 0.6, unguiculus without inner basal lamella, and male ventral organ absent. PMID:25147452

  15. Reconciliation of Gene and Species Trees

    Directory of Open Access Journals (Sweden)

    L. Y. Rusin

    2014-01-01

    Full Text Available The first part of the paper briefly overviews the problem of gene and species trees reconciliation with the focus on defining and algorithmic construction of the evolutionary scenario. Basic ideas are discussed for the aspects of mapping definitions, costs of the mapping and evolutionary scenario, imposing time scales on a scenario, incorporating horizontal gene transfers, binarization and reconciliation of polytomous trees, and construction of species trees and scenarios. The review does not intend to cover the vast diversity of literature published on these subjects. Instead, the authors strived to overview the problem of the evolutionary scenario as a central concept in many areas of evolutionary research. The second part provides detailed mathematical proofs for the solutions of two problems: (i inferring a gene evolution along a species tree accounting for various types of evolutionary events and (ii trees reconciliation into a single species tree when only gene duplications and losses are allowed. All proposed algorithms have a cubic time complexity and are mathematically proved to find exact solutions. Solving algorithms for problem (ii can be naturally extended to incorporate horizontal transfers, other evolutionary events, and time scales on the species tree.

  16. SPECIES DIVERSITY AND STABILITY OF BIRD COMMUNITIES

    Directory of Open Access Journals (Sweden)

    Matsyura M.V.

    2011-12-01

    Full Text Available When comparing the suggested stability indicators, we obtained statistically significant correlations for indicators of annual stability of species and total number and standard deviation of the logarithm of the number. Annual Stability Index can be applied with a high degree of reliability as a characteristic of the averaged structure of the community and its pyramid of abundances. The results of correlation analysis confirm our assumptions about the correlation between stability over the years and indices of species diversity and relative uniformity.The final task of the study was to create a mathematical model of stability, where the independent variables are the indices of species diversity. The calculation of these indices allows forecasting birds’ community stability. According to the result of multiple regression for the indicators of diversity and stability of the breeding birds’ community highest correlation coefficients were obtained fro Shannon index and Simpson's dominance Index.Community stability could be determined by its overall species diversity. When considering the stability of community its diversity should be considered as a combination of uniformity of their total number and number of species. The most suitable predictors for the community stability were the nonparametric index of dominance and information-statistical indices, since they considered simultaneously evenness and richness. The community stability is subject of the complexity of its internal communications pattern.

  17. Diversity in protein glycosylation among insect species.

    Directory of Open Access Journals (Sweden)

    Gianni Vandenborre

    Full Text Available BACKGROUND: A very common protein modification in multicellular organisms is protein glycosylation or the addition of carbohydrate structures to the peptide backbone. Although the Class of the Insecta is the largest animal taxon on Earth, almost all information concerning glycosylation in insects is derived from studies with only one species, namely the fruit fly Drosophila melanogaster. METHODOLOGY/PRINCIPAL FINDINGS: In this report, the differences in glycoproteomes between insects belonging to several economically important insect orders were studied. Using GNA (Galanthus nivalis agglutinin affinity chromatography, different sets of glycoproteins with mannosyl-containing glycan structures were purified from the flour beetle (Tribolium castaneum, the silkworm (Bombyx mori, the honeybee (Apis mellifera, the fruit fly (D. melanogaster and the pea aphid (Acyrthosiphon pisum. To identify and characterize the purified glycoproteins, LC-MS/MS analysis was performed. For all insect species, it was demonstrated that glycoproteins were related to a broad range of biological processes and molecular functions. Moreover, the majority of glycoproteins retained on the GNA column were unique to one particular insect species and only a few glycoproteins were present in the five different glycoprotein sets. Furthermore, these data support the hypothesis that insect glycoproteins can be decorated with mannosylated O-glycans. CONCLUSIONS/SIGNIFICANCE: The results presented here demonstrate that oligomannose N-glycosylation events are highly specific depending on the insect species. In addition, we also demonstrated that protein O-mannosylation in insect species may occur more frequently than currently believed.

  18. Pain, Cannabis Species, and Cannabis Use Disorders

    Science.gov (United States)

    Cohen, Nicole L.; Heinz, Adrienne J.; Ilgen, Mark; Bonn-Miller, Marcel O.

    2016-01-01

    Objective: The purpose of this study was to examine whether individuals who used medical cannabis for chronic pain were at increased risk for cannabis use problems compared with individuals who used medical cannabis for other reasons (e.g., anxiety, insomnia, and muscle spasms). An additional aim was to determine whether individuals who used cannabis for chronic pain, as well as those who reported greater within-group pain levels, demonstrated a species preference (i.e., sativa, indica, hybrids) and the extent to which species preference was associated with cannabis use problems. Method: Participants were 163 medical cannabis users (77% male), recruited from a medical marijuana dispensary in California, who completed assessments of medical cannabis use motives, history, preferences (species type), and problems, as well as current pain level. Results: Individuals who used cannabis to manage chronic pain experienced fewer cannabis use problems than those who did not use it for pain; among those who used it for pain, the average pain level in the past week was not associated with cannabis use problems. Furthermore, individuals who used cannabis for chronic pain were more likely to use indica over sativa. Preference for indica was associated with fewer cannabis use problems than preference for hybrid species. Conclusions: Individuals who use cannabis to manage chronic pain may be at a lower risk for cannabis use problems, relative to individuals who use it for other indications, potentially as a function of their species preference. PMID:27172585

  19. Bracken: estimating species abundance in metagenomics data

    Directory of Open Access Journals (Sweden)

    Jennifer Lu

    2017-01-01

    Full Text Available Metagenomic experiments attempt to characterize microbial communities using high-throughput DNA sequencing. Identification of the microorganisms in a sample provides information about the genetic profile, population structure, and role of microorganisms within an environment. Until recently, most metagenomics studies focused on high-level characterization at the level of phyla, or alternatively sequenced the 16S ribosomal RNA gene that is present in bacterial species. As the cost of sequencing has fallen, though, metagenomics experiments have increasingly used unbiased shotgun sequencing to capture all the organisms in a sample. This approach requires a method for estimating abundance directly from the raw read data. Here we describe a fast, accurate new method that computes the abundance at the species level using the reads collected in a metagenomics experiment. Bracken (Bayesian Reestimation of Abundance after Classification with KrakEN uses the taxonomic assignments made by Kraken, a very fast read-level classifier, along with information about the genomes themselves to estimate abundance at the species level, the genus level, or above. We demonstrate that Bracken can produce accurate species- and genus-level abundance estimates even when a sample contains multiple near-identical species.

  20. Atomic collisions research with excited atomic species

    International Nuclear Information System (INIS)

    Hoogerland, M.D.; Gulley, R.J.; Colla, M.; Lu, W.; Milic, D.; Baldwin, K.G.H.; Buckman, S.J.

    1999-01-01

    Measurements and calculations of fundamental atomic collision and spectroscopic properties such as collision cross sections, reaction rates, transition probabilities etc. underpin the understanding and operation of many plasma and gas-discharge-based devices and phenomena, for example plasma processing and deposition. In almost all cases the complex series of reactions which sustains the discharge or plasma, or produces the reactive species of interest, has a precursor electron impact excitation, attachment, dissociation or ionisation event. These processes have been extensively studied in a wide range of atomic and molecular species and an impressive data base of collision cross sections and reaction rates now exists. However, most of these measurements are for collisions with stable atomic or molecular species which are initially in their ground electronic state. Relatively little information is available for scattering from excited states or for scattering from unstable molecular radicals. Examples of such species would be metastable excited rare gases, which are often used as buffer gases, or CF 2 radicals formed by electron impact dissociation in a CF 4 plasma processing discharge. We are interested in developing experimental techniques which will enable the quantitative study of such exotic atomic and molecular species. In this talk I would like to outline one such facility which is being used for studies of collisions with metastable He(2 3 S) atoms

  1. Exploring similarities among many species distributions

    Science.gov (United States)

    Simmerman, Scott; Wang, Jingyuan; Osborne, James; Shook, Kimberly; Huang, Jian; Godsoe, William; Simons, Theodore R.

    2012-01-01

    Collecting species presence data and then building models to predict species distribution has been long practiced in the field of ecology for the purpose of improving our understanding of species relationships with each other and with the environment. Due to limitations of computing power as well as limited means of using modeling software on HPC facilities, past species distribution studies have been unable to fully explore diverse data sets. We build a system that can, for the first time to our knowledge, leverage HPC to support effective exploration of species similarities in distribution as well as their dependencies on common environmental conditions. Our system can also compute and reveal uncertainties in the modeling results enabling domain experts to make informed judgments about the data. Our work was motivated by and centered around data collection efforts within the Great Smoky Mountains National Park that date back to the 1940s. Our findings present new research opportunities in ecology and produce actionable field-work items for biodiversity management personnel to include in their planning of daily management activities.

  2. Species richness, area and climate correlates

    DEFF Research Database (Denmark)

    Nogues, David Bravo; Bastos Araujo, Miguel

    2006-01-01

    affects: (1) the selection of climate variables entering a species richness model; and (2) the accuracy of models in predicting species richness in unsampled grid cells. Location Western Europe. Methods Models are developed for European plant, breeding bird, mammal and herptile species richness using...... seven climate variables. Generalized additive models are used to relate species richness, climate and area. Results We found that variation in the grid cell area was large (50 × 50 km: 8-3311 km2; 220 × 220: 193-55,100 km2), but this did not affect the selection of variables in the models. Similarly...... support the assumption that variation in near-equal area cells may be of second-order importance for models explaining or predicting species richness in relation to climate, although there is a possibility that drops in accuracy might increase with grid cell size. The results are, however, contingent...

  3. Pain, Cannabis Species, and Cannabis Use Disorders.

    Science.gov (United States)

    Cohen, Nicole L; Heinz, Adrienne J; Ilgen, Mark; Bonn-Miller, Marcel O

    2016-05-01

    The purpose of this study was to examine whether individuals who used medical cannabis for chronic pain were at increased risk for cannabis use problems compared with individuals who used medical cannabis for other reasons (e.g., anxiety, insomnia, and muscle spasms). An additional aim was to determine whether individuals who used cannabis for chronic pain, as well as those who reported greater within-group pain levels, demonstrated a species preference (i.e., sativa, indica, hybrids) and the extent to which species preference was associated with cannabis use problems. Participants were 163 medical cannabis users (77% male), recruited from a medical marijuana dispensary in California, who completed assessments of medical cannabis use motives, history, preferences (species type), and problems, as well as current pain level. Individuals who used cannabis to manage chronic pain experienced fewer cannabis use problems than those who did not use it for pain; among those who used it for pain, the average pain level in the past week was not associated with cannabis use problems. Furthermore, individuals who used cannabis for chronic pain were more likely to use indica over sativa. Preference for indica was associated with fewer cannabis use problems than preference for hybrid species. Individuals who use cannabis to manage chronic pain may be at a lower risk for cannabis use problems, relative to individuals who use it for other indications, potentially as a function of their species preference.

  4. 77 FR 30261 - Petition To List 83 Species of Coral as Threatened or Endangered Under the Endangered Species Act...

    Science.gov (United States)

    2012-05-22

    ... List 83 Species of Coral as Threatened or Endangered Under the Endangered Species Act (ESA) AGENCY... Diversity (CBD) to list 83 coral species as threatened or endangered under the Endangered Species Act (ESA... the U.S. Endangered Species Act (Status Review Report) and the draft Management Report for 82 Corals...

  5. Current understanding of multi-species biofilms

    DEFF Research Database (Denmark)

    Yang, Liang; Liu, Yang; Wu, Hong

    2011-01-01

    every year worldwide to deal with damage to equipment, contaminations of products, energy losses, and infections in human beings resulted from microbial biofilms. Microorganisms compete, cooperate, and communicate with each other in multi-species biofilms. Understanding the mechanisms of multi......Direct observation of a wide range of natural microorganisms has revealed the fact that the majority of microbes persist as surface-attached communities surrounded by matrix materials, called biofilms. Biofilms can be formed by a single bacterial strain. However, most natural biofilms are actually......-species biofilm formation will facilitate the development of methods for combating bacterial biofilms in clinical, environmental, industrial, and agricultural areas. The most recent advances in the understanding of multi-species biofilms are summarized and discussed in the review....

  6. Assessing species vulnerability to climate change

    Science.gov (United States)

    Pacifici, Michela; Foden, Wendy B.; Visconti, Piero; Watson, James E. M.; Butchart, Stuart H. M.; Kovacs, Kit M.; Scheffers, Brett R.; Hole, David G.; Martin, Tara G.; Akçakaya, H. Resit; Corlett, Richard T.; Huntley, Brian; Bickford, David; Carr, Jamie A.; Hoffmann, Ary A.; Midgley, Guy F.; Pearce-Kelly, Paul; Pearson, Richard G.; Williams, Stephen E.; Willis, Stephen G.; Young, Bruce; Rondinini, Carlo

    2015-03-01

    The effects of climate change on biodiversity are increasingly well documented, and many methods have been developed to assess species' vulnerability to climatic changes, both ongoing and projected in the coming decades. To minimize global biodiversity losses, conservationists need to identify those species that are likely to be most vulnerable to the impacts of climate change. In this Review, we summarize different currencies used for assessing species' climate change vulnerability. We describe three main approaches used to derive these currencies (correlative, mechanistic and trait-based), and their associated data requirements, spatial and temporal scales of application and modelling methods. We identify strengths and weaknesses of the approaches and highlight the sources of uncertainty inherent in each method that limit projection reliability. Finally, we provide guidance for conservation practitioners in selecting the most appropriate approach(es) for their planning needs and highlight priority areas for further assessments.

  7. Autofluorescence in eleocytes of some earthworm species.

    Directory of Open Access Journals (Sweden)

    Barbara Płytycz

    2006-04-01

    Full Text Available Immunocompetent cells of earthworms, coelomocytes, comprise adherent amoebocytes and granular eleocytes (chloragocytes. Both cell populations can be expelled via dorsal pores of adult earthworms by exposure to an electric current (4.5 V for 1 min. Analysis by phase contrast/fluorescence microscopy and flow cytometry demonstrated that eleocyte population of several species exhibits a strong autofluorescence. A high percentage (11-35% of autofluorescent eleocytes was recorded in Allolobophora chlorotica, Dendrodrilus rubidus, Eisenia fetida, and Octolasion sp. (O. cyaneum, O. tyrtaeum tyrtaeum and O. tyrtaeum lacteum. In contrast, autofluorescent coelomocytes were exceptionally scarce (less than 1% in representative Aporrectodea sp. (A. caliginosa and A. longa and Lumbricus sp. (L. castaneus, L. festivus, L. rubellus, L. terrestris. Thus, this paper for the first time describes profound intrinsic fluorescence of eleocytes in some--but not all--earthworm species. The function (if any and inter-species differences of the autofluorescent coelomocytes still remain elusive.

  8. The prairie dog as a keystone species

    Science.gov (United States)

    Kotliar, Natasha B.; Miller, Brian J.; Reading, Richard P.; Clark, Timothy W.; Hoogland, John L.

    2006-01-01

    The prairie dog has a pronounced impact on its grassland ecosystem (King 1955; Uresk and Bjugstad 1983; Miller et al. 1994; Society for Conservation Biology 1994; Wuerthner 1997; Johnsgard 2005). They maintain short vegetation by their grazing and by selective removal of tall plants and shrubs; provide shelter, foraging grounds, and nesting habitat for a diverse array of animals; serve as prey for many predators; and alter soil chemistry.Do these impacts mean that the prairie dog is a keystone species? To investigate, we first scrutinize the definition for a keystone species. We then document both vertebrates and invertebrates that associate with prairie dogs and their colony-sites. We examine ecosystem processes at colony-sites, and then assess whether the prairie dog is a legitimate keystone species. Finally, we explore the implications of keystone status for the conservation of prairie dogs.

  9. Forms and genesis of species abundance distributions

    Directory of Open Access Journals (Sweden)

    Evans O. Ochiaga

    2015-12-01

    Full Text Available Species abundance distribution (SAD is one of the most important metrics in community ecology. SAD curves take a hollow or hyperbolic shape in a histogram plot with many rare species and only a few common species. In general, the shape of SAD is largely log-normally distributed, although the mechanism behind this particular SAD shape still remains elusive. Here, we aim to review four major parametric forms of SAD and three contending mechanisms that could potentially explain this highly skewed form of SAD. The parametric forms reviewed here include log series, negative binomial, lognormal and geometric distributions. The mechanisms reviewed here include the maximum entropy theory of ecology, neutral theory and the theory of proportionate effect.

  10. Taxonomy of Penicillium citrinum and related species

    DEFF Research Database (Denmark)

    Houbraken, J.A.M.P.; Frisvad, Jens Christian; Samson, A.F.

    2010-01-01

    are related to P. citrinum, P. gorlenkoanum is revived, Penicillium hetheringtonii sp. nov. and Penicillium tropicoides sp. nov. are described here as new species, and the combination Penicillium tropicum is proposed. Penicillium hetheringtonii is closely related to P. citrinum and differs in having slightly......Penicillium citrinum and related species have been examined using a combination of partial beta-tubulin, calmodulin and ITS sequence data, extrolite patterns and phenotypic characters. It is concluded that seven species belong to the series Citrina. Penicillium sizovae and Penicillium steckii...... broader stipes, metulae in verticils of four or more and the production of an uncharacterized metabolite, tentatively named PR1-x. Penicillium tropicoides resembles P. tropicum, but differs in the slow maturation of the cleistothecia, slower growth at 30A degrees C and the production of isochromantoxins...

  11. WHITE BLISTER SPECIES (Albuginaceae ON WEEDS

    Directory of Open Access Journals (Sweden)

    Karolina Vrandečić

    2011-06-01

    Full Text Available The obligate fungi inside the family Albuginaceae are widespread world wide and cause white rust or white blister disease. Mycopopulation of weeds has been researched within the project „The role of weeds in epidemiology of row-crop diseases“. The aim of this research was to identify white blister species occurring on weeds in Eastern Croatia. Weed plants with disease symptoms characteristic for white blister species have been collected since 2001 on location Slavonia and Baranja country. Determination of white blister species was based on morphological characters of pathogen and the host. Wilsoniana bliti was determined on Amaranthus retroflexus and Amaranthus hybridus leaves. Capsella bursa pastoris is a host for Albugo candida. Ambrosia artemisiifolia is a host for Pustula sp. and Cirsium arvense was found to be host for Pustula spinulosa. Wilsoniana portulaceae was determined on Portulaca oleracea.

  12. Distribution of Vulpia species (Poaceae in Poland

    Directory of Open Access Journals (Sweden)

    Ludwik Frey

    2011-01-01

    Full Text Available The distribution of four species of the genus Vulpia [V. myuros (L. C.C. Gmel., V. bromoides (L. S.F. Gray, V. ciliata Dumort. and V. geniculata (L. Link] reported in Poland has been studied. Currently, V. myuros and especially V. bromoides are very rare species, and their greatest concentration can be found only in the Lower Silesia region. The number of their localities decreased after 1950 and it seems resonable to include both species in the "red list" of threatened plants in Poland: V. myuros in the EN category, V. bromoides in the CR category. V. ciliata and V. geniculata are very rare ephemerophytes and their localities not confirmed during ca 60 years are of historical interest only.

  13. Computational botany methods for automated species identification

    CERN Document Server

    Remagnino, Paolo; Wilkin, Paul; Cope, James; Kirkup, Don

    2017-01-01

    This book discusses innovative methods for mining information from images of plants, especially leaves, and highlights the diagnostic features that can be implemented in fully automatic systems for identifying plant species. Adopting a multidisciplinary approach, it explores the problem of plant species identification, covering both the concepts of taxonomy and morphology. It then provides an overview of morphometrics, including the historical background and the main steps in the morphometric analysis of leaves together with a number of applications. The core of the book focuses on novel diagnostic methods for plant species identification developed from a computer scientist’s perspective. It then concludes with a chapter on the characterization of botanists' visions, which highlights important cognitive aspects that can be implemented in a computer system to more accurately replicate the human expert’s fixation process. The book not only represents an authoritative guide to advanced computational tools fo...

  14. Capsular Polysaccharide Expression in Commensal Streptococcus Species

    DEFF Research Database (Denmark)

    Skov Sørensen, Uffe B; Yao, Kaihu; Yang, Yonghong

    2016-01-01

    Expression of a capsular polysaccharide is considered a hallmark of most invasive species of bacteria, including Streptococcus pneumoniae, in which the capsule is among the principal virulence factors and is the basis for successful vaccines. Consequently, it was previously assumed that capsule....... pneumoniae evolved by import of cps fragments from commensal Streptococcus species, resulting in a mosaic of genes of different origins. The demonstrated antigenic identity of at least eight of the numerous capsular polysaccharide structures expressed by commensal streptococci with recognized serotypes of S...... of Streptococcus pneumoniae and is the basis for successful vaccines against infections caused by this important pathogen. Contrasting with previous assumptions, this study showed that expression of capsular polysaccharides by the same genetic mechanisms is a general property of closely related species...

  15. Combinatorial Cis-regulation in Saccharomyces Species

    Directory of Open Access Journals (Sweden)

    Aaron T. Spivak

    2016-03-01

    Full Text Available Transcriptional control of gene expression requires interactions between the cis-regulatory elements (CREs controlling gene promoters. We developed a sensitive computational method to identify CRE combinations with conserved spacing that does not require genome alignments. When applied to seven sensu stricto and sensu lato Saccharomyces species, 80% of the predicted interactions displayed some evidence of combinatorial transcriptional behavior in several existing datasets including: (1 chromatin immunoprecipitation data for colocalization of transcription factors, (2 gene expression data for coexpression of predicted regulatory targets, and (3 gene ontology databases for common pathway membership of predicted regulatory targets. We tested several predicted CRE interactions with chromatin immunoprecipitation experiments in a wild-type strain and strains in which a predicted cofactor was deleted. Our experiments confirmed that transcription factor (TF occupancy at the promoters of the CRE combination target genes depends on the predicted cofactor while occupancy of other promoters is independent of the predicted cofactor. Our method has the additional advantage of identifying regulatory differences between species. By analyzing the S. cerevisiae and S. bayanus genomes, we identified differences in combinatorial cis-regulation between the species and showed that the predicted changes in gene regulation explain several of the species-specific differences seen in gene expression datasets. In some instances, the same CRE combinations appear to regulate genes involved in distinct biological processes in the two different species. The results of this research demonstrate that (1 combinatorial cis-regulation can be inferred by multi-genome analysis and (2 combinatorial cis-regulation can explain differences in gene expression between species.

  16. Nocardiopsis species: Incidence, ecological roles and adaptations.

    Science.gov (United States)

    Bennur, Tahsin; Kumar, Ameeta Ravi; Zinjarde, Smita; Javdekar, Vaishali

    2015-05-01

    Members of the genus Nocardiopsis are ecologically versatile and biotechnologically important. They produce a variety of bioactive compounds such as antimicrobial agents, anticancer substances, tumor inducers, toxins and immunomodulators. They also secrete novel extracellular enzymes such as amylases, chitinases, cellulases, β-glucanases, inulinases, xylanases and proteases. Nocardiopsis species are aerobic, Gram-positive, non-acid-fast, catalase-positive actinomycetes with nocardioform substrate mycelia and their aerial mycelia bear long chains of spores. Their DNA possesses high contents of guanine and cytosine. There is a marked variation in properties of the isolates obtained from different ecological niches and their products. An important feature of several species is their halophilic or halotolerant nature. They are associated with a variety of marine and terrestrial biological forms wherein they produce antibiotics and toxins that help their hosts in evading pathogens and predators. Two Nocardiopsis species, namely, N. dassonvillei and N. synnemataformans (among the thirty nine reported ones) are opportunistic human pathogens and cause mycetoma, suppurative infections and abscesses. Nocardiopsis species are present in some plants (as endophytes or surface microflora) and their rhizospheres. Here, they are reported to produce enzymes such as α-amylases and antifungal agents that are effective in warding-off plant pathogens. They are prevalent as free-living entities in terrestrial locales, indoor locations, marine ecosystems and hypersaline habitats on account of their salt-, alkali- and desiccation-resistant behavior. In such natural locations, Nocardiopsis species mainly help in recycling organic compounds. Survival under these diverse conditions is mediated by the production of extracellular enzymes, antibiotics, surfactants, and the accumulation of compatible solutes. The accommodative genomic features of Nocardiopsis species support their existence

  17. The Drosophila bipectinata species complex: degree of sterility and ...

    Indian Academy of Sciences (India)

    sophila bipectinata species complex, comprising four closely related species namely D. bipectinata, D. parabipectinata,. D. malerkotliana and D. ... vials with four males (two each from the respective parental species, to increase the probability ...

  18. Cryptic Sebastes norvegicus species in Greenland waters revealed by microsatellites

    DEFF Research Database (Denmark)

    Saha, Atal; Hauser, Lorenz; Hedeholm, Rasmus

    2017-01-01

    Identification of cryptic species can have profound implications in fishery management, conservation and biodiversity contexts. In the North Atlantic, the genus Sebastes is currently represented by four species, although additional cryptic species have been assumed. The connectivity of the gene...

  19. Genetic factors in Threatened Species Recovery Plans on three continents

    Science.gov (United States)

    Threatened species' recovery planning is applied globally to stem the current species extinction crisis. Evidence supports a key role of genetic processes, such as inbreeding depression, in determining species viability. We examined whether genetic factors are considered in threa...

  20. Variation in biofouling on different species of Indian timbers

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; Wagh, A.B.

    Biofouling on twenty species of wood exposed in waters of Mormugao Harbour, Goa, India have been presented. Macrofouling biomass varied from species to species. Maximum biomass was recorded on Artocarpus chaplasha (4 kg/m2) and minimum on Hopea...

  1. Hypoxylon species on beech and other broadleaves

    Directory of Open Access Journals (Sweden)

    Milijašević Tanja

    2004-01-01

    Full Text Available Fungi in the genus Hypoxylon cause wood decay and most of them are saprophytes on dead wood or parasites of weakness. The following species in this genus were identified in this study performed at several localities in Serbia and Montenegro: H. deustum, H. fragiforme, H. nummularium, H. multiforme, H. rubiginosum and H. fuscum. Among them the most significant species is H. deustum, the fungus causing root and butt rot of standing beech trees. It was recorded from all coppice and high forests of beech. This paper presents the morphological characteristics of the recorded fungi their range, plant hosts and significance.

  2. Functional biology of sympatric krill species

    DEFF Research Database (Denmark)

    Agersted, Mette Dalgaard; Nielsen, Torkel Gissel

    2016-01-01

    Here we compare the functional biology of the sympatric krill species, Meganyctiphanes norvegica and Thysanoessa inermis. For M. norvegica, we investigated functional responses on diatoms and copepods, together with prey size spectra on plankton ,400 mm and copepods in the size range 500–3220 mm....... For T. inermis, only prey size spectrum on plankton ,400 mm were investigated. The prey size ranges of both species include organisms ,400 mm, and they consequently graze on several trophic levels. However, T. inermis feed on cells ,10 mm equivalent spherical diameter (ESD), whereas M. norvegica only...

  3. Molecular activation analysis for chemical species studies

    International Nuclear Information System (INIS)

    Chai Zhifang; Mao Xueying; Wang Yuqi; Sun Jingxin; Qian Qingfang; Hou Xiaolin; Zhang Peiqun; Chen Chunying; Feng Weiyu; Ding Wenjun; Li Xiaolin; Li Chunsheng; Dai Xiongxin

    2001-01-01

    The Molecular Activation Analysis (MAA) mainly refers to an activation analysis method that is able to provide information about the chemical species of elements in systems of interest, though its exact definition has remained to be assigned. Its development is strongly stimulated by the urgent need to know the chemical species of elements, because the bulk contents or concentrations are often insignificant for judging biological, environmental or geochemical effects of elements. In this paper, the features, methodology and limitation of MAA were outlined. Further, the up-to-date MAA progress made in our laboratory was introduced as well. (author)

  4. A new dimension in documenting new species

    DEFF Research Database (Denmark)

    Akkari, Nesrine; Enghoff, Henrik; Metscher, Brian D.

    2015-01-01

    We review the state-of-the-art approaches currently applied in myriapod taxonomy, and we describe, for the first time, a new species of millipede (Ommatoiulus avatar n. sp., family Julidae) using high-resolution X-ray microtomography (microCT) as a substantive adjunct to traditional morphological...... examination. We present 3D models of the holotype and paratype specimens and discuss the potential of this non-destructive technique in documenting new species of millipedes and other organisms. The microCT data have been uploaded to an open repository (Dryad) to serve as the first actual millipede cybertypes...

  5. A new alamellate Hygrocybe species from Ecuador

    DEFF Research Database (Denmark)

    Læssøe, Thomas; Boertmann, David

    2008-01-01

    The first known species of Hygrocybe with a smooth hymenophore is described based on material from the eastern slopes of Andean Ecuador. It is considered as incertae sedis in the genus due to a lack of conclusive morphological characters and in the absence of sequence data.......The first known species of Hygrocybe with a smooth hymenophore is described based on material from the eastern slopes of Andean Ecuador. It is considered as incertae sedis in the genus due to a lack of conclusive morphological characters and in the absence of sequence data....

  6. FEATURES DIGESTION OF STURGEON SPECIES (ACIPENSERIDAE (REVIEW

    Directory of Open Access Journals (Sweden)

    M. Simon

    2016-09-01

    Full Text Available Purpose. To review scientific sources are about the anatomical, physiological and biochemical characteristics of the digestive system and proper digestion process in the sturgeon species (Acipenseridae. Outline the common anatomical and morphological characteristics of the gastrointestinal tract. Consider the activity of digestive enzymes and the influence of various factors. Findings. Review of scientific papers reveals that although the digestion of sturgeon are broadly similar to those of the cartilaginous and bony fish, there are a number of species specificity. In particular, sturgeon enzymes have a wider temperature and hydrogen ranges. It is confirmed that temperature adaptations of digestive system poikilothermic organ-isms are realised mainly thanks to reorganisations of fermental systems. It is shown that enzymes in sturgeons are adjustable, as their activity level significantly changes under the influence of divalent metal ions (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+. The assumption that evolutionary adaptation of hydrolytic function of intestines of fishes to temperature conditions of an inhabitancy takes place, apparently, is made. The paper describes the effect of sex and age factors on the level of activity of enzymes of sturgeons. Set out the regularities of circadian rhythms of the fish of this family. Showed specific features of the liver and its involvement in lipid metabolism and antioxidant defense system. Practical value. The knowledge of hydrolysis characteristics of a diet of sturgeon species is important for the efficiency estimation of feeding and understanding of evolutionary and ecological aspects of digestion physiology. Systematized data on the digestive system of fish sturgeon species are of interest a wide range of research in two main areas. Firstly, although the sturgeon are relict species, but the adaptation of their digestive system is still going on, allowing you to analyze the evolutionary development of the

  7. Big data of tree species distributions

    DEFF Research Database (Denmark)

    Serra-Diaz, Josep M.; Enquist, Brian J.; Maitner, Brian

    2018-01-01

    are currently available in big databases, several challenges hamper their use, notably geolocation problems and taxonomic uncertainty. Further, we lack a complete picture of the data coverage and quality assessment for open/public databases of tree occurrences. Methods: We combined data from five major...... and data aggregation, especially from national forest inventory programs, to improve the current publicly available data.......Background: Trees play crucial roles in the biosphere and societies worldwide, with a total of 60,065 tree species currently identified. Increasingly, a large amount of data on tree species occurrences is being generated worldwide: from inventories to pressed plants. While many of these data...

  8. 77 FR 15701 - Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management Plan...

    Science.gov (United States)

    2012-03-16

    ... Species Fishery Management Plan; Amendment 4 AGENCY: National Marine Fisheries Service (NMFS), National.... SUMMARY: This fishery management plan (FMP) amendment addresses Atlantic highly migratory species (HMS... to create an HMS Caribbean Small Boat Commercial Permit (CSBP) allowing fishing for and sales of...

  9. Invasive Species Science Branch: research and management tools for controlling invasive species

    Science.gov (United States)

    Reed, Robert N.; Walters, Katie D.

    2015-01-01

    Invasive, nonnative species of plants, animals, and disease organisms adversely affect the ecosystems they enter. Like “biological wildfires,” they can quickly spread and affect nearly all terrestrial and aquatic ecosystems. Invasive species have become one of the greatest environmental challenges of the 21st century in economic, environmental, and human health costs, with an estimated effect in the United States of more than $120 billion per year. Managers of the Department of the Interior and other public and private lands often rank invasive species as their top resource management problem. The Invasive Species Science Branch of the Fort Collins Science Center provides research and technical assistance relating to management concerns for invasive species, including understanding how these species are introduced, identifying areas vulnerable to invasion, forecasting invasions, and developing control methods. To disseminate this information, branch scientists are developing platforms to share invasive species information with DOI cooperators, other agency partners, and the public. From these and other data, branch scientists are constructing models to understand and predict invasive species distributions for more effective management. The branch also has extensive herpetological and population biology expertise that is applied to harmful reptile invaders such as the Brown Treesnake on Guam and Burmese Python in Florida.

  10. Species composition of a soil invertebrate multi-species test system determines the level of ecotoxicity

    DEFF Research Database (Denmark)

    Sechi, Valentina; D'Annibale, Alessandra; Maraldo, Kristine

    2014-01-01

    A soil multi-species, SMS, experimental test system consisting of the natural microbial community, five collembolan species and a predatory mite along with either Enchytraeus crypticus or the earthworm Eisenia fetida were exposed to α-cypermethrin. A comparison of the performance of these two typ...

  11. The Quercus feeding Stigmella species of the West Palaearctic: new species, key and distribution (Lepidoptera: Nepticulidae)

    NARCIS (Netherlands)

    Nieukerken, van E.J.; Johansson, R.

    2003-01-01

    The species of the Stigmella ruficapitella group occurring in the Western Palaearctic and feeding on Quercus are reviewed. We recognise 19 species, five of which are described as new: Stigmella fasciata sp. n. on Quercus pubescens from Slovenia, Croatia, Greece and Turkey, S. cocciferae sp. n. on Q.

  12. Usefulness of the wildlife species as a focal species in the forest ...

    African Journals Online (AJOL)

    yasinucarlı

    2011-03-14

    Mar 14, 2011 ... keystone species are the most important species in that ecosystems to sustainability. ... bear, Wolf and Eurasian Lynx can be also used as a flagship, indicator and ... Washington's Pacific coast. ... sidered keystones because their effect is not dispro- ..... conservation of South American terrestrial mammals.

  13. A new Amazonian species from the Drosophila annulimana species group (Diptera, Drosophilidae

    Directory of Open Access Journals (Sweden)

    Marco S. Gottschalk

    2012-12-01

    Full Text Available Drosophila caxiuana sp. nov., Drosophila subgenus, is described and illustrated. This new species was collected in the Amazonian Biome (Caquajó river, Portel, Pará, Brazil and is an atypical species to the group due the unusual morphology of the male terminalia.

  14. A Framework for Spatial Risk Assessments: Potential Impacts of Nonindigenous Invasive Species on Native Species

    Directory of Open Access Journals (Sweden)

    Craig R. Allen

    2006-06-01

    Full Text Available Many populations of wild animals and plants are declining and face increasing threats from habitat fragmentation and loss as well as exposure to stressors ranging from toxicants to diseases to invasive nonindigenous species. We describe and demonstrate a spatially explicit ecological risk assessment that allows for the incorporation of a broad array of information that may influence the distribution of an invasive species, toxicants, or other stressors, and the incorporation of landscape variables that may influence the spread of a species or substances. The first step in our analyses is to develop species models and quantify spatial overlap between stressor and target organisms. Risk is assessed as the product of spatial overlap and a hazard index based on target species vulnerabilities to the stressor of interest. We illustrate our methods with an example in which the stressor is the ecologically destructive nonindigenous ant, Solenopsis invicta, and the targets are two declining vertebrate species in the state of South Carolina, USA. A risk approach that focuses on landscapes and that is explicitly spatial is of particular relevance as remaining undeveloped lands become increasingly uncommon and isolated and more important in the management and recovery of species and ecological systems. Effective ecosystem management includes the control of multiple stressors, including invasive species with large impacts, understanding where those impacts may be the most severe, and implementing management strategies to reduce impacts.

  15. 78 FR 65974 - Atlantic Highly Migratory Species; Advisory Panel for Atlantic Highly Migratory Species Southeast...

    Science.gov (United States)

    2013-11-04

    ... Management Councils, the 18 states in the Atlantic and Gulf of Mexico, both the U.S. Virgin Islands and... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC935 Atlantic Highly Migratory Species; Advisory Panel for Atlantic Highly Migratory Species Southeast Data, Assessment...

  16. 76 FR 65700 - Atlantic Highly Migratory Species; Advisory Panel for Atlantic Highly Migratory Species Southeast...

    Science.gov (United States)

    2011-10-24

    .... Virgin Islands and Puerto Rico, and each of the constituent interstate commissions: the Atlantic States... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA776 Atlantic Highly Migratory Species; Advisory Panel for Atlantic Highly Migratory Species Southeast Data, Assessment...

  17. 77 FR 59842 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

    Science.gov (United States)

    2012-10-01

    ... vessels permitted in the Atlantic tunas General category in Puerto Rico and 10 in the U.S. Virgin Islands... [Docket No. 080603729-2454-02] RIN 0648-AW83 Atlantic Highly Migratory Species; 2006 Consolidated Highly... management plan (FMP) amendment addresses Atlantic highly migratory species (HMS) fishery management measures...

  18. 77 FR 19164 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

    Science.gov (United States)

    2012-03-30

    ... RIN 0648-XB121 Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery..., United States Virgin Islands (USVI) St. Thomas, USVI, San Juan, Puerto Rico (PR), Ponce, PR, and Mayaguez... INFORMATION CONTACT: Greg Fairclough or Randy Blankinship at 727-824-5399. SUPPLEMENTARY INFORMATION: Atlantic...

  19. Multilocus phylogeny and coalescent species delimitation in Kotschy's gecko, Mediodactylus kotschyi: Hidden diversity and cryptic species

    Czech Academy of Sciences Publication Activity Database

    Kotsakiozi, P.; Jablonski, D.; Ilgaz, Ç.; Kumlutaş, Y.; Avci, A.; Meiri, S.; Itescu, Y.; Kukushkin, O.; Gvoždík, Václav; Scillitani, G.; Roussos, S. A.; Jandzik, D.; Kasapidis, P.; Lymberakis, P.; Poulakakis, N.

    2018-01-01

    Roč. 125, August (2018), s. 177-187 ISSN 1055-7903 Institutional support: RVO:68081766 Keywords : Gekkonidae * Divergence times * Species delimitation * Species complex * Systematics * Eastern Mediterranean Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 4.419, year: 2016

  20. Setting maximum sustainable yield targets when yield of one species affects that of other species

    DEFF Research Database (Denmark)

    Rindorf, Anna; Reid, David; Mackinson, Steve

    2012-01-01

    species. But how should we prioritize and identify most appropriate targets? Do we prefer to maximize by focusing on total yield in biomass across species, or are other measures targeting maximization of profits or preserving high living qualities more relevant? And how do we ensure that targets remain...

  1. The Scirtothrips perseae species-group (Thysanoptera), with one new species from avocado, Persea americana.

    Science.gov (United States)

    Mound, Laurence A; Hoddle, Mark S

    2016-02-12

    Following recent molecular studies on avocado thrips, a new species is described from Costa Rica, Ecuador, and Colombia from the young leaves of avocado, Persea americana. Scirtothrips hansoni sp.n. is closely related to the Californian pest, S. perseae, and also to S. astrictus from Costa Rica that remains known from a single female. An illustrated key to these three species is provided.

  2. Species composition and abundance of Brevipalpus spp. on different citrus species in Mexican orchards.

    Science.gov (United States)

    Salinas-Vargas, D; Santillán-Galicia, M T; Valdez-Carrasco, J; Mora-Aguilera, G; Atanacio-Serrano, Y; Romero-Pescador, P

    2013-08-01

    We studied the abundance of Brevipalpus spp. in citrus orchards in the Mexican states of Yucatan, Quintana Roo and Campeche. Mites were collected from 100 trees containing a mixture of citrus species where sweet orange was always the main species. Eight collections were made at each location from February 2010 to February 2011. Mites from the genus Brevipalpus were separated from other mites surveyed and their abundance and relationships with the different citrus species were quantified throughout the collection period. A subsample of 25% of the total Brevipalpus mites collected were identified to species level and the interaction of mite species and citrus species were described. Brevipalpus spp. were present on all collection dates and their relative abundance was similar on all citrus species studies. The smallest number of mites collected was during the rainy season. Brevipalpus phoenicis (Geijskes) and Brevipalpus californicus (Banks) were the only two species present and they were found in all locations except Campeche, where only B. phoenicis was present. Yucatan and Campeche are at greater risk of leprosis virus transmission than Quintana Roo because the main vector, B. phoenicis, was more abundant than B. californicus. The implications of our results for the design of more accurate sampling and control methods for Brevipalpus spp. are discussed.

  3. Evaluation of a multiple-species approach to monitoring species at the ecoregional scale

    Science.gov (United States)

    Patricia N. Manley; William J. Zielinski; Matthew D. Schlesinger; Sylvia R. Mori

    2004-01-01

    Monitoring is required of land managers and conservation practitioners to assess the success of management actions. "Shortcuts" are sought to reduce monitoring costs, most often consisting of the selection of a small number of species that are closely monitored to represent the status of many associated species and environmental correlates. Assumptions...

  4. Species status and conservation issues of New Zealand's endemic Latrodectus spider species (Araneae: Theridiidae)

    DEFF Research Database (Denmark)

    Vink, Cor J; Sirvid, Phillip J; Malumbres-Olarte, Jagoba

    2008-01-01

    New Zealand has two endemic widow spiders, Latrodectus katipo Powell, 1871 and L. atritus Urquhart, 1890. Both species face many conservation threats and are actively managed. The species status of the Latrodectus spiders of New Zealand was assessed using molecular (COI, ITS1, ITS2...

  5. New Species of Calamus (Palmae from Lao and Myanmar

    Directory of Open Access Journals (Sweden)

    Andrew Henderson

    2007-06-01

    Full Text Available This paper concerns southern Asian species of Calamus from Beccari’s Groups V and VI. Calamus floribundus var. depauperatus is recognized as a distinct species, C. meghalayensis; C. kingianus is recognized as a distinct species from northeastern India and the Lao population of C. kingianus is recognized as a separate species, C. evansii; recently collected specimens from northern Myanmar are recognized as two distinct species, C. hukaungensis and C. spicatus; C. hypoleucus is recognized as a distinct species from Myanmar and the Lao population of C. hypoleucus is recognized as a distinct species, C minor. Nomenclature, descriptions, illustrations, specimens examined, and distribution maps are given for the new species.

  6. região da floresta estacional decidual do rio grande do sul

    Directory of Open Access Journals (Sweden)

    Franz H. Andrae

    2005-01-01

    Full Text Available In the central part of Rio Grande do Sul State understoreys of 12 stands of Pinus sp. and one of Araucaria angustifolia O.Ktze were studied, all growing on soils, degraded by agriculture. One pine stand, 10 years old, originated from a natural renovation, the others had been planted 25 to 30 years ago, Araucaria was seeded directly. A total of 575 plots were sampled, 25 m² each, distributed systematically within the stands. Measurements included pines overstorey, and all understorey woody species, separeted into layers of more than 1,3 m high and 1,3 to 0,3 m; the layer lower than 0,3 m included only natural renovation of pines. Understoreys were composed by 121 species, ocurring common and high value timber species, ornamental trees, native and exotic fruit tree species. A higher number of species was present with a very few individuals only. The presence of non woody species like grasses, herbs, ferns and lians also was quantified. The number of tree species and the presence of non woody species did not correlat with density of overstorey pines. Abundance and frequency of species showed no significant diferences, when samples were grouped according to their location in the center or close to stands edge. Distribution pattern of understorey trees within stands was quantified, using Cox’ index, species diversity was compared by means of Shannon-index. Similarity of stands was compared by Sörensen-Index. It was concluded, that exotic species planted on poor agricultural soil may not only be of farmers interest because of their high potential for wood production. These plantations also may be considered from conservationist point of view, since they show an unexpected high diversity, so contributing in a longer run to landscape improvement, possibly due to the small extension of stands.

  7. Valuing local endangered species. The role of intra-species substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Maria L. [Department of Economic Analysis, Universidade de Santiago (Spain); IDEGA, Universidade de Santiago de Compostela, Campus Sur, Avda das Ciencias, S/N. 15782, Santiago de Compostela (Spain); Ojea, Elena [IDEGA, Universidade de Santiago de Compostela, Campus Sur, Avda das Ciencias, S/N. 15782, Santiago de Compostela (Spain)

    2008-12-01

    Valuation of endangered species is important in many circumstances, and particularly when assessing the impact of large accidental oil spills. Previous studies have tested the effects of including in the contingent valuation survey reminders about the existence of diverse substitutes (in terms of other natural resources also in danger of extinction in the same area, other programs to be valued, or alternative uses of money). We include a reminder about the existence of the same biological species not being under danger of extinction elsewhere. We believe this reminder allows individuals to make an easy assessment of the biological scarcity of the species they are supposed to value. Thus, the key difference with previous studies is that valuation of endangered species is combined with an assessment of preferences towards conservation of local and native species. Our WTP results are not sensitive to the information provided about other foreign substitutes. Implications of this finding are discussed. (author)

  8. Valuing local endangered species. The role of intra-species substitutes

    International Nuclear Information System (INIS)

    Loureiro, Maria L.; Ojea, Elena

    2008-01-01

    Valuation of endangered species is important in many circumstances, and particularly when assessing the impact of large accidental oil spills. Previous studies have tested the effects of including in the contingent valuation survey reminders about the existence of diverse substitutes (in terms of other natural resources also in danger of extinction in the same area, other programs to be valued, or alternative uses of money). We include a reminder about the existence of the same biological species not being under danger of extinction elsewhere. We believe this reminder allows individuals to make an easy assessment of the biological scarcity of the species they are supposed to value. Thus, the key difference with previous studies is that valuation of endangered species is combined with an assessment of preferences towards conservation of local and native species. Our WTP results are not sensitive to the information provided about other foreign substitutes. Implications of this finding are discussed. (author)

  9. Cross-species amplification of microsatellite loci developed for Passiflora edulis Sims. in related Passiflora Species

    Directory of Open Access Journals (Sweden)

    Gilmara Alvarenga Fachardo Oliveira

    2013-10-01

    Full Text Available The aim of this study was to evaluate the selected 41 SSR markers developed for yellow passion fruit (Passiflora edulis f. flavicarpa Sims. for their transferability to 11 different Passiflora species. Twenty-one SSR were successfully amplified in 10 wild species of passion fruit producing 101 bands. All the markers were amplifiable for at least one species. The mean transferability was 68,8%, ranging from 15,4% (primer PE11 to 100 % (PE13, PE18, PE37, PE41 and PE88. Transferability was higher for the species from the Passiflora subgenus than for those from the Decaloba and Dysosmia subgenus. The results indicated a high level of nucleotide sequence conservation of the primer regions in the species evaluated, and consequently, they could potentially be used for the establishment of molecular strategies for use in passion fruit breeding and genetics.

  10. SESAM – a new framework integrating macroecological and species distribution models for predicting spatio-temporal patterns of species assemblages

    DEFF Research Database (Denmark)

    Guisan, Antoine; Rahbek, Carsten

    2011-01-01

    Two different approaches currently prevail for predicting spatial patterns of species assemblages. The first approach (macroecological modelling, MEM) focuses directly on realized properties of species assemblages, whereas the second approach (stacked species distribution modelling, S-SDM) starts...

  11. Cryptic Species Due to Hybridization: A Combined Approach to Describe a New Species (Carex: Cyperaceae).

    Science.gov (United States)

    Maguilla, Enrique; Escudero, Marcial

    2016-01-01

    Disappearance of diagnostic morphological characters due to hybridization is considered to be one of the causes of the complex taxonomy of the species-rich (ca. 2000 described species) genus Carex (Cyperaceae). Carex furva s.l. belongs to section Glareosae. It is an endemic species from the high mountains of the Iberian Peninsula (Spain and Portugal). Previous studies suggested the existence of two different, cryptic taxa within C. furva s.l. Intermediate morphologies found in the southern Iberian Peninsula precluded the description of a new taxa. We aimed to determine whether C. furva s.l. should be split into two different species based on the combination of morphological and molecular data. We sampled ten populations across its full range and performed a morphological study based on measurements on herbarium specimens and silica-dried inflorescences. Both morphological and phylogenetic data support the existence of two different species within C. furva s.l. Nevertheless, intermediate morphologies and sterile specimens were found in one of the southern populations (Sierra Nevada) of C. furva s.l., suggesting the presence of hybrid populations in areas where both supposed species coexist. Hybridization between these two putative species has blurred morphological and genetic limits among them in this hybrid zone. We have proved the utility of combining molecular and morphological data to discover a new cryptic species in a scenario of hybridization. We now recognize a new species, C. lucennoiberica, endemic to the Iberian Peninsula (Sierra Nevada, Central system and Cantabrian Mountains). On the other hand, C. furva s.s. is distributed only in Sierra Nevada, where it may be threatened by hybridization with C. lucennoiberica. The restricted distribution of both species and their specific habitat requirements are the main limiting factors for their conservation.

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

    Directory of Open Access Journals (Sweden)

    SRI S UDARMIYATI T JITROSOEDIRDJO

    2005-01-01

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

  13. Are Humans the Most Intelligent Species?

    Directory of Open Access Journals (Sweden)

    Robert P. Erickson

    2014-09-01

    Full Text Available Hunt and Jaeggi [1] nicely summarize the point that within the academic field of intelligence, we do not have a commonly understandable definition of what intelligence is. Still the term is used extensively and with consensus to the effect that humans are the most intelligent species. An example is given of this problem, and a definition and solution are suggested.

  14. Molecular species identification and population genetics of ...

    African Journals Online (AJOL)

    Molecular genetic techniques, such as DNA barcoding and genotyping, are increasingly being used to assist with the conservation and management of chondrichthyans worldwide. Southern Africa is a shark biodiversity hotspot, with a large number of endemic species. According to the IUCN Red List, a quarter of South ...

  15. Evaluation of two okra species [Abelmoschusesculentus (L ...

    African Journals Online (AJOL)

    DizMat_Ogwu

    2014-02-26

    Feb 26, 2014 ... African Journal of Biotechnology. Full Length Research Paper. Evaluation of two okra species ..... Amakiri JO, Onofeghara FA (1984). Effect of crude oil pollution on the growth of Zea mays, Abelmoschusesculentusand capsicum frutescans. Oil Pet. Pollut. 1:199-206. Ariyo OJ (1993). Genetic diversity in west ...

  16. Population dynamics of Pseudo-nitzschia species ...

    African Journals Online (AJOL)

    The genus Pseudo-nitzschia is a chain-forming diatom comprising about 30 species some of which are known to produce domoic acid (DA) that causes amnesic shellfish poisoning (ASP). The current study aimed at assessing the population dynamics of Pseudo-nitzschia in the near shore waters of Dar es Salaam. Samples ...

  17. A new Species of Spadella (Benthic Chaetognatha)

    NARCIS (Netherlands)

    Alvariño, Angeles

    1970-01-01

    According to the literature, the genus Spadella Langerhans includes several species, Sp. cephaloptera (Busch) 1851, Sp. schizoptera Conant 1895, Sp. moretonensis Johnston & Taylor 1919, Sp. sheardi Mawson 1944, Sp. johnstoni Mawson 1944, Sp. angulata Tokioka 1951, Sp. nana Owre 1963, Sp. pulchella

  18. Is Echinococcus intermedius a valid species?

    Science.gov (United States)

    Medical and veterinary sciences require scientific names to discriminate pathogenic organisms in our living environment. Various species concepts have been proposed for metazoan animals. There are, however, constant controversies over their validity because of lack of a common criterion to define ...

  19. Geographic distribution of wild potato species

    NARCIS (Netherlands)

    Hijmans, R.J.; Spooner, D.M.

    2001-01-01

    The geographic distribution of wild potatoes (Solanaceae sect. Petota) was analyzed using a database of 6073 georeferenced observations. Wild potatoes occur in 16 countries, but 88% of the observations are from Argentina, Bolivia, Mexico, and Peru. Most species are rare and narrowly endemic: for 77

  20. Invasive species in southern Nevada [Chapter 4

    Science.gov (United States)

    Mathew L. Brooks; Steven M. Ostoja; Jeanne C. Chambers

    2013-01-01

    Southern Nevada contains a wide range of topographies, elevations, and climatic zones emblematic of its position at the ecotone between the Mojave Desert, Great Basin, and Colorado Plateau ecoregions. These varied environmental conditions support a high degree of biological diversity (Chapter 1), but they also provide opportunities for a wide range of invasive species...

  1. Spatial patterns of species diversity in Kenya

    NARCIS (Netherlands)

    Oindo, B.O.

    2001-01-01

    The most striking feature of Earth is the existence of life and the most striking feature of life is its diversity. Explaining patterns of species diversity is one of the most complex problems in ecology. This is because diversity is usually the outcome of many contributing factors whose relative

  2. Mannheimia Species Associated with Ovine Mastitis▿

    OpenAIRE

    Omaleki, Lida; Barber, Stuart R.; Allen, Joanne L.; Browning, Glenn F.

    2010-01-01

    Mannheimia glucosida, M. haemolytica, and M. ruminalis were isolated from cases of acute mastitis in ewes. M. glucosida was found to be a common cause of clinical mastitis in sheep. Selected phenotypic tests in addition to genotyping were needed to definitively identify Mannheimia species causing ovine mastitis.

  3. Antibacterial potential components of Bacillus species and ...

    African Journals Online (AJOL)

    Honey is a sweet viscous liquid produced by honey bee, Apis mellifera from the nectar of plants. Honey is a natural product that has been used from ancient times till now as food and for medicinal purpose. This study was carried out to determine the mode of action of Bacillus species and antibiotics residues in branded and ...

  4. Environmental Politics and the Endangered Species Act.

    Science.gov (United States)

    Sahr, David

    2000-01-01

    Explores the controversial issue of the Endangered Species Act (ESA) discussing the Act and the scope of the extinction problem. Reviews the arguments for and against the ESA, addresses the tactics that have been used in the political struggle over the ESA, and highlights the future of the ESA. Includes teaching activities. (CMK)

  5. Darwin's Book: On the Origin of Species

    Science.gov (United States)

    Hodge, Jonathan

    2013-09-01

    This essay is an interpretation of Charles Darwin's Origin of Species. It focuses on the contents of the Origin as Darwin intended them to be understood and the background to the work, thus revealing the originality (or otherwise) of the work.

  6. Biodiversity and the exotic species threat

    Science.gov (United States)

    Peter S. White

    1998-01-01

    Exotic species invasions, called by one conservation biologist the "least reversible" of all human impacts, cause harm to economies (e.g., fisheries, wildlife populations, tourism), the environment (e.g., in the form of broadcast of pesticides and herbicides), human health and wellbeing (e.g., allergic responses and the increase in fire severity in some...

  7. Unparalleled rates of species diversification in Europe

    Science.gov (United States)

    Valente, Luis M.; Savolainen, Vincent; Vargas, Pablo

    2010-01-01

    The most rapid species radiations have been reported from ‘evolutionary laboratories’, such as the Andes and the Cape of South Africa, leading to the prevailing view that diversification elsewhere has not been as dramatic. However, few studies have explicitly assessed rates of diversification in northern regions such as Europe. Here, we show that carnations (Dianthus, Caryophyllaceae), a well-known group of plants from temperate Eurasia, have diversified at the most rapid rate ever reported in plants or terrestrial vertebrates. Using phylogenetic methods, we found that the majority of species of carnations belong to a lineage that is remarkably species-rich in Europe, and arose at the rate of 2.2–7.6 species per million years. Unlike most previous studies that have inferred rates of diversification in young diverse groups, we use a conservative approach throughout that explicitly incorporates the uncertainties associated with phylogenetic inference, molecular dating and incomplete taxon sampling. We detected a shift in diversification rates of carnations coinciding with a period of increase in climatic aridity in the Pleistocene, suggesting a link between climate and biodiversity. This explosive radiation suggests that Europe, the continent with the world's best-studied flora, has been underestimated as a cradle of recent and rapid speciation. PMID:20106850

  8. Alien invasive species and international trade

    Science.gov (United States)

    Emergency control measures for invasive species often rely on use of pesticides and other destructive practices. Public concern about pesticide contamination of the ground water and the environment has lead to increased restrictions on the use of pesticides for control of many destructive invasive ...

  9. (OLIGOCHAETA) FROM SOUTH AFRICAN RIVERS Two species

    African Journals Online (AJOL)

    portion and may be regarded as a chamber of the ampulla, though its walls may be con- voluted. The duct ..... fall within known variation for the species: dimensions, number of segments, form of the ...... 01igochaeta in Das Tierrich, 10, Berlin.

  10. Some new Australasian species of Xyris

    NARCIS (Netherlands)

    Royen, van P.

    1954-01-01

    During the study of the Xyridaceae of the Malaysian area it was desirable to study those of Australia and Continental Asia as well. The Malaysian species now have, in the meantime, been published (Flora Malesiana, ser. 1, 4, 1953, 366—376). To the new taxa described in Blumea 7, 1953, 307—308 the

  11. On the Origins of a Vibrio species

    DEFF Research Database (Denmark)

    Vesth, Tammi Camilla; Wassenaar, Gertrude Maria; Hallin, Peter Fischer

    2010-01-01

    Thirty-two genome sequences of various Vibrionaceae members are compared, with emphasis on what makes V. cholerae unique. As few as 1,000 gene families are conserved across all the Vibrionaceae genomes analysed; this fraction roughly doubles for gene families conserved within the species V. chole...

  12. Karyotype of some Thai Hypoxidaceae species

    Directory of Open Access Journals (Sweden)

    Ladda Eksomtramage

    2013-08-01

    Full Text Available Somatic chromosome numbers and karyotypes of nine species in three genera of Thai Hypoxidaceae were determinedin root tips. All species are diploid with 2n = 18 and asymmetrical karyotypes including metacentric (m submetacentric (smsubtelocentric (st and also telocentric (t in some species. Satellite chromosomes (SAT were observed in all species studiedexcept in C. latifolia. The karyotypes of Curculigo ensifolia 4m+8sm+6st(2SAT, C. latifolia 2m+14sm+2st, C. megacarpa2m+12sm+4st(2SAT, C. villosa 4m+10sm(2SAT+4st, Hypoxis aurea 2m+8sm+8st(2SAT, Molineria capitulata 2m+10sm+2st (2SAT+4t, M. trichocarpa 2m+10sm+6st(2SAT, M. gracilis and M. latifolia 4m+8sm+4st (2SAT+2t are reported forthe first time. The chromosome relative length of Curculigo, Hypoxis and Molineria range between 3.44-9.55, 4.03-8.12 and3.64-8.97, respectively.

  13. Immunological detection of Fusarium species in cornmeal.

    Science.gov (United States)

    Iyer, M S; Cousin, M A

    2003-03-01

    An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect Fusarium species in foods. Antibodies to proteins extracted from the mycelia of Fusarium graminearum and Fusarium moniliforme (verticillioides) were produced in New Zealand white rabbits. These antibodies detected 13 Fusarium species in addition to the producer strains. Levels of Fusarium semitectum and Fusarium tricinctum strains were below the detection threshold. The specificity of the assay was tested against 70 molds and yeasts belonging to 23 genera. One strain of Monascus species and one strain of Phoma exigua were detected; however, these two molds are not common contaminants of cereal grains or foods and should not interfere with the assay. The indirect ELISA's detection limits for F. graminearum and F. moniliforme were 0.1 and 1 microg of mold mycelium per ml of a cornmeal mixture, respectively. When spores of each mold were added individually to cornmeal mixtures (at ca. 10 spores per g) and incubated at 25 degrees C, these spores were detected by the indirect ELISA when they reached levels of 10(2) to 10(3) CFU/ml after 24 to 36 h. The indirect ELISA developed here shows promise for the detection of Fusarium species in grains or foods.

  14. The South African species of Teucrium (Lamiaceae

    Directory of Open Access Journals (Sweden)

    L. E. Codd

    1977-11-01

    Full Text Available While writing up the three South African species of  Teucrium for the Flora o f Southern Africa it became necessary to replace two well-known names as follows:  T. trifidum Retz. (1779 ( = T.  capense Thunb., 1800 and  T. kraussii Codd  {=T. riparium Hochst., 1845, non Rafin., 1838.

  15. Island Species Richness Increases with Habitat Diversity

    NARCIS (Netherlands)

    Hortal, J.; Triantis, K.A.; Meiri, S.; Thebault, E.M.C.; Sfenthourakis, S.

    2009-01-01

    Species richness is commonly thought to increase with habitat diversity. However, a recent theoretical model aiming to unify niche and island biogeography theories predicted a hump-shaped relationship between richness and habitat diversity. Given the contradiction between model results and previous

  16. Self-thinning in four pine species

    NARCIS (Netherlands)

    Brunet-Navarro, Pau; Sterck, Frank J.; Vayreda, Jordi; Martinez-Vilalta, Jordi; Mohren, Frits

    2016-01-01

    Key message: Self-thinning lines are species- and climate-specific, and they should be used when assessing the capacity of different forest stands to increase biomass/carbon storage. Context: The capacity of forests to store carbon can help to mitigate the effects of atmospheric CO2

  17. Reserve design to maximize species persistence

    Science.gov (United States)

    Robert G. Haight; Laurel E. Travis

    2008-01-01

    We develop a reserve design strategy to maximize the probability of species persistence predicted by a stochastic, individual-based, metapopulation model. Because the population model does not fit exact optimization procedures, our strategy involves deriving promising solutions from theory, obtaining promising solutions from a simulation optimization heuristic, and...

  18. Vanishing Species: The Planet in Crisis

    Indian Academy of Sciences (India)

    Permanent link: https://www.ias.ac.in/article/fulltext/reso/015/04/0321-0336. Keywords. Species; mass extinction; biotic crisis; hotspot. Author Affiliations. Uttam Saikia1 Narayan Sharma Abhijit Das. High Altitude Zoology Field Station, Zoological Survey of India, Saproon, Solan, H.P.173211. Resonance – Journal of Science ...

  19. Radiocaesium accumulation by different plant species

    International Nuclear Information System (INIS)

    Filiptsova, G.G.

    2000-01-01

    Using the model object influence of mineral nutritions level on radiocaesium accumulation by different plant species has been studied. It was shown the wheat roots accumulation the minimal value on radiocaesium on normal potassium level, the rye roots accumulation maximal level radiocaesium. (authors)

  20. Species status of Mill Creek Elliptio

    Energy Technology Data Exchange (ETDEWEB)

    Davis, G.M. [Academy of Natural Sciences (United States); Mulvey, M. [Savannah River Ecology Lab., Aiken, SC (United States)

    1993-12-31

    This report discusses environmental effects of the Savannah River Plant on aqautic populations in Mill Creek and surrounding tributaries. Of particular concern was the status of Elliptio. Genetics and phenotypic characteristics have shown that the current classification system is not adequate for these populations. The appendices characterize genetic variability at different loci, electrophoretic data, allele frequencies, sympatric species, and anatomical characters.